Physiological Modifications of Growth, Biochemical Compositions and Anti-Oxidant Activities in Water-Stressed Beniseed (Sesamum indicum) as Affected by Glycine Betaine

Abstract

Water imbalance limits growth and antioxidant production in plants. This study assessed varying concentrations (1, 2, 3 and 4 g/L) of  glycine betanine (GB) on growth, nutritional contents, and antioxidant production in beniseed under drought conditions. Plant height  (49.40 cm), number of leaves (27), leaf area (231.93 cm² ), specific leaf area (57.98 m2kg^-1 ), and leaf area index (0.62 m²m^-2 ) were  higher in beniseed treated with 4g/L GB compared with lower concentrations of the osmolyte. However, the well-watered treatment  improved significantly the relative growth rate (0.06 mgg^-1day^-1 ) and net assimilation rate (0.02 gm-2day^-1 ). Chlorophyll-a (3.38 mg/g),  chlorophyll-b (3.81mg/g) and total chlorophyll (7.20 mg/g) showed a significant increase in the plant under 3g/LGB. Moisture (91.07%),  fat (2.74%), ash (3.55%), crude fiber (3.51%), and crude protein (4.47%) were significantly higher (p<0.05) in the treatments grown under  4g/LGB. The observation was consistent in sodium, potassium, calcium and magnesium as well as vitamin A, vitamin B5 and vitamin C.  Superoxide dismutase (SOD) (1.58 u/gt), APX (1.18 u/g), CAT (1.58 mg^-1 ), GR (1.59 u/g), GST (14.07 mg^-1 ) and SP (19.06 u/ml) were  higher in the roots of beniseed grown under drought. Conclusively, beniseed grown under,3 and 4g/L GB improved growth attributes  and nutritional contents while high antioxidant production was observed in the roots of beniseed droughted compared with other parts.