Genes up-regulated during red coloration in UV-B irradiated lettuce leaves

Abstract

Molecular analysis of gene expression differences between green and red lettuce leaves was performed using the SSH method. BlastX comparisons of subtractive expressed sequence tags (ESTs) indicated that 7.6% of clones encoded enzymes involved in secondary metabolism. Such clones had a particularly high abundance of flavonoid-metabolism proteins (6.5%). Following SSH, 566 clones were rescreened for differential gene expression using dot-blot hybridization. Of these, 53 were found to overexpressed during red coloration. The up-regulated expression of six genes was confirmed by Northern blot analyses. The expression of chalcone synthase (CHS), flavanone 3-hydroxylase (F3H), and dihydroflavonol 4-reductase (DFR) genes showed a positive correlation with anthocyanin accumulation in UV-B-irradiated lettuce leaves; flavonoid 3',5'-hydroxylase (F3',5'H) and anthocyanidin synthase (ANS) were expressed continuously in both samples. These results indicated that the genes CHS, F3H, and DFR coincided with increases in anthocyanin accumulation during the red coloration of lettuce leaves. This study show a relationship between red coloration and the expression of up-regulated genes in lettuce. The subtractive cDNA library and EST database described in this study represent a valuable resource for further research for secondary metabolism in the vegetable crops.

Comprehensive Dissection of Spatiotemporal Metabolic Shifts in Primary, Secondary, and Lipid Metabolism during Developmental Senescence in Arabidopsis

“…This is in keeping with the observed reduction of kaempferol glycoside levels in the anthocyanin overaccumulator line (pap1-D; Tohge et al, 2005). In addition to the important roles of flavonoids and phenylpropanoids under light stress, nutrient conditions such as nitrogen, sulfur, and phosphorus deficiency as well as high-carbon stress can also cause anthocyanin synthesis (Do and Cormier, 1991;Rajendran et al, 1992;Bonguebartelsman and Phillips, 1995;Nooden et al, 1996;Stewart et al, 2001;Nikiforova et al, 2004;Park et al, 2007). Many studies concerning the relationship between nitrogen and the rate of CO 2 assimilation and photosynthesis have suggested that anthocyanin accumulation is a metabolic marker for carbon/nitrogen imbalance under such stress conditions (Smart, 1994;Zheng et al, 2009).…”

Transcriptome analysis and anthocyanin-related genes in red leaf lettuce

“…Park et al (2007) isolated five fragments of the anthocyanin synthase gene, whose transcription coincided with plant color. However, the molecular mechanism of anthocyanin accumulation in lettuce is still unclear and gene transcription has a poor outcome.…”

Pigments in Grape

“…Ultraviolet irradiation is known to increase the expression of anthocyanin biosynthetic genes in several plant species and also lead to an increase in the accumulation of anthocyanins [70,94]. Research examining the structure of the promoter sequences of two of the structural genes involved in flavonoid biosynthesis in grapes revealed that these genes could be induced by exposure to ultraviolet-A light [95,96].…”