稀土La^（3＋）和维生素C对黄瓜PSⅡ颗粒放氧活性机理影响的初探

PRIMARY STUDY ON EFFECT OF RARE EARTH La￣(3+) AND VITAMIN C ON CUCUMBER PSⅡ PARTICLES O_2-EVOLUTION ACTIVITY MECHKANISM

用１０μｇ／ｇＬａ￣（３＋）、１．０％Ｖｃ、１０μｇ／ｇＬａ￣（３＋）＋１·０％Ｖｃ、蒸馏水四种处理，喷施正处在衰老过程中的黄瓜叶片，一周后提取ＰＳⅡ颗粒，通过ＳＤＳ－ＰＡＧＥ、薄层扫描和Ｃｌａｒｋ测氧等测试技术，发现处理与对照的ＰＳⅡ颗粒在与放氧活性密切相关的３３、２３、１７ｋＤ三肽的相对总含量上有变化，１０μｇ／ｇＬａ￣（３＋）处理比对照减少２８．９％，而１．０％Ｖｃ和１０μｇ／ｇＬａ￣（３＋）＋１．０％Ｖｃ处理的与对照接近。前者的放氧活性降低３７．３％，后者的放氧活性增加６２．４％，是对照的１．６倍，共同处理的结果与对照相近。可见，在光合放氧中，１．０％Ｖｃ与１０μｇ／ｇＬａ￣（３＋）拮抗。而且，３３、２３、１７ｋＤ三肽总量的相对减少与放氧活性的高低呈正相关。

Cucumber leaves in senescence were treated with 10 μg/g La￣(3+)、1.0%Vc、10 μg/gLa￣(3+)+1.o%Vc and distilled water though sparying.After one week,preparated PSⅡ particles of oxygenevolution activity,with SDS-PAGE and clark O_2-determination technology etc.We find thedefference on relative total content of three watersoluble polypeptides(33、23、17kD)concerningwith O_2-evolution activity between treatment and control PSⅡ particles.Treated with 10μg/gLa￣(3+),the three polypeptides total content losed 28.9 per cent relatively,and PSⅡ particles O_2-evolution activity losed 37.3 per cent compared to control.Treated with Vc,the PSⅡ particles O_2-evolution activity increased 62.4 per cent.Treated with La￣(3+) and Vc the result was similar tocontrol.