Chaudhari Diptaraj, Rangappa Krishnappa, Das Anup, Layek Jayanta, Basavaraj Savita, Kandpal Basant Kumar, Shouche Yogesh, Rahi Praveen
National Center for Microbial Resource, National Center for Cell Science, Pune, India.
ICAR Research Complex for North Eastern Hill Region, Umiam, India.
Front Microbiol. 2020 Jun 3;11:968. doi: 10.3389/fmicb.2020.00968. eCollection 2020.
Rhizosphere microbiome significantly influences plant growth and productivity. Legume crops such as pea have often been used as a rotation crop along with rice cultivation in long-term conservation agriculture experiments in the acidic soils of the northeast region of India. It is essential to understand how the pea plant influences the soil communities and shapes its rhizosphere microbiome. It is also expected that the long-term application of nutrients and tillage practices may also have a lasting effect on the rhizosphere and soil communities. In this study, we estimated the bacterial communities by 16S rRNA gene amplicon sequencing of pea rhizosphere and bulk soils from a long-term experiment with multiple nutrient management practices and different tillage history. We also used Tax4Fun to predict the functions of bacterial communities. Quantitative polymerase chain reaction (qPCR) was used to estimate the abundance of total bacterial and members of Firmicutes in the rhizosphere and bulk soils. The results showed that bacterial diversity was significantly higher in the rhizosphere in comparison to bulk soils. A higher abundance of Proteobacteria was recorded in the rhizosphere, whereas the bulk soils have higher proportions of Firmicutes. At the genus level, proportions of , , , , , and were significantly higher in the rhizosphere. At the same time, , , and were more abundant in the bulk soils. Higher abundance of genes reported for plant growth promotion and several other genes, including iron complex outer membrane receptor, cobalt-zinc-cadmium resistance, sigma-70 factor, and ribonuclease E, was predicted in the rhizosphere samples in comparison to bulk soils, indicating that the pea plants shape their rhizosphere microbiome, plausibly to meet its requirements for nutrient uptake and stress amelioration.
根际微生物群对植物生长和生产力有显著影响。在印度东北地区酸性土壤的长期保护性农业试验中，豌豆等豆科作物常被用作与水稻轮作的作物。了解豌豆植株如何影响土壤群落并塑造其根际微生物群至关重要。预计长期的养分施用和耕作方式也可能对根际和土壤群落产生持久影响。在本研究中，我们通过对长期试验中具有多种养分管理措施和不同耕作历史的豌豆根际土壤和大块土壤进行16S rRNA基因扩增子测序，估算了细菌群落。我们还使用Tax4Fun预测细菌群落的功能。采用定量聚合酶链反应（qPCR）估算根际土壤和大块土壤中总细菌及厚壁菌门成员的丰度。结果表明，与大块土壤相比，根际细菌多样性显著更高。根际中变形菌门的丰度更高，而大块土壤中厚壁菌门的比例更高。在属水平上，根际中、、、、、和的比例显著更高。同时，、和在大块土壤中更为丰富。与大块土壤相比，根际样品中预测的促进植物生长的基因以及其他几个基因，包括铁复合物外膜受体、钴 - 锌 - 镉抗性、sigma - 70因子和核糖核酸酶E的丰度更高，这表明豌豆植株塑造了其根际微生物群，可能是为了满足其养分吸收和缓解胁迫的需求。
