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.