Table_3_Regulatory mechanisms and metabolic changes of miRNA during leaf color change in the bud mutation branches of Acer pictum subsp. mono.xlsx

Acer pictum subsp. mono is a colorful tree species with considerable ornamental and economic value. However, little is known about the metabolism and regulatory mechanism of leaf color change in A. p. subsp. mono. To reveal the molecular mechanism of leaf color change in A. p. subsp. mono, the present study examined the bud mutation branches and compared the metabolites of the red leaves (AR) of the bud mutation branches of A. p. subsp. mono with those of the green leaves (AG) of the wild-type branches. It was found that the chlorophyll and carotenoids content of the red leaves decreased significantly, while anthocyanins, and various antioxidant enzymes increased significantly compared with the green leaves. The glycosides cyanidin, pelargonidin, malvidin, petunidin, delphinidin, and peonidin were detected in AR by liquid chromatography-mass spectrometry. The cyanidin glycosides increased, and cyanidin 3-O-glycoside was significantly upregulated. We analyzed the transcriptome and small RNA of A. p. subsp. mono leaves and detected 4061 differentially expressed mRNAs and 116 differentially expressed miRNAs. Through miRNA-mRNA association analysis, five differentially expressed modules were found; one miRNA targeted three genes, and four miRNAs targeted a single gene. Among them, miR160b, miR6300, and miR396g were found to be the key miRNAs regulating stable anthocyanin accumulation in A. p. subsp. mono leaves. By revealing the physiological response of leaf color change and the molecular regulatory mechanism of the miRNA, this study provides new insight into the molecular regulatory mechanism of leaf color change, thereby offering a foundation for future studies.

色木槭（Acer pictum subsp. mono）是一种兼具较高观赏与经济价值的彩叶树种。然而，目前对该树种叶片变色过程中的代谢与调控机制仍了解甚少。为解析色木槭叶片变色的分子机制，本研究选取芽变枝条，将色木槭芽变枝条的红叶（AR）与野生型枝条的绿叶（AG）的代谢物进行了对比分析。研究发现，与绿叶相比，红叶的叶绿素与类胡萝卜素含量显著降低，而花青素与多种抗氧化酶的水平则显著升高。本研究通过液相色谱-质谱联用法（liquid chromatography-mass spectrometry）在红叶（AR）中检测到矢车菊素糖苷、天竺葵素糖苷、锦葵素糖苷、矮牵牛素糖苷、飞燕草素糖苷以及芍药素糖苷。其中矢车菊素糖苷整体含量上升，且矢车菊素3-O-糖苷的表达量显著上调。本研究对色木槭叶片的转录组（transcriptome）与小RNA（small RNA）进行了分析，共鉴定到4061个差异表达信使RNA（mRNA）以及116个差异表达微小RNA（miRNA）。通过miRNA-mRNA关联分析，共筛选得到5个差异表达模块：其中1个miRNA可靶向调控3个基因，另有4个miRNA仅靶向单个基因。其中miR160b、miR6300与miR396g被鉴定为调控色木槭叶片花青素稳定积累的关键miRNA。本研究通过揭示色木槭叶片变色的生理响应与miRNA介导的分子调控机制，为解析叶片变色的分子调控机制提供了新视角，同时也为后续相关研究奠定了基础。