This study clarifies the molecular basis and transcriptional regulation of phenolic acid glycosylation in P. chienii, providing a framework for exploiting its medicinal resources and guiding conservation-oriented breeding.
Abstract
Pseudotaxus chienii, an endangered relic conifer endemic to China, possesses significant medicinal potential, yet its phenolic acid biosynthesis and glycosylation mechanisms remain unelucidated. This study integrated metabolomics, mass spectrometry imaging (MSI), transcriptomics, and molecular biology to systematically characterize the phenolic acid pathway in P. chienii. Untargeted metabolomics identified distinct phenolic acid accumulation patterns between P. chienii and Taxus mairei. MALDI-2 MSI visualized ten phenolic acids, confirming leaves as the primary accumulation site. Genome-wide analysis revealed a complete phenolic acid biosynthesis pathway with key enzyme-encoding genes (4 PAL, 5 CCR, 2 F5H, etc.), while HQT was absent, indicating loss of chlorogenic acid synthesis. We identified 504 glycosyltransferase (GT) genes, with 48 leaf-specific ones (predominantly GT1 subfamily). Promoter and correlation analyses highlighted WRKY (PichiChr12G332970.1) and ERF (PichiChr3G086100.1) as core transcription factors (TFs). EMSA and dual-luciferase assays validated WRKY(PichiChr12G332970.1) directly activating three GT genes. This study clarifies the molecular basis and transcriptional regulation of phenolic acid glycosylation in P. chienii, providing a framework for exploiting its medicinal resources and guiding conservation-oriented breeding.
Findings reveal tissue-specific metabolite accumulation and key genes involved in MIA biosynthesis in N. cadamba that provide valuable insights into specialized metabolism and establish a foundation for future metabolic engineering and functional genomics studies.
Divya Selvakumar, G. Ramalingam, Suganya Balan et al.· Molecular Biology Reports· 0 citations
Terpene synthases (TPS) play a vital role in the
biosynthesis of secondary metabolites involved in plant
defense, development and stress response. Piper
nigrum (black pepper), a commercially important spice
crop, produces diverse terpenoids, yet the genetic basis
of these biosynthetic pathways remains underexplored.
In this study, we identified and characterized a terpene
synthase gene (PnTPS) from P. nigrum using a
biocomputational and molecular approach. Specific
primers were designed from the PnTPS gene sequence
retrieved from the NCBI database and used for PCR
amplification in leaf and stem tissues. The amplified
product was sequenced and the resulting gene was
identified as PCARF which is likely involved in the
biosynthesis of caryophyllene, a key sesquiterpene
compound associated with stress tolerance and
antimicrobial activity.
Functional domain analysis via ScanProsite revealed
the presence of a ferredoxin type iron sulphur binding
domain, characteristic of certain terpene synthases.
This study provides the molecular evidence linking a
PnTPS-derived gene to caryophyllene biosynthesis in
P. nigrum, highlighting its potential role in plant
defense. The findings pave the way for functional
validation and genetic improvement strategies aimed at
enhancing biotic stress resistance in black pepper.
Aparna K. S., Jaysree R. C., Geethalakshmi Sundararaman· Research journal of biotechn...· 0 citations
BACKGROUND
Chrysanthemum morifolium, a perennial herb of the genus Chrysanthemum (Asteraceae), is highly valued for its ornamental, edible and medicinal properties, primarily attributed to its abundant flavonoids. Phenylalanine ammonia-lyase (PAL) is the rate-limiting enzyme initiating the phenylpropanoid pathway, which synthesizes lignin, flavonoids, and phytoalexins, key metabolites for plant growth, development, and stress adaptation. Despite the availability of the chromosome-level C. morifolium genome, the PAL gene family remains insufficiently characterized. Specifically, the expression patterns of CmPAL genes across floral developmental stages, floret types, and various abiotic stresses have not been elucidated.
RESULTS
In this study, 19 CmPAL genes were identified from C. morifolium. Systematic analyses of their molecular evolutionary characteristics, including gene/protein structures, chromosomal localization, phylogenetic relationships, and genome-wide synteny were performed. CmPAL genes were found to be unevenly distributed across 8 of 27 chromosomes, and phylogenetically clustered members exhibited similar gene/protein structures, reflecting evolutionary conservation and functional importance. Expression profiles revealed that CmPAL genes were preferentially expressed in ray florets and at the color-emerging/blooming stages, indicating their involvement in floral pigmentation. Additionally, several CmPALs were significantly upregulated/downregulated under cold, salt, drought, and heavy metal stresses, suggesting roles in abiotic stress responses.
CONCLUSIONS
This study provides a comprehensive characterization and expression profiles of the C. morifolium PAL gene family. These findings provide a valuable genomic resource for functional studies of CmPAL genes, as well as identify candidate genes for molecular breeding to improving flower quality and environmental adaptability of chrysanthemums. Specifically, CmPAL1, 6, 11, and 13 are prioritized as major candidate genes for floral pigmentation, while CmPAL3, 5, 9, 10, and 15 are highlighted for their broad-spectrum stress adaptation roles.
Findings provide insights into the potential multifaceted insecticidal action of benzothiazole in T. castaneum at the transcriptomic level and support its further development as a target-specific grain fumigant.
Kaidi Cui, Xueran Hu, Weifeng Cheng et al.· Pest Management Science· 0 citations
High-temperature stress impairs plant growth and alters secondary metabolism. Polymethoxyflavones (PMFs) are citrus-specific flavonoids with important nutritional benefits; however, their transcriptional responses to heat stress remain poorly understood. Here, five-month-old ‘Ponkan’ citrus seedlings were exposed to 40 °C for 6, 11, and 21 days. HPLC analysis showed that the accumulation of four major PMFs (sinensetin, nobiletin, tangeretin, and 5-demethylnobiletin) was significantly reduced in leaves under heat stress. RNA-seq identified 3424 differentially expressed genes shared across all three time points, which were enriched in pathways associated with microtubule cytoskeleton organization, cell cycle regulation, and glyoxylate and dicarboxylate metabolism. Further analysis of the PMF biosynthetic pathway revealed that 14 of 18 key structural genes, including CHS, CHI, FNSII, and OMT family members, were downregulated by heat treatment. In addition, several bHLH, AP2/EREBP, and MYB transcription factors, known regulators of flavonoid biosynthesis, exhibited expression patterns closely associated with PMF accumulation. RT-qPCR analysis validated the transcriptome results. Collectively, these findings suggest that heat stress suppresses PMF accumulation through coordinated repression of PMF biosynthetic genes and their potential regulators. This study provides new insights into the molecular basis of heat-responsive PMF metabolism and offers potential targets for maintaining citrus nutritional quality under elevated temperatures.
Xiaojuan Liu, Zhenkun Liao, Honglu Hu et al.· Horticulturae· 0 citations
GDSL esterase/lipases (GELPs) are important regulators of plant growth and development, lipid metabolism, and stress responses. However, their genomic characteristics and expression patterns have not been systematically characterized for Juglans mandshurica, a woody oil crop species of significant ecological and economic value. Here, we identified 61 JmGELP genes in J. mandshurica through genome-wide analysis. Phylogenetic analysis classified them into seven major clades, and variations in gene structure and conserved motifs suggested potential functional divergence. Promoter cis-acting element analysis revealed widespread enrichment of motifs responsive to light, phytohormones, and abiotic stresses. Transcriptomic sequencing and qRT-PCR validation revealed distinct tissue-specific and seed development stage-specific expression patterns of JmGELP members, as well as their differential responses to various stress and hormone treatments. Gene Ontology (GO) annotation and protein–protein interaction (PPI) network analyses further supported their involvement in lipid metabolism. In silico analyses of transcription factor binding sites, miRNA targets, and molecular docking predicted that JmGELP-3, -38, and -41 have distinct transcriptional and post-transcriptional regulatory networks and potentially divergent substrate preferences. This study provides the first comprehensive characterization of the GELP family in J. mandshurica, identifying candidate genes that may inform future germplasm improvement and stress-resistance breeding in Juglans species.
Meng Dang, Rui Wang, Zhenlin Shen et al.· International Journal of Mol...· 0 citations
