Tartary buckwheat （Fagopyrum tataricum）， a member of the Fagopyrum genus of the Polygonaceae family， is an annual herbaceous plant known for its medicine and edible qualities. The occurrence of Fagopyrum damping-off has seriously affected the promotion and development of tartary buckwheat cultivation. This study conducted transcriptome analysis on tartary buckwheat treated with jasmonic acid or salicylic acid， revealing that the transcription of the aspartic protease gene FtAPDSLX1 was inducible. Through analyzing gene expression in genotypes showing levels of resistance，significantly higher transcripts of FtAPDSLX1 were detected in resistant line if compared to susceptible ones. Using the representative variety Chuanqiao No. 1 as material， the FtAPDSLX1 gene was cloned with the full-length coding sequence of 1143 base pairs. This gene encodes 380 amino acids， and its promoter contains multiple cis-elements associating with disease resistance. FtAPDSLX1 was up-regulated in the seedlings upon Rhizoctonia solaniand invasion and its expression exhibited significant tissue specificity. Disease resistance analysis of Arabidopsis plants overexpressing FtAPDSLX1 indicated that FtAPDSLX1 led to enhanced resistance against Rhizoctonia solaniand. Overexpressing FtAPDSLX1 resulted in elevated enzymatic activities of SOD and POD. These results suggest that FtAPDSLX1 may participate in the defense against Rhizoctonia solaniin in tartary buckwheat. The functional validation of FtAPDSLX1 and related studies provided a foundation for unraveling the molecular mechanisms underlying Fagopyrum tataricum's resistance to Rhizoctonia solaniand for screening disease-resistant germplasm resources.