|
|
Post by dulanjani on Sept 12, 2015 20:51:16 GMT -6
Rice tungro disease.pdf (804.34 KB) Hi all this is my ppt on Rice tungro disease. and i was reading more about this disease complex and how it is transmitted. What i found would clear our understanding about this matter. Rice tungro virus is transmitted via semi persistent manner by green leaf hopper. To transmit RTBV from singly infected rice plant green leaf hopper need to be fed before from a plant that RTSV infected. Main source of disease is left over infected plants and stubbles and non of these viruses are transmitted by water or water origin. There are resistant rice varieties for green leaf hopper which have antixenosis. This is the paper i got these information from transmisstion of RTBV.pdf (267.15 KB) Here are some interesting points to discuss 1. Are there any alternative hosts for these virus? 2. Can DNA genome of RTBV be integrated in to the Rice plant genome? 3. How can we detect endogeneous viral elements ( parts of viral genome that is integrated in to the plant genome) if there any in the plant genome?
|
|
|
|
RTBV
Sept 13, 2015 10:02:30 GMT -6
Post by gabriela on Sept 13, 2015 10:02:30 GMT -6
Hi all this is my ppt on Rice tungro disease. and i was reading more about this disease complex and how it is transmitted. What i found would clear our understanding about this matter. Rice tungro virus is transmitted via semi persistent manner by green leaf hopper. To transmit RTBV from singly infected rice plant green leaf hopper need to be fed before from a plant that RTSV infected. Main source of disease is left over infected plants and stubbles and non of these viruses are transmitted by water or water origin. There are resistant rice varieties for green leaf hopper which have antixenosis. This is the paper i got these information from Here are some interesting points to discuss 1. Are there any alternative hosts for these virus? 2. Can DNA genome of RTBV be integrated in to the Rice plant genome? 3. How can we detect endogeneous viral elements ( parts of viral genome that is integrated in to the plant genome) if there any in the plant genome? Hi, I found some answers for these questions: 1) What I found is that each of the viruses that together produce the rice tungro disease can be present separately in other plants. However, the symptoms that are observed in the plant are completely different than in RTS disease. 2) Since, we are talking about a retroviruses it has DNA genome; the DNA of pararetroviruses accumulates within the nucleus as multiple copies of a circular chromosome. The life cycle of RTBV is not well known but since its DNA structure does not intergrate into the host's DNA, RTBV's life cycle should follow the general viral reproduction life cycle: the viruses attach to the host cell, injects their contents into the cell nucleus, then change the host cell's metabolism to reproduce new viruses. Like other viruses, everything resources have to come from the host. Rice tungro bacilliform virus (RTBV) replicates only in phloem cells in infected rice plants and its promoter drives strong phloem-specific reporter gene expression in transgenic rice plants. 3) It was kind of difficult to find this question... but the only method that I could find was to sequences motifs and to measure horizontal transfer... is that right? |
|
|
|
RTBV
Sept 13, 2015 15:57:56 GMT -6
Post by omararias on Sept 13, 2015 15:57:56 GMT -6
Hi all, regarding your points of discuss:
There are some reports that presume the presence of the virus in hosts like weed and wild rice species, but they all lack a complete and pure recovering virus material from those infected crops to further analysis.
According to what I have been reading so far it has been found DNA sequences in rice genome that have certain homology with rice tungro bacilliform virus (RTBV), specifically, the homology detected was present in the ORF III, in a site located 55 kb upstream of the gen Wx (highly conserved region among rice species). These data, suggests a possibility that these plant viruses might integrate its DNA into host chromosomes, event that could rarely happen. I suggest that a more elaborated analysis of this sequences may lead to the detection of the endogenous viral elements in hosts. You all will be able to observe this region if you enter the accession number AP000559 in the Genbank.
Hope this information helps with the questions asked.
Thanks.
|
|
|
|
RTBV
Sept 14, 2015 8:22:13 GMT -6
Post by ravendra on Sept 14, 2015 8:22:13 GMT -6
There is lot of research going on regarding abiotic stress like drought stress etc. in rice worldwide. There are labs trying to develop new varieties of rice which can grow with very less water available for irrigation. In case of Rice tungro virus, what is the current trend of research? What are the people trying to do new?
|
|
|
|
RTBV
Sept 14, 2015 22:02:25 GMT -6
Post by dulanjani on Sept 14, 2015 22:02:25 GMT -6
Hi all, regarding your points of discuss: There are some reports that presume the presence of the virus in hosts like weed and wild rice species, but they all lack a complete and pure recovering virus material from those infected crops to further analysis. According to what I have been reading so far it has been found DNA sequences in rice genome that have certain homology with rice tungro bacilliform virus (RTBV), specifically, the homology detected was present in the ORF III, in a site located 55 kb upstream of the gen Wx (highly conserved region among rice species). These data, suggests a possibility that these plant viruses might integrate its DNA into host chromosomes, event that could rarely happen. I suggest that a more elaborated analysis of this sequences may lead to the detection of the endogenous viral elements in hosts. You all will be able to observe this region if you enter the accession number AP000559 in the Genbank. Hope this information helps with the questions asked. Thanks. Thank you Omar for the interesting information. And yes like you said these 2 viruses can be transmitted to weed species in the field via green leaf hopper. And there are many reports about discovery of endogeneous RTBV like elements in Rice genome. In one paper i read they were able to find 29 different segments from rice genome ( variety Japonica). Asian rice species had more RTBV sequences integrated than other species originated from other regions. www.biomedcentral.com/content/pdf/1471-2164-5-80.pdf |
|
|
|
RTBV
Sept 14, 2015 22:08:52 GMT -6
Post by dulanjani on Sept 14, 2015 22:08:52 GMT -6
Hi all this is my ppt on Rice tungro disease. and i was reading more about this disease complex and how it is transmitted. What i found would clear our understanding about this matter. Rice tungro virus is transmitted via semi persistent manner by green leaf hopper. To transmit RTBV from singly infected rice plant green leaf hopper need to be fed before from a plant that RTSV infected. Main source of disease is left over infected plants and stubbles and non of these viruses are transmitted by water or water origin. There are resistant rice varieties for green leaf hopper which have antixenosis. This is the paper i got these information from Here are some interesting points to discuss 1. Are there any alternative hosts for these virus? 2. Can DNA genome of RTBV be integrated in to the Rice plant genome? 3. How can we detect endogeneous viral elements ( parts of viral genome that is integrated in to the plant genome) if there any in the plant genome? Hi, I found some answers for these questions: 1) What I found is that each of the viruses that together produce the rice tungro disease can be present separately in other plants. However, the symptoms that are observed in the plant are completely different than in RTS disease. 2) Since, we are talking about a pararetroviruses it has DNA genome; the DNA of pararetroviruses accumulates within the nucleus as multiple copies of a circular chromosome. The life cycle of RTBV is not well known but since its DNA structure does not intergrate into the host's DNA, RTBV's life cycle should follow the general viral reproduction life cycle: the viruses attach to the host cell, injects their contents into the cell nucleus, then change the host cell's metabolism to reproduce new viruses. Like other viruses, everything resources have to come from the host. Rice tungro bacilliform virus (RTBV) replicates only in phloem cells in infected rice plants and its promoter drives strong phloem-specific reporter gene expression in transgenic rice plants. 3) It was kind of difficult to find this question... but the only method that I could find was to sequences motifs and to measure horizontal transfer... is that right? Yes Gaby thank you for the information, and RTBV like sequences were found integrated to Rice genome like Omar discussed. And a simple experiment to identify integrated genome sequence is to do a southern blot. You only need to prepare different probes to represent the genome of RTBV and using genomic DNA of Rice genome you will be able to identify if there are any RTBV like sequences are integrated to the plant genome. |
|
|
|
RTBV
Sept 14, 2015 22:33:32 GMT -6
Post by dulanjani on Sept 14, 2015 22:33:32 GMT -6
There is lot of research going on regarding abiotic stress like drought stress etc. in rice worldwide. There are labs trying to develop new varieties of rice which can grow with very less water available for irrigation. In case of Rice tungro virus, what is the current trend of research? What are the people trying to do new? Well your question was broad. But i found interesting paper published on 2008. RNA-interference to decrease the accumulation of RTBV in infected plants. RNA-interference is a process where RNA molecules will inhibit the gene expression by inhibiting mRNA. They have developed two transgens that express both sense and anti sense DNA encoding ORF4 of RTBV. Thant produces produces ds RNA. In these transgens difference levels of resistance was observed against RTBV showing mild disease symptoms. But i couldn't found anything that related to RTBV and transgens dealing with abiotic stress. But lot of research are carring out to develop transgens with resistance to RTBV. |
|
|
|
RTBV
Sept 16, 2015 18:57:28 GMT -6
Post by gabriela on Sept 16, 2015 18:57:28 GMT -6
Hi, I found some answers for these questions: 1) What I found is that each of the viruses that together produce the rice tungro disease can be present separately in other plants. However, the symptoms that are observed in the plant are completely different than in RTS disease. 2) Since, we are talking about a pararetroviruses it has DNA genome; the DNA of pararetroviruses accumulates within the nucleus as multiple copies of a circular chromosome. The life cycle of RTBV is not well known but since its DNA structure does not intergrate into the host's DNA, RTBV's life cycle should follow the general viral reproduction life cycle: the viruses attach to the host cell, injects their contents into the cell nucleus, then change the host cell's metabolism to reproduce new viruses. Like other viruses, everything resources have to come from the host. Rice tungro bacilliform virus (RTBV) replicates only in phloem cells in infected rice plants and its promoter drives strong phloem-specific reporter gene expression in transgenic rice plants. 3) It was kind of difficult to find this question... but the only method that I could find was to sequences motifs and to measure horizontal transfer... is that right? Yes Gaby thank you for the information, and RTBV like sequences were found integrated to Rice genome like Omar discussed. And a simple experiment to identify integrated genome sequence is to do a southern blot. You only need to prepare different probes to represent the genome of RTBV and using genomic DNA of Rice genome you will be able to identify if there are any RTBV like sequences are integrated to the plant genome. So, actually if found to be integrated... that is fascinating.... is good to that the properly technique to verify integration will be southern blot. thanks so much for the info  |
|
