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

Shoots of normal cotton seedlings rapidly fixed a pulse of ¹⁴CO₂from the ambient atmosphere and translocated some of the resultinglabeled sucrose to the roots. Roots of these plants assimilatedmost of the radioactivity from a 10-min labeling pulse intoinsoluble cell wall materials and other stable metabolites within4 to 6 hr after the pulse. However, roots of cotton seedlingswhich had been exposed to 1 ppm of Al^3$ for 24 hr before labelingtended to accumulate the ¹⁴C-label as free sucrose. Histologicand microautoradiographic evidence suggested that Al^3$ impairedthe root's capacity to utilize sucrose in further metabolicproducts so that ¹⁴C-labeled sucrose was not polymerized intocell wall materials as it was in the roots of control plants. (Received July 7, 1971; )