Abstract：
5-Azacytidine (AZ) is a DNA methylation inhibitor that has recently demonstrated potential in regulating fruit quality through exogenous application. In this study, we treated mandarin fruits for 4-day storage. Noteworthy were the induced degreening and the enhanced citrus aroma of fruits under AZ treatment, involving the promotion of chlorophyll degradation, carotenoid biosynthesis, and limonene biosynthesis. Key genes associated with these processes exhibited expression level increases of up to 123.8 times. Additionally, AZ treatment activated defense-related enzymes and altered phenylpropanoid carbon allocation towards lignin biosynthesis instead of flavonoid biosynthesis. The expression levels of lignin biosynthesis-related genes increased by nearly 100 times, leading to fortified lignin that is crucial for citrus defense against Penicillium italicum. Currently, the underlying mechanisms of such intense AZ-induced changes in gene expressions remain unclear and further research could help establish AZ treatment as a viable strategy for citrus preservation.
摘要：
5-氮杂胞苷（AZ）是一种DNA甲基化抑制剂，最近显示出通过外源应用调节果实品质的潜力。在这项研究中,我们处理了4天的水果。值得注意的是，在AZ处理下，水果的诱导脱绿和柑橘香气增强，涉及促进叶绿素降解，类胡萝卜素生物合成，和柠檬烯生物合成。与这些过程相关的关键基因表现出表达水平增加高达123.8倍。此外,AZ处理激活了防御相关的酶，并改变了苯丙烷类碳向木质素生物合成而不是类黄酮生物合成的分配。木质素生物合成相关基因的表达水平提高了近100倍，导致强化的木质素，这对于柑橘防御意大利青霉至关重要。目前,如此强烈的AZ诱导的基因表达变化的潜在机制尚不清楚，进一步的研究可能有助于将AZ治疗确立为柑橘保存的可行策略。
