盐胁迫下植物根系分泌物的成分分析与生态功能研究进展

Research Progress in the Composition Analysis and Ecological Function of Plant Root Exudates Under Salt Stress

盐胁迫是常见的非生物胁迫之一,影响植物的生长发育。根系分泌物是植物与根际环境进行“信息”交换的重要媒介。植物在受到盐胁迫时,根系分泌物的组分和含量会发生改变,对盐胁迫下植物的生长发育产生重要影响。本文综述了根系分泌物的成分、检测方式、作用机制及变化调控。其成分主要包括氨基酸、糖类、有机酸和酚酸等。目前对根系分泌物的鉴定和检测方式主要有高效液相色谱、气相色谱-质谱联用、液相色谱-质谱联用以及核磁共振。结合前人研究总结了氨基酸、糖类、有机酸等分泌物在盐胁迫下组成和含量的变化。然后从根际理化环境、根际微生物等方面总结并提出了根系分泌物在盐胁迫下的作用主要包括:(1)作为信号分子调节植物耐盐能力;(2)维持根细胞内稳态;(3)影响根际环境。总结了氨基酸、糖类根系分泌物在盐胁迫下的变化机理,最后指出目前对根系分泌物成分功能的鉴定以及具体作用机制、通路的研究尚有待深入。本综述旨在分析盐胁迫下植物根系分泌物的生态效应,为今后深入挖掘植物响应盐胁迫机理提供参考依据。

Salt stress as one of the common abiotic stresses can affect plant growth and development.Root exudates are considered as an important medium for“information”exchange between plants and rhizosphere environment.When plants sufferred in salt stress,the composition and content of root exudates would change to affect the growth and development of plants.This article summarizes the components,detection methods,mechanism of action and changing trends.Root exudates mainly contained amino acids,sugars,organic acids and phenolic acids,etc.The high performance liquid chromatography(HPLC),gas chromatography-mass spectrometry(GC-MS),liquid chromatography-mass spectrometry(LC-MS)and nuclear magnetic resonance(NMR)are widely used to identify and detect compositions and contents of root exudates.Combined with previous studies,the changes of composition and content of amino acids,sugars,organic acids,etc.under salt stress were summarized.From the aspect of physical and chemical environment and rhizosphere microorganisms,the putative roles of root exudates under salt stress were also summarized,including:(1)acting as signal molecules in plant suffering to salt tolerance;(2)maintaining the homeostasis of root cells;and (3)affecting rhizosphere environment.The change mechanism of amino acids and sugars in salt tolerance of plants were enumerated.Moreover,we pointed out that,the identification of root exudates function and their mechanisms of action on salt stress need further being studied.This review aims to analyze the ecological effects of plant root exudates under salt stress,and provides a reference for further exploring the mechanism of plant response to salt stress in the future.