Globally, the various plant diseases cause significant losses in plant productivity. The estimated loss caused by plant pathogens is approximately 10 to 20%. The losses are about 20% in developed countries and 30-45% in developing countries. The main class of pathogens causing plant diseases includes bacteria, fungi, insects, nematodes and viruses. In nature plants have some kinds of defence system to protect themselves against these pathogens. The defence system of plant is mediated by the disease resistance (R) genes. In plant, R genes direct the recognition of pathogen components which is encoded by avirulence genes (Avr). The interaction between disease resistance (R) genes and their corresponding pathogen avirulence (Avr) genes are the key for identification of a plant is resistance or susceptible to a pathogen attack. This review summarizes the various types of R genes reported and characterized in important plants to understand the plant defence systems.
Resistance gene (R), Plant defence system, Avr and Pathogenesis related proteins.
© The Author(s) 2016. Open Access. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License which permits unrestricted use, sharing, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.