Study On The Basic Physiology Of Salt-tolerance In The Halophytic Aeluropus Sinensis

Plants have many different kinds of salt -tolerance ways, and the salt -tolerance mechanisms are very complex relating to many kinds of biochemical events, thus the plants display singular structures during its adaptation to salt stress. Salt secretion is an important way in various halophytic plants adapting to salt stress, some special epidermis cells of leaves and stems of the recretohalophytes can differentiate into salt glands during its development, the salt which was absorbed into the plants can be secreted from these salt glands, thus the plants can keep a low level of salt. In this experiment, the salt tolerence mechanism of Aeluropus sinensis( monocotyledon) is studied. The main results are shown as fllows:1. The effects of salt-treatment on the growth situations of Aeluropus sinensis(1) The area of leaf from plant grown in the increasing salt concentration became smaller, thus its transpivation fell; the longth of roots was minished, but not very obviously, so that roots could absorb water from higher salinity in case of physiological drought. At the same time, the high of plant, the number of tiller and the volume of roots declined gradually.(2) Comparing with control, the fresh weight, dry weight and water content of the whole plant declined with the increase of NaCl concentration in medium. Although the inorganic dry weight and the organic dry weight declined, the ratio of the organic dry weight and the whole dry weight was increasing. In addition, the ratios of roots and shoots of both fresh weight and dry weight also increased with the increase of NaCl concentration in medium, but that of the fresh weight was higher than that of the dry weight.2. The effects of salt-treatment on osmotic potential of Aeluropus sinensisWith the increase of NaCl concentration, osmotic potential in leaves and roots of plants decreased, while osmotic adjustment ability increased gradually, when the concentrations of Na+ were equal, the osmotic potential in leaves were stronger than thatin roots.3. The effects of salt-treatment on the plasmalemma permeability of AeluropussinensisThe plasmalemma permeability of leaves and roots increased gradually with the increase of NaCl concentration in medium, but the leaves were affected greatly, the roots were affected weakly.4. The effects of salt-treatment on the content of Malon dialdehyda(MDA) of Aeluropus sinensisUnder the salt stress, the content of Malon dialdehyda(MDA) of plants increased with the increase of NaCl concentration, the content of Malon dialdehyda(MDA) in leaves increased significantly, which was much higher than that in roots.5. The effects of salt-treatment on the content of chlorophyll of Aeluropus sinensisThe content of of plants increased with the increase of NaCl concentration, the content of Chla and Chlb of leaves increased, but Chla /b declined gradually.6. The effects of salt-treatment on the contents of inorganic ions and soluable organic components of Aeluropus sinensisThe contents of Na+, K+and Cl" in the leaves and roots of plants increased with the increase of NaCl concentration. At 200mmol/L NaCl, the contents of Na+, K+and Cl" in the roots were 1.10, 1.43 and 1.07 times higher than those of in leaves, the ratios of Na+/K+ increased, but the ratios of leaves were higher than those of in roots.After salt treatment, the contents of soluable organic components increased, the contents of proline, amino acids and soluable sugar increased much higher than organic acids. The ratios of sucrose and soluable sugar increased too.7. The effects of the inhibitor on the growth situations of Aeluropus sinensisAfter the plants were treated respectively with 100mmol/L NaCl and 100mmol/L NaCl+inhibitor, the later enhanced the contents of Na+, K+and Cl" in plants, Na+ especially. The quotiety of Na+ recreted by leaves declined from 82.65% to 35.23%, thus the growth of plants were inhibited.8. The shape and structure of salt glands of Aeluropus sinensisThe salt glands of Aeluropus sinensis distributed around the nervations of leaves mostly. A salt gland c...