MADS-box is a class of transcriptional regulators that are ubiquitous in plants and plays important roles in the process of plant growth and development. Identification and analysis of blueberry MADS-box genes can lay a foundation for their function investigations. In the present study, 249 putative MADS-box genes were identified in the blueberry genome. Those MADS-box genes were distributed on 47 out of 48 chromosomes. The phylogenetic and evolutionary analyses showed that blueberry MADS-box genes were divided into 131 type I members and 118 type II members. The type I genes contained an average of 1.89 exons and the type II genes contained an average of 7.83 exons. Motif analysis identified 15 conserved motifs, of which 4 were related to the MADS domain and 3 were related to the K-box domain. A variety of cis-acting elements were found in the promoter region of the blueberry MADS-box gene, indicating that the MADS-box gene responded to various hormones and environmental alterations. A total of 243 collinear gene pairs were identified, most of which had a Ka/Ks value of less than 1. Nine genes belonging to SEP, AP3/PI, and AGL6 subfamilies were screened based on transcriptomic data. The expression patterns of those nine genes were also verified using quantitative PCR, suggesting that VcMADS6, VcMADS35, VcMADS44, VcMADS58, VcMADS125, VcMADS188, and VcMADS212 had potential functions in blueberry fruit ripening. The results of this study provide references for an in-depth understanding of the biological function of the blueberry MADS-box genes and the mechanism of blueberry fruit ripening.

The glutathione S-transferases (GSTs, EC 2.5.1.18) constitute a versatile enzyme family with pivotal roles in plant stress responses and detoxification processes. Recent discoveries attributed the additional function of facilitating anthocyanin intracellular transportation in plants to GSTs. Our study identified 178 VcGST genes from 12 distinct subfamilies in the blueberry genome. An uneven distribution was observed among these genes across blueberry’s chromosomes. Members within the same subfamily displayed homogeneity in gene structure and conserved protein motifs, whereas marked divergence was noted among subfamilies. Functional annotations revealed that VcGSTs were significantly enriched in several gene ontology and KEGG pathway categories. Promoter regions of VcGST genes predominantly contain light-responsive, MYB-binding, and stress-responsive elements. The majority of VcGST genes are subject to purifying selection, with whole-genome duplication or segmental duplication serving as key processes that drive the expansion of the VcGST gene family. Notably, during the ripening of the blueberry fruit, 100 VcGST genes were highly expressed, and the expression patterns of 24 of these genes demonstrated a strong correlation with the dynamic content of fruit anthocyanins. Further analysis identified VcGSTF8, VcGSTF20, and VcGSTF22 as prime candidates of VcGST genes involved in the anthocyanin intracellular transport. This study provides a reference for the exploration of anthocyanin intracellular transport mechanisms and paves the way for investigating the spectrum of GST functions in blueberries.

Coconut (Cocos nucifera L.) is an important tropical horticultural crop valued for its edible endosperm with high oil content. However, the molecular mechanisms governing carbon partitioning and the regulation of glycolytic genes during endosperm development remain largely unclear. Fructose-1,6-bisphosphate aldolase (FBA), a key enzyme in glycolysis, plays a central role in carbohydrate metabolism, yet its transcriptional regulatory mechanisms in coconut have not been elucidated. In this study, the CoFBA promoter (proFBA) was isolated and used for yeast one-hybrid screening, leading to the identification of a GATA transcription factor, CoGATA2. Subcellular localization analysis confirmed that CoGATA2 is localized in the nucleus. Yeast one-hybrid assays, electrophoretic mobility shift assays (EMSA), and transient expression in coconut protoplasts demonstrated that CoGATA2 directly binds to a proFBA fragment containing the predicted GATA motif and represses CoFBA expression. Moreover, virus-induced gene silencing (VIGS) of CoGATA2 in coconut callus resulted in significant upregulation of CoFBA expression and increased fructose-1,6-bisphosphate (FBP) levels. Collectively, these findings demonstrate that CoGATA2 functions as a transcriptional repressor of CoFBA and that this regulation correlates with altered FBP levels in coconut callus. However, the precise mechanism by which FBP accumulation occurs and its relationship to glycolytic flux require further investigation. This study provides new insights into the transcriptional regulation of a key glycolytic gene in coconut and offers a foundation for future efforts to manipulate carbon partitioning in this important horticultural crop.