Analysis of a seed coat mutant (patchy) in Arabidopsis thaliana

During seed development, many plants synthesize, secrete and extrude large quantities of pectic polysaccharides in the form of mucilage from the epidermal cells of the seed coat. These cells also undergo unique morphological changes throughout their development which have been well described. Phenotypic, genetic and molecular characterization of the patchy (pty-1) mutant in Arabidopsis thaliana was undertaken to further determine the genetic factors controlling the development and morphology of this cell type and its production of mucilage. The pty-1 mutation was found to be the result of a T-DNA insertion event and was mapped to distal locus on chromosome 5. Analysis of double mutant created between pty-1 and mum1 (another known seed coat mutant in Arabidopsis) indicates that pty-1 and mum1 interact synergistically with respect to the extrusion of mucilage, and their mutant phenotypes may be due to the altered chemical composition of pectins. Phenotypic characterization of pty-1, a second stronger pty-2 allele, and the pty-1/pty-2 heteroallelic mutant was performed using both light and scanning electron microscopy. These studies suggested that rather than merely affecting pectin composition, mutations at the PTY locus may control the general morphogenesis of this cell type.Science, Faculty ofBotany, Department ofGraduat