Expression analysis of sweet potato patatin-like protein ( PLP ) genes in response to infection with the root knot nematode Meloidogyne incognita

Sweet potato ( Ipomoea batatas L.), a globally important root crop, is susceptible to the root-knot nematode (RKN) Meloidogyne incognita , which can cause significant yield losses. Previously, transcriptome analysis of the roots of RKN-susceptible and -resistant sweet potato cultivars revealed various genes potentially contributing to protection against RKN infection. Among the genes identified, several genes encoding patatin-like proteins (PLPs), a storage protein found in plants were found. In this study, the roles of PLP genes in the defense response to RKN infection were investigated in susceptible and resistant sweet potato cultivars. In comparison with Arabidopsis , tomato and potato genes revealed a group of sweet potato PLP genes belonging to five different ortholog groups. These five groups contained several unigenes, which showed expression-level changes in sweet potato roots upon nematode infection. These results indicate that PLP genes play a key role in protecting sweet potato roots from RKN infection.