ENGINEERINGPLANTS FORNEMATODERESISTANCE

Abstract

Biotechnology offers sustainable solutions to the problem of plant parasitic nematode control. There are several possible approaches for developing transgenic plants with improved nematode resistance; these include anti-invasion and migration strategies, feeding-cell attenuation, and antinematode feeding and development strategies. The essential elements of an effective control strategy are (a) genes that encode an antinematode effector protein, peptide or interfering RNA and (b) promoters that direct a specific pattern of expression for that effector. This review summarizes information on effectors that act directly against the nematode as well as those aimed at disrupting the nematode feeding site. We discuss patterns of promoter activity that could deliver expression of these effectors in a restricted and directed manner. Societal opposition to the technology of GM-nematode control is also discussed.

Comparative phylogenetic analysis of cystatin gene families from arabidopsis, rice and barley

“…Their endogenous role has been related to the inhibition of endogenous cysteine proteinases-which prevents degradation of storage proteins in developing endosperms-and the regulation Electronic Supplementary Material Supplementary material is available for this article at http://dx.doi.org/10.1007/s00438-005-1147-4 of protein turnover upon seed germination (Arai et al 2002;Corre-Menguy et al 2002;Martı´nez et al 2003b) and of programmed cell death (Solomon et al 1999;Belenghi et al 2003). Their defence role is inferred from their ability to inhibit exogenous proteases such as those present in the digestive tracts of insects, by their activity in bioassays against insects and mites Pernas et al 1998Pernas et al , 2000 and by the enhanced resistance to insects, nematodes, slugs and potyviruses observed in transgenic plants overexpressing PhyCys genes (Vain et al 1998;Gutierrez-Campos et al 1999;Walker et al 1999;Delledonne et al 2001;Atkinson et al 2003). Antifungal activities have also been described for certain PhyCys (Pernas et al 1999;Siqueira-Junior et al 2002;Soares-Costa et al 2002;Martı´nez et al 2003a).…”

Tailoring the Specificity of a Plant Cystatin toward Herbivorous Insect Digestive Cysteine Proteases by Single Mutations at Positively Selected Amino Acid Sites

“…The expression of recombinant cystatins in transgenic crops has been proposed by several authors to prevent herbivory or pathogenic infection (Arai and Abe, 2000;Atkinson et al, 2003;Haq et al, 2004). Cystatins, similar to other competitive protease inhibitors, form a tight complex with the active site of target proteases to cause inhibition and interfere with dietary protein digestive functions in herbivorous organisms (Arai et al, 2002).…”

“…Cystatins expressed in transgenic plant lines were shown to alter the development of herbivorous arthropods and root parasitic nematodes relying on Cys proteases for extracellular protein digestion (e.g. Leplé et al, 1995;Atkinson et al, 2003;Outchkourov et al, 2004). These proteins also show potential for microbial control, as suggested by their deleterious effects against a number of fungal and viral pathogens of agronomic significance (GutierrezCampos et al, 1999;Martinez et al, 2005;Yang and Yeh, 2005;Christova et al, 2006).…”

Genetic Engineering Strategies for Biotic Stress Tolerance in Plants

“…Alternate transgenic approaches and RNAi, which was in fact discovered in the nematode Caenorhabditis elegans (Fire et al 1998 ), provide a better scope for control of plant parasitic nematodes. Some of the strategies used for developing transgenic plants with resistance to nematodes include anti-invasion and migration, anti-nematode feeding and development and feeding-cell attenuation strategies (Atkinson et al 2003 ). Expression of cysteine proteinase inhibitor (cystatin) in transgenic plants helped potato plants resist nematode attack (Cowgill et al 2002 ).…”