Search Results (39)

High temperature (HT) is a crucial environmental factor influencing floral pigmentation and ornamental quality in chrysanthemum (Chrysanthemum morifolium) by modulating anthocyanin biosynthesis. In this study, comparative transcriptome profiling was performed in two F₁ chrysanthemum lines (RO72 and RO99) under high-temperature stress to elucidate the molecular mechanisms behind heat-induced floral color fading. Analysis revealed extensive transcriptional reprogramming of genes associated with anthocyanin metabolism, hormonal signaling, and oxidative stress responses. While structural genes in the anthocyanin biosynthetic pathway (CHS, DFR, ANS, 3MAT and LDOX) were significantly downregulated, key glycosylation-related genes such as UFGT were upregulated, suggesting a compensatory mechanism that enhances pigment stabilization rather than de novo synthesis. This study identified a shift in the MYB–bHLH–WD40 regulatory complex, specifically the upregulation of transcriptional repressors (MYB62, MYB15) and downregulation of activators (MYB106, bHLH49), suggesting a suppressed anthocyanin accumulation. Simultaneously, genes associated with several signaling cascades such as ROS, ABA, and auxin–jasmonate signaling pathways were differentially expressed, suggesting that these alterations may contribute to the repression of pigment biosynthesis and color fading. Collectively, these results hypothesize that high temperature suppresses anthocyanin accumulation through a dual mechanism of transcriptional inhibition and hormonal modulation, while simultaneously promoting pigment stabilization via glycosylation. This study therefore provides fundamental insights into thermal regulation of floral pigmentation and identifies candidate genes and pathways potentially involved in heat-induced floral color fading in chrysanthemum. Full article

The plant epidermis, adorned with trichomes and root hairs, represents a critical interface where developmental programming and environmental responses converge. Although the genetic basis of epidermal patterning has been extensively characterized in model systems, how these pathways are modulated under abiotic stress remains incompletely understood. This review integrates recent advances in epidermal development and stress biology, focusing on MYB–bHLH–WD40 (MBW) complexes, GIS-family C2H2 zinc-finger proteins, and ROOT HAIR DEFECTIVE SIX-LIKE (RSL) transcription factors. These regulators participate in interconnected, organ-specific networks that coordinate trichome and root-hair development. Their activities are shaped by gibberellin–brassinosteroid interactions, ethylene–auxin coordination, jasmonate and abscisic acid signaling, and cytokinin- and nutrient-responsive pathways. We further discuss how reactive oxygen species and calcium oscillations translate transcriptional regulation into polarized cell growth. The resulting epidermal plasticity reflects trade-offs among growth, defense, resource acquisition, and conservation. By integrating single-cell transcriptomics, nutrient sensing, and evolutionary perspectives, this review provides a framework for understanding environmentally responsive epidermal development and identifies opportunities for improving crop resilience. The resulting framework identifies testable opportunities for crop improvement, while emphasizing that native network equivalence, pleiotropic effects, and field-level stress benefits remain to be established in crop species. Full article

Sambucus nigra L. (European elderberry) is distinguished among medicinal and edible plants by its exceptionally high cyanidin-3-O-glucoside (C3G) content, which markedly exceeds that of common berries. This unique phytochemical profile establishes C3G as the principal bioactive constituent underlying the antitumor activity of S. nigra. While numerous reviews on elderberry have been published, none has systematically integrated C3G biosynthesis, transcriptional regulation, in vivo metabolism, and anti-tumor mechanisms specifically in S. nigra—a critical research gap that this review fills for the first time. Herein, we systematically examine the chemical structure and content distribution of C3G in S. nigra, elucidate the phenylpropanoid–flavonoid biosynthetic pathway and the regulatory patterns of the MYB-bHLH-WD40 (MBW) transcriptional complex, and highlight the current research gap regarding the cloning and functional characterization of core MBW factors in this species. We further reveal the absorption and distribution characteristics of C3G in the human body, the gut microbiota-mediated biotransformation process, and the synergistic antitumor effects of its primary metabolite, protocatechuic acid. The molecular mechanisms through which C3G exerts antitumor activity, including the induction of tumor cell apoptosis, cell cycle arrest, inhibition of epithelial–mesenchymal transition, and modulation of key signaling pathways, such as NF-κB, PI3K/AKT/mTOR, and JNK, are systematically elaborated. This is the first review to construct a comprehensive “biosynthetic regulation–in vivo metabolism–antitumor function” framework for C3G in S. nigra, thereby addressing critical research gaps and providing a theoretical foundation for the germplasm breeding of high-C3G cultivars, functional product development, and clinical adjuvant cancer therapy. Full article

Camptotheca acuminata, the primary botanical source of camptothecin (CPT), employs this monoterpenoid indole alkaloid as a key chemical defense against herbivores in addition to its established clinical pharmaceutical importance. Given that Spodoptera frugiperda infestations pose a severe threat to C. acuminata seedlings, we examined integrated, multi-layered defense mechanisms that combine physical barriers with chemical toxins to bolster plant resistance. Physiological analyses revealed that herbivory induces antioxidant enzymes such as superoxide dismutase (SOD) and catalase (CAT), alongside broader metabolic reprogramming. These responses are orchestrated by differential activation of jasmonic acid (JA) and salicylic acid (SA) signaling pathways, which together drive complex defense mobilization, including a marked increase in trichome density. Concurrently, insect herbivory activates the MYB-bHLH-WD40 (MBW) transcriptional complex to promote trichome development while upregulating core CPT biosynthetic genes. In particular, two cytochrome P450 genes, Ca32236 and CaCYP81BQ18, mediate the accumulation of 10-hydroxycamptothecin (10-HCPT), a derivative that is sparingly soluble in water, which enables alkaloid transport and sequestration to specialized storage sites, including trichomes. Collectively, these stress-responsive strategies confer potent insecticidal activity against S. frugiperda and provide valuable insights for improving protection in C. acuminata seedling plantations. Full article

Trichomes are specialized epidermal structures that play pivotal roles in plant defense against biotic and abiotic stresses. Inositol polyphosphate kinase 2 (IPK2) is a key enzyme in inositol phosphate metabolism with diverse functions in eukaryotic cellular processes. However, its involvement in trichome development remains uncharacterized. Here, we systematically analyzed the function of a rice inositol polyphosphate kinase gene (OsIPK2) in trichome development using transgenic rice lines and heterologously expressing Arabidopsis lines. Scanning electron microscopy (SEM) analysis revealed that OsIPK2 acts as an organ-specific modulator of trichome development in rice. Its overexpression repressed macrohair initiation and microhair elongation in leaves, while promoting trichome development on the glumes. Metabolomic profiling revealed that OsIPK2 overexpression reprogrammed cuticular wax metabolism in transgenic rice leaves, shifting fatty acid flux toward long-chain wax precursors and increasing soluble carbohydrate levels. Transcriptomic and qPCR analysis confirmed that OsIPK2 modulated the expression of genes involved in cuticular wax biosynthesis, auxin homeostasis, and the core trichome regulatory cascade in rice. Conversely, heterologous overexpression of OsIPK2 in Arabidopsis strongly suppressed trichome initiation and branching, resulting in drastically reduced trichome density and fewer trichome branches. These phenotypes were associated with the downregulation of the MYB-bHLH-WD40 (MBW) transcriptional complex and its downstream target genes. Collectively, our findings suggest that OsIPK2 modulated trichome development through organ- and species-specific mechanisms. In rice, it coordinated wax metabolism and the OsSPL10-OsSCR1/2-OsWOX3B-OsHL6 cascade to affect organ-specific trichome formation. In Arabidopsis, it inhibited trichome development by repressing the MBW complex. These results uncover a novel role of OsIPK2 in plant epidermal cell fate specification and advance our understanding of the molecular mechanisms underlying organ- and species-specific regulation of trichome development. Full article

Fruit anthocyanins are primary determinants of color, sensory quality, and nutritional value in grapes; however, their endogenous biosynthesis is governed by complex interactions among genetic, environmental, agronomic, and postharvest factors. This review elaborates recent advances in physiology and molecular biology to clarify the biosynthetic mechanisms in grapes, including the coordinated action of structural enzymes, MYB–bHLH–WD40 regulatory complexes, hormone-mediated signaling pathways, and vacuolar transport processes. Key environmental factors, such as temperature fluctuations, light exposure, water availability, and soil properties, regulate these networks, contributing to significant variation in pigmentation profiles across cultivars and growing regions. Strategic agronomic practices, including canopy management, regulated deficit irrigation, balanced nutrient management, and temperature-mitigation techniques, further influence pigmentation by modifying the microclimate of the fruit zone during development. Based on these mechanistic insights, this review evaluates targeted strategies for enhancing anthocyanin accumulation, highlighting recent progress in genetic improvement through CRISPR/Cas genome editing, transgenic approaches, and marker-assisted selection (MAS), which enable precise modulation of biosynthetic and regulatory genes. Complementary postharvest interventions, such as optimized cold storage, modified-atmosphere packaging, hormonal elicitors, and controlled oxidative technologies, provide additional opportunities to maintain or enhance pigment stability after harvest. Collectively, these advances establish a comprehensive framework linking molecular regulation with practical vineyard, breeding, and postharvest strategies, offering an integrated pathway to improve anthocyanin consistency, berry quality, and the phenolic characteristics of grape-derived products. Full article

Anthocyanins are key pigments responsible for apple fruit coloration, influencing not only its appearance and marketability but also contributing significantly to its nutritional and health benefits. In their natural state, anthocyanins are chemically unstable. However, glycosylation modifies them into anthocyanin derivatives known as anthocyanin glycosides, which exhibit markedly enhanced stability and improved water solubility. As a result, most naturally occurring anthocyanins exist in the form of anthocyanin glycosides. The biosynthesis of anthocyanins involves a series of structural genes within the phenylpropanoid and flavonoid pathways (including PAL, C4H, 4CL, CHS, CHI, F3H, DFR, ANS/LDOX, and UFGT). The MYB–bHLH–WD40 transcriptional complex serves as the core regulatory mechanism controlling anthocyanin synthesis, with additional transcription factors also playing important roles. This review systematically summarizes recent advances in the structural characteristics, biosynthetic pathways, molecular regulatory mechanisms, and environmental factors affecting anthocyanin accumulation in apples. These insights are important both for consumer health and for breeding apple cultivars with enhanced anthocyanin content. Full article

Hippeastrum, a perennial herbaceous plant belonging to the Amaryllidaceae family, is widely cultivated for its large, vibrant flowers with diverse petal colors, which have significant ornamental and economic value. However, the mechanisms underlying anthocyanin accumulation in Hippeastrum petals remain poorly understood. To fully explore the involved regulation mechanism was significant for the breeding of Hippeastrum and other Amaryllidaceae family plants. In this study, we selected six Hippeastrum cultivars with distinctly different petal colors. We used metabolomic profiling and high-throughput transcriptomic sequencing to assess varied anthocyanin profiles and associated expression of genes in their biosynthetic pathways. Four key anthocyanins were identified: cyanidin, cyanidin-3-O-rutinoside, delphinidin-3-glucoside, and delphinidin-3-rutinoside. Weighted gene co-expression network analysis (WGCNA) correlated the abundance of these four anthocyanins with transcriptomic data, to suggest three regulatory modules. Nine transcription factors families in these modules were identified and some of them were validated using qRT-PCR. Y2H assay isolated some transcription factors interacted with TTG1 (WD40 protein), including MYB3/39/44/306 and bHLH13/34/110, illustrating the possibility of forming MBW complexes. Our study provides a comprehensive characterization of anthocyanin composition. These findings laid a theoretical foundation for future research on the regulatory mechanisms of pigment accumulation and the breeding of Hippeastrum cultivars with novel petal colors. Full article

The occurrence of anthocyanins in rice (Oryza sativa) and barley (Hordeum vulgare) varies among cultivars, with pigmented varieties (e.g., black rice and purple barley) accumulating higher concentrations due to genetic and environmental factors. The biosynthesis of anthocyanins is regulated by a complex network of structural and regulatory genes. Key enzymes in the pathway include chalcone synthase (CHS), chalcone isomerase (CHI), flavanone 3-hydroxylase (F3H), dihydroflavonol 4-reductase (DFR), anthocyanidin synthase (ANS), and UDP-glucose flavonoid 3-O-glucosyltransferase (UFGT). These genes are tightly controlled by transcription factors (TFs) from the MYB, bHLH (basic helix–loop–helix), and WD40 repeat families, which form the MBW (MYB-bHLH-WD40) regulatory complex. In rice, OsMYB transcription factors such as OsMYB3, OsC1, and OsPL (Purple Leaf) interact with OsbHLH partners (e.g., OsB1, OsB2) to activate anthocyanin biosynthesis. Similarly, in barley, HvMYB genes (e.g., HvMYB10) coordinate with HvbHLH TFs to regulate pigment accumulation. Environmental cues, such as light, temperature, and nutrient availability, further modulate these TFs, influencing the production of anthocyanin. Understanding the genetic and molecular mechanisms behind the biosynthesis of anthocyanins in rice and barley provides opportunities for the development of biofortification strategies that enhance their nutritional value. Full article

In plants, the R2R3-MYB transcription factors are one of the largest MYB gene families. These MYB transcription factors are very important for regulating plant growth and development. RcMYB114, RcbHLH, and RcWD40 promote anthocyanin accumulation by forming the MBW (MYB-bHLH-WD40) complex and determine the rose flower’s color. RcMYB114 genomic sequences differ between the red petal and white varieties. Two non-synonymous substitutions were found in the open reading frame. It leads to a change in amino acids. Here, the anthocyanin content showed that there was no anthocyanin in white petals, while the anthocyanin content in red petals increased firstly at stage 2, decreased slightly at stage 4, and then increased again at stage 5. The spatiotemporal expression pattern analysis showed that RcMYB114 was not expressed in all petals and tissues of white petals at different flower development stages. In red petal varieties, RcMYB114 was highly expressed in petals, followed by styles, and not expressed in stems, young leaves, and stage 1 of flower development. However, RcMYB114 has the highest expression level at the blooming stage. The RcMYB114 sequence contains 9 SNPs in the coding region, 7 of which were synonymous substitutions that had no effect on the translation product and 2 of which were non-synonymous substitutions that resulted in amino acid alteration at positions 116 and 195, respectively. The RcMYB114 gene in red rose was named RcMYB114a, and in white rose was RcMYB114b. RcMYB114c was mutated into leucine via artificial mutation; it was valine at position 116 of RcMYB114a, and Glycine mutated into Arginine at position 195 of RcMYB114a was RcMYB114d. RcMYB114b was the double mutation at positions 116 and 195 of RcMYB114a. The results of yeast two-hybrid experiments showed that RcMYB114a and its missense mutations RcMYB114b, RcMYB114c, and RcMYB114d could both interact with RcbHLH and RcWD40 to form the MYB-bHLH-WD40 complex. A transient transformation experiment in tobacco confirmed that RcMYB114a and its missense mutations RcMYB114b, RcMYB114c, and RcMYB114d could significantly promote the high expression of related structural genes in tobacco, together with the RcbHLH gene, which led to the accumulation of anthocyanins and produced the red color of the leaves. The RcMYB114a gene and its missense mutations RcMYB114b, RcMYB114c, and RcMYB114d interacted with the RcbHLH gene and significantly regulated the accumulation of anthocyanins. The two non-synonymous mutations of RcMYB114 do not affect the function of the gene itself, but the content of the anthocyanins accumulated was different. This study should provide clues and references for further research on the molecular mechanism underlying the determination of rose petal color. Full article

Red-leaf lettuces, rich in bioactive compounds like anthocyanins and flavonoids, offer health benefits by reducing oxidative stress and boosting immunity. This article provides an extensive review of the genetic, epigenetic, environmental, and technological factors influencing anthocyanin biosynthesis and leaf coloration in red-leaf lettuce, emphasizing its significance in agriculture and nutrition. The genetics of anthocyanin biosynthesis, environmental influences, practical applications, agronomic insights, and future directions are the main areas covered. Anthocyanin accumulation is regulated by structural, regulatory, and transporter genes, as well as the MYB-bHLH-WD40 (MBW) complex. Mutations in these genes impact coloration and stress responses. Advances in genomic studies, such as GWAS and QTL mapping, have identified key genes and pathways involved in anthocyanin biosynthesis, aiding breeding programs for desirable traits. In addition, light intensity, stress conditions (e.g., drought, temperature), and phytohormones affect anthocyanin levels and photomorphogenesis in general. Controlled environments, like vertical farms, optimize these conditions to enhance pigmentation and phytochemical content. LED lighting and tailored cultivation techniques improve color intensity, antioxidant capacity, and yield in controlled settings. Sustainable production technologies for red-leaf lettuce in vertical farms are being developed to meet consumer demand and promote functional foods, integrating genetic, epigenetic, and environmental research into agronomy. This review highlights red-leaf lettuce’s aesthetic, nutritional, and functional value, advocating for innovative cultivation methods to enhance its market and health potential. Full article

The trichomes of mustard leaves have significance due to their ability to combat unfavorable external conditions and enhance disease resistance. It was demonstrated that the MYB-bHLH-WD40 (MBW) ternary complex consists of MYB, basic Helix-Loop-Helix (bHLH), and WD40-repeat (WD40) family proteins and plays a key role in regulating trichome formation and density. The bHLH gene family, particularly the Myelocytomatosis (MYC) proteins that possess the structural bHLH domain (termed bHLH-MYC), are crucial to the formation and development of leaf trichomes in plants. bHLH constitutes one of the largest families of transcription factors in eukaryotes, of which MYC is a subfamily member. However, studies on bHLH-MYC transcription factors in mustard have yet to be reported. In this study, a total of 45 bHLH-MYC transcription factors were identified within the Brassica juncea genome, and a comprehensive series of bioinformatic analyses were conducted on their structures and properties: an examination of protein physicochemical properties, an exploration of conserved structural domains, an assessment of chromosomal positional distributions, an analysis of the conserved motifs, an evaluation of the gene structures, microsynteny analyses, three-dimensional structure prediction, and an analysis of sequence signatures. Finally, transcriptome analyses and a subcellular localization examination were performed. The results revealed that these transcription factors were unevenly distributed across 18 chromosomes, showing relatively consistent conserved motifs and gene structures and high homology. The final results of the transcriptome analysis and gene annotation showed a high degree of variability in the expression of bHLH-MYC transcription factors. Five genes that may be associated with trichome development (BjuVA09G22490, BjuVA09G13750, BjuVB04G14560, BjuVA05G24810, and BjuVA06G44820) were identified. The subcellular localization results indicated that the transcription and translation products of these five genes were expressed in the same organelle: the nucleus. This finding provides a basis for elucidating the roles of bHLH-MYC family members in plant growth and development, and the molecular mechanisms underlying trichome development in mustard leaves. Full article

The growing depletion of the ozone layer has led to increased ultraviolet B (UV-B) radiation, prompting plants like the alpine Rhododendron chrysanthum Pall. (R. chrysanthum) to adapt to these harsh conditions. This study explored how abscisic acid (ABA) signaling influences R. chrysanthum’s metabolic responses under UV-B stress. R. chrysanthum was treated with UV-B radiation and exogenous ABA for widely targeted metabolomics, transcriptomics, and proteomics assays, and relevant chlorophyll fluorescence parameters were also determined. It was observed that UV-B stress negatively impacts the plant’s photosynthetic machinery, disrupting multiple metabolic processes. Multi-omics analysis revealed that ABA application mitigates the detrimental effects of UV-B on photosynthesis and bolsters the plant’s antioxidant defenses. Additionally, both UV-B exposure and ABA treatment significantly influenced the phenylpropanoid biosynthesis pathway, activating key enzyme genes, such as 4CL, CCR, and HCT. The study also highlighted the MYB–bHLH–WD40 (MBW) complex’s role in regulating this pathway and its interaction with ABA signaling components. These findings underscore ABA’s crucial function in improving plant resistance to UV-B stress and offer novel insights into plant stress biology. Full article

Anthocyanins, constituents of flavonoid compounds prevalent in plants, possess significant value in both plant development and human nutrition. The regulation of anthocyanin biosynthesis primarily involves the orchestration of MYB, bHLH, and WD40 transcription factors. Consequently, the bHLH family assumes a pivotal role in modulating plant developmental processes. In the present investigation, a transcription factor, denoted as LvbHLH13, was identified as a positive regulator of anthocyanin pigmentation in lily petals. LvbHLH13 is classified within the IIId subgroup of Arabidopsis bHLH proteins. Functional analyses involving the transient expression and gene silencing of LvbHLH13 revealed its capacity to enhance and diminish anthocyanin accumulation, respectively, by modulating the LvMYB5 expression, thereby influencing the downstream structural gene expression. The overexpression of LvbHLH13 resulted in an increase in the expression of the downstream structural genes related to anthocyanin synthesis, whereas silencing of LvbHLH13 correspondingly decreased the expression. Yeast one-hybrid and EMSA assays demonstrated the interaction between LvbHLH13 and the LvMYB5 promoter, leading to the activation of anthocyanin biosynthesis. A further luciferase (LUC) analysis corroborated the stimulatory effect of LvbHLH13 on the LvMYB5 promoter sequence. Consequently, LvbHLH13 assumed a crucial role in lily-petal pigmentation. A yeast two-hybrid analysis revealed that LvbHLH13 diverged from typical bHLH transcription factor behavior as it did not form a complex with MYB to regulate anthocyanin biosynthesis. This discrepancy could be attributed to the deletion of the N-terminal conserved sequence of LvbHLH13. This study provides a new bHLH candidate and bHLH-MYB partner to explore the anthocyanin regulatory network in further research and provides new opportunities for breeding lilies with various anthocyanin contents. These findings lay a theoretical foundation for subsequent investigations into lily flower coloring mechanisms. Full article

Lilium is a genus of important ornamental plants with many colouring pattern variations. Lilium auratum is the parent of Oriental hybrid lilies. A typical feature of L. auratum is the presence of red-orange special raised spots named papillae on the interior tepals. Unlike the usual raised spots, the papillae are slightly rounded or connected into sheets and usually have hairy tips. To elucidate the potential genes regulating papillae development in L. auratum, we performed high-throughput sequencing of its tepals at different stages. Genes involved in the flavonoid biosynthesis pathway were significantly enriched during the colouration of the papillae, and CHS, F3H, F3′H, FLS, DFR, ANS, and UFGT were significantly upregulated. To identify the key genes involved in the papillae development of L. auratum, we performed weighted gene coexpression network analysis (WGCNA) and further analysed four modules. In total, 51, 24, 1, and 6 hub genes were identified in four WGCNA modules, MEbrown, MEyellow, MEpurple, and MEred, respectively. Then, the coexpression networks were constructed, and important genes involved in trichome development and coexpressed with anthocyanin biosynthesis genes, such as TT8, TTG1, and GEM, were identified. These results indicated that the papillae are essentially trichomes that accumulate anthocyanins. Finally, we randomly selected 12 hub genes for qRT-PCR analysis to verify the accuracy of our RNA-Seq analysis. Our results provide new insights into the papillae development in L. auratum flowers. Full article