A novel Pinellia ternata catalase gene PtCAT2 regulates drought tolerance in Arabidopsis by modulating ROS balance

Juanjuan Xu; Ni Du; Tianci Dong; Han Zhang; Tao Xue; Fei Zhao; Fenglan Zhao; Yongbo Duan; Jianping Xue

doi:10.3389/fpls.2023.1206798

A novel Pinellia ternata catalase gene PtCAT2 regulates drought tolerance in Arabidopsis by modulating ROS balance

Front Plant Sci. 2023 Oct 2:14:1206798. doi: 10.3389/fpls.2023.1206798. eCollection 2023.

Authors

Juanjuan Xu¹, Ni Du¹, Tianci Dong¹, Han Zhang¹, Tao Xue¹, Fei Zhao², Fenglan Zhao¹, Yongbo Duan¹, Jianping Xue¹

Affiliations

¹ Anhui Provincial Engineering Laboratory for Efficient Utilization of Featured Resource Plants, College of Life Sciences, Huaibei Normal University, Huaibei, Anhui, China.
² College of Agronomy & Resources and Environment, Tianjin Agricultural University, Tianjin, China.

Abstract

Drought is one of the major abiotic stresses limiting agricultural production, particularly for shallow-rooted plants like Pinellia ternata. It damages plants via oxidative burst, but this effect could be mitigated by catalase (CAT). However, no studies have been reported on CAT homologs in P. ternata, a drought-sensitive plant species. In the present study, a novel CAT gene, PtCAT2, was functionally characterized via overexpression in Arabidopsis and analysis of cis-elements in its promoter. The isolated CAT gene was 1479 bp and encoded a protein containing 242 amino acids. The protein contains the CAT activity motif and the heme-binding site of a typical CAT, and the subcellular analysis indicated that the protein localizes at the cytoplasm and membrane. Moreover, the quantitative real-time reverse transcription PCR indicated that PtCAT2 is expressed ubiquitously in P. ternata and is strongly induced by drought stress and abscisic acid (ABA) signals. PtCAT2 overexpression enhanced the drought tolerance of Arabidopsis, as shown by the 30% increase in plant survival and a five-fold- increase in CAT activity. Moreover, PtCAT2-transgenic plants increased superoxide dismutase and peroxidase activities and reduced malondialdehyde, membrane leakage, and hydrogen peroxide (H₂O₂) (P<0.05). Furthermore, PtCAT2-transgenic plants showed higher tolerance to oxidative stress caused by exogenous H₂O₂ and retained higher chlorophyll and water contents than the WT. The mitochondria function was better maintained as presented by the higher oxygen consumption rate in transgenics under drought stress (P<0.05). The endogenous CATs and drought response-related genes were also upregulated in transgenic lines under drought stress, indicating that PtCAT2 confers drought stress tolerance by enhancing the H₂O₂ scavenging ability of plants to maintain their membrane integrity. These results improve our understanding of the drought response mechanisms and provide a potential breeding strategy for P. ternata genetic improvement.

Keywords: Arabidopsis thaliana; Pinellia ternata; catalase; drought; membrane integrity; reactive oxygen species.

Grants and funding

This work was supported by the National Natural Science Foundation of China (82373993; 82274048), the Key Project of Natural Science Research for Colleges and Universities in Anhui Province (KJ2021A0533; 2023AH050345), and Excellent Scientific Research and Innovation Team of University in Anhui Province (2022AH010029).