Effects of Exogenous Abscisic Acid,Nitric Oxide and Hydrogen Peroxide on Stomatal Movement in Petals and Leaves of Zephyranthes candida

To illustrate the effect of ABA,SNP (sodium nitroprusside) and H₂O₂ on stomata in the petals and leaves of Zephyranthes candida and explain the application of endogenous signal substances in cut flower perservation,the rate of change in stomatal apertures was measured.Results showed that 10-1000 μmol/L SNP and ABA could induce different degrees of stomatal closure in petals and leaves,with stomata in petals having higher sensitivity than that in leaves.When undergoing H₂O₂ treatments, stomata in petals were only affected at 1000 μmol/L less sensitive than that in leaves.These results revealed that the movement of stomata in petals may help delay flower senescence when flowers undergo exogenous hormone treatments.Appropriate exogenous ABA and SNP treatment could delay flower senescence by inducing the closure of petal stomata,reducing the transpiration rate of petals,and maintaining the water potential of plant cells.