Involvement of chloroplast peroxidase on chlorophyll degradation in postharvest broccoli florets and its control by UV-B treatment
Involvement of chloroplast peroxidase on chlorophyll degradation in postharvest broccoli florets and its control by UV-B treatment
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DOI：
10.1016/j.foodchem.2014.05.108
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发表时间：
2014-12-15
期刊：
影响因子：
8.8
通讯作者：
Yamauchi, Naoki
中科院分区：
文献类型：
--
作者：
Aiamla-or, Sukanya;Shigyo, Masayoshi;Yamauchi, Naoki
从绿色和黄绿色西兰花小花中纯化叶绿素（Chl）降解过氧化物酶（PDX），以阐明其生理作用和细胞定位。测定了UV-B处理对氯降解PDX活性的影响。通过离子交换色谱法将降解氯的PDX活性分离为3个组分：Chl-POX1、Chl-POX2和Chl-POX3。叶绿素- pox2和叶绿素- pox3的活性，尤其是叶绿素- pox3的活性，在黄绿色小花中被UV-B辐射明显抑制。从Chl-POX1和PDX3中纯化的cPOX1和cPOX3蛋白分子大小分别为43和34 kDa。cPOX1不存在于叶绿体中，而cPOX3存在于衰老花椰菜的完整叶绿体中。我们认为cPOX3是一种叶绿体PDX，其活性受到UV-B处理的抑制，这表明cPOX3可能参与了储存西兰花小花中Chl的降解。(C) 2014 Elsevier Ltd.版权所有。
Chlorophyll (Chl)-degrading peroxidase (PDX) was purified from green and green-yellow broccoli florets to elucidate the physiological role and cell localisation of Chl-degrading PDX. Effect of UV-B treatment on Chl-degrading PDX activity was also determined. The Chl-degrading PDX activity was separated by an ion exchange chromatography into 3 fractions, Chl-POX1, Chl-POX2 and Chl-POX3. The activities of Chl-POX2 and Chl-POX3, but especially that of Chl-POX3, were found in green-yellow florets and were clearly suppressed by UV-B irradiation. The protein molecular sizes of cPOX1 and cPOX3 purified from Chl-POX1 and PDX3 were 43 and 34 kDa, respectively. The cPOX1 was not located within chloroplast fraction, whereas the cPOX3 was found in intact chloroplasts extracted from senescing broccoli florets. We propose that cPOX3 is a chloroplast PDX and the activity was suppressed by UV-B treatment, suggesting that cPOX3 might be involved in Chl degradation in stored broccoli florets. (C) 2014 Elsevier Ltd. All rights reserved.