description
- Like animals, most diploid plants reproduce sexually after going through genetic reduction (meiosis) to produce specialized haploid gametes (i.e. sperm cells and egg cells) within the male and female sex organs, respectively. However, the process by which plants establish haploid sexual lineages (or germlines) from diploid somatic tissues late in adult life is not yet understood, but is thought to involve large-scale developmental and whole-genome reprogramming. This proposal focuses on uncovering some of the mechanisms involved in this process. We have evidence that novel small-RNA binding Argonaute proteins (AGOs) specifically found in male reproductive organs of cereals and their associated class of small non-coding RNA molecules control the development of the male germline. Intriguingly, these AGOs are expressed in somatic cells surrounding the male germline and sperm cells, yet defects or mutations in these AGOs causes male sterility. In this proposal, we will use various approaches and experimental techniques (eg. developmental genetics, biochemistry, computational and molecular biology) to determine exactly how somatic companion cells regulate the fate of the male germline using two important model crop plants: maize and wheat. We anticipate that this work will not only advance our basic understanding of how plants set their male germline, but will also provide a novel strategy to engineer new breeding tools in agronomically important cereal crops.