Führs Hendrik, Hartwig Moritz, Molina Laura Elisa Buitrago, Heintz Dimitri, Van Dorsselaer Alain, Braun Hans-Peter, Horst Walter J
Institute for Plant Nutrition, Faculty of Natural Sciences, Leibniz University Hannover, Herrenhaeuser Strasse 2, Hannover, Germany.
Proteomics. 2008 Jan;8(1):149-59. doi: 10.1002/pmic.200700478.
The apoplast is known to play a predominant role in the expression of manganese (Mn) toxicity in cowpea (Vigna unguiculata L.) leaves. To unravel early Mn-toxicity responses after 1-3 days Mn treatment also in the leaf symplast, we studied the symplastic reactions induced by Mn in two cultivars differing in Mn tolerance on a total cellular level. Comparative proteome analyses of plants exposed to low or high Mn allowed to identify proteins specifically affected by Mn, particularly in the Mn-sensitive cowpea cultivar. These proteins are involved in CO(2) fixation, stabilization of the Mn cluster of the photosystem II, pathogenesis-response reactions and protein degradation. Chloroplastic proteins important for CO(2) fixation and photosynthesis were of lower abundance upon Mn stress suggesting scavenging of metabolic energy for a specific stress response. Transcriptome analyses supported these findings, but additionally revealed an upregulation of genes involved in signal transduction only in the Mn-sensitive cultivar. In conclusion, a coordinated interplay of apoplastic and symplastic reactions seems to be important during the Mn-stress response in cowpea.
已知质外体在豇豆（Vigna unguiculata L.）叶片中锰（Mn）毒性的表达中起主要作用。为了揭示在1-3天锰处理后叶片共质体中的早期锰毒性反应，我们在全细胞水平上研究了锰对两个锰耐受性不同的豇豆品种共质体反应的影响。对暴露于低锰或高锰环境下的植物进行比较蛋白质组分析，能够鉴定出受锰特异性影响的蛋白质，尤其是在对锰敏感的豇豆品种中。这些蛋白质参与二氧化碳固定、光系统II锰簇的稳定、发病机制反应和蛋白质降解。在锰胁迫下，对二氧化碳固定和光合作用重要的叶绿体蛋白质丰度降低，这表明为特定的胁迫反应消耗了代谢能量。转录组分析支持了这些发现，但还揭示了仅在对锰敏感的品种中参与信号转导的基因上调。总之，在豇豆的锰胁迫反应中，质外体和共质体反应的协同相互作用似乎很重要。
