Journal: Phytobiomes Journal

Abbreviation

Publisher

American Phytopathological Society

Journal Volumes

ISSN

2471-2906

Description

Filters

2019 - 201912020 - 20242
Reset filters

Search Results

Publications 1 - 3 of 3
  • Petunia- and Arabidopsis-Specific Root Microbiota Responses to Phosphate Supplementation
    Item type: Journal Article
    Bodenhausen, Natacha; Somerville, Vincent; Desiro, Alessandro; et al. (2019)
    Phytobiomes Journal
    Phosphorus (P) is a limiting element for plant growth. Several root microbes, including arbuscular mycorrhizal fungi (AMF), have the capacity to improve plant nutrition and their abundance is known to depend on P fertility. However, how complex root-associated bacterial and fungal communities respond to various levels of P supplementation remains ill-defined. Here we investigated the responses of the root-associated bacteria and fungi to varying levels of P supply using 16S rRNA gene and internal transcribed spacer amplicon sequencing. We grew Petunia, which forms symbiosis with AMF, and the nonmycorrhizal model species Arabidopsis as a control in a soil that is limiting in plant-available P and we then supplemented the plants with complete fertilizer solutions that varied only in their phosphate concentrations. We searched for microbes, whose abundances varied by P fertilization, tested whether a core microbiota responding to the P treatments could be identified and asked whether bacterial and fungal co-occurrence patterns change in response to the varying P levels. Root microbiota composition varied substantially in response to the varying P application. A core microbiota was not identified as different bacterial and fungal groups responded to low-P conditions in Arabidopsis and Petunia. Microbes with P-dependent abundance patterns included Mortierellomycotina in Arabidopsis, while in Petunia, they included AMF and their symbiotic endobacteria. Of note, the P-dependent root colonization by AMF was reliably quantified by sequencing. The fact that the root microbiotas of the two plant species responded differently to low-P conditions suggests that plant species specificity would need to be considered for the eventual development of microbial products that improve plant P nutrition.
  • Fungal Microbiome Indicators Are Associated with Genotypic Variation in Pea Root Rot Susceptibility when Intercropped with Barley
    Item type: Journal Article
    Cadot, Selma; Hohmann, Pierre; Hsung, Ming-Hui; et al. (2024)
    Phytobiomes Journal
    Intercropping of legume and cereal crop species shows potential to reduce root disease pressures by changing root-associated microbiomes and improving nitrogen (N) use via soil N-dependent fixation of atmospheric N₂ by symbiotic rhizobia. A two-year field study was conducted to evaluate the effect of pea–barley association on crop performance and on the root fungal community. Five pea cultivars (Alvesta, Karpate, Mytic, Respect, and Vitra) were grown either in pure stands or mixed with one variety of barley (Atrika). We measured crop grain yield and root rot incidence and analyzed root fungal communities. In mixed stands, total grain yield was more stable compared with that in each pure stand, but pea root disease incidence was higher except for cultivars Vitra and Karpate. The effect of cropping system on fungal alpha diversity depended on the cultivar, with Vitra showing higher Shannon diversity and Alvesta showing lower richness in mixed compared with pure stands. All four operational taxonomic units (OTUs) belonging to the Didymellaceae family were positively associated with pea root rot, and another disease-associated OTU in pea, Neoascochyta exitialis, was found to be also part of the barley core microbiome. Eleven of twelve OTUs belonging to the Glomeraceae family were associated with healthy roots and abundant in cultivar Vitra. This study shows how the phenotype and fungal microbiome of different pea cultivars respond distinctly to intercropping. Furthermore, the identification of disease- and health-associated taxa in the pea root fungal community refines the characterization of different cultivar candidates for intercropping.
  • Topography-Driven Shape, Spread, and Retention of Leaf Surface Water Impacts Microbial Dispersion and Activity in the Phyllosphere
    Item type: Journal Article
    Doan, Hung K.; Ngassam, Viviane N.; Gilmore, Sean F.; et al. (2020)
    Phytobiomes Journal
    To study the impact of lateral variation in surface topography on the microbial colonization of plant leaves, we used a two-step casting process to generate topomimetic "replicasts" in polydimethylsiloxane which faithfully resembled leaf surface topography at submicrometer scale. This process revealed that the shape and size of the phyllotelma-the collective body of standing water on a leaf surface-was a function of wetting method and presence of surface features, in particular leaf veins. The use of dyes and fluorescently labeled bacteria showed that these veins, especially on the abaxial side, contributed to the pooling, retention, and lateral spread of water and microorganisms. Bodies of water along veins acted as conduits that allowed bacterial cells to sense chemicals over distances exceeding their body length by four orders of magnitude. Bacterial survival rates under conditions of low relative humidity were twice as high on leaf replicasts as on flat surfaces, suggesting topography-dependent protection from desiccation. Our findings highlight the need for greater quantitative understanding of the impact of leaf surface topography on phyllotelma connectivity and the outcomes of interactions between microorganisms and with their plant host. Such understanding benefits both theory and practice of phyllosphere microbiology in areas such as foliar disease management and food safety of leafy greens.
Publications 1 - 3 of 3