01496naa a2200193 a 450000100080000000500110000800800410001910000160006024501020007626000090017852009550018765000130114265000160115565000130117165300140118470000200119870000190121877300650123716482411999-08-12       1993    bl ---       0--  u    #d1 aRYAN, P. R.  aAluminium toxicity in rootsban investigation of spatial sensitivity and the role of the root cap  c1993  aThe primary symptom of aluminium (Al) toxicity in higher plants is inhibition of root growth. In this study, we investigated the spatial sensitivity of maize (Zea mays L.) roots to Al. A divided-chamber technique indicated that only exposure of the terminal 10 to 15mm of the root to Al resulted in inhibition of growth. Application of Al to all but this apical region of the root had little or no effect on growth for 24h and caused minimal damage to the root tissue. Small agar blocks infused with Al were then applied to discrete areas of the apex of maize roots to determine which section (root cap, meristem or elongation zone) was more important to Al-induced inhibition of growth. The terminal 2.0 to 3.0mm of root (root cap and meristem) must be exposed to Al for inhibition. Application of Al to the 3.0mm of root proximal to this terminal zone (elongation zone) resulted in damage to the root tissue but no significant inhibition of growth.  aroot cap  aroot growth  atoxicity  aAluminium1 aDITOMASO, J. M.1 aKOCHIAN, L. V.  tJournal of Experimental Botanygv.44, n.259, p.437-446, 1993