Sp-miR396a-5p acts as a stress-responsive genes regulator by conferring tolerance to abiotic stresses and susceptibility to Phytophthora nicotianae infection in transgenic tobacco
Sp-miR396a-5p acts as a stress-responsive genes regulator by conferring tolerance to abiotic stresses and susceptibility to Phytophthora nicotianae infection in transgenic tobacco
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Sp-miR396a-5p 通过赋予转基因烟草对非生物胁迫的耐受性和对烟草疫霉感染的易感性，充当胁迫响应基因调节剂
DOI：
10.1007/s00299-015-1847-0
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发表时间：
2015-12-01
影响因子：
6.2
通讯作者：
Zhai, Junmiao
中科院分区：
文献类型：
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作者：
Chen, Lei;Luan, Yushi;Zhai, Junmiao
Sp-miR 396 a-5 p在烟草中的过表达提高了烟草对盐、干旱、低温胁迫的耐受性和对烟草疫霉（Phytophthora nicotianae）侵染的敏感性。microRNA 396（miR 396）是植物中保守的microRNA家族之一，其靶向生长调节因子（growth regulating factors，GRFs）家族。GRF转录因子与生长和应激反应相关。然而，miR 396响应环境胁迫的分子机制是难以捉摸的。本研究旨在探讨番茄miR 396 a-5 p（Sp-miR 396 a-5 p）基因在茄科植物对生物和非生物胁迫响应中的作用。我们发现Sp-miR 396 a-5 p转录水平在盐和干旱胁迫下上调，在致病疫霉（Phytophthora infestans）（P. infestans）感染后下调。因此，Sp-miR 396 a-5 p在烟草中的过表达增强了其对盐、干旱和冷胁迫的耐受性。此外，发现Sp-miR 396 a-5 p的表达在病原体相关的生物胁迫下下调。过表达Sp-miR 396 a-5 p的烟草植物显示出对烟草疫霉（Phytophthora nicotidum，P. nicotidum）感染的增加的易感性。生理分析表明，Sp-miR 396 a-5 p过表达增强了转录调控并减少了活性氧（ROS）的产生。此外，四个Sp-miR 396 a-5 p靶基因，NtGRF 1，NtGRF 3，NtGRF 7和NtGRF 8，在这些植物中下调。我们的研究结果表明，Sp-miR 396 a-5 p通过NtGRF 1和NtGRF 3的调控网络，通过靶向NtGRF 7调节的渗透胁迫响应基因的表达和病原体感染，在非生物胁迫中发挥关键作用。
Overexpression of Sp-miR396a-5p in tobacco increased tolerance to salt, drought, cold stress and susceptibility toPhytophthora nicotianaeinfection. MicroRNA396 (miR396) is one of the conserved microRNA families in plants, and it targeted growth-regulating factors (GRFs) family. The GRF transcription factors are associated with growth and stress responses. However, the molecular mechanisms of miR396 responding to environmental stresses are elusive. The purpose of this study was to explore the function of tomato miR396a-5p (Sp-miR396a-5p) in Solanaceae responses to abiotic and biotic stresses. We showed that Sp-miR396a-5p transcript levels were up-regulated under salt and drought stresses and down-regulated after Phytophthora infestans (P. infestans) infection. Consistently, overexpression of Sp-miR396a-5p in tobacco enhanced its tolerance to salt, drought and cold stresses. Additionally, the expression of Sp-miR396a-5p was found to be down-regulated under pathogen-related biotic stress. Tobacco plants overexpressing Sp-miR396a-5p showed increased susceptibility to Phytophthora nicotianae (P. nicotianae) infection. Physiological analysis indicated that Sp-miR396a-5p overexpression enhanced osmoregulation and decreased production of reactive oxygen species (ROS). Furthermore, four Sp-miR396a-5p target genes, NtGRF1, NtGRF3, NtGRF7 and NtGRF8, were down-regulated in these plants. Our results suggested that Sp-miR396a-5p plays critical roles in both abiotic stresses through targeting NtGRF7-regulated expression of osmotic stress-responsive genes and pathogen infection via the regulatory networks of NtGRF1 and NtGRF3.