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Hydrogen Sulfide Alleviates Cadmium-Induced Cell Death through Restraining ROS Accumulation in Roots of Brassica rapa L. ssp. pekinensis.

Zhang L, Pei Y, Wang H, Jin Z, Liu Z, Qiao Z, Fang H, Zhang Y - Oxid Med Cell Longev (2015)

Bottom Line: Cd-induced cell death in roots was significantly reduced by 5 μM NaHS treatment.In contrast, these effects were reversed by hydroxylamine, a H2S inhibitor.These results suggested that H2S alleviated the cell death caused by Cd via upregulation of antioxidant enzyme activities to remove excessive reactive oxygen species and reduce cell oxidative damage.

View Article: PubMed Central - PubMed

Affiliation: School of Life Science, Shanxi University, Taiyuan 030006, China.

ABSTRACT
Hydrogen sulfide (H2S) is a cell signal molecule produced endogenously and involved in regulation of tolerance to biotic and abiotic stress in plants. In this work, we used molecular biology, physiology, and histochemical methods to investigate the effects of H2S on cadmium- (Cd-) induced cell death in Chinese cabbage roots. Cd stress stimulated a rapid increase of endogenous H2S in roots. Additionally, root length was closely related to the cell death rate. Pretreatment with sodium hydrosulfide (NaHS), a H2S donor, alleviated the growth inhibition caused by Cd in roots-this effect was more pronounced at 5 μM NaHS. Cd-induced cell death in roots was significantly reduced by 5 μM NaHS treatment. Under Cd stress, activities of the antioxidant enzymes were significantly enhanced in roots. NaHS + Cd treatment made their activities increase further compared with Cd exposure alone. Enhanced antioxidant enzyme activity led to a decline in reactive oxygen species accumulation and lipid peroxidation. In contrast, these effects were reversed by hydroxylamine, a H2S inhibitor. These results suggested that H2S alleviated the cell death caused by Cd via upregulation of antioxidant enzyme activities to remove excessive reactive oxygen species and reduce cell oxidative damage.

No MeSH data available.


Related in: MedlinePlus

Effect of H2S on antioxidant enzyme activity in Chinese cabbage roots. Activities of (a) SOD, (b) CAT, (c) POD, and (d) APX. CK: control; NaHS: fumigated with 5 μM NaHS for 24 h; Cd: 5 mM Cd stressed for 48 h; NaHS + Cd: seedlings fumigated with 5 μM NaHS for 24 h and then treated with 5 mM Cd for 48 h; HA + Cd: seedlings treated with 1 mM HA for 4 h and then treated with 5 mM Cd for 48 h; HA: seedlings treated with 1 mM HA for 4 h. Data are mean ± SE of three independent repeats. LSD was used for multiple comparisons; different letters indicate significant differences (P < 0.05).
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fig6: Effect of H2S on antioxidant enzyme activity in Chinese cabbage roots. Activities of (a) SOD, (b) CAT, (c) POD, and (d) APX. CK: control; NaHS: fumigated with 5 μM NaHS for 24 h; Cd: 5 mM Cd stressed for 48 h; NaHS + Cd: seedlings fumigated with 5 μM NaHS for 24 h and then treated with 5 mM Cd for 48 h; HA + Cd: seedlings treated with 1 mM HA for 4 h and then treated with 5 mM Cd for 48 h; HA: seedlings treated with 1 mM HA for 4 h. Data are mean ± SE of three independent repeats. LSD was used for multiple comparisons; different letters indicate significant differences (P < 0.05).

Mentions: It was well known that, under Cd stress, ROS levels can rise to excessive levels, with oxidative damage and cell death as a consequence. Thus, continuous control of ROS and their metabolism is imperative under stress conditions. Plants have several antioxidant enzymes to scavenge ROS: SOD catalyzes superoxide radicals to H2O2 by very rapid dismutation; CAT and several kinds of peroxidases such as POD and APX then scavenge the H2O2 [33]. Chen reported that H2S significantly inhibited H2O2 and O2•− production in leaves and roots of barely [13]. Our results demonstrated that H2S could significantly reduce the ROS accumulation caused by Cd stress (Figure 4). Current research has shown that, as a signal molecule, H2S regulates the metabolism and balance of ROS through upregulating the capacity of the antioxidant system to remove excess ROS. In this research, SOD, CAT, POD, and APX activities were determined to confirm the positive role of H2S in eliminating ROS. Our results showed that Cd stress could improve the activities of SOD, CAT, POD, and APX in roots. Meanwhile, NaHS + Cd treatment led to a significant increase in SOD and CAT activities. In contrast, POD and APX activities showed no difference between Cd and NaHS + Cd treatments. We concluded that H2S was involved in scavenging ROS accumulation via mainly enhancing SOD and CAT activities and partially stimulating POD and APX activities (Figures 6(a)–6(c)).


Hydrogen Sulfide Alleviates Cadmium-Induced Cell Death through Restraining ROS Accumulation in Roots of Brassica rapa L. ssp. pekinensis.

Zhang L, Pei Y, Wang H, Jin Z, Liu Z, Qiao Z, Fang H, Zhang Y - Oxid Med Cell Longev (2015)

Effect of H2S on antioxidant enzyme activity in Chinese cabbage roots. Activities of (a) SOD, (b) CAT, (c) POD, and (d) APX. CK: control; NaHS: fumigated with 5 μM NaHS for 24 h; Cd: 5 mM Cd stressed for 48 h; NaHS + Cd: seedlings fumigated with 5 μM NaHS for 24 h and then treated with 5 mM Cd for 48 h; HA + Cd: seedlings treated with 1 mM HA for 4 h and then treated with 5 mM Cd for 48 h; HA: seedlings treated with 1 mM HA for 4 h. Data are mean ± SE of three independent repeats. LSD was used for multiple comparisons; different letters indicate significant differences (P < 0.05).
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4442412&req=5

fig6: Effect of H2S on antioxidant enzyme activity in Chinese cabbage roots. Activities of (a) SOD, (b) CAT, (c) POD, and (d) APX. CK: control; NaHS: fumigated with 5 μM NaHS for 24 h; Cd: 5 mM Cd stressed for 48 h; NaHS + Cd: seedlings fumigated with 5 μM NaHS for 24 h and then treated with 5 mM Cd for 48 h; HA + Cd: seedlings treated with 1 mM HA for 4 h and then treated with 5 mM Cd for 48 h; HA: seedlings treated with 1 mM HA for 4 h. Data are mean ± SE of three independent repeats. LSD was used for multiple comparisons; different letters indicate significant differences (P < 0.05).
Mentions: It was well known that, under Cd stress, ROS levels can rise to excessive levels, with oxidative damage and cell death as a consequence. Thus, continuous control of ROS and their metabolism is imperative under stress conditions. Plants have several antioxidant enzymes to scavenge ROS: SOD catalyzes superoxide radicals to H2O2 by very rapid dismutation; CAT and several kinds of peroxidases such as POD and APX then scavenge the H2O2 [33]. Chen reported that H2S significantly inhibited H2O2 and O2•− production in leaves and roots of barely [13]. Our results demonstrated that H2S could significantly reduce the ROS accumulation caused by Cd stress (Figure 4). Current research has shown that, as a signal molecule, H2S regulates the metabolism and balance of ROS through upregulating the capacity of the antioxidant system to remove excess ROS. In this research, SOD, CAT, POD, and APX activities were determined to confirm the positive role of H2S in eliminating ROS. Our results showed that Cd stress could improve the activities of SOD, CAT, POD, and APX in roots. Meanwhile, NaHS + Cd treatment led to a significant increase in SOD and CAT activities. In contrast, POD and APX activities showed no difference between Cd and NaHS + Cd treatments. We concluded that H2S was involved in scavenging ROS accumulation via mainly enhancing SOD and CAT activities and partially stimulating POD and APX activities (Figures 6(a)–6(c)).

Bottom Line: Cd-induced cell death in roots was significantly reduced by 5 μM NaHS treatment.In contrast, these effects were reversed by hydroxylamine, a H2S inhibitor.These results suggested that H2S alleviated the cell death caused by Cd via upregulation of antioxidant enzyme activities to remove excessive reactive oxygen species and reduce cell oxidative damage.

View Article: PubMed Central - PubMed

Affiliation: School of Life Science, Shanxi University, Taiyuan 030006, China.

ABSTRACT
Hydrogen sulfide (H2S) is a cell signal molecule produced endogenously and involved in regulation of tolerance to biotic and abiotic stress in plants. In this work, we used molecular biology, physiology, and histochemical methods to investigate the effects of H2S on cadmium- (Cd-) induced cell death in Chinese cabbage roots. Cd stress stimulated a rapid increase of endogenous H2S in roots. Additionally, root length was closely related to the cell death rate. Pretreatment with sodium hydrosulfide (NaHS), a H2S donor, alleviated the growth inhibition caused by Cd in roots-this effect was more pronounced at 5 μM NaHS. Cd-induced cell death in roots was significantly reduced by 5 μM NaHS treatment. Under Cd stress, activities of the antioxidant enzymes were significantly enhanced in roots. NaHS + Cd treatment made their activities increase further compared with Cd exposure alone. Enhanced antioxidant enzyme activity led to a decline in reactive oxygen species accumulation and lipid peroxidation. In contrast, these effects were reversed by hydroxylamine, a H2S inhibitor. These results suggested that H2S alleviated the cell death caused by Cd via upregulation of antioxidant enzyme activities to remove excessive reactive oxygen species and reduce cell oxidative damage.

No MeSH data available.


Related in: MedlinePlus