Search Results (3)

Nekemias grossedentata (Hand.-Mazz.) J. Wen & Z. L. Nie is a medicinal and edible plant with a high dihydromyricetin (DHM) content in its bud tips. Vine tea made from its bud tips has served as a health tea and Chinese herbal medicine for nearly 700 years. However, the molecular mechanisms underlying the high DHM content in N. grossedentata bud tips remain inadequately elucidated. This study conducted qualitative and quantitative analyses of bud tip flavonoids utilizing HPLC and targeted metabolomics. Core genes influencing the substantial synthesis of DHM in N. grossedentata were identified through integrated transcriptome and metabolome analyses. The results revealed that 65 flavonoid metabolites were detected in bud tips, with DHM as the predominant flavonoid (37.5%), followed by myricetin (0.144%) and taxifolin (0.141%). Correlation analysis revealed a significant positive correlation between NgF3′5′H3 expression and DHM content. Co-expression analysis and qRT-PCR validation demonstrated a significant positive correlation between NgMYB71 and NgF3′5′H3, with consistent expression trends across three periods and four tissues. Consequently, NgF3′5′H3 and NgMYB71 were identified as core genes influencing the substantial synthesis of DHM in N. grossedentata. Elevated NgMYB71 expression in bud tips induced high NgF3′5′H3 expression, facilitating extensive DHM synthesis in bud tips. Molecular docking analysis revealed that NgF3′5′H3 had a strong binding affinity for taxifolin. NgF3′5′H3 was the pivotal core node gene in the dihydromyricetin biosynthesis pathway in N. grossedentata and was highly expressed in bud tips. The strong specific binding of NgF3′5′H3 to dihydromyricetin precursor metabolites catalyzed their conversion into DHM, resulting in higher DHM contents in bud tips than in other tissues or plants. This study aimed to elucidate the molecular mechanisms underlying the substantial synthesis of DHM in N. grossedentata, providing a theoretical foundation for enhancing DHM production and developing N. grossedentata resources. Full article

This study aimed to explore the physiological and biochemical mechanisms of the interaction between N. grossedentata and A. nigripes. First, specimens were categorized into low- (6.16% ± 0.66%), medium- (9.23% ± 1.19%), and high-content groups (21.23% ± 1.23%) based on the initial dihydromyricetin concentration in N. grossedentata. Subsequently, we assessed the variations in total flavonoids, dihydromyricetin, myricitrin, and myricetin in plants 24, 48, and 72 h post-feeding. Concurrently, we analyzed the impact of plant leaf consumption on the detoxifying [glutathione S-transferase (GST), carboxylesterase (CarE), acetylcholinesterase (AchE), and cytochrome P450 (CYP450)] and protective enzyme [superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT)] activities in A. nigripes, along with its metabolic processes. The results demonstrated that N. grossedentata enhanced its secondary metabolites, particularly dihydromyricetin, as a defensive response to insect-induced stress. A. nigripes utilized its detoxification and protective enzyme systems to mitigate the effects of high flavonoid levels in the host plant, with particular emphasis on the roles of detoxification enzymes (GST, AchE, CYP450, and CarE) in detoxification metabolism, which showed significant correlation (p < 0.01) with dihydromyricetin, exhibiting correlation coefficients of 0.689, 0.633, 0.579, and 0.561, respectively. Additionally, key flavonoids in N. grossedentata were observed to accumulate with different degrees during digestion and metabolism in insects. These findings lay a theoretical foundation for the further exploration of the molecular mechanisms of A. nigripes adaptation to a flavonoid-rich plant N. grossedentata and inform the development of novel pest control strategies and the selection of resistant plant varieties. Full article

Medicinal plants have long played a crucial role in healthcare systems, but limited genomic information on these species has impeded the integration of modern biological technologies into medicinal plant research. In this study, we selected nine common medicinal plants, each belonging to a different plant family, including Sarcandra glabra (Chloranthaceae), Nekemias grossedentata (Vitaceae), Uraria crinita (Fabaceae), Gynostemma pentaphyllum (Cucurbitaceae), Reynoutria japonica (Polygonaceae), Pseudostellaria heterophylla (Caryophyllaceae), Morinda officinalis (Rubiaceae), Vitex rotundifolia (Lamiaceae), and Gynura formosana (Asteraceae), to estimate their genome sizes and conduct preliminary genomic surveys. The estimated genome sizes by flow cytometry were 3.66 Gb, 0.65 Gb, 0.58 Gb, 1.02 Gb, 3.96 Gb, 2.99 Gb, 0.43 Gb, 0.78 Gb, and 7.27 Gb, respectively. The genome sizes of M. officinalis, R. japonica, and G. pentaphyllum have been previously reported. Comparative analyses suggest that variations in genome size may arise due to differences in measurement methods and sample sources. Therefore, employing multiple approaches to assess genome size is necessary to provide more reliable information for further genomic research. Based on the genome survey, species with considerable genome size variation or polyploidy, such as G. pentaphyllum, should undergo a ploidy analysis in conjunction with population genomics studies to elucidate the development of the diversified genome size. Additionally, a genome survey of U. crinita, a medicinal plant with a relatively small genome size (509.08 Mb) and of considerable interest in southern China, revealed a low heterozygosity rate (0.382%) and moderate repeat content (51.24%). Given the limited research costs, this species represents a suitable candidate for further genomic studies on Leguminous medicinal plants characteristic of southern China. This foundational genomic information will serve as a critical reference for the sustainable development and utilization of these medicinal plants. Full article