MYB transcription factors represent a family of genes that include the conserved MYB DNA-binding domain,and they are widely involved in the regulation of plant development and secondary metabolism.In this study,Part o...MYB transcription factors represent a family of genes that include the conserved MYB DNA-binding domain,and they are widely involved in the regulation of plant development and secondary metabolism.In this study,Part of sequences of two MYB transcription factors was determined through the cDNA microarray hybridization and selection of cDNA library derived from tender shoots.The full-length cDNAs of the genes were obtained with RT-PCR and RACE,and they were 1 132 bp and 1 020 bp,named as CsMYB1 and CsMYB2 (GenBank accession No.HQ660373 and HQ660374), and contained ORFs of 879 bp and 675 bp encoding 292 and 224 amino acids,respectively.Sequences analysis showed that the deduced protein molecular weight of the two genes were 32.9 ku and 25.4 ku, and the proteins contained two conserved MYB domains near the N-terminus and a conserved C1 motif near the R3 domains.The deduced amino acid sequence of CsMYB1 and CsMYB2 from tea plant showed high identity with that of other plants,for instance CsMYB1 shared 57%homology with MYB1 of Gossypium hirsutum and CsMYB2 shared 75% homology with MYBC2 of Vitis vinifera.The result of real time-PCR analysis showed the two genes were expressed constitutively in all tissues with different expression levels,e.g.the relative expression level of CsMYB2 in leaf was hundred times higher than that in root.Additionally,shading enhanced CsMYB1 expression,while the treatment did not alter the expression level of CsMYB2.展开更多
Myeloblastosis(MYB)类转录因子是高等植物中最大的转录因子家族之一,在植物发育及防御反应过程中发挥重要作用,还参与植物对干旱等非生物胁迫的响应。谷子(Setaria italica L.)起源于中国,具有抗旱、耐瘠薄的特性,是研究单子叶作物非...Myeloblastosis(MYB)类转录因子是高等植物中最大的转录因子家族之一,在植物发育及防御反应过程中发挥重要作用,还参与植物对干旱等非生物胁迫的响应。谷子(Setaria italica L.)起源于中国,具有抗旱、耐瘠薄的特性,是研究单子叶作物非生物胁迫抗性的理想材料。本研究对耐低氮胁迫谷子品种郑204经低氮处理后进行转录组分析,鉴定出一个在低氮胁迫条件下明显上调的MYB类转录因子SiMYB42。系统发育树结果表明,SiMYB42属于R2R3-MYB亚族,具有2个MYB保守域;表达模式分析显示,SiMYB42在低氮、高盐、干旱和ABA胁迫条件下表达量显著上调;亚细胞定位、quantitative real-time PCR及转录激活活性分析结果表明,SiMYB42蛋白定位于植物的细胞核和细胞膜中,主要在谷子的叶部或根部表达,具有转录激活活性;基因功能分析结果表明,在正常条件下,转SiMYB42基因拟南芥与野生型Columbia-0拟南芥(WT)无明显差异,但在低氮条件下,转SiMYB42基因拟南芥的主根长、根系表面积及鲜重均显著高于WT,结果证明SiMYB42基因可以提高转基因植物对低氮胁迫的耐性;下游基因表达分析结果显示,在转SiMYB42基因拟南芥中,参与植物氮素转运的硝酸盐转运基因NRT2.1、NRT2.4和NRT2.5的表达水平均高于WT,启动子分析结果显示NRT2.1、NRT2.4和NRT2.5基因启动子序列中均具有MYB结合位点。以上结果证明,SiMYB42可以通过调控下游硝酸盐转运体基因的表达提高植物在低氮条件下的耐性。本研究揭示了SiMYB42基因在低氮胁迫反应途径中的作用,为进一步了解谷子低氮胁迫响应的调控网络奠定了基础。展开更多
文摘MYB transcription factors represent a family of genes that include the conserved MYB DNA-binding domain,and they are widely involved in the regulation of plant development and secondary metabolism.In this study,Part of sequences of two MYB transcription factors was determined through the cDNA microarray hybridization and selection of cDNA library derived from tender shoots.The full-length cDNAs of the genes were obtained with RT-PCR and RACE,and they were 1 132 bp and 1 020 bp,named as CsMYB1 and CsMYB2 (GenBank accession No.HQ660373 and HQ660374), and contained ORFs of 879 bp and 675 bp encoding 292 and 224 amino acids,respectively.Sequences analysis showed that the deduced protein molecular weight of the two genes were 32.9 ku and 25.4 ku, and the proteins contained two conserved MYB domains near the N-terminus and a conserved C1 motif near the R3 domains.The deduced amino acid sequence of CsMYB1 and CsMYB2 from tea plant showed high identity with that of other plants,for instance CsMYB1 shared 57%homology with MYB1 of Gossypium hirsutum and CsMYB2 shared 75% homology with MYBC2 of Vitis vinifera.The result of real time-PCR analysis showed the two genes were expressed constitutively in all tissues with different expression levels,e.g.the relative expression level of CsMYB2 in leaf was hundred times higher than that in root.Additionally,shading enhanced CsMYB1 expression,while the treatment did not alter the expression level of CsMYB2.
文摘Myeloblastosis(MYB)类转录因子是高等植物中最大的转录因子家族之一,在植物发育及防御反应过程中发挥重要作用,还参与植物对干旱等非生物胁迫的响应。谷子(Setaria italica L.)起源于中国,具有抗旱、耐瘠薄的特性,是研究单子叶作物非生物胁迫抗性的理想材料。本研究对耐低氮胁迫谷子品种郑204经低氮处理后进行转录组分析,鉴定出一个在低氮胁迫条件下明显上调的MYB类转录因子SiMYB42。系统发育树结果表明,SiMYB42属于R2R3-MYB亚族,具有2个MYB保守域;表达模式分析显示,SiMYB42在低氮、高盐、干旱和ABA胁迫条件下表达量显著上调;亚细胞定位、quantitative real-time PCR及转录激活活性分析结果表明,SiMYB42蛋白定位于植物的细胞核和细胞膜中,主要在谷子的叶部或根部表达,具有转录激活活性;基因功能分析结果表明,在正常条件下,转SiMYB42基因拟南芥与野生型Columbia-0拟南芥(WT)无明显差异,但在低氮条件下,转SiMYB42基因拟南芥的主根长、根系表面积及鲜重均显著高于WT,结果证明SiMYB42基因可以提高转基因植物对低氮胁迫的耐性;下游基因表达分析结果显示,在转SiMYB42基因拟南芥中,参与植物氮素转运的硝酸盐转运基因NRT2.1、NRT2.4和NRT2.5的表达水平均高于WT,启动子分析结果显示NRT2.1、NRT2.4和NRT2.5基因启动子序列中均具有MYB结合位点。以上结果证明,SiMYB42可以通过调控下游硝酸盐转运体基因的表达提高植物在低氮条件下的耐性。本研究揭示了SiMYB42基因在低氮胁迫反应途径中的作用,为进一步了解谷子低氮胁迫响应的调控网络奠定了基础。
