Exogenous spermine-induced expression of SlSPMS gene improves salinity-alkalinity stress tolerance by regulating the antioxidant enzyme system and ion homeostasis in tomato.
Exogenous spermine-induced expression of SlSPMS gene improves salinity-alkalinity stress tolerance by regulating the antioxidant enzyme system and ion homeostasis in tomato.
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DOI：
10.1016/j.plaphy.2020.09.033
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发表时间：
2020-10
期刊：
影响因子：
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通讯作者：
Jiwen Xu;Jianyu Yang;Zijian Xu;Dingkang Zhao;Xiaohui Hu
中科院分区：
文献类型：
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作者：
Jiwen Xu;Jianyu Yang;Zijian Xu;Dingkang Zhao;Xiaohui Hu
研究了外源精胺（Spm）对番茄幼苗抗盐碱胁迫的作用，发现番茄Spm合成酶基因（SlSPMS）参与了这一调控过程。在正常条件下和盐碱条件下培养的番茄幼苗，每隔2 d分别用100 ml单一浓度的Hoagland营养液100 ml混合液（5 ml 300 mmol/L NaCl、45 ml 300 mmol/L Na 2SO 4、45 ml 300 mmol/L NaHCO 3和5 ml 300 mmol/L Na 2CO 3（pH = 8.90））灌溉。0.5 mM Spm预处理提高了番茄叶片中的超氧化物歧化酶（SOD; EC 1.15.1.1）活性、过氧化氢酶（CAT; EC 1.11.1.6）活性、抗坏血酸过氧化物酶（APX; EC 1.6.4.2）活性和谷胱甘肽还原酶（GR; EC1.11.1.11）活性，并降低了内源性过氧化氢（H2 O2）含量、丙二醛（MDA）含量和相对电导率（REC）。Spm预处理番茄幼苗后，Na+含量下降，K+浓度上升。结果表明，在盐碱胁迫下，经病毒诱导基因沉默的S1 SPMS的抗氧化酶活性和Na+含量均低于正常番茄幼苗，而K+含量高于正常番茄幼苗，表明其耐盐碱性较低。外源Spm不能重建SlSPMS基因沉默番茄幼苗对盐碱胁迫的耐受性。综上所述，外源Spm可以诱导SlSPMS的表达水平，从而调节盐碱环境中番茄幼苗抗氧化酶系统和离子稳态，提高番茄幼苗抗盐碱胁迫的能力。
The study tested the function of exogenous spermine (Spm) in resisting salinity–alkalinity stress in tomato seedlings and found that tomato Spm synthase gene (SlSPMS)was involved in this regulation. The tomato seedlings cultivated in normal conditions or salinity–alkalinity conditions were irrigated with 100 ml one strength Hoagland nutrient solution 100 ml mixed solution (5 ml 300 mmol/L NaCl, 45 ml 300 mmol/L Na2SO4, 45 ml 300 mmol/L NaHCO3, and 5 ml 300 mmol/L Na2CO3(pH = 8.90)) every 2 days, respectively. The 0.5 mM Spm pretreatment improved superoxide dismutase (SOD; EC 1.15.1.1) activity, catalase (CAT; EC 1.11.1.6) activity, ascorbate peroxidase (APX; EC 1.11.1.11) activity, and glutathione reductase (GR; EC 1.6.4.2) activity and decreased endogenous hydrogen peroxide (H2O2) content, malondialdehyde (MDA) content, and relative electrical conductivity (REC) in tomato leaves. Na+content declined and K+concentration rose in tomato seedlings when pre-treated with Spm. However the results showed that under salinity–alkalinity stress, silencing ofSlSPMSwith virus-induced gene silencing had lower antioxidant enzyme activities and higher Na+content and lower K+content than normal tomato seedlings, meaning that they had low salinity–alkalinity tolerance. Exogenous Spm could not reconstruct the tolerance to salinity–alkalinity stress inSlSPMSgene-silencing tomato seedlings. Taken together, exogenous Spm could induce the expression level ofSlSPMS, which regulated the antioxidant enzyme system and ion homeostasis in tomato seedlings living in salinity–alkalinity environment, thereby improving the ability of tomato seedlings to resist salinity–alkalinity stress.