Department of Biology

This proposal describes a next-generation sequencing (NGS)-based approach to identify genes that control unisexual flower development in Zea mays (maize). Maize develops separate male flowers in the tassel and female flowers in the ear (Klein etal., 2018). The development of unisexual flowers is important for hybrid crop production - separate tassel and ear flowers allow humans to very easily make controlled crosses (Phillips, 2010).  Many cereal crops related to maize, like rice and wheat, have unisexual flowers, hampering hybrid seed production (Kellogg, 2015).

Armored scale insects (Hemiptera: Diaspididae) include many destructive pests of orchard crops, forestry, horticulture, and agriculture (Kennett et al., 1990), costing an estimated two billion dollars per year in the US (Miller & Davidson, 2005). They also have an extraordinary tendency to be invasive. As of 2005, the US had 132 species of diaspidids introduced from other countries (Miller et al., 2005), comprising fully 40% of the known US armored scale insect fauna. Of these, 85 (64%) were considered pests.

The micronutrient iron (Fe) is essential for photosynthesis, respiration, and many other processes, but Fe is only sparingly soluble in aqueous solution, making adequate acquisition by plants a serious challenge. Fe is a limiting factor for plant growth on approximately 30% of the world's arable lands. Furthermore, iron is highly reactive and, if over-accumulated, can cause cellular damage.

Eastern white pine (Pinus strobus) is a crucial ecological and economic component of forests in the eastern U.S. and Canada. In the southeastern U.S., white pine is an especially critical associate of forests in the Appalachian Mountains as hemlock trees have been in decline due to the exotic hemlock woolly adelgid (Adelges tsugae).

Many bee pollinators are in decline, and exposure to diseases has been implicated as one of the potential causes Novel work in my lab found that consuming sunflower pollen dramatically reduced bumble bee infection by a gut pathogen. These are exciting results, but at this point we have established this effect only in the lab, with a single sunflower variety, one bumble bee species, and one pathogen species.

This proposal is about programmed cell death and sex determination in maize and the grass family. Programmed cell death is best defined as genetically encoded, actively controlled cellular suicide. Programmed cell death is of fundamental importance in plant development. For example, xylem cells undergo programmed cell death and create an interconnected network of hollow tubes essential for water transport.