title: A truncated Arabidopsis NUCLEOSOME ASSEMBLY PROTEIN 1, AtNAP1;3T, alters plant growth responses to abscisic acid and salt in the Atnap1;3-2 mutant.
abstract: Chromatin remodeling is thought to have crucial roles in plant adaptive response to environmental stimulus. Here, we report that, in Arabidopsis, the evolutionarily conserved histone chaperone, NUCLEOSOME ASSEMBLY PROTEIN 1 (NAP1), is involved in plant response to abscisic acid (ABA), a phytohormone important in stress adaptation. We show that simultaneous loss-of-function of AtNAP1;1, AtNAP1;2, and AtNAP1;3 (the triple mutant m123-1) caused a slight hypersensitive response to ABA in seedling growth. Strikingly, the other triple mutant m123-2 containing a different mutant allele of AtNAP1;3, the Atnap1;3-2 allele, showed a hyposensitive response to ABA and a decreased tolerance to salt stress. This ABA-hyposensitive and salt response phenotype specifically associated with the Atnap1;3-2 mutant allele. We show that this mutant allele produced a truncated protein, AtNAP1;3T, which lacks 34 amino acids at the C-terminus compared to the wild-type protein AtNAP1;3. We further show that the heterozygous plants containing the Atnap1;3-2 mutant allele as well as transgenic plants overexpressing AtNAP1;3T exhibit ABA-hyposensitive phenotype. It thus indicates that AtNAP1;3T functions as a dominant negative factor in ABA response. The expression of some ABA-responsive genes, including genes encoding protein kinases and transcription regulators, was found perturbed in the mutant and in the AtNAP1;3T transgenic plants. Taken together, our study uncovered AtNAP1 proteins as positive regulators and AtNAP1;3T as a negative regulator in ABA signaling pathways, providing a novel link of chromatin remodeling to hormonal and stress responses.
authors.affiliation: Institut de Biologie Moléculaire des Plantes (IBMP) du CNRS, Université de Strasbourg (UdS), 12 rue du Général Zimmer, 67084 Strasbourg Cédex, France; State Key Laboratory of Genetic Engineering, Institute of Plant Biology, Department of Biochemistry, School of Life Sciences, Fudan University, Shanghai 200433, People's Republic of China.
authors.forename: Zi-Qiang
authors.initials: ZQ
authors.lastname: Liu
authors.affiliation: Institut de Biologie Moléculaire des Plantes (IBMP) du CNRS, Université de Strasbourg (UdS), 12 rue du Général Zimmer, 67084 Strasbourg Cédex, France; State Key Laboratory of Genetic Engineering, Institute of Plant Biology, Department of Biochemistry, School of Life Sciences, Fudan University, Shanghai 200433, People's Republic of China.
authors.forename: Juan
authors.initials: J
authors.lastname: Gao
authors.affiliation: State Key Laboratory of Genetic Engineering, Institute of Plant Biology, Department of Biochemistry, School of Life Sciences, Fudan University, Shanghai 200433, People's Republic of China. Electronic address: aiwudong@fudan.edu.cn.
authors.forename: Ai-Wu
authors.initials: AW
authors.lastname: Dong
authors.affiliation: Institut de Biologie Moléculaire des Plantes (IBMP) du CNRS, Université de Strasbourg (UdS), 12 rue du Général Zimmer, 67084 Strasbourg Cédex, France. Electronic address: Wen-Hui.Shen@ibmp-ulp.u-strasbg.fr.
authors.forename: Wen-Hui
authors.initials: WH
authors.lastname: Shen
mesh_terms: D000040:Abscisic Acid / Q000494:pharmacology*; D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D017360:Arabidopsis / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D015152:Blotting, Northern; D015153:Blotting, Western; D002843:Chromatin / Q000302:isolation & purification / Q000502:physiology; D044127:Epigenesis, Genetic / Q000235:genetics / Q000502:physiology; D018506:Gene Expression Regulation, Plant / Q000187:drug effects / Q000235:genetics; D008954:Models, Biological; D056490:Nucleosome Assembly Protein 1 / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D030821:Plants, Genetically Modified / Q000187:drug effects / Q000235:genetics / Q000254:growth & development; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012492:Salts / Q000494:pharmacology*; D036226:Seedlings / Q000187:drug effects / Q000235:genetics / Q000254:growth & development
chemical_list: D029681:Arabidopsis Proteins; D002843:Chromatin; D056490:Nucleosome Assembly Protein 1; D012492:Salts; D000040:Abscisic Acid; D000251:Adenosine Triphosphatases; C498859:NAP1 protein, Arabidopsis