Abstract

The microbial community of complex association of plant is vital for the health of the plant. Plants able to form the microbiome of their rhizosphere as the new advanced research in plant-microbe interaction is revealed. Also, the recent research suggested the fact that the microbial communities help some desert plants in drought tolerance by microbial water production. This study focused on the characterization of rhizosphere bacteria of desert plant Calotropis procera to investigate the relationship between this plant and its rhizosphere microbial communities. The study was achieved via deep sequencing of the V3–V4 regions (∼415 bp) of bacterial 16S rRNA. A total of 2173 operational taxonomic units (OTUs) were assigned sequence tags across samples with at least 97% similarity. A total of 24 OUT is selected with cutoff 1000 abundance. The results showed that the most popular phyla are Acidobacteria (two genera), Actinobacteria (fourteen genera), Bacteroidetes (one genus), Proteobacteria (6 genera), and Firmicutes (nine genera). Highly abundant genera included Ammoniphilus, Bacillus, Iamia (which reported for a first time in soil), Microvirga, Nocardia, Streptomyces, Defluviicoccus, Mycobacterium, Nocardioides, Sphingomonas, Bryobacter, Ammoniphilus, Stenotrophobacter, Arthrobacter, Actinomadura, and Marmoricola. At the species level, high abundance of Nocardia cyriacigeorgica, Rhodospirillales bacterium WX36, and Arthrobacter crystallopoietes in C. procera rhizosphere. These results show that there are at least 20 unknown species (identified at genus or family levels) in C. procera rhizosphere which are not found in rhizosphere free plants.

摘要

植物复杂结合的微生物群落对于植物的健康至关重要。随着植物-微生物相互作用的新的先进研究，揭示了能够形成其根际微生物群的植物。另外，最近的研究表明，微生物群落通过微生物水的生产来帮助一些沙漠植物抗旱。这项研究集中于沙漠植物Calotropis procera的根际细菌的特征，以研究该植物与其根际微生物群落之间的关系。该研究是通过以下途径实现的细菌16S rRNA V3-V4区（约415 bp）的深度测序。共有2173个操作生物分类单位（OTU）被分配了具有至少97％相似性的样品序列标签。总共选择了24个OUT，截止强度为1000。结果表明，最受欢迎的菌群是嗜酸杆菌属（两个属），放线菌属（十四属），拟杆菌属（一个属），变形杆菌属（六个属）和Firmicutes（九属）。高度丰富的属包括：氨纶，芽孢杆菌，Iamia（在土壤中首次报道），Microvirga，诺卡氏菌，链霉菌，脱液球菌，分枝杆菌，诺卡氏菌，鞘氨醇单胞菌，芽孢杆菌，氨纶，嗜单性滋养菌，关节杆菌，Actinomadura和Marmoricola。在种的水平，高丰度的诺卡氏菌cyriacigeorgica，红螺菌目细菌WX36，和节杆菌crystallopoietes在C.的Procera根际。这些结果表明，至少有20种未知的（在属或科两级确定的）下的Procera未在根际自由植物中发现的根际。