Physiological and Biochemical Mechanisms of Exogenous Calcium Chloride on Alleviating Salt Stress in Two Tartary Buckwheat (Fagopyrum tataricum) Varieties Differing in Salinity Tolerance

Salt stress is one of the most serious abiotic stresses limiting plant growth and development. Calcium as an essential nutrient element important signaling molecule plays role in ameliorating adverse effect salinity on plants. This study aimed to investigate impact exogenous calcium improving salt tolerance Tartary buckwheat cultivars, cv. Xinong9920 (salt-tolerant) Xinong9909 (salt-sensitive). Four-week-old seedlings under 100 mM NaCl were treated with without chloride (CaCl2), Ca2+ chelator ethylene glycol tetraacetic acid (EGTA) Ca2+-channel blocker lanthanum (LaCl3) for 10 days. Then, some physiological biochemical indexes determined. The results showed that significantly reduced seedling growth, decreased photosynthetic pigments, inhibited antioxidants antioxidant enzyme activities. However, it increased reactive oxygen species (ROS) levels two cultivars. Exogenous CaCl2 application salt-stressed obviously mitigated negative effects partially restored growth. Ca2+-treated diplayed a suppressed accumulation ROS, contents total chlorophyll, soluble protein, proline antioxidants, elevated activities enzymes compared alone. On contrary, addition 0.5 LaCl3 5 EGTA exhibited opposite those treatment. These indicate can enhance supplementation may be effective practice cultivate saline soils.