Zörb Christian, Herbst Ramona, Forreiter Christoph, Schubert Sven
Institute of Plant Nutrition (IFZ), Justus Liebig University Giessen, Giessen, Germany.
Proteomics. 2009 Sep;9(17):4209-20. doi: 10.1002/pmic.200800791.
It is of fundamental importance to understand the physiological differences leading to salt resistance and to get access to the molecular mechanisms underlying this physiological response. The aim of this work was to investigate the effects of short-term salt exposure on the proteome of maize chloroplasts in the initial phase of salt stress (up to 4 h). It could be shown that sodium ions accumulate quickly and excessively in chloroplasts in the initial phase of moderate salt stress. A change in the chloroplast protein pattern was observed without a change in water potential of the leaves. 2-DE revealed that 12 salt-responsive chloroplast proteins increased while eight chloroplast proteins decreased. Some of the maize chloroplast proteins such as CF1e and a Ca(2+)-sensing receptor show a rather transient response for the first 4 h of salt exposure. The enhanced abundance of the ferredoxin NADPH reductase, the 23 kDa polypeptide of the photosystem II, and the FtsH-like protein might reflect mechanism to attenuate the detrimental effects of Na(+) on the photosynthetic machinery. The observed transient increase and subsequent decrease of selected proteins may exhibit a counterbalancing effect of target proteins in this context. Intriguingly, several subunits of the CF1-CF0 complex are unequally affected, whereas others do not respond at all.
了解导致耐盐性的生理差异并深入探究这种生理反应背后的分子机制至关重要。本研究的目的是调查短期盐胁迫（长达4小时）对盐胁迫初始阶段玉米叶绿体蛋白质组的影响。结果表明，在中度盐胁迫的初始阶段，钠离子在叶绿体中迅速且过量积累。观察到叶绿体蛋白质模式发生变化，而叶片水势未变。双向电泳显示，12种盐响应叶绿体蛋白增加，而8种叶绿体蛋白减少。一些玉米叶绿体蛋白，如CF1e和一种钙传感受体，在盐处理的前4小时表现出相当短暂的反应。铁氧还蛋白NADPH还原酶、光系统II的23 kDa多肽和类FtsH蛋白丰度的增加可能反映了减轻Na(+)对光合机构有害影响的机制。在这种情况下，观察到的所选蛋白质的短暂增加和随后的减少可能表现出目标蛋白质的平衡作用。有趣的是，CF1-CF0复合物的几个亚基受到的影响不均等，而其他亚基则完全没有反应。
