Expression of Lc Gene Driven by a Cotton Fiber Specific Promoter of GhACT1 in Cotton Immature Embryos

[Objective] To promote the study on color improvement in cotton fiber, it is a key to use transgenic approach. [Method] In this study, the maize Lc gene, under the control of the fiber specific promoter of GhACT1, was introduced into cotton by Agrobacterium-mediated method. The integration of maize Lc gene was confirmed by the polymerase chain reaction (PCR) and southern blot, meanwhile follow-up observation of color change during the transgenic plants growing. The expression of transcription level was analyzed by reverse transcription (RT)-PCR amplification. [Result] Our data showed there were 25 lines of positive plants that had no obvious color change. The expression test results of Lc gene showed that there was no expression signal in vegetative parts, including leaf, petiole and stem. However, there were high expression signals in fiber of ovules at 1―12 days post anthesis in transcription level. The result of culturing in vitro showed that red color appeared on the ovules’ surface and the initial fiber turned red under light for 1 week. [Conclusion] The Lc gene driven by the promoter of GhACT1 was introduced into cotton successfully and expressed in ovule and fiber specially, leading to red fiber appeared under light. These data indicate that it is potential to engineer colored fibers through transgenic approach in cotton.