Arabidopsis Toxicos en Levadura (ATL) proteins compose a subfamily of E3 ubiquitin ligases and play major roles in regulating plant growth, cold, drought, oxidative stresses response and pathogen defense in plants. However, the role in enhancing salt tolerance has not been reported to date. Here, we cloned a novel RING-H2 type E3 ubiquitin ligase gene, named IbATL38, from sweetpotato cultivar Lushu 3. This gene was highly expressed in the leaves of sweetpotato and strongly induced by NaCl and abscisic acid (ABA). This IbATL38 was localized to nucleus and plasm membrane and possessed E3 ubiquitin ligase activity. Overexpression of IbATL38 in Arabidopsis significantly enhanced salt tolerance, along with inducible expression of a series of stress-responsive genes and prominently decrease of H₂O₂ content. These results suggest that IbATL38 as a novel E3 ubiquitin ligase may play an important role in salt stress response.

拟南芥毒素（ATL）蛋白组成E3泛素连接酶的一个亚家族，在调节植物生长，寒冷，干旱，氧化应激反应和植物病原体防御中起主要作用。然而，迄今为止尚未报道过在增强盐耐受性中的作用。在这里，我们从甘薯品种Lushu 3克隆了一个新的RING-H2型E3泛素连接酶基因，命名为IbATL38。该基因在甘薯叶片中高度表达，并由NaCl和脱落酸（ABA）强烈诱导。该IbATL38定位于细胞核和质膜，并具有E3泛素连接酶活性。过度表达IbATL38在拟南芥显着增强了耐盐性，并诱导了一系列胁迫响应基因的表达，并显着降低了H ₂ O ₂含量。这些结果表明，IbATL38作为一种新型的E3泛素连接酶可能在盐胁迫响应中起重要作用。