Differential gene expression networks and auxin responses during maize callus induction from explant tissues with contrasting embryogenic potential.

Maize somatic embryogenesis process depends on explant characteristics and genotype. The relationship between explant developmental timing and embryogenic potential of derived tissues is still poorly understood. The present work explored the adjustments of transcriptomes and proteomes from explants with contrasting embryogenic potential - immature and mature zygotic embryos from the Tuxpeño VS-535 genotype - during callus induction.

Hop stunt viroid infection induces heterochromatin reorganization.

Viroids are pathogenic noncoding RNAs that completely rely on their host molecular machinery to accomplish their life cycle. Several interactions between viroids and their host molecular machinery have been identified, including interference with epigenetic mechanisms such as DNA methylation. Despite this, whether viroids influence changes in other epigenetic marks such as histone modifications remained unknown.

Transcriptional Regulation of zma- by Action of Nitrate and Auxin in Maize.

In recent years, miR528, a monocot-specific miRNA, has been assigned multifaceted roles during development and stress response in several plant species. However, the transcription regulation and the molecular mechanisms controlling expression in maize are still poorly explored. Here we analyzed the zma- promoter region and found conserved transcription factor binding sites related to diverse signaling pathways, including the nitrate (TGA1/4) and auxin (AuxRE) response networks.

Occurrence of RNA post-transcriptional modifications in plant viruses and viroids and their correlation with structural and functional features.

Post-transcriptional modifications of RNA bases are widespread across all the tree of life and have been linked to RNA maturation, stability, and molecular interactions. RNA modifications have been extensively described in endogenous eukaryotic mRNAs, however, little is known about the presence of RNA modifications in plant viral and subviral RNAs. Here, we used a computational approach to infer RNA modifications in plant-pathogenic viruses and viroids using high-throughput annotation of modified ribonucleotides (HAMR), a software that predicts modified ribonucleotides using high-throughput RNA sequencing data.

MicroRNA Zma-miR528 Versatile Regulation on Target mRNAs during Maize Somatic Embryogenesis.

MicroRNAs (miRNAs) are small non-coding RNAs that regulate the accumulation and translation of their target mRNAs through sequence complementarity. miRNAs have emerged as crucial regulators during maize somatic embryogenesis (SE) and plant regeneration. A monocot-specific miRNA, mainly accumulated during maize SE, is zma-miR528.

Epidrug Repurposing: Discovering New Faces of Old Acquaintances in Cancer Therapy.

Gene mutations are strongly associated with tumor progression and are well known in cancer development. However, recently discovered epigenetic alterations have shown the potential to greatly influence tumoral response to therapy regimens. Such epigenetic alterations have proven to be dynamic, and thus could be restored.

tasiR-ARFs Production and Target Regulation during In Vitro Maize Plant Regeneration.

During in vitro maize plant regeneration somatic cells change their normal fate and undergo restructuring to generate pluripotent cells able to originate new plants. Auxins are essential to achieve such plasticity. Their physiological effects are mediated by auxin response factors (ARFs) that bind auxin responsive elements within gene promoters.

The explant developmental stage profoundly impacts small RNA-mediated regulation at the dedifferentiation step of maize somatic embryogenesis.

Maize somatic embryogenesis (SE) requires the induction of embryogenic callus and establishment of proliferation before plant regeneration. The molecular mechanisms underlying callus embryogenic potential are not well understood. Here we explored the role of small RNAs (sRNAs) and the accumulation of their target transcripts in maize SE at the dedifferentiation step using VS-535 zygotic embryos collected at distinct developmental stages and displaying contrasting in vitro embryogenic potential and morphology.

Development-Related miRNA Expression and Target Regulation during Staggered In Vitro Plant Regeneration of Tuxpeño VS-535 Maize Cultivar.

In vitro plant regeneration addresses basic questions of molecular reprogramming in the absence of embryonic positional cues. The process is highly dependent on the genotype and explant characteristics. However, the regulatory mechanisms operating during organ differentiation from in vitro cultures remain largely unknown.

MicroRNA Expression and Regulation During Maize Somatic Embryogenesis.

MicroRNAs are tiny molecules that strikingly change their expression patterns and distribution during somatic embryogenesis induction and plant regeneration. It is of great relevance to analyze simultaneously the microRNA and target mRNA fates to understand their role in promoting an adequate embryogenic response to external stimulus in the regenerating tissues. Here we describe a method to evaluate the expression patterns of miRNAs or other sRNAs and their target regulation in distinctive tissues observed during maize plant regeneration.

Maize miRNA and target regulation in response to hormone depletion and light exposure during somatic embryogenesis.

Maize somatic embryogenesis (SE) is induced from the immature zygotic embryo in darkness and under the appropriate hormones' levels. Small RNA expression is reprogrammed and certain miRNAs become particularly enriched during induction while others, characteristic to the zygotic embryo, decrease. To explore the impact of different environmental cues on miRNA regulation in maize SE, we tested specific miRNA abundance and their target gene expression in response to photoperiod and hormone depletion for two different maize cultivars (VS-535 and H-565).