The effect of ascorbic acid on rooting of Tradescantia fluminensis cuttings

Ascorbic Acid (AsA) is a powerful antioxidant, vitamin, and enzyme cofactor that has significant effects on plant's growth and development. A study was performed to investigate the effects of AsA on the formation and growth of adventitious roots in cuttings of Tradescantia fluminensis. The plants were treated by two levels of AsA (0, and 0.5 mM). Lengths and numbers of adventitious roots, free amino acid content, hydrogen peroxide content, ascorbate-peroxidase activity, and AsA/ Dehydroascorbate (DHA) ratio were measured. Application of 0.5 mM AsA reduced the number of adventitious roots but did not affect the lengths of adventitious roots. Supplemental AsA leads to the reduction of free amino acids and hydrogen peroxide contents, and AsA/DHA ratio in comparison to control plants. The activity of ascorbate-peroxidase was increased under AsA application. The addition of AsA to the rooting medium delayed the formation time of adventitious roots in T. fluminensis. The results suggest that the differentiation of parenchymal cells into tracheids during the use of AsA delays because the H2O2 and amino acids are required for lignification of secondary cell walls. We assumed that increasing the activity of APX results in AsA/DHA ratio reduction by the addition of AsA to the rooting medium.