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Exogenous Nitric Oxide (NO) Interferes with Lead (Pb)-Induced Toxicity by Detoxifying Reactive Oxygen Species in Hydroponically Grown Wheat (Triticum aestivum) Roots.

Kaur G, Singh HP, Batish DR, Mahajan P, Kohli RK, Rishi V - PLoS ONE (2015)

Bottom Line: NO supplementation reduced the accumulation of oxidative stress markers (malondialdehyde, conjugated dienes, hydroxyl ions and superoxide anion) and decreased the antioxidant enzyme activity in wheat roots particularly up to 6 h, thereby suggesting its role as an antioxidant.Pb-exposure significantly decreased in vivo NO level.The study concludes that exogenous NO partially ameliorates Pb-toxicity, but could not restore the plant growth on prolonged Pb-exposure.

View Article: PubMed Central - PubMed

Affiliation: Department of Environment Studies, Panjab University, Chandigarh, 160 014, India.

ABSTRACT
Nitric Oxide (NO) is a bioactive signaling molecule that mediates a variety of biotic and abiotic stresses. The present study investigated the role of NO (as SNP [sodium nitroprusside]) in ameliorating lead (Pb)-toxicity in Triticum aestivum (wheat) roots. Pb (50 and 250 μM) alone and in combination with SNP (100 μM) was given to hydroponically grown wheat roots for a period of 0-8 h. NO supplementation reduced the accumulation of oxidative stress markers (malondialdehyde, conjugated dienes, hydroxyl ions and superoxide anion) and decreased the antioxidant enzyme activity in wheat roots particularly up to 6 h, thereby suggesting its role as an antioxidant. NO ameliorated Pb-induced membrane damage in wheat roots as evidenced by decreased ion-leakage and in situ histochemical localization. Pb-exposure significantly decreased in vivo NO level. The study concludes that exogenous NO partially ameliorates Pb-toxicity, but could not restore the plant growth on prolonged Pb-exposure.

No MeSH data available.


Related in: MedlinePlus

SDS–PAGE analysis of (1) The protein profile, (2) SOD activity, and (3) CAT activity in the root extracts of wheat treated for 8 h. In all the figures, a: control; b: 100 μM SNP; c: 50 μM Pb; d: 250 μM Pb; e: 250 μM Pb +SNP; f: 50 μM Pb +SNP.
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pone.0138713.g008: SDS–PAGE analysis of (1) The protein profile, (2) SOD activity, and (3) CAT activity in the root extracts of wheat treated for 8 h. In all the figures, a: control; b: 100 μM SNP; c: 50 μM Pb; d: 250 μM Pb; e: 250 μM Pb +SNP; f: 50 μM Pb +SNP.

Mentions: Activities of scavenging enzymes (SOD, CAT, APX, GPX and GR) increased significantly in wheat roots on Pb-exposure in a dose- and time-dependent manner (Fig 7a–7e). The total soluble protein content was found to increase upon Pb exposure and decrease when supplemented with SNP. Gel electrograph indicates variations in the banding of protein patterns in root extracts of wheat in response to Pb and Pb+SNP treatments for 8 h (Fig 8.1). Exposure to 50 μM Pb enhanced SOD activity by 1.5–1.6- fold over a period of 2–8 h in comparison to their respective controls. However, SOD activity was higher than their respective control by 264% after 8 h of 250 μM Pb-treatment (Fig 7a). The quantitative changes were in accordance with findings of native SDS-PAGE gels. Distinctly resolved bands of SOD were clearly observed in the gel; however, the SOD activity was highest in the root extracts of wheat treated with 250 μM Pb after 8 h (Fig 8.2). CAT activity increased in the range of 22–32% and 30–37% upon exposure to 50 μM and 250 μM Pb, respectively, as compared to the control, over a period of 2–8 h (Fig 7b). The banding pattern of the CAT activity in the root extracts of wheat treated for 8 h clearly indicated that the Pb-treated roots synthesized more CAT than the control, and SNP was not able to ameliorate Pb-induced CAT activity (Fig 8.3). The activity of APX increased by ~1.5-, 1.6-, 1.8- and 2.0-times over that in the control after 2, 4, 6 and 8 h of exposure to 50 μM Pb (Fig 7c). Exposure to 250 μM Pb enhanced GPX activity by ~2.4-, 3.0-, 3.5- and 4.0-fold over the control after 2, 4, 6 and 8 h of exposure (Fig 7d). GR activity increased in the range of ~83–141% and 165–247% over 2–8 h of exposure to 50 and 250 μM Pb, respectively (Fig 7e). However, the induction levels of these scavenging enzymes (except CAT) were reduced upon SNP supplementation. SNP was able to successfully modulate Pb-induced SOD activity at both the concentrations of Pb (50 μM and 250 μM). The ameliorating effect of SNP on Pb-induced APX, GPX and GR upregulation was greater at 50 μM Pb than at 250 μM Pb treatments.


Exogenous Nitric Oxide (NO) Interferes with Lead (Pb)-Induced Toxicity by Detoxifying Reactive Oxygen Species in Hydroponically Grown Wheat (Triticum aestivum) Roots.

Kaur G, Singh HP, Batish DR, Mahajan P, Kohli RK, Rishi V - PLoS ONE (2015)

SDS–PAGE analysis of (1) The protein profile, (2) SOD activity, and (3) CAT activity in the root extracts of wheat treated for 8 h. In all the figures, a: control; b: 100 μM SNP; c: 50 μM Pb; d: 250 μM Pb; e: 250 μM Pb +SNP; f: 50 μM Pb +SNP.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4581626&req=5

pone.0138713.g008: SDS–PAGE analysis of (1) The protein profile, (2) SOD activity, and (3) CAT activity in the root extracts of wheat treated for 8 h. In all the figures, a: control; b: 100 μM SNP; c: 50 μM Pb; d: 250 μM Pb; e: 250 μM Pb +SNP; f: 50 μM Pb +SNP.
Mentions: Activities of scavenging enzymes (SOD, CAT, APX, GPX and GR) increased significantly in wheat roots on Pb-exposure in a dose- and time-dependent manner (Fig 7a–7e). The total soluble protein content was found to increase upon Pb exposure and decrease when supplemented with SNP. Gel electrograph indicates variations in the banding of protein patterns in root extracts of wheat in response to Pb and Pb+SNP treatments for 8 h (Fig 8.1). Exposure to 50 μM Pb enhanced SOD activity by 1.5–1.6- fold over a period of 2–8 h in comparison to their respective controls. However, SOD activity was higher than their respective control by 264% after 8 h of 250 μM Pb-treatment (Fig 7a). The quantitative changes were in accordance with findings of native SDS-PAGE gels. Distinctly resolved bands of SOD were clearly observed in the gel; however, the SOD activity was highest in the root extracts of wheat treated with 250 μM Pb after 8 h (Fig 8.2). CAT activity increased in the range of 22–32% and 30–37% upon exposure to 50 μM and 250 μM Pb, respectively, as compared to the control, over a period of 2–8 h (Fig 7b). The banding pattern of the CAT activity in the root extracts of wheat treated for 8 h clearly indicated that the Pb-treated roots synthesized more CAT than the control, and SNP was not able to ameliorate Pb-induced CAT activity (Fig 8.3). The activity of APX increased by ~1.5-, 1.6-, 1.8- and 2.0-times over that in the control after 2, 4, 6 and 8 h of exposure to 50 μM Pb (Fig 7c). Exposure to 250 μM Pb enhanced GPX activity by ~2.4-, 3.0-, 3.5- and 4.0-fold over the control after 2, 4, 6 and 8 h of exposure (Fig 7d). GR activity increased in the range of ~83–141% and 165–247% over 2–8 h of exposure to 50 and 250 μM Pb, respectively (Fig 7e). However, the induction levels of these scavenging enzymes (except CAT) were reduced upon SNP supplementation. SNP was able to successfully modulate Pb-induced SOD activity at both the concentrations of Pb (50 μM and 250 μM). The ameliorating effect of SNP on Pb-induced APX, GPX and GR upregulation was greater at 50 μM Pb than at 250 μM Pb treatments.

Bottom Line: NO supplementation reduced the accumulation of oxidative stress markers (malondialdehyde, conjugated dienes, hydroxyl ions and superoxide anion) and decreased the antioxidant enzyme activity in wheat roots particularly up to 6 h, thereby suggesting its role as an antioxidant.Pb-exposure significantly decreased in vivo NO level.The study concludes that exogenous NO partially ameliorates Pb-toxicity, but could not restore the plant growth on prolonged Pb-exposure.

View Article: PubMed Central - PubMed

Affiliation: Department of Environment Studies, Panjab University, Chandigarh, 160 014, India.

ABSTRACT
Nitric Oxide (NO) is a bioactive signaling molecule that mediates a variety of biotic and abiotic stresses. The present study investigated the role of NO (as SNP [sodium nitroprusside]) in ameliorating lead (Pb)-toxicity in Triticum aestivum (wheat) roots. Pb (50 and 250 μM) alone and in combination with SNP (100 μM) was given to hydroponically grown wheat roots for a period of 0-8 h. NO supplementation reduced the accumulation of oxidative stress markers (malondialdehyde, conjugated dienes, hydroxyl ions and superoxide anion) and decreased the antioxidant enzyme activity in wheat roots particularly up to 6 h, thereby suggesting its role as an antioxidant. NO ameliorated Pb-induced membrane damage in wheat roots as evidenced by decreased ion-leakage and in situ histochemical localization. Pb-exposure significantly decreased in vivo NO level. The study concludes that exogenous NO partially ameliorates Pb-toxicity, but could not restore the plant growth on prolonged Pb-exposure.

No MeSH data available.


Related in: MedlinePlus