多花黄精PLT基因家族的鉴定与表达分析

Identification and Expressions of PLT Family of Polygonatum cyrtonema

【目的】PLT(Plethora)属于AP2/ERF型转录因子,在植物生长发育及抗胁迫等过程中发挥重要作用。本文旨在探究多花黄精PLT(Polygonatum cyrtonema Hua PLT,PcPLT)基因在根状茎器官生长发育中及盐胁迫下的调控作用,为深入研究PcPLT基因的功能提供理论依据。【方法】基于多花黄精转录组数据库进行PcPLT基因家族鉴定及生物信息学分析,通过qRT-PCR技术检测其在多花黄精不同组织部位及不同浓度NaCl处理下的相对表达量,利用RT-PCR技术构建PcPLT2-2、PcPLT2-7基因融合表达载体,观察其荧光信号验证亚细胞定位。【结果】共鉴定获得15个PcPLT家族成员,该家族无内含子结构,蛋白编码长度为159~601个氨基酸,均为亲水蛋白;进化树分析显示PcPLT与百合科石刁柏(Asparagus officinalis L.)亲缘关系最近;亚细胞定位预测及验证结果显示PcPLT2-2定位于细胞质、细胞核中,PcPLT2-7定位于细胞核中。qRT-PCR结果显示PcPLT2-3和PcPLT2-7在根状茎中表达最高,PcPLT1-3、PcPLT1-4、PcPLT2-7响应盐胁迫调控。【结论】PcPLT不仅具有组织特异性还能提高抗逆性,提示可能作为器官发育调节因子参与多花黄精根状茎膨大的形态建成,为深入研究PLT调控植物根状茎器官生长发育的生物学功能和多花黄精遗传改良奠定基础。

【Objective】Regulatory functions of Polygonatum cyrtonema Hua PLT(PcPLT)in the growth and development of rhizomes of the plant were investigated.【Methods】Based on the P.cyrtonema transcriptome database,the identity and bioinformatics of PcPLT family were obtained.Relative expressions in tissues of the plant and that under NaCl stress were detected using the qRT-PCR technique.The fusion expression vectors of PcPLT2-2 and PcPLT2-7 were constructed,and their fluorescence signals examined to determine subcellular localization.【Results】Fifteen PcPLT family members were identified.They were hydrophilic proteins,absent of intron structure,coded 159-601 amino acids,and evolutionarily closely related to Liliaceae Asparagus officinalis L.The predicted subcellular localization of PcPLT2-2 was in cytoplasm and nucleus,while PcPLT2-7 in nucleus only.PcPLT2-3 and PcPLT2-7 mostly in the rhizomes;and PcPLT1-3,PcPLT1-4,and PcPLT2-7 responsive to salt stress.【Conclusion】PcPLT were tissue-specific and capable of enhancing the stress resistance of P.cyrtonema.They might act as an organ development regulator associated with the morphogenesis of rhizome expansion.If so,the result obtained in this study would be of value for the in-depth understanding of the biological functions of PLT.