Molecular Cloning And Analyses Of Three Genes Related With Fiber Development In Cotton （Gossypium Hirsutum L.） And The Ultrastructure Study Of The Li₁ （Ligon Lintless-1） Mutant Fiber In The Early Development Stage

Cotton fiber is the important textile material, plays an important role in our national economy. The high quality fiber is one of the major goals in the cotton breeding all over the world. So, it is important to elucidate fiber development process and major factors related to fiber quality by cell and molecular biology.The fundamental purpose was to analyze the ultrastructure of mutants(Li1li1) and wilds (li1li1) ovule via TEM (Transmission Electron Microscope),and functional analysis of Three Genes Related with Fiber Development in Cotton (Gossypium hirsutum L.),GhCAS analyze was used the methods prokaryotic expression, subcellular localization and Southern blotting.1. Ultrastructure of fiber differentiation and protuberance are observed by TEM with a view to reveal the structural mechanism of fiber differentiation and elongation, and to analyze main structural factors related to fiber strength. The results showed there were some difference of 3-5 DPA fiber ultrastructure between mutants(Li1li1) and wilds (li1li1). The cell structure of wilds (li1li1) were intact,but mutants(Li1li1) were not intact.2. In this study, GhBRICKI and GhWRM were isolated from the TM-1 ovule on the day of flowering. GhBRICKI contains 258 bp open reading frame, encoding a polypeptide containing 85 amino acids. GhBRICKI was expressed constitutively in every tissue with different expression levels, with the peak in 9 DPA fiber cells and low expression levels in 18,24 DPA fiber cells, roots and stems. Southern blotting showed that GhBRICKI had two copies in allotetraploid cotton genome. A shuttle vector contained GhBRICKI cDNA sequence was transformed into fission yeast. GhBRICKI led to a significant increase in cell length. GhWRM contains 1170 bp open reading frame, encoding a polypeptide containing 389 amino acids. GhWRM was expressed constitutively in every tissue with different expression levels, with the peak in 9 DPA fiber cells and low expression levels in 3,6,18,24 DPA fiber cells, roots and stems. Southern blotting showed that GhWRM had two copies in allotetraploid cotton genome. A shuttle vector contained GhWRM cDNA sequence was transformed into fission yeast. GhWRM led to a significant increase in cell length.3. The whole cDNA of GhCAS (Gossypium hirsutum L. beta-Cyanoalanine Synthase mRNA) was cloned in our lab. Prokaryotic expression showed that GhCAS inhibition prokaryotic organism development. Subcellular localization result indication that GhCAS expression in cell membrane and nucleus,without expression in cytoplasm. Southern blotting showed that GhCAS had two copies in allotetraploid cotton genome.