Linkage between bacterial and fungal rhizosphere communities in hydrocarbon-contaminated soils is related to plant phylogeny

الكتابة العلمية باللغة الانجليزية والمراجعة والدقيق

كتابة ومراجعة الابحاث العلمية

تحليل البيانات

التحليل الاحصائي

المعلوماتية الإحيائية

Phytoremediation is an attractive alternative to excavating and chemically treating contaminated

soils. Certain plants can directly bioremediate by sequestering and/or transforming pollutants, but

plants may also enhance bioremediation by promoting contaminant-degrading microorganisms in

soils. In this study, we used high-throughput sequencing of bacterial 16S rRNA genes and the fungal

internal transcribed spacer (ITS) region to compare the community composition of 66 soil samples

from the rhizosphere of planted willows (Salix spp.) and six unplanted control samples at the site of

a former petrochemical plant. The Bray–Curtis distance between bacterial communities across

willow cultivars was significantly correlated with the distance between fungal communities in

uncontaminated and moderately contaminated soils but not in highly contaminated (HC) soils

(42000 mg kg ! 1 hydrocarbons). The mean dissimilarity between fungal, but not bacterial,

communities from the rhizosphere of different cultivars increased substantially in the HC blocks.

This divergence was partly related to high fungal sensitivity to hydrocarbon contaminants,

as demonstrated by reduced Shannon diversity, but also to a stronger influence of willows on fungal

communities. Abundance of the fungal class Pezizomycetes in HC soils was directly related to

willow phylogeny, with Pezizomycetes dominating the rhizosphere of a monophyletic cluster of

cultivars, while remaining in low relative abundance in other soils. This has implications for plant

selection in phytoremediation, as fungal associations may affect the health of introduced plants and

the success of co-inoculated microbial strains. An integrated understanding of the relationships

between fungi, bacteria and plants will enable the design of treatments that specifically promote

effective bioremediating communities