Activities of some enzymes during seed germination of some leafy vegetables under saline drainage water.
Seeds of five leafy vegetable crops were germinated to determine the effect of saline agriculture drainage water used as a resource to planting high value horticultural crops. Some glycolytic enzymes (Embeden-Meyerhof-Parnas: EMP) and pentose phosphate pathways (PPP) enzymes, namely pyruvate Kinase (PK), lactate dehydrogenase (LDH), glucose 6-phosphate dehydrogenase (G6PDH) and 6-phosphogluconate dehydrogenase (6PGDH) were investigated in addition to alcohol dehydrogenase (ADH). The leafy vegetables included 'Red Giant' mustard greens (Brassica juncea), 'Vitamen Green' salad greens (Brassica rapa [Brassica campestris] (Narinosa Group)), pak choi (Brassica rapa, (Chinensis Group)), 'Winterbor' kale (Brassica oleracea, (Acephala Group)) and tatsoi (Brassica rapa (Narinosa Group)). The enzyme activity levels differed with various varieties in response to different saline concentrations. However, in mustard greens PK and 6PGDH were inhibited while LDH, ADH and G6PDH were activated in response to salinity stress. In salad greens, salinity inhibited both ADH and 6PGDH whereas LDH activity was activated up to 15 dS/m. In addition, in salad greens PK and G6PDH were inhibited with low and activated with high saline concentrations. In tatsoi, salinity activated PK and ADH but inhibited LDH, G6PDH and 6PGDH. ADH and 6PGDH were activated in pak choi seedlings, while LDH was inhibited in response to salinity. PK and G6PDH in pak choi were inhibited at low and moderate (7, 11 and 15 dS/m) saline concentrations, but were stimulated at higher concentrations (19 and 23 dS/m). In kale, the response of the enzyme activities to salinity differed where PK and LDH from (EMP) and G6DH from (PP) pathways were enhanced with the increasing saline concentration, whereas ADH and 6PGDH (PPP) pathways were inhibited in response to the irrigation saline water.