Proceedings of the XLVI Italian Society of Agricultural Genetics - SIGA Annual Congress

Giardini Naxos, Italy - 18/21 September, 2002

ISBN 88-900622-3-1

Poster Abstract - 3.26

EXPRESSION OF WHEAT PATHOGENESIS-RELATED ANTIFUNGAL PROTEINS CONFERS RESISTANCE TO PATHOGENIC FUNGI IN TRANSGENIC PLANTS

FIOCCHETTI F.*, CARUSO C.**, BERTINI L.**, VITTI D.*, CHILOSI G.***, MAGRO P.***, SACCARDO F.*, TUCCI M.****

*) Dipartimento di Produzione vegetale, Università della Tuscia, Viterbo

**) Dipartimento di Agrobiologia e Agrochimica, Università della Tuscia, Viterbo

***) Dipartimento di Protezione delle Piante, Università della Tuscia, Viterbo

****) CNR – IMOF Istituto per il Miglioramento genetico delle Piante da Orto e da Fiore, Portici (NA)

PR proteins, PR genes, fungal pathogens, genetic transformation, plant defence

Plants are constantly challenged by potential pathogens against which they display a complex array of passive, pre-formed structural barriers and inducible defences, activated upon pathogen infection. One of the most characterised components of the inducible defence response is the accumulation of “pathogenesis-related” (PR) proteins, many of which show antifungal activity in vitro. We have recently isolated two cDNA clones, wPR4a and wPR4b, encoding wheatwin1 and wheatwin2, two highly homologous wheat PR proteins of class 4. The two cDNAs were cloned in binary vectors under the control of the constitutive promoter CaMV 35S. The modified vectors were then used for tobacco and tomato transformation via Agrobacterium tumefaciens with the aim of increasing resistance to pathogens of transgenic plants.

The number of inserted copies of the transgenes was investigated and found to range between 2 and 8 in wPR4a transformants and 1 and 5 in wPR4b transformants. Heterologous gene expression was also checked at the mRNA and protein levels using a wPR4b probe and antiwheatwin1 polyclonal antibody, respectively. All transformants were found to express the heterologous gene at moderate to high levels.

Resistance to the fungal pathogen Botrytis cinerea was evaluated on primary (T0) and selfed (T2 generation) transformants upon inoculation on detached leaves, while resistance to the fungal pathogen Sclerotinia sclerotiorum was evaluated on T2 transformants germinating on infected soil. Preliminary results indicate that constitutive expression of wheatwin1 or wheatwin2 confers increased tolerance to transgenic plants.