Biology subjects

Dorantes-Acosta, A. E.

Publications and source records attributed to Dorantes-Acosta, A. E..

4 recordsLinked to original sources

bioRxiv2023

Effect of Sargassum on the Behavior and Survival of the Earthworm Eisenia fetida

In the past decade, Sargassum natans and S. fluitans have massively reached the Mexican Caribbean shores. As a result, Sargassum confinement sites may be affecting the soil quality and health in coastal ecosystems and agroecosystems. The impact of Sargassum (e.g., polyphenols) on soil biodiversity has not yet been evaluated. Terrestrial ecotoxicological tests use the epigean earthworm Eisenia fetida as a model organism to assess the function of soil habitats. This study evaluated the behavior and survival of the earthworm E. fetida exposed to five Sargassum concentrations (0, 25, 50, 75, and 100 %) using two toxicological tests. The avoidance test showed that E. fetida repelled (>80 %) a diet with 100 % Sargassum. In contrast, the acute test recorded a low mortality; however, the growth of E. fetida was lower with increasing Sargassum concentrations. It is concluded that the ability to repel and E. fetida biomass are early warning bioindicators to predict the environmental risk of Sargassum in soil. Therefore, it is relevant to determine the potential risk of using earthworm compost and Sargassum leachates as biofertilizers in agroecosystems.

ecology↗

bioRxiv2023

Control of cell fate specification and patterning by an ancestral microRNA

The formation of an organized body requires the establishment and maintenance of cells with structural and functional distinctive characteristics. A central question in developmental biology is how changes in the regulation of genes drive cell specification and patterning1. microRNAs (miRNAs) are small non-coding RNAs that regulate development through mRNA cleavage and/or translational repression2. In plants, miRNAs regulate key aspects including growth, development, stem cell maintenance, vegetative phase change, leaf morphogenesis, floral organ formation and flowering time3. Biogenesis of plant miRNAs depends on the activity of DICER-LIKE 1 (DCL1), an RNase type III endonuclease that processes double stranded RNA to give rise to mature miRNAs 4. The genomes of todays flora contain at least one bona fide copy of DCL1 5,6. Using Marchantia polymorpha -a model bryophyte that allows comparative approaches to infer characteristics of the ancestral land plant-, we demonstrate that MpDCL1a is required for the biogenesis of miRNAs and uncovered a central role for miR166/Homeodomain Zipper Class III-regulated auxin synthesis in the specification of cell identity, patterning, meristem function, laminar expansion and the development of the body in the last common ancestor of extant land plants.

plant biology↗

bioRxiv2023

Energy-Saving Pretreatments Affect Pelagic Sargassum Composition and DNA Metabarcoding Analysis Reveals the Microbial Community Involved in Methane Yield

Sargassum spp. floods the Caribbean coastlines, causing damage to the local economy and environment. These macroalgae have a low methane yield that makes the anaerobic digestion (AD) process unviable, so low-cost pretreatments are required. This research investigated the efficiency of energy-saving pretreatments, such as water washing, that had not been evaluated for these species. The microbial communities involved in AD of the best and worst-performing systems were also analyzed by high-throughput sequencing. The results showed that water washing pretreatment modified the content of inorganic compounds, fibers, and C:N ratio and increased the methane yield by 38%. The bacterial phyla Bacteroidota, Firmicutes, and Thermotogota, as well as the archaea genera Methanosarcina, RumEn_M2, and Bathyarchaeia, dominated the microbial communities. This study is the first to show the microbial community structure involved in the AD of Sargassum spp. The pretreatments presented in this study may help overcome the previously reported limitations.

bioengineering↗

bioRxiv2017

Marchantia liverworts as a proxy to plants basal microbiomes.

Microbiomes influence plant development, establishment, nutrient acquisition, pathogen defense, and the myriad of roles that ultimately impacts plant health. Plants microbiome are shaped through interactions between the microbes (ranging from cooperative functions to chemical warfare) and a selection process entailed by the host plants that distinguishes between pathogens, commensals, symbionts and transient bacteria. The soil is a primary source for microbes colonizing plants, along with other environmental sources including rain and interactions with other organisms. In this work, we explore the microbiomes through massive sequencing of the 16S rRNA gene in the eldest terrestrial plants: Marchantia liverworts. We compared microbiomes from M. polymorpha, and M. paleacea plants collected in the wild and their soils, all together luckily in the same geographical location (sympatric) thus reducing geographic effects; and also from plants grown in vitro and established from gemmae obtained from the same population of wild plants. Qualitative and quantitative microbiome analysis allowed us to identify microbes conserved in both native and in vitro Marchantia species. While M. polymorpha native plants microbiomes richness is reduced about M. paleacea, containing almost half of the Operative Taxonomic Units (OTUs) observed in M. paleacea, M. polymorpha grown in vitro exhibits larger OTUs. This diversity differences might be the result of impairment to recognize their microbial partners and being an open niche for opportunistic bacteria. The main OTUs in Marchantia microbiomes were assigned to the genera: Methylobacterium, Rhizobium, Paenibacillus, Lysobacter, Pirellula, Steroidobacter, and Bryobacter. The assigned genera correspond to bacteria capable of plant-growth promotion, complex exudates degradation, nitrogen fixation, methylotrophs, and disease-suppressive bacteria, all hosted in the relatively simple anatomy of the plant that provides refuge on their surfaces, rhizoids, and multiple gas chambers that work as specialized niches for different bacterial groups. Marchantia is a promising model to study not only long-term relationships between plants and their microbes but also the transgenerational impact of microbiomes because of Marchantia long 450 million years under climate change conditions testing microbiome configurations.

microbiology↗