Chinese narcissus (Narcissus tazetta var. chinensis) was introduced to China 1300–1400 years ago, and has grown naturally in southeastern China. It is a popular Chinese traditional potted flower and a well-known flowering bulb cultivated worldwide with only two white-tepal triploid cultivars, ‘Jinzhan Yintai’ and ‘Yulinglong’. Recently, a mutant with yellow tepals was observed and promptly became popular. To clarify the key pigment for color difference and its molecular mechanism of accumulation, we conducted pigment metabolite analysis and comparative transcriptome analysis on ‘Jinzhan Yintai’ and the yellow-flowered mutant. The results showed that there was no significant difference in total flavonoid content between the mutant and ‘Jinzhan Yintai’, whereas the total carotenoid content of the mutant was more than 10-fold higher than that of ‘Jinzhan Yintai’. Based on the RNA-sequencing results, sixty-four unigenes, corresponding to 29 enzymes associated with the carotenoid biosynthesis pathway, were analyzed in detail. A comparative KEGG pathway enrichment analysis, in conjunction with quantitative real-time PCR data, revealed the opposite gene expression mode of the carotenoid biosynthesis pathway. Compared with ‘Jinzhan Yintai ’, PSY and PDS were up-regulated in the three mid-flowering stages of the mutant, whereas NCED genes were strongly down-regulated, which likely contributed to carotenoid accumulation in chromoplasts of the tepals in the mutant.
The Lycoris radiata (L’ Herit.) Herb. is a perennial bulbous plant characterized by its high ornamental and medicinal value, exhibiting a unique growth rhythm where the flower and leaf do not coexist and a period of summer dormancy. However, its metabolic response to various developmental stages remains unclear. To address this gap, we conducted a non-targeted metabolomic analysis spanning six developmental stages of L. radiata. The results showed that most differentially accumulated metabolites (DAMs) demonstrated enrichment predominantly in carbohydrate and amino acid metabolism pathways, with the former being more active during vegetative growth and the latter during reproductive stages. The proportion of DAMs categorized under “quaternary ammonium salts”, “tricarboxylic acids and derivatives”, “fatty acids and conjugates”, and “pyrimidine nucleotide sugars” was notably higher in comparisons between the flowering and dormancy stages than in other comparative groups. Furthermore, DAMs involved in the KEGG pathways of C5-branched dibasic acid metabolism and lysine biosynthesis were uniquely identified during the transition from Dormancy to Flowering. The proportion of DAMs associated with “linoleic acids and derivatives” and “pyridines and pyridine derivatives” was notably higher in the leafing out versus flowering comparison than in other comparative groups. Furthermore, the glycolysis/gluconeogenesis pathway was uniquely enriched by DAMs during this phase. This study provided an in-depth view of metabolite changes in L. radiata over its annual growth cycle, enriching our understanding of the regulatory mechanisms governing its development, dormancy, and flowering.
Turpinia arguta is an excellent medicinal plant mainly used for the treatment of pharyngitis, tonsillitis, and tonsillar abscesses. However, an efficient regeneration protocol using tissue cultures for T. arguta does not exist. Its main medicinal constituents are flavonoids, particularly ligustroflavone and rhoifolin. Here, we aimed to establish a tissue culture system for T. arguta for the first time using annual stem segments with axillary buds harvested from the field of the Jiangxi Academy of Forestry as explants by dynamically determining the accumulation of effective functional components in the tissue culture plantlets. Orthogonal tests were conducted to compare the effects of different explant disinfection times, media, and exogenous hormone ratios on the induction of the axillary bud growth, successional proliferation, and rooting of T. arguta stem segments. The best explant disinfection effect was achieved by disinfecting the T. arguta explant with 75% ethanol for 50 s, followed by 0.1% mercuric chloride (HgCl2) for 6 min, and the optimal media for successional proliferation and rooting were Murashige and Skoog (MS) + 0.2 mg/L of 6-benzyladenine (6-BA), + 0.03 mg/L of naphthaleneacetic acid (NAA), and ½ MS + 2.5 mg/L of indole-3-butyric acid + 0.5 mg/L of NAA, respectively. The detection of ligustroflavone and rhoifolin in tissue culture plantlets 0, 3, and 5 months after transplanting showed a significant increasing trend and eventually exceeded the content requirements of the 2020 Edition ofChinese Pharmacopoeia for T. arguta. Our findings provide, for the first time, an effective tissue culture system for T. arguta, thereby providing important information to support the germplasm preservation, innovation, and application of T. arguta in the future.
The dry leaf of Turpinia arguta (Lindl.) Seem. is used in traditional Chinese medicine as a quick-acting product for sore throat and pharyngitis relief. Samples of T. arguta were collected from 40 different habitats mostly located in Jiangxi Province, and leaf appearance traits and dry matter yield were analyzed. HPLC was used to quantify ligustroflavone and rhoifolin, the pharmacological-quality markers for this species, according to the 2020 Edition of Chinese Pharmacopoeia. The correlations between leaf-measurable traits, ligustroflavone and rhoifolin contents, and climate factors were subsequently assessed using Pearson’s two-tailed correlation test and redundancy analysis. The highest dry matter yields were found in locations S(G-mt), Q(J-t), and A(X-t). Ligustroflavone and rhoifolin contents ranged from 0.023% to 1.336% and 0.008% to 0.962%, respectively; the highest levels of ligustroflavone and rhoifolin compounds were found in locations A(X-t) and Y(B-mt). Leaf morphology was influenced by the mean temperature of the warmest quarter, while leaf thickness was affected by the minimum temperature of the coldest month, precipitation seasonality, and solar radiation. Larger and thicker leaves predicted higher yields of ligustroflavone and rhoifolin compounds in T. arguta under Chinese southern conditions, such as those in Anyuan and Quannan counties. Our findings suggest that enhancing the mean diurnal temperature range and implementing appropriate shading during cultivation can enhance the ligustroflavone and rhoifolin compounds of T. arguta.
This study aimed to investigate differences in the leaf biomasses, chemical compositions, and pharmacological activities of Turpinia arguta histocultured seedlings and live seedlings at different harvesting periods (S1, S2, S3, and S4) in order to determine the optimal harvesting period. Eleven indexes, including biomass, key active components, secondary metabolites, nutrient content, and antioxidant activity, were evaluated by high-performance liquid chromatography and colorimetric methods during different harvesting periods. The weights of the 11 indexes were calculated by principal component analysis, and then a comprehensive quality evaluation was performed. The results showed significant differences in leaf biomasses, key active components, secondary metabolites, nutrient contents, and antioxidant activities between the different harvesting periods. The highest quality score was obtained for the S4 period, indicating that the quality of T. arguta was the best at this time and that the S4 period was the most suitable harvesting period. At this period (S4), the medicinal component content, antioxidant activity, and comprehensive quality score of the histocultured seedlings of T. arguta were higher than those of the live seedlings, indicating the importance of tissue culture technology in enhancing the quality of T. arguta. This study provides more novel and abundant information and reference for determining the appropriate harvesting period of T. arguta, with the aim of providing newer scientific guidance for the management of herbs.