Mechanisms of salinity tolerance.
The physiological and molecular mechanisms of tolerance to osmotic and ionic components of salinity stress are reviewed at the cellular, organ, and whole-plant level. Plant growth responds to salinity in two phases: a rapid, osmotic phase that inhibits growth of young leaves, and a slower, ionic phase that accelerates senescence of mature leaves. Plant adaptations to salinity are of three distinct types: osmotic stress tolerance, Na(+) or Cl() exclusion, and the tolerance of tissue to accumulated Na(+) or Cl(). Our understanding of the role of the HKT gene family in Na(+) exclusion from leaves is increasing, as is the understanding of the molecular bases for many other transport processes at the cellular level. However, we have a limited molecular understanding of the overall control of Na(+) accumulation and of osmotic stress tolerance at the whole-plant level. Molecular genetics and functional genomics provide a new opportunity to synthesize molecular and physiological knowledge to improve the salinity tolerance of plants relevant to food production and environmental sustainability.
Munns
Rana
R
CSIRO Plant Industry, Canberra, ACT, Australia. rana.munns@csiro.au
Tester
Mark
M
D001467:Hordeum / Q000502:physiology; D012275:Oryza / Q000502:physiology; D009997:Osmotic Pressure; D018384:Oxidative Stress; D010788:Photosynthesis; D018521:Plant Physiological Phenomena; D018520:Plant Shoots / Q000378:metabolism; D010944:Plants / Q000235:genetics; D015398:Signal Transduction; D012964:Sodium / Q000378:metabolism; D012965:Sodium Chloride / Q000378:metabolism; D013816:Thermodynamics
D012965:Sodium Chloride; D012964:Sodium