Effects of exogenous trehalose on growth of Glycyrrhiza uralensis seedlings and total flavonoid content under salt stress / 中草药

Objective: To study the effects of exogenous trehalose on the growth and total flavonoids content of licorice (Glycyrrhiza uralensis) seedlings under NaCl stress. Methods: Using licorice seedlings as the material, the effects of NaCl stress on physiological growth, enzyme activity, ion content, osmotic regulation and total flavonoid content of licorice seedlings were studied in this experiment, Microsoft Excel 2010 was used for data processing and analysis, and SPSS19.0 statistical software was used for data analysis of variance. Results: Trehalose (10-20 mmol/L) significantly reduced the damage of NaCl to licorice seedlings, and the effect was the best when the concentration of exogenous trehalose was 15 mmol/L. Under NaCl stress, when exogenous trehalose concentration was 15 mmol/L, the growth of licorice seedlings was the most exuberant and the growth amount increased the most, and the K+ and K+/Na+ concentrations that affected the osmotic regulation of licorice seedlings increased the most, while the concentrations of Na+ and Cl- were decreased compared with those without NaCl stress. When the concentration of exogenous trehalose was 15 mmol/L, the activity of antioxidant enzymes in licorice seedlings under NaCl stress could be improved, and the content of light and chlorophyll in plant cells under NaCl stress could be increased. When the concentration of exogenous trehalose was 15 mmol/L, the contents of soluble sugar, proline and cellular regulatory substance MDA in licorice seedlings under NaCl stress could be reduced. Conclusion: The application of exogenous trehalose with appropriate concentration under NaCl stress can promote the growth of licorice seedlings and the accumulation of effective components, reduce the harm of salt damage to the growth of licorice, and enhance the growth ability of Licorice under NaCl stress.

Effects of silicon addition on seed germination and seedling growth of Glvarrhiza uralensis under salt stress / 中草药

Objective: In this study, a water culture experiment was conducted to investigate the effects of silicon addition on the seed germination and seedling growth of Glvarrhiza uralensis under salt stress. Methods: Various components of the experiment were three salt treatments (50, 100, and 150 mmol/L NaCl) and six Si levels (0, 1, 2, 4, 6, and 8 mmol/L) in distilled water. Potassium silicate (K2SO4) was used as a source of Si. Results: The result showed that silicon addition had the significant effect on the seed germination and seedling growth, and this effect was dependent on the salt stress level and silicon addition concentration. Under 50 and 100 mmol/L NaCl stress condition, lower concentration silicon addition had no significant effect on the germination rate, germination index, seedling emergence rate, and radical length, while had the significantly promoted effect on plant height, and root and shoot dry weight of G. uralensis. However, higher concentration silicon addition had the significantly inhibited effect on the seed germination and seedling growth. Under 150 mmol/L NaCl stress condition, silicon addition at lower concentration significantly promoted the seed germination and seedling growth of G. uralensis, including the germination rate, seedling emergence, germination index, seedling vigor, radical and embryo length, and root and shoot dry weight. However, silicon addition at higher concentration significantly inhibited the seedling growth of G. uralensis, while had no significant effect on the seed germination. Conclusion: Silicon is directly involved in the physiological process of the seed germination and seedling growth of G. uralensis under salt stress condition, and this involved extent is dependent on the salt stress level and silicon addition concentration.