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 etiolation mechanism of gold-coloured mutant leaves of Quercus 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 ultra-high performance liquid chromatography-Q(UHPLC-Q)Exactive HF-X and high-throughput RNA sequencing, respectively. The results were as follows: (1) A total of 257 and 357 significantly changed metabolites (SCMs) were respectively identified under the positive ion(POS)mode and the negative ion(NEG)mode. Compared with green leaves, the content of some flavonoids such as quercetin, leucocyanidin, myricetin and their glucoside derivatives(pyranodelphinin A, isorhamnetin 3-glucuronide, etc. )increased significantly in mutant leaves, but the content of chlorophyll a, chlorophyll b, 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. In conclusion, the inhibition of chlorophyll synthesis, chloroplast developmental abnormalities and promotion of flavonoid synthesis were the main factors driving the leaf etiolation in the mutant Q. 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 provides new molecular insights for the phenomenon of leaf etiolation, and also provides the reference for exploring leaf color-related functional genes and breeding of landscape plant. [ABSTRACT FROM AUTHOR]