1 00:00:04,610 --> 00:00:08,490 Of all life on Earth, there's something more mysterious 2 00:00:08,490 --> 00:00:11,690 yet more vital to our survival than anything else. 3 00:00:14,530 --> 00:00:16,410 Its birth is violent. 4 00:00:17,970 --> 00:00:20,170 Much of its life is hidden underground. 5 00:00:23,930 --> 00:00:27,570 And only at the end of its life cycle does it reveal its identity. 6 00:00:30,090 --> 00:00:31,330 The mushroom. 7 00:00:38,250 --> 00:00:40,730 'I'm Professor Richard Fortey. 8 00:00:40,730 --> 00:00:43,650 'I've been fascinated by mushrooms all my life.' 9 00:00:43,650 --> 00:00:45,130 Nice find. 10 00:00:45,130 --> 00:00:47,010 'I love to collect and study them.' 11 00:00:49,370 --> 00:00:53,330 Many people think of mushrooms just as something to eat, 12 00:00:53,330 --> 00:00:55,930 or maybe as decoration in folk tales. 13 00:00:57,210 --> 00:00:59,330 But nothing could be further from the truth. 14 00:01:01,010 --> 00:01:04,170 They have a secret life so magical, 15 00:01:04,170 --> 00:01:06,010 so weird, 16 00:01:06,010 --> 00:01:08,730 that it defies imagination, 17 00:01:08,730 --> 00:01:11,170 and I'm going to reveal it as never before. 18 00:01:15,770 --> 00:01:19,210 I've set up my own lab to unlock the mysteries of mushrooms. 19 00:01:20,690 --> 00:01:22,530 Oh, look at that! 20 00:01:22,530 --> 00:01:23,770 They're like geysers. 21 00:01:25,610 --> 00:01:27,930 I'll discover their astonishing powers. 22 00:01:29,770 --> 00:01:31,210 What makes them the fastest... 23 00:01:32,450 --> 00:01:33,690 ..the largest... 24 00:01:35,370 --> 00:01:38,570 ..and some of the deadliest living things on the planet. 25 00:01:40,250 --> 00:01:43,890 Half a cap will kill you and kill you slowly and painfully. 26 00:01:45,730 --> 00:01:49,610 And I'll meet the people turning those powers to our advantage 27 00:01:49,610 --> 00:01:51,970 to create new medicines 28 00:01:51,970 --> 00:01:53,850 and new materials. 29 00:01:53,850 --> 00:01:56,690 The innovation we have here is the future of energy production 30 00:01:56,690 --> 00:01:59,010 and even devices and products like your iPhone. 31 00:02:00,970 --> 00:02:04,250 To discover what gives mushrooms their extraordinary abilities, 32 00:02:04,250 --> 00:02:08,410 I'm going to follow their story from birth, through life, to death. 33 00:02:09,690 --> 00:02:13,770 A story so strange, it seems almost alien, 34 00:02:13,770 --> 00:02:18,410 yet it will reveal why mushrooms are crucial to all life on Earth, 35 00:02:18,410 --> 00:02:22,730 and why they have a powerful connection to you and me. 36 00:02:35,930 --> 00:02:39,370 The only place many of us encounter mushrooms is here. 37 00:02:42,610 --> 00:02:44,890 Cultivated edible varieties like these, 38 00:02:44,890 --> 00:02:48,690 are all most of us think about when it comes to mushrooms. 39 00:02:48,690 --> 00:02:50,850 We Brits can't get enough. 40 00:02:50,850 --> 00:02:53,410 It's a multimillion pound business in the UK. 41 00:02:55,810 --> 00:02:58,010 But there's so much more to mushrooms 42 00:02:58,010 --> 00:03:00,850 than this fine example in the fresh food counter. 43 00:03:02,210 --> 00:03:06,570 This mushroom is just one species from an enormous kingdom, 44 00:03:06,570 --> 00:03:08,250 the kingdom of the fungi... 45 00:03:09,410 --> 00:03:12,730 ..and fungi are hidden away in all kinds of food products 46 00:03:12,730 --> 00:03:15,410 in this supermarket in ways you wouldn't expect. 47 00:03:19,570 --> 00:03:22,770 Look hard enough and every aisle reveals evidence 48 00:03:22,770 --> 00:03:25,010 of how fungi underpin modern living. 49 00:03:26,410 --> 00:03:27,850 Cheese. 50 00:03:29,130 --> 00:03:32,530 My favourite Stilton cheese, well, it's blue, 51 00:03:32,530 --> 00:03:34,210 and the blue is a fungus. 52 00:03:36,050 --> 00:03:38,650 A lot of fizzy drinks have citric acid in them, 53 00:03:38,650 --> 00:03:41,490 and that's produced by a fungus called Aspergillus niger 54 00:03:41,490 --> 00:03:43,370 in huge quantities. 55 00:03:43,370 --> 00:03:47,170 Many detergents also contain citric acid, just like fizzy drinks. 56 00:03:48,290 --> 00:03:51,970 Ah, here's soy sauce, bread, 57 00:03:51,970 --> 00:03:55,330 Quorn, chocolate, fruit juices. 58 00:03:55,330 --> 00:03:57,130 Well, sometimes they have a bitter taste, 59 00:03:57,130 --> 00:03:59,290 which can be removed by another fungus. 60 00:04:00,570 --> 00:04:02,330 Salmon, red salmon. 61 00:04:02,330 --> 00:04:03,890 The red colour, I'm afraid, 62 00:04:03,890 --> 00:04:06,770 is sometimes due to a fungus called Phaffia. 63 00:04:08,450 --> 00:04:10,330 Some of the protein in pet foods, 64 00:04:10,330 --> 00:04:15,050 which keeps your animals healthy is actually produced by fungi. 65 00:04:16,530 --> 00:04:18,490 And, of course, booze. 66 00:04:18,490 --> 00:04:21,490 The fermenting activity of Saccharomyces, 67 00:04:21,490 --> 00:04:24,130 turning sugars into alcohol. 68 00:04:31,810 --> 00:04:35,370 Clearly, our supermarket shop just wouldn't be the same without fungi. 69 00:04:35,370 --> 00:04:38,570 They're hidden away in all sorts of ways in the products. 70 00:04:38,570 --> 00:04:42,610 They must have a series of special biochemical tricks up their sleeve. 71 00:04:45,410 --> 00:04:48,730 But how exactly is it that they seem to turn up everywhere 72 00:04:48,730 --> 00:04:50,850 and affect so many parts of our lives? 73 00:04:53,810 --> 00:04:57,050 To begin to answer that question, I'm going to a place 74 00:04:57,050 --> 00:04:59,490 where I encounter fungi in all their forms. 75 00:05:01,930 --> 00:05:05,770 Head out into any woodland like this one in the Scottish Borders, 76 00:05:05,770 --> 00:05:07,410 and if you look hard enough, 77 00:05:07,410 --> 00:05:09,610 you'll start finding them everywhere. 78 00:05:21,210 --> 00:05:24,530 To me, they're fascinating. 79 00:05:24,530 --> 00:05:27,730 Some may think they look like any other plant, 80 00:05:27,730 --> 00:05:30,930 but in fact, they're a different organism altogether. 81 00:05:33,090 --> 00:05:35,610 Fungi evolved as a kingdom in their own right, 82 00:05:35,610 --> 00:05:38,690 distinct from plants and animals, 83 00:05:38,690 --> 00:05:42,090 over one and a half billion years ago. 84 00:05:42,090 --> 00:05:43,490 It's thought that in variety, 85 00:05:43,490 --> 00:05:45,970 they outnumber plants by at least ten to one. 86 00:05:47,610 --> 00:05:50,490 And searching for them is my favourite pastime. 87 00:05:54,010 --> 00:05:58,090 Some people might think of autumn as a rather gloomy time of year, 88 00:05:58,090 --> 00:06:00,730 but for me, it's pure joy. 89 00:06:00,730 --> 00:06:03,210 I can take my basket, I can go into the woods... 90 00:06:04,250 --> 00:06:07,090 ..and I can do my mushroom foraying. 91 00:06:07,090 --> 00:06:08,850 I've been doing it for decades. 92 00:06:09,930 --> 00:06:11,210 What's the thrill of it? 93 00:06:11,210 --> 00:06:14,930 Well, to the left of the path, to the right of the path, 94 00:06:14,930 --> 00:06:17,770 dozens of different kinds of fungi are erupting. 95 00:06:18,890 --> 00:06:23,810 But, I suppose, the most primeval feeling, the basic one, 96 00:06:23,810 --> 00:06:27,650 is still the thrill of discovery, the thrill of the chase. 97 00:06:33,330 --> 00:06:37,570 You may not realise that what we call the mushroom is, in fact, 98 00:06:37,570 --> 00:06:39,490 just one type of fungus. 99 00:06:39,490 --> 00:06:42,130 It's the form that we are most familiar with 100 00:06:42,130 --> 00:06:44,650 and it's certainly the easiest to recognise. 101 00:06:47,650 --> 00:06:50,090 The head of a mushroom is its cap. 102 00:06:54,650 --> 00:06:55,810 And many have a stalk. 103 00:07:00,130 --> 00:07:02,050 Look underneath the cap, 104 00:07:02,050 --> 00:07:05,970 and you'll often find a set of sharp ridges known as gills. 105 00:07:05,970 --> 00:07:07,730 Ah-ha! 106 00:07:07,730 --> 00:07:12,530 Well, now, this is, of course, the archetypal mushroom. 107 00:07:12,530 --> 00:07:16,490 It's the one that the, gnomes sit on top of. 108 00:07:16,490 --> 00:07:18,250 It's the fly agaric. 109 00:07:18,250 --> 00:07:22,130 I can see other species really, really close to hand. 110 00:07:22,130 --> 00:07:26,370 This is the king of the edible mushrooms, the cep, 111 00:07:26,370 --> 00:07:27,810 the penny bun, 112 00:07:27,810 --> 00:07:29,170 porcini. 113 00:07:29,170 --> 00:07:32,050 The fact that it's got so many names is a measure 114 00:07:32,050 --> 00:07:36,050 of just how highly regarded it is as an edible fungus. 115 00:07:36,050 --> 00:07:37,330 It's one of the best. 116 00:07:39,770 --> 00:07:42,010 'But as well as the quintessential mushroom...' 117 00:07:42,010 --> 00:07:43,290 Bit hazardous 118 00:07:43,290 --> 00:07:46,650 '..if you look a little harder, you'll find a host of other fungi 119 00:07:46,970 --> 00:07:48,930 'that don't look like mushrooms at all.' 120 00:07:50,330 --> 00:07:53,370 Ah, well, now, here's something completely different. 121 00:07:53,370 --> 00:07:56,450 Perhaps doesn't look like a fungus at first sight to people. 122 00:07:56,450 --> 00:07:58,010 It's one of the coral fungi. 123 00:07:59,250 --> 00:08:01,050 This is an ear fungus. 124 00:08:01,050 --> 00:08:05,530 They're still fungi but they're very, very different sort of fungi. 125 00:08:05,530 --> 00:08:07,530 Yellow brain fungus. 126 00:08:07,530 --> 00:08:10,010 Doesn't look like anything from this Earth, really, does it? 127 00:08:11,250 --> 00:08:12,850 It's the beefsteak fungus. 128 00:08:14,130 --> 00:08:17,610 And you can see why - it looks a bit like raw liver. 129 00:08:19,930 --> 00:08:23,970 'In fact, this organism can take so many weird and wonderful forms, 130 00:08:23,970 --> 00:08:25,970 'knowing what it is you're looking at 131 00:08:25,970 --> 00:08:30,970 'can sometimes be a challenge, even for an experienced forayer like me.' 132 00:08:30,970 --> 00:08:34,770 Wow, now, that is something really weird. 133 00:08:34,770 --> 00:08:36,730 I'm not quite sure what's going on. 134 00:08:36,730 --> 00:08:39,730 It's absolutely extraordinary. That's one coming back to the lab. 135 00:08:42,330 --> 00:08:46,890 Almost every foray I go on, I find something new and intriguing. 136 00:08:46,890 --> 00:08:50,410 Time to take a closer look at exactly what's in my basket. 137 00:08:53,530 --> 00:08:56,690 This is our specially-built mushroom lab 138 00:08:56,690 --> 00:08:58,890 where I'll be unlocking the mysteries of fungi 139 00:08:58,890 --> 00:09:01,850 with the help of mycologist Dr Patrick Hickey. 140 00:09:01,850 --> 00:09:03,850 Well, this is quite a set-up you've got here. 141 00:09:05,650 --> 00:09:08,090 Their first secret is their identity. 142 00:09:09,290 --> 00:09:12,370 So here we are with our haul back from the woods, 143 00:09:12,370 --> 00:09:14,610 and what a variety we've got in the basket. 144 00:09:14,610 --> 00:09:17,650 Of course, we notice things like the colour, of course. 145 00:09:17,650 --> 00:09:18,890 The smell. 146 00:09:18,890 --> 00:09:22,770 Oh, yeah, that's got a really sweet smell to it, very sweet odour. 147 00:09:22,770 --> 00:09:25,970 So fungus identification uses all your senses. 148 00:09:25,970 --> 00:09:28,250 It's a very sensory experience. 149 00:09:28,250 --> 00:09:30,690 But there's another way we can really narrow down 150 00:09:30,690 --> 00:09:33,810 the mystery of a mushroom and positively identify it 151 00:09:33,810 --> 00:09:36,370 and that's by doing something called a spore print. 152 00:09:36,370 --> 00:09:39,250 Every mushroom has its own unique spore print 153 00:09:39,250 --> 00:09:41,850 and to do a spore print, we cut the stem off, 154 00:09:41,850 --> 00:09:44,650 and then place the cap onto a piece of paper 155 00:09:44,650 --> 00:09:46,530 and just leave it for a few hours. 156 00:09:46,530 --> 00:09:49,090 When you come back and lift it up, 157 00:09:49,090 --> 00:09:52,010 you'll see the mushroom has deposited a layer of spores 158 00:09:52,010 --> 00:09:53,850 and they look just like fingerprints. 159 00:09:53,850 --> 00:09:56,330 It's a bit like taking a fingerprint from a mushroom. 160 00:09:57,570 --> 00:10:00,970 These spores are like the seeds of a mushroom 161 00:10:00,970 --> 00:10:04,610 and the patterns they create can reveal some surprises, 162 00:10:04,610 --> 00:10:08,330 even when two mushrooms appear to look the same. 163 00:10:08,330 --> 00:10:10,730 So here we've got two similar looking... 164 00:10:10,730 --> 00:10:13,450 Almost the same, yeah. ..white mushrooms, 165 00:10:13,450 --> 00:10:16,970 but reveal the spores - one's startlingly white 166 00:10:16,970 --> 00:10:19,290 and the other's very black. 167 00:10:19,290 --> 00:10:22,290 Yeah, it's a key in the identification of the mushroom. 168 00:10:28,490 --> 00:10:30,570 So we have such a variety of colours. 169 00:10:30,570 --> 00:10:32,810 We've got a sort of purple here. 170 00:10:32,810 --> 00:10:35,050 We've got cream, we've got white, 171 00:10:35,050 --> 00:10:40,010 very pure white, rust brown, even pinkish. Yeah. 172 00:10:40,010 --> 00:10:43,050 And I have to say what a beautiful pattern it makes too. 173 00:10:43,050 --> 00:10:45,610 I mean, aesthetically, extremely pleasing. 174 00:10:45,610 --> 00:10:48,690 They're wonderful. They're just like the silhouettes of a mushroom, 175 00:10:48,690 --> 00:10:52,490 and that colour of the spore print is unique to that type of mushroom 176 00:10:52,490 --> 00:10:55,370 and they don't change throughout the mushroom's life cycle. 177 00:10:58,850 --> 00:11:00,610 The spore prints reveal 178 00:11:00,610 --> 00:11:05,490 that mushrooms are more varied and complex than they might appear. 179 00:11:05,490 --> 00:11:08,890 Their world is mysterious and little known, 180 00:11:08,890 --> 00:11:13,250 yet they have the power to affect our lives in unexpected ways. 181 00:11:13,250 --> 00:11:15,810 One of the most striking displays of that power 182 00:11:15,810 --> 00:11:18,610 takes us to the most unlikely place. 183 00:11:27,210 --> 00:11:31,130 This is Mark Gilchrist, a consultant pharmacist 184 00:11:31,130 --> 00:11:33,490 at St Mary's Hospital, London. 185 00:11:33,490 --> 00:11:37,090 He spends much of his day administering and prescribing 186 00:11:37,090 --> 00:11:40,450 the most widely-used type of drug on the planet - 187 00:11:40,450 --> 00:11:41,930 antibiotics. 188 00:11:45,330 --> 00:11:47,770 Antibiotics are tremendously important 189 00:11:47,770 --> 00:11:50,050 in our fight against infection. 190 00:11:50,050 --> 00:11:53,490 Up to about 30% of patients within a hospital setting 191 00:11:53,490 --> 00:11:55,490 can be on antibiotics at any one time 192 00:11:55,490 --> 00:11:57,730 and that's used to treat things like pneumonias 193 00:11:57,730 --> 00:11:59,970 to simple skin and soft tissue infections 194 00:11:59,970 --> 00:12:03,090 and prevent surgical site infections post operatively. 195 00:12:05,250 --> 00:12:08,890 The invention of antibiotics has been a game changer 196 00:12:08,890 --> 00:12:12,010 for medicine and mankind. 197 00:12:12,010 --> 00:12:13,570 And we owe it all to fungi. 198 00:12:19,450 --> 00:12:22,770 In 1928, scientist Alexander Fleming 199 00:12:22,770 --> 00:12:24,930 was carrying out research at St Mary's. 200 00:12:26,130 --> 00:12:29,490 He was studying the staphylococcus bacterium, 201 00:12:29,490 --> 00:12:33,610 and left some samples on his desk, before heading off on holiday, 202 00:12:33,610 --> 00:12:36,850 expecting them to grow and develop while he was away. 203 00:12:38,770 --> 00:12:42,090 When Fleming returned from his holiday to resume his research 204 00:12:42,090 --> 00:12:44,850 on bacteria here in this lab, 205 00:12:44,850 --> 00:12:46,970 he noticed something extraordinary. 206 00:12:49,050 --> 00:12:51,890 His bacteria samples were dead. 207 00:12:51,890 --> 00:12:54,410 They had been completely destroyed by fungi. 208 00:12:55,850 --> 00:12:58,650 Intrigued by why this had happened, 209 00:12:58,650 --> 00:13:00,810 Fleming examined his samples further. 210 00:13:02,490 --> 00:13:06,890 He realised that a fungus spore, possibly from a lab below, 211 00:13:06,890 --> 00:13:10,010 must have landed on the gel plate and germinated. 212 00:13:12,850 --> 00:13:16,770 The spore had rapidly started to feed on the contents of the dish, 213 00:13:16,770 --> 00:13:19,450 starving and ultimately killing the bacteria. 214 00:13:21,090 --> 00:13:23,650 The significance wasn't lost on Fleming. 215 00:13:23,650 --> 00:13:26,610 This could be a new way to fight bacterial infection 216 00:13:26,610 --> 00:13:28,330 inside the human body. 217 00:13:29,970 --> 00:13:34,210 His discovery led to the creation of the world's first antibiotic - 218 00:13:34,210 --> 00:13:35,610 penicillin. 219 00:13:37,050 --> 00:13:41,290 And it only happened thanks to some tiny spores from a fungus, 220 00:13:41,290 --> 00:13:42,610 carried on the breeze. 221 00:13:44,490 --> 00:13:48,130 But to understand how those spores came to be there at all, 222 00:13:48,130 --> 00:13:52,450 we need to delve deeper into the secret world of fungi, 223 00:13:52,450 --> 00:13:55,530 right back to the start of their life cycle, 224 00:13:55,530 --> 00:13:58,170 to the moment a new fungus begins. 225 00:14:11,130 --> 00:14:12,490 I've come to Scotland 226 00:14:12,490 --> 00:14:16,410 to see something I've always wanted to see but never have, 227 00:14:16,410 --> 00:14:19,490 although I've rehearsed it many times in my mind's eye. 228 00:14:22,250 --> 00:14:25,810 This is one of the largest mushroom farms in the UK, 229 00:14:25,810 --> 00:14:28,170 and inside each of these polytunnels, 230 00:14:28,170 --> 00:14:32,050 there's a spectacular natural phenomenon taking place - 231 00:14:32,050 --> 00:14:33,450 the birth of fungi. 232 00:14:46,410 --> 00:14:49,810 It's a magical process, normally invisible, 233 00:14:49,810 --> 00:14:54,170 but tonight I'm going to see it clearly for the first time. 234 00:14:57,930 --> 00:14:59,690 Well, to a mushroom person, of course, 235 00:14:59,690 --> 00:15:02,370 this is like being in heaven, 236 00:15:02,370 --> 00:15:07,690 and everywhere you look, it's extraordinary - 237 00:15:07,690 --> 00:15:11,530 this laser torch picks out little white specks. 238 00:15:11,530 --> 00:15:14,530 They're so numerous. This is like shining a beam 239 00:15:14,530 --> 00:15:16,410 up into the Milky Way. 240 00:15:16,410 --> 00:15:20,770 Billions upon billions of spores in the air all around us, 241 00:15:20,770 --> 00:15:24,330 and they're ubiquitous, so they're going up to the ceiling 242 00:15:24,330 --> 00:15:28,090 they're going out the door, they're doubtless going into my lungs. 243 00:15:31,570 --> 00:15:37,250 If you want a graphic demonstration of how prolific mushrooms are, 244 00:15:37,250 --> 00:15:38,530 here it is. 245 00:15:45,490 --> 00:15:48,610 So this is how most fungi begin life. 246 00:15:49,690 --> 00:15:54,370 The mushroom spews out many millions of spores every hour, 247 00:15:54,370 --> 00:15:56,730 for as long as it remains above the ground... 248 00:15:57,970 --> 00:16:01,530 ..each of them carrying the potential to be a new fungus. 249 00:16:03,570 --> 00:16:05,490 It's mesmerising to watch, 250 00:16:05,490 --> 00:16:08,410 but I want to know exactly what's going on here 251 00:16:08,410 --> 00:16:11,410 and to do that, I'll need more than a laser light. 252 00:16:13,890 --> 00:16:15,570 Back in the mushroom lab, 253 00:16:15,570 --> 00:16:19,690 Patrick can reveal the hidden mechanisms of mushroom birth. 254 00:16:19,690 --> 00:16:22,010 A mushroom, also known as a fruiting body, 255 00:16:22,010 --> 00:16:25,130 really is just the reproductive structure of a fungus 256 00:16:25,130 --> 00:16:28,090 and its sole purpose is to produce spores, 257 00:16:28,090 --> 00:16:29,930 so to look at these in more detail, 258 00:16:29,930 --> 00:16:33,170 what I'm going to do is take a very thin section 259 00:16:33,170 --> 00:16:35,130 through this mushroom cap 260 00:16:35,130 --> 00:16:38,130 and put it onto a microscope slide. 261 00:16:44,250 --> 00:16:46,530 There we go... Ah! 262 00:16:46,530 --> 00:16:48,770 That's the business, isn't it? 263 00:16:48,770 --> 00:16:53,370 Yeah, so the large cylindrical kind of clear part of the cell 264 00:16:53,370 --> 00:16:58,130 is the basidium and those little spiky bits protruding from it 265 00:16:58,130 --> 00:17:01,250 are called the sterigmata and they hold the spores in place. 266 00:17:01,250 --> 00:17:03,850 Now, eventually, when those spores are fully ripened, 267 00:17:03,850 --> 00:17:06,450 they'll drop off into that air space between the gills, 268 00:17:06,450 --> 00:17:08,290 and fall down from the mushroom. 269 00:17:08,290 --> 00:17:10,530 That whole structure, including the spores, 270 00:17:10,530 --> 00:17:13,290 is about the width of a human hair, and, remember, these gills 271 00:17:13,290 --> 00:17:16,450 are packed with them. They're completely lined with a layer 272 00:17:16,450 --> 00:17:18,810 of these basidia continually producing spores. 273 00:17:18,810 --> 00:17:20,770 It's a production line. 274 00:17:20,770 --> 00:17:23,570 It's an extraordinary thought, isn't it? This tiny object, 275 00:17:23,570 --> 00:17:26,530 just a few thousandths of a millimetre long, 276 00:17:26,530 --> 00:17:29,410 contains the potentiality for a new mushroom colony. 277 00:17:29,410 --> 00:17:30,650 Exactly. 278 00:17:32,290 --> 00:17:36,650 This constant production line, forming and releasing spores, 279 00:17:36,650 --> 00:17:41,090 is exactly what I saw so vividly in action at the mushroom farm. 280 00:17:41,090 --> 00:17:44,370 But that's just one way mushrooms can spread their spores. 281 00:17:44,370 --> 00:17:47,010 Others do it in a completely different way. 282 00:17:48,650 --> 00:17:51,610 This is an orange peel fungus, 283 00:17:51,610 --> 00:17:53,290 and it's part of a large group 284 00:17:53,290 --> 00:17:57,450 that fire their spores vertically, with explosive results, 285 00:17:57,450 --> 00:18:01,450 as we can see here when the action is slowed down 600 times. 286 00:18:10,210 --> 00:18:11,810 Oh, look at that! 287 00:18:11,810 --> 00:18:13,650 They're like geysers erupting. 288 00:18:18,130 --> 00:18:21,570 The spores are incredibly prolific. Throughout the course of a day, 289 00:18:21,570 --> 00:18:24,450 each fungus might be capable of producing over a million spores 290 00:18:24,450 --> 00:18:26,730 and over the lifetime of that fungus, 291 00:18:26,730 --> 00:18:28,610 we're into tens to hundreds of millions. 292 00:18:35,930 --> 00:18:39,930 Well, that's extraordinary footage. I've never, ever seen anything 293 00:18:39,930 --> 00:18:43,930 so graphically displaying the way fungi get rid of their spores. 294 00:18:43,930 --> 00:18:45,770 It's a truly impressive fungus. 295 00:18:52,050 --> 00:18:56,250 These fungi can reload and fire time and time again, 296 00:18:56,250 --> 00:18:57,770 often for many days on end. 297 00:19:00,570 --> 00:19:01,930 And how that works, 298 00:19:01,930 --> 00:19:04,610 was a brilliant discovery made by someone you wouldn't expect. 299 00:19:13,290 --> 00:19:17,330 Beatrix Potter is famous for penning The Tale Of Peter Rabbit, 300 00:19:17,330 --> 00:19:18,930 but what's less well known, 301 00:19:18,930 --> 00:19:22,050 is that she was one of the leading mushroom biologists of her time. 302 00:19:24,010 --> 00:19:27,410 Both Potter and pioneering biologist Arthur Buller 303 00:19:27,410 --> 00:19:29,850 spent much of their lives trying to find out 304 00:19:29,850 --> 00:19:32,410 how some mushrooms release their spores. 305 00:19:36,610 --> 00:19:39,690 They discovered that a tiny drop of fluid, 306 00:19:39,690 --> 00:19:43,690 now known as Buller's drop, forms at the base of every spore. 307 00:19:48,170 --> 00:19:51,410 As the spore ripens and begins to detach, 308 00:19:51,410 --> 00:19:54,650 the Buller's drop fuses with a second tiny water droplet 309 00:19:54,650 --> 00:19:57,450 that forms at the side of the spore. 310 00:19:57,450 --> 00:20:01,010 Like two raindrops joining together on a windowpane, 311 00:20:01,010 --> 00:20:04,610 this fusion causes a rapid shift in mass 312 00:20:04,610 --> 00:20:07,850 that dislodges the spore, in such a spectacular fashion. 313 00:20:12,810 --> 00:20:15,570 This microscopic process all takes place 314 00:20:15,570 --> 00:20:18,170 in a few millionths of a second 315 00:20:18,170 --> 00:20:20,450 and is key to how many fungi reproduce. 316 00:20:21,690 --> 00:20:24,970 But of them all, there's one particular species 317 00:20:24,970 --> 00:20:26,330 that's a record breaker. 318 00:20:28,810 --> 00:20:31,570 You may think that the fastest organism on the planet 319 00:20:31,570 --> 00:20:34,690 is a cheetah or maybe a peregrine falcon, 320 00:20:34,690 --> 00:20:36,650 but you'd be wrong. 321 00:20:36,650 --> 00:20:39,730 Allowing for scale, the speediest organism on the planet 322 00:20:39,730 --> 00:20:42,050 is actually a tiny fungus. 323 00:20:42,050 --> 00:20:44,570 It grows on top of cowpats. 324 00:20:45,730 --> 00:20:51,810 It's called, Pilobolus crystallinus, or the "Hat Thrower" fungus, 325 00:20:51,810 --> 00:20:54,650 and no other species demonstrates better 326 00:20:54,650 --> 00:20:57,210 the importance of the spore release mechanism. 327 00:21:01,130 --> 00:21:05,370 This little fungus feeds on the dung on herbivores, 328 00:21:05,370 --> 00:21:09,250 but when the supply of nutrients from one pile has been exhausted, 329 00:21:09,250 --> 00:21:10,930 it needs to move on, 330 00:21:10,930 --> 00:21:14,250 and to do that, it has to get out of the dung 331 00:21:14,250 --> 00:21:16,490 and onto new blades of grass. 332 00:21:16,490 --> 00:21:18,370 That's the equivalent of you or I 333 00:21:18,370 --> 00:21:21,690 trying to throw a tennis ball over the Eiffel Tower. 334 00:21:21,690 --> 00:21:23,410 But, then, you or I 335 00:21:23,410 --> 00:21:24,850 can't do this. BANG 336 00:21:24,850 --> 00:21:27,570 MUSIC: "Zorba's Dance" by Mikis Theodorakis 337 00:21:32,610 --> 00:21:36,050 Using water drop acceleration, these spore capsules, 338 00:21:36,050 --> 00:21:39,290 seen as little black hats, can be fired at a speed 339 00:21:39,290 --> 00:21:43,570 of up to 40mph in just two millionths of a second, 340 00:21:43,570 --> 00:21:46,930 pulling an astonishing 20,000 Gs in the process. 341 00:21:48,010 --> 00:21:49,090 BANG 342 00:21:50,490 --> 00:21:53,290 The little "Hat Thrower" fungus is a wonderful example 343 00:21:53,290 --> 00:21:56,370 of the sophistication of fungus evolution. 344 00:21:56,370 --> 00:22:00,010 It throws its spore body more than a thousand times its own length 345 00:22:00,010 --> 00:22:02,730 into clear grass, away from cowpats, 346 00:22:02,730 --> 00:22:05,730 so that the cows will come along, graze the grass, 347 00:22:05,730 --> 00:22:09,730 incorporate the spores and so propagate another generation. 348 00:22:12,850 --> 00:22:16,010 The "Hat Thrower" shows just how ingenious fungi are 349 00:22:16,010 --> 00:22:17,770 when it comes to reproduction. 350 00:22:18,850 --> 00:22:22,490 They will go to extraordinary lengths to ensure their own future. 351 00:22:24,370 --> 00:22:28,290 It's the key to why fungi have become such a dominant life form 352 00:22:28,290 --> 00:22:32,050 with such vast numbers of species all over the planet. 353 00:22:35,770 --> 00:22:41,330 And it's certainly a talent to which humankind owes a great deal. 354 00:22:45,290 --> 00:22:50,090 But as impressive as spore dispersal might be, 355 00:22:50,090 --> 00:22:53,210 it's just the beginning of the fungus's life story. 356 00:22:54,450 --> 00:22:57,930 It's the next stage that truly reveals why they are 357 00:22:57,930 --> 00:23:00,210 so vital to all life on Earth. 358 00:23:02,090 --> 00:23:06,250 So far we've just been looking at the fruit body of the mushroom. 359 00:23:06,250 --> 00:23:10,130 Indeed, I suppose to most people, they think that IS the mushroom. 360 00:23:11,170 --> 00:23:12,930 But it's only part of the story. 361 00:23:14,010 --> 00:23:16,770 To discover how mushrooms relate 362 00:23:16,770 --> 00:23:20,010 to so many other organisms on our planet, 363 00:23:20,010 --> 00:23:23,690 we have to go further, we have to go underground. 364 00:23:34,010 --> 00:23:36,450 You'd be forgiven for thinking that what we see 365 00:23:36,450 --> 00:23:39,730 above the ground is the main part of the fungus... 366 00:23:41,010 --> 00:23:45,850 ..but, in fact, the vast majority of the organism is hidden underground. 367 00:23:45,850 --> 00:23:49,730 It's a huge web of tiny threads, spreading out in search of food. 368 00:23:52,370 --> 00:23:55,170 And the only way many fungi can get what they need, 369 00:23:55,170 --> 00:23:58,330 is by attaching themselves to other organisms, 370 00:23:58,330 --> 00:24:01,250 and engaging in a two-way exchange of nutrients. 371 00:24:05,010 --> 00:24:07,770 It's a process that results in one of the most complex, 372 00:24:07,770 --> 00:24:10,690 yet crucial relationships in the natural world. 373 00:24:15,010 --> 00:24:17,170 To discover how this works, 374 00:24:17,170 --> 00:24:20,530 I'm meeting Kew Gardens mycologist Bryn Dentinger. 375 00:24:23,250 --> 00:24:27,050 Anywhere from 70% to 90% of all plants on Earth 376 00:24:27,050 --> 00:24:31,330 will form a very special intimate relationship with fungi 377 00:24:31,330 --> 00:24:35,370 and the fungi will attach themselves to the plant roots, 378 00:24:35,370 --> 00:24:37,890 either directly penetrating the roots 379 00:24:37,890 --> 00:24:41,010 or sometimes they will form sheaths on the outside, 380 00:24:41,010 --> 00:24:43,650 that will envelop the root like a kind of glove. 381 00:24:44,930 --> 00:24:47,290 This is where the nutrient exchange takes place 382 00:24:47,290 --> 00:24:49,090 between the fungus and the root. 383 00:24:53,130 --> 00:24:56,770 This nutrient exchange works both ways. 384 00:24:56,770 --> 00:25:01,210 The fungus feeds on sugars from the plant that it needs to grow 385 00:25:01,210 --> 00:25:03,650 and in return gives back water and minerals 386 00:25:03,650 --> 00:25:06,490 that the planet is unable to absorb enough of itself. 387 00:25:09,370 --> 00:25:12,970 I'm going to lift up this pine seedling here 388 00:25:12,970 --> 00:25:16,410 and you can see, where I'm pointing with my pinkie, that white fuzz. 389 00:25:16,410 --> 00:25:17,610 Oh, yeah, OK. 390 00:25:17,610 --> 00:25:19,450 Those are the fungal filaments 391 00:25:19,450 --> 00:25:23,250 and it is completely covering the roots of this pine tree right here. 392 00:25:24,610 --> 00:25:27,610 And it extends over a much larger surface area 393 00:25:27,610 --> 00:25:30,050 than the roots can possibly cover, 394 00:25:30,050 --> 00:25:33,090 and this gives them access to all kinds of nutrients 395 00:25:33,090 --> 00:25:34,930 and water, even, from the soil, 396 00:25:34,930 --> 00:25:38,210 so they can extract nitrogen and phosphorous, in particular, 397 00:25:38,210 --> 00:25:39,610 from the soil, 398 00:25:39,610 --> 00:25:41,610 and provide those to the plant, 399 00:25:41,610 --> 00:25:44,850 which the plant will then exchange for sugars 400 00:25:44,850 --> 00:25:46,850 that it produces through photosynthesis. 401 00:25:46,850 --> 00:25:49,050 And the two together make for a better plant? 402 00:25:49,050 --> 00:25:51,890 A better plant and a better fungus, healthier soil. 403 00:25:51,890 --> 00:25:54,730 So it's a win-win situation for both? 404 00:25:54,730 --> 00:25:56,610 It's a win-win situation for both partners 405 00:25:56,610 --> 00:25:58,130 and, in fact, for the entire world. 406 00:26:00,330 --> 00:26:03,570 'We're going to look for evidence of this vital relationship, 407 00:26:03,570 --> 00:26:05,210 'in the wild.' 408 00:26:05,210 --> 00:26:06,610 Well, we can't see them, 409 00:26:06,610 --> 00:26:10,570 but, all around us there are these unseen fungal partners. 410 00:26:10,570 --> 00:26:14,410 They're invisible to us when we just take a nice stroll along a path, 411 00:26:14,410 --> 00:26:16,170 but they're all around us. 412 00:26:16,170 --> 00:26:17,770 Shall we have a go? Let's do it. 413 00:26:19,610 --> 00:26:20,850 I think I've got some. 414 00:26:23,490 --> 00:26:27,130 Well, I mean, you don't have to search for it. 415 00:26:27,130 --> 00:26:30,650 You can see the white tips here. It's very obvious, yeah. 416 00:26:30,650 --> 00:26:34,610 But every one of these tiny little, side-branching roots 417 00:26:34,610 --> 00:26:35,810 is covered in fungus. 418 00:26:39,730 --> 00:26:42,770 There's a fascinating and fundamental relationship 419 00:26:42,770 --> 00:26:45,530 between fungi and land plants, 420 00:26:45,530 --> 00:26:49,890 not just here in Kew and every park in Britain, but in every field. 421 00:26:49,890 --> 00:26:52,690 Without this relationship, plants couldn't thrive. 422 00:26:52,690 --> 00:26:56,010 It's impossible to overstate its importance. 423 00:26:58,370 --> 00:27:01,210 So how exactly does this hidden process happen? 424 00:27:04,090 --> 00:27:07,810 To find out, Patrick has been capturing it in action, 425 00:27:07,810 --> 00:27:10,530 starting from the moment a spore hits the ground. 426 00:27:12,290 --> 00:27:15,050 The primary mission of a fungal spore is to feed 427 00:27:15,050 --> 00:27:17,130 and find food resources. 428 00:27:17,130 --> 00:27:21,730 Now, under the right conditions, the spore starts to germinate and grow. 429 00:27:21,730 --> 00:27:24,610 That's what we can see here. We've placed some spores 430 00:27:24,610 --> 00:27:28,610 into a drop of water and as you can see, they're starting to swell. 431 00:27:28,610 --> 00:27:31,130 There's a little bit of movement starting to go on inside. 432 00:27:31,130 --> 00:27:34,570 Oh, yeah. And already you can see this little bud emerging, 433 00:27:34,570 --> 00:27:37,570 and that little bud is the beginnings of a fungal hypha. 434 00:27:37,570 --> 00:27:39,850 So, what is a hypha? 435 00:27:39,850 --> 00:27:43,130 The hypha is the feeding part of a fungus, the feeding tube, 436 00:27:43,130 --> 00:27:46,290 and the hypha goes in search of water and food 437 00:27:46,290 --> 00:27:48,370 and will continue growing and branching 438 00:27:48,370 --> 00:27:51,570 until it eventually establishes a colony, a fungal colony. 439 00:27:51,570 --> 00:27:53,090 Does it grow very fast? 440 00:27:53,090 --> 00:27:56,410 Once a hypha finds its food source, it can develop very quickly 441 00:27:56,410 --> 00:27:58,250 and form what we call a mycelium. 442 00:27:59,650 --> 00:28:04,930 A mycelium is the scientific name for the fungus's feeding network. 443 00:28:04,930 --> 00:28:07,690 Here magnified 500 times, 444 00:28:07,690 --> 00:28:11,730 we can see one starting to form as many hyphae begin to web together. 445 00:28:13,250 --> 00:28:15,850 Essentially, it is a fungus's root system, 446 00:28:15,850 --> 00:28:18,890 a complex series of feeding tubes. 447 00:28:18,890 --> 00:28:22,930 It's not unlike a microscopic human digestive system, 448 00:28:22,930 --> 00:28:25,290 processing food that allows it to grow. 449 00:28:26,530 --> 00:28:31,330 Within these tubes are the nutrients that are a fungus's entire future. 450 00:28:31,330 --> 00:28:33,170 And you can see the network forming now. 451 00:28:33,170 --> 00:28:35,290 Yeah, and this is in the centre of the colony. 452 00:28:35,290 --> 00:28:38,530 You have this branched network that keeps on feeding nutrients 453 00:28:38,530 --> 00:28:41,370 through the colony and sharing its water and resources. 454 00:28:41,370 --> 00:28:43,530 And that's only half a millimetre square? 455 00:28:43,530 --> 00:28:46,090 Roughly half a millimetre is the sort of field of view 456 00:28:46,090 --> 00:28:47,330 that we're looking at here 457 00:28:47,330 --> 00:28:48,930 and it's very much like a road network - 458 00:28:48,930 --> 00:28:50,730 we've got these kind of main motorways, 459 00:28:50,730 --> 00:28:52,610 we've got lots of little side routes in there 460 00:28:52,610 --> 00:28:56,770 and we've got flow of nutrients, water and it's very dynamic. 461 00:28:56,770 --> 00:28:59,050 For example, if I was to break one of these tracks, 462 00:28:59,050 --> 00:29:01,810 the fungus would very quickly adapt and form new connections. 463 00:29:01,810 --> 00:29:04,450 And form new connections and new routes. Mmm. 464 00:29:04,450 --> 00:29:06,610 It's extraordinary how bustling it is. 465 00:29:06,610 --> 00:29:09,370 Of course I can now see what we saw with Bryn Dentinger - 466 00:29:09,370 --> 00:29:13,490 how efficient these hyphae are at gathering nutrients 467 00:29:13,490 --> 00:29:15,050 and moving through the soil. 468 00:29:15,050 --> 00:29:17,970 Absolutely, and even in the most dry soil environments, 469 00:29:17,970 --> 00:29:20,810 fungi are able to draw up the moisture from the soil 470 00:29:20,810 --> 00:29:24,050 and transfer it into the plants through this co-operation. 471 00:29:24,050 --> 00:29:26,650 It is extraordinary, extraordinary footage. 472 00:29:28,730 --> 00:29:32,490 Although the mycelium is almost entirely invisible to us, 473 00:29:32,490 --> 00:29:35,170 it makes up the vast majority of the organism. 474 00:29:36,250 --> 00:29:38,690 And its size can be truly breathtaking. 475 00:29:39,850 --> 00:29:43,290 So big, in fact, it can often extend for miles. 476 00:29:47,090 --> 00:29:51,810 The biggest organism in the world is not the blue whale, 477 00:29:51,810 --> 00:29:58,690 but a mycelium that spreads across an incredible 2,384 acres 478 00:29:58,690 --> 00:30:00,970 in Oregon's Blue Mountains. 479 00:30:02,250 --> 00:30:05,850 It's called Armillaria mellea, or the honey fungus, 480 00:30:05,850 --> 00:30:09,730 and this example is thought to be over 2,000 years old. 481 00:30:11,970 --> 00:30:15,250 It's a mind-boggling example of how far a mycelium can grow. 482 00:30:17,570 --> 00:30:23,050 But it also reveals just how destructive a feeding fungus can be. 483 00:30:24,370 --> 00:30:27,250 These are clumps of honey fungus. 484 00:30:27,250 --> 00:30:30,130 It's the same fungus that spread inexorably 485 00:30:30,130 --> 00:30:32,930 through the forests of Oregon 486 00:30:32,930 --> 00:30:36,370 and it demonstrates a very different, some would say sinister, 487 00:30:36,370 --> 00:30:39,370 relationship between mycelium and trees. 488 00:30:42,650 --> 00:30:44,930 Unlike the balanced nutrient exchange 489 00:30:44,930 --> 00:30:48,570 that we see between most fungi and their plant partners, 490 00:30:48,570 --> 00:30:54,450 honey fungus takes much more from its host than it gives. 491 00:30:54,450 --> 00:30:57,250 It consumes all the sugars it needs, 492 00:30:57,250 --> 00:30:59,730 but crucially doesn't give back enough water and nutrients 493 00:30:59,730 --> 00:31:01,570 to help the tree grow properly. 494 00:31:03,130 --> 00:31:07,250 As a result, the greedy mycelium of this fungus thrives, 495 00:31:07,250 --> 00:31:09,690 while the tree slowly weakens. 496 00:31:12,290 --> 00:31:14,970 Honey fungus is a slow killer. 497 00:31:14,970 --> 00:31:18,610 It advances from tree to tree on hidden threads. 498 00:31:18,610 --> 00:31:22,170 As our tree population ages and some sickens, 499 00:31:22,170 --> 00:31:25,170 the rise of honey fungus is inexorable. 500 00:31:28,490 --> 00:31:31,650 But it's not the biggest threat to our plants and trees. 501 00:31:31,650 --> 00:31:36,130 There's another species of fungus whose hunger is even more deadly. 502 00:31:37,810 --> 00:31:40,850 I've come to Norfolk to find evidence of a fungus 503 00:31:40,850 --> 00:31:42,930 that's very difficult to see, 504 00:31:42,930 --> 00:31:45,010 but whose eating habits, 505 00:31:45,010 --> 00:31:50,010 are threatening to wipe out one of Britain's oldest trees. 506 00:31:50,010 --> 00:31:53,850 Just a few years ago, a new killer arrived in Britain - 507 00:31:53,850 --> 00:31:55,170 ash dieback disease, 508 00:31:55,170 --> 00:31:58,010 or Chalara fraxinea, to give it its scientific name... 509 00:31:59,010 --> 00:32:02,210 ..and no fungus better demonstrates 510 00:32:02,210 --> 00:32:04,290 the greed of mycelium for nourishment... 511 00:32:05,850 --> 00:32:08,370 ..and if it has its way, maybe, 512 00:32:08,370 --> 00:32:11,010 magnificent forest trees like this ash 513 00:32:11,010 --> 00:32:13,050 may yet become just a part of history. 514 00:32:15,930 --> 00:32:19,210 David Bole of the Wildlife Trust knows all too well 515 00:32:19,210 --> 00:32:21,690 just how destructive this fungus has become. 516 00:32:21,690 --> 00:32:25,330 And there's quite a lot of dieback in here, isn't there? 517 00:32:25,330 --> 00:32:26,650 Yeah. 518 00:32:26,650 --> 00:32:30,010 This is one of the first woods where we discovered it. 519 00:32:30,010 --> 00:32:34,170 What we're finding now is that there's over 500 cases 520 00:32:34,170 --> 00:32:38,250 in the wider environment and as we do more in-depth surveys, 521 00:32:38,250 --> 00:32:40,410 more and more cases are coming to the fore. 522 00:32:40,410 --> 00:32:42,530 Take me through the symptoms. 523 00:32:42,530 --> 00:32:46,370 Well, the first thing to look for is this, the black leaves, 524 00:32:46,370 --> 00:32:47,570 which we've got here 525 00:32:47,570 --> 00:32:52,010 and we've got a really good example on this little, young tree here. 526 00:32:52,010 --> 00:32:54,290 The leaves have died but they're black. 527 00:32:54,290 --> 00:32:57,410 They really don't look healthy and they're hanging onto the tree. 528 00:32:57,410 --> 00:32:59,210 I notice they die from the top too, 529 00:32:59,210 --> 00:33:01,850 so they're dead up here but still green down here. 530 00:33:01,850 --> 00:33:04,410 Yes, you know, it's called dieback and that's a good way 531 00:33:04,410 --> 00:33:07,050 to think of it - we have the tree slowly dying back. 532 00:33:08,250 --> 00:33:12,250 Other symptoms are these diamond-shaped lesions. 533 00:33:12,250 --> 00:33:15,690 The fungus lands on the leaves, the mycelia come in, 534 00:33:15,690 --> 00:33:20,090 and works its way up and down the cells of the tree 535 00:33:20,090 --> 00:33:23,690 and forms these very particular diamond-shaped lesions. 536 00:33:26,010 --> 00:33:29,690 This process is rather eerily called necrotrophy, 537 00:33:29,690 --> 00:33:32,010 which means eating the dead. 538 00:33:32,010 --> 00:33:34,090 The feeding hyphae of ash dieback 539 00:33:34,090 --> 00:33:36,170 attach themselves to their tree hosts 540 00:33:36,170 --> 00:33:38,490 in the same way as other fungi, 541 00:33:38,490 --> 00:33:42,130 but they obtain their sugars without providing any nutrients 542 00:33:42,130 --> 00:33:43,490 or water in return. 543 00:33:45,250 --> 00:33:47,850 It's all one-way traffic 544 00:33:47,850 --> 00:33:49,330 and has a fatal outcome. 545 00:33:52,130 --> 00:33:53,410 OK. 546 00:33:53,410 --> 00:33:55,410 OK, so let's just have a look inside. 547 00:33:56,490 --> 00:33:58,890 Oh, yeah. You can see discolouration. 548 00:33:58,890 --> 00:34:00,810 It's absolutely patent. 549 00:34:00,810 --> 00:34:05,370 So the disease has entered here and this is the fungal mycelia, 550 00:34:05,370 --> 00:34:08,170 which are starting to work its way inside the tree. 551 00:34:08,170 --> 00:34:10,250 The mycelia get inside all the cells 552 00:34:10,250 --> 00:34:12,730 that transport the water up and down the tree 553 00:34:12,730 --> 00:34:14,570 and stop the water transport 554 00:34:14,570 --> 00:34:17,890 and so the tree effectively dies of thirst, if you like. 555 00:34:25,090 --> 00:34:29,330 It's a sad end to one of our most beautiful and elegant forest trees. 556 00:34:29,330 --> 00:34:31,290 It really, really is, yes. 557 00:34:31,290 --> 00:34:33,970 I mean, we'll probably lose a generation of ash 558 00:34:33,970 --> 00:34:36,050 but let's hope we see that coming back. 559 00:34:39,090 --> 00:34:42,690 Ash dieback demonstrates just what happens when the delicate balance 560 00:34:42,690 --> 00:34:45,570 between plant and fungus gets out of kilter... 561 00:34:46,810 --> 00:34:49,170 ..and that's what allows this disease 562 00:34:49,170 --> 00:34:50,850 to spread so far and so fast. 563 00:34:53,810 --> 00:34:58,250 It also shows just what a voracious eater fungal mycelium can be. 564 00:35:00,010 --> 00:35:02,010 But though this unstoppable appetite 565 00:35:02,010 --> 00:35:04,450 can be deadly in the natural world, 566 00:35:04,450 --> 00:35:08,770 some scientists are looking to turn it to our advantage. 567 00:35:23,250 --> 00:35:28,290 This is Eben Bayer, an entrepreneur based in New York. 568 00:35:28,290 --> 00:35:31,450 He noticed something intriguing that happens, 569 00:35:31,450 --> 00:35:34,730 when some mycelium spreads out in search of food. 570 00:35:37,970 --> 00:35:40,450 First time I saw mycelium in action was holding 571 00:35:40,450 --> 00:35:43,050 clumps of woodchips together on my family farm 572 00:35:43,050 --> 00:35:44,850 and rather than falling apart, 573 00:35:44,850 --> 00:35:48,130 they'd be held together by these white fibre strands. 574 00:35:48,130 --> 00:35:51,210 One night, sitting at home on my futon in my apartment, 575 00:35:51,210 --> 00:35:54,530 I got this crazy idea about, "Hey, mycelium seems to grow, 576 00:35:54,530 --> 00:35:56,890 "and glue the forest floor together. 577 00:35:56,890 --> 00:35:58,610 "Maybe we can use it as a glue." 578 00:36:01,770 --> 00:36:06,250 Eben saw huge potential in this binding property of mycelium. 579 00:36:06,250 --> 00:36:09,370 He used it to create a new kind of packaging, 580 00:36:09,370 --> 00:36:11,690 one that he believes could, ultimately, 581 00:36:11,690 --> 00:36:15,050 become an eco-friendly alternative to some plastics. 582 00:36:17,450 --> 00:36:20,490 Just in packaging alone, there's like billions of dollars 583 00:36:20,490 --> 00:36:22,210 of Styrofoam used every year, 584 00:36:22,210 --> 00:36:26,010 somewhere between $3.5 and $5 billion of styrene, 585 00:36:26,010 --> 00:36:28,970 and the biggest issue with plastics is at their end of life 586 00:36:28,970 --> 00:36:31,610 and with our material, you get something that, 587 00:36:31,610 --> 00:36:34,250 at the end of its useful life, can be composted, right. 588 00:36:34,250 --> 00:36:37,890 Your packaging becomes a nutrient for your neighbourhood, not a pollutant. 589 00:36:39,890 --> 00:36:43,570 To make his new material, Eben mimics what happens in nature. 590 00:36:44,650 --> 00:36:49,210 He takes some ground corn stalks and seeds them with fungus spores. 591 00:36:49,210 --> 00:36:52,730 The spores germinate, and begin to feed on the stalks, 592 00:36:52,730 --> 00:36:58,450 breaking down and digesting them, so the mycelium can start to grow. 593 00:36:58,450 --> 00:37:02,090 The mixture is then placed inside a mould and left 594 00:37:02,090 --> 00:37:04,890 for the mycelium to perform its biological magic. 595 00:37:06,370 --> 00:37:10,370 So, they'll sit on a rack like this for anywhere from 24 to 72 hours. 596 00:37:10,370 --> 00:37:12,450 It doesn't look like anything's happening, 597 00:37:12,450 --> 00:37:14,290 but the mycelium is already going to work, 598 00:37:14,290 --> 00:37:16,770 growing and extending out from every one of these particles 599 00:37:16,770 --> 00:37:18,730 and building a strong, tough network. 600 00:37:18,730 --> 00:37:21,610 And within 24 hours, this part will look a little white 601 00:37:21,610 --> 00:37:24,410 and that's the mycelium gluing everything together. 602 00:37:30,770 --> 00:37:33,450 So this is a finished corner block. 603 00:37:33,450 --> 00:37:36,210 It's been grown in our production process, it's been moulded 604 00:37:36,210 --> 00:37:40,050 and all of this came from that loosie-goosie agricultural by-product 605 00:37:40,050 --> 00:37:41,250 you saw at the beginning. 606 00:37:41,250 --> 00:37:42,610 Pretty incredible, huh? 607 00:37:47,770 --> 00:37:49,570 What we've done with mycelium here, 608 00:37:49,570 --> 00:37:52,050 which is basically leveraging a living organism 609 00:37:52,050 --> 00:37:53,690 to create really great technology, 610 00:37:53,690 --> 00:37:56,290 is where the excitement is, that's where the innovation is 611 00:37:56,290 --> 00:37:59,130 and that's where the solutions are going to be for the next 100 years. 612 00:38:01,850 --> 00:38:06,050 So the mushroom mycelium could help us tackle the global problem, 613 00:38:06,050 --> 00:38:07,850 of plastic waste, 614 00:38:07,850 --> 00:38:11,130 but Eben's work also demonstrates another important trait 615 00:38:11,130 --> 00:38:12,450 of the feeding mycelium. 616 00:38:15,010 --> 00:38:18,050 While some fungi feed on living organisms, 617 00:38:18,050 --> 00:38:21,730 others only eat those that are dead. 618 00:38:21,730 --> 00:38:25,970 These fungi are able to break down and digest organic waste 619 00:38:25,970 --> 00:38:28,730 and in doing so, recycle it. 620 00:38:30,410 --> 00:38:32,890 This process is called saprotrophy 621 00:38:32,890 --> 00:38:36,530 and it's absolutely vital in the natural world. 622 00:38:37,930 --> 00:38:41,450 In this damp wood, the litter of leaves, 623 00:38:41,450 --> 00:38:45,410 indeed, every twig, is being consumed by mycelium, 624 00:38:45,410 --> 00:38:48,570 that breaks down the cellulose and other compounds. 625 00:38:48,570 --> 00:38:49,570 Even... 626 00:38:50,730 --> 00:38:53,450 Even wood can be digested by fungi. 627 00:38:53,450 --> 00:38:56,850 The hard lignin that gives the wood its strength 628 00:38:56,850 --> 00:39:02,010 can be consumed and the wood reduced to little more than rubble. 629 00:39:02,010 --> 00:39:06,010 Were it not for the relentless activity of mycelium, in fact, 630 00:39:06,010 --> 00:39:12,050 the whole planet would be covered with a mass of undigested scrub. 631 00:39:16,010 --> 00:39:20,090 It's hard to overstate the importance of saprotrophic fungi. 632 00:39:20,090 --> 00:39:23,930 They have successfully recycled the world's natural waste 633 00:39:23,930 --> 00:39:26,850 for hundreds of millions of years, 634 00:39:26,850 --> 00:39:30,930 making entire ecosystems habitable for animal and plant life. 635 00:39:32,250 --> 00:39:34,610 So how do they achieve this crucial trick? 636 00:39:38,450 --> 00:39:41,330 So, Patrick, let's talk rot. 637 00:39:41,330 --> 00:39:43,570 Few people realise just how important 638 00:39:43,570 --> 00:39:46,810 those saprotropes fungi are in nature. 639 00:39:46,810 --> 00:39:48,130 How does it work? 640 00:39:48,130 --> 00:39:50,330 Well, fungi are really quite invasive. 641 00:39:50,330 --> 00:39:53,930 The fungi have this mycelium, which penetrates deep into the waste 642 00:39:53,930 --> 00:39:56,130 and unlike us, where our stomachs are internal, 643 00:39:56,130 --> 00:40:00,010 the fungi secrete their digestive juices out into the environment 644 00:40:00,010 --> 00:40:03,490 and start breaking down the complex molecules, 645 00:40:03,490 --> 00:40:06,330 things like cellulose, into more simple forms. 646 00:40:06,330 --> 00:40:08,930 This is via a myriad of those little hyphal threads. 647 00:40:08,930 --> 00:40:10,090 That's right. 648 00:40:10,090 --> 00:40:13,130 And to demonstrate just how effective saprotrophic fungi are 649 00:40:13,130 --> 00:40:17,130 at breaking down organic matter, I've put several days of kitchen waste 650 00:40:17,130 --> 00:40:19,930 into this beaker and I've filmed it over two weeks 651 00:40:19,930 --> 00:40:22,770 to see just how quickly it goes down, it rots down. 652 00:40:24,050 --> 00:40:26,930 SQUELCHING 653 00:40:28,010 --> 00:40:30,530 So there it is, just sort of sinking down. 654 00:40:30,530 --> 00:40:34,370 Yeah. Lots of juice exuding from the vegetables. 655 00:40:34,370 --> 00:40:37,730 So the invisible threads of the mycelium are getting in there, 656 00:40:37,730 --> 00:40:40,610 breaking vegetables and the other organic waste, 657 00:40:40,610 --> 00:40:42,490 into something they can use. 658 00:40:44,210 --> 00:40:45,850 The other important thing to note here 659 00:40:45,850 --> 00:40:48,290 is that when all these vegetables did go into the beaker, 660 00:40:48,290 --> 00:40:51,010 they already had spores on them, so they were already pre-seeded 661 00:40:51,010 --> 00:40:53,250 with the spores. Because spores are everywhere. 662 00:40:53,250 --> 00:40:55,810 Exactly, when you bring the food back from the supermarket, 663 00:40:55,810 --> 00:40:59,130 it'll already have a coating of a whole cocktail of different spores 664 00:40:59,130 --> 00:41:02,010 and as soon as those fungi are in a slightly warm environment, 665 00:41:02,010 --> 00:41:04,410 it becomes quite a feeding frenzy, if you like. 666 00:41:08,130 --> 00:41:11,850 So, Richard, I'm going to show you the results of the one 667 00:41:11,850 --> 00:41:13,490 that I prepared two weeks ago. 668 00:41:15,450 --> 00:41:18,290 Well, it couldn't be much clearer than that. 669 00:41:18,290 --> 00:41:21,090 Yeah. Look how far it's gone down. This was the start point and... 670 00:41:21,090 --> 00:41:22,610 At least a third. 671 00:41:22,610 --> 00:41:25,770 ..it's gone down about a third and I'd expect, within another two weeks, 672 00:41:25,770 --> 00:41:27,450 to be almost to the bottom. 673 00:41:27,450 --> 00:41:29,290 If this process wasn't happening 674 00:41:29,290 --> 00:41:31,650 we would just be surrounded by organic waste matter. 675 00:41:31,650 --> 00:41:33,650 Heaps of vegetables. Exactly. 676 00:41:33,650 --> 00:41:37,010 What it does show is just what makes the fungi 677 00:41:37,010 --> 00:41:41,930 such efficient seekers after, scavengers after nutrition. 678 00:41:41,930 --> 00:41:43,810 Yep. 679 00:41:43,810 --> 00:41:45,850 Extraordinary. 680 00:41:45,850 --> 00:41:49,330 The brilliant way the mycelium of a saprotrophic fungus 681 00:41:49,330 --> 00:41:54,090 uses digestive juices just like humans to break down waste 682 00:41:54,090 --> 00:41:57,610 makes it a recycling machine like no other. 683 00:41:57,610 --> 00:42:00,650 And it doesn't stop there. 684 00:42:00,650 --> 00:42:03,730 For as saprotrophic fungi recycle organic matter, 685 00:42:03,730 --> 00:42:08,290 they're performing a key role in creating healthy soil, 686 00:42:08,290 --> 00:42:13,490 soil that can, in turn, sustain new plant life 687 00:42:13,490 --> 00:42:16,890 and that's also a home for a host of other life forms, 688 00:42:16,890 --> 00:42:19,570 tiny micro-organisms that live within it. 689 00:42:20,770 --> 00:42:22,450 And for some fungi, 690 00:42:22,450 --> 00:42:27,210 the arrival of these new guests is just another feeding opportunity. 691 00:42:29,010 --> 00:42:32,530 These oyster mushrooms, or Pleurotus, 692 00:42:32,530 --> 00:42:36,850 have mycelium that breaks down the wood in rotting logs. 693 00:42:38,170 --> 00:42:40,050 They're quite efficient at doing this, 694 00:42:40,050 --> 00:42:43,890 but they have a shortage of one essential element, nitrogen 695 00:42:43,890 --> 00:42:45,890 and to make good this deficiency, 696 00:42:45,890 --> 00:42:47,770 they've evolved a very special trick. 697 00:42:52,770 --> 00:42:54,970 From the end of some of its hyphae, 698 00:42:54,970 --> 00:42:57,650 the oyster mushroom emits tiny lassos 699 00:42:57,650 --> 00:43:00,130 that secrete a powerful toxin. 700 00:43:00,130 --> 00:43:01,850 And it does this for one reason - 701 00:43:03,610 --> 00:43:06,050 nematode worms. 702 00:43:06,050 --> 00:43:09,130 These tiny organisms live within the logs 703 00:43:09,130 --> 00:43:10,770 and happen to be rich in the nitrogen 704 00:43:10,770 --> 00:43:12,770 that the hungry mushroom needs. 705 00:43:14,050 --> 00:43:17,890 The oyster mushroom lures the nematodes towards their tiny lassos 706 00:43:17,890 --> 00:43:19,330 before enveloping them. 707 00:43:20,890 --> 00:43:24,170 Once trapped, it's curtains for the little worm, 708 00:43:24,170 --> 00:43:26,250 and dinner for the mushroom 709 00:43:26,250 --> 00:43:28,810 as it gets the nitrogen-rich fluid it needs. 710 00:43:31,210 --> 00:43:35,170 The oyster mushroom's rather gruesome feeding trick 711 00:43:35,170 --> 00:43:39,650 demonstrates yet again just how sophisticated a fungus can be 712 00:43:39,650 --> 00:43:42,130 when it comes to getting the food it needs. 713 00:43:47,890 --> 00:43:51,850 It's a talent that, once again, we humans are looking to harness. 714 00:43:55,290 --> 00:43:58,730 Over in Washington State, mycologist Paul Stamets 715 00:43:58,730 --> 00:44:02,170 has turned to our hungry friend the oyster mushroom, 716 00:44:02,170 --> 00:44:04,810 in the hope he can use it on a truly grand scale - 717 00:44:04,810 --> 00:44:08,690 to tackle some of our most pressing environmental problems, 718 00:44:08,690 --> 00:44:10,850 such as chemical pollution. 719 00:44:14,170 --> 00:44:18,970 One of my great realisations in life is that habitats have immune systems 720 00:44:18,970 --> 00:44:20,490 just like we do, 721 00:44:20,490 --> 00:44:23,730 but mushrooms are the bridges between the two. 722 00:44:23,730 --> 00:44:27,970 These things unravel and break down large molecules into smaller ones 723 00:44:27,970 --> 00:44:31,210 that are very useful for other members in the ecological community. 724 00:44:32,330 --> 00:44:37,210 That course of that decomposition, has many different properties 725 00:44:37,210 --> 00:44:39,210 that we can use for breaking down toxic waste. 726 00:44:40,770 --> 00:44:42,530 That looks good. 727 00:44:42,530 --> 00:44:44,810 Paul discovered that mushroom mycelium 728 00:44:44,810 --> 00:44:49,370 can break down the hydrocarbons present in much chemical waste. 729 00:44:49,370 --> 00:44:52,530 It's a process he calls bioremediation. 730 00:44:52,530 --> 00:44:55,690 The mushroom is greedily eating the pollutants away. 731 00:45:04,090 --> 00:45:06,330 It looks convincing in the lab, 732 00:45:06,330 --> 00:45:08,770 but does it work in practice? 733 00:45:08,770 --> 00:45:12,650 Paul's theory was recently put to the test on an industrial level 734 00:45:12,650 --> 00:45:15,370 when a heavily-polluted petrochemical site 735 00:45:15,370 --> 00:45:17,850 was seeded with oyster mushroom mycelium. 736 00:45:19,610 --> 00:45:22,330 The work was carried out by environmental engineer 737 00:45:22,330 --> 00:45:23,330 Howard Sprouse. 738 00:45:24,930 --> 00:45:27,050 Yeah, bring her down a little for me. 739 00:45:27,050 --> 00:45:31,370 After just two days, the team found that their polluted pile 740 00:45:31,370 --> 00:45:34,730 had been transformed by the mushroom mycelium 741 00:45:34,730 --> 00:45:36,890 and was now teeming with new life. 742 00:45:38,290 --> 00:45:43,530 Well, this is interesting. We've got lots of worms in here now. 743 00:45:43,530 --> 00:45:45,130 That's a good sign. 744 00:45:45,130 --> 00:45:48,690 If it drops any more, we're going to be able to use this soil anywhere. 745 00:45:50,490 --> 00:45:52,650 The contaminate has gone... 746 00:45:53,690 --> 00:45:58,330 ..the decomposition process that the fungi have started 747 00:45:58,330 --> 00:46:02,410 is continued by other soil microorganisms 748 00:46:02,410 --> 00:46:05,970 and you end up with soil that's richer than it was when you started. 749 00:46:09,930 --> 00:46:12,970 Paul's study shows that oyster mushroom mycelium 750 00:46:12,970 --> 00:46:15,690 can not only digest chemical waste - 751 00:46:15,690 --> 00:46:18,970 it also manages to create an entirely new ecosystem 752 00:46:18,970 --> 00:46:21,130 in the process. 753 00:46:21,130 --> 00:46:26,250 At a time when the Earth is suffering from toxin exposure, 754 00:46:26,250 --> 00:46:30,930 erosion of habitats, overpopulation, 755 00:46:30,930 --> 00:46:34,090 deforestation, loss of soil integrity... 756 00:46:35,930 --> 00:46:40,210 ..mushrooms present themselves with unique properties 757 00:46:40,210 --> 00:46:44,850 that can address all those problems with a single group, 758 00:46:44,850 --> 00:46:47,010 and that's what I find so exciting - 759 00:46:47,010 --> 00:46:49,610 that the solutions are literally underfoot. 760 00:46:53,490 --> 00:46:55,650 Paul's work shows just how great 761 00:46:55,650 --> 00:46:58,010 the potential of fungus mycelium might be. 762 00:47:00,050 --> 00:47:04,170 Its hidden underground threads act upon their natural environment 763 00:47:04,170 --> 00:47:07,930 in truly remarkable ways we are only now beginning to realise. 764 00:47:10,490 --> 00:47:12,610 But as vital as it could be to us, 765 00:47:12,610 --> 00:47:15,850 the mycelium's feeding quest has one simple goal... 766 00:47:17,970 --> 00:47:19,850 ..to produce its fruiting body... 767 00:47:21,050 --> 00:47:24,290 ..bringing the organism to the end of its life cycle. 768 00:47:29,690 --> 00:47:33,810 We've seen how mycelium can form complex feeding webs 769 00:47:33,810 --> 00:47:37,450 and how the mycelium underpins so many of Earth's ecosystems... 770 00:47:39,050 --> 00:47:42,890 ..yet that mycelium itself has only one purpose... 771 00:47:44,170 --> 00:47:50,210 ..to fulfil its own life cycle and to lead once again to the mushroom. 772 00:47:58,370 --> 00:48:02,450 For the fungus, this final stage simply means reproduction 773 00:48:02,450 --> 00:48:04,690 and the dispersal of billions of spores. 774 00:48:05,890 --> 00:48:07,690 'But for another species, 775 00:48:07,690 --> 00:48:10,890 'it's just the beginning of its relationship with fungi.' 776 00:48:10,890 --> 00:48:12,170 Nice find. 777 00:48:12,170 --> 00:48:14,570 'And that species is us.' 778 00:48:14,570 --> 00:48:15,810 Ah. 779 00:48:15,810 --> 00:48:17,770 The sulphur tuft. 780 00:48:17,770 --> 00:48:18,770 Very abundant. 781 00:48:19,890 --> 00:48:22,010 Very inedible. 782 00:48:22,010 --> 00:48:24,690 'Its mythical status in folklore and magic 783 00:48:24,690 --> 00:48:29,450 'has made the mushroom an object of both fascination and fear.' 784 00:48:29,450 --> 00:48:31,890 Well, now, this is a troublemaker. 785 00:48:32,930 --> 00:48:35,770 'And sometimes that fear can be for good reason.' 786 00:48:37,170 --> 00:48:41,410 Poison pie is, as its name suggests, not a good thing to eat. 787 00:48:44,690 --> 00:48:46,330 Go out into any woodland 788 00:48:46,330 --> 00:48:50,170 and you're likely to encounter a wide range of poisonous fungi 789 00:48:50,170 --> 00:48:53,530 that you certainly would not want on your dinner plate. 790 00:48:53,530 --> 00:48:56,450 People get a big nervous about this one... 791 00:48:56,450 --> 00:48:58,130 the Sickener. 792 00:48:58,130 --> 00:49:00,930 Well, the name tells you everything. You don't want to eat it. 793 00:49:03,690 --> 00:49:06,130 The notion that fungi can be poisonous 794 00:49:06,130 --> 00:49:08,130 is what frightens us most about them. 795 00:49:12,010 --> 00:49:16,170 This is the most poisonous mushroom known to man. 796 00:49:16,170 --> 00:49:17,770 It's the death cap. 797 00:49:17,770 --> 00:49:20,730 People have eaten it, apparently in mistake for a field mushroom. 798 00:49:20,730 --> 00:49:22,410 I can't think how. 799 00:49:22,410 --> 00:49:26,770 But they'd have cause to regret it, because half a cap of one of these 800 00:49:26,770 --> 00:49:29,450 is enough to kill a grown man 801 00:49:29,450 --> 00:49:31,210 and slowly 802 00:49:31,210 --> 00:49:32,330 and painfully. 803 00:49:37,290 --> 00:49:39,490 I've been a field mycologist for many years 804 00:49:39,490 --> 00:49:43,810 and know to avoid dangerous mushrooms like the death cap, 805 00:49:43,810 --> 00:49:48,090 but their toxicity does raise an interesting question - 806 00:49:48,090 --> 00:49:51,130 what is it that gives mushrooms the power to kill? 807 00:49:52,850 --> 00:49:56,010 To explore this, I've come back to the lab once final time. 808 00:49:57,650 --> 00:50:01,970 Every fungus will have a cocktail of different chemicals within it, 809 00:50:01,970 --> 00:50:05,050 and depending on what type it is, there's various different types 810 00:50:05,050 --> 00:50:08,650 of poisonous chemicals which are present in these mushrooms. 811 00:50:08,650 --> 00:50:12,650 Possibly one of the worst ones is something like the destroying angel. 812 00:50:12,650 --> 00:50:14,690 Or the death cap, which is its close relative. 813 00:50:14,690 --> 00:50:18,490 Or the death cap, and those have a substance called amatoxins, 814 00:50:18,490 --> 00:50:20,930 which are deadly toxic. 815 00:50:20,930 --> 00:50:24,530 You'd only have to eat one or two of these to be completely poisoned. 816 00:50:24,530 --> 00:50:28,130 You'll end up with liver failure, kidney failure and death 817 00:50:28,130 --> 00:50:31,370 and it's a really quite nasty way to go. 818 00:50:31,370 --> 00:50:35,690 So we know that mushrooms are toxic, but why are they toxic? 819 00:50:35,690 --> 00:50:39,170 Well, there's a theory that mushrooms evolved to become toxic 820 00:50:39,170 --> 00:50:42,170 in order to discourage predators from eating them, 821 00:50:42,170 --> 00:50:44,410 but I'm not sure that's exactly the case, 822 00:50:44,410 --> 00:50:48,530 so I've set up a little test with a selection of mushrooms 823 00:50:48,530 --> 00:50:51,250 and we've brought in a guest to do the test for us. 824 00:50:54,490 --> 00:50:58,690 Patrick has offered a selection of five mushrooms to a hungry slug, 825 00:50:58,690 --> 00:51:01,410 one of which is poisonous to humans. 826 00:51:01,410 --> 00:51:02,810 But which will it prefer? 827 00:51:04,650 --> 00:51:06,890 After a look around and having a nibble of one or two, 828 00:51:06,890 --> 00:51:08,930 he seems to have settled on this one. 829 00:51:08,930 --> 00:51:12,330 Oh, the sulphur tuft, which is famously bitter and poisonous. 830 00:51:12,330 --> 00:51:14,410 Yeah, it doesn't seem to bother the slug 831 00:51:14,410 --> 00:51:18,210 and, in fact, he seems to be having a tasty meal on the gills, there. 832 00:51:18,210 --> 00:51:21,730 So what we've seen is certainly not in support of the idea 833 00:51:21,730 --> 00:51:24,570 that fungi are kind of protecting themselves from being eaten 834 00:51:24,570 --> 00:51:28,130 until mature. In fact, you could argue that that mushroom 835 00:51:28,130 --> 00:51:30,410 actually wants to be eaten, 836 00:51:30,410 --> 00:51:32,970 so what's it all about? 837 00:51:32,970 --> 00:51:34,730 I think, really, the bigger picture 838 00:51:34,730 --> 00:51:37,050 is the diversity within the fungal kingdom, 839 00:51:37,050 --> 00:51:40,610 in that the fungi produce thousands of different chemicals 840 00:51:40,610 --> 00:51:43,610 and it just so happens that some of those are toxic to us, 841 00:51:43,610 --> 00:51:46,730 whereas they might not be toxic to something like a slug or an insect. 842 00:51:46,730 --> 00:51:50,170 In fact, it may be a very important food source for those animals. 843 00:51:50,170 --> 00:51:53,610 So you've just got a huge spectrum of different types of chemicals. 844 00:51:53,610 --> 00:51:55,610 And we're only just beginning to explore 845 00:51:55,610 --> 00:51:57,850 the implications of some of these. Absolutely. 846 00:52:01,210 --> 00:52:03,690 We don't yet fully understand why some fungi 847 00:52:03,690 --> 00:52:06,330 have such a potent effect on us. 848 00:52:06,330 --> 00:52:07,650 More research is needed. 849 00:52:09,570 --> 00:52:11,610 But, already, we're beginning to exploit 850 00:52:11,610 --> 00:52:15,930 some of their seemingly sinister behaviours for our own benefit. 851 00:52:17,130 --> 00:52:19,530 Can I introduce you to cordyceps? 852 00:52:19,530 --> 00:52:22,850 These are dried specimens of a very famous fungus, 853 00:52:22,850 --> 00:52:26,850 famous in Chinese medicine for curing all manner of ills. 854 00:52:26,850 --> 00:52:30,410 It's a curious fungus with a strange, parasitic lifestyle. 855 00:52:34,130 --> 00:52:37,610 Unlike most fungi, it doesn't feed on dead matter 856 00:52:37,610 --> 00:52:40,130 but instead seeks out a very different host. 857 00:52:42,130 --> 00:52:44,930 Like something out of science fiction, 858 00:52:44,930 --> 00:52:48,170 this fungus grows inside insects, 859 00:52:48,170 --> 00:52:51,970 slowly killing them until the fruiting body is ready to emerge. 860 00:52:59,930 --> 00:53:03,930 But despite its rather, alien life habits, 861 00:53:03,930 --> 00:53:06,650 the chemicals concealed inside the cordyceps 862 00:53:06,650 --> 00:53:09,930 may yet prove crucial to a major medical breakthrough. 863 00:53:13,450 --> 00:53:17,050 Doctor Cornelia De Moor from the University of Nottingham 864 00:53:17,050 --> 00:53:20,370 is using this little mushroom in a cutting-edge treatment 865 00:53:20,370 --> 00:53:22,690 for one of our most feared diseases - 866 00:53:22,690 --> 00:53:24,170 cancer. 867 00:53:27,370 --> 00:53:32,850 So in cordyceps there are very high levels of this cordycepin... 868 00:53:33,930 --> 00:53:35,410 ..and cordycepin is a compound 869 00:53:35,410 --> 00:53:37,450 that is actually only very slightly changed 870 00:53:37,450 --> 00:53:41,530 from a very common compound that you find in all cells called adenosine. 871 00:53:41,530 --> 00:53:44,050 It's only one oxygen difference. 872 00:53:44,050 --> 00:53:47,250 But for some reason, only cordyceps fungi make cordycepin 873 00:53:47,250 --> 00:53:49,930 while all organisms make adenosine. 874 00:53:51,850 --> 00:53:56,530 This unique compound produced by cordyceps has long been of interest 875 00:53:56,530 --> 00:54:00,770 to alternative medicine in the treatment of cancerous tumours, 876 00:54:00,770 --> 00:54:05,370 but how it worked was never clear and Cornelia was keen to find out. 877 00:54:08,570 --> 00:54:12,130 What surprises immensely the first time we treated cells 878 00:54:12,130 --> 00:54:15,850 with cordycepin is when we put cordycepin on cells like that, 879 00:54:15,850 --> 00:54:19,450 they changed shape into cells like that 880 00:54:19,450 --> 00:54:24,930 in which the little grains are gone and the cells start to shrink. 881 00:54:24,930 --> 00:54:26,610 So when we saw this, 882 00:54:26,610 --> 00:54:30,450 we knew there was something quite fundamental happening to the cells 883 00:54:30,450 --> 00:54:33,330 and that then led to our later discoveries 884 00:54:33,330 --> 00:54:34,850 on the affects of cordycepin. 885 00:54:39,970 --> 00:54:42,210 Cornelia knew that with any cancer, 886 00:54:42,210 --> 00:54:45,570 in order for the individual cells to multiply and grow, 887 00:54:45,570 --> 00:54:47,610 they must join themselves together 888 00:54:47,610 --> 00:54:51,930 using tiny stems called poly-A tails. 889 00:54:51,930 --> 00:54:54,930 And it's here that she has discovered that cordycepin 890 00:54:54,930 --> 00:54:56,250 plays a crucial role. 891 00:54:57,850 --> 00:55:01,050 So we've been doing some work on breast cancer cells, 892 00:55:01,050 --> 00:55:03,490 which we've been treating with cordycepin, 893 00:55:03,490 --> 00:55:07,010 and what we're seeing is that the cordycepin appears to stop 894 00:55:07,010 --> 00:55:09,330 the making of the long poly-A tail, 895 00:55:09,330 --> 00:55:11,410 so it might not kill the cell 896 00:55:11,410 --> 00:55:16,290 but the most important thing - it stops the growth of the cancer cell, 897 00:55:16,290 --> 00:55:20,090 by cutting off the machinery that is necessary for cell growth. 898 00:55:21,570 --> 00:55:24,810 It is a completely new mechanism for a cancer drug, 899 00:55:24,810 --> 00:55:28,770 so all other cancer drugs work on completely different principles, 900 00:55:28,770 --> 00:55:31,410 not on inhibiting this polyadenylation, 901 00:55:31,410 --> 00:55:34,770 so it could be the first of a new class of drugs, 902 00:55:34,770 --> 00:55:37,930 not only for cancer, but also for inflammatory diseases. 903 00:55:40,850 --> 00:55:43,890 Medical breakthroughs, from Fleming's penicillin 904 00:55:43,890 --> 00:55:48,130 to cutting edge cancer research, reveal an extraordinary truth. 905 00:55:49,210 --> 00:55:51,770 The cells of fungi have the ability 906 00:55:51,770 --> 00:55:55,090 to interact with our own cells on a profound level... 907 00:55:57,970 --> 00:56:01,810 ..to alter them in ways that affect our health, even our survival. 908 00:56:04,250 --> 00:56:05,770 And this is a powerful clue 909 00:56:05,770 --> 00:56:10,370 to the true relationship between fungi and us. 910 00:56:10,370 --> 00:56:13,890 Time and again, we seem to discover deep biological connections 911 00:56:13,890 --> 00:56:16,450 between ourselves and the fungi. 912 00:56:17,570 --> 00:56:20,250 But what could we have in common with a mushroom? 913 00:56:21,730 --> 00:56:24,330 To find out the answer, we have to delve deep 914 00:56:24,330 --> 00:56:26,530 into our own evolutionary history. 915 00:56:29,210 --> 00:56:33,690 As we've seen, fungi are neither plant nor animal. 916 00:56:33,690 --> 00:56:35,650 Early in the story of life on Earth, 917 00:56:35,650 --> 00:56:40,850 they established themselves as a kingdom in their own right. 918 00:56:40,850 --> 00:56:44,490 But it's the moment when this happened that is truly significant. 919 00:56:46,650 --> 00:56:50,130 At the point when plants and animals diverged, 920 00:56:50,130 --> 00:56:52,690 the fungi were still part of that animal branch. 921 00:56:54,650 --> 00:56:57,250 It was not until about ten million years later 922 00:56:57,250 --> 00:56:59,690 that they began their own evolutionary journey 923 00:56:59,690 --> 00:57:01,130 as a distinct kingdom. 924 00:57:02,170 --> 00:57:06,930 This explains why they have retained a number of key biological traits 925 00:57:06,930 --> 00:57:10,810 that make them much more animal than plant, much more like us. 926 00:57:14,210 --> 00:57:16,970 Traits we've seen time and time again, 927 00:57:16,970 --> 00:57:19,690 as we've explored their fascinating life cycle... 928 00:57:21,010 --> 00:57:24,290 ..from the explosive way that they release their spores... 929 00:57:25,730 --> 00:57:30,370 ..to the way they feed and digest other organisms, much as we do. 930 00:57:31,570 --> 00:57:33,210 At every stage of their life, 931 00:57:33,210 --> 00:57:36,770 fungi reveal just how much like us they are. 932 00:57:36,770 --> 00:57:40,290 It's a powerful connection, that explains why we work 933 00:57:40,290 --> 00:57:41,890 so well together. 934 00:57:41,890 --> 00:57:46,050 So we are all much more mushroom than you could ever imagine. 935 00:57:47,250 --> 00:57:51,650 And because of this close affinity, sometimes the fungi work with us, 936 00:57:51,650 --> 00:57:53,650 and even sometimes against us... 937 00:57:54,810 --> 00:57:58,410 ..and that is the true magic of mushrooms.