Regulation of Development of the Storage Root of Sugarbeet

Small cells, found in the cambial regions of the sugarbeet storage root are relatively more efficient at accumulating sucrose than the large cells of the parenchymatous zones (Milford, 1973). As part of a wider investigation into the regulation of cambial activity in sugarbeet, the role of the gibberellins in cell division and expansion has been studied. Analyses of endogenous gibberellin-like substances of sugarbeet and mangold shoots and storage roots through the vegetative developmental period have revealed that the activity of the major gibberellin-like substance in the storage root is highest during the period in which cell expansion(rather than cell division )is the predominant factor in storage root growth. This suggests that the endogenous gibberellin-like substance is involved in the regulation of cell expansion in the storage root, Studies with excised sugarbeet seedling roots have demonstrated that an auxin (lAA), a cytokinin (BA), myo-inositol and sucrose are required to stimulate cambial activity. Exogenously applied G3 was not essential for cambial activity, but the application of a growth retardant which may act by interfering with gibberellin biosynthesis reduced the expansion of the parenchyma cells. This provided further evidence that endogenous gibberellins are involved in the stimulation of cell expansion in this zone of the young root. Sugarbeet cell suspension cultures were used to determine the role of gibberellins in cell division and expansion in a system free from the interacting influences of the whole plant. An exogenous supply of GA^ did not influence culture growth, but studies with growth retardants and analyses of endogenous gibberellin-like substances provided evidence that the cells can satisfy their own gibberellin requirement. Gibberellins seem likely to be associated with the cell expansion process in this system. It is proposed that the regulation the sugarbeet storage root involves an like substance or substances. Means by might be applied to improve the sucrose crop are discussed.

Name dc:type.qualificationname

PhD

Level dc:type.qualificationlevel

Doctoral

Grantor dc:publisher.institution

De Montfort University

Year dc:date.issued

1982

Author dc:creator

• Smith, Jane Isobel

Licence

• https://dora.dmu.ac.uk/bitstreams/9d46d9dd-760b-422c-8090-842ac62c01cc/download