Furthermore, the role of the three B. pseudomallei T3SS in causing plant disease is evaluated and the implication of the ability of B. pseudomallei to infect plants is discussed. Methods Bacterial strains, plasmids and growth conditions All bacterial strains, plasmids used and constructed are listed in Table 1. All strains of B. thailandensis and B. pseudomallei were cultured at 37°C in Luria-Bertani (LB) medium or on Tryptone Soy Agar (TSA) plates. To obtain log-phase culture, 250 μL of overnight culture was inoculated into 5 mL LB medium and cultured for 2.5 hours with constant NSC23766 research buy shaking at 100 rpm. Escherichia coli strains were cultivated at 37°C in LB medium. Antibiotics were added

to the media at the following final concentrations of 100 μg/mL (ampillicin); 25 μg/mL (kanamycin); 10 μg/mL (tetracycline); and 25 μg/mL (zeocin) for E. coli, 250 μg/mL (kanamycin); 40 μg/mL (tetracycline); 25 μg/mL (gentamicin) and 1000 μg/mL (zeocin) for B. pseudomallei. All antibiotics were purchased from Sigma (St Louis, MO, USA). Table 1 All bacterial strains, plasmids used and PND-1186 in vitro constructed. Name Description Source or Reference pK18mobsacB oriT; KmR; sacB gene [32] pGEM-tet pGEM containing a tetracycline resistance cassette, TetR, AmpR Y. Chen, unpublished pCLOXZ1 pGEM containing a zeocin resistance cassette, ZeoR, AmpR Y. Chen,

unpublished pT3SS1/upstream/downstream/tet pK18mobsacB containing upstream and downstream of TTSS1 flanking a tet cassette, KmR, TetR This study pT3SS2/upstream/downstream/tet pK18mobsacB containing upstream and downstream of TTSS2 flanking a tet Ribonucleotide reductase cassette, KmR, TetR This study pT3SS3/upstream/downstream/zeo pK18mobsacB containing upstream and downstream

of TTSS3 flanking a zeo cassette, KmR, ZeoR This study E. coli     DH5α Infection strain Lab stock TG1 Cloning host Zymo Research SM10λpir Conjugation strain [33] B. thailandensis     ATCC700388   ATCC B. pseudomallei     K96243 Clinical isolate Thailand 561 Kangaroo isolate Eu Hian Yap, unpublished 612, 490 Avian isolates Eu Hian Yap, unpublished 77/96, 109/96 Soil isolates Eu Hian Yap, unpublished KHW Wild-type parental strain, clinical isolate, KmS [20] KHWΔT3SS1 BPSS1386-1411 region was replaced with tet cassette, TetR, KmS This study KHWΔT3SS2 BPSS1592-1629 region was replaced with tet cassette, TetR, KmS This study KHWΔT3SS3 Napabucasin cost BPSS1520-1552 region was replaced with zeo cassette, ZeoR, KmS This study Plant material Tomato seeds of the Solanum lycopersicum variety Season Red F1 Hybrid (Known-You Seeds Distribution (S.E.A) Pte Ltd) and Arabidopsis thaliana (Loh Chiang Shiong, NUS) were surface sterilized with 15% bleach solution for 15 minutes with vigorous shaking. The seeds were rinsed in sterile distilled water and germinated in MS agar medium. The seedlings were cultivated with a photoperiod of 16 hour daylight and 8 hour darkness. One month old plantlets were used for infection.