Analysis of the Function and Regulatory Mechanisms of the AmFLS Gene, Encoding the Flavonol Synthase in Abelmoschus manihot L.

Heterologous expression of the honeysuckle R2R3-MYB transcription factor LjMYB106 enhances phenylpropanoid and flavonoid metabolism in Arabidopsis thaliana and Nicotiana benthamiana

Lonicera japonica Thunb. is a traditional medicinal plant rich in bioactive flavonoids, but the transcriptional regulation of flavonoid biosynthesis remains unclear. In this study, we identified LjMYB106, an R2R3-MYB transcription factor associated with flavonoid accumulation, from floral developmental transcriptomes. Sequence and phylogenetic analyses showed that LjMYB106 contains conserved R2 and R3 MYB domains and is closely related to homologous MYB proteins. Heterologous overexpression of LjMYB106 in Arabidopsis thaliana and Nicotiana benthamiana increased total flavonoid and p-coumaric acid contents. Integrated transcriptomic and widely targeted metabolomic analyses in A. thaliana showed that LjMYB106 overexpression was associated with changes in phenylpropanoid and flavonoid biosynthetic pathways. qRT-PCR validation further showed that PAL, C4H, 4CL, CHS, DFR, and ANS homologs were up-regulated, whereas CHI, F3H, and FLS homologs were down-regulated in LjMYB106-overexpressing plants. Subcellular localization and yeast transactivation assays indicated that LjMYB106 is a nuclear protein with transcriptional activation activity. These results suggest that LjMYB106 is a candidate regulator of phenylpropanoid and flavonoid metabolism and provide a basis for further studies of MYB-mediated flavonoid regulation in L. japonica.

Genome-wide analysis of the pectin acetylesterase (PAE) gene family in tomato and SlPAE16 functional characterization associated with pedicel abscission.

Pectin acetylesterase (PAE) regulates pectin acetylation, which affects plant growth, development, and stress tolerance. While their functions are well-defined in models like Arabidopsis, we still know surprisingly little about how they operate in tomatoes (Solanum lycopersicum). We identified 17 SlPAE genes using tomato genome-wide analysis. These genes were classified phylogenetically into three conserved subfamilies, with branch members sharing domain architectures, motifs, and genomic structure. Promoter cis-element analysis identified multiple motifs related to hormone signaling, light response, and stress response. Spatiotemporal expression patterns obtained via qRT-PCR revealed the functional roles of SlPAE genes. Notably, silencing SlPAE16 effectively retarded pedicel abscission, a process mediated by the inhibition of TAPG1/2/4 expression. These findings clarify the functional diversity within the PAE gene family, providing a much-needed framework for future research into their specific biological roles in tomatoes.

From genome to gene module: decoding the BsAlfin2-BsTT2 regulatory network controlling low temperature-induced anthocyanin biosynthesis in Begonia semperflorens

Begonia semperflorens is an important ornamental plant worldwide, but its practical application is severely limited by low temperature sensitivity. However, the molecular regulatory mechanisms underlying low temperature-induced anthocyanin biosynthesis remain unclear. In this study, we assembled a high-quality chromosome-level B. semperflorens genome. Through genomic and MYB gene family analysis, we identified a key transcription factor BsTT2, which directly binds to the BsDFR promoter and enhances its activity, thereby driving anthocyanin accumulation in B. semperflorens. Furthermore, using BsTT2 as bait, we identified its interacting protein BsAlfin2. Under low temperature-induced reactive oxygen species (ROS) signaling, BsAlfin2 undergoes nuclear translocation and forms a complex with BsTT2, synergistically enhancing the activation of the BsDFR promoter and significantly improving anthocyanin production efficiency. Based on these results, we propose a previously uncharacterized BsAlfin2/BsTT2-BsDFR regulatory module, which reveals a molecular links low-temperature ROS signaling to anthocyanin biosynthesis in B. semperflorens. In summary, this study not only provides chromosome-level genomic resources for B. semperflorens research but also elucidates a key molecular module in low temperature-induced anthocyanin biosynthesis regulatory pathway, laying a theoretical and data foundation for future studies on leaf color improvement and stress resistance breeding in Begonia.

Screening and functional characterization of R2R3-MYB transcription factors regulating anthocyanin biosynthesis in lotus (Nelumbo nucifera).

Anthocyanin biosynthesis is a key process determining flower color in lotus. In this study, 145 MYB transcription factors were identified from the lotus genome, of which 124 belong to the R2R3-MYB subfamily. Based on phylogenetic analysis and short-term light-induced transcriptome data, NnMYB38 and NnMYB114 were selected for further characterization. Expression of NnMYB38 and NnMYB114 was significantly higher in red-flowered lotus, with NnMYB38 showing a positive correlation with anthocyanin content. Transient overexpression in Nicotiana benthamiana revealed that NnMYB38 induced significant anthocyanin accumulation by upregulating multiple structural genes. In transgenic Arabidopsis, both MYB TFs promoted anthocyanin accumulation in mature seeds, and the seedlings of NnMYB114-OE line exhibited red pigmentation. Dual-luciferase assays confirmed that both transcription factors significantly activated the promoters of NnDFR and NnANS, indicating their crucial regulatory roles in anthocyanin biosynthesis. In this study, we screened and identified the regulatory functions of two MYB TFs in lotus anthocyanin biosynthesis, providing new insights into the molecular mechanisms underlying lotus flower coloration.

An R2R3-MYB Gene GhMYBPA of Gossypium hirsutum Promotes Proanthocyanidin Accumulation and Improves Heat Tolerance in Arabidopsis.

Genome-Wide Analysis of the GGPS Gene Family in Phoebe zhennan and Analysis of the Role of PzGGPS12 in Terpenoid Biosynthesis.

Geranylgeranyl diphosphate synthase (GGPS) is a key enzyme in terpenoid biosynthesis, but its role in Phoebe zhennan remains largely unknown. Here, 14 PzGGPS genes were identified and classified into three groups with conserved gene structures and motifs. Among them, PzGGPS12 was identified as a key gene for terpenoid biosynthesis, wood fragrance formation, and drought tolerance. Functional analyses showed that PzGGPS12 catalyzes the production of terpene precursors and promotes the accumulation of mono-, sesqui-, di-, and triterpenoids, thereby enhancing drought resistance through metabolic flux regulation. Furthermore, PzNAC6, PzWRKY12, and PzC3H8 were identified as major upstream transcription factors controlling the PzGGPS12 expression. These results reveal the regulatory network of PzGGPS12 and highlight its dual roles in wood fragrance formation and drought adaptation, providing new insights into terpenoid metabolism and molecular breeding of P. zhennan.