The accumulation of citric acid and associated correlative strain indexes were investigated in the seedlings of Puccinellia tenuiflora (Griseb.) Scribn. et Merr. stressed with 0-175 mmol/L Na 2CO 3. The results ...The accumulation of citric acid and associated correlative strain indexes were investigated in the seedlings of Puccinellia tenuiflora (Griseb.) Scribn. et Merr. stressed with 0-175 mmol/L Na 2CO 3. The results showed that the citric acid accumulation is a specific physiological respond of this plant to alkali_stress. On the contrary, the citric acid content decreased slightly in this plant stressed with 0-400 mmol/L neutral salt NaCl. The accumulation of citric acid increased with increasing strength of alkali_stress, the citric acid content increased gently when the strength was lower than 100 mmol/L Na 2CO 3, but increased obviously when the strength was higher than 100 mmol/L Na 2CO 3. The citric acid rapidly accumulated at early alkali_stress, an obvious raise can be mensurated after 4 h. About 48 h after treatment, the amount of citric acid accumulated nearly reached the maximum. In various parts of P. tenuiflora seedlings alkali_stressed for 144 h, the order of citric acid content from high to low is: old leaf, mature leaf, old leaf sheath, young leaf sheath, young stem, old stem, and young leaf. In the mature leaf, the citric acid content gradually increased with increasing strength of alkali_stress, while the citric acid content increased sharply in old leaf and sheath just for strength higher than 125 mmol/L. There was little change of citric acid content in stem, but no change in young leaf. The results of the experiment showed that citric acid was outstanding among accumulated organic acid caused by alkali_stress. The contribution of other organic acids was negligible.展开更多
文摘The accumulation of citric acid and associated correlative strain indexes were investigated in the seedlings of Puccinellia tenuiflora (Griseb.) Scribn. et Merr. stressed with 0-175 mmol/L Na 2CO 3. The results showed that the citric acid accumulation is a specific physiological respond of this plant to alkali_stress. On the contrary, the citric acid content decreased slightly in this plant stressed with 0-400 mmol/L neutral salt NaCl. The accumulation of citric acid increased with increasing strength of alkali_stress, the citric acid content increased gently when the strength was lower than 100 mmol/L Na 2CO 3, but increased obviously when the strength was higher than 100 mmol/L Na 2CO 3. The citric acid rapidly accumulated at early alkali_stress, an obvious raise can be mensurated after 4 h. About 48 h after treatment, the amount of citric acid accumulated nearly reached the maximum. In various parts of P. tenuiflora seedlings alkali_stressed for 144 h, the order of citric acid content from high to low is: old leaf, mature leaf, old leaf sheath, young leaf sheath, young stem, old stem, and young leaf. In the mature leaf, the citric acid content gradually increased with increasing strength of alkali_stress, while the citric acid content increased sharply in old leaf and sheath just for strength higher than 125 mmol/L. There was little change of citric acid content in stem, but no change in young leaf. The results of the experiment showed that citric acid was outstanding among accumulated organic acid caused by alkali_stress. The contribution of other organic acids was negligible.
