title: SIZ1 small ubiquitin-like modifier E3 ligase facilitates basal thermotolerance in Arabidopsis independent of salicylic acid.
abstract: 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.
authors.affiliation: Center for Plant Environmental Stress Physiology, Purdue University, West Lafayette, Indiana 47907, USA.
authors.forename: Chan Yul
authors.initials: CY
authors.lastname: Yoo
authors.forename: Kenji
authors.initials: K
authors.lastname: Miura
authors.forename: Jing Bo
authors.initials: JB
authors.lastname: Jin
authors.forename: Jiyoung
authors.initials: J
authors.lastname: Lee
authors.forename: Hyeong Cheol
authors.initials: HC
authors.lastname: Park
authors.forename: David E
authors.initials: DE
authors.lastname: Salt
authors.forename: Dae-Jin
authors.initials: DJ
authors.lastname: Yun
authors.forename: Ray A
authors.initials: RA
authors.lastname: Bressan
authors.forename: Paul M
authors.initials: PM
authors.lastname: Hasegawa
mesh_terms: 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*
chemical_list: 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