A downstream mediator in the growth repression limb of the jasmonate pathway.
Wounding plant tissues initiates large-scale changes in transcription coupled to growth arrest, allowing resource diversion for defense. These processes are mediated in large part by the potent lipid regulator jasmonic acid (JA). Genes selected from a list of wound-inducible transcripts regulated by the jasmonate pathway were overexpressed in Arabidopsis thaliana, and the transgenic plants were then assayed for sensitivity to methyl jasmonate (MeJA). When grown in the presence of MeJA, the roots of plants overexpressing a gene of unknown function were longer than those of wild-type plants. When transcript levels for this gene, which we named JASMONATE-ASSOCIATED1 (JAS1), were reduced by RNA interference, the plants showed increased sensitivity to MeJA and growth was inhibited. These gain- and loss-of-function assays suggest that this gene acts as a repressor of JA-inhibited growth. An alternative transcript from the gene encoding a second protein isoform with a longer C terminus failed to repress jasmonate sensitivity. This identified a conserved C-terminal sequence in JAS1 and related genes, all of which also contain Zim motifs and many of which are jasmonate-regulated. Both forms of JAS1 were found to localize to the nucleus in transient expression assays. Physiological tests of growth responses after wounding were consistent with the fact that JAS1 is a repressor of JA-regulated growth retardation.
Department of Plant Molecular Biology, University of Lausane, Biophore, CH-1015 Lausane, Switzerland.
Yuanxin
Y
Yan
Stéphanie
S
Stolz
Aurore
A
Chételat
Philippe
P
Reymond
Marco
M
Pagni
Lucie
L
Dubugnon
Edward E
EE
Farmer
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D003517:Cyclopentanes / Q000378:metabolism* / Q000494:pharmacology*; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D017343:Genes, Plant; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D020411:Oligonucleotide Array Sequence Analysis; D054883:Oxylipins / Q000378:metabolism* / Q000494:pharmacology*; D030821:Plants, Genetically Modified; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D021381:Protein Transport / Q000187:drug effects; D034622:RNA Interference; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
D029681:Arabidopsis Proteins; D003517:Cyclopentanes; C525049:JAS1 protein, Arabidopsis; D009687:Nuclear Proteins; D054883:Oxylipins; D020033:Protein Isoforms; D012333:RNA, Messenger; D012097:Repressor Proteins; C011006:jasmonic acid