Some important biochemical changes orchestrating flower development and senescence in Nicotiana plumbaginifolia Viv. and Petunia hybrida Vilm. flowers

A comparative study of some biochemical parameters and expression patterns during flower development and senescence in Nicotiana plumbaginifolia and Petunia hybrida was carried out to ascertain the differences between the two important ornamentals. Lipid peroxidation (LPO) was found to increase throughout flower development and senescence in P. hybrida whereas in N. plumbaginifolia it decreased towards flower opening and showed a sharp increase towards senescence. Membrane stability index showed a marginal decrease towards senescence in the flowers of both the plants. Activities of the antioxidant enzymes (superoxide dismutase, catalase, ascorbate peroxidase, and lipoxygenase) increased up to the open flower stage (stage IV) and decreased thereafter towards the senescent stage in the flowers from both the plant species. The pre-senescent stages in flowers from both the plants did not show up the detection of ethylene in the petal tissues on gas chromatograph while as a climacteric rise in the ethylene concentration was exhibited by the senescent stages of both the flowers under study. mRNA-transcripts of senescence associated gene DAD1 were found to accumulate in the open flower stage (stage IV) in N. plumbaginifolia and those of ETR1 and SAG12 were found to accumulate in the open flower stage (stage IV) in P. hybrida.

Automated summary

The comparative study between Nicotiana plumbaginifolia and Petunia hybrida revealed differences in lipid peroxidation, membrane stability, and antioxidant enzyme activities during flower development and senescence. Both plants showed an increase in antioxidant enzyme activities up to the open flower stage, followed by a decrease towards senescence. Ethylene was detected only in the senescent stages of both flowers, indicating a climacteric rise. Transcripts of senescence-associated genes were found to accumulate in the open flower stage for both plant species.