Delayed-ripening tomato strategy: The trait was achieved by a biotechnologist who effectively __________ a key ripening gene (for example, polygalacturonase).

Introduction / Context:
Delaying tomato ripening was achieved by reducing the expression of genes involved in softening, notably polygalacturonase. Early implementations used antisense RNA or co-suppression to silence gene expression.

Given Data / Assumptions:

• Polygalacturonase contributes to pectin breakdown.
• Antisense constructs reduce the target mRNA abundance.
• Goal is to slow, not abolish, ripening to maintain quality.

Concept / Approach:
Gene silencing (by antisense or RNA interference) decreases enzyme levels without relocating or necessarily replacing the gene. This post-transcriptional approach is precise and preserves overall plant development.

Step-by-Step Solution:

Verification / Alternative check:
Commercial and academic literature explicitly describes antisense-mediated silencing of the polygalacturonase gene in delayed-ripening tomatoes.

Why Other Options Are Wrong:

Common Pitfalls:
Equating gene knockout with silencing; early products used antisense rather than full knockouts.

Final Answer:
silenced.