钙和水杨酸对亚高温胁迫下番茄叶片保护酶活性的调控作用

为了明确Ca²⁺和水杨酸对番茄耐亚高温特性的调控作用，在番茄第1花序第1花开花当天进行昼间亚高温（35 ℃）胁迫处理，并在亚高温处理区喷施10 mmol·L^-1CaCl₂和0.2 mmol·L^-1水杨酸（SA）水溶液，以25 ℃喷施清水为对照，研究叶片保护酶活性（SOD、POD和CAT）和可溶性蛋白质含量的变化.结果表明：亚高温处理使叶片中SOD、CAT、POD活性降低，在处理结束时，SOD、CAT、POD活性分别比对照降低了14.82%、31.84%和 26.34%.而亚高温条件下喷施CaCl₂和SA可以显著降低番茄叶片MDA含量，提高SOD、POD和CAT活性，并使这些指标达到或超过对照水平.说明Ca²⁺和水杨酸对亚高温条件下番茄植株叶片保护酶活性具有正调控作用,这种调控作用可能对亚高温条件下番茄的光合系统起到保护作用.

Regulation effect of calcium and salicylic acid on defense enzyme activities in tomato leaves under sub-high temperature stress.

In order to investigate the regulation effect of Ca2+ and salicylic acid (SA) on the sub-high temperature resistance of tomato plants, the plants were treated with sub-high temperature (35 ℃) at day time during their 1st inflorescence flowering, and CaCl2 (10 mmol·L-1) and SA (02 mmol·L-1) were foliar sprayed to study the variations of the activities of defense enzymes (SOD, POD, and CAT) and the content of soluble protein in tomato leaves, taking spraying clear water under 25 ℃ at day time as the control. The results showed that under the sub-high temperature stress, the SOD, CAT and POD activities in tomato leaves were decreased by 1482%, 3184%, and 2634%, respectively, while spraying CaCl2 (10 mmol·L-1) and SA (02 mmol·L-1) decreased the leaf MDA content and increased the leaf SOD, POD and CAT activities and soluble protein content, compared with the control, indicating that Ca2+ and SA had positive regulation effect on the defense enzyme activities in tomato leaves, which could protect the photosynthetic system of tomato under the sub-high temperature stress to a certain degree.