Role of GSL8 in low calcium tolerance in .

Calcium (Ca) deficiency affects the yields and quality of agricultural products. Susceptibility to Ca deficiency varies among crops and cultivars; however, its genetic basis remains largely unknown. Genes required for low Ca tolerance in have been identified. In this study, we identified a novel gene required for low Ca tolerance in . We isolated a mutant sensitive to low Ca concentrations and identified () as a gene responsible for low Ca tolerance. is a paralog of the previously identified low Ca tolerance gene , which encodes β-1,3 glucan(callose) synthase. Under low Ca conditions, the shoot growth of mutants were inhibited compared to wild-type plants. A grafting experiment indicated that the shoot, but not root, genotype was important for the shoot growth phenotype. The ectopic accumulation of callose under low Ca conditions was reduced in mutants. We further investigated the interaction between and by testing the double mutant for sensitivity to low Ca concentrations. The double mutant exhibited a more severe phenotype than the single mutant under 0.3 mM Ca, indicating additive effects of and with respect to low Ca tolerance. These results establish that genes are required for low Ca tolerance in .