Genetic and metabolic control of grain shape and weight in wheat

小麦粒形和粒重是与产量相关的重要参数。因此，关于小麦潜在决定因素和机制的知识具有高度的经济相关性。我们在这里利用两个独特的模型显示增加谷物重量的潜在不同的机制。在高产冬小麦品种Prinz的遗传背景内的渐渗代表合成小麦M6的基因组片段，其与籽粒大小，特别是粒长的数量性状基因座相关。转基因系，来自冬小麦品种Certo，过表达来自大麦的蔗糖转运蛋白基因，赋予增加的谷粒重量，主要与更高的谷粒宽度有关。我们计划在这些模型中分析与性状粒度和形状规格相关的特征。将使用组织学分析来鉴定显示细胞数量和/或细胞扩增差异的颗粒组织。将对籽粒发育进行全面的表型分析，包括母体和子代籽粒器官中的组织特异性转录物、代谢物和激素谱分析。主要目的是了解在谷物发育过程中响应代谢信号的细胞分裂和膨胀调节的信号通路。参与调控子房和果皮生长的基因网络将从与平行发育和生理研究相关的转录组数据中推断。预期的结果将导致更深入地了解生理，分子和代谢网络的规格的粒度和重量。这些知识在未来将使育种者能够制定策略，以提高产量潜力。

Grain shape and weight in wheat are important yield-related parameters. Knowledge about underlying determinants and mechanisms in wheat is therefore of high economic relevance. We here make use of two unique models displaying increased grain weight by potentially different mechanisms. An introgression, within the genetic background of the high-yield winter wheat variety Prinz, represents a genomic fragment of the synthetic wheat M6, which is related to a quantitative trait locus for grain size, especially grain length. A transgenic line, derived from the winter wheat variety Certo, overexpressing a sucrose transporter gene from barley confers increased grain weight, predominantly related to higher grain width. We plan to analyse characteristics associated with specification of the traits grain size and shape in these models. Histological analyses will be used to identify those grain tissues showing differences in cell number and/or cell expansion. Comprehensive phenotyping of grain development will be performed including tissue-specific transcript, metabolite and hormone profiling in maternal and filial grain organs. Main objective is to understand signalling pathways responsible for cell division and expansion modulations during grain development in response to metabolic signals. Gene networks involved in the regulation of ovary and pericarp growth will be inferred from transcriptome data linked to parallel developmental and physiological studies. The expected outcome will lead to deeper understanding of the physiological, molecular and metabolic network underlying the specification of grain size and weight. Such knowledge in the future will allow breeders to develop strategies to increase yield potential.