NaCl胁迫对马铃薯组培苗生理生化的影响

Effects of NaCl Stress on Physiology and Biochemistry of Potato Plantlets in Tissue Culture

为探究盐胁迫对马铃薯生理的影响,以耐盐品种‘陇薯5号’组培苗为试材,采取添加0 mmol/L,100 mmol/L,300 mmol/L,500 mmol/L,700 mmol/L和900 mmol/L NaCl的MS培养基模拟盐胁迫的方法,筛选盐胁迫生理测定的适宜盐浓度,并测定适宜胁迫浓度下(0 mmol/L NaCl为对照)、胁迫不同时间(0, 20 h, 24 h,48 h, 72 h和96 h)的过氧化氢酶(CAT)、超氧化物歧化酶(SOD)和过氧化物酶(POD)等抗氧化酶的活性,膜脂过氧化物质丙二醛(MDA)含量,脯氨酸(PRO)、可溶性蛋白和可溶性糖等可溶性物质的含量。结果表明,这7项参数可以作为马铃薯耐盐性鉴定的生理指标,CAT活性与其他指标呈负相关,其他各指标彼此之间均显著或极显著正相关;与对照相比CAT活性整体呈下降趋势,POD活性和SOD活性相对含量上升;MDA含量增幅较小;在24 h时与对照相比,PRO、可溶性蛋白和可溶性糖含量增幅分别为-1%、45.3%和83.8%,而在48 h当PRO相对增幅达380%时,可溶性蛋白和可溶性糖相对增量减少。因此盐胁迫下马铃薯可能通过提高抗氧化酶活性,增加并有序调节可溶性物质来增强耐盐性。本研究为深入研究马铃薯盐胁迫生理机制,筛选和培育耐盐品种提供参考。

In order to investigate the effect of salt stress on potato physiology, ’Longshu No.5’, a salt-tolerant seeding,was used as the test material. The MS medium supplemented with 0 mmol/L, 100 mmol/L, 300 mmol/L, 500 mmol/L,700 mmol/L and 900 mmol/L NaCl was used to simulate the salt stress, screening the suitable salt concentration for salt stress. Seven indicators related to antioxidant, membrane peroxidation and soluble substance regulation pathways were determined at 6 stress time points(0, 20 h, 24 h, 48 h, 72 h and 96 h) under suitable salt stress concentration(0 mmol/L NaCl was control), including catalase, superoxide dismutas and peroxidase activity, malondialdehyde, proline, soluble protein and soluble sugar content. The results showed that these 7 parameters could be used as physiological indexes to identify the salt tolerance of potato. Besides, there was a negative correlation between CAT activity and other indexes, however there was a significant or extremely significant positive correlation between the other indexes. The activity of CAT showed a decrease trend, but the activity of SOD and POD were relatively increase. The relative content of proline, soluble protein and soluble sugar increased by-1%,45.3% and 83.8% at 24 h, respectively. However, the content soluble protein and soluble sugar were decreased when the growth content of proline was 380% at 48 h. Therefore, the study indicated that potato may enhance salt tolerance via enhancing the activity of antioxidant enzymes, increasing and ordering regulation soluble substances at high salt stress. Finally, the study provides a reference for the further study physiological mechanism of salt stress in potato and the selection and cultivation of salt-tolerant varieties.