LESS INVOLVEMENT OF PHOSPHORUS DEFICIENCY IN THE INHIBITION OF ROOT ELONGATION OF PEA-SEEDLINGS BY ALUMINUM

Aluminium (AI) considerably inhibited the root elongation of Alaska pea seedlings at pH 4.5 and higher than 10-4M. After the transfer of seedlings which had been treated by 10-3M Al for only 3 hr to water, there was almost no recovery in the elongation of root. Pre- or posttreatment by phosphorus did not show any protection for the Al-inhibited root elongation. Unlike the root, shoot elongation was much less inhibited by AI. The amounts of Al in roots increased somewhat proportionally with the increasing concentration of Al in the treatment, but Al in shoots was not altered much. Al-treatment at 10-1 M for enough period needed for complete inhibition, did not bring about significant changes in phosphate esters and nucIeotides, and phenol-extracted nucleic acids in pea roots. Results are discussed in relation to the mechanisms of A1 toxicity. © 1979 Taylor & Francis Group, LLC.