吲哚乙酸跨界信号调节植物与细菌互作

摘要

As the most common and naturally-occurring phytohormone of the auxin class,indole-3-acetic acid(IAA)involves in regulating many aspects of plant growth and development. The studies revealed that in nature,not only plant may synthesize the IAA,but also a variety of microorganisms including both phytopathogens and plant growth-promoting bacteria possess the ability of producing the auxin phytohormone inducing plant diseases or promoting plant growth. Interestingly,apart from being the secondary bacterial metabolite interfering the hormone homeostasis of host plants,IAA can also be a signaling molecule modulating gene expression and physiology in bacteria, consequently regulating the plant-bacteria interaction through integration into the complex regulatory network in bacteria. This review provides insights into the recent research progresses on IAA biosynthesis pathways and its regulations in bacteria,IAA-mediated control of bacterial gene expression,physiology and behavior,as well as the interaction with host plants varying from pathogenesis to phytostimulation. The review also highlights that IAA can not only modulate the plant growth,development and defense,but also act as cross-kingdom signal molecules playing a critical role in the regulation of the plant-microbe interactions. The review aims to develop novel strategies for the improvement of the plant-growth promotion and tolerance to both biotic and abiotic stresses by further studying and better understanding of the IAA-mediated cross-kingdom signalling mechanisms and genetically manipulating the bacterial IAA signal pathways.%吲哚-3-乙酸（indole-3-acetic acid，IAA）作为植物体内普遍存在的内源生长素参与调节植物生命活动的诸多方面。研究发现，自然界中不仅植物可以合成 IAA，许多微生物（包括植物病原菌或益生菌）同样具有分泌 IAA 的能力，可以诱发植物病害，或促进植物生长。有趣的是 IAA 不仅作为细菌的次生代谢物干扰寄主植物的激素稳态，也作为信号分子影响细菌基因表达和生理活动，通过整合进入细菌复杂代谢网络，调节植物与细菌的相互作用。通过讨论植物相关细菌 IAA 的生物合成途径及其调控，以及参与调节细菌基因表达、影响细菌生理和行为及其与寄主植物的互作等，概述该领域的研究动态与进展，揭示 IAA 不仅调节植物生长发育和防御，也作为跨界信号在调控植物与微生物互作中发挥重要作用，旨在为深入研究和更好地了解 IAA 跨界信号机制，通过遗传操纵细菌 IAA 信号通路以改善植物生长发育及其胁迫耐力提供新思路。