Defense proteins
In wild type M. truncatula, the concentration of Trypsin inhibitor (TI) was significantly higher in cauterized caterpillar than control and normal caterpillar. It indicates that effectors in S. exigua caterpillar labial saliva have suppressive effect on the JA-mediated IR. Since, this labial salivary-specific suppression of TI was abolished in ethylene insensitive skl mutant, it indicates that ethylene plays role in this mechanism. Activity of another defense related protein, laccase-like multi-copper oxidase (LMCO), was neither affected by caterpillar herbivory nor any labial saliva-specific effect were observed in both genotypes. Thus, ethylene is not involved.