Iceland poppy has one-of-a-kind floral colour Floral colours are usually designated by pigments such as flavonoids, carotenoids or betalains. But the colour of the flowers of the yellow Iceland poppy is down to a group of pigments called nudicaulins. Health © Shutterstock Nudicaulins refers to a group of alkaloid compounds found in the petals of the Papaver nudicaule (Iceland poppy) flower. A close analysis of this special plant and its organs during different development stages revealed that nudicaulin pigments are located only in petals. Now, with the unfolding of the chemical structure of nudicaulins, other unique molecular structures have come to the fore, signalling a breakthrough in plant biology and biochemistry. The Biosyn-Nudicaul project aimed to understand the make-up and distribution of nudicaulins, investigate their physiological and ecological functions, and uncover their potential for use in drugs. To achieve these objectives, biosynthetic studies were used to either inject labelled precursors into plant material before identifying their derived isotopomers, or to apply a non-invasive technique such as plant illumination, which led to the production of isotopologues. A comparison of the metabolic profile of white flowers from Iceland poppy plants with that of the yellow flowers showed that the only difference was the absence of nudicaulins. Further research results indicate that the metabolic pathway responsible for the biosynthesis of nudicaulins is inactive in white petals, since the corresponding genes and enzymes are not expressed. The fact that nudicaulin pigments are located only in the petals points to these pigments playing a major role in the flower's pollination mechanism. The example of nudicaulins is unique and work in this project has revealed the presence of a novel pathway, which represents a breakthrough in plant biology and biochemistry.