Abstract
Bacterial leaf streak (BLS), caused by Xanthomonas oryzae pv. oryzicola (Xoc), is a bacterial disease affecting rice production in Asia and Africa, whose severity is expected to increase with climate change. Identification of new quantitative-trait loci (QTL) or resistance genes for BLS resistance is essential for developing resistant rice. A genome-wide association study to identify QTL associated with BLS resistance was conducted using phenotypic and genotypic data from 429 rice accessions. Of 47 QTL identified, 45 were novel and two co-localized with previously reported QTL or genes conferring BLS resistance. qBLS6.2 on chromosome 6 explained the greatest phenotypic variation. Combined analysis of differential expression and annotations of predicted genes near qBLS6.2 based on haplotype and disease phenotype identified OsBLS6.2 (LOC_Os06g02960) as a candidate gene for qBLS6.2. OsBLS6.2 knockout plants showed higher resistance to Xoc than wild-type plants. Many other candidate genes for resistance to Xoc were identified.
