We study pollen development using a blend of classic techniques in genetics and microscopy with powerful new genomic tools, such as single-cell RNA-sequencing. Current projects include:

Deciphering and controlling cell fate in plants

What if it was possible to reprogram a seedling leaf cell directly into pollen? This would shortcut a large portion of a plant’s life cycle as well as make key genetic events during meiosis accessible to manipulation. We are dissecting the gene regulatory circuits that control cell fate in plants, with an emphasis on pollen development. By combining research into the pathways that control pollen differentiation in vivo with synthetic approaches to reprogram cell fate in vitro, our aim is to both gain a deeper understanding of cell differentiation and establish new tools in plant breeding.

Fig. 1. Schematic of pollen development in maize.
- Read more -

The “Forgotten” Generation: The far-reaching impact of the haploid gametophyte on plant genetics

When we draw family trees in plant biology, we often focus on the relationship between diploid plants (Fig. 2b). This is an approximation. In reality, flowering plants alternate between a diploid generation and a multicellular haploid generation (Fig. 2c). One focus of the lab is to explore what happens when this approximation goes wrong.

Fig. 2. Pollen is not a plant gamete, but rather a multicellular haploid organism with active gene expression. (a) Micrograph of pollen grains from a single plant stained with iodine (from Parnell, 1921). These pollen grains are segregating a mutation in a starch biosynthesis gene. Pollen grains with the mutation do not stain with iodine. (b) A hypothetical genetic family tree tracing a recessive allele (red) through three generations of diploid plants. (c) In reality, each diploid generation alternates with a haploid generation (male pollen or the female embryo sac). Selection on the haploid phase can alter allele frequencies in the following diploid generation. In this example, pollen grains with the white allele die more frequently (marked by the “x”s) and are therefore less likely to transmit the white allele.
- Read more -