Tsalgatidou Polina C, Boutsika Anastasia, Papageorgiou Anastasia G, Dalianis Andreas, Michaliou Maria, Chatzidimopoulos Michael, Delis Costas, Tsitsigiannis Dimitrios I, Paplomatas Epaminondas, Zambounis Antonios
Department of Agriculture, University of the Peloponnese, 24100 Kalamata, Greece.
Institute of Plant Breeding and Genetic Resources, ELGO-DEMETER, 57001 Thessaloniki, Greece.
Plants (Basel). 2024 Feb 20;13(5):567. doi: 10.3390/plants13050567.
The peach ( L.) is one of the most important stone-fruit crops worldwide. Nevertheless, successful peach fruit production is seriously reduced by losses due to the causal agent of brown rot. Chitosan has a broad spectrum of antimicrobial properties and may also act as an elicitor that activate defense responses in plants. As little is known about the elicitation potential of chitosan in peach fruits and its impact at their transcriptional-level profiles, the aim of this study was to uncover using RNA-seq the induced responses regulated by the action of chitosan in fruit-chitosan- interaction. Samples were obtained from fruits treated with chitosan or inoculated with , as well from fruits pre-treated with chitosan and thereafter inoculated with the fungus. Chitosan was found to delay the postharvest decay of fruits, and expression profiles showed that its defense-priming effects were mainly evident after the pathogen challenge, driven particularly by modulations of differentially expressed genes (DEGs) related to cell-wall modifications, pathogen perception, and signal transduction, preventing the spread of fungus. In contrast, as the compatible interaction of fruits with was challenged, a shift towards defense responses was triggered with a delay, which was insufficient to limit fungal expansion, whereas DEGs involved in particular processes have facilitated early pathogen colonization. Physiological indicators of peach fruits were also measured. Additionally, expression profiles of particular genes highlight the direct antimicrobial activity of chitosan against the fungus. Overall, the results clarify the possible mechanisms of chitosan-mediated tolerance to and set new foundations for the potential employment of chitosan in the control of brown rot in peaches.
桃（L.）是全球最重要的核果类作物之一。然而，由褐腐病病原菌导致的损失严重降低了桃果实生产的成功率。壳聚糖具有广泛的抗菌特性，还可能作为一种激发子激活植物的防御反应。由于对壳聚糖在桃果实中的激发潜力及其对转录水平谱的影响了解甚少，本研究的目的是利用RNA测序揭示壳聚糖在果实 - 壳聚糖相互作用中所调节的诱导反应。样本取自用壳聚糖处理或接种了 的果实，以及先用壳聚糖预处理然后接种该真菌的果实。发现壳聚糖可延缓果实采后腐烂，表达谱表明其防御引发作用主要在病原菌侵染后明显，特别是通过与细胞壁修饰、病原菌感知和信号转导相关的差异表达基因（DEG）的调控，从而防止真菌扩散。相反，当果实与 的亲和性相互作用受到挑战时，会延迟引发向防御反应的转变，这不足以限制真菌扩展，而参与特定过程的DEG促进了病原菌的早期定殖。还测量了桃果实的生理指标。此外，特定 基因的表达谱突出了壳聚糖对该真菌的直接抗菌活性。总体而言，这些结果阐明了壳聚糖介导的对 的耐受性的可能机制，并为壳聚糖在控制桃褐腐病中的潜在应用奠定了新基础。
