Physiological responses of plants to salinity: A review

Abstract

Root-zone salinization presents a challenge to plant productivity that is effectively countered by salt-tolerant halophytic plants, but unfortunately, much less successfully by major crop plants. The way in which salt affects plant metabolism is reviewed. Cellular events triggered by salinity, namely salt compartmentation, osmotic adjustment and cell wall hardening are connected to the whole plant responses, namely leaf necrosis, altered phenology and ultimately plant death. The roles of ion exclusion and K/Na discrimination in mediating crop response to salt appear to be central to the tolerance response, but they are by no means essential. The processes involved in regulating ion uptake at the membrane level are considered. Recent work elucidating the interaction between calcium and salinity tolerance is reviewed.