Genome-wide identification and characterization of the KNOX gene family in <i>Vitis amurensis</i>

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 <i>Vitis amurensis</i> 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.