[Investigation and application of Dendrobium resources in Qinba Mountains with a discussion on industrial poverty alleviation model].

The Dendrobium species are rare and endangered medicinal plants, and it is difficult to investigate their wild resources with conventional methods because of typical epiphytic herbaceous. We explored Dendrobium resources(include culture resource) of Qinba Mountains and the boundary Mountain area in Hubei, Chongqing using the methods of literatures and field investigation, and found that the cultural base of Dendrobium were profound in Qinba Mountains region. Furthermore, its germplasm resources of Dendrobium were established for the first time in Wanzhou Luotian town. In case the advantages of local rock resources and poverty alleviation demand, we have actively carried out the cultivating mode of Dendrobium which grow on rock, and the poverty alleviation model of local characteristic Dendrobium industry were established preliminarily. Our application case can provide reference for the mining and transformation of traditional Chinese medicine resources census results.

[Original materials of traditional Chinese medicinal names of "Jinchai" and "Jinchai Shihu" based on vegetative morphology].

"Jinchai Shihu" were called Jinchai and recoded in "Taishang Zhouhou Yujingfang" of Tang Dynasty, which first clearly documented the name of Shihu in complex Dendrobium medicines and were condiered as superior medicinal articles. Morphological features are one of the naming principles for Chinese medicines. In this paper, botanical origin plants under the names of "Jinchai" and "Jinchai Shihu" were investigated. Based on documents from the local Chronicles and historical accounts, the Chinese characters of Jinchai have the distinctive features of gold color and two hair clasps. Moreover, the hair clasps are usually cylindrical in shape with uniform thickness in middle and upper part, and tapers off to the foot. And its bottom part style is simple and head part is complex. Thus we speculated the herbal "Jinchai" and "Jinchai Shihu" should have similar morphologic features as Chinese characters of Jinchai, including golden color and hairpin shape of stems without braches, short and solid sterm. After comparing the dried vegetative morphology of 10 common medicinal Dendrobium species, we suggested that of Dendrobium flexicaule matches well with the morphological features from historical herbal records.

[Investigation of original materials under traditonal Chinese medicine names of "Jinchai" and "Jinchai Shihu"].

To clear from botanical view the original materials under the traditional Chinese medicine names of "Jinchai", "Jinchai Shihu" within the genus Dendrobium of the family Orchidaceae. Combined of different methods including study of historical records from the local chronicles and historical accounts of past event in Hubei, Sichuan, Chongqing, Henan and Shaanxi provinces, interviewing face to face with the old traditional Chinese workers and folk doctors in 20 downtowns and countrysides, such as, Laohekou, Lichuan, Fangxian, Xixia, Neixiang, and Ankang, and collecting a few plants of "Jinchai" for taxonomic identification. The traditional Chinese medicine names of "Jinchai", "Jinchai Shihu" were widely used by the local people from the eastern Chongqing, western Hubei, northeasten Sichuan, southeastern Shaanxi, western Henan. Those two names were frequently found in the local Chronicles and historical accounts of past event, even in the local daily life such as folk songs and stories. The botanical identification results showed that a endemic species of D. flexicaule is the original materials of the traditional Chinese medicine names "Jinchai" and "Jinchai Shihu", and this species are also called "Longtoujin", "Renzijin", "Huanzijin" and "Longtoufengweijin" by the local people. The dried artifactitious specimens of D. flexicaule are traditionally named as "Jinerhuan". The botanic resource plants of the traditional Chinese medicine names of "Jinchai", "Jinchai Shihu" are the endemic species of D. flexicaule that is distributed mainly in central areas of China including eastern Chongqing, western Hubei, northeasten Sichuan, southeastern Shaanxi, and western Henan, rather than D. nobile as referring in both Chinese and English version of Flora of China, and in official recorded serious versions of The Chinese Pharmacopoeia since 1977. In order to avoid confusion in the traditional Chinese medicine dendrobiums industry, the Chinese name of D. nobile is suggested as "Biancao Shihu", which characterized one stem feature of this species, and the traditional Chinese medicine names "Jinchai" or "JinchaiShihu" is suggested to refer to the species D. flexicaule.

Comparative analysis of the mitochondrial genomes of four Dendrobium species (Orchidaceae) reveals heterogeneity in structure, synteny, intercellular gene transfer, and RNA editing.

The genus Dendrobium, part of the Orchidaceae family, encompasses species of significant medicinal, nutritional, and economic value. However, many Dendrobium species are threatened by environmental stresses, low seed germination rates, and overharvesting. Mitochondria generate the energy necessary for various plant life activities. Despite their importance, research on the mitochondrial genomes of Dendrobium species is currently limited. To address this gap, we performed a comprehensive genetic analysis of four Dendrobium species-D. flexicaule, D. nobile, D. officinale, and D. huoshanense-focusing on their mitochondrial and chloroplast genomes to elucidate their genetic architecture and support conservation efforts. We utilized advanced sequencing technologies, including Illumina for high-throughput sequencing and Nanopore for long-read sequencing capabilities. Our findings revealed the multichromosomal mitochondrial genome structures, with total lengths ranging from 596,506 bp to 772,523 bp. The mitochondrial genomes contained 265 functional genes, including 64-69 protein-coding genes, 23-28 tRNA genes, and 3 rRNA genes. We identified 647 simple sequence repeats (SSRs) and 352 tandem repeats, along with 440 instances of plastid-to-mitochondrial gene transfer. Additionally, we predicted 2,023 RNA editing sites within the mitochondrial protein-coding genes, predominantly characterized by cytosine-to-thymine transitions. Comparative analysis of mitochondrial DNA across the species highlighted 25 conserved genes, with evidence of positive selection in five genes: ccmFC, matR, mttB, rps2, and rps10. Phylogenetic assessments suggested a close sister relationship between D. nobile and D. huoshanense, and a similar proximity between D. officinale and D. flexicaule. This comprehensive genomic study provides a critical foundation for further exploration into the genetic mechanisms and biodiversity of Dendrobium species, contributing valuable insights for their conservation and sustainable utilization.

Tryptophan decarboxylase plays an important role in ajmalicine biosynthesis in Rauvolfia verticillata.

Tryptophan decarboxylase (TDC) converts tryptophan into tryptamine that is the indole moiety of ajmalicine. The full-length cDNA of Rauvolfia verticillata (RvTDC) was 1,772 bps that contained a 1,500-bp ORF encoding a 499-amino-acid polypeptide. Recombinant 55.5 kDa RvTDC converted tryptophan into tryptamine. The K (m) of RvTDC for tryptophan was 2.89 mM, higher than those reported in other TIAs-producing plants. It demonstrated that RvTDC had lower affinity to tryptophan than other plant TDCs. The K (m) of RvTDC was also much higher than that of strictosidine synthase and strictosidine glucosidase in Rauvolfia. This suggested that TDC might be the committed-step enzyme involved in ajmalicine biosynthesis in R. verticillata. The expression of RvTDC was slightly upregulated by MeJA; the five MEP pathway genes and SGD showed no positive response to MeJA; and STR was sharply downregulated by MeJA. MeJA-treated hairy roots produced higher level of ajmalicine (0.270 mg g(-1) DW) than the EtOH control (0.183 mg g(-1) DW). Highest RvTDC expression level was detected in hairy root, about respectively 11, 19, 65, and 109-fold higher than in bark, young leaf, old leaf, and root. Highest ajmalicine content was also found in hairy root (0.249 mg g(-1) DW) followed by in bark (0.161 mg g(-1) DW) and young leaf (0.130 mg g(-1) DW), and least in root (0.014 mg g(-1) DW). Generally, the expression level of RvTDC was positively consistent with the accumulation of ajmalicine. Therefore, it could be deduced that TDC might be the key enzyme involved in ajmalicine biosynthesis in Rauvolfia.