Plant hormone and MAPK signalling pathways in wheat
Foroud NA, Goyal RK, Laroche A, Ellis BE, Tulpan D, Liu Z, Pan Y. Plant hormone and MAPK signalling pathways in wheat. Plants from Sea to Sky: 2017 Joint Meeting of the Canadian Society of Plant Biologists and the Canadian Society for Horticultural Science Vancouver. Vancouver BC, Canada, July 4-7, 2017.
Mitogen-activated protein kinases (MAPKs) and plant hormones are important signalling molecules regulating plant development and defence responses. Cross-talk between these two signalling pathways has been reported in plants. Despite their importance in biological processes the MAPK signalling cascades are poorly characterized in important cereal crops, such as wheat. We recently surveyed the genomic DNA database in Ensembl Plant and identified the MAPK members of the MAP kinase (MPK) and MAPK kinase (MKK) subfamilies in wheat and related species. Seventeen MPKs and 12 MKKs, along with multiple genomic copies, were identified in hexaploid wheat. Orthologous naming was assigned based on the accepted MAPK nomenclature to facilitate comparisons with other plant species. Hormone signalling pathways have received considerably more attention in wheat compared with MAPKs, and increasing evidence indicates that these pathways differ in cereals compared with dicots and, to a lesser extent, other monocots. In an RNA-sequencing experiment, differential gene expression was analyzed in wheat spikes treated with salicylic acid, methyl-jasmonate, or ethephon. The wheat MAPK sequences were mapped onto this data-set to observe how hormone treatments affected expression of MAPK genes. The methyl-jasmonate treatment was most effective in eliciting expression of numerous MAPKs in wheat spikes. Experiments are currently underway to determine which MPKs are differentially activated in response to these three hormones.