Nematode resistance

Summary Plant‐parasitic nematodes are major pests of both temperate and tropical agriculture. Many of the most damaging species employ an advanced parasitic strategy in which they induce redifferentiation of root cells to form specialized feeding structures able to support nematode growth and reproduction over several weeks. Current control measures, particularly in intensive agriculture systems, rely heavily on nematicides but alternative strategies are required as effective chemicals are withdrawn from use. Here, we review the different approaches that are being developed to provide resistance to a range of nematode species. Natural, R gene‐based resistance is currently exploited in traditional breeding programmes and research is ongoing to characterize the molecular basis for the observed resistant phenotypes. A number of transgenic approaches hold promise, the best described being the expression of proteinase inhibitors to disrupt nematode digestion. The application of plant‐delivered RNA interference (RNAi) to silence essential nematode genes has recently emerged as a potentially valuable resistance strategy. Contents Summary 27 I. Introduction 28 II. Root‐knot and cyst nematode parasitism 28 III. Natural resistance genes 29 IV. Transgenic proteinase inhibitor (PI)‐based control of plant‐parasitic nematodes 34 V. Other anti‐nematode proteins 36 VI. In planta RNAi to target plant‐parasitic nematodes 38 VII. Concluding remarks 39 Acknowledgements 40 References 40