Analysis Of The Differentally Expressed Genes During The Initial Development Of Cotton Fiber And Cloning Of Three GhTLP Family Genes In Gossypium Hirsutum

Cotton is the important economic crops in the world and cotton fiber is a major source of natural fiber in the textile industry. The cotton fiber development is a biological process in which fiber cells divide and extend rapidly, involving a large number of related gene expression in the stages of cell differentiation, elongation, maturation and cellulose metabolism. So the cloning research of cotton fiber development-related genes not only has the useful for genetic improvement of cotton fiber, but also for the study of plant cell elongation and biological construction of cell wall.The0DP A,1DPA ovules of upland cotton genetic standard line TM-1and three fuzzless-lintless mutants (MD17, Xu-142FLM, SL1-7-1) were used to analyze the differential expression of the initial development of cotton fiber.90differentially expressed sequences had been obtained in total. According to the GO analysis results,21sequences were found the hits and detected via RT-PCR. Then11differentially expressed sequences were obtained.According to differential display sequences, a novel cotton gene had been cloned and was named GhTLP2. GhTLP2and another gene GhTLP7were belonged to the same gene family. The expression patterns showed that these two genes were expressed constitutively in every tissue with different expression levels, with the peak in6-9DPA fiber cells. We constructing GhTLP2and GhTLP7fusion expression vector with GFP respectively, and using gene gun bombardment transformation method to bombard the onion epidermis. The subcellular localization revealed that these two genes located in the cell membrane. Results of Southern hybridization showed that these two genes had multiple copies in Gossypium hirsutum TM-1.In addition, through electronic cloning, we obtained GhTLP1gene sequences which belonged to GhTLP gene family in cotton, and analyzed the related bioinformatics information for the GhTLP gene family. Translating these novel three GhTLP genes into protein sequences, bioinformatics analysis showed that these proteins had several glycosylation sites at their N-terminal. Due to no corresponding signal peptide, glycosylation regulation of these proteins had little probability in the post-translational modification. Because there was no signal peptide structure at their N-terminal, these proteins were not secreted proteins. Results of Phosphorylation site prediction showed that these three proteins which translated from three GhTLP genes contained more protein phosphorylation site and these sites were mainly hydroxy-amino acids. It revealed that phosphorylation is the major post-translational modification of these proteins, and the hydroxy-amino acids were the major phosphorylation sites. Furthermore, those three proteins in cotton which translated from three GhTLP genes all had conservative region of tubby-like protein family and f-box region. Cluster analysis showed that all three genes had little variation in plant species, and their conservative region had a strong conservative.