The antibiotic peptaibol alamethicin from Trichoderma permeabilises Arabidopsis root apical meristem and epidermis but is antagonised by cellulase-induced resistance to alamethicin

• DOI: 10.1186/s12870-018-1370-x
• Publication Date: 2018-08-10T12:15:13Z
• Authors: Bradley R. Dotson; Dia Soltan; John Schmidt; Mariam Areskoug; Kenny Rabe; Corné Swart; Susanne Widell; Allan G. Rasmusson
• Keywords: Alamethicin; Endodermis; Trichoderma; Protoplast

Trichoderma fungi live in the soil rhizosphere and are beneficial for plant growth pathogen resistance. Several species strains currently used worldwide co-cultivation with crops as a biocontrol alternative to chemical pesticides even though little is known about exact mechanisms of interaction. We earlier found alamethicin, peptide antibiotic secreted by Trichoderma, efficiently permeabilise cultured tobacco cells. However, pre-treatment cellulase made cells resistant subsequent suggesting potential mechanism tolerance needed mutualistic symbiosis.We here investigated intact sterile-grown Arabidopsis thaliana seedlings germinated water or medium. These could be permeabilised alamethicin but not if pretreated cellulase. By following fluorescence from membrane-impermeable DNA-binding probe propidium iodide, we mainly root tips, especially apical meristem epidermis cells, cap basal nor cortex Alamethicin permeabilisation cellulase-induced resistance were confirmed developing quantitative situ assay based on NADP-isocitrate dehydrogenase accessibility. The combined assays also showed that hyperosmotic treatment after pretreatment abolished induced resistance.We conclude presence cell-specific permeabilisation, it, tip model organism A. thaliana. suggest contact between plasma membrane cell wall remain. Our results indicate mode avoid negative effects localises point damage response. open up identification genetic components essential plants.