Polygonatum cyrtonema Hua is a traditional Chinese herb propagated using rhizomes, and excessive demand for seedlings and quality deterioration caused by rhizome propagation has highlighted that seed propagation may be an ideal solution to address these issues. However, the molecular mechanisms involved in P. cyrtonema Hua seed germination and emergence stages are not well understood. Therefore, in the present study, we performed transcriptomics combined with hormone dynamics during different seed germination stages, and 54,178 unigenes with an average length of 1390.38 bp (N50 = 1847 bp) were generated. Significant transcriptomic changes were related to plant hormone signal transduction and the starch and carbohydrate pathways. Genes related to ABA(abscisic acid), IAA(Indole acetic acid), and JA(Jasmonic acid) signaling, were downregulated, whereas genes related to ethylene, BR(brassinolide), CTK(Cytokinin), and SA(salicylic acid) biosynthesis and signaling were activated during the germination process. Interestingly, GA biosynthesis- and signaling-related genes were induced during the germination stage but decreased in the emergence stage. In addition, seed germination significantly upregulated the expression of genes associated with starch and sucrose metabolism. Notably, raffinose biosynthesis-related genes were induced, especially during the emergence stage. In total, 1171 transcription factor (TF) genes were found to be differentially expressed. Our results provide new insights into the mechanisms underlying P. cyrtonema Hua seed germination and emergence processes and further research for molecular breeding.

Glutathione S-transferases (GSTs) are members of a protein superfamily with diverse physiological functions, including cellular detoxification and protection against oxidative damage. However, there is limited research on GSTs responding to cadmium (Cd) stress. This study classified 46 GST genes in Dendrobium officinale (D. officinale) into nine groups using model construction and domain annotation. Evolutionary analysis revealed nine subfamilies with diverse physical and chemical properties. Prediction of subcellular localization revealed that half of the GST members were located in the cytoplasm. According to the expression analysis of GST family genes responding to Cd stress, DoGST5 responded significantly to Cd stress. Transient expression of DoGST5-GFP in tobacco leaves revealed that DoGST5 was localized in the cytoplasm. DoGST5 overexpression in Arabidopsis enhanced Cd tolerance by reducing Cd-induced H₂O₂ and O₂⁻ levels. These findings demonstrate that DoGST5 plays a critical role in enhancing Cd tolerance by balancing reactive oxygen species (ROS) levels, offering potential applications for improving plant adaptability to heavy metal stress.

Polygonatum cyrtonema (P. cyrtonema) is a valuable rhizome-propagating traditional Chinese medical herb. Polysaccharides (PCPs) are the major bioactive constituents in P. cyrtonema. However, the molecular basis of PCP biosynthesis in P. cyrtonema remains unknown. In this study, we measured the PCP contents of 11 wild P. cyrtonema germplasms. The results showed that PCP content was the highest in Lishui Qingyuan (LSQY, 11.84%) and the lowest in Hangzhou Lin’an (HZLA, 7.18%). We next analyzed the transcriptome profiles of LSQY and HZLA. Through a qRT-PCR analysis of five differential expression genes from the PCP biosynthesis pathway, phosphomannomutase, UDP-glucose 4-epimerase (galE), and GDP-mannose 4,6-dehydratase were determined as the key enzymes. A protein of a key gene, galE1, was localized in the chloroplast. The PCP content in the transiently overexpressed galE1 tobacco leaves was higher than in the wild type. Moreover, luciferase and Y1H assays indicated that PcWRKY31 and PcWRKY34 could activate galE1 by binding to its promoter. Our research uncovers the novel regulatory mechanism of PCP biosynthesis in P. cyrtonema and is critical to molecular-assisted breeding.

Mycorrhizal symbiosis represents a ubiquitous mutualistic relationship in nature, wherein mycorrhizal fungi enhance the host plant’s ability to absorb water and nutrients from the soil. In return, the host plant supplies the fungi with essential nutrients necessary for their metabolic activities. However, research focusing on the regulatory mechanisms governing mycorrhizal symbiosis in Dendrobium officinale remains limited. This study systematically investigates the regulatory mechanisms of mycorrhizal symbiosis on transcriptional synthesis in D. officinale by establishing a mycorrhizal symbiotic system, complemented by phenotypic observation, physiological measurement, and transcriptome sequencing. The results indicate that mycorrhizal symbiosis promotes both growth and nutrient absorption in D. officinale, concurrently increasing polysaccharide content. Through transcriptome analysis, we identified 59 differentially expressed genes associated with polysaccharide metabolism, alongside key genes and transcription factors integral to the regulatory network. Notably, the glycosyltransferase gene DoUGT83A1 was found to negatively regulate the mycorrhizal symbiotic system when heterologously expressed in tomato. This study provides a fundamental theoretical basis for elucidating the molecular mechanisms underlying polysaccharide synthesis in D. officinale and offers new insights for optimizing cultivation practices to enhance medicinal quality.

To select and breed superior varieties of Dendrobium officinale with high quality and strong resistance to adverse conditions, a systematic selection process was employed to screen for outstanding strains, complemented by tissue culture for seed propagation. Following screening and self-purification, a new variety, ‘Tiefeng No.1’, was developed. Between 2019 and 2023, a comprehensive assessment of its characteristics, regional product ratio tests, and productivity research was meticulously conducted. The results indicated that the new variety of Dendrobium officinale is stable and of excellent quality. The polysaccharide content ranged from 44.35% to 58.55%, and the mannose content varied from 14.03% to 22.38%, both of which meet the standards set by the Chinese Pharmacopoeia (2020). The anthocyanidin content was measured at 94.76 to 115.43 μg/g, which is double that of the Yueqing landraces. It exhibits good frost resistance and disease resistance. Through production verification and demonstration, ‘Tiefeng No.1’ has proven to possess excellent quality and high yield, showcasing significant potential for promotion in the primary growing regions.

Dendrobium officinale is a traditional and valuable medicinal herb, with extensive research conducted on its polysaccharides, alkaloids, and other components, yet studies on anthocyanins remain limited. In this study, we analyzed the expression levels of GST family genes in green and purplish D. officinale and found that DoGSTF11 is highly expressed in the purplish variety. DoGSTF11 is localized to the nucleus and cell membrane but lacks transcriptional activation activity. Overexpression of DoGSTF11 in tomato enhances anthocyanin accumulation, suggesting a role in anthocyanin sequestration or transport. Yeast two-hybrid (Y2H) and bimolecular fluorescence complementation (BiFC) assays further revealed that DoGSTF11 interacts with DoGST31, while DoIDD12 and DoNF-YB3 are potential transcriptional regulators based on promoter-binding assays and expression correlation. In conclusion, our study demonstrates that DoGST11 positively regulates anthocyanin accumulation in D. officinale. These findings provide valuable insights into the metabolic engineering of flavonoids in D. officinale.