(This is a piece I wrote for my Mushrooms of Field and Forest Class at Cornell University for the cornell mushroom blog, hence the academic tone and citations. But it seemed fit for this blog as well. Enjoy!)
The farmers of Japan say thunderstorms are good luck– they make the mushrooms grow.1 And mushrooms and thunderstorms are partners in folklore all over the world. The ancient god Soma may even have been a mushroom himself. In the book, Soma: Divine Mushroom of Immortality, Gordon Wasson2 argues that Amanita muscaria, the classic red or yellow fly agaric, is the identity of the mysterious Soma, god of the RgVeda, a sacred collection of ancient Vedic Sanskrit hymns. These hymns are some of the world’s oldest religious texts, and from them we know Soma is “the child of the thunderstorm”. Is Soma really a mushroom? Are mushrooms the children of thunderstorms? Read on.
Science, alas, has had little to say about mushrooms and thunderstorms. Until now. Recently, scientists in Japan have demonstrated a link between lightning and prolific mushroom fruiting.1 Although their interest in lightning and mushrooms is not driven by a religious quest, their research may inadvertently shed light on an ethnographic mystery.
In Japan, mushrooms are particularly coveted for their delicious, nutritional, and medicinal qualities and demand is outstripping supply. But now scientists are finding ways to harness the power of electricity to increase mushroom production. Can you imagine farms where man-made lightning bolts strike the ground and induce large flushes of mushrooms? Well, this is what scientists in Japan are doing.3
Today, shiitake (Lentinula edodes), buna-shimeji (Hypsizygus marmoreus), eryngii (Pleurotus eryngii), and matsutake (Tricholoma matsutake) mushrooms are high value health foods in Japan.1,3 Matsutakes now sell for $439 U.S. dollars a pound.3 Before you think you might get rich by growing some, you must consider that these are ectomycorrhizal mushrooms that only grow symbiotically with their pine tree hosts, so the world’s harvest is entirely collected from the wild. Although harvest of these mushrooms in Japan peaked at 12,000 metric tons in 1941, harvest declined to 34 metric tons in 2005, not due to lack of demand but due to many threats to these red pine forests, including a pine wood nematodeinfestation that has been wreaking havoc in these ecosystems.3 People want more mushrooms. Let’s harness the power of lightning.
The use of direct current (DC) electric fields on living tissue is not a new idea, but has a long and contentious history. Even back in 1985, when Robinson 4 wrote a review of the topic, he was able to find 8 reliable reports involving plant cells and 4 on animal cells responding to DC fields. The reports ranged from growth of neurons towards the negative electrode to a “healing” response of wounds. Many of these observations seem to have been dismissed as “laboratory curiosities,” unlikely to have much real world application. In Japan, though, electrical stimulation has been used in the production of Shiitake, Buna-shimejo, and eryngii mushrooms for almost half a decade. And this technology doesn’t seem to be limited to mushrooms, as farmers are also using electromagnetic field technology in the production of tomato, lettuce, strawberry, and some ornamental plants.
Lightning is notoriously disobedient, so Islam and Ohga built a “Small Population Lightning Generator” (SPLG), conveniently powered by rechargeable AA batteries.3 This device can be wheeled through the forest, and administers 50kV electric pulses to the ground through its electrode wheels. No, it isn’t exactly like lightning—it’s more like the shock you get from a metal doorknob after dancing in your polyester leisure suit. The SPLG delivers maybe 500 milliJoules of energy per zap; a bolt of lightning might deliver one billion times more than that. Other studies have delivered shocks as low as 30kV and shown increases in mushroom yields.1 One Fall day in a Japanese forest, Islam and Ohga trundled the SPLG across their 2 by 3 meter experimental plots in parallel passes that were each 0.10 meters apart.3
The results were yields of matsutake mushrooms just about double the yields in unzapped control plots. A monstrous flush came two weeks after the pulse and a second one nearly as large 3 weeks after. But it wasn’t just the quantity that increased, the quality, as measured by weight and size of individual matustake mushrooms also showed dramatic increases: Harvests from the zapped plots were, on average, almost 70% heavier then controls.3 If you thought mushrooms were magical all on their own, the combination of mushrooms and electricity might knock your socks off.
Fungi are mysterious things and the mechanism by which electrical stimulation promotes mushroom fruiting is still not much understood. Perhaps the mushroom mycelium is responding to an apparent threat of death by redoubling its reproductive efforts? Many electrifying questions remain. Like: how does the zapping affect forest trees? Can the high fruiting rates be sustained without damaging the mushroom-tree symbiosis? When’s the next thunderstorm due in my neighborhood?
In the meantime, if you feel like experimenting (safely, of course) with mushrooms and electricity, you might want to check out this intriguing post about a New York City mycophile who grew his mushrooms amid Jazz music, artificial fog, and static electricity. Or, next time you go in the woods foraging for mushrooms, look for trees recently struck by lightning. Who knows what you will find. Maybe you will even have an encounter with the god Soma, child of the thunderstorm.
- 1. S. Tsukamoto, H. Kudoh, S. Ohga, K. Yamamoto, and H. Akiyama, “Development of an automatic electrical stimulator for mushroom sawdust bottle,” in Proceeding of the 15th Pulsed Power Conference, pp. 1437–1440, Monterey, Calif, USA, June 2005
- 2. R.G. Wasson. “Soma: Divine Mushroom of Immortality.” 1968.
- 3. F. Islam and S. Ohga, “The response of fruit body formation on Tricholoma matsutake in situ condition by applying electric pulse stimulator,” ISRN Agronomy, vol. 2012, Article ID 462724, 6 pages, 2012. doi:10.5402/2012/462724
- 4. K. R. Robinson, “The responses of cells to electrical fields: a review,” Journal of Cell Biology, vol. 101(6): 2023–2027, 1985.
- 5. S. Tsukamoto, T. Maeda, M. Ikeda, and H. Akiyama, “Application of pulsed power to mushroom culturing,” in Proceedings of the 14th IEEE International Pulsed Power Conference, pp. 1116–1119, Dallas, Texas, USA, June 2003.
- 6. W. R. Adey, “Biological Effects of Electromagnetic Fields,” in Journal of Cellular Biochemistry 51:410-416. 1993.
- 7. S. Ohga and S. Iida. “Effect of electric impulse on sporocarp formation of ectomycorrhizal fungus Laccaria laccata in Japanese red pine plantation.” J. Forest Res. 6: 37-41. 2001.