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Nectar contains antimicrobial constituents including hydrogen peroxide, yet it is unclear how widespread nectar hydrogen peroxide might be among plant species or how effective it is against common nectar microbes.Here, we surveyed 45 flowering plant species across 23 families and reviewed the literature to assess the field‐realistic range of nectar hydrogen peroxide (Aim 1). We experimentally explored whether plant defense hormones increase nectar hydrogen peroxide (Aim 2). Further, we tested the hypotheses that variation in microbial tolerance to peroxide is predicted by the microbe isolation environment (Aim 3); increasing hydrogen peroxide in flowers alters microbial abundance and community assembly (Aim 4), and that the microbial community context affects microbial tolerance to peroxide (Aim 5).Peroxide in sampled plants ranged from undetectable toc3000 μM, with 50% of species containing less than 100 μM. Plant defensive hormones did not affect hydrogen peroxide in floral nectar, but enzymatically upregulated hydrogen peroxide significantly reduced microbial growth.Together, our results suggest that nectar peroxide is a common but not pervasive antimicrobial defense among nectar‐producing plants. Microbes vary in tolerance and detoxification ability, and co‐growth can facilitate the survival and growth of less tolerant species, suggesting a key role for community dynamics in the microbial colonization of nectar.
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Electrically polarized nanoscale surfaces generate reactive oxygenated and chlorinated species for deactivation of microorganisms
Because of the decreasing supply of new antibiotics, recent outbreaks of infectious diseases, and the emergence of antibiotic-resistant microorganisms, it is imperative to develop new effective strategies for deactivating a broad spectrum of microorganisms and viruses. We have implemented electrically polarized nanoscale metallic (ENM) coatings that deactivate a wide range of microorganisms including Gram-negative and Gram-positive bacteria with greater than 6-log reduction in less than 10 minutes of treatment. The electrically polarized devices were also effective in deactivating lentivirus andCandida albicans. The key to the high deactivation effectiveness of ENM devices is electrochemical production of micromolar cuprous ions, which mediated reduction of oxygen to hydrogen peroxide. Formation of highly damaging species, hydroxyl radicals and hypochlorous acid, from hydrogen peroxide contributed to antimicrobial properties of the ENM devices. The electric polarization of nanoscale coatings represents an unconventional tool for deactivating a broad spectrum of microorganisms through in situ production of reactive oxygenated and chlorinated species.
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- Award ID(s):
- 1905341
- PAR ID:
- 10547063
- Publisher / Repository:
- AAAS
- Date Published:
- Journal Name:
- Science Advances
- Volume:
- 10
- Issue:
- 31
- ISSN:
- 2375-2548
- Page Range / eLocation ID:
- eado5555
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1126/sciadv.ado5555
