Light-harvesting chlorophyll a/b-binding proteins, positively involved in abscisic acid signalling, require a transcription repressor, WRKY40, to balance their function.
The light-harvesting chlorophyll a/b-binding (LHCB) proteins are the apoproteins of the light-harvesting complex of photosystem II. In the present study, we observed that downregulation of any of the six LHCB genes resulted in abscisic acid (ABA)-insensitive phenotypes in seed germination and post-germination growth, demonstrating that LHCB proteins are positively involved in these developmental processes in response to ABA. ABA was required for full expression of different LHCB members and physiologically high levels of ABA enhanced LHCB expression. The LHCB members were shown to be targets of an ABA-responsive WRKY-domain transcription factor, WRKY40, which represses LHCB expression to balance the positive function of the LHCBs in ABA signalling. These findings revealed that ABA is an inducer that fine-tunes LHCB expression at least partly through repressing the WRKY40 transcription repressor in stressful conditions in co-operation with light, which allows plants to adapt to environmental challenges.
Bioinformatics and Systems Biology Laboratory of the Ministry of Education, Scholl of Life Sciences, Tsinghua University, Beijing 100084, PR China.
Rui
R
Liu
Yan-Hong
YH
Xu
Shang-Chuan
SC
Jiang
Kai
K
Lu
Yan-Fen
YF
Lu
Xiu-Jing
XJ
Feng
Zhen
Z
Wu
Shan
S
Liang
Yong-Tao
YT
Yu
Xiao-Fang
XF
Wang
Da-Peng
DP
Zhang
D000040:Abscisic Acid / Q000378:metabolism* / Q000494:pharmacology; D017360:Arabidopsis / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D061146:Chlorophyll Binding Proteins / Q000235:genetics / Q000378:metabolism*; D018506:Gene Expression Regulation, Plant; D018525:Germination; D045342:Light-Harvesting Protein Complexes / Q000235:genetics / Q000378:metabolism; D008190:Lyases / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D045332:Photosystem II Protein Complex / Q000235:genetics / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012639:Seeds / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D015398:Signal Transduction; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
D029681:Arabidopsis Proteins; C423618:CAB2 protein, Arabidopsis; D061146:Chlorophyll Binding Proteins; C513983:LHCB4.1 protein, Arabidopsis; C490432:LHCB5 protein, Arabidopsis; C529795:Lhcb6 protein, Arabidopsis; D045342:Light-Harvesting Protein Complexes; D045332:Photosystem II Protein Complex; D014157:Transcription Factors; C512070:WRKY40 protein, Arabidopsis; D000040:Abscisic Acid; D008190:Lyases; C561080:GUN5 protein, Arabidopsis
Abscisic acid signalling; Arabidopsis thaliana; WRKY40 transcription factor.; light-harvesting chlorophyll a/b-binding protein; post-germination growth; seed germination