Effects of hypoxia on cut carnation flowers (Dianthus caryophyllus L.): longevity, ability to survive under anoxia, and activities of alcohol dehydrogenase and pyruvate kinase
Chen Xiuhua and Theophanes Solomos
Postharvest Biology and Technology Vol: 7 Issue: 4 Pages: 317-329
1996
บทคัดย่อ
Carnation flowers (Dianthus caryophyllus L.) were kept at 18°C in the dark, either in air, or 1.22 or 2.74 kPa O2. Hypoxia induced an increase and decline in the extractable activities of ADH and PK, respectively. Neither of the levels of O2 increased the rate of ethanol evolution. Upon transferring the flowers to anoxia, there was an increase in ADH activity in all treatments, but flowers pretreated with hypoxia maintained a higher level of activity than did the normoxic ones. The rate of ethanol evolution under anoxia was inversely related to the pretreatment concentrations of O2. The activity of PK decreased under anoxia in all treatments. Hypoxic pretreatments enhanced the viability of flowers in anoxia. The increase in ADH activity in flower petals kept under 1.22 kPa O2 was due to the increase in the Adh1 isoform. The same O2 concentration decreased the rate of CO2 evolution by about 30% below the preclimacteric minimum of the controls. Furthermore, it completely suppressed the rise in C2H4 evolution and prolonged the vase-life of the flowers to 53 days, i.e. about 7.5-fold more than that of the air samples.