RXLR and CRN Effectors from the Sunflower Downy Mildew Pathogen Plasmopara halstedii Induce Hypersensitive-Like Responses in Resistant Sunflower Lines

摘要: Plasmopara halstedii is an obligate biotrophic oomycete causing downy mildew disease on sunflower, Helianthus annuus, economically important oil crop. Severe symptoms of the (e.g., plant dwarfism, leaf bleaching, sporulation and production infertile flower) strongly impair seed yield. Pl resistance genes conferring to specific P. pathotypes were located sunflower genetic map but yet not cloned. They are present in cultivated lines protect them against disease. Among 16 different recorded France, pathotype 710 frequently found, therefore continuously controlled by genes. High-throughput sequencing cDNA from led us identify potential effectors with characteristic RXLR or CRN motifs described other oomycetes. Expression six putative effectors, five one CRN, was analyzed qRT-PCR pathogen spores infecting leaves selected for functional analyses. We developed a new method transient expression showed first time subcellular localization fused fluorescent protein cells. Overexpression 3 induced hypersensitive-like cell death reactions some near-isogenic resistant susceptible corresponding lines, suggesting they could be involved loci-mediated resistances.