High carbon dioxide pre-treatment activates the defense mechanism and avoid responses induced by chilling temperature storage in cherimoya fruit
M.I. Escribano, A.D. Molina-Garcia, C. Merodio
ISHS Acta Horticulturae 600: 361-367.
2003
บทคัดย่อ
The potential of 20% CO2 plus 20% O2 for 3 days pre-treatment to activate the defense mechanism and to alleviate the characteristic responses of chilling injury during long-term storage of cherimoya fruit at 6ºC has been analyzed. Immunoassays studies, with antisera against PR-Q and PR-2 proteins, revealed that CO2 pre-treatment provoked coordinated induction of chitinase-like protein and 1,3-b-glucanase, which was reverted after transfer to air. When cherimoya fruit was long-term stored at chilling temperature, a significant increase in lignin accumulation and PAL activity was observed. Pre-treatments with high CO2 levels avoided rigidity and arrested both the increase in PAL activity and lignin accumulation. Other biochemical responses associated to long exposure to chilling temperature are accumulation of putrescine and ADC activity upswing. The effect of high CO2 in delaying the putrescine content rise and the increase in ADC activity in fruit stored, in response to chilling temperature storage, is also described. As chilling temperature causes cytoplasmic acidosis, as we previously reported by 32P-NMR spectroscopy, the structural and biochemical responses observed in CO2-treated cherimoyas must be related to changes in cytoplasmic pH.