A constitutive serine protease inhibitor suppresses herbivore performance in tea ().

Protease inhibitors promote herbivore resistance in diverse plant species. Although many inducible protease inhibitors have been identified, there are limited reports available on the biological relevance and molecular basis of constitutive protease inhibitors in herbivore resistance. Here, we identified a serine protease inhibitor, , from the tea plant (). Expression of was not strongly affected by the assessed biotic and abiotic stresses. and experiments showed that CsSERPIN1 strongly inhibited the activities of digestive protease activities of trypsin and chymotrypsin. Transient or heterologous expression of significantly reduced herbivory by two destructive herbivores, the tea geometrid and fall armyworm, in tea and plants, respectively. The expression of in did not negatively influence the growth of the plants under the measured parameters. Our findings suggest that can inactivate gut digestive proteases and suppress the growth and development of herbivores, making it a promising candidate for pest prevention in agriculture.