外源蔗糖显著缓解盐和热胁迫对菠菜PSⅡ颗粒的伤害

以菠菜(Spinacia oleracea)叶片的PSII颗粒为材料, 利用高温(30°C和40°C)和高盐(400 mmol.L-1 和800 mmol.L-1 NaCl)处理, 研究外源蔗糖在盐、热胁迫下对PSII的保护作用。实验结果表明: 盐、热胁迫均对PSII造成伤害, 使PSII的最大光化学效率(Fv/Fm)显著下降, 盐、热胁迫同时存在时对PSII伤害更为严重。在PSII的保存液中加入不同浓度的蔗糖(100-800 mmol.L-1)后, 能显著缓解盐和热及盐热胁迫共同作用对菠菜PSII颗粒的伤害, 并且在一定浓度范围内, 随蔗糖浓度的提高, 保护作用越明显。说明一定浓度的外源蔗糖可以显著缓解盐、热胁迫对PSII的伤害。

Role of Exogenous Sucrose in Protecting PSII Particles Against Salt Stress and Heat Stress

To examine the effect of exogenous sucrose in protecting photosystem II (PSII) against salt and heat stress, PSII (BBY particles of PSII) prepared from the leaves of spinach (Spinacia oleracea) were treated with high temperature (30°C and 40°C) and salt solution (400 mmol.L-1 and 800 mmol.L-1 NaCl), and PSII activity was determined with the plant efficiency analyser (PEA). Salt and heat stress led to serious damage to PSII, inducing a marked decrease of PSII photochemistry (Fv/Fm). Under a combination of salt stress and high temperature, PSII activity was decreased more markedly than that under a single stress. The addition of different concentrations of sucrose (100-800 mmol.L-1) in storage buffer significantly alleviated the damage of high salt (400 mmol.L-1 and 800 mmol.L-1 NaCl) and high temperature (30°C and 40°C), or the combined stresses, to spinach PSII particles. Thus, exogenous sucrose significantly alleviated the damage induced by high salt and temperature to spinach PSII particles in vitro.