中文摘要：

吲哚-3-乙酸（又称IAA或生长素）,在植物生长发育中具有重要的调控作用,其作用主要通过信号转导途径来完成.生长素受体是其信号转导的关键元件之一.本研究通过RACE克隆,获得了茶树中生长素受体CsTIR1基因的cDNA全长序列（NCBI登录号：JX050147）.CsTIR1序列全长2 315 bp,含1 746 bp的完整开放阅读框,编码581个氨基酸,预测分子量65.18 kD,理论等电点（pI）5.64.茶树CsTIR1与烟草TIR1的相似性最高达82%,亲缘关系最近.CsTIR1含有1个F-box结构域和6个LRR结构域,三级结构形如＂蘑菇状＂.CsTIR1在茶树的根、茎、叶和花中具有组织表达特异性;其表达受IAA诱导,3种不同浓度的IAA均能诱导CsTIR1上调表达,且在50 μmol·L^-1浓度下表达量最大;ABA、GA3、MeJA和BR等激素也能够显著上调其表达;CsTIR1在越冬休眠芽中的表达量低,在活跃期中上调表达.

英文摘要：

Indole-3-acetic acid （IAA or auxin）, functioning via its signal transduction, plays a pivotal role in plant growth and development regulation. Transport inhibitor response 1 （TIR1） protein, an auxin receptor, is one of the most critical components in IAA signaling pathway. The full-length cDNA sequence of CsTIR1 gene was obtained by using RACE technique, and submitted to GenBank with accession number JX050147. The CsTIR1 cDNA length was 2 315 bp, and contained a 1 746 bp open reading frame （ORF）, encoding 581 amino acid residues. The molecular weight and theoretic isoelectric point of CsTIR1 protein are 65.18 kD and 5.64, respectively. In addition, CsTIR1 protein had the highest sequence similarity about 82% and the closest genetic relationship to Nicotiana tabacum. The CsTIR1 was predicted to contain one F-box and six leucine-rich-repeat （LRR） domains, which forming the ＇stem＇ and ＇cap＇, respectively. And its tertiary structure is shaped as a mushroom. Semi-quantitative RT-PCR results suggested that CsTIR1 expression showed a tissue-specificity among root, stems, leaves and flowers. The further investigation indicated that the transcript of CsTIR1 was regulated by phytohormones. In a time-course assay, it was found that CsTIR1 was significantly up-regulated when tea plant treated with three different IAA concentration and various plant hormones （ABA, GA3, MeJA and BR）, and showed the highest expression level under 50 μmol·L^-1 IAA concentration. Finally, the expression of CsTIR1 was detected in bud dormancy-active cycle during winter and CsTIR1 showed a low transcription level in dormant buds but expressed abundantly in active buds.