摘要
MYB转录因子以保守的DNA结合域为共同特征,是植物最大的转录因子家族之一,广泛参与植物代谢调控。本文根据植物中MYB转录因子的DNA保守结构域,通过RT-PCR和RACE的方法从大豆品种吉林3号的叶片中分离得到了2个MYB基因GmMYBJ6和GmMYBJ7,并对其结构特征和表达特性进行了分析鉴定。基因组DNA序列分析表明,两个基因都含有两个内含子;酵母系统检测表明,两个基因均具有转录激活活性;β-半乳糖甘酶活性分析表明,内含子的存在使两个基因的转录激活活性明显降低;实时荧光定量PCR检测结果显示,GmMYBJ6在大豆中的表达受ABA、GA3和NAA的诱导,而GmMYBJ7的表达则受ABA和NAA的诱导;半定量RT-PCR分析表明,两个基因在大豆的根、茎、叶、花和未成熟种子中均有表达。GmMYBJ6和GmMYBJ7为典型的R2R3-MYB转录因子新基因;他们在大豆中的表达可能与ABA和NAA的信号转导途径有关。
Plant R2R3-myb genes are widely distributed in higher plants and comprise one of the largest known families of regu-latory proteins. In the past decades, its biochemical and molecular characteristics were extensively studied and reported to be in-volved in many physiological and biochemical processes. On the based of its conserved DNA-binding domain, two MYB-like genes from soybean cultivar Jilin 3 were cloned by RT-PCR and RACE methods, named GmMYBJ6 and GmMYBJ7 （GenBank accession No. DQ902863 and DQ902864）, which contained an ORF of 786 bp and 969 bp encoding 261 and 322 amino acids respectively. Genomic DNA sequences analysis showed that both the two genes contained two introns. Meanwhile, the transcrip-tion level of the two genes was investigated by semi-quantitative RT-PCR, and the result showed that the two genes were ex-pressed in root, stems, leaves, flowers and immature seeds of soybean. Furthermore, the yeast one-hybrid assay showed that the two MYB proteins had transcriptional activation functions. But the levels of their transcriptional activity were lower when the introns existed. Fluorescence real-time quantification PCR analysis indicated that the expression of GmMYBJ6 and GmMYBJ7 genes could be induced by ABA and NAA, respectively. And their expressions were changed with the inducible time. In conclu-sion, GmMYBJ6 and GmMYBJ7 genes isolated from soybean are new members of MYB transcription factor family, which may play key roles in the signal transduction related to ABA and NAA in soybean.
出处
《作物学报》
CAS
CSCD
北大核心
2008年第7期1179-1187,共9页
Acta Agronomica Sinica
基金
中国-荷兰国际合作项目
中国农业科学院基本科研业务费支持项目
关键词
MYB转录因子
基因表达调控
内含子
转录激活活性
MYB transcription factor
Gene expression and regulation
Intron
Transcriptional activity
