Low level of polymorphism in two putative NPR1 homologs in the Vitaceaefamily

Background  

Grapevine is subjected to numerous pests and diseases resulting in the use of phytochemicals in large quantities. The will to decrease the use of phytochemicals leads to attempts to find alternative strategies, implying knowledge of defence mechanisms. Numerous studies have led to the identification of signalling pathways and regulatory elements involved in defence in various plant species. Nonexpressor of Pathogenesis Related 1 (NPR1) is an important regulatory component of systemic acquired resistance (SAR) in Arabidopsis thaliana.