文档介绍：
桔小实蝇不同发育阶段及组织中酚氧化酶
生化特性比较研究#
白平平,陈二虎,豆威,王进军**
5
10
15
(西南大学植物保护学院,昆虫学及害虫控制工程重庆市市级重点实验室,重庆 400716)
摘要:比较分析桔小实蝇 Bactrocera dorsalis(Hendel)不同发育阶段及组织中酚氧化酶
(Phenoloxidase, PO)的生化特性,结果发现,桔小实蝇不同发育阶段及组织中的酚氧化酶活
性存在显著性差异(P<),其中酚氧化酶的活力在 3 龄幼虫期最高( U/mg),
在成虫酶活力最低( U/mg)。在桔小实蝇不同组织中酚氧化酶活性亦存在显著性差异,
其中在表皮的酶活力( U/mg)显著高于中肠( U/mg)和脂肪体( U/mg)
(P<)。分别以邻苯二酚和 L-多巴为底物对酚氧化酶动力学参数(Km 和 Vm)的分析
发现,桔小实蝇不同发育阶段的酚氧化酶对底物的亲和力有所差异;而不同组织间酚氧化酶
对底物的亲和力无显著性差异。此外,以邻苯二酚为底物,桔小实蝇不同发育阶段及组织酚
氧化酶酶促反应的最适 pH 和温度均相同,均为 pH 和 37 ℃。酚氧化酶活力高低及分布
与该虫的生长发育紧密相关,研究结果进一步证实了酚氧化酶在昆虫发育和免疫中所起的重
要性。
关键词:桔小实蝇;酚氧化酶;生化特性;发育阶段;组织
中图分类号:
20
Comparative studies on biochemical characteristics of
phenoloxidase from Bactrocera dorsalis (Hendel) in
different developmental stages and tissues
BAI Pingping, CHEN Erhu, DOU Wei, WANG Jinjun
25
30
35
40
(Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection,
Southwest University, Chongqing 400716)
Abstract: This study aims pare and analysis the biochemical characterizations of
phenoloxidase (PO) in different developmental stages and tissues from Bactrocera dorsalis
(Hendel). The PO activities varied significantly during the different developmental stages of B.
dorsalis. The enzyme activity in the 3rd instar larva was the highest ( U/mg), while the
lowest in the adult ( U/mg). Moreover, PO activity was also significantly difference among
the tissues and the PO activity in the cuticle ( U/mg) was significantly higher than that in
the midgut ( U/mg) and fat body ( U/mg). Further ic parison
found that the Km values of PO from different developmental stages were significantly different
and the results showed that the affinity of PO was the highest in the pupa and the lowest in the 1st
instar larva, but it was no difference in different tissues. Besides, the effect of pH and temperature
on the activity of PO test showed that PO from different