Cloning And Expression Analysis Of Cotton Cellulose Synthase Genes

Cotton is a primary economic crop and its fibers are important substances to textile industry and others. Understanding of cellulose synthesis by identification of the related genes is scientifically significant for improving cotton quality. Moreover, cotton fibers are excellent model metarials to experiments, because they are single cells.Cellulose is synthesized by the cellulose synthase complex which is located in the plasma membrane. In cotton, only GhCesA1, GhCesA2 and GhCesA3 have the fμll-length CDs. GhCesAl and GhCesA2 are secondary cell wall genes, and GhCesA3 is primary cell wall gene. According to published EST sequences, three new genes were cloned from Gossypium hirsutum, which were termed GhCesA5, GhCesA8 and GhCesA10. Their CDs are 3288bp,3120bp and 3207bp, encoding 1096,1039 and 1069 amino acids. GhCesA5 and GhCesA10 express in all developing stages, GhCesA8 specificly expresse during the secondary cell wall stage. The CesAs expressed in the upland cotton are consistent with the sealand cotton except the CesA8, which express later in upland cotton than sealand cotton, and the function of GhCesA5 and GhCesA8 may partial complementary with each other.Western bloting indicated that GhCESA1 and GhCESA2 don't express until 19DAP, consistent with the RT-PCR results, GhSUSYl expression was very high in the whole stages of cotton fiber developing. The activity of GhCESAs in vitro suggested that the larger plasma membrane fragments have the higher activity, and the highest activity at the secondary wall stage.Transgenic technology has becoming a very important method for the cotton breeding. In this research, we selected two cellulose synthesis related genes, GhSuSy1 and GhSGT1, and construct five vectors:pC1300-SCFP-GhSuSy1, pC1300-SCFP-GhSGT1, pC1300-E6-GhSGT1, pART-E6-GhSGT1 and pART-E6-GhCAL. The genes transforma-tion mediated by the Agrobacterium though the cotton pollen tubes, and we have got some seeds of the To generation. The positive transgenic seeds are undering screening.