title: COS1: an Arabidopsis coronatine insensitive1 suppressor essential for regulation of jasmonate-mediated plant defense and senescence.
abstract: The Arabidopsis thaliana CORONATINE INSENSITIVE1 (COI1) gene encodes an F-box protein to assemble SCF(COI1) complexes essential for response to jasmonates (JAs), which are a family of plant signaling molecules required for many essential functions, including plant defense and reproduction. To better understand the molecular basis of JA action, we screened for suppressors of coi1 and isolated a coi1 suppressor1 (cos1) mutant. The cos1 mutation restores the coi1-related phenotypes, including defects in JA sensitivity, senescence, and plant defense responses. The COS1 gene was cloned through a map-based approach and found to encode lumazine synthase, a key component in the riboflavin pathway that is essential for diverse yet critical cellular processes. We demonstrated a novel function for the riboflavin pathway that acts downstream of COI1 in the JA signaling pathway and is required for suppression of the COI1-mediated root growth, senescence, and plant defense.
authors.affiliation: Laboratory of Plant Signal Transduction, Institute of Molecular and Cell Biology, National University of Singapore, 117604 Republic of Singapore.
authors.forename: Shi
authors.initials: S
authors.lastname: Xiao
authors.forename: Liangying
authors.initials: L
authors.lastname: Dai
authors.forename: Fuquan
authors.initials: F
authors.lastname: Liu
authors.forename: Zhilong
authors.initials: Z
authors.lastname: Wang
authors.forename: Wen
authors.initials: W
authors.lastname: Peng
authors.forename: Daoxin
authors.initials: D
authors.lastname: Xie
mesh_terms: D000375:Aging; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000254:growth & development / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism*; D001483:Base Sequence; D003001:Cloning, Molecular; D018744:DNA, Plant / Q000737:chemistry / Q000235:genetics; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000378:metabolism; D015183:Restriction Mapping; D013489:Suppression, Genetic
chemical_list: D029681:Arabidopsis Proteins; C112279:COI1 protein, Arabidopsis; D018744:DNA, Plant; D011994:Recombinant Proteins