Communicating with Plants

- Molly Cadle-Davidson

Talking to plants is something we tend to think of as fantasy, but in the world of biologicals, it’s happening every day.

Trichoderma is a microscopic organism that colonizes on the root structure of the host plant and then multiplies and thrives as the host plant grows. Multifunctional and crop-specific blends of beneficial strains of Trichoderma microbials actually have the ability to communicate with plants and change them from a physiological standpoint. It’s a technology — known as iGET (Induced Gene Expression Triggers Technology) — that’s redefining what humans are able to do to improve the plants we grow.

These biologicals first colonize the crop root system. Their association with the plant induces changes in plant gene expression and physiology to enhance multiple biochemical pathways. Root colonization by the seed treatment can affect the physiology of the whole plant, even foliar/leaf biology, such that crop stresses like dry weather can be alleviated, for example.

Trichoderma communicates with the plant by producing chemical signals the plant perceives. The technology has been demonstrated on corn, wheat, soybeans, peanuts, cotton, alfalfa/clover, dry beans and vegetables.

A good example of this in action is a trial done on drought-stressed tomatoes. Treatment with ABM’s Trichoderma resulted in much healthier plants able to withstand the lack of water, whereas the control plants wilted and were unable to maintain photosynthetic efficiency.

One of the ways the Trichoderma does this is via an overarching biochemical pathway that is triggered by these chemical signals — the reactive oxygen cycling pathway. Reactive oxygen species are what we call “free radicals”. They are highly reactive, stress-generated molecules that inflict damage to DNA, proteins and membranes in cells where they are found.

Plants under stress such as drought, salt, or heat, for example, generate free radicals; however, plants also possess the reactive oxygen cycling pathway to get rid of free radicals and mitigate stress damage.

As a consequence of Trichoderma signals upregulating this pathway, the plant is able to eliminate free radicals and function normally even in a stressed environment.

The technology is seeing great success, but there’s more to be learned. Not all of these chemical signals have been discovered yet — we know there are many others, not all of which have been adequately characterized. Right now, we are only eavesdropping on the communications between microbe and plant — the future lies in fully understanding the conversation and gaining the ability to focus it on the topics important to optimized agricultural production.