Integration of Transcriptomic and Metabolomic Analysis Reveals Possible Molecular Mechanisms of Leaf Growth and Development in Disanthus cercidifolius var. longipes
Disanthus cercidifolius var. longipes is an important but rare tree species used in plant studies due to its highly ornamental leaves. However, its sciophilous nature and low photosynthetic efficiency make it difficult to cultivate on a large scale. In this study, we collected leaves of D. cercidifolius var. longipes at three developmental stages to assess its photosynthetic capacity and photoprotection mechanisms. Primary metabolites were quantified and separate and joint analyses of the transcriptome and metabolome were carried out. Our results revealed significant changes in the contents of flavonoids, free amino acids, and other substances during development. Metabolome and transcriptome analyses showed that the photosynthesis-related pathways changed rapidly, increasing at first and then decreasing. Under low photosynthetic capacity, flavonoids and anthocyanins were synthesized to achieve photoprotection, with synthesis of these compounds and other pathway-related genes and metabolites showing a significant increase. Total flavonoids also followed this trend. Our findings provide insights into the shade-loving plant's photoprotection mechanisms and nutrient synthesis strategy, which involve quick nutrient production over a short period. This study could aid in developing D. cercidifolius var. longipes into a street or foliage tree through selective breeding. Overall design: To assess its photosynthetic capacity and photoprotection mechanisms, the leaves of D. cercidifolius var. longipes at three developmental stages were collected, and their primary metabolites were quantified. Separate and joint analyses of the transcriptome and metabolome were carried out.