Construction And Genetic Transformation Of Over-expression And RNAi Vector Of Vernalization Gene VRN1,VRN3in Common Wheat

In order to further explore the function of vernalization gene VRN1, VRN3in theprocess of wheat development, two varieties were selected: Xinchun NO.2(XC2) andJing841(J841). Under vernalization and non-vernalization treament, spikedifferentiation was observed and the transcription of VRN1, VRN3in apical meristemsand leaves was analyzed for two varieties. By construction and genetic transformationof over-expression and RNAi vector of gene VRN1, VRN3, Wheat new germplasmresources were created. The results were as follows:1. The spike differentiation for XC2from3leaf stage to heading withinvernalization treament advanced nearly one week comparative to XC2withinnon-vernalization treatment. The winter varity, J841did not flower until the end ofexperiment under non-vernalization treatment, and the apices maintained in the singlestage. After five weeks vernalization treatment, the apices of J841differentiatedquickly and finish spike differentiation in6weeks. Therefore, winter wheat variety ismore sensitively to cold temperature.2. The transcription of VRN1in different varieties was different. Under twotreatments, in the spring vareity, the transcription level of VRN1in leaves was higherthan that in shoot apices in the early stage of growth. But as the growth of wheat, thetranscription level of VRN1in shoot apices increased and surpassed VRN1transcriptlevels in leaves. This expression profile illustrated that the VRN1expression in leavesand shoot meristems was out of sync, demonstrating that the function of VRN1isdiscrete in these two tissues.3. In the two varieties, the expression levels of VRN3in apical meristems was verylow and nearly zero under two treatments. In both varieties after vernalizationtreatment, the up-regulation of VRN3in leaves seems synchronize with theup-regulation of VRN1and at this period the spike differentiation was in the femalestamen differentiation—pistil stigma feather formation. We inferred that the functionof VRN3mainly produce florigen, which will be transported to apices and induce the transcription of VRN1in apices. The high VRN1transcript levels in apices willpromote the transition from vegetative growth to reproductive development.4. The over-expression and RNAi vector of gene VRN1, VRN3was constructedand introduced into wheat apical meristems by Agrobacterium-mediatedtransformation. The positive transgenic wheat was obtained, by Glufosinate and PCR.