Biology subjects

Lozano-Enguita, A.

Publications and source records attributed to Lozano-Enguita, A..

2 recordsLinked to original sources

bioRxiv2025

Root growth promotion by Penicillium melinii: mechanistic insights and agricultural applications

O_LIThis study characterizes Penicillium melinii, an endophytic fungus isolated from Arabidopsis thaliana roots, as a plant growth-promoting fungus with potential use as a model to study root development and as a biostimulant for sustainable agriculture. Although endophytes are known to promote plant growth, the underlying molecular mechanisms often remain poorly understood. Here, we aimed to elucidate how P. melinii enhances root system development and to assess its applicability across different crops. C_LIO_LIPhenotypic assays were conducted in Arabidopsis, quinoa and tomato under in vitro, greenhouse and field conditions. Root architecture and biomass were quantified using image-based phenotyping. Transcriptomic and phytohormone profiling assessed plant responses, and fungal genome sequencing coupled with secretome analysis was used to identify candidate effectors and metabolic traits. C_LIO_LIP. melinii consistently promoted root growth and increased plant biomass across species and environments, both in vitro and in the greenhouse. In tomato field trials, this translated into a significant increase in yield. The fungus colonized root surfaces without vascular penetration and triggered a mild transcriptomic response: early activation of stress-response genes followed by their attenuation and sustained upregulation of auxin-related pathways. Notably, the interaction modulates the SLR-ARF-LBD pathway and the number of pre-branch sites probably through increased auxin signalling in the oscillation zone. Additional hormonal changes were limited and mainly associated with the attenuation of the plant response to microorganisms. C_LIO_LIP. melinii enhances lateral root formation through a subtle molecular and metabolic dialogue with the host plant, underscoring its relevance as a model for studying root developmental plasticity. Its strong and reproducible growth-promoting effect, demonstrated with different fungal strains and under controlled and field conditions, supports its potential as a biostimulant for sustainable crop production. C_LI

plant biology↗

bioRxiv2025

DNA Methylation Dynamics Reveal Unique Plant Responses and Transcriptional Reprogramming to Combined Heat and Phosphate Deficiency Stress

Plants adapt to environmental challenges through epigenetic mechanisms that modulate gene expression without altering DNA sequence. Among these, DNA methylation is central to balancing genome stability and transcriptional flexibility. We analyzed methylation dynamics in Arabidopsis thaliana under heat, phosphate deficiency, and their combination--conditions that frequently co-occur in nature--using whole-genome bisulfite sequencing, small RNA-seq and RNA-seq of shoots and roots in a setup closely mimicking field conditions. Stress-specific patterns emerged: heat and combined stress led to CHH hypomethylation in both shoot and root, while phosphate deficiency triggered hypermethylation in shoots but hypomethylation in roots. Importantly, the epigenetic response to combined stress was not a mere additive effect of individual stresses but displayed a distinct methylation signature. While both RdDM and CMT2 pathways contributed to heat-induced changes, CMT2 predominated under phosphate deficiency and combined stress, underscoring mechanistic specificity. Methylation changes concentrated in transposable elements (TEs) and intergenic regions, yet TE methylation shifts showed limited correlation with TE or adjacent gene expression, suggesting methylation does not act as a direct transcriptional switch. Instead, stress-induced methylation may influence chromatin accessibility at regulatory regions, particularly transcription factor binding sites; GATA motifs appeared as especially relevant in our analyses. A striking signature emerged in the nuclear mitochondrial DNA (NUMT) region, where hypomethylation under heat and combined stress correlated with upregulation of oxidative phosphorylation genes, critical for thermotolerance. Our findings highlight DNA methylation as an intricate regulatory layer integrating environmental signals into plant adaptive responses, offering a foundation for strategies to harness epigenetic plasticity for crop resilience under climate change.

plant biology↗