This action funds an NSF National Plant Genome Initiative Postdoctoral Research Fellowship in Biology for FY 2016. The fellowship supports a research and training plan in a host laboratory for the Fellow who also presents a plan to broaden participation in biology. The title of the research and training plan for this fellowship to Dr. Alex Harkess is "The origins of reproductive phasiRNAs in the angiosperms". The host institution for the fellowship is the Donald Danforth Plant Science Center and the sponsoring scientist is Dr. Blake Meyers.
All flowering plants have structures called anthers that produce male pollen during reproduction. In the sub-group of monocots, a unique class of small molecules, called small RNAs, are expressed in anthers just before pollen is produced. These small RNAs regulate how genes are turned on and off at specific times, thus likely ensuring normal reproduction. Despite the importance of these small RNAs, details of their function and regulation are not well understood. This project investigates when and how these small RNAs evolved in the grasses, thereby clarifying their functional importance in the context of evolution. Information will be conveyed through an outreach project with public gardens. In collaboration with the Longwood Garden (Philadelphia, PA) and the Missouri Botanic Garden (St. Louis, MO), the genome of the Longwood Hybrid water lily will be sequenced, and the resulting information will contribute to a public garden exhibit that connects genetics to evolution in this group of early-diverging flowering plants.
The aims of this project are to identify the key evolutionary events underlying the origin of 21 and 24nt phased, secondary, small interfering RNAs particularly in the monocots. Interestingly, a duplication event led to the presence of a monocot-specific Dicer-like protein, DCL5. Transcriptome sequencing of meiotic anthers across diverse groups of monocots will be used to carefully pinpoint the phylogenetic placement of the duplication event that led to the divergence of Dicer-like 3 (DCL3) and Dicer-like 5 (DCL5) in the monocots. After identifying this duplication event, a phylogenetically diverse subset of DCL5 genes will be transformed into the maize male-sterile DCL5 knockout to attempt to rescue function. Simultaneously, in situ hybridization and immunolocalizations will be performed across phylogenetically diverse monocots to identify potential changes in protein localization in the anther, further clarifying function during reproductive development.
