A combined 15N tracing/proteomics study in Brassica napus reveals the chronology of proteomics events associated with N remobilisation during leaf senescence induced by nitrate limitation or starvation
A combined 15N tracing/proteomics study in Brassica napus reveals the chronology of proteomics events associated with N remobilisation during leaf senescence induced by nitrate limitation or starvation
复制标题
DOI：
10.1002/pmic.200800984
复制
发表时间：
2009-07-01
期刊：
影响因子：
3.4
通讯作者：
Avice, Jean-Christophe
中科院分区：
文献类型：
--
作者：
Desclos, Marie;Etienne, Philippe;Avice, Jean-Christophe
我们的目标是确定在氮素再动员过程中出现的与油菜衰老相关或不相关的叶片蛋白质组变化，以响应不同的硝酸盐有效性。通过N-15示踪、叶绿素水平、总蛋白含量和基于衰老相关基因12/Cab基因表达的分子指标跟踪了N的再动员和叶片的衰老状态。与氮素再动员相关的三个阶段被区分出来。蛋白质组学显示，在氮素再动员过程中，参与代谢、能量、解毒、胁迫反应、蛋白质分解和蛋白质折叠的55个蛋白质被显著诱导。特异性鉴定了四种蛋白水解酶。FtsH是一种氯化蛋白水解酶，在氮素再动员的早期阶段被瞬时诱导。考虑到氮素再动员、叶绿素和蛋白质含量的动态变化，FtsH的表达模式表明该酶可能参与了叶绿体蛋白的降解。天冬氨酸蛋白水解酶在叶片衰老初期升高并维持在较高水平，提示该酶参与了叶片衰老过程中的蛋白分解。两种蛋白酶体β亚基A1和衰老相关基因12在衰老后期被诱导并持续增加，这表明这些酶更特异地参与了叶片衰老末期发生的蛋白分解过程。
Our goal was to identify the leaf proteomic changes which appeared during N remobilisation that were associated or not associated with senescence of oilseed rape in response to contrasting nitrate availability. Remobilisation of N and leaf senescence status were followed using N-15 tracing, patterns of chlorophyll level, total protein content and a molecular indicator based on expression of senescence-associated gene 12/Cab genes. Three phases associated with N remobilisation were distinguished. Proteomics revealed that 55 proteins involved in metabolism, energy, detoxification, stress response, proteolysis and protein folding, were significantly induced during N remobilisation. Four proteases were specifically identified. FtsH, a chloroplastic protease, was induced transiently during the early stages of N remobilisation. Considering the dynamics of N remobilisation, chlorophyll and protein content, the pattern of FtsH expression indicated that this protease could be involved in the degradation of chloroplastic proteins. Aspartic protease increased at the beginning of senescence and was maintained at a high level, implicating this protease in proteolysis during the course of leaf senescence. Two proteases, proteasome beta subunit A1 and senescence-associated gene 12, were induced and continued to increase during the later phase of senescence, suggesting that these proteases are more specifically involved in the proteolysis processes occurring at the final stages of leaf senescence.