Institute of Soil, Water and Environmental Sciences, The Volcani Center, Agricultural Research Organization, P.O. Box 6, Bet Dagan 50250, Israel.
Appl Environ Microbiol. 2011 Jul;77(14):4924-30. doi: 10.1128/AEM.00148-11. Epub 2011 May 27.
Adding biochar to soil has environmental and agricultural potential due to its long-term carbon sequestration capacity and its ability to improve crop productivity. Recent studies have demonstrated that soil-applied biochar promotes the systemic resistance of plants to several prominent foliar pathogens. One potential mechanism for this phenomenon is root-associated microbial elicitors whose presence is somehow augmented in the biochar-amended soils. The objective of this study was to assess the effect of biochar amendment on the root-associated bacterial community composition of mature sweet pepper (Capsicum annuum L.) plants. Molecular fingerprinting (denaturing gradient gel electrophoresis and terminal restriction fragment length polymorphism) of 16S rRNA gene fragments showed a clear differentiation between the root-associated bacterial community structures of biochar-amended and control plants. The pyrosequencing of 16S rRNA amplicons from the rhizoplane of both treatments generated a total of 20,142 sequences, 92 to 95% of which were affiliated with the Proteobacteria, Bacteroidetes, Actinobacteria, and Firmicutes phyla. The relative abundance of members of the Bacteroidetes phylum increased from 12 to 30% as a result of biochar amendment, while that of the Proteobacteria decreased from 71 to 47%. The Bacteroidetes-affiliated Flavobacterium was the strongest biochar-induced genus. The relative abundance of this group increased from 4.2% of total root-associated operational taxonomic units (OTUs) in control samples to 19.6% in biochar-amended samples. Additional biochar-induced genera included chitin and cellulose degraders (Chitinophaga and Cellvibrio, respectively) and aromatic compound degraders (Hydrogenophaga and Dechloromonas). We hypothesize that these biochar-augmented genera may be at least partially responsible for the beneficial effect of biochar amendment on plant growth and viability.
向土壤中添加生物炭具有环境和农业潜力，因为它具有长期的碳固存能力和提高作物生产力的能力。最近的研究表明，土壤施用以促进植物对几种主要叶部病原体的系统抗性。这种现象的一个潜在机制是与根相关的微生物激发子，其在添加生物炭的土壤中某种程度上增加。本研究的目的是评估生物炭添加对成熟甜椒（Capsicum annuum L.）植物根相关细菌群落组成的影响。16S rRNA 基因片段的分子指纹图谱（变性梯度凝胶电泳和末端限制性片段长度多态性）显示，生物炭添加和对照植物的根相关细菌群落结构明显分化。两种处理的根际 16S rRNA 扩增子的焦磷酸测序共产生了 20142 个序列，其中 92%至 95%与变形菌门、拟杆菌门、放线菌门和厚壁菌门有关。由于生物炭添加，拟杆菌门的相对丰度从 12%增加到 30%，而变形菌门的相对丰度从 71%减少到 47%。与拟杆菌门相关的黄杆菌属是生物炭诱导作用最强的属。该组的相对丰度从对照样品中总根相关操作分类单位（OTUs）的 4.2%增加到生物炭添加样品中的 19.6%。其他生物炭诱导的属包括几丁质和纤维素降解菌（分别为噬几丁质菌和纤维弧菌）和芳香族化合物降解菌（氢单胞菌和脱氯单胞菌）。我们假设这些生物炭增强的属至少部分负责生物炭添加对植物生长和活力的有益影响。
