Molecular and biochemical characterization of postharvest senescence in broccoli
Molecular and biochemical characterization of postharvest senescence in broccoli
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DOI：
10.1104/pp.125.2.718
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发表时间：
2001-02-01
期刊：
影响因子：
7.4
通讯作者：
Buchanan-Wollaston, V
中科院分区：
文献类型：
--
作者：
Page, T;Griffiths, G;Buchanan-Wollaston, V
以青花菜（Brassica oleracea L.）var Italica）小花导致与发育中所见的表型变化相似的表型变化。叶片衰老为了更详细地比较这两个过程，我们研究了收获后在两种不同温度下储存的西兰花小花的分子和生化变化。我们发现，在较冷的温度下储存延缓衰老的症状在生化和基因表达水平。关键的生化成分（脂质，蛋白质和叶绿素）和基因表达模式的变化发生在收获的组织以及之前的任何可见的衰老迹象进行检测。使用以前确定的衰老增强基因，也是新分离的，差异表达的基因，我们发现，这些大多数表现出类似的增强表达在采后西兰花在发育叶片衰老。在生化水平上，当在室温下储存时，收获后检测到膜脂肪酸的快速损失。然而，脂质过氧化产物水平没有相应增加。这与保护性抗氧化基因的表达增加一起表明，在采后衰老的初始阶段，利用可用的脂质作为能量来源，发生细胞成分的有序分解。因此，西兰花小花的采后变化与发育叶片衰老的过程有许多相似之处。
Postharvest senescence in broccoli (Brassica oleracea L. var Italica) florets results in phenotypic changes similar to those seen in developmental. leaf senescence. To compare these two processes in more detail, we investigated molecular and biochemical changes in broccoli florets stored at two different temperatures after harvest. We found that storage at cooler temperatures delayed the symptoms of senescence at both the biochemical and gene expression levels. Changes in key biochemical components (lipids, protein, and chlorophyll) and in gene expression patterns occurred in the harvested tissue well before any visible signs of senescence were detected. Using previously identified senescence-enhanced genes and also newly isolated, differentially expressed genes, we found that the majority of these showed a similar enhancement of expression in postharvest broccoli as in developmental leaf senescence. At the biochemical level, a rapid loss of membrane fatty acids was detected after harvest, when stored at room temperature. However, there was no corresponding increase in levels of lipid peroxidation products. This, together with an increased expression of protective antioxidant genes, indicated that, in the initial stages of postharvest senescence, an orderly dismantling of the cellular constituents occurs, using the available lipid as an energy source. Postharvest changes in broccoli florets, therefore, show many similarities to the processes of developmental leaf senescence.