In plants, the overexpression of lectin genes confers resistance to:
In plants, the overexpression of lectin genes confers resistance to:
Select an option to attempt
Correct Answer: Option B
Explanation
Lectins as insect resistance genes in plants:Plant lectins are carbohydrate-binding proteins:• When expressed in plant tissues (leaves, seeds), lectins bind to glycoproteins in the insect's midgut epithelium.• Disrupts digestion, nutrient absorption, and midgut cell integrity.• Reduces insect survival, growth, and reproduction → plant resistance to insect herbivory.Examples:• Snowdrop lectin (GNA from Galanthus nivalis): effective against aphids and some Lepidoptera.• Concanavalin A (ConA): binds glucose/mannose residues in insect gut.Application: Transgenic expression of lectin genes in crop plants (rice, wheat) for pest resistance is an active research area.Distinction: Lectins work as INSECT DETERRENTS (binding to gut glycoproteins), not as anti-herbivore TOXINS (like Bt toxin, which forms pores in the insect gut membrane).Answer: Lectins confer insect resistance by binding to glycoproteins in insect digestive systems, disrupting digestion.