1990 Fiscal Year Final Research Report Summary
Physiological and Biochemical Studies on the Responses and Adaptation of Plants to Salt Stress.
| Project/Area Number |
63480052
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
土壌・肥料
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| Research Institution | Okayama University |
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Principal Investigator |
KAWASAKI Toshio Okayama University Research Institute for Bioresources Professor, 資源生物科学研究所 (90033109)
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| Co-Investigator(Kenkyū-buntansha) |
SHIBASAKA Mineo Okayama University Research Institute for Bioresources Research Associate, 資源生物科学研究所, 助手 (60226165)
MORITSUGU Masumi Kagawa University Department of Agriculture Professor, 農学部, 教授 (80033116)
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| Project Period (FY) |
1988 – 1990
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| Keywords | Calcium / Halophyte / Potassium / Salicornia / Salt tolerance / Sodium / Respiration |
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| Research Abstract |
The responses and adaptation of plants on salt stress were investigated physiologically and biochemically, mainly using a multi-compartment transport box technique. Excised roots of Salicornia (Salicornia Virginica L.) and barley (Hordeum vulgare L., cv. Akashinriki) were used as experimental materials.
The results showed that Ca considerably depressed Na absorption and translocation in both Salicornia and barley roots. High concentrations of NaCl inhibited the absorption and translocation of K in the roots of both plants in the absence of Ca, especially in barley. However, Ca addition alleviated greatly the adverse effect of NaCl on K uptake in the both Salicaornia and barley roots. In contrast to barley, high concentrations of NaCl appeared to stimulate K uptake in Salicornia roots in the presence of Ca.
To investigate the mechanism of NaCl-stimulated K uptake in Salicornia roots in more detail, DNP, CCCP and vanadate were used as metabolic inhibitors. The stimulating effect of NaCl on K uptake was inhibited by DNP and CCCP, but not by vanadate. The results suggest that the NaCl-stimulated K uptake is involved in the energy metabolism, but not in ATPase activity.
In addition, it was found that NaCl up to 200 mM stimulated K uptake and the respiratory activity in Salicornia roots, while increasing concentrations of NaCl inhibited both activities in barley roots.
From the results, Salicornia seems to be more effective than barley in protecting the K-nutrition in its roots from the adverse effect of salt stress. The findings show that Salicornia responded to high NaCl concentrations by regulating a more efficient K uptake which results in a higher K content in the roots in the presence of Ca.
The results in the present experiments give us an important approach in the study of salt tolerance in plants.
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