Scientist Develops Soybeans More Efficient in Making Nodules and Fixing Nitrogen

South Dakota State University (SDSU) plant scientist Senthil Subramanian is leading a new research that will identify the plant mechanisms that direct and coordinate the formation of soybean nodules. With this knowledge, Subramanian hopes to develop soybeans that are more efficient in making nodules and fixing nitrogen by manipulating the molecular mechanisms that regulate these functions.

Plants cannot use atmospheric nitrogen despite its abundance, Subramanian explained. Legumes, such as soybean plants, have the capacity to form mutually beneficial relationships with the bacterium Rhizobium in the soil to fix nitrogen. Rhizobium enters the root cells of young plants and triggers nodule-formation to house the bacteria. Within the nodules, two distinct zones — one that fixes the nitrogen and another that transports it to the plant — are formed from the same pre-existing root cells. The expression of specific genes in a particular root cell determines the zone in which it will function, Subramanian explained, so he is identifying which micro-RNAs direct gene expression to achieve this differentiation.

For more information about this research, read the SDSU news release available at http://www.sdstate.edu/news/articles/plant-scientist-receives-nsf-career-award.cfm.