title: 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.
authors.affiliation: Research Planning & Information Division, National Institute of Agricultural Biotechnology, Suwon, Korea. jongsug@rda.go.kr
authors.forename: Jong-Sug
authors.initials: JS
authors.lastname: Park
authors.forename: Myoung-Gun
authors.initials: MG
authors.lastname: Choung
authors.forename: Jung-Bong
authors.initials: JB
authors.lastname: Kim
authors.forename: Bum-Soo
authors.initials: BS
authors.lastname: Hahn
authors.forename: Jong-Bum
authors.initials: JB
authors.lastname: Kim
authors.forename: Shin-Chul
authors.initials: SC
authors.lastname: Bae
authors.forename: Kyung-Hee
authors.initials: KH
authors.lastname: Roh
authors.forename: Yong-Hwan
authors.initials: YH
authors.lastname: Kim
authors.forename: Choong-Ill
authors.initials: CI
authors.lastname: Cheon
authors.forename: Mi-Kyung
authors.initials: MK
authors.lastname: Sung
authors.forename: Kang-Jin
authors.initials: KJ
authors.lastname: Cho
mesh_terms: D000217:Acyltransferases / Q000235:genetics / Q000378:metabolism; D000429:Alcohol Oxidoreductases / Q000235:genetics / Q000378:metabolism; D000872:Anthocyanins / Q000378:metabolism*; D015152:Blotting, Northern; D020224:Expressed Sequence Tags; D018506:Gene Expression Regulation, Plant / Q000528:radiation effects*; D015723:Gene Library; D017343:Genes, Plant; D018545:Lactuca / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects*; D006899:Mixed Function Oxygenases / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism / Q000528:radiation effects*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D014466:Ultraviolet Rays
chemical_list: D000872:Anthocyanins; D010940:Plant Proteins; D006899:Mixed Function Oxygenases; D000429:Alcohol Oxidoreductases; C056570:dihydroflavanol 4-reductase; C048797:flavanone 3-dioxygenase; D000217:Acyltransferases; C055296:6'-deoxychalcone synthase; C020141:flavanone synthetase