Membrane nanodomains to shape plant cellular functions and signaling.

Plasma membrane (PM) nanodomains have emerged as pivotal elements in the regulation of plant cellular functions and signal transduction. These nanoscale membrane regions, enriched in specific lipids and proteins, behave as regulatory/signaling hubs spatially and temporally coordinating critical cellular functions. In this review, we first examine the mechanisms underlying the formation and maintenance of PM nanodomains in plant cells, highlighting the roles of PM lipid composition, protein oligomerization and interactions with cytoskeletal and cell wall components.

Live Single-Cell Transcriptional Dynamics in Plant Cells.

Transcriptional reprogramming plays a key role in a variety of biological processes. Recent advances in RNA imaging techniques have allowed to visualize, in vivo, transcription-related mechanisms in different organisms. The MS2 system constitutes a robust method that has been used for over two decades to image multiple steps of a transcript's life cycle from "birth to death" with high spatiotemporal resolution in the animal field.

smFISH for Plants.

Single-molecule fluorescence in situ hybridization (smFISH) is a powerful method for the visualization and quantification of individual RNA molecules within intact cells. With its ability to probe gene expression at the single cell and single-molecule level, the technique offers valuable insights into cellular processes and cell-to-cell heterogeneity. Although widely used in the animal field, its use in plants has been limited.

Uncoupling Aluminum Toxicity From Aluminum Signals in the STOP1 Pathway.

Aluminum (Al) is a major limiting factor for crop production on acidic soils, inhibiting root growth and plant development. At acidic pH (pH < 5.5), Al ions are the main form of Al present in the media.

Root responses to aluminium and iron stresses require the SIZ1 SUMO ligase to modulate the STOP1 transcription factor.

STOP1, an Arabidopsis transcription factor favouring root growth tolerance against Al toxicity, acts in the response to iron under low Pi (-Pi). Previous studies have shown that Al and Fe regulate the stability and accumulation of STOP1 in roots, and that the STOP1 protein is sumoylated by an unknown E3 ligase. Here, using a forward genetics suppressor screen, we identified the E3 SUMO (small ubiquitin-like modifier) ligase SIZ1 as a modulator of STOP1 signalling.

Under phosphate starvation conditions, Fe and Al trigger accumulation of the transcription factor STOP1 in the nucleus of Arabidopsis root cells.

Low-phosphate (Pi) conditions are known to repress primary root growth of Arabidopsis at low pH and in an Fe-dependent manner. This growth arrest requires accumulation of the transcription factor STOP1 in the nucleus, where it activates the transcription of the malate transporter gene ALMT1; exuded malate is suspected to interact with extracellular Fe to inhibit root growth. In addition, ALS3 - an ABC-like transporter identified for its role in tolerance to toxic Al - represses nuclear accumulation of STOP1 and the expression of ALMT1.

Immunological determinants of ventilatory changes induced in mice by dermal sensitization and respiratory challenge with toluene diisocyanate.

The objective of the study was to characterize better the immunologic mechanisms underlying a previously developed animal model of chemical-induced asthma. BALB/c and severe combined immunodeficiency disease (SCID) mice received toluene diisocyanate (TDI) or vehicle on each ear on day 1 and/or day 7. On day 10, they were intranasally challenged with TDI or vehicle.

Solid-phase synthesis of model libraries of 3alpha,17beta-dihydroxy-16alpha-(aminoethyl-N-substituted)-5alpha-androstanes for the development of steroidal therapeutic agents.

The solid-phase synthesis of 16alpha-derivatives of 5alpha-androstane-3alpha, 17beta-diol with one, two or three levels of molecular diversity was accomplished using the diethylsilyloxy linker. Libraries with one level of diversity (10 members) and two levels of diversity (40 members) were synthesized in a parallel fashion in good yields and acceptable HPLC purities for the majority of library members. Compounds with three levels of diversity (15 pools) were realized in a split and pool fashion to allow further deconvolution by the positional scanning method.