RNA Interference of Effector Gene Mc16D10L Confers Resistance Against Meloidogyne chitwoodi in Arabidopsis and Potato.

Meloidogyne chitwoodi, a quarantine pathogen, is a significant problem in potato-producing areas worldwide. In spite of considerable genetic diversity in wild potato species, no commercial potato cultivars with resistance to M. chitwoodi are available. Nematode effector genes are essential for the molecular interactions between root-knot nematodes and their hosts. Stable transgenic lines of Arabidopsis and potato (Solanum tuberosum) with resistance against M. chitwoodi were developed. RNA interference (RNAi) construct pART27(16D10i-2) was introduced into Arabidopsis thaliana and potato to express double-stranded RNA complementary to the putative M. chitwoodi effector gene Mc16D10L. Plant-mediated RNAi led to a significant level of resistance against M. chitwoodi in Arabidopsis and potato. In transgenic Arabidopsis lines, the number of M. chitwoodi egg masses and eggs was reduced by up to 57 and 67% compared with empty vector controls, respectively. Similarly, in stable transgenic lines of potato, the number of M. chitwoodi egg masses and eggs was reduced by up to 71 and 63% compared with empty vector controls, respectively. The relative transcript level of Mc16D10L was reduced by up to 76% in M. chitwoodi eggs and infective second-stage juveniles that developed on transgenic pART27(16D10i-2) potato, suggesting that the RNAi effect is systemic and heritable in M. chitwoodi.