Study On The Differential Proteins Of Fruit Dehiscent In Different Pollinated Duweiwendan Pomelo

Duweiwendan pomelo is precious fruit in Fujian, which is excellent in quality, but the fruit cracking is serious problem. It has the self-incompatibility and fruit cracking can be controlled by Guanxi-pollinated. But the seed number increases significantly. Therefore, it's very important and pratical to study molecular mechanism on fruit cracking. It can raise the fruit quality of Duweiwendan pomelo highly and the economic efficiency.In this study, Duweiwendan pomelo (Citrus grandis (L.) Osbeck.cv. Duweiwendan) was used. Proteomic techniques were used to compare the proteomes of pericarp and ovary between Guanxi-pollinated and self pollination. The results of this study were as follows:1. Protein extraction method is an important technological factor which directly influence the protein spot number and map quality in 2-DEgel. In this study, by comparing two different methods, trichloroacetic acid/acetone precipitation (TCA) and distilling directly, it showed that TCA couldn't effectively extract protein from pericarp and ovary of Duwei- wendan pomelo. But the 2-DE gels of distilling directly method had a clean background, and protein spots were clearly seen. So distilling directly method was suited for Duweiwendan pomelo protein extraction.2. Proteomic approach was applied to compare the proteome changes of pericarp between Guanxi-pollinated and self pollination. There were 13 differential expressed proteins, 9 proteins down-regulated and 4 proteins up-regulated. 10 proteins in total were identified by MALDI-TOF-TOF / MS.Among these proteins, two proteins were unknown. The other 8 proteins were categorized into classes by function. Cytosolic glutamine synthetase plays a very important role in nitrogen assimilation process. 2,3-bisphosphoglycerate-independent phosphoglycerate mutase related to energy metabolism. S-adenosyl-L-homocysteine hydrolase related to intracellular methylation reaction. NADP-dependent malic enzyme is the key enzyme of Malic Acid metabolism. Fructose-bisphosphate aldolase-like belongs to the associated protein in photosynthesis. SOD and catalase are antioxidant related proteins.3. Proteomic approach was applied to compare the proteome changes of ovary between Guanxi-pollinated and self pollination. There were 28 differential expressed proteins, 21 proteins down-regulated and 7 proteins up-regulated. A total of 20 proteins were identified by MALDI-TOF-TOF / MS.Among these proteins, five proteins were unknown. According to the function, some proteins related to fruit cracking were found. Calmodulin and calreticulin precursor are related to calcium ion concentration of cells. APX1 and L-ascorbate oxidase have a close relationship with antioxidation. Putative nascent polypeptide associated complex alpha chain is not fully understood.As a result of the changes in expression level of these proteins, pericarp and ovary of Duweiwendan pomelo develop abnormally, which might lead to fruit cracking.