General use of antisense RNA in transgenic plants: what is the typical outcome on target gene expression?

Introduction / Context:Antisense RNA is a precision tool for downregulating specific genes in plants. It has been used to modify traits such as ripening rate, pigment accumulation, and metabolic profiles by reducing the expression of a single gene at a time.

Given Data / Assumptions:

• Antisense transcripts are complementary to a particular mRNA.
• Silencing acts post-transcriptionally by blocking translation or promoting mRNA degradation.
• Targeting is gene-specific.

Concept / Approach:When antisense RNA hybridizes to its target, ribosomes cannot efficiently translate the duplex, or nucleases degrade it. The phenotypic effect reflects the reduced protein level for that gene, offering controlled modulation without altering other unrelated genes.

Step-by-Step Solution:

Verification / Alternative check:Notable examples include delayed-softening tomatoes via antisense polygalacturonase and color pathway modulation via antisense chalcone synthase.

Why Other Options Are Wrong:

• A/B: Antisense does not globally activate or eliminate entire pathways.
• C: It is not limited to virus coat proteins; many endogenous plant genes have been targeted.
• E: Antisense reduces, not increases, translation.

Common Pitfalls:Assuming nonspecific effects; proper design ensures specificity and minimizes off-targets.

Final Answer:Reduce or eliminate expression of an individual, targeted gene