Abstract
BACKGROUND: Acer pseudosieboldianum (Pax) Komarov, is a colorful leaf species belonging to the family Aceraceae, mainly distributed in Northeast China, Russia, and northern Korea. The leaves of Acer pseudosieboldianum are green in spring and summer, and turning red in autumn, which is of high ornamental value. In previous study, a mutant maple was selected with alternating red-green leaf color in spring and summer. However, the reason for the color mutation was not clear. Therefore, UPLC /LC-MS and RNA-seq were used to analyze the anthocyanin components and related differentially expressed genes in the spring leaf color changes of A. pseudosieboldianum mutant, which can provide broader insights into the complex coloration process of leaf color. RESULTS: The results showed that the mutant leaves contained a total of 50 anthocyanin metabolites. In all differential metabolites of anthocyanins, Cyanidin-3,5-O-diglucoside, Cyanidin-3-O-glucoside, Cyanidin-3-O-sambubioside not only had higher content, but also showed significant changes at different stages. Especially, the consistent high content of anthocyanins in Cyanidin-3-O-glucoside, which are the main pigments for leaf color. In addition, 11,522 genes were found to be significantly differentially with 5,477 genes up-regulated, and 6,045 genes down-regulated. We identified relevant information for differentially expressed genes (DEGs) associated with leaf color, including 20 structural genes involved in anthocyanin biosynthesis, 12 transcription factors, and eight genes related to anthocyanin transport. CONCLUSIONS: Among all anthocyanins of A. pseudosieboldianum mutant leaf, Cyanidin-3-O-glucoside remained high in all three stages of leaves, which is main substances for the leaf color. Additionally, 20 structure gene, 12 transcription factors and some genes associated with anthocyanin synthesis and transport were screened and there was a complex metabolic network in mutant leaves. This study provided a basis for resource innovation and landscaping applications of Acer plants by analyzing the anthocyanin metabolites and expression of DEGs in the leaf coloring process.