Mature Rhizomes Research Articles

Comparison of Polygonatum sibiricum Polysaccharides Found in Young and Mature Rhizomes.

The main active component of Polygonatum sibiricum (P. sibiricum) rhizome is Polygonatum sibiricum Polysaccharide (PsP) with antioxidant function. At present, only the mature rhizome of P. sibiricum is used to extract PsP, while the young rhizome of by-product is discarded directly as waste, resulting in significant wastage of P. sibiricum resources. We used ultrasound-assisted extraction-deep eutectic solvents (UAE-DESs) method to extract PsP of young and mature rhizomes, respectively. The extraction rate, structure composition and antioxidant ability of PsP between young and mature rhizomes were compared, so as to provide references for comprehensive utilization of P. sibiricum resources. The PsP extraction rate (33.88 ± 1.95%) of young rhizome was close to that (45.08 ± 1.92%) of mature rhizomes. The main component (PsP-2) of the PsP in young rhizome contained six kinds of monosaccharides, which belonged to acidic polysaccharides. The above characteristics of the PsP of young rhizome were similar to those of mature rhizome. The PsP of young rhizome also exhibited similar biological activity to that of the mature rhizome, which indicated even more advantages in DPPH free radical scavenging ability. The results of this study support the utility of the young rhizome, consequently helping to avoid unnecessary waste and provide reference for comprehensive utilization of P. sibiricum.

Exploring Steroidal Saponin Composition and Morphometric Characteristics of Rhizomes from Trillium govanianum Wall. ex D. Don: Inference for Medicinal Properties and Genetic Stock Improvement.

Trillium govanianum, a medicinal herb, exhibiting diverse morphometric traits and phytochemicals across developmental stages of plants. The changes in the chemical profile and steroidal saponin levels in the rhizome of T. govanianum across different developmental stages were previously unknown. This study categorizes rhizomes into three types based on scar presence: juvenile (5-10 scars, Type I), young (11-19 scars, Type II), and mature (21-29 scars, Type III). Rhizomes show varying sizes (length 1.2-4.7 cm, girth 0.3-1.6 cm), weight (0.18-5.0 g), and extractive yields (9.7-16.1 % w w-1), with notable differences in saponin content (5.95-21.9 mg g-1). Ultra-high performance liquid chromatography-MS/MS (UHPLC-QTOF-MS/MS)-based chemical profiling identifies 31 phytochemicals, mainly including diverse saponins. Ultra-high performance liquid chromatography coupled with evaporative light scattering detection (UHPLC-ELSD)-based quantitative analysis of seven key saponins reveals stage-specific accumulation patterns, with protodioscin (P) and dioscin (DS) predominant in mature rhizomes. Statistical analysis confirms significant variation (p=0.001) in saponin levels across developmental stages with chemical constituent protodioscin (P=4.03±0.03-15.76±0.14 mg g-1, PAve=9.79±3.03 mg g-1) and dioscin (DS=1.23±0.06-3.93±0.07 mg g-1, DSAve=2.59±0.70 mg g-1), with acceptable power (p=0.738; |δ|>0.5) statistics for effective sample size (n=27 samples used in the study) of T. govanianum. Principal Component Analysis (PCA) and Euclidean clustering further highlighted chemotype distinctions.

Recombination of endophytic bacteria in asexual plant Ligusticum chuanxiong Hort. caused by transplanting.

Long-term asexual reproduction can easily lead to the degradation of plant germplasm, serious diseases and insect pests, reduction of production and even catastrophic crop failure. "Mountain Breeding and Dam Cultivation" is the main cultivation mode of Ligusticum chuanxiong Hort., which successfully avoided the germplasm degradation caused by long-term asexual reproduction. The recombination of endophytic fungi of L. chuanxiong caused by off-site transplantation was considered to be an important reason for its germplasm rejuvenation. However, whether bacteria have the same regularity is not yet known. In this study, we carried out the experiment of cultivating propagation materials of L. chuanxiong in different regions and transplanting them to the same region. High-throughput sequencing was performed to analyze the bacterial communities in L. chuanxiong and its soil. The results showed that after transplanting, the plant height, tiller number, fresh weight, etc. of L. chuanxiong in mountainous areas were significantly higher than those in dam areas. At the same time, significant changes had taken place in the endophytic bacteria in reproductive material stem nodes (Lingzi, abbreviated as LZ). The diversity and abundance of bacteria in dam area LZ (YL) are significantly higher than those in mountainous area LZ (ML). The relative abundance of bacteria such as Xanthobacteraceae, Micromonosporaceae, Beijerinkiaceae, Rhodanobacteria, in ML is significantly higher than YL, mainly classified in Proteobateria and Actinobacteriota. In addition, the abundance advantage of Actinobacteriota still exists in MY (underground mature rhizomes obtained by ML). Meanwhile, the bacterial community was different in different area of transplanting. The diversity of bacterial communities in dam soil (YLS) is significantly higher than that in mountain soil (MLS). MLS had more Acidobacteriota than YLS. Comparative analysis showed that 74.38% of bacteria in ML are found in MLS, and 87.91% of bacteria in YL are found in YLS. We can conclude that the community structure of endophytic bacteria recombined after the transplantation of L. chuanxiong, which was related to the bacterial community in soils. Moreover, after transplanting in mountainous areas, LZ accumulated more potentially beneficial Actinobacteriota, which may be an important reason for promoting the rejuvenation of germplasm in L. chuanxiong. However, this hypothesis requires more specific experiments to verify. This study provided a new idea that off-site transplanting may be a new strategy to restore vegetative plant germplasm resources.

Evaluation of Gigantochloa scortechinii and soil interaction in three study sites in Malaysia

Understanding the productivity and physiological status of an organ (rhizome) function can lead into a sustainable production of sympodial bamboo. Nutrient elements and ash content (AC) are among the indicators to indicate the productivity and physiological status of an individual bamboo organ. The present study aimed to (a) determine the concentration of macronutrient elements of Gigantochloa scortechinii's rhizomes at four different ages collected at three study sites, and (b) investigate their relationship with AC. The destructive sampling was conducted on a set of four consecutive rhizomes using the selective random sampling method. Middle rhizome wall portion was used to determine the macronutrient elements and AC. All primary and secondary macronutrients were found to be different (p ≤ 0.01) at different study sites, except for the magnesium (Mg). The changes in nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and Mg from new sprout to mature rhizome showed a strongly positive relationship with AC. Thus, the N, P, K, Ca, and Mg concentrations decreased with rhizome age, resulting in a decrease in AC. The present study suggests that the suitable harvesting of individual bamboo culm and rhizome is at mature and older age while the remaining younger age bamboo is kept being grown so that the bamboo production is sustainable in terms of the physiological functions.

Effects of Nutrients and Growth Regulators on Seed Germination and Development of Juvenile Rhizome Proliferation of Gastrodia elata In Vitro

Two prevalent issues with Gastrodia elata growing in a natural wild environment are the necessary symbiotic seed germination with Mycena spp. and the long growing cycle of protocorms into mature rhizomes with Armillaria mellea. This study explored the most suitable nutrients to germinate seeds and the developmental stages and propagated protocorm/juvenile rhizomes (jrhs) through a tissue culture approach. Adding humic acid, mashed potato, peptone, and (indole-3-acetic acid) IAA to the 2 g/L Hyponex 7-6-19 basal medium accelerated seed germination into protocorms with an average length of 2 mm. The nutrients best for the in vitro propagation of jrhs consisted of 1 g/L Hyponex 7-6-19 and MS salts with 1/2 NH4NO3 and KNO3, 2 mg/L BA, 2 mg/L NAA, 2 g/L tryptone, 2 g/L glutamic acid, 1 g/L chitosan, 10 g/L apple puree, 20 g/L mashed potato, 100 mL/L coconut water, and 1.5 g/L A. mellea powder, at a pH level of 6. The maximum length and number of jrhs were 17.2 ± 0.8 mm and 76.6, respectively, in two subcultures. The in vitro propagation system started from seeds of G. elata can be employed as a potential method to propagate protocorm/jrhs for the cultivation of mature rhizomes from indoor or outdoor cultures.

Chemical Composition of the Essential Oil and the Solvent Extracts of Curcuma Pseudomontana Rhizomes and in Vitro Evaluation of their Antioxidant and Anti-Inflammatory Activities

The phytoconstituents of the essential oil isolated by hydrodistillation and solvent extracts (PE, BZ, DCM, EtOAc and EtOH) of mature rhizomes of turmeric (Curcuma pseudomontana) were analyzed by GC–MS. The major constituents identified in the oil and the extracts were Benzofuran (6.93%), γ-Curcumene (11.18%), β-Elemenone (22.14%), Germacrone (15.15%), Phenol, 2-Methyl-5-(1,2,2-trimethylcyclopentyl)- (29.58%), Germacrene (8.78%), Italicene (15.30%), Xanthorrhizol (56.52%), Pseudocumenol (24.56%) and Epicurzerenolne (4.95%). Analyzing the anti-inflammatory activity of essential oils (EO), and solvent extracts using HRBC stabilization and antioxidant activity. The results of GC MS analysis showed that while Pseudocumenol the major componenets in the essential oil. Xanthorrhizol is the major component in BZ, DCM and EtOH extracts of the matured rhizomes of C. psedomonata. The results of EO and the solvent extracts from Curcuma possessed good anti-inflammatory and antioxidant activities and hence can be used in natural preservative ingredients in food and/ or pharmaceutical industries.

Transcriptome and metabolite profiling to identify genes associated with rhizome lignification and the function of ZoCSE in ginger (Zingiber officinale).

Ginger (Zingiber officinale Roscoe) is an important spice crop in China, and fresh ginger rhizomes are consumed as vegetable in Sichuan and Chongqing. However, tissue lignification accelerates with rhizome maturation, resulting in the loss of edible quality. To understand the molecular mechanisms of texture modification during rhizome development, we investigated lignin accumulation patterns and identified the key genes associated with lignin biosynthesis using gas chromatography-mass spectrometry (GC-MS), liquid chromatography-tandem mass spectrometry (LC-MS/MS) and RNA-sequencing (RNA-Seq). Results showed that the contents of total lignin and its precursors exhibited notable declines with tissue maturation. However, the lignin composition was remarkably modified and syringyl lignin was deposited in mature rhizomes, leading to ginger lignification. Transcriptome analysis displayed 32 lignin biosynthetic genes were dramatically downregulated with rhizome development, including caffeoylshikimate esterase (CSE ), 4-coumarate-CoA ligase , laccase , cinnamoyl-CoA reductase , cinnamyl-alcohol dehydrogenase , peroxidase and caffeic acid 3-O-methyltransferase , indicating that lignin reduction might be attributed to deficiency in intermediates or the downregulation of key biosynthetic enzymes. Furthermore, overexpressing ZoCSE in Nicotiana benthamiana L. enhanced the total lignin content, suggesting its fundamental role in lignin biosynthesis. RNA-Seq also identified candidate lignin production regulators, including hormone-related genes and NAC/MYB transcription factors (ZoNAC1 , ZoNAC4 , ZoMYB14 and ZoMYB17 ). This result provides a molecular basis for lignin accumulation in ginger.

Zingiber zerumbet Rhizome Essential Oil: Chemical Composition, Antimicrobial and Mosquito Larvicidal Activities

Aims: In the present study, the chemical constituents, antimicrobial and larvicidal potentials of hydrodistilled essential oil from the rhizome of Zingiber zerumbet were evaluated.
 Study Design: The study was designed in different phases which are: collection of mature rhizomes of Zingiber zerumbet, hydrodistillation of essential oils, chemical analysis of the essential oils, determination of the antimicrobial potential and evaluation of larvicidal activity.
 Place and Duration of Study: The study was conducted at School of Natural Science, Vinh University, Vinh City, Nghệ An Province, Vietnam. The duration of the study was between August and December 2018.
 Methodology: The rhizomes of Z. zerumbet were collected from Bến En National Park, Thanh Hóa Province, Vietnam, in August 2018. The air-dry sample was subjected to hydrodistillation process using Clevenger-apparatus to obtained essential oils. We evaluated the larvicidal potential of the oil against Culex quinquefasciatus and Aedes albopictus at 24 h and 48 h according to World Health Organisation protocol. The antimicrobial activity (MIC) was determined by microdilution broth susceptibility assay. Statistical analysis was performed using GraphPad Prism (version 7.02). The LC50 values, LC90 values and 95% confidence limits were obtained by using XLSTAT v. 2018.5.
 Results: The most abundant compound of the essential oil was zerumbone (51.3%). The essential oil showed mortality of 98.3% (24 h) and 100% (48 h) against the Ae. albopictus at concentration of 100 µg/mL. In the same vein, mortality of 100% was displayed against Cx. quinquefasciatus under the tested time and concentration. The essential oil exhibited larvicidal activity towards Cx. quinquefasciatus showing minimum lethal concentrations, LC50, values of 33.28 mg/mL (24 h) and 21.81 mg/mL (48 h). The LC50 values of 55.75 µg/mL and 36.22 µg/mL at 24 h and 48 h respectively were obtained against Ae. albopictus. The result of the antimicrobial test indicated that Z. zerumbet oil inhibited the growth of Aspergillus niger (ATCC 9763) with MIC of 50.0 µg/mL.
 Conclusion: Results demonstrated that the essential oil of Z. zerumbet was effective in the control of tested mosquitoes, Culex quinquefasciatus and Aedes albopictus and the microbe, Aspergillus niger.

Ultrastructure of Hirschmanniella diversa early-stage infection in browning rhizomes of Indian lotus.

Browning rhizome (also known as “browning tuber disease”) in Indian lotus (Nelumbo nucifera) caused by the nematode Hirschmanniella diversa is an emerging agronomic problem. In this study, the authors documented the early infection processes of H. diversa in the apices of young rhizomes of Indian lotus by electron microscopy analysis using an artificial inoculation method. Nematodes were attracted to young rhizome apices, invading them via narrow indentations by 4.5 hr after inoculation. Host cells adjacent to the cavity around the invading nematodes were absent and appeared to have disintegrated during infestation. Following contact with the nematodes, host cell walls and cellular contents became electron-dense and less defined, likely due to digestive enzymes secreted by the invading nematodes. Nematodes invaded to a depth of about 1 mm by 24 hr after inoculation, but did not penetrate the plant any further vertically, similar to the observation of browning in mature rhizomes in the field. The authors propose that the invasion sites of young rhizome apices become blackish-brown blotches as rhizomes mature in the field due to oxidation.

Antimutagenic, antitumor and estrogen receptor binding activity of the rare plant Shortia galacifolia: An ethnobotanical and chemosystematic approach.

Shortia and other members of the Diapensiaceae family have ethnomedicinal history in both Eastern and Western hemispheres. Based on ethnopharmacological and chemosystematic evidence, pharmacological and toxicological bioassays were conducted on the rare plant Oconee Bell, Shortia galacifolia. Extracts were examined in assays for antimutagenicity, antitumor and estrogen receptor (ER)-binding activity. Antitumor activity was assessed by the tumor induction assay (TiA), using Agrobacterium tumefaciens based on its ability to transform plant tissue. Antimutagenicity was examined using the Ames bacterial reverse mutation test. Recombinant human ERα and ERβ proteins were utilized to screen extracts for receptor selectivity. All concentrations of extracts inhibited A. tumefaciens-induced tumor formation on potato discs, with the mature rhizome extracts having the most marked inhibition. All three plant extracts significantly inhibited the formation of histidine-independent revertant colonies after exposure to the mutagen 2-aminoanthracene (2-AA) in the Ames Salmonella mutagenicity assay. In the ER binding assays, ERβ, but not ERα, displayed affinity for Shortia extracts. Antitumor, ER binding and antimutagenic activities of S. galacifolia extracts were identified using rapid bench-top assays and warrant further investigations.

Crystal structure of a novel Kunitz type inhibitor, alocasin with anti-Aedes aegypti activity targeting midgut proteases.

The pesticidal properties of many Kunitz-type inhibitors have been reported previously; however, the mechanism of action is not well established. In this study, the activity of alocasin against Aedes aegypti is demonstrated and the structure-activity relationship of this Kunitz-type inhibitor is explained through X-ray structure analyses. Alocasin was purified from mature rhizomes of Alocasia as a single polypeptide chain of ∼ 20 kDa. The structure at 2.5 Å resolution revealed a Kunitz-type fold, but variation in the loop regions makes this structure unique; one loop with a single disulfide bridge is replaced by a long loop with two bridges. Alignment of homologous sequences revealed that this long loop contains a conserved Arg residue and modeling studies showed interaction with the catalytic Ser residue of trypsin-like enzymes. The anti-Aedes aegypti activity of alocasin is examined and discussed in detail. The in vitro activity of alocasin against midgut proteases of Aedes aegypti showed profound inhibition. Further, morphological changes in larvae upon treatment with alocasin revealed its activity against Ae. aegypti. Docking studies of alocasin with trypsin (5G1), a midgut protease involved in the development cycle and blood meal digestion, illustrated its insecticidal activity. The three-dimensional structure of alocasin was determined and its structure-function relationship established for its anti Ae. aegypti activity. © 2018 Society of Chemical Industry.

Assessment of Proximate Composition, Minerals status and Phytochemical Constituents of Hedychium spicatum (Zingiberaceae)

Hedychium spicatum Buch-Ham ex Smith (Family Zingiberaceae) is one of the most important aromatic and medicinal plant, commonly known as Kapoor Kachri, Ban-Haldi or Spiked Ginger lily. Fresh and mature rhizomes of H. spicatumwere collected from Different areas of Himachal Pradesh and were analysed for proximate composition, minerals and phytochemical constituents by following standard procedure. Significant variation was observed in the moisture content (7.34 to 8.40 per cent), crude protein (27.45 to 30.73 per cent), crude fat content (3.9 to 4.5 per cent), ash (6.5 to 7.6 per cent), crude fibre (7.75 to 8.65 per cent) and carbohydrate content (40.65 to 45.36 per cent). The mineral content in ppm showed high variation i.e. magnesium, copper, iron, zinc, manganese, calcium, phosphorus and potassium which ranged from 1716–8617, 12.6–44.4, 402.5–747.1, 78.2–275.5, 258.3–1040, 8440–9290, 1500–3100 and 14450–30300, respectively. Phytochemical constituents showed considerable variation in the antioxidant activity (44.99–61.28 μg/ml), total phenols (2.29–3.88 mg/g), flavonoids (33.47–35.83 mg/g), PPO activity (0.007–0.024 ΔO.D/min), total carotenoids (104.13–123.76 μg/100 ml), lycopene (9.48–13.60 μg/100 ml) and ascorbic acid (3.74–5.89 mg/100g), respectively.

Production of immature rhizomes by breaking dormancy under low temperature of Gastrodia elata Blume

Gastrodia elata Blume is usually planted as immature rhizomes in April and harvested as mature rhizomes in November the following year. 70% of the total production of G. elata in Korea is consumed raw and only 30% consumed after processing. However, the price of G. elata decrease greatly in November due to seasonal high production at. The production of G. elata should therefore preferably be constant all around the year. Thus, this study was conducted to investigate the possibility of a stable production of immature rhizomes by breaking dormancy by low temperature treatment. After harvesting G. elata in the fall, it was planted in the medium (peatmoss 80% + perlite 20%, moisture content 30 ± 2%) and kept at 5 ± 1 °C from week 2 to week 10. Bolting was subsequently induced at 25 ± 1 °C, and produced the seeds of G. elata by artificial fertilization. These seeds were induced to protocorm formation by Mycena spp., and immature rhizomes produced by Armillaria spp. [1]. As the result, the number of days to emergence showed short as the time of low temperature treatment period was elongated, but the emergence rate, peduncle length, the number of valid blooming, the number of valid pod increased. The natural fertilization rate of G. elata was 0.3%, whereas the artificial fertilization rate increased with 70.4% when it was bolting after low temperature treatment for more than 4 weeks at 5 °C. However, it was low compared to that of 90.4% when it was harvested in natural condition of the spring [2]. After seed (10,000˜20,000 seeds per pod) treated by breaking dormancy under low temperature condition, the protocorm formation rate of the germinated seed was from 2.2 to 2.6% and its immature rhizomes formation rate was from 8.7 to 9.5%. Formation of protocorm and immature rhizomes were proportional to the low temperature treatment period. As the results of these experiments, even though formation ratio of protocorm and immature rhizomes from G. elata harvested in the fall is lower than in the spring, it is considerably higher than the natural germination conditions. Thus, a constant year-round production of G. elata would be available due to the application of breaking dormancy technology under low temperature treatment.

Direct Organogenesis from Rhizome Explants in Marsilea quadrifolia L.: A Threatened Fern Species

An efficient micropropagation protocol has been developed for Marsilea quadrifolia L. through direct organogenesis. The mature rhizomes were used as explants and successfully sterilized using 0.1% HgCl2 for the establishment of cultures. The multiple shoots were differentiated from the explants on Murashige and Skoog (MS) medium augmented with 6-benzylaminopurin (BAP). Full strength MS medium was reported to be effective for the induction of sporophytes from the rhizomes after four weeks of inoculation. Maximum response (96%) with average of 6.2 shoots (2.72 cm length) was achieved on full strength of MS medium augmented with 0.5 mg/L BAP in culture initiation experiments. The cultures were further proliferated in clusters (79.0±0.37 shoots per explant) with stunted growth on half strength MS medium supplemented with 0.25 mg/L BAP after four weeks. These stunted shoots were elongated (5.30 cm long) on half MS medium devoid of growth hormones. Root induction and proliferation (3.0–4.0 cm long) were observed after 4th subculture of sporophytes on hormone-free half strength MS medium. The rooted plantlets were hardened in the fern house for 4-5 weeks and transferred to the field with 92% survival rate. There were no observable differences in between in vivo grown and in vitro propagated plantlets in the field.

In vitro propagation and field establishment of Eulophia cullenii (Wight) Bl., a critically endangered orchid of Western Ghats, India through culture of seeds and axenic seedling-derived rhizomes

An efficient protocol has been devised for the propagation and field establishment of Eulophia cullenii (Wight) Bl., a terrestrial orchid having ornamental potentialities, and is critically endangered in Western Ghats, India. Seeds extracted from 60–90-d-old capsules germinated in ½ MS, ¼ MS, Knudson C, or Mitra liquid medium developed into 1.4–2.5-mm-diameter protocorms in 60 d. Supplementation of organic additives like coconut water, peptone, yeast extract, and casein acid hydrolysate (CH) significantly enhanced protocorm growth. Upon subculture onto agar-gelled Mitra medium fortified with 0.05% CH, 56% of protocorms regenerated into shoots through the formation of linear mini-rhizomes. The regenerated shoots grew vigorously in ½ MS, producing new rhizomes. Mature rhizomes from axenic seedlings produced maximum (13 ± 1.4) shoots/whole rhizome in ½ MS fortified with 44.4 μM 6-benzylaminopurine (BAP), in 120–150 d. Horizontal and longitudinal halves of the rhizome also gave multiple shoots (6–8.5) in the presence of 44.4 μM BAP. Shoots or shoot clumps sub-cultured onto ½ MS basal medium produced roots followed by rhizomes in 60–150 d. Seedlings with mature rhizomes showed 70% establishment in the nursery and added a new rhizome at the end of one growth cycle. An average of 70.6% of the rhizomes originating from seedlings during the second growth cycle sprouted to produce new shoots, when planted in the native localities. Asymbiotic germination and cloning through rhizomes thus can provide a large number of vigorous plants of E. cullenii for ornamental exploitation as well as eco-restoration, if rhizome as storage organ is ensured in the propagule.

English

This study is a pioneer report on the development of an environmentally safe in vitroregeneration protocol for Curcuma, Kaempferia and Zingiber. The germplasm of the species was collected from Myanmar, a Southeast Asian country, rich in unexplored Zingiberaceae genetic resources. Rhizome buds were directly regenerated on the Murashige and Skoog medium containing a growth regulator, 6-benzyladenine and a commercial fungicide, Benlate (50% of Benomyl). The pre-treatment protocol did not contain HgCl2, a toxic pollutant for Curcuma amada,Curcuma longa, Zingiber barbatum and Kaempferia galanga. Plantlets were regenerated from the buds without any intervention of the callus phase. The contamination free survival of the bud explants from Curcuma, Zingiber andKaempferia was more than 75, 57 and 53%, respectively. Buds from immature rhizomes were difficult to regenerate on the media, as well as resulted in higher contamination percentages while the buds from mature rhizomes efficiently regenerated with very few contamination percentages. The contamination was in the range of 0 to 39% among the different accessions. This was also the first report of direct in vitro regeneration of plantlets from Z. barbatum bud explants. The protocol was cost-beneficial, time saving and effective for the conservation of Zingiberaceae genetic resources.   Key words: Conservation, regeneration, Zingiberaceae, tissue culture, Curcuma,Zingiber, Myanmar.

Rapid micropropagation of Boesenbergia rotunda (L.) Mansf. Kulturpfl. (a valuable medicinal plant) from shoot bud explants

A successful protocol was developed for mass propagation of Boesenbergia rotunda (L.) Mansf. Kulturpfl., an important medicinal plant. Numerous shoots were induced from young shoot bud of B. rotunda mature rhizome on Murashige and Skoog (1962) medium supplemented with 30.0 g/l sucrose, 2.0 g/l gelrite, different concentrations of 6-benzylaminopurine (BAP) and α-naphtaleneacetic acid (NAA). Plant medium supplemented with different concentrations of BAP alone or with NAA produced varying degree of multiple shoots. A supplementation of 2.0 mg/l BAP and 0.5 mg/l NAA gave the best result. Ninety percent of the explants induced multiple shoots within 10 to 14 days of inoculation with five maximum numbers of shoots per explant. The numbers of multiple shoots was low during initial subculture but increased after third subculture and were slightly decreased after fourth subculture. Rooting was spontaneous in almost all the treatments after 10 to 14 days of culture. Micropropagated plantlets were successfully acclimatized. Key words: Boesenbergia rotunda, micropropagation, medicinal plant, Zingiberaceae.

Anti-<i>Candida</i> and radical scavenging activities of essential oils and oleoresins of <i>Zingiber officinale</i> Roscoe and essential oils of other plants belonging to the family Zingiberaceae

Essential oils of young and mature rhizomes, air-dried and steamed rhizomes, and seed rhizomes of Zingiber officinale Roscoe (ginger) were prepared, and their inhibition of filamentation by Candida albicans was examined. Ginger essential oils, and particularly those from seed and air-dried rhizomes, had potent inhibitory activity compared to ginger oleoresins obtained by ethanol and hypercritical carbon dioxide extraction and essential oils of 5 other plants in the family Zingiberaceae. Of the constituents, [6]-shogaol was most active against filament formation and growth of C. albicans, followed by citral and [6]-gingerol. Ginger oleoresin, and especially that obtained by ethanol extraction, with a high [6]-gingerol content exhibited potent scavenging activity against 1,1-diphenyl-2-picrylhydrazyl radicals in comparison to essential oils of ginger and other Zingiberaceae plants.

Colleters in monocots: New record for Orchidaceae

Colleters are widely occurring in eudicots showing relevant taxonomic importance in several families. Nevertheless, there are few records in monocots, restricted to only one description of these glands in Orchidaceae. The genus Oncidium is polyphyletic, currently the subject of taxonomic studies. In this context, the secretory structures can be an important diagnostic character that may help in the delineation of this group. O. flexuosum Sims presents colleters in vegetative – leaf primordium of protocorms, apical and axillary buds in the mature rhizomes – and reproductive organs – at the base of bracts, bracteoles and sepals. All the colleters observed are finger-like trichomes, composed of two uniseriated cells, where the apical one is elongated and possesses dense cytoplasm. The exsudate accumulates in a subcuticular space, causing displacement of the cuticle. Histochemical tests indicate the presence of mucilage in association with lipophilic and proteinic compounds inside the secretory cell. Secretion is abundant, hyaline and slightly viscous. The localization of the trichomes and their exsudate indicate the involvement of these colleters with the protection of meristematic regions in vegetative and reproductive organs. These results can be useful in the taxonomy of the genus Oncidium and for future studies about colleters in monocots.

Ergothioneine accumulation in a medicinal plant Gastrodia elata.

Ergothioneine (ERG) has long been recognized as a potent and stable antioxidant. In nature, ERG is synthesized only in fungi and mycobacteria, not in plants. The lifecycle of Gastrodia elata, an achlorophyllous orchid plant, is completely dependent on the presence of symbiotic fungi, particularly Armillaria mellea. In this study, we report for the first time that G. elata accumulated ERG whose levels were correlated with the concentrations of ERG in A. mellea. The contents of ERG in G. elata were significantly higher in actively developing tissues, such as seed capsules and newly growing corms, than in mature rhizomes. The ERG levels in rhizomes were significantly correlated with antioxidant capacities and were quantitatively comparable to the previously established major pharmacological components in G. elata. These results indicated that ERG is a newly found functional substance in G. elata, which may be responsible for the beneficial health effects of G. elata on various human diseases. Key words: Gastrodia elata, Armillaria mellea, ergothioneine, antioxidant.