Abstract Amino acids (AAs) play a critical role in resistance response and biosynthesis of volatile compounds (VOCs) in fruit. In this study, we inoculated apple fruits (cv. Delicious) with Penicillium expansum to investigate the effect of different AA accumulation on the biosynthesis of branched-chain VOCs at different stages of colonization. Generally, infection significantly increased the total AAs in fruit by 38.65 %. Of the 17 AAs detected in fruit, the contents of Asp, Val, Leu, Ala, Ser, Cys, Thr, His, Agr, Glu, Met, Gly, and Pro increased in the early and middle stages of colonization ( 6 DAI). Moreover, infection promoted higher activities of PDC and PDH involved in branched-chain VOCs biosynthesis, leading to increased contents of branched-chain VOCs. These results suggest that P. expansum increases AA’s accumulation and release of branched-chain VOCs in apple fruit.

中文翻译：

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Penicillium expansum – 通过增加氨基酸积累诱导苹果果实中支链挥发性化合物的释放

摘要 氨基酸（AAs）在水果抗性反应和挥发性化合物（VOCs）的生物合成中起着关键作用。在这项研究中，我们用Penicillium expansum 接种苹果果实（cv. Delicious），以研究不同AA 积累对不同定植阶段支链VOC 生物合成的影响。一般来说，感染使水果中的总氨基酸显着增加了 38.65%。在水果中检测到的 17 种氨基酸中，Asp、Val、Leu、Ala、Ser、Cys、Thr、His、Agr、Glu、Met、Gly 和 Pro 的含量在定植早期和中期增加（6 DAI） . 此外，感染促进了参与支链 VOC 生物合成的 PDC 和 PDH 的更高活性，导致支链 VOC 含量增加。这些结果表明 P.