For years, scientists have tried to increase the rate of nitrogen fixation in legumes by altering rhizobia bacterioid function or interactions that take place between the bacterioid and the root nodule cells.
Tegeder took a different approach: 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. “They are bigger, grow faster and generally look better than natural soybean plants,” Tegeder said. “Some evidence we have suggests they might also be highly efficient under stressful conditions like drought.”
The technique not only produces healthier plants and more seeds, it reduces the need for fertilizer, the overuse of which can be an environmental issue.