Combined metabolome and transcriptome analyses of photosynthetic pigments in red maple

Leaf color is affected primarily by the content and proportion of various pigments. Not only do photosynthetic pigments display various colors, they are also key to the physiological activities of plants. To precisely elucidate the mechanisms of chlorophyll and carotenoid biosynthesis and their interactions in red maple, transcriptomic and metabolomic profiling were performed on green, red and yellow leaves from a selected red maple mutant. In the chlorophyll pathway, ArPOR1, ArCLH2, and ArCLH4 positively regulated chlorophyll a, and made it the dominant pigment in green leaves, whereas ArNOL8 and ArNOL14 negatively regulated chlorophyll synthesis. In the carotenoid pathway, under the positive regulation of ArLUT5-1 and ArLUT5-4, the synthesis of carotenoids changed from alpha-branch to beta-branch during the gradual senescence of leaves. Through integrated data analysis, we obtained genes that directly coordinated between carotenoid and chlorophyll biosynthesis. Ultimately, the results of this paper will be a valuable resource for future research on gene-to-metabolite correlations in red maple, and provide basic information toward facilitating the improvement of color in foliage plants.