Determination of the yield

Determination of the yield

Procedure:

β- galactosidase assay was performed in a 96 well format. Briefly, 4000-5000 cells were plated in 96 well tissue culture coated plate. Cells were transfected with reporter plasmid after 18 -24 hrs and after 48 hrs the cells were washed once with D-PBS. 50μl of lysis buffer was added to the well and cells were lysed by freezing plate at -70°C and thawing at 37°C. Cells were pipette up and down and then the plate was centrifuged at 9000 X g for 5 minutes. The supernatant from each plate was transferred to clean eppendorf tube. Immediately prior to assay the ONPG cocktail was prepared as below: 47 μl 0.1 M sodium phosphate (pH 7.5)22 μl 4 mg/ml ONPG1 μl 100X Mg solution30μl of each well extract was added to microtitre well plate and70μl of ONPG cocktail was added to each well. The plate was kept on ice throughout the procedure. After addition of ONPG cocktail the plate was transferred to 37°C and the development of colour was monitored every 10 minutes for development of color. After development of yellow colour, the reaction was stopped by addition of 150μl of 1M sodium carbonate to each well

Lysis Buffer: 0.1% Triton X-100/0.1 M Tris-HCl (pH 8.0). 450 ml distilled water 50 ml 1M Tris-HCl (pH 8.0) 0.5 ml Triton X-100 detergent • 100X Mg++ solution: 0.1 M magnesium chloride 4.5 M 2-mercaptoethanol Stored at 4°C. • 0.1 M sodium phosphate (pH 7.5)41 ml 0.2 M Na2HPO4 9 ml 0.2 M Na H2PO4 50 ml distilled water • 4 mg/ml ONPG (o-nitrophenyl-β-D-galactopyranoside) in 0.1 M sodium phosphate (pH 7.5) containing 2 mM β-mercaptoethanol, Stored at –20°C. • 0.1 mg/ml β-gal standard: 0.1 mg/ml β-gal in 0.1 M sodium phosphate (pH 7.5) containing 2 mM 2-mercaptoethanol Stored at 4°C. • 1 M sodium carbonate in water

Solutions:

β-gal assay in transfected cells

Total cellular polyphosphates were quantified viapolyacrylamide-Tris borate gel electrophoresis (PAGE-TBE).Briefly, PAGEwas performed with Tris-borate buffer (pH 8.3) todeterminethe quantityand the typeof polyphosphatesextracted fromyeaststrains. Equal amount of total RNA (20 to 100 μg) was loadedon 34%PAGE-TBE gel (22cm long, 16 cm wide and 0.8 mm thick) and electrophoresedat 500Voltsfor 20-24 hin cold-roomtill the marker dye bromophenol blue(BPB)had migrated 15-16 cm awayfrom the well.After electrophoresis, total polyphosphates werevisualizedby staining the gel with 0.05%toluidine blue staining solutionfollowed by destaining. Polyphosphates wereobserved both as asmearin the top most portion of the gel as well asdiscreet bands of long chain polyphosphatesand shortchain polyphosphatesin middle andbottom half of the gel,respectively.Polyphosphateband intensity in the gelwas quantified using ImageJ software (http://rsbweb.nih.gov/ij/)and relative amountsof long chain and short chain polyphosphatesin C. glabratacells werecalculated

Quantitative analysisof polyphosphates

Complementary-DNA synthesis was doneusing reverse transcriptase enzyme and oligo-dT primers. For this, 1 μg good quality RNA was treated with1μl(1 unit) DNase I for 15 min to remove DNA contamination. Next, SuperScript III First-Strand Synthesis System kit (Invitrogen) was used to synthesize cDNA according to the manufacturer’s instructions. cDNA synthesized was stored at -20 ̊C till further use

Synthesis of complementary DNA (cDNA)

media containing 50 μM 2’2’-dipyridyland grown for 24 h at 28°C with continuous shaking at 200 rpm. Cells were harvested by centrifugation at 7000 g for 10 min at 4 °C, washed twice with 50 mM phosphate buffer (pH-7.4), and finally resuspended in phosphate buffer. The bacterial suspension was then diluted with chelex-100 treated PS to get a final OD600of 1.0 and incubated at 28°C for 5 min. Iron transport assay was initated by adding 55FeCl3(American radiolabeled chemicals, Inc., St. Louis, USA,specific activity 10.18 mci/mg) to a final concentration of 0.4 μM into the bacterial suspension. The radiolabelled stock solution was diluted with water and 1M sodium ascorbate for 55Fe3+uptake and 55Fe2+uptake studies, respectively. For uptake of FeCl3bound vibrioferrin, both vibrioferrin (7.6 mM stock) and 55FeCl3were incubated in 1:1 ratio by diluting it appropriately with water and uptake was initiated with a final concentartion of 0.4 μM. To stop the uptake, 200 μl of bacterial cell suspension was layered and immediately centifuged (13000 g; 1 min) through 300 μl of di-butylphthalate and di-octyl phthalate (1:1) mixture. The upper aqueous layer and organic solvent was aspirated, and pellet was resuspended in 100 μl Triton-X-100. The suspension was added to 5 ml scintillation cocktail, and radioactivity count was determined in the 3H channel of scintillation counter (Perkin Elmer, Liquid Scintillation analyzer, Tri-Carb 2910 TR, USA). As control, both Fe2+and Fe3+uptake assays were performed in presence of proton motive force uncoupler carbonylcyanidep-trifluoromethoxyphenylhydrazone (FCCP; 50 μM), to distinguish between non-specific uptake of readiolabelled Fe by the bacterial cells. However, no significant increase in the incorporation of Fe2+and Fe3+ was observed in presence of FCCP, which indicated that iron uptake by these strains is energy-dependent process

In vitro transport assay was performed by using radiolabelled iron to measure the capacity of Xanthomonas oryzaepv. oryzicola strains to transport 55Fe(II) and 55Fe(III) forms of iron as described previously with slight modifications (Ardon et al., 1997; Velayudhan et al., 2000). For iron uptake asssay, Xocwild-type BXOR1 strain, ∆rpfF mutant and the complemented strain harboring full length rpfFgenewere grown overnight in PS medium. 0.2% of the overnight grown culture was inoculated in fresh P

55Fe uptake assay

For complementation studies, C. glabrataORFs, CgFTR1(1.22 kb), CgFET3(1.91 kb), CgYFH1(0.53 kb), CgCCW14(0.64 kb), CgMAM3(1.91 kb)andCgHOG1(1.34 kb) were PCR amplified from wild-type genomic DNA using Phusion high-fidelity DNA polymerase and cloned down-stream of the PGK1promoter intothe XmaIand XhoI, XbaIand XmaI, XmaIand XhoI, BamHIand SalI, XmaIand XhoI, and BamHIand XmaIsites, respectively, in the CEN-ARS containing plasmid pGRB2.2 (pRK74). For over-expression studies, C. glabrataORFs, CgCCC1(0.95 kb), CgYAP5(1.05 kb)andCgMRS4(0.92 kb) were PCR amplified from wild-type genomic DNA using Phusion high-fidelity DNA polymerase and cloned down-stream of the constitutive promoter PDC1into the BamHI and SalI, XbaIand XmaI, and XmaI and XhoIsites, respectively, in the CEN-ARS containing plasmid obtained from Addgene (Addgene-ID 45323). All clones were verified by PCR and sequencing analysis

Cloning of C. glabrataORFs

For complementation studies, C. glabrataORFs, CgFTR1(1.22 kb), CgFET3(1.91 kb), CgYFH1(0.53 kb), CgCCW14(0.64 kb), CgMAM3(1.91 kb)andCgHOG1(1.34 kb) were PCR amplified from wild-type genomic DNA using Phusion high-fidelity DNA polymerase and cloned down-stream of the PGK1promoter intothe XmaIand XhoI, XbaIand XmaI, XmaIand XhoI, BamHIand SalI, XmaIand XhoI, and BamHIand XmaIsites, respectively, in the CEN-ARS containing plasmid pGRB2.2 (pRK74). For over-expression studies, C. glabrataORFs, CgCCC1(0.95 kb), CgYAP5(1.05 kb)andCgMRS4(0.92 kb) were PCR amplified from wild-type genomic DNA using Phusion high-fidelity DNA polymerase and cloned down-stream of the constitutive promoter PDC1into the BamHI and SalI, XbaIand XmaI, and XmaI and XhoIsites, respectively, in the CEN-ARS containing plasmid obtained from Addgene (Addgene-ID 45323). All clones were verified by PCR and sequencing analysis

Cloning of C. glabrataORFs