Figure 2.

Scanning electron microscopy pictures of the seed surface of A. thaliana and C. sativa treated with plasma for two exposure times (1 min and 15 min) and compared to the control (0 min). The plasma treatment has an increased effect on the surface smoothing that therefore depends on the treatment time. The pictures (A–C) correspond to A. thaliana seeds. The pictures (D–F) correspond to C. sativa. In the first column, the seeds are not treated (A,D); In the second column, the seeds are exposed to the plasma for 1 min (B,E); And in the third column (C,F) the treatment time is 15 min. For the pictures of whole seeds (1) the scale bars are 200 µm, and for the pictures of one cell (2) the scale bars are 20 µm. i: radial cell wall, ii: columella.