Abstract Increased salinity, as consequence of the ongoing climate change, has a significant impact on crop production worldwide. The overexpression of rice ACYL-COA-BINDING PROTEIN4 (OsACBP4) protects transgenic rice and Arabidopsis from salinity stress, while OsACBP4-RNAi lines were more susceptible than the vector control (VC) and wild type (WT). The overexpression of AtACBP2, the Arabidopsis OsACBP4 homologue, also conferred salinity protection in transgenic rice and Arabidopsis. When OsACBP4 expression was investigated using s-glucuronidase (GUS) reporter fusion, OsACBP4pro::GUS expression was induced after salt treatment of transgenic rice seedlings. Electrophoretic mobility shift assays verified that four salinity-responsive elements in the OsACBP4 5’-flanking region interacts with nuclear protein from salt-treated rice. RNA-sequencing and qRT-PCR on salt-treated rice OsACBP4-overexpressors (OEs), revealed an upregulation of all five genes encoding acyl-CoA synthase, essential in fatty acid elongation, over the controls. Furthermore, GC-MS analysis showed differences in fatty acid content between the leaves of the OsACBP4-OEs and the controls. Taken together, OsACBP4 may play a role in salinity responses by regulating lipid metabolism through binding acyl-CoA esters in vegetative tissues as recombinant OsACBP4 was subsequently confirmed to bind long-chain acyl-CoA esters in isothermal titration calorimetry assays.

中文翻译：

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水稻 ACYL-COA-BINDING PROTEIN4 的过表达提高了转基因水稻的耐盐性

摘要 由于持续的气候变化，盐度增加对全球作物生产产生重大影响。水稻 ACYL-COA-BINDING PROTEIN4 (OsACBP4) 的过表达保护转基因水稻和拟南芥免受盐分胁迫，而 OsACBP4-RNAi 系比载体对照 (VC) 和野生型 (WT) 更易感。AtACBP2（拟南芥 OsACBP4 同系物）的过表达也赋予转基因水稻和拟南芥的盐度保护。当使用 s-葡萄糖醛酸酶 (GUS) 报告基因融合研究 OsACBP4 表达时，OsACBP4pro::GUS 表达在转基因水稻幼苗的盐处理后被诱导。电泳迁移率变化分析证实 OsACBP4 5' 侧翼区域中的四个盐度响应元件与盐处理水稻的核蛋白相互作用。对盐处理的水稻 OsACBP4 过表达子 (OE) 进行的 RNA 测序和 qRT-PCR 显示，与对照相比，编码酰基辅酶 A 合酶的所有五个基因均上调，这对脂肪酸延伸至关重要。此外，GC-MS 分析显示 OsACBP4-OE 和对照的叶子之间的脂肪酸含量存在差异。总之，OsACBP4 可能通过结合营养组织中的酰基辅酶 A 酯调节脂质代谢在盐度反应中发挥作用，因为随后在等温滴定量热法中证实重组 OsACBP4 与长链酰基辅酶 A 酯结合。GC-MS 分析显示 OsACBP4-OE 和对照的叶子之间的脂肪酸含量存在差异。总之，OsACBP4 可能通过结合营养组织中的酰基辅酶 A 酯调节脂质代谢在盐度反应中发挥作用，因为随后在等温滴定量热法中证实重组 OsACBP4 与长链酰基辅酶 A 酯结合。GC-MS 分析显示 OsACBP4-OE 和对照的叶子之间的脂肪酸含量存在差异。总之，OsACBP4 可能通过结合营养组织中的酰基辅酶 A 酯调节脂质代谢在盐度反应中发挥作用，因为随后在等温滴定量热法中证实重组 OsACBP4 与长链酰基辅酶 A 酯结合。