Limits...
Methane protects against polyethylene glycol-induced osmotic stress in maize by improving sugar and ascorbic acid metabolism

View Article: PubMed Central - PubMed

ABSTRACT

Although aerobic methane (CH4) release from plants leads to an intense scientific and public controversy in the recent years, the potential functions of endogenous CH4 production in plants are still largely unknown. Here, we reported that polyethylene glycol (PEG)-induced osmotic stress significantly increased CH4 production and soluble sugar contents in maize (Zea mays L.) root tissues. These enhancements were more pronounced in the drought stress-tolerant cultivar Zhengdan 958 (ZD958) than in the drought stress-sensitive cultivar Zhongjiangyu No.1 (ZJY1). Exogenously applied 0.65 mM CH4 not only increased endogenous CH4 production, but also decreased the contents of thiobarbituric acid reactive substances. PEG-induced water deficit symptoms, such as decreased biomass and relative water contents in both root and shoot tissues, were also alleviated. These beneficial responses paralleled the increases in the contents of soluble sugar and the reduced ascorbic acid (AsA), and the ratio of AsA/dehydroascorbate (DHA). Further comparison of transcript profiles of some key enzymes in sugar and AsA metabolism suggested that CH4 might participate in sugar signaling, which in turn increased AsA production and recycling. Together, these results suggested that CH4 might function as a gaseous molecule that enhances osmotic stress tolerance in maize by modulating sugar and AsA metabolism.

No MeSH data available.


Effects of CH4 pretreatment on seedling growth, soluble sugar content, and lipid peroxidation in maize seedlings of ZD958 upon 20% PEG-6000 treatment.(a) 5-d-old seedlings were preincubated in the solution containing the indicated concentrations of CH4 for 1 d, and then transferred to half-strength Hoagland solutions with or without 20% PEG-6000 for another 5 d. Photographs were then taken. Bar = 10 cm. Meanwhile, fresh weight (b) and dry weight (c) were measured in both root and shoot tissues. The contents of soluble sugar (d) and TBARS (e) in root tissues were also determined. Control seedlings were incubated in Hoagland solution alone. Data are presented as means ± SE (5 root or shoot parts per experiment performed three times). Bars with different letters denote significant differences according to multiple comparisons (P < 0.05).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC5384014&req=5

f3: Effects of CH4 pretreatment on seedling growth, soluble sugar content, and lipid peroxidation in maize seedlings of ZD958 upon 20% PEG-6000 treatment.(a) 5-d-old seedlings were preincubated in the solution containing the indicated concentrations of CH4 for 1 d, and then transferred to half-strength Hoagland solutions with or without 20% PEG-6000 for another 5 d. Photographs were then taken. Bar = 10 cm. Meanwhile, fresh weight (b) and dry weight (c) were measured in both root and shoot tissues. The contents of soluble sugar (d) and TBARS (e) in root tissues were also determined. Control seedlings were incubated in Hoagland solution alone. Data are presented as means ± SE (5 root or shoot parts per experiment performed three times). Bars with different letters denote significant differences according to multiple comparisons (P < 0.05).

Mentions: Different concentrations of CH4 (0.13, 0.65, and 1.30 mM CH4) were used to mimic endogenous CH4-related responses in ZD958 under PEG stress. Our experiments showed that pretreatments with CH4 partially alleviated the loss of fresh and dry weight in both root and shoot tissues of ZD958 caused by PEG (Fig. 3a–c). The maximal protective response was observed in 0.65 mM CH4-pretreated plants. When CH4 was applied alone, only dry weight in root tissues of ZD958 was obviously increased, by comparison with the control samples. Soluble sugar content was significantly enhanced by PEG-6000, which was further strengthened after CH4 pretreatment, with maximal responses at 0.65 and 1.30 mM (Fig. 3d). To further assess the protective effects of CH4, PEG-induced oxidative damage to cell membranes in root tissues was investigated. Because of the stressed plant tissues containing anthocyanin and other interfering compounds, the TBARS content, an important indicator of lipid peroxidation and free radical generation, were measured. Treatment with 20% PEG-6000 for 5 d caused a significant increase in TBARS content compared with the control samples (Fig. 3e). By contrast, the amount of the increased TBARS content triggered by PEG-6000 was reduced by CH4 pretreatment, with the maximal reduction observed at 0.65 mM CH4. No significant changes occurred in CH4-pretreated alone samples. Therefore, 0.65 mM CH4 was applied in the following experiments.


Methane protects against polyethylene glycol-induced osmotic stress in maize by improving sugar and ascorbic acid metabolism
Effects of CH4 pretreatment on seedling growth, soluble sugar content, and lipid peroxidation in maize seedlings of ZD958 upon 20% PEG-6000 treatment.(a) 5-d-old seedlings were preincubated in the solution containing the indicated concentrations of CH4 for 1 d, and then transferred to half-strength Hoagland solutions with or without 20% PEG-6000 for another 5 d. Photographs were then taken. Bar = 10 cm. Meanwhile, fresh weight (b) and dry weight (c) were measured in both root and shoot tissues. The contents of soluble sugar (d) and TBARS (e) in root tissues were also determined. Control seedlings were incubated in Hoagland solution alone. Data are presented as means ± SE (5 root or shoot parts per experiment performed three times). Bars with different letters denote significant differences according to multiple comparisons (P < 0.05).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5384014&req=5

f3: Effects of CH4 pretreatment on seedling growth, soluble sugar content, and lipid peroxidation in maize seedlings of ZD958 upon 20% PEG-6000 treatment.(a) 5-d-old seedlings were preincubated in the solution containing the indicated concentrations of CH4 for 1 d, and then transferred to half-strength Hoagland solutions with or without 20% PEG-6000 for another 5 d. Photographs were then taken. Bar = 10 cm. Meanwhile, fresh weight (b) and dry weight (c) were measured in both root and shoot tissues. The contents of soluble sugar (d) and TBARS (e) in root tissues were also determined. Control seedlings were incubated in Hoagland solution alone. Data are presented as means ± SE (5 root or shoot parts per experiment performed three times). Bars with different letters denote significant differences according to multiple comparisons (P < 0.05).
Mentions: Different concentrations of CH4 (0.13, 0.65, and 1.30 mM CH4) were used to mimic endogenous CH4-related responses in ZD958 under PEG stress. Our experiments showed that pretreatments with CH4 partially alleviated the loss of fresh and dry weight in both root and shoot tissues of ZD958 caused by PEG (Fig. 3a–c). The maximal protective response was observed in 0.65 mM CH4-pretreated plants. When CH4 was applied alone, only dry weight in root tissues of ZD958 was obviously increased, by comparison with the control samples. Soluble sugar content was significantly enhanced by PEG-6000, which was further strengthened after CH4 pretreatment, with maximal responses at 0.65 and 1.30 mM (Fig. 3d). To further assess the protective effects of CH4, PEG-induced oxidative damage to cell membranes in root tissues was investigated. Because of the stressed plant tissues containing anthocyanin and other interfering compounds, the TBARS content, an important indicator of lipid peroxidation and free radical generation, were measured. Treatment with 20% PEG-6000 for 5 d caused a significant increase in TBARS content compared with the control samples (Fig. 3e). By contrast, the amount of the increased TBARS content triggered by PEG-6000 was reduced by CH4 pretreatment, with the maximal reduction observed at 0.65 mM CH4. No significant changes occurred in CH4-pretreated alone samples. Therefore, 0.65 mM CH4 was applied in the following experiments.

View Article: PubMed Central - PubMed

ABSTRACT

Although aerobic methane (CH4) release from plants leads to an intense scientific and public controversy in the recent years, the potential functions of endogenous CH4 production in plants are still largely unknown. Here, we reported that polyethylene glycol (PEG)-induced osmotic stress significantly increased CH4 production and soluble sugar contents in maize (Zea mays L.) root tissues. These enhancements were more pronounced in the drought stress-tolerant cultivar Zhengdan 958 (ZD958) than in the drought stress-sensitive cultivar Zhongjiangyu No.1 (ZJY1). Exogenously applied 0.65&thinsp;mM CH4 not only increased endogenous CH4 production, but also decreased the contents of thiobarbituric acid reactive substances. PEG-induced water deficit symptoms, such as decreased biomass and relative water contents in both root and shoot tissues, were also alleviated. These beneficial responses paralleled the increases in the contents of soluble sugar and the reduced ascorbic acid (AsA), and the ratio of AsA/dehydroascorbate (DHA). Further comparison of transcript profiles of some key enzymes in sugar and AsA metabolism suggested that CH4 might participate in sugar signaling, which in turn increased AsA production and recycling. Together, these results suggested that CH4 might function as a gaseous molecule that enhances osmotic stress tolerance in maize by modulating sugar and AsA metabolism.

No MeSH data available.