Correct blue-light regulation of pea Lhcb genes in an Arabidopsis background.
Irradiation of etiolated Arabidopsis or pea, or dim-red-light-grown pea seedling with a single, short (under 10 s) pulse of blue light (threshold at 0.1 mumol/m2) is sufficient to induce the expression of specific members of the Lhcb gene family including the pea Lhcb1*4 gene and the Arabidopsis Lhcb1*3 gene. Other Lhcb genes, such as the pea Lhcb1*3 gene and the Arabidopsis Lhcb1*1 and 1*2 genes are unaffected by this blue-light treatment. Transgenic Arabidopsis bearing pea Lhcb1*3::Gus (beta-glucuronidase), pea Lhcb1*4::Gus or Arabidopsis Lhcb1*3::Gus constructs were used to determine if pea and Arabidopsis employ a similar mechanism to achieve blue-light induced Lhcb expression. Examination of the respective Gus expression patterns in white-light-grown seedlings indicates that the pea promoters are active and properly expressed in the Arabidopsis background. Irradiation of dark-grown Arabidopsis with a 20 s pulse of blue light with a total fluence of 100 mumol/m-2 results in expression of the pea Lhcb1*4::Gus (beta-glucuronidase) construct, but not of the pea Lhcb1*3::Gus construct indicating that the pea promoters respond correctly to blue light in the Arabidopsis background. Fluence-response, time-course and reciprocity characteristics for the blue-light-induced expression of the pea Lhcb1*4::Gus construct closely resemble those of the endogenous Arabidopsis Lhcb genes, confirming the proper interpretation of the Arabidopsis blue-light-signaling mechanism by the pea Lhcb1*4 promoter and suggesting that the signaling mechanisms in the two plants are very similar, if not identical. Fluence response data for the steady-state level of transcript derived from an Arabidopsis Lhcb1*3::Gus construct extending 200 bp upstream of the site of transcription indicate that the blue light responsive elements(s) are contained within this 200 bp region.
Tilghman
J A
JA
Department of Biological Sciences, University of Illinois at Chicago 60607, USA.
Gao
J
J
Anderson
M B
MB
Kaufman
L S
LS
D017360:Arabidopsis; D018506:Gene Expression Regulation, Plant / Q000528:radiation effects*; D017343:Genes, Plant / Q000528:radiation effects*; D008027:Light; D018532:Pisum sativum / Q000235:genetics / Q000254:growth & development; D045322:Photosynthetic Reaction Center Complex Proteins / Q000235:genetics* / Q000528:radiation effects; D010834:Phytochrome / Q000378:metabolism; D030821:Plants, Genetically Modified; D013997:Time Factors; D014158:Transcription, Genetic / Q000528:radiation effects; D019076:Transgenes / Q000528:radiation effects; D014466:Ultraviolet Rays
D045322:Photosynthetic Reaction Center Complex Proteins; D010834:Phytochrome