Modification of gibberellin signalling (metabolism & signal transduction) in sugar beet: analysis of potential targets for crop improvement

Euphemia Mutasa-Gottgens, Aiming Qi, Stephen Thomas, Ann Mathews, Andrew Phillips, Peter Hedden

Research output: Contribution to journalArticlepeer-review

24 Citations (Scopus)


Sugar beet, Beta vulgaris spp. vulgaris is a biennial long day plant with an obligate requirement for vernalization (prolonged exposure to low temperature). As a spring crop in temperate European climates, it is vulnerable to vernalization-induced premature bolting and flowering, resulting in reduced crop yield and quality. Gibberellins (GAs) play important roles in key physiological processes including stem elongation (bolting) and flowering and are, therefore, potential targets for controlling reproductive growth in sugar beet. We show that the BvGA20ox gene, which encodes an enzyme necessary for GA biosynthesis, was transcriptionally activated in apices of sugar beet plants after vernalization and that GA metabolism can be manipulated to delay bolting in vernalized plants. We demonstrate that down-regulation of GA responses by transformation with the Arabidopsis thaliana gai gene (which represses GA signalling), under its own promoter (pgai::gai) or deactivation of GA by over-expression of the Phaseolus coccineus (bean) GA2ox1 gene, which inactivates GA, increased the required post vernalization thermal time (an accurate and stable measure of physiological time), to bolt by similar to 300A degrees Cd. This resulted in agronomically significant bolting time delays of similar to 2 weeks and 3 weeks in the pgai::gai and 35S::PcGA2ox1 plants, respectively. Our data represent the first transgenic sugar beet model to (1) show that GA signalling can be used to improve crops by manipulation of the transition to reproductive growth; and (2) provide evidence that GA is required for seed set in sugar beet.

Original languageEnglish
Pages (from-to)301-308
Number of pages8
JournalTransgenic Research
Issue number2
Publication statusPublished - Apr 2009


Dive into the research topics of 'Modification of gibberellin signalling (metabolism & signal transduction) in sugar beet: analysis of potential targets for crop improvement'. Together they form a unique fingerprint.

Cite this