Halotolerant Eukaryotes

Effects of Sodium and Potassium Salts on the Growth of a Halophyte

“…The control plants, grown at a concentration of only 1 mM KCl in the standard culture solution without NaCl addition showed a value of 8% potassium per leaf dry weight, equivalent to 450 meq/liter potassium on a tissue water basis and also exhibited higher concentrations of Ca and Mg in the leaves compared with the plants receiving NaCI. This potassium concentration is far higher than that reported for glycophytes (3), and these results indicate the "craving for salt" character of the dicot halophytes (8). They also imply that the growth improvement observed was not ion-specific but depended on the amount of absorbable salts in the rooting medium.…”

“…This growth stimulation effect can be best interpreted in assuming that the growth response to salts is controlled by water relations (8). MUNNS et al (8) suggested that since halophytes have a low hydraulic conductance and a low root: shoot ratio expressed on a dry weight basis, they require a lower internal water potential than glycophytes to absorb water.…”

“…MUNNS et al (8) suggested that since halophytes have a low hydraulic conductance and a low root: shoot ratio expressed on a dry weight basis, they require a lower internal water potential than glycophytes to absorb water. GALE et al (5) demonstrated that the beneficial effect of NaCI on the growth of Atriplex halimus was mainly associated with the alleviation of the adverse effect of moisture stress, including low atmospheric humidity.…”

Benthic Macroalgae of Shark Bay, Western Australia

“…While salinity is a measure of total salts (grams of salts per kilogram of solution), it also describes biologically significant aspects of the physics and chemistry of water including total osmo-concentration (osmotic pressure), ion composition and density of water. High salinities have been shown to decrease growth (Munns et al 1983), photosynthesis (Gordon et al 1980, Lehnberg 1978 and respiration rates (Lehnberg 1978). More research as to the cause of the patterns in distribution and growth of the primary producers in relation to salinity within Shark Bay is needed.…”

SALT TOLERANCE IN THE HALOPHYTE SUAEDA MARITIMA (L.) DUM.

“…Tolerance depends on osmotic adjustment within the body of the plant, normally achieved by significant accumulation of sodium and chloride ions in the root and their subsequent transport to the shoot (see Flowers, Hajibagheri & Clipson, 1986), thus maintaining shoot tissue water potentials more negative than those of the external medium (Clipson et al, 1985). Halophytes maintain shoot ion concentration relatively constant (Munns, Greenway & Kirst, 1983) through a relationship between ion transport and growth. In practice, restriction of transport of ions across the root has to be exercised to prevent excessive ion accumulation within the shoot.…”