Kirsten Jørgensen

Short presentation

Research: The research is to understand the role of cyanogenic glucosides in the cassava plant (Manihot esculenta Crantz). The expression patterns of the genes involved in the biosynthesis of the cyonogenic glucosides are being examined during plant development and in response to abiotic and biotic stress factors like salinity, drought and viral attack. We want to characterise the promotors of the genes encoding the enzymes involved in the biosynthesis to investigate the regulation of the production of cyanogenic glucosides. To investigate cellular localisation and turnover of cyanogenic glucosides, we have cellularly localised the synthesis of the cyanogenic glucosides in the petiole and leaf blade of the first unfolded leaf by using in situ PCR and antibodies specific for the enzymes involved. In the petiole the synthesis is found in the cortex, endodermis and phloem and xylem parenchyma cells. As the cyanogenic glucosides mainly are synthesised in the the top of the cassava plant and is stored in the tuberous roots a transport of these compounds or derivatives has been suggested and is currently being investigated. In almonds s difference of localisation of β-glucosidase activity between bitter and sweet varieties was found (Sánchez-Pérez et al., 2008). The aim is to investigate the turnover of cyanogenic glucosides in different cassava cultivars and determine whether the difference in high- and low-cyanide cultivars is to some extent due to a difference in localisation and regulation of the breakdown enzymes, linamarase and α-HNL.  Specialist in histology and physiology of plants determining at both the transcriptional and cellular level where the active ingredients are produced and localised.