Document Type : Research Paper


1 M.Sc. Student of Horticulture, Faculty of Agriculture, University of Kurdistan, Sanandaj, Iran

2 Associate Professor, Department of Horticulture, Faculty of Agriculture, University of Kurdistan, Sanandaj, Iran

3 Assistant Professor, Department of Horticulture, Faculty of Agriculture, University of Kurdistan, Sanandaj, Iran


Background and Objectives
Salinity and salt accumulation in the soil surface is one of the most important abiotic stresses that limit agricultural crop production in the arid and semi-arid regions of Iran. Thus, finding an alternative production technique or materials to alleviate stress condition is a research priority. One way to decrease the harmful effects of salinity is the foliar application of some chemicals such as Gamma-amino butyric acid (GABA) to increase plant tolerance to salinity. GABA is often accumulated in plants in response to live and non-live stresses such as drought, salinity, oxygen deficit, heat shocks and contamination of pathogens.
Materials and Methods
The current study was carried out to monitor the GABA effects on tomato physiological changes under salinity stress. The plants were grown in hydroponic system and received 0 and 50 mM NaCl as control and salinity stress, respectively. GABA at three concentrations 0, 10 and 20 mM was applied as a foliar application in either control or salinity treatments. Physiological characteristics of relative water content (RWC), membrane stability index (MSI), proline, total soluble protein (TSP) and enzymes activity, chlorophyll a, chlorophyll b, total chlorophyll and total soluble carbohydrates (TSC) were measured.
The results showed that salinity stress and GABA were effective on the physiological characteristics of tomato. GABA can increase the tolerance of plants to environmental stresses, including salinity stress. MSI, chlorophyll a, total chlorophyll, carotenoids in salinity treatments were lower than control while TSC, proline, peroxidase and SOD increased. RWC, MSI, proline, TSC of GABA treated plant were greater than untreated in either salinity or control conditions. Also, SOD and peroxidase activity elevated in GABA treated plant under salinity stress.
GABA increased antioxidant capacity in the plant and thus might eliminate radicals and prevents the destruction of cell membrane tissue, including the chloroplast membrane. In general, the results showed that in salinity stress conditions, GABA application as a compatible osmolytes might improve the tomatoes physiological performance and alleviate salinity stress.


Main Subjects

Ashraf, M. (2004). Some important physiological selection criteria for salt tolerance in plants. Flora, 199(5), 362-376.
Bates, L. S., Waldren, R. P. and Teare, I. D. (1973). Rapid determination of free proline for water-stress studies. Plant and Soil, 39(1), 205-207.
Beyer, W. F. and Fridovich, I. (1987). Assaying for superoxide dismutase activity: some large consequences of minor changes in conditions. Analytical biochemistry, 161(2), 559-566.
Bradford, M. M. (1976). A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding. Journal of Analytical Biochemistry, 72(1-2), 248-254.
Deewatthanawong, R., Nock, J. F. and Watkins, C. B. (2010). γ-Aminobutyric acid (GABA) accumulation in four strawberry cultivars in response to elevated CO2 storage. Postharvest Biology and Technology, 57(2), 92-96.
Dorais, M., Dorval, R., Demers, D., Micevic, D., Turcotte, G., Hao, X., Papadopoulos, A. P., Ehret, D. L. and Gosselin, A. (1998). Improving tomato fruit quality by increasing salinity: effects on ion uptake, growth and yield. XXV International Horticultural Congress, Part 1: Culture Techniques with Special Emphasis on Environmental Implications, 511, 185-196.
El-Fouly, M. M., Moubarak, Z. M. and Salama, Z. A. (2000). Micronutrient foliar
application increases salt tolerance of tomato seedlings. International Symposium on Techniques to Control Salination for Horticultural Productivity, 573, 467-474.
Fait, A., Yellin, A. and Fromm, H. (2006). GABA and GHB neurotransmitters in plants and animals. In Baluska, F., Mancuso, D., Volkmann, D. Communication in plants (pp. 171-185). Berlin: Springer.
FAO. (2013). Statistics for Perennial Crops and Fruits. FAO Publication, Rome, Italy.
Galmes, J., Flexas, J., Save, R. and Medrano, H. 2007. Water relations and stomatal characteristics of Mediterranean plants with different growth forms and leaf habits: responses to water stress and recovery. Journal of Plant and Soil, 290(1-2), 139-155.
Hemeda, H. M. and Kelin, B. P. (1990). Effects of naturally occurring antioxidants on peroxidase activity of vegetables extracts. Journal of Food Science, 55(1), 184-185.
Houimli, S. I. M., Denden, M. and Mouhandes, B. D. (2010). Effects of 24-epibrassinolide on growth, chlorophyll, electrolyte leakage and proline by pepper plants under NaCl-stress. EurAsian Journal of BioSciences, 4, 96-104.
Irigoyen, J. J., Einerich, D. W. and Sanchez-Diaz, M. (1992). Water stress induced changes in concentrations of proline and total soluble sugars in nodulated alfalfa (Medicago sativa) plants. Journal of Physiologia Plantarum, 84(1), 55-60.
Jalili marandi, R., Jalil doost ali, P. and Hasani, A. (2009). Determination of tolerance of two apple rootstocks to different concentrations of sodium chloride under in vitro conditions. Iranian Journal of Horticultural Sciences, 40(2), 29-36. [In Farsi]
Kafi, M. and Rahimi, Z. (2011). Effect of salinity and silicon on root characteristics, growth, water status, proline content and ion accumulation of purslane (Portulaca oleracea L.). Soil Science and Plant Nutrition, 57(2), 341-347.
Kavikishore, P. B., Songam, S., Amr, R. N. and Naidu, S. (2005). Regulation of proline biosynthesis, degradation, uptake and transport in higher plants: Its implications in plant grow than abiotic stress tolerance. Current Science, 88(3), 424-438.
Khan, M. A. and Duke, N. C. (2001). Halophytes–A resource for the future. Wetlands Ecology and Management, 9(6), 455-456.
Kinnersley, A. M. and Turano, F. J. (2000). Gamma aminobutyric acid (GABA) and plant responses to stress. Critical Reviews in Plant Sciences, 19(6), 479-509.
Krishnan, S., Laskowski, K., Shukla, V. and Merewitz, E.B. (2013). Mitigation of drought stress damage by exogenous application of a non-protein amino acid γ–aminobutyric acid on perennial ryegrass. Journal of the American Society for Horticultural Science, 138(5), 358-366.
Lichtenthaler, H. K. and Buschmann, C. (2001). Extraction of phtosynthetic tissues:
Chlorophylls and carotenoids. Current Protocols in Food Analytical Chemistry: John Wiley & Sons, Inc.
Molazem, D., Qurbanov, E. M. and Dunyamaliyev, S. A. (2010). Role of proline, Na and chlorophyll content in salt tolerance of corn (Zea mays L.). American-Eurasian Journal of Agricultural and Environmental Science, 9(3), 319-324.
Sairam, R. K., Rao, K. V. and Srivastava, G. C. (2002). Differential response of wheat genotypes to long term salinity stress in relation to oxidative stress, antioxidant activity and osmolyte concentration. Plant Science, 163(5), 1037-1046.
Shaha, S. H. (2007). Effects of salt stress on mustard as affected by gibberellic acid application. General and Applied Plant Physiology, 33(1-2), 97-106.
Shang, H., Cao, S., Yang, Z., Cai, Y. and Zheng, Y. (2011). Effect of exogenous γ-aminobutyric acid treatment on proline accumulation and chilling injury in peach fruit after long-term cold storage. Journal of Agricultural and Food Chemistry, 59(4), 1264-1268.
Shelp, B. J., Bown, A. W. and McLean, M. D. (1999). Metabolism and functions of gamma-aminobutyric acid. Trends in Plant Science, 4(11), 446-452.
Shelp, B. J., Bozzo, G. G., Trobacher, C. P., Chiu, G. and Bajwa, V. S. (2012). Strategies and tools for studying the metabolism and function of γ-aminobutyrate in plants. I. Pathway Structure. Botany, 90(8), 651-668.
Shi, S. Q., Shi, Z., Jiang, Z. P., Qi, L. W., Sun, X. M., Li, C. X., Liu, J. F., Xiao, W. F. and Zhang, S. G. (2010). Effects of exogenous GABA on gene expression of Caragana intermedia roots under NaCl stress: Regulatory roles for H2O2 and ethylene production. Plant, Cell and Environment, 33(2), 149-162.
Sivritepe, N., Sivritepe, H. O., Celik, H. and Katkat, A.V. (2010). Salinity responses of grafted grapevines: Effects of scion and rootstock genotypes. Notulae Botanicae Horti Agrobotanici Cluj-Napoca, 38(3), 193-201.
Song, H., Xu, X., Wang, H., Wang, H. and Tao, Y. (2010). Exogenous γ‐aminobutyric acid alleviates oxidative damage caused by aluminium and proton stresses on barley seedlings. Journal of the Science of Food and Agriculture, 90(9), 1410-1416.
Sotripopoulos, T. E. (2007). Effect of NaCl and CaCl2 on grown and contents of minerals, chlorophyll, proline and sugar in the apple rootstock M4 cultured in vitro. Biologia Plantrum, 51(1), 177-180.
Tanou, G., Molassiotis, A. and Diamantidis, G. (2009). Induction of reactive oxygen species and necrotic death-like destruction in strawberry leaves by salinity. Environmental and Experimental Botany, 65(2), 270-281.
Tester, M. and Davenport, R. (2003). Na+ tolerance and Na+ transport in higher plants. Annals of Botany, 91(5), 503-527.
Yin, C., Wang, X., Duan, B., Luo, J. and Li, C. (2005). Early growth, dry matter allocation and water use efficiency of two sympatric Populus species as affected by water stress. Environmental and Experimental Botany, 53(3), 315-322.