Antisense inhibition of a spermidine synthase gene highlights the role of polyamines for stress alleviation in pear shoots subjected to salinity and cadmium
Antisense inhibition of a spermidine synthase gene highlights the role of polyamines for stress alleviation in pear shoots subjected to salinity and cadmium
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DOI：
10.1016/j.envexpbot.2011.03.001
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发表时间：
2011-09
影响因子：
5.7
通讯作者：
X. Wen;Y. Ban;H. Inoue;N. Matsuda;M. Kita;T. Moriguchi
中科院分区：
文献类型：
--
作者：
X. Wen;Y. Ban;H. Inoue;N. Matsuda;M. Kita;T. Moriguchi
3个转基因欧洲梨(PyrusCommis L.)利用苹果精胺合成酶基因(MdSPDS1)的反义定向构建，获得了精胺合成酶(SPDS)表达和亚精胺(SPD)滴度降低的品系。在盐胁迫或镉胁迫下，反义品系的生长抑制比野生型(WT)更严重。与WT相比，反义品系在胁迫下没有有效地诱导抗氧化系统，如谷胱甘肽(GSH)含量、谷胱甘肽还原酶(GR)和超氧化物歧化酶(SOD)活性以及脯氨酸的积累。在反义品系中，抗氧化系统功能的降低伴随着丙二醛(MDA)的更大积累，丙二醛是脂质过氧化的指标。外源Spd显著改善了植株的生长抑制、Spd水平和抗氧化系统参数。无论在盐胁迫还是镉胁迫下，GSH含量、GR和SOD活性以及Pro积累量均与Spd、腐胺(Put)和总多胺滴度呈正相关。相反，在两种胁迫条件下，丙二醛水平与这些多胺含量呈显著负相关。因此，对胁迫处理的反应首先在SPDS反义欧洲梨中被发现，结果进一步证明了多胺在盐和镉胁迫耐受性中的重要作用，其中多胺至少部分地通过影响抗氧化系统来发挥作用。
Three transgenic European pear (Pyrus communis L.) lines with reduced spermidine synthase (SPDS) expression and spermidine (Spd) titers were developed using a construct containing an apple SPDS gene (MdSPDS1) in antisense orientation. After exposure to either salt or cadmium stress, growth inhibition was more severe in the antisense lines than in the wild-type (WT). The antioxidant system, as shown by glutathione (GSH) content, activity of glutathione reductase (GR) and superoxide dismutase (SOD), and proline accumulation, was not effectively induced under stress in the antisense lines as compared with the WT. The reduction in antioxidant system function in the antisense lines was accompanied by a greater accumulation of malondialdehyde (MDA), an indicator of lipid peroxidation. Growth inhibition, Spd level, and parameters indicative of the antioxidant system were significantly ameliorated by exogenous Spd application. Under either salt or cadmium stress, GSH content, GR and SOD activity, and proline accumulation were positively correlated with Spd, putrescine (Put), and total polyamine titers. Conversely, MDA level showed a significantly negative correlation with these polyamines under both stress conditions. Thus, the responses to stress treatments were first identified in the SPDS antisense European pears, and the results provide further evidence for the important role of polyamines in both salt and cadmium stress tolerance, in which the polyamines act, at least in part, by influencing the antioxidant system.