Plant defence mechanisms: relevance to agriculture in Africa

A vital priority for Africa today is to feed its burgeoning population while sustaining agricultural production and safeguarding the natural environment. It is anticipated that agricultural biotechnology will suit the African farming community excellently in terms of acceptability and affordability, and therefore make a major contribution towards the improvement of food production and alleviation of poverty. A major hurdle towards food production in Africa is the huge crop losses caused by pests and diseases. In addition to the fact that control by means of pesticides is often harmful to the environment, a great proportion of the African farmers, especially subsistence farmers, do not have access to modern pesticides. Inherent resistance provided via the seed, thus harnessing the plant’s own defence mechanisms, would be one of the simplest solutions to pest and disease control in Africa. It boils down to the fact that plant biologists have to incorporate the technology into the seed. Otherwise, other methods of harnessing the plant’s defence mechanisms have to be devised. Key events of the plant’s defence mechanisms are discussed in relation to resistance manipulation. They include eliciting, with special reference to resistance (R) genes, and signalling events, the hypersensitive response (HR) and systemic acquired resistance (SAR). In this regard, recent insights and potential applications are accentuated. It is concluded that plant biologists have a major task to continue studies on plant defence mechanisms in an effort to provide fresh insights for the design of new and effective disease control strategies. The importance of such research in Africa, especially in the public sector, is stressed. Also, it is emphasised that the technological outcomes of the research should be protected in patents and made available to African farmers at affordable prices. Another challenge is the application of modern biotechnology in Africa; however, when packaged in the seed, the application of this cutting-edge concept would become natural, even to the most traditional farmer