Basic β-1,3-Glucanase from Drosera binata Exhibits Antifungal Potential in Transgenic Tobacco Plants

Abstract

The basic β-1,3-glucanase of the carnivorous plant Drosera binata was tested as a purified protein, as well as under the control of a double CaMV35S promoter in transgenic tobacco for its capability to inhibit the growth of Trichoderma viride, Rhizoctonia solani, Alternaria solani, and Fusarium poae in an in-vitro assay. The purified protein inhibited tested phytopathogens but not the saprophytic fungus T. viride. Out of the analysed transgenic plants, lines 13, 16, 19, and 22 exhibited high DbGluc1 transcript abundance normalised to the actin transcript. Because of DbGluc1 transgene expression, lines 13 and 16 showed a 1.7-fold increase and lines 19 and 22 showed more than a 2-fold increase in total β-1,3-glucanase activity compared to the non-transgenic control. In accordance with the purified β-1,3-glucanase in-vitro antifungal assay, crude protein extracts of lines 19 and 22 significantly inhibited the growth of phytopathogens (14–34%). Further analyses revealed that the complementary action of transgenic β-1,3-glucanase and 20% higher activity of endogenous chitinase(s) in these lines were crucial for maximising the antifungal efficiency of crude protein extracts.

Structural and Functional Analysis of the Bacterial Community in the Soil of Continuously Cultivated Lonicera japonica Thunb. and Screening Antagonistic Bacteria for Plant Pathogens

“…Chitinase and β-glucanase are major components of the fungal cell wall, and antagonistic bacteria may inhibit the growth of pathogenic fungi by secreting chitinase and β-glucanase, thereby inhibiting the growth of pathogenic fungi. The β-glucanase enzyme directly attacks glucan on fungal hyphae, inhibiting fungal growth, and the oligosaccharides produced during hydrolysis act as exciters in the plant hypersensitive response, inducing a plant defense response [79]. Bacillus has been shown to strengthen the cell wall and immunity against pathogen infections and plays an important role in tomato and rice disease resistance systems [80].…”

Biological Potential of Carnivorous Plants from Nepenthales

“…It should also be mentioned that the proteins found in pitcher fluid also exhibit a significant antibacterial/antifungal effect. They are pathogenesis-related proteins protecting carnivorous plants during the digestion of prey [76][77][78][79].…”

Assessing biocontrol and plant growth promoting traits of Trichoderma longibrachiatum GFT2, and its effect on root nodules development of Arachis hypogea

“…The developed colour was measured spectrophotometrically (EI) at 540 nm. Chitinase activity was determined by estimating reducing sugar concentrations as evidence for the quantity of released N-acetyl -D-glucosamine (NAGA), whereas endo β -1,4-glucanase activity was determined by estimating reducing saccharide concentrations as evidence for the quantity of released glucose (Rajninec et al, 2021). The concentration was calculated against the standard glucose curve (10-1000 g/mL) for endo β 1,4-glucanase activity.…”