Biology subjects

Feola Conz, R.

Publications and source records attributed to Feola Conz, R..

3 recordsLinked to original sources

bioRxiv2026

Digging for meaningful connections: associations between root phenotypes and rhizosphere microbial diversity in maize

Drought threatens food security globally. Adaptive root phenotypes and microbiomes can improve maize (Zea mays L.) water uptake and tolerance to drought. However, synergisms between root phenotypes and microbiomes remain underexplored. We aimed to investigate the association between varying root phenotypes and rhizosphere microbiomes under field-scale drought. We grew 22 maize inbred lines in the field under optimal water availability and drought imposed by excluding rain with rainout shelters. We quantified grain yield and measured root architectural and anatomical phenotypes on root crown and cross-section images obtained by laser ablation tomography, respectively. We characterized rhizosphere prokaryotic and fungal communities with DNA metabarcoding of ribosomal markers. Rhizosphere microbial diversity predominantly associated with root anatomy rather than root architecture. Cortical parenchyma wall width explained 13.1% of the variance of the prokaryotic {beta}-diversity and correlated with grain yield under control conditions. Under the same conditions, number of cortical cell files and metaxylem vessels explained 1.4-2.1% of the variance of prokaryotic and fungal {beta}-diversities. No effect of the root phenotypes was observed under drought. We found 248 significant correlations between microbial taxa abundances and root anatomical phenotypes, especially cortex-related phenotypes such as number of cell files and living cortical area. Overall, a greater number of correlations was found under control conditions. We identified root phenotypes explaining a small but significant percentage of the variance of the microbial {beta}-diversity, mostly under optimal water availability. We showed that especially root anatomy is associated with rhizosphere microbial diversity in field-grown maize.

systems biology↗

bioRxiv2025

Soil microbial and plant responses to increasing antibiotic concentration: a case study of five antibiotics

Antibiotic contamination from biogenic waste in agricultural soils poses a significant threat to soil health and crop productivity. We investigated the effect of antibiotics on the soil microbial community, antibiotic resistance genes (ARGs) and mobile genetic elements (MGEs) and plant productivity in a six week greenhouse trial. Here, Spinacia oleracea (spinach) and Raphanus sativus (radish) were grown from seed and a mix of five antibiotics, namely sulfamethoxazole, trimethoprim, enrofloxacin, clarithromycin and chlortetracycline, were added to the soil at concentrations 0, 0.1, 1 and 10 mg kg-1 soil dry weight (c0, c0.1, c1 and c10, respectively). Overall, we found that the antibiotic treatments significantly impacted prokaryotic -diversity and prokaryotic and fungal {beta}-diversity. Human and plant pathogen abundance did not increase under antibiotic exposure, but there was a significant reduction of plant growth-promoting bacteria. Moreover, the c10 treatment significantly increased the abundance of MGE intI1 indicative of horizontal gene transfer and ARG sul1 antibiotic resistance and significantly lowered radish biomass and nitrogen uptake, while spinach biomass and nitrogen uptake were unaffected. In summary, our study showed that antibiotic exposure significantly changed prokaryotic community diversity and taxonomy, while fungi remained largely unaffected. The reduction of plant growth-promoting bacteria may have a significant impact on soil nutrient cycling and crop productivity, but more research is needed to understand the long-term impact of these co-applied antibiotics on food production. Additionally, more studies are needed to understand the effect of antibiotics on realistic, field scale, conditions to fully understand the impact on environmental and human health. ImportanceAgricultural soils are increasingly contaminated with complex mixtures of antibiotics from various biogenic sources, yet we lack a clear understanding of their specific ecological impact. While many studies investigate antibiotics, they often are studied in pollution sources like manure which contain confounding factors like heavy metals. To provide clear mechanistic insight, we investigated the effects of a complex, five-antibiotic mixture on the soil-plant system, independent of other contaminants. This revealed that the effect of antibiotics extends beyond selecting for antibiotic resistance. Specifically, the reduction of prokaryotic diversity and plant growth-promoting bacteria under antibiotic exposure can have potential detrimental effects on plant and soil health. Moreover, we found that antibiotic exposure can reduce plant biomass and nitrogen uptake, but this is highly plant dependent. This research highlights the critical need to monitor antibiotic pollution due to its potential detrimental effect on plant health and alterations to the soil microbiome.

microbiology↗

bioRxiv2024

Microbial resistance and resilience to drought under organic and conventional farming

The impacts of climate change, such as drought, can affect soil microbial communities. These communities are crucial for soil functioning and crop production. Organic and conventional cropping systems promote distinct soil microbiomes and soil organic carbon contents, which might maintain different capacities to mitigate drought effects on cropping systems. A field-scale drought simulation was performed in long-term organically and conventionally managed cropping systems differing in fertilization and pesticide application. The soil microbiome was assessed during and after drought in bulk soil, rhizosphere, and roots of wheat. We found that drought shifted microbial community structures, affecting fungi more strongly than prokaryotes. Microbial communities associated with crops (i.e. rhizosphere and root) were more strongly influenced by drought compared to bulk soil communities. A drought legacy effect was observed in the bulk soil after harvesting and rewetting. The resistance and resilience of the soil microbiome to severe drought did not significantly differ across the organic and conventional cropping systems, although few individual genera (e.g. Streptomyces, Rhizophagus, Actinomadura, and Aneurinibacillus) showed system-specific drought responses. All cropping systems showed relative increases in potential plant growth-promoting genera under drought. This agricultural field study indicated that fungal communities might be less resistant to drought than prokaryotic communities in cropping systems and these effects get more pronounced in closer association with plants. Organic fertilization or the reduction in pesticide application might not have the ability to buffer severe drought stress and additional farming practices might have to be incorporated to improve drought tolerance in cropping systems.

microbiology↗