Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China.
Key Laboratory of Southwest China Wildlife Resources Conservation (Ministry of Education), China West Normal University, Nanchong, China.
BMC Plant Biol. 2021 Dec 29;21(1):605. doi: 10.1186/s12870-021-03336-4.
The APETALA2/ethylene response factor (AP2/ERF) family are important regulatory factors involved in plants' response to environmental stimuli. However, their roles in salt tolerance in Lotus corniculatus remain unclear.
Here, the key salt-responsive transcription factor LcERF056 was cloned and characterised. LcERF056 belonging to the B3-1 (IX) subfamily of ERFs was considerably upregulated by salt treatment. LcERF056-fused GFP was exclusively localised to nuclei. Furthermore, LcERF056- overexpression (OE) transgenic Arabidopsis and L. corniculatus lines exhibited significantly high tolerance to salt treatment compared with wild-type (WT) or RNA interference expression (RNAi) transgenic lines at the phenotypic and physiological levels. Transcriptome analysis of OE, RNAi, and WT lines showed that LcERF056 regulated the downstream genes involved in several metabolic pathways. Chromatin immunoprecipitation-quantitative polymerase chain reaction (ChIP-qPCR) and yeast one-hybrid (Y1H) assay demonstrated that LcERF056 could bind to cis-element GCC box or DRE of reactive oxygen species (ROS)-related genes such as lipid-transfer protein, peroxidase and ribosomal protein.
Our results suggested that the key regulator LcERF056 plays important roles in salt tolerance in L. corniculatus by modulating ROS-related genes. Therefore, it may be a useful target for engineering salt-tolerant L. corniculatus or other crops.
AP2/ETH 响应因子（AP2/ERF）家族是植物响应环境刺激的重要调节因子。然而，它们在百脉根耐盐性中的作用尚不清楚。
本研究克隆并鉴定了关键的盐响应转录因子 LcERF056。LcERF056 属于 ERF 的 B3-1（IX）亚家族，在盐处理下表达水平显著上调。LcERF056-GFP 融合蛋白仅定位于细胞核。此外，与野生型（WT）或 RNA 干扰表达（RNAi）转基因系相比，LcERF056 过表达（OE）转基因拟南芥和百脉根系在表型和生理水平上对盐处理表现出显著的耐受性。OE、RNAi 和 WT 系的转录组分析表明，LcERF056 调控了参与几种代谢途径的下游基因。染色质免疫沉淀-定量聚合酶链反应（ChIP-qPCR）和酵母单杂交（Y1H）实验表明，LcERF056 可以与脂质转移蛋白、过氧化物酶和核糖体蛋白等与活性氧（ROS）相关基因的 GCC 框或 DRE 顺式元件结合。
我们的研究结果表明，关键调控因子 LcERF056 通过调节 ROS 相关基因在百脉根耐盐性中发挥重要作用。因此，它可能是工程耐盐百脉根或其他作物的有用目标。
