外源脱落酸对低温胁迫下圆柏属植物幼苗生理特性的影响

Effect of exogenous abscisic acid on physiological characteristics of Sabina seedlings under low temperature stress

以3 a生圆柏和祁连圆柏幼苗为材料,采用不同浓度脱落酸(ABA)预处理两种圆柏属幼苗,测定-4℃低温胁迫处理第9 d叶片相对含水量(RWC)、相对电导率(REC)、丙二醛(MDA)、可溶性糖(SS)、可溶性蛋白(SP)、脯氨酸(Pro)和类胡萝卜素(Car)含量及超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、抗坏血酸氧化酶(APX)和谷胱甘肽还原酶(GR)活性,分析外源ABA对低温胁迫下圆柏属植物叶片膜脂过氧化和渗透调节物质的影响,为培育较多品种的抗冷冻常绿植物提供理论依据.结果表明:低温胁迫下,一定浓度的ABA预处理能有效保护幼苗叶片膜系统的稳定性、增加渗透调节物质含量和提高抗氧化酶活性,其中30 mg·L-1ABA预处理对提高圆柏抗寒性效果最好,40 mg·L-1ABA预处理对提高祁连圆柏抗寒性效果最好,且在外源ABA预处理下,祁连圆柏的抗寒性比圆柏的强.因此,施用适合浓度的ABA在提高圆柏属植物抗寒性方面具有较好的应用价值.

The effect of exogenous ABA on membrane lipid peroxidation,osmotic regulation substances and antioxidant enzyme activities in the leaves of Sabina species under low temperature stress at -4 ℃ for 9 days was analyzed by determining the relative water content （RWC）,relative electrical conductivity （REC）,contents of malondialdehyde （MDA）,soluble sugar （SS）,soluble protein （SP）,proline （Pro）and carotenoid （Car）, activities of superoxide dismutase （SOD ）,peroxidase （POD ）,catalase （CAT ）,ascorbic acid peroxidase （APX）and glutathione reductase （GR）in the leaves of 3-year-old seedlings of Sabina przewalskii and Sabina chinensis pretreated with different concentrations of ABA to provide a theoretical basis for fostering more anti-freeze evergreen varieties.The results indicated that certain concentrations of ABA could maintain the stability of membrane system and increase the contents of osmotic regulators and antioxidant enzyme activities,enhance freezing tolerance of plant,the optimum ABA concentration was found to be 30 mg/L for Sabina chinensis and 40 mg/L for Sabina przewalskii.The chilling tolerance of Sabina przewalskii is stronger than that of Sabina chinensis in the pretreatments with ABA.It is demonstrated that appropriate concentration of ABA could help to increase the chilling resistance of Sabina species.