RESUMO
Native plants in extreme environments may harbor some unique microbial communities with particular functions to sustain their growth and tolerance to harsh conditions. The aim of this study was to investigate the bacterial communities profiles in some native plants and samples of the Moroccan phosphate mine ecosystem by assessing the percentages of taxonomic identification using six hypervariable regions of the 16S rRNA. The rhizosphere of the three wild plants in the Moroccan phosphate mine is characterized by interesting bacterial diversity including Proteobacteria (62.24%, 71.15% and 65.61%), Actinobacteria (22.53%, 15.24%, 22.30%), Bacteroidetes (7.57%; 4.23%; 7.63%), and Firmicutes (5.82%; 1.17%; 2.83%). The bulk phosphate mine samples were dominated by Actinobacteria with average relative abundance of 97.73% that are different from those inferred in the rhizosphere samples of the native plants. The regions V3, V4 and V67 performed better in the taxonomic profiling at different taxonomic levels. Results indicated that both plant genotype and mainly soil conditions may be involved in the shaping of bacterial diversity. Such indication was also confirmed by the prediction of functional profiles that showed enrichment of many functions related to biological nitrogen fixation in the rhizosphere of native plants and the stress related functions in the bulk phosphate mine in comparison with the wheat rhizosphere samples.
Assuntos
Actinobacteria , Microbiota , Actinobacteria/genética , Bactérias/genética , Microbiota/genética , Fosfatos , Plantas/genética , RNA Ribossômico 16S/genética , Rizosfera , Solo , Microbiologia do SoloRESUMO
The diversity of thermophilic bacteria was investigated in four hot springs, three salt marshes and 12 desert sites in Morocco. Two hundred and forty (240) thermophilic bacteria were recovered, identified and characterized. All isolates were Gram positive, rod-shaped, spore forming and halotolerant. Based on BOXA1R-PCR and 16S rRNA gene sequencing, the recovered isolates were dominated by the genus Bacillus (97.5%) represented by B. licheniformis (119), B. aerius (44), B. sonorensis (33), B. subtilis (subsp. spizizenii (2) and subsp. inaquosurum (6)), B. amyloliquefaciens (subsp. amyloliquefaciens (4) and subsp. plantarum (4)), B. tequilensis (3), B. pumilus (3) and Bacillus sp. (19). Only six isolates (2.5%) belonged to the genus Aeribacillus represented by A. pallidus (4) and Aeribacillus sp. (2). In this study, B. aerius and B. tequilensis are described for the first time as thermophilic bacteria. Moreover, 71.25%, 50.41% and 5.41% of total strains exhibited high amylolytic, proteolytic or cellulolytic activity respectively.
Assuntos
Bacillaceae/classificação , Bacillaceae/isolamento & purificação , Bacilos Gram-Positivos/classificação , Bacilos Gram-Positivos/isolamento & purificação , Fontes Termais/microbiologia , Microbiologia do Solo , Microbiologia da Água , Bacillaceae/genética , Bacillaceae/efeitos da radiação , Biodiversidade , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Bacilos Gram-Positivos/genética , Bacilos Gram-Positivos/efeitos da radiação , Dados de Sequência Molecular , Marrocos , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Esporos Bacterianos/citologiaRESUMO
The diversity of thermophilic bacteria was investigated in four hot springs, three salt marshes and 12 desert sites in Morocco. Two hundred and forty (240) thermophilic bacteria were recovered, identified and characterized. All isolates were Gram positive, rod-shaped, spore forming and halotolerant. Based on BOXA1R-PCR and 16S rRNA gene sequencing, the recovered isolates were dominated by the genus Bacillus (97.5%) represented by B. licheniformis (119), B. aerius (44), B. sonorensis (33), B. subtilis (subsp. spizizenii (2) and subsp. inaquosurum (6)), B. amyloliquefaciens (subsp. amyloliquefaciens (4) and subsp. plantarum (4)), B. tequilensis (3), B. pumilus (3) and Bacillus sp. (19). Only six isolates (2.5%) belonged to the genus Aeribacillus represented by A. pallidus (4) and Aeribacillus sp. (2). In this study, B. aerius and B. tequilensis are described for the first time as thermophilic bacteria. Moreover, 71.25%, 50.41% and 5.41% of total strains exhibited high amylolytic, proteolytic or cellulolytic activity respectively.
Assuntos
Bacillaceae/classificação , Bacillaceae/isolamento & purificação , Bacilos Gram-Positivos/classificação , Bacilos Gram-Positivos/isolamento & purificação , Fontes Termais/microbiologia , Microbiologia do Solo , Microbiologia da Água , Biodiversidade , Bacillaceae/genética , Bacillaceae/efeitos da radiação , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Bacilos Gram-Positivos/genética , Bacilos Gram-Positivos/efeitos da radiação , Dados de Sequência Molecular , Marrocos , Filogenia , /genética , Análise de Sequência de DNA , Esporos Bacterianos/citologiaRESUMO
Drought is the single largest abiotic stress factor leading to reduced crop yields. The identification of differentially expressed genes and the understanding of their functions in environmentally stressful conditions are essential to improve drought tolerance. Transcriptomics is a powerful approach for the global analysis of molecular mechanisms under abiotic stress. To identify genes that are important for drought tolerance, we analyzed mRNA populations from untreated and drought-stressed leaves of Triticum durum by cDNA- -amplified fragment length polymorphism (cDNA-AFLP) technique. Overall, 76 transcript- -derived fragments corresponding to differentially induced transcripts were successfully sequenced. Most of the transcripts identified here, using basic local alignment search tool (BLAST) database, were genes belonging to different functional categories related to metabolism, energy, cellular biosynthesis, cell defense, signal transduction, transcription regulation, protein degradation and transport. The expression patterns of these genes were confirmed by quantitative reverse transcriptase real-time polymerase chain reaction (qRT- -PCR) based on ten selected genes representing different patterns. These results could facilitate the understanding of cellular mechanisms involving groups of genes that act in coordination in response to stimuli of water deficit. The identification of novel stress-responsive genes will provide useful data that could help develop breeding strategies aimed at improving durum wheat tolerance to field stress.
