Sarcocornia fruticosa recovery capacity after exposure to co-existed water and salinity stress

Abstract

The capacity of halophytes species to resist abiotic stress has been tested on multiple occasions. The ability of these species such as Sarcocornia fruticosa to cope with severe stress conditions has been shown, as well as their utility as a phytoremediation tool or even as potential crop species. However, there is a lack of literature on the effect that these abiotic factors have on their physiological response after a recovery period. In a greenhouse experiment, S. fruticosa plants were subjected to a combination of water regimen (water stress/field capacity) and salinity concentration (171/510 mM NaCl) grown conditions for 30 days. After these stress periods, plants were left 15 days in recovery conditions (field capacity and 171 mM NaCl). To study the effect of stress during both periods, osmotic potential, net photosynthetic rate, stomatal conductance, intercellular CO2 concentration, quantum efficiency of PS II, OJIP-derived parameters and photosynthetic pigment concentrations were measured. Our results show the already known resistance of this species to drought and salinity stress. However, the combination of both factors did affect the ability of S. fruticosa to maintain its level of carbon assimilation due to a decrease in stomatal conductance. In addition, the recovery period helped us to describe a synergic effect of both abiotic factors showing that plants subjected to both stresses received a better response during the recovery period than those only affected by salinity stress.