Squash (Cucurbita pepo) and watermelon (Citrullus lanatus)genetic transformation for resistance to Papaya ringspot virus: type Watermelon (PRSV-W) and Zucchini yellow mosaic virus (ZYMV)

• Grant number: 07/01186-0
• Support Opportunities: Regular Research Grants
• Start date: August 01, 2007
• End date: July 31, 2009
• Field of knowledge: Agronomical Sciences - Agronomy - Plant Health
• Principal Investigator: Beatriz Madalena Januzzi Mendes
• Grantee: Beatriz Madalena Januzzi Mendes
• Host Institution: Centro de Energia Nuclear na Agricultura (CENA). Universidade de São Paulo (USP). Piracicaba , SP, Brazil

Abstract

Virus diseases can be considered the main problem affecting cucurbits production. These diseases reduce productivity and fruit quality. In Brazil, 8 virus were described affecting cucurbits. Papaya ringspot virus type W (PRSV-W) and Zucchini yellow mosaic virus (ZYMV) are considered the most important virus diseases of these crops, occurring in all cultivated areas. The control of these diseases is difficult as Citrullus lanatus and Cucurbita pepo genotypes do not present any resistance or tolerance to these virus. Also, the efficiency of controlling virus dissemination and vector chemical control is very low. An alternative for controlling virus diseases is the production of transgenic plants expressing pathogen genes, applying the Pathogen-Derived Resistance concept. The objective of this project is the development of squash and watermelon transgenic plants via Agrobacteirum tumefaciens, containing fragments of PRSV-W and ZYMV coat protein genes, in a gene construction type hairpin, and evaluation for disease resistance. The gene expression will be driven by 35S promoter and Nos terminator, and transgenic shoots will be selected by nptII selection gene. After genetic transformation transgenic adventitious shoots will be identified by PCR. The PCR positive shoots will be cultivated and the developed plants acclimatized to greenhouse. The transgene integration and expression will be confirmed by Southern and northern blot analyses. The transgenic plants will be inoculated with the pathogens and evaluated for symptoms and virus development. (AU)