盐胁迫对薄皮甜瓜‘灰鼠’离子平衡、膜脂过氧化及渗透调节物质积累的影响

Effects of salt stress on ion balance, membrane lipid peroxidation, and osmotic regulation substance accumulation in thin skin muskmelon ‘Huishu’

  • 摘要: 【目的】 研究薄皮甜瓜‘灰鼠’对盐(NaCl)胁迫的生理响应机制,为甜瓜栽培及示范推广提供理论依据。 【方法】 采用基质盆栽试验,分别观测其在100 mmol/L NaCl胁迫5 d及胁迫20 d后在幼苗生长、离子稳态、抗氧化酶系统及渗透调节物质的变化情况。 【结果】 盐胁迫抑制了幼苗生长,破坏了离子平衡及抗氧化系统。甜瓜株高、叶柄长、叶片数随盐胁迫时间的延长而显著降低,茎粗、叶柄粗、叶片厚度随盐胁迫时间的延长而显著增加。盐胁迫后Na+外排速度降低,Na+含量增加,K+外流流速增大,K+含量减少。丙二醛含量显著增加,SOD、POD、CAT酶活性先升高后降低;可溶性糖、可溶性蛋白、游离脯氨酸含量显著增加。 【结论】 盐胁迫下,薄皮甜瓜‘灰鼠’通过限制自身生长,增加叶片Na+含量、减少K+含量,并提高抗氧化酶活性,积累更多的渗透调节物质缓解盐胁迫。

     

    Abstract: 【Objective】 To explore the physiological response mechanism of thin-skinned melon ‘Huishu’ to salt (NaCl) stress and provide theoretical basis for melon cultivation, demonstration and promotion. 【Methods】 In this study, a substrate pot experiment was conducted to observe the changes in seedling growth, ion homeostasis, antioxidant enzyme system, and osmoregulation substances after 100 mmol/L NaCl short-term stress (5 d) and long-term stress (20 d). 【Results】 Salt stress inhibited seedling growth, destroyed ion balance and antioxidant systems. The plant height, petiole length, and leaf number decreased significantly with the prolongation of salt stress time, while the diameter, petiole diameter, and leaf thickness increased significantly with the prolongation of salt stress time. After salt stress, the Na+ efflux velocity decreased, the Na+ content increased, the K+ outflow velocity increased, and the K+ content decreased. The content of malondialdehyde increased significantly. The content of malondialdehyde significantly increased, and the activities of SOD, POD, and CAT enzymes first increased and then decreased; the content of soluble sugar, soluble protein, and free proline increased significantly. 【Conclusion】 Under salt stress, the thin-skinned melon ‘Huishu’ responds to salt stress by limiting its own growth, increasing the Na+ content and reducing the K+ content of its leaves, improving the antioxidant enzyme system, and accumulating more osmoregulation substances.

     

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