Impact of plant elicitor peptides on growth, reproduction, and nematode resistance

The goal of this study was to determine if increasing the expression of genes encoding
plant elicitor propeptides (ProPEPs) in Arabidopsis thaliana could protect against
damage by the root-knot nematode (Meloidogyne incognita), a major pest of many
crops. When wild type Arabidopsis (WT, Col-0) and lines that overexpress AtPROPEP1,
AtPROPEP2, and AtPROPEP3 were challenged with M. incognita, all 3 ProPEP genes
suppressed the number of galls/gram of root and enhanced the number of seed
pods/plant compared to Col-0. Infested plants that overexpressed AtPROPEP2
and AtPROPEP3 also were larger and less chlorotic than Col-0. To assess whether
ProPEP overexpression caused any fitness costs in the absence of pests, health and
reproduction was also compared in unchallenged plants. In the absence of infestation,
all lines that overexpressed AtPROPEP2 and AtPROPEP3 produced as many or more
seed pods as WT controls. This suggests that overexpression of certain ProPEP
genes can protect plants from the negative effects of nematode infection without
compromising plant fitness in the absence of nematodes.