Growth and Stomatal Responses of Bread Wheat Genotypes in Tolerance to Salt Stress
Plant growth is affected by the osmotic stress as well as toxicity of salt in leaves. In order to study of salt stress effects on stomatal conductance and growth rate and relationship between them as wells osmotic and Na+-specific effects on these traits, four bread wheat genotypes differing in salt tolerance were selected. Salinity was applied when the leaf 4 was fully expanded. Sodium (Na+) concentrations in flag leaf blade at 3 salinity levels (0, 100 and 200 mM NaCl) were measured. Salt-tolerant genotypes showed higher stomatal conductance and growth rate compared to salt-sensitive ones. After 10 and 20 days exposure to salt, stomatal conductance and relative growth rate were reduced, but the reduction was greater in sensitive genotypes. Growth rate was reduced severely in the first period (1-10 days) of salt commencements and it was due to osmotic effect of salt not Na+ toxicity. In the second period (11-20 days) after salt treatment growth reduced only when salt accumulated to toxic concentrations in the leaves. A positive relationship between stomatal conductance and relative growth rate showed that stomatal conductance can be a reliable indicator of growth rate, and finally can be considered as a sensitive indicator of the osmotic stress. It seems 20 days after salinity, the major effect of salt, especially at low to moderate salinity levels on growth properties was due to the osmotic effect of salt, not to Na+-specific effects within the plant.
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 James, R. A., Caemmerer, S. V., Condon, A. G., Zwart, A. B., Munns, R, 2008: Genetic variation in tolerance to the osmotic stress component of salinity stress in durum wheat. Functional Plant Biology 35, 111-123.
 Munns, R., 2002: Comparative physiology of salt and water stress. Plant Cell and Environment 25, 239-250.
 Munns, R., and M. Tester, 2008: Mechanisms of Salinity Tolerance. Annual Review of Plant Biology 59, 651-81.
 Munns, R., 1993: Physiological processes limiting plant growth in saline soil: some dogmas and hypotheses. Plant, Cell & Environment 16, 15- 24.
 Cramer, G.R., G.L. Alberico., and C. Schmidt, 1994: Salt tolerance is not associated with the sodium accumulation of two maize hybrids. Australian Journal of Plant Physiology 21, 675-692.
 Rivelli, A.R., R.A. James., R. Munns., and A.G. Condon, 2002: Effect of salinity on water relations and growth of wheat genotypes with contrasting sodium uptake. Functional Plant Biology 29, 1065-1074.
 Zhang, J., W. Jia., J. Yang., and A. M. Ismail, 2006. Role of ABA in integrating plant responses to drought and salt stresses. Field Crops Research 97, 111-119.
 James, R. A., Rivelli, A. R., Munns, R., von Caemmerer S, 2002: Factors affecting CO2 assimilation, leaf injury and growth in salt-stressed durum wheat. Functional Plant Biology 29, 1393-1403.
 Cramer, G. R. 1992. Kinetics of maize leaf elongation. II. Responses of a Na-excluding cultivar and a Na-including cultivar to varying Na/Ca salinities. Journal of Experimental Botany 43, 857-64
 Huang, C. X., and R. F. M. van Steveninck, 1989: Maintenance of low Cl− concentrations in mesophyll cells of leaf blades of barley seedlings exposed to salt stress. Plant Physiology 90, 1440-43.
 Netondo, G. W., C. O. John, and E. Beck. 2004 b. Sorghum and Salinity: II. Gas Exchange and Chlorophyll Fluorescence of Sorghum under Salt Stress. Crop Sciences 44: 806-811.
 Rahnama, A., R. A. James, K. Poustini and R. Munns, 2010: Stomatal conductance as a screen for osmotic stress tolerance in durum wheat growing in saline soil. Functional Plant Biology 37, 255-269.
 El-Hendawy, S.E., Y. Hu., and U. Schmidhalter, 2005: Growth, ion content, gas exchange, and water relations of wheat genotypes differing in salt tolerances. Australian Journal of Agricultural Research 56, 123- 134.
 Schachtman, D.P., and R. Munns, 1992: Sodium accumulation in leaves of Triticum species that differ in salt tolerance. Australian Journal of Plant Physiology 19, 331-340.
 Davenport, R., R.A. James., A. Zakrisson-Plogander., M. Tester., and R. Munns, 2005: Control of sodium transport in durum wheat. Plant Physiology 137, 807-818.
 Husain, S., R. Munns., and A.G. Condon, 2003: Effect of sodium exclusion trait on chlorophyll retention and growth of durum wheat in saline soil. Australian Journal of Agricultural Research 54, 589-597.
 Poustini, K., A. Siosemardeh., and M. Ranjbar, 2007: Proline accumulation as a response to salt stress in 30 wheat (Triticum aestivum L.) cultivars differing in salt tolerance. Genetic Resources and Crop Evolution 54 (5), 925-934.
 Shah, S.H., J. Gorham., B.P. Forster., and R.G. Wyn Jones, 1987: Salt tolerance in the Triticeae: the contribution of the D genome to cation selectivity in hexaploid wheat. Journal of Experimental Botany 38, 254- 269.
 Neumann, P, 1997: Salinity resistance and plant growth revisited. Plant Cell and Environment 20, 1193-1198.
 Poustini, K., and A. Siosemardeh, 2004: Ion distribution in wheat cultivars in response to salinity stress. Field Crops Research 85, 125- 133.
 Zhu, J.K., 2001: Plant salt tolerance. Trends in Plant Science 6, 66-71
 Flowers, T. J., and A. R. Yeo, 1981. Variability in the resistance of sodium chloride salinity within rice (Oryza sativa L.) varieties. New Phytologist 88, 363-373.
 Robinson, J. M. 1988. Does O2 photoreduction occur within chloroplast in vivo? Physiologia Plantarum 72, 666-680.
 Koyro, H. W, 2006. Effect of salinity on growth, photosynthesis, water relations and solute composition of the potential cash crop halophyte Plantago coronopus (L.). Environmental and Experimental Botany 56, 136-146.
 Yeo, A. R., and T. Flowers, 1986: Salinity resistance in rice (Oryza sativa L.) and a pyramiding approach to breeding varieties for saline soils. Australian Journal of Plant Physiology 13, 161-173.
 Lu, Z., Percy, R. G., Qualset, C. O., Zeiger, E, 1998: Stomatal conductance predicts yields in irrigated Pima cotton and bread wheat grown at high temperatures. Journal of Experimental Botany 49, 453- 460.
 Hern├índez, J. A., Jiménez, A., Mullineaux, P., Sevilla, F. 2000: Tolerance of pea (Pisum sativum L.) to long-term salt stress is associated with induction of antioxidant defences. Plant, Cell and Environment 23, 853-862.
 Jiang, Q., Roche, D., Monaco, T. A., Hole, D, 2006. Stomatal conductance is a key parameter to assess limitations to photosynthesis and growth potential n barley genotypes. Plant Biology 8, 515-521.
 Munns R., R. A. James., X. R. R. Sirault., R. T. Furbank, and H. G. Jones. 2010. New phenotyping methods for screening wheat and barley for beneficial responses to water deficit. Journal of Experimental Botany. P:1-9.