Akhtar Jumana, Galloway Andrew F, Nikolopoulos Georgios, Field Katie J, Knox Paul
Centre for Plant Sciences, Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT UK.
Plant Soil. 2018;428(1):57-65. doi: 10.1007/s11104-018-3670-1. Epub 2018 May 4.
Understanding the structures and functions of carbon-based molecules in soils is an important goal in the context of soils as an ecosystem function of immense importance. Polysaccharides are implicated in maintaining soil aggregate status but have not been extensively dissected in terms of their structures and soil adhesion properties. This is largely because of the technical difficulties in identifying polysaccharide structures and quantifying any functional properties.
Here, we describe the use of a novel nitrocellulose-based adhesion assay to determine the relative capacities for soil adhesion of over twenty plant and microbial polysaccharides that are likely to be present in soil and to contribute to organic matter content and properties. Weights of soil adhered to spots of known amounts of specific polysaccharides were quantified by scanning of the nitrocellulose sheets.
The most effective polysaccharides identified from this survey included chitosan, β-1,3-glucan, gum tragacanth, xanthan and xyloglucan. We also demonstrate that the soil adhesion assay is suitable to assess the soil-binding properties of plant exudates.
The soil adhesion assay will be useful for the functional dissection of the organic matter components of soils and also of the factors involved in soil attachment to plant roots and in rhizosheath formation.
鉴于土壤作为具有极其重要生态系统功能的实体，了解土壤中碳基分子的结构与功能是一个重要目标。多糖与维持土壤团聚体状态有关，但在其结构和土壤黏附特性方面尚未得到广泛剖析。这主要是由于在鉴定多糖结构和量化任何功能特性方面存在技术困难。
在此，我们描述了一种基于新型硝化纤维素的黏附测定法，用于确定二十多种可能存在于土壤中并对土壤有机质含量和性质有贡献的植物和微生物多糖的相对土壤黏附能力。通过扫描硝化纤维素片来量化附着在已知量特定多糖斑点上的土壤重量。
本次调查确定的最有效的多糖包括壳聚糖、β-1,3-葡聚糖、刺梧桐胶、黄原胶和木葡聚糖。我们还证明，土壤黏附测定法适用于评估植物分泌物的土壤结合特性。
土壤黏附测定法将有助于对土壤有机质成分以及参与土壤附着于植物根系和根际鞘形成的因素进行功能剖析。
