Enhanced soybeans with 36% more seeds, doubled nitrogen fixation: research


In Washington, Washington State University biologist Mechthild Tegeder developed a way to dramatically increase the yield and quality of soybeans. Her greenhouse-grown soybean plants fix twice as much nitrogen from the atmosphere as their natural counterparts, grow larger and produce up to 36 percent more seeds.

Tegeder designed a novel way to increase the flow of nitrogen from specialized bacteria in soybean root nodules to the seed-producing organs. She increased the number of proteins that help move nitrogen from the rhizobia bacteria to the plant’s leaves, seed-producing organs and other areas where it is needed. The additional transport proteins sped up the overall export of nitrogen from the root nodules. This initiated a feedback loop that caused the rhizobia to start fixing more atmospheric nitrogen, which the plant then used to produce more seeds.

She found the increased rate of nitrogen transport kicked the plants into overdrive. “They are bigger, grow faster and generally look better than natural soybean plants,” Tegeder said.