Transcriptome Analysis and Reactive Oxygen Species Detection Suggest Contrasting Molecular Mechanisms in ' Response to Different Formae Speciales of .

Revealing plant-pathogen interactions is important for resistance breeding, but it remains a complex process that presents many challenges. leaf spot of poplars (MLSP) is the main disease in poplars; in China, its pathogens consist of two formae speciales, namely, f. sp. (MO) and f. sp. (MU). However, the mechanism of the molecular interaction between poplars and the two formae speciales, especially for an incompatible system, remains unclear. In this study, we conducted transcriptome sequencing and reactive oxygen species (ROS) staining based on the interactions between and the two formae speciales. The results show that the gene expression patterns of induced by MO and MU were significantly different, especially for the genes associated with biotic stress. Furthermore, MO and MU also triggered distinct ROS reactions of , and ROS (mainly HO) burst was only observed around the cells penetrated by MU. In conclusion, this study suggested that experienced different resistance reactions in response to the two formae speciales of , providing valuable insights for further understanding the host-pathogen interactions of MLSP.