Identification and characterization of potential regulators of flavonoid biosynthetic pathway in Arachis hypogaea

Abstract

. Arachis hypogaea is one of the major agricultural crops of Pakistan, the seed of which is widely used as food and in the oil seed industry. The plant also accrues a number of secondary metabolites that act as active ingredients such as flavonoids. Plant flavonoids play a vital role in various biological processes. The current study is focus on characterization of key regulators of flavonoid biosynthetic pathway in cultivated peanut varieties of Pakistan, focusing on the genes encoding enzymes for the biosynthetic reactions. In current study nine structural genes have been identified in flavonoid biosynthetic pathway in Arachis hypogaea including full length cDNAs of cinnamate-4- hydroxylase (AhC4H), 4-hydroxycinnamoyl-CoA ligase 3 (Ah4CL3), chalcone synthase (AhCHS), chalcone isomerase, flavonone 3-hydroxylase (AhF3H), dihydroflavonol 4- reductase (AhDFR), flavonol synthase (AhFLS), leucoanthocyanidin reductase (AhLAR) and anthocyanidin synthase (AhANS) and NCBI and peanut EST database has been used in this study, along with Arabidopsis gene database from NCBI was used as reference.Genomic annotation was made according to sequence similarities and later expression profiling of the representative genes have been done after induction of elicitor, drought stress. Furthermore, in silico analysis revealed those proteins of all candidate genes have conserved domains. Relative expression analysis showed that expression of these genes was induced by abiotic stress, i. e. drought. Core promoter region and cis-regulatory elements are also identified using computational methods. Candidate promotors are correlated to genomic features and expression analysis data from structural genes of flavonoid biosynthetic pathway. Furthermore, eight transcription factors MYB7, MYB111, MYB123, bHLH042, EGL3, GL3, COP1, CSU2 has been identified in Arachis hypogaea

genome mainly belongs to MYB family bHLH and WD40 family. This study would provide a better understanding of the underlying molecular mechanism of flavonoid biosynthetic pathway in Arachis hypogaea.