摘要
1.Introduction Cereal crop plants,which provide human societies around the world with a large proportion of their daily carbohydrate requirements,are subject to continual attack by potentially pathogenic fungi.The fungi can penetrate the outer layers of plants in a number of ways,but plants will usually resist infection.However,in some cases,the fungi will overcome the plant’s defenses and establish infection.When agriculturally important plant species succumb to pathogen attack,the resulting reduction in yields or complete destruction of the crop can have devastating social,environmental,and financial effects on national and international communities.During the co-evolution of plants and pathogenic fungi,plants have developed a range of defense strategies against fungal infection,while the fungi,in parallel,have developed new tactics to achieve penetration and infection,and/or to overcome the existing resistance mechanisms of plants.This constant battle for supremacy continues today,and a key and continual objective in cropimprovement programs around the world is to provide plants with an(at least temporary)advantage over the fungi.
