Host-Delivered RNAi to Control Root-Knot Nematodes

A study to determine if transgenic plants can be used as RNA interference (RNAi) delivery systems to control parasites, such as root-knot nematodes, was conducted by David Fairbairn and colleagues at the University of Queensland in Australia. Root knot nematodes are among the most economically damaging plant-parasitic nematodes, and can severely reduce yield in several crop species.

RNAi is a mechanism whereby double-stranded RNA (dsRNA) is used to inhibit the expression of genes with complementary sequences in transgenic organisms. Fairbairn’s group produced transgenic tobacco plants expressing different double stranded dsRNA molecules. The researchers hoped that nematodes fed with the transgenic plant will result in RNAi-mediated silencing of the nematode gene called MjTis11. Once silenced, a significant decrease in nematode populations is expected due to reduction in their fertility or egg hatching rate.  

The group however found that even though there was silencing of MjTis11, there was no effect on fecundity or egg hatching rate observed. Further research was recommended to determine the level of down-regulation of MjTis11 or to search for a more appropriate gene to target for pest lethality than the one examined.

For details, subscribers can access the paper published in the journal Planta at http://www.springerlink.com/content/d5714j54572t34u6/.