nature insight: Plant defence

Plant defence
Vol. 411, No. 6839 (14 June 2001).
|PDF(89K)|

Cover illustration
(Image courtesy of P.REYMOND/E.FARMER)

This is an exciting time to be interested in plant science. The advances in plant molecular biology, of which the sequencing of the Arabidopsis thaliana genome is but the most visible manifestation, are providing revelations on a weekly basis, and one of the faster moving fields within plant science is the study of plant defence mechanisms. While many immunologists may view the mammalian immune system as a pinnacle of evolution, natural selection has honed the defence strategies of plants over 1.6 billion years without recourse to antibodies, T cells and the like, producing systems no less subtle or effective.

One theme that emerges in this Insight is how molecules and mechanisms involved in plant defence have direct homologues in animals. Some of the plant resistance genes are cousins of the Toll-like receptors important in animal innate immunity; post-transcriptional gene silencing in plants seems practically identical to RNAi discovered nearly simultaneously in Caenorhabditis elegans; and the programmed cell death used to isolate and excise diseased plant tissue proceeds in ways both similar and different to the induction of apoptosis in animals. But despite the similarities, these systems have evolved in directions and to levels of sophistication not seen in animals.

A knowledge of plant defence strategies also has practical applications. Even our current knowledge of defence mechanisms is being, or soon will be, exploited to produce improved disease resistance in crops. But evolution has been doing this for millions of years. We will need to learn lessons from ecology as well as biochemistry if we are to apply our emerging understanding of plant defence in any meaningful way.

Seven articles is too few to provide anything but a survey of some aspects of this fascinating subject. However, we hope that this Insight will give readers a better idea of the armaments employed for the battle raging in our own backyards.

Christopher Surridge Senior Editor