Search Results (287)

Erythropoiesis is a tightly regulated developmental process that requires the switch from fetal hemoglobin (HbF) to adult hemoglobin (HbA). In β-hemoglobinpathies such as SCD and β-thalassemia, disease severity is influenced by the fetal-to-adult hemoglobin switch because persistence or induction of HbF will ameliorate the clinical manifestations. miRNAs play an essential role in regulating this switch by modulating the expression levels of key transcription factors, such as BCL11A, KLF1, and MYB, which repress γ-globin expression. Multiple miRNAs have been identified as potential modulators of the hemoglobin switch, including miR-144, miR-486, miR-26b, and miR-15a. The molecular interactions between miRNA and γ-to β-globin switch have the potential for new therapeutic interventions that aim to reactivate HbF expression to ameliorate β-hemoglobinopathies such as SCD and β-thalassemia. In this review, the latest advancements in miRNA-mediated regulation of Hb switching and nanoparticle-based strategies for miRNA delivery are explored. Full article

Powdery mildew (PM) is a major disease affecting bitter gourd cultivation, and resolving the molecular regulatory mechanisms underlying PM resistance is important for bitter gourd molecular breeding for resistance. In this study, morphological and molecular methods were used to identify the PM pathogen in bitter gourd, and comparative transcriptome analysis was performed on leaves of the resistant cultivar R and the susceptible cultivar S after PM infection. The morphological and molecular identification results showed that the PM pathogen in bitter gourd was Podosphaera xanthii. Scanning electron microscopy results revealed that the P. xanthii exhibited distinct growth patterns in the R and S after P. xanthii infection. Compared to the S, the R exhibited 3966, 2729, 5891, and 3878 differentially expressed genes (DEGs) at 0, 2, 3, and 4 days after P. xanthii infection, respectively. KEGG enrichment analysis showed that DEGs were primarily enriched in plant–pathogen interactions, MAPK signaling pathway plants, and plant hormone signal transduction pathways. Transcription factor (TF) analysis of differentially expressed genes revealed that MYB, bHLH, and ERF family members could be involved in the defense process against the P. xanthii infection. Moreover, the analysis of the MLO genes revealed that Moc10g30350.1 could be involved in regulating PM resistance. These findings could enrich the molecular theoretical basis for resistance to PM, and provide new insights for the molecular breeding process of bitter gourd resistance to PM. Full article

Seed coat color in peanut (Arachis hypogaea L.) is a critical agronomic trait that affects both nutritional quality and market appeal. In this study, we identified two bHLH transcription factor genes, AhWSC1a and AhWSC1b, homologues of Arabidopsis TRANSPARENT TESTA 8, as indispensable gatekeepers of basal flavonoid pigmentation. QTL-seq analysis of a recombinant inbred line population derived from a black-testa parent (S3) and a white-testa parent (S2) revealed that recessive loss-of-function mutations in both AhWSC1a/1b abolish proanthocyanidin biosynthesis, resulting in a white testa. Integrated metabolomic and transcriptomic profiling confirmed the absence of proanthocyanidins and a strong repression of late anthocyanin-pathway genes (DFR, LDOX) in the mutants. Molecular assays further demonstrated that AhWSC1 physically interacts with the R2R3-MYB regulator AhTc1 to form a functional MBW complex that activates AhDFR and AhLDOX transcription. In this research, we also found that the black testa phenotype may arise from elevated AhTc1 expression associated with a structural variant (SV); however, in the SV background, the introduction of ahwsc1a/1b mutant leads to a significant suppression of AhTc1 expression. Notably, because AhWSC1 is transcriptionally silent in hairy-root systems, overexpression of AhTc1 alone failed to induce these late-stage anthocyanin biosynthesis genes, highlighting AhWSC1 as an indispensable, rate-limiting hub of anthocyanin biosynthesis pathway regulation. Collectively, our findings establish AhWSC1a and AhWSC1b as master regulators of peanut testa pigmentation, elucidate the molecular basis of classical white testa inheritance, and provide genetic targets for precision-breeding of nutritionally enhanced cultivars. Full article

Plant roots form highly specialized apoplastic barriers that regulate the exchange of water, ions, and solutes between the soil and vascular tissues, thereby protecting plant survival under environmental stress. Among these barriers, the endodermis and exodermis play essential roles, enhanced by suberin lamellae and lignin-rich Casparian strips (CS). Recent advances have shown that these barriers are not static structures but are dynamic systems, rapidly adapting in response to drought, salinity and nutrient limitation. The R2R3-MYB transcription factor (TF) family is essential to this adaptive plasticity. These TFs serve as key regulators of hormonal and developmental signals to regulate suberin and lignin biosynthesis. Studies across different species demonstrate both conserved regulatory structure and species-specific adaptations in barrier formation. Suberization provides a hydrophobic structure that limits water loss and ion toxicity, while lignification supports structural resilience and pathogen defense, with the two pathways exhibiting adaptive and interactive regulation. However, significant knowledge gaps remain regarding MYB regulation under combined abiotic stresses, its precise cell-type-specific activity, and the associated ecological and physiological trade-offs. This review summarizes the central role of root barrier dynamics in plant adaptation, demonstrating how MYB TFs regulate suberin and lignin deposition to enhance crop resilience to environmental stresses. Full article

Fragaria vesca L., a widely distributed model species, serves as a key resource for studying the evolution and genetics of the Fragaria genus. Research has shown that R2R3-MYB transcription factors are crucial for plant growth and development. However, their specific role in cold resistance in F. vesca is not well understood. In this study, we used the latest genome data for the strawberry (F. vesca v6.0). We performed a genome-wide identification of the R2R3-MYB gene family in F. vesca. We identified a total of 106 R2R3-FvMYBs. Based on their predicted functions in plants, we classified these genes into 25 distinct subfamilies. We then conducted a comprehensive bioinformatics analysis of this family. We performed a detailed examination of the R2R3-FvMYBs structures and physicochemical properties. This analysis provided five key parameters for each protein: molecular weight, the number of amino acids, theoretical isoelectric point, grand average of hydropathicity (GRAVY), and instability index. Gene duplication analysis suggested that segmental duplications were a primary driver of the proliferation of this gene family. Promoter cis-acting element prediction revealed that a large proportion of R2R3-FvMYBs possess elements predominantly associated with phytohormone responsiveness and biotic/abiotic stress responses. Quantitative real-time reverse transcription PCR (qRT-PCR) results confirmed that the expression levels of several R2R3-FvMYBs were upregulated under cold stress. Furthermore, compared to wild-type controls, the overexpression of FvMYB103 in Arabidopsis thaliana enhanced cold tolerance, accompanied by increases in the relevant physiological indices. Collectively, these findings support further investigation into R2R3-MYB gene family to directly assess their contribution to cold resistance. Full article

The corolla of Rehmannia glutinosa typically exhibits a stable reddish-purple color, but a naturally occurring yellow-flowered variant has recently been identified. To clarify the molecular basis of flower color variant, metabolomics, transcriptomics, and variant analyses were integrated. Metabolomic profiling revealed that the yellow phenotype was associated with lower anthocyanin levels and higher carotenoid levels. Specifically, the decreased cyanidin-3-O-glucoside led to a loss of red, while increased lutein provided the basis for the yellow color. Transcriptomic analysis revealed a downregulation of anthocyanin biosynthetic genes, including CHS, CHI, F3H, DFR, and ANS, in the yellow-flowered variant, and three S6-subgroup R2R3-MYB genes, including the known anthocyanin activator RgMYB41 (gene-DH2020_015992), were downregulated. Variant analysis showed that A12S and G255E in the gene-DH2020_015992 transcription factor were predicted to markedly alter protein conformation and potentially impair regulatory function. Subcellular localization and transcriptional activation assays further supported the functional characterization of gene-DH2020_015992 as a transcription factor. Collectively, these findings suggest that flower color variation in R. glutinosa is driven by MYB-mediated repression of anthocyanin biosynthesis and by carotenoid accumulation. This study provides a comprehensive genetic explanation for flower color variation in R. glutinosa and offers a theoretical foundation for floral pigmentation in plants. Full article

Background: Rosa chinensis, commonly known as the Chinese rose, is one of the most economically significant ornamental plants worldwide. The Rosa chinensis cultivar ‘Rainbow’s End’ notably transitions in color from yellow to red throughout its blooming phase; however, the chemical and molecular foundations underlying this floral color transformation remain inadequately understood. Methods: This study used the petals of the Rosa ‘Rainbow’s End’ cultivar at four developmental stages (R1, R2, R3, and R4) for targeted metabolomic and transcriptomic analyses. Results: Targeted metabolomic analyses revealed that the majority of anthocyanidin metabolites were highest at stages R2 and R3 and lowest at R1 and R4. In contrast, most carotenoid metabolites reached their highest levels at R1 and declined continuously from R2 to R4. These results were consistent with the color phenotype of Rosa ‘Rainbow’s End’ petals and suggested that both anthocyanins and carotenoids play critical roles in flower color variation. Specifically, an upregulation of CHS, ANS, and UGT genes in the anthocyanin biosynthesis pathway was observed in R2 and R3, coinciding with the expression of two MYB transcription factors (MYB14 and MYB54). Conversely, consistent downregulation of PSY, PDS, Z-ISO, ZDS, CHYB, and NCED genes in the carotenoid biosynthesis pathway was detected in R2 to R4 and was associated with four MYB transcription factors (MYB20, MYB43, MYB44, and MYB86). Conclusions: Rosa ‘Rainbow’s End’ is an excellent model for studying variations in flower color. The expression patterns of the identified structural genes involved in anthocyanin and carotenoid biosynthesis pathways, along with the related MYB transcription factors, were aligned with the levels of metabolite changes in the petals of four flowering stages. These genes and transcription factors are likely responsible for the color shifts in Rosa ‘Rainbow’s End’. This study clarifies the mechanisms underlying color changes in Rosa ‘Rainbow’s End’ and provides a theoretical basis for future flower breeding efforts. Full article

Background: Anthocyanins and proanthocyanidins (PAs), as flavonoid compounds with potent antioxidant activity, exhibit significant health-promoting and medicinal properties. Black wolfberry (Lycium ruthenicum Murr.) is renowned for its exceptional anthocyanin content; however, the regulatory mechanisms of anthocyanin biosynthesis remain poorly understood, limiting its biotechnological potential. This study aimed to elucidate the transcriptional regulatory function of LrMYB30 in anthocyanin biosynthesis in black wolfberry. Methods: The regulatory function of LrMYB30 was investigated using virus-induced gene silencing (VIGS), yeast one-hybrid assays, and dual-luciferase reporter assays in black wolfberry. Results: VIGS demonstrated that silencing LrMYB30 promoted anthocyanin accumulation while reducing PA content, establishing that the LrMYB30 transcription factor as a negative regulator of anthocyanin synthesis. Yeast one-hybrid and dual-luciferase reporter assays confirmed that LrMYB30 directly binds to and activates the promoter of LrANR, a key structural gene in PA biosynthesis. In contrast, LrMYB30 neither binds to nor suppresses the promoters of the critical anthocyanin biosynthesis genes LrUF3GT and LrDFR. Conclusions: Thus, LrMYB30 redirects the flavonoid metabolic flux from anthocyanin to PA synthesis through transcriptional activation of LrANR during later fruit development, reducing anthocyanin accumulation and delaying coloration. These findings reveal a novel regulatory mechanism in black wolfberry pigmentation and maturation, providing genetic targets for molecular breeding of high-anthocyanin cultivars. Full article

Stem strength significantly influences ornamental plant output, ornamental value, and commodity prices. Lignin is a crucial component that confers mechanical strength to plant stems. In this study, an R2R3-type MYB transcription factor related to lignin synthesis was identified in Iris laevigata and named IlMYB86. The IlMYB86 protein is localized solely in the nucleus and functions as a transcriptional activator. Genetic transformation of IlMYB86 in tobacco resulted in taller plants with thicker stem diameter and increased stem pressure. In addition, the lignin content of the transgenic IlMYB86 tobacco plants increased, which was accompanied by the upregulation of 4CL and HCT, two key genes involved in lignin synthesis. Furthermore, IlMYB86 enhanced the photosynthetic capacity of transgenic tobacco by increasing the chlorophyll content, net photosynthetic rate, stomatal conductance, intercellular CO₂ concentration, and transpiration rate. This study provides insight into the regulation of lignin biosynthesis, which could contribute to the molecular genetic engineering and breeding of ornamental plants. Full article

Red walnuts have been widely studied because of their strong antioxidant activity and ornamental value. However, research on the mechanism of anthocyanin biosynthesis in walnuts remains in the initial stage. The regulatory mechanism of TT2-type R2R3-MYB transcription factors in anthocyanin biosynthesis in walnuts is also unclear. Therefore, this study used ‘D2-1’ and ‘Jinghong 1’ walnuts as plant materials. The testa of ‘Jinghong 1’ was red, and its anthocyanin content was significantly higher than that of ‘D2-1’, mainly composed of cyanidin-3-O-arabinoside, cyanidin-3-O-galactoside, and cyanidin-3-O-glucoside. Differentially expressed genes between ‘D2-1’ and ‘Jinghong 1’ testa were enriched in phenylpropanoid biosynthesis and flavonoid biosynthesis. Next, this study identified a TT2-type R2R3-MYB transcription factor JrMYB1L, which was involved in regulating the anthocyanin biosynthesis in the testa of ‘Jinghong 1’. The overexpression of JrMYB1L could promote anthocyanin accumulation in walnut leaves and activate the expression of JrCHS, JrCHI, JrF3H, JrDFR, JrANS, JrUFGT, JrLAR, and JrANR. In addition, yeast two-hybrid results proved that JrMYB1L, JrbHLH42, and JrWD40 proteins could interact with each other. The results of yeast one-hybrid and dual-luciferase assays indicated that JrMYB1L could activate the expression of JrCHS and JrUFGT by binding to their promoters. Based on the above results, this study proposed a possible regulatory mechanism. JrMYB1L activated the expression of JrCHS and JrUFGT in the form of JrMYB1L-JrbHLH42-JrWD40 complex, thereby promoting anthocyanin accumulation in the testa of ‘Jinghong 1’. In summary, this study lays a theoretical foundation for revealing the regulatory mechanism of anthocyanin biosynthesis in red walnut and contributes to the breeding of new varieties of red walnuts with more edible and ornamental value. Full article

Anthocyanins pigment plant tissues, mitigate biotic and abiotic stresses, and deliver human health benefits; raising their content in mung bean (Vigna radiata) sprouts is a long-standing research target. Transcriptome analysis identified VrNAC25, a NAC transcription factor whose expression closely parallels anthocyanin accumulation; functional validation in mung bean confirmed that VrNAC25 acts as a positive regulator of the pathway. Although VrNAC25 does not bind to the promoters of the key structural genes VrDFR or VrLDOX, it indirectly controls anthocyanin synthesis by interacting with the core R2R3-MYB activator VrMYB90, previously established as the central regulator of anthocyanin production in mung beans. This interaction operates at both transcriptional and protein levels, thereby amplifying the expression of downstream structural genes and boosting pigment accumulation. Our findings refine the molecular network governing anthocyanin biosynthesis in sprouts and provide a clear theoretical basis for breeding or biotechnological strategies aimed at enhancing the nutritional quality and commercial value of mung bean products through light treatment or by selecting an anthocyanin-rich mung bean variety. Full article

Pearl millet (Pennisetum glaucum (L.) R. Br.) is widely recognized for its high tolerance to marginal environments. However, a systematic understanding of its organ-specific transcriptional adaptation mechanisms under individually applied abiotic stresses remains limited. In this study, we conducted a comparative transcriptome analysis of leaves and roots subjected to six distinct stress treatments (Ion stress: CdCl₂/NaCl; Water stress: PEG/Waterlogging; Temperature stress: Heat/Cold), revealing fundamental differences in defense strategies between the two organs. Across all stresses, leaves showed more differentially expressed genes (DEGs) (213) than roots (118), yet the transcriptional responses were largely stress-specific. Carotenoid biosynthesis was the only pathway co-activated in leaves under both water and temperature stress. In contrast, roots exhibited a robust and conserved strategy, with significant enrichment of phenylpropanoid and flavonoid biosynthesis pathways consistently observed across all six stresses. This cross-stress synergistic response involved more than 300 enzyme genes in roots, including key enzymes such as peroxidases (128) and shikimate O-hydroxycinnamoyltransferases (33), which collectively contribute to root-specific cell wall reinforcement and oxidative stress defense. Interaction network analysis further revealed that the MYB transcription factor family serves as a central regulatory hub in root stress responses, with key nodes PMF4G04191 and PMF5G01787 frequently interacting with pathway genes under all stress conditions. This study elucidates the organ-specific and cross-stress defense mechanisms in pearl millet, providing valuable transcriptomic resources and candidate genes for molecular-assisted breeding of multi-stress-tolerant varieties. Full article

Solanum aculeatissimum is a medicinally and economically significant crop characterized by its aerial organs, which are densely covered with trichomes and spines. Trichomes serve as crucial sites for the synthesis of secondary metabolites in medicinal plants and represent important structural adaptations for resisting biotic and abiotic stresses. Elucidating the molecular mechanisms underlying trichome formation in S. aculeatissimum holds significant implications for enhancing both its medicinal value and stress resistance. The R2R3-MYB subfamily, the largest within the MYB transcription factor family, plays a pivotal role in regulating trichome development. Here, we present the first genome-wide identification of the R2R3-MYB gene family in S. aculeatissimum, characterizing 99 members. Phylogenetic analysis classified these SaMYBs into 10 groups. Cis-element predictions in their promoter regions revealed an abundance of light-responsive, phytohormone-responsive, and abiotic stress-responsive elements, suggesting roles in environmental adaptation. Furthermore, synteny analysis identified 25 segmentally duplicated gene pairs, and the purifying selection has been the dominant evolutionary force. Through comparative transcriptomic analysis of leaves from wild-type and sparse-trichome plants, we identified 16 differentially expressed SaMYB genes, comprising 3 upregulated and 13 downregulated genes. Subsequent qRT-PCR analysis showed that SaMYB1, SaMYB59, and SaMYB36 were highly expressed during early leaf development. Virus-induced gene silencing (VIGS) targeting these candidates demonstrated that silencing SaMYB59 significantly reduced trichome density, whereas silencing SaMYB1 or SaMYB36 produced no observable phenotypic change, confirming SaMYB59 as a key positive regulator of trichome formation. Our findings provide crucial molecular targets for elucidating the mechanisms of trichome development in S. aculeatissimum and establish a theoretical foundation for genetic improvement of this medicinal plant through regulation of the SaMYB59 gene. Full article

Seed oil content and fatty acid (FA) composition collectively determine the quality and economic value of Brassica napus. Little is known about the role of R2R3-MYB transcription factors (TFs) in regulating FA biosynthesis in B. napus. Here, BnaC04.MYB89 was found to be expressed primarily in developing seeds. Overexpression of BnaC04.MYB89 consistently decreased FA levels, as evidenced by its effect in both the Arabidopsis thaliana myb89-1 mutant and B. napus seeds. RNA-seq of developing seeds at 30 DAP (days after pollination) revealed marked suppression of FA biosynthetic genes in BnaC04.MYB89-overexpressing plants compared to the K407 control. ChIP (Chromatin immunoprecipitation) analysis revealed that BnaC04.MYB89 directly inhibited the expression of BnaA03.BCCP1 and BnaC03.HD while indirectly regulating that of BnaA09.BADC1, BnaA03.BADC3, BnaA03.MOD1, and BnaA08.FAT8, thereby reducing seed FA accumulation. Collectively, these results elucidate the role for BnaC04.MYB89 and provide new insights into the transcriptional regulatory network controlling seed oil accumulation in B. napus. Full article

Sugar transporters of the SWEET family play a crucial role in sugar partitioning and fruit quality, yet their functions remain uncharacterized in Chinese bayberry (Morella rubra). In this study, we present the first genome-wide identification and characterization of the SWEET gene family in species, revealing 15 MrSWEET genes distributed across eight chromosomes. Phylogenetic analysis classified these genes into four conserved clades with distinct tissue-specific expression patterns. During fruit ripening, transcripts of MrSWEET1, 2b, 4, and 15 accumulated progressively, with MrSWEET15 showing the strongest increase. Weighted gene co-expression network analysis (WGCNA) identified a “lightcyan” module that correlates strongly with fruit sugar content (r > 0.8) and contains MrSWEET15, three additional MrSWEET genes, and 47 transcription factors (Dof, MYB, NAC, ERF, MADS, WRKY). Promoter analysis of MrSWEET15 revealed the presence of light- and hormone-responsive cis-elements (MYB, MYC, HY5, bZIP, and Dof), and MYB1, HY5, and Dof1.5 expression profiles are synchronized with MrSWEET15, suggesting potential regulatory relationships. These findings establish MrSWEET15 as a priority candidate for sugar transport in Chinese bayberry and our understanding of the molecular basis of sugar transport and fruit quality formation. Full article