Correct option is B
Pathogenesis-Related (PR) proteins are a group of plant proteins involved in defense against pathogens. They have diverse enzymatic activities that degrade pathogen cell walls or inhibit pathogen growth.
Correct Matching of PR Proteins to Their Activities:
PR2 → β-1,3-glucanase (A - i)
- PR2 proteins degrade β-1,3-glucans, which are major components of fungal cell walls.
- This activity helps plants defend against fungal pathogens.
PR3 → Chitinase (B - ii)
- PR3 proteins act as chitinases, breaking down chitin, a key component of fungal cell walls.
- This enzyme plays a crucial role in antifungal defense.
PR6 → Proteinase Inhibitor (C - iii)
- PR6 proteins function as proteinase inhibitors, preventing pathogen-derived proteases from degrading plant proteins.
- These inhibitors are effective against herbivorous insects and microbial pathogens.
PR10 → Ribonuclease-like (D - iv)
- PR10 proteins have ribonuclease-like activity, breaking down RNA to interfere with pathogen metabolism.
- They are involved in broad-spectrum resistance against different pathogens.
Information Booster:
- PR proteins are involved in systemic acquired resistance (SAR), helping plants resist future infections.
- β-1,3-glucanases (PR2) hydrolyze fungal cell wall glucans, weakening fungal defenses.
- Chitinases (PR3) break down chitin, preventing fungal penetration in plant tissues.
- Proteinase inhibitors (PR6) block pathogen and insect digestive enzymes, protecting plant proteins.
- Ribonuclease-like PR10 proteins degrade pathogen RNA, disrupting pathogen function.
- PR proteins are induced by biotic stress (pathogens, insects) and abiotic stress (salinity, drought).
- Transgenic plants overexpressing PR proteins show increased resistance to fungal and bacterial infections.
