• ISSN 1008-505X
  • CN 11-3996/S
师新新, 张佳祺, 张雨萌, 王妮, 马金荣, 肖凯. 小麦钾离子通道蛋白基因TaPC1介导植株抵御低钾逆境功能研究[J]. 植物营养与肥料学报, 2020, 26(5): 840-849. DOI: 10.11674/zwyf.19381
引用本文: 师新新, 张佳祺, 张雨萌, 王妮, 马金荣, 肖凯. 小麦钾离子通道蛋白基因TaPC1介导植株抵御低钾逆境功能研究[J]. 植物营养与肥料学报, 2020, 26(5): 840-849. DOI: 10.11674/zwyf.19381
SHI Xin-xin, ZHANG Jia-qi, ZHANG Yu-meng, WANG Ni, MA Jin-rong, XIAO Kai. Functional characterization on the wheat potassium channel gene TaPC1 in mediating plant adaptation to potassium deprivation[J]. Journal of Plant Nutrition and Fertilizers, 2020, 26(5): 840-849. DOI: 10.11674/zwyf.19381
Citation: SHI Xin-xin, ZHANG Jia-qi, ZHANG Yu-meng, WANG Ni, MA Jin-rong, XIAO Kai. Functional characterization on the wheat potassium channel gene TaPC1 in mediating plant adaptation to potassium deprivation[J]. Journal of Plant Nutrition and Fertilizers, 2020, 26(5): 840-849. DOI: 10.11674/zwyf.19381

小麦钾离子通道蛋白基因TaPC1介导植株抵御低钾逆境功能研究

Functional characterization on the wheat potassium channel gene TaPC1 in mediating plant adaptation to potassium deprivation

  • 摘要:
    目的 钾离子通道 (potassium channel, PC) 蛋白通过介导离子跨膜转运,增强低钾胁迫下植株对钾素的吸收和利用能力。本研究以采用RNAseq鉴定小麦应答低钾基因获得的PC家族基因TaPC1为对象,对该基因分子特征、应答低钾表达模式及其介导植株抵御低钾逆境的能力进行研究。
    方法 采用生物信息学工具分析TaPC1分子特征,采用溶液培养法培养丰钾 (K2O 6 mmol/L )、低钾 (K2O 0.06 mmol/L) 处理小麦和转化株系幼苗,采用 DNA 重组技术构建TaPC1亚细胞定位和表达质粒,利用农杆菌介导法遗传转化烟草。采用常规植株形态、生理和qPCR方法测定植株生长、生理指标和基因表达。
    结果 TaPC1与植物种属PC家族基因具有较高的同源性,该基因编码蛋白具有植物种属PC蛋白跨膜域保守特征,翻译蛋白经内质网分选后定位于细胞质膜。低钾 (0.06 mmol/L) 处理下,根、叶中TaPC1表达增强;将低钾处理植株转入丰钾 (6 mmol/L) 营养液进行恢复处理后,根、叶中该基因表达下调,表明TaPC1呈低钾应答表达模式。基因遗传转化结果表明,与野生型 (WT) 对照相比,低钾处理下,超表达TaPC1烟草株系植株干物质积累量增多,细胞活性氧累积量减少,细胞保护酶 (SOD、CAT和POD) 活性提高,丙二醛含量降低。基因表达分析表明,低钾处理下,转化株系内细胞保护酶编码基因NtSOD1NtCAT1;1NtPOD1;2NtPOD1;6的转录本丰度较野生型 (WT) 显著增多,表明上述基因通过增强表达,在改善转化株系低钾处理下细胞活性氧稳态中发挥重要作用。此外,与WT相比,低钾处理下转化株系的钾累积量显著增多,光合碳同化能力增强。
    结论 TaPC1呈低钾胁迫增强表达模式,上调表达该基因能显著增强植株钾素吸收,有效维持低钾逆境下的细胞活性氧稳态特征,在改善植株光合物质生产和抵御低钾逆境能力中发挥重要作用。

     

    Abstract:
    Objectives Potassium channel (PC) proteins mediate the transportation of potassium ion (K+) across the cellular membranes and play critical roles in improving plant uptake and utilization of potassium under the potassium starvation stress. In this study, we characterized the molecular characterization, expression patterns and function of TaPC1, a differentially expressed gene under low-K stress identified by our previous RNAseq analysis.
    Methods Using bioinformatic tools analyzed the molecular property of TaPC1. Adopting hydroponic culture solutions supplemented with sufficient K (6 mmol/L K2O) and deficient K (0.06 mmol/L K2O) grew the plants of wheat and transgenic lines. Utilizing DNA recombinant approach constructed the expression plasmids for subcellular location and overexpression of TaPC1. Using genetic transformation approach mediated by Agobacterium tumefaciens transforms leaf discs of tobacco. Adopting conventional phenotypic, physiological and qPCR methods studied the plant growth traits, physiological traits and gene expression patterns.
    Results TaPC1 shared high similarities to its plant homologous genes. The protein translated by TaPC1 possessed the conserved transmembrane domains shared by PC proteins and targets to cytoplasm membrane after endoplasmic reticulum (ER) sorted. Under K-deficient treatment, the expression of TaPC1 was upregulated in both roots and leaves. Moreover, its induced transcripts in above tissues were gradually reduced following the sufficient-K recovery treatment (6 mmol/L K2O), suggesting that it responds to the modified external K levels at transcriptional level. Compared with wild type (WT), the tobacco lines with TaPC1 overexpression were shown to be improved on plant biomass production and cellular antioxidant enzymatic (SOD, CAT and POD) activities and reduced on malondialdehyde (MDA) contents. Expression analysis on the genes encoding antioxidant enzymes revealed that a suite of them, including, NtSOD1, NtCAT1;1, NtPOD1;2 and NtPOD1;6, were upregulated on transcripts in the K-deprived transgenic lines with respect to the WT plants challenged by K deprivation, which suggested the involvement of these genes in mediating reactive oxygen species homeostasis in the K-deficient plants. In addition, the transgenic lines displayed much more accumulated potassium in plants and more improved photosynthetic function than WT under K-deficient treatment.
    Conclusions Our investigation indicated that TaPC1 is K starvation-response in expression, whose overexpression confers plants improved K accumulation and cellular ROS homeostasis. Thus, TaPC1 plays critical roles in positively regulating the biomass production and mediating the low-K tolerance of plants.

     

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