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Relationship between polar basipetal auxin transport and acropetal Ca 2+ transport into tomato fruits

1987; Wiley; Volume: 71; Issue: 3 Linguagem: Inglês

10.1111/j.1399-3054.1987.tb04350.x

1399-3054

Gary S. Bañuelos, F. Bangerth, Horst Marschner,

Plant Physiology and Cultivation Studies

The dependence of acropetal Ca 2+ transport on polar basipetal indoleacetic acid (IAA) transport was investigated in excised tomato fruits ( Lycopersicon esculentum L. Mill.) using an in vitro fruit system. Auxin transport inhibitors like triiodobenzoic acid (TIBA), chlorofluorenolmethyl ester (CME) and naphthylphthalamic acid (NPA) were used in order to investigate the effect of restricted polar basipetal auxin transport on the acropetal transport of 45 Ca 2+ , 86 Rb + and 98 Sr 2+ into the same fruits. TIBA and CME inhibited basipetal transport of IAA. particularly in 10‐ to 12‐day‐old tomato fruits, and simultaneously restricted the acropetal transport of 45 Ca 2+ . The auxin transport inhibitors failed to significantly reduce the upward transport of 86 Rb + and the transport of 96 Sr 2+ was less inhibited than that of 45 Ca 2+ . TIBA and CME did not significantly affect the acropetal transport of labelled water into the fruit, nor the cation‐exchange capacity or K + and Mg 2+ concentrations in the tomato fruit. These results support the view that a part of the Ca 2+ ‐specific acropetal transport into tomato fruits is associated with the polar basipetal IAA transport. This Ca 2+ transport is independent of the transpiration stream into the fruit and the cation exchange capacity of the fruit tissue.