The positional distributions in potential of lateral root budding and oxygen uptake rate were examined using the segments of madder and horseradish hairy roots with a length of 5.0 x 10(-3) m obtained at different mean distances from the root tips of I = 7.5 x 10(-3)-47.5 x 10(-3) M. The average rate of lateral root budding and oxygen uptake rate of the roots with smaller I values were higher and both the rates gradually decreased with increase in 1 value. Positive relations were observed between the rates of lateral root budding and oxygen uptake of both the hairy roots. ne relation indicated that the potential of lateral root budding was suppressed at the oxygen uptake rates of 0.15 x 10(-5) and 0.32 x 10(-5) mol O-2/(h m) for madder and horseradish hairy roots, respectively. (C) 2002 Elsevier Science B.V. All rights reserved.