转桑树MAPK5基因拟南芥在不同逆境胁迫下的抗性分析

发布时间：2018-01-22 04:43

  本文关键词： 桑树 MAPK 非生物胁迫 胁迫响应 启动子　出处：《林业科学》2017年09期 　论文类型：期刊论文

【摘要】：【目的】植物促分裂原活化蛋白激酶(MAPK)在响应生物与非生物胁迫中发挥重要作用。本研究通过分析桑树(川桑)B家族MAPK基因MnMAPK5的亚细胞定位和启动子活性,并将其转入拟南芥中进行过表达研究,探讨MnMAPK5在逆境胁迫下的作用机制。【方法】将MnMAPK5的上游启动子连接到p BI121载体上,通过花粉介导法转入拟南芥中,经高温、低温、NaCl和PEG处理后进行GUS染色分析。通过构建过表达载体,将MnMAPK5转化到拟南芥中,用T3转基因植株进行抗逆境胁迫分析。【结果】MnMAPK5基因的编码蛋白定位于细胞质和细胞核中。在拟南芥中检测MnMAPK5启动子驱动的GUS活性的结果显示,MnMAPK5启动子活性受到了高温、低温、高盐和干旱胁迫的诱导。在高盐、干旱、低温和H_2O_2处理条件下,过表达MnMAPK5抑制了转基因拟南芥的萌发和生长。在盐胁迫下,过表达MnMAPK5提高了转基因植株中的MDA含量和POD活性,降低了CAT活性、可溶性糖含量和H_2O_2含量;在干旱胁迫下,过表达MnMAPK5提高了转基因拟南芥中的MDA和H_2O_2含量,降低了CAT和POD活性;在低温下,转基因拟南芥相比野生型植株表现出更低的CAT活性、POD活性、脯氨酸含量和可溶性糖含量;在氧化环境胁迫下,转基因拟南芥的MDA含量显著高于野生型拟南芥,而脯氨酸含量和可溶性糖含量要低。此外,在各个胁迫环境条件下,AtPOD、AtCAT和AtRD22等胁迫相关基因的表达量在转基因植株低于野生型拟南芥。【结论】MnMAPK5启动子在转基因拟南芥中的活性受到了不同非生物胁迫的诱导。过量表达MnMAPK5降低了拟南芥对非生物胁迫的抵抗能力,表明MnMAPK5在逆境胁迫下起着负调控作用。
[Abstract]:[objective] Plant mitogen-activated protein kinase (MAPK) plays an important role in response to biotic and abiotic stress. Subcellular localization and promoter activity of B family MAPK gene MnMAPK5. It was transferred into Arabidopsis thaliana to investigate the mechanism of MnMAPK5 under stress. [methods] the upstream promoter of MnMAPK5 was ligated to p BI121 vector. Arabidopsis thaliana was transformed into Arabidopsis thaliana by pollen-mediated method. GUS staining was carried out after high temperature, low temperature and PEG treatment. MnMAPK5 was transformed into Arabidopsis thaliana by construction of overexpression vector. T3 transgenic plants were used to analyze the stress resistance. [results] the coding protein of MnMAPK5 gene was located in cytoplasm and nucleus. Detection of gu driven by MnMAPK5 promoter in Arabidopsis thaliana. The results of S-activity showed that. The activity of MnMAPK5 promoter was induced by high temperature, low temperature, high salt and drought stress. Overexpression of MnMAPK5 inhibited the germination and growth of transgenic Arabidopsis thaliana. Under salt stress, overexpression of MnMAPK5 increased MDA content and POD activity in transgenic plants. The activity of CAT, the content of soluble sugar and the content of H _ 2O _ 2 were decreased. Under drought stress, overexpression of MnMAPK5 increased the contents of MDA and H _ 2O _ 2 and decreased the activities of CAT and POD in transgenic Arabidopsis thaliana. At low temperature, transgenic Arabidopsis thaliana showed lower CAT activity, proline content and soluble sugar content than wild-type plants. Under oxidative stress, the MDA content of transgenic Arabidopsis thaliana was significantly higher than that of wild type Arabidopsis thaliana, while the content of proline and soluble sugar was lower. The expression of stress related genes such as AtCAT and AtRD22 in transgenic plants was lower than that in wild type Arabidopsis thaliana. [conclusion] the activity of MnMAPK5 promoter in transgenic Arabidopsis thaliana was different from that in transgenic Arabidopsis. Overexpression of MnMAPK5 reduced the resistance of Arabidopsis thaliana to abiotic stress. The results suggest that MnMAPK5 plays a negative regulatory role under stress.
【作者单位】： 西南大学家蚕基因组生物学国家重点实验室农业部蚕桑生物学与遗传育种重点实验室;
【基金】：国家现代农业产业技术体系建设专项(CARS-18-ZJ0201) 国家农业部公益性行业(农业)科研专项(201403064)
【分类号】：Q943.2
【正文快照】： 促分裂原活化蛋白激酶(mitogen-activatedprotein kinases,MAPK)在植物响应逆境胁迫中发挥着重要的作用,可将细胞外的信号转入胞内,影响其下游基因的表达,从而调节生物体内各种生理反应,响应外界环境。植物中的MAPK基因最早在紫花苜蓿(Medicago sativa)中被鉴定,此后陆续在拟，

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