Synergistic effect of kinetin and spermine on some physiological aspects of seawater stressed Vigna sinensis plants.

The effect of kinetin, spermine and their combination on growth vigor, photosynthetic pigments, some metabolites, some enzymes, polyamines and productivity of salt-stressed Vigna sinensis plants was investigated. Salt stress reduced all evaluated growth criteria and yield components of used plants. Chlorophyll (CHL (a, b, carotenoids, carbohydrates, protein, spermidine and spermine level as well as and amylase activity were also decreased in response to salinity. On the other hand, proline, K(+), Na(+) and putrescine concentration, and peroxidase activity were increased in the salt-stressed plants. Exogenous application of kinetin and spermine mitigated the deleterious effects of salinity stress on growth and yield of the used plants. Conversely, the combined treatment of kinetin and spermine induced additional reduction in growth and yield of the stressed plants, and the effect appeared to be constitutive. The protective effect of kinetin and spermine on V. sinensis plants appeared mainly due to the enhancement effect of these growth regulators on chlorophylls and protein content and polyamines titer.