# LhSBP1 Gene of Liriodendron Hybrid Enhances the Cold Resistance of Plants by Regulating ROS Metabolism

## TL;DR

The LhSBP1 gene from Liriodendron hybrid improves plant cold resistance by reducing harmful oxygen molecules and boosting protective enzymes.

## Contribution

This study demonstrates the conserved role of LhSBP1 in enhancing cold tolerance across two plant species through ROS regulation.

## Key findings

- LhSBP1 overexpression in Arabidopsis reduced ROS and MDA levels and increased antioxidant enzyme activities.
- Transgenic poplar with LhSBP1 showed improved cold tolerance with reduced ROS and increased antioxidant enzyme activities.
- The LhSBP1 gene provides a genetic resource for breeding cold-tolerant woody plants.

## Abstract

Selenium-Binding Protein 1 (SBP1), involved in selenium metabolism, contributes to plant stress response. However, it is currently unknown whether the SBP1 protein from Liriodendron hybrid (LhSBP1) plays a role in response to cold stress. In this study, transgenic overexpression lines of LhSBP1 in Arabidopsis thaliana and Populus deltoides × P. euramericana cv. ‘Nanlin 895’, were used as materials to conduct phenotypic observations and physiological and biochemical determinations under cold stress. The results showed that the full-length CDS sequence of LhSBP1 gene was cloned, with a length of 1467 bp, encoding 488 amino acids. Under cold stress, physiological and biochemical indexes showed that the contents of reactive oxygen species (ROS) and malondialdehyde (MDA) in transgenic Arabidopsis were lower, with the contents of hydrogen peroxide (H2O2) and superoxide anion (O2−) being 0.72 and 0.71 times those of the wild type, respectively, and the MDA content was 0.53 times that of the wild type. Compared with the wild type, the activities of antioxidant enzymes including superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) increased by 1.2, 1.75, and 1.48 times respectively, and the soluble protein content increased by 1.41 times, which significantly improved the cold tolerance of Arabidopsis. The contents of H2O2, O2−, and MDA in LhSBP1 transgenic ‘Nanlin 895’ poplar were 0.63 and 0.67 times and 0.6 times those of wild type, respectively. The activities of SOD, POD and CAT were increased by 1.37, 1.48, and 1.44 times, and the soluble protein was increased by 1.28 times, which significantly improved the cold tolerance of ‘Nanlin 895’ poplar. Taken together, this study utilized two model plant systems to demonstrate the positive and conserved functions of LhSBP1 in plant cold tolerance defense response, which provided valuable genetic resources for the breeding of cold-tolerance woody plants.