Soybean GmMYB76, GmMYB92, and GmMYB177 genes confer stress tolerance in transgenic Arabidopsis plants
Soybean GmMYB76, GmMYB92, and GmMYB177 genes confer stress tolerance in transgenic Arabidopsis plants
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DOI：
10.1038/cr.2008.280
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发表时间：
2008-10-01
期刊：
影响因子：
44.1
通讯作者：
Chen, Shou-Yi
中科院分区：
文献类型：
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作者：
Liao, Yong;Zou, Hong-Feng;Chen, Shou-Yi
MYB类转录因子含有约50个氨基酸的保守MYB DNA结合结构域，并且参与植物生长、发育、代谢和胁迫反应的许多方面的调节。从大豆植物中，我们确定了156个GmMYB基因使用我们以前获得的206 MYB unigenes，48个被发现有全长开放阅读框。检测了所有这些基因的表达，我们发现43个基因的表达在阿坝、盐、干旱和/或冷胁迫处理后发生了变化。选择三个GmMYB基因GmMYB 76、GmMYB 92和GmMYB 177用于进一步分析。使用酵母测定系统，发现GmMYB 76和GmMYB 92具有反式激活活性，并且可以形成同源二聚体。GmMYB 177似乎没有反式激活活性，但可以与GmMYB 76形成异二聚体。酵母单杂交实验表明，三种GmMYB均能与TCT CAC CTA CC和达特AAC GGT TTT TT和CCG GAA AAA AGG AT结合，但结合亲和力不同。过量表达GmMYB 76或GmMYB 177的转基因拟南芥比转GmMYB 92基因的拟南芥表现出更好的耐盐性和抗冻性。然而，这些转基因植物表现出降低的敏感性阿坝处理在发芽阶段相比，野生型植物。这三个GmMYB基因差异影响一个子集的压力响应基因除了他们的调节一个共同的子集的压力响应基因。这些结果表明，这三个GmMYB基因可能发挥不同的作用，在胁迫耐受性，可能通过调节应激反应基因。
MYB-type transcription factors contain the conserved MYB DNA-binding domain of approximately 50 amino acids and are involved in the regulation of many aspects of plant growth, development, metabolism and stress responses. From soybean plants, we identified 156 GmMYB genes using our previously obtained 206 MYB unigenes, and 48 were found to have full-length open-reading frames. Expressions of all these identified genes were examined, and we found that expressions of 43 genes were changed upon treatment with ABA, salt, drought and/or cold stress. Three GmMYB genes, GmMYB76, GmMYB92 and GmMYB177, were chosen for further analysis. Using the yeast assay system, GmMYB76 and GmMYB92 were found to have transactivation activity and can form homodimers. GmMYB177 did not appear to have transactivation activity but can form heterodimers with GmMYB76. Yeast one-hybrid assay revealed that all the three GmMYBs could bind to cis-elements TAT AAC GGT TTT TT and CCG GAA AAA AGG AT, but with different affinity, and GmMYB92 could also bind to TCT CAC CTA CC. The transgenic Arabidopsis plants overexpressing GmMYB76 or GmMYB177 showed better performance than the GmMYB92-transgenic plants in salt and freezing tolerance. However, these transgenic plants exhibited reduced sensitivity to ABA treatment at germination stage in comparison with the wild-type plants. The three GmMYB genes differentially affected a subset of stress-responsive genes in addition to their regulation of a common subset of stress-responsive genes. These results indicate that the three GmMYB genes may play differential roles in stress tolerance, possibly through regulation of stress-responsive genes.