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Two independent light signals cooperate in the activation of the plastid psbD blue light‐responsive promoter in Arabidopsis
Author(s) -
Mochizuki Takateru,
Onda Yayoi,
Fujiwara Emi,
Wada Masamitsu,
Toyoshima Yoshinori
Publication year - 2004
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2004.06.052
Subject(s) - blue light , cryptochrome , arabidopsis , red light , transcription (linguistics) , shade avoidance , plastid , light intensity , rna polymerase , chemistry , biology , microbiology and biotechnology , gene , biophysics , rna , biochemistry , chloroplast , botany , physics , optoelectronics , optics , circadian clock , linguistics , philosophy , mutant
The psbD blue light‐responsive promoter (BLRP), whose activation has been considered to require strong blue light, is recognized only by SIG5 among six σ 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 μmol m −2 s −1 through cryptochromes. Besides this weak blue light, the psbD BLRP activation required the stronger light such as 50 μmol 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.