花楸体细胞胚发生过程中抗氧化酶活性的变化

Changes of Antioxidative Enzyme Activity in Somatic Embryogenesis of Sorbus pohuashanesis Hedl

花楸体细胞胚发生过程中,胚性愈伤组织可溶性蛋白含量高于其他类型的愈伤组织,非胚性愈伤组织中超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性均高于其他类型的愈伤组织;SOD、POD活性均在胚性细胞向球形胚转化时下降,球形胚向心形胚发育时下降,心形胚向鱼雷形胚和鱼雷形胚向子叶形胚发育时再升高;CAT活性变化规律与SOD和POD活性变化不同,从胚性细胞到鱼雷形胚的3个发育时间内表现为下降-升高-下降的趋势,鱼雷形胚向子叶胚发育时略有回升。据此认为,SOD酶活性降低似可作为花楸胚性细胞分化以及胚胎早期发育的一个判断指标。

During somatic embryogenesis of Sorbus pohuashanesis, the content of soluble protein in embryonic callus was higher than that in other types of calli and the activities of SOD （superoxide dismitase）, POD （peroxides） and CAT （catalase） in non-embryonic callus were higher than that in other types of calli; the activities of SOD and POD decreased from embryogenic tissues to globular embryos, decreased from globular embryos toheart-shaped embryos, and increased again from heart-shaped embryos to torpedo embryos and from torpedo embryos to cotyledon embryos. The activity variation pattern of CAT differed from SOD and POD, showed a decrease-increase-decrease pattern during the first 3 stages from embryogenic tissues to torpedo embryos and increased slightly in the last stage from torpedo embryos to cotyledon embryos. Accordingly, SOD activity decreased may be an index of differentiation of embryogenic cells and early development of somatic embryos of Sorbus pohuashanesis.