Abstract
Sugars serve function as signal molecules that regulate plant metabolism. It seems that sugar signalling regulates cell wall synthesis and remodeling, since cell wall materials are major sink for nutrient. However, relation between sugar signalling and cell wall metabolism remains obscure.
We isolated a mutant of Arabidopsis that shows altered sensitivity to stresses that perturb cell surface stability. In seedlings of this mutant, content of cell wall cellulose significantly decreased when sugar content of medium is high. Growth of the seedlings also showed higher sensitivity to sugar content of medium. Recent studies indicated that growth of Arabidopsis seedlings are regulated by carbon:nitrogen ratio, and that deficiency of nitrogen results in increased sugar sensitivity. Therefore we examined basic nitrogen metabolism of the mutant. We found that amino acid metabolism of this mutant showed significant abnormality. It seems that aberrant carbon:nitrogen metabolism of this mutant affects sugar sensitivity and cellulose synthesis simultaneously.
