Dr. Kessler’s research explores the molecular mechanisms behind plant reproduction. In angiosperms, successful pollination depends on intercellular communication between the male gametophyte (also known as the pollen tube) and female cells as the pollen lands on the stigma and sends out a pollen tube that travels through the transmitting tract of the style to reach the ovary. The synergid cells of the female gametophyte (also known as the embryo sac) emit signals to attract pollen tubes and then communicate with the pollen tubes so that they know when to cease tip growth and burst to release the sperm cells so that double fertilization can occur to produce viable seeds. This process is known as pollen tube reception and is the main focus of the Kessler Lab. Our studies with the Arabidopsis thaliana MLO protein NORTIA and the receptor-like kinase FERONIA have shown that pollen tube reception and powdery mildew infection may use similar molecular mechanisms. We are using NORTIA as an anchor molecule to learn more about the intricate signaling mechanism that takes place in the ~30-minute “communication phase” when the pollen tube arrives at the ovule and prepares to release the sperm cells.
A second project in the Kessler Lab uses natural variation in Arabidopsis accessions to explore other components of fertility and ultimately seed yield. Genome wide association studies (GWAS) have revealed candidate loci for genes that may be responsible for determining how many seeds a plant produces. We are currently taking a reverse genetic approach to assay the candidate genes for functions in plant fertility.
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