Molecular Characterization of a Fus3/Kss1 Type MAPK from Puccinia striiformis f. sp. tritici, PsMAPK1

Abstract

Puccinia striiformis f. sp. tritici (Pst) is an obligate biotrophic fungus that causes the destructive wheat stripe rust disease worldwide. Due to the lack of reliable transformation and gene disruption method, knowledge about the function of Pst genes involved in pathogenesis is limited. Mitogen-activated protein kinase (MAPK) genes have been shown in a number of plant pathogenic fungi to play critical roles in regulating various infection processes. In the present study, we identified and characterized the first MAPK gene PsMAPK1 in Pst. Phylogenetic analysis indicated that PsMAPK1 is a YERK1 MAP kinase belonging to the Fus3/Kss1 class. Single nucleotide polymerphisms (SNPs) and insertion/deletion were detected in the coding region of PsMAPK1 among six Pst isolates. Real-time RT-PCR analyses revealed that PsMAPK1 expression was induced at early infection stages and peaked during haustorium formation. When expressed in Fusarium graminearum, PsMAPK1 partially rescued the map1 mutant in vegetative growth and pathogenicity. It also partially complemented the defects of the Magnaporthe oryzae pmk1 mutant in appressorium formation and plant infection. These results suggest that F. graminearum and M. oryzae can be used as surrogate systems for functional analysis of well-conserved Pst genes and PsMAPK1 may play a role in the regulation of plant penetration and infectious growth in Pst.

Mitogen-Activated Protein Kinase Signaling in Plant-Interacting Fungi: Distinct Messages from Conserved Messengers

“…Complementation assays in the surrogate basidiomycete U. maydis also indicate that MAPK1 (here renamed Put-Kss1-2), from the rust fungus Puccinia triticina, can overcome mating and pathogenicity defects of U. maydis kss1-1 and kss1-2 single mutants or kss1-1 kss1-2 double mutants (Hu et al, 2007). It was also shown that MAPK1 (here renamed Pst-Kss1), from the rust fungus Puccinia striiformis, partially complements the corresponding kss1 mutants from F. graminearum and M. oryzae (Guo et al, 2011). Interestingly, the expression of Pst-Kss1 is induced at early infection stages and peaks during formation of the haustorium, suggesting that Kss1/ Fus3-type MAPKs are involved in the virulence of rust fungi, perhaps by controlling IRM associated with the differentiation of haustoria.…”

CtPMK1, a mitogen‐activated‐protein kinase gene, is required for conidiation, appressorium formation, and pathogenicity of Colletotrichum truncatum on soybean

“…For example, PsMAPK1 of P. striiformis f. sp. tritici (Pst) can partially rescue the map1 mutant of F. oxysporum and pmk1 mutant of M. oryzae (Guo et al, 2011), which also suggests that the biochemical functions of Fus3/Kss1-related MAPKs are conserved in phytopathogenic fungi.…”

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

“…Our observation showed that heterologous expression of MlpHog1 in FgHog1 mutant did not fully complement the defects on environmental stresses, sexual reproduction and plant infection, which is similar to the phenomenon that PstMAPK1 and PstILC1 from Puccinia striiformis partially complemented the defects of corresponding ascomycetous mutants (Guo et al 2011;Liu et al 2014). Based on the bioinformatics analysis, the intact Hog1 pathway is present in M. larici-populina and MlpHog1 displays the high degree of conservation.…”

“…For example, the yeast transformants expressing MoMsn2 from M. oryzae restored growth to the ΔScmsn2 yeast mutant on medium (Zhang et al 2014). MAPK1 from the wheat stripe rust Puccinia striiformis partially complemented the corresponding kss1 mutants of F. graminearum and M. oryzae (Guo et al 2011). For the oomycete Phytophthora infestans, Picdc14 appears to be functionally equivalent to cdc14 of S. cerevisiae based on its complementation of the cdc14-1 ts mutation (Ah Fong and Judelson 2003).…”