The importance of fungal plant pathogens

Fungal plant diseases have profound effects on food production and society in general. Modern industrial society has evolved a number of methods for the control of plant disease comprising hygenic agricultural practice, breeding plants for disease resistance and the use of anti-fungal chemicals. Such measures are needed to produce crops of consistent quality and yield but contribute greatly to the cost of food production. Despite these advances, some 5–10 per cent of crop plants in Europe and North America are still lost to disease. Fungal races which can overcome resistance and which are insensitive to fungicides are constantly arising. Most farmers in underdeveloped countries are unable to afford either fungicides or the latest resistance-bred seeds and losses of 50 per cent are not unusual in these areas. Increasing human populations and concern over the excessive use of many fungicides has emphasized the need to understand fully the biochemical and genetic interactions between plant and pathogen in order to find new strategies to combat disease.

Fungal plant disease occurs because some fungi have evolved the ability to penetrate and colonize plant tissue. Fungal pathogens have evolved along with their host plants for many millions of years and have had a major impact on crop production since the first attempts at organized agriculture. In addition to pathogens, there are many fungal species that interact intimately with plants symbiotically.