Peptone

The strains and plasmids used in this study are shown in Supplementary Table 1. E. coli strains were grown in Luria-Bertani medium (10 g/L tryptone, 5 g/L yeast extract, 10 g/L NaCl, pH 7.0) at 37 °C. L. enzymogenes strains were grown at 28 °C in Luria-Bertani medium and 10% TSB. For the preparation of culture media, tryptone, peptone, beef extract, and yeast extract were purchased from Sangon Biotech (Shanghai, China). When required, antibiotics were added (30 μg/mL kanamycin sulfate, 50 μg/mL gentamycin) to the E. coli or L. enzymogenes cultures. The bacterial growth in liquid medium was determined by measuring the optical density at 600 nm (OD600) using a Bioscreen-C Automated Growth Curves Analysis System (OY Growth Curves FP-1100-C, Helsinki, Finland).

The strains and plasmids used in this study are listed in Table S1. E. coli strains were grown in Luria Bertani medium (10 g/L tryptone, 5 g/L yeast extract, 10 g/L NaCl, pH 7.0) at 37 °C. X. campestris strains were grown at 28 °C in NYG medium (5 g/L peptone, 3 g/L yeast extract, 20 g/L glycerol, pH 7.0) or nutrient broth agar (NA) (5 g/L peptone, 3 g/L beef extract, 10 g/L sucrose, 1 g/L yeast extract, pH 7.0). For culture medium preparation, tryptone, peptone, beef extract, and yeast extract were purchased from Sangon Biotech. When required, antibiotics were added at the following concentration: 100 μg/ml sodium ampicillin, 30 μg/ml kanamycin sulphate, and 30 μg/ml gentamycin for E. coli or 50 μg/ml rifampicin for X. campestris.

L. edodes (NACC6250, from the Jiangsu Agricultural Microbial Germplasm Resources Collection of China) was used as the wild-type (WT) strain. The WT, CK (empty-vector controls), and LEGGT-silenced, LECSL-silenced L. edodes strains were cultured at 25 °C in a solid complete yeast medium (CYM). The formulation of the CYM medium was based on the method of Zhang et al. [17 (link)]: 1% maltose (biochemical grade, Sangon, Shanghai, China), 2% glucose (biotech. grade, Sangon, Shanghai, China), 0.2% yeast extract (for microbiological grade, Sangon, Shanghai, China), 0.2% peptone (for microbiological grade, Sangon, Shanghai, China), 0.05% MgSO₄·7H₂O (biochemical grade, Sangon, Shanghai, China), and K₂HPO₄ (biochemical grade, Sangon, Shanghai, China).
After culturing for 10 days in a constant-temperature incubator at 25 °C, ten pieces of mycelial blocks were aseptically picked and used to inoculate 100 mL of CYM, then incubated in an oscillator at 25 °C and 100 rpm/min for 7 days. Subsequently, the mycelial blocks were evenly broken in aseptic conditions, and 10 mL of broken mycelium was pipetted into 100 mL of CYM liquid medium. The culture was continued for 25 days in an oscillator at 25 °C and 100 rpm/min.

P. igniarius (NACC6220) was provided by the Jiangsu Agricultural Microbial Germplasm Resources Collection of China. The fermentation experiments were performed in 250 mL flasks containing 100 mL of complete yeast medium (CYM) broth (1% maltose (biochemical grade, Sangon, Shanghai, China), 2% glucose (biotech grade, Sangon, Shanghai, China), 0.2% yeast extract (microbiological grade, Sangon, Shanghai, China), 0.2% peptone (microbiological grade, Sangon, Shanghai, China), 0.05% MgSO₄·7H₂O (biochemical grade, Sangon, Shanghai, China), and K₂HPO₄ (biochemical grade, Sangon, Shanghai, China) at 28 °C and 150 r·min⁻¹ for 8 days.

Restriction enzymes, T4 DNA ligase, and DNA polymerase were purchased from Takara Biomedical Technology Co., Ltd. (Beijing, China). EasyPure Plasmid Miniprep Kit was purchased from Tsingke Biotechnology Co., Ltd. (Beijing, China). TIANquick Midi Purification Kit was purchased from Tiangen Biotech Co., Ltd. (Beijing, China). Rapid Yeast Genomic DNA Isolation Kit, yeast powder, peptone, kanamycin, ampicillin, G418 sulfate, and YNB (yeast nitrogen base, without amino acid and ammonium sulfate) were purchased from Sangon Biotech Co., Ltd. (Shanghai, China). GlcNAc was purchased from Aladdin Bio-Chem Technology Co., Ltd. (Shanghai, China). All chemicals used were of analytical grade.

The bacterial strains and plasmids used in the present study are shown in Table S1 in the supplemental material. Xanthomonas campestris pv. campestris wild-type strain XC1 and its derivatives were grown at 28°C in XYS medium (0.7 g L⁻¹ K₂HPO₄, 0.2 g L⁻¹ KH₂PO₄, 1 g L⁻¹ (NH₄)₂SO₄, 0.1 g L⁻¹ MgCl₂·6H₂O, 0.01 g L⁻¹ FeSO₄·7H₂O, 0.001 g L⁻¹ MnCl₂·4H₂O, 5 g L⁻¹ sucrose, and 0.0625% yeast extract, pH 7.0), NYG medium (5 g L⁻¹ peptone, 3 g L⁻¹ yeast extract, and 20 g L⁻¹ glycerol), Luria-Bertani (LB) medium (5 g L⁻¹ yeast extract, 10 g L⁻¹ peptone, and 10 g L⁻¹ sodium chloride), or nutrient agar (NA) medium (5 g L⁻¹, 3 g L⁻¹ beef extract, 10 g L⁻¹ sucrose, and 1 g L⁻¹ yeast extract, pH 7.0). Tryptone, peptone, beef extract, and yeast extract were purchased from Sangon Biotech (Shanghai, China). E. coli DH5α cells were used as hosts for constructing all recombinant vectors. E. coli strains were cultured at 37°C in LB medium. Antibiotics were then added at the following concentrations when needed: 25 μg mL⁻¹ rifamycin (Rif), 50 μg mL⁻¹ kanamycin (Km), 20 μg mL⁻¹ gentamicin (Gm), and 100 μg mL⁻¹ ampicillin (Amp). Bacterial growth was determined by measuring optical density at a wavelength of 600 nm (OD₆₀₀).