Sayed Tahir Shah
Project Title: Exploring genome size-nutrient-drought interactions in wheat
Summary: Nutrient and water availability limit agricultural productivity across many environments. Drought stress greatly reduces nutrients uptake thus resulting in retarded plant growth. There is an urgent need to develop crops that are nitrogen (N), Phosphorus (P)- and water-use efficient, to decrease fertilizer use, under drought, whilst maintaining or enhancing yield. Nucleic acids are amongst the most N- and P-demanding biomolecules of the cell. As such DNA and RNA do not just carry genetic information, but also generate N and P demands in the cell. Furthermore, the transcriptome is particularly N and P demanding, but its volume and content can potentially be genetically and epigenetically regulated. RNA and DNA together account for a considerable component of organic P in the cell (perhaps 40-60%), but how these percentages vary, and are influenced by genome size, breeding and N and P limitation is currently unknown.
The N and P costs of nucleic acids should lead to resource demand trade-offs between the nucleic acid sinks, proteins and pigments (chlorophyll) during growth, when under limiting nutrients and water availability. It is known that high ploidy levels and increased genome size may result in increased N- and P- demands. By comparing wheat lines of diverse geographical origin, different genome size and varying ploidy levels (diploids, tetraploids and hexaploids), under various water and nutrient regimes, we can determine if ploidy (diploids, tetraploids and hexaploids), under various water and nutrient regimes, we can determine if ploidy level has an effect on N-, P- and water-use efficiency.