Abstract
Excision and subsequent incubation of the apices (1 cm) of wheat (Triticum aestivum L.) seedling roots in simple media severely reduced elongation from 28 mm·(24 h)-1 in intact roots to a maximum of 2 mm·(24 h)-1 in excised roots. The reduction in growth was accompanied by a loss of cell turgor in the growing zone but was correlated with a hardening of the cell walls in this region. Rheological properties were measured as percent extensibility (both plastic and elastic) using a tensiometer, and as instantaneous volumetric elastic modulus (ε i) using the pressure probe. Excision decreased plastic and elastic properties with a half-time of some 60 min. Plastic extension was reduced from 2.5% to 0.9% and elastic from 4.8% to 2.6% for an 8-g load. By contrast, ε i was increased by excision. The observed reduction in root elongation rate was accompained by a reduction in mature cell length from 240 μm to 40 μm and a shortening of the zone of cell expansion.
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Abbreviations
- ε i :
-
instantaneous volumetric elastic modulus
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Pritchard, J., Wyn Jones, R.G. & Tomos, A.D. Control of wheat root growth. The effects of excision on growth, wall rheology and root anatomy. Planta 176, 399–405 (1988). https://doi.org/10.1007/BF00395421
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DOI: https://doi.org/10.1007/BF00395421