Earliest open-field trials of a genetically altered organism: Which case is widely cited as among the first field tests?

Introduction / Context:
Understanding biotechnology history helps frame regulatory evolution and public perception. One of the first and most publicized field trials involved genetically modified microbes designed to reduce frost damage in crops by removing the ice-nucleation activity from Pseudomonas syringae (“ice-minus”).

Given Data / Assumptions:

• Timeline matters: early to mid-1980s marked initial outdoor tests.
• “Ice-minus” field trials preceded widespread GM crop trials like Bt corn and herbicide-tolerant soybean.

Concept / Approach:
Ice-nucleation proteins promote frost formation near 0 °C. The modified strain lacking this activity was proposed to reduce frost injury by outcompeting native “ice-plus” bacteria on leaf surfaces. Field tests on strawberries (and potatoes) in the 1980s became a landmark in GMO regulation and public debate.

Step-by-Step Solution:

Verification / Alternative check:
Contemporary reports and regulatory records document these tests and the associated legal and public actions, distinguishing them from later plant transgenic releases.

Why Other Options Are Wrong:

• Bt corn, Flavr Savr, herbicide-tolerant soybean: later 1990s milestones.
• Recombinant vaccinia for wildlife immunization was tested, but the iconic first crop-related GMO field test narrative generally centers on ice-minus bacteria.

Common Pitfalls:
Assuming the first high-profile GM foods (e.g., Flavr Savr) were also the first field trials; overlooking microbial trials that preceded transgenic crops.

Final Answer:
Strawberry seedlings sprayed with “ice-minus” bacteria (modified Pseudomonas syringae)