Fig 3.

Enhanced accumulation of hydrogen peroxide in wheat guard cells after pretreatment with oxo-C14-HSL.A. Control leaves showing urediniospore (arrow) germination with directional growth of the hyphae towards stomatal opening (arrowhead) (control). Pathogen interaction with guard cells of oxo-C14-HSL pretreated leaves results in a significant accumulation of H₂O₂ (oxo-C14-HSL). Sterile-grown wheat cv. Bobwhite plants were pretreated with AHL solvent (control) or oxo-C14-HSL. Subsequently, leaves were inoculated with Puccinia graminis f. sp. tritici. DAB staining was performed 2 days after inoculation. On the right: exemplary leaves at 11 dai showing the differences in pustules development between control and oxo-C14-HSL-treated plants.B. The percentage of guard cells with higher accumulation of H₂O₂ as shown in A, 2 dai with P. graminis. **P ≤ 0.005 in Student's t-test. Experiment was repeated four times.C. Pustules development on wheat plants grown on soil for 10 days and inoculated three times with MgSO₄ (control), S. meliloti attM or S. meliloti expR+. Representative images were taken 5 dai with P. graminis using a standard binocular.