title: Nia1 and Nia2 are involved in exogenous salicylic acid-induced nitric oxide generation and stomatal closure in Arabidopsis.
abstract: Phytohormone salicylic acid (SA) plays important roles in plant responses to environmental stress. However, knowledge about the molecular mechanisms for SA affecting the stomatal movements is limited. In this paper, we demonstrated that exogenous SA significantly induced stomatal closure and nitric oxide (NO) generation in Arabidopsis guard cells based on genetic and physiological data. These effects were significantly inhibited by the NO scavenger c-PTIO, NO synthase (NOS) inhibitor L-NAME or nitrate reductase suppressor tungstate respectively, implying that NOS and nitrate reductase (NR) participate in SA-evoked stomatal closing. Furthermore, the effects of SA promotion of stomatal closure and NO synthesis are significantly suppressed in NR single mutants of nia1, nia2 or double mutant nia1/nia2, compared with the wild type plants. This suggests that both Nia1 and Nia2 are involved in SA-stimulated stomatal closure. In addition, pharmacological experiments showed that protein kinases, cGMP and cADPR are involved in SA-mediated NO accumulation and stomatal closure induced by SA in Arabidopsis.
authors.affiliation: Henan Key Laboratory of Plant Stress Biology, College of Life Science, Henan University, Kaifeng 475004, China.
authors.forename: Fushun
authors.initials: F
authors.lastname: Hao
authors.forename: Shiling
authors.initials: S
authors.lastname: Zhao
authors.forename: Huan
authors.initials: H
authors.lastname: Dong
authors.forename: Huan
authors.initials: H
authors.lastname: Zhang
authors.forename: Lirong
authors.initials: L
authors.lastname: Sun
authors.forename: Chen
authors.initials: C
authors.lastname: Miao
mesh_terms: D017360:Arabidopsis / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D036563:Cyclic ADP-Ribose / Q000378:metabolism; D006152:Cyclic GMP / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D009536:Niacinamide / Q000494:pharmacology; D050901:Nitrate Reductase / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism* / Q000494:pharmacology; D009599:Nitroprusside / Q000494:pharmacology; D010069:Oxadiazoles / Q000494:pharmacology; D054046:Plant Stomata / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D011494:Protein Kinases / Q000378:metabolism; D011810:Quinoxalines / Q000494:pharmacology; D020156:Salicylic Acid / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects
chemical_list: C095284:1H-(1,2,4)oxadiazolo(4,3-a)quinoxalin-1-one; D029681:Arabidopsis Proteins; D010069:Oxadiazoles; D047428:Protein Kinase Inhibitors; D011810:Quinoxalines; D036563:Cyclic ADP-Ribose; D009599:Nitroprusside; D009536:Niacinamide; D009569:Nitric Oxide; D050901:Nitrate Reductase; D011494:Protein Kinases; D006152:Cyclic GMP; D020156:Salicylic Acid