Linking rhizosphere soil microbial activity and plant resource acquisition strategy

Abstract

Plants live in association with a diversity of soil microorganisms, which are extremely important in affecting plant growth and soil biogeochemical cycling. By adopting plant trait‐based approaches, we explored the linkages between rhizosphere soil microbial activity and plant resource acquisition strategy of above‐ and below‐ground across a range of tree species in a subtropical evergreen mixed forest. The microbial activities were represented by diverse extracellular enzymes relevant to carbon, nitrogen and phosphorus cycling and soil organic carbon (SOC) mineralization. At the species level, leaf and root traits were mainly represented by two leading dimensions, that is, the ‘fast‐slow’ economics spectrum on which leaf and root traits were well aligned and the orthogonal collaboration gradient in the root. Both extracellular enzymes and SOC mineralization in the rhizosphere varied greatly across plant species. We found that diverse rhizosphere soil microbial activities positively correlated with the classical ‘fast‐slow’ conservation gradient of plant resource acquisition (especially above‐ground), that is, the rhizosphere soil microbes associated with fast‐growing plant species feature higher metabolism than that of slow‐growing plant species. In comparison, rhizosphere soil microbial activities were independent of the plant collaboration gradient in the root, and it might be an alternative exploitative strategy in foraging soil nutrients for plants. Synthesis. Our study strengthens the multivariate nature of plant resource acquisition in adapting to above‐ and below‐ground stresses. The findings on the linkages between rhizosphere soil microbial activity and plant resource acquisition strategy have the potential to improve our understanding and prediction of plant species turnover impacts on soil biogeochemical cycles.

The Multiple Promoting Effects of Suaeda glauca Root Exudates on the Growth of Alfalfa under NaCl Stress

“…The RE treatment further increased the activities of urease and neutral phosphatase in rhizosphere soil ( Figure 3 a,d), although not significantly. The high enzyme activity in rhizosphere soil is not only derived from the direct release of enzymes from plant roots, but also affected by soil microbial activity [ 75 ]. This is because REs contain a large number of compounds that act as signals for establishing and regulating plants’ interactions with microorganisms.…”

Impacts of Oak Mulch Amendments on Rhizosphere Microbiome of Citrus Trees Grown in Florida Flatwood Soils

“…The relative abundances of the bacterial populations in the rhizosphere were estimated to range anywhere between 10 and 100 times greater than in the bulk soil [37]. The diversity of bacteria within the rhizosphere serves as a useful indicator in determining the health status of the plant-host [21]. Typically, greater bacterial diversity in the rhizosphere correlates with benefits in plant health, specifically through key microbe functions, such as enhanced growth and disease suppression [40].…”

“…Microorganisms from the bulk soil are recruited to the rhizosphere through the release of root exudates, which vary according to plant species, age, and stress levels [20]. During periods of abiotic stress, greater amounts of root exudates are released, signaling microorganisms to migrate from the bulk soil to the rhizosphere, much of which alleviate stress in a variety of different ways [21]. Bacteria within the rhizosphere that have the capability to promote plant development are known as plant growth-promoting rhizobacteria (PGPR) [22,23].…”

A trait‐based framework linking the soil metabolome to plant–soil feedbacks

“…Soil metabolites can also have indirect effects on plants by affecting the structure and functioning of soil microbial communities, as well as soil nutrient availability (Inderjit & Weiner, 2001; Hu et al ., 2018). For instance, a recent analysis of trait relationships in 20 subtropical tree species found that fast‐growing species have a higher activity of microbial extracellular enzymes involved in C‐, P‐ and N‐cycling in their rhizosphere (Han et al ., 2023), which could benefit other species by increasing organic matter mineralisation and nutrient availability.…”