# Genome-wide identification and characterization of the KNOX gene family in Vitis amurensis

## TL;DR

This study identifies and characterizes KNOX genes in Vitis amurensis, revealing their roles in plant growth, fruit quality, and cold resistance.

## Contribution

The first comprehensive analysis of the KNOX gene family in Vitis amurensis, including gene classification and expression patterns.

## Key findings

- Ten KNOX genes were identified and classified into two subclasses in Vitis amurensis.
- Class I KNOX genes showed tissue-specific expression, while Class II genes were ubiquitously expressed.
- VaKNOX2, VaKNOX3, and VaKNOX5 are linked to fruit quality, and VaKNOX6 and VaKNOX7 are associated with cold resistance.

## Abstract

The KNOX (KNOTTED1-like homeobox gene) gene family plays a pivotal role in controlling plant growth, maturation, and morphogenesis. However, the function of KNOX in Vitis amurensis has not yet been reported. This study identified and characterized the entire KNOX gene family in Vitis amurensis.

By employing bioinformatic approaches, the phylogenetic relationships, chromosomal positions, gene architectures, conserved motifs, cis-regulatory elements present in promoter regions, and gene expression profiles of KNOX gene family members in Vitis amurensis were identified and analyzed.

Ten KNOX genes spanning nine chromosomes were discovered, and these genes were subsequently categorized into two distinct subclasses. The promoter regions of members of the KNOX gene family include cis-acting elements that are involved in plant growth, hormonal regulation, and stress and light responses. An examination of the expression profiles of KNOX genes in different tissues of Vitis amurensis revealed that genes in Class I presented tissue-specific expression patterns, whereas genes belonging to Class II presented more ubiquitous expression across various tissues. The expression levels of Vitis amurensis KNOTTED1-like homeobox (VaKNOX)2, VaKNOX3, and VaKNOX5 were highest in fruits. VaKNOX2, VaKNOX3, and VaKNOX5 can serve as candidate genes for enhancing fruit quality. The expression levels of VaKNOX6 and VaKNOX7 were much higher in cold environments than in normal conditions. Through in-depth research into the functions of VaKNOX6 and VaKNOX7, we aimed to improve the cold resistance of grapevine varieties.