蚜虫取食中的细胞壁修饰与免疫功能

Effects of aphid saliva on plant cell wall structure and defensive mechanisms

蚜虫是世界性害虫,它通过独特的口针结构和丰富的唾液组分破坏植物细胞壁,穿过表皮细胞和叶肉细胞间隙,克服多重植物抗性,到达韧皮部取食为害。已有报道蚜虫唾液中含有多种细胞壁修饰酶能够降解修饰细胞壁,帮助蚜虫在细胞间刺探,更为有效的定位韧皮部。而细胞壁作为保护植物细胞的重要屏障,能感知和传递细胞壁损伤信号,通过调控细胞壁修饰酶的表达水平启动胞内诱导抗性,从而影响蚜虫的刺探、取食和定殖。此外,蚜虫唾液中的一些效应因子还能抑制细胞壁免疫和胞内抗性。可见,细胞壁免疫在蚜虫持续取食和成功定殖中发挥重要功能。为深入理解细胞壁免疫在蚜虫刺探与取食过程中的作用机制,本文概述了蚜虫唾液关键组分对细胞壁修饰与免疫的调控作用,从植物细胞壁多糖结构修饰、损伤信号传导和胞内抗性等方面重点论述对蚜虫取食行为的影响,结合病原菌与细胞壁免疫互作机制,进一步揭示蚜虫与细胞壁免疫互作新机制,为基于阻断蚜虫韧皮部取食的分子抗虫育种提供新思路。

The unique structure of the stylet and components of the saliva of aphids allow them to penetrate plant epidermis and mesophyll cells without stimulating the plant’s defensive mechanisms.Aphid saliva consists of a variety of cell wall modifying enzymes(CWMEs)that can degrade or modify cell wall components,thereby facilitating penetration by the aphid’s mouthparts.In addition to protecting the protoplast,the cell wall also plays an important role in intracellular defense.Components of aphid saliva are able to suppress cell wall immunity(CWI)and other intracellular defenses,thereby allowing aphids prolonged access to the phloem.This paper reviews the effects of aphid saliva on cell wall modification and immunity,and the effects of cell wall polysaccharide structural modification,damage signaling and intracellular defense,on the feeding behavior of aphids.In addition,case studies of interactions between pathogenic bacteria and CWI are provided to elucidate the novel mechanism underlying aphid-CWI interactions.It is hoped that this review provides information useful for developing targeted pest control technologies based on manipulating the feeding efficiency of piercing-sucking pests.