Resistance of transgenic papaya trees to papaya ringspot in Brazil

Author(s):  
Paulo Ernesto Meissner Filho ◽  
Alberto Duarte Vilarinhos ◽  
Vania Jesus dos Santos de Oliveira ◽  
Dreid de Cerqueira Silveira da Silva ◽  
Vanderlei da Silva Santos ◽  
...  

Abstract: The objective of this work was to evaluate the resistance of transgenic papaya populations (PTPs) to Papaya ringspot virus-P (PRSV-P). 'Sunrise Solo' transgenic papaya plants were produced with the gene of the PRSV-P protein coat, and PRSV was mechanically inoculated in plants in greenhouse conditions. The presence of the CP/PRSV gene and homozygosis were evaluated by polymerase chain reaction (PCR). Selected plants and the 'Sunrise Solo' control were transplanted to the field for agronomic evaluations. The plants evaluated in greenhouse conditions showed resistance between 96.3 and 5.8%, without variation of symptoms. The PTPs 1/6, 1/7, 1/9, 1/10, 1/15, 2/38, 2/41, 2/56, 2/65, 3/27, 3/46, 3/48, 4/9, 4/27, 8/4, 8/23, 8/33, 18/3, 18/4, 18/8, 18/22, 18/27, 28/97, 28/104, and 28/110 showed no symptoms, they were ELISA negative, and most of them contained the CP and NPT II genes. PTPs 1/6 and 3/46 had the CP gene in homozygosis and in double insertion. PTPs 1/6/20, 1/6/59, 1/6/64, 1/6/90, 3/46/44, 3/46/52, and 18/27/97 had a well-formed fruit cluster, piriform fruit weighing approximately 500 grams, orange pulp, and less than 10% carpelloidy. PTPs 1/6/59 and 3/46/52 show resistance to PRSV, good agronomic characteristics, and the CP gene in homozygosis.

Plant Disease ◽  
1997 ◽  
Vol 81 (11) ◽  
pp. 1231-1235 ◽  
Author(s):  
M. Ravelonandro ◽  
R. Scorza ◽  
J. C. Bachelier ◽  
G. Labonne ◽  
L. Levy ◽  
...  

Transgenic plum trees (Prunus domestica) containing the plum pox potyvirus coat protein (PPV-CP) gene were inoculated with PPV by aphid feeding or chip budding. Infection was monitored by evaluation of virus symptoms, DAS-ELISA, and immunoblot assays. Based on observations and analyses over 3 years including two dormancy cycles, one out of five transgenic clones (C-5), was found to be resistant to infection whether inoculated by aphids or by chip budding. PPV could not be detected in any inoculated plants of the C-5 clone by immunoblot or immunocap-ture-reverse transcriptase-polymerase chain reaction assays. To our knowledge, this is the first P. domestica clone resistant to PPV infection produced by genetic engineering.


2007 ◽  
Vol 90 (6) ◽  
pp. 1517-1525 ◽  
Author(s):  
Chandra K Singh ◽  
Abhishek Ojha ◽  
Devendra N Kachru

Abstract To comply with international labeling regulations for genetically modified (GM) crops and food, and to enable proper identification of GM organisms (GMOs), effective methodologies and reliable approaches are needed. The spurious and unapproved GM planting has contributed to crop failures and commercial losses. To ensure effective and genuine GM cultivation, a methodology is needed to detect and identify the trait of interest and concurrently evaluate the structural and functional stability of the transgene insert. A multiple polymerase chain reaction (PCR) approach was developed for detection, identification, and gene stability confirmation of cry1Ac transgene construct in Bt cotton. As many as 9 samples of Bt cotton hybrid seeds comprising 3 approved Bt hybrids, MECH-12Bt, MECH-162Bt, MECH-184Bt, and a batch of 6 nonapproved Bt hybrids were tested. Initially, single standard PCR assays were run to amplify predominant GM DNA sequences (CaMV 35S promoter, nos terminator, and npt-II marker gene); a housekeeping gene, Gossypium hirsutum fiber-specific acyl carrier protein gene (acp1); a trait-specific transgene (cry1Ac); and a sequence of 7S 3 transcription terminator which specifically borders with 3 region of cry1Ac transgene cassette. The concurrent amplification of all sequences of the entire cassette was performed by 3 assays, duplex, triplex, and quadruplex multiplex PCR assays, under common assay conditions. The identity of amplicons was reconfirmed by restriction endonuclease digestion profile. The 2 distinct transgene cassettes, cry1Ac and npt-II, of the Bt cotton were amplified using the respective forward primer of promoter and reverse primer of terminator. The resultant amplicons were excised, eluted, and purified. The purified amplicons served as template for nested PCR assays. The nested PCR runs confirmed the transgene construct orientation and identity. The limit of detection as established by our assay for GM trait (cry1Ac) was 0.1. This approach can be adopted as a standard procedure for complete molecular characterization of Bt cotton. These assays will be of interest and use to importers, breeders, research laboratories, safety regulators, and food processors for detection of cry1Ac bearing GMOs.


Author(s):  
G. W. Hacker ◽  
I. Zehbe ◽  
J. Hainfeld ◽  
A.-H. Graf ◽  
C. Hauser-Kronberger ◽  
...  

In situ hybridization (ISH) with biotin-labeled probes is increasingly used in histology, histopathology and molecular biology, to detect genetic nucleic acid sequences of interest, such as viruses, genetic alterations and peptide-/protein-encoding messenger RNA (mRNA). In situ polymerase chain reaction (PCR) (PCR in situ hybridization = PISH) and the new in situ self-sustained sequence replication-based amplification (3SR) method even allow the detection of single copies of DNA or RNA in cytological and histological material. However, there is a number of considerable problems with the in situ PCR methods available today: False positives due to mis-priming of DNA breakdown products contained in several types of cells causing non-specific incorporation of label in direct methods, and re-diffusion artefacts of amplicons into previously negative cells have been observed. To avoid these problems, super-sensitive ISH procedures can be used, and it is well known that the sensitivity and outcome of these methods partially depend on the detection system used.


2006 ◽  
Vol 175 (4S) ◽  
pp. 485-486
Author(s):  
Sabarinath B. Nair ◽  
Christodoulos Pipinikas ◽  
Roger Kirby ◽  
Nick Carter ◽  
Christiane Fenske

1991 ◽  
Vol 66 (04) ◽  
pp. 500-504 ◽  
Author(s):  
H Peretz ◽  
U Seligsohn ◽  
E Zwang ◽  
B S Coller ◽  
P J Newman

SummarySevere Glanzmann's thrombasthenia is relatively frequent in Iraqi-Jews and Arabs residing in Israel. We have recently described the mutations responsible for the disease in Iraqi-Jews – an 11 base pair deletion in exon 12 of the glycoprotein IIIa gene, and in Arabs – a 13 base pair deletion at the AG acceptor splice site of exon 4 on the glycoprotein IIb gene. In this communication we show that the Iraqi-Jewish mutation can be identified directly by polymerase chain reaction and gel electrophoresis. With specially designed oligonucleotide primers encompassing the mutation site, an 80 base pair segment amplified in healthy controls was clearly distinguished from the 69 base pair segment produced in patients. Patients from 11 unrelated Iraqi-Jewish families had the same mutation. The Arab mutation was identified by first amplifying a DNA segment consisting of 312 base pairs in controls and of 299 base pairs in patients, and then digestion by a restriction enzyme Stu-1, which recognizes a site that is absent in the mutant gene. In controls the 312 bp segment was digested into 235 and 77 bp fragments, while in patients there was no change in the size of the amplified 299 bp segment. The mutation was found in patients from 3 out of 5 unrelated Arab families. Both Iraqi-Jewish and Arab mutations were detectable in DNA extracted from blood and urine samples. The described simple methods of identifying the mutations should be useful for detection of the numerous potential carriers among the affected kindreds and for prenatal diagnosis using DNA extracted from chorionic villi samples.


2017 ◽  
Vol 23 (1) ◽  
Author(s):  
N.NANDHA KUMAR ◽  
K. SOURIANATHA SUNDARAM ◽  
D. SUDHAKAR ◽  
K.K. KUMAR

Excessive presence of polysaccharides, polyphenol and secondary metabolites in banana plant affects the quality of DNA and it leads to difficult in isolating good quality of DNA. An optimized modified CTAB protocol for the isolation of high quality and quantity of DNA obtained from banana leaf tissues has been developed. In this protocol a slight increased salt (NaCl) concentration (2.0M) was used in the extraction buffer. Polyvinylpyrrolidone (PVP) and Octanol were used for the removal of polyphenols and polymerase chain reaction (PCR) inhibitors. Proteins like various enzymes were degraded by Proteinase K and removed by centrifugation from plant extract during the isolation process resulting in pure genomic DNA, ready to use in downstream applications including PCR, quantitative polymerase chain reaction (qPCR), ligation, restriction and sequencing. This protocol yielded a high molecular weight DNA isolated from polyphenols rich leaves of Musa spp which was free from contamination and colour. The average yields of total DNA from leaf ranged from 917.4 to 1860.9 ng/ìL. This modified CTAB protocol reported here is less time consuming 4-5h, reproducible and can be used for a broad spectrum of plant species which have polyphenol and polysaccharide compounds.


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