Carboxyhemoglobin in Cardiac Surgery Patients and Its Association with Risk Factors and Biomarkers of Hemolysis.

BACKGROUND: Cardiac surgery with cardiopulmonary bypass (CPB) is associated with hemolysis. Yet, there is no easily available and frequently measured marker to monitor this hemolysis. However, carboxyhemoglobin (CO-Hb), formed by the binding of carbon monoxide (a product of heme breakdown) to hemoglobin, may reflect such hemolysis. We hypothesized that CO-Hb might increase after cardiac surgery and show associations with operative risk factors and indirect markers for hemolysis. METHODS: We conducted a retrospective descriptive cohort study of data from on-pump cardiac surgery patients. We analyzed temporal changes in CO-Hb levels and applied a generalized linear model to assess patient characteristics associated with peak CO-Hb levels. Additionally, we examined their relationship with red blood cell (RBC) transfusion and bilirubin levels. RESULTS: We studied 38,487 CO-Hb measurements in 1735 patients. CO-Hb levels increased significantly after cardiac surgery, reaching a peak CO-Hb level 2.1 times higher than baseline (P < .001) at a median of 17 hours after the initiation of surgery. Several factors were independently associated with higher peak CO-Hb, including age (P < .001), preoperative respiratory disease (P = .001), New York Heart Association Class IV (P = .019), the number of packed RBC transfused (P < .001), and the duration of CPB (P = .002). Peak CO-Hb levels also significantly correlated with postoperative total bilirubin levels (Rho = 0.27, P < .001). CONCLUSIONS: CO-Hb may represent a readily obtainable and frequently measured biomarker that has a moderate association with known biomarkers of and risk factors for hemolysis in on-pump cardiac surgery patients. These findings have potential clinical implications and warrant further investigation.

Uncovering the genomic regions underlying grain iron and zinc content using genome-wide association mapping in finger millet.

Finger millet, being rich source of essential minerals like iron and zinc, is an ideal model to identify candidate genes contributing to high grain iron content (GIC) and zinc content (GZC) in plants. Hence, finger millet diversity panel comprised of 202 genotypes was evaluated in two geographical locations and found to have a wide variation for GIC and GZC. A genome-wide association study using 2977 single nucleotide polymorphism (SNP) markers identified reliable marker-trait associations (MTAs). The use of general linear model (GLM) and mixed linear model (MLM) approaches revealed 5 and 8 common MTAs linked to GIC and GZC, respectively, for both Almora and Pantnagar locations, with a high level of significance (P < 0.01). However, 12 significant MTAs were found to be linked with GIC for Pantnagar location alone. The MTAs were associated with specific genes that produce ferritin (Fer1), iron-regulated transporter-like protein (IRT2), and yellow stripe-like 2 proteins (YSL2). These genes are likely linked to GIC variation in finger millet. Additionally, the variation in GZC in finger millet was connected to genes that encode zinc transporters, namely ZIP1 protein (ZIP1) and ZTP29-like protein (ZTP29). Compared to low GIC and GZC genotypes, high GIC and GZC genotypes exhibited greater relative expression of these genes. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-023-03889-1.

Detection of COVID-19 Infection in CT and X-ray images using transfer learning approach.

BACKGROUND: The infection caused by the SARS-CoV-2 (COVID-19) pandemic is a threat to human lives. An early and accurate diagnosis is necessary for treatment. OBJECTIVE: The study presents an efficient classification methodology for precise identification of infection caused by COVID-19 using CT and X-ray images. METHODS: The depthwise separable convolution-based model of MobileNet V2 was exploited for feature extraction. The features of infection were supplied to the SVM classifier for training which produced accurate classification results. RESULT: The accuracies for CT and X-ray images are 99.42% and 98.54% respectively. The MCC score was used to avoid any mislead caused by accuracy and F1 score as it is more mathematically balanced metric. The MCC scores obtained for CT and X-ray were 0.9852 and 0.9657, respectively. The Youden's index showed a significant improvement of more than 2% for both imaging techniques. CONCLUSION: The proposed transfer learning-based approach obtained the best results for all evaluation metrics and produced reliable results for the accurate identification of COVID-19 symptoms. This study can help in reducing the time in diagnosis of the infection.

Automatic breast lesion segmentation in phase preserved DCE-MRIs.

We offer a framework for automatically and accurately segmenting breast lesions from Dynamic Contrast Enhanced (DCE) MRI in this paper. The framework is built using max flow and min cut problems in the continuous domain over phase preserved denoised images. Three stages are required to complete the proposed approach. First, post-contrast and pre-contrast images are subtracted, followed by image registrations that benefit to enhancing lesion areas. Second, a phase preserved denoising and pixel-wise adaptive Wiener filtering technique is used, followed by max flow and min cut problems in a continuous domain. A denoising mechanism clears the noise in the images by preserving useful and detailed features such as edges. Then, lesion detection is performed using continuous max flow. Finally, a morphological operation is used as a post-processing step to further delineate the obtained results. A series of qualitative and quantitative trials employing nine performance metrics on 21 cases with two different MR image resolutions were used to verify the effectiveness of the proposed method. Performance results demonstrate the quality of segmentation obtained from the proposed method.

Differential proteomic profile of X- and Y- sorted Sahiwal bull semen.

The identification of differential proteins between X- and Y-sperm may be useful for immunological sexing of sperm. Hence, the present study was aimed to compare the protein profile of X- and Y-sorted Sahiwal bull semen using SDS-PAGE and Liquid Chromatography coupled with Mass Spectrometry (Nano LC-MS). Semen sample (n = 6) were categorized into three groups i.e., group I (X-sorted), group II (Y-sorted) and control group (both X- and Y- sperms). SDS PAGE revealed specific proteins of molecular weight between 18 and 24 kDa and between 30 and 37 kDa were present in X-sorted sperms. Also, band corresponding to 25 kDa was specific to Y-sorted sperms. Data obtained from Nano LC/MS is analysed by search engine database i.e., MASCOT and SEQUEST HT. Total, 241 proteins were identified, out of which 113 were differentially expressed between X- and Y-sorted sperms, in which 54 proteins showed at least two unique peptides. Out of 54 proteins, 27 were upregulated in X-sorted sample, 3 were upregulated in Y-sorted sample and 24 were differentially downregulated. Highly upregulated protein in X-sperm viz. Armadillo repeat containing 12 protein, NDC1 transmembrane nucleoporin, ß-nerve growth factor, C-type natriuretic peptide, Nucleobindin-2, Phosphoglycerate mutase 2, Calmodulin along with one uncharacterised protein having accession number F1MN9 may have potential to be used as biomarker for separating X and Y sperm.

Mainstreaming Barahnaja cultivation for food and nutritional security in the Himalayan region.

Selective production of input intensive crops in the present scenario have resulted in productivity stagnation or even decline due to excessive usage of chemicals, affecting the farmers economically. Sustainable agriculture is the way to increase agricultural productivity and economic prosperity by protecting all natural resources. It maintains a balance of soil fertility with crop productivity and nutritional quality. The mixed cropping systems followed earlier in different regions according to their tradition, climatic zone, soil and water conditions were climate-smart approaches to sustainable food production based on practical experiences over the years of old generations. The life style changes, imbalance in farming system in last 70 years and demand for more food as well as declining land resources resulted in intensive agriculture. Besides, least returns and less demand of ethnic crops gave more preference to major staple food crops. Barahnaja is a traditional orphan crops based mixed cropping system practiced in Himalayan region due to its sustainability and assured crop harvest during erratic weather conditions. This traditional farming method is an exemplary scientific approach to derive innovations with respect to productivity, quality, plant soil interactions and organic agriculture. The main focus of the review is to substantiate the characteristics of the traditional mixed cropping system by describing the advantages of the system and opportunities for scientific innovation towards new knowledge and sustainability.

An Omics Study of Iron and Zinc Homeostasis in Finger Millet: Biofortified Foods for Micronutrient Deficiency in an Era of Climate Change?

The future of food and sustainability of the staple food crops are of utmost importance in the 21st century. Micronutrient deficiency, for example, in iron and zinc, is a common cause of human diseases. Mineral content of the staple food crops has therefore crosscutting importance for food engineering and planetary health. Finger millet, a staple food of agricultural importance worldwide, is rich in iron and zinc, and an ideal model to study the prospects of biofortified foods in times of climate change. We report here a multiomics study of the iron and zinc homeostasis in the finger millet. We identified and characterized 15 candidate genes potentially involved in iron and zinc homeostasis pathways in the finger millet. Structural and functional annotation of the candidate genes revealed a high similarity index with their respective homologs (Oryza sativa, Triticum aestivum, Zea mays, Hordeum vulgare, and Setaria italica). Transcriptome-wide expression analysis showed that genes involved in uptake and translocation of iron and zinc are highly expressed in the GP-1 genotype, while those involved in bioavailability of iron and zinc are expressed more in the GP-45 genotype of the finger millet. In conclusion, finger millet, being a stress-resilient crop, utilizes a combination of strategies in iron and zinc homeostasis pathway, which appear to play an important role in food crop acquisition of iron and zinc, despite environmentally limiting conditions. These data offer molecular insights on iron and zinc accumulation and paves the way for new strategies toward staple food crop with mineral biofortification.

Computational analysis of microarray data of Arabidopsis thaliana challenged with Alternaria brassicicola for identification of key genes in Brassica.

BACKGROUND: Alternaria blight, a recalcitrant disease caused by Alternaria brassicae and Alternaria brassicicola, has been recognized for significant losses of oilseed crops especially rapeseed-mustard throughout the world. Till date, no resistance source is available against the disease; hence, plant breeding methods cannot be used to develop disease-resistant varieties. Therefore, in the present study, efforts have been made to identify resistance and defense-related genes as well as key components of JA-SA-ET-mediated pathway involved in resistance against Alternaria brasscicola through computational analysis of microarray data and network biology approach. Microarray profiling data from wild type and mutant Arabidopsis plants challenged with Alternaria brassicicola along with control plant were obtained from the Gene Expression Omnibus (GEO) database. The data analysis, including DEGs extraction, functional enrichment, annotation, and network analysis, was used to identify genes associated with disease resistance and defense response. RESULTS: A total of 2854 genes were differentially expressed in WT9C9; among them, 1327 genes were upregulated and 1527 genes were downregulated. A total of 1159 genes were differentially expressed in JAM9C9; among them, 809 were upregulated and 350 were downregulated. A total of 2516 genes were differentially expressed in SAM9C9; among them, 1355 were upregulated and 1161 were downregulated. A total of 1567 genes were differentially expressed in ETM9C9; among them, 917 were upregulated and 650 were downregulated. Besides, a total of 2965 genes were differentially expressed in contrast WT24C24; among them, 1510 genes were upregulated and 1455 genes were downregulated. A total of 4598 genes were differentially expressed in JAM24C24; among them, 2201 were upregulated and 2397 were downregulated. A total of 3803 genes were differentially expressed in SAM24C24; among them, 1819 were upregulated and 1984 were downregulated. A total of 4164 genes were differentially expressed in ETM24C24; among them, 1895 were upregulated and 2269 were downregulated. The upregulated genes of Arabidopsis thaliana were mapped and annotated with CDS sequences of Brassica rapa obtained from PlantGDB database. Additionally, PPI network of these genes were constructed to investigate the key components of hormone-mediated pathway involved in resistance during pathogenesis. CONCLUSION: The obtained information from present study can be used to engineer resistance to Alternaria blight caused by Alternaria brasscicola through molecular breeding or genetic manipulation-based approaches for improving Brassica oilseed productivity.

Transcriptome wide identification and characterization of regulatory genes involved in EAA metabolism and validation through expression analysis in different developmental stages of finger millet spikes.

Finger millet is a rich source of seed storage proteins (SSPs). Various regulatory genes play an important role to maintain the quality and accumulation of SSPs in crop seeds. In the present study, nine regulatory genes of EAAs metabolic pathway, i.e., aspartate kinase, homoserine dehydrogenase, threonine synthase, threonine dehydratase, dihydrodipicolinate synthase, cystathionine γ synthase, anthranilate synthase, acetolactate synthase and lysine 2-oxoglutarato reductase/saccharopine dehydrogenase (LOR/SD) were identified from the transcriptomic data of developing spikes of two finger millet genotypes, i.e., GP-45 and GP-1. Results of sequence alignment search and motif/domain analysis showed high similarity of nucleotide sequences of identified regulatory genes with their respective homologs in rice. Results of promoter analysis revealed the presence of various cis-regulatory elements, like nitrogen responsive cis-elements (O2-site and GCN4), light responsive cis-elements, and stress responsive cis-elements. The presence of nine regulatory genes identified from the transcriptomic data of GP-45 and GP-1 was further confirmed by real time expression analysis in high and low protein containing genotypes, i.e., GE-3885 and GE-1437. Results of real time expression analysis showed significantly higher expression (p ≤ 0.01) of regulatory genes in GE-3885 rather than GE-1437 under control and treatment condition. Crude protein content of GE-3885 was found to be significantly higher (p ≤ 0.01) in comparison to GE-1437 under control condition, while under treatment condition GE-1437 was found to be more responsive to KNO3 treatment rather than GE-3885.

Role of calreticulin in biotic and abiotic stress signalling and tolerance mechanisms in plants.

Calreticulin (CRT) is calcium binding protein of endoplasmic reticulum (ER) which performs plethora of functions besides it's role as molecular chaperone. Among the three different isoforms of this protein, CRT3 is most closely related to primitive CRT gene of higher plants. Based on their distinct structural and functional organisation, the plant CRTs have been known to contain three different domains: N, P and the C domain. The domain organisation and various biochemical characterstics of plant and animal CRTs are common with the exception of some differences. In plant calreticulin, the important N-glycosylation site(s) are replaced by the glycan chain(s) and several consensus sequences for in vitro phosphorylation by protein kinase CK2 (casein kinase-2), are also present unlike the animal calreticulin. Biotic and abiotic stresses play a significant role in bringing down the crop production. The role of various phytohormones in defense against fungal pathogens is well documented. CRT3 has been reported to play important role in protecting the plants against fungal and bacterial pathogens and in maintaining plant innate immunity. There is remarkable crosstalk between CRT mediated signalling and biotic, abiotic stress, and phytohormone mediated signalling pathways The role of CRT mediated pathway in mitigating biotic and abiotic stress can be further explored in plants so as to strategically modify it for development of stress tolerant plants.

Complementary Proteomics, Genomics approaches identifies potential pathogenicity/virulence factors in Tilletia indica induced under the influence of host factor.

Karnal bunt disease of wheat is incited by quarantine fungal pathogen T. indica. Till date, there is little information on the pathogenic mechanisms involved in Karnal bunt. In order to understand the molecular mechanisms of disease pathogenesis, highly aggressive T. indica TiK isolate was cultured in the presence of host factor extracted from developing spikes of wheat variety WH-542. Modulation in protein profile of mycelial proteins and secretome from TiK cultured in the absence and presence of host factor was analyzed by 2-DE. Fifteen and twenty nine protein spots were up-regulated/differentially regulated in the proteome of mycelial and secreted proteins, respectively and identified using MALDI-TOF/TOF. Identified proteins are involved in suppression of host defense responses, lignin degradation of plant cell wall, penetration, adhesion of pathogen to host tissues, pathogen mediated reactive oxygen species generation, hydrolytic enzymes, detoxification of host generated reactive oxygen species. Further, integration of proteomic and genomic analysis has led to candidate pathogenicity/virulence factors identification. They were functionally annotated by sequence as well as structure based analysis. In this study, complementation of proteomics and genomics approaches resulted in novel pathogenicity/virulence factor(s) identification in T. indica.

Automatic and fast segmentation of breast region-of-interest (ROI) and density in MRIs.

Accurate segmentation of the breast region of interest (BROI) and breast density (BD) is a significant challenge during the analysis of breast MR images. Most of the existing methods for breast segmentation are semi-automatic and limited in their ability to achieve accurate results. This is because of difficulties in removing landmarks from noisy magnetic resonance images (MRI) due to similar intensity levels and the close connection to BROI. This study proposes an innovative, fully automatic and fast segmentation approach to identify and remove landmarks such as the heart and pectoral muscles. The BROI segmentation is carried out with a framework consisting of three major steps. Firstly, we use adaptive wiener filtering and k-means clustering to minimize the influence of noises, preserve edges and remove unwanted artefacts. The second step systematically excludes the heart area by utilizing active contour based level sets where initial contour points are determined by the maximum entropy thresholding and convolution method. Finally, a pectoral muscle is removed by using morphological operations and local adaptive thresholding on MR images. Prior to the elimination of the pectoral muscle, the MR image is sub divided into three sections: left, right, and central based on the geometrical information. Subsequently, a BD segmentation is achieved with 4 level fuzzy c-means (FCM) thresholding on the denoised BROI segmentation. The proposed method is validated using the 1350 breast images from 15 female subjects. The pixel-based quantitative analysis showed excellent segmentation results when compared with manually drawn BROI and BD. Furthermore, the presented results in terms of evaluation matrices: Acc, Sp, AUC, MR, P, Se and DSC demonstrate the high quality of segmentations using the proposed method. The average computational time for the segmentation of BROI and BD is 1 minute and 50 seconds.

Augmentation of crop productivity through interventions of omics technologies in India: challenges and opportunities.

With the continuous increase in the population of developing countries and decline of natural resources, there is an urgent need to qualitatively and quantitatively augment crop productivity by using new tools and technologies for improvement of agriculturally important traits. The new scientific and technological omics-based approaches have enabled us to deal with several issues and challenges faced by modern agricultural system and provided us novel opportunities for ensuring food and nutritional security. Recent developments in sequencing techniques have made available huge amount of genomic and transcriptomic data on model and cultivated crop plants including Arabidopsis thaliana, Oryza sativa, Triticum aestivum etc. The sequencing data along with other data generated through several omics platforms have significantly influenced the disciplines of crop sciences. Gene discovery and expression profiling-based technologies are offering enormous opportunities to the scientific community which can now apply marker-assisted selection technology to assess and enhance diversity in their collected germplasm, introgress essential traits from new sources and investigate genes that control key traits of crop plants. Utilization of omics science and technologies for crop productivity, protection and management has recently been receiving a lot of attention; the majority of the efforts have been put into signifying the possible applications of various omics technologies in crop plant sciences. This article highlights the background of challenges and opportunities for augmentation of crop productivity through interventions of omics technologies in India.

Molecular modeling, docking and protein-protein interaction analysis of MAPK signalling cascade involved in Camalexin biosynthesis in Brassica rapa.

Phytoalexins are small antimicrobial molecules synthesized and accumulated by plants upon exposure to pathogens. Camalexin is an indole-derived phytoalexin, which is accumulated in plants including Arabidopsis thaliana, and other Brassicaceae, which plays a major role in disease resistance against fungal pathogens. The productivity of Brassica crops is adversely affected by Alternaria blight disease, which is caused by Alternaria brassicae. In Arabidopsis thaliana, MAP kinase signalling cascade is known to be involved in synthesis of camalexin, which contributes to disease resistance against a necrtrophic fungal pathogen, Botrytis cinerea. In the present study, MAPK signalling cascade leading to biosynthesis of camalexin that triggers defense responses in B. rapa upon exposure to the most devastating nectrophic fungus, Alternaria brassicae has been elucidated with the help of previously reported MAPK cascade in Arabidopsis thaliana, Molecular modelling, docking, and protein-protein interaction analysis of MAP kinases retrieved from Brassica rapa genome have been carried out to reveal the above cascade. The tertiary structure prediction of MAPKs obtained through molecular modelling revealed that all the protein models fulfil the criteria of being the stable structures. The molecular docking of predicted models for elucidating potential partners of MAPKs revealed strong interactions between MKK1, MKK4, MKK5, MAPK3 and MAPK6 with MKK9. The MAPK signalling cascade also shows different genes that express and play major role in camalexin biosynthesis in B. rapa during defense response to A. brassicae. The understanding of MAPK defense signaling pathway in B. rapa against devastating fungal pathogen Alternaria brassicae would help in devising strategies to develop disease resistance in Brassica crops.

Integrated proteomics, genomics, metabolomics approaches reveal oxalic acid as pathogenicity factor in Tilletia indica inciting Karnal bunt disease of wheat.

Tilletia indica incites Karnal bunt (KB) disease in wheat. To date, no KB resistant wheat cultivar could be developed due to non-availability of potential biomarkers related to pathogenicity/virulence for screening of resistant wheat genotypes. The present study was carried out to compare the proteomes of T. indica highly (TiK) and low (TiP) virulent isolates. Twenty one protein spots consistently observed as up-regulated/differential in the TiK proteome were selected for identification by MALDI-TOF/TOF. Identified sequences showed homology with fungal proteins playing essential role in plant infection and pathogen survival, including stress response, adhesion, fungal penetration, invasion, colonization, degradation of host cell wall, signal transduction pathway. These results were integrated with T. indica genome sequence for identification of homologs of candidate pathogenicity/virulence related proteins. Protein identified in TiK isolate as malate dehydrogenase that converts malate to oxaloacetate which is precursor of oxalic acid. Oxalic acid is key pathogenicity factor in phytopathogenic fungi. These results were validated by GC-MS based metabolic profiling of T. indica isolates indicating that oxalic acid was exclusively identified in TiK isolate. Thus, integrated omics approaches leads to identification of pathogenicity/virulence factor(s) that would provide insights into pathogenic mechanisms of fungi and aid in devising effective disease management strategies.

Secretome Analysis Identifies Potential Pathogenicity/Virulence Factors of Tilletia indica, a Quarantined Fungal Pathogen Inciting Karnal Bunt Disease in Wheat.

Tilletia indica is a smut fungus that incites Karnal bunt in wheat. It has been considered as quarantine pest in more than 70 countries. Despite its quarantine significance, there is meager knowledge regarding the molecular mechanisms of disease pathogenesis. Moreover, various disease management strategies have proven futile. Development of effective disease management strategy requires identification of pathogenicity/virulence factors. With this aim, the present study was conducted to compare the secretomes of T. indica isolates, that is, highly (TiK) and low (TiP) virulent isolates. About 120 and 95 protein spots were detected reproducibly in TiK and TiP secretome gel images. Nineteen protein spots, which were consistently observed as upregulated/differential in the secretome of TiK isolate, were selected for their identification by MALDI-TOF/TOF. Identified proteins exhibited homology with fungal proteins playing important role in fungal adhesion, penetration, invasion, protection against host-derived reactive oxygen species, production of virulence factors, cellular signaling, and degradation of host cell wall proteins and antifungal proteins. These results were complemented with T. indica genome sequence leading to identification of candidate pathogenicity/virulence factors homologs that were further subjected to sequence- and structure-based functional annotation. Thus, present study reports the first comparative secretome analysis of T. indica for identification of pathogenicity/virulence factors. This would provide insights into pathogenic mechanisms of T. indica and aid in devising effective disease management strategies.

Identification and characterization of finger millet OPAQUE2 transcription factor gene under different nitrogen inputs for understanding their role during accumulation of prolamin seed storage protein.

In this study, we report the isolation and characterization of the mRNA encoding OPAQUE2 (O2) like TF of finger millet (FM) (Eleusine coracana) (EcO2). Full-length EcO2 mRNA was isolated using conserved primers designed by aligning O2 mRNAs of different cereals followed by 3' and 5' RACE (Rapid Amplification of cDNA Ends). The assembled full-length EcO2 mRNA was found to contain an ORF of 1248-nt coding the 416 amino acids O2 protein. Domain analysis revealed the presence of the BLZ and bZIP-C domains which is a characteristic feature of O2 proteins. Phylogenetic analysis of EcO2 protein with other bZIP proteins identified using finger millet transcriptome data and O2 proteins of other cereals showed that EcO2 shared high sequence similarity with barley BLZ1 protein. Transcripts of EcO2 were detected in root, stem, leaves, and seed development stages. Furthermore, to investigate nitrogen responsiveness and the role of EcO2 in regulating seed storage protein gene expression, the expression profiles of EcO2 along with an α-prolamin gene were studied during the seed development stages of two FM genotypes (GE-3885 and GE-1437) differing in grain protein content (13.8 and 6.2%, respectively) grown under increasing nitrogen inputs. Compared to GE-1437, the EcO2 was relatively highly expressed during the S2 stage of seed development which further increased as nitrogen input was increased. The Ecα-prolamin gene was strongly induced in the high protein genotype (GE-3885) at all nitrogen inputs. These results indicate the presence of nitrogen responsiveness regulatory elements which might play an important role in accumulating protein in FM genotypes through modulating EcO2 expression by sensing plant nitrogen status.

Modeling of the jasmonate signaling pathway in Arabidopsis thaliana with respect to pathophysiology of Alternaria blight in Brassica.

The productivity of Oilseed Brassica, one of the economically important crops of India, is seriously affected by the disease, Alternaria blight. The disease is mainly caused by two major necrotrophic fungi, Alternaria brassicae and Alternaria brassicicola which are responsible for significant yield losses. Till date, no resistant source is available against Alternaria blight, hence plant breeding methods can not be used to develop disease resistant varieties. Jasmonate mediated signalling pathway, which is known to play crucial role during defense response against necrotrophs, could be strengthened in Brassica plants to combat the disease. Since scanty information is available in Brassica-Alternaria pathosystems at molecular level therefore, in the present study efforts have been made to model jasmonic acid pathway in Arabidopsis thaliana to simulate the dynamic behaviour of molecular species in the model. Besides, the developed model was also analyzed topologically for investigation of the hubs node. COI1 is identified as one of the promising candidate genes in response to Alternaria and other linked components of plant defense mechanisms against the pathogens. The findings from present study are therefore informative for understanding the molecular basis of pathophysiology and rational management of Alternaria blight for securing food and nutritional security.

In Silico Identification of Mimicking Molecules as Defense Inducers Triggering Jasmonic Acid Mediated Immunity against Alternaria Blight Disease in Brassica Species.

Alternaria brassicae and Alternaria brassicicola are two major phytopathogenic fungi which cause Alternaria blight, a recalcitrant disease on Brassica crops throughout the world, which is highly destructive and responsible for significant yield losses. Since no resistant source is available against Alternaria blight, therefore, efforts have been made in the present study to identify defense inducer molecules which can induce jasmonic acid (JA) mediated defense against the disease. It is believed that JA triggered defense response will prevent necrotrophic mode of colonization of Alternaria brassicae fungus. The JA receptor, COI1 is one of the potential targets for triggering JA mediated immunity through interaction with JA signal. In the present study, few mimicking compounds more efficient than naturally occurring JA in terms of interaction with COI1 were identified through virtual screening and molecular dynamics simulation studies. A high quality structural model of COI1 was developed using the protein sequence of Brassica rapa. This was followed by virtual screening of 767 analogs of JA from ZINC database for interaction with COI1. Two analogs viz. ZINC27640214 and ZINC43772052 showed more binding affinity with COI1 as compared to naturally occurring JA. Molecular dynamics simulation of COI1 and COI1-JA complex, as well as best screened interacting structural analogs of JA with COI1 was done for 50 ns to validate the stability of system. It was found that ZINC27640214 possesses efficient, stable, and good cell permeability properties. Based on the obtained results and its physicochemical properties, it is capable of mimicking JA signaling and may be used as defense inducers for triggering JA mediated resistance against Alternaria blight, only after further validation through field trials.