Figure 2. The increase in actin filament abundance following chitin elicitation requires the LYK receptor.

(a) Analysis of filament density was performed on Arabidopsis WT or mutant hypocotyls treated with mock, 1 μM elf26 or 1 μM chitin for 5 min. WT epidermal cells after elf26 or chitin treatments had a significant increase in filament abundance. Treatment with elf26 increased the filament abundance in lyk1 lyk4 double mutant cells, however, chitin treatment did not. The actin arrays in efr mutant cells were significantly more abundant following chitin treatments, but were unresponsive to elf26 treatments. (b) The extent of filament bundling was measured on the images used for a. No significant change in filament bundling following treatment with MAMPs was observed compared with respective mock controls. Values given are mean±s.e.m. (n⩾200 cells from 10 hypocotyls for each treatment and genotype; ***P<0.001 compared with respective mock control; ND, no significant difference; Student's t-test).