Herbivorous Insect Causes Deficiency of Pigment - Protein Complexes in an Oval - Pointed Cecidomyiid Gall of Machilus Thunbergii Leaf

Abstract

This research compared the chlorophyll biosynthetic and degradation pathways, pigment-protein complexes, and thylakoid morphology of a mature oval-pointed cecidomyiid gall and the infected leaf of host plant Machilus thunbergii Sieb & Zucc (Lauraceae). The mature gall always possesses far less photosynthetic pigment than the infected leaf. The content of anthocyanin and tannin of the gall are much higher than in the infected leaf. Both the mole percent of porphyrin and the ratio of pheophytin/chlorophyllide are much different between the gall and infected leaf, suggesting their chlorophyll biosynthetic and degradation pathways are much different. While the infected leaf may take the degradation pathway of chlorophyll®pheophytin®pheophorbide as the major route, the cicedomyiid gall may take chlorophyll®chlorophyllide®pheophorbide as the major route. The infected leaf still possesses the CPI and CPII pigment-protein complexes fractionated by Thornber system, or the A1, AB1, AB2, AB3 pigment-protein complexes fractionated by the MARS system while the mature gall contains only CPII or AB3. Electron microscopy demonstrated that the mature gall has normal grana and thylakoid morphology. It is still unknown whether the unique deficiency of pigment-protein complexes is ubiquitous and how the cecidomyiid insects cause the deficiency of some pigment-protein complexes.