Identification and characterization of anthocyanins' composition and regulatory genes involved in anthocyanins biosynthesis in water dropwort (Oenanthe javanica).

Abstract

Main conclusion: This study showed that anthocyanin was the main pigments related to purple stem and OjUFGT1 is involved in anthocyanin glycosylation in water dropwort. Water dropwort is a kind of aquatic vegetable with many medicinal values. In the study, the green-stem water dropwort 'FQ1H' and purple-stem water dropwort 'Sq013' were selected as plant materials. The anthocyanins composition was determined by UPLC-MS/MS and the transcript profile was analyzed based on RNA-seq in water dropwort. Nine anthocyanins were identified from water dropwort by UPLC-MS/MS. Petunidin and anthocyanin have higher content, which play a crucial role in the formation of purple stem. In total, 20,478 DEGs were identified in the purple stem, which might have a high correlation with anthocyanin accumulation. The expressions of 26 DEGs encoding anthocyanin biosynthesis structural genes were determined. Furthermore, co-expression analysis indicated that many R2R3-MYB and bHLH transcription factors were potentially involved in anthocyanin biosynthesis. In vitro enzyme activity assay showed that glycosyltransferase OjUFGT1 recognizes UDP-galactose as glycosyl donor and converts cyanidin to cyanidin-3-O-galactoside. In summary, these results may facilitate the development of our breeding and utilization for the high-anthocyanin water dropwort in the future.