PLS-based integration of metabolomics and transcriptomics to reveal the effect of different growth years on Eurycoma longifolia roots and hairy root cultures

Abstract

Growth years are important factors that affect the accumulation of secondary metabolites in Eurycoma longifolia roots. This study aimed to investigate the effect of different growth years on the metabolites and gene expression of E. longifolia roots and hairy root cultures. To achieve this, metabolite profiles and candidate transcripts of terpenoid backbone biosynthesis and sesquiterpenoid and triterpenoid pathways of 1- and 11-year old E. longifolia roots and hairy root cultures were obtained and integrated using partial least squares (PLS). Integration of eighty-two metabolites and forty-five selected candidate genes using PLS successfully differentiated 1-, 11-year-old E. longifolia roots and hairy root cultures, indicating significant metabolite-gene expression differences in response to different growth years and root types. Amino acids, 2-C-methyl-D-erythritol-4-phosphate cytidylyl-transferase (MCT) and acetyl-CoA C-acetyltransferase (AACT) were responsible for the discrimination of 1-year-old E. longifolia root. Quassinoids of eurycomanone and eurycomalactone and genes linked to the upstream synthesis in mevalonate (MVA) pathway contributed to the discrimination of the11-year-old E. longifolia root. 11-hydroxycanthin-6-one and genes that participate in the methylerythritol phosphate (MEP) pathway upstream of terpenoid biosynthesis were responsible for the discrimination of E. longifolia hairy root cultures.