Isolation and Abiotic Stress Resistance Analyses of a Catalase Gene from<i>Ipomoea batatas</i>(L.) Lam

Abstract

As an indicator of the antioxidant capability of plants, catalase can detoxify reactive oxygen species (ROS) generated by environmental stresses. Sweet potato is one of the top six most important crops in the world. However, its catalases remain largely unknown. In this study, a catalase encoding gene, <i>IbCAT2</i> (accession number: KY615708), was identified and cloned from sweet potato cv. Xushu 18. It contained a 1479 nucleotides' open reading frame (ORF). S-R-L, Q-K-L, and a putative calmodulin binding domain were located at the C-terminus of IbCAT2, which suggests that IbCAT2 could be a peroxisomal catalase. Next-generation sequencing (NGS) based quantitative analyses showed that <i>IbCAT2</i> was mainly expressed in young leaves and expanding tuberous roots under normal conditions. When exposed to 10% PEG6000 or 200 mmol/L NaCl solutions, <i>IbCAT2</i> was upregulated rapidly in the first 11 days and then downregulated, although different tissues showed different degree of change. Overexpression of <i>IbCAT2</i> conferred salt and drought tolerance in <i>Escherichia coli</i> and <i>Saccharomyces cerevisiae</i>. The positive response of <i>IbCAT2</i> to abiotic stresses suggested that <i>IbCAT2</i> might play an important role in stress responses.