RESUMEN

We investigated the effects of salinity on ion accumulation and expression of candidate salt tolerance genes in the highly tolerant salt accumulating halophyte Salicornia dolichostachya and the taxonomically related glycophytic Spinacia oleracea. S. dolichostachya, in comparison with S. oleracea, constitutively expressed SOS1 at a high level, but did not detectably express HKT1;1. These findings suggest that the constitutive high level of shoot salt accumulation in S. dolichostachya is accomplished through enhancement of SOS1-mediated Na(+) xylem loading, in combination with complete suppression of HKT1;1-mediated Na(+) retrieval from the xylem. Our findings demonstrate the importance of gene expression comparisons between highly tolerant halophytes and taxonomically related glycophytes to improve the understanding of mechanisms of Na(+) movement and salt tolerance in plants.

Asunto(s)

Proteínas de Transporte de Catión/genética , Chenopodiaceae/metabolismo , Proteínas de Plantas/genética , Proteína SOS1/genética , Cloruro de Sodio/farmacología , Simportadores/genética , Proteínas de Transporte de Catión/metabolismo , Chenopodiaceae/efectos de los fármacos , Chenopodiaceae/genética , Proteínas de Plantas/metabolismo , Raíces de Plantas/metabolismo , Plantas Modificadas Genéticamente , Proteína SOS1/metabolismo , Salinidad , Tolerancia a la Sal , Sodio/metabolismo , Intercambiadores de Sodio-Hidrógeno/genética , Simportadores/metabolismo , Xilema/efectos de los fármacos , Xilema/genética , Xilema/metabolismo