Grape Small Auxin Upregulated RNA (SAUR) 041 Is a Candidate Regulator of Berry Size in Grape

Grape (Vitis vinifera) is an important horticultural crop that can be used to make juice and wine. However, the small size of the berry limits its yield. Cultivating larger berry varieties can be an effective way to solve this problem. As the largest family of auxin early response genes, SAUR (small auxin upregulated RNA) plays an important role in the growth and development of plants. Berry size is one of the important factors that determine grape quality. However, the SAUR gene family’s function in berry size of grape has not been studied systematically. We identified 60 SAUR members in the grape genome and divided them into 12 subfamilies based on phylogenetic analysis. Subsequently, we conducted a comprehensive and systematic analysis on the SAUR gene family by analyzing distribution of key amino acid residues in the domain, structural features, conserved motifs, and protein interaction network, and combined with the heterologous expression in Arabidopsis and tomato. Finally, the member related to grape berry size in SAUR gene family were screened. This genome-wide study provides a systematic analysis of grape SAUR gene family, further understanding the potential functions of candidate genes, and provides a new idea for grape breeding.