1 State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences , Beijing 100101 , People's Republic of China.
3 University of Chinese Academy of Sciences , Beijing 100049 , People's Republic of China.
Philos Trans R Soc Lond B Biol Sci. 2019 Mar 4;374(1767):20180314. doi: 10.1098/rstb.2018.0314.
Effector proteins present in aphid saliva are thought to modulate aphid-plant interactions. Armet, an effector protein, is found in the phloem sap of pea-aphid-infested plants and is indispensable for the survival of aphids on plants. However, its function in plants has not been investigated. Here, we explored the functions of Armet after delivery into plants. Examination of the transcriptomes of Nicotiana benthamiana and Medicago truncatula following transgenic expression of Armet or infiltration of the protein showed that Armet activated pathways associated with plant-pathogen interactions, mitogen-activated protein kinase and salicylic acid (SA). Armet induced a fourfold increase in SA accumulation by regulating the expression of SAMT and SABP2, two genes associated with SA metabolism, in Armet-infiltrated tobacco. The increase in SA enhanced the plants' resistance to bacterial pathogen Pseudomonas syringae but had no detectable adverse effects on aphid survival or reproduction. Similar molecular responses and a chlorosis phenotype were induced in tobacco by Armet from two aphid species but not by locust Armet, suggesting that the effector function of Armet may be specific for aphids. The results suggest that Armet causes plants to make a pathogen-resistance decision and reflect a novel tripartite insect-plant-pathogen interaction. This article is part of the theme issue 'Biotic signalling sheds light on smart pest management'.
在蚜虫唾液中存在的效应蛋白被认为可以调节蚜虫与植物的相互作用。Armet 是一种效应蛋白，存在于受豌豆蚜虫侵染的植物韧皮部汁液中，对于蚜虫在植物上的生存是必不可少的。然而，其在植物中的功能尚未被研究过。在这里，我们探索了 Armet 进入植物后的功能。在转 Armet 表达或蛋白浸润后，对 Nicotiana benthamiana 和 Medicago truncatula 的转录组进行检测，结果表明 Armet 激活了与植物-病原体相互作用、丝裂原活化蛋白激酶和水杨酸 (SA) 相关的途径。Armet 通过调节与 SA 代谢相关的两个基因 SAMT 和 SABP2 的表达，诱导烟草中 SA 积累增加了四倍。SA 的增加通过调节与 SA 代谢相关的两个基因 SAMT 和 SABP2 的表达，增强了植物对细菌病原体丁香假单胞菌的抗性，但对蚜虫的存活或繁殖没有明显的不利影响。两种蚜虫的 Armet 而非蝗虫的 Armet 在烟草中诱导了相似的分子反应和黄化表型，这表明 Armet 的效应功能可能是针对蚜虫的。这些结果表明，Armet 促使植物做出抗病原体的决定，并反映了一种新的三方昆虫-植物-病原体相互作用。本文是主题为“生物信号揭示智能害虫管理”的特刊的一部分。
