Researchers have discovered that certain proteins in plants are used to increase or decrease the scent of the plant to ensure their survival. The scent of a plant can repel organisms that may want to consume the plant, and it can also attract organisms so they can help spread their pollen. Joshua Widhalm, a horticulturist at Purdue University, ran computer simulations to inspect the movement of petunia scent compounds. The result of the test was, the compounds were unable to move quick enough to avoid damaging the plant. So, the researchers came to believe that there must be some sort of courier system moving the compounds out.
In a more recent study, a Purdue biochemist, Natalia Dudareva, and her team observed genetic changes of a petunia plant from its initial budding stage. Within the study, it was observed that the least amount of organic compound was found in the budding stage. The stage where the organic compound levels were at an all-time high was during the flower opening stage. Once the flowers opened, the gene PhABCG1 produced levels of proteins that was 100 times higher than the budding stage. Petunias which produced 70-80% less of the PhABCG1 were genetically engineered. Petunias that produced normal amounts of PhABCG1 were healthier than the genetically engineered petunias which produced 70-80% less of the protein. Engineered petunias released half the amount of scent compounds, but the levels inside the plant cells built up to double the normal amount. The flowers with the lowest levels of PhABCG1 had an accumulation of compounds which led to the degradation of cell membranes. This is the first study to have successfully identified a protein which transports scent compounds out of a cell.