Heterologous Expression of PaMT3-1 Gene from Phytolacca americana Enhances Salt and Osmotic Stress Tolerance in Arabidopsis thaliana

doi:10.13304/j.nykjdb.2024.0300

Abstract

Abstract:

Metallothionein （MT） is a cysteine-rich， low molecular weight metal binding protein， which is crucial for regulating metal homeostasis and enhancing tolerance to abiotic stress. The cadmium-resistant metallothionein gene PaMT3-1 from Phytolacca americana was introduced into Arabidopsis， and the root length， fresh weight， physiological and biochemical indexes of transgenic strains and wild type were determined under 100 mmol·L^-1 NaCl and 200 mmol·L^-1 mannitol stress. The results showed that the expression of PaMT3-1 in transgenic Arabidopsis plants increased resistance to salt and osmotic stress. Compared to the wild-type， the transgenic lines exhibited significantly greater root length， fresh weight， and chlorophyll content. The root lengths of transgenic lines OE1 and OE3 was more than twice that of wild-type line when treated by 100 mmol·L^-1 NaCl and 200 mmol·L^-1 mannitol， and the transgenic lines exhibited a notable increase in proline content and activities of peroxidase （POD）， superoxide dismutase （SOD） and catalase （CAT） under stress conditions. Particularly， the POD activity in OE1 treated by 200 mmol·L^-1 mannitol was 9.85 times higher than that of the control. Above results indicated the transgenic lines had enhancement of osmotic adjustment ability and antioxidant enzyme activities. MT gene responded to abiotic stress in plants through various mechanisms， and could be used as a universal gene resource for plant resistance to various abiotic stresses， which provided a reference for molecular improvement of crop resistance.

Key words: metallothionein, antioxidation, salt stress, osmotic stress

摘要：

金属硫蛋白（metallothionein，MT）是低分子量、富含半胱氨酸的金属结合蛋白，在维持金属稳态和非生物胁迫耐受性中起着重要作用。将来自垂序商陆的具有镉离子抗性的金属硫蛋白基因PaMT3-1转化拟南芥，测定转基因株系和野生型在100 mmol·L^-1 NaCl和200 mmol·L^-1甘露醇胁迫下的根长、鲜重及生理生化指标。结果表明，PaMT3-1提高了转基因拟南芥对盐胁迫和渗透胁迫的抗性。转基因株系的根长、鲜重、叶绿素含量显著高于野生型，其中，转基因株系OE1和OE3经100 mmol·L^-1 NaCl和200 mmol·L^-1甘露醇胁迫后，根长均为野生型的2倍以上。转基因株系在逆境胁迫下的脯氨酸含量和过氧化物酶、超氧化物歧化酶和过氧化氢酶活性较野生型显著增强，其中转基因株系OE1经甘露醇胁迫后的过氧化物酶活性为对照的9.85倍。由此表明，转基因株系的细胞渗透调节能力和抗氧化酶活性显著增强，MT基因通过多种机制响应植物抵御非生物胁迫，可作为植物对多种非生物逆境的通用抗逆基因资源，为作物抗逆分子改良提供了参考。

关键词: 金属硫蛋白, 抗氧化, 盐胁迫, 渗透胁迫

CLC Number:

Yueriyeti Sali, Nuerbiye Yisimayi, Aliya Waili, Lingna CHEN, Yongkun CHEN. Heterologous Expression of PaMT3-1 Gene from Phytolacca americana Enhances Salt and Osmotic Stress Tolerance in Arabidopsis thaliana[J]. Journal of Agricultural Science and Technology, 2025, 27(9): 92-98.

约日耶提·萨力, 努尔比耶·依斯马依, 阿丽亚·外力, 陈凌娜, 陈永坤. 异源表达垂序商陆PaMT3-1基因提高拟南芥盐和渗透胁迫抗性[J]. 中国农业科技导报, 2025, 27(9): 92-98.

Figures/Tables 5

Fig. 1 Plant expression vector diagram for Arabidopsis transformation

Fig. 2 Screening of Arabidopsis seeds with the PaMT3-1 gene and identification of transgenic linesA： Seed resistance screening； B： PCR detection， M—DNA molecular weight ladder DL2000， +—Positive control，-—Negative control， OE1~OE4—Transgenic lines； C： Expression level of PaMT3-1 gene， different capital letters indicate significant differences between different lines at P<0.01 level

Fig. 3 Root length and fresh weight of transgenic Arabidopsis under salt and osmotic stressNote： Different capital and lowercase letters indicate significant differences between different lines at P<0.01 and P<0.05 levels， respectively.

Fig. 4 Phenotype of wild-type and PaMT3-1 overexpressed Arabidopsis under salt and osmotic stress

Fig. 5 Physiological indices of stress resistance in WT and PaMT3-1 overexpressed Arabidopsis under salt and osmotic stressNote： Different capital and lowercase letters indicate significant differences between different lines at P<0.01 and P<0.05 levels， respectively.

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