FIG. 1.

Genetic organization and restriction maps of the Hrp clusters of X. oryzae pv. oryzicola, which were cloned in p6, pPha21, pA1-E2, and pPK12.3. Colored open arrows indicate the positions and orientations of the hrp, hrc, and hpa genes. Black rectangles above open arrows indicate the positions of the PIP boxes. Red arrows below the plasmid maps indicate the positions and orientations of the marker-exchanged insertions, and the major phenotypes of the mutants are represented below the corresponding restriction maps. −, either no HR in tobacco or no pathogenicity in adult rice plants and no water-soaking symptoms in rice seedlings. ±, weak pathogenicity in formation of short lesion length in adult rice plants but no water-soaking symptoms in rice seedlings (data not shown). Tnp, transposase. Enzyme sites from the vector are shown in parentheses. E, EcoRI; K, KpnI.