In a study with broad implications for agriculture, researchers at Kyushu University in Japan have produced transgenic tobacco plants that can sustain photosynthesis when the temperatures soar (Science 287, 476–479, 2000). Taking a cue from desert plants that reduce synthesis of trienoic fatty acids in chloroplasts at high temperatures, the researchers produced two transgenic tobacco lines containing an additional chloroplast-specific Δ-3 desaturase gene from Arabidopsis thaliana. Cosuppression led to a reduction of Δ-3 desaturase gene expression in these plants and a concomitant reduction in trienoic fatty acids. As a result, the transgenic plants had a higher photosynthetic activity at growing temperatures of 40°C (which greatly diminishes photosynthesis in wild-type plants) than at 25°C. The scientists suggest that the use of endogenous genes avoided unexpected deleterious effects sometimes associated with gene manipulation using exogenous DNA. “This study may open the door for the use of gene manipulation techniques to breed new crops or trees that can adapt to inevitable changes in the global climate,” says Koh Iba, a plant physiologist on the research team. “For example, it may be interesting to improve the adaptability of trees in [colder environments]…to a high-temperature environment.”