Microbial communities from Southern African dryland soils: 16S rRNA, fungal ITS and shotgun metagenomics

In this study we evaluated how edaphic microbial communities assemble and potentially function under contrasted poly-extreme conditions (arid vs hyperarid / saline vs non-saline) in two drylands located in South Africa National Parks, the arid Namaqua NP and the hyperarid Richtersveld NP, using metabarcoding and shotgun sequencing. Surface soil samples were collected at three individual and distant (>5km) sites in each dryland. At each site, four true replicates of plant-free soil were sterilely collected (n = 12 per dryland). The extracted mDNA was sent for amplicon (n = 24; 12 per dryland) and shotgun (n = 2; 1 per dryland) sequencing. Our results show that the fungal communities were significantly influenced by aridity and salinity, while the bacterial and archaeal one only by salinity. The microbial communities from the hyperarid and the saline soils presented very similar potential functional and stress response capacities.

本研究以南非国家公园内两处干旱生境——干旱型纳马夸国家公园（Namaqua NP）与超干旱型里希特菲尔德国家公园（Richtersveld NP）为研究对象，在多极端对比条件（干旱vs超干旱/盐渍化vs非盐渍化）下，采用宏条形码测序（metabarcoding）与鸟枪法测序（shotgun sequencing），解析了土壤微生物群落的组装模式与潜在功能。本研究在每处干旱区设置3个独立且间距大于5km的采样位点，于每个采样位点无菌采集4份无植物表层土壤重复样本（每处干旱区共12份样本）。提取的微生物DNA（mDNA）被用于扩增子测序（共计24份，每处干旱区12份）与鸟枪法测序（共计2份，每处干旱区1份）。研究结果表明：真菌群落显著受干旱度与盐度的共同调控，而细菌与古菌群落仅受盐度影响；超干旱生境与盐渍化土壤中的微生物群落，其潜在功能与应激响应能力高度相似。