<i>fbaB</i> is required for full virulence and growth of <i>X. oryzae</i> pv. <i>oryzicola in planta</i>.

<p>(A) Symptoms caused by different <i>X. oryzae</i> pv. <i>oryzicola</i> strains suspended in water to OD₆₀₀ = 0.3 (approximately 1×10⁸ cfu/ml) on inoculated leaves of the host rice cv. Shanyou63 (susceptible cultivar) (2-month-old) by leaf-needling inoculation. Photographs were taken 14 days post-inoculation. RS105, the wild-type strain; RΔ<i>fbaB</i>, the <i>fbaB</i> deletion mutant; CRΔ<i>fbaB</i>, the complemented strain of RΔ<i>fbaB</i> with the <i>fbaB</i> gene; RΔ<i>hrcV</i>, a type III-deficient strain as a negative control. (B) Lesion lengths of rice bacterial leaf streak caused by different <i>X. oryzae</i> pv. <i>oryzicola</i> strains in rice. Values are the means ± standard deviations (SD) from three repeats, each with five leaves. The different symbol in each horizontal data column results from a paired, two-tailed Student <i>t</i> test relative to the wild-type. **, P = 0.01. (C) Bactrial growth capacity in inoculated leaves. Bacteria were recovered from the inoculated leaves every 24 hours in a period of 4 days post inoculation, and homogenized in sterile water. The homogenates were diluted and plated on NA plates with appropriate antibiotics. Bacterial CFU were counted after incubation at 28°C for 3 days. Data are the mean ± SD from three repeats.