THE EFFECT OF HYDROGEN PEROXIDE (H2O2) ON PHOTOSYNTHESIS OF Ficus deltoidea Jack var. trengganuensis Corner Norsyamila Othman, Mohammad Moneruzzaman Khandaker, Abd Jamil Zakaria and Nashriyah Mat Faculty of Bioresources and Food Industry, Universiti Sultan Zainal Abidin, Tembila Campus, 22200 Besut, Terengganu ABSTRACT A field experiment was conducted to evaluate the effect of hydrogen peroxide (H2O2) concentration on photosynthetic activity of Ficus deltoidea Jack var. trengganuensis Corner at FBIM farm, Terengganu. The plant was collected from Jambu Bongkok, Marang and propagated under sunlight-proof shade house. After 3 months, a total of 35 plants were selected and applied with 0 mM (as control), 5 mM, 10 mM, 15 mM and 20 mM H2O2. The physiological activity was monitored monthly and measured during 10 am to 12 pm by using Handheld Photosynthesis System (CI-340, CID Inc., USA). Results showed that chlorophyll content, photosynthesis rate and carbon dioxide (CO2) accumulation of Ficus deltoidea var. trengganuensis were significantly increased after treated with 5 mM H2O2. Besides that, other H2O2 treatments (10 mM, 15 mM and 20 mM) resulted in negative outcomes which is lower in photosynthetic activity as compared with control (0 mM H2O2). Thus, this study showed that application of definite concentration of H2O2 can increase the photosynthetic activity of Ficus deltoidea var. trengganuensis. OBJECTIVE METHODOLOGY To determine the effects of different hydrogen peroxide (H2O2) concentrations on photosynthesis of Ficus deltoidea var. trengganuensis. The experimental design was constructed A total of 35 plants were planted in polybags prior to treatments The plants were irrigated twice a day and fertilized once every fortnight during treatments The parameters of chlorophyll content, photosynthesis rate and CO2 accumulation were measured and recorded every month Data and statistical analysis (ANOVA) This experiment took place under sunlight-proof shade house which covers approximately 40 m2 area. Five H2O2 treatments were set up, by using a Complete Randomized Design (CRD) with seven replicates. The treatments were 1) 0 mM H2O2 (T1) as control; 2) 5 mM H2O2 (T2); 3) 10 mM H2O2 (T3); 4) 15 mM H2O2 (T4); and 5) 20 mM H2O2 (T5). The method of application used was by spraying the H2O2 once a week on the leaf of Ficus deltoidea var. trengganuensis. Figure 1: Ficus deltoidea var. trengganuensis INTRODUCTION Ficus deltoidea Jack is an epiphytic shrub, which can be easily found in coastal area, with almost all parts are considered to have medicinal properties. Hydrogen peroxide (H2O2) is a product of peroxisomal and chloroplastic oxidative reactions and known as the most stable form of the Reactive Oxygen Species (ROS), which involves in wide variety of reaction and signalling cascades that influences all aspects of plant growth and development, and the integration of plant defense1. RESULTS AND DISCUSSION Figure 2: Effects of H2O2 on chlorophyll content (A), photosynthesis (B) and carbon dioxide accumulation (C) of Ficus deltoidea var. trengganuensis. From the statistical analysis (One-way ANOVA), the chlorophyll content, photosynthesis rate and CO2 accumulation were significantly affected by the H2O2 treatments, with the p-value of 0.36, 0.00, and 0.002, respectively. In chlorophyll content, the 5 mM H2O2 treatment (67.29 ± 3.78 CCI) was significantly different with 20 mM H2O2 treatment (54.63 ± 2.59 CCI). On top of that, there were significance differences between 5 mM H2O2 (4.15 ± 0.64 ɥmol m2 s-1) treatment with 10 mM H2O2 (1.74 ± 0.62 ɥmol m2 s-1), 15 mM H2O2 (1.61 ± 0.17 ɥmol m2 s-1) and 20 mM H2O2 (1.29 ± 0.17 ɥmol m2 s-1) treatments for photosynthesis rate measurements. In CO2 accumulation, 5 mM H2O2 (4.15 ± 0.64 mmol L-1) application was significantly different with control (8.29 ± 1.20 mmol L-1), 10 mM H2O2 (5.28 ± 1.15 mmol L-1), 15 mM H2O2 (3.39 ± 0.43 mmol L-1) and 20 mM H2O2 (3.56 ± 0.53 mmol L-1) treatments. Generally, the plants that were treated with 5 mM H2O2 gave higher values. This was followed by control treatment and other H2O2 treatments (10 mM, 15 mM, 20 mM). Besides that, previous research showed that plant growth and developmental increment can be promoted by optimum level of hydrogen peroxide2. It acts as a messenger molecule which involved in adaptive signalling for triggering tolerance against abiotic stresses when applied at low or normal concentrations (1-5 µmol g-1 FW). On the other hand, applying H2O2 at high concentration (above 7 µmol g-1 FW) will result in cell death3. CONCLUSION ACKNOWLEDGEMENTS REFERENCES The photosynthetic activity of Ficus deltoidea var. trengganuensis was significantly increased by the application of 5 mM H2O2 as compared to other treatments. This was shown by the chlorophyll content value of 67.29 ± 3.78 CCI, photosynthesis rate value of 4.15 ± 0.64 ɥmol m2 s-1 and CO2 accumulation value of 16.6 ± 2.99 mmol L-1 CO2. The authors are thankful to other FBIM staff for their encouragement and support in the field and laboratory. This research was funded partly by the FRGS Grant No. FRGS/2/2014/SG03/UNISZA/02/1. 1 Jubany-Mari, T., Munne-Bosch, S. and Alegre, L. 2010. Redox regulation of water stress responses in field-grown plants: Role of H2O2 and ascorbate. Plant Physiology and Biochemistry. 48: 351-358. 2 Peng, L. T., Jiang, Y. M., Yang, S. Z. and Pan, S. Y. 2005. Accelerated senescence of fresh-cut Chinese Water Chestnut tissues in to Hydrogen Peroxide accumulation. J. Plant Physiol. Mol. Biol. 31: 527-532. 3 Cheeseman, J. M. 2006. Hydrogen Peroxide concentration in leaves under natural conditions. J. Exp. Bot. 57: 2435-2444. URC 2015, Universiti Sultan Zainal Abidin, Terengganu. 14-16 April 2015