SIZ1 small ubiquitin-like modifier E3 ligase facilitates basal thermotolerance in Arabidopsis independent of salicylic acid.
Small ubiquitin-like modifier (SUMO) conjugation/deconjugation to heat shock transcription factors regulates DNA binding of the peptides and activation of heat shock protein gene expression that modulates thermal adaptation in metazoans. SIZ1 is a SUMO E3 ligase that facilitates SUMO conjugation to substrate target proteins (sumoylation) in Arabidopsis (Arabidopsis thaliana). siz1 T-DNA insertional mutations (siz1-2 and siz1-3; Miura et al., 2005) cause basal, but not acquired, thermosensitivity that occurs in conjunction with hyperaccumulation of salicylic acid (SA). NahG encodes a salicylate hydroxylase, and expression in siz1-2 seedlings reduces endogenous SA accumulation to that of wild-type levels and further increases thermosensitivity. High temperature induces SUMO1/2 conjugation to peptides in wild type but to a substantially lesser degree in siz1 mutants. However, heat shock-induced expression of genes, including heat shock proteins, ascorbate peroxidase 1 and 2, is similar in siz1 and wild-type seedlings. Together, these results indicate that SIZ1 and, by inference, sumoylation facilitate basal thermotolerance through processes that are SA independent.
Yoo
Chan Yul
CY
Center for Plant Environmental Stress Physiology, Purdue University, West Lafayette, Indiana 47907, USA.
Miura
Kenji
K
Jin
Jing Bo
JB
Lee
Jiyoung
J
Park
Hyeong Cheol
HC
Salt
David E
DE
Yun
Dae-Jin
DJ
Bressan
Ray A
RA
Hasegawa
Paul M
PM
D017360:Arabidopsis / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D000076249:Heat Shock Transcription Factors; D006360:Heat-Shock Proteins / Q000378:metabolism; D008025:Ligases / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D009154:Mutation; D018085:Regulon / Q000502:physiology; D020156:Salicylic Acid / Q000378:metabolism*; D025841:Small Ubiquitin-Related Modifier Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D013696:Temperature; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D044767:Ubiquitin-Protein Ligases / Q000235:genetics / Q000378:metabolism / Q000502:physiology*
D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins; D000076249:Heat Shock Transcription Factors; D006360:Heat-Shock Proteins; D025841:Small Ubiquitin-Related Modifier Proteins; D014157:Transcription Factors; D044767:Ubiquitin-Protein Ligases; D008025:Ligases; C502552:SIZ1 protein, Arabidopsis; D020156:Salicylic Acid