The bacterium Agrobacterium tumifaciens is a sophisticated plant pathogen causing gall-like tumours in its hosts. Upon infection, it introduces a small section of its own DNA (called T-DNA) into the host plant’s genome and this results in the formation of a plant tumour. The T-DNA carries genes for the production of plant hormones (auxin and cytokinins) thus altering the hormonal balance in the plant cell so that its division is no longer controlled and tumours form. In addition, the inserted bacterial DNA also reprograms the plant to make chemicals called opines, which the bacteria then use as a source of nutrition.
By infecting carrot slices with these tumourogenic bacteria, I have generated an immortal and undifferentiated type of carrot tissue that uniquely produces opines. I have now made a soup with these cells, harvested from many infected carrot slices, and I’m pleased to report that it tastes divine, with the bacterial opines producing a stunning and unique flavour.
This is the starting point for some further explorations in which it might be possible to clone in various flavour pathways into the carrot cells, so that one could directly grow carrot soup in the lab (with onion or coriander flavour pathways engineered into it) without ever having to resort to soil grown a carrot, onion or herb.