Contents - Faperta

232 Biotechnological Approaches for Pest Management and Ecological Sustainability
Plant Lectins
Plant lectins are a heterogeneous group of sugar binding proteins, which have a protective
function against a range of organisms. Plant lectins are particularly effective against
the sap sucking Hemiptera (Shukle and Murdock, 1983; Czapla and Lang, 1990; Powell
et al., 1993, 1995; Hilder et al., 1995) (Table 7.5). Lectins from Canavalia ensiformis (L.) DC
(Concanavalin A), Amaranthus caudatus L., Lens culinaris Medik., and Galanthus nivalis L.
induced signifi cant mortality in Acyrthosiphon pisum (Harris) (Rahbe et al., 1995). Snowdrop,
garlic, and chickpea lectins have shown adverse effects on survival, growth, and development
of H. armigera (Shukla, Arora, and Sharma, 2005; H.C. Sharma et al., 2005). Many
mannose-binding lectins were toxic to A. pisum. Concanavalin A has also been tested against
Aphis gossypii Glover, Aulacorthum solani Kalten., Macrosiphum euphorbiae (Thomas),
Macrosiphum albifrons Essig, and M. persicae at concentrations between 10 and 1500 μg mL1 .
Mortality was quite variable from one species to another. No part of the digestive tract
contained detectable amounts of endoprotease activity (Rahbe et al., 1995). Plant lectins
have shown biological activity against a range of insects. However, consideration should
be given with regard to their deployment in transgenic plants because of their known
toxicity to mammals and humans.
Tobacco
The gene for snowdrop lectin (GNA) expressed in tobacco plants has shown enhanced
resistance to peach potato aphid, M. persicae, and pea lectin in tobacco to H. virescens
(Boulter et al., 1990). Greater insecticidal activity has been observed in chitin binding lectins
and the lectin gene in wheat germ and common bean. Fall armyworm, S. frugiperda
TABLE 7.5
Insect-Resistant Transgenic Crops Expressing Plant Lectin Genes
Crop Inserted Gene Useful Trait References
Tobacco GNA from
Galanthus nivalis
Resistant to peach potato aphid, Myzus
persicae.
Boulter et al. (1990)
Pea lectin Resistant to Heliothis virescens. Boulter et al. (1990)
Cotton GNA Reduced larval weight of cotton bud
worm, Heliothis virescens.
Rice GNA Resistant to brown planthopper,
Nilaparvata lugens and green leafhopper,
Nephotettix virescens.
Resistant to potato leafhopper, Empoasca
fabae.
Potato GNA and ConA Less susceptible to peach potato aphid,
Myzus persicae.
Tomato GNA Reduction in larval biomass of tomato
moth, Leacanobia oleracea.
Maize Wheat agglutinin
(WGA)
Moderate activity against Ostrinia nubilalis
and Diabrotica sp.
Mustard WGA Antibiotic, antifeedant, and insecticidal to
mustard aphid, Lipaphis erysimi.
Sugarcane GNA Increased antibiosis to larvae of sugarcane
grubs, Antitrogus consanguineus.
Satyendra, Stewart, and
Wilkins (1998)
C.D. Yang et al. (1998)
Habibi, Backus, and Czapla
(1992)
Gatehouse et al. (1999)
Fitches, Gatehouse, and
Gatehouse (1997)
Maddock et al. (1991)
Kanrar et al. (2002)
Nutt et al. (1999)