CLONING AND FUNCTIONAL CHARACTERIZATION OF ORNITHINE DECARBOXYLASE IN TAPESIA YALLUNDAE
E MUELLER1,2, A BAILEY1, A RENWICK2 and P BOWYER1
1Plant Molecular Pathology, IACR Long Ashton Research Station, University of Bristol, Long Ashton, Bristol BS18 9AF, UK; 2Zeneca Agrochemical, Jeallots Hill, Berks, UK
Ornithine decarboxylase (ODC) is a key enzyme in the polyamine biosynthetic pathway. Most fungi use ODC as a key enzyme to polyamine biosynthesis, in contrast to plants which possess an alternative route via arginine decarboxylase (ADC). Polyamine biosynthesis (and in particular ODCase) is thus a good target for developing new fungicides. Polyamines also play an important role in fungal differentiation and development.
ODC from Tapesia yallundae (eyespot) was cloned and we are in the process of disrupting the endogenous ODC. We are also complementing ODC mutants in Aspergillus nidulans and Septoria nodorum. The disrupted eyespot clones will be tested for their pathogenicity and the feasibility of using ODC as a fungicide target will be assessed.
Eyespot has a distinct life cycle involving development of unusual infection structures. We are going to investigate the involvement and regulation of ODC in these processes by promoter-reporter gene fusion using green fluorescence protein (GFP) from the jellyfish Aequorea victoria.