Apple (Malus domestica) is a woody fruit tree belonging to the Rosaceae family, genus Malus. It has been widely reported that MYB transcription factors are critical regulators for the red color of apple peel by activating the expression of anthocyanin biogenesis genes. However, it is still not clear what the molecular mechanism for the yellow color of apple peel is. In order to investigate key genes and metabolites responsible for yellow coloration of apple peel, three strains of apples, “Venus Gold (Ype)” with yellow peel, “Yanfu8 (Mpe)” with medium red peel, and “Red love” with dark red peel, were selected in this study. Transcriptomic and metabolomic profiles were obtained for the peels of the three apple strains. After analyzing the transcriptomic profiles and being verified with qRT-PCR experiments, our results suggest that LAR1 is a critical gene for the yellow color of Ype peel. Analysis of metabolomic profiles revealed that the abundances of catechin and epicatechin in Ype peel were higher than those in Rpe, indicating an important reason for the yellow color of Ype peel. Furthermore, when comparing volatile metabolites from Ype, Mpe, and Rpe, hundreds of volatile metabolites show significantly different abundances, suggesting that apples with different peel colors have different odors. Our results uncover a novel metabolic mechanism for yellow coloration, where high expression of LAR1 promotes accumulation of catechin and epicatechin, providing the first integrated transcriptomic and metabolomic evidence for this pathway in apple peel.

Lily (Lilium spp.) is a perennial ornamental plant valued for its striking ornamental value and the edible and medicinal properties of its bulbs. Compared to other lilies, Oriental lilies are characterized by their large flowers and strong fragrance, making them one of the most popular types of lilies on the market. It is important to identify optimal parts of lily bulbs for rapid propagation of tissue culture seedlings. In this study, bulb scales of the Oriental lily ‘Pacific Ocean’ were used to explore the optimal parts for the tissue culture bulb induction. After 30 days of inoculation of lily scales in the induction medium, our results showed that Middle Central regions of the Inner layer scales (MCI) had the highest induction rate of 90.27 % among all regions from all layers of scales. In scales of all layers, the basal parts had the best longitudinal induction effects, followed by the middle and apical parts. Among all layers, the inner layers also had the lowest rates of contaminations. When taking both induction rate and contamination rate into account, MCI also represents the best choice among all compared parts. In summary, our results formed a practical guide for large-scale propagation of Oriental lily using tissue culture seedlings.

Red Fruit Ginseng (Campanumoea lancifolia), widely cultivated in Yunnan, Guizhou, Sichuan, and Guangxi, in China, is valued for its sweet-tasting fruit and medicinal potential. In this study, leaves of the Yunnan Maguan variety were used as explants to establish an efficient tissue culture system for callus induction, adventitious bud regeneration, and rooting. Different combinations of cytokinins and auxins were tested to determine the optimal balance of plant growth regulators (PGRs). Our results indicated that when the combined concentration of kinetin (KT) and 6-benzylaminopurine (6-BA) in the primary culture medium was lower than 1.0 mg/L, callus induction was the most effective, with treatments of 0.5 mg/L KT + 0.2 mg/L 6-BA and 0.2 mg/L KT + 0.8 mg/L 6-BA showing higher induction rates compared to other groups. During the subculture, 0.5 mg/L 6-BA promoted vigorous adventitious bud growth, while higher levels inhibited development. For rooting, 0.5 mg/L indole-3-acetic acid (IAA) combined with 0.2 mg/L 1-naphthaleneacetic acid (NAA) induced the highest root number and healthiest plantlets, outperforming indole-3-butyric acid (IBA). The optimized protocol resulted in over 80% explant survival and produced vigorous seedlings suitable for acclimatization. This leaf-derived regeneration method provides a reliable approach for large-scale propagation, conservation, and potential pharmacological applications of Red Fruit Ginseng, contributing to the sustainable utilization and commercial development of this valuable medicinal plant.

Induction of callus is an important step to produce high-quality seedlings, to promote the large-scale production of seedings, and to establish stable transgenic methods. To establish an efficient callus-based regeneration system for lily, in this study, we used the scales of Lilium regale as explants and employed plant tissue thin-layer culture to induce callus tissues. To examine the effects of different types and concentrations of plant growth regulators (PGRs) on the induction of lily callus tissues and plant regeneration, we designed orthogonal experiments using three PGRs: 6-BA, NAA, and PIC, with each regulator at three concentration levels. The results indicated that a suitable medium for inducing callus under the experimental conditions was 1.00 mg/L 6-BA + 0.05 mg/L NAA + 2.00 mg/L PIC, pH = 5.8 because in this medium, callus tissue showed a good balance of induction and contamination rate, as well as very low redifferentiation into bulbs. Under the experimental conditions, a suitable medium for callus expansion was 1 mg/L 6-BA + 0.5 mg/L NAA, pH = 5.8. We also showed that the induced callus tissues could develop into seedlings. These findings provide important references for optimizing in vitro culture systems of Lilium regale and offer supports for tissue culture studies of other lily species.

TCP transcription factors constitute a key regulatory family in plants, playing crucial roles in plant growth and development. Although this gene family has been extensively studied across diverse plant species, research in Gypsophila paniculata remains limited. Through genome-wide identification and analysis, this study identified 17 GpTCP in G. paniculata. Our analysis revealed that all GpTCP proteins contain a conserved TCP domain, with subcellular localization predictions indicating nuclear localization. Promoter analysis identified multiple cis-regulatory elements associated with plant organ development and growth regulation. Chromosomal synteny studies showed that gene expansion within the G. paniculata TCP gene family occurred after subfamily differentiation. Over-expression of GpTCP10 in Arabidopsis thaliana caused root development inhibition, leaf curling, smaller flowers, and yellowing of flowers. Further studies showed that in two normally growing G. paniculata varieties with different flower sizes, GpTCP10 was specifically expressed in leaf and floral tissues, with significantly higher expression levels in the smaller-flowered G. paniculata. These findings reveal the evolutionary characteristics of the TCP family in G. paniculata, and highlight the role of GpTCP10 in regulating organ growth and development in transgenic Arabidopsis thaliana and floral organ size in G. paniculata.

Cucumber Fusarium wilt, which is induced by the soil-borne pathogen Fusarium oxysporum f. sp. Cucumerinum (FOC), represents a highly destructive disease. Cucumber seedling grafted onto figleaf gourd (Cucurbita ficifolia Bouché) rootstock (CFC) demonstrated better resistance to FOC. However, the molecular mechanism underlying this enhanced disease resistance capability is largely unknown. To elucidate this, we performed transcriptome, small RNA, and degradome sequencing for leaves from CFC and self-grafted cucumbers (SGC) as controls, with and without FOC infections, respectively. Our results indicated that three NAC genes, all predicted as targets of csa-miR164, were significantly up-regulated in CFC after FOC infection. Co-transformation assay in Nicotiana benthamiana confirmed that csa-miR164f directly inhibits NAC2, and transient overexpression of NAC2 in cucumber enhanced resistance to FOC, supporting its positive role in defense. Therefore, our results suggest that three NACs, upregulated in CFC, as an alternative pathway, enhance the reactive oxygen species burst and hypersensitive response, which further elevates the resistance to FOC infection. These results provide new insights into the molecular basis for improved FOC resistance in CFC.