title: The Arabidopsis AP2/ERF transcription factor RAP2.6 participates in ABA, salt and osmotic stress responses.
abstract: AP2/ERF proteins play crucial roles in various biological processes. RAP2.6, an Arabidopsis AP2/ERF family member, has been reported to function in plant response to biotic stress, but whether it also functions in plant response to abiotic stress is not known. In this work, we demonstrate that in wild-type Arabidopsis, the expression of RAP2.6 is responsive to abscisic acid (ABA) and different stress conditions such as high salt, osmotic stress, and cold. Trans-activating ability tests in yeast demonstrate that RAP2.6 could act as a transactivator. RAP2.6 is able to bind to the GCC and CE1 cis-elements, as confirmed by both electrophoretic mobility shift assay (EMSA) and yeast one-hybrid assay. Experiments with RAP2.6-YFP fusion protein indicated that RAP2.6 is nuclear localized. Overexpression of RAP2.6 conferred hypersensitivity to exogenous ABA and abiotic stresses during seed germination and early seedling growth in Arabidopsis. The ABA content in RAP2.6 overexpressor lines decreased after being treated with salt. Furthermore, transcripts of AtABI4 and some stress inducible genes increased, and loss of ABI4 function rescues the hypersensitive phenotype of RAP2.6 overexpression lines under ABA and stress treatment. These results suggest that RAP2.6 participates in abiotic stress, possibly through the ABA-dependent pathway.
authors.affiliation: Shanghai Institute of Plant Physiology and Ecology, Chinese Academy of Sciences, 300 Fenglin Road, Shanghai 200032, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhu
authors.forename: Jiantao
authors.initials: J
authors.lastname: Zhang
authors.forename: Xiaoshu
authors.initials: X
authors.lastname: Gao
authors.forename: Jianhua
authors.initials: J
authors.lastname: Tong
authors.forename: Langtao
authors.initials: L
authors.lastname: Xiao
authors.forename: Wenbin
authors.initials: W
authors.lastname: Li
authors.forename: Hongxia
authors.initials: H
authors.lastname: Zhang
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology; D000064:Acclimatization / Q000235:genetics*; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D004351:Drug Resistance / Q000235:genetics; D018506:Gene Expression Regulation, Plant; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics; D009997:Osmotic Pressure / Q000502:physiology; D030821:Plants, Genetically Modified; D020218:Response Elements; D055049:Salt Tolerance / Q000235:genetics; D012492:Salts / Q000494:pharmacology; D017386:Sequence Homology, Amino Acid; D013312:Stress, Physiological / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D014162:Transfection; D015003:Yeasts / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; C549102:RAP2.6 protein, Arabidopsis; D012492:Salts; D014157:Transcription Factors; D000040:Abscisic Acid