title: Phytochrome B Negatively Affects Cold Tolerance by RegulatingOsDREB1Gene Expression through Phytochrome Interacting Factor-Like Protein OsPIL16 in Rice.
abstract: Cross talk between light signaling and cold signaling has been elucidated in the model plantArabidopsisand tomato, but little is known about their relationship in rice. Here, we report thatphytochrome B(phyB) mutants exhibit improved cold tolerance compared with wild type (WT) rice (Oryza sativaL. cv. Nipponbare). ThephyBmutants had a lower electrolyte leakage index and malondialdehyde concentration than the WT, suggesting that they had greater cell membrane integrity and less lipid peroxidation. Real-time PCR analysis revealed that the expression levels ofdehydration-responsive element binding protein 1(OsDREB1)family genes, which functions in the cold stress response in rice, were increased in thephyBmutant under normal and cold stress conditions. PIFs are central players in phytochrome-mediated light signaling networks. To explore the relationship between rice PIFs andOsDREB1gene expression, we produced overexpression lines of ricePIFgenes.OsDREB1family genes were up-regulated inOsPIL16-overexpression lines, which had improved cold tolerance relative to the WT. Chromatin immunoprecipitation (ChIP)-qPCR assay revealed that OsPIL16 can bind to the N-box region ofOsDREB1Bpromoter. Expression pattern analyses revealed thatOsPIL16transcripts were induced by cold stress and was significantly higher in thephyBmutant than in the WT. Moreover, yeast two-hybrid assay showed that OsPIL16 can bind to rice PHYB. Based on these results, we propose that phyB deficiency positively regulatesOsDREB1expression through OsPIL16 to enhance cell membrane integrity and to reduce the malondialdehyde concentration, resulting in the improved cold tolerance of thephyBmutants.
authors.affiliation: Shandong Rice Research Institute, Shandong Academy of Agricultural Sciences Jinan, China.
authors.forename: Yanan
authors.initials: Y
authors.lastname: He
authors.affiliation: Shandong Rice Research Institute, Shandong Academy of Agricultural SciencesJinan, China; College of Life Sciences, Shandong Normal UniversityJinan, China.
authors.forename: Yaping
authors.initials: Y
authors.lastname: Li
authors.affiliation: Shandong Rice Research Institute, Shandong Academy of Agricultural SciencesJinan, China; College of Life Sciences, Shandong Normal UniversityJinan, China.
authors.forename: Lixin
authors.initials: L
authors.lastname: Cui
authors.affiliation: Shandong Rice Research Institute, Shandong Academy of Agricultural Sciences Jinan, China.
authors.forename: Lixia
authors.initials: L
authors.lastname: Xie
authors.affiliation: Shandong Rice Research Institute, Shandong Academy of Agricultural Sciences Jinan, China.
authors.forename: Chongke
authors.initials: C
authors.lastname: Zheng
authors.affiliation: Shandong Rice Research Institute, Shandong Academy of Agricultural Sciences Jinan, China.
authors.forename: Guanhua
authors.initials: G
authors.lastname: Zhou
authors.affiliation: Shandong Rice Research Institute, Shandong Academy of Agricultural Sciences Jinan, China.
authors.forename: Jinjun
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Shandong Rice Research Institute, Shandong Academy of Agricultural Sciences Jinan, China.
authors.forename: Xianzhi
authors.initials: X
authors.lastname: Xie
keywords: OsDREB1; cold stress; phytochrome B; phytochrome interacting factor-like protein; rice