EFFECT OF AUXINHORMONE LANTHANIDE COMPLEXES ON THE GROWTH OF WHEAT COLEOPTILE

Naphthalene-1-acetic acid (HNAA), dichlorophenoxy acetic acid (HDAA), and indole-3-acetic acid (HIAA) are auxinhormones that can affect the growth of plants. The lanthanide complexes of the above auxinhormone L nA(3). 3H(2)O (Ln = La3+, Ce3+, Sm3+, Er3+, Yb3+; HA = HNAA, HDAA, HIA A; A = NAA(-), DAA(-), IAA(-)) were synthesized and are characterized in this paper. The solubility and IR spectra of these complexes were a lso studied. Experiments of the effects of LnCl(3). nH(2)O, HA, and Ln A(3). 3H(2)O on the growth rate of wheat coleoptile sections show, tha t LnCl(3). nH(2)O promotes the growth of wheat coleoptile when this co mpounds concentration is lower than 2 x 10(-5) M and the promotion is very significant when the concentration of Ln(3+) is lower than 8 x 10 (-6) M. It was also found that the effect of LnA(3). 3H(2)O on the gro wth of wheat coleoptile is stronger than that of LnCl(3). nH(2)O and H A, which indicates that the combination of Ln(3+) with HA act synergis tically.