Sang Wen, Huang Zeng-Rong, Qi Yi-Ping, Yang Lin-Tong, Guo Peng, Chen Li-Song
Institute of Horticultural Plant Physiology, Biochemistry and Molecular Biology, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
College of Resource and Environmental Science, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
J Proteomics. 2015 Jun 18;123:128-46. doi: 10.1016/j.jprot.2015.04.007. Epub 2015 Apr 17.
Limited data are available on boron (B)-toxicity-responsive proteins in plants. We first applied 2-dimensional electrophoresis (2-DE) to compare the effects of B-toxicity on leaf protein profiles in B-tolerant Citrus sinensis and B-intolerant Citrus grandis seedlings, and identified 27 (20) protein species with increased abundances and 23 (25) protein species with decreased abundances from the former (latter). Generally speaking, B-toxicity increased the abundances of protein species involved in antioxidation and detoxification, proteolysis, cell transport, and decreased the abundances of protein species involved in protein biosynthesis in the two citrus species. The higher B-tolerance of C. sinensis might include following several aspects: (a) protein species related to photosynthesis and energy metabolism in C. sinensis leaves were more adaptive to B-toxicity than in C. grandis ones, which was responsible for the higher photosynthesis and for the better maintenance of energy homeostasis in the former; and (b) the increased requirement for detoxification of reactive oxygen species and cytotoxic compounds due to decreased photosynthesis was less in B-toxic C. sinensis leaves than in B-toxic C. grandis ones. B-toxicity-responsive protein species involved in coenzyme biosynthesis differed between the two species, which might also contribute to the higher B-tolerance of C. sinensis.
B-toxicity occurs in many regions all over the world, especially in arid and semiarid regions due to the raising of B-rich water tables with high B accumulated in topsoil. In China, B-toxicity often occurs in some citrus orchards. However, the mechanisms of citrus B-tolerance are still not fully understood. Here, we first used 2-DE to identify some new B-toxicity-responsive-proteins involved in carbohydrate and energy metabolism, antioxidation and detoxification, signal transduction and nucleotide metabolism. Our results showed that proteins involved in photosynthesis and energy metabolism displayed more adaptive to B-toxicity in B-tolerant C. sinensis than in B-intolerant C. grandis, which might play a key role in citrus B-tolerance. Therefore, our results reveal some new mechanisms on plant B-response and tolerance.
关于植物中硼（B）毒性响应蛋白的数据有限。我们首先应用二维电泳（2-DE）来比较硼毒性对耐硼的甜橙和不耐硼的柚幼苗叶片蛋白质谱的影响，并从前者（后者）中鉴定出丰度增加的27（20）种蛋白质和丰度降低的23（25）种蛋白质。一般来说，硼毒性增加了两种柑橘中参与抗氧化和解毒、蛋白水解、细胞运输的蛋白质的丰度，并降低了参与蛋白质生物合成的蛋白质的丰度。甜橙较高的耐硼性可能包括以下几个方面：（a）甜橙叶片中与光合作用和能量代谢相关的蛋白质比柚叶片中的蛋白质对硼毒性更具适应性，这使得前者具有更高的光合作用和更好的能量稳态维持能力；（b）由于光合作用降低，甜橙叶片中对活性氧和细胞毒性化合物解毒的需求增加幅度小于柚叶片。两种植物中参与辅酶生物合成的硼毒性响应蛋白种类不同，这也可能是甜橙耐硼性较高的原因。
硼毒性在世界各地的许多地区都有发生，特别是在干旱和半干旱地区，因为富含硼的地下水位上升，表土中积累了高浓度的硼。在中国，一些柑橘果园经常出现硼毒性问题。然而，柑橘耐硼的机制仍未完全了解。在这里，我们首次使用二维电泳来鉴定一些参与碳水化合物和能量代谢、抗氧化和解毒、信号转导以及核苷酸代谢的新的硼毒性响应蛋白。我们的结果表明，与不耐硼的柚相比，耐硼的甜橙中参与光合作用和能量代谢的蛋白质对硼毒性表现出更强的适应性，这可能在柑橘耐硼性中起关键作用。因此，我们的结果揭示了植物对硼响应和耐受的一些新机制。
