Methane alleviates copper-induced seed germination inhibition and oxidative stress in Medicago sativa
Methane alleviates copper-induced seed germination inhibition and oxidative stress in Medicago sativa
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DOI：
10.1007/s10534-017-9989-x
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发表时间：
2017-01
期刊：
影响因子：
3.5
通讯作者：
Muhammad Kaleem Samma;Heng Zhou;Weiti Cui;Kaikai Zhu;Jing Zhang;W. Shen
中科院分区：
文献类型：
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作者：
Muhammad Kaleem Samma;Heng Zhou;Weiti Cui;Kaikai Zhu;Jing Zhang;W. Shen
最近的研究结果发现甲烷（CH 4）对动物氧化应激的保护作用。然而，CH 4在植物中可能的生理作用仍然是未知的。采用生理、组织化学和分子生物学方法，研究了CH 4对苜蓿种子萌发过程中铜胁迫的影响。内源产生的CH 4显着增加铜胁迫苜蓿种子，这是模仿0.39 mM CH 4。CH 4预处理可显著缓解Cu胁迫对种子萌发和幼苗生长的抑制作用。Cu的积累也受到明显的抑制。同时，α/β淀粉酶活性和糖含量增加，这与缓解CH 4对种子萌发的抑制作用一致。铜引发的氧化胁迫也得到缓解，这是证实了减少脂质过氧化和减少铜诱导的质膜完整性的损失在CH 4预处理苜蓿幼苗。抗氧化酶（APX、SOD、CAT和POD）的总酶活性和同工酶活性以及相应的转录本（APX 1/2、Cu/Zn SOD和Mn-SOD）的测定结果表明，CH 4恢复了细胞的氧化还原平衡。此外，铜诱导的脯氨酸积累部分受损的甲烷，这是支持脯氨酸代谢的交替。这些结果表明，CH 4对缓解Cu胁迫对种子萌发的抑制有积极作用，并主要通过增强抗氧化防御作用重建氧化还原稳态。
Recent results discovered the protective roles of methane (CH4) against oxidative stress in animals. However, the possible physiological roles of CH4in plants are still unknown. By using physiological, histochemical and molecular approaches, the beneficial role of CH4in germinating alfalfa seeds upon copper (Cu) stress was evaluated. Endogenous production of CH4was significantly increased in Cu-stressed alfalfa seeds, which was mimicked by 0.39 mM CH4. The pretreatment with CH4significantly alleviated the inhibition of seed germination and seedling growth induced by Cu stress. Cu accumulation was obviously blocked as well. Meanwhile,α/βamylase activities and sugar contents were increased, all of which were consistent with the alleviation of seed germination inhibition triggered by CH4. The Cu-triggered oxidative stress was also mitigated, which was confirmed by the decrease of lipid peroxidation and reduction of Cu-induced loss of plasma membrane integrity in CH4-pretreated alfalfa seedlings. The results of antioxidant enzymes, including ascorbate peroxidase (APX), superoxide dismutase (SOD), catalase (CAT), and guaiacol peroxidase (POD) total or isozymatic activities, and corresponding transcripts (APX1/2,Cu/Zn SODandMn-SOD), indicated that CH4reestablished cellular redox homeostasis. Further, Cu-induced proline accumulation was partly impaired by CH4, which was supported by the alternation of proline metabolism. Together, these results indicated that CH4performs an advantageous effect on the alleviation of seed germination inhibition caused by Cu stress, and reestablishment of redox homeostasis mainly via increasing antioxidant defence.