The physical presence of plant roots and the compounds they release have a number of effects upon the substrate in which they grow, including the cohesion between roots and soil. Whilst we are aware that roots protect soil from erosion, we have limited knowledge about the plant traits most important for increasing root-substrate cohesion. Understanding these traits would be instrumental for developing crops that reduce soil erosion. In recent years, there has been a growing interest in characterising how roots cohere with their substrates, particularly soils. However, most studies have compared plant species with different root systems in unsterile, complex soils using time- and labour-intensive experiments that require specialist equipment. This has prevented scientists from quantifying the plant-specific traits that modify cohesion in a detailed and timely manner. In this thesis, I optimised a quick, high-throughput experimental method based on measuring the centrifugal force required to detach Arabidopsis thaliana seedlings from an agar medium. This enabled me to use genetic and molecular approaches to quantify the contribution of known traits and novel genes to root-substrate cohesion. I found changes to root hair development and morphology, root exudate composition, subcellular vesicle trafficking pathways and ATP-Binding Cassette transporter function affects root adhesiveness in Arabidopsis. I also show that the findings of this method can translate to work with mature plants in soils, indicating that this experimental approach is an efficient way to identify plant-specific traits that affect root-substrate cohesion before studying their contribution in complex soils. These results are at the forefront of describing plant-dependent requirements for root-substrate interactions and provide a foundation for evaluating how plants adhere to and cohere with their substrates and identifying the genes that regulate these mechanisms.
Searching for plant traits that affect root-substrate cohesion in Arabidopsis thaliana
Eldridge, B. M. (Author). 28 Sep 2021
Student thesis: Doctoral Thesis › Doctor of Philosophy (PhD)