Transcriptome characterization and metabolite accumulation: novel insights into metabolite biosynthesis during...

Leafdevelopment represents a crucial stage in the plant life cycle, involving complex morphogenetic and physiological processes governed by evolving molecular mechanisms and metabolite profiles. The growth and maturation of Angiopteris fokiensis Hieron, a species used in traditional Chinese medicine, are characterized by fluctuating metabolite accumulation patterns regulated by largely unknown molecular pathways.

Touncover these pathways, we employed next-generation sequencing to construct the A. fokiensis leaf transcriptome at two distinct developmental stages, allowing for a comprehensive analysis of gene expression dynamics while emphasizing the identification of genes that regulate leaf development and metabolite synthesis. The de novo assembly of high-quality sequencing reads generated 117,627 unigenes averaging 1,308 base pairs in length. FPKM analysis uncovered significant transcriptomic alterations during leaf development. Additionally, non-targeted metabolomics identified 1,494 distinct analytes, with lipids representing the most abundant metabolite class in both A. fokiensis samples. In the 'phenylalanine, tyrosine and tryptophan biosynthesis' pathway, two downregulated arogenate dehydrogenase (NADP+) genes (Unigene23378-S4 and Unigene47537-S2) in Stage1 correlated with reduced L-tyrosine levels. In the 'galactose metabolism' pathway, the upregulation of three beta-galactosidase genes (Unigene43641-S6, Unigene43648-S6, Unigene47074-S1) and the downregulation of one (Unigene28294-S2) corresponded to decreased alpha-lactose levels.

This study provides an in-depth examination of the dynamic transcriptomic and metabolomic changes occurring during A. fokiensis leaf development, revealing key regulatory networks and enhancing the annotation of theA. fokiensis genome. These findings lay a crucial groundwork for future research on this medicinal plant.