A Recessive Arabidopsis Mutant That Grows Photoautotrophically under Salt Stress Shows Enhanced Active Oxygen Detoxification

Abstract

Mutagenized Arabidopsis seedlings (ecotype Columbia) were screened for the ability to grow photoautotrophically on solid medium containing 200 mM NaCl. A novel mutant line, designated pst1 (for photoautotrophic salt tolerance1 ), was obtained. There were no significant differences between pst1 and wild-type plants with regard to their ability to induce proline as an osmoregulatory solute. In addition, the content of monovalent cations in pst1 plants grown with or without salt stress was equal to that in the wild type. We observed that light, even at moderate intensities, increased the effects of salt stress on wild-type plants. The pst1 seedlings were nearly 10 times more tolerant to methyl viologen than were wild-type seedlings. We also found that the activities of the active oxygen scavengers superoxide dismutase and ascorbate peroxidase were enhanced significantly in pst1 plants. The pst1 plants also were tolerant to other stresses, such as high light intensity and toxic monovalent cations. The recessive nature of the pst1 mutation indicates that the potential for salt-stress tolerance is blocked in wild-type Arabidopsis.

Alleviation of field water stress in wheat cultivars by using silicon and salicylic acid applied separately or in combination

“…However, in the view of Møller et al (2007), a balance between ROS generation and the activities of antioxidant enzymes may ensure the extent to which oxidative damage and signalling will take place. In fact, capacity to scavenge ROS may promote drought tolerance in plants (Tsugane et al 1999).…”

Plant Salinity Stress: Many Unanswered Questions Remain

“…Salinity impairs plant growth and development via water stress, cytotoxicity due to excessive uptake of ions such as sodium (Na + ) and chloride (Cl − ), and nutritional imbalance. Additionally, salinity is typically accompanied by oxidative stress due to generation of reactive oxygen species (ROS) (Tsugane et al., 1999; Hernandez et al., 2001; Isayenkov, 2012).…”

Understanding and Improving Salt Tolerance in Plants

“…The Arabidopsis pst1 ( photoautotrophic salt tolerance 1 ) mutant is more tolerant to salt stress than the wild type. The observed salt tolerance was attributed to higher activities of superoxide dismutase and ascorbate peroxidase than those in wild‐type Arabidopsis (Tsugane et al, 1999). Thus, ROS detoxification is an important part of salt‐stress tolerance.…”