Functional analysis of the aroC gene encoding chorismate synthase from Xanthomonas oryzae pathovar oryzae

• Published in: Microbiological research Vol. 167; no. 6; pp. 326 - 331
• Main Authors: Song, Eun-Sung, Park, Young-Jin, Noh, Tae-Hwan, Kim, Yeong-Tae, Kim, Jeong-Gu, Cho, Heejung, Lee, Byoung-Moo
• Format: Journal Article
• Language: English
• Published: Germany Elsevier GmbH 20.06.2012
• Subjects: Amino acids; Amino Acids, Aromatic - metabolism; aroC; aroC gene; Aromatics; Blight; Chorismate synthase; Complementation; Culture Media - chemistry; DNA Transposable Elements; DNA, Bacterial - chemistry; DNA, Bacterial - genetics; Gene Deletion; Genetic Complementation Test; Leaves; Mutagenesis, Insertional; Mutant; Oryza - microbiology; Oryza sativa; Pathogens; Phosphorus-Oxygen Lyases - genetics; Phosphorus-Oxygen Lyases - metabolism; Pigment; Pigmentation; Pigments; Pigments, Biological - metabolism; Plant Diseases - microbiology; Plant Leaves - microbiology; Polymerase Chain Reaction; Prototrophy; Sequence Analysis, DNA; transposon mutagenesis; Transposons; Virulence; Xanthomonas - enzymology; Xanthomonas - genetics; Xanthomonas - growth & development; Xanthomonas oryzae; Xanthomonas oryzae pv. oryzae; aroC; Pigment; Xanthomonas oryzae pv. oryzae; Mutant
• ISSN: 0944-5013; 1618-0623
• DOI: 10.1016/j.micres.2011.11.002

Xanthomonas oryzae pv. oryzae causes bacterial blight in rice, and this bacterial blight has been widely found in the major rice-growing areas. We constructed a transposon mutagenesis library of X. oryzae pv. oryzae and identified a mutant strain (KXOM9) that is deficient for pigment production and virulence. Furthermore, the KXOM9 mutant was unable to grow in minimal medium lacking aromatic amino acids. Thermal asymmetric interlaced-PCR and sequence analysis of KXOM9 revealed that the transposon was inserted into the aroC gene, which encodes a chorismate synthase in various bacterial pathogens. In planta growth assays revealed that bacterial growth of the KXOM9 mutant in rice leaves was severely reduced. Genetic complementation of this mutant with a 7.9-kb fragment containing aroC restored virulence, pigmentation, and prototrophy. These results suggest that the aroC gene plays a crucial role in the growth, attenuation of virulence, and pigment production of X. oryzae pv. oryzae.