Biotechnology and Plant Improvement Laboratory, Centre of Biotechnology of Sfax (CBS)/University of Sfax, B.P ''1177'', 3018, Sfax, Tunisia.
Laboratory of Legumes, Centre of Biotechnology Bordj Cedria, BP 901, 2050, Hammam Lif, Tunisia.
Plant Physiol Biochem. 2019 Sep;142:384-394. doi: 10.1016/j.plaphy.2019.08.001. Epub 2019 Aug 2.
Superoxide dismutases (SODs) play a pivotal role in improving abiotic stress tolerance in plant cells. A novel manganese superoxide dismutase gene, denoted as TmMnSOD, was identified from Triticum monococcum. The encoded protein displayed high sequence identity with MnSOD family members and was highly homologous to TdMnSOD from durum wheat. Furthermore, the 3D structure analysis revealed that TmMnSOD displayed homotetramer subunit organization, incorporating four Mn ions. Notably, TmMnSOD structure contains predominantly alpha helices with three beta sheets. On the other hand, under stress conditions, TmMnSOD transcript level was significantly up-regulated by salt, oxidative and heavy metal stresses. At the functional level, TmMnSOD imparts tolerance of yeast and E. coli cells under diverse stresses. Promoter analysis of TmMnSOD gene showed the presence of a great number of salt and pathogen-responsive cis-regulatory elements, highlighting the interest of this gene in breeding programs towards improved tolerance to salt stress in wheat.
超氧化物歧化酶（SOD）在提高植物细胞的非生物胁迫耐受性方面起着关键作用。本研究从野生二粒小麦中鉴定到一个新型锰超氧化物歧化酶基因，命名为 TmMnSOD。该编码蛋白与 MnSOD 家族成员具有高度的序列同一性，与硬粒小麦中的 TdMnSOD 高度同源。此外，三维结构分析表明 TmMnSOD 呈现四聚体亚基组织，包含四个 Mn 离子。值得注意的是，TmMnSOD 结构主要由α螺旋和三个β片层组成。另一方面，在胁迫条件下，盐、氧化和重金属胁迫显著上调 TmMnSOD 的转录水平。在功能水平上，TmMnSOD 赋予酵母和大肠杆菌细胞在各种胁迫下的耐受性。TmMnSOD 基因启动子分析表明存在大量的盐和病原体响应的顺式调控元件，这突出了该基因在小麦耐盐胁迫育种计划中的重要性。
