Signaling in plants during induction of resistance against pathogens

摘要

In plants, initial pathogen infection induces resistance against further infection. The resistance thus induced can be systemic, long lasting and effective against a broad spectrum of pathogens. This response is termed as 'systemic, acquired resistance' (SAR). It is an important component of plant defense against pathogen infection. It offers protection against a broad spectrum of micro-organisms similar to immunization in mammals. In recent years, tremendous progress has been made in understanding the molecular events that take place in the initiation and maintenance of SAR. Development of resistance is correlated with the accumulation of salicylic acid (SA) as well as the expression of a number of pathogenesis-related (PR) proteins. The role of systemic signals like salicylic acid, ethylene, jasmonates and electrical signals linking SAR and defence responses are detailed. The underlying mechanisms of immunization in plants and animals are discussed with special emphasis on the role of receptors and secondary messengers.