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A mechanism of growth inhibition by abscisic acid in germinating seeds of Arabidopsis thaliana based on inhibition of plasma membrane H+-ATPase and decreased cytosolic pH, K+, and anions.

Planes MD, Niñoles R, Rubio L, Bissoli G, Bueso E, García-Sánchez MJ, Alejandro S, Gonzalez-Guzmán M, Hedrich R, Rodriguez PL, Fernández JA, Serrano R - J. Exp. Bot. (2014)

Bottom Line: Concerning the latter effect, several mutants of Arabidopsis thaliana with improved capability for H(+) efflux (wat1-1D, overexpression of AKT1 and ost2-1D) are less sensitive to inhibition by ABA than the wild type.The mechanism of inhibition of the H(+)-ATPase by ABA and its effects on cytosolic pH and membrane potential in roots were different from those in guard cells.ABA did not affect the in vivo phosphorylation level of the known activating site (penultimate threonine) of H(+)-ATPase in roots, and SnRK2.2 phosphorylated in vitro the C-terminal regulatory domain of H(+)-ATPase while the guard-cell kinase SnRK2.6/OST1 did not.

View Article: PubMed Central - PubMed

Affiliation: Instituto de Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia-Consejo Superior de Investigaciones Científicas, Camino de Vera, 46022 Valencia, Spain.

No MeSH data available.


Related in: MedlinePlus

Effect of ABA on chloride concentrations in root epidermal cells measured with microelectrodes. (A) Cytosolic chloride ([Cl–]i) results of a typical experiment with the wild type (Col-0; continuous line), the sextuple knock-out in ABA receptors 112458 pyr/pyl (pyr/pyl; long dashes), and the slah3-1 mutant (short dashes). (B) External chloride ([Cl–]e), Results of a typical experiment with the three genotypes as in (A). (C) Average of three experiments±standard error. * indicates significant differences (P<0.01 by Student’s t-test) compared with the wild type.
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Figure 7: Effect of ABA on chloride concentrations in root epidermal cells measured with microelectrodes. (A) Cytosolic chloride ([Cl–]i) results of a typical experiment with the wild type (Col-0; continuous line), the sextuple knock-out in ABA receptors 112458 pyr/pyl (pyr/pyl; long dashes), and the slah3-1 mutant (short dashes). (B) External chloride ([Cl–]e), Results of a typical experiment with the three genotypes as in (A). (C) Average of three experiments±standard error. * indicates significant differences (P<0.01 by Student’s t-test) compared with the wild type.

Mentions: In order to investigate the effect of ABA on anion transport in root epidermal cells, we measured cytosolic (Fig. 7A, C) and extracellular (Fig. 7B) chloride with Cl–-sensitive microelectrodes in different genotypes. In wild-type Arabidopsis, ABA induced a fast decrease of cytosolic Cl– during the first 5min followed by a slow decrease that lasted for 30min (Fig. 7A). The first phase correlated with an increase in external Cl–, but during the second slow phase there was no increase in external Cl– (Fig. 8B), suggesting vacuolar compartmentation of the anion. The first phase of Cl– efflux was not observed in either the 112458 pyr/pyl or slah3-1 mutant, although they exhibited the second slow phase (Fig. 7A, B). Therefore most of the efflux of Cl– induced by ABA was mediated by the PYR/PYL receptors by activating the SLAH3 channel, with the probable vacuolar compartmentation of the slow phase being independent of both systems. In the wild type, the total decrease of cytosolic Cl– induced by ABA after 30min was about 50%, while in 112458 pyr/pyl and slah3-1 it was only about 25% (Fig. 7C).


A mechanism of growth inhibition by abscisic acid in germinating seeds of Arabidopsis thaliana based on inhibition of plasma membrane H+-ATPase and decreased cytosolic pH, K+, and anions.

Planes MD, Niñoles R, Rubio L, Bissoli G, Bueso E, García-Sánchez MJ, Alejandro S, Gonzalez-Guzmán M, Hedrich R, Rodriguez PL, Fernández JA, Serrano R - J. Exp. Bot. (2014)

Effect of ABA on chloride concentrations in root epidermal cells measured with microelectrodes. (A) Cytosolic chloride ([Cl–]i) results of a typical experiment with the wild type (Col-0; continuous line), the sextuple knock-out in ABA receptors 112458 pyr/pyl (pyr/pyl; long dashes), and the slah3-1 mutant (short dashes). (B) External chloride ([Cl–]e), Results of a typical experiment with the three genotypes as in (A). (C) Average of three experiments±standard error. * indicates significant differences (P<0.01 by Student’s t-test) compared with the wild type.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4321545&req=5

Figure 7: Effect of ABA on chloride concentrations in root epidermal cells measured with microelectrodes. (A) Cytosolic chloride ([Cl–]i) results of a typical experiment with the wild type (Col-0; continuous line), the sextuple knock-out in ABA receptors 112458 pyr/pyl (pyr/pyl; long dashes), and the slah3-1 mutant (short dashes). (B) External chloride ([Cl–]e), Results of a typical experiment with the three genotypes as in (A). (C) Average of three experiments±standard error. * indicates significant differences (P<0.01 by Student’s t-test) compared with the wild type.
Mentions: In order to investigate the effect of ABA on anion transport in root epidermal cells, we measured cytosolic (Fig. 7A, C) and extracellular (Fig. 7B) chloride with Cl–-sensitive microelectrodes in different genotypes. In wild-type Arabidopsis, ABA induced a fast decrease of cytosolic Cl– during the first 5min followed by a slow decrease that lasted for 30min (Fig. 7A). The first phase correlated with an increase in external Cl–, but during the second slow phase there was no increase in external Cl– (Fig. 8B), suggesting vacuolar compartmentation of the anion. The first phase of Cl– efflux was not observed in either the 112458 pyr/pyl or slah3-1 mutant, although they exhibited the second slow phase (Fig. 7A, B). Therefore most of the efflux of Cl– induced by ABA was mediated by the PYR/PYL receptors by activating the SLAH3 channel, with the probable vacuolar compartmentation of the slow phase being independent of both systems. In the wild type, the total decrease of cytosolic Cl– induced by ABA after 30min was about 50%, while in 112458 pyr/pyl and slah3-1 it was only about 25% (Fig. 7C).

Bottom Line: Concerning the latter effect, several mutants of Arabidopsis thaliana with improved capability for H(+) efflux (wat1-1D, overexpression of AKT1 and ost2-1D) are less sensitive to inhibition by ABA than the wild type.The mechanism of inhibition of the H(+)-ATPase by ABA and its effects on cytosolic pH and membrane potential in roots were different from those in guard cells.ABA did not affect the in vivo phosphorylation level of the known activating site (penultimate threonine) of H(+)-ATPase in roots, and SnRK2.2 phosphorylated in vitro the C-terminal regulatory domain of H(+)-ATPase while the guard-cell kinase SnRK2.6/OST1 did not.

View Article: PubMed Central - PubMed

Affiliation: Instituto de Biología Molecular y Celular de Plantas, Universidad Politécnica de Valencia-Consejo Superior de Investigaciones Científicas, Camino de Vera, 46022 Valencia, Spain.

No MeSH data available.


Related in: MedlinePlus