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Want drought-resistant plants? Fungus is here to help.

Both of these soy plants experienced six days of drought conditions, but the one on the right was treated with a fungus. (Adaptive Symbiotic Technologies)
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As a society, we’re quite germaphobic. Anti-bacterial soap seems to go hand in hand with daily showering and there’s a certain comfort in drinking bottled water, as opposed to the tap. Despite scant evidence that suggests any actual advantage to such practices, it’s become a hardline worldview of sorts.

Naturally, this approach extends to agricultural practices. Before crops are sown, it’s not uncommon to steam the soil to clear away weeds, pests and pathogens. Antifungals are often also used to disinfect seeds and prevent diseases during germination. A new generation of farmers in Japan has even gone as far as eschewing the messy business of irrigation altogether, opting instead to grow crops in clean, tightly-controlled indoor environments consisting of little more than a diet of drip-fed nutrients and optimized LED lighting.

Rusty Rodriguez, a microbiologist and chief executive of Seattle-based Adaptive Symbiotic Technologies, believes he’s hit upon a better method for boosting crop production. His crops, raised at various test sites throughout the country, have been shown to be more healthy and resilient than their conventionally-tilled counterparts. On minimal amounts of water, they’re able to flourish in extreme heat and cold.

And these special plants aren’t by any means sterile. In fact, each of them has been treated with fungi that alter the plant’s physiology so that, over time, the plants become more efficient at metabolizing water, nutrients and sunlight. The fungus also protects them from oxidization, a byproduct of heat stress.

“What happens when certain types of fungus are transferred over is that the plants photosynthesize more, but with less,” he explains, adding that they also require less fertilizer.

For farmers, the potential implications are tremendous. As the world warms, shifting climate patterns are already stressing large swaths of the land that have long been reliably arable and bountiful. Like Columbia, Brazil is seeing lower crop yields due to disease and weaker rain cycles that typically come in from the humid Amazon region in the north. This year’s rainy season was officially the driest since they began keeping record 84 years ago.

Meanwhile, rising temperatures in California and stretches of the southwest have only exacerbated a severe drought. In this region, without water to evaporate and dissipate the additional heat, much of it starts to descend toward the ground, drying out plants and making the surrounding air even hotter. It’s estimated that the drought will cost the state $2.2 billion, according to a recent study by the University of California in Davis.

And globally, agriculture has struggled to keep pace with a growing world population that’s predicted to increase by 2.5 billion by 2050. During that time span, demand is expected to go up by as much as 14 percent each decade as the food supply shrinks, diminishing at a rate of up to 2 percent during that time span, according to a report from the United Nation’s Intergovernmental Panel on Climate Change.

To improve crop yields, scientists have concentrated many of their efforts on reworking the plant’s genetic code, either through cross-breeding or genetic modification, to better adapt to dry spells. And so far, DroughtGard maize is the lone genetically-modified drought-tolerant crop on the commercial market, despite several decades of research.

“Companies have spent billions of dollars moving genes around to make plants drought-tolerant and it just hasn’t worked out very well,” Rodriguez says.

Rodriguez’s solution, BioEnsure, an additive, was born out of an investigation into certain native plants capable of surviving extreme temperatures. He first spotted them in the mid-90’s, growing along areas of Yellowstone National Park where geothermal vents baked the surrounding soil temperatures to well over 150 degrees Fahrenheit. There, amidst such seemingly uninhabitable conditions, plant communities actually appeared to be thriving.

Rodriguez and his wife took some samples back to a lab where an analysis uncovered the presence of a peculiar set of microscopic fungi called endophytes. Like humans, wild plants host an entire ecosystem of microbes, known as a microbiome, which plays a symbiotic role in their overall well-being. And though little is known about this interplay within plant populations, a notable finding back in the 70’s that showed fescue grass had harbored an endophyte that made them more resistant to insect attacks has since sparked some interest in this area of research.

But in this case, can a microbe really allow plants to grow in an environment so extreme that even geologists have classified it as sterile? To find out, Rodriguez scrubbed the Yellowstone plants clean and subjected them to the same conditions. Alone, neither plant nor fungi were able to survive very long.

The discovery set off Rodriguez’s decade-long mission to isolate similar endophtyes that can also be coated onto the seeds of a wide variety of crops, which include staples such as corn and rice, to enable them to grow in equally harsh conditions. After some trial and error, he identified about a half dozen strains that can be combined them into a commercial formulation thatt’s both non-toxic and versatile enough to be plugged into existing agricultural practices.

“One of the difficult things about developing a product was figuring out how to make it work along with all the other agricultural applications that seeds are put through, which includes problematic things like antifungal treatment,” he says. “We had decided on the onset that we wanted to develop an additive that fits the way agriculture industry does its business, instead of forcing them adapt to our product, because that’s probably not going work.”

While Rodriguez and his team are optimistic about the technology, others aren’t entirely sold on the premise that similar results can be achieved on a commercial level. There’s still, for instance, the very real possibility that adding fungus may negatively affect the host plant in ways that haven’t been accounted for.

“Typically, there is a metabolic cost of hosting an endophyte, so that crops with endophytes are likely to grow less and be less productive,” Richard Richards of the Australian Commonwealth Scientific and Industrial Research Organization, pointed out in an interview with Nature last year.

In response to his skeptics, Rodriguez has highlighted data from field tests, conducted in several states, that have shown encouraging results. In 2012, a trial of BioEnsure-treated corn in Michigan during a drought that ravaged the Midwest produced an 85 percent higher yield​. A separate trial in a greenhouse found that BioEnsure-treated crops used a third less water. 

The company was also recently chosen as a one of 17 finalists for the United States Agency for International Development’s Securing Water for Food Grand Challenge, a collaboration with governmental agencies in Sweden and the Netherlands that awards up $32 million in funding for innovative ideas that tackle problems of global water and food scarcity.

Adaptive Symbiotic Technologies plans to start manufacturing BioEnsure for industrial use in the fall. The company is currently negotiating with a distributor, with an initial product suitable for corn and rice crops slated for the growing season starting in December. Currently, BioEnsure can be legally sold in 18 states

For individual farmers and other small-scale growers, the company is also working on a consumer version that can be applied by hand.