description
- Food security represents a major global issue. Significant improvements in crop yields are urgently required to meet the 50% increase in world population by 2050. The degree of root branching determines the efficiency of water uptake and acquisition of nutrients in crops. This research proposal aims to investigate the role of phosphite in improving root branching. There are several reports that suggest that Phosphites have biostimulant properties. We have tested the effects of phosphites in several crops and find about 30% increase in root growth. This project will investigate the mode of phosphite action and if improved root architecture result in improvement in yield. To help our studies, we have already identified several genes and signals that are important for this process. This includes two key plant hormones auxin and cytokinin and two proteins called BIG and ARF19. These genes and signals are known to regulate root development and root branching. For example, BIG is known to regulate auxin transport via regulating the activity of an auxin transport protein called PIN1. We will test if increased auxin accumulation mediated by BIG and PIN1 can be amplified via a special auxin inducible protein called ARF19 that regulate where root branches are formed. We also propose to manipulate level of a class of cytokinin called cis zeatin that show an induction in phosphite treated root tissues. We will manipulate endogenous cis zeatin levels by regulating cis zeatin biosynthesis or degradation. We will perform a series of experiments to test the role of these signals and proteins in regulating root branching. Next, we will undertake a series of physiological studies in two commercially important crops wheat and oilseed rape to determine whether phosphite treatment can improve resource use efficiency. The plants will be subjected to nutrient or water deficiency and its effect on above ground physiology assessed. We will also assess relationship between root system architecture and grain yield in the field. Finally we will investigate in which crops phosphites promote root growth. Our industrial partners will undertake a series of studies on biostimulant properties of phosphites in field trials. These partners will test several different phosphite formulations and their effect in a range of crops and in different agro climatic conditions. The knowledge gained from this study will provide information about the key genes and processes controlling root branching. Also by optimising doses, timing of application and treatments this project will provide a clear framework for phosphite treatment in a number of crops. With crops yielding better returns, this research is likely to have a direct impact on farm income leading to improved nutritional, financial and social stability.