Analysis of the inhibitory effect of rapamycin on Fusarium asiaticum by next generation RNA sequencing

Fusarium asiaticum was used to investigate factors affecting the regulation of deoxynivalenol (DON) production. In liquid medium supplemented with a low concentration of rapamycin, F. asiaticum grew at approximately 40% of its normal rate but did not produce DON. RNA levels were measured by next generation RNA sequencing. In low concentration rapamycin, expression levels of DON-related genes were low, but expression of the FaTor (target of rapamycin of F.asiaticum) gene was not suppressed. However, expression of the FaTap42 gene, which interacts with FaTor, was suppressed to nearly 70%. FaSit4 and FaPpg1 genes, which were downstream of FaTap42, were down regulated. However, expression of the FaPp2A gene, another phosphatase downstream of FaTap42, was not affected by low concentration rapamycin. These findings reveal that low concentration rapamycin differentially suppresses genes downstream of the FaTor pathway.