Articles
RESEARCH ON ISOLATED CARNATION PETALS
Isolated petals taken from young flowers usually outlast their intact counterparts.
ACC applied to isolated petals results in accelerated senescence, but response to ACC increases with petal age.
Distinct areas of isolated carnation petals also vary in their response to ACC. Apparently conversion of ACC to ethylene is a rate-limiting step in the senescence of young petal tissues.
Auxins taken up by isolated carnation petals also result in rapid senescence, but petals with their bases removed are unable to respond to exogenous auxin.
Exposure to ethylene, like auxin, causes incurling and loss of fresh weight in isoloated carnation petals, but these two phenomena apparently occur somewhat independently of each other.
Application of gibberellins and cytokinins increases isolated petal longevity.
Cytokinins not only inhibit synthesis of ACC and ethylene in isolated petals, but they also inhibit the response of the petals to exogenously-applied ACC or ethylene.
In Tradescantia isolated petal application of various polyamines reduces ethylene synthesis, but does not prevent loss of membrane integrity during senescence.
Isolated petal systems provide a practical method for studying independent activities of the petal tissues, as well as examining the roles which other floral organs may play in influencing the senescence of petals.