Correlation of leaf senescence and gene expression/activities of chlorophyll degradation enzymes in harvested Chinese flowering cabbage (Brassica rapa var. parachinensis)
Correlation of leaf senescence and gene expression/activities of chlorophyll degradation enzymes in harvested Chinese flowering cabbage (Brassica rapa var. parachinensis)
复制标题
收获的白菜（Brassica rapa var. parachinensis）叶片衰老与叶绿素降解酶基因表达/活性的相关性
DOI：
10.1016/j.jplph.2011.06.011
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发表时间：
2011-11-15
影响因子：
4.3
通讯作者：
Pang, Xuequn
中科院分区：
文献类型：
--
作者：
Zhang, Xuelian;Zhang, Zhaoqi;Pang, Xuequn
菜心是我国主要叶菜类蔬菜之一。由于收获后叶绿素降解，它们的叶子迅速变黄，这限制了它们的销售。本研究采用乙烯和6-苄基氨基嘌呤（6-BA）处理甘蓝叶片，研究黑暗条件下叶片衰老和叶绿素降解与基因表达/活性的相关性。几个衰老相关标记的模式，包括一个典型的标记，衰老相关基因SAG 12的表达，表明乙烯加速叶片衰老的白菜，而6-BA延缓这一进程。与BrSAG（12）基因的表达趋势相似，脱镁叶绿素酶（BrPPH）、脱镁叶绿酸a加氧酶（BrPAO）和红色叶绿素分解代谢物还原酶（BrRCCR）3个叶绿素降解相关基因的表达在乙烯处理和对照叶片中均被强烈激活，而6-BA处理叶片的表达没有明显增加。在衰老过程中，各处理的Mg-脱螯合酶活性总体呈上升趋势，而6-BA处理的活性上升滞后。然而，叶绿素酶活性以及BrChlase 1和BrChlase 2的表达在所有处理中随着孵育而降低。综上所述，BrPPH、BrPAO和BrRCCR的表达以及Mg-脱螯合酶的活性与暗条件下大白菜叶片衰老过程中叶绿素的降解密切相关。(C)2011年Elsevier GmbH。All rights reserved.
Chinese flowering cabbage is one of the main leafy vegetables produced in China. They have a rapid leaf yellowing due to chlorophyll degradation after harvest that limits their marketing. In the present study, leaf senescence of the cabbages was manipulated by ethylene and 6-benzyl aminopurine (6-BA) treatment to investigate the correlation of leaf senescence and chlorophyll degradation related to gene expression/activities in the darkness. The patterns of several senescence associated markers, including a typical marker, the expression of senescence-associated gene SAG 12, demonstrated that ethylene accelerated leaf senescence of the cabbages, while 6-BA retarded this progress. Similar to the trends of BrSAG(12) gene expression, strong activation in the expression of three chlorophyll degradation related genes, pheophytinase (BrPPH), pheophorbide a oxygenase (BrPAO) and red chlorophyll catabolite reductase (BrRCCR), was detected in ethylene treated and control leaves during the incubation, while no evident increase was recorded in 6-BA treated leaves. The overall dynamics of Mg-dechelatase activities in all treatments displayed increasing trends during the senescence process, and a delayed increase in the activities was observed for 6-BA treated leaves. However, chlorophyllase activity as well as the expression of BrChlase1 and BrChlase2 decreased with the incubation in all treatments. Taken together, the expression of BrPPH, BrPAO and BrRCCR, and the activity of Mg-dechelatase was closely associated with the chlorophyll degradation during the leaf senescence process in harvested Chinese flowering cabbages under dark conditions. (C) 2011 Elsevier GmbH. All rights reserved.