苏拉威西凤果叶片在不同低温胁迫下的生理特性变化

摘要

After firstly trained at 15℃ for 72 h in an illuminated incubator, the 3-year-old Garcinia celebica seedlings were placed under 3,6, or 9℃ for 36h for the experiment to observe the physiological responses of the plants to low temperatures.The contents of chlorophyll, soluble proteins and soluble sugars, as well as the activities of SOD and POD in the leaves of the seedlings were determined.It was found that the seedlings could restore their normal growth after an exposure to 6 or 9℃.Nevertheless, there were significant physiological alternations occurred to the plants due to the treatments.The contents of total chlorophyll, chlorophyll a, and chlorophyll b in the leaves were significantly lowered as compare to control.The soluble protein or soluble sugar content increased at 6℃ and 9℃, and peaked at 6℃.On the other hand, both of thesedecreased sharply at 3℃, and became lower than control.Meanwhile, the activities of SOD and POD in the leaves increased under 6℃ and 9℃ stresses.It was concluded that G.celebica responded to the temperatureat 6℃ or 9℃ to tolerate the cold stressby accumulating soluble proteins and sugars regulating osmosisin the tissues, and at the same time, enhancing the activities of SOD and PODfor an improved adaptability to the environmental change.%以3年生苏拉威西凤果Garcinia celebica L.幼苗为试材,经15℃光照培养箱炼苗72 h后,分别在3、6、9℃进行低温胁迫36 h,测定不同低温下叶片的叶绿素、可溶性蛋白、可溶性糖含量及SOD(超氧化物歧化酶)、POD(过氧化物酶)的活性.结果表明:经过低温胁迫的所有幼苗均能恢复正常生长,3℃低温的小苗出现轻微脱水现象.不同温度下的生理指标有明显变化:总叶绿素、叶绿素a、叶绿素b的含量均比对照有明显下降;可溶性蛋白、可溶性糖含量在6~9℃内随温度降低而上升,在6℃时达到最高值,但二者的含量在3℃时急剧下降,并显著低于对照;SOD、POD活性均在6~9℃内随温度降低而上升.推测苏拉威西凤果在6~9℃内出现应激反应,通过可溶性蛋白、可溶性糖的积累及SOD、POD活性的提高来适应低温胁迫.