Biology subjects

Rodriguez-Villalon, A.

Publications and source records attributed to Rodriguez-Villalon, A..

3 recordsLinked to original sources

bioRxiv2022

A phloem-localized Arabidopsis metacaspase (AtMC3) improves drought tolerance

Increasing drought phenomena pose a serious threat to agricultural productivity. Although plants have multiple ways to respond to the complexity of drought stress, the underlying mechanisms of stress sensing and signalling remain unclear. The role of the vasculature, in particular the phloem, in facilitating inter-organ communication is critical. Here, we investigated the role of AtMC3, a phloem-specific member of the metacaspase family, in osmotic stress responses in Arabidopsis thaliana. Overexpression of AtMC3 conferred drought tolerance by enhancing the differentiation of the metaphloem sieve elements and maintaining higher levels of vascular-mediated transportation, whilst plants lacking the protein showed an impaired response to drought and inability to respond effectively to the hormone abscisic acid. Analyses of the proteome in plants with altered AtMC3 levels revealed differential abundance of proteins related to osmotic stress. Overall, our data highlight the importance of AtMC3 and vascular plasticity in fine-tuning early drought responses at the whole plant level without affecting growth or yield.

plant biology↗

bioRxiv2022

Evolutionary PTEN Gene Divergence Underpins the Remodeling of Plant Vacuolar Compartments

Membrane fusion and fission are fundamental processes in sustaining cellular compartmentalization. Fission of a lipid bilayer requires a furrow formation that brings membranes in close proximity prior to a contiguous membrane cleavage. Although plant ancestors abandoned cleavage furrow-mediated cytokinesis more than 500 million years ago, here we show that plants still employ this mechanical principle to divide embryonic vacuoles. The evolutionary divergence in PHOSPHATASE AND TENSIN HOMOLOG DELETED ON CHROMOSOME TEN (PTEN) enzymes was required to coordinate this process, as Arabidopsis loss-of-function pten2a pten2b mutants contain hyper compartmentalized embryonic vacuoles. In contrast, PTEN2 overexpression hinders lytic and secretion cellular pathways downstream of TGN in xylem cells. These processes are critical for the formation of secondary cell walls in xylem cells and depend on a poorly characterized and evolutionarily novel N-terminal domain in PTEN2s. The PTEN2 subfamily appeared with the emergence of the Phragmoplastophyta clade, when vacuolar compartments enlarged and cleavage furrow-mediated cytokinesis became extinct. Together, our work suggests that the evolutionary innovation of the PTEN family is conserved across terrestrial plants and central to vacuolar remodelling.

plant biology↗

bioRxiv2021

A molecular framework for proximal secondary vein branching in the Arabidopsis thaliana embryo

O_LIThe establishment of a closed vascular network in foliar organs is achieved through the coordinated specification of newly recruited procambial cells, their proliferation and elongation. An important, yet poorly understood component of this process, is secondary vein branching; a mechanism employed in Arabidopsis thaliana cotyledons to extend vascular tissues throughout the organs surface by secondary vein formation. C_LIO_LITo investigate the underlying molecular mechanism in vein branching, we analyzed at a single-cell level the discontinuous vein network of cotyledon vascular pattern 2 (cvp2) cvp2-like 1 (cvl1). Utilizing live-cell imaging and genetic approaches we uncovered two distinct branching mechanisms during embryogenesis. C_LIO_LISimilar to wild type, distal veins in cvp2 cvl1 embryos emerged from the bifurcation of cell files contained in the midvein. However, the branching events giving rise to proximal veins are absent in this mutant. Restoration of proximal branching in cvp2 cvl1 cotyledons could be achieved by increasing OCTOPUS dosage as well as by silencing of RECEPTOR LIKE PROTEIN KINASE 2 (RPK2) expression. The RPK2-mediated restriction of proximal branching is auxin and CLE-independent. C_LIO_LIOur work defines a genetic network conferring plasticity to Arabidopsis embryos to adapt the spatial configuration of vascular tissues to organ growth. C_LI

plant biology↗