CONTROLLING THE INDUCTION OF PARTHENOGENESIS IN TRANSGENIC RICE VIA POST-TRANSLATIONAL ACTIVATION OF PsASGR-BBML AND DETERMINING THE EFFECT OF EGG CELL PLOIDY LEVEL ON PENETRANCE OF PARTHENOGENESIS

Doubled-haploid (DH) technology significantly shortens the process of generating homozygous lines and it involves haploid induction followed by chromosome doubling. Parthenogenesis, which involves embryogenesis from unfertilized egg cells, can be used for in vivo haploid induction and an AP2 transcription factor, PsASGR-BBML induces parthenogenesis in a natural apomict Pennisetum squamulatum. PsASGR-BBML transgenes promote parthenogenesis in several crop plants, however their dominant nature inhibits their use for DH technology. We show that a post-translational activation system can be used to regulate PsASGR- BBML at anthesis. Also, in rice transformed with PsASGR-BBML, parthenogenesis occurs in reduced egg cells and this may be one cause for the observed low penetrance of the trait and abnormalities in developing ovaries. In natural apomicts, which are mostly polyploid, parthenogenesis occurs in unreduced egg cells. Here, we tried to observe if seed-set and penetrance of parthenogenesis is affected by the ploidy level of egg cells in transgenic rice.