- Sep 16, 2019
Date & Location: September 16, 2019, at 4p; Room 1200 Molecular Plant Sciences Building
Subject: The zygotic transition in rice and application to self-propagating hybrid crops
Host: Erich Grotewold
About the Speaker
University: University of California, Davis
Abstract: The zygotic transition, from a fertilized egg to an embryo, is central to animal and plant reproduction. Using Oryza sativa (rice) as a model flowering plant, transcriptome analysis shows that in contrast to animals, transcription of the zygotic genome is activated within unicellular plant zygotes. Initial zygotic transcription is primarily from the maternal genome, but genes encoding putative pluripotency factors are unexpectedly expressed from the paternal genome, including the BBM (BABY BOOM) transcription factors. Ectopic expression of rice BBM1 in the egg cell bypasses the fertilization checkpoint in the female gamete and produces parthenogenic embryos. Thus, the fertilization requirement for embryo initiation might be mediated by male genome activation of embryogenic factors. When parthenogenesis is combined with genome editing to substitute mitosis for meiosis (MiMe), clonal progeny that retain genome-wide parental heterozygosity are produced. This research establishes the feasibility of engineering asexual reproduction in crops (synthetic apomixis), to enable the maintenance of hybrids clonally through seed propagation.