Anthocyanins are the main pigments in flowers and fruits. These pigments are responsible for the red, red-purple, violet, and purple color in plants, and act as insect and animal attractants. In this study, phenotypic analysis of the purple flower color in eggplant indicated that the flower color is controlled by a single dominant gene, FAS. Using an F₂ mapping population derived from a cross between purple-flowered ‘Blacknite’ and white-flowered ‘Small Round’, Flower Anthocyanidin Synthase (FAS) was fine mapped to an approximately 165.6-kb region between InDel marker Indel8-11 and Cleaved Amplified Polymorphic Sequences (CAPS) marker Efc8-32 on Chromosome 8. On the basis of bioinformatic analysis, 29 genes were subsequently located in the FAS target region, among which were two potential Anthocyanidin Synthase (ANS) gene candidates. Allelic sequence comparison results showed that one ANS gene (Sme2.5_01638.1_g00003.1) was conserved in promoter and coding sequences without any nucleotide change between parents, whereas four single-nucleotide polymorphisms were detected in another ANS gene (Sme2.5_01638.1_g00005.1). Crucially, a single base pair deletion at site 438 resulted in premature termination of FAS, leading to the loss of anthocyanin accumulation. In addition, FAS displayed strong expression in purple flowers compared with white flowers and other tissues. Collectively, our results indicate that Sme2.5_01638.1_g00005.1 is a good candidate gene for FAS, which controls anthocyanidin synthase in eggplant flowers. The present study provides information for further potential facilitate genetic engineering for improvement of anthocyanin levels in plants.

Anthocyanins are important secondary metabolites in fruits, and anthocyanin accumulation in the flesh of peach exhibits a spatial pattern, but the relevant mechanism is still unknown. In this study, the yellow-fleshed peach, cv. ‘Jinxiu’, with anthocyanin accumulation in the mesocarp around the stone was used as the experimental material. Red flesh (RF) and yellow flesh (YF) were sampled separately for flavonoid metabolite (mainly anthocyanins), plant hormone, and transcriptome analyses. The results showed that the red coloration in the mesocarp was due to the accumulation of cyanidin-3-O-glucoside, with an up-regulation of anthocyanin biosynthetic genes (F3H, F3′H, DFR, and ANS), transportation gene GST, and regulatory genes (MYB10.1 and bHLH3). Eleven ERFs, nine WRKYs, and eight NACs were also defined as the candidate regulators of anthocyanin biosynthesis in peach via RNA-seq. Auxin, cytokinin, abscisic acid (ABA), salicylic acid (SA), and 1-aminocyclopropane-1-carboxylic acid (ACC, ethylene precursor) were enriched in the peach flesh, with auxin, cytokinin, ACC, and SA being highly accumulated in the RF, but ABA was mainly distributed in the YF. The activators and repressors in the auxin and cytokinin signaling transduction pathways were mostly up-regulated and down-regulated, respectively. Our results provide new insights into the regulation of spatial accumulation pattern of anthocyanins in peach flesh.

Charcoal-based fertilizer could be used extensively and is environmentally friendly. An experiment was designed to investigate the effects of different charcoal-based fertilizer application methods on soil microbiology and grape quality in a vineyard to guide the cultivation of ‘Shine-Muscat’. A control treatment without fertilization and six other treatments were set up. Four treatments applied carbon-based fertilizer as a base fertilizer with or without potassium fulvic acid, a complex microbial agent, or Bacillus subtilis, and two treatments were only applied with two applications of carbon-based fertilizer or compound fertilizer during the expansion period. The results showed that the bacterial phyla were mainly Proteobacteria and Bacteroidetes. Ascomycota, Basidiomycota, and Mortierellomycota dominated the fungal community. At the genus level, the composition of fungi, compared to bacteria, varied significantly, while the dominant flora differed among fertilization practices. Application of charcoal-based fertilizer enriched beneficial microorganisms, while chemical fertilizers enriched pathogenic microorganisms. The addition of microbial fungicides and biostimulants for a period reduced the size of the microbial network, lowered positive correlations, and enhanced resistance to adverse conditions and diseases and there was no significant correlation between agronomic traits and microbial network topology. A combination of soil microbial and grape agronomic traits suggests that a charcoal-based fertilizer base, with microbial fungicides applied, is the optimal fertilization regimen for grape.

Finger citron (Citrus medica ‘Fingered’) is used as a raw material for essential oil extraction due to its distinctive fragrance. Studies have predominantly focused on the fruit, but the aroma components of the leaves have not yet been systematically compared. This study used headspace solid-phase microextraction gas chromatography mass spectrometry combined with the relative odor activity value (ROAV) and molecular docking to analyze the volatile compound composition, aroma characteristics, and interactions with human olfactory receptor OR1A1 in leaves of different finger citron cultivars. Based on pooled samples of six individual plants per cultivar, a total of 394 compounds were tentatively identified among all of the cultivars, with terpenoids being the most abundant class. (+)-Sylvestrene, geranial, and neral were the three components with the highest relative contents. Analysis of the pooled samples preliminarily revealed differences in volatile composition among cultivars. Yunfoshou had the relatively highest total volatile content. The volatile profiles of QingyiTongzi, Xiuzhen, Tianci, Cuiyu, Kaixin, and Guangfoshou were relatively similar to each other but differed from those of Yangguang and Yunfoshou. Thirteen key aroma-active compounds were screened using ROAV analysis, and linalool exhibited the highest ROAV across all of the cultivars. The aroma profiles of all of the cultivars were predominantly floral. Molecular docking predictions showed that the binding energies of the 13 key aroma compounds with OR1A1 ranged from −5.859 to −8.652 kcal/mol, with Asn109 and Tyr258 involved in hydrogen bonding and hydrophobic interactions, respectively. This study preliminarily reveals the aroma characteristics of leaves from different finger citron cultivars and provides a preliminary theoretical basis for finger citron breeding and the development of deep-processed leaf products.