BACKGROUND Archaea are important to the carbon and nitrogen cycles, but it remains uncertain how rising atmospheric carbon dioxide concentrations ([CO(2)]) will influence the structure and function of soil archaeal communities. METHODOLOGY/PRINCIPAL FINDINGS We measured abundances of archaeal and bacterial 16S rRNA and amoA genes, phylogenies of archaeal 16S rRNA and amoA genes, concentration...

A novel optical method for non-invasive, quantitative and high-resolution imaging of spatial and temporal pH dynamics in soils mediated by plant roots is introduced. This method overcomes present limitations of measurement of pH, mainly short-term and punctiform measurements, by recording long-term dynamics of the micro-pattern of pH in the root-soil interface without disturbance of the biologi...

All processes and functions taking place in the rhizosphere are dominated by the activities of plant roots, rhizosphere microorganisms and root-microorganism interactions, and enzymes are recognized as main actors of all activities occurring in rhizosphere environments. Rhizosphere enzymes have, in general, a higher activity than those operating in bulk soil, as the rhizosphere soil is richer i...

A. Mukherjee Department of Geology & Geophysics, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302, India Abstract Irrigation with arsenic (As)-rich groundwater in agricultural soil is one of the major causes for As contamination in rice. This can be observed in Bangladesh where the highest levels of As were reported in rice grains. However, As risk assessment in rice base...

The surge of interest in fluorescent pseudomonads was spurred by discoveries that members of this group are capable of increasing plant growth and suppressing disease upon introduction into the soil or rhizosphere (Burr et al., 1978; Kloepper and Schroth, 1981; Olsen and Misaghi, 1982, 1984; Weller and Cook, 1983). These bacteria produce iron chelators (siderophores) in vitro with high stabilit...

Poaceae plants release 2'-deoxymugineic acid (DMA) and related phytosiderophores to chelate iron (Fe), which often exists as insoluble Fe(III) in the rhizosphere, especially under high pH conditions. Although the molecular mechanisms behind the biosynthesis and secretion of DMA have been studied extensively, little information is known about whether DMA has biological roles other than chelating...

rhizosphere has different chemical and biological properties from the bulk soil. information about phosphorus (p) availability in the rhizosphere soils treated with municipal sewage sludge (mss) is limited. therefore, the objectives of this research were to evaluate the rhizospheric effects of wheat (triticum aestivum l.) on phosphorus availability and biological properties in 10 calcareous soi...

in a greenhouse experiment, changes in inorganic phosphorus fractions as well as their availability in the rhizosphere of rice (oryza sativa c.v. khazar) crop, following an application of 40 mg p (as monocalcium phosphate per kg of soil) were investigated in paddy soils north of iran. the study was performed as a 14×2 factorial in a completely randomized design of two factors namely: soil at 14...