Accumulation of pathogenesis-related type-5 like proteins in phytoplasma-infected garland chrysanthemum Chrysanthemum coronarium.

Soluble proteins extracted from leaves, apical shoots, axillary shoots, and stems of garland chrysanthemum plants infected by onion yellows phytoplasma were analyzed by two-dimensional gel electrophoresis. Computerized matching analysis revealed that at least six soluble proteins were accumulated specifically in phytoplasma-infected garland chrysanthemum. N-terminal amino acids sequences of these soluble proteins, determined by Edman degradation, shared high sequence similarities with those of pathogenesis-related type-5 (PR-5) proteins such as tobacco thaumatin-like protein. Accumulation of these six proteins was also found in garland chrysanthemum plants infected by other phytoplasmas. These results demonstrate that phytoplasmal infection induces the accumulation of PR-5 like proteins in garland chrysanthemum plants.