Extraradical Mycorrhizal Hyphae Promote Soil Carbon Sequestration through Difficultly Extractable Glomalin-Related Soil Protein in Response to Soil Water Stress

• Published in: Microbial ecology Vol. 86; no. 2; pp. 1023 - 1034
• Main Authors: Wang, Yu-Juan, He, Xin-Hua, Meng, Lu-Lu, Zou, Ying-Ning, Wu, Qiang-Sheng
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.08.2023; Springer Nature B.V
• Subjects: Arbuscular mycorrhizas; Biomedical and Life Sciences; Carbon; Carbon - metabolism; Carbon Sequestration; Chambers; Dehydration - metabolism; Ecology; Emissions; Fungal Proteins - metabolism; Fungi; Geoecology/Natural Processes; Glycoproteins - metabolism; Hydrophobicity; Hyphae; Inoculation; Leaves; Life Sciences; Microbial Ecology; Microbiology; Moisture content; Mycorrhizae; Nature Conservation; Organic carbon; Organic soils; Plant growth; Plant Microbe Interactions; Plants; Proteins; Soil; Soil - chemistry; Soil aggregates; Soil microorganisms; Soil stability; Soil stresses; Soil water; Water; Water potential; Water Quality/Water Pollution; Water stress; Citrus; Organic carbon; Water stress; Arbuscular mycorrhiza; Glomalin
• ISSN: 0095-3628; 1432-184X
• DOI: 10.1007/s00248-022-02153-y

Soil water stress (WS) affects the decomposition of soil organic carbon (SOC) and carbon (C) emissions. Glomalin, released by arbuscular mycorrhizal fungi into soil that has been defined as glomalin-related soil protein (GRSP), is an important pool of SOC, with hydrophobic characteristics. We hypothesized that mycorrhizal fungi have a positive effect on SOC pools under soil WS for C sequestration in GRSP secreted by extraradical mycorrhizal hyphae. A microsystem was used to establish a root chamber (co-existence of roots and extraradical mycorrhizal hyphae) and a hyphal chamber (the presence of extraradical mycorrhizal hyphae) to study changes in plant growth, leaf water potential, soil aggregate stability, SOC, GRSP, C concentrations in GRSP (C GRSP ), and the contribution of C GRSP to SOC after inoculating Rhizophagus intraradices with trifoliate orange ( Poncirus trifoliata ) in the root chamber under adequate water (AW) and WS. Inoculation with R . intraradices alleviated negative effects on leaf water potential and plant growth after 7 weeks of WS. Soil WS decreased SOC and mean weight diameter (MWD), while AMF inoculation led to an increase in SOC and MWD in both chambers, with the most prominent increase in the hyphal chamber under WS. The C concentration in easily extractable GRSP (EE-GRSP) and difficultly extractable GRSP (DE-GRSP) was 7.32 − 12.57 and 24.90 − 32.60 mg C/g GRSP, respectively. WS reduced C GRSP , while AMF mitigated the reduction. Extraradical mycorrhizal hyphae increased GRSP production and C GRSP , along with a more prominent increase in DE-GRSP under WS than under AW. Extraradical mycorrhizal hyphae increased the contribution of C DE-GRSP to SOC only under WS. C EE-GRSP and C DE-GRSP were significantly positively correlated with SOC and MWD. It is concluded that extraradical mycorrhizal hyphae prominently promoted C sequestration of recalcitrant DE-GRSP under soil WS, thus contributing more organic C accumulation and preservation in aggregates and soil C pool.