Oxalic acid pretreatment reduces chilling injury in Hami melons (Cucumis melo var. reticulatus Naud.) by regulating enzymes involved in antioxidative pathways
Oxalic acid pretreatment reduces chilling injury in Hami melons (Cucumis melo var. reticulatus Naud.) by regulating enzymes involved in antioxidative pathways
复制标题
草酸预处理通过调节参与抗氧化途径的酶来减少哈密瓜（Cucumis melo var. reticulatus Naud.）的冷害
DOI：
10.1016/j.scienta.2018.06.084
复制
发表时间：
2018-11-18
影响因子：
4.3
通讯作者：
Li Dou-Dou
中科院分区：
文献类型：
--
作者：
Wang Jing;Mao Lin-Chun;Li Dou-Dou
哈密瓜（Cucumis melo var. reticulatus Naud.）是一种贮藏期短的热带水果。为了延长新鲜度，水果在低温（3摄氏度）下储存，尽管这可能导致包括皮肤损伤在内的冷伤（CI），水果外皮上有许多微小的棕色斑点，容易腐烂，特别是在重新加热时，形成小坑，表面变褐与感官质量的丧失有关。我们的初步研究发现，在25℃条件下，用15 mmol L-1草酸（OA）预处理10 min，可有效降低3℃条件下哈密瓜的CI。本研究旨在证实上述结果，并确定参与抗氧化途径的酶是否在CI降低中起作用。测定抗氧化途径相关酶活性及相关基因表达水平。3℃贮藏42 d前的OA预处理提高了谷胱甘肽还原酶（GR）、抗坏血酸过氧化物酶（APX）和过氧化物酶（POD）的活性，Cm-GR、Cm-APX和Cm-POD基因的表达量高于对照组。与对照组相比，oa处理组的抗坏血酸（MA）和谷胱甘肽（GSH）含量也保持较高。OA处理抑制了H2O2和O-2（-）积累，延缓了膜脂氧化，CI指数低于对照。这些结果表明，参与抗氧化途径的酶在OA治疗后CI的缓解中发挥作用。
The Hami melon (Cucumis melo var. reticulatus Naud.) is a tropical fruit with a short storage period. To prolong freshness, the fruit is stored at low temperatures (3 degrees C), although this can lead to chilling injury (CI) involving skin lesions, numerous tiny brown spots on the rind of the fruit, susceptibility to decay, especially upon re warming, the formation of small pits, and browning of the surface associated with a loss of sensory quality. Our preliminary research revealed that pretreatment with 15 mmol L-1 oxalic acid (OA) for 10 min at 25 degrees C effectively reduced CI in Hami melons stored at 3 degrees C. The current work was conducted to confirm the above results and determine whether enzymes involved in antioxidative pathways play a role in the decreased CI. The activities of enzymes related to antioxidative pathways and expression levels of the corresponding genes were measured. OA pretreatment prior to storage at 3 degrees C for 42 d increased the activities of glutathione reductase (GR), ascorbate peroxidase (APX), and peroxidase (POD), and led to higher expression levels of the Cm-GR, Cm-APX, and Cm-POD genes relative to the control group. The OA-treated group also maintained higher contents of ascorbic acid (MA) and glutathione(GSH) compared with the control group. OA treatment inhibited H2O2 and O-2(-) accumulation, delayed membrane lipid oxidation, and led to a lower CI index compared with the control fruit. These results indicate that enzymes involved in antioxidative pathways play a role in the alleviation of CI upon OA treatment.