Dendrobium denneanum is an important medicinal and ornamental plant. Its ornamental and medicinal values are affected by its vegetative growth conditions and chemical composition accumulation. This study adopted an orthogonal experimental design to treat D. denneanum with nine different levels of nitrogen (N), potassium (K), and phosphorus (P). The morphological indicators of the plant were positively correlated with the nitrogen concentration. The polysaccharide content was the highest at 1500 mg·L⁻¹ nitrogen and 3000 mg·L⁻¹ phosphorous and was 26.84% greater than the control. The flavonoid content increased by 36.2% at 500 mg·L⁻¹ nitrogen, 2000 mg·L⁻¹ phosphorous, and 300 mg·L⁻¹ potassium. Principal component score analysis showed that nitrogen had the most significant impact on the various indicators of D. denneanum, followed by phosphorus and potassium. The comprehensive score showed that the T9 treatment (N: 1500 mg·L⁻¹, P: 3000 mg·L⁻¹, K: 500 mg·L⁻¹) had the strongest effect on D. denneanum. Transcriptional analysis showed that compared with the control, the T9 treatment led to 2277 differentially expressed genes (1230 upregulated and 1047 downregulated). This includes fifteen genes enriched in the MAPK signaling pathway, five genes in phenylpropanoid biosynthesis, and two genes in flavonoid biosynthesis. These genes may be involved in regulating plant growth and the biosynthesis of polysaccharides and flavonoids. This study provides guidance for the optimal use of N, P, and K in the cultivation of D. denneanum.

Polysaccharides extracted from Taxus media hrough an aqueous method were further refined by removing proteins via the Sevag technique and purified by dialysis. The separation of these polysaccharides was accomplished using a DEAE-cellulose chromatog-raphy column, yielding two distinct fractions, named CPTM-P1 and CPTM-P2. Notably, CPTM-P1 emerged as the primary polysaccharide component within Taxus media. Consequently, a comprehensive analysis focusing exclusively on CPTM-P1 was undertaken. The molecular weight of CPTM-P1 was established through gel permeation chromatography (GPC), and its monosaccharide composition was deciphered using HPLC-MS. The structure was further elucidated through nuclear magnetic resonance (NMR) spectroscopy. The molecular weight of CPTM-P1 was determined to be 968.7 kDa. The monosaccharide composition consisted of galactose (Gal), arabinose (Ara), galacturonic acid (Gal-UA), glucose (Glc), rhamnose (Rha), xylose (Xyl), mannose (Man), fucose (Fuc), glucuronic acid (Glc-UA), and ribose (Rib). The proportional distribution of these components was 30.53%, 22.00%, 5.63%, 11.67%, 11.93%, 1.69%, 8.50%, 1.23%, 5.63%, and 1.17%, respectively. This confirmed CPTM-P1 as an acidic heteropolysaccharide with a glycuronic acid backbone. Moreover, CPTM-P1 showed immunoenhancing properties, effectively augmenting the secretion of nitric oxide and cytokines (TNF-α, IL-1β, and IL-6). Additionally, it significantly enhances the phagocytic capacity of RAW264.7 cells. These findings underscore the potential application of these polysaccharides in functional foods and pharmaceuticals, providing a solid scientific basis for further exploration and utilization of Taxus media polysaccharides.

The NAC transcription factor family represents a large group of plant-specific genes involved in various biological processes, including secondary metabolite biosynthesis, responses to biotic and abiotic stresses, and hormone signaling. Taxus yunnanensis, a well-known medicinal plant, is the natural source of the anticancer diterpene paclitaxel. Despite the biological importance of NAC transcription factors, no comprehensive genome-wide study of the NAC gene family has been conducted in T. yunnanensis. In this study, 44 NAC genes were identified from the T. yunnanensis genome. Gene structure analysis revealed that the number of exons ranged from 1 to 7, with most genes containing 2 to 3 exons. Chromosomal mapping showed an uneven distribution of TyuNACs across the 11 chromosomes. Duplication type analysis indicated that dispersed duplication is the primary mechanism driving the expansion of the TyuNACs, accounting for the largest proportion (24 genes), followed by tandem (12 genes) and proximal duplications (8 genes); no whole-genome or segmental duplication events were detected. Cis-regulatory element analysis suggested that TyuNACs are involved in key biological processes such as development, light response, stress adaptation, and hormone signaling. Expression profiling revealed diverse tissue-specific expression patterns, with most TyuNACs highly expressed in bark. Moreover, qRT-PCR analysis demonstrated that several TyuNACs respond to methyl jasmonate (MeJA) treatment. Yeast one-hybrid and related assays revealed that TyuNAC30 functions as a negative regulator of TyuDBTNBT, a key enzyme gene in the paclitaxel biosynthetic pathway. This study presents the comprehensive genome-wide characterization of the NAC transcription factor family in T. yunnanensis. The findings underscore the predominant role of dispersed duplication in the expansion of the TyuNAC family, with additional contributions from tandem and proximal duplications. Importantly, TyuNAC30 was identified as a negative regulator of TyuDBTNBT, suggesting a key role in the transcriptional regulation of paclitaxel biosynthesis. These findings offer valuable insights for further exploration of the functional roles of NAC genes, particularly their involvement in the regulatory mechanisms underlying paclitaxel biosynthesis.

The construction of the Sichuan–Chongqing double-city economic circle represents a critical measure for high-quality development in China. The coordinated development of industry and economy is conducive to high-quality regional economic growth and the construction of a high-standard market system. This study selects 19 data indexes of the tourism industry and regional economy in the Sichuan–Chongqing region from 2000 to 2020 and analyzes the coupling coordination degree of them through a coupling coordination model. Such being the case, the gray correlation analysis method is used to explore the key factors affecting the coupling difference. It is found that the comprehensive development index of the tourism industry system and regional economic system of the Sichuan–Chongqing region witnesses a steady growth, but the overall performance of the regional economic system lags behind that of the tourism industry system. From the perspective of coupling coordination degree, the coupling coordination between the tourism industry and regional economy in the Sichuan–Chongqing region is increasingly strengthened, with the whole system being in the stage of running-in and high-level coupling. It has achieved the leap from unbalanced development to well-coordinated development. From the perspective of gray correlation analysis, the per capita consumption level of residents and regional GDP are the key factors affecting the coupling and coordination differences of the Sichuan–Chongqing circle.