Wounds inf horticultural crops are the main penetration sites for postharvest fungal pathogens. Wounding is accompanied by the formation of free radicals such as semiquinones, lipoperoxyl radicals and, possibly, reactive oxygen species (ROS) such as superoxide anion (O- 2) and hydrogen peroxide (H2O2), which are known to be generated in plant tissues following elicitor treatment or challenge by incompatible pathogens. Rapid colonisation of wounds by antagonistic micro-organisms is crucial for efficient prevention of pathogen attack. We compared two yeast isolates with high (LS-28, Cryptococcus laurentii) and low (LS-11, Rhodotorula glutinis) antagonistic activity to assess (i) their ability to colonise apple wounds and (ii) for their in vitro resistance to oxidative stress caused by H2O2 and an O- 2 generating system. LS-28 was able to colonise apple wounds at a higher level than the less efficient antagonist LS-11 for a time interval of 2 hours to 7 days after application. LS-28 was also more resistant to H2O2 treatment. Analogous results were obtained following treatment with an O-2 generating system.
Resistance to oxidative stress and activity of antagonistic yeasts against postharvest pathogens
CASTORIA, Raffaello;DE CURTIS, Filippo;LIMA, Giuseppe;
1999-01-01
Abstract
Wounds inf horticultural crops are the main penetration sites for postharvest fungal pathogens. Wounding is accompanied by the formation of free radicals such as semiquinones, lipoperoxyl radicals and, possibly, reactive oxygen species (ROS) such as superoxide anion (O- 2) and hydrogen peroxide (H2O2), which are known to be generated in plant tissues following elicitor treatment or challenge by incompatible pathogens. Rapid colonisation of wounds by antagonistic micro-organisms is crucial for efficient prevention of pathogen attack. We compared two yeast isolates with high (LS-28, Cryptococcus laurentii) and low (LS-11, Rhodotorula glutinis) antagonistic activity to assess (i) their ability to colonise apple wounds and (ii) for their in vitro resistance to oxidative stress caused by H2O2 and an O- 2 generating system. LS-28 was able to colonise apple wounds at a higher level than the less efficient antagonist LS-11 for a time interval of 2 hours to 7 days after application. LS-28 was also more resistant to H2O2 treatment. Analogous results were obtained following treatment with an O-2 generating system.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
