Physiological responses to salt stress in young umbu plants

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• 作者：Elizamar Cirí ; aco da Silva ; Rejane Jurema Mansur Custó ; dio Nogueira ; Francisco Pinheiro de Araú ; jo ; Natoniel Franklin de Melo ; André ; Dias de Azevedo Neto
• 关键词：Spondias tuberosa ; Water potential ; Transpiration ; Organic solutes ; Sodium ; Chloride
• 刊名：Environmental and Experimental Botany
• 出版年：2008
• 出版时间：May 2008
• 年：2008
• 卷：63
• 期：1-3
• 页码：147-157
• 全文大小：961 K

文摘

Soil salinity affects plant growth and development due to harmful ion effects and water stress caused by reduced osmotic potential in the soil solution. In order to evaluate the effects of salt stress in young umbu plants, research was performed in green house conditions at the Laboratory of Plant Physiology at Federal Rural University of Pernambuco, Brazil. Growth, stomatal behaviour, water relations, and both inorganic and organic solutes were studied aiming for a better understanding of the responses of umbu plants to increasing salinity. Plants were grown in washed sand with Hoagland and Arnon nutrient solution with 0, 25, 50, 75, and 100 mM NaCl. Growth, leaf water potential, transpiration, and diffusive resistance were evaluated. Na⁺, K⁺, Cl⁻, soluble carbohydrates, and free amino acid contents were measured in several plant organs. Most variables were affected with salinity above 50 mM NaCl showing decreases in: number of leaves, plant height, stems diameter, and dry masses, and increases in root-to-shoot ratio. Reductions in ψ_pd were observed in plants grown under 75 and 100 mM NaCl. All salt levels above zero increased Na⁺ and Cl⁻ contents in leaves. However, K⁺ content was not affected. Na⁺ and Cl⁻ in stems and roots reached saturation in treatments above 50 mM NaCl. Organic solute accumulation in response to salt stress was not observed in umbu plants. These results suggest that umbu plants tolerate salt levels up to 50 mM NaCl without showing significant physio-morphological alterations.