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Nitric oxide induces the alternative oxidase pathway in Arabidopsis seedlings deprived of inorganic phosphate.

Royo B, Moran JF, Ratcliffe RG, Gupta KJ - J. Exp. Bot. (2015)

Bottom Line: The effects of the phosphate supply on growth, the production of NO, respiration, the AOX level and the production of superoxide were compared for wild-type (WT) seedlings and the nitrate reductase double mutant nia.Phosphate deprivation increased NO production in WT roots, and the AOX level and the capacity of the alternative pathway to consume electrons in WT seedlings; whereas the same treatment failed to stimulate NO production and AOX expression in the nia mutant, and the plants had an altered growth phenotype.It is concluded that NO is required for the induction of the AOX pathway when seedlings are grown under phosphate-limiting conditions.

View Article: PubMed Central - PubMed

Affiliation: Department of Plant Sciences, University of Oxford, South Park Road, Oxford OX1 3RB, UK Institute of Agrobiotechnology, IdAB-CSIC-Public University of Navarre-Government of Navarre, Avda. Pamplona 123, E-31192, Mutilva, Navarre, Spain.

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Effect of Pi supply on superoxide and H2O2 levels in Arabidopsis roots. (A) NBT staining for superoxide; and (B) DAB staining for H2O2. Measurements were made on the roots of 14-d-old WT and nia seedlings grown on a medium containing 0 or 1mM Pi; and 200 μM GSNO was used for the NO donor treatment. Image intensities were quantified by Image J software. Means (n=3) with different letters are significantly different (one-way ANOVA, P<0.05).
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Figure 5: Effect of Pi supply on superoxide and H2O2 levels in Arabidopsis roots. (A) NBT staining for superoxide; and (B) DAB staining for H2O2. Measurements were made on the roots of 14-d-old WT and nia seedlings grown on a medium containing 0 or 1mM Pi; and 200 μM GSNO was used for the NO donor treatment. Image intensities were quantified by Image J software. Means (n=3) with different letters are significantly different (one-way ANOVA, P<0.05).

Mentions: AOX helps to minimize ROS production under conditions that lead to over-reduction of ubiquinone (Maxwell et al., 1999). While only low levels of superoxide were detected in WT and nia roots grown on 1mM Pi, the level increased in nia plants grown on 0mM Pi (Fig. 5A; Supplementary Fig. S5). Thus the inability of the nia mutant to induce AOX under low Pi conditions has a deleterious effect on one of the mechanisms controlling ROS levels in the roots. Increased levels of superoxide can increase H2O2, but DAB staining showed no change in root H2O2 levels in all treatments (Fig. 5B; Supplementary Fig. S6).


Nitric oxide induces the alternative oxidase pathway in Arabidopsis seedlings deprived of inorganic phosphate.

Royo B, Moran JF, Ratcliffe RG, Gupta KJ - J. Exp. Bot. (2015)

Effect of Pi supply on superoxide and H2O2 levels in Arabidopsis roots. (A) NBT staining for superoxide; and (B) DAB staining for H2O2. Measurements were made on the roots of 14-d-old WT and nia seedlings grown on a medium containing 0 or 1mM Pi; and 200 μM GSNO was used for the NO donor treatment. Image intensities were quantified by Image J software. Means (n=3) with different letters are significantly different (one-way ANOVA, P<0.05).
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4588884&req=5

Figure 5: Effect of Pi supply on superoxide and H2O2 levels in Arabidopsis roots. (A) NBT staining for superoxide; and (B) DAB staining for H2O2. Measurements were made on the roots of 14-d-old WT and nia seedlings grown on a medium containing 0 or 1mM Pi; and 200 μM GSNO was used for the NO donor treatment. Image intensities were quantified by Image J software. Means (n=3) with different letters are significantly different (one-way ANOVA, P<0.05).
Mentions: AOX helps to minimize ROS production under conditions that lead to over-reduction of ubiquinone (Maxwell et al., 1999). While only low levels of superoxide were detected in WT and nia roots grown on 1mM Pi, the level increased in nia plants grown on 0mM Pi (Fig. 5A; Supplementary Fig. S5). Thus the inability of the nia mutant to induce AOX under low Pi conditions has a deleterious effect on one of the mechanisms controlling ROS levels in the roots. Increased levels of superoxide can increase H2O2, but DAB staining showed no change in root H2O2 levels in all treatments (Fig. 5B; Supplementary Fig. S6).

Bottom Line: The effects of the phosphate supply on growth, the production of NO, respiration, the AOX level and the production of superoxide were compared for wild-type (WT) seedlings and the nitrate reductase double mutant nia.Phosphate deprivation increased NO production in WT roots, and the AOX level and the capacity of the alternative pathway to consume electrons in WT seedlings; whereas the same treatment failed to stimulate NO production and AOX expression in the nia mutant, and the plants had an altered growth phenotype.It is concluded that NO is required for the induction of the AOX pathway when seedlings are grown under phosphate-limiting conditions.

View Article: PubMed Central - PubMed

Affiliation: Department of Plant Sciences, University of Oxford, South Park Road, Oxford OX1 3RB, UK Institute of Agrobiotechnology, IdAB-CSIC-Public University of Navarre-Government of Navarre, Avda. Pamplona 123, E-31192, Mutilva, Navarre, Spain.

No MeSH data available.


Related in: MedlinePlus