Investigating the initial signalling mechanisms underpinning gene-for-gene mediated Systemic Acquired Resistance in Arabidopsis thaliana

National Overseas Scholarship Scheme to study abroad.Plants deploy two key active defensive strategies to combat microbial pathogens; (i) Recognition of Pathogen-Associated Molecular Patterns (PAMPs) by extracellular surface receptors leading to the activation of PAMP-Triggered Immunity (PTI); (ii) Recognition of pathogen effector activity, usually intracellularly, by host Resistance (R) proteins leading to Effector-Triggered Immunity (ETI). ETI is characterised by a rapid localised Hypersensitive Response (HR). HR induces Systemic Acquired Resistance (SAR) through the production of an inducible immune signal(s), leading to broad spectrum systemic resistance. I investigated the earliest events associated with SAR signalling using plant electrophysiology, SAR mutants and a unique promoter-luciferase fusion that captures early systemic transcriptional events associated with ETI. We describe the transcriptional dynamics of A70 (At5g56980), a gene of unknown function (Truman et al. 2007), in local and systemic tissue following challenge with different elicitors and virulent or avirulent pathogen challenges. We provide evidence that A70 responds to a jasmonate (JA) related signal that is rapidly generated following ETI recognition. We further evaluate A70::LUC reporter activity in response to JA stimulus and correlate activity with histological expression of a JA repressor reporter (JAZ10::GUS) and A70::GFP reporter in systemically responding leaves following avirulent pathogen challenges. Finally, we examine changes in electrophysiological signals following ETI in local and systemic leaves. Focussing on events underpinning initiation, propagation and perception of SAR-inducing signals within the first 6-8 h of pathogen challenge we provide new insight into the integrated signalling mechanisms, dynamics and connectivity underpinning systemic immune responses. We conclude that there are multicomponent signals that link ETI induced transcriptional and electrical signals, with a COI1 receptor dependent propagative transcriptional wave the leads to rapid temporal spatial activation of jasmonate responsive genes in systemic responding leaves.Ministry of Social Justice and Empowerment, Indi

Harvesting Image Databases from The Web

The research work presented here includes data mining needs and study of their algorithm for various extraction purpose. It also includes work that has been done in the field of harvesting images from web. Here the proposed method is to harvest image databases from web. We can automatically generate a large number of images for a specified object. By applying concept of data mining and the algorithm from data mining which is used for extraction of data or harvesting images. A multimodal approach employing text ,metadata and visual  features is used to gather many high-quality images from the web. The modules can be made to find query images by selecting images where nearby text is top ranked by the topic i.e., formation of image clusters then download associate images by using approaches like web search, image search and Google images. Apply re-ranking algorithm and then filtering process to harvest the images.Currently, image search gives a very low precision (only about 4%) and is not used for the harvesting experiments. Since the movements of the technologies are growing rapidly the kinds of work also need to be grown up. This work shows an approach to harvest a large number of images of a particular class automatically and to achieve this with high precision by providing training databases so that a new object model can be learned effortlessly. Many other tools also are available for harvesting images from web .An approach in this paper is original and up to the mark. Keywords: Legacy code, re-engineering, class diagrams, Aggregation, Association, Attribute

Low-level laser therapy in the management of muscle fatigue caused after long Endodontic procedure

The masticatory muscles may undergo fatigue due to prolonged mouth opening during the endodontic procedures. Low-level laser can be used to treat muscle fatigue due its capacity to produce reactive oxygen species and improve function of mitochondria. Aim: To determine the effectiveness of low-level laser therapy in the management of masticatory muscle fatigue caused after long endodontic procedure under Local anesthesia. MATERIAL AND METHODS: 44 patients complaining of reduced mouth opening and pain while mouth opening, after long endodontic therapy were considered for the study and were randomly allocated into study and control group. In the study group, low-level laser was applied while patients of control group didn't receive any therapy. In the study group, Visual analogue scale (VAS) score of pain was taken after endodontic therapy, immediately after laser therapy and 4 hours after endodontic therapy. Mouth opening of the patients was measured, before and after endodontic procedure and immediately after laser therapy. In the control group, VAS score of pain was recorded immediately after endodontic therapy and 4 hours after endodontic therapy. Statistical analysis used: ANOVA test and un-paired t-test was used for the data analysis. RESULTS: When both groups were compared, a statistically significant (P=0.0000) reduction with fatigue was found. CONCLUSIONS: The low-level laser can be a useful procedure immediately post long endodontic procedure causing masticatory muscle fatigue. Hence, this therapy can be considered as an add-on therapeutic procedure along with prolonged endodontic appointments to relieve the patient from the discomfort. Key words:Muscle fatigue, Masticatory muscles, Low-level laser therapy

Superconductivity in single crystals of a quasi-one dimensional infinite chain cuprate Srx_xCa1−x_{1-x}CuO2_2 at 90 K

Although there is no complete theory of high temperature superconductivity, the importance of CuO$_2$ planes in cuprate superconductors is confirmed from both theory and experiments. Strong Coulomb repulsion between electrons on the CuO$_2$ plane makes the resultant electron system highly correlated and a difficult problem to solve since exact solutions of many-body Hamiltonian in two dimensions do not exist. If however, superconductivity can arise in structures having chains rather than planes and having a high critical temperature, then the high temperature superconductivity problem could become more tractable since exact solutions in one dimension do exist. In this paper, we report the observation of bulk superconductivity in single crystals of a cuprate Sr$_x$Ca$_{1-x}$CuO$_2$ at very high critical temperature, T$_c$, of $\sim$ 90 K whose structure reveals the presence of infinite double chains of Cu-O-Cu-O instead of CuO$_2$ planes, thus, ensuring quasi-one dimensional superconductivity. Bulk superconducting behaviour was observed in \textit{dc} magnetisation, \textit{ac} susceptibility as well as resistance measurements. The observation of bulk superconductivity in Sr$_x$Ca$_{1-x}$CuO$_2$ having chains of Cu-O-Cu-O rather than planes of CuO$_2$ at a high T$_c$ of 90 K is expected to profoundly impact our understanding of high temperature superconductivity.Comment: 15 pages, 4 figure

A Review On: Carica Papaya

<p>Fruits and vegetables are an important part of a healthy diet. In this regard, Carica papaya (Papaya) is one of 4,444 species native to Mexico and northern South America, and now naturalized in many regions of the world, including 4,444 tropical and subtropical regions. Papaya pulp is rich in minerals and many vitamins, and the seeds contain glucosinolates, tocopherols, carotenoids, and benzyl isothiocyanates. Due to the presence of phenols, flavonoids, and alkaloids as the main phytochemicals, papaya is known for its numerous activities, including. More specifically, papaya fruit is used in the production of numerous processed foods, including jams, jellies, pickles, candied fruits, purees, concentrates, and canned slices/pieces. Fruit peels are used in cosmetics, wastewater treatment, animal feed, and as a binder in ceramics. Papaya leaves, bark, roots, and seeds have also been shown to have insecticidal and repellent properties. This review mainly focuses on the different phytochemicals found in different parts of Plant C. Papaya and its pharmacological properties and various other uses. To prepare this review, a literature search was conducted using classic herbal and fruit books. Online scientific databases (e.g. PubMed, Scopus, Sci Finder, Science Direct, Web of Science, Wiley Online, Google Scholar, ResearchGate, and other search engines) were searched up to October 2020 for valid reports; We found studies and surveys. All literature on the proposed topic was analyzed and summarized in this review article.</p&gt

Chloroplasts play a central role in facilitating MAMP‐triggered immunity, pathogen suppression of immunity and crosstalk with abiotic stress

Microbe‐associated molecular pattern (MAMP)‐triggered immunity (MTI) research has traditionally centred around signal transduction pathways originating from activated membrane‐localized pattern recognition receptors (PRRs), culminating in nuclear transcription and posttranslational modifications. More recently, chloroplasts have emerged as key immune signalling hubs, playing a central role in integrating environmental signals. Notably, MAMP recognition induces chloroplastic reactive oxygen species (cROS) that is suppressed by pathogen effectors, which also modify the balance of chloroplast‐synthesized precursors of the defence hormones, jasmonic acid, salicylic acid (SA) and abscisic acid. This study focuses on how well‐characterized PRRs and coreceptors modulate chloroplast physiology, examining whether diverse signalling pathways converge to similarly modulate chloroplast function. Pretreatment of receptor mutant plants with MAMP and D(Damage)AMP peptides usually protect against effector modulation of chlorophyll fluorescence and prevent Pseudomonas syringae effector‐mediated quenching of cROS and suppression of maximum dark‐adapted quantum efficiency (the ratio of variable/maximum fluorescence [Fv/Fm]). The MTI coreceptor double mutant, bak1‐5/bkk1‐1, exhibits a remarkable decrease in Fv/Fm compared to control plants during infection, underlining the importance of MTI‐mediated signalling in chloroplast immunity. Further probing the role of the chloroplast in immunity, we unexpectedly found that even moderate changes in light intensity can uncouple plant immune signalling

Spatiotemporal patterns of intracellular Ca 2+ signalling govern hypo‐osmotic stress resilience in marine diatoms

This is the final version. Available from Wiley via the DOI in this record. Diatoms are globally important phytoplankton that dominate coastal and polar‐ice assemblages. These environments exhibit substantial changes in salinity over dynamic spatiotemporal regimes. Rapid sensory systems are vital to mitigate the harmful consequences of osmotic stress. Population‐based analyses have suggested that Ca2+ signalling is involved in diatom osmotic sensing. However, mechanistic insight of the role of osmotic Ca2+ signalling is limited. Here, we show that Phaeodactylum Ca2+ elevations are essential for surviving hypo‐osmotic shock. Moreover, employing novel single‐cell imaging techniques we have characterised real‐time Ca2+ signalling responses in single diatom cells to environmental osmotic perturbations. We observe that intracellular spatiotemporal patterns of osmotic‐induced Ca2+ elevations encode vital information regarding the nature of the osmotic stimulus. Localised Ca2+ signals evoked by mild or gradual hypo‐osmotic shocks are propagated globally from the apical cell tips, enabling fine‐tuned cell volume regulation across the whole cell. Finally, we demonstrate that diatoms adopt Ca2+‐independent and dependent mechanisms for osmoregulation. We find that efflux of organic osmolytes occurs in a Ca2+‐independent manner, but this response is insufficient to mitigate cell damage during hypo‐osmotic shock. By comparison, Ca2+‐dependent signalling is necessary to prevent cell bursting via precise coordination of K+ transport, and therefore is likely to underpin survival in dynamic osmotic environments.Natural Environment Research Council (NERC)H2020 European Research Council (ERC

Cold-induced [Ca2+](cyt) elevations function to support osmoregulation in marine diatoms

Diatoms are a group of microalgae that are important primary producers in a range of open ocean, freshwater, and intertidal environments. The latter can experience substantial long- and short-term variability in temperature, from seasonal variations to rapid temperature shifts caused by tidal immersion and emersion. As temperature is a major determinant in the distribution of diatom species, their temperature sensory and response mechanisms likely have important roles in their ecological success. We examined the mechanisms diatoms use to sense rapid changes in temperature, such as those experienced in the intertidal zone. We found that the diatoms Phaeodactylum tricornutum and Thalassiosira pseudonana exhibit a transient cytosolic Ca2+ ([Ca2+]cyt) elevation in response to rapid cooling, similar to those observed in plant and animal cells. However, [Ca2+]cyt elevations were not observed in response to rapid warming. The kinetics and magnitude of cold-induced [Ca2+]cyt elevations corresponded with the rate of temperature decrease. We did not find a role for the [Ca2+]cyt elevations in enhancing cold tolerance but showed that cold shock induces a Ca2+-dependent K+ efflux and reduces mortality of P. tricornutum during a simultaneous hypo-osmotic shock. As intertidal diatom species may routinely encounter simultaneous cold and hypo-osmotic shocks during tidal cycles, we propose that cold-induced Ca2+ signaling interacts with osmotic signaling pathways to aid in the regulation of cell volume. Our findings provide insight into the nature of temperature perception in diatoms and highlight that cross-talk between signaling pathways may play an important role in their cellular responses to multiple simultaneous stressors