The effect of phenylmercuric acetate on salt tolerance in wheat

Sodium chloride reduced the growth of the wheat cultivar Armada. Although phenylmercuric acetate (PMA) also reduced the growth under non-saline conditions, in the presence of sodium chloride (100 mM) fresh weight, dry weight and leaf area per plant were promoted particularly when sprayed with PMA at 50 mgrM. Both net photosynthesis and transpiration were reduced by PMA but the reduction was greater in the absence rather than the presence of NaCl. Furthermore PMA lowered shoot sodium contents and promoted the selectivity for K over Na under saline conditions. Any beneficial effects of PMA are the consequences of improved water relations, lowered ion content and increased leaf area for photosynthesis.