Project description:In a context of climate change, deciphering signaling pathways leading to plant adaptation to drought, water availability, and salt tolerance is a crucial question. A common crossing point of these plant stresses is their impact on plant water potential, a composite physico-chemical variable reflecting the availability of water for the plant biological and biochemical processes such as growth or stomatal aperture. The water potential of plant cells is mainly driven by their turgor pressure and osmotic potential. Here we investigated the effect of a variety of osmotic treatments in the root of Arabidopsis plants grown in hydroponics. Measurement of the cortical cells turgor pressure with a cell pressure probe allowed to control the intensity of the treatments and, in particular, preserve the cortex from plasmolysis. Transcriptome analyses at early time point (15min) showed specific and quantitative transcriptomic responses for both osmotic and turgor pressures in the root. Our results highlight how water-related biophysical parameters can shape the transcriptome and provide putative candidates to explore further the early perception of water stress in plants.
Project description:ABSTRACT: Background: Though central to our understanding of how roots perform their vital function of scavenging water and solutes from the soil, no direct genetic evidence currently exists to support the foundational model that suberin acts to form a chemical barrier limiting the extracellular, or apoplastic, transport of water and solutes in plant roots. Methodologies/Principle Findings: Using the newly characterized enhanced suberin1 (esb1) mutant, we established a connection in Arabidopsis thaliana between suberin in the root, and both water movement through the plant, and solute accumulation in the shoot. Esb1 mutants, characterized by increased root suberin, were found to have reduced day time transpiration rates, and increased water use efficiency during their vegetative growth period. Furthermore, these changes in suberin and water transport were associated with decreases in the accumulation of Ca, Mn and Zn, and increases in the accumulation of Na, S, K, As, Se and Mo in the shoot. Conclusions/Significance: Here we present direct genetic evidence establishing that suberin in the roots plays a critical role in controlling both water and mineral ion uptake and transport to the leaves. The changes observed in the elemental accumulation in leaves are also interpreted as evidence that a significant component of the radial root transport of Ca, Mn and Zn occurs in the apoplast. Keywords: genomic hybridization bulked segregant analysis