Division of Applied Life Sciences (BK21 program), IALS, PMBBRC, Gyeongsang National University, Jinju, 660-701, Korea,
Planta. 2013 Sep;238(3):459-74. doi: 10.1007/s00425-013-1900-6. Epub 2013 Jun 2.
Miscanthus sinensis is a promising bioenergy crop; however, its genome is poorly represented in sequence databases. As an initial step in the comprehensive analysis of the M. sinensis proteome, we report a reference 2-DE protein map of the leaf. A total of 316 protein spots were excised from the gels, digested with trypsin and subjected to matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS) or MALDI-TOF/TOF MS. Two hundred and thirty-two protein spots were identified, which are involved in a variety of cellular functions through distinct metabolic pathways. Functional annotation of the proteins revealed a nearly complete C3 and C4 cycle, starch and sugar synthesis pathway, glycolysis pathway, a significant portion of the pentose phosphate pathway, and many enzymes involved in secondary metabolism such as flavonoid/isoflavonoid, kaurene, chalcone, sesquiterpene and lignin biosynthesis. Other proteins belong to primary metabolism, transcription, protein synthesis, protein destination/storage, disease/defense, cell growth/division, transportation and signal transduction. To test the applicability of the constructed map, we studied the effect of heat stress on M. sinensis leaf proteome. Twenty-five protein spots were upregulated, five were newly induced and twenty-five spots were downregulated by heat treatment. The differentially accumulated proteins were involved in photosynthesis, energy metabolism, gene transcription, protein kinases and phosphatases, signal transduction, protein synthesis and heat shock responses. C4-specific pyruvate orthophosphate dikinase, Rubisco large subunit, Rubisco activase and some associated proteins were upregulated during heat stress and tend to restore upon recovery. Identification of these proteins provides some important clues regarding the way M. sinensis copes with hot climate. This work represents the first extensive proteomic description of M. sinensis and provides a reference map and heat-responsive candidates for future molecular and physiological studies of this bioenergy crop.
中国芒是一种很有前途的生物能源作物，但它在序列数据库中的基因组代表性很差。作为芒属植物蛋白质组综合分析的初步步骤，我们报道了叶片的参考 2-DE 蛋白质图谱。从凝胶中切下了 316 个蛋白质斑点，用胰蛋白酶消化后进行基质辅助激光解吸/电离飞行时间质谱（MALDI-TOF MS）或 MALDI-TOF/TOF MS 分析。鉴定了 232 个蛋白质斑点，这些蛋白质涉及多种细胞功能，通过不同的代谢途径进行。蛋白质的功能注释表明，几乎完整的 C3 和 C4 循环、淀粉和糖合成途径、糖酵解途径、戊糖磷酸途径的很大一部分以及许多参与黄酮类/异黄酮、贝壳杉烯、查尔酮、倍半萜和木质素生物合成的次生代谢的酶。其他蛋白质属于初级代谢、转录、蛋白质合成、蛋白质定位/储存、疾病/防御、细胞生长/分裂、运输和信号转导。为了测试构建图谱的适用性，我们研究了热应激对中国芒叶片蛋白质组的影响。25 个蛋白质斑点上调，5 个新诱导，25 个斑点下调。差异积累的蛋白质涉及光合作用、能量代谢、基因转录、蛋白激酶和磷酸酶、信号转导、蛋白质合成和热激反应。C4 特异性丙酮酸正磷酸二激酶、Rubisco 大亚基、Rubisco 激活酶和一些相关蛋白在热应激下上调，在恢复时趋于恢复。这些蛋白质的鉴定为中国芒应对炎热气候的方式提供了一些重要线索。这项工作代表了对芒属植物进行的首次广泛蛋白质组学描述，为该生物能源作物的未来分子和生理研究提供了参考图谱和热响应候选基因。
