Impairment of sucrose utilization for cell wall formation in the roots of aluminum-damaged cotton seedlings

摘要

Shoots of normal cotton seedlings rapidly fixed a pulse of14CO2from the ambient atmosphere and translocated some of the resulting labeled sucrose to the roots. Roots of these plants assimilated most of the radioactivity from a 10-min labeling pulse into insoluble cell wall materials and other stable metabolites within 4 to 6 hr after the pulse. However, roots of cotton seedlings which had been exposed to 1 ppm of Al3$for 24 hr before labeling tended to accumulate the14C-label as free sucrose. Histologic and microautoradiographic evidence suggested that Al3$impaired the root's capacity to utilize sucrose in further metabolic products so that14C-labeled sucrose was not polymerized into cell wall materials as it was in the roots of control plants.