Zhi Ruochen, Deng Jian, Xu Yuling, Xu Miaoping, Zhang Shuohong, Han Xinhui, Yang Gaihe, Ren Chengjie
College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China; The Research Center of Recycle Agricultural Engineering and Technology of Shaanxi Province, Yangling, 712100, Shaanxi, China.
College of Life Sciences, Yan'an University, Yan'an, 716000, China.
J Environ Manage. 2023 Feb 15;328:116998. doi: 10.1016/j.jenvman.2022.116998. Epub 2022 Dec 12.
Soil Phosphorous (P) availability is a limiting factor for plant growth and regulates biological metabolism in plantation ecosystems. The effect of variations in soil microbial P cycling potential on the availability of soil P during succession in plantation ecosystems is unclear. In this study, a metagenomics approach was used to explore variations in the composition and diversity of microbial P genes along a 45-year recovery sequence of Robinia pseudoacacia on the Loess Plateau, as well soil properties were measured. Our results showed that the diversity of P cycling genes (inorganic P solubilization and organic P mineralization genes) increased significantly after afforestation, and the community composition showed clear differences. The gcd and ppx genes were dominant in inorganic P transformation, whereas phnM gene dominated the transformation of organic P. The abundance of genes involved in inorganic P solubilization and organic P mineralization was significantly positively correlated with P availability, particularly for phnM, gcd, ppx, and phnI genes, corresponding to the phyla Gemmatimonadetes, Acidobacteria, Bacteroidetes, and Planctomycetes. The critical drivers of the microbial main genes of soil P cycling were available P (AP) and total N (TN) in soil. Overall, these findings highlight afforestation-induced increases in microbial P cycling genes enhanced soil P availability. and help to better understand how microbial growth metabolism caused by vegetation restoration in ecologically fragile areas affects the soil P cycling.
土壤磷（P）有效性是植物生长的限制因素，并调节人工林生态系统中的生物代谢。人工林生态系统演替过程中，土壤微生物磷循环潜力的变化对土壤磷有效性的影响尚不清楚。在本研究中，采用宏基因组学方法，沿着黄土高原45年的刺槐恢复序列，探索微生物磷基因组成和多样性的变化，并测定土壤性质。我们的结果表明，造林后磷循环基因（无机磷溶解和有机磷矿化基因）的多样性显著增加，群落组成也存在明显差异。gcd和ppx基因在无机磷转化中占主导地位，而phnM基因在有机磷转化中占主导地位。参与无机磷溶解和有机磷矿化的基因丰度与磷有效性显著正相关，特别是phnM、gcd、ppx和phnI基因，分别对应于芽单胞菌门、酸杆菌门、拟杆菌门和浮霉菌门。土壤磷循环微生物主要基因的关键驱动因素是土壤有效磷（AP）和全氮（TN）。总体而言，这些发现突出了造林导致微生物磷循环基因增加，提高了土壤磷有效性，并有助于更好地理解生态脆弱地区植被恢复引起的微生物生长代谢如何影响土壤磷循环。
