Elicitor activity of identified P. halstedii 57 kDa protein. Figure (A) shows a 13% SDS-PAGE of the P. halstedii protein purification. Lane 2 (P) displays the ammonium sulphate precipitate, lane 3 (FT) shows the purified proteins of the flow-through, lane 4 (57 kDa) displays the gel extraction section from lane 3 at Mr 50-70 kDa and lane 5 (<35 kDa) shows the gel extraction section from lane 3 at Mr below 35 kDa. The diagram (B) shows the effect of the extracted proteins of the flow-through to the ethylene induction of sunflower leave-disks 3 h after infiltration. The three columns display the activity of the gel extraction section of the 57 kDa protein (lane 4, 57 kDa), the gel extraction section of proteins <35 kDa (lane 5, <35 kDa) and the negative control. M represents marker (n = 3).