There are currently 402 studies in the GENERA database.

Advanced Search

General Information

Document type
  • Peer-reviewed journal article
GE organism
  • squash
GE trait
  • disease resistance
  • USA, China


Safety for environment
  • no effect

Indirect costs of a nontarget pathogen mitigate the direct benefits of a virus-resistant transgene in wild Cucurbita Open Access

Sasu, MA; Ferrari, MJ; Du, D; Winsor, JA; Stephenson, AG
Proc Natl Acad Sci U S A.. 2009 November. 106(45):19067-19071

Link to full text (open access, freely available)

PMID: 19858473 DOI: 10.1073/pnas.0905106106 ISSN: 1091-6490


Virus-resistant transgenic squash are grown throughout the United States and much of Mexico and it is likely that the virus-resistant transgene (VRT) has been introduced to wild populations repeatedly. The evolutionary fate of any resistance gene in wild populations and its environmental impacts depend upon trade-offs between the costs and benefits of the resistance gene. In a 3-year field study using a wild gourd and transgenic and nontransgenic introgressives, we measured the effects of the transgene on fitness, on herbivory by cucumber beetles, on the incidence of mosaic viruses, and on the incidence of bacterial wilt disease (a fatal disease vectored by cucumber beetles). In each year, the first incidence of zucchini yellow mosaic virus occurred in mid-July and spread rapidly through the susceptible plants. We found that the transgenic plants had greater reproduction through both male and female function than the susceptible plants, indicating that the VRT has a direct fitness benefit for wild gourds under the conditions of our study. Moreover, the VRT had no effect on resistance to cucumber beetles or the incidence of wilt disease before the spread of the virus. However, as the virus spread through the fields, the cucumber beetles became increasingly concentrated upon the healthy (mostly transgenic) plants, which increased exposure to and the incidence of wilt disease on the transgenic plants. This indirect cost of the VRT (mediated by a nontarget herbivore and pathogen) mitigated the overall beneficial effect of the VRT on fitness.


Cucurbita pepo, Erwinia tracheiphyla, plant–herbivore–pathogen interaction, zucchini yellow mosaic virus, cucumber beetles


Funding source
  • National Science Foundation
Funding country
  • United States
Funding type
  • government

Links to outside analysis of this resource

Please contact us if you know of an independent summary or analysis of this resource.

Cite this study


Sasu, MA, MJ Ferrari, D Du, JA Winsor, AG Stephenson. "Indirect costs of a nontarget pathogen mitigate the direct benefits of a virus-resistant transgene in wild Cucurbita." Proc Natl Acad Sci U S A. 106.45 (2009): 19067-19071. Web. 7 Dec. 2023.


Sasu, MA., Ferrari, MJ., Du, D., Winsor, JA., & Stephenson, AG. (2009). Indirect costs of a nontarget pathogen mitigate the direct benefits of a virus-resistant transgene in wild Cucurbita. Proc Natl Acad Sci U S A., 106(45), 19067-19071. doi:10.1073/pnas.0905106106

Please verify citations before use, citations are automatically generated based on information stored within the GENERA database and therefore may or may not be correct.