scholarly journals Generation of Transgenic Papaya with Double Resistance to Papaya ringspot virus and Papaya leaf-distortion mosaic virus

2009 ◽  
Vol 99 (11) ◽  
pp. 1312-1320 ◽  
Author(s):  
Yi-Jung Kung ◽  
Huey-Jiunn Bau ◽  
Yi-Ling Wu ◽  
Chiung-Huei Huang ◽  
Tsui-Miao Chen ◽  
...  

During the field tests of coat protein (CP)-transgenic papaya lines resistant to Papaya ringspot virus (PRSV), another Potyvirus sp., Papaya leaf-distortion mosaic virus (PLDMV), appeared as an emerging threat to the transgenic papaya. In this investigation, an untranslatable chimeric construct containing the truncated CP coding region of the PLDMV P-TW-WF isolate and the truncated CP coding region with the complete 3′ untranslated region of PRSV YK isolate was transferred into papaya (Carica papaya cv. Thailand) via Agrobacterium-mediated transformation to generate transgenic plants with resistance to PLDMV and PRSV. Seventy-five transgenic lines were obtained and challenged with PRSV YK or PLDMV P-TW-WF by mechanical inoculation under greenhouse conditions. Thirty-eight transgenic lines showing no symptoms 1 month after inoculation were regarded as highly resistant lines. Southern and Northern analyses revealed that four weakly resistant lines have one or two inserts of the construct and accumulate detectable amounts of transgene transcript, whereas nine resistant lines contain two or three inserts without significant accumulation of transgene transcript. The results indicated that double virus resistance in transgenic lines resulted from double or more copies of the insert through the mechanism of RNA-mediated posttranscriptional gene silencing. Furthermore, three of nine resistant lines showed high levels of resistance to heterologous PRSV strains originating from Hawaii, Thailand, and Mexico. Our transgenic lines have great potential for controlling a number of PRSV strains and PLDMV in Taiwan and elsewhere.

2008 ◽  
Vol 98 (7) ◽  
pp. 848-856 ◽  
Author(s):  
H.-J. Bau ◽  
Y.-J. Kung ◽  
J. A. J. Raja ◽  
S.-J. Chan ◽  
K.-C. Chen ◽  
...  

A virus identified as a new pathotype of Papaya leaf distortion mosaic virus (PLDMV, P-TW-WF) was isolated from diseased papaya in an isolated test-field in central Taiwan, where transgenic papaya lines resistant to Papaya ringspot virus (PRSV) were evaluated. The infected plants displayed severe mosaic, distortion and shoe-stringing on leaves; stunting in apex; and water-soaking on petioles and stems. This virus, which did not react in enzyme-linked immunosorbent assay with the antiserum to the PRSV coat protein, infected only papaya, but not the other 18 plant species tested. Virions studied under electron microscope exhibited morphology and dimensions of potyvirus particles. Reverse transcription-polymerase chain reaction conducted using potyvirus-specific primers generated a 1,927-nucleotide product corresponding to the 3′ region of a potyvirus, showing high sequence identity to the CP gene and 3′ noncoding region of PLDMV. Search for similar isolates with the antiserum against CP of P-TW-WF revealed scattered occurrence of PLDMV in Taiwan. Phylogenetic analysis of PLDMV isolates of Taiwan and Japan indicated that the Taiwan isolates belong to a separate genetic cluster. Since all the Taiwan isolates infected only papaya, unlike the cucurbit-infecting Japanese P type isolates, the Taiwan isolates are considered a new pathotype of PLDMV. Susceptibility of all our PRSV-resistant transgenic papaya lines to PLDMV indicates that the virus is an emerging threat for the application of PRSV-resistant transgenic papaya in Taiwan and elsewhere.


Plant Disease ◽  
2004 ◽  
Vol 88 (4) ◽  
pp. 352-358 ◽  
Author(s):  
Michael J. Davis ◽  
Zhentu Ying

Papaya (Carica papaya) was transformed via Agrobacterium-mediated transformation with four constructs containing either the unmodified or modified coat protein (CP) gene of Florida isolate H1K of Papaya ringspot virus (PRSV). The CP genes were in the sense orientation (S-CP), antisense orientation (AS-CP), sense orientation with a frame-shift mutation (FS-CP), or sense orientation mutated with three-in-frame stop codons (SC-CP). In all, 256 putative transgenic lines with the CP constructs were inoculated mechanically with PRSV H1K. None of the lines was immune to PRSV; however, highly resistant lines were found in each CP transgene group. For breeding purposes, 21 PRSV-resistant lines representing the four transgene constructs were selected and crossed with six papaya genotypes. The lines from the FS-CP and SC-CP transgene groups were highly fertile, but those from the S-CP and AS-CP transgene groups were practically infertile. Plants derived from 54 crosses and representing 17 transgenic lines were planted in the field. After 1 year in the field, 293 of the 1,258 the plants (23.3%) became naturally infected with PRSV; whereas, 29 of 30 of the nontransgenic control plants (96.7%) became infected. The incidence of PRSV infection varied in the R1 progeny depending on both the transgenic line and the nontransgenic parent.


Plant Disease ◽  
2004 ◽  
Vol 88 (6) ◽  
pp. 594-599 ◽  
Author(s):  
Huey-Jiunn Bau ◽  
Ying-Huey Cheng ◽  
Tsong-Ann Yu ◽  
Jiu-Sherng Yang ◽  
Pan-Chi Liou ◽  
...  

Four transgenic papaya lines expressing the coat protein (CP) gene of Papaya ringspot virus (PRSV) were evaluated under field conditions for their reaction to PRSV infection and fruit production in 1996 to 1999. Plants were exposed to natural virus inoculation by aphids in two adjacent fields in four different plantings at the same sites. None of the transgenic lines showed severe symptoms of PRSV whereas control nontransgenic plants were 100% severely infected 3 to 5 months after planting. In the first and second trials, 20 to 30% of the transgenic plants showed mild symptoms consisting of confined mottling or chlorotic spots on leaves. The number of transgenic plants with mild symptoms fluctuated according to the season and weather conditions, with a tendency to increase in the winter or rainy season and decrease in the summer. Also, the incidence of the mild symptoms in the third trial increased significantly due to infection by root rot fungi during the rainy season. Interestingly, there was no apparent adverse effect on fruit yield and quality in transgenic plants with mild symptoms. In the first and second experiments, transgenic lines yielded 10.8 to 11.6 and 54.3 to 56.7 times more marketable fruit, respectively, than controls. All transgenic plants produced fruit of marketable quality with no ringspots or distortion.


2009 ◽  
Vol 18 (6) ◽  
pp. 971-986 ◽  
Author(s):  
Ming-Jen Fan ◽  
Shu Chen ◽  
Yi-Jung Kung ◽  
Ying-Huey Cheng ◽  
Huey-Jiunn Bau ◽  
...  

2009 ◽  
Vol 35 (3) ◽  
pp. 223-225 ◽  
Author(s):  
José Segundo Giampan ◽  
Jorge Alberto Marques Rezende ◽  
Sônia Maria De Stefano Piedade

O ZLCV é um tospovírus encontrado com freqüência causando severos danos em cucurbitáceas. Nesse trabalho avaliaram-se os danos causados pelo ZLCV em abobrinha de moita 'Caserta', em campo na ESALQ/USP, Piracicaba-SP, onde esse vírus é freqüente. Plantas obtidas pela semeadura direta foram monitoradas periodicamente quanto à infecção pelo ZLCV por meio dos sintomas e por PTA-ELISA. Monitorou-se ainda a contaminação com Papaya ringspot virus - type W e Zucchini yellow mosaic virus, desconsiderando a produção dessas plantas. As plantas foram agrupadas em função da época de aparecimento dos sintomas do ZLCV, avaliando a produção de frutos comerciais (FC) e não comerciais (FNC) de cada grupo e comparando com a de plantas que permaneceram sem sintomas até o final do experimento. As plantas que apresentaram sintomas até os 23 dias após a emergência (DAE) não produziram qualquer tipo de frutos. FC foram colhidos de plantas que apresentaram sintomas a partir dos 42 DAE. Mesmo assim, houve redução de 78,5 % na produção de FC. Plantas que mostraram sintomas por ocasião da última colheita (55 DAE) apresentaram redução na produção de FC de 9,6 %. A infecção com o ZLCV até o início da frutificação inviabiliza a produção de FC de abobrinha de moita 'Caserta'.


2001 ◽  
Vol 82 (11) ◽  
pp. 2827-2836 ◽  
Author(s):  
Chu-Hui Chiang ◽  
Ju-Jung Wang ◽  
Fuh-Jyh Jan ◽  
Shyi-Dong Yeh ◽  
Dennis Gonsalves

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.


Plant Disease ◽  
2021 ◽  
Author(s):  
Juan F Cornejo-Franco ◽  
Edison Gonzalo Reyes-Proaño ◽  
Dimitre Mollov ◽  
Joseph Mowery ◽  
Diego Fernando Quito-Avila

A study was conducted to investigate epidemiological aspects of papaya virus E (PpVE), a cytorhabdovirus commonly found in papaya (Carica papaya L.) plantings of Ecuador. Besides papaya, PpVE was found in three Fabaceae weeds, including Rhynchosia minima, Centrosema plumieri and Macroptilium lathyroides; the latter being the species with the highest virus prevalence. Greenhouse experiments showed that in M. lathyroides, single infections of PpVE induce only mild leaf mosaic, whereas in mixed infections with cowpea severe mosaic virus, PpVE contributes to severe mosaic. In papaya, PpVE did not induce noticeable symptoms in single or mixed infections with papaya ringspot virus. Transmission experiments confirmed that whiteflies (Bemisia tabaci) transmit PpVE in a semi-persistent, non-propagative manner.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Jinlong Guo ◽  
Shiwu Gao ◽  
Qinliang Lin ◽  
Hengbo Wang ◽  
Youxiong Que ◽  
...  

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.


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