| Publication Type | J |
| Authors | Hariadi, Y., K. Marandon, Y. Tian, S. E. Jacobsen and S. Shabala |
| Title | Ionic and osmotic relations in quinoa (Chenopodium quinoa Willd.) plants grown at various salinity levels |
| Source | Journal of Experimental Botany |
| Author Keywords | Halophyte ion loading membrane transport osmotic adjustment potassium salt stress sequestration sodium plasma-membrane transporters induced potassium efflux salt tolerance compatible solutes abiotic stress bread wheat durum-wheat barley water mechanisms |
| Abstract | Ionic and osmotic relations in quinoa (Chenopodium quinoa Willd.) were studied by exposing plants to six salinity levels (0-500 mM NaCl range) for 70 d. Salt stress was administered either by pre-mixing of the calculated amount of NaCl with the potting mix before seeds were planted or by the gradual increase of NaCl levels in the irrigation water. For both methods, the optimal plant growth and biomass was achieved between 100 mM and 200 mM NaCl, suggesting that quinoa possess a very efficient system to adjust osmotically for abrupt increases in NaCl stress. Up to 95% of osmotic adjustment in old leaves and between 80% and 85% of osmotic adjustment in young leaves was achieved by means of accumulation of inorganic ions (Na+, K+, and Cl-) at these NaCl levels, whilst the contribution of organic osmolytes was very limited. Consistently higher K+ and lower Na+ levels were found in young, as compared with old leaves, for all salinity treatments. The shoot sap K+ progressively increased with increased salinity in old leaves; this is interpreted as evidence for the important role of free K+ in leaf osmotic adjustment under saline conditions. A 5-fold increase in salinity level (from 100 mM to 500 mM) resulted in only a 50% increase in the sap Na+ content, suggesting either a very strict control of xylem Na+ loading or an efficient Na+ removal from leaves. A very strong correlation between NaCl-induced K+ and H+ fluxes was observed in quinoa root, suggesting that a rapid NaCl-induced activation of H+-ATPase is needed to restore otherwise depolarized membrane potential and prevent further K+ leak from the cytosol. Taken together, this work emphasizes the role of inorganic ions for osmotic adjustment in halophytes and calls for more in-depth studies of the mechanisms of vacuolar Na+ sequestration, control of Na+ and K+ xylem loading, and their transport to the shoot. |
| Author Address | [Hariadi, Yuda; Shabala, Sergey] Univ Tasmania, Sch Agr Sci, Hobart, Tas 7001, Australia. [Hariadi, Yuda] Univ Jember, Dept Phys, Fac Math & Nat Sci, Jember 68121, East Java, Indonesia. [Marandon, Karl] Inst Polytech LaSalle Beauvais, F-60026 Beauvais, France. [Tian, Yu] NE Normal Univ, Inst Grassland Sci, Key Lab Vegetat Ecol, Minist Educ, Changchun 130024, Peoples R China. [Jacobsen, Sven-Erik] Univ Copenhagen, Dept Agr & Ecol, Fac Life Sci, DK-2630 Taastrup, Denmark. Shabala, S, Univ Tasmania, Sch Agr Sci, Private Bag 54, Hobart, Tas 7001, Australia. Sergey.Shabala@utas.edu.au |
| ISSN | 0022-0957 |
| ISBN | 0022-0957 |
| 29-Character Source Abbreviation | J. Exp. Bot. |
| Publication Date | Jan |
| Year Published | 2011 |
| Volume | 62 |
| Issue | 1 |
| Beginning Page | 185-193 |
| Digital Object Identifier (DOI) | 10.1093/jxb/erq257 |
| Unique Article Identifier | ISI:000284951900016 |
