Trichoderma viride cellulase induces resistance to the antibiotic pore-forming peptide alamethicin associated with changes in the plasma membrane lipid composition of tobacco BY-2 cells

Abstract

BackgroundAlamethicin is a membrane-active peptide isolated from the beneficial root-colonising fungus Trichoderma viride. This peptide can insert into membranes to form voltage-dependent pores. We have previously shown that alamethicin efficiently permeabilises the plasma membrane, mitochondria and plastids of cultured plant cells. In the present investigation, tobacco cells (Nicotiana tabacum L. cv Bright Yellow-2) were pre-treated with elicitors of defence responses to study whether this would affect permeabilisation.ResultsOxygen consumption experiments showed that added cellulase, already upon a limited cell wall digestion, induced a cellular resistance to alamethicin permeabilisation. This effect could not be elicited by xylanase or bacterial elicitors such as flg22 or elf18. The induction of alamethicin resistance was independent of novel protein synthesis. Also, the permeabilisation was unaffected by the membrane-depolarising agent FCCP. As judged by lipid analyses, isolated plasma membranes from cellulase-pretreated tobacco cells contained less negatively charged phospholipids (PS and PI), yet higher ratios of membrane lipid fatty acid to sterol and to protein, as compared to control membranes.ConclusionWe suggest that altered membrane lipid composition as induced by cellulase activity may render the cells resistant to alamethicin. This induced resistance could reflect a natural process where the plant cells alter their sensitivity to membrane pore-forming agents secreted by Trichoderma spp. to attack other microorganisms, and thus adding to the beneficial effect that Trichoderma has for plant root growth. Furthermore, our data extends previous reports on artificial membranes on the importance of lipid packing and charge for alamethicin permeabilisation to in vivo conditions.

Combined small RNA and gene expression analysis revealed roles of miRNAs in maize response to rice black-streaked dwarf virus infection

“…The height of plants is shown to correlate with the composition of the cell wall, which are associated with metabolism and biosynthesis of cellulose, lignin, hemicellulose and pectin 7 , 33 , 34 . Cellulose is a major class of polysaccharide, which is the main ingredients of plant cell wall, and was closely relative to plant defense 35 . We identified a variety of gene families involved in cell wall synthesis and degradation, and the expression of these genes altered when the maize infected by RBSDV (Table 4 ).…”

Increasing phosphatidylinositol (4,5) bisphosphate biosynthesis affects plant nuclear lipids and nuclear functions

“…Increased lipid kinase activity has been measured in embryogenic carrot cells during enzymatic cell wall digestion [92] and because others had shown that the lipid composition of PM isolated from protoplasts isolated with enzymatic digestion was different from that of cells in both plants and oomycetes [93,94], we compared the lipid composition of the protoplast PMs with that previously reported for cell PMs [54]. The NT and HK lines had multiple common changes when comparing their respective protoplast PM and cell PM lipid classes and lipid molecular species (Supplemental Table 2).…”

Special issue in honour of Prof. Reto J. Strasser - Action of alamethicin in photosystem II probed by the fast chlorophyll fluorescence rise kinetics and the JIP-test

“…1A). AMT has a broad range of biological activities by interacting with cell membranes, including cytolytic activity towards mammalian cells, tissue damage in insect larvae, and antimicrobial activity (Meyer and Reusser 1967, Dathe et al 1998, Fehri et al 2007, Thippeswamy et al 2009, Aidemark et al 2010.…”