低温弱光胁迫下外源ASA与CaCl_2对菊花叶片AsA-GSH循环的影响

Effects of Exogenous Acetylsalicylic Acid and Calcium Chloride on AsA-GSH Cycle in Chrysanthemum Leaves under Stress of Low Temperature and Poor Light

以切花菊品种‘神马’为材料,研究了低温弱光胁迫下乙酰水杨酸(ASA)和CaCl_2处理对菊花叶片抗坏血酸-谷胱甘肽循环中防御系统酶活性和抗氧化物质含量的影响,探讨了ASA和CaCl_2缓解菊花对低温弱光胁迫效应的可能的生理机制。结果表明:低温弱光胁迫下,菊花叶片超氧化物歧化酶(SOD)、抗坏血酸过氧化物酶(APX)、谷胱甘肽还原酶(GR)、单脱氢抗坏血酸还原酶(MDAR)和脱氢抗坏血酸还原酶(DHAR)的活性均呈不同程度先上升后下降趋势,但与对照相比,外源ASA、CaCl_2和ASA+CaCl_2处理显著提高了菊花叶片SOD、APX、GR、MDAR和DHAR活性,其中以ASA+CaCl_2处理的效果最为显著。低温弱光胁迫下,菊花叶片还原型抗坏血酸(As A)和还原型谷胱甘肽(GSH)含量减少,氧化型抗坏血酸(DAs A)和氧化型谷胱甘肽(GSSG)含量增加,但与对照相比,外源ASA、CaCl_2和ASA+CaCl_2处理显著减小了As A和GSH含量的下降幅度以及DHA和GSSG含量的上升幅度,并减少了菊花叶片H2O2的含量。表明低温弱光胁迫下,外源ASA和CaCl_2处理可通过提高As A-GSH循环系统的代谢活动,减轻了活性氧对菊花幼苗的伤害,从而提高了菊花对低温弱光的耐性,而且ASA与CaCl_2复配处理优于ASA或CaCl_2单独处理。

Taking cut flower chrysanthemum ‘Shenma’ as testmaterial, the effects of acetylsalicylic acid （ASA） and CaCl2treatments on antioxidant enzyme activities and antioxidant substances in the AsA-GSH cycle of the leaves ofchrysanthemum under stress of low temperature and poor light were investigated, and the possible physiological mechanismsof ASA and CaCl2 was discussed. The results showed that under the stress of low temperature and poor light, the activities ofperoxide dismutase （SOD）, ascorbate peroxidase （APX）, glutathione reductase （GR）, monodehydroascorbate reductase（MDAR） and dehydroascorbate reductase （DHAR） of the leaves of chrysanthemum increased at first and then decreased inall treatments, but they increased significantly by the treatments of ASA and CaCl2 addition compared with those of controls,and the effects of Induced resistance effect of ASA and CaCl2 mixture treatments was better than single ASA orCaCl2.treatment. Also, under the stress of low temperature and poor light, contents of ascorbate （AsA） and glutathione （GSH）decreased while the contents of dehydroascorbate （DAsA） and oxidized glutathione （GSSG） increased in the leaves ofchrysanthemum, but ASA, CaCl2 and ASA＋CaCl2 treatments reduced the scope of reduction of the contents of AsA and GSHand the scope of increasing of the contents of DAsA and GSSG of the leaves of chrysanthemum compared with the controls,and also ASA, CaCl2 and ASA＋CaCl2 treatments reduced significantly the contents of H2O2 of the leaves of chrysanthemum.The results indicated that ASA and CaCl2 treatments could lighten the damage from H2O2 by increasing the AsA-GSH cyclesystems, so that increase the damage from the stress of low temperature and poor light, Induced resistance effect of ASA andCaCl2 mixture was better than single ASA or CaCl2.