# Identification of OCT Family Genes in Tomato (Solanum lycopersicum) and Function of SlOCT20 Under Cold Stress

## TL;DR

This study identifies the SlOCT20 gene in tomatoes and shows it helps plants tolerate cold stress by reducing oxidative damage.

## Contribution

The study discovers a new gene, SlOCT20, that positively regulates cold stress tolerance in tomatoes.

## Key findings

- SlOCT20 is localized in the cell membrane and plays a role in cold stress resistance.
- Silencing SlOCT20 reduces cold tolerance and increases oxidative stress in tomatoes.
- Transcriptome and qRT-PCR analyses confirmed SlOCT20's key role in cold stress response.

## Abstract

Tomato, as a vegetable crop that prefers warmth, has relatively high requirements for planting temperature. Cold stress often occurs in tomato cultivation, especially in early spring and late autumn. Cold stress not only affects the growth, development and yield of tomatoes, but in severe cases, it can also lead to the direct death of tomato plants. Screening cold-resistant genes and analyzing their regulatory mechanisms of cold resistance are of great significance for enhancing the pertinence of stress-resistant breeding. This study identified the cold-resistant gene SlOCT20 in cultivated tomatoes and analyzed the molecular mechanisms by which it regulates tomato cold resistance, providing a new regulatory mechanism of plant cold resistance.

Plant organic cation transporters (OCTs) are involved in a variety of beneficial biological processes, such as cadaverine transfer in plants and soil, and play an active role in the formation of plant stress resistance. In this study, 52 OCT family genes were identified in tomato, and comprehensive bioinformatics analyses of these numbers, such as promoter cis-acting elements, gene mapping and collinearity, protein characterization and phylogenetic analysis. By analyzing the expression of tomato OCT family genes under cold and salt stresses using transcriptome data and qRT-PCR experiments, a key gene regulating cold stress tolerance, SlOCT20, was identified. Subcellular localization experiments indicated that SlOCT20 was mainly localized in the cell membrane. When the SlOCT20 gene was silenced in tomato, the tolerance to cold stress was significantly reduced and oxidative stress was aggravated, indicating that this gene positively regulates the tolerance to cold stress in tomato.