Characterization of the AID-v1 library. (a) Fitness impact of the GAL1pr-OsTIR1(F74G) expression construct. For each ORF, the fitness impact was estimated as the colony size of the OsTIR1⁺ strain relative to the OsTIR1⁻ strain in the AID-v1 library (OsTIR1⁺/OsTIR1⁻), determined according to Fig. 2 c. Distributions of relative colony sizes for two sets of ORFs (4,698 non-essential ORFs or 624 not affected proteins in Fig. 2 d). Median ± mad (median absolute deviation) relative fitness is indicated. (b) Expression levels of essential and degraded proteins in the AID-v1 library (Fig. 2 c), according to fitness of OsTIR1⁺ strains. Protein abundance (mNG signal corrected for background fluorescence, mNG-bkg) in the OsTIR1⁻ background; abundance bins defined in Fig. S2 f; P value in a Mann–Whitney U test. (c) Number of OsTIR1⁺ strains in the AID-v1 library with essential and degraded proteins, stratified by essential gene type: core or variable according to Peter et al. (2018), with or without suppressors according to van Leeuwen et al. (2020). (d and e) Protein levels (mNG signal in units of background fluorescence, mNG/bkg) in the AID-v1 library determined according to Fig. 2 c. Essential and non-essential ORFs (d) and strains with normal or impaired fitness based on colony size measurements (e) are marked. Top and right, normalized frequency distributions of protein levels in each category.