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Al partitioning patterns and root growth as related to Al sensitivity and Al tolerance in wheat

Author:
Samuels, T.D., Kucukakyuz, K., Rincon-Zachary, M.
Source:
Plant physiology 1997 v.113 no.2 pp. 527-534
ISSN:
0032-0889
Subject:
Triticum aestivum, roots, aluminum, quantitative analysis, dose response, phytotoxicity, cultivars, translocation (plant physiology), biological resistance
Abstract:
Studies of Al partitioning and accumulation and of the effect of Al on the growth of intact wheat (Triticum aestivum L.) roots of cultivars that show differential Al sensitivity were conducted. The effects of various Al concentrations on root growth and Al accumulation inthe tissue were followed for 24 h. At low external Al concentrations, Al accumulation in the root tips was low and root growth was either unaffected or stimulated. Calculations based on regression analysis of growth and Al accumulation in the root tips predicted that 50% root growth inhibition in the Al-tolerant cv Atlas 66 would be attained when the Al concentrations were 105 micromolar in the nutrient solution and 376.7 micrograms Al g-1 dry weight in the tissue. In contrast, in the Al-sensitive cv Tam 105, 50% root growth inhibition would be attained when the Al concentrations were 11 micromolar in the nutrient solution and 546.2 micrograms Al g-1 dry weight in the tissue. The data support the hypotheses that differential Al sensitivity correlates with differential Al accumulation in the growing root tissue, and that mechanisms of Al tolerance may be based on strategies to exclude Al from the root meristems.
Agid:
664666