Overexpression of a Wheat Aquaporin Gene, TdPIP2;1, Enhances Salt and Drought Tolerance in Transgenic Durum Wheat cv. Maali
Overexpression of a Wheat Aquaporin Gene, TdPIP2;1, Enhances Salt and Drought Tolerance in Transgenic Durum Wheat cv. Maali
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DOI：
10.3390/ijms20102389
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发表时间：
2019-05-02
影响因子：
5.6
通讯作者：
Masmoudi, Khaled
中科院分区：
文献类型：
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作者：
Ayadi, Malika;Brini, Faical;Masmoudi, Khaled
在这项研究中，我们产生了转基因硬粒小麦品种。 Maali 在 PrTdPIP2;1 启动子或组成型 PrCaMV35S 启动子的控制下过表达小麦质膜水通道蛋白 TdPIP2;1 基因。对小麦植株中融合体 PrTdPIP2;1::TdPIP2;1::GusA 的组织化学分析表明，在稳定转化的小麦 T3 植株的叶、茎和根中检测到了 β-葡萄糖醛酸酶 (GUS) 活性。我们的结果表明，过表达 TdPIP2;1 基因的转基因小麦品系表现出提高的发芽率和生物量产量，并在高盐和渗透胁迫条件下在芽中保留低 Na+ 和高 K+ 浓度。在一项关于盐或干旱胁迫的温室条件下的长期研究中，转基因 TdPIP2;1 品系产生了饱满的籽粒，而野生型 (WT) 植物要么在盐胁迫下在营养阶段死亡，要么在干旱胁迫下表现出籽粒灌浆急剧减少。对用融合 PrTdPIP2;1::GusA 转化的小麦植物进行实时 RT-PCR 实验，我们发现在盐和干旱胁迫下，植物根部 GusA 转录物的积累有所增加。对转基因小麦 TdPIP2;1 品系抗氧化防御系统的研究表明，这些品系比野生型植物更有效地诱导抗氧化酶过氧化氢酶 (CAT) 和超氧化物歧化酶 (SOD) 活性，这与较低的丙二醛和过氧化氢含量有关。总而言之，这些结果表明，TdPIP2;1 基因在通过降低单位叶面积蒸腾量（气孔导度）和转基因 TdPIP2;1 品系中有效的干旱和耐盐性来减少叶片水分蒸发（水损失）以应对水分亏缺方面具有很高的潜力。
In this study, we generated transgenic durum wheat cv. Maali overexpressing the wheat plasma membrane aquaporin TdPIP2;1 gene under the control of PrTdPIP2;1 promoter or under the constitutive PrCaMV35S promoter. Histochemical analysis of the fusion PrTdPIP2;1::TdPIP2;1::GusA in wheat plants showed that the -glucuronidase (GUS) activity was detected in the leaves, stems and roots of stably transformed wheat T3 plants. Our results showed that transgenic wheat lines overexpressing the TdPIP2;1 gene exhibited improved germination rates and biomass production and retained low Na+ and high K+ concentrations in their shoots under high salt and osmotic stress conditions. In a long-term study under greenhouse conditions on salt or drought stress, transgenic TdPIP2;1 lines produced filled grains, whereas wild-type (WT) plants either died at the vegetative stage under salt stress or showed drastically reduced grain filling under drought stress. Performing real time RT-PCR experiments on wheat plants transformed with the fusion PrTdPIP2;1::GusA, we showed an increase in the accumulation of GusA transcripts in the roots of plants challenged with salt and drought stress. Study of the antioxidant defence system in transgenic wheat TdPIP2;1 lines showed that these lines induced the antioxidative enzymes Catalase (CAT) and Superoxide dismutase (SOD) activities more efficiently than the WT plants, which is associated with lower malondialdehyde and hydrogen peroxide contents. Taken together, these results indicate the high potential of the TdPIP2;1 gene for reducing water evaporation from leaves (water loss) in response to water deficit through the lowering of transpiration per unit leaf area (stomatal conductance) and engineering effective drought and salt tolerance in transgenic TdPIP2;1 lines.