Stop and smell the roses…while you still can. A study from Alon Cna’ani at the Hebrew University suggests that the rise in global temperature will take a toll on floral fragrance. In his work, published last year in Plant, Cell & Environment, Cna’ani’s group demonstrated that at different temperatures the production of scent in petunia flowers changes. Their work identified a gene important in the regulation of scent production; through genetic manipulation, Cna’ani was able to not only show that the gene could be re-engineered to make floral scent temperature-independent, but also that the same gene played a role in the expression of pigments in petals (as described in a separate paper in The New Phytologist). The genetic linkage between the scent and color traits may indicate an evolutionary advantage, allowing flowers to respond to their specific environment and climate.
The temperature change in the experiment (a mere 6 Celsius) was enough to notably decrease production of fragrance-creating enzymes. Thus, as global temperatures rise, fragrance may decline. While floral smells may seem the least pressing concern with imminent flooding, arctic restructuring, and weather destabilization, there is a delicate role fragrance plays in pollination, germination, and the spread of flora in ecosystems.
These studies, in which Cna’ani de-coupled the natural scent-temperature dependency through genetic engineering, also open an interesting page of the discussion around GMOs. For generations, humans have bred plants extensively to preserve the traits most desirable. Being able to genetically modify flowers to be more fragrant is akin to genetically modifying apples to be sweeter, or rice to be more nutritious (both changes that, while well-received by consumers, many anti-GMOers balk at). At the moment, noone has objected to such manipulation of flowers; however, this is further evidence that cherry-picking traits genetically can be as simple as mutating a single gene.