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A different role for hydrogen peroxide and the antioxidative system under short and long salt stress in Brassica oleracea roots.

Hernandez M, Fernandez-Garcia N, Diaz-Vivancos P, Olmos E - J. Exp. Bot. (2009)

Bottom Line: The results confirm a drastic decrease in the antioxidant enzymes catalase, ascorbate peroxidase, and peroxidases under short salt treatments.Ascorbate was progressively accumulated and its redox state maintained, but glutathione was highly accumulated at 24 h of salt treatment, but then its concentration and redox state progressively decreased.In conclusion, the increase in ascorbate levels and the maintenance of the redox state seem to be critical for root growth and development under salt stress.

View Article: PubMed Central - PubMed

Affiliation: Department of Abiotic Stress and Plant Pathology, CEBAS-Consejo Superior de Investigaciones Cientificas, Murcia, Spain.

ABSTRACT
Salinity affects normal growth and development of plants depending on their capacity to overcome the induced stress. The present study was focused on the response and regulation of the antioxidant defence system in Brassica oleracea roots under short and long salt treatments. The function and the implications of hydrogen peroxide as a stressor or as a signalling molecule were also studied. Two different zones were analysed--the elongation and differentiation zone and the fully differentiated root zone--in order to broaden the knowledge of the different effects of salt stress in root. In general, an accumulation of hydrogen peroxide was observed in both zones at the highest (80 mM NaCl) concentration. A higher accumulation of hydrogen peroxide was observed in the stele of salt-treated roots. At the subcellular level, mitochondria accumulated hydrogen peroxide in salt-treated roots. The results confirm a drastic decrease in the antioxidant enzymes catalase, ascorbate peroxidase, and peroxidases under short salt treatments. However, catalase and peroxidase activities were recovered under long salt stress treatments. The two antioxidant molecules analysed, ascorbate and glutathione, showed a different trend during salt treatments. Ascorbate was progressively accumulated and its redox state maintained, but glutathione was highly accumulated at 24 h of salt treatment, but then its concentration and redox state progressively decreased. Concomitantly, the antioxidant enzymes involved in ascorbate and glutathione regeneration were modified under salt stress treatments. In conclusion, the increase in ascorbate levels and the maintenance of the redox state seem to be critical for root growth and development under salt stress.

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Hydrogen peroxide location in root tissues using DAB. Zone I (A and B, arrows indicate the beginning of the staining in the stele) and zone II (C and D; E and F are magnifications of the boxed area in C and D) of Brassica oleracea roots grown under control conditions (A, C, and E) and with 80 mM NaCl (B, D, and F) during 14 d.
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fig2: Hydrogen peroxide location in root tissues using DAB. Zone I (A and B, arrows indicate the beginning of the staining in the stele) and zone II (C and D; E and F are magnifications of the boxed area in C and D) of Brassica oleracea roots grown under control conditions (A, C, and E) and with 80 mM NaCl (B, D, and F) during 14 d.

Mentions: In view of these results, H2O2 was studied using different techniques to locate the tissue distribution and subcellular location of H2O2 production. To avoid a greater body of data, these experiments have been developed at 80 mM of NaCl and 14 d of salt treatment (Figs 2, 3) when greater differences were observed.


A different role for hydrogen peroxide and the antioxidative system under short and long salt stress in Brassica oleracea roots.

Hernandez M, Fernandez-Garcia N, Diaz-Vivancos P, Olmos E - J. Exp. Bot. (2009)

Hydrogen peroxide location in root tissues using DAB. Zone I (A and B, arrows indicate the beginning of the staining in the stele) and zone II (C and D; E and F are magnifications of the boxed area in C and D) of Brassica oleracea roots grown under control conditions (A, C, and E) and with 80 mM NaCl (B, D, and F) during 14 d.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC2803216&req=5

fig2: Hydrogen peroxide location in root tissues using DAB. Zone I (A and B, arrows indicate the beginning of the staining in the stele) and zone II (C and D; E and F are magnifications of the boxed area in C and D) of Brassica oleracea roots grown under control conditions (A, C, and E) and with 80 mM NaCl (B, D, and F) during 14 d.
Mentions: In view of these results, H2O2 was studied using different techniques to locate the tissue distribution and subcellular location of H2O2 production. To avoid a greater body of data, these experiments have been developed at 80 mM of NaCl and 14 d of salt treatment (Figs 2, 3) when greater differences were observed.

Bottom Line: The results confirm a drastic decrease in the antioxidant enzymes catalase, ascorbate peroxidase, and peroxidases under short salt treatments.Ascorbate was progressively accumulated and its redox state maintained, but glutathione was highly accumulated at 24 h of salt treatment, but then its concentration and redox state progressively decreased.In conclusion, the increase in ascorbate levels and the maintenance of the redox state seem to be critical for root growth and development under salt stress.

View Article: PubMed Central - PubMed

Affiliation: Department of Abiotic Stress and Plant Pathology, CEBAS-Consejo Superior de Investigaciones Cientificas, Murcia, Spain.

ABSTRACT
Salinity affects normal growth and development of plants depending on their capacity to overcome the induced stress. The present study was focused on the response and regulation of the antioxidant defence system in Brassica oleracea roots under short and long salt treatments. The function and the implications of hydrogen peroxide as a stressor or as a signalling molecule were also studied. Two different zones were analysed--the elongation and differentiation zone and the fully differentiated root zone--in order to broaden the knowledge of the different effects of salt stress in root. In general, an accumulation of hydrogen peroxide was observed in both zones at the highest (80 mM NaCl) concentration. A higher accumulation of hydrogen peroxide was observed in the stele of salt-treated roots. At the subcellular level, mitochondria accumulated hydrogen peroxide in salt-treated roots. The results confirm a drastic decrease in the antioxidant enzymes catalase, ascorbate peroxidase, and peroxidases under short salt treatments. However, catalase and peroxidase activities were recovered under long salt stress treatments. The two antioxidant molecules analysed, ascorbate and glutathione, showed a different trend during salt treatments. Ascorbate was progressively accumulated and its redox state maintained, but glutathione was highly accumulated at 24 h of salt treatment, but then its concentration and redox state progressively decreased. Concomitantly, the antioxidant enzymes involved in ascorbate and glutathione regeneration were modified under salt stress treatments. In conclusion, the increase in ascorbate levels and the maintenance of the redox state seem to be critical for root growth and development under salt stress.

Show MeSH