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1.
Environ Monit Assess ; 195(12): 1411, 2023 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-37922020

RESUMO

Invasive alien species have become the second major threat to biodiversity affecting all three major ecosystems (terrestrial, marine, and freshwater). Increasing drivers such as habitat destruction, expanding horticulture and aquaculture industries, and global pet and food trade have created pathways for exotic species to be introduced leading to severe impacts on recipient ecosystems. Although relatively less studied than terrestrial ecosystems, freshwater ecosystems are highly susceptible to biological invasions. In India, there has been a noticeable increase in the introduction of alien fish species in freshwater environments. In the current study, we aimed to understand how climate change can affect the dynamics of the biological invasion of invasive alien fishes in India. We also evaluated the river-linking project's impact on the homogenization of biota in Indian freshwater bodies. We used species occurrence records with selected environmental variables to assess vulnerable locations for current and future biological invasion using species distribution models. Our study has identified and mapped the vulnerable regions to invasion in India. Our research indicates that the interlinking of rivers connects susceptible regions housing endangered fish species with invasive hotspots. Invasive alien fishes from the source basin may invade vulnerable basins and compete with the native species. Based on the results, we discuss some of the key areas for the management of these invasive alien species in the freshwater ecosystems.


Assuntos
Ecossistema , Espécies Introduzidas , Animais , Monitoramento Ambiental , Biodiversidade , Peixes , Espécies em Perigo de Extinção , Índia
2.
Mol Phylogenet Evol ; 174: 107547, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35690379

RESUMO

Snails of the genus Cremnoconchus - the only freshwater members of the gastropod family Littorinidae - are endemic to the spray zones of numerous waterfalls in the Western Ghats of India. Cremnoconchus consists of nine described and possibly numerous undescribed species as many of these appear to be restricted to specific waterfalls. This is the first attempt at resolving the relationships between the various species in this genus and establishing its monophyly in the family. Further, we also undertake species delimitation analysis to characterize cryptic diversity in this group. Phylogenetic analyses based on nuclear and mitochondrial genes support the monophyly of Cremnoconchus within the family. A fossil-calibrated Bayesian time tree suggests that this freshwater lineage diverged from its marine counterparts around 90.40 million years ago. The separation of Cremnoconchus from its marine ancestors might have been facilitated by the break-up of Gondwana or fluctuating sea levels during this period. Species delimitation analysis retrieved 12 potentially undescribed species in this group. These species formed two distinct clades in the phylogeny, one largely confined to the northern Western Ghats and the other to the central Western Ghats. Species belonging to the northern and central Western Ghats seem to have separated around 56.11 mya, i.e. after the northern Western Ghats were formed. Additionally, spatial isolation due to the patchiness of suitable habitats (waterfalls) and low mobility might have facilitated their diversification.


Assuntos
Gastrópodes , Animais , Teorema de Bayes , Meio Ambiente , Gastrópodes/genética , Índia , Filogenia , Caramujos
3.
J Chem Ecol ; 44(6): 611-620, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29797164

RESUMO

Camptothecin (CPT), a monoterpene indole alkaloid, is a potent inhibitor of eukaryotic topoisomerase I (Top 1). Because of this property, several derivatives of CPT are widely used as chemotherapeutic agents. The compound is produced by several plant species, including Nothapodytes nimmoniana (Family: Icacinaceae) presumably as a deterrent to insect pests. Here, we report, a lepidopteran larva, Lymantria sp. of Lymantriidae family which feeds voraciously on the leaves of N. nimmoniana, without any adverse consequences. Larval body weight and molting period were unaffected despite captive feeding of the larva with CPT enriched leaves. Mass spectrometric analysis indicated that nearly 46% of the ingested CPT was excreted while the rest was sequestered predominantly in the exuviae and setae (~35%). Although most of the CPT was in the parental form as found in the plant, traces of inactive, sulfated forms of CPT were recovered from the larva. Compared to that in plant, there were no critical mutations at the CPT binding domain of the insect's Top 1. The gut pH of the larva was alkaline (pH 10.0). The alkaline gut environment converts CPT from its active, lactone form to inactive, carboxylate form. It is likely that such conversion might help the larva to reduce the overall burden of CPT in its gut. We discuss the results in the context of the mechanisms of resistance adapted by insects to plant toxins.


Assuntos
Camptotecina/farmacologia , Magnoliopsida/química , Mariposas/efeitos dos fármacos , Sequência de Aminoácidos , Animais , Sítios de Ligação , Camptotecina/química , Camptotecina/classificação , Camptotecina/metabolismo , Cromatografia Líquida de Alta Pressão , DNA Topoisomerases Tipo I/química , DNA Topoisomerases Tipo I/genética , DNA Topoisomerases Tipo I/metabolismo , Resistência a Medicamentos , Concentração de Íons de Hidrogênio , Proteínas de Insetos/antagonistas & inibidores , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Mucosa Intestinal/metabolismo , Intestinos/química , Larva/metabolismo , Espectroscopia de Ressonância Magnética , Magnoliopsida/metabolismo , Mariposas/crescimento & desenvolvimento , Mariposas/metabolismo , Mutação , Folhas de Planta/química , Folhas de Planta/metabolismo , Espectrometria de Massas por Ionização por Electrospray
4.
J Plant Res ; 129(6): 1033-1040, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27624169

RESUMO

The center of diversity of Piper nigrum L. (Black Pepper), one of the highly valued spice crops is reported to be from India. Black pepper is naturally distributed in India in the Western Ghats biodiversity hotspot and is the only known existing source of its wild germplasm in the world. We used ecological niche models to predict the potential distribution of wild P. nigrum in the present and two future climate change scenarios viz (A1B) and (A2A) for the year 2080. Three topographic and nine uncorrelated bioclim variables were used to develop the niche models. The environmental variables influencing the distribution of wild P. nigrum across different climate change scenarios were identified. We also assessed the direction and magnitude of the niche centroid shift and the change in niche breadth to estimate the impact of projected climate change on the distribution of P. nigrum. The study shows a niche centroid shift in the future climate scenarios. Both the projected future climate scenarios predicted a reduction in the habitat of P. nigrum in Southern Western Ghats, which harbors many wild accessions of P. nigrum. Our results highlight the impact of future climate change on P. nigrum and provide useful information for designing sound germplasm conservation strategies for P. nigrum.


Assuntos
Mudança Climática , Ecossistema , Piper nigrum/fisiologia , Dispersão Vegetal , Índia , Modelos Teóricos
5.
World J Microbiol Biotechnol ; 31(10): 1629-39, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26289161

RESUMO

Fungal endophytes inhabit living tissues of plants without any apparent symptoms and in many cases are known to produce secondary metabolites similar to those produced by their respective host plants. However on sub-culture, the endophytic fungi gradually attenuate their ability to produce the metabolites. Attenuation has been a major constraint in realizing the potential of endophytic fungi as an alternative source of plant secondary metabolites. In this study, we report attempts to restore camptothecine (CPT) production in attenuated endophytic fungi isolated from CPT producing plants, Nothapodytes nimmoniana and Miquelia dentata when they are passed through their host plant or plants that produce CPT and when treated with a DNA methyl transferase inhibitor. Attenuated endophytic fungi that traversed through their host tissue or plants capable of synthesizing CPT, produced significantly higher CPT compared to the attenuated fungi. Attenuated fungus cultured in the presence of 5-azacytidine, a DNA methyltransferase inhibitor, had an enhanced CPT content compared to untreated attenuated fungus. These results indicate that the attenuation of CPT production in endophytic fungi could in principle be reversed by eliciting some signals from plant tissue, most likely that which prevents the methylation or silencing of the genes responsible for CPT biosynthesis.


Assuntos
Camptotecina/metabolismo , Endófitos/metabolismo , Fungos/metabolismo , Magnoliopsida/microbiologia , Metabolismo Secundário , Azacitidina/metabolismo , Endófitos/efeitos dos fármacos , Endófitos/enzimologia , Inibidores Enzimáticos/metabolismo , Epigênese Genética , Fungos/efeitos dos fármacos , Fungos/enzimologia , Fungos/isolamento & purificação , Metiltransferases/antagonistas & inibidores
6.
Zootaxa ; (3796): 33-61, 2014 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-24870664

RESUMO

Reproductive modes are diverse and unique in anurans. Selective pressures of evolution, ecology and environment are attributed to such diverse reproductive modes. Globally forty different reproductive modes in anurans have been described to date. The genus Nyctibatrachus has been recently revised and belongs to an ancient lineage of frog families in the Western Ghats of India. Species of this genus are known to exhibit mountain associated clade endemism and novel breeding behaviours. The purpose of this study is to present unique reproductive behaviour, oviposition and parental care in a new species Nyctibatrachus kumbara sp. nov. which is described in the paper. Nyctibatrachus kumbara sp. nov. is a medium sized stream dwelling frog. It is distinct from the congeners based on a suite of morphological characters and substantially divergent in DNA sequences of the mitochondrial 16S rRNA gene. Males exhibit parental care by mud packing the egg clutch. Such parental care has so far not been described from any other frog species worldwide. Besides this, we emphasize that three co-occurring congeneric species of Nyctibatrachus, namely N. jog, N. kempholeyensis and Nyctibatrachus kumbara sp. nov. from the study site differ in breeding behaviour, which could represent a case of reproductive character displacement. These three species are distinct in their size, call pattern, reproductive behaviour, maximum number of eggs in a clutch, oviposition and parental care, which was evident from the statistical analysis. The study throws light on the reproductive behaviour of Nyctibatrachus kumbara sp. nov. and associated species to understand the evolution and adaptation of reproductive modes of anurans in general, and Nyctibatrachus in particular from the Western Ghats.


Assuntos
Comunicação Animal , Anuros/fisiologia , Evolução Biológica , RNA Ribossômico 16S/genética , Comportamento Sexual Animal , Animais , Anuros/anatomia & histologia , Anuros/classificação , Feminino , Índia , Masculino , Oviposição , Comportamento Paterno
7.
Steroids ; 205: 109390, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38367679

RESUMO

The Genus Dysoxylum (Meliaceae) consists of approximately 80 species that are abundant in structurally diverse triterpenoids. The present study focused on isolating new triterpenoids from the bark of Dysoxylum malabaricum, one of the predominant species of Dysoxylum present in India. The methanol-dichloromethane bark extract was subjected to LCMS profiling followed by silica gel column chromatography and HPLC analysis to target new compounds. Two new ring A-modified cycloartane-type triterpenoids (1 and 2) were isolated from the bark extract. Spectroscopic methods like NMR, HRESIMS data, and electronic circular dichroism calculations elucidated the structuresandabsolute configurations of the isolated compounds. These compounds were evaluated for their cytotoxic potential against breast cancer cells and displayed notable cytotoxicity. Compound 1 exhibited the highest cytotoxicity against the MDA-MB-231 cells and induced apoptotic cell death. Also, it was able to inhibit glucose uptake and increase nitric oxide production in breast cancer cells.


Assuntos
Antineoplásicos Fitogênicos , Neoplasias da Mama , Meliaceae , Triterpenos , Humanos , Feminino , Estrutura Molecular , Casca de Planta/química , Antineoplásicos Fitogênicos/farmacologia , Antineoplásicos Fitogênicos/química , Triterpenos/farmacologia , Triterpenos/química , Meliaceae/química , Extratos Vegetais/química
8.
J Assoc Physicians India ; 61(2): 110-3, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24471249

RESUMO

OBJECTIVES: To monitor the different antithrombotic drug combinations, determine the incidence, magnitude of bleeding and the association of HAS-BLED risk scoring schema with the magnitude of bleeding as defined using TIMI bleeding criteria. METHODS: A prospective observational study in a cohort of patients for a period of 8 months, at one of the tertiary care center-Krishna Institute of Medical Sciences, Hyderabad, was conducted. Consecutive patients were enrolled and followed from the date of admission till the adverse events are perceived/date of discharge. Pearson Correlation Statistics (Fisher's z Transformation) is applied to assess the association between HAS-BLED risk factors and the total risk score with bleeding criteria. RESULTS: A total of 400 cases were collected during the 8-month study period, of which 372 satisfied the inclusion criteria. Among them 34 (9.1%) bleeding cases were reported with mean (+/- SD) age of 57.8 (+/- 14.19) years. Bleeding occurred mostly in males 79.4% and a HAS-BLED Score of > or = 3 has been observed in 67.6% (n = 23) patients out of 34 bled patients. Two antiplatelets + One anticoagulant is the most common combination which caused bleeding in 41.2% (n = 14). Stroke history, bleeding predisposition, labile INR's are the HAS-BLED risk factors which are significant (< 0.05) with the TIMI Bleeding Criteria. CONCLUSION: There was a linear correlation between the HAS-BLED risk score and the TIMI bleeding criteria-higher the risk score the more frequent is the incidence of major bleeding. A HAS-BLED risk score of > or = 3 is associated with TIMI major bleeding.


Assuntos
Anticoagulantes/efeitos adversos , Fibrinolíticos/efeitos adversos , Hemorragia/induzido quimicamente , Inibidores da Agregação Plaquetária/efeitos adversos , Adulto , Idoso , Estudos de Coortes , Quimioterapia Combinada/efeitos adversos , Epistaxe/induzido quimicamente , Feminino , Hemorragia Gastrointestinal/induzido quimicamente , Hematúria/induzido quimicamente , Hemoptise/induzido quimicamente , Humanos , Hemorragias Intracranianas/induzido quimicamente , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Hemorragia Bucal/induzido quimicamente , Estudos Prospectivos , Medição de Risco , Fatores de Risco , Índice de Gravidade de Doença , Centros de Atenção Terciária
9.
Front Agron ; 5: 1134514, 2023 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-39071943

RESUMO

Introduction: Use of chemical fertilization and pesticides not only harm the environment but also have detrimental consequences on human health. In recent years, there has been a major emphasis worldwide on natural agriculture methods. Regenerative agriculture is known across the world as a combination of nature-friendly farming practices such as no-till, cover cropping, crop-rotation, agroforestry and use of organic home-based/farm-based ingredients to revive soil health. In India, a number of farmers are slowly adopting these practices using home-based mixtures and farmyard manure for soil rejuvenation and pest management. In order to evaluate the efficacy of the regenerative agriculture practices, this study compared conventional and regenerative agriculture plots for their soil bacterial and nutrient profiles. Methods: Two crops - ragi (Finger millet, an old world cereal eaten in India) and vegetable (tomato/beans), and different lengths (≤3 and >5 years) of regenerative practices were additional metrics considered to understand variabilities due to crop-type and period of application. The common regenerative agriculture practices used by farmers in this study included a mix of practices such as mulching, minimal-till, inter-cropping, crop-rotation, along with application of farmyard manure and other home-based concoctions rich in nutrients and microbes for enriching the soil. Results: We found that all regenerative practices were effective in bringing about an enrichment for soil bacteria with a more heterogeneous composition. Additionally, in regenerative vegetable (RV) versus conventional vegetable (CV) and barren land (BL) plots the relative percentage abundance of Actinobacteriota (RV-7.47%/ CV-6.24%/BL -7.02%) and Chloroflexi (RV-9.37%/ CV-6.63%/BL-8.75%) was slightly higher. In contrast, levels of Acidobacteriota (RV-8.1%/ CV-9.88%/BL-9.62%) was significantly lower. Similarly, regenerative ragi (RR) in comparison with conventional ragi (CR) and barren land (BL) plots saw higher representation of Firmicutes (RR-5.45%/ CR-2.38%/BL-1.45%) and Actinobacteriota (RR-11.53%/ CR-7.08%/BL-7.15%) and a concurrent reduction in Acidobacteriota (RR-6.91%/CR-7.39%/ BL-9.79%). The RV plots were found to be enriched for Plant Growth Promoting Rhizobacteria (PGPRs) - Pseudomonas sp. (RV-0.51%/CV-0.01%/BL-0.21%), and RR plots were enriched for Bacillus sp. (RR-1.35%/CR-0.95%/BL-0.61%), and Mesorhizobium sp. (0.30%/0.12%/0.21%), which are known to play significant roles in vegetable and ragi growth respectively. Discussion: Interestingly, long-term regenerative agriculture was able to support good nutrient composition while enhancing Soil Organic Carbon (SOC) levels. In all, the regenerative agriculture practices were found to be effective in improving bacterial community structure and simultaneously improving soil health. We found that BL soil with eucalyptus plantation showed among the least bacterial diversity suggesting detrimental impact on soil health.

10.
Steroids ; 200: 109315, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37777040

RESUMO

The cytotoxic dichloromethane-methanol bark extract of Dysoxylum malabaricum was subjected to bioassay-guided fractionation, followed by systematic dereplication to focus on the identification of new compounds. From the bark of Dysoxylum malabaricum, two new cycloartane-type triterpenoids were isolated in addition to two previously known triterpenoids. The structures and absolute configurations of the isolated compounds were elucidated unambiguously via NMR, HRESIMS data, and electronic circular dichroism calculations. The isolated compounds were tested for their cytotoxic potential against the panel of breast, lung, and hypopharynx cancer cell lines and displayed notable cytotoxicity against breast cancer cell lines. Compound 3 exhibited the most potent cytotoxic effect with an IC50 14 µM against MCF-7 cell lines and induced cell cycle arrest. Through western blot and cell cycle analysis, it was revealed that compound 3 halts the G0/G1 phase of the cell cycle by inhibiting CDC20 and CDC25 enzymes.


Assuntos
Antineoplásicos Fitogênicos , Antineoplásicos , Meliaceae , Triterpenos , Humanos , Linhagem Celular Tumoral , Antineoplásicos Fitogênicos/farmacologia , Antineoplásicos Fitogênicos/química , Meliaceae/química , Triterpenos/farmacologia , Triterpenos/química , Estrutura Molecular
11.
Mol Ecol ; 21(22): 5484-96, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23043256

RESUMO

Tropical trees often display long-distance pollen dispersal, even in highly fragmented landscapes. Understanding how patterns of spatial isolation influence pollen dispersal and interact with background patterns of fine-scale spatial genetic structure (FSGS) is critical for evaluating the genetic consequences of habitat fragmentation. In the endangered tropical timber tree Dysoxylum malabaricum (Meliaceae), we apply eleven microsatellite markers with paternity and parentage analysis to directly estimate historic gene flow and contemporary pollen dispersal across a large area (216 km(2)) in a highly fragmented agro-forest landscape. A comparison of genetic diversity and genetic structure in adult and juvenile life stages indicates an increase in differentiation and FSGS over time. Paternity analysis and parentage analysis demonstrate high genetic connectivity across the landscape by pollen dispersal. A comparison between mother trees in forest patches with low and high densities of adult trees shows that the frequency of short-distance mating increases, as does average kinship among mates in low-density stands. This indicates that there are potentially negative genetic consequences of low population density associated with forest fragmentation. Single isolated trees, in contrast, frequently receive heterogeneous pollen from distances exceeding 5 km. We discuss the processes leading to the observed patterns of pollen dispersal and the implications of this for conservation management of D. malabaricum and tropical trees more generally.


Assuntos
Fluxo Gênico , Genética Populacional , Endogamia , Meliaceae/genética , Pólen/genética , Conservação dos Recursos Naturais , DNA de Plantas/genética , Ecossistema , Índia , Repetições de Microssatélites , Polinização , Árvores/genética , Clima Tropical
12.
Pharm Biol ; 50(8): 948-53, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22480277

RESUMO

CONTEXT: Phyllanthus (Euphorbiaceae) species are traditionally well-known for their medicinal properties including hepatoprotective activity. OBJECTIVE: The study assessed the hepatoprotective and antioxidant activities of 11 Phyllanthus species, P. amarus Schumach., P. urinaria L., P. debilis Klein ex Willd, P. tenellus Roxb., P. virgatus G. Forst., P. maderaspatensis L., P. reticulatus Poir., P. polyphyllus Willd., P. emblica L., P. indofischerii Bennet. and P. acidus (L.) Skeels. MATERIALS AND METHODS: The dried leaves and stems of each plant species were extracted in methanol and successively in water. The extracts were screened for hepatoprotective activity at a concentration of 50 µg/mL against tert-butyl hydroperoxide (t-BH) induced toxicity in HepG2 cells. Seven extracts from five species that showed hepatoprotective activity were assessed for their 50% effective concentration (EC50) values and their antioxidant activity using a DPPH assay. Phyllanthin and hypophyllanthin contents were also determined in these Phyllanthus species. RESULTS: The methanol extracts of P. polyphyllus, P. emblica and P. indofischeri showed high levels of hepatoprotective activity with EC50 values of 12, 19 and 28 µg/mL and IC50 of 3.77, 3.38 and 5.8 µg/mL for DPPH scavenging activity respectively against an IC50 of 3.69 µg/mL for ascorbic acid. None of these activities could be attributed to phyllanthin and hypophyllanthin. DISCUSSION AND CONCLUSION: The hepatoprotective and antioxidant activities of P. indofischeri are demonstrated for the first time in literature. The study also confirms the hepatoprotective and antioxidant activities of leaves of P. emblica and P. polyphyllus. The molecule(s) responsible for the activities is being investigated.


Assuntos
Fígado/efeitos dos fármacos , Phyllanthus/química , Extratos Vegetais/farmacologia , Folhas de Planta/química , Caules de Planta/química , Substâncias Protetoras/farmacologia , Antioxidantes/química , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Etnofarmacologia , Células Hep G2 , Humanos , Índia , Concentração Inibidora 50 , Lignanas/análise , Metanol/química , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Substâncias Protetoras/química , Substâncias Protetoras/isolamento & purificação , Solventes/química , terc-Butil Hidroperóxido
13.
J Chem Ecol ; 37(5): 533-6, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21499721

RESUMO

Camptothecin (CPT), a monoterpene indole alkaloid, is a potent inhibitor of eukaryotic toposiomerase-I. Several derivatives of CPT are in clinical use against ovarian and lung cancers. CPT has been reported from several plant species belonging to the order Asterids, with the highest concentration in Nothapodytes nimmoniana (family Icacinaceae). In this paper, we report an intriguing observation of chrysomelid beetles (Kanarella unicolor Jacobby) feeding on the leaves of N. nimmoniana without any apparent adverse effect. LC-MS/MS analysis of the beetles indicated that 54.9% of the ingested CPT's was recovered from the wings, followed by lesser amounts in the head and abdomen. LC-HRMS analysis revealed that most of the CPT in the insect body was in the parental form available in the plants without any major metabolizable products, including sulfated and glucuronilated forms. The mechanism by which the beetles are able to tolerate substantially high levels of CPT in their body tissue is under investigation.


Assuntos
Antineoplásicos Fitogênicos/metabolismo , Camptotecina/metabolismo , Besouros/metabolismo , Magnoliopsida/metabolismo , Magnoliopsida/parasitologia , Animais , Folhas de Planta/metabolismo , Folhas de Planta/parasitologia
14.
J Genet ; 1002021.
Artigo em Inglês | MEDLINE | ID: mdl-34057147

RESUMO

The apparent absence of Himalayan low-elevation taxa in the central Indian region and resumption of their distribution in the high elevation of Western Ghats has puzzled biogeographers for several decades. Many theories have been proposed to explain this but attempts remain futile owing to insufficient empirical support. Here, we have employed a montane tree species, Rhododendron arboreum to investigate this pattern by integrating past ecological niche modelling with molecular signatures. Reconstruction of paleo-ecological niche from interglacial to Last Glacial Maxima (LGM) portrayed a gradual depletion of vegetation cover with extreme impoverishment in the Holocene. A similar pattern was also reflected from genetic signatures; population history revealed a very recent split between the Himalayas and Western Ghats in the late Quaternary. A few other tree species exhibiting the same disjunction demonstrated a similar modification of paleo-ecological niche from last interglacial. The study clearly indicated that the populations in the Western Ghats to be a relictual remnants of a once continuous distribution of R. arboreum.


Assuntos
Variação Genética , Genética Populacional , Haplótipos , Modelos Genéticos , Filogeografia , Rhododendron/classificação , Rhododendron/genética , Ecossistema , Rhododendron/crescimento & desenvolvimento , Especificidade da Espécie
15.
Microbiol Res ; 242: 126595, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33017769

RESUMO

Antagonism of plant pathogenic fungi by endophytic fungi is a well-known phenomenon. In plate assays, the antagonism could be due to mycoparasitism, competition for space or antibiosis, involving a chemical diffusate, or a volatile organic compound (VOC). In this study, we demonstrate that besides mycoparasitism, VOCs play a major role in antagonism of pathogenic fungi by four endophytic fungi belonging to the genus Trichoderma. Using a double-plate assay, we show that all the four endophytic Trichoderma species significantly inhibited mycelial growth of three of the four pathogens, (Sclerotinia sclerotiorum-TSS, Sclerotium rolfsii-CSR and Fusarium oxysporum-CFO), while that of Macrophomina phaseolina-CMP was not affected. GC-MS analysis of the pure cultures of one of the endophytic fungi studied, namely, Trichoderma longibrachiatum strain 2 (Acc. No. MK751758) and the pathogens, F. oxysporum-CFO and M. phaseolina-CMP revealed the presence of several VOCs including hydrocarbons, alcohols, ketones, aldehydes, esters, acids, ethers and different classes of terpenes. In mixed double plates, where the endophyte was grown along with either of the two plant pathogens, F. oxysporum-CFO or M. phaseolina-CMP, there was an induction of a number of new VOCs that were not detected in the pure cultures of either the endophyte or the pathogens. Several of these new VOCs are reported to possess antifungal and cytotoxic activity. We discuss these results and highlight the importance of such interactions in endophyte-pathogen interactions.


Assuntos
Fungos/efeitos dos fármacos , Doenças das Plantas/microbiologia , Plantas/microbiologia , Trichoderma/metabolismo , Compostos Orgânicos Voláteis/farmacologia , Antibiose , Antifúngicos/farmacologia , Ascomicetos , Agentes de Controle Biológico , Endófitos/efeitos dos fármacos , Fusarium/efeitos dos fármacos , Hypocreales , Trichoderma/classificação , Trichoderma/isolamento & purificação
16.
Sci Rep ; 10(1): 3237, 2020 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-32094443

RESUMO

Endophytes, both of bacterial and fungal origin, are ubiquitously present in all plants. While their origin and evolution are enigmatic, there is burgeoning literature on their role in promoting growth and stress responses in their hosts. We demonstrate that a salt-tolerant endophyte isolated from salt-adapted Pokkali rice, a Fusarium sp., colonizes the salt-sensitive rice variety IR-64, promotes its growth under salt stress and confers salinity stress tolerance to its host. Physiological parameters, such as assimilation rate and chlorophyll stability index were higher in the colonized plants. Comparative transcriptome analysis revealed 1348 up-regulated and 1078 down-regulated genes in plants colonized by the endophyte. Analysis of the regulated genes by MapMan and interaction network programs showed that they are involved in both abiotic and biotic stress tolerance, and code for proteins involved in signal perception (leucine-rich repeat proteins, receptor-like kinases) and transduction (Ca2+ and calmodulin-binding proteins), transcription factors, secondary metabolism and oxidative stress scavenging. For nine genes, the data were validated by qPCR analysis in both roots and shoots. Taken together, these results show that salt-adapted Pokkali rice varieties are powerful sources for the identification of novel endophytes, which can be used to confer salinity tolerance to agriculturally important, but salt-sensitive rice varieties.


Assuntos
Endófitos/fisiologia , Genes de Plantas , Oryza/genética , Oryza/microbiologia , Tolerância ao Sal/genética , Cloreto de Sódio/farmacologia , Endófitos/efeitos dos fármacos , Endófitos/isolamento & purificação , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Ontologia Genética , Anotação de Sequência Molecular , Micélio/efeitos dos fármacos , Micélio/crescimento & desenvolvimento , Oryza/efeitos dos fármacos , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/crescimento & desenvolvimento , Potássio/metabolismo , Mapas de Interação de Proteínas/genética , Controle de Qualidade , Reprodutibilidade dos Testes , Salinidade , Tolerância ao Sal/efeitos dos fármacos , Sódio/metabolismo , Estresse Fisiológico/efeitos dos fármacos , Estresse Fisiológico/genética , Transcriptoma/genética
17.
J Genet ; 982019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31819027

RESUMO

Amphibians show a very high level of diversity and endemism and are facing global declines from the past few decades. Studies have shown that the molecular tools can be helpful in their conservation efforts. In India, more than 80% of amphibians are endemic and most show a narrow range of distribution. Most of the Indian amphibians lack information on their genetic diversity. In this study, were view the overall trend on amphibian studies in India with the specific focus on conservation genetics. Overall, of the 173 studies, only 14 dealt with the conservation of amphibians through genetic tools and five studies estimated the genetic diversity or gene structure. Here, we discuss the gaps and provide future directions on how genetic studies can be helpful in Indian amphibian conservation.


Assuntos
Anfíbios/genética , Conservação dos Recursos Naturais , Anfíbios/classificação , Animais , Biodiversidade , Bases de Dados Factuais , Marcadores Genéticos , Variação Genética , Índia , Filogeografia , Densidade Demográfica
18.
J Chromatogr Sci ; 46(4): 362-8, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18402730

RESUMO

Camptothecin (CPT), a monoterpene alkaloid, is an important anti-cancer compound obtained from several plant sources including Camptotheca acuminta (from China) and Nothapodytes nimmoniana (from India). Currently, by far the highest levels of CPT (approximately 0.3% w/w) are reported from Nothapodytes nimmoniana, a small tree distributed in the Western Ghats, India. In recent years because of the heavy demand, there has been a serious threat of extinction of the populations of the tree in the Western Ghats forest of south India. Several studies have chemically profiled populations of the species in the Western Ghats to identify sources of high yield and therefore to enable the sustainable production and harvesting of CPT. In this study, using both high-performance liquid chromatography and liquid chromatography-mass spectrometry, we report for the first time the identification of trees that produce at least 5- to 8-fold more CPT than hitherto reported. Furthermore, we show for the first time the production of a few minor camptothecines, including 10-hydroxy camptothecin, in the stem and root bark extracts of the tree. These results have important implications for not only harnessing the high-yielding individuals for clonal multiplication but also for exploiting some of the minor camptothecines, which also have been shown to have important anti-cancer and anti-viral activity.


Assuntos
Alcaloides/isolamento & purificação , Camptotecina/isolamento & purificação , Magnoliopsida/química , Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas/métodos , Casca de Planta/química , Raízes de Plantas/química , Caules de Planta/química
19.
J Genet ; 97(4): 1001-1006, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30262713

RESUMO

Phyllanthus emblica and P. indofischeri, commonly known as the Indian gooseberry, are important nontimber forest product (NTFP) species widely distributed across the Indian subcontinent. The fruits of these species are rich in vitamin C and are used in the preparation of a number of herbal medicines for treating a wide range of disorders. Due to the increased demand, they have been harvested extensively and form a major source of income for the forest-dwelling communities living in southern India. There are limited studies to understand the impact of harvesting on the genetic structure of these species. In this study, 15 polymorphic microsatellite markers have been developed for P. emblica and were characterized by screening 20 individuals each of P. emblica and P. indofischeri. The number of alleles per locus ranged 2-9 for P. emblica and 2-11 for P. indofischeri. The observed and expected heterozygosity of P. emblica ranged 0-1 and 0.401-0.825, respectively. Similarly, the observed and expected heterozygosity of P. indofischeri ranged 0.5-1 and 0.366-0.842, respectively. Cross-amplification of the designed primers was assessed with seven related Phyllanthus species. The microsatellite markers developed can be used for studying the population genetic structure, gene flow and genetic diversity of P. emblica and P. indofischeri.


Assuntos
Genética Populacional , Repetições de Microssatélites/genética , Phyllanthus emblica/genética , Plantas Medicinais/genética , Florestas , Humanos , Índia
20.
3 Biotech ; 8(3): 135, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29479511

RESUMO

A number of studies have shown that there could be widespread substitution and/or adulteration (hereafter referred to as substitution) in raw herbal trade of medicinal plants. Substitution could potentially endanger the health and safety of the consumers. In this study, the extent of adulteration in raw herbal trade of 30 important medicinal plants in South India was analyzed. Biological reference material (BRM) consisting of taxonomically authenticated samples of each of the 30 species along with 14 other co-occurring and congeneric allied species that are likely to be used in adulteration was established. DNA barcode signatures of 124 BRM using two candidate regions, nr-ITS and psbA-trnH were identified. A total of 203 herbal trade samples representing the 30 medicinal plant species were collected from 34 locations in South India. Using the DNA barcode sequences of the BRM as reference, the analysis indicated that the substitution ranged from 20 to 100%. Overall, approximately 12% of the market samples were adulterated. Considering the potential health hazard that such adulteration can cause, the need for a national regulatory framework that can authenticate and regulate raw herbal trade in the country is discussed.

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