Morphophysiology and biochemistry of Prosopis strombulifera under salinity. Are halophytes tolerant to all salts?

Abstract

Prosopis genus is an important member of semiarid, arid and saline environments around the world. This genus includes shrubs and trees that exhibit a high economic and ecological potential in different American regions. These plants are considered to be unique terrestrial species due to their combined ability to fix nitrogen and grow under high-salinity conditions. The South American halophyte, Prosopis strombulifera (Lam) Benth, is distributed from the Arizona desert (U.S.A.) to Patagonia (Argentina) and is especially abundant in the salinized areas of central Argentina. The soil of these areas is characterized by similar proportions of NaCl and Na2SO4. P. strombulifera species showed a halophytic response to NaCl surviving up to 1 M NaCl in in-vitro experiments, but in contrast, a strong growth inhibition at lower Na2SO4 concentrations was observed. These differential responses to the most abundant salts present in salinized soils of Argentina make this species an excellent model to study salt-tolerance mechanisms in halophytic plants. This chapter provides an overview of different salt tolerance mechanisms in the American halophyte Prosopis strombulifera, especially phytohormone pattern, oxidative responses and production of biomolecules. This halophyte may be considered as a new useful genetic source to improve crop salt tolerance and a promising plant as source of natural products for pharmaceutical industry.