Effect of calcium and calmodulin antagonists on ethylene biosynthesis in tomato fruits.
Njoroge, C.K., Kerbel, E.L. and Briskin, D.P.
Journal of the Science of Food and Agriculture. Volume 76, Number 2, Feb 1998. Pages 209-214.
1998
บทคัดย่อ
The aim of this work was to elucidate the mode of action of calcium in calcium-inhibited ethylene biosynthesis. In one experiment, mature green tomatoes were treated with 1.5% (w/v) CaCl2 + 60 micromolar N-6(aminohexyl)-1-naphthalene-sulphonamide (W5). 1.5% (w/v) CaCl2 + 60 micromolar N-6(aminohexyl)-5-chloro-1-naphthalenesulphonamide (W7), 1.5% (w/v) CaCl2 alone or distilled water (control). The control and the W7 treatment had much higher ethylene production than either the CaCl2 treatment alone or the CaCl2 + W5 treatment. In another experiment, similar tomatoes were treated with 1.5% (w/v) CaCl2 + 15 micromolar trifluoperazine (TFP). 1.5% (w/v) CaCl2 only, or distilled water (control). The treatment with 1.5% CaCl2 + 15 micromolar TFP gave higher ethylene production than 1.5% (w/v) CaCl2 without TFP, and nearly the same level as the control towards the end of the experimental period. For enzyme and intermediate metabolite assays, mature green tomatoes were treated with 1.5% (w/v) CaCl2 plus either W5 or W7. W5 treatment had a lower ethylene forming enzyme (EFE) activity, higher 1-aminocyclopropane-1-carboxylic acid (ACC) concentration, similar levels of ACC synthase activity and 1-(malonylamino)-cyclopropane-1-carboxylic acid concentration, compared to the control and W7 treatment. As W7 is a more potent calmodulin antagonist than W5, these results suggest a calcium-calmodulin inactivation of EFE act