Understanding the foliar uptake of amino acids

Abstract

Research to enhance crop yields in an environmentally sustainable fashion is of great interest to the agricultural sector to meet the increasing demand in the face of pressure to reduce pesticide use.
Biostimulants, such as naturally occurring amino acids, are environmentally benign plant treatments that potentially enable improved yield, growth, and resistance to external environmental factors. Amino acids can reduce the impact of abiotic stress, stimulate plant defence mechanisms, and improve rate of photosynthesis. The foliar application of amino acids is known to increase the overall yield and quality of some plant species. However, there are several gaps in our understanding of their mode of action that prevent us from realising their full potential.
This project investigates the movement of amino acids in soybeans using isotopically and fluorescently labelled amino acids. By tracing amino acid movement using sensitive detection methods, such as mass spectrometry, a clearer understanding of the timescale of uptake of the amino acids, their movement around the plant, and their eventual break down and metabolism, has been gained.
In summary, this thesis aims to reduce the dependence on agrochemicals, aligning with the key characteristics of sustainable chemistry, by understanding the mechanisms by which amino acids improve crop yields and targeting them more effectively. Results show rapid uptake of the labelled tryptophan treatment within the four hours of application and movement around the plant to all plant parts with metabolism starting around 48 hours after application.