Overexpression of FvBBX22 from Fragaria Vesca Promotes Anthocyanin Synthesis and Delays Flowering Time in Arabidopsis thaliana

doi:10.13560/j.cnki.biotech.bull.1985.2026-0204

Abstract

Abstract:

Objective BBX transcription factors play important roles in plant growth and development, and exploring the biological functions of FvBBX22 provides genetic resources for strawberry molecular breeding. Method Using Fragaria vesca ‘Ruegen’ as experimental material, the FvBBX22 gene was cloned by RT-PCR. The physicochemical properties and structural characteristics of its protein, as well as its phylogenetic tree, were analyzed using bioinformatics methods. An overexpression vector for the FvBBX22 gene was constructed, and transgenic Arabidopsis plants were obtained via the floral dip method. The flowering phenotype of transgenic Arabidopsis was observed, and anthocyanin content in leaves was measured. The expression levels of genes related to anthocyanin biosynthesis and flowering pathways were detected by RT-qPCR. Additionally, the tissue-specific expression pattern of FvBBX22 in Fragaria vesca was analyzed. Result The full-length CDS of FvBBX22 was 864 bp, encoding 287 amino acids. It contained two conserved B-box domains and belonged to subgroup Ⅳ of the BBX family. Phylogenetic analysis revealed that the BBX22 proteins from F. vesca and Rubus argutus (of the Rosaceae family) are closely related. Tissue-specific expression analysis showed that FvBBX22 is expressed in all tissues of F. vesca, with the highest expression in stems, followed by leaves. In Arabidopsis plants overexpressing FvBBX22, leaves appeared light purple, and anthocyanin content was significantly higher than that in wild-type Arabidopsis. Analysis of the expression of genes involved in the anthocyanin biosynthesis pathway revealed significantly elevated levels of AtCHS, AtCHI, AtF3H, AtDFR, AtANS, and AtUF3GT. However, the flowering time of transgenic Arabidopsis was delayed. Analysis of the expression of genes involved in the flowering pathway revealed significantly reduced levels of AtCO, AtFT, AtFUL, and AtLFY. Conclusion FvBBX22 promotes anthocyanin accumulation and delays flowering time in Arabidopsis.

Key words: strawberry, BBX22, anthocyanin, flowering, functional analysis, gene cloning, bioinformatics analysis, expression analysis

DONG Xiang-xiang, HOU Wei-wei, MIAO Bai-ling, CHEN Juan-juan, LI Liang-jie, ZHAI Min, ZHU Qing-song, LIU Song-hu. Overexpression of FvBBX22 from Fragaria Vesca Promotes Anthocyanin Synthesis and Delays Flowering Time in Arabidopsis thaliana[J]. Biotechnology Bulletin, 2026, 42(9): 231-237.

Figures/Tables 4

Fig. 1 Phylogenetic analysis of BBX22 proteins from different species

Fig. 2 Expression analysis of FvBBX22 in different tissues (A), DNA-level identification (B) and gene expression level analysis (C) of A. thaliana overexpressing FvBBX22Different lowercase letters indicate significant differences (P<0.05). The same below

Fig. 3 Effects of FvBBX22 overexpression in A. thaliana on anthocyanin content and expression levels of anthocyanin-synthesis-related genesA: Leaf phenotype. B: Determination of anthocyanin content in leaves. C‒H: Expression levels of anthocyanin synthesis related genes

Fig. 4 Flowering phenotype and expression analysis of flowering-related genes in A. thaliana overexpressing FvBBX22A: Flowering phenotype. B: Statistics of flowering time. C‒F: Expression levels of flowering-related genes

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