Vol. 83 No: 4

Title:
Role of sucrose synthase and invertases during petal senescence in rose (Rosa hybrida L.)

Authors:
NAVEEN KUMAR, GIRISH CHAND SRIVASTAVA and KIRAN DIXIT

pp: 520-524

Abstract:
The roles of sucrose synthase and invertases were explored in relation to petal senescence in rose (Rosa hybrida L.). A developmental shift in the activities of these enzymes was observed. Higher sucrose synthase activity (0.52 – 0.95 μmol sucrose min^-1 mg^-1 protein) was observed during the initial stages (S1 and S2) of flower bud development, in contrast to invertases. However, the lower activity (0.56 μmol sucrose min^-1 mg^-1 protein) of sucrose synthase at a later stage (S6) of senescence could help the mobilisation of vacuolar sucrose.The different isoforms of invertase exhibited variable levels of activity. Insoluble acid invertases (IAI) were the most active (11.01 μmol glucose min^-1 mg^-1 protein), followed by soluble acid invertases (SAI; 8.02 μmol glucose min^-1 mg^-1 protein), and soluble neutral invertases (SNI; 0.74 μmol glucose min^-1 mg^-1 protein) at Stage-4. A significant decline in invertase activities (IAI, 0.98; SAI, 1.25; SNI, 0.32 μmol glucose min^-1 mg^-1 protein) coincided with higher levels of ethylene production at the later stages (S5 and S6) of flower bud development and senescence. We propose that developmental as well as ethylene-mediated pathways account for petal senescence in rose.

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