Collaborative Research: Genetic Comparisons of Abscission Zones in Grasses

在农业的黎明，我们的祖先收获野生谷物，并开始年复一年地重新种植。这一过程迅速导致了对留在植物上的谷物的选择，而不是落在地上。现在，一万年后的今天，这种留在工厂直到收获的能力具有明显的经济重要性。从落下的野生谷物和不落下来的栽培谷物的变化是由正常(即野生)过程中自然发生的突变引起的。然而，不同籽粒的脱粒过程是不同的。例如，野生水稻的掉籽细节与野生高粱或野生谷子不同。这个项目将发现是什么自然突变导致了种植的谷物，以及在水稻、高粱和谷子中播种的自然过程是否在遗传上相似。因为在植物上保留种子是农业的基础，这是植物的一个明显的方面，可以吸引所有教育水平的学生。俄克拉荷马州立大学的硕士教师和本科教育专业的学生，以及本科理科专业的学生和当地的高中生，都将积极参与该项目所需的观察和数据收集。种子的脱落通过一个特有的薄弱环节--离散区(AZ)发生，在这个区域，细胞和细胞壁的内容物被修饰，使果实从母体植株上脱落。这个项目将测试发育是否通常是保守的，即AZ是否是通过在不同时间或不同位置激活保守的发育程序而产生的，或者发展是否通过使用新的基因组合产生新的结构(在这种情况下，AZ)。具体地说，重组自交系和野生材料将被用来识别在模式物种绿谷子(Setaria Viridis)中促成粉碎的基因。这些研究将得到绿色谷子与短柄小米和大米的转录数据的补充。这些研究将检验这样的假设，即AZ发育的某些方面在三个物种之间是相同的，但许多方面是不同的，因为AZ在每个物种中形成的位置不同。然后，调查将扩大到许多其他草，其中一些类似于谷子、水稻和担子，一些显示出明显的种子脱落模式。这些结果将定义在生态和经济关键路径上并行和收敛进化的程度。

At the dawn of agriculture, our ancestors harvested wild grains and began replanting them year after year. This process rapidly led to selection for grains that stayed on the plant, instead of falling on the ground. Now, 10,000 years later, this capacity to stay on the plant until harvest has obvious economic importance. The change from wild grains that fall and cultivated ones that do not is caused by naturally occurring mutations in a normal (that is wild) process. However, the process of shedding seeds occurs differently in different grains. For example, the details of dropping seeds in wild rice are different from those in wild sorghum or wild millet. This project will discover what natural mutations led to the cultivated grains, and whether the natural process of shedding seeds in rice, sorghum, and millet is genetically similar. Because retaining seeds on the plant is the very basis of agriculture, it is an obvious aspect of plants that can engage students at all education levels. Master teachers and undergraduate education majors at Oklahoma State University, as well as undergraduate science majors and local high school students, will participate actively in the observations and data collection required for the project.Shedding of seeds occurs via a characteristic zone of weakness, the abscission zone (AZ), in which the contents of cells and cell walls are modified to allow a fruit to fall off the parent plant. This project will test whether development is generally conservative, i.e., whether the AZ is produced by activating a conserved developmental program at different times or in different locations, or whether development produces novel structures (in this case, the AZ) by using novel gene combinations. Specifically, recombinant inbred lines and wild accessions will be used to identify genes that contribute to shattering in the model species green millet (Setaria viridis). These studies will be complemented by transcriptomic data on green millet in comparison to Brachypodium distachyon and rice. These investigations will test the hypothesis that some aspects of AZ development are shared among the three species but that many aspects differ because the AZ forms in a different position in each. The investigation will then be expanded to many other grasses, some of which are similar to millet, rice and Brachypodium, and some of which show distinct patterns of seed shedding. The results will define the extent of parallel and convergent evolution in an ecologically and economically critical pathway.