Nepenthes Khasiana Research Articles

Transcriptomic and metabolomic responses to varying nutrient conditions reveal new insights into pitcher formation in Nepenthes khasiana.

Nepenthes are carnivorous plants that colonize habitats poor in soil nutrients. To survive, Nepenthes develop pitchers capable of capturing and digesting attracted prey. Prey-derived nutrients are then absorbed to support plant growth and reproduction. So far, pitcher formation in Nepenthes is a poorly understood biological process. To shed light on the formation of Nepenthes pitchers, we grew dissected shoot apices of 3-month-old N. khasiana seedlings in Murashige and Skoog (MS) medium of varying strengths viz. full-strength MS (1 MS), quarter-strength MS (1/4 MS), and one-eighth strength MS (1/8 MS), including those lacking nitrogen (N), phosphorus (P), and potassium (K) and in the presence of N-1-naphthylphthalamic acid (NPA). We sequenced the transcriptome and performed gas chromatography-mass spectrometry to determine changes in gene expression patterns and primary metabolite accumulations in response to the varying nutrient conditions. Shoots grown in 1 MS or NPA-containing 1/4 MS and 1/8 MS failed to develop pitchers. Remarkably, pitcher formation is restored when N was removed from 1 MS. Transcriptomic response to nutrient-sufficient and nutrient-deficient conditions are associated with the enrichment of several defence-related genes, including two JA-mediated defence response genes, WRKY51 and WRKY11, respectively. Further, metabolomic response to the varying nutrient conditions identifies glutamic acid as a key metabolite, accumulating at lower and higher levels in shoots with and without pitchers, respectively. Together, our findings suggest that failure to form pitchers may be associated with the suppression of the JA-signalling pathway, whereas the induction of the JA-mediated defence response is linked to pitcher formation in N. khasiana.

New distribution records of the endemic pitcher plant, Nepenthes khasiana Hook. f. and identification of threats in Meghalaya, India

Aim: The present study entails new distribution records along with the identification of threats to the pitcher plant, Nepenthes khasiana Hook. f. in Meghalaya, India. Methodology: A trail survey was employed to find the distribution of pitcher plants in different locations of the Garo, Khasi, and Jaintia hills of Meghalaya between 2018 and 2022. Results: The present study reported some new distribution records in the Garo, Jaintia, and Khasi Hills of Meghalaya mostly in private lands which are scatteredly distributed. They are adversely threatened due to large-scale jhum cultivation, mining, traffic, road construction, human pressure, and tourism as depicted in the present study. Besides, the pitcher plants have been wiped out from many areas of Meghalaya which was earlier reported. Interpretation: The present work documented the distribution of pitcher plants in some new areas of the Garo, Khasi, and Jaintia Hills of Meghalaya. The population of the pitcher plant is sharply declining in Meghalaya due to various threat factors. Hence, the conservation of pitcher plant need urgent attention. Therefore, an action plan is required to safeguard the pitcher plant in these habitats. Besides public awareness, stakeholder participation is the paramount need of the hour to protect and preserve the plants. Further, new areas also need to be explored for the distribution of pitcher plants in other areas of the state including intensive studies in Garo, Khasi and Jaintia Hills. Key words: Carnivorous plants, Endemic, Meghalaya, Nepenthes khasiana, Pitcher plant

Unlocking the phytochemicals in unopened pitcher fluids of Nepenthes khasiana -a GC–MS study

BackgroundThe pitcher plant, Nepenthes khasiana is utilized by several indigenous groups in Meghalaya, India owing to its medicinal properties. Due to their therapeutic qualities, a pioneer work was undertaken where the GC–MS technique was used to detect and identify the phytochemical substances present in the unopened pitcher fluids of N. khasiana. Materials and methodsSample preparation and extraction of the methanol fraction of N. khasiana pitcher fluid were done following standard methods and exposed to GC–MS for phytochemical profiling. ResultsThe GC–MS study revealed 22 compounds in total, each of which had different phytochemical properties. The metabolites present were coronavirus inhibitors, antioxidants, antimicrobials, cure urolithiasis, hypocholesterolemic, and can cure cancer. Lipinski's Rule of 5 also depicted that 19 compounds of 22 have the potential to make active oral drugs for humans. ConclusionThe metabolites present in pitcher fluids could be used in drug formulation in pharmacology. Even, the fluids can be used as raw medicine for poor people owing to their medicinal properties as depicted in GC–MS however, further research on quantitative and qualitative investigation, its clinical trial on animals along with cytotoxic study are required for a concrete conclusion.

Prey Selection by Pitcher Plant, Nepenthes khasiana in Meghalaya, India

Nepenthes khasiana, an endangered pitcher plant endemic to Meghalaya and southern Assam, India seems to develop a pitcher for trapping small animals as their prey to supplement the nutrient deficiency which occurs in the soil. A study on the enigmatic meat-eating choice of N. khasiana is scarce. Hence, this study was conducted to find out their prey species covering all three hills of Meghalaya, India. A total of 90 pitcher samples (30 from each hill) were collected randomly and preserved in 70% alcohol which was further identified at the lower taxa level. A total of 71 species were identified up to the species level while another five were identified up to their genus level. Among this, 90.8% of species were insects (69 species) while the remaining 9.2% (7 species) were non-insect species. All these seven non-insect species belonged to single order Arachnida. The majority of them (71.1%, 54 species) were capable of flying while the remaining 28.9% (22 species) were incompetent to fly. Those species which were incompetent to fly belonged to orders Araneae, Dermaptera, Diptera, Hemiptera, Lepidoptera, and Odonata. The prey constituted the highest 23 species belonging to the order Hymenoptera followed by 11 species under Coleoptera, 9 species under Diptera, 7 species under Araneae, 6 species each under Hemiptera and Blattodea, 5 species each under Orthoptera and Lepidoptera, 2 species under Odontata and 1 species each under Mantodea and Dermaptera. The orders Hymenoptera and Diptera together contributed 83.3% of the total feeding spectrum. This further indicates the sustainable management of biodiversity securing the abundance of animal prey species for the conservation of pitcher plants in this landscape.

Identifying conservation priority areas and predicting the climate change impact on the future habitats of endangered Nepenthes khasiana Hook.f. utilizing ecological niche modelling

Developing strategies for effective species conservation is necessary to counter the ever-fluctuating environmental conditions with increasing anthropogenic activities. Studies have proven Ecological Niche Modelling (ENM) as an effective tool for sustainable conservation. Nepenthes khasiana Hook.f. is an endangered pitcher plant facing a constant decline in population due to anthropogenic activities. This study aimed to locate the most suitable areas for re-establishing the species in natural habitats using Maximum Entropy (MaxEnt) modelling, and to forecast the effects of current and future climate conditions on its distribution throughout Northeast India. The potential suitable areas in future climate under three Representative Concentration Pathway (RCP) scenarios and in the current climate were predicted utilizing the 30 occurrence data, bioclimatic predictors, and variables from BCC-CSM1.1 model and WorldClim respectively. The results of the current study showed significant relationships among annual precipitation, precipitation in the driest month, seasonality of precipitation, annual range iso-thermality of temperature, mean diurnal range [Mean of monthly (max temp - min temp)], and the distribution of the analysed species. The optimum model performance was represented by the AUC value of 0.972 ± 0.007. The model predicted 10.70% of the NE Indian region as climatically suitable, which will expand under RCP4.5 and RCP6.0, reaching 15.35%, and 12.64%, respectively. However, this may degrade significantly under RCP8.5, reducing to 8.14%. Based on the analysis of modelling results it was found that the Nokrek belt and the Khasi hills as highly suitable regions for the reintroduction of the species. The study revalidated ENM as an effective means to identify new populations and predict the influence of climate change on the future habitat which can benefit the concurrent species management strategies.

Genetic Basis of Carnivorous Leaf Development.

Plant carnivory is often manifested as dramatic changes in the structure and morphology of the leaf. These changes appear to begin early in leaf development. For example, the development of the Sarracenia purpurea leaf primordium is associated with the formation of an adaxial ridge, whose growth along with that of the leaf margin resulted in a hollow structure that later developed into a pitcher. In Nepenthes khasiana, pitcher formation occurs during the initial stages of leaf development, although this has not been shown at the primordial stage. The formation of the Utricularia gibba trap resulted from the growth of the dome-shaped primordium in both the longitudinal and transverse directions. Recent research has begun to unfold the genetic basis of the development of the carnivorous leaf. We review these findings and discuss them in relation to the flat-shaped leaves of the model plant Arabidopsis.

A Preliminary Study on Anti-Mycobacterium, Anti-Candida Activity and Morphological Clustering of Fifteen Folk Medicinal Plants of Assam, India

Antimicrobial resistance against Mycobacterium and Candida are vital problems in immunocompromised patients. The current study was aimed to investigate the antimicrobial efficacy of fifteen folk medicinal plants found in Assam. Ethanolic plant extracts by well diffusion assay showed antimicrobial activity of 7 species against Mycobacterium smegmatis (ATCC®607TM) and 9 species against Candida albicans (ATCC®90028TM). Nepenthes khasiana exhibited highest zone of inhibition 21±0.5 mm against Mycobacterium smegmatis and this is the first report of Nepenthes khasiana showing anti-Mycobacterium activity from North East India. Mesua ferrea leaf extract first time exhibited good anti-candidal activity than the other studied species with zone of inhibition 11.83±0.76 mm. The impact of morphological characters on mechanistic convergence of anti-Mycobacterium and anti-Candida activities among the studied species was also assessed. Approximately 27 discrete morphological characters were used to prepare data matrix. Majority rule consensus tree of morphological data matrix with branch support ≥50 % using Mesquite 3.61 found that nearly 66.67 % species exhibited mechanistic convergence of anti-Mycobacterium and anti-Candida activity in combination congruent to morphological clustering. However, the clades viz., rosids, Murraya, Crinum and Alpinia showed partial congruence with angiosperm phylogeny group IV classification. A larger dataset including more than one representative species of each genus of the studied family and use of extensive morphological characters may exhibit a better mechanistic convergence.

Endophytic fungal diversity of endemic carnivorous plant Nepenthes khasiana in Meghalaya, India

The present investigation deals with the isolation of endophytic fungi from leaf, stem, root and pitcher cup tissue segments of the endemic carnivorous plant Nepenthes khaisana collected from its natural habitat for a period of one year at monthly intervals. Out of 576 tissue segments inoculated, a total of 39 fungal endophytes along with mycelia sterilia were isolated from the host plant. To assess the diversity of fungal endophytes, the colonization frequency (%CF) was first recorded using past software and MS excel. The fungal isolates were mainly composed of the phylum Ascomycota, followed by Zygomycota and Oomycota. The highest percentage colonization frequency on an average of three replicates were recorded in pitcher cup tissues followed by root, stem and least was recorded in leaf of the host plant. Among the isolates, Globisporangium irregulare (83.33%) showed high % CF in leaf, Juxtiphoma eupyrena (83.33%) reported to have maximum % CF in the stem, Talaromyces ruber (66.66%) was recorded high % CF in root and mycelia sterilia (white) were showed the highest % CF in the segments of leaf. The diversity index analyses of Shannon-Weiner, Simpson*s index, species richness and species evenness of diversity showed that leaf of N. Khasiana has the highest diversity than the other parts of the plant. So, with the help of the present finding, we conclude that the distribution of fungal endophytes and their % colonization frequencies vary within different tissues of the host plant and thus, this confirms tissue specificity nature of endophytic fungi.

Pitchers of Nepenthes khasiana express several digestive-enzyme encoding genes, harbor mostly fungi and probably evolved through changes in the expression of leaf polarity genes

BackgroundA structural phenomenon seen in certain lineages of angiosperms that has captivated many scholars including Charles Darwin is the evolution of plant carnivory. Evidently, these structural features collectively termed carnivorous syndrome, evolved to aid nutritional acquisition from attracted, captured and digested prey. We now understand why plant carnivory evolved but how carnivorous plants acquired these attributes remains a mystery. In an attempt to understand the evolution of Nepenthes pitcher and to shed more light on its role in prey digestion, we analyzed the transcriptome data of the highly specialized Nepenthes khasiana leaf comprising the leaf base lamina, tendril and the different parts/zones of the pitcher tube viz. digestive zone, waxy zone and lid.ResultsIn total, we generated around 262 million high-quality Illumina reads. Reads were pooled, normalized and de novo assembled to generate a reference transcriptome of about 412,224 transcripts. We then estimated transcript abundance along the N. khasiana leaf by mapping individual reads from each part/zone to the reference transcriptome. Correlation-based hierarchical clustering analysis of 27,208 commonly expressed genes indicated functional relationship and similar cellular processes underlying the development of the leaf base and the pitcher, thereby implying that the Nepenthes pitcher is indeed a modified leaf. From a list of 2386 differentially expressed genes (DEGs), we identified transcripts encoding key enzymes involved in prey digestion and protection against pathogen attack, some of which are expressed at high levels in the digestive zone. Interestingly, many of these enzyme-encoding genes are also expressed in the unopened N. khasiana pitcher. Transcripts showing homology to both bacteria and fungi were also detected; and in the digestive zone, fungi are more predominant as compared to bacteria. Taking cues from histology and scanning electron microscopy (SEM) photomicrographs, we found altered expressions of key regulatory genes involved in leaf development. Of particular interest, the expression of class III HOMEODOMAIN-LEUCINE ZIPPER (HD-ZIPIII) and ARGONAUTE (AGO) genes were upregulated in the tendril.ConclusionsOur findings suggest that N. khasiana pitchers employ a wide range of enzymes for prey digestion and plant defense, harbor microbes and probably evolved through altered expression of leaf polarity genes.

An Invitro Comparison of Dissolution of Human Pulp in Sodium Hypochlorite, Ethanolic Extract and Digestive Secretion of Insectivorous Plants

The tissue dissolution property of irrigating solutions is important for successful endodontic treatment. Sodium hypochlorite (NaOCl) is a well-known tissue dissolvent, but no data have been published on herbal alternative to NaOCl. The purpose of this study was to investigate the pulp tissue dissolution capacity of sodium hypochlorite, ethanolic extract of Drosera rotundifolia and digestive fluid of Nepenthes khasiana. Freshly extracted intact vital teeth, extracted for orthodontic and impaction reasons were collected and stored at – 20 ˚C. The pulp tissues were removed by splitting of the teeth when required. Method: The pulp tissues were randomly divided into 4 groups (n = 10), individual sample was weighed 7 mg each. The groups were as follows, Group I: 5% NaOCl, Group II: digestive fluid of Nepenthes khasiana, Group III: Drosera rotundifolia (ethanolic extract), Group IV: distilled water. The test solutions were added to tubes containing tissue samples, the tissues were removed from the test solutions at 5, 15, 20, 30 min, 1,2,3,4,5,6,7 hr blotted dry with the tissue paper and weighed using precision balance. Results: The results showed complete dissolution of pulp tissue in Group I at 20 minutes, Group II at 7 hr, Group III and IV showed no dissolution of pulp at the investigated time intervals. Conclusion: The digestive fluid of Nepenthes khasiana could be considered as an herbal alternative to NaOCl for pulp tissue dissolution as it completely dissolved the pulp tissue similar to 5% NaOCl, but at different time intervals.

ASYMMETRIC LEAVES1 and REVOLUTA are the key regulatory genes associated with pitcher development in Nepenthes khasiana

Nepenthes develops highly specialized insect-eating organs called pitchers that provide adequate insect-derived nutrients to the plants to offset low nutrient availability in their natural habitat. But so far, the molecular basis of Nepenthes pitcher development remains largely unknown. In an attempt to unravel the underlying mechanisms of pitcher formation, we made morphological observations of the developing N. khasiana leaf and performed RNA-seq to identify genes controlling pitcher development. Histology and scanning electron microscopy photomicrographs show that pitcher formation in N. khasiana occurs early in development and shares anatomical features with the young in-rolled leaf base lamina. Analysis of the RNA-seq data indicated that the modification of the leaf into a pitcher is associated with the altered expressions of leaf polarity genes ASYMMETRIC LEAVES1 (AS1) and REVOLUTA (REV). In fact, both genes displayed exclusive or relatively higher expressions in the tip of the leaf that later developed into a pitcher. We propose that NkAS1 may act to inhibit lamina outgrowth and promote the formation of the tendril. Increased NkREV expression may have been involved in the formation of the N. khasiana pitcher. This dataset will allow further research into this area and serve as the basis for understanding Nepenthes pitcher development.

Phylogeny and Biogeography of Carnivorous Plant Family Nepenthaceae With Reference to the Indian Pitcher Plant Nepenthes Khasiana Reveals an Indian Subcontinent Origin of Nepenthes Colonization in South East Asia During the Miocene Epoch

Carnivorous plants popularly known as green predators have long fascinated scientists and general public alike owing to their fascinating trapping mechanisms. Botanical carnivory has evolved independently in five angiosperm orders. In spite of these independent origins, a remarkable convergence of morphological and physiological mechanisms is observed amongst carnivorous plants when it comes to prey capture, assimilation and digestion of animal proteins. The family Nepenthaceae, a monotypic family of the order Caryophyllales exhibits the phenomenon of convergence in morphological traits which makes it difficult to address phylogenetic issues. Using comparative analysis of molecular markers from the nuclear, mitochondrial and plastid DNA the monophyly of the Nepenthaceae family is tested. Sequences from the Indian Nepenthes khasiana, Drosera peltata and Drosera burmannii from the Northeastern state of Meghalaya representing the two important carnivorous families in the order Caryophyllales were determined and analysed using Bayesian and Maximum Likelihood methods. This study examines a genus level analysis by integrating different molecular matrices to existing fossil data on carnivorous plants in a RelTime tree environment for assessing divergence times of the extant Nepenthes species with a focus on its evolutionary origin. Our study has enabled age estimations as well as ancestral area reconstruction to illuminate Nepenthaceae phylogeny and biogeographic history. Divergence time estimates revealed that N. khasiana has an intermediary position between some vestige Western Nepenthes outliers and rest of the taxa by sharing some of the ancient derived traits. Our molecular data speculates Nepenthes evolution to have occurred in the Northern Tethys from the European Eocene (held by fossil pollen records) and a Gondwanaland origin with separation of the Indian plate from Madagascar. Bio-molecular marker data hints at diversification of the family Nepenthaceae from its sister clade Ancistrocladaceae-Dioncophyllaceae in the Early Eocene. These three families had a monophyletic origin of botanical carnivory by getting diversified from Droseraceae in the Late Cretaceous. Colonization of Nepenthes species occurred in South East Asia from an ancient Indian stock (N. khasiana) during 8.16-15 Mya.

Nepenthes khasiana Hook. f. (Nepenthaceae) from Assam

Nepenthes khasiana , an endangered species, listed in Appendix I of CITES, is the only species of the genus known to occur in India. It is a rare endemic species hitherto recorded from Meghalaya. It is threatened due to several factors including wanton destruction of its habitat by coal mining and harvesting for medicinal preparations.

Nepenthes khasiana mediated synthesis of stabilized gold nanoparticles: Characterization and biocompatibility studies

The current study summarizes a unique green process for the synthesis of gold nanoparticles by simple treatment of gold salts with aqueous extract of Nepenthes khasiana (NK)—a red listed medicinal plant and its characterization. Study on the effect of different process parameters like temperature, pH and stirring on surface and stability characteristics has been demonstrated. Formation of GNPs was visually observed by change in color from colorless to wine red and characterized by UV-Visible spectroscopy, FT-IR spectroscopy, Zetasizer, X-RD, ICP-AES, SEM-EDAX, AFM and TEM. In vitro stability studies of gold colloidal dispersion in various blood components suggest that, NK mediated GNPs exhibit remarkable in vitro stability in 2% bovine serum albumin, 2% human serum albumin (HSA), 0.2M histidine, and 0.2M cysteine but unstable in 5% NaCl solution and acidic pH. Biocompatibility of NK stabilized GNPs against normal mouse fibroblasts (L929) cell lines revealed nontoxic nature of GNPs and thus provides exceptional opportunities for their uses as nanomedicine for diagnosis and drug therapy. The role of antioxidant phytochemicals (flavonoids and polyphenols) of NK extract in synthesis of biocompatible and stabilized GNPs was demonstrated by estimating total flavonoid content, total phenolic content and total antioxidant capacity of extract before and after formation of GNPs. Fast and easy synthesis of biocompatible GNPs possesses unique physical and chemical features which serve as an advantage for its use in various biomedical applications. The overall approach designated in the present research investigation for the synthesis of GNPs is based on all 12 principles of green chemistry, in which no man-made chemical other than the gold chloride was used.

In Vitro Antioxidant and Hepatoprotective Potential of Nepenthes <i>Khasiana</i> Hook. F against Ethanol-Induced Liver Injury in Rats

Purpose: To evaluate the in vitro antioxidant and hepatoprotective activity of Nepenthes khasiana leaf extracts against ethanol-induced hepatotoxicity. Approach: In vitro antioxidant activity was measured spectrophotometrically for the methanolic and aqueous leaf extracts of N. khasiana using different assays i.e DPPH, superoxide anion and hydroxyl radical scavenging activity. For hepatoprotective effect, the rats of either sex were administered with 30% w/v ethanol at a dose of 5 g/kg b.w. orally for three weeks. Methanolic extract of N. khasiana leaf was administered to the experimental rats at 100 mg, 200 mg and 400 mg/kg, p.o. for three weeks. The hepatic markers such as alanine aminotransferase (ALT), aspartate amino transferase (AST), alkaline phosphatase (ALP), total bilirubin and total proteins were evaluated and supported by histopathological studies of the liver. Findings: The methanolic leaf extract of N. khasiana exhibited strong antioxidant capacity with IC 50 values of 23.33±0.441, 62.75±0.713 and 38.38±0.425 μg/mL respectively and this extract was selected for hepatoprotective studies. The results showed that administration of methanolic leaf extract of N. khasiana reversed the liver damage due to alcohol as evident from histopathological studies of the liver. The HPTLC fingerprinting analysis of the methanolic leaf extract of N. khasiana at different wavelengths revealed presence of many compounds which may provide basic information regarding the isolation, purification, characterization and identification of marker chemical compounds of the plant species. Originality: The present study is the first time evaluation of the hepatoprotective effect of the methanolic leaf extract of N. khasiana on ethanol-induced liver injury in rat models. The isolation and characterisation of the active principle require extensive research in the future. Conclusion: From our study, the methanolic leaf extract of N. khasiana shows potent hepatoprotective effects, hence it can be used as a natural protecting agent against liver damage.

Propagation of Threatened <i>Nepenthes khasiana</i>: Methods and Precautions

Ex-situ conservation is an important key in the management of rare, endangered and threatened (RET) plant species and its effectiveness depends on several factors. Maintenance of viable germplasm and its subsequent propagation plays an important role in long term conservation of many RET species. Nepenthes khasiana is a rare and gravely threatened species in the wild due to over-collection and other threats. The species needs urgent in-situ and ex-situ conservation. Development of easy to propagate techniques would pave faster multiplication for its use of educational, medicinal and horticultural purpose. In the present paper, successful propagation technique of Nepenthes khasiana through seeds is demonstrated along with detailed information on precautions to be taken during the adoption of the techniques.

Genetic fidelity assessment in micropropagated plants using cytogenetical analysis and heterochromatin distribution: a case study with Nepenthes khasiana Hook f.

Rapid clonal propagation of selected genotypes has been one of the most extensively exploited approaches of biotechnology. However, inclusion of somaclonal variations in tissue-culture-derived plants results in the production of undesirable plant off-types which limits its applications in tissue culture industry. Therefore, the most critical concern has been the maintenance of genetic uniformity of micropropagated plants. Assessment of genetic fidelity in tissue-culture-raised plants of three consecutive regenerations of Nepenthes khasiana has been successfully carried out using chromosome counts and heterochromatin distribution pattern wherein changes in the number of chromosomes and the distribution of AT and GC base pairs were recorded. The cells studied in the plantlets of the first regeneration (23.33 %) showed deviant number of chromosome which was increased to 33.33 % and 40 % in the plantlets of the second and the third regenerations, respectively. Also, 4',6-diamidino-2-phenylindole (DAPI)(+) and chromomycin A3 (CMA)(+) binding sites, on an average of 5.74 ± 0.47 and 5.00 ± 0.30, were observed in the plantlets of the first regeneration. Subsequently, DAPI(+) binding sites were increased to 6.61 ± 0.39 and 6.74 ± 0.57 in the plantlets of the second and the third regenerations, respectively, with a corresponding decrease in the CMA(+) binding sites (4.63 ± 0.45 and 4.16 ± 0.47 CMA(+) sites in the plantlets of the second and the third regenerations, respectively). The study reveals an increase in cytological variations in the morphologically similar micropropagated plants of N. khasiana with the subsequent regenerations which further necessitate the determination of genetic integrity of micropropagated plants.

Green Synthesis Of Gold Nanoparticles From The Leaf Extract Of Nepenthes Khasiana And Antimicrobial Assay

Synthesis of nanoparticles from various biological systems has been reported, but among all, biosynthesis of nanoparticles from plants is considered as the most suitable method. The use of plant material not only makes the process eco-friendly but also the abundance makes it more economical. The aim of this study was to investigate the ability of this plant to synthesis gold nanoparticles and study the properties of the nanoparticles thus produced. Antimicrobial activity and medicinal values of Nepenthes khasiana fascinated us to utilize it for biosynthesis of gold nanoparticles. The synthesized gold nanoparticles were characterized by UV-vis spectrophotometry, Scanning Electron Microscopy, X-ray Diffraction, Fourier Transform Infra-red Spectroscopy and Transmission Electron Microscopy. Different time intervals for the reaction with aqueous chloroauric acid solution increase in the absorbance with time and became constant giving a maximum absorbance at 599.78 nm at three hours of incubation. The results from XRD, TEM and SEM supports the biosynthesis of triangular and spherical shaped Gold nanoparticles between 50nm to 80 nm. In this study, the antimicrobial property of the AuNPS was exploited against human pathogenic micro-organisms. The results of TEM, SEM, FT-IR, UV-VIS and XRD confirm that the leaves extract of N. Khasiana can be used to produce Gold nanoparticles with significant amount of antimicrobial activity. Copyright © 2015 VBRI Press.

Modern Pollen Record on Bat Guano Deposit from Siju Cave and its Implication to Palaeoecological Study in South Garo Hills of Meghalaya, India

Meghalaya is well known for its rich tropical biodiversity and numerous natural caves. The Siju Cave of Meghalaya, also known as cave of the bat, is among the longest caves on the Indian subcontinent. The palynological study of fifty bat-guano samples from Siju Cave and of thirty surface soil and moss cushion from the area immediate surrounding the cave reflects the close similarity between the modern pollen and vegetation in the region in the two areas sampled. The resulting palynodata comprise mainly the native flora, dominated by riparian taxa like Duabanga, Syzygium, Careya, and Ficus, along with evergreen and deciduous elements in the region. The evergreen taxa Mesua, Elaeocarpus ,a ndGarcinia, along with Impatiens, reflect the high precipitation in the region. The climate of the region and the vegetation are strongly influenced by the Simsang River, and the heavy rainfall results in the dominance of riparian taxa and other high-rainfall indicator taxa. The occurrence of pollen from Nepenthes khasiana ,a n endemic and endangered plant of Meghalaya, in bat guano is significant and may be due to its insectivorous and entomophilous nature. However, medicinal plants like Swertia chirata, Cinchona, and Rauvolfia are not encountered in the bat-guano sediments, despite their luxuriant growth around the cave, and these species could be avoided by the insects due to their alkaloid contain and bitter taste. The presence of highland taxa such as Pinus, Abies, Picea, and Larix in the bat guano deposit is significant and suggestive of high winds from higher altitudes, or the pollen may be introduced by the return of migratory Siberian birds during winter to the nearby Siju wildlife and bird sanctuary. The recovery of cerealia along with Areca catechu and Citrus pollen indicate the human activity in the region. The abundance of fungal remains, namely Meliola, Glomus, and Microthyriaceae along with degraded palynomorphs are suggestive of strong microbial activity under warm and humid conditions during sedimentation in the region. The main objective of this study is to identify the potential of bat guano for palaeoecological research and as supportive data for surface and sedimentary soil profiles in the South Garo Hills of Meghalaya. The palynodata from the bat guano of the Siju Cave provides a useful source for palaeoecological information for the South Garo Hills, where intensive natural and human-caused forest fires, heavy rainfall, and soil erosion occur every year and there is a relative scarcity of the lake, wetland, and swamp habitats that normally preserve pollen.

Pollen morphology of Nepenthes khasiana Hook. f. (Nepenthaceae), an endemic insectivorous plant from India

The pollen morphology of Nepenthes khasiana (the pitcher plant) from India, was investigated using both light microscopy and scanning electron microscopy. This was to investigate fine details that may contribute to the taxonomic characterisation of species, as well as to utilise the knowledge of its morphology in order to correlate it with Bornean Nepenthes species. The size of the tetrad is the defining feature. The pollen grain is non-aperturate, the sexine is spinuliferous and thicker than the nexine. The study indicates that the species is similar in shape, aperture and ornamentation, and can be discriminated by the size of the tetrad, the length of the spines and the exine thickness. The size of the tetrad (30.7 μm) is closer to two Bornean species such as N. rafflesiana and N. mirabilis (30.5 and 31.0 μm respectively). These observations will be helpful in morphotaxonomy for accurate identification. This will help in finding these taxa from modern and sub-surface soils in order to study the present status of pollen preservation and decipher the palaeovegetation and past climate of the region.