title: Overexpression of SeNHX1 improves both salt tolerance and disease resistance in tobacco.
abstract: Recently, we found NHX1, the gene encoding a Na(+)/H(+) exchanger, participated in plant disease defense. Although NHX1 has been confirmed to be involved in plant salt tolerance, whether the NHX1 transgenic plants exhibit both salt tolerance and disease resistance has not been investigated. The T1 progenies of Nicotiana tabacum L. lines expressing SeNHX1 (from Salicornia europaea) were generated for the present study. Compared with PBI-type control plants, SeNHX1 transgenic tobaccos exhibited more biomass, longer root length, and higher K(+)/Na(+) ratio at post germination or seedling stage under NaCl treatment, indicating enhanced salt tolerance. The vacuolar H(+) efflux in SeNHX1 transgenic tobacco was increased after treatment of NaCl with different concentration. Meanwhile, the SeNHX1 transgenic tobaccos showed smaller wilted spot area, less H2O2 accumulation in leaves after infection of Phytophthora parasitica var. nicotianae. Further investigation demonstrated a larger NAD(P)(H) pool in SeNHX1 transgenic tobacco. These evidences revealed that overexpression of SeNHX1 intensified the compartmentation of Na(+) into vacuole under salt stress and improved the ability of eliminating ROS after pathogen attack, which then enhanced salt tolerance and disease resistance simultaneously in tobacco. Our findings indicate NHX1 has potential value in creating crops with both improved salt tolerance and disease resistance.
authors: a Key Laboratory of Plant Molecular Physiology; Institute of Botany ; Chinese Academy of Sciences ; Beijing , PR China.
authors: Xianyang
authors: X
authors: Chen
authors: Hexigeduleng
authors: H
authors: Bao
authors: Jie
authors: J
authors: Guo
authors: Weitao
authors: W
authors: Jia
authors: Yinxin
authors: Y
authors: Li
mesh_terms: D019663:Chenopodiaceae / Q000378:metabolism*; D060467:Disease Resistance / Q000187:drug effects / Q000276:immunology*; D009249:NADP / Q000378:metabolism; D010838:Phytophthora / Q000187:drug effects / Q000502:physiology; D010935:Plant Diseases / Q000276:immunology* / Q000382:microbiology*; D030821:Plants, Genetically Modified; D011522:Protons; D055049:Salt Tolerance / Q000187:drug effects; D012965:Sodium Chloride / Q000494:pharmacology; D014026:Nicotiana / Q000187:drug effects / Q000235:genetics / Q000276:immunology* / Q000502:physiology*; D014617:Vacuoles / Q000187:drug effects / Q000378:metabolism
chemical_list: D011522:Protons; D012965:Sodium Chloride; D009249:NADP
keywords: Na+/H+ exchanger; SeNHX1; disease resistance; salt tolerance; tobacco; vacuolar H+ flux