Cloning of NBS-LRR-encoding Resistance Gene Analogues Using RGA Approach and the Advance in Cucurbit Crops

As majority resistance genes encode a highly conserved protein domain,RGA approach is a method of using the conserved protein domain design degenerate primers to clone resistance gene analogs from plant gDNA or cDNA. With the assembling of genome sequence in various plant species and the development of bioinformatics,the cloning of plant disease resistance genes have made great progress,more than 100 resistance genes have been cloned. Related studies showed that majority of plant disease resistance genes encode a conserved NBS-LRR,STK,LZ,TIR functional structure and majority of them belonging to NBS-LRR class. Using conserved NBS-LRR-encoding domain to design degenerate primer has amplified a number of RGA. In this article,the structure characteristics and function of NBS-LRR-encoding resistance genes and the advance in cloning NBS-LRR-encoding resistance genes using RGA approach and application in cucurbit crops has been reviewed and its future development and application has also been discussed.