Biology subjects

Marsch-Martinez, N.

Publications and source records attributed to Marsch-Martinez, N..

5 recordsLinked to original sources

bioRxiv2026

The transcription factor ESR2/DRNL/BOL differentially regulates de novo organogenesis, regeneration, and lateral root development in Arabidopsis thaliana

Plant regeneration requires coordinated transcriptional and hormonal regulation to re-establish organ identity. The AP2/ERF transcription factor ENHANCER OF SHOOT REGENERATION 2 /DORNROESCHEN-LIKE / BOLITA (ESR2/DRNL/BOL) expressed in aerial organ founder cells promotes shoot formation, but its broader role across organogenic contexts remains unclear. Here, using loss-of-function and inducible overexpression lines of Arabidopsis thaliana, we demonstrate that ESR2 exerts context-dependent and antagonistic effects on shoot and root development. ESR2 activation promotes shoot and aerial-like tissue formation and enhances callus proliferation, particularly under cytokinin-rich conditions. Conversely, ESR2 suppresses or delays multiple de novo root formation programs, including adventitious, basal, and regenerated roots, while its loss enhances root initiation and growth. Expression analyses reveal that ESR2 promoter activity is found at de novo formed basal and adventitious root primordia and emerged root apical meristems, suggesting a role in conferring regenerative competence while restricting their developmental progression. Moreover, it is expressed in newly established quiescent centers of lateral roots in intact plants and the loss of ESR2 function strongly and negatively affects lateral root initiation, revealing an unanticipated developmental role of ESR2 and its requirement for lateral root formation. Together, these findings identify ESR2 as a shared molecular regulator governing early organogenesis in intact plants and plant explants; it establishes an aerial organ fate bias while maintaining the competence for -and limiting the progression of- de novo root development in explants.

plant biology↗

bioRxiv2025

The transcription factor NO TRANSMITTING TRACT / WIP2 regulates cytokinin homeostasis in Arabidopsis

NO TRANSMITTING TRACT / WIP2 (NTT/WIP2) is a zinc finger transcription factor that alters developmental programs in Arabidopsis when overexpressed. Loss of NTT function, alone or in combination with closely related genes, leads to developmental defects in gynoecia and roots, respectively. Its overexpression phenotype resembles the effects of cytokinin treatments, suggesting a potential connection to this hormonal pathway. To further investigate this connection, we conducted cytokinin content and response evaluations, and transcriptome analyses in an inducible NTT line. Alterations in cytokinin content and response, as evaluated with the TCSn::GFP line, were observed. In both cases, as in the global expression analyses, the observed changes were dependent on the tissue analyzed. Moreover, Y1H and transactivation assays suggested direct NTT binding to the IPT5, AHP6 and CKX7, regulatory regions. We propose that NTT, among other mechanisms, regulates development through the modulation of cytokinin homeostasis at different levels, including its local concentration. Since NTT is a target of AUXIN RESPONSE FACTOR 5 / MONOPTEROS, the results presented here indicate that NTT connects an auxin input to a change in cytokinin levels.

plant biology↗

bioRxiv2024

ESR2 orchestrates cytokinin dynamics leading to developmental reprogramming and green callus formation

Callus formation and shoot regeneration are natural plant abilities triggered by stress and damage. They are also key components of tissue culture, which for many species is crucial for gene editing, transformation, propagation, and other technologies, and their study provides valuable insights into plant development. The transcription factor ENHANCER OF SHOOT REGENERATION 2 (ESR2/DRNL/BOL/SOB) promotes green callus formation in roots and shoot regeneration when overactive, while the phythormone cytokinin plays a prominent role in both phenomena. Yet, the positive action of ESR2 on the cytokinin pathway had not been previously described. We explored the effects of ESR2 and found that cytokinin content and the expression of the cytokinin biosynthesis gene ISOPENTENYLTRANSFERASE 5 (IPT5) increase in plants where ESR2 activity is induced. ESR2 also regulates the cytokinin signaling repressor ARABIDOPSIS HISTIDINE PHOSPHOTRANSFER 6 (AHP6), and surprisingly, the ESR2-stimulated green calli formation requires both IPT5 and AHP6. Therefore, ESR2 promotes both cytokinin biosynthesis and cytokinin signaling inhibition and requires a paradoxical combination of these two for green callus induction. This finding provides a foundation to better understand the processes involved in tissue reprogramming towards callus formation and the role of ESR2 in shoot regeneration and the development of new organs.

plant biology↗

bioRxiv2020

High-resolution temporal transcript profiling during Arabidopsis thaliana gynoecium morphogenesis uncovers the chronology of gene regulatory network activity and reveals novel developmental regulators

The gynoecium is the most complex organ formed by the flowering plants. It encloses the ovules, provides a surface for pollen contact and self-incompatibility reactions, allows pollen tube growth and, post fertilization, and develops into the fruit. Consequently, the regulation of gynoecium morphogenesis is complex and appropriate timing of this process in part determines reproductive success. However, little is known about the global control of gynoecium development, even though many regulatory genes have been characterized. Here, we characterized dynamic gene expression changes using laser-microdissected gynoecium tissue from four developmental stages in Arabidopsis. We provide a high-resolution map of global expression dynamics during gynoecium morphogenesis and link these to the gynoecium interactome. We reveal groups of genes acting together early and others acting late in morphogenesis. Clustering of co-expressed genes enables comparisons between the leaf, shoot apex, and gynoecium transcriptomes allowing the dissection of common and distinct regulators. Furthermore, our results lead to the discovery of the LESSER FERTILITY1-4 (LEF1-4) genes, which, when mutated, lead to impaired gynoecium expansion, illustrating that global transcriptome analyses reveal yet unknown developmental regulators. Our data show that highly interacting proteins, such as SEPALLATA3, AGAMOUS, and TOPLESS are expressed more evenly during development, but switch interactors in time, whereas stage-specific proteins have only few interactors. Our analysis connects specific transcriptional regulator activities, protein interactions, and underlying metabolic processes towards the development of a dynamic network model for gynoecium development.

plant biology↗

bioRxiv2018

An interaction map of transcription factors controlling gynoecium development in Arabidopsis

Flowers are composed of different organs, whose identity is defined at the molecular by the combinatorial activity of transcription factors (TFs). MADS-box TFs interact forming complexes that have been schematized in the quartet model. The gynoecium is the female reproductive part in the flower, crucial for plant reproduction, and fruit and seed production. Once carpel identity is established, a gynoecium containing many tissues arises. Several TFs have been identified as regulators of gynoecium development, and some of these TFs form complexes. However, broad knowledge about the interactions among these TFs is still scarce. In this work, we used a systems biology approach to understand the formation of a complex reproductive unit as the gynoecium by mapping binary interactions between well-characterized TFs. We analyzed over 3500 combinations and detected more than 200 protein-protein interactions (PPIs), resulting in a process specific interaction map. Topological analyses suggest hidden functions and novel roles for many TFs. Furthermore, a relationship between TFs involved in auxin and cytokinin signaling pathways and other TFs was observed. We analyzed the network by combining PPI data, expression and genetic data, allowing us to dissect it into several dynamic spatio-temporal sub-networks related to gynoecium development subprocesses.

plant biology↗