EFFECT OF KINETIN ON PLANT‐RESPONSE TO SALINITY

Kinetin applied to tobacco plants had a marked dwarfing effect and, in suitable concentration, prevented the appearance of saline‐induced leaf‐necrosis. In experiments lasting for 24 h, kinetin effected a reduction of salt transport from the roots to the shoot, without affecting salt uptake. However, Na⁺ and Cl^‐ analysis of plants exposed to 6 weeks of salination revealed that kinetin accentuated salt accumulation in the shoot and thus the necrosis‐prevention effect of kinetin did not stem from retardation of salt accumulation in the plant. It is suggested that the effect of salinity on leaf‐necrosis was related to its effect on acceleration of leaf senescence and that kinetin prevented salinity damage by retarding cellular senescence and breakdown.