2018 ASHS Annual Conference

The AGAMOUS (AG) gene is required for development of some reproductive organs. Here we report that expression of an rPTAGI::GUS fusion gene is sufficient to produce a flowerless phenotype in tobacco, a model plant. The rPTAGI sequence is an intron sequence cloned from the AGAMOUS gene of poplar. The flowerless phenotype has been observed in both greenhouse and field conditions. We have observed that shoots of the rPTAGI::GUS flowerless plants are flowerless if they are grafted onto wild-type plant rootstocks. On the other hand, wild-type plant shoots flower normally if they are grafted onto rootstocks derived from the rPTAG2I::GUS flowerless plants. We have investigated the molecular basis of the flowerless phenotype observed in the rPTAGI::GUS plants via analyses of transcriptomes of shoot tip tissues of both wild type and transgenic plants. We have observed that expression of a number of flowering genes is altered in the rPTAGI::GUS plants when compared to the wild type plants. We believe that the rPTAG2I::GUS gene may provide a better tool to reduce pollen- and seed-mediated gene spread problems of transgenic woody plants.