Effects of sodium chloride stress and calcium supply on growth, potassium uptake, and internal chloride and sodium levels of winter wheat seedlings.
The effects of saline conditions on the K+ (86Rb), Na+ and Cl- uptake and growth of 6-day-old wheat (Triticum aestivum L. cv. GK Szeged) seedlings were studied in the absence and presence of Ca2+. It was found that on direct NaCl treatment the K+ uptake of the roots in the absence of Ca2+ declined significantly with increasing salinity. The reverse was true, however, in the case of NaCl pretreatment: seedlings grown under highly saline conditions (50 mM NaCl) absorbed more K+ than those pretreated with low levels of NaCl (1 or 10 mM NaCl). The data indicate a definite Na(+)-induced K+ uptake inhibition and/or feed-back regulation in the K+ uptake of roots under the above-mentioned growth conditions. As regards the Ca2+ effect, it was established that supplemental Ca2+ counteracts the unfavourable effect of saline conditions as concerns both the K+ uptake of the roots and the dry matter yield of the seedlings. The internal concentrations of Na+ and Cl- in the seedlings increased in proportion to increasing salinity. Marked differences were experienced, however, in the internal concentrations of Na+ and Cl- in the roots and shoots, respectively. It was concluded that under these experimental conditions the salt tolerance of wheat could be related to its capability of restricting the transport of Na+ at low and moderate levels to the shoots, where it is highly toxic.
Zsoldos
F
F
Department of Plant Physiology, József Attila University, Szeged, Hungary.
Haunold
E
E
Vashegyi
A
A
Herger
P
P
D001692:Biological Transport; D002118:Calcium / Q000378:metabolism*; D002712:Chlorides / Q000378:metabolism*; D011188:Potassium / Q000378:metabolism*; D012639:Seeds / Q000378:metabolism; D012965:Sodium Chloride / Q000378:metabolism*; D014908:Triticum / Q000254:growth & development* / Q000378:metabolism
D002712:Chlorides; D012965:Sodium Chloride; D011188:Potassium; D002118:Calcium