Microbial Population and Community Dynamics on Plant Roots and Their Feedbacks on Plant Communities

Abstract

The composition of the soil microbial community can be altered dramatically due to association with individual plant species, and these effects on the microbial community can have important feedbacks on plant ecology. Negative plant-soil feedback plays primary roles in maintaining plant community diversity, whereas positive plant-soil feedback may cause community conversion. Host-specific differentiation of the microbial community results from the trade-offs associated with overcoming plant defense and the specific benefits associated with plant rewards. Accumulation of host-specific pathogens likely generates negative feedback on the plant, while changes in the density of microbial mutualists likely generate positive feedback. However, the competitive dynamics among microbes depends on the multidimensional costs of virulence and mutualism, the fine-scale spatial structure within plant roots, and active plant allocation and localized defense. Because of this, incorporating a full view of microbial dynamics is essential to explaining the dynamics of plant-soil feedbacks and therefore plant community ecology.

Functional Soil Microbiome: Belowground Solutions to an Aboveground Problem

“…This effect comes from the negative impact of soil-borne pathogens and predators, which limits the establishment of a diverse plant community, whereas the positive feedback is from host mutualists, thus delineating both effects originating at the multidimensional cost of virulence and mutualism (Bever et al, 2012). There are both positive and negative soil community feedback activities playing crucial roles in the establishment of plant population structure.…”

Plant growth promotion by streptomycetes: ecophysiology, mechanisms and applications

“…Rhizodeposition consists of numerous compounds such as ionic secretions, free oxygen and water, enzymes, [154,155] proteins, mucilage, amino acids, organic acids, sugars, and phenolics [69]. These compounds act as nutritional resources, chemoattractants, chemorepulsants, and signaling compounds that shape the microbial community structure and activity of different groups of microorganisms and have a significant influence on plant rootmicroorganism interactions [70]. The PGPS are widely recognized to be good rhizosphere colonizers and their rhizosphere competence may be partially explained by several chemotaxic features, such as bacterial rate multiplication, quorum sensing-controlled gene expression, amino acids, antibiotics, and siderophore synthesis [71].…”

Host plant physiology and mycorrhizal functioning shift across a glacial through future CO2 gradient

“…In our system, shifts in the functioning of mycorrhizal associations with rising [CO 2 ] could alter plant-soil feedbacks (PSF; Mangan et al, 2010;Bever et al, 2012) that influence invasive plant dynamics (Johnson et al, 2013). PSF can facilitate the spread of invasive plants if the invader disrupts positive PSF in the native community (Callaway et al, 2008) or if the invader experiences positive PSF itself (Zhang et al, 2010;Hayward et al, 2015).…”