Biology subjects

Armijos, C. E.

Publications and source records attributed to Armijos, C. E..

2 recordsLinked to original sources

bioRxiv2026

Stage-Specific RNA Turnover Drives Small RNA Dynamics in Arabidopsis-Colletotrichum Interactions

Small RNAs (sRNAs) are key regulators of plant defense and have been implicated in cross-kingdom interactions with pathogens. The hemibiotrophic fungus Colletotrichum higginsianum infects Arabidopsis thaliana through three stages: appressorial penetration, biotrophy, and necrotrophy. However, the dynamics of fungal and plant sRNA populations across these three stages have not been elucidated. Using high-throughput sequencing, we profiled sRNAs from A. thaliana and C. higginsianum during in planta appressorium (PA), biotrophic (BP), and necrotrophic (NP) phases, and compared them to fungal mycelia (MY) and in vitro appressoria (VA). Our analyses revealed stage-specific patterns in sRNA accumulation in both the plant and the pathogen. In C. higginsianum, sRNAs were dominated by 29 nt species in PA, BP, MY, and VA, but shifted to 18 nt in NP, consistent with RNA degradation during host cell death. In A. thaliana, sRNAs transitioned from 30-33-nt in PA/BP to a 21 nt dominant peak in NP. Also, TE-derived siRNAs and other regulatory sRNAs (miRNAs, ncRNA, snoRNAs and snRNAs) declined during NP. A total of 62 host miRNAs showed differential accumulation, including core plant developmental regulators active across infection stages, and stage-specific miRNAs such as miR396, miR170/171, miR472, and miR858b. tRFs displayed opposite trends in host and pathogen: fungal tRFs declined in NP, while host misc-tRFs, 5'-tRFs, and 3'-tRFs increased, suggesting contrasting regulatory roles. These results provide new insights into RNA-mediated plant-fungal interactions.

plant biology↗

bioRxiv2024

First whole genome assembly of Vaccinium floribundum Kunth, an emblematic Andean species

BackgroundVaccinium floribundum Kunth, known as "mortino," is an endemic shrub species of the Andean region adapted to harsh conditions in high-altitude ecosystems. It plays an important ecological role as a pioneer species in the aftermath of deforestation and human-induced fires within paramo ecosystems, emphasizing its conservation value. While previous studies have offered insights into the genetic diversity of mortino, comprehensive genomic studies are still missing to fully understand the unique adaptations of this species and its population status, highlighting the importance of generating a reference genome for this plant. ResultsONT and Illumina sequencing were used to establish a reference genome for this species. Three different de novo genome assemblies were generated and compared for quality, continuity and completeness. The Flye assembly was selected as the best and refined by filtering out short ONT reads, screening for contaminants and genome scaffolding. The final assembly has a genome size of 529 MB, containing 1,317 contigs and 97% complete BUSCOs, indicating a high level of integrity of the genome. Additionally, the LAI Index of 12.93, further categorizes this assembly as a reference genome. ConclusionsThe genome of V. floribundum reported in this study is the first reference genome generated for this species, providing a valuable tool for further studies. This high-quality genome, based on the quality and completeness parameters obtained, will not only help uncover the genetic mechanisms responsible for its unique traits and adaptations to high-altitude ecosystems, but will also contribute to conservation strategies for a species endemic to the Andes.

genomics↗