Ghorbel Mouna, Besbes Malek, Haddaji Najla, Bouali Nouha, Brini Faiçal
Biology Department, Faculty of Science, University of Hail, Ha'il 2440, Saudi Arabia.
Laboratory of Biotechnology and Plant Improvement, Center of Biotechnology of Sfax, Sfax 3018, Tunisia.
Antioxidants (Basel). 2022 Nov 8;11(11):2208. doi: 10.3390/antiox11112208.
Catalase is a crucial enzyme in antioxidant defense systems protecting eukaryotes from oxidative stress. These proteins are present in almost all living organisms and play important roles in controlling plant responses to biotic and abiotic stresses by catalyzing the decomposition of HO. Despite their importance, little is known about their expression in the majority of monocotyledonous species. Here, we isolated and characterized two novel catalase genes from and , designated as TtCAT1 and HvCAT1, respectively. Phylogenetic analysis revealed that TtCAT1 and HvCAT1 presented 492 aa and shared an important identity with other catalase proteins belonging to subfamily 1. Using bioinformatic analysis, we predicted the 3D structure models of TtCAT1 and HvCAT1. Interestingly, analysis showed that the novel catalases harbor a peroxisomal targeting signal (PTS1) located at their C-terminus portion, as shown for other catalase proteins. In addition, this motif is responsible for the in silico peroxisomal localization of both proteins. Finally, RT-qPCR analysis showed that TtCAT1 and HvCAT1 are highly expressed in leaves in normal conditions but faintly in roots. Moreover, both genes are upregulated after the application of different stresses such as salt, osmotic, cold, heavy metal, and hormonal stresses. The positive responses of TtCAT1 and HvCAT1 to the various stimuli suggested that these proteins can help to protect both species against environmental stresses.
过氧化氢酶是抗氧化防御系统中的一种关键酶，可保护真核生物免受氧化应激。这些蛋白质几乎存在于所有生物体中，通过催化过氧化氢的分解，在控制植物对生物和非生物胁迫的反应中发挥重要作用。尽管它们很重要，但对于它们在大多数单子叶植物物种中的表达却知之甚少。在这里，我们从[物种名称1]和[物种名称2]中分离并鉴定了两个新的过氧化氢酶基因，分别命名为TtCAT1和HvCAT1。系统发育分析表明，TtCAT1和HvCAT1有492个氨基酸，与属于亚家族1的其他过氧化氢酶蛋白具有重要的同源性。通过生物信息学分析，我们预测了TtCAT1和HvCAT1的三维结构模型。有趣的是，分析表明，这两种新的过氧化氢酶在其C末端部分含有一个过氧化物酶体靶向信号（PTS1），其他过氧化氢酶蛋白也是如此。此外，该基序负责这两种蛋白质在计算机模拟中的过氧化物酶体定位。最后，RT-qPCR分析表明，TtCAT1和HvCAT1在正常条件下在叶片中高表达，但在根中微弱表达。此外，在施加盐、渗透、冷、重金属和激素等不同胁迫后，这两个基因均上调。TtCAT1和HvCAT1对各种刺激的积极反应表明，这些蛋白质可以帮助保护这两个物种免受环境胁迫。
