Possible role of light in the maintenance of EIN3/EIL1 stability in Arabidopsis seedlings.
To examine the mechanism of EIN3-mediated gene expression by ethylene, the expression patterns of ethylene-inducible genes by ethylene were monitored in Col-0 and ethylene signaling mutants. In Col-0, the inducibility of ACC oxidase by ethylene in light-grown seedlings was much higher than in dark-grown seedlings. While the expression of ACC oxidase was highly increased by ethylene not only in Col-0 but in ein3-1 under light treatment, this pattern was completely abrogated in etiolated ein3-1 seedlings, suggesting the expression of EIN3-mediated ACC oxidase genes could be affected by light. To check if the level of EIN3 and EIL1 was regulated by light, cell-free degradation assays were performed. This resulted in the rapid degradation of these proteins within 1h after adding dark-grown cell extracts and this degradation was retarded by light-grown extracts. Here, we propose that light may act as a negative regulator in the destabilization of EIN3/EIL1.
Lee
Jae-Hoon
JH
Department of Biology, College of Science, Yonsei University, Seoul 120-749, Republic of Korea. jae-hoon.lee@yale.edu
Deng
Xing Wang
XW
Kim
Woo Taek
WT
D000594:Amino Acid Oxidoreductases / Q000096:biosynthesis / Q000235:genetics; D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D004268:DNA-Binding Proteins; D003624:Darkness; D005030:Ethylenes / Q000494:pharmacology; D018506:Gene Expression Regulation, Plant; D008027:Light; D009154:Mutation; D009687:Nuclear Proteins / Q000378:metabolism*; D036226:Seedlings / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics; D014157:Transcription Factors / Q000378:metabolism*
D029681:Arabidopsis Proteins; D004268:DNA-Binding Proteins; C494589:EIL1 protein, Arabidopsis; C106987:EIN3 protein, Arabidopsis; D005030:Ethylenes; D009687:Nuclear Proteins; D014157:Transcription Factors; C036216:ethylene; D000594:Amino Acid Oxidoreductases; C059460:1-aminocyclopropane-1-carboxylic acid oxidase