Publications by authors named "Udayasuriyan V"

Article Synopsis
  • Eight indigenous Bacillus thuringiensis isolates from Western Ghats showed over 90% effectiveness against the pest Helicoverpa armigera, with seven containing cry2A gene subfamilies.
  • The cry2Aa gene from the most effective isolate (Nn10), which achieved 100% mortality in tests, was cloned and expressed in recombinant strains to combat pest resistance.
  • Sequence analysis revealed high homology to the holotype cry2Aa gene, while bioassay tests confirmed that the recombinant Cry2Aa protein from Nn10 was toxic to Helicoverpa armigera at an LC50 value of 7.26 μg/ml.
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Codon usage bias is the preferential or non-random use of synonymous codons, a ubiquitous phenomenon observed in bacteria, plants and animals. Different species have consistent and characteristic codon biases. Codon bias varies not only with species, family or group within kingdom, but also between the genes within an organism.

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In this study, we report a novel indigenous Bacillus thuringiensis (Bt) isolate, T26, which showed spores and crystals under scanning electron microscope and pathogenicity against the pink bollworm (Pectinophora gossypiella Saunders) in artificial diet based bioassay. SDS-PAGE analysis of the spore-crystal mixture of the Bt isolate, T26 revealed presence of three major protein bands of approximate molecular weights of 80, 55 and 40 kDa. The draft genome assembly consists of 56 scaffolds with an entire draft genome size of 5,054,095 bp.

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Bacillus thuringiensis is a spore-forming bacterium that is pathogenic towards a range of insect and nematode species and had been widely used as a biopesticide. In this study, we present the morphological, molecular and genetic characteristics of an indigenous Bt isolate T414 which displayed an effective toxicity against Pectinophora gossypiella. Scanning electron microscopy revealed the presence of bipyramidal, spherical and cubic shaped protein crystals in its spore-crystal suspension.

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The pink bollworm (PBW), (Saund.) does not feed on leaves in natural circumstances. We made an attempt with the first instar larva (5 days old) and found it eats the leaf in the absence of other foods.

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A chimeric Bacillus thuringiensis toxin (Bt) gene, cry2AX1was cloned in a bi-selectable marker free binary vector construct. The cry2AX1 gene, driven by the Chrysanthemum rbcS1 promoter, was introduced into JK1044R, the restorer line (Oryza sativa L. ssp.

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The insecticidal cry genes of Bacillus thuringiensis (Bt) have been successfully used for development of insect resistant transgenic rice plants. In this study, a novel cry2AX1 gene consisting a sequence of cry2Aa and cry2Ac gene driven by rice rbcS promoter was introduced into a rice cultivar, ASD16. Among 27 putative rice transformants, 20 plants were found to be positive for cry2AX1 gene.

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Bacillus thuringiensis is a major source of insecticidal genes imparting insect resistance in transgenic plants. Level of expression of transgenes in transgenic plants is important to achieve desirable level of resistance against target insects. In order to achieve desirable level of expression, rice chloroplast transit peptide sequence was fused with synthetic cry2AX1 gene to target its protein in chloroplasts.

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Discovery of novel cry genes of Bacillus thuringiensis (Bt) with higher toxicity is important for the development of transgenic Bt crops resistant to target pests. Two new indigenous isolates of Bt were characterized for their colony type, crystal inclusion and toxicity with Helicoverpa armigera Hubner and Spodoptera litura Linn. Screening of cry2A genes from the two new isolates of Bt, T30 and T48, by PCR with cry2A family primers showed the presence of cry2A genes only in the isolate T30.

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Bacillus thuringiensis (Bt) is popularly known as insecticidal bacterium. However, non-insecticidal Bt strains are more extensively available in natural environment than the insecticidal ones. Parasporin (PS) is a collection of genealogically heterogeneous Cry proteins synthesized in non-insecticidal isolates of Bt.

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The insecticidal crystal protein(s) encoded by cry gene(s) of Bacillus thuringiensis (Bt) have been used for insect control both as biopesticides and in transgenic plants. A new 3'-truncated cry1Ab gene was cloned from an indigenous isolate of Bt, A19-31. Nucleotide sequencing and homology search revealed that the deduced amino acid sequence of Cry1Ab toxin of Bt strain A19-31 had a variation of two amino acid residues with the holotype sequence, Cry1Ab1.

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The Western Ghats of India is the one of the world's 10 "Hottest biodiversity hotspots" that runs along the western part of India through four states including Tamil Nadu. The only biodiversity reserve in the Western Ghats is the Nilgiri biosphere located in the Tamil Nadu state. In the present study, 525 soil samples were collected from all the 14 different divisions of the Western Ghats in Tamil Nadu state, India.

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Bacillus thuringiensis is the major source for transfer of genes to impart insect resistance in transgenic plants. Cry2A proteins of B. thuringiensis are promising candidates for management of resistance development in insects owing to their difference from the currently used Cry1A proteins, in structure and insecticidal mechanism.

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A fusion plasmid, pRKC, was constructed, using pACYC184, RSF1010 and a kanamycin-resistance cartridge from pUC4K, to convey thecryIA(a) gene intoAzospirillum spp. With the pRKC plasmid, the number of putative transconjugants obtained inA. lipoferum was about 300-fold higher than inA.

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We cloned the cryIA(a) gene from Bacillus thuringiensis strain FU-2-7, one of the toxin genes encoding lepidopteran-specific protoxins. Sequence analysis of the gene showed two amino acid differences (Pro77 to Leu and Phe965 to Ser) from the CryIA(a) of B. thuringiensis strain HD-1.

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