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

• Published in: Plant cell reports 2007-04, Vol.26 (4), p.507-516
• Main Authors: PARK, Jong-Sug, CHOUNG, Myoung-Gun, CHO, Kang-Jin, KIM, Jung-Bong, HAHN, Bum-Soo, KIM, Jong-Bum, BAE, Shin-Chul, ROH, Kyung-Hee, KIM, Yong-Hwan, CHEON, Choong-Ill, SUNG, Mi-Kyung
• Format: Article
• Language: English
• Subjects: Acyltransferases - genetics; Acyltransferases - metabolism; Alcohol Oxidoreductases - genetics; Alcohol Oxidoreductases - metabolism; Anthocyanins - metabolism; Biological and medical sciences; Biotechnology; Blotting, Northern; Expressed Sequence Tags; Fundamental and applied biological sciences. Psychology; Gene expression; Gene Expression Regulation, Plant - radiation effects; Gene Library; Genes, Plant; Lactuca - genetics; Lactuca - metabolism; Lactuca - radiation effects; Mixed Function Oxygenases - genetics; Mixed Function Oxygenases - metabolism; Molecular and cellular biology; Molecular Sequence Data; Plant Leaves - genetics; Plant Leaves - metabolism; Plant Leaves - radiation effects; Plant Proteins - genetics; Plant Proteins - metabolism; Ultraviolet Rays; Vegetables
• ISSN: 0721-7714; 1432-203X
• DOI: 10.1007/s00299-006-0255-x

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.