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

doi:10.13560/j.cnki.biotech.bull.1985.2023-0516

Abstract

Abstract:

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.

Key words: root exudates, salt stress, component identification, rhizosphere environment, rhizosphere microorganisms, mechanism of salt tolerance, changing mechanism

WANG Yu-qing, MA Zi-qi, HOU Jia-xin, ZONG Yu-qi, HAO Han-rui, LIU Guo-yuan, WEI Hui, LIAN Bo-lin, CHEN Yan-hong, ZHANG Jian. Research Progress in the Composition Analysis and Ecological Function of Plant Root Exudates Under Salt Stress[J]. Biotechnology Bulletin, 2024, 40(1): 12-23.

Figures/Tables 3

References 81

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分类方式 Classification method	种类 Type	物质类别 Category of substances	成分 Component	主要功能 Main function
有机物 Organic matter	低分子有机物 Low molecular weight organics	糖类^[17] Sugars	果糖、麦芽糖、半乳糖、鼠李糖等	提供营养来源
		有机酸^[18] Organic acids	柠檬酸、酒石酸、草酸、丁二酸、苹果酸等	提供营养来源；螯合难溶性矿物质；诱导微生物的化学信号
		氨基酸^[19] Amino acids	苏氨酸、丙氨酸、亮氨酸、脯氨酸、苯丙氨酸等	提供营养来源；螯合难溶性矿物质；诱导微生物的化学信号
		酚酸类^[20] Phenolic acids	肉桂酸、阿魏酸、原儿茶酸、水杨酸等	化感作用的主要影响因子
	高分子黏胶物 Polymer viscose	各种酶类^[21] Various enzymes	淀粉酶、脂肪酶、酸/碱性磷酸酶等	促进有机物转化；促进有机分子释放磷；缓解植物毒害
	高分子黏胶物 Polymer viscose	黏胶物质^[21] Viscose substances	多聚半乳糖醛酸、甘草素、木犀草素等	提供营养来源；缓解植物毒害
无机物Inorganic matter		质子与无机离子^[22] Protons and inorganic ions	H⁺、K⁺、Na⁺、Mg²⁺、Ca²⁺等	调节土壤pH及氧化还原电位

分类方式 Classification method	种类 Type	物质类别 Category of substances	成分 Component	主要功能 Main function
有机物 Organic matter	低分子有机物 Low molecular weight organics	糖类^[17] Sugars	果糖、麦芽糖、半乳糖、鼠李糖等	提供营养来源
		有机酸^[18] Organic acids	柠檬酸、酒石酸、草酸、丁二酸、苹果酸等	提供营养来源；螯合难溶性矿物质；诱导微生物的化学信号
		氨基酸^[19] Amino acids	苏氨酸、丙氨酸、亮氨酸、脯氨酸、苯丙氨酸等	提供营养来源；螯合难溶性矿物质；诱导微生物的化学信号
		酚酸类^[20] Phenolic acids	肉桂酸、阿魏酸、原儿茶酸、水杨酸等	化感作用的主要影响因子
	高分子黏胶物 Polymer viscose	各种酶类^[21] Various enzymes	淀粉酶、脂肪酶、酸/碱性磷酸酶等	促进有机物转化；促进有机分子释放磷；缓解植物毒害
	高分子黏胶物 Polymer viscose	黏胶物质^[21] Viscose substances	多聚半乳糖醛酸、甘草素、木犀草素等	提供营养来源；缓解植物毒害
无机物Inorganic matter		质子与无机离子^[22] Protons and inorganic ions	H⁺、K⁺、Na⁺、Mg²⁺、Ca²⁺等	调节土壤pH及氧化还原电位

技术 Technology	优点 Advantages	缺点 Disadvantages	检测组分 Detected components
气相色谱-质谱联用（GC-MS）^[31]	进样量小、灵敏度高、分辨率高，能检测到样本中相对含量较低的代谢物	一些极性代谢物需提前进行衍生化处理，能鉴定到的代谢物比LC-MS要少	以热稳定性好的挥发物质和极性小的小分子化合物为主，如烷烃、酯类、有机酸、氨基酸等
液相色谱-质谱联用（LC-MS）^[32]	高效快速、灵敏度高、样品只需进行简单预处理或衍生化	不同设备的数据库无法通用	适用于含量少、不易分离获得或在分离过程中易失活的组分分析，极性或热稳定性差、不易挥发的大分子物质，如蛋白质、多肽、多聚物等
核磁共振（NMR）^[33]	高效快速、未知化合物损失少、样品制备时间短	灵敏度比MS要低很多	适用于复杂基质样本的检测和化合物结构的分析
高效液相色谱（HPLC）^[34]	可连续进样、灵敏度高、分离效率高、操作方便	分析成本高，分析时间长	大多是沸点高、热稳定性差、相对分子质量大于400以上的有机物

技术 Technology	优点 Advantages	缺点 Disadvantages	检测组分 Detected components
气相色谱-质谱联用（GC-MS）^[31]	进样量小、灵敏度高、分辨率高，能检测到样本中相对含量较低的代谢物	一些极性代谢物需提前进行衍生化处理，能鉴定到的代谢物比LC-MS要少	以热稳定性好的挥发物质和极性小的小分子化合物为主，如烷烃、酯类、有机酸、氨基酸等
液相色谱-质谱联用（LC-MS）^[32]	高效快速、灵敏度高、样品只需进行简单预处理或衍生化	不同设备的数据库无法通用	适用于含量少、不易分离获得或在分离过程中易失活的组分分析，极性或热稳定性差、不易挥发的大分子物质，如蛋白质、多肽、多聚物等
核磁共振（NMR）^[33]	高效快速、未知化合物损失少、样品制备时间短	灵敏度比MS要低很多	适用于复杂基质样本的检测和化合物结构的分析
高效液相色谱（HPLC）^[34]	可连续进样、灵敏度高、分离效率高、操作方便	分析成本高，分析时间长	大多是沸点高、热稳定性差、相对分子质量大于400以上的有机物