A novel herbicide-inducible male sterility system

Heterosis is a phenomenon that first-generation offspring perform better than their parents. Conventional breeding methods have their shortcomings. It would be optimal to construct inducible male sterile plants.

We developed a novel system for creating male sterile transgenic plants by downregulating the specific expression of the glyphosate tolerance CP4 EPSPS gene in male reproductive tissues. Transcriptional repression was achieved by manipulating DNA binding proteins with their specific corresponding sites. We transferred the CP4 EPSPS gene driven by a modified CaMV 35S promoter with three tetracycline operator copies in the vicinity of the TATA box and tetracycline repressor gene under the control of an anther-specific promoter Osg6B to Arabidopsis thaliana. As a result, we successfully obtained controllable transgenic plants: the whole plant could tolerate exposure of glyphosate but the male tissue was sensitive.

The novel inducible male sterility system is applied and easy to handle, so it might be applicable to a wide range of crop plants.