Field Evaluation of Transgenic and Classical Sources of Resistance

Sharp, Gail L.; Martin, John M.; Lanning, S. P.; Blake, N. K.; Brey, Christopher W.; Sivamani, Elumalai; Qu, Rongda; Talbert, L. E.

doi:10.2135/cropsci2002.0105

Cited by 29 publications

(14 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In our previous studies, we had examined nine different ULGCS lines for five generations under greenhouse conditions and found the trait to be heritable and stable (Rathore et al ., ; Sunilkumar et al ., ). As mentioned earlier, there are reports showing that transgene efficacy that was observed under greenhouse conditions either weakened or showed variability under field conditions (Bahieldin et al ., ; Brandle et al ., ; Dietz‐Pfeilstetter, ; Sharp et al ., ; Stam et al ., ). Prior to our use of RNAi to obtain the ULGCS trait, we had attempted to employ antisense technology to achieve the same objective.…”

Section: Discussionmentioning

confidence: 99%

“…Similarly, Sharp et al . () observed that transgenic wheat plants expressing viral coat proteins against wheat mosaic virus were resistant in greenhouse studies, but lost this trait in the field. In a separate study conducted on wheat, researchers reported that the effect of transgene expression varied from year to year, based on the climatic conditions of a particular growing season (Bahieldin et al ., ).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

RNAi‐mediated Ultra‐low gossypol cottonseed trait: performance of transgenic lines under field conditions

Palle

Campbell

Pandeya

et al. 2012

Plant Biotechnology Journal

View full text Add to dashboard Cite

SummaryCottonseed remains a low-value by-product of lint production mainly due to the presence of toxic gossypol that makes it unfit for monogastrics. Ultra-low gossypol cottonseed (ULGCS) lines were developed using RNAi knockdown of d-cadinene synthase gene(s) in Gossypium hirsutum.The purpose of the current study was to assess the stability and specificity of the ULGCS trait and evaluate the agronomic performance of the transgenic lines. Trials conducted over a period of 3 years show that the ULGCS trait was stable under field conditions and the foliage/floral organs of transgenic lines contained wild-type levels of gossypol and related terpenoids. Although it was a relatively small-scale study, we did not observe any negative effects on either the yield or quality of the fibre and seed in the transgenic lines compared with the nontransgenic parental plants. Compositional analysis was performed on the seeds obtained from plants grown in the field during 2009. As expected, the major difference between the ULGCS and wild-type cottonseeds was in terms of their gossypol levels. With the exception of oil content, the composition of ULGCS was similar to that of nontransgenic cottonseeds. Interestingly, the ULGCS had significantly higher (4%-8%) oil content compared with the seeds from the nontransgenic parent. Field trial results confirmed the stability and specificity of the ULGCS trait suggesting that this RNAi-based product has the potential to be commercially viable. Thus, it may be possible to enhance and expand the nutritional utility of the annual cottonseed output to fulfil the ever-increasing needs of humanity.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

RNAi‐mediated Ultra‐low gossypol cottonseed trait: performance of transgenic lines under field conditions

Palle

Campbell

Pandeya

et al. 2012

Plant Biotechnology Journal

View full text Add to dashboard Cite

show abstract

“…While field evaluations need to be undertaken, as often transgenes in wheat are not effective under field conditions (Sharp et al, 2002), this study provides evidence that the transgene is not temperature sensitive. This work has confirmed that the transgenic hairpin is effective at temperatures up to 24°C.…”

Section: Discussionmentioning

confidence: 79%

RNAi‐Mediated, Stable Resistance to Triticum mosaic virus in Wheat

et al. 2016

View full text Add to dashboard Cite

Triticum mosaic virus (TriMV) was discovered in 2006 and affects wheat (Triticum spp.) production systems in the Great Plains of the United States. Genetic resistance is available in a few commercial varieties; however, it is not effective above 20°C. RNA interference (RNAi) was evaluated as an alternative strategy to generate resistance to TriMV. An RNAi pANDA‐mini‐based hairpin expression vector was created from 272 bp of the TriMV coat protein (CP) sequence. Immature embryos of the wheat cultivar ‘Bobwhite’ were co‐transformed by biolistic particle delivery system with the pANDA::TriMVCP vector and pAHC20, containing the bar gene for glufosinate selection. T0 plants were analyzed by PCR for the presence of the RNAi TriMV CP fragment. Transgenic T1 lines were tested for transgene expression via reverse transcription PCR Virus resistance was evaluated by mechanical inoculation with TriMV and indirect enzyme‐linked immunosorbant assay (ELISA). Several lines were identified that were resistant, having little or no viral RNA. Resistant lines underwent single plant selection to the T6 generation. Real‐time PCR and ELISA showed that T6 lines had a high level of resistance when challenged with the virus. To test if the transgene would behave similarly in an adapted variety, homozygous transgenic T3 lines were crossed with the virus‐susceptible winter wheat, ‘Overley.’ Real‐time PCR results indicate decreased viral titer by as much as 20‐fold in the T6 transgenic lines, the F1 crosses, and the BC1F1 lines when compared with control plants, providing evidence that this RNAi‐silencing construct can provide stable resistance to TriMV and has great potential benefits to both breeders and producers.

show abstract

“…To date, Wsm1 is the only named gene conferring resistance to WSMV (Friebe et al, 1991) and being used in cultivar improvement (Baley et al, 2001; Sharp et al, 2002; Divis et al, 2006). Wsm1 was transferred from Th.…”

mentioning

confidence: 99%

“…Although Wsm1 confers a high level of resistance to WSMV under field conditions, the presence of the T4DL·4Ai#2S translocation had detrimental effects on bread‐making quality and other agronomic parameters (Seifers et al, 1995). Baley et al (2001) and Sharp et al (2002) analyzed the effect of the T4DL·4Ai#2S translocation under inoculated and noninoculated conditions in Montana spring wheats. Wsm1 provided a high level of resistance in the presence of the virus but, under noninoculated conditions, the presence of the T4DL·4Ai#2S translocation caused an 11 to 28% decrease in grain yield.…”

mentioning

confidence: 99%

Wheat–Thinopyrum Intermedium Recombinants Resistant to Wheat Streak Mosaic Virus and Triticum Mosaic Virus

Friebe

Wilson

et al. 2009

Crop Science

View full text Add to dashboard Cite

To date, only one gene conferring resistance to Wheat streak mosaic virus (WSMV) designated as Wsm1 was transferred from Thinopyrum intermedium (Host) Barkworth and Dewey to wheat (Triticum aestivum L.) in the form of a compensating Robertsonian translocation T4DL·4JsS. Wsm1 confers high levels of resistance to WSMV under field conditions; however, in certain genetic backgrounds and environments, the presence of the T4DL·4JsS translocation reduces agronomic performance. The objective of this study was to shorten the Th. intermedium segment in the T4DL·4JsS translocation. We recovered one proximal (rec36) and four distal (rec45, rec64, rec87, rec213) primary recombinants. Genomic in situ hybridization and molecular marker analyses determined the size of the Th. intermedium segments in the distal recombinants to be about 20% of the 4DS‐4JsS arm. All primary recombinant stocks, together with appropriate controls, were evaluated for their resistance to WSMV and Triticum mosaic virus (TriMV) in greenhouse tests. Whereas the distal recombinants rec45, rec64, rec87, and rec213 were resistant to both WSMV and TriMV at low temperatures of 18°C, the proximal recombinant rec36 reacted susceptible, which mapped the Wsm1 gene to the distal 20% of the 4DS‐4JsS arm. We successfully shortened the Th. intermedium segment while still retaining the Wsm1 gene. The T4DL·4DS‐4JsS recombinant chromosome of the rec213 stock was transferred to adapted Kansas hard red winter wheat cultivars.

show abstract

Field Evaluation of Transgenic and Classical Sources of Resistance

Cited by 29 publications

References 2 publications

RNAi‐mediated Ultra‐low gossypol cottonseed trait: performance of transgenic lines under field conditions

RNAi‐mediated Ultra‐low gossypol cottonseed trait: performance of transgenic lines under field conditions

RNAi‐Mediated, Stable Resistance to Triticum mosaic virus in Wheat

Wheat–Thinopyrum Intermedium Recombinants Resistant to Wheat Streak Mosaic Virus and Triticum Mosaic Virus

Contact Info

Product

Resources

About