explant sterilization Archives - Tissue Culture Network

Home » explant sterilization

Plant tissue culture is notoriously vulnerable to microbial contamination, with microbes hitchhiking on explant surfaces, in culture media, on tools, and even in the air of transfer areas. Conventional sterilization—typically bleach, ethanol, antibiotics, or metallic nanoparticles—can suppress contaminants but often damages sensitive tissues or disrupts morphogenesis. A 2021 open-access study explored a novel, plant-based alternative: fumigation using turmeric rhizome and benzoin resin smoke, and found it can significantly reduce contamination—and in some cases eliminate it entirely—while leveraging carbon nanodots present in the smoke as the likely antimicrobial agents. What the researchers tested Explants from three ornamental species: Rhododendron yedoense var. poukhanense (Explant 1), Hedera helix (Explant 2), and Rosa hybrida ‘Red Sandra’ (Explant 3). Three fumigation strategies: Method A: Fumigate culture plates (media only) over turmeric or benzoin smoke for 3min at 15cm, seal until use. Method B: Directly fumigate explants over smoke for 10s at 30cm, then culture. Method C: Collect smoke soot, disperse in 20% ethanol, immerse explants for 5min, then culture. All cultures used MS medium with 3% sucrose and 0.8% plant agar, incubated at 25±2°C with a 16h photoperiod. Contamination was assessed at 2 days (bacteria) and 7 days (fungi). Key findings Method A (fumigating media only) was insufficient overall. Turmeric-smoked plates reduced contaminants for two species (Explant 1 and 3), but benzoin-smoked plates showed no benefit; media-only fumigation did not reliably control surface contaminants on the explants themselves. Method B (direct explant fumigation) worked broadly. Depending on species and fumigant, inhibition ranged from partial to complete: for example, turmeric achieved 100% inhibition in Rosa; benzoin reached 80% in some cases. Method C (smoke-soot dip) also worked well. Turmeric soot pretreatment cut contamination to as low as 16% in Rhododendron and 20% inhibition in Hedera, while benzoin soot achieved 100% inhibition in Rosa in this regimen. Across species, the most consistently effective workflows were direct explant fumigation (Method B) and soot pretreatment (Method C). The authors highlight turmeric direct fumigation and benzoin soot pretreatment as standouts for eliminating surface contaminants in Rosa. Why smoke works: carbon nanodots with bioactive coatings The team characterized soot from both turmeric and benzoin smoke using UV–Vis spectroscopy, FTIR, and TEM, confirming the presence of carbon nanoparticles (5–50nm for turmeric;

Fumigation for Plant Tissue Culture: What a 2021 Study Reveals About Turmeric, Benzoin Resin, and Carbon Nanodots

A 2021 study introduces a green alternative to harsh surface sterilants in plant tissue culture: brief fumigation with turmeric or benzoin resin smoke…

0 Comments