TY - JOUR
T1 - Photo‐oxidative damage in the ripening tomato fruit
T2 - Protective role of superoxide dismutase
AU - Rabinowitch, Haim D.
AU - Sklan, David
AU - Budowski, Pierre
PY - 1982/3
Y1 - 1982/3
N2 - Factors relating to photo‐oxidative damage in tomatoes were investigated during maturation of the fruit and upon induction of sunscald. Superoxide dismutase (SOD) activity passed through a minimum at the mature‐green and breaker stages of ripening and availability of zinc and copper did not appear to be a limiting factor in the synthesis of the enzyme. Iron levels were maximal and total carotenoid concentrations were lowest during the same mature‐green and breaker stages of maturation, while chlorophyll was starting to decrease but was still present in large amounts. Peroxidase activity decreased steadily during ripening. Artificial induction of tolerance to photodynamic damage by controlled heat treatment was accompanied by an increase in SOD activity, while carotenoid levels and peroxidase activity did not change. These findings support the thesis that the previously reported susceptibility of tomatoes to photodynamic damage, i.e. sunscald, during the mature‐green and breaker stages of maturation is related to enhanced formation of superoxide ions, at a time when chloroplast structure begins to break down. SOD, by scavenging the superoxide, appears to supplement the protective action of carotenoids against photo‐oxidative injury.
AB - Factors relating to photo‐oxidative damage in tomatoes were investigated during maturation of the fruit and upon induction of sunscald. Superoxide dismutase (SOD) activity passed through a minimum at the mature‐green and breaker stages of ripening and availability of zinc and copper did not appear to be a limiting factor in the synthesis of the enzyme. Iron levels were maximal and total carotenoid concentrations were lowest during the same mature‐green and breaker stages of maturation, while chlorophyll was starting to decrease but was still present in large amounts. Peroxidase activity decreased steadily during ripening. Artificial induction of tolerance to photodynamic damage by controlled heat treatment was accompanied by an increase in SOD activity, while carotenoid levels and peroxidase activity did not change. These findings support the thesis that the previously reported susceptibility of tomatoes to photodynamic damage, i.e. sunscald, during the mature‐green and breaker stages of maturation is related to enhanced formation of superoxide ions, at a time when chloroplast structure begins to break down. SOD, by scavenging the superoxide, appears to supplement the protective action of carotenoids against photo‐oxidative injury.
KW - Carotenoids
KW - chlorophyll
KW - peroxidase
UR - http://www.scopus.com/inward/record.url?scp=84987045001&partnerID=8YFLogxK
U2 - 10.1111/j.1399-3054.1982.tb00273.x
DO - 10.1111/j.1399-3054.1982.tb00273.x
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AN - SCOPUS:84987045001
SN - 0031-9317
VL - 54
SP - 369
EP - 374
JO - Physiologia Plantarum
JF - Physiologia Plantarum
IS - 3
ER -