College of Resources and Environmental Sciences, National Academy of Agriculture Green Development, Key Laboratory of Plant-Soil Interactions, Ministry of Education, China Agricultural Universitygrid.22935.3f, Beijing, China.
National Observation and Research Station of Agriculture Green Development, Quzhou, Hebei, China.
mSystems. 2022 Feb 22;7(1):e0110721. doi: 10.1128/msystems.01107-21. Epub 2022 Jan 11.
Enhancing soil phosphate solubilization is a promising strategy for agricultural sustainability, while little is known about the mechanisms of how microorganisms cope with differing phosphorus availability. Using a combination of genome-resolved metagenomics and amplicon sequencing, we investigated the microbial mechanisms involved in phosphorus cycling under three agricultural treatments in a wheat-maize rotation system and two natural reforestation treatments. Available soil phosphorus was the key factor shaping bacterial and fungal community composition and function across our agricultural and reforestation sites. Membrane-bound quinoprotein glucose dehydrogenase (PQQGDH) and exopolyphosphatases (PPX) governed microbial phosphate solubilization in agroecosystems. In contrast, genes encoding glycerol-3-phosphate transporters (, , and ) displayed a significantly greater abundance in the reforestation soils. The gene encoding PQQGDH was found to be the best determinant for bioavailable soil phosphorus. Metagenome-assembled genomes (MAGs) affiliated with and were obtained from agricultural soils. Their MAGs harbored not only but also the gene encoding low-affinity phosphate transporters. MAGs obtained from reforestation soils were affiliated with and . These contain genes but no , and thereby are indicative of a phosphate transporter strategy. Our study demonstrates that knowledge of distinct microbial phosphorus acquisition strategies between agricultural and reforestation soils could help in linking microbial processes with phosphorus cycling. The soil microbiome is the key player regulating phosphorus cycling processes. Identifying phosphate-solubilizing bacteria and utilizing them for release of recalcitrant phosphate that is bound to rocks or minerals have implications for improving crop nutrient acquisition and crop productivity. In this study, we combined functional metagenomics and amplicon sequencing to analyze microbial phosphorus cycling processes in natural reforestation and agricultural soils. We found that the phosphorus acquisition strategies significantly differed between these two ecosystems. A microbial phosphorus solubilization strategy dominated in the agricultural soils, while a microbial phosphate transporter strategy was observed in the reforestation soils. We further identified microbial taxa that contributed to enhanced phosphate solubilization in the agroecosystem. These microbes are predicted to be beneficial for the increase in phosphate bioavailability through agricultural practices.
提高土壤中磷的溶解能力是农业可持续发展的一种很有前景的策略，但人们对微生物如何应对不同磷可用性的机制知之甚少。本研究采用宏基因组学和扩增子测序相结合的方法，研究了在小麦-玉米轮作系统和两种自然恢复处理下，三种农业处理下参与磷循环的微生物机制。土壤有效磷是塑造农业和恢复区土壤细菌和真菌群落组成和功能的关键因素。膜结合醌蛋白葡萄糖脱氢酶（PQQGDH）和外多磷酸盐酶（PPX）控制着农业生态系统中的微生物磷酸盐溶解。相比之下，编码甘油-3-磷酸转运蛋白（、、和）的基因在恢复区土壤中丰度显著更高。编码 PQQGDH 的基因被发现是可利用土壤磷的最佳决定因素。从农业土壤中获得了与 和 相关的宏基因组组装基因组（MAG）。它们的 MAG 不仅含有 ，还含有低亲和力磷酸盐转运蛋白的 基因。从恢复区土壤中获得的 MAG 与 和 有关。这些 MAG 含有 基因，但没有 基因，表明它们采用了磷酸盐转运蛋白策略。本研究表明，了解农业和恢复区土壤中不同的微生物磷获取策略，可以帮助将微生物过程与磷循环联系起来。土壤微生物组是调节磷循环过程的关键因素。鉴定能够释放与岩石或矿物质结合的难溶性磷酸盐的溶磷细菌，并利用它们来提高作物对营养物质的获取和作物生产力，具有重要意义。在本研究中，我们结合功能宏基因组学和扩增子测序来分析自然恢复和农业土壤中的微生物磷循环过程。我们发现，这两个生态系统的磷获取策略有显著差异。在农业土壤中，微生物磷溶解策略占主导地位，而在恢复区土壤中，观察到微生物磷酸盐转运策略。我们进一步鉴定了有助于提高农业生态系统中磷酸盐溶解能力的微生物类群。这些微生物被预测通过农业实践增加磷酸盐的生物有效性是有益的。
