Mutations in the Promoter and Coding Regions of Cause Gain of Virulence of to in Soybean.

threatens soybean production worldwide, and the cultivation of soybean cultivars carrying genes is the most effective way to control this pathogen. However, DNA mutations in the genes of can escape recognization of the corresponding genes, leading to the loss of soybean resistance. In this study, we investigated sequence polymorphism and transcript level of the gene in Chinese isolates of . Twenty-four mutations resulting in five unique alleles were discovered in the coding region from 32 isolates. The transcripts were detectable in the isolates containing (I), (II), (III), and (IV) but not in the isolates containing (V). Promoter and 5'-UTR sequence analysis revealed eight unique mutations in the promoter region of (V), suggesting that the mutations could result in the loss of (V) transcription. Virulence tests indicated the isolates containing (II) and (IV) were virulent, suggesting that the mutations in the coding regions of (II) and (IV) caused the gain of virulence to . Based on DNA mutations of in virulent alleles, two SNP markers and one PCR-based marker were developed successfully for detecting the virulence of isolates to . These findings provide new insights into escape mechanisms of and effective support for accurate pathotype identification of using molecular methods.