H2O2参与冷激处理对番茄果实抗冷性及抗氧化酶活性的影响

本研究以“佳粉1号”番茄为试材,研究了H2O2参与冷激处理对番茄果实抗冷性及抗氧化酶活性的影响。结果表明冷激处理降低了果实的冷害发生率和冷害指数,诱导了冷藏初期番茄果实中H2O2含量的升高,延缓了丙二醛的增加,提高了低温下果实内过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)的活性。用二甲基硫脲(DMTU)抑制内源H2O2能够削弱冷激处理所诱导的番茄果实冷害发生率的降低及对MDA累积的延缓作用,且CAT和APX的活性在冷藏初期受到抑制。结果表明,冷激处理可以有效提高番茄的耐冷性,减少低温对细胞膜系统的伤害,提高抗氧化酶的活性,而抑制内源H2O2后有效抑制了由冷激诱导的耐冷性的提高,说明冷藏初期内源H2O2参与了冷激介导番茄果实抗冷性的提高。

Effects of H2O2 on Cold Tolerance and Antioxidant Enzyme Activities of Tomato by Cold-shock Treatment

The effects of hydrogen peroxide on the increased cold tolerance of tomato by cold-shock treatment and metabolism of dynamic changes of antioxidant enzyme system were studied. Cold-shock treatment reduced the chilling injury rate and chilling injury index, enhanced the endogenous H2O2 content in the beginning of storage, postponed the increases of MDA and increased the activities of CAT and APX. The MDA content increased after pretreatment with dimethylthiourea before cold-shock treatment. Furthermore, the activities of CAT and APX were inhibited. These results indicated that cold-shock increases cold tolerance of tomato, reduces the effects on the injury of cell membrane and increases the activities of the antioxidant enzymes. Pretreatment with dimethylthiourea (a trap for H2O2) remarkably inhibits cold tolerance induced by cold-shock. All the results showed that endogenous H2O2 may improve the tolerance cold shock-enhanced tomatoes.