Anurag Kumar Sahu

Molecular characterizations of two begomoviruses infecting Vinca rosea and Raphanus sativus in India

Dear Editor Samples of Vinca rosea and Raphanus sativus leaves showing typical leaf curling were collected from gardens and fields of Bhatinda, Punjab (India). An expected product of～550 bp in size was amplified from total DNA extracts of symptomatic leaf samples with universal primers

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.

Molecular in silico structure and recombination analysis of betasatellite in Calotropis procera associated with begomovirus

The uncharacterised betasatellite of begomovirus associated with Calotropis procera was characterised by using molecular and in silico tools and techniques. Attempts to identify the presence of a DNA-β in the infected C. procera samples, using rolling circular amplification (RCA) followed by restriction digestion, produced a ca. 1.4 kb product, corresponding to that expected for a full-length amplicon from a betasatellite, which was sequenced (accession number HQ631430). During BLASTp, analysis of second reading frame of HQ631430 (HQ631430/2-f) against Protein Databank revealed 35% identity with Tryptophanyl–tRNA synthetase of Giardia lamblia (3FOC). Ramachandran plot of HQ631430/2-f.pdb had only 57.1% residues in the most favoured region while 3FOC.pdb had 94.2% residues in the most favoured region; therefore, only template 3FOC.pdb model could be placed in good quality category. The protein binding function was predicted for HQ631430/2-f as an important functional site of the model with 0.29 confidence level through 3d2GO. The Croton yellow vein mosaic betasatellite (GU111995 CroYVMB) serve as major parent and Croton yellow vein mosaic betasatellite-Panipat 8 (HM143908 PaLCuVM) as minor parent for HQ631430. Perhaps this is the first report of recombination in Croton yellow vein mosaic betasatellite (HQ631430).

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.

Current status of Potyvirus in India

Potyvirus particles are flexuous rods of 700–900 nm in length and contain one positive sense single-stranded genomic RNA molecule of approximately 10 kb, 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.

First report on the association of a begomovirus with chrysanthemum indicum exhibiting yellowing of leaf vein disease characterized by molecular studies

ABSTRACT Infected leaf samples of an ornamental plant Chrysanthemum indicum showing yellowing of leaf veins were collected from gardens of New Delhi (India). An expected PCR product of size ~500 bp was amplified from total DNA extracts of symptomatic leaf samples with universal primers on the gene of coat protein region of begomovirus DNA-A component. The presence of begomoviruses was also confirmed by Southern blot analysis using control cloned DNA-A probe of Cotton leaf curl virus. Sequence analysis of the virus infecting Chrysanthemum indicum showed 99% nucleotide sequence identity with Clerodendron yellow mosaic virus (EF408037).

Molecular Characterization of Begomoviruses and DNA Satellites Associated with a New Host Spanish Flag (Lantana camara) in India

In the year 2010 yellowing of leaf vein disease was observed on Spanish Flag (Lantana camara) in Sirsa, Haryana province, India. There was no earlier report of association of begomovirus and DNA satellites with Lantana camara. Therefore, molecular characterization and understanding of the genomic analysis of begomovirus infecting Lantana camara is imperative for the pathogen diagnosis and disease management. This is the first report and molecular characterization of a begomovirus associated with its two satellites infecting a new host Lantana camara in India.

Molecular diversity of monopartite begomovirus coat protein and betasatellite associated with different crop species in India

The diversity of begomovirus and associated betasatellite complexes was analyzed from infected leaf samples of radish, tomato, chili, torai (ridge gourd), cotton, spinach, citrus and guar bean collected from different geographical regions of northern India. Leaves showing the characteristic begomovirus symptoms were used for cloning and sequencing for further characterization of the begomovirus complexes. In the present study, coat protein (CP) was amplified from eight different infected crop samples and betasatellites from only six. Our results showed significant diversity of CP and betasatellites of monopartite begomovirus in different crops in northern India. Phylogenetic analysis of CP and betasatellites test sequences exhibit a close relationship to diverse crops infecting begomovirus complexes. This strengthens the increase of host range of begomovirus in India.

Transmission and host interaction of Geminivirus in weeds

Abstract Geminivirus are an outsized varied family of plant viruses that infect an expansive assortment of plants such as weeds, crops, and ornamentals and cause a noteworthy loss to agriculture and horticulture worldwide. Weeds are extensively scattered worldwide and have high environmental adaptability. Weeds are considered as sources of new viruses and as reservoirs of unidentified economically important viruses but are often neglected during diversity study. Many scientific reports have demonstrated that weeds serve as a reservoir or as alternative hosts for Geminivirus survival and spread in the absence of the main crops. Thus, there is a pressing need for additional information on the diversity and distribution of geminiviruses in weeds.

Molecular Markers: Tool for Genetic Analysis

The development of molecular techniques for genetic analysis has led to a great augmentation in our knowledge of animal genetics and our understanding of the structure and behavior of various animal genomes. These molecular techniques, in particular the applications of molecular markers, have been used to scrutinize DNA sequence variations in and among animal species and to create new sources of genetic variation by introducing new and favorable traits from landraces and related animal species.