Molecular characterization of a Hog1-type MAPK, MlpHog1, from Melampsora larici-populina

Abstract

The obligate biotrophic fungus Melampsora larici-populina (Mlp) causes devastating poplar foliar rust disease. In pathogens, the Hog1-type mitogen-activated protein kinase (MAPK) gene is involved in both pathogenesis and the response to various stresses, including osmotic stress. However, there are few reports on its role in M. larici-populina. In the present study, we identified and characterized the Hog1-type MAPK gene, MlpHog1, in M. larici-populina. The MlpHog1 protein consists of 356 amino acids and contains a conserved TGY motif. The function of MlpHog1 was probed by mutant complementation studies. Expression of MlpHog1 could partially complement the osmoregulation, sexual reproduction and pathogenicity defects of the Fusarium graminearum Hog1 mutant and largely rescued the response of the mutant to cytoplasm membrane and oxidative stresses. These observations suggest that MlpHog1 may play a role in the infectious growth of M. larici-populina and the response of the fungus to various environmental stresses.

Functional characterization of Melampsora larici‐populina Hog1‐type MAPK in response to osmotic stress

“…In our previous study, partial complementation of the hyperosmotic stress response defect of the F. graminearum Hog1 mutant by the MlpHog1 gene demonstrated the functional conservation MlpHog1 and FgHog1 (Yu et al, 2016). Unfortunately, at present, this poplar rust fungus still cannot be genetically manipulated to understand the function of genes of interest in M. laricipopulina, even in a host-induced RNAi system (Qi et al, 2018).…”

“…The vector pFL2:: MlpHog1 (Yu et al, 2016) was transformed into protoplasts of the M. oryzae Hog1 mutant Δ OSM1 as described previously (Sweigard et al, 1992). Geneticin‐resistant transformants were confirmed by PCR analysis with primers MlpHog1‐F/RP27 and pFL2 insert/R (Table S1).…”

“…There were few reports on how the HOG pathway responds to hyperosmotic stress in M. larici‐populina . Previously, we conducted the molecular characterization of the Hog1‐type MAPK gene, MlpHog1 (Yu et al, 2016), and here we explored its potential function in response to osmotic stress.…”

Response of putative pathogenicity-related genes in Tilletia indica inciting Karnal bunt of wheat

“…Previously, few pathogenicity genes have been identified and characterized in other fungi like M. grisea Hog1 homolog OSM1 which is essential for survival because it is required for tolerating desiccation, UV-light, and osmotic stresses (Dixon et al 1999). MlpHog1 gene may play a role in the infectious growth of Melampsora larici-populina and the response of the fungus to various environmental stresses (Yu et al 2016).…”

MOLECULAR CLONING OF Ganoderma boninense HOG1-TYPE MITOGEN-ACTIVATED PROTEIN KINASE (MAPK) cDNA AND TRANSCRIPTIONAL RESPONSE TO SALINITY STRESS

“…In a study on necrotrophic fungus which causes the southern corn leaf blight, Cochliobolus heterostrophus Hog1 MAPK mutants produced smaller appressoria and caused weaken disease symptoms on maize (Igbaria et al, 2008). In a recent study, mutant complementation of Melamspora larici-populina Hog1 MAPK (MlpHog1) suggested that the protein could be involved in various environmental stresses and infectious growth (Yu et al, 2016). However, the absence of Hog1 MAPK did not perpetually affect the fungal pathogenicity as shown in the studies on Colletotrichum orbiculare (Kojima et al, 2004) and Bipolaris oryzae (Moriwaki et al, 2006).…”