外源硫化氢对干旱胁迫下玉米幼苗水分生理特性的影响

采用溶液培养方法,研究了0.01、0.1、0.3、0.6、1 mmol·L-1等不同浓度外源硫化氢供体硫氢化钠(Na HS)对干旱条件下玉米幼苗叶片及根系水分生理特性的影响。结果表明,干旱胁迫显著提高了玉米幼苗根系活力、根系和叶片可溶性糖含量、可溶性蛋白含量和脯氨酸含量,显著降低了叶绿素含量及叶片和根系相对含水量。外源0.01 mmol·L-1Na HS预处理可以显著增加干旱胁迫下根叶相对含水量、脯氨酸含量、叶绿素含量及根系可溶性糖和可溶性蛋白含量,但对叶片可溶性糖和可溶性蛋白含量及根系活力没有显著影响。外源0.1 mmol·L-1和0.3 mmol·L-1Na HS预处理均可以显著增加干旱胁迫下根叶相对含水量、脯氨酸含量、叶绿素含量、根系可溶性糖和可溶性蛋白含量及根系活力,但对叶片可溶性糖和可溶性蛋白含量没有显著影响。外源0.6 mmol·L-1Na HS预处理可以显著增加干旱胁迫下根叶相对含水量、叶绿素a含量、叶片可溶性糖含量、根系可溶性蛋白含量及根系活力,但对根系脯氨酸含量、叶片可溶性蛋白和叶绿素b含量没有显著影响,显著降低了根系可溶性糖和脯氨酸含量。外源1 mmol·L-1Na HS预处理可以显著增加干旱胁迫下根系相对含水量、可溶性蛋白含量及根系活力,但对叶片相对含水量、可溶性蛋白和叶绿素a含量没有显著影响,显著降低了根叶可溶性糖和脯氨酸含量以及叶绿素b含量。这说明,低浓度硫化氢在一定程度上可以增加干旱胁迫下植株的渗透调节物质含量,从而维持自身的水分平衡,提高对干旱环境的适应能力。

Effects of exogenous hydrogen sulfide on water physiological characteristics of maize seedling under drought stress

Effects of different concentrations of exogenous hydrogen sulfide were studied on the physiological characteristics of maize seedlings under drought conditions. The results showed that pretreatment with 0.01 mmol·L^-1 NaHS could significantly increase relative water content (RWC), proline content in root and leaf, chlorophyll content and soluble sugar and soluble protein content in root, but this had no significant effects on soluble sugar content and soluble protein content in leaf under drought stress. Pretreatment with exogenous 0.1 mmol·L^-1 and 0.3 mmol·L^-1 NaHS could significantly increase RWC, proline contents in root and leaf, chlorophyll content, soluble protein and soluble sugar content of root and root activity, but these had no significant impacts on soluble sugar content and soluble protein content in leaf under drought stress. Pretreatment with 0.6 mmol·L^-1 NaHS could significantly increase RWC of root and leaf, chlorophyll A content, soluble sugar content, soluble protein contents in leaf and root activity, but this had no significant effects on proline content, soluble protein in root and chlorophyll B content. Pretreatment with 0.6 mmol·L^-1 NaHS significantly reduced soluble sugar and proline contents in root under drought stress. Pretreatment with 1 mmol·L^-1 NaHS could significantly increase root RWC, soluble protein content and root activity, but this had no significant effects on leaf relative water content, soluble protein and chlorophyll A content. Pretreatment with 1 mmol·L^-1 NaHS could significantly reduce soluble sugar and proline content in root and leaf, and chlorophyll B content under drought stress. Our results suggested that low concentrations of exogenous hydrogen sulfide could maintain the water balance and increase the drought-resistance of plant through increasing the contents of osmoregulation substances.