The SUMO E3 ligase, AtSIZ1, regulates flowering by controlling a salicylic acid‐mediated floral promotion pathway and through affects on FLC chromatin structure

• DOI: 10.1111/j.1365-313x.2007.03359.x
• Publication Date: 2008-01-25T10:49:49Z
• Authors: Jing Bo Jin; Yin Hua Jin; Jiyoung Lee; Kenji Miura; Chan Yul Yoo; Woe‐Yeon Kim; Michael Van Oosten; Youbong Hyun; David E. Somers; Ilha Lee; Dae‐Jin Yun; Ray A. Bressan; Paul M. Hasegawa
• Keywords: Flowering Locus C; Wild type

Summary Loss‐of‐function siz1 mutations caused early flowering under short days. plants have elevated salicylic acid (SA) levels, which are restored to wild‐type levels by expressing nahG , bacterial salicylate hydroxylase. The of was suppressed indicating that SIZ1 represses the transition mainly through suppressing SA‐dependent floral promotion signaling Previous results shown exogenous SA treatment does not suppress late autonomous pathway mutants. However, mutation accelerated time an mutant, luminidependens reducing expression FLOWERING LOCUS C ( FLC ), a repressor. This result suggests promotes expression, possibly SA‐independent pathway. Evidence indicates is required for full activation in late‐flowering FRIGIDA background. Interestingly, increased and locus d fld suggesting repressing FLD. Consistent with this, facilitates sumoylation FLD can be three predicted motifs (i.e. FLDK3R). Furthermore, FLDK3R protoplasts strongly reduced transcription compared this affect linked acetylation histone 4 chromatin. Taken together, suggest repressor only pathway, but also activity sumoylation,