Proteomic analysis of Mesembryanthemum crystallinum leaf microsomal fractions finds an imbalance in V-ATPase stoichiometry during the salt-induced transition from C3 to CAM
Proteomic analysis of Mesembryanthemum crystallinum leaf microsomal fractions finds an imbalance in V-ATPase stoichiometry during the salt-induced transition from C3 to CAM
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DOI：
10.1042/bj20121087
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发表时间：
2013-03-01
影响因子：
4.1
通讯作者：
Thiel, Gerhard
中科院分区：
文献类型：
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作者：
Cosentino, Cristian;Di Silvestre, Dario;Thiel, Gerhard
盐生植物中胚草（Mesembryocarcinumstachum）通过吸收盐分并将C3光合作用转换为景天酸代谢（CAM）来适应盐胁迫。在这一过程中起重要作用的是中央液泡膜中的运输蛋白。在本研究中，我们研究了在盐胁迫适应过程中的微粒体中的蛋白质组成的动态变化。把这个叶子叠起来。用400 mM NaCl挑战的植物在处理的第4天积累盐，并且仅在第12天积累苹果酸;因此切换到CAM遵循任何盐适应的初始步骤，但延迟。使用无标记和半定量方法，我们确定了对照植物和处理12天后收获的植物的蛋白质组之间最显着的变化; 14种蛋白质的丰度受到显着影响。蛋白质组学分析表明，V-ATPase（vacuolar H ~+-ATPase）全酶的大部分亚基均为蛋白质组。盐处理在短期内（4天）的所有亚基的丰度有所下降。长期的适应，包括切换到CAM，伴随着所有可检测的亚基的代表性的强烈增加。由于这种增加是亚基特异性的，最高的上升发生在亚基E和C，数据表明，长期适应盐胁迫与V-ATP酶亚基化学计量的变化，并突出了这种全酶的结构可塑性。
The halophyte Mesembryanthemum crystallinum adapts to salt stress by salt uptake and switching from C3 photosynthesis to CAM (crassulacean acid metabolism). An important role in this process is played by transport proteins in the tonoplast of the central vacuole. In the present study we examine dynamic changes in the protein composition during salt-stress adaptation in microsomes from M. crystallinum leaves. Plants challenged with 400 mM NaCl accumulate salt by day 4 of treatment and malic acid only at day 12; a switching to CAM hence follows any initial steps of salt adaptation with a delay. Using a label-free and semiquantitative approach, we identified the most dramatic changes between the proteome of control plants and plants harvested after 12 days of the treatment; the abundance of 14 proteins was significantly affected. The proteomic data revealed that the majority of the subunits of V-ATPase (vacuolar H+-ATPase) holoenzyme. The salt treatment somewhat decreased the abundance of all subunits in the short term (4 days). Long-term adaptation, including the switching to CAM, goes together with a strong increase in the representation of all detectable subunits. Because this increase is subunit-specific, with the highest rise occurring for subunits E and c, the data suggest that long-term adaptation to salt stress correlates with a change in V-ATPase subunit stoichiometry and highlight the structural plasticity of this holoenzyme.