image: A typical Ghanaian peasant livestock farmer providing information on Cleome viscosa in his left hand, known to be poisonous to livestock and Cleome gynandra in his right hand, which is not poisonous but used as a vegetable among the indigenous people. view more
Credit: Charles Domozoro
Since the identifying features of plants are rapidly digested in the stomach of herbivores it is often difficult to tell if and how an animal has been poisoned. Such misdiagnoses are costly to the agricultural industry and also mean that statistics on how widespread is poisoning are inaccurate. The practical application of this technique means that when a cow or sheep dies, if a sample of the rumen contents is taken within a day, it can be stored or used immediately to determine if plant poisoning was the cause of death.
Domozoro uses plant material, extracted from Ghanaian animals within 24 hours of death, as the template to amplify specific DNA sequences to give a plant-fingerprint: this is specific to the species of plant present in the animal's rumen. Domozoro has affiliations with the Council for Scientific and Industrial Research in Ghana and so the first database he has used to search for a match consists of the known DNA sequences of ~40 poisonous Ghanaian plant species. This only represents a fraction of the known poisonous plants in Ghana and there is a need to keep expanding the database. The technique could be used to identify poisonous plants from any country as long as their DNA sequence is known: "The procedure can be applied anywhere, but the reference database will need to be carefully selected to include the geographical range", explains Domozoro.