Biology subjects

Romero-Campero, F. J.

Publications and source records attributed to Romero-Campero, F. J..

9 recordsLinked to original sources

bioRxiv2026

Photoperiodic Plasticity of Transcriptomic and Photosynthetic Rhythms in the Liverwort Marchantia polymorpha

Earth's translation around the Sun and tilted rotational axis drive periodic seasonal changes in day length, or photoperiod, in temperate zones. In photosynthetic organisms, light acts not only as an environmental cue but also as the primary energy source. Therefore, characterizing the plasticity of oscillating molecular systems during photoperiod acclimation is essential for understanding the temporal orchestration of physiological processes in these organisms. Although photoperiodic plasticity has been extensively studied in angiosperms and microalgae, its impact on the molecular rhythms in non-vascular plants (bryophytes) remains poorly understood. In this study, we performed an integrative temporal analysis combining transcriptomic and photosynthetic approaches in the non-vascular model plant Marchantia polymorpha. Plants were grown under long (summer) and short (winter) photoperiods and subsequently transferred to constant light or darkness to unravel the light/dark-responsive and circadian components of their rhythmic transcriptome profiles. Plants under short photoperiod exhibited a higher number of rhythmic genes and an advance in their expression pattern, affecting several pathways including photosynthesis. However, only ~25% of these genes remained oscillating under constant conditions. We further identified dusk responsiveness and dawn anticipation as key features of the rhythmic patterns in Marchantia polymorpha. These patterns were associated with specific transcription factors, highlighting a potential role for MpHY5 in circadian regulation in this liverwort. Consistent with the transcriptomic results, analyses of photosynthetic physiology and chloroplast photorelocation revealed a general anticipation under short photoperiods and mechanisms mitigating photooxidative stress at dawn in both photoperiods.

plant biology↗

bioRxiv2026

Unveiling the Epigenomic Control of Temperature Acclimation in Marine Phytoplankton through Multiomics Integration

Temperature plays a central role in marine phytoplankton biogeographical dynamics, physiology and gene expression. Nonetheless, the transcriptional regulatory mechanisms controlling temperature acclimation in marine phytoplankton are yet to be characterized. Ostreococcus tauri was chosen as a model species for green marine phytoplankton due to its cellular and genomic simplicity, as well as its evolutionary position within the green lineage. In this study, epigenomic and transcriptomic data were integrated to characterize changes induced by temperature in the trimethylation of histone 3 at lysines 27 and 4 (H3K27me3 and H3K4me3) epigenetic marks established by the Polycomb (PcG) and Trithorax group (TrxG) complexes, respectively. H3K27me3 was found to be a repressive mark responding to temperature, showing predominantly significant increased levels at high temperatures. While H3K4me3 was associated with active transcription, presenting less evident variations in cultures acclimated to different temperatures. H3K27me3 was found only marginally associated with transposable elements, being mostly involved in the repression of specific biological processes, such as gene expression control by transcription factors, meiosis, motors proteins and cytoskeletal structures. No significant conservation was found between the H3K27me3 gene targets in the model plant Arabidopsis thaliana and Ostreococcus tauri. Nonetheless, transcriptions factors belonging to the MADS-box, WRKY and AP2 families were consistently repressed by H3K27me3 in both species, unveiling that, although the specific downstream targets of this epigenetic mark have diversified during evolution, its role in modulating higher order regulatory nodes remains evolutionary conserved.

plant biology↗

bioRxiv2026

Transcriptomic Insights into Drought Tolerance Enhancement in Bread Wheat Induced by a Microalgae-based Biostimulant

Bread wheat (Triticum aestivum) is a staple food crucial for global caloric intake and food security. The current climate emergency demands the development of sustainable agricultural practices, particularly in the context of drought-induced yield reductions in bread wheat. Microalgae-based biostimulants have emerged as promising tools to enhance crop tolerance to drought stress while concurrently mitigating atmospheric CO2 accumulation. This study characterizes the transcriptomic responses to the foliar application of the microalgae-based biostimulant LRMTM in drought-stressed and fully irrigated wheat plants unveiling its mode of action. Drought stress at the tillering stage significantly altered gene expression activating key pathways related to phosphate starvation response (PSR), inositol phosphate signaling, and tocopherol biosynthesis. The application of the microalgae-based biostimulant LRMTM in drought-stressed plants further enhanced the expression of drought-responsive genes, particularly those involved in PSR and carbon fixation. Specific responses to LRMTM treatment in drought-stressed plants were also found related to abscisic acid (ABA) signaling activating genes involved in stomata closure, which plays a critical role in drought tolerance. In fully irrigated plants, LRMTM treatment was also beneficial modulating circadian rhythms, shade avoidance and attenuating stress responses. Phenotypic analysis showed that LRMTM-treated plants exhibited enhanced drought tolerance, increased height and spike length even under fully irrigated conditions. These results indicate that the microalgae-based biostimulant LRMTM not only enhances wheat response to drought but also promotes growth and productivity in both stressed and non-stressed conditions which could contribute to the development of sustainable agriculture in the face of the current climate challenges.

plant biology↗

bioRxiv2023

PharaohFUN: PHylogenomic Analysis foR plAnt prOtein History and FUNction elucidation

Since DNA sequencing has become commonplace, the development of efficient methods and tools to explore gene sequences has become indispensable. In particular, despite photosynthetic eukaryotes constituting the largest percentage of terrestrial biomass, computational functional characterization of gene sequences in these organisms still predominantly relies on comparisons with Arabidopsis thaliana and other angiosperms. This paper introduces PharaohFUN, a web application designed for the evolutionary and functional analysis of protein sequences in photosynthetic eukaryotes, leveraging orthology relationships between them. PharaohFUN incorporates a homogeneous representative sampling of key species in this group, bridging clades that have traditionally been studied separately, thus establishing a comprehensive evolutionary framework to draw conclusions about sequence evolution and function. For this purpose, it incorporates modules for exploring gene tree evolutionary history, expansion and contraction events, ancestral states, domain identification, multiple sequence alignments, and diverse functional annotation. It also incorporates different search modes to facilitate its use and increase its reach within the community. Tests were performed on the whole transcription factor toolbox of Arabidopsis thaliana and on CCA1 protein to assess its utility for both large-scale and fine-grained phylogenetic studies. These exemplify how PharaohFUN accurately traces the corresponding evolutionary histories of these proteins by unifying results for land plants, streptophyte and chlorophyte microalgae. Thus, PharaohFUN democratizes access to these kind of analyses in photosynthetic organisms for every user, independently of their prior training in bioinformatics.

evolutionary biology↗

bioRxiv2023

Multiomics responses to seasonal variations in diel cycles in the marine phytoplanktonic picoeukaryote Ostreococcus tauri

Earth tilted rotation and translation around the Sun produce one of the most pervasive periodic environmental signals on our planet giving rise to seasonal variations in diel cycles. Although marine phytoplankton plays a key role on ecosystems and present promising biotechnological applications, multiomics integrative analysis of their response to these rhythms remains largely unexplored. We have chosen the marine picoeukaryote Ostreococcus tauri as model organism grown under summer long days, winter short days, constant light and constant dark conditions to characterize these responses in marine phytoplankton. Although 80% of the transcriptome present diel rhythmicity under both seasonal conditions less than 5% maintained oscillations under all constant conditions. A drastic reduction in protein abundance rhythmicity was observed with 55% of the proteome oscillating. Seasonally specific rhythms were found in key physiological processes such as cell cycle progression, photosynthetic efficiency, carotenoid content, starch accumulation and nitrogen assimilation. A global orchestration between transcriptome, proteome and physiological dynamics was observed with specific seasonal temporal offsets between transcript, protein and physiological peaks.

plant biology↗

bioRxiv2023

A Proxitome-RNA-capture Approach Reveals that Processing Bodies Repress Co-Regulated Hubs

Cellular condensates are usually ribonucleoprotein assemblies with liquid- or solid-like properties. Because they lack a delineating membrane, the compositional determination of condensates is laborious. Here we set up a pipeline for proximity-biotinylation-dependent capture of RNA to investigate the RNA composition of the condensate in Arabidopsis known as the processing bodies (PBs). Using this pipeline together with in situ protein-protein interaction and RNA detection, in silico, and high-resolution imaging approaches, we studied PBs under normal and heat stress conditions. The composition of PBs in RNAs is much more dynamic than that of the total transcriptome. RNAs involved in cell wall development and regeneration, hormonal signaling, secondary metabolism/defense, and RNA metabolism were enriched in PBs. RNA binding proteins and liquid-to-solid phase transitions modulated specificity of RNA recruitment in PBs. Surprisingly, RNAs were sometimes recruited together with their encoded proteins. In PBs RNAs follow distinct fates, with small liquid-like PBs modulating RNA decay while larger ones storage. The size and properties of PBs are regulated by the actin polymerization cAMP receptor (SCAR)-WASP family verprolin homologous (WAVE) complex. SCAR/WAVE modulates signaling by shuttling RNAs between PBs and the translational machinery adjusting the ethylene signaling pathway. Heat stress leads to the storage of immunity-related RNAs in PBs by reducing PBs dynamics, suggesting why processes such as immunity malfunction under heat stress. In summary, we provide a method to identify RNAs in condensates which allowed us to reveal a mechanism for RNA fate regulation.

plant biology↗

bioRxiv2023

CONSTANS alters the circadian clock in Arabidopsis thaliana

AbstractPlants are sessile organisms that have acquired highly plastic developmental strategies to adapt to the environment. Among these processes, the floral transition is essential to ensure reproductive success and is finely regulated by several internal and external genetic networks. The photoperiodic pathway, which controls the plant response to day length, is one of the most important pathways controlling flowering. In Arabidopsis photoperiodic flowering, CONSTANS (CO) is the central gene activating the expression of the florigen FLOWERING LOCUS T (FT) in the leaves at the end of a long day. CO expression is strongly regulated by the circadian clock. However, to date, no evidence has been reported regarding a feedback loop from the photoperiod pathway back to the circadian clock. Using transcriptional networks, we have identified relevant network motifs regulating the interplay between the circadian clock and the photoperiod pathway. Gene expression, chromatin immunoprecipitation experiments and phenotypic analysis allowed us to elucidate the role of CO over the circadian clock. Plants with altered CO expression showed a different internal clock period, measured by daily rhythmic movements in the leaves. We show that CO is able to activate key genes related to the circadian clock, such as CCA1, LHY, PRR5 and GI, at the end of a long day by binding to specific sites on their promoters. Moreover, a significant number of PRR5 repressed target genes are upregulated by CO, and this could explain the phase transition promoted by CO. The CO-PRR5 complex interacts with the bZIP transcription factor HY5 and helps to localize the complex in the promoters of clock genes. Our results indicate that there may be a feedback loop in which CO communicates back to the circadian clock, feeding seasonal information to the circadian system.

plant biology↗

bioRxiv2021

ALGAEFUN with MARACAS, microALGAE FUNctional enrichment tool for MicroAlgae RnA-seq and Chip-seq AnalysiS

BackgroundMicroalgae are emerging as promising sustainable sources for biofuels, biostimulants in agriculture, soil bioremediation, feed and human nutrients. Nonetheless, the molecular mechanisms underpinning microalgae physiology and the biosynthesis of compounds of biotechnological interest are largely uncharacterized. This hinders the development of microalgae full potential as cell-factories. The recent application of omics technologies into microalgae research aims at unraveling these systems. Nevertheless, the lack of specific tools for analysing omics raw data generated from microalgae to provide biological meaningful information are hampering the impact of these technologies. The purpose of ALGAEFUN with MARACAS consists in providing researchers in microalgae with an enabling tool that will allow them to exploit transcriptomic and cistromic high-throughput sequencing data. ResultsALGAEFUN with MARACAS consists of two different tools. First, MARACAS (MicroAlgae RnA-seq and Chip-seq AnalysiS) implements a fully automatic computational pipeline receiving as input RNA-seq (RNA sequencing) or ChIP-seq (chromatin immunoprecipitation sequencing) raw data from microalgae studies. MARACAS generates sets of differentially expressed genes or lists of genomic loci for RNA-seq and ChIP-seq analysis respectively. Second, ALGAEFUN (microALGAE FUNctional enrichment tool) is a web-based application where gene sets generated from RNA-seq analysis as well as lists of genomic loci from ChIP-seq analysis can be used as input. On the one hand, it can be used to perform Gene Ontology and biological pathways enrichment analysis over gene sets. On the other hand, using the results of ChIP-seq data analysis, it identifies a set of potential target genes and analyses the distribution of the loci over gene features. Graphical representation of the results as well as tables with gene annotations are generated and can be downloaded for further analysis. ConclusionsALGAEFUN with MARACAS provides an integrated environment for the microalgae research community that facilitates the process of obtaining relevant biological information from raw RNA-seq and ChIP-seq data. These applications are designed to assist researchers in the interpretation of gene lists and genomic loci based on functional enrichment analysis. ALGAEFUN with MARACAS is publicly available on https://greennetwork.us.es/AlgaeFUN/.

bioinformatics↗

bioRxiv2020

A gene regulatory network critical for axillary bud dormancy directly controlled by Arabidopsis BRANCHED1

The control of branch outgrowth is critical for plant fitness, stress resilience and crop yield. The Arabidopsis thaliana transcription factor BRANCHED1 (BRC1) plays a pivotal role in this process as it integrates signals that inhibit axillary bud growth to control shoot branching. Despite the remarkable activity of BRC1 as a potent growth inhibitor, the mechanisms by which it promotes and maintains bud dormancy are still largely unknown. Here we combine ChIP-seq, transcriptomic and systems biology approaches to characterise the BRC1-regulated gene network. We identify a group of BRC1 direct target genes encoding transcription factors (BTFs) that orchestrate, together with BRC1, an intricate transcriptional network enriched in abscisic acid signalling components. The BRC1 network is enriched in feed-forward loops and feed-back loops, robust against noise and mutation, reversible in response to stimuli, and stable once established. This knowledge is fundamental to adapt plant architecture and crop production to ever-changing environmental conditions.

plant biology↗