scholarly journals Homology-Dependent Virus Resistance in Transgenic Plants with the Coat Protein Gene of Sweet Potato Feathery Mottle Potyvirus: Target Specificity and Transgene Methylation

1999 ◽  
Vol 89 (5) ◽  
pp. 385-391 ◽  
Author(s):  
S. Sonoda ◽  
M. Mori ◽  
M. Nishiguchi
Keyword(s):  
Coat Protein ◽  
Sweet Potato ◽  
Virus Resistance ◽  
Potato Virus X ◽  
Transcriptional Gene Silencing ◽  
Target Specificity ◽  
Post Transcriptional Gene Silencing ◽  
Resistant Lines ◽  
Nontranslated Region ◽  
Transgenic Lines

Nicotiana benthamiana plants were transformed with the coat protein (CP) coding sequence and the 3′ nontranslated region (NTR) of the severe strain of sweet potato feathery mottle potyvirus (SPFMV-S). Regenerated lines were screened for virus resistance using recombinant potato virus X (PVX) engineered to contain the sequence homologous to the transgene. Out of 19 transgenic lines, 7 showed virus resistance after inoculation by the recombinant PVX. In most of the resistant lines, relatively low steady-state accumulation of the CP gene mRNA and little or no protein products were observed, suggesting that the resistance was manifested by a post-transcriptional gene-silencing mechanism. The resistant lines could be divided into two groups according to the target specificity of the silencing mechanism; one group recognizing the 3′ part of the transgene mRNA and the other not only the 3′ part, but also the 5′ and the central part of the transgene mRNA. Particular regions of the transgene corresponding to the RNA target in the resistant lines were differentially methylated compared with the transgene sequence in a susceptible line.

scholarly journals Double-Virus Resistance of Transgenic Oriental Melon Conferred by Untranslatable Chimeric Construct Carrying Partial Coat Protein Genes of Two Viruses

Plant Disease ◽  
2010 ◽  
Vol 94 (11) ◽  
pp. 1341-1347 ◽  
Author(s):  
Hui-Wen Wu ◽  
Tsong-Ann Yu ◽  
Joseph A. J. Raja ◽  
Serene Judith Christopher ◽  
Sine-Lan Wang ◽  
...  
Keyword(s):  
Coat Protein ◽  
Virus Resistance ◽  
Zucchini Yellow Mosaic Virus ◽  
Inverse Correlation ◽  
Underlying Mechanism ◽  
Yellow Mosaic Virus ◽  
Transcriptional Gene Silencing ◽  
Oriental Melon ◽  
Post Transcriptional Gene Silencing ◽  
Transgenic Lines

Production of oriental melon (Cucumis melo var. makuwa) in Asia is often limited by two potyviruses, the watermelon infecting type of Papaya ringspot virus (PRSV W) and Zucchini yellow mosaic virus (ZYMV). In order to engineer transgenic resistance to these two viruses, an untranslatable chimeric DNA comprising partial coat protein (CP) sequences of ZYMV and PRSV W was constructed and used to transform the elite cultivar of oriental melon, Silver Light, by Agrobacterium. Greenhouse evaluation by mechanical challenges with ZYMV and PRSV W, alone or together, identified transgenic lines exhibiting different levels of resistance or complete immunity to ZYMV and PRSV W. Molecular analyses of transgenic lines revealed random insertion of transgene into the host genome, with insert numbers differing among transformants. There was no correlation between transgene insert numbers and the degree of resistance expressed by transgenic lines. The levels of accumulation of transgene transcript varied among transgenic lines. However, an inverse correlation was observed between the level of accumulation of transgene transcripts and the degree of virus resistance. Moreover, small interfering (si)RNA was readily detected from the immune and highly resistant lines, but not from the weakly resistant and susceptible lines. Altogether, our results indicated that RNA-mediated post-transcriptional gene silencing (PTGS) was the underlying mechanism of double-virus resistance of the transgenic melon lines. The segregation analysis of the R1 progeny of the immune line ZW-1 indicated that the single inserted transgene is associated with the resistance phenotype and is inherited as a dominant trait. These transgenic melon lines with high degrees of resistance to ZYMV and PRSV W have great potential for the control of ZYMV and PRSV W in C. melo in Asia and elsewhere.

scholarly journals Comparative reactions of recombinant papaya ringspot viruses with chimeric coat protein (CP) genes and wild-type viruses on CP-transgenic papaya

2001 ◽  
Vol 82 (11) ◽  
pp. 2827-2836 ◽  
Author(s):  
Chu-Hui Chiang ◽  
Ju-Jung Wang ◽  
Fuh-Jyh Jan ◽  
Shyi-Dong Yeh ◽  
Dennis Gonsalves
Keyword(s):  
Coat Protein ◽  
Sequence Similarity ◽  
Transcriptional Gene Silencing ◽  
Papaya Ringspot Virus ◽  
Wild Type ◽  
Coding Region ◽  
Transgenic Papaya ◽  
Cp Gene ◽  
Post Transcriptional Gene Silencing

Transgenic papaya cultivars SunUp and Rainbow express the coat protein (CP) gene of the mild mutant of papaya ringspot virus (PRSV) HA. Both cultivars are resistant to PRSV HA and other Hawaii isolates through homology-dependent resistance via post-transcriptional gene silencing. However, Rainbow, which is hemizygous for the CP gene, is susceptible to PRSV isolates from outside Hawaii, while the CP-homozygous SunUp is resistant to most isolates but susceptible to the YK isolate from Taiwan. To investigate the role of CP sequence similarity in overcoming the resistance of Rainbow, PRSV HA recombinants with various CP segments of the YK isolate were constructed and evaluated on Rainbow, SunUp and non-transgenic papaya. Non-transgenic papaya were severely infected by all recombinants, but Rainbow plants developed a variety of symptoms. On Rainbow, a recombinant with the entire CP gene of YK caused severe symptoms, while recombinants with only partial YK CP sequences produced a range of milder symptoms. Interestingly, a recombinant with a YK segment from the 5′ region of the CP gene caused very mild, transient symptoms, whereas recombinants with YK segments from the middle and 3′ parts of the CP gene caused prominent and lasting symptoms. SunUp was resistant to all but two recombinants, which contained the entire CP gene or the central and 3′-end regions of the CP gene and the 3′ non-coding region of YK, and the resulting symptoms were mild. It is concluded that the position of the heterologous sequences in the recombinants influences their pathogenicity on Rainbow.

RNAi effects on regulation of endogenous acid invertase activity in potato (Solanum tuberosum L.) tubers

2008 ◽  
Vol 5 (2) ◽  
pp. 107-112 ◽  
Author(s):  
Zhang Chi ◽  
Xie Cong-Hua ◽  
Song Bo-Tao ◽  
Liu Xun ◽  
Liu Jun
Keyword(s):  
Solanum Tuberosum ◽  
Solanum Tuberosum L ◽  
Pcr Amplification ◽  
Invertase Activity ◽  
Northern Blotting ◽  
Acid Invertase ◽  
Transcriptional Gene Silencing ◽  
Post Transcriptional Gene Silencing ◽  
Transgenic Lines ◽  
Potential Strategy

AbstractIn plants, acid invertases are known to be the key enzymes cleaving sucrose into reducing sugars (RS) (glucose and fructose). To improve the quality of potato (Solanum tuberosum L.) chips, which is largely influenced by RS accumulation in tubers stored at low temperature, a part of acid invertase cDNA with hairpin RNA (hpRNA) structure was transformed into potato cv. N2. Detection of polymerase chain reaction (PCR) amplification and Northern blotting suggested that the RNA interference (RNAi) vector was successfully transformed into cv. N2. The analysis of acid invertase activity in the plantlets and microtubers of RNAi transgenic lines indicated that the expression of the acid invertase was significantly repressed by the activity of RNAi of plantlets by an average 69.8% (with the exception of line Ni-1) with a maximal decrease of 78% (line Ni-4), and the highest decrease of activity in microtubers of 68%. Compared with that of well-inhibited antisense inv transgenic plants, the comparative downregulation of RNAi suggests a distinct alteration of endogenous acid invertase activity and a potential strategy for post-transcriptional gene silencing (PTGS) in modulation of cold-sweetening in potato.

scholarly journals Transgenic Sugarcane Resistant toSorghum mosaic virusBased on Coat Protein Gene Silencing by RNA Interference

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Jinlong Guo ◽  
Shiwu Gao ◽  
Qinliang Lin ◽  
Hengbo Wang ◽  
Youxiong Que ◽  
...  
Keyword(s):  
Rna Interference ◽  
Coat Protein ◽  
Mosaic Virus ◽  
Resistance Rate ◽  
Mosaic Disease ◽  
Artificial Inoculation ◽  
Multiple Sequence ◽  
Sugarcane Cultivar ◽  
Resistant Lines ◽  
Transgenic Lines

As one of the critical diseases of sugarcane, sugarcane mosaic disease can lead to serious decline in stalk yield and sucrose content. It is mainly caused byPotyvirus sugarcane mosaic virus(SCMV) and/orSorghum mosaic virus(SrMV), with additional differences in viral strains. RNA interference (RNAi) is a novel strategy for producing viral resistant plants. In this study, based on multiple sequence alignment conducted on genomic sequences of different strains and isolates of SrMV, the conserved region of coat protein (CP) genes was selected as the target gene and the interference sequence with size of 423 bp in length was obtained through PCR amplification. The RNAi vector pGII00-HACP with an expression cassette containing both hairpin interference sequence andcp4-epspsherbicide-tolerant gene was transferred to sugarcane cultivar ROC22 viaAgrobacterium-mediated transformation. After herbicide screening, PCR molecular identification, and artificial inoculation challenge, anti-SrMV positive transgenic lines were successfully obtained. SrMV resistance rate of the transgenic lines with the interference sequence was 87.5% based on SrMV challenge by artificial inoculation. The genetically modified SrMV-resistant lines of cultivar ROC22 provide resistant germplasm for breeding lines and can also serve as resistant lines having the same genetic background for study of resistance mechanisms.

scholarly journals The coat protein of potato virus X is a strain-specific elicitor of Rx1-mediated virus resistance in potato

1995 ◽  
Vol 8 (6) ◽  
pp. 933-941 ◽  
Author(s):  
Abdelhafid Bendahmane ◽  
Bärbel A. Köhm ◽  
Cynthia Dedi ◽  
David C. Baulcombe
Keyword(s):  
Coat Protein ◽  
Potato Virus ◽  
Virus Resistance ◽  
Potato Virus X

scholarly journals Host-induced avirulence of hibiscus chlorotic ringspot virus mutants correlates with reduced gene-silencing suppression activity

2006 ◽  
Vol 87 (2) ◽  
pp. 451-459 ◽  
Author(s):  
Chunying Meng ◽  
Jun Chen ◽  
Jinrong Peng ◽  
Sek-Man Wong
Keyword(s):  
Gene Silencing ◽  
Green Fluorescence Protein ◽  
Potato Virus X ◽  
Serial Passage ◽  
Ringspot Virus ◽  
Transcriptional Gene Silencing ◽  
Turnip Crinkle Virus ◽  
Induced Mutations ◽  
Post Transcriptional Gene Silencing ◽  
Local Lesion Host

Post-transcriptional gene silencing (PTGS) and virus-encoded gene-silencing suppressors are defence and counterdefence strategies developed by host and pathogens during evolution. Using a green fluorescence protein-based transient suppression system, the coat protein (CP) of Hibiscus chlorotic ringspot virus (HCRSV) was identified as a strong gene-silencing suppressor. CP suppressed sense RNA-induced but not dsRNA-induced local and systemic PTGS. This is different from another virus in the genus Carmovirus, Turnip crinkle virus (TCV), the CP of which strongly suppresses dsRNA-induced PTGS. HCRSV CP domain deletion mutants lost their suppression function, indicating that the complete CP is essential for suppression of PTGS. When CP was expressed from a Potato virus X (PVX) vector, it was able to enhance the symptom severity and to increase the accumulation of PVX RNA. Here, it is proposed that HCRSV CP suppresses PTGS at the initiation step, which is different from TCV CP. In addition, a previous study demonstrated that CP mutants resulting from serial passage of HCRSV in its local lesion host also showed a significantly reduced suppression function, indicating that host-induced mutations that lead to avirulence of HCRSV in kenaf correlate with its reduced ability to suppress PTGS.

scholarly journals A single chimeric transgene derived from two distinct viruses confers multi-virus resistance in transgenic plants through homology-dependent gene silencing

2000 ◽  
Vol 81 (8) ◽  
pp. 2103-2109 ◽  
Author(s):  
Fuh-Jyh Jan ◽  
Carmen Fagoaga ◽  
Sheng-Zhi Pang ◽  
Dennis Gonsalves
Keyword(s):  
Gene Silencing ◽  
Virus Resistance ◽  
Fluorescent Protein ◽  
Gene Segment ◽  
N Gene ◽  
Transcriptional Gene Silencing ◽  
Multiple Resistance ◽  
Cp Gene ◽  
Transgenic Lines ◽  
Green Fluorescent

We showed previously that 218 and 110 bp N gene segments of tomato spotted wilt virus (TSWV) that were fused to the non-target green fluorescent protein (GFP) gene were able to confer resistance to TSWV via post-transcriptional gene silencing (PTGS). N gene segments expressed alone did not confer resistance. Apparently, the GFP DNA induced PTGS that targetted N gene segments and the incoming homologous TSWV for degradation, resulting in a resistant phenotype. These observations suggested that multiple resistance could be obtained by replacing the GFP DNA with a viral DNA that induces PTGS. The full-length coat protein (CP) gene of turnip mosaic virus (TuMV) was linked to 218 or 110 bp N gene segments and transformed into Nicotiana benthamiana. A high proportion (4 of 18) of transgenic lines with the 218 bp N gene segment linked to the TuMV CP gene were resistant to both viruses, and resistance was transferred to R2 plants. Nuclear run-on and Northern experiments confirmed that resistance was via PTGS. In contrast, only one of 14 transgenic lines with the TuMV CP linked to a 110 bp N gene segment yielded progeny with multiple resistance. Only a few R1 plants were resistant and resistance was not observed in R2 plants. These results clearly show the applicability of multiple virus resistance through the fusion of viral segments to DNAs that induce PTGS.

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