Proceedings of the XLVII Italian
Society of Agricultural Genetics - SIGA Annual Congress
Verona,
Italy - 24/27 September, 2003
ISBN 88-900622-4-X
Poster
Abstract - 5.04
PROJECT
EURICE: ANTIFUNGAL GENES IN RICE AS A STRATEGY FOR CROP PROTECTION –
THIRD YEAR ACTIVITIES
E. LUPOTTO - (Coordinator) on
behalf of the EURICE (QLK5-CT1999-1484) Consortium
Istituto
Sperimentale per la Cerealicoltura, via Stezzano 24, 24126 Bergamo (Italy)
biotechnology,
crop protection, fungal pathogens, defence genes
The Project EURICE aims to improve and evaluate the use of genes involved in defence against pathogenic fungi in the control of rice blast (Magnaporthe grisea) and other fungal diseases, as major pests for rice in Europe. This approach aims to create new rice genotypes enhanced for resistance and addresses to the obtention of modified cultivars protected against massive attacks of the pathogens, as well as to an evaluation of the genetically modified genotypes in the environment. Three genes of different origin, shown to be implicated in the process of fungal infection, were chosen as potential source of resistance because of their different characteristics and modality of action: the maize gene b32, the fungal gene AFP, and the insect gene cecA. They were initially cloned under the strong monocot promoter ubi1 of maize and introduced into chosen European rice varieties (Oryza sativa L. ssp. japonica). The rice genotypes chosen are representative of the main rice cultivating regions in Europe: Italy, Spain, Greece and France. First events of transformation were subjected to molecular and genetic analyses; expression of the transgenes in leaf tissues at various stages of plant development was confirmed, and seed amplified for the first field trial, which has been carried out in Italy, summer season 2002, and evaluated. Meantime, the most susceptile old Italian variety Maratelli was transformed with single and combination of genes in order to assess the “gene pyramiding” strategy. To date, in vitro assays and pathogenicity tests on primary regenerants and T1 plants confirmed protection against leaf blast for at least two of the three genes under study, being the gene afp the most promising one. During the second year, a potential inducible promoter was also confirmed to be suitable for the project’s purposes: the maize ZmPR4 promoter. Expression vectors were constructed with the antifungal genes driven by p-ZmPR4 and plants are being raised. The conventional field trials carried out in Greece within the project, established an efficient protocol for the evaluation of leaf and neck blast disease in the field, by means of the Honey Comb design, and pathogenicity assays in greehouse conditions supported by confocal microscopy analyses allowed to define parameters for a detailed study of the plant/pathogen interaction. A simple and reproducible Detached Leaf Test (DLT) was sut up, as a tool for testing blast development on young leaves, and proved useful in screening trangenic plants, showing strong inhibition in the blast disease symptoms of transgenic plants. Objectives and detailed results of the third year activities are reported in the poster. The theme of the project is related to project SAFEMAIZE (ICA4-CT2000-30033) on maize, also funded by European Commission within the 5th Framework Programme.