Abstract Volatile organic compounds (VOCs) can play an essential role in eliciting an induced defense response in exposed plants. Preceding research showed that Puccinia triticina (Pt) infected resistant wheat emitted VOCs that induced a defense response in uninfected exposed wheat (UR) plants. The current study aimed to determine the biochemical nature of this induced defense response in the UR plants. Seedlings exposed to infected resistant plant VOCs for 8 h were used for proteomic analysis. A total of 26 proteins were up-regulated and 55 proteins were down-regulated. Five up-regulated chaperones proteins (Hsp70, chaperonin 60 subunit beta 3, ClpC, ClpC1 and ClpC2), two elongation factor-Tu, four isoforms of glyceraldehyde-3-phosphate dehydrogenase and xyloglucan galactosyltransferase are generally associated with plant defense responses. The proteomic expression profiles were supported by gene transcript expression patterns showing down-regulated phosphoglycerate kinase, up-regulated ClpC2 chaperone and unchanged carbonic anhydrase encoding transcript levels. In addition, the mitochondrial Cu/Zn superoxide dismutase (Cu/Zn-SOD Mt) encoding gene transcripts and SOD enzymatic activity were significantly induced at 8, 24 and 48 h post volatile exposure (hpe) relative to control (0 hpe). Salicylic acid quantities were significantly induced in the UR plants at 8, 24 and 48 hpe. These findings suggested that induced salicylic acid could be involved in the signaling of biochemical changes in the UR plants upon the reception of the VOCs emitted by the Pt infected wheat plants. The current study thus contributed to improving our understanding of the nature of the biochemical induced defence responses during VOCs exposed uninfected plants in an interplant signaling event.

中文翻译：

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描绘暴露于小麦粉锈菌感染小麦释放的挥发物的抗性幼苗的诱导防御反应

摘要 挥发性有机化合物 (VOCs) 可以在暴露植物中引发诱导防御反应方面发挥重要作用。先前的研究表明，小麦锈菌 (Pt) 感染的抗性小麦会释放 VOC，从而在未受感染的暴露小麦 (UR) 植物中诱导防御反应。目前的研究旨在确定 UR 植物中这种诱导防御反应的生化性质。将幼苗暴露于受感染的抗性植物 VOC 8 小时，用于蛋白质组学分析。总共有 26 种蛋白质被上调，55 种蛋白质被下调。五种上调的伴侣蛋白（Hsp70、伴侣蛋白 60 亚基 beta 3、ClpC、ClpC1 和 ClpC2）、两种延伸因子-Tu、四种甘油醛-3-磷酸脱氢酶和木葡聚糖半乳糖基转移酶通常与植物防御反应相关。蛋白质组表达谱得到基因转录表达模式的支持，显示磷酸甘油酸激酶下调、ClpC2 分子伴侣上调和碳酸酐酶编码转录水平不变。此外，相对于对照 (0 hpe)，在挥发性暴露 (hpe) 后 8、24 和 48 小时，线粒体 Cu/Zn 超氧化物歧化酶 (Cu/Zn-SOD Mt) 编码基因转录物和 SOD 酶活性被显着诱导。在 8、24 和 48 hpe 的 UR 植物中显着诱导了水杨酸的量。这些发现表明，诱导水杨酸可能参与 UR 植物在接受 Pt 感染小麦植物释放的 VOC 后的生化变化信号。