Abstract Chitosan has a broad-spectrum antimicrobial activity and has been used to control or delay postharvest decay of fruit. In this study, transcriptomic and metabolomics analyses were used to evaluate the effect of chitosan treatment on the resistance to Botrytis cinerea of two grape varieties (‘Kyoho’ and ‘Shine Muscat’) that differ in their resistance to this pathogen. Meantime, the effect of chitosan treatment on B. cinerea mycelium growth was analyzed by scanning electron microscope. The physiological indicators of disease and antioxidant enzyme activities of grape fruit after chitosan treatment were also measured. The results showed that chitosan treatment inhibited the damage of B. cinerea to grape fruit. At same time, chitosan could destroy the mycelium of B. cinerea and increase the antioxidant enzyme activities of grape fruit. The differentially expressed genes (DEGs) from treated or non-treated samples with chitosan were mainly enriched in the recognition of fungal diseases, plant hormone biosynthesis and signal transduction, and secondary metabolism. We detected a large number of secondary metabolites using the metabolome that were different in ‘Kyoho’ and ‘Shine Muscat’, such as epigallocatechin gallate, catechin, resveratrol etc. In conclusion, chitosan treatment improved disease resistance of grape fruit, and we established a possible model for chitosan regulating disease resistance of ‘Kyoho’ and ‘Shine Muscat’. We found that the expression of DEGs in disease perception, plant hormone biosynthesis and signal transduction, and secondary metabolism differ between ‘Kyoho’ and ‘Shine Muscat’ after chitosan treatment, which helps to clarify the possible mechanism of chitosan providing tolerance to B. cinerea.

中文翻译：

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综合转录组学和代谢组学数据探索壳聚糖对葡萄采后葡萄灰霉病抗性的影响

摘要 壳聚糖具有广谱抗菌活性，已被用于控制或延缓果实采后腐烂。在这项研究中，转录组学和代谢组学分析用于评估壳聚糖处理对两种葡萄品种（“巨峰”和“闪耀麝香葡萄”）对灰葡萄孢的抗性的影响，这两种葡萄品种对这种病原体的抗性不同。同时，通过扫描电子显微镜分析壳聚糖处理对灰霉病菌菌丝体生长的影响。还测定了壳聚糖处理后葡萄果实的病害生理指标和抗氧化酶活性。结果表明壳聚糖处理抑制了灰霉病菌对葡萄果实的危害。同时壳聚糖可以破坏灰霉病菌的菌丝体，提高葡萄果实的抗氧化酶活性。壳聚糖处理或未处理样品的差异表达基因（DEGs）主要富集在真菌病害识别、植物激素生物合成和信号转导、次生代谢等方面。我们利用'Kyoho'和'Shine Muscat'不同的代谢组检测到大量次生代谢物，如表没食子儿茶素没食子酸酯、儿茶素、白藜芦醇等。总之，壳聚糖处理提高了葡萄果实的抗病能力，我们建立了壳聚糖调节“巨峰”和“闪耀马斯喀特”抗病性的可能模型。我们发现，经过壳聚糖处理后，'巨峰'和'闪耀麝香'在疾病感知、植物激素生物合成和信号转导以及次生代谢中DEGs的表达不同，