Genomics of Plant Stress Laboratory, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal.
Plant Mol Biol. 2013 Jul;82(4-5):439-55. doi: 10.1007/s11103-013-0073-9. Epub 2013 May 24.
High salinity causes remarkable losses in rice productivity worldwide mainly because it inhibits growth and reduces grain yield. To cope with environmental changes, plants evolved several adaptive mechanisms, which involve the regulation of many stress-responsive genes. Among these, we have chosen OsRMC to study its transcriptional regulation in rice seedlings subjected to high salinity. Its transcription was highly induced by salt treatment and showed a stress-dose-dependent pattern. OsRMC encodes a receptor-like kinase described as a negative regulator of salt stress responses in rice. To investigate how OsRMC is regulated in response to high salinity, a salt-induced rice cDNA expression library was constructed and subsequently screened using the yeast one-hybrid system and the OsRMC promoter as bait. Thereby, two transcription factors (TFs), OsEREBP1 and OsEREBP2, belonging to the AP2/ERF family were identified. Both TFs were shown to bind to the same GCC-like DNA motif in OsRMC promoter and to negatively regulate its gene expression. The identified TFs were characterized regarding their gene expression under different abiotic stress conditions. This study revealed that OsEREBP1 transcript level is not significantly affected by salt, ABA or severe cold (5 °C) and is only slightly regulated by drought and moderate cold. On the other hand, the OsEREBP2 transcript level increased after cold, ABA, drought and high salinity treatments, indicating that OsEREBP2 may play a central role mediating the response to different abiotic stresses. Gene expression analysis in rice varieties with contrasting salt tolerance further suggests that OsEREBP2 is involved in salt stress response in rice.
高盐度会导致全球范围内水稻产量的显著损失，主要是因为它抑制了生长并降低了粮食产量。为了应对环境变化，植物进化出了几种适应机制，其中涉及许多应激响应基因的调节。在这些基因中，我们选择了 OsRMC 来研究其在水稻幼苗受到高盐胁迫时的转录调控。盐处理强烈诱导其转录，并表现出应激剂量依赖性模式。OsRMC 编码一种受体样激酶，被描述为水稻盐胁迫反应的负调节剂。为了研究 OsRMC 如何受到高盐度的调节，构建了一个盐诱导的水稻 cDNA 表达文库，并随后使用酵母单杂交系统和 OsRMC 启动子作为诱饵进行筛选。由此，鉴定出两个转录因子（TFs），OsEREBP1 和 OsEREBP2，属于 AP2/ERF 家族。这两个 TFs 都被证明可以结合到 OsRMC 启动子中的相同 GCC 样 DNA 基序上，并负调控其基因表达。对鉴定出的 TFs 在不同非生物胁迫条件下的基因表达进行了特征描述。本研究表明，OsEREBP1 的转录水平不受盐、ABA 或严寒（5°C）的显著影响，仅受干旱和适度寒冷的轻微调节。另一方面，OsEREBP2 的转录水平在冷、ABA、干旱和高盐处理后增加，表明 OsEREBP2 可能在介导对不同非生物胁迫的反应中发挥核心作用。在具有不同耐盐性的水稻品种中的基因表达分析进一步表明，OsEREBP2 参与了水稻的盐胁迫反应。
