Chinese cabbage is rich in vitamins, fibre, and nutrients and is one of the primary vegetables consumed in autumn and winter in South Asia. ‘Purple pak choi’ sprouts are particularly rich in anthocyanins and are favoured by consumers. However, reports on the regulation of anthocyanin synthesis in purple pak choi sprouts do not exist. In this study, we examined the phenotypic development of purple pak choi sprouts after germination. The total anthocyanin content increased from 0.02 to 0.52 mg/g FW from days 0 to 6. RNA-seq data analysis revealed an increase in differentially expressed genes corresponding to the development of purple pak choi sprouts. Expression pattern analysis of genes associated with the anthocyanin biosynthesis pathway revealed a significant upregulation of structural genes during the purple phase, suggesting that the transcription factors PAP2 and MYBL2 may play crucial regulatory roles. BraPAP2.A03, BraTT8.A09, and BraMYBL2.A07 exhibited strong interactions with key genes in the anthocyanin biosynthesis pathway, specifically BraDFR.A09. Furthermore, the expression of BraPAP2.A03 aligned with the expression patterns of most anthocyanin biosynthesis-related genes, whereas those of BraTT8.A09 and BraMYBL2.A07 corresponded with the expression pattern of BraDFR.A09. These results provide valuable insights into regulatory mechanisms underlying anthocyanin synthesis in purple pak choi sprouts.

Orychophragmus violaceus is an ornamental plant belonging to the Brassicaceae family, known for its profusion of white to light purple, pink, and purple flowers that bloom in early spring. However, there is a lack of reports regarding the localization of the genes responsible for flower color. The aim of this research was to locate the key genes controlling flower color variation in O. violaceus, providing loci for its genetic improvement of flower color. In this study, we constructed an F₂ mapping population using the purebred white flower mutant line OvW-1 and the purebred purple flower line OvP-37, obtained candidate regions of the Ovwf locus using BSA-seq, and then used extreme recessive white-flowered plants for fine-mapping and combined with RNA-seq to predict key genes controlling the white-flowered trait. Genetic analysis indicated that the Ovwf trait is governed by a single recessive locus, designated as without cytoplasmic inheritance. Subsequently, BSA-seq and fine-mapping of the Ovwf locus within a 1.37 Mb interval. Gene annotation revealed that this interval encompasses 76 genes, of which only two genes—OV03G032130 and OV03G032280—are potentially implicated in anthocyanin biosynthesis. Further RNA-seq analysis suggested that only OvANS (OV03G032130) was differentially expressed, which may be a critical gene influencing the white flower locus Ovwf. This is the first report of fine-mapping of the flower color locus in O. violaceus. These findings contribute valuable insights into the mechanisms underlying flower color variation in O. violaceus and present a promising target for the breeding of colorful varieties.

The plant phytohormone abscisic acid (ABA) plays important roles in plant development. The ABA receptors PYR/PYL/RCAR (PYLs) interact with the type 2C protein phosphatases (PP2Cs) in response to ABA. In the present study, 25 homologous PYL genes (BrPYLs) were identified in the Chinese cabbage (Brassica rapa subsp. pekinensis (Lour.) Hanelt) genome, which were annotated onto all of the 10 chromosomes and 3 sub-genomes in Chinese cabbage. The whole genome annotation and gene structures were predicted and analyzed. The selection pressures and divergence timings of duplicated genes were analyzed. Phylogenetic analysis of BrPYLs, along with their Arabidopsis counterparts, divided into three subfamilies. In addition, in silico transcript expression analysis showed some BrPYLs had high expression levels in different tissues. Real-time RT-PCR analysis revealed that 10 BrPYLs are highly responsive to abiotic treatments. 6 out of the 25 BrPYL genes were highly induced by different abiotic stresses, which might be utilized to improve the abiotic tolerance of Chinese cabbage. Taken together, this study provides genetic information of the BrPYL gene family in Chinese cabbage, which may play several roles in plant defense environmental changes. This work may be useful for future functional analysis of other BrPYL genes in Chinese cabbage.