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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Root-to-shoot signalling when soil moisture is heterogeneous: increasing the proportion of root biomass in drying soil inhibits leaf growth and increases leaf abscisic acid concentration
AU - Martin-Vertedor, Ana Isabel
AU - Dodd, Ian C.
PY - 2011/7
Y1 - 2011/7
N2 - To determine whether root-to-shoot signalling of soil moisture heterogeneity depended on root distribution, wild-type (WT) and abscisic acid (ABA)-deficient (Az34) barley (Hordeum vulgare) plants were grown in split pots into which different numbers of seminal roots were inserted. After establishment, all plants received the same irrigation volumes, with one pot watered (w) and the other allowed to dry the soil (d), imposing three treatments (1 d : 3 w, 2 d : 2 w, 3 d : 1 w) that differed in the number of seminal roots exposed to drying soil. Root distribution did not affect leaf water relations and had no sustained effect on plant evapotranspiration (ET). In both genotypes, leaf elongation was less and leaf ABA concentrations were higher in plants with more roots in drying soil, with leaf ABA concentrations and water potentials 30% and 0.2 MPa higher, respectively, in WT plants. Whole-pot soil drying increased xylem ABA concentrations, but maximum values obtained when leaf growth had virtually ceased (100 nM in Az34, 330 nM in WT) had minimal effects (<40% leaf growth inhibition) when xylem supplied to detached shoots. Although ABA may not regulate leaf growth in vivo, genetic variation in foliar ABA concentration in the field may indicate different root distributions between upper (drier) and lower (wetter) soil layers.
AB - To determine whether root-to-shoot signalling of soil moisture heterogeneity depended on root distribution, wild-type (WT) and abscisic acid (ABA)-deficient (Az34) barley (Hordeum vulgare) plants were grown in split pots into which different numbers of seminal roots were inserted. After establishment, all plants received the same irrigation volumes, with one pot watered (w) and the other allowed to dry the soil (d), imposing three treatments (1 d : 3 w, 2 d : 2 w, 3 d : 1 w) that differed in the number of seminal roots exposed to drying soil. Root distribution did not affect leaf water relations and had no sustained effect on plant evapotranspiration (ET). In both genotypes, leaf elongation was less and leaf ABA concentrations were higher in plants with more roots in drying soil, with leaf ABA concentrations and water potentials 30% and 0.2 MPa higher, respectively, in WT plants. Whole-pot soil drying increased xylem ABA concentrations, but maximum values obtained when leaf growth had virtually ceased (100 nM in Az34, 330 nM in WT) had minimal effects (<40% leaf growth inhibition) when xylem supplied to detached shoots. Although ABA may not regulate leaf growth in vivo, genetic variation in foliar ABA concentration in the field may indicate different root distributions between upper (drier) and lower (wetter) soil layers.
KW - Hordeum vulgare
KW - ABA
KW - chemical signals
KW - leaf elongation
KW - mutant
KW - partial root zone drying
KW - root distribution
KW - soil moisture heterogeneity
KW - split pot
UR - http://www.scopus.com/inward/record.url?scp=79958751935&partnerID=8YFLogxK
U2 - 10.1111/j.1365-3040.2011.02315.x
DO - 10.1111/j.1365-3040.2011.02315.x
M3 - Journal article
AN - SCOPUS:79958751935
VL - 34
SP - 1164
EP - 1175
JO - Plant, Cell and Environment
JF - Plant, Cell and Environment
SN - 0140-7791
IS - 7
ER -