Development of Virus Resistance Transgenic Cotton Using Cotton Leaf Curl Virus Antisense ßC1 Gene.

Cotton (Gossypium hirsutum L.) is the most economically important crop in the world and produced 90% of the total natural cellulose fiber which is utilized to make cotton fabrics. The production of cotton is affected by many several diseases, and among them, viral disease, especially leaf curl, is the most destructive disease caused by a begomovirus transmitted by whiteflies vector. Plant biotechnology has provided an opportunity to develop transgenic plant with variable traits against biotic and abiotic stress such as resistance against pathogens, yield, quality, and salinity. Transgenic cotton (Gossypium hirsutum L., cv. Coker 312) plants were raised against leaf curl disease using bC1 gene in antisense orientation through Agrobacterium-mediated transformation somatic embryogenesis system. In this chapter, a standardized protocol will be given to raise virus resistance transgenic cotton.

First complete genome sequence of circulating dengue virus serotype 3 in Jeddah, Saudi Arabia.

Here we report the first full-length genome sequence of dengue virus serotype 3 (DENV-3) from a strain isolated from a patient in Jeddah, Saudi Arabia, in 2014. The genome consists of 10 635 bp and shows close similarity to circulating genotype III isolates from Singapore, suggesting possible importation, most probably during religious pilgrimages to Saudi Arabia.

A more elaborative way to check codon quality: an open source program.

Relative Synonymous Codon Usage (RSCU) and Relative Adaptiveness of a Codon (RAC) table bias importance in gene expression are well documented in the literature. However, to improve the gene expression we need to figure out which codons are optimal for the expression in order to synthesise an appropriate DNA sequence. An alternative to the manual approach, which is obviously a tedious task, is to set up software on your computer to perform this. Though such kinds of programs are available on the internet, none of them are open-source libraries. Here, one can use our Perl program to do his or her task more easily and efficiently. It is free for everyone.

Chlorotic curly stunt: a severe begomovirus disease of bottle gourd in northern India.

Bottle gourd (Lagenaria siceraria) an important vegetable crop in India was observed to be affected by a chlorotic curly stunt disease (CCSD) during 2003-2006 in the vegetable growing areas of Delhi and adjoining state of Haryana. The affected plants are severely stunted and bear very small chlorotic and mildly curled leaves. Incidence of the disease varied from 4.7 to 36%. The disease could be easily transmitted by whitefly, Bemisia tabaci but not by sap. The causal virus was found to be a Begomovirus on the basis of whitefly transmission and sequence identity of putative coat protein (CP) and replication initiator protein (Rep) genes. The virus was transmitted to Cucumis sativus, Luffa acutangula, L. cylndrica, Lycopersicon esculentum, Nicotiana tabacum and Praecitrullus fistulosus but not to Citrullus lunatus, Cucumis melo, Cucurbita moschata and Vigna unguiculata. The N-terminal 60 amino acids of CP of the virus had 100% sequence identity with all the isolates of Tomato leaf curl New Delhi virus (ToLCNDV) and two isolates of Squash leaf curl China virus (SLCCV). The full length amino acid sequence of the CP and Rep genes had 100% similarity with ToLCNDV-Svr and -Luffa isolates. The phylogenetic analysis showed that the virus associated with CCSD of bottle gourd belongs to ToLCNDV cluster of the begomoviruses. This is the first record of emergence of a Begomovirus associated severe disease in bottle gourd in India.

First Report of Association of Tomato leaf curl virus-New Delhi with Yellow Mosaic Disease of Luffa cylindrica in India.

Sponge gourd (Luffa cylindrica), an important cucurbitaceous vegetable in India, is affected by a disease (2) causing yellow spots on newly emerged leaves, mosaic, mild leaf curling and distortion, small leaves, and misshapen fruits. Nearly 100% of sponge gourd plants were symptomatic in Delhi. Geminivirus-like particles were observed with electron microscopy of uranyl acetate-stained leaf-dip preparations of the diseased plants collected from experimental fields at the Indian Agricultural Research Institute in New Delhi during May and June of 2002. The virus was transmitted by the whitefly (Bemisia tabaci) to sponge and ridge gourd (L. acutangula) after an acquisition and inoculation access period of 24 h each. Whitefly-inoculated plants produced typical yellow mosaic symptoms and contained geminate particles. Nucleic acid extracted from the field-infected and experimentally infected plants hybridized with 32P-labeled probe to DNA-A of Indian cassava mosaic virus, suggesting association of a begomovirus. The viral DNA, isolated by the alkali denaturation method (1) from the experimentally infected sponge gourd plants, was cloned in pBS SK+ at the EcoRI site. A clone with an insert of 2,658 bp was sequenced (GenBank Accession Nos. AJ557219, AJ555488, and AY309957) which shared 89.6 to 95.1% identity with the DNA-A of different strains of Tomato leaf curl virus-New Delhi (ToLCV-NDe). The highest sequence identity (95.1%) was with the severe strain of ToLCV-NDe (GenBank Accession No. U15015). The data suggest that the begomovirus associated with the yellow mosaic disease of L. cylindrica in India is a putative strain of ToLCV-NDe. Reference: (1) K. M. Srivastava et al. J. Virol. Methods 51:297, 1995. (2) A. Varma and B. K. Giri. Virus diseases. Pages 225-245 in: Cucurbits. N. M. Nayar and T. A More, eds. Oxford and IBH Publishing House Private Ltd., New Delhi, India, 1998.