Colonisation of Oncidium orchid roots by the endophyte Piriformospora indica restricts Erwinia chrysanthemi infection, stimulates accumulation of NBS-LRR resistance gene transcripts and represses their targeting micro-RNAs in leaves.

摘要: Erwinia chrysanthemi (Ec) is a destructive pathogen which causes soft-rot diseases in diverse plant species including orchids. We investigated whether colonization of Oncidium roots by the endophytic fungus Piriformospora indica (Pi) restricts Ec-induced disease development leaves, and this might be related to regulation nucleotide binding site-leucine rich repeat (NBS-LRR) Resistance (R) genes. Root stackings Pi progression leaves. Since does not inhibit Ec growth on agar plates, we tested NBS-LRR R gene transcripts levels their potential target miRNAs leaves regulated Pi. Using bioinformatic tools, first identified sequences from Oncidium, are predicted targets miRNAs. Among them, expression two genes was repressed accumulation several regulatory miRNA stimulated plants. This correlated with development, jasmonic salicylic acid accumulation, ethylene synthesis H2O2 production after infection Interestingly, root restricted accompanied higher defense-related lower level miRNA. Based these data propose that controls mRNAs circuit correlates protection plants against infection, molecular biochemical investigations will demonstrate future whether, if so, what extent observations each other.