Localization and expression analysis of a novel catalase from Triticum monococcum TmCAT1 involved in response to different environmental stresses

• Published in: Plant physiology and biochemistry 2019-06, Vol.139, p.366-378
• Main Authors: Tounsi, Sana, Kamoun, Yosra, Feki, Kaouthar, Jemli, Sonia, Saïdi, Mohamed Najib, Ziadi, Hajer, Alcon, Carine, Brini, Faiçal
• Format: Article
• Language: English
• Subjects: Abiotic stress; Catalase; Life Sciences; Peroxisomal targeting signal; Peroxisome; Vegetal Biology; Wheat
• ISSN: 0981-9428; 1873-2690
• DOI: 10.1016/j.plaphy.2019.03.039

Catalase proteins play a crucial role in detoxifying hydrogen peroxide, generated during plant growth, and in response to various environmental stresses. Despite their importance, little is known about their localization and expression in wheat. In this study, we identified and characterized a novel peroxisomal catalase gene from Triticum monococcum, designated as TmCAT1. Phylogenetic analysis revealed that TmCAT1 shared high identity with TdCAT1 and other plant catalases belonging to subfamily 1. We predicted the 3D structure model and the oligomerization arrangement of TmCAT1. Besides, we displayed an arrangement in asymmetric unit, which involved interactions including, mainly, residues from N-terminal domain. Interestingly, sequence analysis indicated that TmCAT1, like TdCAT1, had the peroxisomal targeting signal (PTS1) around its C-terminus. Transient expression of TmCAT1-GFP and TdCAT1-GFP in tobacco leaves revealed that the two fused proteins are targeted into peroxisomes. However, the truncated forms lacking the tripeptide QKL remained in the cytosol. Concerning the expression profile analysis, TmCAT1 is expressed especially in leaves in normal condition. On the other hand, it is up-regulated by different stress incorporating salt, osmotic, oxidative, heavy metal and hormones stresses. Functional analysis by heterologous expression in yeast cells showed that TmCAT1 improved tolerance to multiple abiotic stresses. The presence of important cis-regulatory elements in the promoter region of TmCAT1 strongly reinforces the interest of this gene in plant adaptation to various stresses. •A novel peroxisomal catalase gene, TmCAT1, was identified from Triticum monococcum.•TmCAT1 is targeted into peroxisomes by PTS1 system.•TmCAT1 is up-regulated by different stress incorporating salt, osmotic, oxidative, heavy metal and hormones stresses.•Functional analysis by heterologous expression in yeast cells showed that TmCAT1 improved tolerance to multiple abiotic stresses.•TmCAT1 promoter sequence showed numerous cis-regulatory elements implicated in plant development.