Transport de Na+ dans les feuilles et sensibilité des plantes à NaCl. I. Évaluation d'un effet piège au niveau des tiges

Effects of NaCl on Flows of N and Mineral Ions and on NO3- Reduction Rate within Whole Plants of Salt-Sensitive Bean and Salt-Tolerant Cotton

“…This result concurs with the reported sensitivity of bean and tolerance of cotton to salinity (Greenway and Munns, 1980;Brugnoli and Lauteri, 1991 by Slama (1991) for the same cultivars. The growth of bean was more depressed by exogenous NaCl than the growth of cotton during the exponential growth phase between 12 and 28 d, as well as during the initial, nonexponential growth phase, since both slope and y intercept for the linear regression of the logarithm of plant dry weight versus time were decreased more by the presence of 50 m NaCl for bean than for cotton.…”

“…On the basis of their tolerance or sensitivity, plants commonly are distinguished as halophytes, which naturally grow on saline soils, and glycophytes or nonhalophytes (Flowers and Yeo, 1988). Although crop species are nonhalophytes and their growth and yield are depressed by salinity, they display a wide range of sensitivity to salinity (Greenway and Munns, 1980; Slama, 1991). The main problem for a plant in saline media is that on the one hand, since extemal osmotic potential is much lower than in nonsaline soils, osmotica must be accumulated to high levels to create a water potential gradient to facilitate inward water movement, whereas on the other hand increasing concentrations of ions in the symplasm eventually may become toxic (Greenway and Munns, 1980).…”

“…The present paper reports on the effects of mild NaCl stress on flows of Na+, K+,Ca",Mg2+,) in whole plants of bean (Phaseolus vulgaris L. cv Gabriella) and cotton (Gossypium hirsutum L. cv Akala), which were chosen for their difference in sensitivity to NaCl salinity (Brugnoli and Lauteri, 1991;Slama, 1991). Both of these species reduce NO3-predominantly in the shoot (Andrews, 1986), which is contrary to white lupin and castor bean, for which data on the effects of NaCl on partitioning of ions and N are available (Jeschke et al, 1992, and refs.…”

Salinity effects on germination, growth and mineral nutrition of Ricinus communis seedlings

“…Because of their significant volume compared to the whole of the organs of the plant and their strong intrinsic capacity of accumulation, the stems take part obviously in the protection of the leaves against Na + (Hajji 1983, Jacoby 1965, Morard 1981, Rains 1969, Walker 1986. In this context, a study presented an incompatible result with this assumption that the stems protect the leaves against invasion by Na + by reabsorbing this ion starting from the sap from the xylem, and while functioning like traps for this ion (Slama 1991). So based on the stability of the tolerance to salinity from germinative stage to seedlings stage, the provenance of Kairouan was identified as the most tolerant and the provenance of Grombalia as the most sensitive to salt toxicity.…”