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Gloser, V.

Publications and source records attributed to Gloser, V..

2 recordsLinked to original sources
bioRxiv2026

The coordination between xylem and bark hydraulics in temperate Rosaceae species

Xylem and bark properties influence tree growth and drought resistance, yet their functional coordination and their environmental drivers remain unclear. We assessed xylem-bark coordination in branches of eight temperate woody Rosaceae species spanning different ecological preferences. We quantified xylem hydraulic efficiency and safety alongside bark traits governing permeability, hygroscopic water exchange, water storage, and anatomy, and evaluated phylogenetic signal and climatic associations. Bark water vapor conductance (Gbark) increased with maximum xylem hydraulic conductivity (Kh) and with xylem water potential at 50% loss of conductivity (P50), indicating species with more efficient but more embolism-vulnerable xylem developed more permeable bark. Species with higher Gbark showed reduced hygroscopic absorption time, consistent with faster rehydration from atmospheric water vapor. Both Gbark and P50 were phylogenetically conserved and covaried with climatic factors, namely air temperature, vapor pressure deficit (VPD), and isothermality. Species from warmer, high-VPD climates with greater diurnal temperature variability combined higher bark permeability with more vulnerable xylem, implying a shift from embolism avoidance to embolism tolerance strategies. Overall, xylem and bark hydraulics in Rosaceae evolved in concert along diurnal and annual gradients of evaporative demand, showing that drought resistance in woody angiosperms cannot be understood without considering bark traits alongside xylem function. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=104 SRC="FIGDIR/small/730605v1_ufig1.gif" ALT="Figure 1"> View larger version (41K): org.highwire.dtl.DTLVardef@449b24org.highwire.dtl.DTLVardef@2586c8org.highwire.dtl.DTLVardef@1b3dc8dorg.highwire.dtl.DTLVardef@154adda_HPS_FORMAT_FIGEXP M_FIG C_FIG Caption: This study shows that xylem and bark in Rosaceae species form an integrated functional system in which xylem hydraulic safety, efficiency, and bark permeability are jointly tuned along diurnal and annual gradients of air temperature and evaporative demand.

plant biology↗
bioRxiv2023

Cytokinins control secondary cell wall formation in the inflorescence stem of Arabidopsis

Spatiotemporal control over developmental programs is vital to all organisms. Here we show that cytokinin (signaling) deficiency leads to early secondary cell wall (SCW) formation in Arabidopsis inflorescence stem that associates with precocious upregulation of a SCW transcriptional cascade controlled by NAC TFs (NSTs). We demonstrate that cytokinin signaling through the AHK2/3 and the ARR1/10/12 suppresses the expression of several NSTs and SCW formation in the apical portions of stems. Exogenous cytokinin application reconstituted both proper development and apical-basal gradient of NST1 and NST3 in a cytokinin biosynthesis-deficient mutant. We show that AHK2 and AHK3 required functional NST1 or NST3 to control SCW initiation in the interfascicular fibers, further evidencing that cytokinins act upstream of NSTs transcription factors. The premature onset of a rigid SCW biosynthesis and altered expression of NST1/3 and VND6/7 due to cytokinin deficiency led to the formation of smaller tracheary elements (TEs) and impaired hydraulic conductivity. We conclude that cytokinins downregulate NSTs to inhibit premature SCW formation in the apical part of the inflorescence stem, facilitating thus the development of fully functional TEs and interfascicular fibers. Summary statementCytokinins attenuate premature secondary cell wall (SCW) formation via downregulating the expression of NAC TFs, the master switches of SCW transcriptional cascade, thus affecting the tracheary elements size and conductivity.

plant biology↗