Bacterial rhizosphere community profile at different growth stages of Umorok (Capsicum chinense) and its response to the root exudates
Bacterial rhizosphere community profile at different growth stages of Umorok (Capsicum chinense) and its response to the root exudates
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DOI：
10.1007/s10123-019-00097-x
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发表时间：
2020-05-01
影响因子：
3.1
通讯作者：
Devi, Indira S.
中科院分区：
文献类型：
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作者：
Devi, Phazna T. A.;Sahoo, Dinabandhu;Devi, Indira S.
微生物群的作用是生物体不可缺少的组成部分。植物积极招募特定的微生物群落来建立有利的栖息地，每个物种的微生物群都是独特的，为植物的生长和生产力提供了新的机会。Umorok是印度东北部的一种本土辣椒品种，其产量受到各种因素的高度影响；因此，分析了根际细菌及其与根分泌物释放的关系，以证明根际细菌对植物生长和健康的影响。采用高效液相色谱法对根分泌物进行基本分析后，采用趋化性试验对其可培养和宏基因组细菌DNA进行了鉴定。幼苗期γ -变形菌、α -变形菌和放线菌种类较多，β -变形菌种类较少，花期和结实期微生物多样性下降。然而，无论多样性如何，每个生长阶段都保持相似的细菌种群数量。假单胞菌、芽孢杆菌和伯克氏菌的数量在开花和结实期增加了数倍。此外，趋化性分析揭示了根分泌物化学成分对特定微生物招募的优势。根分泌物的化学成分分析表明，有机酸、酚类物质和黄酮类物质的浓度存在显著变化，有利于独特的细菌种类。因此，除了典型的植物-细菌协同作用外，根系分泌物还赋予和限制了相关的微生物种群。该研究强调了每个生长阶段存在的微生物负荷类型的信息，这对于开发Umorok整体作物改良的微生物联盟包至关重要。
The role of microflora is an indispensable part of the living organisms. Plants actively recruit specific microbial community to establish favorable habitat with the distinct microbiome, essentially unique for each species, offering new opportunities for plant growth and productivity. Umorok, an indigenous chili variety of northeastern India, production is highly affected by various factors; therefore, rhizosphere bacteria and their relationship with the root exudates released were analyzed to demonstrate rhizosphere bacterial impact on plant growth and health. Culturable and metagenomic bacterial DNA was characterized and the chemical nature of the root exudate was analyzed using chemotaxis assay after its basic analysis in HPLC. Juvenile stage exhibited diverse bacterial species of gammaproteobacteria, alphaproteobacteria, and actinobacteria but lacked the betaproteobacteria while the microbial diversity was reduced in flowering and fruiting stages. However, every growth stage maintained a similar amount of bacterial population regardless of diversity. The population of Pseudomonas, Bacillus, and Burkholderia species was increased several folds in flowering and fruiting stage. Further, the chemotaxis assay unveiled the advantage of root exudate chemical composition for specific microbial recruitment. The chemical composition analysis of root exudates showed substantial variation in the concentration of organic acids, phenolics, and flavonoids that are favoring unique bacterial species. Thus, root exudates confer and limit the related microbial population besides typical plant-bacterial synergetic association. This study emphasized information about the type of microbial load present in each growth stage, which is essential to develop a microbial consortia package for Umorok overall crop improvement.