摘要
以大田栽培的十年生雌性银杏植株为实验材料,研究自然条件下叶片衰老过程中叶绿体光合能力的变化.结果表明:叶绿体的光合能力随叶片的衰老持续下降,总叶绿素含量迅速下降,类胡萝卜素含量没有明显变化,而类胡萝卜素与叶绿素比值呈上升趋势,在衰老末期较为显著;叶绿体中ATP含量、叶绿体放氧活性、电子传递活性、光合磷酸化活性、Mg 2+-ATPase和Ca 2+-ATPase的活性均下降,且Ca 2+-ATPase活性明显弱于Mg 2+-ATPase活性;叶绿体内SOD,POD,APX和CAT四种抗氧化保护酶活性均呈先升后降的趋势,衰老后期活性最高,衰老末期四种抗氧化保护酶活性同时大幅下降,叶绿体在叶片衰老过程中具有较强活性氧清除的酶促能力.
Changes in photosynthetic abilities in the chloroplasts of 10-year-old female ginkgo leaves during senescence were studied in the field under natural environmental conditions.The results showed that the photosynthetic abilities gradually decreased as the leaves senesced,the content of total chlorophyll decreased rapidly while the contents of carotenoids changed little during,but the ratio of carotenoids/chlorophyll increased,particularly in the final senescence.The content of ATP,the activity of O 2 evolution of chloroplasts,the electron transport activities,the activity of photo-phosphorylation and the activity of Ca 2+-ATPase and Mg 2+-ATPase declined as the leaf senesced,and the activity of Ca 2+-ATPase was significantly lower than that of Mg 2+-ATPase.The activities of the antioxidative enzymes,such as superoxide dismutase(SOD),peroxidase(POD),ascorbate peroxidase(APX)and catalase(CAT)were strengthened then declined,peaked in the late senescence.Until the final senescence,activities of four kinds of enzymes were decreased significantly.The antioxidant enzyme system plays a key role in elimination of reactive oxygen species from leaf expansion to late senescence.
作者
杨贤松
YANG Xiansong(College of Food and Bio-engineering,Bengbu University,Bengbu 233030,China)
出处
《牡丹江师范学院学报（自然科学版）》
2019年第4期50-54,共5页
Journal of Mudanjiang Normal University：Natural Sciences Edition
基金
安徽省自然科学基金项目(11040606M79)
蚌埠学院自然科学基金项目(2017GJPY07)
关键词
银杏
叶片衰老
光合能力
Ginkgo(Ginkgo biloba L.)
leaf senescence
photosynthetic abilities
