College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China; Key Laboratory of Arable Land Conservation (North China), Ministry of Agriculture, Key Laboratory of Plant-Soil Interactions, Ministry of Education, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China; Key Laboratory of Alpine Ecology and Biodiversity, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China.
College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China; Key Laboratory of Arable Land Conservation (North China), Ministry of Agriculture, Key Laboratory of Plant-Soil Interactions, Ministry of Education, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China.
Sci Total Environ. 2019 Mar 20;657:1237-1245. doi: 10.1016/j.scitotenv.2018.12.126. Epub 2018 Dec 11.
Increased spring precipitation in semi-arid grasslands could improve annual primary productivity. However, little is known about the responses of soil microbes to individual spring precipitation. In this study, we combined phospholipid fatty acid (PLFA) and DNA-based high-throughput sequencing analyses to investigate short-term (days) shifts in the soil microbial community composition after a simulated spring precipitation. Under field conditions, the soils (approx. -0.3 MPa) were exposed to either a watering of 20 cm or natural drought, and soil samples were collected at days 1, 3, 5, 8, and 12 after watering. Soil labile organic carbon (C) and nitrogen (N) as well as microbial biomass C (MBC) were positively correlated with soil water content (SWC). Spring watering significantly increased plant phosphorus (P) uptake, but had no impact on soil available P (AP). Watering increased the PLFA biomarkers indicative for Gram-negative (G) bacteria and fungi. Two phyla of G bacteria, Proteobacteria and Bacteroidetes, as well as the fungal phylum Ascomycota were more abundant when SWC increased. In addition to SWC and its related environmental factors such as C and N availabilities, AP appeared to be an important factor in shaping the soil microbial community composition. The study highlights the combination use of the methods based on different microbial biomarkers (PLFA vs. DNA), and the results were in line with each other. While the PLFA-based method was more sensitive to short-term shifts in soil microbial community composition in response to a precipitation event, DNA-based method could provide more information on the microbial taxa at a finer taxonomic resolution. Our results provide methodological insights for future research on short-term response of soil microbial community to changing environmental conditions.
半干旱草原春季降水增加可能会提高年初级生产力。然而,对于土壤微生物对单次春季降水的响应却知之甚少。在这项研究中,我们结合磷脂脂肪酸(PLFA)和基于 DNA 的高通量测序分析,研究了模拟春季降水后土壤微生物群落组成的短期(天)变化。在田间条件下,将土壤(约-0.3 MPa)分别进行 20 cm 的浇水或自然干旱处理,并在浇水后第 1、3、5、8 和 12 天采集土壤样品。土壤易分解有机碳(C)和氮(N)以及微生物生物量 C(MBC)与土壤含水量(SWC)呈正相关。春季浇水显著增加了植物磷(P)的吸收,但对土壤有效磷(AP)没有影响。浇水增加了指示革兰氏阴性(G)细菌和真菌的 PLFA 生物标志物。当 SWC 增加时,G 细菌的两个门,变形菌门和拟杆菌门,以及真菌门子囊菌门的生物标志物更为丰富。除了 SWC 及其相关环境因素(如 C 和 N 的可利用性)之外,AP 似乎也是塑造土壤微生物群落组成的重要因素。该研究强调了基于不同微生物生物标志物(PLFA 与 DNA)的方法的组合使用,并且结果彼此一致。虽然基于 PLFA 的方法对土壤微生物群落组成对降水事件的短期变化更为敏感,但基于 DNA 的方法可以在更精细的分类学分辨率下提供更多有关微生物分类群的信息。我们的研究结果为未来研究土壤微生物群落对环境条件变化的短期响应提供了方法学见解。