Biology subjects

Goldy, C.

Publications and source records attributed to Goldy, C..

4 recordsLinked to original sources

bioRxiv2026

A triple fluorescent marker for live imaging of plant cell morphogenesis

Live imaging of plant subcellular structures is key to deciphering the spatiotemporal bases of cellular processes, and their functional impact on growth and morphogenesis at various biological scales. Live imaging of plant cells essentially relies on expression of fluorescent markers labeling cells or subcellular structures of interest. Simultaneous multi-channel imaging of several markers is still not routine practice in plant cell biology, owing to issues linked to genetic or spectral compatibility of markers, differences in expression levels, silencing, toxicity, etc. Here we designed a three-color marker in Arabidopsis thaliana and Capsella rubella, enabling high-resolution live imaging of plant morphogenesis, including labeling of the cell membrane, the nucleus and the microtubule cytoskeleton. Detection of MT arrays involved the development of a MAP4-MBD-based microtubule marker optimized for plant cells. The three-color marker allows visualization of the three-dimensional organization and dynamics of plant microtubules within the intracellular space with unprecedented precision, in various organs including the root and shoot meristems, the leaf, anther, and gynoecium. Our results demonstrate the potential of such single-construct strategy for cell biology studies in plants.

plant biology↗

bioRxiv2025

Actin Counters Geometry to Guide Plant Cell Division

In multicellular organisms, cell division shapes tissue architecture, cell identity, and function. In walled organisms like plants, division plane orientation irreversibly defines tissue topology and is tightly regulated. While divisions often follow the shortest path enclosing cell volume, certain cells deviate, dividing perpendicular to the growth axis. Tissue-scale mechanical stress has been proposed to guide such orientation, but how these cues are integrated remains unclear. Here, we re-examine the role of the actin cytoskeleton in orienting cell division in Arabidopsis root epidermis. Combining cell biology, genetics, pharmacological treatments, 3D segmentation, and modelling, we show that actin is a central molecular actor required to establish cell division orientation against the geometrical rules, highlighting its role in integrating spatial information.

plant biology↗

bioRxiv2025

Epistasis between Na+/K+-ATPase Substitutions May Influence Salinity Tolerance in Steinernema Entomopathogenic Nematodes

Soil salinity varies widely across geographies both due to natural factors and human activities, including agriculture, road salt application, sea level rise, and desertification. Increases in soil salinity may affect organisms widely and particularly impact soil foodwebs. As parasites, entomopathogenic nematodes (EPNs) occupy crucial links in soil foodwebs and are important for agriculture as biological control agents of insect pests. Previous research found that the EPN Steinernema carpocapsae may exhibit higher salt tolerance than several of its congeners. We recently identified that S. carpocapsae uniquely evolved two amino acid substitutions in the first extracellular loop of the sodium pump (Na{square}/K{square}-ATPase). Here, we tested if these substitutions explain S. carpocapsaes reported lower sensitivity to salt. Our results confirm that S. carpocapsae exhibits higher salt tolerance and show it can more effectively locate and infect insect hosts than its congeners S. feltiae and S. hermaphroditum in highly saline environments. We then retraced the evolution of the two amino acid substitutions in S. carpocapsae by introducing them alone and in combination in Caenorhabditis elegans using CRISPR genome engineering. We found that C. elegans mutants with single substitutions showed improved salt tolerance. However, this improvement disappeared in the double mutant, whose sodium pump mimicked that of S. carpocapsae. This pattern of negative epistasis between the amino acid substitutions suggests they are not responsible for variation in salt tolerance between Steinernema species. Sodium pump evolution in S. carpocapsae might instead be driven by encounters with cardiac glycosides, which are released into soil by several clades of plants including milkweeds, sequestered by some of this EPNs herbivorous insect hosts, and known to target the first extracellular loop of the sodium pump. Our findings provide valuable insights into EPN adaptation to changes in environmental sodium levels and may have implications for their use in biological control.

ecology↗

bioRxiv2021

SCL28 promotes cell expansion and endoreplication in Arabidopsis by activating SIAMESE-RELATED cyclin-dependent kinase inhibitors.

The processes that contribute to plant organ morphogenesis are spatial-temporally organized. Within the meristem the mitotic cell cycle produces new cells that subsequently engage in specific cell expansion and differentiation programs once they exit the division competent zone. The latter is frequently accompanied by endoreplication, being an alternative cell cycle that replicates the DNA without nuclear division, causing a stepwise increase in somatic ploidy. We have previously shown that the Arabidopsis SCL28 transcription factor promotes progression through G2/M and modulates division plane orientation. Here, we demonstrate that SCL28 co-express and regulates genes specific to cell elongation and differentiation, including genes related to cell wall and cytoskeleton assembly. Consistently, this correlates with defects in post-mitotic cell expansion in a scl28 mutant. Strikingly, SCL28 controls expression of 6 members of the SIAMESE/SIAMESE-RELATED (SIM/SMR) family, encoding cyclin-dependent kinase inhibitors with a role in promoting mitotic cell cycle exit and endoreplication onset, both in response to developmental and environmental cues. Consistent with this role, scl28 mutants displayed reduced endoreplication, both in roots and leaves. Altogether, these results suggest that SCL28 controls cell expansion and differentiation by promoting endoreplication onset and by modulating aspects of the biogenesis, assembly and remodeling of the cytoskeleton and cell wall.

plant biology↗