外源2,3-丁二醇对匍匐翦股颖耐热性的影响

Preliminary study on improving heat resistance of creeping bentgrass by exogenous 2, 3-butaneglycol

摘要:

针对匍匐剪股颖(Agrostis stolonifera)在北过渡带不能安全越夏的问题，本试验模拟设置人工气候热胁迫(37 ℃/32 ℃，昼/夜)，通过喷施 300 μmol/L 2，3-丁二醇(2，3‐butanediol，BD)，测定分析匍匐翦股颖 Penn A4 幼苗在热胁迫第 0、7、14、21、28 天时叶片光合色素、细胞膜损伤程度、抗氧化酶活及渗透调节物质含量的变化，研究外源 BD 对 Penn A4 耐热性的影响。结果表明：常温环境下，经 BD 处理的 Penn A4 各项生理指标较对照组无显著差异(P＞0. 05)；高温胁迫下，随着胁迫时间的延长，BD 处理显著减缓了 Penn A4 叶片光合色素的降解速度(P＜0. 05)，有效抑制了叶片电解质外渗，降低了丙二醛和过氧化氢含量。与高温对照相比，外源 BD 提高了热胁迫下(≤14 d)Penn A4 植株的超氧化物歧化酶、过氧化物酶、抗坏血酸过氧化物酶和谷胱甘肽还原酶活性，促进了游离脯氨酸和可溶性蛋白含量的积累。叶面喷施 BD 通过提高胁迫前期 Penn A4 植株的抗氧化酶活性和渗透调节物质含量，维持了细胞膜的稳定性和活性氧的代谢平衡，缓解了高温造成的氧化损伤，提高了匍匐剪股颖耐热性。

Abstract:

In order to solve the problem that the creeping bentgrass(Agrostis stolonifera) could not survive the summer safely in the north transition zone，this experiment simulated the heat stress of artificial climate(37 ℃/32 ℃，day/night). By spraying 300μ mol/L 2，3‐butanediol(BD)，the changes of leaf photosynthetic pigment，cell membrane damage degree，antioxidant enzyme activity and osmotic regulation substance content in Penn A4 seed‐ lings of creeping bentgrass at 0，7，14，21 and 28 days under heat stress were determined and analyzed. The effect of exogenous BD on heat resistance of Penn A4 was studied in this way. The results showed that under normal tempera‐ ture environment，physiological indexes of Penn A4 treated with BD showed no significant difference compared with the control group(P＞0. 05). The results also implied under high temperature stress，BD treatment significantly slowed down the degradation rate of photosynthetic pigments in Penn A4 leaves(P＜0. 05)，effectively inhibited leaf electrolyte exosmotic，and reduced the contents of malondialdehyde and hydrogen peroxide with the extension of stress time. Compared with the high temperature control，exogenous BD increased the activities of superoxide dis‐ mutase，peroxidase，ascorbate peroxidase and glutathione reductase of Penn A4 plants under heat stress(≤14 d)， and promoted the accumulation of free proline and soluble protein content. In short，foliar spraying of BD could in‐ crease the antioxidant enzyme activity and osmotic adjustment substance content of Penn A4 plants in the early stage of stress，maintain the stability of cell membrane and the metabolic balance of reactive oxygen species，thereby allevi‐ ating the oxidative damage caused by high temperature and improving the plant heat resistance.