Analysis of the regulatory mechanisms of morphogenesis in grape berries with different fruit shapes based on transcriptome

• Our observation and study found that there was not much difference in fruit shape between the three varieties at the young fruit stage, but there was a large difference in fruit shape at the enlargement stage and veraison stage, and the vertical and horizontal meridians were significantly increased. This result is consistent with the results of cell microstructure. • Transcriptome analysis of fruit samples 25 days after anthesis showed that the differential genes were mainly enriched in the plant hormone signal transduction pathway, and the expression of differential genes affected the expansion and division of grape fruit cells. • The real-time PCR results showed that the expression of differentially differentiated genes was consistent with the trend of qRT-PCR results, indicating that the transcriptome data results were reliable. • Combined with the comprehensive analysis of transcriptome differential gene samples and fruit hormone content, it was found that the regulation of differential genes would lead to the accumulation of plant hormone content, which would cause fruit expansion and affect its fruit shape and fruit development. Fruit shape is one of the important appearance quality, which directly affects the choice of consumers, so it is of great significance to study the formation mechanism of appearance shape for improving grapevines appearance quality. In this study, three grapevine varieties, namely 'Rizamat', 'Victoria', and 'Fujiminori', exhibiting distinct grapevine shapes, were selected as the research subjects. Transcriptome sequencing analysis was conducted on key stages of grapevines morphogenesis, while the endogenous hormone content in berries at different developmental stages was also determined. The results showed that there was no significant difference in vertical and horizontal diameters between the three berry varieties at the young fruit stage and the veraison, and the difference in vertical and horizontal diameters of grapevine at the enlargement stage was the most significant among the three grapevine varieties. At the fruit enlargement stage, the longitudinal diameter of 'Rizamat' reached 25.0 mm, followed by 'Victoria' (22.9 mm), and 'Fujiminoru' was the smallest (18.2 mm). The transverse diameter of 'Victoria' was 17.4 mm and 'Fujiminoru' was 16.1 mm, which was significantly higher than that of 'Rizamat' (14.9 mm), and the shape index showed that 'Rizamat'> 'Victoria'> 'Fujiminoru'. A total of 2288 differential genes were obtained by transcriptome sequencing of the pulp 25 days after anthesis, and KEGG was significantly enriched in the "plant hormone signal transduction" pathway, including 13 auxin signaling pathways, 2 cytokinin signaling pathways, 2 abscisic acid signaling pathways, 1 brassinolide signaling pathway, and 2 differentially expressed genes related to methyl jasmonate signaling pathway. A total of 1520 differentially expressed transcription factors were recorded, including 115 and 112 AP2/ERF-ERF and bHLH, respectively. In addition, the oblong variety 'Rizamat' was significantly higher than in the other two varieties. The contents of IAA, GA3 and ZT were significantly correlated with differential gene Vitis_vinifera_newGene_3009, SAUR71-like, TIFY9 and VIT_14s0030g02310 . In conclusion, the difference in the expression of gene expression related to plant hormone signal transduction regulates the difference in ZT and GA3 accumulation in fruits, which is one of the reasons for the morphological differences of 'Rizamat', 'Victoria' and 'Fujiminori'.