Identification and Expression Profiling of Two Saudi Arabia Catalase Genes from Wheat and Barley in Response to Abiotic and Hormonal Stresses

Abstract

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 H2O2. 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 Triticum turgidum and Hordeum vulgare, 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.

Catalase Gene Family in Durum Wheat: Genome-Wide Analysis and Expression Profiling in Response to Multiple Abiotic Stress Conditions

“…Om Rabiaa, a local Tunisian variety) is highly expressed in the whole plant at all developmental stages [ 13 ]. The same findings were observed in the Waha ecotype, a Saudi variety [ 14 ], and in Triticum monococcum [ 15 ]. Moreover, TdCAT1 is regulated by bivalent cations and by the calcium/Calmodulin complex [ 16 ].…”

“…Gene expression is controlled by the complex interaction of different cis-acting elements and trans-acting factors that participate in different pathways [ 26 ]. Previous investigations have confirmed that catalase genes could be induced by different treatments, such as salt stress [ 14 , 16 ], cold [ 10 , 29 , 37 ], drought [ 7 , 14 , 16 , 29 , 37 , 38 ], ABA [ 7 , 14 , 16 , 28 , 38 ], SA [ 16 ], and light [ 39 ].…”

“…durum var. Waha) [ 14 ] were grown in a growth chamber at 23–25 °C with an illumination of 16/8 h light/dark. Almost 50 seeds were treated with 30 mL of a 0.5% sodium hypochlorite solution for 15 to 20 min prior to incubation; they were then washed four times with 50 mL of sterile water.…”

“…Numerous studies have demonstrated that the regulation of plant CAT gene expression affects how the organism develops, matures, and responds to environmental cues [ 11 , 12 , 13 ]. In Arabidopsis thaliana , AtCAT genes encode for a small family of proteins (three isoforms known as AtCAT1, AtCAT2, and AtCAT3), which catalyze the oxidation of H 2 O 2 and are crucial for maintaining the equilibrium of ROSs [ 14 ]. The AtCAT1 gene expression is increased by ABA through the MAPK cascades [ 15 , 16 ], but it does not appear to be affected by circadian rhythms.…”

Genome-Wide Identification and Expression Analysis of Catalase Gene Families in Triticeae

“…The absence of expected signal peptides and transmembrane regions indicates that these proteins are non-secreted rather than membrane-bound. Interestingly, none of the discovered CAT proteins had a transmembrane domain, contrary to prior findings for several CAT proteins, such as SlCAT1 in tomato [ 46 ], TtCAT1, and HvCAT1 [ 47 ]. A similar outcome was also noted in durum wheat [ 13 ], but in oat, all discovered CAT proteins lacked a transmembrane region, except for AvCAT5 [ 14 ].…”