渗透胁迫和外源KT对金银花离体叶片保护酶活性的影响

Effect of Osmotic Stress and Exogenous KT on Protective Enzyme Activity in Isolated Leaves of Honeysuckle

[目的]研究了金银花离体叶片的抗旱性。[方法]采用PEG模拟干旱方法,在离体条件下,用聚乙二醇(PEG 6000)形成渗透胁迫,通过对超氧化物歧化酶(SOD)、过氧化物酶(POD)活性、丙二醛(MDA)以及叶绿素含量4个指标测定,研究了不同浓度PEG和外源激动素对金银花离体叶片保护酶活性的渗透胁迫影响。[结果]随着PEG浓度增加,SOD、POD活性和MDA含量升高,叶绿素含量降低。在25%PEG渗透胁迫条件下叶绿素含量比对照降低了54.4%。加入外源激动素(KT)后,MDA含量降低,SOD、POD活性和叶绿素含量升高。在5%PEG渗透胁迫条件下叶绿素含量升高了36.2%。[结论]外源激动素在一定程度上能减缓PEG的渗透胁迫,这与它们对体内自由基的调节是分不开的。

[Objective] The purposed to study the drought resistance of isolated leaves of honeysuckle. [Method] Under the isolated culture condition, PEG 6000 was used form osmotic stress by simulating drought with PEG. Through determining the four indexes namely super oxide dismutase （SOD）, peroxidose （POD） activities, malondialdelyde （MDA） and chlorophyll contents, the osmotic stress effects of different concentration of PEG and exogenous KT on protective enzyme activity in isolated leaves of Honeysuckle. [Result] With increment of PEG concentration, the SOD and POD activity and MDA content was increased, while the chlorophyll content of Honeysuckle was decreased. Under the condition of 25 % PEG osmotic stress, the chlorophyll content was decreased by 54.4 % compared with CK. When the exogenous KT was added, MDA content of Honeysuckle was decreased and the SOD and POD activity and chlorophyll content was increased. The chlorophyll content of Honeysuckle was increased by 36.2 % under the condition of 5 %PEG osmotic stress. [Conclusion]The exogenous hormone could alleviate PEG osmotic stress to some extent, which was inseparable with their internal adjustment to the free radical.