圆果黄麻纤维素合成酶基因CcCesA1的克隆、反义载体构建及转化拟南芥

以圆果黄麻(Corchorus capsularis L.) “179”茎部韧皮为材料，利用同源克隆和RACE技术，克隆黄麻纤维素合成酶基因CcCesA1 5¢端500 bp序列外的全部cDNA。其序列长度为2529 bp，编码627氨基酸残基，经Blast基因比对和蛋白质结构分析，确定是黄麻纤维素合成酶基因。半定量RT-PCR分析表明，CcCesA1在植株不同部位表达量具组织差异性，依次为茎部韧皮>根>叶>顶芽>麻骨。利用CcCesA1基因部分cDNA序列和3¢UTR区，构建黄麻CcCesA1基因反义载体，用测序验证的阳性质粒转化模式植物拟南芥。Southern结果表明，外源基因以单拷贝方式整合进入基因组，转基因拟南芥生长严重受阻，植株变得矮小且茎部易弯曲倒伏，角果数量变少，长度变短，纤维素含量有不同程度的降低，本研究结果表明，所克隆的黄麻CcCesA1基因除了参与植物其他生理代谢过程外，还参与纤维素的生物合成。

Cloning for Cellulose Synthetase Gene CcCesA1 from Jute (Corchorus capsularis L.), Antisense Vector Construction,and Transformation of Arabidopsis

We took stem bark of jute cultivar 179 (Corchorus capsularis L.) as materials, successfully cloned the full-length cDNA of jute cellulose synthetase gene except 500 bp of 5'' terminal,using homologous cloning and modified RACE techniques. The sequence length is 2529 bp, encoding a 627 amino acids protein. Gene alignment and protein structure analysis showed that it belongs to jute cellulose Synthetase gene family. Semi-quantitative RT-PCR analysis indicated that the expression level of CcCesA1 gene in different parts of plant was bark > root > leaf > bud > sticks. Using partial cDNA and 3'' UTR region of CcCesA1 gene, constructed the antisense vector of the jute CcCesA1 gene, the positive plasmids were transformed into the model plant Arabidopsis thaliana. Southern blot analysis showed that the exogenous genes were transformed into Arabidopsis genome as one copy. The growth of tansgenic Arabidopsis was badly inhibited so that plants became dwarf with easing bending stem, shorter silique, and less silique numbers. This finding shows that CcCesA1 gene is involved in not only cellulose synthesis, but also other plant growth process.