Transgenic Resistance to the Colorado Potato Beetle in Bt-expressing Eggplant Fields

Abstract

<jats:p>Colorado potato beetle (CPB; <jats:italic>Leptinotarsa decemlineata</jats:italic>-Say) is a serious pest because it has developed resistance against insecticides. Three transgenic eggplant (<jats:italic>Solanum melongena</jats:italic> L.) lines bearing a mutagenized <jats:italic>Bacillus thuringiensis</jats:italic> Berl. gene coding for the Cry3B toxin, and the nontransformed control DR2-line were tested in field trials to assess their insect resistance. The transgenic lines 3-2, 6-1, and 9-8 were tested at two different locations in a randomized complete-block design. Samples were taken biweekly to assess the level of CPB and the presence of other insects. At harvest, total yield and fruit number per plot were recorded. Two transgenic lines showed high levels of resistance at both locations, as measured by CPB abundance and yield. Fruit production was almost twice as great in the highly resistant lines (3-2 and 9-8) as in the nontransformed control. The 6-1 transgenic line showed an intermediate level of resistance; it was similar to the control under heavy CPB pressure and was comparable to the other transgenic lines under milder infestations. Analysis by double antibody sandwich–enzyme linked immunosorbent assay (DAS–ELISA), performed on different tissues, revealed a lower amount of Cry3B protein in the 6-1 transgenic line than in lines 3-2 and 9-8. No detrimental effects on nontarget arthropods (including the chrysomelid <jats:italic>Altica</jats:italic>) were evident. Field observations confirmed that Bt may be able to control CPB infestation in eggplant, representing a potential effective and environmentally safe means of pest control.</jats:p>

Assessing Potential Impact of Bt Eggplants on Non-Target Arthropods in the Philippines

“…Limited work has examined the impact of Bt eggplants producing coleopteran-active Cry3Bb [59,60], but to our knowledge this is the first report of a field study that assessed the impact of Bt eggplants expressing Cry1Ac on NTAs and other organisms. This study helps to address concerns on the potential environmental risks to NTAs of Bt eggplant cultivation in the Philippines and similar areas.…”

Development of selectable marker-free transgenic potato plants expressingcry3Aagainst the Colorado potato beetle (Leptinotarsa decemlineataSay)

“…The CPB is a destructive and invasive pest in potato crops, and numerous measures have been implemented to control damage by this damage. Transgenic cry3A potato, produced by biotechnology and genetic engineering, have proven to be highly efficient in improving resistance to CPB . However, it is difficult for it to enter the market because of consumer concerns regarding the safety of genetically modified crops, especially the safety of antibiotic SMGs .…”

Evaluation of the resistance of transgenic potato plants expressing various levels of Cry3A against the Colorado potato beetle (Leptinotarsa decemlineataSay) in the laboratory and field

“…Other recently used measures have had no obvious effects on the control of the CPB on account of various limiting factors, such as environmental conditions, or the application being time consuming and labour intensive. It has been previously reported that biotechnology and genetic engineering improve the resistance of potatoes to the CPB 6–9. These genetically modified potatoes contained the Cry3A toxin encoded by a single gene, cry3a , which has been cloned and expressed in potatoes specifically to target the CPB 6–9.…”

“…It has been previously reported that biotechnology and genetic engineering improve the resistance of potatoes to the CPB 6–9. These genetically modified potatoes contained the Cry3A toxin encoded by a single gene, cry3a , which has been cloned and expressed in potatoes specifically to target the CPB 6–9. Cry3A in potatoes resistant to the CPB has been available commercially in the United States since 1996; however, those varieties with the cry3a gene had been taken off the market in 2001 owing to low sales and buyer concerns about genetically modified organisms 10.…”