Peptide Feeding and Mechanical Wounding for Tomato Seedlings.

Plants need to respond appropriately to wounding and herbivorous insects. Peptide signals have been implicated in local and systemic induction of appropriate plant defense responses. To study these peptide signals and their perception in host plants, it is important to have reproducible bioassays. Several assays, such as treatment of peptide solution via pressure infiltration, have been developed. Here, we provide detailed protocols for peptide feeding and mechanical wounding for tomato seedlings. To directly introduce peptides into tomato seedlings, peptide solution is fed through the excised stem via the transpiration stream. To mimic the wounding caused by insect feeding, leaflets of tomato seedlings are mechanically damaged with a hemostat; and wounded and systemic unwounded leaves are harvested and analyzed separately. Samples from both assays may be further assessed by examining the transcript level of marker genes by quantitative real-time PCR (qRT-PCR).