Improving abiotic stress tolerance in crops (Invited Review)

Global annual losses in agricultural production from salt-affected land are in excess of US$12 billion and rising. Shabala identifies physiological mechanisms conferring salinity tolerance in halophytes that can be introduced into non-halophyte crop species to improve their performance under saline conditions. The specific traits that are discussed and advocated include: manipulation of trichome shape, size and density to enable their use for external Na⁺ sequestration; increasing the efficiency of internal Na⁺ sequestration in vacuoles by the orchestrated regulation of tonoplast NHX exchangers and slow and fast vacuolar channels, combined with greater cytosolic K⁺ retention; controlling stomata aperture and optimizing water use efficiency by reducing stomata density; and efficient control of xylem ion loading.