Plants evolved different defense mechanisms, both active and passive, to combat pathogen attack. The well-studied R-gene mediated defense is often very specific to a particular plant genotype or cultivar and a particular race of a pathogen. In contrast, nonhost resistance can act against all races of a particular pathogen and can occur in all cultivars of a plant species. This is apparent from the fact that plants resist most potential pathogens present in the environment, but become susceptible to only a few that eventually lead to disease. This broad spectrum resistance has been studied in the past decade and several preformed and constitutive plant responses are attributed to be components apart from the induced responses. Past studies suggest that nonhost resistance is complex and involves multiple layers of constitutive and induced defense responses. This is controlled by multiple genes and a coordinated regulation is necessary for achieving the resistance. <br />Molecular mechanisms underlying nonhost resistance have started emerging. In the recent past several forward and reverse genetic screens were performed to identify candidate genes. From these studies more information that can answer the following questions is emerging and this is expected to provide a comprehensive understanding on molecular mechanisms of nonhost resistance. <br /> <br />What is the role of PTI and ETI? <br />Can nonhost resistance include some R-genes? <br />What is the role of incompatible physiology? <br />What is the genetic basis? <br /> <br />The aim of this research topic is to present recent information that provides answers to the above said questions. This topic covers bacterial, fungal and oomycete pathogens and viruses. Other closely related biotic factors like insect resistance are also welcome.
Plants evolved different defense mechanisms, both active and passive, to combat pathogen attack. The well-studied R-gene mediated defense is often very specific to a particular plant genotype or cultivar and a particular race of a pathogen. In contrast, nonhost resistance can act against all races of a particular pathogen and can occur in all cultivars of a plant species. This is apparent from the fact that plants resist most potential pathogens present in the environment, but become susceptible to only a few that eventually lead to disease. This broad spectrum resistance has been studied in the past decade and several preformed and constitutive plant responses are attributed to be components apart from the induced responses. Past studies suggest that nonhost resistance is complex and involves multiple layers of constitutive and induced defense responses. This is controlled by multiple genes and a coordinated regulation is necessary for achieving the resistance. <br />Molecular mechanisms underlying nonhost resistance have started emerging. In the recent past several forward and reverse genetic screens were performed to identify candidate genes. From these studies more information that can answer the following questions is emerging and this is expected to provide a comprehensive understanding on molecular mechanisms of nonhost resistance. <br /> <br />What is the role of PTI and ETI? <br />Can nonhost resistance include some R-genes? <br />What is the role of incompatible physiology? <br />What is the genetic basis? <br /> <br />The aim of this research topic is to present recent information that provides answers to the above said questions. This topic covers bacterial, fungal and oomycete pathogens and viruses. Other closely related biotic factors like insect resistance are also welcome.
