A vacuolar Na+/H+ antiporter gene, IbNHX2, enhances salt and drought tolerance in transgenic sweetpotato
A vacuolar Na+/H+ antiporter gene, IbNHX2, enhances salt and drought tolerance in transgenic sweetpotato
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DOI：
10.1016/j.scienta.2016.01.027
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发表时间：
2016-03
影响因子：
4.3
通讯作者：
B. Wang;H. Zhai;Shaozhen He;Huan Zhang;Zhiyuan Ren;Dongdong Zhang;Qingchang Liu
中科院分区：
文献类型：
--
作者：
B. Wang;H. Zhai;Shaozhen He;Huan Zhang;Zhiyuan Ren;Dongdong Zhang;Qingchang Liu
植物液泡Na+/H+反向转运蛋白（NHX）通过将Na+从细胞质中分隔到液泡中，在植物对非生物胁迫的适应中起着重要作用。本研究从耐盐甘薯（Ipomoea batatas（L.）林。）ND 98线。IbNHX 2由542个氨基酸残基组成，具有保守的阿米洛利结合结构域“FFIYLLPPI”和阳离子/H+交换结构域，与其他植物物种中鉴定的液泡Na+/H+反向转运蛋白具有较高的氨基酸同一性（73.72-96.13%）。IbNHX 2基因组DNA含有14个外显子和13个内含子。用脱落酸（阿坝）、NaCl和聚乙二醇（PEG）诱导IbNHX 2的表达。其过表达显著增强了转基因甘薯的耐盐性和耐旱性。结果表明，转基因甘薯叶片中脯氨酸含量、超氧化物歧化酶（SOD）活性和光合作用活性显著提高，丙二醛（MDA）和H2 O2含量显著降低。在盐胁迫和干旱胁迫下，转基因植株中的吡咯啉-5-羧酸合酶（P5 CS）、SOD、过氧化氢酶（CAT）、玉米黄嘌呤环氧化酶（ZEP）、9-顺式环氧类胡萝卜素双加氧酶（NCED）、醛氧化酶（AO）、胚胎发育后期丰富蛋白（莱亚）、psbA和磷酸核酮糖激酶（phosphoribulokinase）等逆境响应基因表达上调。这些结果表明IbNHX 2在甘薯耐盐性和耐旱性中具有明显的作用。IbNHX 2基因具有提高植物耐盐性和耐旱性的潜力。
Plant vacuolar Na+/H+antiporters (NHX) play a critical role in adaption to abiotic stresses by compartmentalizing Na+into vacuoles from the cytosol. In this study, a vacuolar Na+/H+antiporter gene, namedIbNHX2, was isolated and characterized from salt-tolerant sweetpotato (Ipomoea batatas(L.) Lam.) line ND98. IbNHX2 consisted of 542 amino acid residues with a conserved binding domain ‘FFIYLLPPI’ for amiloride and a cation/H+exchanger domain, and shared a high amino acid identity (73.72–96.13%) with the identified vacuolar Na+/H+antiporters in other plant species. The genomic DNA ofIbNHX2contained 14 exons and 13 introns. Expression ofIbNHX2was induced by abscisic acid (ABA), NaCl and polyethylene glycol (PEG). Its overexpression significantly enhanced salt and drought tolerance in the transgenic sweetpotato. An significant increase of proline content and superoxide dismutase (SOD) and photosynthesis activities and significant reduction of malonaldehyde (MDA) and H2O2content were found in the transgenic sweetpotato plants. Up-regulation of the stress-responsive genes encoding pyrroline-5-carboxylate synthase (P5CS), SOD, catalase (CAT), zeaxanthinepoxidase (ZEP), 9-cis-epoxycarotenoid dioxygenase (NCED), aldehyde oxidase (AO), late embryogenesis abundant protein (LEA), psbA and phosphoribulokinase (PRK) in the transgenic plants was also found under salt and drought stresses. The overall results demonstrate the explicit role ofIbNHX2in conferring salt and drought tolerance of sweetpotato. TheIbNHX2gene has the potential to be used for improving salt and drought tolerance of plants.