Publications by authors named "Robert Chretien"

The use of fungicides to manage disease has led to multiple environmental externalities, including resistance development, pollution, and non-target mortality. Growers have limited options as legacy chemistry is withdrawn from the market. Moreover, fungicides are generally labeled for traditional soil-based production, and not for liquid culture systems.

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Controlled environment agriculture hydroponic systems grow plants year-round without restriction from outside environmental conditions. In order to further improve crop yield, plant growth-promoting bacteria were tested on hydroponically grown lettuce () plants. From our bacterial endophyte library, we found one bacterium, IALR632, that is promising in promoting lettuce growth in multiple hydroponic systems.

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Article Synopsis
  • Phosphate is crucial for plant growth, but only a small fraction is accessible, leading to pollution from excess fertilizer use and environmental issues like algal blooms.
  • Research identified five bacteria that can solubilize phosphate, promoting the growth of plants such as tall fescue, pepper, and tomato in greenhouse settings.
  • These bacteria, particularly IALR1325, utilize mechanisms like pH reduction through gluconic acid to help make phosphate available for plant uptake and could be key for sustainable agriculture.
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Conventional Agrobacterium-mediated transformation methods rely on complex and genotype-specific tissue culture media for selection, proliferation, and regeneration of genetically modified cells. Resulting transgenic plants may not only contain selectable marker genes but also carry fragments of the vector backbone. Here, we describe a new method for the production of transgenic plants that lack such foreign DNA.

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An important component of conventional sense, antisense, and double-strand RNA-based gene silencing constructs is the transcriptional terminator. Here, we show that this regulatory element becomes obsolete when gene fragments are positioned between two oppositely oriented and functionally active promoters. The resulting convergent transcription triggers gene silencing that is at least as effective as unidirectional promoter-to-terminator transcription.

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