Nutrient release by cellular disintegration in developing barley seeds

同化物由营养器官输送，进入发育中的大麦籽粒的母体部分，并通过与母子交界处的细胞解体有关的过程释放到子代组织。与胚乳供应的营养释放相关的一个主要因素是小Jekyll蛋白。由于蛋白质的异位表达会立即引发细胞死亡，因此Jekyll在滋养谷物组织中的作用必须经过微调调节。在这里，将创建高度特异和高仿射的抗Jekyll重组抗体，并用于Jekyll-蛋白质复合体的免疫沉淀。经过沉淀和络合纯化后，共沉淀的蛋白质将被质谱学鉴定。转录本、代谢物和激素图谱将在三种不同的营养谷物组织(珠心、珠心突起、胚胎周围区域)中平行进行，这些组织表达Jekyll并靠近发育中的胚乳和胚。对野生型谷物和Jekyll表达被抑制的谷物进行的比较研究将发现与Jekyll作用密切相关的过程。通过图谱和免疫沉淀/MS分析描述的调节化合物将被比较，以确认独立方法的结果。我们期望了解以特定于发展的方式调节Jekyll活动的相互作用的组成部分。我们计划描绘不同滋养组织同化物释放的代谢规律，并进一步对发育中的胚胎区进行三维建模。这一新知识使人们对决定谷物部分、胚乳和胚胎的重要经济性状的生理过程有了更深入的了解。

Assimilates are delivered by vegetative organs, enter the maternal part of developing barley grains and are released to the filial tissues by processes related to cellular disintegration at maternal/filial boundaries. A major player associated to nutrient release for endosperm supply is the small Jekyll protein. Because ectopic expression of the protein immediately initiates cell death, Jekyll action in nourishing grain tissues has to undergo fine-tuned regulation. Here, highly specific and high affine anti-Jekyll recombinant antibodies will be created and used for immunoprecipitation of the Jekyll-protein complex. After precipitation and complex purification, co-precipitated proteins will be identified by mass spectroscopy. Transcript, metabolite and hormone profiling will be done in parallel in three different nourishing grain tissues (nucellus, nucellar projection, embryo-surrounding region) expressing Jekyll and being in close proximity to developing endosperm and embryo. A comparative study in wild type grains and grains with repressed Jekyll expression will identify processes tightly correlated to Jekyll action. Regulatory compounds depicted by both, profiling and immunoprecipitation/MS analysis will be compared to confirm results of the independent methods. We expect knowledge about interacting components regulating Jekyll activity in a development-specific manner. We plan delineation of metabolic regulation of assimilate release from the different nourishing tissues, furthermore 3-D modelling of the developing embryo region. The new knowledge leads to a deeper understanding of physiological processes determining economically important characters of the grain parts endosperm and embryo.