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Year: 2010 Title: ?? Bt plants and effects on soil micro-organisms. Journal: CAB Reviews: Perspectives in Agriculture, Veterinary Science, Nutrition and Natural Resources 5, 036, 1-19 Accession Number: CABI:20103160296 Label: InRe ImpactBiol Keywords: genetic engineering; genetic transformation; nontarget effects; nontarget organisms; reviews; risk assessment; soil flora; soil properties; species diversity; transgenic plants bacterium; genetic manipulation; genetically engineered plants; genetically modified plants; GMOs; non-target organisms; non-target species; nontarget species Abstract: The continued and increasing adoption of genetically modified plants (GMPs) in agriculture has raised both perspectives on increasing the productivity and some concern over their potential effects on the environment, especially on soil. These effects include unintentional changes in the chemical compositions of root exudates, and the direct or indirect effects of transgenic plants on non-target species of soil microorganisms that have a key role in the maintenance of soil quality and environmental sustainability. Therefore any change to the quality of crop residues and rhizosphere inputs could modify the dynamics of the composition and activity of organisms in soil. One of the most common transgenic traits in commercial GMPs is insect resistance based on the expression of Cry toxin derived from Bacillus thuringiensis (Bt), and it is crucial that risk assessment studies on the use of Bt crops consider the impacts on micro-organisms in soil. This review summarizes the results of most of the studies that have been conducted to specifically test the effects of Bt plants on soil microbial communities, and examines the role of soil properties as one of the most important factors to be considered to study the interactions between micro-organisms and Bt plants. Most studies suggest that the Bt plants that have been released for commercial purposes could cause small changes in microbial communities and these are often transient in duration. However, experimental results are often contrasting and, given our limited knowledge of the soil system and the linkage with the soil microbial community's diversity and function, more work needs to be done on a case-by-case basis to further evaluate the effects of Bt plants on soil micro-organisms and soil ecosystem functions. URL: <Go to ISI>://20103160296 Author Address: CRA - Centro di Ricerca per lo studio delle Relazioni tra Pianta e Suolo, Via della Navicella, 2-00184 Roma, Italy. XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX Author: Mohr Toni J, Mammarella Nicole D, Hoff Troy, Woffenden Bonnie J, Jelesko John G, McDowell John M, Year: 2010 Title: * The Arabidopsis Downy Mildew Resistance Gene RPP8 Is Induced by Pathogens and Salicylic Acid and Is Regulated by W Box cis Elements. Journal: Molecular Plant-Microbe Interactions 23, 10, 1303-1315. Date: 2010/09/10 Label: FuRe Abstract: Plants disease resistance (R) genes encode specialized receptors that are quantitative, rate-limiting defense regulators. R genes must be expressed at optimum levels to function properly. If expression is too low, downstream defense responses are not activated efficiently. Conversely, overexpression of R genes can trigger autoactivation of defenses with deleterious consequences for the plant. Little is known about R gene regulation, particularly under defense-inducing conditions. We examined regulation of the Arabidopsis thaliana gene RPP8 (resistance to Hyaloperonospora arabidopsidis, isolate Emco5). RPP8 was induced in response to challenge with H. arabidopsidis or application of salicylic acid, as shown with RPP8-Luciferase transgenic plants and quantitative reverse-transcription polymerase chain reaction of endogenous alleles. The RPP1 and RPP4 genes were also induced by H. arabidopsidis and salicylic acid, suggesting that some RPP genes are subject to feedback amplification. The RPP8 promoter contains three W box cis elements. Site-directed mutagenesis of all three W boxes greatly diminished RPP8 basal expression, inducibility, and resistance in transgenic plants. Motif searches indicated that the W box is the only known cis element that is statistically overrepresented in Arabidopsis nucleotide-binding leucine-rich repeat promoters. These results indicate that WRKY transcription factors can regulate expression of surveillance genes at the top of the defense-signaling cascade. URL: http://dx.doi.org/10.1094/MPMI-01-10-0022