SIZ1, a small ubiquitin-related modifier ligase, controls cold signaling through regulation of salicylic acid accumulation.
Low temperature induces several genes to acquire plant cold tolerance. Here, we demonstrate that accumulation of salicylic acid (SA) is involved in the regulation of the DREB1A/CBF3 regulon and plant tolerance to cold stresses. The SA-accumulating mutant siz1 exhibits sensitivity to chilling and freezing conditions and decreased expression of DREB1A/CBF3 and its regulon genes. Reduction of SA levels in siz1 by nahG restored cold sensitivity and down-regulation of these genes. Database analyses and RT-PCR analysis revealed that the ice1 mutation also increased expression of SA-responsive genes. As well as siz1, another SA-accumulating mutant acd6 exhibited freezing sensitivity and the sensitivity was suppressed in acd6 nahG plants. Taken together, these data indicate that SA is involved in regulation of cold signaling.
Miura
Kenji
K
Graduate School of Life and Environmental Sciences, Initiative for the Promotion of Young Scientists' independent Research, University of Tsukuba, Gene Research Center 220, 1-1-1 Ten-nou dai, Tsukuba 305-8572, Japan. kmiura@gene.tsukuba.ac.jp
Ohta
Masaru
M
D000064:Acclimatization; D017487:Ankyrins / Q000378:metabolism; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D003080:Cold Temperature; D015536:Down-Regulation; D018506:Gene Expression Regulation, Plant; D008025:Ligases / Q000235:genetics / Q000378:metabolism*; D006899:Mixed Function Oxygenases / Q000235:genetics / Q000378:metabolism*; D020156:Salicylic Acid / Q000378:metabolism*; D015398:Signal Transduction; D014157:Transcription Factors / Q000378:metabolism
C480953:ACD6 protein, Arabidopsis; D017487:Ankyrins; D029681:Arabidopsis Proteins; C510502:ICE1 protein, Arabidopsis; D014157:Transcription Factors; D006899:Mixed Function Oxygenases; C022619:salicylate 1-monooxygenase; D008025:Ligases; C502552:SIZ1 protein, Arabidopsis; D020156:Salicylic Acid