EFFECT OF GROWTH RETARDANTS ALAR AND MEIA ON PEROXIDASE AND IAA-OXIDASE ACTIVITY IN STEMS OF TOBACCO SEEDLINGS

Plant growth retardants Alar (dimethylhydrazide of succinic acid) and its structural analogue MEIA (β-monomethyl ester of itaconic acid) at a concentration 2000mg/l sprayed at the fourth true leaf stage of tobacco seedlings caused identical retardation in stem growth from the second till the tenth day after treatment. Soluble peroxidase activity in stems of the treated plants increased on the second day after treatment and remained the same until the end of the investigated period. IAA-oxidase activity also increased on the second day after treatment, but later dropped slowly and reached the control level. Alar and MEIA did not influence peroxidase and IAA-oxidase activity in vitro. From the second day till the end of the investigated period an increase in total phenols and in the level of chlorogenic acid in the stems of the treated plants was also observed. The increase of IAAoxidase activity post treatment with growth retardants Alar and MEIA probably took part in the regulation of stem growth of tobacco seedlings. The regulation of enzyme activity might not be direct and could be due to the participation of phenol compounds.

[1]  S. Petkova,et al.  Possibilities for regulation stem growth of tobacco seedlings by treatment with some growth retardants , 1994 .

[2]  T. Ramp,et al.  UNSYMMETRICAL DIMETHYLHYDRAZINE AND DAMINOZIDE RESIDUES IN FRESH AND PROCESSED CHERRIES AND APPLES , 1989 .

[3]  H. Greppin,et al.  A two‐step control of basic and acidic peroxidases and its significance for growth and development , 1985 .

[4]  H. Tigier,et al.  Effect of dicarboxylic acids on the peroxidase‐IAA oxidase isozymes of soybean callus , 1983 .

[5]  R. Menhenett.  Evidence that Daminozide, but not Two Other Growth Retardants, Modifies the Fate of Applied Gibberellin A9 in Chrysanthemum morifolium Ramat , 1980 .

[6]  K. Jindal,et al.  Effect of Succinic Acid‐2,2‐Dimethylhydrazide on Endogenous Auxin Level in Apple Shoots , 1977 .

[7]  H. Fahimi,et al.  A new sensitive colorimetric assay for peroxidase using 3,3'-diaminobenzidine as hydrogen donor. , 1973, Analytical biochemistry.

[8]  J. W. Dicks.  Uptake and distribution of the growth retardant, aminozide, in relation to control of latera shoot elongation in Chrysanthemum morifolium , 1972 .

[9]  S. Wittwer.  Growth regulants in agriculture * , 1971 .

[10]  P. Kadkade,et al.  The effect of growth regulatory chemicals on abscission and IAA-oxidizing enzyme system of dwarf bean seedlings , 1969 .

[11]  T. Caspar,et al.  The Effect of CCC and Amo‐1618 on Growth, Catalase, Peroxidase and Indoleacetic Acid Oxidase Activity of Young Barley Seedlings , 1968 .

[12]  D. J. Reed,et al.  Plant Growth Retardant B-995: A Possible Mode of Action , 1965, Science.