Research On A Pavement Cell Mutant E83 Of Arabidopsis Thaliana

Leaf epidermis cell is a kind of cell that is irregular in shape and size. Adjacent cells niche into each other through lobes and necks to form a continuous surface. Pavement cells, trichome cells and stomatal guard cells together constitute the outmost layer of plant which has functions of gas exchange and protection. The morphogenesis of Arabidopsis leaf pavement cell is controlled by a series of mechanisms, including distribution of pavement cells, determination of cell shape and size, any factor that affect these mechanisms can lead to abnormal morphogenesis of pavement cell.In our research, from an ethyl methane sulfonate (EMS)-mutagenized Arabidopsis population, we isolated a large pavement cell mutant e83. The mutant exhibits larger pavement cells in rosette leaf which is 10 times as large as wild-type. This large cells are about 10% of the total normal pavement cells. On the other hand, the root of mutant is shorter than wild-type. Analysis indicated that in the mutant, the cell sizes become larger in root elongation zone while the cell numbers are reduced. The rosette leaves are left-right asymmetry in the mutant. The mutant growth is slightly delayed in germination, bolting, flowering and silique maturity. The mutant exhibits twisted siliques and reduced fertility due to decreased pollen grains in some anthers. The mature mutant has a little dwarf phenotype.Using a map-based cloning approach, based on the large pavement cell phenotype, we found the mutant gene is at a region of 306 kb, ranging from 2354 kb to 2660 kb on the left arm of chromosome 1. The analysis and identification indicated that gene A possibly the targeting gene which encodes a DNA polymerase submit. We speculated that the mutation of A gene might result in the abnormal replication of pavement cell DNA, and affect the pavement cell morphogenesis.