UGPase与USPase编码基因在滇杨正、倒扦插苗中的组织特异性表达

Tissue Specific Expression of UGPase and USPase Encoding Genes in Upright and Inverted Cuttings of Populus yunnanensis

细胞壁对植物生长发育发挥着重要调控作用,而UDPG是植物细胞壁合成的主要前体物质,主要来源于UGPase和USPase催化葡萄糖-1-P和UTP生成。利用生物信息学软件和在线网站对滇杨PyUGPase-A、PyUGPase-B和PyUSPase基因编码蛋白进行预测和分析,同时以1年生滇杨正、倒扦插苗为材料,测量其主枝长度和主枝粗度,并对3个目标基因在茎尖、嫩叶、成熟叶、茎和根中表达量进行RT-qPCR分析,探究PyUGPase和PyUSPase基因在滇杨正、倒扦插苗中的组织特异性表达规律,从而为揭示PyUGPase和PyUSPase基因调控细胞壁合成进而调控滇杨生长的机制提供依据。结果表明:PyUGPase-A、PyUGPase-B和PyUSPase基因全长和编码的氨基酸分别为1410 bp和469个氨基酸、1410 bp和469个氨基酸、1875 bp和624个氨基酸;3个蛋白均不存在信号肽和跨膜结构域,且均定位于细胞质内的一种亲水稳定性蛋白酶;PyUGPase和PyUSPase基因编码的氨基酸序列和其他植物UGPase和USPase基因编码的氨基酸序列相似性达85%以上。倒扦插苗的主枝长度和粗度均低于正扦插苗,但差异不显著。PyUGPase-A和PyUGPase-B基因在2种类型扦插苗的成熟叶中表达量相对较高,但在倒扦插苗的嫩叶中上调表达;而PyUSPase基因在正、倒扦插苗的根中表达量较高,且在5个组织中均呈现下调表达。

The plant cell wall fundamentally determines plant growth.Furthermore,UDPG is the essential precursor for cell wall biosynthesis in plant,and it is demonstrated that the pool of UDPG is mainly derived from Glu-1-P and UTP by UGPase and USPase.In this study,the PyUGPase-A,PyUGPase-B and PyUSPase of Populus yunnanensis encoding proteins were predicted and analyzed by bioinformatics tools and URL.Meanwhile,one-year-old upright and inverted cuttings of Populus yunnanensis were used as materials,and theirmain branch length and diameter were measured,the analysis on the three genes expression in stem tips,tender leaves,mature leaves,stems and roots of upright and inverted cuttings of P.yunnanensis were carried out by RT-qPCR technology.The aim was to explore the tissue specific expression patterns of the 3 genes,and provided a preliminary research basis for revealing the mechanism of the 3 genes regulating cell wall synthesis and deeply regulating the growth of P.yunnanensis.The results showed that the full length and encoded amino acids of PyUGPase-A,PyUGPase-B and PyUSPase genes were 1410 bp and 469 amino acids,1410 bp and 469 amino acids,1875 bp and 624 amino acids,respectively.All the 3 proteins did not exist in the peptide and transmembrane domain,and they were all positioned within the cytoplasm of a hydrophilic protease.Homology comparison analysis showed that the amino acid encoded by PyUGPase and PyUSPase genes were highly homologous(>85%)with those encoded by UGPase and USPase genes in other species.The main branch length and diameter of inverted cuttings were lower than those of upright cuttings,but the differences were not significant.The expression of PyUGPase-A and PyUGPase-B genes were relatively high in the mature leaves of the 2 types of cuttings,and up-regulated in the tender leaves of inverted cuttings.However,PyUSPase gene was down-regulated in the 5 tissues and highly expressed in roots.