A new study by the University of Cambridge reveals the critical role of the hormone gibberellin in the formation and function of nitrogen-fixing nodules in legumes, offering potential for more productive and environmentally-friendly agricultural practices.
Researchers from the University of Cambridge have achieved a significant scientific breakthrough, unveiling how the plant hormone gibberellin (GA) plays a crucial role in the formation and maturation of nitrogen-fixing root nodules in legumes. The findings, published in The Plant Cell, promise to revolutionize legume crop yields and inspire advancements in sustainable agriculture.
Utilizing a cutting-edge biosensor known as nlsGIBBERELLIN PERCEPTION SENSOR 2 (GPS2), the researchers demonstrated that GA is pivotal during various stages of nodule formation and development. This discovery resolves previously conflicting reports about GA’s role, highlighting its essential presence at specific times and locations within the roots.
“There were some confusing and conflicting reports about the function of GA in nodule symbiosis,” Alexander Jones, research group leader at the Sainsbury Laboratory Cambridge University (SLCU), said in a news release.
“Experiments showed that adding GA reduces nodulation and removing GA increases nodulation in legumes like Medicago truncatula, which suggests GA is antagonistic towards nodulation. But there is also a legume mutant in peas that produces less GA and has fewer nodules, which suggests that GA is somehow required for nodulation,” he added.
Jones’ colleague Colleen Drapek, a research associate at the (SLCU), utilized the advanced biosensor to map GA’s distribution in the roots of legumes. She noticed an accumulation of GA at the early stage of nodule development in the nodule primordium, a critical zone where cell division initiates nodule formation.
“Right at the beginning of nodule formation, you start to see an accumulation of GA in the nodule primordia, but very little GA anywhere else in the root,” Drapek said in the news release. “As the root nodule further develops, you see GA accumulating at quite high concentrations and remaining at high levels in the mature nodule.”
This research is not just academic; its implications could be transformative. Legume crops naturally obtain nitrogen via a symbiotic relationship with nitrogen-fixing bacteria, forming root nodules. However, cereal crops, such as wheat, maize and rice, lack this ability and rely heavily on synthetic fertilizers, which are costly and environmentally damaging. Understanding GA’s role in nodulation brings scientists a step closer to transferring nitrogen-fixing capabilities from legumes to cereals, potentially creating self-fertilizing crops.