MpMYBS3 as a crucial transcription factor of cold signaling confers the cold tolerance of banana
MpMYBS3 as a crucial transcription factor of cold signaling confers the cold tolerance of banana
复制标题
MpMYBS3作为寒冷信号的关键转录因子赋予香蕉耐冷性
DOI：
10.1007/s11240-015-0932-y
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发表时间：
2016-04-01
影响因子：
3
通讯作者：
Yi, Gan-jun
中科院分区：
文献类型：
--
作者：
Dou, Tong-xin;Hu, Chun-hua;Yi, Gan-jun
香蕉（Musaspp.）是重要的热带作物。低温是影响全球香蕉生产的主要环境胁迫之一。不同品种的香蕉表现出高度的耐冷性遗传变异。与卡文迪什香蕉相比，大蕉具有上级耐寒性。克隆大蕉耐冷基因并对其功能进行分析，可以揭示大蕉耐冷的分子机制。我们之前对冷敏感的卡文迪什香蕉和耐寒的大蕉进行了比较转录组分析，确定了几个大蕉耐寒候选基因。本研究克隆了一个编码转录因子的大交候选基因MpMYBS 3（homolog of MYBS 3 in rice）。氨基酸序列比对表明，MpMYBS 3属于R1型MYB转录因子。亚细胞定位分析表明MpMYBS 3定位于细胞核。MpMYBS 3基因在香蕉中的异源过量表达表明，转基因香蕉的耐冷性显著高于野生型，这可能与脯氨酸积累增加、丙二醛含量和电解质渗漏减少有关。令人惊讶的是，MYBS 3抑制了香蕉中众所周知的ICE 1-CBF依赖的冷信号传导途径：冷处理后，MaCBF 1和MaCBF 2基因在转录水平上受到抑制。而在低温胁迫下，过表达MpMYBS 3的转基因香蕉中MaMKRY 46基因被显著诱导。这些结果表明，MYBS 3介导的冷信号是香蕉冷适应的关键因素。
Banana (Musaspp.) is an important tropical crops. Low temperature is one of the key environmental stresses, which greatly affects the global banana production. Different varieties of banana exhibit a high degree of genetic variability for cold tolerance. Compared with Cavendish banana, Dajiao has superior cold tolerance. Cloning of Dajiao cold-tolerant genes and characterization of their functions could reveal the molecular mechanism of cold tolerance in Dajiao. Our previous comparative transcriptome analysis of cold-sensitive Cavendish banana and cold-tolerant Dajiao identified several cold-tolerance candidate genes in Dajiao. In this study, a Dajiao candidate gene,MpMYBS3(homolog ofMYBS3in rice), encoding a transcription factor, was cloned and characterized. Amino acid sequence alignments showed that MpMYBS3 belongs to the R1-type MYB transcription factors. Subcellular localization analysis indicated that MpMYBS3 is located in the nucleus. Heterologous overexpression ofMpMYBS3in banana showed that the transgenic lines had significantly higher cold tolerance than the wild-type, which might be associated with the increased accumulation of proline, and a reduction in malondialdehyde content and electrolyte leakage. Surprisingly, MYBS3 repressed the well-known ICE1–CBF-dependent cold signaling pathway in banana: theMaCBF1andMaCBF2genes were repressed at the transcriptional level after cold treatment. However,MaMKRY46was significantly induced in transgenic bananas overexpressingMpMYBS3under cold stress. These findings suggest that MYBS3-mediated cold signaling as a key player in cold adaptation of banana.