EFFECT OF TI(IV) ON FE ACTIVITY IN CAPSICUM-ANNUUM

Capsicum annuum, L. Plants (cv Bunejo) were treated with Ti4+ ascorbat e via soil, via leaves, and via soil plus via leaves. The Fe activity was measured through the catalase and peroxidase enzymes and the activ e fraction of Fe (Fe2+) and Ti was determined in leaves, fruits, chlor oplasts and chromoplasts. The Ti concentration increased in leaves and chloroplasts with Ti-treatments, but this did not bring about any var iation in fruits and chromoplasts. The activities studied were enhance d by the application of Ti, and the Fe2+ concentration was higher in t he isolated organelles and in the leaves and the fruits of the Ti trea ted plants. These results support the previous hypothesis that Ti3+/Ti 4+, owing to its low redox potential, improves the Fe activity in plan ts, inducing a shift of the equilibrium Fe2+/Fe3+ towards Fe2+ improvi ng the Fe nutritional status of plants.