TY - JOUR
T1 - Regulatory aspects of ethanol fermentation in immature and mature citrus fruit
AU - Shi, Jian Xin
AU - Riov, Joseph
AU - Goren, Raphael
AU - Goldschmidt, Eliezer E.
AU - Porat, Ron
PY - 2007/1
Y1 - 2007/1
N2 - Molecular aspects of ethanol fermentation in citrus fruit were investigated in immature and mature 'Star Ruby' grapefruit (Citrus paradisi Macf.) and 'Murcott' mandarin (Citrus reticulata Blanco). Transcript levels of pyruvate decarboxylase (PDC) and alcohol dehydrogenase (ADH), which play a central role in ethanol fermentation, were detectable in all stages of fruit development, but accumulation of acetaldehyde (AA) and ethanol was evident only as fruit approached maturation or after several weeks of storage. Treatment of mature fruit with ethylene enhanced ethanol fermentation in grapefruit but not in mandarin. Immature fruit of both cultivars, on the other hand, responded to ethylene by prominent, although transient, enhancement of ethanol fermentation. Exposure of mature or immature fruit to anaerobic conditions (N2 atmosphere) upregulated the expression of PDC and ADH, and increased the levels of AA and ethanol. Exposure of mature fruit to anaerobic conditions also increased the enzymatic activities of PDC and ADH. The data indicate that the potential for ethanol fermentation exists in citrus fruit throughout development, even under aerobic conditions, but AA and ethanol are detected mainly toward maturation or under prolonged storage. However, prominent, long-term molecular induction of ethanol fermentation occurs only under anaerobic conditions imposed by N2 atmosphere.
AB - Molecular aspects of ethanol fermentation in citrus fruit were investigated in immature and mature 'Star Ruby' grapefruit (Citrus paradisi Macf.) and 'Murcott' mandarin (Citrus reticulata Blanco). Transcript levels of pyruvate decarboxylase (PDC) and alcohol dehydrogenase (ADH), which play a central role in ethanol fermentation, were detectable in all stages of fruit development, but accumulation of acetaldehyde (AA) and ethanol was evident only as fruit approached maturation or after several weeks of storage. Treatment of mature fruit with ethylene enhanced ethanol fermentation in grapefruit but not in mandarin. Immature fruit of both cultivars, on the other hand, responded to ethylene by prominent, although transient, enhancement of ethanol fermentation. Exposure of mature or immature fruit to anaerobic conditions (N2 atmosphere) upregulated the expression of PDC and ADH, and increased the levels of AA and ethanol. Exposure of mature fruit to anaerobic conditions also increased the enzymatic activities of PDC and ADH. The data indicate that the potential for ethanol fermentation exists in citrus fruit throughout development, even under aerobic conditions, but AA and ethanol are detected mainly toward maturation or under prolonged storage. However, prominent, long-term molecular induction of ethanol fermentation occurs only under anaerobic conditions imposed by N2 atmosphere.
KW - Alcohol dehydrogenase
KW - Anaerobic stress
KW - Citrus paradisi
KW - Citrus reticulata
KW - Ethylene
KW - Pyruvate decarboxylase
UR - http://www.scopus.com/inward/record.url?scp=33847251152&partnerID=8YFLogxK
U2 - 10.21273/jashs.132.1.126
DO - 10.21273/jashs.132.1.126
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AN - SCOPUS:33847251152
SN - 0003-1062
VL - 132
SP - 126
EP - 133
JO - Journal of the American Society for Horticultural Science
JF - Journal of the American Society for Horticultural Science
IS - 1
ER -