The gene GeDTC encoding the dicarboxylate-tricarboxylate carrier protein in Gastrodia elata was cloned by specific primers which were designed based on the transcriptome data of G. elata. Bioinformatics analysis on GeDTC gene was carried out by using ExPASY, ClustalW, MEGA, etc. Positive transgenic plants and potato minituber were obtained by virtue of the potato genetic transformation system. Agronomic characters, such as size, weight, organic acid content, and starch content, of potato minituber were tested and analyzed and GeDTC gene function was preliminarily investigated. The results showed that the open reading frame of GeDTC gene was 981 bp in length and 326 amino acid residues were encoded, with a relative molecular weight of 35.01 kDa. It was predicted that the theoretical isoelectric point of GeDTC protein was 9.83, the instability coefficient was 27.88, and the average index of hydrophilicity was 0.104, which was indicative of a stable hydrophilic protein. GeDTC protein had a transmembrane structure and no signal peptide and was located in the inner membrane of mitochondria. The phylogenetic tree showed that GeDTC was highly homologous with DTC proteins of other plant species, among which GeDTC had the highest homology with DcDTC(XP＿020675804.1) in Dendrobium candidum, reaching 85.89%. GeDTC overexpression vector pCambia1300-35Spro-GeDTC was constructed by double digests, and transgenic potato plants were obtained by Agrobacterium-mediated gene transformation. Compared with the wild-type plants, transgenic potato minituber harvested by transplanting had smaller size, lighter weight, lower organic acid content, and no significant difference in starch content. It is preliminarily induced that GeDTC is the efflux channel of tricarboxylate and related to the tuber development, which lays a foundation for further elucidating the molecular mechanism of G. elata tuber development.
Gastrodia/genetics* ; Phylogeny ; Amino Acids ; Cloning, Molecular

This study explored the preservation effect of strigolactone analogs on Gastrodia elata tubers and screened out the suitable preservation measures of G. elata to provide a safer and more effective method for its storage and preservation. Fresh G. elata tubers were treated with 7FGR24, 2,4-D isooctyl ester, and maleic hydrazide, respectively. The growth of flower buds, the activities of CAT, and MDA, and the content of gastrodin and p-hydroxybenzyl alcohol were measured to compare the effects of different compounds on the storage and preservation of G. elata. The effects of different storage temperatures on the preservation of 7FGR24 were compared and analyzed. The gibberellin signal transduction receptor gene GeGID1 was cloned, and the effect of 7FGR24 on the expression level of GeGID1 was analyzed by quantitative polymerase chain reaction(qPCR). The toxicity of the G. elata preservative 7FGR24 was analyzed by intragastric administration in mice to evaluate its safety. The results showed that compared with 2,4-D isooctyl ester and maleic hydrazide, 7FGR24 treatment had a significant inhibitory effect on the growth of G. elata flower buds, and the CAT enzyme activity of G. elata was the highest, indicating that its preservation effect was stronger. Different storage temperatures had different effects on the preservation of G. elata, and the preservation effect was the strongest at 5 ℃. The open reading frame(ORF) of GeGID1 gene was 936 bp in length, and its expression level was significantly down-regulated after 7FGR24 treatment, indicating that 7FGR24 may inhibit the growth of flower buds by inhibiting the gibberellin signal of G. elata, thereby exerting a fresh-keeping effect. Feeding preservative 7FGR24 had no significant effect on the behavior and physiology of mice, indicating that it had no obvious toxicity. This study explored the application of the strigolactone analog 7FGR24 in the storage and preservation of G. elata and preliminarily established a method for the storage and preservation of G. elata, laying a foundation for the molecular mechanism of 7FGR24 in the storage and preservation of G. elata.
Animals ; Mice ; Gastrodia ; Gibberellins ; Maleic Hydrazide ; Esters

This study aims to screen a strain from Armillaria for the cultivation of Gastrodia elata. Specifically, Armillaria strains were isolated from different producing areas of G. elata and identified. Based on the growth characteristics of the strains and the experiment on the cultivation of G. elata, an optimal A. gallica strain was screened out. The specific process is as follows. The fungus-gro-wing materials of G. elata were collected from four producing areas and the Armillaria strains were isolated(G,Y,S,H). The strains were then identified based on morphological observation and phylogeny analysis and the commonly used strains were determined. The sucrase genotypes of the strains were identified according to our previous research findings, and the growth characteristics of the strains, such as growth rate, diameter, dry weight, and polysaccharide content of the rhizomorphs, were measured. According to the biological characteristics and sucrase genotypes, two strains were selected for the cultivation of G. elata. The tuber yield and the content of gastrodin and p-hydroxybenzyl alcohol in the tuber of G. elata were measured to select the optimal strain. The results showed that the four strains were all A. gallica. The rhizomorphs of strains G and H of the same sucrase genotype had larger/higher length, growth rate, diameter, branch number, dry weight, and polysaccharide content than those of strains S and Y of the same sucrase genotype. The tuber yield and the total content of gastrodin and p-hydroxybenzyl alcohol in tuber of G. elata cultivated with strain H were 6.528 kg·m~(-2) and 0.566%, respectively, which were 4.58 and 1.30 folds those of G. elata cultivated with strain S. Strains H and S were screened out from four strains of A. gallica based on the growth characteristics and sucrase genotype. According to the tuber yield and content of total gastrodin and p-hydroxybenzyl alcohol in the tuber of G. elata, strain H was identified as the optimal one. The findings in this study are expected to lay a basis for cultivating G. elata with high yield and quality of tubers.
Armillaria/genetics* ; Gastrodia ; Polysaccharides

As an important active ingredient in the rare Chinese herb Gastrodiae Rhizoma and also the main precursor for gastrodin biosynthesis, 4-hydroxybenzyl alcohol has multiple pharmacological activities such as anti-inflammation, anti-tumor, and anti-cerebral ischemia. The pharmaceutical products with 4-hydroxybenzyl alcohol as the main component have been increasingly favored. At present, 4-hydroxybenzyl alcohol is mainly obtained by natural extraction and chemical synthesis, both of which, however, exhibit some shortcomings that limit the long-term application of 4-hydroxybenzyl alcohol. The wild and cultivated Gastrodia elata resources are limited. The chemical synthesis requires many steps, long time, and harsh reaction conditions. Besides, the resulting by-products are massive and three reaction wastes are difficult to treat. Therefore, how to artificially prepare 4-hydroxybenzyl alcohol with high yield and purity has become an urgent problem facing the medical researchers. Guided by the theory of microbial metabolic engineering, this study employed the genetic engineering technologies to introduce three genes ThiH, pchF and pchC into Escherichia coli for synthesizing 4-hydroxybenzyl alcohol with L-tyrosine. And the fermentation conditions of engineering strain for producing 4-hydroxybenzyl alcohol in shake flask were also discussed. The experimental results showed that under the conditions of 0.5 mmol·L~(-1) IPTG, 15 ℃ induction temperature, and 40 ℃ transformation temperature, M9 Y medium containing 200 mg·L~(-1) L-tyrosine could be transformed into(69±5)mg·L~(-1) 4-hydroxybenzyl alcohol, which has laid a foundation for producing 4-hydroxybenzyl alcohol economically and efficiently by further expanding the fermentation scale in the future.
Benzyl Alcohols ; Escherichia coli/metabolism* ; Gastrodia/chemistry* ; Metabolic Engineering ; Tyrosine/metabolism*

Due to the special biological characteristics, Gastrodia elata suffers from high resource consumption and low utilization rate in modern agricultural production, which significantly block the green and healthy development of this industry. Based on the theory and technology in ecological cultivation of Chinese medicinal materials, this study analyzed the challenges in ecological cultivation of G. elata, such as waste of fungus material, a few cultivation modes available, continuous cropping obstacles, frequent occurrence of diseases, and poor stability of ecological structure. According to the production practice, the following suggestions were proposed for ecological cultivation of G. elata: following the principle of environmental protection and no pollution, selecting suitable habitats to yield high-quality medicinal materials, committing to green control of diseases and pests, upgrading industrial structure to maximize the benefits, establishing a sound mechanism for protecting the genetic diversity of wild G. elata, carrying out simulative habitat cultivation to improve medicinal material quality, adopting science-based planning of fungus resources to relieve forestry pressure, enhancing the recycling and utilization of fungus materials, and applying diversified cultivation modes to improve the stability of ecological structure. The result is expected to provide a reference for the quality development of G. elata industry.
Agriculture ; Gastrodia/chemistry* ; Plants, Medicinal/chemistry*

Tuber rot has become a serious problem in the large-scale cultivation of Gastrodia elata. In this study, we compared the resistance of different ecotypes of G. elata to tuber rot by field experiments on the basis of the investigation of G. elata diseases. The histological observation and transcriptome analysis were conducted to reveal the resistance differences and the underlying mechanisms among different ecotypes. In the field, G. elata f. glauca had the highest incidence of tuber rot, followed by G. elata f. viridis, and G. elata f. elata and G. elata f. glauca×G. elata f. elata showed the lowest incidence. Tuber rot showcased obvious plant source specificity and mainly occurred in the buds and bottom of G. elata plants. After infection, the pathogen spread hyphae in host cortex cells, which can change the endophytic fungal community structure in the cortex and parenchyma of G. elata. G. elata f. glauca had thinner lytic layer and more sugar lumps in the parenchyma than G. elata f. elata. The transcription of genes involved in immune defense, enzyme synthesis, polysaccharide synthesis, carbohydrate transport and metabolism, hydroxylase activity, and aromatic compound synthesis had significant differences between G. elata f. glauca and G. elata f. elata. These findings suggested that the differences in resis-tance to tuber rot among different ecotypes of G. elata may be related to the varied gene expression patterns and secondary metabolites. This study provides basic data for the prevention and control of tuber rot and the improvement of planting technology for G. elata.
Ecotype ; Gastrodia/microbiology* ; Gene Expression Profiling ; Plant Tubers/genetics*

Brown rot is a common disease in the cultivation and production of Gastrodia elata, but its pathogens have not been fully revealed. In this study, the pathogenic fungi were isolated and purified from tubers of 77 G. elata samples with brown rot. Pathogens were identified by the pathogenicity test and morphological and molecular identification. The pathogenicity of each pathogen and its inhibitory effects on Armillaria gallica were compared. The results showed that 119 strains of fungi were isolated from tubers of G. elata infected with brown rot. Among them, the frequency of separation of Ilyonectria fungi was as high as 42.01%. The pathogenicity test showed that the pathogenicity characteristics of six strains of fungi were consistent with the natural symptoms of brown rot in G. elata. The morphological and molecular identification results showed that the six strains belonged to I. cyclaminicola and I. robusta in the Nectriaceae family of Sordariomycetes class, respectively. Both types of fungi could produce pigments, conidia, and chlamycospore, and the growth rate of I. cyclaminicola was significantly higher than that of I. robusta. The comparison of pathogenicity showed that the spots formed by I. cyclaminicola inoculation were significantly larger than those of I. robusta inoculation, suggesting I. cyclaminicola was superior to I. robusta in pathogenicity. The results of confrontation culture showed that I. cyclaminicola and I. robusta could signi-ficantly inhibit the germination and cordage growth of A. gallica. A. gallica also inhibited the growth of pathogens, and I. cyclaminicola was less inhibited as compared with I. robusta. The results of this study revealed for the first time that I. cyclaminicola and I. robusta were the pathogens responsible for G. elata brown rot.
Fungi ; Gastrodia ; Plant Tubers ; Spores, Fungal ; Virulence

The continuous cropping obstacle of Gastrodia elata is outstanding, but its mechanism is still unclear. In this study, microbial changes in soils after G. elata planting were investigated to explore the mechanism correlated with continuous cropping obstacle. The changes of species and abundance of fungi and bacteria in soils planted with G. elata after 1, 2, and 3 years were compared. The pathogenic fungi that might cause continuous cropping diseases of G. elata were isolated. Finally, the prevention and control measures of soil-borne fungal diseases of G. elata were investigated with the rotation planting pattern of "G. elata-Phallus impudicus". The results showed that G. elata planting resulted in the decrease in bacterial and fungal community stability and the increase in harmful fungus species and abundance in soils. This change was most obvious in the second year after G. elata planting, and the soil microbial community structure could not return to the normal level even if it was left idle for another two years. After G. elata planting in soils, the most significant change was observed in Ilyonectria cyclaminicola. The richness of the Ilyonectria fungus in soils was significantly positively correlated with the incidence of G. elata diseases. When I. cyclaminicola was inoculated in the sterile soil, the rot rate of G. elata was also significantly increased. After planting one crop of G. elata and one to three crops of P. impudicus, the fungus community structure in soils gradually recovered, and the abundance of I. cyclaminicola decreased year by year. Furthermore, the disease rate of G. elata decreased. The results showed that the cultivation of G. elata made the Ilyonectria fungi the dominant flora in soils, and I. cyclaminicola served as the main pathogen of continuous cropping diseases of G. elata, which could be reduced by rotation planting with P. impudicus.
Bacteria ; Fungi ; Gastrodia/microbiology* ; Mycobiome ; Soil ; Soil Microbiology

Mycena, a symbiont of Gastrodia elata, promotes seed germination of G. elata and plays a crucial role in the sexual reproduction of G. elata. However, the lack of genetic transformation system of Mycena blocks the research on the interaction mechanism of the two. In order to establish the protoplast transformation system of Mycena, this study analyzed the protoplast enzymatic hydrolysis system, screened the resistance markers and regeneration medium, and explored the transient transformation. After hydrolysis of Mycena hyphae with complexes enzymes for 8 h and centrifugation at 4 000 r·min~(-1), high-concentration and quality protoplast was obtained. The optimum regeneration medium for Mycena was RMV, and the optimum resistance marker was 50 mg·mL~(-1) hygromycin. The pLH-HygB-HuSHXG-GFP-HdSHXG was transformed into the protoplast of Mycena which then expressed GFP. The established protoplast transformation system of Mycena laid a foundation for analyzing the functional genes of Mycena and the molecular mechanism of the symbiosis of Mycena and G. elata.
Agaricales ; Gastrodia/genetics* ; Protoplasts ; Symbiosis/genetics* ; Transformation, Genetic

This study aims to explore the resource utilization of used fungus-growing materials produced in the cultivation of Gastrodia elata. To be specific, based on the production practice, this study investigated the recycling mechanism of used fungus-growing materials of G. elata by Phallus inpudicus. To screen edible fungi with wide adaptability, this study examined the allelopathic effects of Armillaria mellea secretions on P. impudicus and 6 kinds of large edible fungi and the activities of enzymes related to degradation of the used fungus-growing materials of G. elata. The results showed that P. impudicus can effectively degrade cellulose, hemicellulose, and lignin in used fungus-growing materials of G. elata. The cellulase activity of A. mellea was significantly higher than that of P. impudicus, and the activities of lignin peroxidase, polyphenol oxidase, and xylanase of P. impudicus were significantly higher than those of A. mellea, which was the important reason why A. mellea and P. impudicus used different parts and components of the used fungus-growing materials to absorb carbon sources and develop ecological niche differences. The growth of P. impudicus was significantly inhibited on the used fungus-growing materials of G. elata. The secretions of A. mellea had allelopathic effects on P. impudicus and other edible fungi, and the allelopathic effects were related to the concentration of allelopathy substances. The screening result showed that the growth and development of L. edodes and A. auricular were not significantly affected by 30% of A. mellea liquid, indicating that they had high resistance to the allelopathy of A. mellea. The results showed that the activities of extracellular lignin peroxidase, polyphenol oxidase, and xylanase of the two edible fungi were similar to those of P. impudicus, and the cellulase activity was higher than that of P. impudicus. This experiment can be further verified by small-scale production tests.
Agaricales ; Ascomycota ; Basidiomycota ; Catechol Oxidase ; Cellulases ; Gastrodia