ISHS Acta Horticulturae 636: XXVI International Horticultural Congress: Key Processes in the Growth and Cropping of Deciduous Fruit and Nut Trees
THE EFFECT OF IBA ON THE CA2+ ABSORPTION AND CA2+-ATPASE ACTIVITY AND THEIR ULTRACYTOCHEMICAL LOCALIZATION IN APPLE ROOTS |
| Authors: | Y. Hong-Qiang, J. Yu-Ling, Z. Lian-Zhong, C. Ming-Gang |
| Keywords: | Malus hupenensis, roots, auxin, calcium, uptake, Ca2+-ATPase, location |
| Abstract:
The uptake rate of Ca2+ and Ca2+-ATPase ultracytochemical localization were studied using Malus hupenensis Rehd seedlings and pot-cultured two-year-old apple trees (‘Starkrimson’/Malus hupenensis Rehd), after treatment with IBA. The results showed, IBA increased activity of roots and Ca2+-ATPase and rate of Ca2+ uptake. But Ca2+ uptake rates were inhibited by 2,4-DNP, the metabolic inhibitor, and the inhibition degree was higher under low Ca2+ concentrations (0 ~ 0.5 mmol/L) than high Ca2+ concentrations (0.5 ~ 5 mmol/L). The Km and Imax and the ratio (Imax/Km) all increased, and the inhibition degrees were higher in excised root than intact roots after roots were treated with IBA. The Imax and a (Imax/Km) increased but the Km after spraying IBA on leaves. 2,4-DNP inhibited the effects of IBA on Ca2+ absorption. Ca2+-ATPase was located on the cytoplasmic membrane and the vacuolar membrane. The activity of Ca2+-ATPase on the cytoplasmic membrane was increased significantly after treating by IBA. | |
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