Improving NaCl resistance of red-osier dogwood: role of CaCl2 and CaSO4

Abstract

The influence of Ca 2+ salts on the resistance of red-osier dogwood (Cornus sericea) seedlings to salinity was investigated. Red-osier dogwood seedlings were exposed to 5 and 10 mM of CaCl 2 or CaSO 4 in the presence or absence of 50 mM NaCl for 40 days in a controlled environment. Seedlings exposed to CaCl 2 and CaSO 4 recovered from NaClinduced transpiration reduction after 20 days at a concentration of 10 mM and after 30 days at a concentration of 5 mM; while in absence of additional Ca 2+ , the seedlings recovered only after 40 days. Addition of 10 mM Ca 2+ to NaCl treatment also limited the accumulation of proline in leaf tissues and caused an increase in leaf and lateral shoot K + content. These results suggest that 10 mM Ca 2+ could alleviate, at least in part, the osmotic effect of NaCl on red-osier dogwood via control of stomatal closure. On the other hand, ion analysis showed that Ca 2+ addition was able to reduce the NaCl-induced Na + concentration only in stem tissues suggesting that Ca 2+ had only a limited effect on the ionic stress. The present study also showed an unexpected NaCl-induced increase in Ca 2+ content of leaves, lateral shoots and stems that was not observed in our previous hydroponics experiments and seems to be more characteristic of plants growing on sandy soils.

Does CaCl2 Play a Role in Improving Biomass Yield and Quality of Cardoon Grown in a Floating System under Saline Conditions?

“…Some authors suggested that Ca can help to mitigate also the osmotic effect of salinity through the accumulation of organic solutes such as proline and glycinebetaine (Girija et al, 2002). Proline is a compatible solute involved in osmotic adjustment and acts as a non-toxic osmotic solute stabilizing the structure of macromolecules and organelles in plants subjected to salt stress (Munns and Tester, 2008;Renault and Affifi, 2009). CaCl 2 was found to mitigate the NaCl-induced stress through the enhancement of proline accumulation in many plant species [e.g.…”

Signal regulation of proline metabolism in callus of the halophyte Nitraria tangutorum Bobr. grown under salinity stress

“…However, the addition of 10 mM Ca 2? together with NaCl treatment reduces the accumulation of proline in leaf tissues of red-osier dogwood (Renault and Affifi 2009). These studies provide the evidence that exogenous Ca supplement can regulate proline levels in high plants exposed to salinity stress, whereas the conclusions are different, and even contradictory.…”

Amendments to saline-sodic soils showed long-term effects on improving growth and yield of rice (Oryza sativaL.)

“…Although alleviation of Na + toxicity by supplemental Ca 2+ was confirmed, the responses varied with different plant species. Under similar saline-sodic conditions, amendments of Ca 2+ were found to obviously increase K + /Na + selectivity of both roots and shoots (SA and ST values) in Medicago sativa (Al-Khateeb, 2006) and Cornus sericea (Renault & Affifi, 2009). This is in contrast with Wang, Zhang & Flower (2007), who reported that amendments of Ca 2+ had no influence on SA and ST values of Suaeda maritima.…”