Inhibition of ethylene biosynthesis by antisense ACC\ud oxidase RNA prevents chilling injury in Charentais\ud cantaloupe melons

摘要

Non-freezing low temperature storage causes injury to\udmelons and most other fruit and vegetables of tropical and\udsubtropical origin. We demonstrate here that ethylene\udsuppression through an antisense ACC oxidase (ACO)\udgene considerably reduced the sensitivity of Charentais\udcantaloupe melons to chilling injury. In contrast to wildtype\udfruit, antisense ACO melons did not develop the characteristic\udchilling injury of pitting and browning of the rind\udneither when stored at low temperature (3 weeks at 2 °C)\udnor upon rewarming. Treating antisense melons with\ud10 p.p.m. ethylene for more than 1 d prior to cold storage\udresulted in the restoration of chilling sensitivity.When the\udethylene treatment was performed after cold storage, the\udchilling injury symptoms did not appear. The tolerance\udto chilling was associated with a lower accumulation of\udethanol and acetaldehyde, reduced membrane deterioration\udand higher capacity of the fruit to remove active\udoxygen species. The activities of catalase, superoxide dismutase\udand peroxidase were markedly increased in antisense\udACO fruit in comparison with wild-type fruit,\udparticulary upon rewarming and post-storage ethylene\udtreatment. Severe chilling injury symptoms were correlated\udwith a lower activity of activated oxygen scavenging\udenzymes. These results demonstrate that ethylene acts in\udconjunction with low temperature to induce metabolic\udshifts that participate in the development of chilling injury.