Arabidopsis De-etiolated 1 （DET1） is one of the key repressors that maintain the etiolated state of seedlings in darkness. The plant hormone gibberellic acid （GA） also participates in this process, and plants defi...Arabidopsis De-etiolated 1 （DET1） is one of the key repressors that maintain the etiolated state of seedlings in darkness. The plant hormone gibberellic acid （GA） also participates in this process, and plants deficient in GA synthesis or signaling show a partially de.etiolated phenotype in darkness. However, how DET1 and the GA pathway work in concert in repressing photomorphogenesis remains largely unknown. In this study, we found that the abundance of DELLA proteins in detl-1 was increased in comparison with that in the wildtype plants. Mutation in DET1 changed the sensitivity of hypocotyl elongation of mutant seedlings to GA and paclobutrazol （PAC）, an inhibitor of GA synthesis. However, we did not find obvious differences between detl-1 and wild-type plants with regard to the bioactive GA content or the GA signaling upstream of DELLAs. Genetic data showed that removal of several DELLA proteins suppressed the detl-1 mutant phenotype more obviously than GA treatment, indicating that DET1 can regulate DELLA proteins via some other mechanisms. In addition, a large-scale transcriptomic analysis revealed that DET1 and DELLAs play antagonistic roles in regulating expression of photosynthetic and cell elongation-related genes in etiolated seedlings. Taken together, our results show that DET1 represses photomorphogenesis in darkness in part by reducing the abundance of DELLA proteins.展开更多
基金This work was supported by grants to H.C. from the National Natural Science Foundation of China （31271294）, the National Program on Key Basic Research Project of China （973 Program： 2011CB100101）, the National High Technology Research and Development Program of China （863 Pro- gram： 2012AA10A304）, the Ministry of Agriculture of China （948 Program： 2011-G2B）, and State Key Laboratory of Protein and Plant Gene Research and grants to X.W.D. from the National Natural Science Foundation of China （31330048, U1031001）, the National Program on Key Basic Research Project of China （973 Program： 2012CB910900）, Peking-Tsinghua Center for Life Sciences, and State Key Laboratory of Protein and Plant Gene Research.ACKNOWLEDGMENTS We thank Renbo Yu, Jie Dong, and other laboratory members for their constructive discussion and help. No conflict of interest declared.
文摘Arabidopsis De-etiolated 1 （DET1） is one of the key repressors that maintain the etiolated state of seedlings in darkness. The plant hormone gibberellic acid （GA） also participates in this process, and plants deficient in GA synthesis or signaling show a partially de.etiolated phenotype in darkness. However, how DET1 and the GA pathway work in concert in repressing photomorphogenesis remains largely unknown. In this study, we found that the abundance of DELLA proteins in detl-1 was increased in comparison with that in the wildtype plants. Mutation in DET1 changed the sensitivity of hypocotyl elongation of mutant seedlings to GA and paclobutrazol （PAC）, an inhibitor of GA synthesis. However, we did not find obvious differences between detl-1 and wild-type plants with regard to the bioactive GA content or the GA signaling upstream of DELLAs. Genetic data showed that removal of several DELLA proteins suppressed the detl-1 mutant phenotype more obviously than GA treatment, indicating that DET1 can regulate DELLA proteins via some other mechanisms. In addition, a large-scale transcriptomic analysis revealed that DET1 and DELLAs play antagonistic roles in regulating expression of photosynthetic and cell elongation-related genes in etiolated seedlings. Taken together, our results show that DET1 represses photomorphogenesis in darkness in part by reducing the abundance of DELLA proteins.
