Characterization and diagnostic marker development for Yr28-rga1 conferring stripe rust resistance in wheat

• Published in: European journal of plant pathology 2020-02, Vol.156 (2), p.623-634
• Main Authors: Zheng, Shigang, Wu, Yu, Zhou, Min, Zeng, Lian, Liu, Rong, Li, Yunfang, Liu, Zehou, Zhang, Chihong, Lu, Lu, Zhang, Lei
• Format: Article
• Language: English
• Subjects: Agriculture; Biomedical and Life Sciences; Cultivars; Diagnostic systems; Disease control; Ecology; Gene sequencing; Genes; Germplasm; High temperature; Life Sciences; Losses; Marker-assisted selection; Markers; NBS-LRR gene; NBS-LRR protein; Plant breeding; Plant Pathology; Plant resistance; Plant Sciences; Protein structure; Proteins; Stripe rust; Wheat
• ISSN: 0929-1873; 1573-8469
• DOI: 10.1007/s10658-019-01912-x

Stripe rust is one of the most devastating wheat diseases and developing resistant cultivars is the most economical way to manage this disease. More than 80 stripe rust resistance genes ( Yr genes) have formally been mapped. However, a lack of diagnostic markers has partially restricted the deployment of some resistance genes in molecular breeding. Among them, Yr28 showed high-temperature adult plant resistance (HT-APR) to stripe rust in the field, but it is rarely employed in wheat breeding. Here, Yr28-rga1 was found and isolated through the co-segregated marker mwg634 of Yr28 . The gene sequence of Yr28-rga1 - 4A and Yr28-rga1 - 4B were almost the same between PI648511 and other wheat germplasm, including Chinese Spring (CS), Avocet, Yanzhan1, and Chuanyu12, but Yr28-rga1 - 4D showed only 88% identity between PI648511 and the others. Further, the high similarity in conserved domains to other wheat R proteins indicated that Yr28-RGA1 was a typical NBS-LRR protein. But the low identity in amino sequences also suggested that it was a novel gene. The specific 3-D protein structure in LRR regions also indicated that Yr28-rga1 - 4D from PI648511 might have different functional responses to disease. Furthermore, two gene-specific markers of cib-Yr28M1 and cib-Yr28M2 were developed for Yr28-rga1 . Only 24 accessions showed identity to PI648511 on Yr28-rga1 locus in a panel of 672 wheat germplasms. The two diagnostic markers also revealed the positive correlation of Yr28-rga1 and stripe rust resistance (R 2  > 0.8; p