Fractions of soil phosphorus mediated by rhizospheric phoD-harbouring bacteria of deep-rooted desert species are determined by fine-root traits
Soil phosphorus (P) availability is a crucial factor determining primary productivity in terrestrial ecosystem. Plant functional traits and microbes under P-deficient conditions can respond positively to increase soil P bioavailability. Whether and/or how the fine-root traits (FRTs) of deep-rooted d...
| Authors: | , , , , , |
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| Format: | article |
| Publication Date: | 2024 |
| Country: | España |
| Institution: | Universitat Autònoma de Barcelona |
| Repository: | Dipòsit Digital de Documents de la UAB |
| Language: | English |
| OAI Identifier: | oai:ddd.uab.cat:312728 |
| Online Access: | https://ddd.uab.cat/record/312728 https://dx.doi.org/urn:doi:10.1111/1365-2435.14635 |
| Access Level: | Open access |
| Keyword: | Carboxylates Desert ecosystem Functional microbes Functional traits Phosphorus cycling Root traits |
| Summary: | Soil phosphorus (P) availability is a crucial factor determining primary productivity in terrestrial ecosystem. Plant functional traits and microbes under P-deficient conditions can respond positively to increase soil P bioavailability. Whether and/or how the fine-root traits (FRTs) of deep-rooted desert species affect the rhizosphere and bulk soil community of phoD-harbouring bacteria and thus improve the availability of soil P, however, remains unclear. We conducted a three-year artificial outdoor pot experiment of P supply using Alhagi sparsifolia Shap. (hereafter Alhagi) to address this gap. Fine-root samples from 1- and 3-year-old Alhagi seedlings and samples of the rhizospheres and bulk soil were collected. High-throughput sequencing, sequential extraction and root system scanning were used to determine soil phoD-harbouring bacteria community, Hedley-P fractions and the FRTs. Fine-root surface area (RSA), specific root length, foliar Mn concentration (indicating the quantities of root carboxylates that are released) and acid phosphatase (APase) activity were significantly higher in the no-P supply compared with the high-P supply conditions. APase activity was significantly higher by 27%, but the foliar Mn concentration was remarkably lower by 26%, in the 3- than the 1-year-old seedlings. The rhizospheric concentrations of labile P, moderately labile P, inorganic P and organic P in the no-P supply condition were 5%, 11%, 10% and 21% higher, respectively, in the 3- than the 1-year-old seedlings. RSA and the foliar Mn concentration were dominated root predictors for the rhizospheric phoD-harbouring bacteria community for the 1-year-old seedlings, whereas fine-root P concentration was the dominated root predictor for the rhizospheric and bulk soil phoD-harbouring bacteria communities for the 3-year-old seedlings. Soil water content, as the most dominant soil factor driving the variation of phoD-harbouring bacteria community, notably could not be ignored. FRTs were the main factors that directly and positively determined rhizospheric phoD-harbouring bacteria community and thus influenced soil P availability, but bulk soil phoD-harbouring bacteria community were dominated by inorganic P concentration. The importance of fine-root morphological traits to soil P availability gradually increased as the plants grew. Overall, our results emphasize the significance of rhizospheric phoD-harbouring bacteria determined by the effect of FRTs on the bioavailability of soil P. Read the free Plain Language Summary for this article on the Journal blog. |
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