Genome-Wide Analysis of Serine Carboxypeptidase-Like Acyltransferase Gene Family for Evolution and Characterization of Enzymes Involved in the Biosynthesis of Galloylated Catechins in the Tea Plant (Camellia sinensis)

Abstract

Tea (Camellia sinensis L.) leaves synthesize and concentrate a vast array of galloylated catechins (e.g., EGCG and ECG) and non-galloylated catechins (e.g., EGC, catechin, and epicatechin), together constituting 8%-24% of the dry leaf mass. Galloylated catechins account for a major portion of soluble catechins in tea leaves (up to 75%) and make a major contribution to the astringency and bitter taste of the green tea, and their pharmacological activity for human health. However, the catechin galloylation mechanism in tea plants is largely unknown at molecular levels. Previous studies indicated that glucosyltransferases and serine carboxypeptidase-like acyltransferases (SCPL) might be involved in the process. However, details about the roles of SCPLs in the biosynthesis of galloylated catechins remain to be elucidated. Here, we performed the genome-wide identification of SCPL genes in the tea plant genome. Several SCPLs were grouped into clade IA, which encompasses previously characterized SCPL-IA enzymes with an acylation function. Twenty-eight tea genes in this clade were differentially expressed in young leaves and vegetative buds. We characterized three SCPL-IA enzymes (CsSCPL11-IA, CsSCPL13-IA, CsSCPL14-IA) with galloylation activity toward epicatechins using recombinant enzymes. Not only the expression levels of these SCPLIA genes coincide with the accumulation of galloylated catechins in tea plants, but their recombinant enzymes also displayed β-glucogallin:catechin galloyl acyltransferase activity. These findings provide the first insights into the identities of genes encoding glucogallin:catechin galloyl acyltransferases with an active role in the biosynthesis of galloylated catechins in tea plants.

CsbZIP1-CsMYB12 mediates the production of bitter-tasting flavonols in tea plants (Camellia sinensis) through a coordinated activator–repressor network

“…For the cold treatment experiments, tea plant leaves were collected during the cold acclimation (CA) process. Control (CK): 25 °C; CA 1 -6 h: 10 °C for 6 h; CA 1 -7 days: from 10 °C to 4 °C for 7 days; CA 2 -7 days: from 4 °C to 0 °C for 7 days; DA-7d: recover under 25 °C to 20 °C for 7 days, as described previously 42 . Transcriptome data from experiments with tea cv.…”

CsTCPs regulate shoot tip development and catechin biosynthesis in tea plant (Camellia sinensis)

“…These materials were used for metabolite analysis, RNA extraction for transcriptome sequencing or qRT-PCR analysis. Transcriptomic data from various experimental treatments (MeJA, polyethylene glycol, NaCl and cold, and shade) were retrieved from previous studies and the Tea Plant Information Archive ( http://tpia.teaplant.org/index.html ) 43 , 61 – 63 .…”

Genome-wide analysis of the serine carboxypeptidase-like protein family in Triticum aestivum reveals TaSCPL184-6D is involved in abiotic stress response

“…The SCPL gene family plays an important functional role in plants. Whole-genome analysis of SCPL genes has been performed in a variety of plants and allowed for the identification of 71 putative SCPL genes in rice ( O. sativa ), 54 in Arabidopsis ( A. thalianna ), 57 in poplar and 47 in the tea plant ( Camellia sinensis ) [ 52 – 54 ]. However, no systemic analysis of the SCPL gene family has been reported in wheat.…”

“…The phylogenetic analysis showed that wheat, tea, poplar and Arabidopsis have more genes in the CPI and CPII subfamilies. This indicates that the SCPL s in these different species might be undergoing conservative evolution [ 52 – 54 ].…”

“…Whole-genome analysis of the SCPL gene family has been previously performed on a variety of plants. These studies have allowed the identification of 71 putative SCPL genes in rice ( O. sativa ), 54 in Arabidopsis ( A. thalianna ), 57 in poplar and 47 in the tea plant ( Camellia sinensis ) [ 52 – 54 ]. Here, we conducted a comprehensive genome-wide analysis of SCPL gene family in wheat and identified a total of 210 SCPL genes.…”