橡胶草MADS-box转录因子基因TkSOC1-1克隆与表达模式分析

Cloning and Expression Analysis of MADS-box Transcription Factor Gene TkSOC1-1 from Taraxacum kok-saghyz Rodin

为了解析MADS-box转录因子在调控橡胶草生长发育中的功能,从橡胶草种质20112中克隆TkSOC1-1基因,其ORF全长660 bp,编码219个氨基酸。蛋白结构特征分析结果表明,TkSOC1-1蛋白具有MADS-box家族特有的保守结构域。不同物种SOC1同源蛋白的亲缘关系分析结果显示,TkSOC1-1与莴苣Ls SOC1-1亲缘关系最近,其蛋白序列间的一致性达到87.67%。亚细胞定位结果表明,TkSOC1-1定位在细胞核中。进一步采用RT-qPCR技术分析基因的表达模式,结果表明,TkSOC1-1在橡胶草的不同组织均有表达,其中在根中表达量最高。在Na Cl高盐胁迫处理下,Tk SOC1-1显著上调表达,而在PEG-4000模拟的干旱胁迫处理下,TkSOC1-1则呈现明显下调表达。在外施植物激素茉莉酸甲酯和乙烯利条件下,TkSOC1-1转录水平显著提高,均在处理后6 h达到最高值,分别是未处理的64.4倍和10.7倍;而外施脱落酸之后,TkSOC1-1表达水平则显著下降。研究结果表明,Tk SOC1-1参与橡胶草对胁迫响应以及激素信号传导过程,但应对不同胁迫以及不同激素的响应机制不同。本研究为揭示TkSOC1-1基因在橡胶草生长发育和逆境响应中的功能提供了依据。

In order to analyze the function of the MADS-box transcription factor in the growth and development of Taraxacum kok-saghyz Rodin,TkSOC1-1 was cloned from the line of 20112 in Taraxacum kok-saghyz Rodin.The total length of its ORF was 660 bp,encoding 219 amino acids.The results of protein structural characterization analysis showed that TKSOC1-1 had a unique conserved domain of MADS-box family.Phylogenetic analysis of SOC1 homologous proteins from different species indicated that TkSOC1-1 showed the closest relative to lettuce LsSOC1-1,with 87.67%identity between their protein sequences.Subcellular localization analysis showed that TKSOC1-1 was localized to the nucleus.Furtherly,the gene expression pattern was analyzed by RT-qPCR,and the results showed that TkSOC1-1 was expressed in different tissues of Taraxacum kok-saghyz Rodin,and the highest expression level was found in the root.TkSOC1-1 expression was significantly up-regulated under salt stress treated by NaCl,while it was significantly down-regulated under drought stress treatment simulated by PEG-4000.The transcript level of TkSOC1-1 was distinctly increased after exogenous methyl jasmonate and ethephon treatments,both reaching the highest value at 6 h after treatment,which were 64.4 and 10.7 times higher than those without treatment,respectively.However,the expression level of TkSOC1-1 was significantly decreased after treated by exogenous abscisic acid.The results showed that TkSOC1-1 was involved in the response process to stress as well as hormone signaling in Taraxacum kok-saghyz Rodin,but the mechanisms were different in response to different stresses and different hormones.This study provided a basis for studying the role of TkSOC1-1 in the growth and development,and stress response in Taraxacum kok-saghyz Rodin.