探討造癭昆蟲基因分子演化關係及蟲癭組織蛋白質體組成-以樟科楨楠屬植物及癭蚋科昆蟲為例

Abstract

本論文主要分兩方面探討台灣楨楠屬植物上之雙翅目癭蚋科蟲癭的生長情況。一由基因序列演化分析探討雙翅目癭蚋科蟲癭彼此間的親源遠近關係，再利用二維電泳探究蟲癭組織與植物組織當中蛋白質成分的差異，以期瞭解蟲癭的發生機制。並綜合討論癭蚋分子演化關係、蟲癭型態發生、與癭蚋外型解剖間相互的關係。本研究取台灣八種楨楠上的九型蟲癭，共四十種樣本做癭蚋基因演化關係。而蟲癭組織蛋白質分析取三種楨楠、兩型蟲癭，共六種樣本作蛋白質二維電泳及定序。由造癭昆蟲基因演化分析得知，造出同型蟲癭的癭蚋，為分類學上較親近的種。種的親緣遠近關係與寄主植物的種類較無關連。而造莖部癭的癭蚋較造葉部癭的癭蚋早演化出來。而癭蚋幼蟲解剖分析支持前述推論。植物分類學上，莖部癭所具有之型態特徵亦被認為是較早出現的形態。由蟲癭組織蛋白質體二維電泳分析得知，不同型蟲癭彼此間蛋白質差異不大，但蟲癭外型與蛋白質相關。同型蟲癭在不同楨楠屬植物上的蛋白質差異較前述為大，可能因植物種類不同，對相似化學物質的反應不同所致。蟲癭組織當中RuBisCO蛋白質表現量較正常植物組織大幅下降，進而推測蟲癭組織已喪失光合作用的功能。

Cecidology is the study of plant galls, where insects and other organisms breed their offsprings. Cecidology crosses multiple areas such as ecology, insect taxonomy, botanical taxonomy, botanic pathology, parasitology, and it’s a special research subject. Little is known regarding the interaction between gall insects and their host at molecular level. In Taiwan, Machilus (Lauraceae) plants have the widest variety of gall shapes among all plant species. Cecidomyiidae (Dipteria) is the major gall inducing insects on Machilus. To understand the relationship between gall insects and their hosts, we first identified different species of gall insect through insect genomics and the responses of the host were studied through plant proteomics. In insect genomics, we used COI gene to classify 40 unknown species collected from 9 different types of galls on 8 Machilus species. These cecidomyiidae gall inducing midges could be classified into 7 tribes, 11 genus, and 15 species. Our data indicate that insects which make same type of galls are closer species. The anatomical evidence and ecological theories also supports genomic evidence. In plant proteomics, we found that galls were benignancy tissue growth of plant. Because RuBisCO protein expression in gall tissues was largely decreased, galls might be the storage organisms of plants. Combine genomic and proteomic outcomes, we suggest that same or closer insect species secretes same chemicals to induce same shape of galls, and it has nothing to do with host plants within Machilus genus. Some proteins might also affect the forming of different gall shapes as significant protein variations were observed between gall and normal plant tissues.