Treatment of flag leaves and ears of wheat plants with MJ (jasmonic acid methylester) (10−5 and 10−4m) did not increase ethylene production, but it did accelerate senescence as indicated by the loss of chlorophyll. MJ also caused the closure of stomata, and consequently the rates of transpiration and photosynthesis decreased. Early maturity shortened the grain filling period, so the thousand grain weight was lower. Although ethylene elicited the same physiologic effects, the syndrome of senescence by MJ is independent of the former. We conclude that senescence and death in wheat are far from being elucidated; however, MJ and ethylene seem to participate in the phenomenon.Facultad de Ciencias Agrarias y Forestales