Difficulty: Easy
Correct Answer: Particle bombardment (gene gun) to shoot DNA into plant cells
Explanation:
Introduction:Stable plant transformation requires delivering DNA across the cell wall and membrane into the nucleus, followed by integration and expression. Multiple techniques exist, but only a few reliably produce stable transformants in diverse species and tissues.
Given Data / Assumptions:
Concept / Approach:Evaluate each method for proven ability to yield stable integration. Particle bombardment propels DNA-coated microprojectiles through the cell wall into cells, where DNA can integrate and be expressed. This approach complements Agrobacterium-mediated transformation and is useful for monocots or recalcitrant tissues.
Step-by-Step Solution:
1) Prepare DNA-coated gold or tungsten particles.2) Accelerate particles toward target tissue (callus, embryos, leaves) using gas pressure or vacuum.3) Select transformed cells using selectable markers and regenerate plants via tissue culture.Verification / Alternative check:Successful transformation is confirmed by selectable marker expression, PCR/Southern blot for integration, and inheritance of the transgene in progeny.
Why Other Options Are Wrong:
a) Heterokaryon formation with animal cells is irrelevant for stable plant genetic engineering.c) E. coli does not transfer T-DNA; Agrobacterium does.d) Tobamoviruses replicate episomally; routine stable integration via TMV infection is not standard.e) Passive soaking with salts does not cross the cell wall effectively for stable nuclear integration.Common Pitfalls:Assuming any bacterium can deliver plant genes; confusing transient viral expression with genomic transformation.
Final Answer:Particle bombardment (gene gun).
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