论文题目：Ectopic overexpression of a membrane‐tethered transcription factor geneNAC60from oilseed rape positively modulates programmed cell death and age‐triggered leaf senescence
论文作者：Jingli Yan, Qinqin Chen, Xing Cui, Peiyu Zhao, Shidong Gao, Bo Yang, Jian‐Xiang Liu, Tiantian Tong, Michael K. Deyholos, Yuan‐Qing Jiang
论文摘要：Senescence is an integrative final stage of plant development that is governed by internal and external cues. The NAC (NAM, ATAF1/2, CUC2) transcription factor (TF) family is specific to plants and membrane‐tethered NAC TFs (MTTFs) constitute a unique and sophisticated mechanism in stress responses and development. However, the function of MTTFs in oilseed rape (Brassica napusL.) remains unknown. Here, we report that BnaNAC60 is a MTTF associated with endoplasmic reticulum (ER) membrane. Expression ofBnaNAC60was induced during the progression of leaf senescence. Translocation of BnaNAC60 into nuclei was induced by ER stress and oxidative stress treatments. It binds to the NTLBS motif, rather than the canonical NAC recognition site (NACRS). Overexpression ofBnaNAC60devoid of transmembrane domain, but not the full‐lengthBnaNAC60,induces significant ROS accumulation and hypersensitive response (HR)‐like cell death in both tobacco and oilseed rape protoplasts. Moreover, ectopic overexpressionBnaNAC60devoid of transmembrane domain, but not the full‐lengthBnaNAC60in Arabidopsis also induces precocious leaf senescence. Furthermore, screening and expression profiling identified an array of functional genes that are significantly induced byBnaNAC60expression. Further it was found that BnaNAC60 can activate the promoter activities ofBnaNYC1,BnaRbohD,BnaBFN1,BnaZAT12and multipleBnaVPEsin a dual‐luciferase reporter assay. Electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation coupled to quantitative PCR (ChIP‐qPCR) assays revealed that BnaNAC60 directly binds to the promoter regions of these downstream target genes. To summarize, our data show that BnaNAC60 is a MTTF that modulates cell death, ROS accumulation and leaf senescence.