PhD Student Boston University Boston, Massachusetts
Body of Abstract: Plants and bacteria share a symbiotic relationship that is fundamental for carbon and nitrogen cycling in our ecosystem. Plants provide carbohydrates from photosynthesis to bacteria, which reciprocally contribute nutrients such as nitrogen and solubilized phosphate to the plant. Central to this interaction is the plant’s microbial carrying capacity, the maximum number of bacteria a plant can support, largely determined by the carbon amount released by the plant through exudation. This study aims to elucidate the dynamics between plant growth and microbial carrying capacity in Arabidopsis thaliana. Arabidopsis thaliana's growth follows a logistic model, characterized by a rapid growth phase that eventually decelerates as the plant matures, coinciding with a systemic accumulation of unused photosynthates and a subsequent reduction in photosynthesis. Concurrently, the plant's microbial carrying capacity expands, yet the nature of this expansion as the plant enters into its maturity is unclear. To shed light on this, we use Bacillus subtilis as a bacterial model organism and employ quantitative PCR to enumerate the number of bacteria cells that grow throughout the development of an Arabidopsis thaliana plant. The research aims to enhance our understanding of plant-microbe interactions and could potentially inform further studies on the microbial carrying capacity of plants.