October 2009: GDCB Professor Michael Muszynski receives sponsored research award from Syngenta Seeds

Dr. Michael Muszynski, Adjunct Assistant Professor in GDCB, has been awarded $247,086 from Syngenta Seeds for his research project entitled, “Molecular Isolation and Functional Characterization of the Gametophyte Factor1 (ga1) Locus of Maize.”

Interactions between the pollen and pistil leading to compatible or incompatible fertilization have been extensively studied in several solanaceous and cruciferous species but little is known regarding this process in cereals. Although maize (Zea mays) is normally a self-compatible species; a few loci that prevent reciprocal crossing have been identified. Demerec first identified the gametophyte factor1 (ga1) locus from a variety of popcorn in 1929. Plants carrying the dominant Ga1 allele can only be successfully fertilized by their own pollen and not by pollen from ga1 plants. But both Ga1 and ga1 pollen fertilize ga1 plants with equal efficiencies. Thus, the dominant Ga1 allele mediates unidirectional cross-incompatibility that functions gametophytically in the pollen but sporophytically in the silk (pistil). Although first described nearly 80 years ago, nothing is known about the molecular mechanisms of Ga1 unidirectional cross-incompatibility. To gain insight into the molecular mechanisms underlying Ga1 function and as a first step towards engineering a fertilization control system in maize, the research project will isolate the Ga1 gene using a map-based cloning approach. In addition, this research will functionally characterize the Ga1 mutation and gene in order to understand the molecular mechanisms by which Ga1 mediates unidirectional cross incompatibility.

The project research will pinpoint and validate the Ga1 gene using previous fine mapping results from Syngenta Seeds. The sequences of gene models from a defined region of the maize genome will be compared between several recessive ga1 and dominant Ga1 maize lines to identify the molecular lesions that lead to cross incompatibility and would explain Ga1 function.