Control of stem bending in cut gerbera flowers through application of dithiothreitol and thioglycolic acid as wound reaction inhibitors

Abstract

ABSTRACT Bend neck of scape and short vase life are the most important problems of cut gerbera flowers in postharvest stage. Inhibitors of laccase enzyme influence lignin formation at cut stem end of flowers. In this study, cut gerbera (Gerbera jamesonii cv. Intense) flowers were subjected to laccase enzyme inhibitors including Dithiothreitol (DTT: 0.05, 0.1, 0.2 mM), Thioglycolic acid (TGA: 0.25, 0.5, 1 mM), or Cetyltrimethylammonium bromide (CTAB: 8, 10, 12 mM) for 20 h as pulse treatment. Results showed that 0.2 mM DTT prevented stem bending appropriately. Also, increased the vase life, maintained relative fresh weight, improved water uptake, inhibited laccase activity, and delayed the anthocyanin degradation and lignin formation. Treatment of 0.5 mM TGA had a desirable effect in extending vase life and control of stem bending. However, CTAB had negative effects on vase life of cut gerbera flowers. Thus, the presence of inhibitors in vase solution had a positive effect on control of lignin formation in end of cut stems. Our results confirmed a decrease in lignin formation at cut stem end by DTT 0.2 mM and TGA 0.5 mM. This study suggested that laccase enzyme inhibitors in vase solution are sufficient to maintain water flow process and control stem bending in cut gerbera flowers.