Overexpression of MfPIP2-7 from Medicago falcata promotes cold tolerance and growth under NO3 (-) deficiency in transgenic tobacco plants.
Overexpression of MfPIP2-7 from Medicago falcata promotes cold tolerance and growth under NO3 (-) deficiency in transgenic tobacco plants.
复制标题
苜蓿中 MfPIP2-7 的过度表达可促进转基因烟草植物在 NO3 (-) 缺乏下的耐冷性和生长。
DOI：
10.1186/s12870-016-0814-4
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发表时间：
2016-06-14
影响因子：
5.3
通讯作者：
Lu S
中科院分区：
文献类型：
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作者：
Zhuo C;Wang T;Guo Z;Lu S
质膜内在蛋白（PIPs）属于水通道蛋白（AQP）超家族，根据序列相似性分为PIP 1和PIP 2两大类。几种PIP 2起水通道的作用，而PIP 1具有低或没有水通道活性，但通过与PIP 2相互作用而在水渗透性中起作用。本研究从具有极强耐寒性的豆科牧草苜蓿（Medicago falcata）中分离到一个冷应答PIP 2基因，命名为MfPIP 2 -7，并对过表达MfPIP 2 -7的转基因烟草植株进行了抗寒性分析。MfPIP 2 -7的转录通过4 - 12 h的冷处理和2 h的脱落酸（阿坝）处理诱导。阿坝合成抑制剂预处理阻断了冷诱导的MfPIP 2 -7转录，表明阿坝参与了冷诱导的镰形藻MfPIP 2 -7转录。过量表达MfPIP 2 -7导致转基因烟草（Nicotiana tabacum L.）对冷冻、低温和NO3−缺乏的耐受性增强。植物与野生型相比。此外，MfPIP 2 -7被证明促进H2 O2在酵母中的扩散。与依赖H2 O2的野生型相比，在转基因植株中观察到一些胁迫响应基因如NtERD 10 B、NtERD 10 C、NtDREB 1和2以及硝酸还原酶（NR）编码基因（NtNIA 1和NtNIA 2）的较高转录水平。此外，转基因植株中NR活性增加，导致游离氨基酸组分和浓度的改变。结果表明，MfPIP 2 -7通过促进H2 O2扩散，进而上调NIA和多个胁迫响应基因的表达，在植物对冷冻、低温和NO3−缺乏的耐受性中起重要作用。本文的在线版本（doi：10.1186/s12870-016-0814-4）包含补充材料，可供授权用户使用。
Plasma membrane intrinsic proteins (PIPs), which belong to aquaporins (AQPs) superfamily, are subdivided into two groups, PIP1 and PIP2, based on sequence similarity. Several PIP2s function as water channels, while PIP1s have low or no water channel activity, but have a role in water permeability through interacting with PIP2. A cold responsive PIP2 named as MfPIP2-7 was isolated from Medicago falcata (hereafter falcata), a forage legume with great cold tolerance, and transgenic tobacco plants overexpressing MfPIP2-7 were analyzed in tolerance to multiple stresses including freezing, chilling, and nitrate reduction in this study. MfPIP2-7 transcript was induced by 4 to 12 h of cold treatment and 2 h of abscisic acid (ABA) treatment. Pretreatment with inhibitor of ABA synthesis blocked the cold induced MfPIP2-7 transcript, indicating that ABA was involved in cold induced transcription of MfPIP2-7 in falcata. Overexpression of MfPIP2-7 resulted in enhanced tolerance to freezing, chilling and NO3− deficiency in transgenic tobacco (Nicotiana tabacum L.) plants as compared with the wild type. Moreover, MfPIP2-7 was demonstrated to facilitate H2O2 diffusion in yeast. Higher transcript levels of several stress responsive genes, such as NtERD10B, NtERD10C, NtDREB1, and 2, and nitrate reductase (NR) encoding genes (NtNIA1, and NtNIA2) were observed in transgenic plants as compared with the wild type with dependence upon H2O2. In addition, NR activity was increased in transgenic plants, which led to alterations in free amino acid components and concentrations. The results suggest that MfPIP2-7 plays an important role in plant tolerance to freezing, chilling, and NO3− deficiency by promoted H2O2 diffusion that in turn up-regulates expression of NIAs and multiple stress responsive genes. The online version of this article (doi:10.1186/s12870-016-0814-4) contains supplementary material, which is available to authorized users.