摘要:根系分泌物是由植物根系主动或被动分泌的多种生物化学物质, 在介导植物根际微环境间的物质交换、能量传递和信息交流中具有重要作用, 是植物响应外界胁迫的重要途径。生物和非生物胁迫会改变根系分泌物的组成和数量, 使植物根系分泌物中的防御性化合物含量增加。植物运用不同的根系分泌物模式抵御生物和非生物胁迫, 包括释放有毒物质直接防御、释放挥发性物质吸引天敌以及与微生物互作抵御生物胁迫; 释放具有渗透调节功能及抗氧化能力的根系分泌物以及协同激素信号抵抗非生物胁迫。此外, 根系分泌物的流动局部地提高了许多常见代谢物的浓度, 不仅可以改变土壤的理化性质及微生物活性, 还会影响土壤-植物界面的许多生理生化过程, 直接或间接地提高植物抗逆性。本文综述了生物与非生物胁迫对植物根系分泌物组成和数量的影响, 总结了根系分泌物介导植物防御生物与非生物胁迫的方式, 并对未来的研究方向进行了展望, 旨在为更深层次地研究植物在逆境胁迫下的适应性机制提供参考。
关键词:根系分泌物/
生物胁迫/
非生物胁迫/
土壤微生物/
植物抗逆性
Abstract:Root exudates are a variety of biochemical substances actively or passively secreted by plant roots that play an important role in mediating material exchange, energy transfer and information exchange in plant rhizosphere microenvironments, as well as in plant responses to environmental stresses. Biotic and abiotic stresses can change the composition and quantity of root exudates and increase the content of defensive compounds in plant root exudates. Plants use different root exudates to resist biotic and abiotic stresses, including releasing toxic substances for direct defense, releasing volatile substances to attract natural enemies, interacting with microorganisms to resist biotic stresses, releasing root exudates with osmotic regulation and antioxidant capacity and coordinating hormone signals to resist abiotic stress. Additionally, root exudate flow increases the concentration of many common metabolites, changing the soil physical and chemical properties and microbial activities, and affecting the physiological and biochemical processes at the soil-plant interface, thereby, directly or indirectly improving plant stress resistance. In this paper, the effects of biotic and abiotic stresses on the composition and quantity of plant root exudates were reviewed, the mechanisms of plant defense against biotic and abiotic stresses mediated by root exudates were summarized, and the aspects needed to be further studied were also suggested, to provide a reference for further research on the adaptive mechanism of plants under stress.
Key words:Root exudates/
Biotic stress/
Abiotic stress/
Soil microorganism/
Plant resistance
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