Journal Article

Genetic analysis of salt tolerance in Arabidopsis: evidence for a critical role of potassium nutrition

Zhu, J.K. (University of Arizona, Tucson.), Xiong, L, Liu, J

1998

Overview

A large genetic screen for sos (for salt overly sensitive) mutants was performed in an attempt to isolate mutations in any gene with an sos phenotype. Our search yielded 28 new alleles of sos1, nine mutant alleles of a newly identified locus, SOS2, and one allele of a third salt tolerance locus, SOS3. The sos2 mutations, which are recessive, were mapped to the lower arm of chromosome V, approximately 2.3 centimorgans away from the marker PHYC. Growth measurements demonstrated that sos2 mutants are specifically hypersensitive to inhibition by Na+ or Li+ and not hypersensitive to general osmotic stresses. Interestingly, the SOS2 locus is also necessary for K+ nutrition because sos2 mutants were unable to grow on a culture medium with a low level of K+. The expression of several salt-inducible genes was superinduced in sos2 plants. The salt tolerance of sos1, sos2, and sos3 mutants correlated with their K+ tissue content but not their Na+ tissue content. Double mutant analysis indicated that the SOS genes function in the same pathway. Based on these results, a genetic model for salt tolerance mechanisms in Arabidopsis is presented in which SOS1, SOS2, and SOS3 are postulated to encode regulatory components controlling plant K+ nutrition that in turn is essential for salt tolerance

• Publisher: American Society of Plant Physiologists
• Subject: ALLELES / Arabidopsis / Arabidopsis - drug effects / Arabidopsis - genetics / Arabidopsis - physiology / ARABIDOPSIS THALIANA / CAESIUM / CARTE GENETIQUE / CESIO / CESIUM / Cesium - pharmacology / CESIUM CHLORIDE / CHEMICAL COMPOSITION / chemical constituents of plants / CHLORIDES / Chlorides - pharmacology / CHLORURE / CHLORURE DE POTASSIUM / CHLORURE DE SODIUM / Chromosome Mapping / CHROMOSOME MAPS / CLORURO POTASICO / CLORURO SODICO / CLORUROS / COMPOSICION QUIMICA / COMPOSITION CHIMIQUE / CONTENIDO MINERAL / Crosses, Genetic / drug effects / ESTRES / Ethyl Methanesulfonate / EXPRESION GENICA / EXPRESSION DES GENES / Fast Neutrons / FITOTOXICIDAD / GENE / GENE EXPRESSION / GENE INTERACTION / GENES / Genes, Plant / Genetic loci / GENETIC MAPPING / GENETIC MAPS / Genetic mutation / genetics / Hypersensitivity / INDUCED MUTATION / INTERACCION DE GENES / INTERACTION GENIQUE / LITHIUM / LITHIUM CHLORIDE / Lithium Chloride - pharmacology / LITIO / LOCI / LOCUS / MANITOL / MANNITOL / MAPAS GENETICOS / metabolism / MINERAL CONTENT / MINERAL NUTRIENTS / MUTACION INDUCIDA / Mutagenesis / MUTANT / MUTANTES / MUTANTS / MUTATION PROVOQUEE / NUTRIENTES MINERALES / Nutrition / Osmolar Concentration / OSMOTIC STRESS / pharmacology / physiology / PHYTOTOXICITE / PHYTOTOXICITY / Plant cells / Plants / PLANTULAS / PLANTULE / POTASIO / POTASSIUM / Potassium - metabolism / POTASSIUM CHLORIDE / Potassium Chloride - pharmacology / SALT TOLERANCE / SEEDLINGS / SODIO / SODIUM / SODIUM CHLORIDE / Sodium Chloride - pharmacology / SOS1 LOCUS / SOS2 LOCUS / SOS3 LOCUS / STRESS / SUBSTANCE NUTRITIVE MINERALE / SUSCEPTIBILITY / TENEUR EN ELEMENTS MINERAUX / TOLERANCE AU SEL / TOLERANCIA A LA SAL