Fig. 2

Deletion or overexpression of XrvB in Xoc distinctly regulated the transcriptions of type III secretion system (T3SS) genes, revealed by RT-qPCR analysis. a Deletion of xrvB enhanced the transcription levels of T3SS genes. The Xoc wild-type strain GX01 and the xrvB deletion mutant ΔxrvB were cultured in XOM2 or NB to an OD₆₀₀ of 0.6, or grown in host plants for 24 h, and total RNA was isolated. The expression levels of several hrp/hrc genes encoding the components of T3SS apparatus (hrpF, hrpB1, hrcV, hrcN, and hrcU) and effector genes (xopL, xopR, and avrBs3), as well as the T3SS key regulator genes (hrpG and hrpX) were determined by RT-qPCR. b Overexpression of xrvB reduced the transcription levels of the T3SS genes. Values are the means ± SD (n = 3 biological replicates). Differences were evaluated by Student's t-test (**P < 0.01)