Zhou Y-J, Xue J-G, Wang X-G, Zhang X-Q
Department of Grassland Science, China Agricultural University, Beijing, China.
Genet Mol Res. 2012 Nov 12;11(4):3923-32. doi: 10.4238/2012.August.17.5.
Buffalograss, Buchloe dactyloides, is a dioecious species native to the Great Plains of North America. The florets at the early stages of development possess both gynoecium and androecium organ primordia but later become unisexual. Very little is known about the proteomic changes that occur when the florets change from hermaphroditism to unisexuality. We compared the protein composition of florets at the hermaphroditic stage with that at the unisexual stage. The development stage of the floret was determined by stereomicroscopic observation. Two-dimensional gel electrophoresis was used to separate the proteins extracted from female and male inflorescences. Stage- specific protein maps, with an average of about 400 spots per map, were analyzed with the protein analysis software. Eighteen spots were found to be differentially expressed between the hermaphrodite and unisexual stages. Of these, 12 were present at both stages but with a different expression value. Four specific spots appeared at the hermaphrodite stage and disappeared at the unisexual stage. Two specific protein spots were associated with female and male floret differentiation. One appears to be associated with contabescence in the female floret and the final protein appears to lead to the abortion of gynoecium in the male floret. The MALDI TOF/TOF technique was used for peptide mass fingerprinting of the differentially expressed proteins and the MASCOT software was used to search the protein database. However, only two protein spots were identified from the database. These were aldolase1 and Os05g0574400 (similar to malate dehydrogenase). This type of proteomic study can help to identify novel protein products and determine the mechanisms involved in the floral sex differentiation process in buffalo grass.
野牛草（Buchloe dactyloides）是一种雌雄异株的物种，原产于北美大平原。发育早期的小花同时具有雌蕊和雄蕊原基，但后来变为单性花。关于小花从雌雄同体转变为单性花时发生的蛋白质组变化，人们了解甚少。我们比较了雌雄同体阶段和单性花阶段小花的蛋白质组成。通过立体显微镜观察确定小花的发育阶段。使用二维凝胶电泳分离从雌花序和雄花序中提取的蛋白质。用蛋白质分析软件分析每个平均约有400个斑点的阶段特异性蛋白质图谱。发现有18个斑点在雌雄同体阶段和单性花阶段之间差异表达。其中，12个在两个阶段都存在，但表达值不同。4个特异性斑点出现在雌雄同体阶段，在单性花阶段消失。两个特异性蛋白质斑点与雌花和雄花的分化有关。一个似乎与雌花的衰老有关，最后一个蛋白质似乎导致雄花中雌蕊的败育。使用基质辅助激光解吸电离飞行时间串联质谱（MALDI TOF/TOF）技术对差异表达蛋白质进行肽质量指纹分析，并使用MASCOT软件搜索蛋白质数据库。然而，从数据库中仅鉴定出两个蛋白质斑点。它们是醛缩酶1和Os05g0574400（类似于苹果酸脱氢酶）。这种蛋白质组学研究有助于鉴定新的蛋白质产物，并确定野牛草花性别分化过程中涉及的机制。
