Control of wheat root growth. The effects of excision on growth, wall rheology and root anatomy

✍ Scribed by J. Pritchard; R. G. Wyn Jones; A. D. Tomos

• Publisher: Springer-Verlag
• Year: 1988
• Tongue: English
• Weight: 652 KB
• Volume: 176
• Category: Article
• ISSN: 0032-0935
• DOI: 10.1007/bf00395421

✦ Synopsis

Excision and subsequent incubation of the apices (1 cm) of wheat (Triticum aestivum L.) seedling roots in simple media severely reduced elongation from 28 ram.(24 h) -1 in intact roots to a maximum of 2 ram. (24 h)-1 in excised roots. The reduction in growth was accompanied by a loss of cell turgot 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 (ei) using the pressure probe. Excision decreased plastic and elastic properties with a half-time of some 60 rain. 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, ef was increased by excision. The observed reduction in root elongation rate was accompanied by a reduction in mature cell length from 240 gm to 40 gm and a shortening of the zone of cell expansion.