http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
Changes in growth, invertase, and carbohydrates in salt stressed Cucumis sativus
Cucurbits are moderately sensitive to salinity stress. Experiments were done to examine the physiological effects of NaCl on the growth and development of cucumber leaves and roots. Sodium chloride shock caused an inhibition of growth for the first 24 to 48 hours after initial treatment The response to stress varied with the salt concentration and the age of the leaf at the time of treatment. Leaf expansion and leaf emergence decreased with increasing NaCl in the solution media. The plastochron index was delayed at 80 mM salt, but was relatively unchanged in the 40 mM salt treatment This may indicate a change in the developmental physiology of the plant at higher salt levels. Root osmotic potential decreased within thirty minutes after salt shock and remained lower than the control for at least 24 hours. The plants wilted and regained turgor within the first six hours. Root invertase activity increased after six hours in 80 mM NaCl and remained higher than the control for at least seven days. Because the invertase did not increase until six hours after salt shock, it may not be involved in the initial recovery of turgor. However, it may play a role in long term osmotic adjustment. The transport sugars sucrose, raffinose, and stachyose decreased on days 1, 3, and 5 after NaCl shock. Myo-inositol, galactose, glucose, and fructose increased on day 3 then dropped to levels similar to the controls. Melibiose increased over time, perhaps as an indication of root injury or senescence. Reducing sugars may play a role in osmotic adjustment at salt levels less than those used in this study. Elemental analysis showed that Na+ concentrations increased dramatically in the roots within 24 hours while the Ca[^2+], Mg[^2+], and K+ concentrations decreased...