Engineering virus resistance in plants: which genetic strategies have been used to create resistance against plant viral infections?

Introduction / Context:
Transgenic strategies for plant virus resistance predate RNA interference and include “pathogen-derived resistance.” By expressing viral components in the plant, replication or movement of the invading virus can be impaired.

Given Data / Assumptions:

• Coat protein–mediated resistance can block uncoating or assembly dynamics.
• Movement/nucleocapsid proteins can interfere with cell-to-cell or systemic spread.
• Satellite RNAs can attenuate symptom development with certain helper viruses.

Concept / Approach:
Each approach exploits molecular interference. Coat protein expression often yields broad resistance to related strains. Movement/nucleocapsid protein expression can disrupt trafficking. Satellite RNA can modulate pathogenicity by competing for replication machinery.

Step-by-Step Solution:

Verification / Alternative check:
Classic examples include coat-protein-mediated resistance in tobacco and squash, and satellite RNA approaches against Cucumber mosaic virus.

Why Other Options Are Wrong:

• A/B/C alone are incomplete.
• E is incorrect; RNAi is powerful but not the only method historically or currently used.

Common Pitfalls:
Assuming a single universal mechanism; efficacy is virus- and host-dependent.

Final Answer:
All of these