ISHS Acta Horticulturae 134: Regulation of Growth and Endogenous Hormones, XXI IHC
REGULATION OF SUCROSE TRANSPORT IN BARLEY BY ABSCISIC ACID |
| Authors: | M. Dingkuhn, K. Dörffling, A. Tietz |
| Abstract:
Detached barley caryopses and isolated endosperm tissue of different developmental stages were incubated in 14C-sucrose solutions. After incubation periods of 6.5 to 18.0 hours, the effect of exogenously applied ABA on 14C-incorporation rates and 14C-starch formation was investigated. In endosperm tissue as well as in whole grains collected 1–2 weeks after anthesis, 10-5M ABA significantly promoted 14C-uptake and fixation. In later developmental stages, 14C-incorporation was either reduced (3–4 weeks after anthesis) or not significantly affected. The ABA actions observed both in intact grains and in isolated endosperm were closely corresponding. Moreover, they were similar to results obtained with intact plants in former experiments (Tietz et al., 1981). The observed effects did not appear to be due to ABA-induced changes in membrane permeabilities for sucrose and/or respiration activity. It is concluded that exogenous ABA modifies the endospermal assimilate sink activity via active transport processes and/or starch formation. | |
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