Study On The Function Of Kinesin-13 In Cotton Fiber Development

Cotton fiber is the most important fiber resources for textile industry. Researches on molecular mechanism of cotton fiber development is not only in favor of revealing the theoretical problems of plant cell elongation and cellulose biogenesis,but also in favor of making the foundation on improving the fiber qualities through genetic engineering. Kinesin is a protein belonging to a class of motor proteins. Kinesins can move along microtubule filaments,and are powered by the hydrolysis of ATP. The active movement of kinesins supports its key roles in cell formation and cell elongation. Arabidopsis AtKinesin-13 A knockout mutant plants exhibited more branching points in a thichome. Cotton fibers derived from the epidermis of the ovule are single cells which have been found to share a similar development mechanism with Arabidopsis trichome. Does the Kinesin-13 play a similar role in cotton fiber? In this study, GhKinesin-13 was cloned from cotton fiber and then transformed into Arabidopsis to investigate the effects of change in expression level on the Arabidopsis trichome, and to further discuss the biological functions of GhKinesin-13 in cotton fiber development. This study provided the theory basis for the cotton fiber improvement. The results of the study are as follows:1.Using the protein sequence of Atkinesin13 A as a probe, seven genes showed high sequence homology were obtained by using a genome database of Gossypium raimondii diploid cotton search with Blast alignment. These sequences were used to design primers,and then seven genes were isolated from cotton fiber of upland by using RT-PCR. Based on the homology level of the seven genes with Atkinesin13 A and Atkinesin13 B, they were respectively designated as GhKIS13A1, GhKIS13A2,GhKIS13A3,GhKIS13B1,GhKIS13B2,GhKIS13B3,and GhKIS13B4. Bioinformatic analysis showed that seven proteins contained typical KISC domains which belong to the central motor,the ATP-binding sites and microtubule binding sites. Multiple sequence alignment and phylogenetic tree analysis revealed that seven genes can be divided into Kinesin13 A and Kinesin13 B. The qRT-PCR showed that the seven GhKinesin13 subfamily genes expressed in all tissues of cotton,but showed different expression pattern.The highest expression of the GhKISA1 in the secondary period of the cotton fiber wall thick(30DPA) and suggesting that it may play an important role in cotton fiber development. This study can make the foundation for studying the functions of Ghkinesin13 subfamily genes in fiber development. To further study GhKinesin13 subfamily genes function in cotton foundation.2.To study the function of GhKISA1 genes,plant overexpression vector was constructed by Gateway technology and transformed into Arabidopsis by agrobacterium-mediated genetic transformation system.Compared with wild type,the number of leaf trichomes and its branching points of transgenic Arabidopsis plants were obviously less than wild type. The results showed that GhKIS13A1 can inhibit the formation of Arabidopsis trichomes, suggesting that the gene may play an important role in the development of epidermal hairs.3.Through the method of genetic transformation by agrobacterium infect cotton hypocotyl to cotton YZ-1 and Xinluzao 33, with transfer culturing and Kana screening, it has been embryoid body-cells androoting,To further study GhKinesin13 subfamily genes function in cotton foundation.