Arbuscular mycorrhizal symbiosis is an association that provides nutritional benefits to plants. Importantly, it induces a physiological state allowing plants to respond to a subsequent pathogen attack in a more rapid and intense manner. Consequently, mycorrhiza-colonized plants become less susceptible to root and shoot pathogens. This study aimed to identify some of the molecular players and potential mechanisms related to the onset of defense priming by mycorrhiza colonization, as well as miRNAs that may act as regulators of priming genes. The upregulation of cellulose synthases, pectinesterase inhibitors, and xyloglucan endotransglucosylase/hydrolase, as well as the downregulation of a pectinesterase, suggest that the modification and reinforcement of the cell wall may prime the leaves of mycorrhizal plants to react faster and stronger to subsequent pathogen attack. This was confirmed by the findings of miR164a-3p, miR164a-5p, miR171e-5p, and miR397, which target genes and are also related to the biosynthesis or modification of cell wall components. Our findings support the hypothesis that the reinforcement or remodeling of the cell wall and cuticle could participate in the priming mechanism triggered by mycorrhiza colonization, by strengthening the first physical barriers upstream of the pathogen encounter.

MicroRNAs (miRNAs) are short endogenous non-coding RNAs that regulate gene expression at the post-transcriptional level through mRNA cleavage or translational repression. In plants, miRNAs play pivotal roles in a wide range of biological processes, including development, growth, and responses to biotic and abiotic stresses. Central to these processes is the plant cell wall, a dynamic structure that not only provides mechanical support but also functions as the first line of defense against environmental challenges and pathogen attack. The plant cell wall must maintain a fine balance between rigidity and plasticity, enabling rapid remodeling in response to developmental cues and stress signals. This remodeling process requires tight and coordinated regulation of genes involved in cell wall biosynthesis, modification, and degradation. Emerging evidence indicates that miRNAs are key regulators of these processes, modulating the expression of transcription factors, enzymes, and signaling components associated with cell wall dynamics. In addition to their intracellular roles, miRNAs can also function as mobile signals, linking cell wall remodeling with intercellular communication through plasmodesmata and coordinating responses at the tissue level. Furthermore, recent studies suggest that pathogen-derived small RNAs may contribute an additional regulatory layer by targeting host genes associated with cell wall structure and connectivity. In this review, we summarize recent advances in the identification and functional characterization of miRNAs involved in the regulation of plant cell wall responses. We highlight their regulatory implications, target genes, and roles in integrating developmental, stress-related, and intercellular communication pathways. Understanding the RNA-mediated control of cell wall dynamics provides new insights into plant adaptability and resilience, with potential applications in crop improvement and stress tolerance engineering.

Viroids are the simplest known infectious agents, consisting of noncoding circular RNAs that replicate autonomously in plant hosts while inducing profound and systemic alterations in host biology. This apparent paradox positions viroids as powerful models for understanding how RNA molecules encode biological information independently of protein translation. A hallmark of viroid infection is the production of viroid‐derived small interfering RNAs (vd‐siRNAs) by the host RNA silencing machinery. Here, we propose that vd‐siRNAs function not merely as antiviroid byproducts, but as active effectors that translate RNA structural information into gene regulatory activity. Through sequence complementarity and selective incorporation into Argonaute complexes, vd‐siRNAs influence host gene expression at multiple levels, including transcript abundance, protein accumulation, epigenetic states, and metabolic pathways. Importantly, their effects extend beyond individual targets and are consistent with broader perturbations of interconnected host regulatory networks, potentially contributing to coordinated transcriptional reprogramming and disease‐associated phenotypes. By integrating molecular, transcriptomic, epigenetic, and systems‐level evidence, we propose a “structure‐to‐network” perspective in which viroid RNAs function as minimal informational systems capable of interfacing with complex cellular pathways. Within this context, vd‐siRNAs emerge as mechanistic links between RNA architecture and multiscale biological responses. Finally, we discuss how this framework expands our understanding of RNA‐mediated regulation and highlights the broader regulatory potential of structured noncoding RNAs.

Arbuscular mycorrhizal symbiosis leads to differential regulation of genes and miRNAs associated with the cell wall and cuticle in tomato leaves. Mendoza-Soto, A.B, Rodríguez-Corral, A.Z., Castro-Martínez, C., López-Meyer, M. Instituto Politécnico Nacional, CIIDIR-Sinaloa, Depto. Biotecnología Agrícola. Blv. Juan de Dios Bátiz 250. Guasave, Sinaloa, México. CP 81000. Arbuscular mycorrhizal symbiosis is an association that provides nutritional benefits to plants. Furthermore, it induces a physiological state that allows plants to response in a more rapid and intense manner to a subsequent biotic attack, thus mycorrhizal plants become less susceptible to both root, as well as shoot pathogens. Our research aims to identify the molecular mechanisms related to the induction of systemic defense by mycorrhiza colonization. We identified genes responsive to the symbiosis related to the biogenesis of the cell wall, as well as its organization and modification. We observed a transcriptional induction of two cellulose synthase genes, an endoglucanase 1, a xyloglucan endotransglucosylase/hydrolase and a pectinesterase inhibitor. In contrast, a pectinesterase, and a NAD-dependent epimerase/hydrolase showed repression. Coinciding with the induction of two cellulose synthase genes, we also observed a higher accumulation of cellulose in leaves of mycorrhizal tomato plants. We identified two induced genes related to fatty acid metabolism; the enoyl reductase gene, and the long chain fatty acid CoA ligase gene. Also, we observed the repression of the 4-coumarate CoA ligase gene, which may be related to the biosynthesis of cuticle components. Regulatory mechanisms for the triggering of priming by mycorrhiza colonization may involve miRNAs along with other regulators. MicroRNAs (miRNAs) are 21-24 nt non-coding RNAs that regulate gene expression at the post-transcriptional level in plants. One objective of our research is to identify the possible role of miRNA as regulators of priming in leaves of mycorrhizal tomato. We observed a repression of miR164a-3p, miR164a-5p, and miR398b; these miRNAs are also related with cell wall. These results support the hypothesis that reinforcement of cell wall and cuticle could play a role in the priming mechanism triggered by mycorrhiza colonization by strengthen the first physical barriers for pathogens. Arbuscular mycorrhizal symbiosis leads to differential regulation of genes and miRNAs associated with the cell wall and cuticle in tomato leaves. Mendoza-Soto, A.B, Rodríguez-Corral, A.Z., Castro-Martínez, C., López-Meyer, M. Instituto Politécnico Nacional, CIIDIR-Sinaloa, Depto. Biotecnología Agrícola. Blv. Juan de Dios Bátiz 250. Guasave, Sinaloa, México. CP 81000. Arbuscular mycorrhizal symbiosis is an association that provides nutritional benefits to plants. Furthermore, it induces a physiological state that allows plants to response in a more rapid and intense manner to a subsequent biotic attack, thus mycorrhizal plants become less susceptible to both root, as well as shoot pathogens. Our research aims to identify the molecular mechanisms related to the induction of systemic defense by mycorrhiza colonization. We identified genes responsive to the symbiosis related to the biogenesis of the cell wall, as well as its organization and modification. We observed a transcriptional induction of two cellulose synthase genes, an endoglucanase 1, a xyloglucan endotransglucosylase/hydrolase and a pectinesterase inhibitor. In contrast, a pectinesterase, and a NAD-dependent epimerase/hydrolase showed repression. Coinciding with the induction of two cellulose synthase genes, we also observed a higher accumulation of cellulose in leaves of mycorrhizal tomato plants. We identified two induced genes related to fatty acid metabolism; the enoyl reductase gene, and the long chain fatty acid CoA ligase gene. Also, we observed the repression of the 4-coumarate CoA ligase gene, which may be related to the biosynthesis of cuticle components. Regulatory mechanisms for the triggering of priming by mycorrhiza colonization may involve miRNAs along with other regulators. MicroRNAs (miRNAs) are 21-24 nt non-coding RNAs that regulate gene expression at the post-transcriptional level in plants. One objective of our research is to identify the possible role of miRNA as regulators of priming in leaves of mycorrhizal tomato. We observed a repression of miR164a-3p, miR164a-5p, and miR398b; these miRNAs are also related with cell wall. These results support the hypothesis that reinforcement of cell wall and cuticle could play a role in the priming mechanism triggered by mycorrhiza colonization by strengthen the first physical barriers for pathogens.

La diabetes mellitus (DM) es una epidemia creciente que plantea una gran amenaza para la salud mundial. Se estima que actualmente 527 millones de personas alrededor del mundo tienen DM y que en los próximos 25 años la prevalencia mundial aumentará alrededor de un 46%. La DM es una afección grave crónica que ocurre cuando se elevan los niveles de glucosa en la sangre, debido a que el organismo no puede producir suficiente hormona insulina o no la puede utilizar eficazmente.

El descubrimiento de los microRNAs (miRNAs) ha revolucionado la biomedicina moderna. Estas pequeñas moléculas de RNA, de 18-24 nucleótidos, son reguladores clave de la expresión génica, actuando como "interruptores" que controlan la activación o silenciamiento de genes en momentos críticos. Su impacto en la comprensión de procesos celulares y enfermedades ha sido reconocido con el Premio Nobel de Medicina. Los miRNAs se han convertido en herramientas prometedoras en el diagnóstico y tratamiento de enfermedades complejas como el Alzheimer, la diabetes mellitus tipo 2 (DM2), y las enfermedades cardiovasculares, consolidándose como un pilar en la medicina de precisión.