Figure 5.

Lesion initials occur preferentially in mesophyll cells, as detected by aniline blue staining. Plants were grown and lesions were induced as explained in Figure 4. Each microlesion was detected as a callose deposit and recorded according to its relative position on the leaf. The diagram to the right shows a transverse cut of an Arabidopsis leaf with labels corresponding to different cell types (E, epidermis; M, mesophyll cells; P, parenchyma cells; S, stomate).