SIZ1 small ubiquitin-like modifier E3 ligase facilitates basal thermotolerance in Arabidopsis independent of salicylic acid

Chan Yul Yoo, Kenji Miura, Jing Bo Jin, Jiyoung Lee, Hyeong Cheol Park, David E. Salt, Dae-Jin Yun, Ray A. Bressan, Paul M. Hasegawa

Research output: Contribution to journalArticlepeer-review

137 Citations (Scopus)


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, thermo-sensitivity 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.

Original languageEnglish
Pages (from-to)1548-1558
Number of pages11
JournalPlant Physiology
Issue number4
Publication statusPublished - Dec 2006


  • heat-shock-protein
  • stress transcription factors
  • plant-disease resistance
  • molecular chaperones
  • DNA-binding
  • in-vivo
  • acquired thermotolerance
  • multiprotein complex
  • SUMO-1 modification
  • temperature stress

Cite this