The DNA genomes of isolates of rice tungro bacilliform virus from Bangladesh, India, Indonesia, Malaysia and Thailand were cloned and compared with that of the type isolate from the Philippines. Restriction endonuclease maps revealed differences between the isolates and cross-hybridization showed that they fell into two groups, those from the Indian subcontinent and those from south-east Asian countries. The genomes of isolates from the Indian subcontinent contained a deletion of 64 bp when compared with those from south-east Asia. The implications of this variation are discussed.
Coat protein genes CP1, CP2 and CP3 of an isolate (MaP1) of rice tungro spherical virus (RTSV) from Malaysia were isolated, cloned and sequenced. Comparative analysis indicated that MaP1 isolate is closely related to the Philippine isolate.
Production of proteins in plants for human health applications has become an attractive strategy attributed by their potentials for low-cost production, increased safety due to the lack of human or animal pathogens, scalability and ability to produce complex proteins. A major milestone for plant-based protein production for use in human health was achieved when Protalix BioTherapeutics produced taliglucerase alfa (Elelyso®) in suspension cultures of a transgenic carrot cell line for the treatment of patients with Gaucher's disease, was approved by the USA Food and Drug Administration in 2012. In this review, we are highlighting various approaches for plant-based production of proteins and recent progress in the development of plant-made therapeutics and biologics for the prevention and treatment of human diseases.
Southern highbush blueberry (interspecific hybrids of Vaccinium corymbosum L.) is cultivated near wild V. corymbosum as well as closely related species in Florida, USA. The expansion of blueberry cultivation into new areas in Florida and deployment of new cultivars containing viruses can potentially increase the diversity of viruses in wild and cultivated V. corymbosum. In this study, viral diversity in wild and cultivated blueberries (V. corymbosum) is described using a metagenomic approach. RNA viromes from V. corymbosum plants collected from six locations (two cultivated and four wild) in North Central Florida were generated by high throughput sequencing (HTS) and analyzed using a bioinformatic analysis pipeline. De novo assembled contigs obtained from viromes of both commercial and wild sites produced sequences with similarities to plant virus species from a diverse range of families (Amalgaviridae, Caulimoviridae, Endornaviridae, Ophioviridae, Phenuiviridae, and Virgaviridae). In addition, this study has enabled the identification of blueberry latent virus (BlLV) and blueberry mosaic associated ophiovirus (BlMaV) for the first time in Florida, as well as a tentative novel tepovirus (blueberry virus T) (BlVT) in blueberry. To the best of our knowledge, this is the first study that compares viral diversity in wild and cultivated blueberry using a metagenomic approach.
A growing number of metagenomics-based approaches have been used for the discovery of viruses in insects, cultivated plants, and water in agricultural production systems. In this study, sixteen blueberry root transcriptomes from eight clonally propagated blueberry plants of cultivar 'Emerald' (interspecific hybrid of Vaccinium corymbosum and V. darrowi) generated as part of a separate study on varietal tolerance to soil salinity were analyzed for plant viral sequences. The objective was to determine if the asymptomatic plants harbored the latent blueberry red ringspot virus (BRRV) in their roots. The only currently known mechanism of transmission of BRRV is through vegetative propagation; however, the virus can remain latent for years with some plants of 'Emerald' never developing red ringspot symptoms. Bioinformatic analyses of 'Emerald' transcriptomes using de novo assembly and reference-based mapping approaches yielded eight complete viral genomes of BRRV (genus Soymovirus, family Caulimoviridae). Validation in vitro by PCR confirmed the presence of BRRV in 100% of the 'Emerald' root samples. Sequence and phylogenetic analyses showed 94% to 97% nucleotide identity between BRRV genomes from Florida and sequences from Czech Republic, Japan, Poland, Slovenia, and the United States. Taken together, this study documented the first detection of a complete BRRV genome from roots of asymptomatic blueberry plants and in Florida through in silico analysis of plant transcriptomes.
An efficient electrochemical impedance genosensing platform has been constructed based on graphene/zinc oxide nanocomposite produced via a facile and green approach. Highly pristine graphene was synthesised from graphite through liquid phase sonication and then mixed with zinc acetate hexahydrate for the synthesis of graphene/zinc oxide nanocomposite by solvothermal growth. The as-synthesised graphene/zinc oxide nanocomposite was characterised with scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy and X-ray diffractometry (XRD) to evaluate its morphology, crystallinity, composition and purity. An amino-modified single stranded DNA oligonucleotide probe synthesised based on complementary Coconut Cadang-Cadang Viroid (CCCVd) RNA sequence, was covalently bonded onto the surface of graphene/zinc oxide nanocomposite by the bio-linker 1-pyrenebutyric acid N-hydroxysuccinimide ester. The hybridisation events were monitored by electrochemical impedance spectroscopy (EIS). Under optimised sensing conditions, the single stranded CCCVd RNA oligonucleotide target could be quantified in a wide range of 1.0×10-11M to 1.0×10-6 with good linearity (R =0.9927), high sensitivity with low detection limit of 4.3×10-12M. Differential pulse voltammetry (DPV) was also performed for the estimation of nucleic acid density on the graphene/zinc oxide nanocomposite-modified sensing platform. The current work demonstrates an important advancement towards the development of a sensitive detection assay for various diseases involving RNA agents such as CCCVd in the future.