| 1. |
- Abdelfattah, Ahmed, et al.
(författare)
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Revealing Cues for Fungal Interplay in the Plant-Air Interface in Vineyards
- 2019
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Ingår i: Frontiers in Plant Science. - : Frontiers Media SA. - 1664-462X. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- Plant-associated microorganisms play a crucial role in plant health and productivity. Belowground microbial diversity is widely reported as a major factor in determining the composition of the plant microbiome. In contrast, much less is known about the role of the atmosphere in relation to the plant microbiome. The current study examined the hypothesis that the atmospheric microbiome influences the composition of fungal communities of the aboveground organs flowers, fruit, and leaves) of table grape and vice versa. The atmosphere surrounding grape plantings exhibited a significantly higher level of fungal diversity relative to the nearby plant organs and shared a higher number of phylotypes 5,536 OTUs, 40.3%) with the plant than between organs of the same plant. Using a Bayesian source tracking approach, plant organs were determined to be the major source of the atmospheric fungal community 92%). In contrast, airborne microbiota had only a minor contribution to the grape microbiome, representing the source of 15, 4, and 35% of the fungal communities of leaves, flowers, and fruits, respectively. Moreover, data indicate that plant organs and the surrounding atmosphere shared a fraction of each other's fungal communities, and this shared pool of fungal taxa serves as a two-way reservoir of microorganisms. Microbial association analysis highlighted more positive than negative interactions between fungal phylotypes. Positive interactions were more common within the same environment, while negative interactions appeared to occur more frequently between different environments, i. e., atmosphere, leaf, flower, and fruit. The current study revealed the interplay between the fungal communities of the grape phyllosphere with the surrounding air. Plants were identified as a major source of recruitment for the atmospheric microbiome, while the surrounding atmosphere contributed only a small fraction of the plant fungal community. The results of the study suggested that the plant-air interface modulates the plant recruitment of atmospheric fungi, taking a step forward in understanding the plant holobiont assembly and how the atmosphere surrounding plants plays a role in this process. The impact of plants on the atmospheric microbiota has several biological and epidemiological implications for plants and humans.
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| 2. |
- Belgacem, Imen, et al.
(författare)
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Transcriptomic Analysis of Orange Fruit Treated with Pomegranate Peel Extract (PGE)
- 2019
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Ingår i: PLANTS. - : MDPI AG. - 2223-7747. ; 8:4
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Tidskriftsartikel (refereegranskat)abstract
- A Pomegranate Peel Extract (PGE) has been proposed as a natural antifungal substance with a wide range of activity against plant diseases. Previous studies showed that the extract has a direct antimicrobial activity and can elicit resistance responses in plant host tissues. In the present study, the transcriptomic response of orange fruit toward PGE treatments was evaluated. RNA-seq analyses, conducted on wounded fruits 0, 6, and 24 h after PGE applications, showed a significantly different transcriptome in treated oranges as compared to control samples. The majority (273) of the deferentially expressed genes (DEGs) were highly up-regulated compared to only 8 genes that were down-regulated. Gene Ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) pathway enrichment analysis showed the involvement of 1233 gene ontology (GO) terms and 35 KEGG metabolic pathways. Among these, important defense pathways were induced and antibiotic biosynthesis was the most enriched one. These findings may explain the underlying preventive and curative activity of PGE against plant diseases.
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| 3. |
- Casini, Giulia, et al.
(författare)
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Endophytic fungal communities of ancient wheat varieties
- 2019
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Ingår i: Phytopathologia Mediterranea. - 0031-9465. ; 58:1, s. 151-162
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Tidskriftsartikel (refereegranskat)abstract
- The fungal community composition and structure of two ancient tetraploid wheat varieties, native to the Sicilian territory of Italy, Perciasacchi (winter wheat) and Tumminia (spring wheat) were investigated using High Throughput Sequencing (HTS). This showed a predominance of Ascomycetes and Basidiomycetes including Alternaria, Fusarium, Mycosphaerella, Filobasidium, Cystofilobasidium, Cryptococcus, Leucosporidium, Dioszegia, Puccinia, Sporobolomyces, Aureobasidium, Cladosporium, Holtermanniella and Gibberella. Principal Coordinates Analysis (PCoA) and Linear discriminant analysis Effect Size (LEfSe) showed that Aureobasidium, Leucosporidium and Puccinia differentiated between the two wheat varieties. In addition, the microbial association analysis suggested that some endophytic taxa play important roles within the wheat fungal community. Genera such as Cryptococcus and Cystofilobasidium were shown to have consistent antagonistic activity against Gibberella spp., while, Acremonium and a group of unidentified ascomycetes had mutual exclusion relationships with Puccinia. Since both Gibberella and Puccinia contain several economically important pathogens of wheat, the detected fungal interactions may indicate microbial-mediated resistance in these wheat varieties.
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| 4. |
- Solanki, Manoj Kumar, et al.
(författare)
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Shifts in the Composition of the Microbiota of Stored Wheat Grains in Response to Fumigation
- 2019
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Ingår i: Frontiers in Microbiology. - : Frontiers Media SA. - 1664-302X. ; 10
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Tidskriftsartikel (refereegranskat)abstract
- While the wheat-associated microbiome is of major agricultural importance, little is known about the alterations in wheat grain microbial community composition during storage. Characterization of the bacterial and fungal communities in stored wheat grains revealed the impact of phosphine fumigation, one of the most effective methods to eliminate insects in stored commodities, on the composition of the wheat grain microbiome. High-throughput amplicon sequencing of the bacterial 16S rRNA gene and fungal internal transcribed spacer (ITS) region was used to analyze the wheat grain microbiome at different times over as 6 months period of storage. Higher bacterial diversity was found across the samples during the first (immediately after harvest) and second (3 months later) time points, with a predominance of Proteobacteria, Firmicutes, Actinobacteria, Bacteroidetes and Planctomycetes. A two-fold decrease in the number of bacterial operational taxonomic units (OTUs) was observed in wheat grains at the last time point (6 months later), following phosphine treatment. In contrast to the effect of phosphine on bacteria, it did not affect fungal diversity in stored grains. The majority of fungal sequences were assigned to Ascomycota, followed by Basidiomycota, Glomeromycota, and unidentified fungi, which were evenly distributed throughout the storage period. Alpha and beta diversity analyses were confirmed by examination of the cultured microbial taxa obtained from the stored wheat grains. Mycotoxin analysis of wheat grains collected after phosphine fumigation revealed the presence of Fusarium toxins, primarily deoxynivalenol (DON). Several mycotoxigenic Fusarium spp. were also detected in the same samples. Results of the present study indicate that microbiome of stored, whole wheat grains was strongly affected by phosphine fumigation, which changed the structure of the microbial community leading to shifts in species composition toward mycotoxigenic strains. A better understanding of the complex interactions within the microbial communities of stored grains will assist in the development of novel biocontrol strategies to overcome mycotoxin contamination.
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