Research output: Contribution to Journal/Magazine › Journal article › peer-review
Enhanced root growth of the brb (bald root barley) mutant in drying soil allows similar shoot physiological responses to soil water deficit as wild-type plants. / Dodd, Ian C.; Diatloff, Eugene.
In: Functional Plant Biology, Vol. 43, No. 2, 04.01.2016, p. 199-206.Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Enhanced root growth of the brb (bald root barley) mutant in drying soil allows similar shoot physiological responses to soil water deficit as wild-type plants
AU - Dodd, Ian C.
AU - Diatloff, Eugene
PY - 2016/1/4
Y1 - 2016/1/4
N2 - The genetics, molecular biology and nutrient uptake of plant root hair mutants have been studied in detail, but their physiological responses to soil drying have not. Thus, the root hairless brb (bald root barley) barley (Hordeum vulgare L.) mutant and its wild type (WT) were grown in drying soil. Well-watered, pre-tillering plants showed no genotypic differences in daily transpiration and leaf elongation rate, and the ratio of day to night leaf elongation (D/N, a sensitive indicator of water stress). After withholding water for 25 days, root hydraulic conductivity and xylem ABA concentration were similar between genotypes, but WT plants had more tillers and D/N was more than halved in brb. To avoid possible developmental and nutritional differences confounding responses to water deficit, pre-tillering plants were allowed to dry soils of high and low phosphorus (P) status. Although leaf area, leaf water potential and shoot fresh weight (FW) were similar in the two genotypes, root FW of brb was greater by 44 and 18% in a high and low P soil respectively. This adaptive response allowed brb to maintain similar shoot growth and transpiration as WT plants, despite decreased effective root surface area in the absence of root hairs.
AB - The genetics, molecular biology and nutrient uptake of plant root hair mutants have been studied in detail, but their physiological responses to soil drying have not. Thus, the root hairless brb (bald root barley) barley (Hordeum vulgare L.) mutant and its wild type (WT) were grown in drying soil. Well-watered, pre-tillering plants showed no genotypic differences in daily transpiration and leaf elongation rate, and the ratio of day to night leaf elongation (D/N, a sensitive indicator of water stress). After withholding water for 25 days, root hydraulic conductivity and xylem ABA concentration were similar between genotypes, but WT plants had more tillers and D/N was more than halved in brb. To avoid possible developmental and nutritional differences confounding responses to water deficit, pre-tillering plants were allowed to dry soils of high and low phosphorus (P) status. Although leaf area, leaf water potential and shoot fresh weight (FW) were similar in the two genotypes, root FW of brb was greater by 44 and 18% in a high and low P soil respectively. This adaptive response allowed brb to maintain similar shoot growth and transpiration as WT plants, despite decreased effective root surface area in the absence of root hairs.
KW - leaf elongation
KW - rhizosphere
KW - soil drying
KW - water uptake
KW - ORYZA-SATIVA L.
KW - ABSCISIC-ACID
KW - HAIR DEVELOPMENT
KW - HYDRAULIC CONDUCTIVITY
KW - HORDEUM-VULGARE
KW - LEAF EXPANSION
KW - STRESS
KW - ACCUMULATION
KW - ACQUISITION
KW - ELONGATION
U2 - 10.1071/FP15303
DO - 10.1071/FP15303
M3 - Journal article
VL - 43
SP - 199
EP - 206
JO - Functional Plant Biology
JF - Functional Plant Biology
SN - 1445-4408
IS - 2
ER -