The SCF(COI1) ubiquitin-ligase complexes are required for jasmonate response in Arabidopsis.
Xie and colleagues previously isolated the Arabidopsis COI1 gene that is required for response to jasmonates (JAs), which regulate root growth, pollen fertility, wound healing, and defense against insects and pathogens. In this study, we demonstrate that COI1 associates physically with AtCUL1, AtRbx1, and either of the Arabidopsis Skp1-like proteins ASK1 or ASK2 to assemble ubiquitin-ligase complexes, which we have designated SCF(COI1). COI1(E22A), a single amino acid substitution in the F-box motif of COI1, abolishes the formation of the SCF(COI1) complexes and results in loss of the JA response. AtRbx1 double-stranded RNA-mediated genetic interference reduces AtRbx1 expression and affects JA-inducible gene expression. Furthermore, we show that the AtCUL1 component of SCF(COI1) complexes is modified in planta, where mutations in AXR1 decrease the abundance of the modified AtCUL1 of SCF(COI1) and lead to a reduction in JA response. Finally, we demonstrate that the axr1 and coi1 mutations display a synergistic genetic interaction in the double mutant. These results suggest that the COI1-mediated JA response is dependent on the SCF(COI1) complexes in Arabidopsis and that the AXR1-dependent modification of the AtCUL1 subunit of SCF(COI1) complexes is important for JA signaling.
Xu
Linghui
L
Institute of Biotechnology Research, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
Liu
Fuquan
F
Lechner
Esther
E
Genschik
Pascal
P
Crosby
William L
WL
Ma
Hong
H
Peng
Wen
W
Huang
Dafang
D
Xie
Daoxin
D
D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D017360:Arabidopsis / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D044842:Cullin Proteins; D003517:Cyclopentanes / Q000494:pharmacology*; D015870:Gene Expression; D008025:Ligases / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D054883:Oxylipins; D010453:Peptide Synthases / Q000235:genetics / Q000378:metabolism*; D010937:Plant Growth Regulators / Q000494:pharmacology; D030821:Plants, Genetically Modified; D044843:SKP Cullin F-Box Protein Ligases; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction / Q000187:drug effects; D020798:Two-Hybrid System Techniques; D044767:Ubiquitin-Protein Ligases; D014452:Ubiquitins / Q000378:metabolism
D029681:Arabidopsis Proteins; C112279:COI1 protein, Arabidopsis; D018797:Cell Cycle Proteins; C100318:Cullin 1; D044842:Cullin Proteins; D003517:Cyclopentanes; D054883:Oxylipins; D010937:Plant Growth Regulators; D014452:Ubiquitins; C011006:jasmonic acid; D044843:SKP Cullin F-Box Protein Ligases; D044767:Ubiquitin-Protein Ligases; D008025:Ligases; D010453:Peptide Synthases