Into the root: the cytokinin-dependent regulation of rhizobial infection

深入根部：根瘤菌感染的细胞分裂素依赖性调节

• 批准号: RGPIN-2018-05040
• 负责人: Szczyglowski, Krzysztof
• 金额: $ 3.64万
• 依托单位: University of Western Ontario
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=689997
• 关键词: Into; root; cytokinin; dependent; regulation

Leguminous plants, such as garden pea and soybean, have a mechanism for sustainable growth through “self-fertilization” resulting from their interactions with nitrogen-fixing soil bacteria, commonly known as rhizobia. This symbiotic liaison renders the host plant capable of tapping into the reservoir of nitrogen stored in the Earth's atmosphere, making its growth independent from soil nitrogen. The high efficacy of nitrogen-fixing symbiosis is determined primarily by the legumes' ability to host rhizobia within intracellular root compartments, ensuring reliable nutrition for both partners. Current knowledge suggests that this useful ability could be extended to other plants, including major cereal crops. If successful, this would lead to a new generation of crops that are less dependent on industrial fertilizers, thereby making agriculture more efficient and environmentally-friendly. In order to reach this goal, several important obstacles need to be overcome. Further advancement in the knowledge of the plant mechanisms that select for and promote the accommodation of rhizobia is critical. The proposed research aims at contributing to this knowledge by investigating a role of the plant hormone cytokinin in these processes. Cytokinins are known to regulate soil nutrient acquisition by plants and we and other have shown that they also play a central role during nitrogen-fixing root nodule symbiosis. Using genetics and genomics tools available for the model legume, Lotus japonicus, we will further define how cytokinins regulate the predisposition of legume roots to symbiotic infection. Acquiring this knowledge is crucial to any rational consideration of transferring the capacity for nitrogen-fixing symbiosis to other crops, such as nitrogen-greedy cereals. The same research may also contribute to advancement of methods for the effective selection of microbial communities (microbiomes) which, like those in the human gut, provide many additional useful services, including defence against pathogens and resistance to abiotic stress.

豌豆和大豆等豆科植物具有通过与固氮土壤细菌（通常称为根瘤菌）相互作用的“自体受精”来实现可持续生长的机制，这种共生关系使宿主植物能够利用土壤的养分。氮储存在地球大气中，使其生长独立于土壤氮。固氮共生的高效性主要取决于豆科植物在细胞内根部寄生根瘤菌的能力。目前的知识表明，这种有用的能力可以扩展到其他植物，包括主要的谷类作物，如果成功的话，这将导致新一代作物对工业肥料的依赖减少，从而使为了实现这一目标，需要克服一些重要的障碍，进一步了解选择和促进根瘤菌适应的植物机制至关重要。通过研究植物激素的作用来了解这一知识众所周知，细胞分裂素可以调节植物对土壤养分的获取，我们和其他人已经证明它们在固氮根瘤共生过程中也发挥着核心作用。我们将进一步确定细胞分裂素如何调节豆科植物根部对共生感染的倾向。获得这一知识对于合理考虑将固氮共生能力转移到其他作物（例如）至关重要。同样的研究还可能有助于改进有效选择微生物群落（微生物组）的方法，这些微生物群落与人类肠道中的微生物群落一样，提供许多额外的有用服务，包括防御病原体和抵抗非生物胁迫。 。