# Genome-Wide Characterization of Kiwifruit Invertase Gene Family Reveals Roles of AcCWINV4 in Sugar Accumulation and Cold Tolerance

## TL;DR

This study identifies and characterizes invertase genes in kiwifruit, focusing on AcCWINV4's role in sugar accumulation and cold tolerance.

## Contribution

The study reveals the functional role of AcCWINV4 in kiwifruit sugar metabolism and cold stress response through gene silencing.

## Key findings

- 25 invertase genes were identified and analyzed in the kiwifruit genome.
- AcCWINV4 is associated with sugar accumulation during post-harvest ripening.
- VIGS confirmed AcCWINV4's role in cold tolerance and sugar regulation.

## Abstract

Invertase, a core catalyst in sugar metabolism, irreversibly hydrolyzes sucrose into hexoses, establishing the fundamental biochemical pathway for carbon allocation in plants and playing pivotal roles in plant growth development, fruit quality regulation, and stress response. In the present study, we identified a total of 25 invertase genes from the kiwifruit (Actinidia chinensis cv Hongyang) genome and systematically analyzed the physicochemical properties, chromosomal localization, genomic features, and gene evolution patterns of the AcINV family. The evaluation of selection pressure indices robustly demonstrated that the INV family underwent purification selection during domestication. Furthermore, based on the correlation between gene expression levels during the post-harvest ripening stage of kiwifruit and soluble sugar content, we identified the potential gene AcCWINV4 as being associated with sugar accumulation. Furthermore, virus-induced gene silencing (VIGS) of AcCWINV4 confirmed its functional role in fruit sugar accumulation and plant response to cold stress. This study provides critical theoretical support for breeding cold-tolerant and high-quality kiwifruit varieties using molecular biological methods.