Three tandemly aligned LEA genes from Medicago truncatula confer differential protection to Escherichia coli against abiotic stresses
Three tandemly aligned LEA genes from Medicago truncatula confer differential protection to Escherichia coli against abiotic stresses
复制标题
来自蒺藜苜蓿的三个串联排列的 LEA 基因为大肠杆菌提供了针对非生物胁迫的差异保护
DOI：
10.32615/bp.2019.112
复制
发表时间：
2020
影响因子：
1.5
通讯作者：
刘瑞娟
中科院分区：
文献类型：
--
作者：
张业猛;王海庆;刘德梅;刘瑞娟
Late embryogenesis abundant (LEA) proteins are important for abiotic stress tolerance in diverse organisms. Within.the LEA protein superfamily, group 4 members are characterized by a conserved N-terminal region and a structurally.disordered C-terminal region that varies regarding length and amino acid content. Previous in vitro assays have suggested.that the conserved N-terminal region shared by group 4 LEA proteins is critical for forming an amphipathic α-helix.and protecting enzymatic activities from the adverse effects of desiccation or freezing. However, the cellular roles of.the varying C-terminal region remain largely to be characterized. Medicago truncatula contains five subgroup LEA4B.proteins encoding loci of which three are tandemly arranged on chromosome 7 due to local gene duplication events..In this study, abiotic stresses and addition of abscisic acid (ABA) induced the transcription of the four LEA4B genes..Escherichia coli cells overexpressing the three tandemly aligned LEA genes indicated significantly increased tolerance.to salt, osmotic, heat, and freezing stresses. However, the extent of the protective effects on the survival and growth of.bacterial cells differed among the LEA proteins, potentially because of variations in the C-terminal region. This possibility.was further supported by the observation that the protective effects of the native truncated MtLEA3140, which only.contains a conserved N-terminal region, were inferior to the effects of the full-length mutant version. The results suggest.that the structurally flexible C-terminal region of group 4 LEA proteins plays roles in protecting cells from damages caused.by various abiotic stresses, and provide clues for elucidating the mechanisms underlying the intracellular functions of.these proteins
