Biology subjects

Gallego, D.

Publications and source records attributed to Gallego, D..

2 recordsLinked to original sources

bioRxiv2020

The risk of Xylella fastidiosa outbreaks will decrease in the Mediterranean olive-producing regions

The bacterium Xylella fastidiosa (Xf) is a worldwide distributed invasive insect-borne plant pathogen, which causes lethal diseases to many economically-important crops including olives, citrus, almonds and grapes as well as numerous forest, ornamental, and uncultivated plants. The Mediterranean basin is the top supplier of olive oil with 93% of the world production and is consequently highly concerned about the recent invasion of Xf in Europe. Recently, bioeconomic models estimated putative losses induced by the spread of Xf across the European olive-producing area ranging from 1.9 to 5.2 billion euros over 50 years; however, such models did not take into account the insect vectors, which constitute a key driver of Xf spread. In the present study, we used bioclimatic species distribution models to predict the current and future climate suitability of the Mediterranean area for the main efficient or putative transmitters of Xf to olive (i.e. Philaenus spumarius, Neophilaenus campestris and Aphrophora alni). An important part of the total extent of the Mediterranean olive-producing area, mainly situated in southern Spain, Turkey and Greece, is predicted as currently poorly suitable for these vector species. Moreover, models forecast that nearly the totality of the Mediterranean olive-producing regions will likely become climatically little suitable for these vectors by 2050 due to climate change. In Europe, Xf outbreaks have occurred so far only in localities predicted as climatically suitable for these main vector species (e.g. the Apulia region of Italy) while the areas predicted as poorly suitable are still apparently Xf-free, which suggests that climate tolerances of vectors might play a main role in shaping Xf outbreaks patterns. This pattern highlights the crucial necessity of accounting for vectors when assessing risk of Xf outbreaks, and when considering vector-borne diseases in general. The risk maps presented here will have important practical application for the optimization of current and future strategies to control Xf in the Mediterranean region.

ecology↗

bioRxiv2019

Rhizosphere metagenomics of mine tailings colonizing plants: assembling and selecting synthetic bacterial communities to enhance in situ bioremediation

Mine tailings phytostabilization has been proposed as a bioremediation strategy to constrain the contaminants dispersion using plants to limit the effects of erosion. Rhizospheric bacteria impact plant health and facilitate plant establishment through their metabolic functions, which could be relevant in bioremediation strategies. We studied both culturable and metagenomic diversity or rhizospheric bacteria of mine tailings colonizing plants of an abandoned mine operation in Nacozari de Garcia, Sonora, Mexico. Diversity was described through amplification of the 16S rRNA gene and whole metagenome shotgun sequencing of both environmental and cultured rhizosphere associated microbes. The culturable bacteria were assembled in a synthetic community (SC; 235 bacteria genera). Subsequently, we performed an experimental evolution setup with the SC, selecting for heavy metal resistance, microbial competition, and the ability for growing in plant-derived nutrient sources. The selection experiment show that bacteria diversity decreases from the environmental culture-free microbiomes to the mine tailings rhizospheres and the experimental evolution outcome: the synthetic community (FSC; 43 bacteria genera). The rhizosphere communities shifted from the dominance of Actinobacteria in their environment to Proteobacteria in the cultivated consortia and the synthetic communities. Both environmental and cultured metagenomes contained plant-growth promotion, heavy-metal homeostasis, and antibiotic resistance predicted genes. The FSC included predicted proteins related to plant-growth promotion such as siderophore production and plant hormone regulation proteins. We reconstructed a metagenome assembled genomic sequence named Enterobacter sp., Nacozari. The recovered Enterobacter sp. Nacozari, have predicted coding genes for direct and indirect plant growth promotion along with adhesion and oxidative stress-related proteins. The metabolic potential of the FSC presents promising features that might make it useful for plant-growth promotion in tailored phytostabilization strategies for the abandoned mine-tailings of Nacozari.

genomics↗