Origin and Dynamics of Rwt6, a Wheat Gene for Resistance to Nonadapted Pathotypes of Pyricularia oryzae.

Avirulence of Eleusine isolates of Pyricularia oryzae on common wheat is conditioned by at least five avirulence genes. One is PWT3 corresponding to resistance gene Rwt3 located on chromosome 1D. We identified a resistance gene corresponding to a second avirulence gene, PWT6, and named it Rmg9 (Rwt6). Rwt6 was closely linked to Rwt3. A survey of the population of Aegilops tauschii, the D genome donor to common wheat, revealed that some accessions from the southern coastal region of the Caspian Sea, the birthplace of common wheat, carried both genes. Rwt6 and Rwt3 carriers accounted for 65 and 80%, respectively, of accessions in a common wheat landrace collection. The most likely explanation of our results is that both resistance genes were simultaneously introduced into common wheat at the time of hybridization of Triticum turgidum and A. tauschii. However, a prominent difference was recognized in their geographical distributions in modern wheat; Rwt3 and Rwt6 co-occurred at high frequencies in regions to the east of the Caspian Sea, whereas Rwt6 occurred at a lower frequency than Rwt3 in regions to the west. This difference was considered to be associated with range of pathotypes to which these genes were effective. A. tauschii accessions carrying Rwt3 and Rwt6 also carried Rwt4, another resistance gene involved in the species specificity. We suggest that the gain of the D genome should have given an adaptive advantage to the genus Triticum by conferring disease resistance.

Effects of Dapagliflozin on Adipose and Liver Fatty Acid Composition and mRNA Expression Involved in Lipid Metabolism in High-Fat-Fed Rats.

BACKGROUND: SGLT2 inhibitor enhances not only glucose excretion but also fatty acid utilization. Those facts suggest that SGLT2 inhibitor affects fat accumulation and lipid storage. OBJECTIVE: In the present study, we evaluated the effects of dapagliflozin on fatty acid composition and gene expression involved in fatty acid metabolism in rat adipose and liver tissues. METHODS: We administered 1 mg/kg/day dapagliflozin for 7 weeks to male high-fat-fed rats (DAPA group), and then weights and 22 fatty acid contents in the epididymal (EPI), mesenteric (MES), retroperitoneal (RET), and subcutaneous (SUB) adipose tissues, and the liver were compared with the vehicle-administered control group. RESULTS: In the EPI, RET, and SUB in the DAPA group, contents of several fatty acids were lower (P<0.05) than those in the control group, while no significant difference was detected in tissue weight. In the MES, tissue weight and a wide variety of fatty acid contents, including saturated, monounsaturated, and polyunsaturated fatty acids, were lower (P<0.05). As for the liver tissue, no significant difference was observed in fatty acid contents between the groups. mRNA expression of Srebp1c in EPI was significantly higher (P<0.05) in the DAPA group than in the control group, while Scd1 expression in the liver was lower (P<0.01). CONCLUSION: These results suggest that dapagliflozin might suppress lipid accumulation especially in the MES, and could reduce contents of fatty acids not in the liver but in adipose tissues in high-fat-fed rats. In addition, dapagliflozin could influence mRNA expression involved in lipogenesis in the EPI and liver.