Functional analysis of the ver gene using antisense transgenic wheat

The function of ver203 , a gene related to vernalization in winter wheat, was investigated by expression of a complementary DNA as an antisense RNA in transgenic plants. A verc203:gus fusion‐expression plasmid was constructed in pBI221, which contains a CaMV (cauliflower mosaic virus) 35S‐promoter, a gus gene and a nos terminator. The construct was then introduced into the plant by the pollen‐tube pathway. The results showed that heading was strongly inhibited in 6 of 326 vernalized antisense transgenic winter wheat plants, until both the vernalized control winter wheat and sense transgenic plants ripened. The hybridization analysis of DNA, amplification of the insert DNA sequences with PCR, northern blot analysis with double‐ and single‐stranded probes, and detection of GUS activity by X‐gluc assay gave strong positive results. This suggests that the VER203 protein plays an important role in controlling heading and flower development in winter wheat.