摘 要 ：MYB类蛋白是一类与植物防卫反应有关的转录因子家族，本研究利用构建的甜橙健株与感染黄龙病的病株差减（SSH）文库，采用RACE技术克隆了一个MYB类基因的cDNA全长序列，命名为CsMYB（GenBank登录号为HQ841074）。柑橘CsMYB基因的cDNA全长为1 306 bp，生物信息学分析显示，该基因包括一个909 bp的完整开放读码框以及一个典型的26 bp poly-A，编码302个氨基酸，分子量为32.97 kD，等电点为8.5。同时，还有MYB类基因的保守特征区域，即在N端有两个典型的MYB DNA结合域：R2和R3。实时荧光定量PCR分析表明，柑橘CsMYB基因受到黄龙病菌侵染后的不同时期表达量不同，伴随着黄龙病病程的变化呈现不同的表达变化。推测CsMYB基因是一个转录因子，可能参与柑橘对黄龙病菌的防御反应过程。
Abstract:In the present study, according to the results of Citrus sinensis SSH library analysis, primers of one up-regulation expressed EST sequence were designed, a MYB type gene was cloned by rapid amplification of cDNA ends (RACE). This gene was named as CsMYB, and submitted in GenBank (accession No. HQ841074). The full-length cDNA sequence of CsMYB is 1 306 bp, including an open reading frame (ORF) of 909 bp and the typical 26 bp poly-A. Bioinformatics analysis showed that the gene putatively encodes a protein which has 302 amino acids with molecular weight 32.97 kD, and its theoretical pI is 8.5. The CsMYB gene contains two typical conserved motifs: R2 and R3. The gene expression profile under the treatment of Ca. Liberibacter asiaticus(Las) was investigated by Real-time qPCR. The results showed that CsMYB gene expression varied at different times infected by Las, and was different in huanglongbing development progresses. Therefore, the CsMYB gene is speculated to be a transcription factor and possibly to be involved in the procedure induced defense of Las.