Singh, K and Rani, A and Paul, A and Dutt, Som and Joshi, Robin and Gulati, Ashu and Ahuja, Paramvir Singh and Kumar, Sanjay (2009) Differential display mediated cloning of anthocyanidin reductase gene from tea (Camellia sinensis) and its relationship with the concentration of epicatechins. Tree Physiology, 29 (6). pp. 837-846. ISSN 0829-318X

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Tea [Camellia sinensis (L.) O. Kuntze] leaves are a major source of epicatechin (EC) and its gallolyl derivatives epicatechin gallate, epigallocatechin and epigallocatechin gallate, collectively known as epicatechins (ECs). Epicatechins are important factors determining tea quality, and they also possess many medicinal properties. To gain further information about the regulation of the biosynthesis of ECs, we cloned the gene encoding anthocyanidin reductase from tea (CsANR) by first quantifying changes in the concentrations of ECs in response to drought, gibberellic acid (GA(3)), abscisic acid (ABA) and wounding treatments, followed by differential display of mRNAs and analysis of those bands exhibiting a change in expression paralleling the treatment-induced changes observed in the EC data. Analysis of 133 bands yielded a partial cDNA of CsANR that was later cloned to the full length by rapid amplification of the cDNA ends. The full-length CsANR (Accession No. AY641729 comprised 1233bp with an ORF of 1014bp (from 79 to 1092bp) encoding a polypeptide of 337 amino acids. Expression of CsANR in an Escherichia coli expression vector yielded a functional protein that catalyzed the conversion of cyanidin to EC in the presence of NADPH. Analysis of ECs and gene expression in leaves at different developmental stages and across five tea clones exhibiting variable concentrations of ECs revealed a positive correlation between concentration of ECs and CsANR expression. Expression of CsANR was down-regulated in response to drought, ABA and GA(3) treatments and up-regulated in response to wounding.

Item Type: Article
Uncontrolled Keywords: catechin; flavonoid;
Subjects: Plant Biotechnology
Depositing User: Dr. Aparna Maitra Pati
Date Deposited: 28 Dec 2011 11:40
Last Modified: 09 Apr 2013 07:51

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