Low temperature regulates Arabidopsis Lhcb gene expression in a light-independent manner.
Low temperature treatment of dark-grown seedlings of Arabidopsis thaliana results in a rapid increase in the amount of mRNAs encoding for the major polypeptides of the light-harvesting complex of photosystem II (Lhcb1 genes). This increase is transient and seems to be due mainly to the accumulation of Lhcb1*3 transcripts, indicating that low temperature differentially regulates the expression of the Arabidopsis Lhcb1 gene family in the dark. A 1.34 kb fragment of the Lhcb1*3 promoter is sufficient to confer low temperature regulation to a reporter gene in transgenic Arabidopsis etiolated seedlings, suggesting that the regulation is occurring at the transcriptional level. The cold-induced accumulation of Lhcb1*3 mRNA is not part of a general response to stressful conditions since no accumulation is detected in response to water stress, anaerobiosis or salt stress. The amount of Lhcb1*3 mRNA decrease in response to exogenous abscisic acid (ABA) suggesting that this phytohormone acts as a negative regulator. Moreover, the accumulation of Lhcb1*3 mRNAs in cold-treated ABA deficient etiolated seedlings is higher than that of wild-type and ABA insensitive etiolated seedlings, indicating that low temperature regulation of Lhcb1*3 is not mediated by ABA.
Capel
J
J
Departamento de Biología Molecular y Virología Vegetal, CIT-INIA, Madrid, Spain.
Jarillo
J A
JA
Madueño
F
F
Jorquera
M J
MJ
Martínez-Zapater
J M
JM
Salinas
J
J
D000040:Abscisic Acid / Q000378:metabolism / Q000494:pharmacology; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000528:radiation effects; D003080:Cold Temperature; D018506:Gene Expression Regulation, Plant / Q000187:drug effects / Q000528:radiation effects; D017343:Genes, Plant; D008027:Light; D005810:Multigene Family; D045322:Photosynthetic Reaction Center Complex Proteins / Q000235:genetics; D045332:Photosystem II Protein Complex; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism
D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D012333:RNA, Messenger; D018749:RNA, Plant; D000040:Abscisic Acid