Integrative analysis of metabolome and transcriptome reveals the different metabolite biosynthesis profiles related to palatability in winter and spring shoot in Moso bamboo

As a traditional vegetable, Moso bamboo shoot has high nutritional and medicinal values. However, a comprehensive and dynamic evaluation of metabolites present in Moso bamboo shoot is lacking, and the causes and regulatory mechanism of palatability deterioration from winter shoot to spring shoot remain unclear. Herein, an integrative analysis of metabolome and transcriptome profiles was conducted in winter and spring shoots of Moso bamboo. Totally 909 metabolites were identified and characterized for the first time, mainly divided into 12 different categories, of which lipids and phenolic acids were the most diverse. Analysis of differentially accumulated metabolites revealed that the differences between spring and winter shoots in accumulation of about 20% metabolites were significant. Gallic acid was identified as the differentially accumulated metabolite related to bitterness of Moso bamboo shoots, and its significant increase promoted the content of hydrolyzed tannin, resulting in the increased bitterness of spring shoot. This process was positively regulated by key enzyme genes in the hydrolyzed tannin biosynthesis pathway, such as DAHPS, DHQS, DHQ and SDH. In addition, cinnamic acid, ferulic acid, UDP-glucose and UDP-xylose were identified as the differentially accumulated metabolites related to roughness of Moso bamboo shoots, and their significant variation increased the contents of lignin, cellulose and hemicellulose. Accordingly, this process was positively regulated by most enzyme genes involved in lignin, cellulose and hemicellulose biosynthesis pathway. The present study advances our understanding of metabolite accumulation and molecular mechanism of palatability translation in Moso bamboo shoots. The data sets provided here will ultimately inspire biotechnological strategies for edible quality improvement of bamboo shoots.