Analysis of the Temperature-Sensitive acw Mutants Defective in Cell Elongation and Cell Wall Biosynthesis

Abstract

Plant cell wall biosynthesis is indispensable to cell elongation and expansion that occur in the morphogenesis. However, the molecular mechanisms of cell wall biosynthesis in the cell growth are poorly understood. To understand the mechanisms, we have been studying seven temperature sensitive elongation-deficient acw1~7 mutants that have altered cell wall structures. Previously, we reported the analysis of acw1 (3), 2, 7 mutants and demonstrated that these ACW genes are required for cellulose biosynthesis. In this study, acw4, 5 and 6 were analyzed in detail.
We analyzed the sugar composition of the mutant cell walls. The results showed that these mutations affect not only cellulose biosynthesis but also non-crystalline polysaccharide biosynthesis. We mapped these mutation loci to chr. 1 (acw4 and 6) and chr. 4 (acw5). Currently, we are progressing the complementation tests for gene isolation.