三个脐橙品种果实主要细胞壁酶动态变化研究

以罗伯逊脐橙、丰脐、纽荷尔脐橙果实为试材,对其果皮和果肉的果胶甲酯酶(PE)、多聚半乳糖醛酸酶(PG)、β-葡萄糖苷酶和纤维素酶(CX)的动态变化进行研究。结果表明,三个品种PE活性均为果肉明显高于果皮,其中纽荷尔和罗脐分别在果实膨大期、转色期和成熟期出现三个峰值;PE活性变幅纽荷尔大于罗脐,丰脐变化较平稳。PG活性果肉略高果皮,且皆在转色期开始快速升高。首次对脐橙果实β-葡萄糖苷酶研究表明,该酶活性微弱,成熟期活性最高,纽荷尔高于丰脐和罗脐;动态变化中果皮和果肉无明显差异。酶活性高峰出现的时间为PE早于PG和β-葡萄糖苷酶;PE和PG是影响脐橙果实发育的主要酶,β-葡萄糖苷酶可能是PE和PG的补充。

Studies on Cell Wall Enzymes of Navel Orange (Citrus sinesis) Fruit

Navel orange (Citrus sinensis cvs.Robertson,Fengqi and Newhall) were chosen as testing materials in Zhoupo,Jingyan County.The studies of pectinmethylesterase (PE),polygalacturonase (PG),β-glycosidase and cellulase in navel orange during development of fruits were shown as follows.PE,PG and β-glycosidase could be tested at different stages.PE activity of pulp was greater than that of peel obviously,the changes of PE activities from Newhall and Robertson navel oranges had three peaks;PE activity of Newhall varied greatly than those of Robertson and Fengqi.PG activity was greater at maturity stage than at young and the expanding stages;PG activity in pulp was greater than in peel.β-glycosidase activity was tested firstly in fruits and the peak of β-glycosidase activity was at maturity stage.The peak of PE activity appeared earlier than those of PG and β-glycosidase.PE and PG were the major enzymes effected the development of navel orange fruits.