DNase and RNase Responses of Petunia × hybrida During Transition to Flowering as Affected by Light Treatments

The responses of DNase and RNase isoforms and their specific activities following transition to flowering (1 to 6 weeks) were examined in Petunia × hybrida under different light conditions. Petunia × hybrida plants formed flower buds at the 4th week in the case of high light and at the 6th week in the far-red light treatment, while no flower bud formation was observed upon red light and control light treatments. The DNase and RNase activities decreased from the 1st to the 6th week during transition to flowering. Native-PAGE analysis revealed the appearance of one DNase (D1) and seven RNase (R1 - R7) isoforms in all light treatments. It is assumed that the progress of the flowering could be related to the disappearance or reduction of D1 DNase band intensity and disappearance of R1, R2 and R7 RNase isoforms. Consequently, these isoforms could be used as potent biochemical markers of flower bud formation under light intensity as well as light quality treatments.