Protective effect of Gastrodia elata Blume in a Caenorhabditis elegans model of Alzheimer's disease based on network pharmacology

The aim of the present study was to investigate the protective effect of Gastrodia elata Blume (GEB) against Caenorhabditis elegans (C. elegans) in Alzheimer's disease (AD) through network pharmacology. Firstly, the active constituents of GEB through ETCM and BATMAN-TCM databases were collected and its potential AD-related targets in Swiss Target Prediction were predicted. The potential targets related to AD were collected from the GeneCards, OMIM, CTD and DisGeNET databases, and the differential genes (DEGs) between the normal population and the AD patient population in GSE5281 chip of the Gene Expression Omnibus database were collected at the same time. The intersection of the three targets yielded 59 key targets of GEB for the treatment of AD. The drug-active ingredient-target-AD network diagram was constructed and visualized with Cytoscape software to obtain the core components. Subsequently, protein-protein interaction analysis (PPI) was performed on 59 key targets through STRING database, and Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses was performed on 59 key targets. Finally, molecular docking was conducted between core components and core targets using AutoDock software, and the C. elegans AD model was used for experimental verification to explore the regulatory paralysis effect of core components on the C. elegans model, β-amyloid (Aβ) plaque deposition, and quantitative polymerase chain reaction verification of the regulatory effect of components on targets. The GEB components 4,4'-dihydroxydiphenyl methane (DM) and protocatechuic aldehyde (PA) were found to be most strongly associated with AD, and five core targets were identified in the PPI network, including GAPDH, EP300, HSP90AB1, KDM6B, and CREBBP. In addition to GAPDH, the other four targets were successfully docked with DM and PA using AutoDock software. Compared with the control group, 0.5 mM DM and 0.25 mM PA significantly delayed C. elegans paralysis (P<0.01), and inhibited the aggregation of Aβ plaques in C. elegans. Both DM and PA could upregulate the expression level of core target gene HSP90AB1 (P<0.01), and DM upregulated the expression of KDM6B (P<0.01), suggesting that DM and PA may be potential active components of GEB in the treatment of AD.

Studies on the mechanism of energy metabolism via AMPK/PGC-1α signaling pathway induced by compatibility of Ligusticum chuanxiong Hort and Gastrodia

AMP-activated protein kinase (AMPK) regulates overall energy consumption and energy intake through cytokines. Ligusticum striatum DC (CX) combined with Gastrodia elata Blume (TM) has been used for migraine treatment for millennia. When used alone in clinical practice, CX causes symptoms of thirst, irritability, and yellow urine and has influenced the levels of cytokines such as AMP that activate the AMPK pathway of energy metabolism. However, relationships between this compatibility prescription, integral biological energy metabolism, and the AMPK pathway remain unclear. Studies were performed by treating normal rats with physiological saline, CX extract, CX coupled TM extract, and TM extracts separately for 4 weeks. Food intake, water intake, urine output, stool output, and body weight were monitored once a week by the metabolic cage method. Values of FBG, BUN, TP, TC and TG in blood samples were detected approaching the whole blood automatic detector from 1 to 4 weeks. Na+ -K+ -ATPase, Ca2+ -Mg2+ -ATPase, cAMP, and cGMP activity were determined by the enzyme-linked immunosorbent assay (ELISA); the biological samples that were obtained at 1, 2, 3, and 4 weeks after drug administration were tested by GC-TOF-MS. Then real-time PCR and Western Blot were applied to detect changes in expression of some substances involved in energy metabolism. The results demonstrated that administering CX alone increased energy input, mobility, and respiratory exchange ratio, accelerated energy consumption, and caused inflammatory infiltration in the liver. CX coupled with TM led to lower energy metabolism and liver damage in comparison with CX used alone. Moreover, CX-treated rats harbored higher levels of differential metabolites (including pyrophosphate, oxaloacetic acid, and galactinol). Glycerophospholipid metabolism and the citrate cycle are closely related to the differential metabolites above. In addition, CX-induced unbalanced energy metabolism depends on cAMP activation mediated by the AMPK/PGC-1α pathway in rats. Our findings suggest that CX-induced energy metabolism imbalance was corrected after coupling with TM by mediating the AMPK/PGC-1α pathway.

The Gastrodia menghaiensis (Orchidaceae) genome provides new insights of orchid mycorrhizal interactions

BACKGROUND

To illustrate the molecular mechanism of mycoheterotrophic interactions between orchids and fungi, we assembled chromosome-level reference genome of Gastrodia menghaiensis (Orchidaceae) and analyzed the genomes of two species of Gastrodia.

RESULTS

Our analyses indicated that the genomes of Gastrodia are globally diminished in comparison to autotrophic orchids, even compared to Cuscuta (a plant parasite). Genes involved in arbuscular mycorrhizae colonization were found in genomes of Gastrodia, and many of the genes involved biological interaction between Gatrodia and symbiotic microbionts are more numerous than in photosynthetic orchids. The highly expressed genes for fatty acid and ammonium root transporters suggest that fungi receive material from orchids, although most raw materials flow from the fungi. Many nuclear genes (e.g. biosynthesis of aromatic amino acid L-tryptophan) supporting plastid functions are expanded compared to photosynthetic orchids, an indication of the importance of plastids even in totally mycoheterotrophic species.

CONCLUSION

Gastrodia menghaiensis has the smallest proteome thus far among angiosperms. Many of the genes involved biological interaction between Gatrodia and symbiotic microbionts are more numerous than in photosynthetic orchids.

Mycorrhizal Switching and the Role of Fungal Abundance in Seed Germination in a Fully Mycoheterotrophic Orchid, Gastrodia confusoides

Mycorrhizal associations are essential for orchid germination and seedling establishment, and thus may constrain the distribution and abundance of orchids under natural conditions. Previous studies have shown that germination and seedling establishment in several orchids often decline with increasing distance from adult plants, resulting in non-random spatial patterns of seedling establishment. In contrast, individuals of the fully mycoheterotrophic orchid Gastrodia confusoides often tend to have random aboveground spatial patterns of distribution within bamboo forests. Since G. confusoides is parasitic on litter-decaying fungi, its random spatial patterns of distribution may be due to highly scattered patterns of litter-decaying fungi within bamboo forests. To test this hypothesis, we first identified the main mycorrhizal fungi associating with developing seeds and adult plants at a bamboo forest site in Taiwan using Miseq high-throughput DNA sequencing. Next, we combined seed germination experiments with quantitative PCR (qPCR) analyses to investigate to what extent the abundance of mycorrhizal fungi affected spatial patterns of seed germination. Our results show that seed germination and subsequent growth to an adult stage in G. confusoides required a distinct switch in mycorrhizal partners, in which protocorms associated with a single Mycena OTU, while adults mainly associated with an OTU from the genus Gymnopus. A strong, positive relationship was observed between germination and Mycena abundance in the litter, but not between germination and Gymnopus abundance. Fungal abundance was not significantly related to the distance from the adult plants, and consequently germination was also not significantly related to the distance from adult plants. Our results provide the first evidence that the abundance of litter-decaying fungi varies randomly within the bamboo forest and independently from G. confusoides adults.

New taxa of tribe Gastrodieae (Epidendroideae, Orchidaceae) from Yunnan, China and its conservation implication

Gastrodia longistyla, a new species of Orchidaceae from Yunnan Province, China, is described and illustrated. It is morphologically similar to Gastrodia peichatieniana, but can be easily distinguished from the latter by having a rhombic epichile, long column (6.0-7.5 mm long), and a needle-shaped appendage (1.8-3.2 mm in length) at the base of the stigma. Identification key and colour photographs are provided. A preliminary risk-of-extinction assessment, according to the IUCN Red List Categories and Criteria, is given for the new species. The plastome of G. longistyla is 30464 bp in length with GC content approximately 24.8%, and the plastome does not contain some housekeeping genes, such as matK, rpl16, or all photosynthesis genes. In addition, the G. longistyla plastome lacks an IR region. This indicates that the plastome is in the last stage of degradation.

Gastrodia remodels intestinal microflora to suppress inflammation in mice with early atherosclerosis

Atherosclsis is a critical actuator causing cardiac-cerebral vascular disease with a complicated pathogeneon, refered to the disorders of intestinal flora and persistent inflammation. Gastrodin (4-(hydroxymethyl) phenyl-β-D- Glucopyranoside) is the most abundant glucoside extracted from the Gastrodiaelata, which is a traditional Chinese herbal medicine for cardiac-cerebral vascular disease, yet its mechanisms remain little known. In the present study, the gastrodia extract and gastrodin attenuate the lipid deposition and foam cells on the inner membrane of the inner membrane of the thoracic aorta in the early atherosclerosis mice. Blood lipid detection tips that TC and LDL-C were reduced in peripheral blood after treatment with the gastrodia extract and gastrodin. Furthermore, unordered gut microbes are remodeled in terms of bacterial diversity and abundance at family and genus level. Also, the intestinal mucosa damage and permeability were reversed, accompaniedwith the reducing of inflammatory cytokines. Our findings revealed that the functions of gastrodia extract and gastrodin in cardiac-cerebral vascular disease involved to rescued gut microbes and anti-inflammation may be the mechanismof remission lipid accumulation.

Pharmacokinetic comparative study of GAS with different concentration of tetramethylpyrazine and ferulic acid on liver-yang hyperactivity migraine model by blood-brain microdialysis method

Gastrodia elata and Ligusticum chuanxiong are used to treat primary headaches for many years. Gastrodin (GAS) and tetramethylpyrazine (TMP)/ferulic acid (FA) are the main active ingredients of Gastrodia elata and Ligusticum chuanxiong, respectively. Previous studies demonstrated the pharmacokinetics of GAS, TMP, and FA in the blood and brain interstitial fluids (BIF) in healthy animals but not in animal model with liver-yang hyperactivity migraine. Hence, this study examined the pharmacokinetics of GAS after its oral administration in the presence of different concentrations of TMP and FA in animals with liver-yang migraine hyperactivity. In the control group, GAS was administrated without TMP and FA. Pharmacokinetic parameters were determined using the blood-brain microdialysis in combination with the high-performance liquid chromatography method. Results revealed that the maximum drug concentrations (C_max) in the serum, area under curve (AUC), and mean residence time (MRT) of GAS decreased in normal animals, whereas C_max increased significantly in model animals. These findings indicate that varying concentrations of TMP and FA play an important role in the pharmacokinetics of GAS in both normal and migraine model animals, validating the utility of the ancient formulation.

Herbal decoction of Gastrodia, Uncaria, and Curcuma confers neuroprotection against cerebral ischemia in vitro and in vivo

"Tianma" (Gastrodia) and "gouteng" (Uncaria) are both widely used to treat cerebral ischemia. At the same time, "ezhu" (Curcuma longa) or turmeric, is derived from the dried roots of C. longa. It is a polyphenol known for its anti-inflammatory effects and its promotion of blood vessel endothelial function. This study explored the neuroprotective effects of a water extract of "tianma", "gouteng", and "ezhu" against ischemic injury. Flow cytometry analysis showed that Gastrodia, Uncaria, and Curcuma reduced the proportion of apoptotic cells in CoCl₂ induced B35 (P = 0.0027) and SH-SY5Y (P = 0.0006) cell sample relative to the respective control group. Western blot indicated that Gastrodia, Uncaria, and Curcuma upregulated the expression of Bcl-2 and inversely downregulated Bax and Caspase-3 (P < 0.001). The infarct volume observed in the Gastrodia, Uncaria, and Curcuma group was also decreased compared with the control group (P < 0.05). Immunofluorescence detection revealed a lower expression of Caspase-7 in the Gastrodia, Uncaria, and Curcuma group than in the control group, while expression was negligible in the sham group. Gastrodia, Uncaria, and Curcuma confer neuroprotective effects in CoCl₂ induced B35/SH-SY5Y cells and a rat model of ischemia by way of its anti-apoptotic effects.

A complete chloroplast genome sequence of Gastrodia elata (Orchidaceae) represents high sequence variation in the species

Gastrodia elata is a non-photosynthetic saprophytic plant of medicinal use in the oriental countries. We report the second complete chloroplast (cp) genome of G. elata from a sample collected in Korea. The length of cp genome is only 35,180 bp: there is no inverted repeated region and many photosynthesis genes are missing compared to typical angiosperm cp genomes. It includes 20 protein-coding genes, 3 rRNAs, and 5 tRNAs. The overall GC content of the genome was 26.7%. Relatively, high intra-specific variation (457 SNPs and 670 indels) is detected in the species comparing it with other seed plants.

Pharmacokinetic comparative study of tetramethylpyrazine and ferulic acid and their compatibility with different concentration of gastrodin and gastrodigenin on blood-stasis migraine model by blood-brain microdialysis method

Tianma pills, a traditional formula made from Ligusticum chuanxiong and Gastrodia elata, are efficacious for the treatment of primary headache. Tetramethylpyrazine (TMP) and Ferulic acid (FA) are the bioactive ingredients of Ligusticum chuanxiong, while Gastrodin and Gastrodigenin are the bioactive ingredients of Gastrodia elata. Pharmacokinetic assessment of TMP, FA, gastrodin or gastrodigenin in blood or brain interstitial fluid (BIF) has been reported in healthy animals. However, the pharmacokinetic properties of TMP and FA have not been studied when they are co-administered in a blood-stasis migraine model. The present research investigated the pharmacokinetic behavior of TMP and FA after oral administration in the presence of different concentrations of gastrodin and gastrodigenin in a blood-stasis migraine model. Pharmacokinetic parameters were determined using blood-brain microdialysis in combination with the UHPLC-MS method. Compared to the control group, in which TMP and FA were administrated without gastrodin or gastrodigenin, the T_1/2, MRT, C_max and AUC_0-∞ of TMP and FA were increased. These results indicate that varying concentrations of gastrodin and gastrodigenin play an important role in affecting the pharmacokinetics of TMP and FA. Low concentrations of gastrodin and gastrodigenin (similar to those found in Tianma pills) were more efficacious, validating the utility of the ancient formulation.

Affiliation with Natural Products at KIB of Prof. Zhou Jun: On the Occasion of 80th Anniversary of Kunming Institute of Botany, CAS

Prof. Zhou Jun, Academician of Chinese Academy of Sciences (1999), is a phytochemist and medicinal chemist of China. He is one of the pioneers of Kunming Institute of Botany, CAS and a major founder of the State Key Laboratory of Phytochemistry and Plant Resources in West China. The chemical compositions of some TCM from genus of Dioscorea, Aconitum, Panax, Paris, Cynanchum, Gastrodia, Dendrobium etc. and family Asclepiadaceae, Caryophyllaceae, Hypoxidaceae etc. have been explored by Prof. Zhou's team as steroids, triterpenoids, alkaloids, cyclic peptides and phenols etc., which revealed the main active composition of those TCM such as Panax notoginseng, Paris yunnanensis and Gastrodia elata.

A Review on Central Nervous System Effects of Gastrodin

Rhizoma Gastrodiae (also known as Tian ma), the dried rhizome of Gastrodia elata Blume, is a famous Chinese herb that has been traditionally used for the treatment of headache, dizziness, spasm, epilepsy, stoke, amnesia and other disorders for centuries. Gastrodin, a phenolic glycoside, is the main bioactive constituent of Rhizoma Gastrodiae. Since identified in 1978, gastrodin has been extensively investigated on its pharmacological properties. In this article, we reviewed the central nervous system (CNS) effects of gastrodin in preclinical models of CNS disorders including epilepsy, Alzheimer's disease, Parkinson's disease, affective disorders, cerebral ischemia/reperfusion, cognitive impairment as well as the underlying mechanisms involved and, where possible, clinical data that support the pharmacological activities. The sources and pharmacokinetics of gastrodin were also reviewed here. As a result, gastrodin possesses a broad range of beneficial effects on the above-mentioned CNS diseases, and the mechanisms of actions include modulating neurotransmitters, antioxidative, anti-inflammatory, suppressing microglial activation, regulating mitochondrial cascades, up-regulating neurotrophins, etc. However, more detailed clinical trials are still in need for positioning it in the treatment of neurological disorders.

A method for facilitating the seed germination of a mycoheterotrophic orchid, Gastrodia pubilabiata, using decomposed leaf litter harboring a basidiomycete fungus, Mycena sp

BACKGROUND

Mycoheterotrophic plants are one of the most difficult plant groups to conserve because they are entirely dependent on symbiotic fungi. Establishment of viable culture systems would greatly aid their conservation. We describe a simple culture system for the mycoheterotrophic orchid, Gastrodia pubilabiata, that does not require laboratory facilities. The orchid is symbiotic with leaf-litter-decomposing fungi.

RESULTS

Gastrodia pubilabiata seeds were incubated in plastic boxes or glass bottles filled with leaf litter collected from the natural habitat of the species. Seed germination was observed after 35 days and seedling development followed. Fungal isolates from seedlings were identified as Mycenaceae (Basidiomycota), a leaf-litter-decomposing mycorrhizal fungus of Gastrodia species.

CONCLUSION

Our method can be used to conserve endangered mycoheterotrophic plants associated with leaf litter-decomposing fungi efficiently, and can also serve as a model system for physiological and molecular studies of such plants.

Effects of Polysaccharide of Gastrodia Elata Blume and Electro-Acupuncture on Expressions of Brain-Derived Neurotrophic Factor and Stem Cell Factor Protein in Caudate Putamen of Focal Cerebral Ischemia Rats

Background

The aim of this study was to explore the neural protective effect of polysaccharide of Gastrodia elata Blume (PGB) and electro-acupuncture (EA) on focal cerebral ischemia rats.

Material/Methods

A total of 40 Sprague-Dawley rats were randomly divided into 5 groups (normal group, model group, PGB group, EA group and PGB+EA group). The model was prepared by middle cerebral artery occlusion (MCAO). Two week after modeling, rats were given PGB, EA, or a combination of the 2 in continuous treatment for 2 successive weeks. 14 days after modeling, expressions of BDNF and SCF protein in the caudate putamen (CPu) were detected by immunohistochemistry.

Results

Positive expression of BDNF and SCF protein was found in the right caudate putamen of each group of rats. Expressions of BDNF and SCF in the CPu of the model group were higher than normal group (P<0.05). Compared with the model group, the expressions of BDNF and SCF in the CPu of the PGB group, the EA group, and the PGB plus EA group increased significantly (P<0.05). The expressions of BDNF and SCF obviously increased in the PGB plus EA group compared to those of the EA group and the PGB group (P<0.05).

Conclusions

PGB and EA up-regulated the expressions of BDNF and SCF protein in the CPu of focal cerebral ischemia rats, and the combination of PGB+EA has a synergistic effect on the recovery from cerebral ischemia.

Embryology of two mycoheterotrophic orchid species, Gastrodia elata and Gastrodia nantoensis: ovule and embryo development

BACKGROUND

Gastrodia elata, a famous herbal medicine, has been received great attention on its treatments of headache, vertigo and epilepsy. Gastrodia nantoensis is a newly described species from central Taiwan with potential medicinal value. Gastrodia species are fully mycoheterotrophic orchids, and the courses of their seed development are more rapid as compared to the chlorophyllous orchids. A better understanding of their reproductive biology would provide insights into the propagation and conservation of the mycoheterotrophic orchid species.

RESULTS

Based on the histological and histochemical investigations, we observed some notable features in ovule and embryo development. First, only the archesporial cell and/or megasporocyte are present within their ovaries at the time of anthesis. Second, their suspensors consist of a single cell and their mature embryos consist of a gradient of small to large cells. Nile red staining of a globular embryo reveals the presence of cuticular material in the surface wall of embryo proper and the lateral walls of suspensor cell, indicating that the basal wall of suspensor cell is the major route for nutrient supply from maternal tissues to embryo proper. Third, their seed coats are derived from a single integument, and lignin but not cuticular material is present in the outer most layer of seed coat and persists through seed maturation.

CONCLUSIONS

The faster seed development of Gastrodia species is due to the speedy courses of ovule and embryo development. In the mature seeds, the presence of a differentiated apical zone in embryo proper suggests the easy-to-germinate character. This study provides basic knowledge for further molecular studies on embryo development and symbiotic germination of Gastrodia species.

How do fungal partners affect the evolution and habitat preferences of mycoheterotrophic plants? A case study in Gastrodia

PREMISE OF THE STUDY

Since mycoheterotrophic plants (MHPs) completely depend on their mycorrhizal fungi for carbon, selection of fungal partners has an important role in the speciation of MHPs. However, the causes and mechanisms of mycobiont changes during speciation are not clear. We tested fungal partner shifts and changes in mycorrhizal specificity during speciation of three closely related MHPs-Gastrodia confusa (Gc), G. pubilabiata (Gp), and G. nipponica (Gn) (Orchidaceae)-and correlations between these changes and the vegetation types where each species grows.

METHODS

We investigated the diversity of mycobionts of the three species by sequencing nrDNA ITS, and the sequence data were subjected to test changes in fungal specificity and fungal partner shifts among the three species. Furthermore, we conducted multivariate analysis to test for differences in mycobiont communities of vegetation types where each species grows.

KEY RESULTS

Two saprobic Basidiomycota, Marasmiaceae and Mycenaceae, were dominant fungal partners of the three species, and Gn was simultaneously associated with the ectomycorrhizal Russulaceae and Sebacinaceae. Although mycobiont composition differed among the three species, they also sometimes shared identical fungal species. Multivariate analysis revealed that mycobiont communities of the three species in bamboo thickets differed significantly from those in other vegetation types.

CONCLUSIONS

Fungal partner shifts are not necessarily associated with the evolution of MHPs, and fungal specificity of Gc and Gp was significantly higher than that of Gn, implying that the specificity fluctuates during speciation. Further, Gc exclusively inhabits bamboo thickets, which suggests that adaptation to particular fungi specific to bamboo thickets triggered speciation of this species.

The importance of associations with saprotrophic non-Rhizoctonia fungi among fully mycoheterotrophic orchids is currently under-estimated: novel evidence from sub-tropical Asia

BACKGROUND AND AIMS

Most fully mycoheterotrophic (MH) orchids investigated to date are mycorrhizal with fungi that simultaneously form ectomycorrhizas with forest trees. Only a few MH orchids are currently known to be mycorrhizal with saprotrophic, mostly wood-decomposing, fungi instead of ectomycorrhizal fungi. This study provides evidence that the importance of associations between MH orchids and saprotrophic non-Rhizoctonia fungi is currently under-estimated.

METHODS

Using microscopic techniques and molecular approaches, mycorrhizal fungi were localized and identified for seven MH orchid species from four genera and two subfamilies, Vanilloideae and Epidendroideae, growing in four humid and warm sub-tropical forests in Taiwan. Carbon and nitrogen stable isotope natural abundances of MH orchids and autotrophic reference plants were used in order to elucidate the nutritional resources utilized by the orchids.

KEY RESULTS

Six out of the seven MH orchid species were mycorrhizal with either wood- or litter-decaying saprotrophic fungi. Only one orchid species was associated with ectomycorrhizal fungi. Stable isotope abundance patterns showed significant distinctions between orchids mycorrhizal with the three groups of fungal hosts.

CONCLUSIONS

Mycoheterotrophic orchids utilizing saprotrophic non-Rhizoctonia fungi as a carbon and nutrient source are clearly more frequent than hitherto assumed. On the basis of this kind of nutrition, orchids can thrive in deeply shaded, light-limiting forest understoreys even without support from ectomycorrhizal fungi. Sub-tropical East Asia appears to be a hotspot for orchids mycorrhizal with saprotrophic non-Rhizoctonia fungi.

Chemical and morphological filters in a specialized floral mimicry system

Many plant species attract insect pollinators through chemical mimicry of their oviposition sites, often detaining them in a trap chamber that ensures pollen transfer. These plant mimics are considered to be unspecialized at the pollinator species level, yet field observations of a mycoheterotrophic rainforest orchid (Gastrodia similis), which emits an odour reminiscent of rotting fruit, indicate that it is pollinated by a single drosophilid fly species (Scaptodrosophila bangi). We investigated the roles of floral volatiles and the dimensions of the trap chamber in enforcing this specialization, using gas chromatography-mass spectrometry analyses, bioassays and scanning electron microscopy. We showed that G. similis flowers predominantly emit three fatty-acid esters (ethyl acetate, ethyl isobutyrate and methyl isobutyrate) that were shown in experiments to attract only Scaptodrosophila flies. We additionally showed that the trap chamber, which flies enter into via a touch-sensitive 'trapdoor', closely matches the body size of the pollinator species S. bangi and plays a key role in pollen transfer. Our study demonstrates that specialization in oviposition site mimicry is due primarily to volatile chemistry and is reflected in the dimensions of the trapping apparatus. It also indicates that mycoheterotrophic plants can be specialized both on mycorrhizal fungi and insect pollinators.

Analysis of microsatellites in the vulnerable orchid Gastrodia flavilabella: the development of microsatellite markers, and cross-species amplification in Gastrodia

BACKGROUND

Gastrodia flabilabella is a mycoheterotrophic orchid that obtains carbohydrates and nutrients from its symbiotic mycorrhizal fungi. The species is an endemic and vulnerable species enlisted in the "A Preliminary Red List of Taiwanese Vascular Plants" according to the IUCN Red List Categories and Criteria Version 3.1. G. flabilabella dwells the underground of broadleaf and coniferous forest with richness litter. Based on herbarium records, this species is distributed in central Taiwan. Twenty eight microsatellite loci were developed in G. flabilabella and were tested for cross-species amplification in additional taxa of G. confusoides, G. elata, and G. javanica. We estimated the genetic variation that is valuable for conservation management and the development of the molecular identification system for G. elata, a traditional Chinese medicine herb.

RESULTS

Microsatellite primer sets were developed from G. flabilabella using the modified AFLP and magnetic bead enrichment method. In total, 257 microsatellite loci were obtained from a magnetic bead enrichment SSR library. Of the 28 microsatellite loci, 16 were polymorphic, in which the number of alleles ranged from 2 to 15, with the observed heterozygosity ranging from 0.02 to 1.00. In total, 15, 13, and 7 of the loci were found to be interspecifically amplifiable to G. confusoides, G. elata, and G. javanica, respectively.

CONCLUSIONS

Amplifiable and transferable microsatellite loci are potentially useful for future studies in investigating intraspecific genetic variation, reconstructing phylogeographic patterns among closely related species, and establishing the standard operating system of molecular identification in Gastrodia.