干旱胁迫对马铃薯抗旱生理影响及相关基因的表达

Drought Resistance Physiology and Related Gene Expression of Potato upon Drought Stresses

为了探究马铃薯的抗旱机制,本研究以‘宣薯2号’马铃薯为材料,分析了不同程度的干旱胁迫对马铃薯植株抗旱生理的影响和相关基因的表达。结果表明,在重度干旱胁迫下马铃薯的叶片相对含水量大幅下降,但在轻度干旱胁迫下含水量没有显著变化。随着胁迫时间的延长,叶片的相对电导率、叶绿素、类胡萝卜素和可溶性糖含量均逐渐上升,而蒸腾速率、气孔导度和净光合速率逐渐降低。在重度干旱胁迫下,叶片的胞间CO_(2)浓度显著升高,可溶性蛋白含量呈现先升高后下降的变化,而轻度干旱胁迫下可溶性蛋白含量与对照组相比没有显著差异。在轻度和重度干旱下,光合作用相关基因的表达量均上调,且重度干旱下上调水平更高。但在重度干旱处理下,多个抗氧化和干旱相关基因的表达量下调,但轻度和重度干旱处理间的变化不明显。本研究结果丰富了对马铃薯抗旱生理的认知,也为进一步研究马铃薯抗逆性提供科学依据。

Potato cultivar ’Xuanshu2’ was used as the material, and then the effects of various drought stresses on the drought resistance physiological characteristics and related gene expression of potato plants were investigated to explore the drought resistance mechanism of potato. The results showed that the relative water content in potato leaves drastically decreased under severe drought stress, whereas no significantly changed under mild drought stress. Along with the extension of drought stress time, the relative conductivity, chlorophyll, carotenoid and soluble sugar contents in leaves all increased, while the transpiration rate, stomatal conductance and net photosynthetic rate in leaves all decreased. The soluble protein content in leaves first enhanced and then drastically declined, and the intercellular CO_(2)concentration significantly increased under severe drought stress. However, those under mild drought stress were no significant differences with the control. The photosynthetic related gene expression levels were induced under mild and severe drought stresses, and the percentage of up-regulation under severe drought stress was higher. The expression levels of several antioxidant-and drought-related genes were inhibited. However,the changes between mild and severe drough t treatments were not significant. The findings enriched the understanding of the physiology of potato drought resistance. It provides a scientific basis for further study of potato stress resistance.