Nitrogen fixation and CO2 exchange in soybeans (Glycine max L.) inoculated with mixed cultures of different microorganisms

Legume species identity and soil nitrogen supply determine symbiotic nitrogen‐fixation responses to elevated atmospheric [CO2]

“…If species vary in their relative reliance on soil N, its availability might modulate the legume response to [CO 2 ] (Høgh‐Jensen & Schjoerring, 1997; Lee et al ., 2003a). In addition, legume–rhizobium relationships can be highly species‐specific, and fixation rates can be strongly dependent on both legume species and bacterial strain (Shabayev et al ., 1996; Provorov & Tikhonovich, 2003). If legumes differ in their N requirements and relationships with N‐fixing bacteria, these species could exhibit a range of dependence on bacterial N fixation.…”

Beneficial microorganisms for soybean (Glycine max (L.) Merr), with a focus on low root-zone temperatures

“…Expression of these genes results in rhizobial production of Nod factors, strain-specific lipochitooligosaccharides that cause root hairs of responsive hosts to curl and promote the growth of infection tubes that allow rhizobia to enter the root interior (Van Rhijn et al 2001;Cocking 2003). Infected legumes produce leghemoglobin, restricting the free oxygen concentration in nodules to protect the oxygen-sensitive rhizobial enzyme nitrogenase (Senthilkumar and Madhaiyan 2009). Following infection, the host plant continues to produce a number of phenolic compounds that promote rhizobial growth and development, such as coumestrol and daidzein (Vlassak and Vanderleyden 1997).…”

“…These species are thus hypothesized to be selected for their benefits to the host plant, whether through improved nutrition, phytohormone production, biocontrol of pathogens, or other mechanisms. Decades of research into beneficial microorganisms such as rhizobia, vesicular-arbuscular mycorrhizae, and plant-growth-promoting rhizobacteria (PGPR) have identified a number of species that improve plant growth in many crops and under a range of environmental conditions (Kloepper and Schroth 1981;Kloepper et al 1989;Bloemberg and Lugtenberg 2001;Avis et al 2008;Senthilkumar and Madhaiyan 2009;Spaepen et al 2009;Hayat et al 2010;Glick 2012). PGPR can be separated by location into intracellular (iPGPR) and extracellular (ePGPR) strains (Martínez-Viveros et al 2010) or by mechanism of action into biofertilizers, phytostimulants, and biopesticides (Dela-Peña and Loyola-Vargas 2014).…”