Effect of Dionaea muscipula extract and plumbagin on maceration of potato tissue by Pectobacterium atrosepticum

Abstract

Pectobacterium atrosepticum (Pba) is a plant pathogen that causes major crop losses. Dionaea muscipula extracts and their antibacterial constituent, plumbagin, inhibit Pba growth in vitro. However, this effect is reduced when the extracts are added to bacterial cultures present on potato tubers or suspended in potato tuber filtrate (PF). To explain this, we examined the response mechanism of Pba cells to Dionaea extract and plumbagin and compared it with the effect of a bactericidal peptide -CAMEL. The addition of the extract and plumbagin to a Pba1043 culture in stationary phase increased the extracellular pectate lyase (Pel) activity in the presence of PF. While the addition of the Dionaea extract and plumbagin caused a dramatic reduction in RNA and protein synthesis in Pba1043, it did not result in cellular damage. PF alone increased the expression of Pba genes encoding protein components of cellular efflux pump systems: ompX, acrA and emrA. Application of both PF and plumbagin resulted in a synergistic stimulation of acrA gene expression. Plumbagin added to potato tubers inoculated with a field isolate Pba5A/1/2005 increased extracellular Pel activity and reduced tissue maceration but did not affect bacterial counts per gram of tissue. These results show that plumbagin in the presence of compounds from potato tuber stimulates Pel production/secretion in Pba cells and increases the expression of the acrA gene. This may be the molecular basis for the less pronounced effects of Dionaea extract on Pba in planta relative to those observed in vitro.

3-Chloroplumbagin Induces Cell Death in Breast Cancer Cells Through MAPK-Mediated Mcl-1 Inhibition

“…The source of ChPL were 8-week-old Dionaea muscipula plants cultured in vitro according to a previously published procedure (Szpitter et al, 2014).…”

Antibacterial activity of caffeine against plant pathogenic bacteria

“…After 24 h incubation at 28°C (48 h at 21°C for Cms), the lowest concentration of caffeine inhibiting bacterial growth was designated as the minimum inhibitory concentration (MIC). The minimum bactericidal concentration (MBC) was defined as the lowest concentration of caffeine that eliminated 99.9% of bacterial cells within 24 h (Thornsberry, 1991;Szpitter et al, 2014). Experiments were performed in triplicate.…”

“…Effect of caffeine on DNA replication, RNA and protein biosynthesis in bacterial cells. The procedures of Wegrzyn et al (1991) and Szpitter et al (2014) were followed. Briefly, Dsol, Rsol, Pba, Pcc, Cms, Pst, Xcc suspensions were adjusted to OD 580 = 0.1.…”