An aspartic protease 47 causes quantitative recessive resistance to rice black-streaked dwarf virus disease and southern rice black-streaked dwarf virus disease
Zhaoyun Wang* , Lian Zhou*, Ying Lan, Xuejuan Li, Jian Wang, Jingfang Dong, Wei Guo,Dedao Jing, Qing Liu, Shaohong Zhang, Zhiyang Liu, Wenjuan Shi,Wu Yang, Tifeng Yang,Feng Sun, Linlin Du, Hua Fu, Yamei Ma, Yudong Shao, Luo Chen, Jitong Li, Shuo Li, Yongjian Fan, Yunyue Wang, Hei Leung, Bin Liu, Yijun Zhou, Junliang Zhao and Tong Zhou
New Phytologist
Abstract
Rice black-streaked dwarf virus disease (RBSDVD) and southern rice black-streaked dwarfvirus disease (SRBSDVD) are the most destructive viral diseases in rice. Progress is limited inbreeding due to lack of resistance resource and inadequate knowledge on the underlyingfunctional gene.
Using genome-wide association study (GWAS), linkage disequilibrium (LD) decay analyses,RNA-sequencing, and genome editing, we identified a highly RBSDVD-resistant variety andits first functional gene.
A highly RBSDVD-resistant variety W44 was identified through extensive evaluation of adiverse international rice panel. Seventeen quantitative trait loci (QTLs) were identified amongwhich qRBSDV6-1 had the largest phenotypic effect. It was finely mapped to a 0.8–1.2 Mbregion on chromosome 6, with 62 annotated genes. Analysis of the candidate genes underlyingqRBSDV6-1 showed high expression of aspartic proteinase 47 (OsAP47) in a susceptiblevariety, W122, and a low resistance variety, W44. OsAP47 overexpressing lines exhibited significantlyreduced resistance, while the knockout mutants exhibited significantly reducedSRBSDVD and RBSDVD severity. Furthermore, the resistant allele Hap1 of OsAP47 is almostexclusive to Indica, but rare in Japonica.
Results suggest that OsAP47 knockout by editing is effective for improving RBSDVD andSRBSDVD resistance. This study provides genetic information for breeding resistant cultivars.
Key words:aspartic proteinase, quantitativetrait loci (QTLs), resistance variety, riceblack-streaked dwarf virus (RBSDV),southern rice black-streaked dwarf virus(SRBSDV).
