R. K. Gaur

Complete nucleotide sequence of a begomovirus associated with satellites molecules infecting a new host Tagetes patula in India

In the year 2012 leaf curl disease was observed on Marigold (Tagetes patula) in Lakshmangrh, Sikar province of India. Affected plants were severely stunted with apical leaf curl and crinkled leaves, symptoms typical of begomovirus infection. This is the first report of complete nucleotide sequence of a begomovirus associated with satellites molecules infecting a new host Tagetes patula in India.

Effect of nitric oxide signaling in bacterial‑treated soybean plant under salt stress

To understand protective roles of nitric oxide against salt stress, the effects of exogenous sodium nitroprusside on activities of lipoxygenase, peroxidase, phenylalanine ammonialyase, catalase, superoxide dismutase enzymes, proline accumulation, and distribution of sodium in soybean plants under salt were determined. Application of sodium nitroprussidexa0+xa0bacterium enhanced plant growth-promotion characteristics, activities of different enzymes, and proline accumulation in the presence of sodium nitroprusside under salt stress. Treatment with NaCl at 200xa0mM and sodium nitroprusside (0.1xa0mM) reduced Na+ levels but increased K+ levels in leaves in comparison with the NaCl-treated plants. Correspondingly, the plants treated with exogenous sodium nitroprusside and NaCl maintained a lower ratio of [Na+]/[K+] in NaCl-stressed plants.

Recognition of Errors in the Refinement and Validation of Three-Dimensional Structures of AC1 Proteins of Begomovirus Strains by Using ProSA-Web

The structural model of begomovirus AC1 protein is useful for understanding biological function at molecular level and docking study. For this study we have used the ProSA program (Protein Structure Analysis) tool to establish the structure prediction and modeling of protein. This tool was used for refinement and validation of experimental protein structures. Potential problems of protein structures based on energy plots are easily seen by ProSA and are displayed in a three-dimensional manner. In the present study we have selected different AC1 proteins of begomovirus strains (YP_003288785, YP_002004579, and YP_003288773) for structural analysis and display of energy plots that highlight potential problems spotted in protein structures. The 3D models of Rep proteins with recognized errors can be effectively used for in silico docking study for development of potential ligand molecules against begomovirus infection.

First report of airborne begomovirus infection in Melia azedarach (Pride of India), an ornamental tree in India

The begomovirus infection in plants has been widely reported throughout the world. The chief carrier of this virus is the whitefly. All of the reports, however, concern plants that grow at a stumpy height from the ground; moreover, the whitefly transmits the begomovirus infection to plants at this low height only by residing under their leaves. To date, there has been no record of the begomovirus infection in trees as the prevalence of the whitefly at tree level is unlikely. For this reason, this study focuses on and presents the first report of airborne begomovirus infection in an ornamental tree—the Melia azedarach (or Pride of India) found on the Indian subcontinent.

Computational Analysis and Predicting Ligand Binding Site in the Rose leaf curl virus and Its Betasatellite Proteins: A Step Forward for Antiviral Agent Designing

Computational approach was done in protein molecules of the Rose leaf curl virus and its betasatellite component isolated from Rose plants. Moreover in-depth study was done using in silico approach such as restriction map, GC profile and prediction of binding sites for ligand molecule analysis. Hence, an approach has been taken into consideration to unearth a treatment against geminiviruses, resulting in huge yield loss across the globe. This study provides a great deal of novel knowledge and will be employed for the selection of inhibitors in opposition to geminivirus proteins focusing on begomovirus and paves a way for developing antiviral agents in the near future.

First report of a begomovirus associated with betasatellites infecting spinach (Spinacia oleracea) in India

Spinach (Spinacia oleracea) leaves with vein yellowing and reduced leaf size were observed in Rasidpura, Rajasthan Province, India. The complete DNA-A and betasatellite sequences of the virus isolated from infected spinach leaves were determined and comprised 2,753 and 1,367 nucleotides, respectively. The sequence had the highest level of nucleotide sequence identity (88xa0%) with an isolate of Papaya leaf curl virus and likely represents a new species, for which we propose the name Spinach yellow vein Sikar virus. This is the first report of a Begomovirus associated with satellite molecules infecting the host S. oleracea in India.

Current status of Potyvirus in India

Potyvirus particles are flexuous rods of 700–900u2009nm in length and contain one positive sense single-stranded genomic RNA molecule of approximately 10u2009kb, which is encapsidated by a single type of coat protein. According to available NCBI database, Potyvirus infection is prominently present in Solanaceae, Leguminosae and Cucurbitaceae families in India. Potyviruses can induce a wide range of different symptoms in infected host plants including mosaic, stripe, mottling, vein clearing, vein banding, ringspots, necrotic or chlorotic lesions, flower breaking, stunting, wilting, and most commonly lead tostunting and yield losses. PCR-based methods for the detection and identification of potyviruses rely on degenerate primers designed for conserved regions. Potyvirus infection requires the interaction of host factors with viral proteins and RNA for its replication and systemic spread, i.e interaction between VPg and eIF4E is required for Potyvirus genome translation. Mutations in host translational initiation factor eIF4E cause the conformational shift in encoded proteins which are unable to bind with viral protein (VPg), resulting in broad-spectrum Potyvirus resistance.

Understanding Functional Genomics of PTGS Silencing Mechanisms for Tobacco Streak Virus and Other Ilarviruses Mediated by RNAi and VIGS

Post-transcriptional gene silencing (PTGS) is a successful technology for the investigation of functions of gene in plants. In general, this phrase refers to the capability of a cell to avert the expression of a definite gene. PTGS can be achieved either by RNA interference (RNAi) or virus-induced gene silencing (VIGS). Tobacco Streak Virus (genus Ilarvirus and family Bromoviridae) consists of a tripartite genome and infects plants by causing symptoms like necrosis and leaf puckering. Ilarvirus are the most imperative viruses, thus causing enormous economic losses worldwide by plummeting crop production by its quantity and quality. Virus infection in plants is known to activate the silencing pathway in which siRNAs are produced. There are numerous reports for the genus Ilarvirus, which have confirmed that RNAi is engineered to target viral RNA in plants. RNA silencing is a high-throughput tool for restraining gene expression carried out by sequence-specific manner, chiefly via transcriptional repression or RNA degradation. As a retort to this defence mechanism, many ilarviruses programme gene silencing suppressor proteins performing at diverse stages in the silencing pathway.

Interaction between viral proteins with the transmission of Potyvirus

Potyviridae is the largest family in plant viruses, in which a group of potyviruses constitutes a very important role in causing diseases in plants. The organisation of the viral genome is positive-sense RNA, ranging in size from 9000 to 12000u2009bp. The viral genome encodes a large polyprotein that is processed by three virus-encoded proteinases (two proteinases and helper component proteinase) to yield the mature products. This review concentrates on the interaction between viral proteins with the transmission of Potyvirus. Transmission and long-distance movement of Potyvirus is only possible through vector and that time interaction between two viral proteins takes place, named as helper component-proteinase and coat protein. Interaction between NIb, NIa, 6K2 as well as with CI (helicase activity) also involved in the replication of potyviruses. Some researchers developed a yeast two-hybrid system and biomolecular fluorescence complementation system technology which proved the interaction among the viral protein. At last all proteins are correlated with each other and play a very significant role in the transmission of Potyvirus.

In Silico Study of the Geminiviruses Infecting Ornamental Plants

Over the past few decades, there has been more interest in Geminiviruses, especially Mastrevirus and Begomovirus, as many of the diseases they cause have now reached epidemic magnitude. Ornamental plants are widely distributed in India and across the globe having high environmental adaptability. Their farming forms a major branch of horticulture. At most of the places, crops stay in the field for a particular season, while different ornamental plants grow in or nearby these agricultural fields throughout the year. Ornamental plants serve as an alternative host for Geminiviruses in the absence of the main crops and considered as a source of new viruses or reservoirs of unidentified viruses which are often neglected during diversity studies. Ornamental plants may allow the spread and transmission of Geminiviruses back to crop plants when the cropping season returns, which enhances the host range of these viruses. Thus, there is a pressing need for additional information on the diversity and distribution of Geminiviruses in ornamental plants.