37 research outputs found

    Regulation of Nectar Secretion and Volatile Emission in Plants bei Jasmonates

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    Inducible indirect defences of plants include secretion of extrafloral nectar (EFN) and emission of volatile organic compounds (VOC), which are essential to attract plant defenders. Although the regulation of these defences is understood to be controlled by jasmonates (jasmonic acid, JA and related compounds), fundamental questions such as the ecological and evolutionary constraints that were involved shaping these traits and the evolutionary trajectory of the underlying signalling pathways remain unresolved. The focus of this thesis is to illuminate these questions from various angles using different model systems particularly selected to address each individual question. The first aim was to understand the spatial distribution of these indirect defences in the light of plant defence theories. It was found that defences are allocated in proportion to the value of the respective plant part for future fitness in Phaseolus lunatus and Ricinus communis. Next, the temporal pattern in EFN secretion was investigated. In lima bean, it was revealed that JA-regulated EFN secretion depends on the ambient light regime and is mediated by the formation of the amino acid conjugate, JA-Ile. To find parallels in the regulatory process of nectar secretion, the role of jasmonates in floral nectar (FN) secretion was explored as a next step and it was shown that JA treatment can trigger higher FN secretion in Brassica napus. Finally, the regulation of indirect defences was studied in the fern species Pteridium aquilinum to compare the ecological function and signalling pathways with known regulatory process in more derived plant species. The results obtained suggest a different and yet unclear ecological function of EFN and a very different signalling pathway for the emission of VOCs and EFN secretion in P. aquilinum

    The Role of Jasmonates in Floral Nectar Secretion

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    Plants produce nectar in their flowers as a reward for their pollinators and most of our crops depend on insect pollination, but little is known on the physiological control of nectar secretion. Jasmonates are well-known for their effects on senescence, the development and opening of flowers and on plant defences such as extrafloral nectar. Their role in floral nectar secretion has, however, not been explored so far. We investigated whether jasmonates have an influence on floral nectar secretion in oil-seed rape, Brassica napus. The floral tissues of this plant produced jasmonic acid (JA) endogenously, and JA concentrations peaked shortly before nectar secretion was highest. Exogenous application of JA to flowers induced nectar secretion, which was suppressed by treatment with phenidone, an inhibitor of JA synthesis. This effect could be reversed by additional application of JA. Jasmonoyl-isoleucine and its structural mimic coronalon also increased nectar secretion. Herbivory or addition of JA to the leaves did not have an effect on floral nectar secretion, demonstrating a functional separation of systemic defence signalling from reproductive nectar secretion. Jasmonates, which have been intensively studied in the context of herbivore defences and flower development, have a profound effect on floral nectar secretion and, thus, pollination efficiency in B. napus. Our results link floral nectar secretion to jasmonate signalling and thereby integrate the floral nectar secretion into the complex network of oxylipid-mediated developmental processes of plants

    Predictive Internet of Things Based Detection Model of Comatose Patient using Deep Learning

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    The needs and demands of the healthcare sector are increasing exponentially. Also, there has been a rapid development in diverse technologies in totality. Hence varied advancements in different technologies like Internet of Things (IoT) and Deep Learning are being utilised and play a vital role in healthcare sector. In health care domain, specifically, there is also increasing need to find the possibility of patient going into coma. This is because if it is found that the patient is going into coma, preventive steps could be initiated helping patient and this could possibly save the life of the patient. The proposed work in this paper is in this direction whereby the advancement in technology is utilised to build a predictive model towards forecasting the chances of a patient going into coma state. The proposed system initially consists of different medical devices like sensors which take inputs from the patient and helps aid to monitor the condition of the patient. The proposed system consists of varied sensing devices which will help to record patient’s details such as blood pressure (B.P.), pulse rate, heart rate, brain signal and continuous monitoring the motion of coma patient. The various vital parameters from the patient are taken in continuously and displayed across a graphical display unit. Further as and when even if one vital parameter exceeds certain thresholds, the probability that patient will go into coma increases. Immediately an alert is given in. Further, all such records where there are chances that patient goes into coma state are stored in cloud. Subsequently, based on the data retrieved from the cloud a predictive model using Convolutional Neural Network (CNN) is built to forecast the status of the coma patient as an output for any set of health-related parameters of the patient. The effectiveness of the built predictive model is evaluated in terms of performance metrics such as accuracy, precision and recall. The built forecasting model displays high accuracy up to 98%. Such a system will greatly benefit health sector and coma patients and enable build futuristic and superior predictive and preventive model helping in reducing cases of patient going into coma state

    Testing the optimal defence hypothesis for two indirect defences: extrafloral nectar and volatile organic compounds

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    Many plants respond to herbivory with an increased production of extrafloral nectar (EFN) and/or volatile organic compounds (VOCs) to attract predatory arthropods as an indirect defensive strategy. In this study, we tested whether these two indirect defences fit the optimal defence hypothesis (ODH), which predicts the within-plant allocation of anti-herbivore defences according to trade-offs between growth and defence. Using jasmonic acid-induced plants of Phaseolus lunatus and Ricinus communis, we tested whether the within-plant distribution pattern of these two indirect defences reflects the fitness value of the respective plant parts. Furthermore, we quantified photosynthetic rates and followed the within-plant transport of assimilates with 13C labelling experiments. EFN secretion and VOC emission were highest in younger leaves. Moreover, the photosynthetic rate increased with leaf age, and pulse-labelling experiments suggested transport of carbon to younger leaves. Our results demonstrate that the ODH can explain the within-plant allocation pattern of both indirect defences studied

    N-methylpyrrolidone: Isolation and characterization of the compound from the marine sponge Clathria frondifera (class:Demospongiae)

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    235-238An investigation of the chemical composition of the marine sponge Clathria frondifera resulted in the isolation of the compound N-methylpyrrolidone which is widely used in the petrochemical, microelectronics fabrication, paint and pharmaceutical industry. This is the first report on the isolation and structural characterization of N-methylpyrrolidone from a marine source. The compound was purified by column chromatography and analyzed by TLC. The functional groups were analyzed by FTIR spectrum. The structure of the compound was established by spectroscopic analysis (UV, 1H and 13C NMR) and elucidated with the aid of COSY, HMQC, and HMBC experiments

    Phenotypic diversity of Methylobacterium associated with rice landraces in North-East India.

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    The ecology and distribution of many bacteria is strongly associated with specific eukaryotic hosts. However, the impact of such host association on bacterial ecology and evolution is not well understood. Bacteria from the genus Methylobacterium consume plant-derived methanol, and are some of the most abundant and widespread plant-associated bacteria. In addition, many of these species impact plant fitness. To determine the ecology and distribution of Methylobacterium in nature, we sampled bacteria from 36 distinct rice landraces, traditionally grown in geographically isolated locations in North-East (NE) India. These landraces have been selected for diverse phenotypic traits by local communities, and we expected that the divergent selection on hosts may have also generated divergence in associated Methylobacterium strains. We determined the ability of 91 distinct rice-associated Methylobacterium isolates to use a panel of carbon sources, finding substantial variability in carbon use profiles. Consistent with our expectation, across spatial scales this phenotypic variation was largely explained by host landrace identity rather than geographical factors or bacterial taxonomy. However, variation in carbon utilisation was not correlated with sugar exudates on leaf surfaces, suggesting that bacterial carbon use profiles do not directly determine bacterial colonization across landraces. Finally, experiments showed that at least some rice landraces gain an early growth advantage from their specific phyllosphere-colonizing Methylobacterium strains. Together, our results suggest that landrace-specific host-microbial relationships may contribute to spatial structure in rice-associated Methylobacterium in a natural ecosystem. In turn, association with specific bacteria may provide new ways to preserve and understand diversity in one of the most important food crops of the world

    Mismatch in receiver responses to multimodal signals in a diurnal gecko

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    Multimodal signals are used by many animals for intraspecific communication and can provide information about sex identity as well as quality of the signaller. In diurnal geckos of the genus Cnemaspis, chromatic colour patches in males evolved after chemical secretions, providing us with an opportunity to examine the utility of evolving multimodality. We quantified signal components and receiver responses in Cnemaspis mysoriensis to determine the relative importance of chemical and visual traits for intraspecific communication. Digital imagery and spectrophotometry of lizards revealed the presence of two distinct male morphs (yellow-gular and white-gular) and one female form (white-gular). All males, but no females, had yellow eye rims. Characterization of chemical secretions from the ventral precloacal and femoral glands of all lizard forms revealed no differences between male morphs. However, all males differed from females in a few key compounds. We then exposed lizards to only chemical stimuli, only visual stimuli, or both chemical and visual stimuli of conspecific males and females. We found that females were responsive to the chemical stimuli alone as well as the multimodal stimuli of males, whereas males were only responsive to the multimodal stimuli of other males. Neither chemical or visual components of females elicited a response from conspecifics. Thus, while the chemical secretions of males are sufficient for females to elicit a response, multimodal stimuli are necessary for males to respond. Based on variation in signalling traits and receiver responses, we conclude that: (1) chemical secretions signal both sex identity and male quality; (2) eye rim colour encodes information about sex identity; and (3) gular colour in males is probably not a redundant trait, providing some information to males, but not females. We conclude that the secondary evolution of visual signals in C. mysoriensis therefore enhances male-male social interactions and not communication in general. (C) 2018 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved

    Marine organisms in Indian medicine and their future prospects

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    139-145The marine ecosystem is a rich source of both biological and chemical diversity which has been explored in the discovery of unique chemicals, having potential for industrial development as pharmaceuticals, cosmetics, nutritional supplements, molecular probes, fine chemicals and agrochemicals. In recent years, a significant number of novel metabolites with potent pharmacological properties have been discovered from marine organisms. In the present paper various research reports on some marine organisms used in different Indian systems of medicine have been discussed for further developments
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