Multiplication of tobacco mosaic virus in tobacco callus tissues and in vitro selection for viral disease resistance

1989 ◽  
Vol 8 (8) ◽  
pp. 433-436 ◽  
Author(s):  
Hideyoshi Toyoda ◽  
Kazuyuki Chatani ◽  
Yoshinori Matsuda ◽  
Seiji Ouchi
Keyword(s):  
Disease Resistance ◽  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
In Vitro Selection ◽  
Viral Disease ◽  
Tobacco Callus ◽  
Selection For ◽  
Callus Tissues

scholarly journals Expression of the Baculovirus p35 Protein in Tobacco Affects Cell Death Progression and Compromises N Gene-Mediated Disease Resistance Response to Tobacco mosaic virus

2003 ◽  
Vol 16 (6) ◽  
pp. 485-494 ◽  
Author(s):  
Olga del Pozo ◽  
Eric Lam
Keyword(s):  
Cell Death ◽  
Disease Resistance ◽  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
N Gene ◽  
Resistance Response ◽  
Tobacco Plants ◽  
Loop Region ◽  
Hr Cell Death

The p35 protein from baculovirus is a broad-range caspase inhibitor and suppresses programmed cell death in animals. We report here the effects of transgenic expression in tobacco of the p35 protein during the hypersensitive response (HR). Expression of p35 causes partial inhibition of nonhost HR triggered by bacteria and gene-for-gene HR triggered by virus. Infection of p35-expressing tobacco plants with Tobacco mosaic virus (TMV) disrupts N-mediated disease resistance, causing systemic spreading of the virus within a resistant background. Mutant variants altered in aspartate residues within the loop region of p35 are inefficient substrates for caspases in vitro, and they do not suppress caspase proteolytic activity in animal systems. Tobacco plants expressing these mutant variants of the p35 protein do not show inhibition of HR cell death or enhanced virus systemic movement. Thus, HR inhibition and TMV systemic spreading phenotype in p35-expressing plants correlate with the ability of the p35 protein to suppress caspase activity in animal systems. In addition, a C-terminal truncated variant of p35 is unable to suppress cell death in animals as well as HR cell death in transgenic tobacco. Our results provide evidence for the participation of caspase-like proteases during the HR. In addition, they suggest that timely activation of cell death is necessary for effective TMV containment within the primary infection site.

scholarly journals Somaclonal variations for crop improvement: Selection for disease resistant variants in vitro

2018 ◽  
Vol 5 (2) ◽  
pp. 44-54 ◽  
Author(s):  
Veena S Anil ◽  
Savitha Lobo ◽  
Spurti Bennur
Keyword(s):  
Disease Resistance ◽  
In Vitro Selection ◽  
Crop Improvement ◽  
Epigenetic Changes ◽  
Somaclonal Variations ◽  
Disease Resistant ◽  
Biotechnological Approach ◽  
Selection For ◽  
Pressure Selection

Somaclonal variations (SV) are genetic or epigenetic changes induced in plant cell and tissue culture. Induction of somaclonal variation, is an alternate approach to conventional breeding and transgenic approaches to introduce desirable genetic variability in the gene pool. SVs that occur spontaneously in culture induce changes in a range of plant characters. However, the probability of improving a key agronomic trait such as disease resistance can be cumbersome when left to chance alone. The efficiency of developing disease resistant SVs is better with the imposition of an appropriate in vitro selection pressure. Selection agents that have been applied include pathogen elicitors, pathogen culture filtrate and purified pathotoxins. This method of SV selection has been successful in enhancing disease resistance in several crops and it is an accepted biotechnological approach with tremendous potential for crop improvement.

scholarly journals Role of the 3′ tRNA-Like Structure in Tobacco Mosaic Virus Minus-Strand RNA Synthesis by the Viral RNA-Dependent RNA Polymerase In Vitro

2000 ◽  
Vol 74 (24) ◽  
pp. 11671-11680 ◽  
Author(s):  
T. A. M. Osman ◽  
C. L. Hemenway ◽  
K. W. Buck
Keyword(s):  
Rna Polymerase ◽  
Tobacco Mosaic Virus ◽  
Mosaic Virus ◽  
Untranslated Region ◽  
Rna Synthesis ◽  
Central Core ◽  
Minus Strand ◽  
Stem Loop ◽  
Polymerase Binding

ABSTRACT A template-dependent RNA polymerase has been used to determine the sequence elements in the 3′ untranslated region of tobacco mosaic virus RNA that are required for promotion of minus-strand RNA synthesis and binding to the RNA polymerase in vitro. Regions which were important for minus-strand synthesis were domain D1, which is equivalent to a tRNA acceptor arm; domain D2, which is similar to a tRNA anticodon arm; an upstream domain, D3; and a central core, C, which connects domains D1, D2, and D3 and determines their relative orientations. Mutational analysis of the 3′-terminal 4 nucleotides of domain D1 indicated the importance of the 3′-terminal CA sequence for minus-strand synthesis, with the sequence CCCA or GGCA giving the highest transcriptional efficiency. Several double-helical regions, but not their sequences, which are essential for forming pseudoknot and/or stem-loop structures in domains D1, D2, and D3 and the central core, C, were shown to be required for high template efficiency. Also important were a bulge sequence in the D2 stem-loop and, to a lesser extent, a loop sequence in a hairpin structure in domain D1. The sequence of the 3′ untranslated region upstream of domain D3 was not required for minus-strand synthesis. Template-RNA polymerase binding competition experiments showed that the highest-affinity RNA polymerase binding element region lay within a region comprising domain D2 and the central core, C, but domains D1 and D3 also bound to the RNA polymerase with lower affinity.

In vitro Selection for Fusaric Acid Resistant Barley Plants

1987 ◽  
Vol 99 (2) ◽  
pp. 159-163 ◽  
Author(s):  
H. S. Chawla ◽  
G. Wenzel
Keyword(s):  
In Vitro Selection ◽  
Fusaric Acid ◽  
Selection For

An analysis of tobacco mosaic virus replicative structures synthesized in vitro

1986 ◽  
Vol 6 (6) ◽  
pp. 455-465 ◽  
Author(s):  
Nevin Dale Young ◽  
Milton Zaitlin
Keyword(s):  
Tobacco Mosaic Virus ◽  
Mosaic Virus
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