Resistance to both cyst and root-knot nematodes conferred by transgenic Arabidopsis expressing a modified plant cystatin.

Plant nematodes are major pests of agriculture. Transgenic plant technology has been developed based on the use of proteinase inhibitors as nematode anti-feedants. The approach offers prospects for novel plant resistance and reduced use of environmentally damaging nematicides. A modified rice cystatin, Oc-I delta D86, expressed as a transgene in Arabidopsis thaliana, has a profound effect on the size and fecundity of females for both Heterodera schachtii (beet-cyst nematode) and Meloidogyne incognita (root-knot nematode). No females of either species achieved the minimum size they require for egg production. Ingestion of Oc-I delta D86 from the plant was correlated with loss of cysteine proteinase activity in the intestine thereby suppressing normal growth, as required of an effective antifeedant plant defence.