title: Arabidopsis AtNAP functions as a negative regulator via repression of AREB1 in salt stress response.
abstract: AtNAP , an Arabidopsis NAC transcription factor family gene, functions as a negative regulator via transcriptional repression of AREB1 in salt stress response. AtNAP is an NAC family transcription factor in Arabidopsis and is known to be a positive regulator of senescence. However, its exact function and underlying molecular mechanism in stress responses are not well known. Here, we investigated functional roles of AtNAP in salt stress response. AtNAP expression significantly increased at the seedling stage, with higher expression in both shoots and roots under NaCl, mannitol, and ABA treatments. T-DNA insertional loss-of-function mutants of AtNAP were more tolerant to salt stress than wild type (WT), whereas AtNAP-overexpressing transgenic plants (OXs) were more sensitive to salt stress than WT during germination, seedling development, and mature plant stage. Transcript levels of stress-responsive genes in the ABA-dependent pathway, such as AREB1, RD20, and RD29B, were significantly higher and lower in atnap mutants and AtNAP OXs, respectively, than in WT under salt stress conditions, suggesting that AtNAP might negatively regulate the expression of those genes under salt stress conditions. Indeed, AtNAP repressed the promoter activity of AREB1 under normal and salt stress conditions. These results indicate that AtNAP functions as a negative regulator in the salt stress response. Our results, together with previous studies, suggest that AtNAP functions as a negative regulator in osmotic stress responses, whereas it functions as a positive regulator in senescence.
authors: Department of Molecular Biology, Pusan National University, Busan, 609-735, South Korea.
authors: Hye-Yeon
authors: HY
authors: Seok
authors: Department of Molecular Biology, Pusan National University, Busan, 609-735, South Korea.
authors: Dong-Hyuk
authors: DH
authors: Woo
authors: Department of Molecular Biology, Pusan National University, Busan, 609-735, South Korea.
authors: Linh Vu
authors: LV
authors: Nguyen
authors: Department of Molecular Biology, Pusan National University, Busan, 609-735, South Korea.
authors: Huong T
authors: HT
authors: Tran
authors: Department of Molecular Biology, Pusan National University, Busan, 609-735, South Korea.
authors: Vaishali N
authors: VN
authors: Tarte
authors: Department of Molecular Biology, Pusan National University, Busan, 609-735, South Korea.
authors: Syed Muhammad Muntazir
authors: SM
authors: Mehdi
authors: Department of Molecular Biology, Pusan National University, Busan, 609-735, South Korea.
authors: Sun-Young
authors: SY
authors: Lee
authors: Department of Molecular Biology, Pusan National University, Busan, 609-735, South Korea. moonyh@pusan.ac.kr.
authors: Yong-Hwan
authors: http://orcid.org/0000-0003-1226-2262
authors: YH
authors: Moon
mesh_terms: D017360:Arabidopsis / Q000187:drug effects / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D050976:Basic-Leucine Zipper Transcription Factors / Q000235:genetics / Q000378:metabolism*; D002135:Calcium-Binding Proteins / Q000235:genetics / Q000378:metabolism; D057773:Cold Shock Proteins and Peptides / Q000235:genetics / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D009997:Osmotic Pressure; D030821:Plants, Genetically Modified; D011401:Promoter Regions, Genetic; D036226:Seedlings / Q000235:genetics / Q000254:growth & development; D012965:Sodium Chloride / Q000494:pharmacology; D013312:Stress, Physiological / Q000235:genetics*
chemical_list: D029681:Arabidopsis Proteins; D050976:Basic-Leucine Zipper Transcription Factors; D002135:Calcium-Binding Proteins; D057773:Cold Shock Proteins and Peptides; D012965:Sodium Chloride; C508877:At1g45249 protein, Arabidopsis; C110811:NAP protein, Arabidopsis; C417972:RD20 protein, Arabidopsis; C000595439:RD29B protein, Arabidopsis
keywords: AtNAP; NAC transcription factor; Negative regulator; Osmotic stress; Promoter repression; Salt stress; Senescence; Transcriptional repressor