Isolation of a subfamily of genes for R2R3-MYB transcription factors showing up-regulated expression under nitrogen nutrient-limited conditions
Isolation of a subfamily of genes for R2R3-MYB transcription factors showing up-regulated expression under nitrogen nutrient-limited conditions
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DOI：
10.1023/b:plan.0000009296.91149.34
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发表时间：
2003-09
影响因子：
5.1
通讯作者：
Kunihiko Miyake;Takuro Ito;M. Senda;R. Ishikawa;T. Harada;M. Niizeki;S. Akada
中科院分区：
文献类型：
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作者：
Kunihiko Miyake;Takuro Ito;M. Senda;R. Ishikawa;T. Harada;M. Niizeki;S. Akada
植物R2R3-MYB转录因子由100多个拷贝的基因编码。在这项研究中，我们试图分离参与豆类固氮调控的R2R3-MYB超家族的一些成员。通过差异杂交筛选了含该超家族R2R3-MYB片段的300个重组质粒克隆，分离出在氮素营养限制条件下表达上调的R2R3-MYB基因。研究人员鉴定了两组克隆，每组克隆似乎都代表了一个对氮饥饿做出反应的基因。通过聚合酶链式反应进一步分离出基因的全部编码区，命名为LjMYB101和LjMYB102。用来自LjMYB101的探针对莲花基因组文库进行筛选，分离到第三个基因LjMYB103。此外，还分离到一个大豆同源基因LjMYB101，命名为GmMYB101。序列比对表明，这些基因均属于该超家族的第10亚组。基因的表达分析表明，MYB101的器官特异性和硝酸盐调控的表达谱与CHSinLotus和大豆中的非常相似，这表明MYB101可能在响应硝酸盐饥饿时调节类黄酮的生物合成中发挥作用。另一方面，LjMYB101和LjGln1在结构和功能上存在有趣的关系，这表明MYB101在调节氮代谢方面具有替代作用。
Plant R2R3-MYB transcription factors are encoded by more than 100 copies of genes. In this study, we attempted to isolate some members of theR2R3-MYBsuperfamily involved in regulation of nitrogen fixation in legumes. A library of 300 recombinant plasmid clones containing theR2R3-MYBfragments of the superfamily was screened by differential hybridization to isolateR2R3-MYBgenes whose expression was up-regulated under nitrogen nutrient-limited conditions. Two groups of clones were identified, each of which seemed to represent a gene responsive to nitrogen starvation. The entire coding regions for the genes were further isolated by PCR and were designatedLjMYB101andLjMYB102. By screening a genomic library ofLotus japonicuswith a probe derived fromLjMYB101, the third gene,LjMYB103, was isolated. In addition, a candidate for the soybean orthologue ofLjMYB101was isolated and designatedGmMYB101. Sequence alignment of the genes with members of the plantR2R3-MYBsuperfamily showed that they all belonged to the subgroup 10 of the superfamily. The expression analysis of the genes showed that the organ-specific and nitrate-regulated expression profile ofMYB101was very similar to that ofCHSinLotusas well as in soybean, suggesting a possible role for MYB101 in regulation of flavonoid biosynthesis in response to nitrate starvation. On the other hand, an interesting relationship, in structure and function, was found betweenLjMYB101andLjGln1, suggesting an alternative role for MYB101 in regulation of nitrogen metabolism.