Effects of gibberellic acid on growth and photosynthetic pigments of <i>Hibiscus sabdariffa</i> L. under salt stress

Abstract

Today, there is emerging focus on the importance of medicinal plants that have occupied a significant position in solving the health care problems in human life. Karkade is an important medicinal plant and is used for curing various illnesses. The aim of this study was to improve growth performance by enhancing the photosynthetic pigments and enzyme carbonic anhydrase (CA) activity of Hibiscus sabdariffa L. (cv. Sabahia 17) under NaCl stress. Under non-saline condition, application of GA₃ enhanced growth parameters (shoot length, shoot fresh weight (FW), shoot dry weight (DW), root FW, root DW, leaf area), relative water content (RWC), CA activity, anthocyanin and photosynthetic pigments (chlorophyll (Chl) a, Chl b, and total Chl). However, the application of GA₃ reduced the inhibitory effect of NaCl on growth attributes and photosynthetic pigments by inducing the enzymes CA activity and enhancing RWC. Therefore, it is concluded that GA₃ might help in the tolerance of plants to salt stress.

Key words: Carbonic anhydrase, Karkade, medicinal plant, photosynthetic pigments, relative water content, salinity.