Fernández-Llamosas Helga, Díaz Eduardo, Carmona Manuel
Microbial and Plant Biotechnology Department, Centro de Investigaciones Biológicas Margarita Salas-CSIC, Ramiro de Maeztu 9, 28040 Madrid, Spain.
Microorganisms. 2021 Mar 8;9(3):554. doi: 10.3390/microorganisms9030554.
Proficient crop production is needed to ensure the feeding of a growing global population. The association of bacteria with plants plays an important role in the health state of the plants contributing to the increase of agricultural production. Endophytic bacteria are ubiquitous in most plant species providing, in most cases, plant promotion properties. However, the knowledge on the genetic determinants involved in the colonization of plants by endophytic bacteria is still poorly understood. In this work we have used a genetic approach based on the construction of , and knockout mutants to show that the motility mediated by a functional flagellum and the type IV, and the adhesion modulated by exopolysaccarides are required for the efficient colonization of rice roots by the endophyte sp. CIB. Moreover, we have demonstrated that expression of an exogenous diguanylate cyclase or phophodiesterase, which causes either an increase or decrease of the intracellular levels of the second messenger cyclic di-GMP (c-di-GMP), respectively, leads to a reduction of the ability of sp. CIB to colonize rice plants. Here we present results demonstrating the unprecedented role of the universal second messenger cyclic-di-GMP in plant colonization by an endophytic bacterium, sp. CIB. These studies pave the way to further strategies to modulate the interaction of endophytes with their target plant hosts.
需要高效的作物生产来确保养活不断增长的全球人口。细菌与植物的关联在植物健康状况中起着重要作用，有助于提高农业产量。内生细菌在大多数植物物种中普遍存在，在大多数情况下具有促进植物生长的特性。然而，对于内生细菌定殖于植物所涉及的遗传决定因素仍知之甚少。在这项工作中，我们采用了基于构建、和敲除突变体的遗传方法，以表明功能性鞭毛介导的运动性、IV型以及胞外多糖调节的黏附对于内生菌sp. CIB有效定殖水稻根是必需的。此外，我们已经证明，分别导致第二信使环二鸟苷酸（c-di-GMP）细胞内水平升高或降低的外源二鸟苷酸环化酶或磷酸二酯酶的表达，会导致sp. CIB定殖水稻植株的能力降低。在此，我们展示的结果证明了通用第二信使环二鸟苷酸在内生菌sp. CIB定殖植物过程中前所未有的作用。这些研究为进一步调控内生菌与其目标植物宿主相互作用的策略铺平了道路。
