根际促生菌调控植物根系发育的信号与分子机制研究进展

Research Progressing in Signals and Molecular Mechanisms of Plant Growth-Promoting Rhizobacteria to Regulate Plant Root Development

根际促生菌对植物的生长和健康具有重要作用,是微生物肥料的主要菌种来源,对促进化肥减施增效和农业绿色发展意义重大。根际促生菌主要通过活化根际养分和促进根系发育提高养分的利用效率、促进植物的生长。根际促生菌的定殖能调控植物根系构型(Root System Architecture,RSA),影响主根的伸长,促进侧根和根毛的发育。根际促生菌一方面分泌各种植物激素直接影响其根系发育,另一方面通过分泌多种信号物质调控植物根系的内源激素途径而影响RSA。根际促生菌种类众多,对根系的影响也复杂多样,为了利用根际促生菌及其代谢物质调控形成不同作物的理想RSA,促进根际养分的吸收利用,仍需系统发掘根际促生菌调控RSA的新型信号物质,深入揭示它们的作用机制,促进根际促生菌在减肥增效和农业绿色发展中的应用。综述了目前已经鉴定的根际促生菌调控RSA的激素和信号,总结了根际促生菌信号物质调控植物RSA的分子机制的研究进展,并对今后的研究提出展望。

Plant growth-promoting rhizobacteria(PGPRs)play essential roles in plant growth and health,they are the major source of microbial fertilizers,and contribute significantly to the reduction of chemical fertilizer input and green development of agriculture.PGPRs promote plant growth and improve nutrients use efficiency through two central mechanisms:activating rhizosphere nutrients and improving root development.Rhizosphere colonization of PGPRs can regulate the root system architecture(RSA),affecting the elongation of the primary root and promoting the formation of lateral roots and root hairs.PGPRs secrete phytohormones to be involved in the root development directly,and some signal molecules to regulate RSA indirectly mediated by the plant endogenous molecular pathways.PGPRs have various effects on plant RSA,many novel signals secrete from PGPRs to affect plant RSA,and their regulating mechanisms are required to be explored,which may be used to form the ideal RSAs for different crops to increase nutrient use efficiency.Finally,these studies will enhance the contribution of PGPRs to the reduction of chemical fertilizers input and the green development of agriculture.This paper reviewed the identified phytohormones and signals secreted by PGPRs,summarized their molecular mechanisms to regulate plant RSA,and proposed the perspectives for future research.