Abstract

Plant disease resistance is one of the most desirable traits for agricultural production, especially in the present time of fear over food production and crop security. Disease plays an important role in crop production and quality of products. The one key factor of food security and production is plant disease resistance. Several resistance gene(s) are reported from the same host range to overcome against disease resistance. These resistance (R) genes are not durable in many cases because of rapid changes in the pathogen population to overcome the resistance that they confer. For diagnosing such type of situation, continuous search of durable resistance sources from across the genera/species are desirable. Second type of resistance that is nonhost resistance has been described as inaccessibility. Nonhost resistance is regarded as a robust protection against pathogenic microorganisms because of its durability. The mechanisms of nonhost resistance could also be exploited to improve the resistance in a range of crop plants. Recently several components of nonhost resistance have been identified but such resistance is one of the least understood phenomenons in the area of plant microbe interaction. Molecular mechanism of nonhost resistance is not fully understood. Though, nonhost resistance will help biologist to engineer the plants for more durable resistance against important plant diseases. Therefore, non-host resistance seems to be one avenue under consideration for significant improvement of agriculture production in future.

Key words: resistance gene, hypersensitive response, leucine rich repeat.

Abbreviation

HR, Hypersensitive response; Avr, Avirulence; NHR, nonhost resistance; TTSS, Type III secretion system.