The changes of ethylene gas accumulation, antioxidant system activity, and secondary metabolite synthesis during in vitro adventitious root formation of Phyllanthus amarus

Abstract

This study investigated the changes in ethylene gas accumulation, antioxidant system activity, and secondary metabolite synthesis during the in vitro formation of adventitious roots in Phyllanthus amarus. The results indicated that longitudinal thin cell layer (lTCL) internode explants exhibited significantly higher ethylene accumulation and increased root weight during adventitious root formation. The results also showed enhanced antioxidant enzyme activities, including APX, CAT, SOD, DPPH, phenolic, and vitamin C in lTCL-internode explants. In addition, the levels of important secondary metabolites were enhanced in lTCL-internode explants compared to internode explants. Phyllanthin and hypophyllanthin contents in adventitious roots were significantly increased compared with the control. These findings suggest that the TCL culture technique can effectively promote adventitious root growth and optimize the production of bioactive compounds in P. amarus explants. This study provides valuable insights into the relationship between ethylene, antioxidant systems, and secondary metabolite synthesis, thus opening up possibilities for improving plant tissue culture and secondary metabolite production in this plant.