Avesani Sara, Lazazzara Valentina, Buti Matteo, Oberhuber Michael, Robatscher Peter, Perazzolli Michele
Center for Agriculture Food Environment (C3A), University of Trento, San Michele all'Adige, Italy.
Laboratory for Flavours and Metabolites, Laimburg Research Centre, Auer (Ora), Italy.
Physiol Plant. 2025 Jul-Aug;177(4):e70412. doi: 10.1111/ppl.70412.
Volatile organic compounds (VOCs) are produced by grapevine leaves in response to phytopathogen infection. In particular, 2-phenylethanol and β-cyclocitral were triggered by Plasmopara viticola inoculation in downy mildew-resistant genotypes, but no information is available on their involvement in plant resistance induction. This study aimed to clarify transcriptional and metabolic changes associated with VOC-induced resistance activated by 2-phenylethanol and β-cyclocitral treatments against P. viticola. Both VOCs decreased downy mildew severity on grapevine leaf disks by complex reprogramming of the grapevine transcriptome at 1 and 6 days post inoculation. RNA-Seq analysis showed the modulation of transcripts related to defense (chitinases, defense-related proteins, and pathogenesis-related proteins), oxidative stress (glutathione S-transferases and peroxidases), secondary metabolism (nitrilases, stilbene synthases, and terpene synthases), signal transduction (e.g., kinases, receptor kinases, and calmodulins), and transcription (bHLH, ERF, MYB, NAC, and WRKY transcription factors) in leaf disks treated with 2-phenylethanol and β-cyclocitral. VOC treatments also caused changes in the leaf metabolome, and pathway analysis of metabolic features with significant changes in abundance in 2-phenylethanol- and β-cyclocitral-treated leaf disks revealed the reprogramming of amino acid, carbohydrate, flavonoid, phenylpropanoid, and terpenoid metabolism. In particular, compounds with increases in abundance belonged to putative carbohydrates, carboxylic acids, and phenylpropanoids in 2-phenylethanol-treated samples, or carboxylic acids and terpenoids in β-cyclocitral-treated samples, including molecules possibly associated with plant defense against pathogens, such as 3-dehydroquinic acid, 4-thujanol, aromadendrin, camphor, p-coumaryl alcohol, and perillaldehyde. Correlation analysis between transcriptomic and metabolomic data indicated that 2-phenylethanol and β-cyclocitral act as resistance inducers against downy mildew in grapevine.
挥发性有机化合物（VOCs）由葡萄叶片在应对植物病原体感染时产生。特别是，2-苯乙醇和β-环柠檬醛在抗霜霉病基因型中由葡萄生单轴霉接种引发，但关于它们参与植物抗性诱导的信息尚无报道。本研究旨在阐明与2-苯乙醇和β-环柠檬醛处理激活的针对葡萄生单轴霉的VOC诱导抗性相关的转录和代谢变化。两种VOCs通过接种后1天和6天对葡萄转录组的复杂重编程降低了葡萄叶片圆片上霜霉病的严重程度。RNA测序分析表明，在经2-苯乙醇和β-环柠檬醛处理的叶片圆片中，与防御（几丁质酶、防御相关蛋白和病程相关蛋白）、氧化应激（谷胱甘肽S-转移酶和过氧化物酶）、次生代谢（腈水解酶、芪合酶和萜类合酶）、信号转导（如激酶、受体激酶和钙调蛋白）以及转录（bHLH、ERF、MYB、NAC和WRKY转录因子）相关的转录本受到调控。VOC处理还导致叶片代谢组发生变化，对2-苯乙醇和β-环柠檬醛处理的叶片圆片中丰度有显著变化的代谢特征进行通路分析，揭示了氨基酸、碳水化合物、黄酮类、苯丙烷类和萜类代谢的重编程。特别是，丰度增加的化合物在2-苯乙醇处理的样品中属于推定的碳水化合物、羧酸和苯丙烷类，或在β-环柠檬醛处理的样品中属于羧酸和萜类，包括可能与植物抵御病原体相关的分子，如3-脱氢奎尼酸、4-侧柏醇、香豆素、樟脑、对香豆醇和紫苏醛。转录组学和代谢组学数据之间的相关性分析表明，2-苯乙醇和β-环柠檬醛作为葡萄霜霉病的抗性诱导剂发挥作用。
