Identification and Dissection of Amino Acid Residue 43 as the Key Polymorphic Determinant of Xcc Flagellin for Arabidopsis Defense Elicitation.
(A) Defense elicitation activity of purified His-tagged flagellins carrying one, two, or three amino acid changes as noted, with defense elicitation assayed as seedling growth inhibition. Arabidopsis Col-0 seedlings were treated with water (mock), 10 μM flg22, or 5 μM of the designated purified His-tagged flagellin. Means ± se are shown.
(B) PR-1 gene expression activated by flg22 peptide or by purified His-tagged flagellins that carry the Asp-43 residue, consistent with the results shown in (A). Data are for semiquantitative PCR performed on Arabidopsis Col-0 or fls2-101 mutant seedling samples taken 24 h after exposure to elicitor. Actin expression was monitored as a control.
(C) Defense elicitation activity of purified His-tagged flagellins carrying different amino acids at Xcc flagellin residue 43, assayed as for (A). Means ± se are shown.