STIMULATION OF GROWTH AND PHOSPHOLIPASE-A2 BY THE PEPTIDES MASTOPARAN AND MELITTIN AND BY THE AUXIN 2,4-DICHLOROPHENOXYACETIC ACID

The peptide mastoparan from wasp venom and the peptide melittin from bee venom stimulated growth in etiolated zucchini (Cucurbita pepo L.) hypocotyls. Both peptides were only effective in hypocotyls with abraded cuticles. At concentrations of 2-mu-g ml-1 peptide growth was stimulated 72% by mastoparan and 50% by melittin after 2 h as compared to the controls. Mastoparan (5-mu-g ml-1), melittin (10-mu-g l-1) and 2,4-dichlorophenoxyacetic acid (5 x 10(-4) M) stimulated accumulation of C-14-choline-labeled lysophosphatidylcholine in less than 10 min in cultured soybean cells (Glycine max L.), all to about the same extent. The effects of these peptides are among the first to be reported on plant cells and may be related to important events coupled to growth stimulation.