By Roberta Friedman, Ph.D.
Contributing Editor

A published report of viral recombination in an engineered plant does not mean that transgenic, virally resistant plant seeds should be shelved, scientists say. Instead, the research points to ways of predicting that the release of such plants will be safe.

In the experiments reported in Science, Michigan State University researchers engineered nicotiana plants to express the coat protein of the cowpea chloritic mottle virus, missing one-third of its genome at the 3' end. The viral fragment didn't confer viral resistance, but was an artificial construct to study viral recombination.

The researchers then attempted to infect the engineered plants by inoculating new leaves with a construct consisting of the missing 3' end.

Risk assessment

Four of 125 plants developed systemic infection, indicating that the two pieces of viral RNA had combined and restored a functional capsid gene. The recombined RNA proved to be slight variants of the original virus. A commentary in Science by plant biotech researchers