5个大豆AT-hook基因GmAHLs的克隆与定位分析

Cloning and localization analysis on five AT-hook genes GmAHLs from Glycine max

从大豆[Glycine max(Linn.)Merr.]中克隆出5个AT-hook基因,分别命名为GmAHL1、GmAHL2、GmAHL3、GmAHL4和GmAHL5,其中,GmAHL5为GmAHL1的重复基因。序列分析结果表明:5个GmAHLs蛋白的AT-hook基序分别位于其氨基酸序列的42~54、39~51、42~54、41~53及42~54处,且GmAHL1和GmAHL5蛋白的氨基酸序列相同。大豆GmAHLs蛋白和野大豆(G.soja Sieb.et Zucc.)Gs AHLs蛋白与其他植物H1组蛋白的亲缘关系较远,说明GmAHLs蛋白不属于H1组蛋白。GmAHL1基因在所有检测的组织中均不表达;GmAHL2基因主要在花、种子、叶片和根中表达;GmAHL3基因主要在花、叶片、茎和根尖分生组织中表达,在果荚中不表达,但在根瘤中有表达;GmAHL4基因在根瘤中高度表达,在根、茎端分生组织、茎和果荚中也有较高表达;GmAHL5基因主要在叶片、种子、根尖分生组织和花中表达。GmAHL2基因在根中的表达受氨的诱导,GmAHL3基因在根中的表达受硝酸盐、尿素和根瘤菌的抑制。亚细胞定位分析结果表明:大豆GmAHLs蛋白定位于细胞核。研究结果显示:大豆GmAHLs基因均非组成型表达基因,其中GmAHL2、GmAHL3和GmAHL4基因的表达具有特异性,且可被外源氮素和根瘤菌处理诱导或抑制。

Five AT-hook genes were cloned from Glycine max( Linn.) Merr.,which were named as GmAHL1,GmAHL2,GmAHL3,GmAHL4,and GmAHL5,respectively,in which,GmAHL5 is duplicated gene of GmAHL1. The sequence analysis result shows that AT-hook motifs of five GmAHLs proteins are located in their amino acid sequences of 42-54,39-51,42-54,41-53,and 42-54,respectively,and GmAHL1 and GmAHL5 proteins share the same amino acid sequence. There is a distant relationship between GmAHLs proteins from G. max and Gs AHLs proteins from G. soja Sieb. et Zucc. with H1 histones from other species,meaning that GmAHLs proteins do not belong to H1 histones. GmAHL1 gene doesn't express in all tissues tested; GmAHL2 gene mainly expresses in flower,seed,leaf,and root;GmAHL3 gene mainly expresses in flower,leaf,stem,and root tip meristem,does not in pod,but does in root nodule; GmAHL4 gene highly expresses in root nodule,and also relatively highly does in root,shoot apical meristem,stem,and pod; GmAHL5 gene mainly expresses in leaf,seed,root tip meristem,and flower. Expression of GmAHL2 gene in root is induced by ammonia,while that of GmAHL3 gene in root is inhibited by nitrate,urea,and rhizobia. The subcellular location analysis result shows that GmAHLs proteins from G. max are located in cell nucleus. It is suggested that GmAHLs genes from G.max are nonconstitutive expression genes,in which,expressions of GmAHL2,GmAHL3,and GmAHL4 genes have specificity and can be induced or suppressed by exogenous nitrogen and rhizobia.