Identification and characterization of catalase genes in Eleusine coracanaunder abiotic stresses

Abstract

Reactive oxygen species (ROS) are byproducts of metabolic processes such as respiration and photosynthesis in plants. Production of ROS leads to rapid cell damage, and plants developed a complex system of enzymatic and non-enzymatic antioxidants to scavenge these ROS. Catalase is an important enzyme, which plays a key role in elimination of toxic effects of hydrogen peroxide and plays a major role as an antioxidant. When characterizing heat responsive genes in finger millet (Eleusine coracana L.) using a suppression subtractive hybridization (SSH) library, we isolated two catalase genes and named them as EcCATA1 and EcCATB1. The lengths of the EcCATA1 and EcCATB1 open reading frames were 1 482 and 1 426 bp, respectively. We characterized these genes under different abiotic stresses and in different tissues. The tissue wise expression revealed that EcCATA1 expression was higher in leaves whereas EcCATB1 expression was higher in roots than in other organs. Under stress conditions, the expression of EcCATA1 was highest under salt stress followed by mannitol treatment. In the case of EcCATB1, the highest expression was observed under mannitol treatment followed by cold and dehydration. We also studied expression of both the genes under heat stress in different finger millet genotypes and observed that expressions of these genes can be correlated with heat tolerance. For both the genes, a detailed computational investigation was also performed for understanding their structural properties and physicochemical characteristics. Overall, this is the first study to identify and characterize catalase genes from climate resilient finger millet crop.