Xinyue Cui’s research while affiliated with Anhui Agricultural University and other places

The cell wall is the first barrier against external adversity and plays roles in maintaining normal physiological functions of fungi. Previously, we reported a nucleosome assembly protein, MoNap1, in Magnaporthe oryzae that plays a role in cell wall integrity (CWI), stress response, and pathogenicity. Moreover, MoNap1 negatively regulates the expression of MoSMI1 encoded by MGG_03970. Here, we demonstrated that deletion of MoSMI1 resulted in a significant defect in appressorium function, CWI, cell morphology, and pathogenicity. Further investigation revealed that MoSmi1 interacted with MoOsm1 and MoMps1 and affected the phosphorylation levels of MoOsm1, MoMps1, and MoPmk1, suggesting that MoSmi1 regulates biological functions by mediating mitogen‐activated protein kinase (MAPK) signalling pathway in M. oryzae. In addition, transcriptome data revealed that MoSmi1 regulates many infection‐related processes in M. oryzae, such as membrane‐related pathway and oxidation reduction process. In conclusion, our study demonstrated that MoSmi1 regulates CWI by mediating the MAPK pathway to affect development and pathogenicity of M. oryzae.

Rice blast, caused by Magnaporthe oryzae, is a fungal disease that causes devastating damage to rice production worldwide. During infection, pathogens secrete effector proteins that modulate plant immunity. Disulfide bond formation catalyzed by protein disulfide isomerases (PDI) is essential for protein folding and maturation. However, the biological function of Pdi1 in M. oryzae has not yet been characterized. In this study, we identified the endoplasmic reticulum (ER)-located protein, MoPdi1, in M. oryzae. MoPdi1 regulates conidiation, cell wall stress, and pathogenicity of M. oryzae. Furthermore, the CGHC active sites in the a and a' redox domain of MoPdi1 were essential for the biological function of MoPDI1. Further tests demonstrated that MoPdi1 was involved in the regulation of ER stress and positively regulated ER phagy. We also found that MoPdi1 interacted with MoHut1. Deletion of MoPDI1 led to the bereft of MoHut1 dimerization, which depends on the formation of disulfide bonds. In addition, MoPdi1 affected the normal secretion of the cytoplasmic effector AVR-Pia. We provided evidence that MoHut1 is important for the vegetative growth, conidiation, and pathogenicity in M. oryzae. Therefore, our findings could provide a suitable target point for designing antifungal agrochemicals against rice blast fungus.

Rotational straw return technique is considered an effective measure for improving soil quality and maintaining soil microorganisms. However, there are few reports on the influence of wheat–maize crop rotation and straw-returning tillage on crop soil microbial communities in China. This study aimed to investigate how wheat or maize straw-incorporation practices affect bacterial and fungal communities under wheat–maize rotational farming practices. To clarify the effects of straw incorporation on microbial composition, microbial communities from soils subjected to different treatments were identified using high-throughput sequencing. Our results showed that, before corn planting, wheat and maize straw returning reduced bacterial density and increased their diversity but had no effect on fungal diversity. However, before wheat planting, returning wheat and corn stalks to the field increased the diversity of soil bacteria and fungi, whereas returning corn stalks to the field reduced the diversity of fungi and other microorganisms. Straw return significantly increased the relative abundance of Ascomycota in the first season and decreased it in the second season; however, in the second season, wheat straw return increased the relative abundance of Bradyrhizobium , which can promote the soil microbial nitrogen cycle and provide nitrogen to the soil. Wheat and maize straw return increased the relative abundance of Chaetomium , whereas, individually, they decreased the relative abundance. In addition, we detected two fungal pathogens ( Fusarium and Trichoderma ) under the two planting patterns and found that the relative abundance of pathogenic Fusarium increased with wheat straw return (FW and SW). Trichoderma increased after treatment with maize straw return before wheat planting (S group). These results suggest that wheat straw return (FW and SW) and maize straw return might have a negative impact on the pathogenic risk. Therefore, further studies are needed to determine how to manage straw returns in agricultural production.

Nap1 is an evolutionarily conserved protein from yeast to human and is involved in diverse physiological processes, such as nucleosome assembly, histone shuttling between the nucleus and cytoplasm, transcriptional regulation, and the cell cycle regulation. In this paper, we identified nucleosome assemble protein MoNap1 in Magnaporthe oryzae and investigated its function in path-ogenicity. Deletion of MoNAP1 resulted in reduced growth and conidiation, decreased appresso-rium formation rate, and impaired virulence. MoNap1 affects appressorium turgor and utilization of glycogen and lipid droplets. In addition, MoNap1 is involved in the regulation of cell wall, oxidation , and hyperosmotic stress. The subcellular localization experiments showed that MoNap1 is located in the cytoplasm. MoNap1 interacts with MoNbp2, MoClb3, and MoClb1 in M. oryzae. Moreover , deletion of MoNBP2 and MoCLB3 has no effects on vegetative growth, conidiation, and path-ogenicity. Transcriptome analysis reveals that MoNAP1 is involved in regulating pathogenicity, the melanin biosynthetic process. Taken together, our results showed that MoNap1 plays a crucial role in growth, conidiation, and pathogenicity of M. oryzae.