代谢组与转录组联合解析赤皮青冈叶片黄化变异机制

In order to reveal the albino mechanism of gold-coloured mutant leaves of Cyclobalanopsis gilva, a naturally-occurring leaf-color mutant was used as experimental materials, and the metabolome and transcriptome of mutant leaves and normal green leaves were analyzed by UHPLC-Q Exactive HF-X and high-throughput RNA sequencing, respectively. The results were as follows: ( 1 ) 257 and 357 significantly changed metabolites ( SCMs ) were respectively identified under the positive ion mode and the negative ion mode. Compared with green leaves, the content of some flavonoids such as quercetin, leucoyanidin, myricetin and their derivatives (pyranodelphinin A, isorhamnetin 3-glucuronide, etc. ) increased significantly in mutant leaves, but the content of chlorophylls and carotenoids decreased significantly. ( 2 ) A total of 4 146 differentially expressed genes (DEGs) were detected, of which 1 711 were up-regulated and 2 435 were down-regulated. ( 3 ) KEGG enrichment analysis showed that SCMs and DEGs were mainly enriched in photosynthesis, porphyrin and chlorophyll metabolism and flavonoid biosynthesis. The research results indicate that inhibition of chlorophyll synthesis, chloroplast developmental abnormalities and promotion of flavonoid synthesis were the main factors driving the golden leaf coloration in the mutant C. gilva. In addition, the genes of the MYB and bHLH families were significantly up-regulated in mutant leaves, confirming these two types of transcription factors were involved in regulating flavonoid biosynthesis. This study provided new molecular insights into the phenomenon of leaf etiolation, and also provided reference for exploring leaf color-related functional genes and breeding of landscape plant.