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草业学报 ›› 2022, Vol. 31 ›› Issue (1): 118-130.DOI: 10.11686/cyxb2021189

• 研究论文 • 上一篇    

全基因组水平紫花苜蓿TCP基因家族的鉴定及其在干旱胁迫下表达模式分析

魏娜(), 李艳鹏, 马艺桐, 刘文献()   

  1. 兰州大学草地农业生态系统国家重点实验室,兰州大学农业农村部草牧业创新重点实验室,兰州大学草地农业教育部工程研究中心,兰州大学草地农业科技学院,甘肃 兰州 730020
  • 收稿日期:2021-05-07 修回日期:2021-07-07 出版日期:2021-12-01 发布日期:2021-12-01
  • 通讯作者: 刘文献
  • 作者简介:Corresponding author. E-mail: liuwx@lzu.edu.cn
    魏娜(1999-),女,甘肃白银人,在读硕士。E-mail: wein20@lzu.edu.cn
  • 基金资助:
    甘肃省教育厅优秀研究生“创新之星”项目(2021CXZX-139);兰州大学中央高校基本科研业务费专项资金(lzujbky-2021-it05)

Genome-wide identification of the alfalfa TCP gene family and analysis of gene transcription patterns in alfalfa (Medicago sativa) under drought stress

Na WEI(), Yan-peng LI, Yi-tong MA, Wen-xian LIU()   

  1. State Key Laboratory of Grassland Argo-ecosystems,Key Laboratory of Grassland Livestock Industry Innovation,Ministry of Agriculture and Rural Affairs,Engineering Research Center of Grassland Industry,Ministry of Education,College of Pastoral Agriculture Science and Technology,Lanzhou University,Lanzhou 730020,China
  • Received:2021-05-07 Revised:2021-07-07 Online:2021-12-01 Published:2021-12-01
  • Contact: Wen-xian LIU

摘要:

紫花苜蓿是世界最重要的豆科牧草之一,干旱是影响其产量和地理分布的关键瓶颈。在紫花苜蓿响应干旱胁迫过程中,转录因子发挥着重要的调控作用。TCP(teosinte branchesd 1/cycloidea/pro-liferating cell factors)为植物特有的转录因子,在植物生长、发育、响应逆境胁迫中都具有重要的生物学功能。截至目前,该基因家族在紫花苜蓿中的分布以及响应干旱胁迫的生物学功能仍未见报道。因此,为进一步挖掘紫花苜蓿中响应干旱胁迫功能基因,本研究利用生物信息学方法在全基因组水平对TCP基因家族进行了鉴定,并对其系统进化、基因结构、染色体定位、共线性分析以及干旱胁迫下的表达模式进行了分析。结果表明,紫花苜蓿基因组中共鉴定出40个MsTCP基因,不均匀地分布于20条染色体上,其中包括17对旁系同源基因对,且都是基因片段复制事件。系统发育和保守结构域分析发现,MsTCP基因可以分为2个大分支和3个亚家族(PCF, CIN与CYC/TB1),同一分支中的成员具有相同氨基酸数目的TCP结构域,同亚家族中的成员具有相似的保守基序与基因结构。此外,通过分析紫花苜蓿响应干旱转录组数据共鉴定出4个可能与紫花苜蓿响应干旱胁迫有关的MsTCP基因(MsTCP23MsTCP27MsTCP29MsTCP33)。qRT-PCR结果进一步表明PEG模拟干旱胁迫处理后,这4个基因的表达量在根和叶中均显著上调,进一步确定了这些基因的确响应紫花苜蓿干旱胁迫。该研究为后期深入解析紫花苜蓿响应干旱胁迫理论以及通过基因工程技术创制高抗旱紫花苜蓿新种质奠定基础。

关键词: 紫花苜蓿, 系统发育分析, 干旱胁迫, 基因表达分析

Abstract:

Alfalfa (Medicago sativa) is the most important legume forage in the world. However, its yield and geographical distribution are often influenced by drought. Transcription factors play important regulatory roles in alfalfa’s response to drought stress. Teosinte branched 1/cycloidea/pro-liferating cell factors (TCP) is a plant-specific transcription factor with important functions in plant growth, development, and stress resistance. However, its distribution and potential function in the response to drought stress have not been reported. To explore the responses of functional genes to drought stress in alfalfa, we identified members of the TCP gene family in alfalfa using bioinformatic methods. Further analyses were conducted to clarify the phylogeny and determine their gene structure, chromosome location, collinearity, and transcriptional patterns under drought stress. Our analyses identified 40 MsTCP genes that were unevenly distributed among the 20 chromosomes in the alfalfa genome. Among the MsTCP genes, 17 pairs were paralogous genes arising from gene fragment replication events. In a phylogenetic analysis, MsTCP genes formed two large branches and clustered into three subfamilies (PCF, CIN, and CYC/TB1). Conserved domain analyses revealed that members in the same branch of the phylogenetic tree contain TCP domains with the same number of amino acids, and that the members of the same subfamily have similar conserved motifs and gene structures. Analyses of transcriptome data from alfalfa under drought stress revealed four MsTCP genes (MsTCP23MsTCP27MsTCP29, and MsTCP33) that may be involved in the drought response. The results of qRT-PCR analyses confirmed that these four genes were significantly up-regulated in roots and leaves of plants under a simulated drought (polyethylene glycol) treatment, providing further evidence that they participate in the drought response. These results lay the foundation for further research on the response to drought stress in alfalfa, and will be useful for generating new varieties of drought-resistant alfalfa using genetic engineering technology.

Key words: alfalfa, phylogenetic analysis, drought stress, gene expression analysis