INTRODUCTION: Induction and accumulation of pathogenesis related (PR) proteins upon biotic and abiotic stresses have been widely reported and are considered important features of plant defence response. Implication of PR proteins in the mechanism of disease resistance is supported by the antifungal activity in vitro that most of them possesses. Furthermore, transgenic plants expressing PR genes gained increased levels of resistance against a number of fungal pathogens. Seeds contain different defence related PR proteins with antifungal activity that protect them in field or during the resting stage. Many of them are specifically induced upon pathogen infection or after treatment with chemical inducers of systemic acquired resistance (SAR). However. SAR activation results in the development of a broad-spectrum systemic resistance that is not effective against all pathogens. Many evidences suggest that salicylic acid (SA) plays a key role in both SAR signalling and disease resistance. However. it was found that some pathogen-inducible genes did not respond to SAR activators in wheat. Evidence is emerging that strongly suggest the importance of jasmonic acid (JA) and ethylene as alternative signals in the induction of resistance specifically efficient against distinct pathogens. In the past year our research activity has been focused on the structural and functional characterisation of several antifungal proteins from wheat and other plants of commercial interest. In particular. a number of different products belonging to the large family of pathogenesis related (PR) proteins have been isolated and characterised. Well known antifungal proteins such as basic b1-3 glucanases (PR-2). basic cbitinases (PR-3), trimatin (PR-5). trypsin inhibitors (PR-6) and peroxidases (PR-9) were found to be expressed in wheat seeds. Moreover. four homologous proteins (wheatwinl, wheatwin2, wheatwin3 and wheatwin4) belonging to the scarcely studied PR4 family were purified and characterised. These proteins displayed strong antifungal activity in vitro by inhibiting hypha! growth of several fungi, including wheat pathogens. More recently. the cDNAs coding wheatwinl and wheatwin2 (wPR-4a and wPR-4b, respectively) have been isolated and both recombinant proteins have been expressed in E. coli
Molecular characterization of PR-4 antifungal proteins from wheat
L Leonardi;
2001
Abstract
INTRODUCTION: Induction and accumulation of pathogenesis related (PR) proteins upon biotic and abiotic stresses have been widely reported and are considered important features of plant defence response. Implication of PR proteins in the mechanism of disease resistance is supported by the antifungal activity in vitro that most of them possesses. Furthermore, transgenic plants expressing PR genes gained increased levels of resistance against a number of fungal pathogens. Seeds contain different defence related PR proteins with antifungal activity that protect them in field or during the resting stage. Many of them are specifically induced upon pathogen infection or after treatment with chemical inducers of systemic acquired resistance (SAR). However. SAR activation results in the development of a broad-spectrum systemic resistance that is not effective against all pathogens. Many evidences suggest that salicylic acid (SA) plays a key role in both SAR signalling and disease resistance. However. it was found that some pathogen-inducible genes did not respond to SAR activators in wheat. Evidence is emerging that strongly suggest the importance of jasmonic acid (JA) and ethylene as alternative signals in the induction of resistance specifically efficient against distinct pathogens. In the past year our research activity has been focused on the structural and functional characterisation of several antifungal proteins from wheat and other plants of commercial interest. In particular. a number of different products belonging to the large family of pathogenesis related (PR) proteins have been isolated and characterised. Well known antifungal proteins such as basic b1-3 glucanases (PR-2). basic cbitinases (PR-3), trimatin (PR-5). trypsin inhibitors (PR-6) and peroxidases (PR-9) were found to be expressed in wheat seeds. Moreover. four homologous proteins (wheatwinl, wheatwin2, wheatwin3 and wheatwin4) belonging to the scarcely studied PR4 family were purified and characterised. These proteins displayed strong antifungal activity in vitro by inhibiting hypha! growth of several fungi, including wheat pathogens. More recently. the cDNAs coding wheatwinl and wheatwin2 (wPR-4a and wPR-4b, respectively) have been isolated and both recombinant proteins have been expressed in E. coliI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
