title: NADPH oxidase AtrbohD and AtrbohF function in ROS-dependent regulation of Na⁺/K⁺homeostasis in Arabidopsis under salt stress.
abstract: Maintaining cellular Na(+)/K(+) homeostasis is pivotal for plant survival in saline environments. However, knowledge about the molecular regulatory mechanisms of Na(+)/K(+) homeostasis in plants under salt stress is largely lacking. In this report, the Arabidopsis double mutants atrbohD1/F1 and atrbohD2/F2, in which the AtrbohD and AtrbohF genes are disrupted and generation of reactive oxygen species (ROS) is pronouncedly inhibited, were found to be much more sensitive to NaCl treatments than wild-type (WT) and the single null mutant atrbohD1 and atrbohF1 plants. Furthermore, the two double mutant seedlings had significantly higher Na(+) contents, lower K(+) contents, and resultant greater Na(+)/K(+) ratios than the WT, atrbohD1, and atrbohF1 under salt stress. Exogenous H(2)O(2) can partially reverse the increased effects of NaCl on Na(+)/K(+) ratios in the double mutant plants. Pre-treatments with diphenylene iodonium chloride, a widely used inhibitor of NADPH oxidase, clearly enhanced the Na(+)/K(+) ratios in WT seedlings under salt stress. Moreover, NaCl-inhibited inward K(+) currents were arrested, and NaCl-promoted increases in cytosolic Ca(2+) and plasma membrane Ca(2+) influx currents were markedly attenuated in atrbohD1/F1 plants. No significant differences in the sensitivity to osmotic or oxidative stress among the WT, atrbohD1, atrbohF1, atrbohD1/F1, and atrbohD2/F2 were observed. Taken together, these results strongly suggest that ROS produced by both AtrbohD and AtrbohF function as signal molecules to regulate Na(+)/K(+) homeostasis, thus improving the salt tolerance of Arabidopsis.
authors: State Key Laboratory of Cotton Biology, Henan Key Laboratory of Plant Stress Biology, College of Life Science, Henan University, Kaifeng 475004, China.
authors: Liya
authors: L
authors: Ma
authors: Huan
authors: H
authors: Zhang
authors: Lirong
authors: L
authors: Sun
authors: Yiheng
authors: Y
authors: Jiao
authors: Guozeng
authors: G
authors: Zhang
authors: Chen
authors: C
authors: Miao
authors: Fushun
authors: F
authors: Hao
mesh_terms: D017360:Arabidopsis / Q000378:metabolism*; D001483:Base Sequence; D017931:DNA Primers; D006706:Homeostasis; D019255:NADPH Oxidases / Q000378:metabolism*; D018384:Oxidative Stress; D018408:Patch-Clamp Techniques; D011188:Potassium / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D012492:Salts; D012964:Sodium / Q000378:metabolism*; D013312:Stress, Physiological
chemical_list: D017931:DNA Primers; D017382:Reactive Oxygen Species; D012492:Salts; D012964:Sodium; D019255:NADPH Oxidases; D011188:Potassium