ÃÞ »¨ ѧ ±¨ Cotton Science 2010£¬22£¨1£©£º10-16
Functional Analysis of GhCCR4 Gene in the Epidermal Cells of Cotton Ovules Abstract: In this paper, the role of GhCCR 4 in cotton fiber development was examined. Because the generating of transgenic cotton needs a long period of time and the transformation efficiency is still low, transient expression assay system was chosen for test of GhCCR4 function in cotton fibers by using cotton ovule culture and biolistic transformation techniques. Transient expression vector of cotton GhCCR4 gene was constructed. The transient expression vector pGUS-CCR4 is driven by CaMV35S promoter with GUS reporter gene and GhCCR4 gene. The result showed that the highest transformation efficiency of GUS was obtained when 0 day of anthesis (0 DPA) ovules were applied. The optimal conditions for bombardment include helium pressures of 1350 psi, distance of 9 cm and bomb times of twice. Histochemical staining showed that high level of GhCCR4 gene expression was detected during the fiber rapid elongation stage and the fiber secondary wall thickening stage in cultured ovules. Measurement of fiber length in different developmental stage showed that the fiber length of the transgenic plants at the stage of 8 DPA was not different as comparing with that of the wild-type plants. However, the fiber length in the transgenic plants reduced 19% comparing with wild-type plants at the stage of 27 DPA. Transmission electron microscopy(TEM) demonstrated that the wall thickness of transgenic fiber increased by 17% of that of the wild type.
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