Salinity induced the changes of root growth and antioxidative responses in two wheat cultivars
Salinity induced the changes of root growth and antioxidative responses in two wheat cultivars
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DOI：
10.1007/s00709-013-0579-7
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发表时间：
2014-07
期刊：
影响因子：
2.9
通讯作者：
Jing Zhang;X. Duan;Fan Ding;Haizhen Ma;Tengguo Zhang;Yingli Yang
中科院分区：
文献类型：
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作者：
Jing Zhang;X. Duan;Fan Ding;Haizhen Ma;Tengguo Zhang;Yingli Yang
以耐旱的宁春和干旱敏感的西汉两个小麦品种为材料，研究了不同浓度NaCl胁迫对小麦根系生长的抑制机制，并比较了两个小麦品种的抗氧化反应。在盐胁迫下，宁春的发芽率、幼苗生长和膜脂过氧化作用均低于西汉。细胞活力的丧失与NaCl胁迫对根系生长的抑制有关。此外，H2O2清除剂二甲基硫脲和过氧化氢酶（CAT）处理部分阻断了盐诱导的根系生长和细胞活力的负面影响。此外，还观察到盐胁迫下两种小麦根系超氧自由基和H2O2水平的增加，CAT和二胺氧化酶（DAO）活性的增强以及谷胱甘肽还原酶（GR）活性的抑制。NaCl处理仅使西汉根中的羟自由基含量增加，且不同浓度NaCl处理后，耐旱的宁春和干旱敏感的西汉根中可溶性过氧化物酶（POD）、抗坏血酸过氧化物酶（APX）、超氧化物歧化酶（SOD）和细胞壁结合POD活性的变化不同。因此，盐胁迫可能通过细胞外H2O2的产生导致细胞活力的丧失，这是导致两个小麦品种根系生长受到抑制的主要原因。耐旱的宁春根系H2O2积累量增加可能是由于POD和GR活性降低，细胞壁结合POD和DAO活性增强所致，而干旱敏感的西汉根系H2O2水平升高可能是由于APX和GR的抑制以及SOD和DAO的激活所致。
This study aimed to investigate the inhibitory mechanism of root growth and to compare antioxidative responses in two wheat cultivars, drought-tolerant Ningchun and drought-sensitive Xihan, exposed to different NaCl concentrations. Ningchun exhibited lower germination rate, seedling growth, and lipid peroxidation than Xihan when exposed to salinity. The loss of cell viability was correlated with the inhibition of root growth induced by NaCl stress. Moreover, treatments with H2O2scavenger dimethylthiourea and catalase (CAT) partly blocked salinity-induced negative effects on root growth and cell viability. Besides, the enhancement of superoxide radical and H2O2levels, and the stimulation of CAT and diamine oxidase (DAO) as well as the inhibition of glutathione reductase (GR) were observed in two wheat roots treated with salinity. However, hydroxyl radical content increased only in Xihan roots under NaCl treatment, and the changes of soluble peroxidase (POD), ascorbate peroxidase (APX), superoxide dismutase (SOD), and cell-wall-bound POD activities were different in drought-tolerant Ningchun and drought-sensitive Xihan exposed to different NaCl concentrations. In conclusion, salinity might induce the loss of cell viability via a pathway associated with extracellular H2O2generation, which was the primary reason leading to the inhibition of root growth in two wheat cultivars. Here, it was also suggested that increased H2O2accumulation in the roots of drought-tolerant Ningchun might be due to decreased POD and GR activities as well as enhanced cell-wall-bound POD and DAO ones, while the inhibition of APX and GR as well as the stimulation of SOD and DAO was responsible for the elevation of H2O2level in drought-sensitive Xihan roots.