Thursday, October 10, 2013

Microbial Improvements in Agriculture

 By Asta Stojanovski
(Image Source)

With the global population growing and increasing urbanization of the population, production of an adequate amount of food is becoming a major agricultural concern.  Increasing food production and productivity of crops is therefore of great importance to the industry. However, it is well known that currently used agricultural methods have a plethora of negative environmental consequences. Therefore one of the major challenges currently facing the industry is enhancing the productivity of food crops while mitigating the environmental impacts.

Scientists think this can be achieved by utilizing microbial communities in place of fertilizers and pesticides.  According to a new report by the American Academy of Microbiology titled “How Microbes Can Help Feed the World” there are plenty of development possibilities that could be capitalized on to use microbe-plant interactions to improve crop yields across the globe.   The report describes the scientific challenges currently faced, failures of biocontrol in the past, and new avenues that are currently being pursued.  It also provides recommendations for translating research into practical applications which is where most developments in the field of plant biotechnology are lost. 

(Rhizobium)
In addition to this report, there have been many other developments that could provide crop improvements by taking advantage of various microbial species. While it has long been known that the rhizobia bacteria inhabit and provide usable nitrogen to legume plants, it was not until recently that the mechanism of nutrient exchange or the precise interaction between microbes and plant were described.  Recent research at the MU Bond Life Sciences Center have elucidated the interaction-response relationship that allows rhizobia to form symbiotic relationships with legume crops but not others and are currently working on transferring the trait to other crop plants, such as corn. 

Rebecca Bell observing tomatoes in FDA lab
Additionally, researchers from the FDA’s “Team Tomato,” recently described characterization of a soil bacterium, Paenibacillus, which is harmless to humans but lethal to Salmonella that could be utilized in place of fumigants to reduce risk of salmonella outbreaks. Currently the FDA and the EPA are working together to develop an organic treatment using paenibacillus.  Arbuscular mycorrhizal fungi (AMF) have also been identified as an important microbe for the production of Cassava plants in the tropics. It has been shown by researchers in Columbia that Cassava inoculated in vitro with a mass produced mycorrrhizal fungus, Rhizophagus irregularis, has much higher yields of dry biomass compared to plants treated with traditional phosphate fertilizers.  These discoveries offer clear directions for the manipulation of microbes and soil constituents to crops advantage and will undoubtedly provide improved yields without requiring heavy use of chemicals.

It is important however to remember that these plant-microbe interactions do not occur in an isolated environment and that the whole micro-ecosystem must be taken into consideration to prevent disruptions in its functioning. Improvements in understanding the microbiome will undoubtedly lead to more discoveries with wide implications, for both agriculture and beyond.  Additionally, it can be very difficult to transform scientific discovery and knowledge into a practical application with commercial relevance. This will be one of the key challenges for these developments as time progresses. While there are still a number of hurdles to be overcome before these discoveries are rendered commercially available and implemented on a large scale, the advances in the field hold promise for improved agricultural production without sacrificing environmental health.