Biology subjects

Hernandez-Alvarez, C.

Publications and source records attributed to Hernandez-Alvarez, C..

3 recordsLinked to original sources

bioRxiv2024

Rhizosphere Microbiome Influence on Tomato Growth under Low-Nutrient Settings

Studies have shown that reduced nutrient availability enhances microbial diversity around plant roots, positively impacting plant productivity. However, the specific contributions of rhizosphere microbiomes in nutrient-poor environments still need to be better understood. This study investigates the role of Plant Growth-Promoting Rhizobacteria (PGPR) in enhancing the growth of Solanum lycopersicum under hydroponic conditions. We hypothesised that nutrient limitation would increase the selection of beneficial bacterial communities, compensating for nutrient deficiencies. Our hydroponic system, with treatments consisting of 50% reduced fertiliser application supplemented with a soil-derived inoculum, exhibited greater bacterial diversity and biomass than controls, suggesting a successful enrichment of PGPR that compensates for nutrient deficiencies. Using 16S rRNA gene sequencing, we found a significant enrichment (p [≤] 0.001) and correlation with beneficial plant traits (p [≤] 0.05) of bacterial genera such as Luteolibacter, Sphingopyxis, and Kaistia. Shotgun metagenomics identified the critical role of Methyloversatilis in nitrogen fixation and other key taxa bacterial proteins in plant-bacteria interactions. Additionally, our findings identify core taxa across different cultivation systems. These results support the potential for microbiome engineering to enhance microbial diversity and plant productivity, offering a path to reduce fertiliser use in agriculture and improve sustainability.

genomics↗

bioRxiv2023

A Study of Microbial Diversity in a Biofertilizer Consortium

Biofertilizers supply living microorganisms to help plants grow and maintain their health. In this study, we examine the microbiome composition of a commercial biofertilizer that has been proven to promote plant growth. Using ITS and 16S rRNA gene sequence analyses, we describe the microbial communities of the biofertilizer, with 182 fungal species and 964 bacterial genera identified. The biofertilizer contains a variety of microorganisms that had been reported to enhance nutrient uptake, phytohormone production, stress tolerance, and pathogen resistance in plants. Plant roots created a microenvironment that boosted bacterial diversity but filtered fungal communities. We propose using plant roots as bioreactors to sustain dynamic environments that promote the proliferation of microorganisms with biofertilizer potential. However, preserving the fungal-inoculated substrate is crucial to maintain fungal diversity in the root fraction. The study suggests that bacteria grow close to plant roots, while root-associated fungi may be a subset of the substrate fungi. These findings indicate that the composition of the biofertilizer may be influenced by the selection of microorganisms associated with plant roots, which could have implications for the effectiveness of the biofertilizer in promoting plant growth.

microbiology↗

bioRxiv2020

Testing the two-step model of plant root microbiome acquisition under multiple plant species and soil sources

The two-step model for plant root microbiomes considers soil as the primary microbial source. Active selection of the plants bacterial inhabitants results in a biodiversity decrease towards roots. We collected in situ ruderal plant roots and their soils and used these soils as the main microbial input for single genotype tomatoes grown in a greenhouse. We massively sequenced the 16S rRNA and shotgun metagenomes of the soils, in situ plants, and tomato roots. Tomato roots did follow the two-step model, while ruderal plants did not. Ruderal plants and their soils are closer than tomato and its soil, based on protein comparisons. We calculated a metagenomic tomato root core of 51 bacterial genera and 2,762 proteins, which could be the basis for microbiome-oriented plant breeding programs. The tomato and ruderal metagenomic differences are probably due to plant domestication trade-offs, impacting plant-microbe interactions.

microbiology↗