Two independent light signals cooperate in the activation of the plastid psbD blue light-responsive promoter in Arabidopsis.
The psbD blue light-responsive promoter (BLRP), whose activation has been considered to require strong blue light, is recognized only by SIG5 among six sigma factors of plastid RNA polymerase in Arabidopsis. We found SIG5 transcript accumulation was rapidly induced after a 30-min induction time by blue light (470 nm) with an intensity threshold of 5 micromol m(-2)s(-1) through cryptochromes. Besides this weak blue light, the psbD BLRP activation required the stronger light such as 50 micromol m(-2)s(-1) irrespective of blue or red light (660 nm). Thus, the two independent light signalings, the cryptochrome-mediated signaling to induce SIG5 transcription and the stronger light-dependent signaling, cooperate to activate the psbD BLRP.
Department of Bioscience and Nano-biotechnology Research Center, School of Science and Technology, Kwansei Gakuin University, Gakuen 2-1, Sanda, Hyogo 669-1337, Japan.
Takateru
T
Mochizuki
Yayoi
Y
Onda
Emi
E
Fujiwara
Masamitsu
M
Wada
Yoshinori
Y
Toyoshima
D017360:Arabidopsis / Q000235:genetics* / Q000528:radiation effects; D029681:Arabidopsis Proteins / Q000235:genetics*; D018506:Gene Expression Regulation, Plant / Q000235:genetics* / Q000528:radiation effects; D007700:Kinetics; D008027:Light; D008029:Lighting; D045332:Photosystem II Protein Complex / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics* / Q000528:radiation effects; D021122:Protein Subunits / Q000235:genetics; D014158:Transcription, Genetic / Q000235:genetics / Q000528:radiation effects
D029681:Arabidopsis Proteins; D045332:Photosystem II Protein Complex; D021122:Protein Subunits; C479885:PsbD protein, Arabidopsis