Hoecker Nadine, Lamkemeyer Tobias, Sarholz Barbara, Paschold Anja, Fladerer Claudia, Madlung Johannes, Wurster Karl, Stahl Mark, Piepho Hans-Peter, Nordheim Alfred, Hochholdinger Frank
ZMBP, Center for Plant Molecular Biology, Department of General Genetics, University of Tuebingen, Tuebingen, Germany.
Proteomics. 2008 Sep;8(18):3882-94. doi: 10.1002/pmic.200800023.
Heterosis describes the superior performance of heterozygous F(1)-hybrids compared to their homozygous parental inbred lines. Heterosis is already manifested during early maize (Zea mays L.) primary root development. In this study, the most abundant soluble proteins have been investigated before the phenotypic manifestation of heterosis in 3.5-day-old primary roots in the flint inbred line UH002, the dent inbred line UH301 and the corresponding hybrid UH301 x UH002. In CBB-stained 2-DE gels, 150 of 304 detected proteins (49%) were accumulated in a nonadditive fashion in the hybrid compared to the average of their parental inbred lines (Student's t-test: p < 0.05). Remarkably, expression of 51% (76/150) of the nonadditively accumulated proteins exceeded the high parent or was below the low parent. ESI-MS/MS identified 75 of the 76 proteins that belonged to these expression classes. The most abundant functional classes among the 75 proteins that were encoded by 60 different genes were metabolism (58%) and disease and defense (19%). Nonadditive protein accumulation in primary roots of maize hybrids might be associated with heterosis manifestation. Identification of these proteins could therefore contribute to the better understanding of the molecular basis of heterosis.
杂种优势描述了杂合F(1)杂种与其纯合亲本自交系相比的优越表现。杂种优势在玉米（Zea mays L.）早期初生根发育过程中就已显现。在本研究中，在硬质自交系UH002、马齿自交系UH301以及相应的杂种UH301×UH002的3.5日龄初生根中，在杂种优势表型出现之前对最丰富的可溶性蛋白质进行了研究。在考马斯亮蓝染色的双向电泳凝胶中，与亲本自交系的平均值相比，在杂种中检测到的304种蛋白质中有150种（49%）以非加性方式积累（学生t检验：p<0.05）。值得注意的是，51%（76/150）的非加性积累蛋白质的表达超过高亲本或低于低亲本。电喷雾串联质谱法鉴定出属于这些表达类别的76种蛋白质中的75种。由60个不同基因编码的75种蛋白质中，最丰富的功能类别是代谢（58%）和疾病与防御（19%）。玉米杂种初生根中的非加性蛋白质积累可能与杂种优势表现相关。因此，鉴定这些蛋白质有助于更好地理解杂种优势的分子基础。
