Identification and characterization of transcription factors regulating aspects of grain quality in wheat and related species

Grain quality is influenced by the coordination of carbohydrate, protein and lipid metabolism during the development of grain. Therefore, the understanding of the molecular mechanisms regulating seed storage protein genes (SSPs) and starch metabolism genes expression and accumulation should provide insights into the genetic control of the grain quality. The aim of this study was to compare between the known and novel orthologous TFs in both families (TaSPA/ TaBLZ1; O2 family) and (RSR1/ Q; euAP2 clade) were identified that the master regulators of grain quality and characterized in detail. Comparison across Triticeae species showed the differences and similarities between them such as changes in sequence, exon arrangement, and expression (temporal and spatial), which may reflect the divergence in the function of these genes and therefore the different quality profiles in the grains of the species examined. Also, microRNA172 is considered to play a vital role in regulating the targets of euAP2 genes during the development of both the spikelet initiation, floral and grain development. The expression level was compared between microRNA172 and their target, and the result revealed that microRNA172 was negatively regulated by their target. In addition, I aimed to explore the function of TaSPA (bZIP) by using RNAi. Protein interactions were also investigated between different TFs, and the result showed that TFs are a part of the network of proteins which were required for the control of the regulation of these genes.Together, this work provides a comparative approach in terms of the molecular and structural levels to determine how variation in TFs regulating grain storage metabolism could explain the variation in quality profile between species. This could be pivotal for floral and grain development, highlighting potential targets for genetic manipulation to improve future wheat yields.