Iffis Bachir, St-Arnaud Marc, Hijri Mohamed
Institut de Recherche en Biologie Végétale, Université de Montréal, MontréalQC, Canada.
Front Plant Sci. 2017 Aug 8;8:1381. doi: 10.3389/fpls.2017.01381. eCollection 2017.
Phytoremediation is a promising green technology based on the use of plants to cleanup soils from organic and inorganic pollutants. Microbes, particularly bacteria and fungi, that closely interact with plant roots play key roles in phytoremediation processes. In polluted soils, the root-associated microbes contribute to alleviation of plant stress, improve nutrient uptake and may either degrade or sequester a large range of soil pollutants. Therefore, improving the efficiency of phytoremediation requires a thorough knowledge of the microbial diversity living in the rhizosphere and in close association with plant roots in both the surface and the endosphere. This study aims to assess fungal ITS and bacterial 16S rRNA gene diversity using high-throughput sequencing in rhizospheric soils and roots of three plant species (, and ) growing spontaneously in three petroleum hydrocarbon polluted sedimentation basins. Microbial community structures of rhizospheric soils and roots were compared with those of microbes associated with arbuscular mycorrhizal fungal (AMF) spores to determine the links between the root and rhizosphere communities and those associated with AMF. Our results showed a difference in OTU richness and community structure composition between soils and roots for both bacteria and fungi. We found that petroleum hydrocarbon pollutant (PHP) concentrations have a significant effect on fungal and bacterial community structures in both soils and roots, whereas plant species identity showed a significant effect only on the roots for bacteria and fungi. Our results also showed that the community composition of bacteria and fungi in soil and roots varied from those associated with AMF spores harvested from the same plants. This let us to speculate that in petroleum hydrocarbon contaminated soils, AMF may release chemical compounds by which they recruit beneficial microbes to tolerate or degrade the PHPs present in the soil.
植物修复是一项很有前景的绿色技术，它基于利用植物来清除土壤中的有机和无机污染物。与植物根系密切相互作用的微生物，尤其是细菌和真菌，在植物修复过程中发挥着关键作用。在污染土壤中，与根相关的微生物有助于缓解植物胁迫、改善养分吸收，并且可能降解或隔离多种土壤污染物。因此，提高植物修复效率需要深入了解根际以及根表和根内与植物根系紧密相关的微生物多样性。本研究旨在利用高通量测序技术评估三种自发生长在三个石油烃污染沉降盆地中的植物物种（、和）的根际土壤和根系中的真菌ITS和细菌16S rRNA基因多样性。将根际土壤和根系的微生物群落结构与丛枝菌根真菌（AMF）孢子相关的微生物群落结构进行比较，以确定根和根际群落与AMF相关群落之间的联系。我们的结果表明，细菌和真菌在土壤和根系中的OTU丰富度和群落结构组成存在差异。我们发现，石油烃污染物（PHP）浓度对土壤和根系中的真菌和细菌群落结构均有显著影响，而植物物种身份仅对根系中的细菌和真菌有显著影响。我们的结果还表明，土壤和根系中细菌和真菌的群落组成与从同一植物收获的AMF孢子相关的群落组成不同。这使我们推测，在石油烃污染的土壤中，AMF可能释放化学化合物，通过这些化合物招募有益微生物来耐受或降解土壤中存在的PHPs。
