Laboratory of Behavioral Ecology and Evolution, Department of Biological Sciences, Seoul National University, Seoul, 151-742, South Korea.
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, East Beijing Road 71, Nanjing, 210008, China.
Sci Rep. 2019 Jan 29;9(1):866. doi: 10.1038/s41598-018-37565-9.
Studying how metagenome composition and diversity varies along environmental gradients may improve understanding of the general principles of community and ecosystem structuring. We studied soil bacterial metagenomes along a precipitation gradient on the eastern Tibetan Plateau, varying between 500 mm and 60 mm mean annual precipitation (MAP). We found that lower MAP was strongly associated with reduced functional diversity of bacterial genes. It appears that extreme environmental conditions associated with aridity constrain the diversity of functional strategies present in soil biota - analogous to broad scale patterns found in plant functional diversity along environmental gradients. In terms of specific functions, more extreme arid conditions were also associated with increased relative abundance of genes related to dormancy and osmoprotectants. Decreased relative abundance of genes related to antibiotic resistance and virulence in more arid conditions suggests reduced intensity of biotic interaction under extreme physiological conditions. These trends parallel those seen in earlier, more preliminary comparisons of metagenomes across biomes.
研究宏基因组组成和多样性如何沿环境梯度变化，可能有助于更好地理解群落和生态系统结构的一般原则。我们研究了青藏高原东部一个降水梯度上的土壤细菌宏基因组，年平均降水量（MAP）从 500 毫米到 60 毫米不等。我们发现，较低的 MAP 与细菌基因功能多样性的降低密切相关。看来，与干旱相关的极端环境条件限制了土壤生物群中存在的功能策略的多样性——类似于在沿环境梯度的植物功能多样性中发现的广泛模式。就具体功能而言，更极端的干旱条件也与与休眠和渗透保护剂相关的基因的相对丰度增加有关。在更干旱的条件下，与抗生素抗性和毒力相关的基因的相对丰度降低，表明在极端生理条件下生物相互作用的强度降低。这些趋势与更早的、更初步的生物群落间宏基因组比较中观察到的趋势相似。
