TY - JOUR
T1 - Root suberin forms an extracellular barrier that affects water relations and mineral nutrition in Arabidopsis
AU - Baxter, Ivan
AU - Hosmani, Prashant S
AU - Rus, Ana
AU - Lahner, Brett
AU - Borevitz, Justin O
AU - Muthukumar, Balasubramaniam
AU - Mickelbart, Michael V
AU - Schreiber, Lukas
AU - Franke, Rochus B
AU - Salt, David E
PY - 2009/5/22
Y1 - 2009/5/22
N2 - 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. 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. 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.
AB - 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. 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. 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.
KW - radial hydraulic conductivity
KW - Zea-Mays L.
KW - apoplastic transport
KW - chemical-composition
KW - plant-roots
KW - identification
KW - biosynthesis
KW - exodermis
KW - acid
KW - gene
U2 - 10.1371/journal.pgen.1000492
DO - 10.1371/journal.pgen.1000492
M3 - Article
SN - 1553-7390
VL - 5
JO - PLoS Genetics
JF - PLoS Genetics
IS - 5
M1 - e1000492
ER -