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Submitted to: BMC Plant Biology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 2/12/2015 Publication Date: 2/27/2015 Citation: Naoumkina, M.A., Thyssen, G.N., Fang, D.D. 2015. RNA-seq analysis of short fiber mutants Ligon-lintless-1 (Li1) and – 2 (Li2) revealed important role of aquaporins in cotton (Gossypium hirsutum L.) fiber elongation. Biomed Central (BMC) Plant Biology. 15:65. Interpretive Summary: Cotton fiber length is a key determinant of fiber quality for the textile industry. Understanding the molecular basis of fiber elongation would provide a means for improvement of fiber length. Ligon lintless-1 (Li1) and Ligon lintless-2 (Li2) are monogenic and dominant mutations, that result in an extreme reduction in the length of lint fiber to approximately 6 mm on mature seeds. In a near-isogenic state with wild type (WT) cotton these two short fiber mutants provide an excellent model system to study mechanisms of fiber elongation. Technical Abstract: Cotton fiber is the most prevalent natural raw material used in the textile industry. The length of the fiber is one of the most important characteristics and affects spinning efficiency and the quality of the resulting yarn. The identification of the genes that control fiber elongation is important to cotton breeders and researcher to develop a new cotton varieties with superior fiber characteristics. Our laboratory uses two short fiber mutants, Ligon lintless-1(Li1) and Ligon lintless-2 (Li2) as a model system to study fiber elongation. Both mutations are monogenic and dominant, that result in an extreme reduction in the length of lint fiber to approximately 6 mm on mature seeds. In this study we used next generation sequencing to identify common fiber elongation related genes in developing fibers of Li1 and Li2 mutants independent of environmental conditions. We found that aquaporins were one of the most significantly over-represented gene families among common down-regulated genes in Li1 and Li2 fibers. Aquaporins facilitate the efficient transport of water and other small molecules across membranes in plants and other organisms. The osmotic concentration and the concentrations of soluble sugars were lower in fiber cells of both short fiber mutants than in wild type, whereas the concentrations of ions were significantly higher in mutants during rapid cell elongation. Thus, the results suggest that reduced osmotic pressure and low expression of aquaporins, causing cessation of fiber elongation in short fiber mutants. |
