Department of Plant Sciences, University of Cambridge, Cambridge, UK.
NIAB EMR, East Malling, UK.
Mol Plant Pathol. 2021 Sep;22(9):1082-1091. doi: 10.1111/mpp.13098. Epub 2021 Jun 22.
Many aphid-vectored viruses are transmitted nonpersistently via transient attachment of virus particles to aphid mouthparts and are most effectively acquired or transmitted during brief stylet punctures of epidermal cells. In Arabidopsis thaliana, the aphid-transmitted virus cucumber mosaic virus (CMV) induces feeding deterrence against the polyphagous aphid Myzus persicae. This form of resistance inhibits prolonged phloem feeding but promotes virus acquisition by aphids because it encourages probing of plant epidermal cells. When aphids are confined on CMV-infected plants, feeding deterrence reduces their growth and reproduction. We found that CMV-induced inhibition of growth as well as CMV-induced inhibition of reproduction of M. persicae are dependent upon jasmonate-mediated signalling. BRASSINOSTEROID INSENSITIVE1-ASSOCIATED KINASE1 (BAK1) is a co-receptor enabling detection of microbe-associated molecular patterns and induction of pattern-triggered immunity (PTI). In plants carrying the mutant bak1-5 allele, CMV induced inhibition of M. persicae reproduction but not inhibition of aphid growth. We conclude that in wildtype plants CMV induces two mechanisms that diminish performance of M. persicae: a jasmonate-dependent and PTI-dependent mechanism that inhibits aphid growth, and a jasmonate-dependent, PTI-independent mechanism that inhibits reproduction. The growth of two crucifer specialist aphids, Lipaphis erysimi and Brevicoryne brassicae, was not affected when confined on CMV-infected A. thaliana. However, B. brassicae reproduction was inhibited on CMV-infected plants. This suggests that in A. thaliana CMV-induced resistance to aphids, which is thought to incentivize virus vectoring, has greater effects on polyphagous than on crucifer specialist aphids.
许多蚜虫传播的病毒通过病毒颗粒与蚜虫口器的短暂附着非持久传播，并且在表皮细胞的短暂刺探中最有效地获得或传播。在拟南芥中，蚜虫传播的病毒黄瓜花叶病毒（CMV）诱导对多食性蚜虫桃蚜的取食抑制。这种形式的抗性抑制了韧皮部的长时间取食，但促进了蚜虫对病毒的获取，因为它鼓励了对植物表皮细胞的探测。当蚜虫被限制在感染 CMV 的植物上时，取食抑制会降低它们的生长和繁殖。我们发现，CMV 诱导的生长抑制以及 CMV 诱导的桃蚜繁殖抑制都依赖于茉莉酸介导的信号转导。BRASSINOSTEROID INSENSITIVE1-ASSOCIATED KINASE1（BAK1）是一种共受体，能够检测微生物相关的分子模式并诱导模式触发免疫（PTI）。在携带突变体 bak1-5 等位基因的植物中，CMV 诱导桃蚜繁殖抑制，但不抑制蚜虫生长。我们得出结论，在野生型植物中，CMV 诱导了两种机制来降低桃蚜的表现：一种是依赖茉莉酸和 PTI 的机制，它抑制蚜虫的生长，另一种是依赖茉莉酸、独立于 PTI 的机制，它抑制繁殖。两种十字花科专食性蚜虫，李氏蚜和甘蓝蚜，在限制于感染 CMV 的拟南芥上时，生长不受影响。然而，B. brassicae 的繁殖在感染 CMV 的植物上受到抑制。这表明，在拟南芥中，CMV 诱导的对蚜虫的抗性，被认为是促进病毒传播的诱因，对多食性蚜虫的影响大于对十字花科专食性蚜虫的影响。
