Li Zhenxiang, Jing Shizhao, Wang Da, Song Zichao, An Boyang, Wang Saige, Liu Fanghua, Di Ning, Aradottir Gudbjorg Inga, Sun Jianghua, Tan Xiaoling, Qu Cheng, Kang Zhiwei
College of Life Science/Hebei Basic Science Center for Biotic Interactions, Institute of Life Science and Green Development, Hebei University, Baoding, China.
College of Plant Protection, Hebei Agricultural University, Baoding, China.
Plant Cell Environ. 2024 Dec 30. doi: 10.1111/pce.15351.
Wheat (Triticum aestivum L.) is one of the most important staple crops all over the world. Its productivity is adversely affected by aphid infestation. Plant volatiles play a critical role in plant communication, inducing direct and indirect defenses against insect pests. However, little is known about the priming mechanism of key volatiles in wheat. To determine whether and how plant volatile induced defense priming in wheat against the grain aphid Sitobion avenae, a combination of insect bioassays, phytohormone and defense metabolite quantification, and transcriptome analyses were performed using an important aphid damage-induced plant volatile, methyl salicylate (MeSA). MeSA treatment primed wheat for enhanced accumulation of salicylic acid, flavonoid and benzoxazinoids (BXs), and increased resistance to S. avenae and attractiveness to an aphid parasitoid Aphelinus asychis. Supplementation with a BX (2,4-dihydroxy-7-methoxy-2H-1,4-benzoxazin-3(4H)-one) and two flavonoids (xanthohumol and isobavachalcone) in artificial diet impaired the survival, development and fecundity of S. avenae. Moreover, MeSA treatment induced wheat volatile emission especially MeSA. Functional investigation of odorant-binding proteins (OBPs) in A. asychis revealed that AasyOBP4 is responsible for the recognition of MeSA. Taken together, our results provide insights into the molecular mechanism of MeSA-mediated defense in wheat and propose MeSA as a phytoprotectant for crop protection and sustainable agriculture.
小麦（Triticum aestivum L.）是世界上最重要的主食作物之一。其生产力受到蚜虫侵害的不利影响。植物挥发物在植物通讯中起着关键作用，可诱导对害虫的直接和间接防御。然而，关于小麦中关键挥发物的引发机制知之甚少。为了确定植物挥发物是否以及如何诱导小麦对麦长管蚜（Sitobion avenae）产生防御引发作用，我们使用一种重要的蚜虫损害诱导型植物挥发物水杨酸甲酯（MeSA），进行了昆虫生物测定、植物激素和防御代谢物定量分析以及转录组分析。MeSA处理使小麦中水杨酸、类黄酮和苯并恶嗪类化合物（BXs）的积累增强，并提高了对麦长管蚜的抗性以及对蚜虫寄生蜂燕麦蚜茧蜂（Aphelinus asychis）的吸引力。在人工饲料中添加一种BX（2,4 - 二羟基 - 7 - 甲氧基 - 2H - 1,4 - 苯并恶嗪 - 3(4H)-酮）和两种类黄酮（黄腐酚和异补骨脂查尔酮）会损害麦长管蚜的存活、发育和繁殖力。此外，MeSA处理诱导了小麦挥发物的释放，尤其是MeSA。对燕麦蚜茧蜂中气味结合蛋白（OBPs）的功能研究表明，AasyOBP4负责识别MeSA。综上所述，我们的研究结果为MeSA介导的小麦防御分子机制提供了见解，并提出将MeSA作为一种植物保护剂用于作物保护和可持续农业。
