中国农业科学 ›› 2016, Vol. 49 ›› Issue (2): 381-390.doi: 10.3864/j.issn.0578-1752.2016.02.018

• 研究简报 • 上一篇    下一篇

枳NLP转录因子克隆及其在不同水分条件下的表达

曹雄军1,2,卢晓鹏1,熊江1,李静1,吴倩1,周芳芳1,谢深喜1   

  1. 1湖南农业大学园艺园林学院/国家柑橘改良中心长沙分中心/湖南省作物种质创新与资源利用重点实验室,长沙 410128
    2广西农业科学院葡萄与葡萄酒研究所,南宁530007
  • 收稿日期:2015-07-09 出版日期:2016-01-16 发布日期:2016-01-16
  • 通讯作者: 谢深喜,E-mail:shenxixie@163.com
  • 作者简介:曹雄军,E-mail:cxj4310@126.com
  • 基金资助:
    国家现代农业(柑橘)产业技术体系(CARS-027)、湖南省科技计划项目(2014NK3003)、湖南省研究生科研创新项目(CX2013B289)

Cloning and Expression of Poncirus Trifoliata (L.) Raf. NIN- Like Transcription Factors under Different Water Conditions

CAO Xiong-jun1,2, LU Xiao-peng1, XIONG Jiang1, LI Jing1, WU Qian1, ZHOU Fang-fang1, XIE Shen-xi1   

  1. 1College of Horticulture and Landscape, Hunan Agricultural University/National Center for Citrus Improvement (Changsha)/Hunan Provincial Key Laboratory of Crop Germplasm Innovation and Utilization, Changsha 410128
    2Grape and Wine Research Institute, Guangxi Academy of Agricultural Science, Nanning 530007
  • Received:2015-07-09 Online:2016-01-16 Published:2016-01-16

摘要: 【目的】分析柑橘砧木枳(Poncirus trifoliata (L.) Raf.)参与氮素吸收与同化的重要转录因子NLP在干旱胁迫下的表达模式,为柑橘在干旱胁迫条件下对氮素吸收与同化的调控机理提供研究参考。【方法】以柑橘砧木枳为试验材料,在甜橙(Citrus sinensis (L.) Osb.)基因组数据库的基础上,利用生物信息学筛选获得甜橙NLP,并以此设计引物扩增枳NLP的CDS全长并测序。利用ClustalX和MEGA程序进行序列比对和系统发育分析,利用实时荧光定量PCR技术分析不同水分条件下的枳NLP的表达模式。【结果】筛选并克隆获得了4条枳NLP序列,为PtNLP2PtNLP4PtNLP7PtNLP8。序列比对分析表明枳NLP之间的蛋白质序列一致性为45.13%,均具有明显的RWP-RK和PB1结构域。枳与甜橙的NLP蛋白质序列的一致性极高,分别为97.57%、96.47%、99.0%及97.33%。系统发育分析表明枳NLP可分为4个进化类型,与拟南芥的NLP分类一致,即PtNLP2AtNLP1/2一类,PtNLP4AtNLP4/5一类,PtNLP7AtNLP6/7一类,PtNLP8AtNLP8/9一类。在不同水分条件下,枳NLP的表达模式在叶与根中存在差异。随着基质水分含量的减少,枳叶NLP呈现先上升再下降的趋势。与对照(相对持水量为61.0%)相比,叶PtNLP2PtNLP4PtNLP7PtNLP8的表达量在相对持水量为15.4%时上调至最高水平,分别上调了2.9、3.5、5.9及2.8倍,之后持续下调;到相对持水量为9.4%时,其表达水平低于对照但无显著差异。而枳根NLP的表达量在对照中最高,后随着水分的散失呈总体下降趋势且差异显著,与对照相比,根PtNLP2PtNLP4PtNLP7PtNLP8的最大下调倍数分别为6.7、2.8、4.8及2.3。复水后,枳叶与根NLP的表达量低于复水前,且与对照差异显著。【结论】枳NLP的表达与土壤的水分条件密切相关。枳叶片NLP的表达水平在干旱胁迫前、中期上调,后期下调;而枳根NLP的表达水平在干旱胁迫下持续下调。其中,PtNLP2PtNLP7的表达量在枳根响应干旱胁迫中变化较大。

关键词: 枳, NLP转录因子, 氮, 干旱胁迫, 基因表达

Abstract: 【Objective】The objective of this study was to analyze the expression of Poncirus trifoliata (L.) Raf. NIN-like transcription factors to discuss the regulation mechanism of nitrogen assimilation under different water conditions in citrus.【Method】 Primers were designed to amplify the sequences of the NLP genes CDS of Poncirus trifoliate (L.) Raf.based on orange genome databases and molecular biology. Alignment of the sequences was performed using ClustalX and phylogenetic analysis of this alignment was conducted using MEGA. Analysis of the Relative NLP genes expression data under different water conditions using Real-Time Quantitative PCR.【Result】Four Poncirus trifoliata (L.) Raf. NLP genes: PtNLP2, PtNLP4, PtNLP7 and PtNLP8 were obtained. The sequence alignment analysis showed that the identity of all NIN-like proteins was 45.13%, and possessed both the RWP-RK and PB1 domain, and all NIN-like proteins were high identity to sweet orange, respectively 97.57%, 96.47%, 99% and 97.33%. Phylogenic analysis has indicated that the 4 Poncirus trifoliata (L.) Raf. NLP genes can be classified into four groups with Arabidopsis (PtNLP2 and AtNLP1/2, PtNLP4 and AtNLP4/5, PtNLP7 and AtNLP6/7, PtNLP8 and AtNLP8/9). There were differences in the expression pattern of NLP genes in Poncirus trifoliata (L.) Raf. leaves and roots. The results indicated that with the decrease of soil water, the expression level of NLP genes in Poncirus trifoliata (L.) Raf. leaves were up-regulated. The PtNLP2, PtNLP4, PtNLP7 and PtNLP8 expression level were the highest when the relative water capacity was 15.4%, they were 2.9, 3.5, 5.9 and 2.8 folds higher respectively compared to the control (the relative water holding capacity was 61.0%). After that, the gene expression level began to down-regulate and had no statistically significant difference between the control and the relative water holding capacity of 9.4%. While the expression level of NLP genes in Poncirus trifoliata (L.) Raf. roots of control were the highest, and the gene expression pattern showed a down-regulated trend accompanied by the loss of soil water and the difference was statistically significant. The PtNLP2, PtNLP4, PtNLP7 and PtNLP8 expression level of roots were maximum down-regulated by 6.7, 2.8, 4.8 and 2.3 folds respectively compared with the control. The expression of NLP genes in Poncirus trifoliata (L.) Raf. leaves and roots remained at the low expression level after rewatering and had statistically significant difference compared with the control.【Conclusion】The expression of Poncirus trifoliata (L.) Raf. NLP genes is closely related to the water condition of soil. The expression level of NLP genes in Poncirus trifoliata (L.) Raf. leaves were up-regulated by drought stress, and then down-regulated when the water deficit was very serious. But the expression level of NLP genes in Poncirus trifoliata (L.) Raf. roots were down-regulated continuously accompanied by the loss of soil water, and expression of the PtNLP2 and PtNLP7 had a great change in roots.

Key words: Poncirus trifoliata (L.) Raf., NLP transcription factors, nitrogen, drought stress, gene expression