Fluorescence-based Bacterial Growth Assay

Overnight cultures were adjusted to an OD₆₀₀ of 1.0 and diluted by 1:100 into fresh agrobacterium minimal medium containing 25 μg. ml^-1 thiamine (APExBIO, USA) (ABT) (79 (link)) supplemented with 5 g · L⁻¹ glucose (Sangon Biotech, PRC) and 2 g · L⁻¹ Casamino Acids (Sangon Biotech). Bacterial strains were grown in ABTCG medium with an initial inoculum of OD₆₀₀ of 0.01. An aliquot (100 μL) was transferred to a polystyrene, black 96-well plate (Corning, USA). Arbitrary fluorescence intensity units (FIUs) were measured with an excitation wavelength of 488 nm, and the cell density (OD₆₀₀ values) of different samples was simultaneously measured. Relative fluorescence units (RFUs) were determined by normalizing the FIU values against OD₆₀₀ values as reported previously (78 (link)). Three biological repeats were performed, and each biological repeat contained at least four technical replicates.