Molecular Characterization of the Thaumatin-like Protein PR-NP24 in Tomato Fruits

Pathogenesis-related proteins play significant roles in plant responses to pathogen infection and environmental stresses. PR-5 proteins are thaumatin-like proteins (TLPs) and can improve plant resistance to diseases. In this study, a protein named PR-NP24 belonging to the PR-5 family was found to be specifically expressed in tomato exocarp. Subsequently, PR-NP24 and orthologous TLPs were identified in partial Solanaceae species. The differential expression patterns of the PR-NP24 protein in the exocarp of tomato were further analyzed, which resulted in a better understanding of PR-NP24 regulation in plant responses to abiotic and biotic stresses. Accumulation of PR-NP24 induced by salt (NaCl) treatment could promote plant resistance against invasive fungal pathogens. This study concluded that the regulation of PR-NP24 in tomato exocarp could possibly be applied to improve the harvest management of tomato fruits as well as be of practical significance to control the allergenic potentials of the fruits of other plants.