Microbial diversity in soil: ecological theories, the contribution of molecular techniques and the impact of transgenic plants and transgenic microorganisms

Effect of transgenic alfalfa plants with introduced gene for Alfalfa Mosaic Virus coat protein on rhizosphere microbial community composition and physiological profile

“…The small size and rapid growth of microorganisms also allow for complex community interactions to be studied much more readily than with plants or animals (Garland 1997). Microbial diversity within the soil is crucial to many functions, but it was difficult to determine the major components in the past (Lynch et al 2004). Additionally, variation in micro-Effect of transgenic alfalfa plants on soil microbial communities 769 bial community structure may have effects on ecosystems processes (e.g.…”

“…Rhizospheric environments are "hot spots" for bacterial gene transfer, since enhanced nutrient availability and water/exudate fluxes stimulate bacterial activity and consequently horizontal gene transfer processes, occurring by conjugation, transformation and transduction (Giovannetti et al 2005). It is well established that plant breeding by traditional techniques, as well as using genetic modification, might affect the structural and functional diversity of the rhizosphere microbial community, through for example an altered root morphology and physiology or plant exudates, and thus might affect the balance of plant-beneficial and deleterious microbes (Lynch et al 2004).…”

Herbicides in the Soil Environment: Linkage between Bioavailability and Microbial Ecology

“…denaturing or thermal gradient gel electrophoresis [DGGE/TGGE], terminal restriction fragment length polymorphism [T-RFLP]). These and other methods have been summarized in the excellent reviews by Torsvik et al (1996), Preston-Mafham et al (2002), Lynch et al (2004), Kirk et al (2004), Ogram et al (2007) and Garland et al (2007). Unintended consequences of herbicide applications may be the reduction of sensitive populations and/or stimulation of a certain microbial group with or without detriment to co-existing microbial populations that may compete for available resources.…”

Qualitative analysis of the vaginal microbiota of healthy cattle and cattle with genital-tract disease

“…Recent studies that incorporate disease assessment in a clinical setting have been notable for their focus on ecological interactions, based on the new data provided through a metagenomic approach. Studies on the composition of microbial communities in diverse environments have revealed the existence of intricate ecological interactions (Kent and Triplett, 2002;Baudoin et al, 2003), and how environmental degradation and other anthropogenic activities impact these communities (Garbeva et al, 2004;Lynch et al, 2004). In hosts, studies have shown that changes in the constitution of communities can lead to health disorders (Seksik et al, 2003;Ott et al, 2004;Turnbaugh and Gordon, 2009); however, the identification of the microbial community requires cultivation of isolated strains in vitro, thus excluding several organisms whose unique physiologies do not allow cultivation.…”