枣结果枝cDNA文库的构建与部分ESTs分析

Construction and Partial ESTs Analysis of a cDNA Library for Fruit-bearing Shoot in Ziziphus jujuba

用定向克隆法构建了枣(Ziziphus jujubaMill)生长初期结果枝的部分cDNA文库,获得1338个阳性克隆,有557个携带cDNA片段,选取469个长度在500 bp以上的进行测序,得到390个有用序列,其中281个ESTs与NCBI中已知功能基因相似性较高(其中重复性ESTs 101个),有68个ESTs是NCBI中有序列注释的未知蛋白,有41个ESTs是NCBI中没有的未知序列(新基因)。将已知基因进行功能分类,其中包含有参与基础代谢的基因46个,蛋白质合成与转运基因27个,光合作用基因24个,细胞结构基因22个,信号转导基因19个,细胞生长基因19个,抗病防御基因11个,花发育基因6个,膜运输基因4个,金属转运基因2个。抗逆基因的表达可能与枣树本身耐寒、耐旱、耐瘠薄、耐重金属等抵抗不良环境能力强的性状有关。

By using directional cloning,a cDNA Library in the fruit-bearing shoot of Ziziphus jujuba Mill during the early stages of flower bud differentiation was constructed.In 1 388 positive clones,557 cDNA inserts were obtained.469 cDNA inserts,length over 500 bp,were selected and sequenced,390 useful inserts were obtained at last.In these useful sequences,281 ESTs（among them there were 101 repetitive ESTs） were higher similarity with the known genes of CNBI,and 68 ESTs were unknown protein that its sequence had published, another 41 ESTs were unknown sequence （new gene） .The known genes were classified by the classification way of arabidopsis thaliana genes, the result indicated that there were the basal metabolism gene 46 genes,the protein synthesis and transfer gene including 27 genes,the photosyn- thesis gene including 24 genes, the cytoarchitecture gene including 22 genes, the signal transduction gene including 19 genes, the auxesis gene including 19 genes, the resistance adversity gene including 11 genes,the flower development gene including 6 genes, the membrane traffic gene including 4 genes, and the metal transfer gene including 2 genes. The ex- pression of some genes may be relation to the properties of jujube trees＇s high resistance to the adverse environment,for example, cold resistance, drought resistance, barrenness tolerance and heavy metal tolerance.