Recently, the research team of Guo Wei, an innovation team for the prevention and control of mycotoxins in agricultural products, used Verticillium dahlia as the material to analyze the molecular mechanism of the RNA-binding protein VdNop12 involved in fungal pathogenicity and low-temperature adaptation. The relevant research results were published in the journal Environmental Microbiology (5 years IF: 5.442) with the title "VdNop12, containing two tandem RRM domains, is a crucial factor for pathogenicity and cold adaption in Verticillium dahliae".

In order to survive in changing environmental conditions, fungi have developed sophisticated mechanisms to sense and respond to a number of environmental factors.

Among these, temperature is one of the most ubiquitous and most important. When temperature rises above or drops below specific thresholds, fungal cells mount heat/cold shock responses. Although the participation of several fungal proteins in response to elevated host temperature has been reported in various pathogens, morphological changes and expression of virulence genes in fungi during cold shocks are less understood. Verticillium dahliae is a plant pathogenic fungus widely distributed in temperate regions of the world. In forms microsclerotia to survive in the soil for many years and can regerminate under suitable conditions to cause wilt disease. There are more than 200 hosts of this pathogen including cotton, potatoes, tomatoes, peppers and others. In this study, we identified and characterized a novel pathogenicity related gene, VdNop12, by screening an ATMT-mediated insertional mutational library of Verticillium dahliae. Bioinformatics analysis revealed that VdNop12 is an RNA binding protein containing two tandem RNA recognition motif domains. Targeted disruption of VdNop12 resulted in a reduction in vegetative growth, conidiation and cell wall integrity. Besides, the mutant showed more sensitivity to low temperature compared with the wildtype and the complementation strains. Yeast complementation assay showed that VdNop12 can ScNop12 mutant of Saccharomyces cerevisiae at 15oC. Moreover, loss of VdNop12 resulted in the downregulation of gene expression related to cAMP-dependent protein kinase (PKA) and mitogen-activated protein kinase (MAPK) pathways in V. dahliae. Our results demonstrate a role of RBPs in the regulation of morphology, stress response, and pathogenic development in V. dahliae.

This work laid a foundation for explaining the widespread distribution of Verticillium dahliae, and also provided a reference for the research on low temperature adaptability of other filamentous fungi including yeast.

Our doctoral student Zhang Jun and graduated master student Cui Weiye are the co-first authors, Hafiz Abdul Haseeb a doctoral foreigner student also participated in the research work, and Guo Wei is the corresponding author. This research as partially supported by National Natural Science Foundation of China (No. 31670143), Beijing Natural Science Foundation (No. 6192023), National Key R&D Program of China (2017YFC1600903) and Elite Youth Program of Chinese Academy of Agricultural Sciences for WG.

Fig. 4 The loss of VdNop12 resulted in defects in pathogenicity on cotton plants. 

Fig. 8 VdNop12 restores the growth defects of temperature-sensitive Nop12p mutant of S. cerevisiae at 15 °C.

Link to the paper:https://sfamjournals.onlinelibrary.wiley.com/doi/abs/10.1111/1462-2920.15268