Sghaier-Hammami Besma, Redondo-López Inmaculada, Valero-Galvàn José, Jorrín-Novo Jesús V
Laboratory of Extremophile Plants, Biotechnology Centre of Borj Cedria, P. O. Box 901, 2050, Hammam-Lif, Tunisia.
Agroforestry and Plant Biochemistry and Proteomics Research Group, Department of Biochemistry and Molecular Biology, University of Cordoba-CeiA3, Cordoba, Spain.
Planta. 2016 Feb;243(2):369-96. doi: 10.1007/s00425-015-2404-3. Epub 2015 Sep 30.
Contrary to the orthodox seeds, recalcitrant Holm oak seeds possess the enzymatic machinery to start germination during the maturation phase. The protein profile of the different parts, mature seeds, of the Holm oak, a non-orthodox plant species, has been characterized using one- and two-dimensional gel electrophoresis coupled to matrix-assisted laser desorption ionization-time of flight mass spectrometry. Protein content and profiles of the three seed tissues (cotyledon, embryonic axis and tegument) were quite different. The embryonic axis showed 4-fold and 20-fold higher protein content than the cotyledon and the tegument, respectively. Two hundred and twenty-six variable proteins among the three seed parts were identified, being classified according to their function into eight main groups. The cotyledon presented the highest number of metabolic and storage proteins (89% of them are legumin) compared to the embryonic axis and tegument. The embryonic axis had the highest number of the species within the protein fate group. The tegument presented the largest number of the defense-/stress-related and cytoskeleton proteins. This distribution is in good agreement with the biological role of the tissues. The study of the seed tissue proteome demonstrated a compartmentalization of pathways and a division of metabolic tasks between embryonic axis, cotyledon and tegument. This compartmentalization uncovered in our study should provide a starting point for understanding, at the molecular level, the particularities of the recalcitrant seeds.
与正统种子不同，顽拗型栓皮栎种子在成熟阶段具备启动萌发的酶机制。利用一维和二维凝胶电泳结合基质辅助激光解吸电离飞行时间质谱，对非正统植物物种栓皮栎不同部位（成熟种子）的蛋白质谱进行了表征。三种种子组织（子叶、胚轴和种皮）的蛋白质含量和图谱差异很大。胚轴的蛋白质含量分别比子叶和种皮高4倍和20倍。在三种种子部位中鉴定出226种可变蛋白，并根据其功能分为八个主要类别。与胚轴和种皮相比，子叶中代谢和储存蛋白的数量最多（其中89%是豆球蛋白）。胚轴在蛋白质命运组中的物种数量最多。种皮中防御/应激相关蛋白和细胞骨架蛋白的数量最多。这种分布与各组织的生物学作用高度一致。种子组织蛋白质组的研究表明，胚轴、子叶和种皮之间存在代谢途径的区室化和代谢任务的分工。我们研究中发现的这种区室化现象应能为从分子水平理解顽拗型种子的特性提供一个起点。
