บทคัดย่องานวิจัย

หมวดหมู่ : ฐานข้อมูลงานวิจัย

Effect of high CO2 levels on phenol metabolism in table grape fruit stored at low temperature.

Sanchez-Ballesta M.T., Maldonado R., Escribano M.I., Merodio C.

5th International Postharvest Symposium . Volume of Abstract . Verona, Italy 6-11 June 2004, p.66

2004

บทคัดย่อ

Effect of high CO2 levels on phenol metabolism in table grape fruit stored at low temperature. Short-term exposure to high CO2 before storage at low temperature is an effective postharvest technology to control some physiopathological disorders, thereby extending the storage period of fruit and vegetables.Different studies have demonstrated that the exposure of fruits to moderate stress conditions can induce resistance to severe stresses.However, the molecular mechanisms implicated in the effectiveness of the treatments with high CO2 levels are still unknown.In grape, o­ne of the best characterised defence reactions upon infection by Botrytis cinerea is related to the accumulation of phytoalexins.We have analysed the potential of 20% CO2 plus 20% O2 for 3 days pretreatment in table grape (Vitis vinifera L. cv Cardinal) to maintain the quality and to prolong postharvest storage period.The physiological results indicate that high CO2 maintained table grape fruit quality during low temperature storage and avoided browning and rigidity of the stalks.Differences in the relative amount of polyphenol fractions as a response to post-harvest applied CO2 at low temperature have been also observed.Some of these phenolic compounds determine table grape quality characteristics of colour and taste such as bitterness and astringency and contribute to the their potential health benefits.

In order to understand the molecular mechanisms activated by high CO2 pretreatment in table grape we have focused our study o­n a number of cDNAs of the phenylpropanoid pathway.Using degenerate primers we have isolated three cDNAs encoding a L-phenylalanine ammonia-lyase (PAL), the entry-point enzyme of the phenylpropanoid pathway, chalcone synthase (CHS), the key enzyme of the flavonoid pathway and stilbene synthase (STS), which catalyse the synthesis of resveratrol the major phytoalexin in grape.The potential role of this gene as markers of the effectiveness of high CO2 levels to delay the loss of fruit quality will be discussed.