Dose Dependent Response of Epibrassinolide on the Growth, Photosynthesis and Antioxidant System of Tomato Plants

The aim of this study was to explore the response of varied doses of epibrassinolide (EBL) in tomato plants that induced upregulation of antioxidant system which protect photosynthetic apparatus. Seeds were sown in pots and allowed to germinate under natural environmental conditions. At 35–39 day stage (5 days), foliage of plants was sprayed with double distilled water (control), 10⁻¹⁰, 10⁻⁸ or 10⁻⁶ M of EBL and allows to grow. Plants were sampled at 45 and 60 days to assess the various growths parameters, photosynthetic characteristics, biochemical parameters, and the remaining plants were allowed to grow up to maturity to study the yield characteristics. The plant that developed from the EBL possessed higher growth, photosynthetic attributes, leaf protein content, antioxidant enzymes and proline content over the control. Out of the three concentrations of EBL tested, foliar spray of 10-8 M of EBL proved best and increased the values for shoot fresh mass (33% and 40%), root fresh mass (28% and 36%), shoot dry mass (36% and 41%), root dry mass (28% and 37%), carbonic anhydrase activity (26% and 33%), net photosynthetic rate (31% and 38%), and protein content (26% and 34%) at 45 and 60 days after sowing respectively over their control.