Principal Supervisor name and department:
Dr Stephen Jackson (Life Sciences)
Second Supervisor name and department:
Dr Jay Moore (Systems Biology)
Dr Andrea Howard (Life Sciences)
Where will the student be based? Warwick School of Life Sciences
PhD project title: Regulation of the Juvenile-Adult developmental phase transition in crop plants
Project description:
Work in our lab in both Brassica and Antirrhinum has shown that in juvenile plants that have
not yet undergone the juvenile-adult phase transition, the key floral inducer FLOWERING LOCUS T
(FT) is repressed even in strong floral-inducing conditions. This repression of FT gene expression is
lifted following the juvenile-adult phase transition and could explain why juvenile plants are unable
to flower. The FLC gene is known to be a strong repressor of flowering and is known to regulate FT
gene expression in adult Arabidopsis plants; Furthermore plants with high levels of FLC expression
have a prolonged juvenile phase. Another gene, TEMPRANILLO (TEM), as well as a microRNA
(miRNA156) have also been shown to affect juvenility in Arabidopsis.
Whilst Arabidopsis has only one FLC gene in Brassica there are four, one of which (FLC1) has
been shown by our group to be expressed at a high level during the juvenile phase before falling to a
low level in adult plants. We will investigate the hypothesis that the Brassica FLC1 gene is responsible
for the repression of FT gene expression in juvenile plants thus preventing them from being induced
to flower. The roles of TEM and miRNA156 in regulating juvenility in Brassica will also be examined.
We will make use of the extensive Brassica genetic resources that we have available in the
Warwick Crop Centre, particularly the double haploid substitution lines which have already been
screened to identify near isogenic lines that differ in their juvenile phase length. Part of the project
will involve comparative transcriptome sequence analysis of Brassica lines that have different
juvenile phase lengths, ie. the plants will have been grown for the same length of time but one line
will be adult whilst the other still juvenile. This will identify genes that are specific for the juvenile
developmental phase and, together with other results from the project, will help to construct a
model for the regulation of juvenility in Brassica. This model will then be tested in other crop plants
such as Antirrhinum.
Key experimental skills involved:
Physiological assay to measure juvenility
Molecular cloning
Gene expression analysis (RNASeq analysis, real-time PCR)
Bioinformatics (transcriptome sequence analysis)
References:
Huijser and Schmid (2011) The control of developmental phase transitions in plants. Development
138: 4117-4129
Deng et al. (2011) FLOWERING LOCUS C (FLC) regulates development pathways throughout the life
cycle of Arabidopsis. PNAS 108: 6680-6685
Willmann and Poethig (2011) The effect of the floral repressor FLC on the timing and progression of
vegetative phase change in Arabidopsis. Development 138: 677 – 685
Castillejo and Pelaz (2008) The balance between CONSTANS and TEMPRANILLO activities determines
FT expression to trigger flowering. Curr. Biol. 18: 1338 - 1343
Contact details for application enquiries:
Dr Stephen Jackson, Email: Stephen.Jackson@warwick.ac.uk
School of Life Sciences
Gibbet Hill campus
Warwick University
Coventry CV4 7AL
Keywords: Gene expression, molecular biology, plants, juvenility, flowering, crop
Please state below which hazards may be connected with this studentship:
The studentship will entail work involving:
Chemicals – high toxicity and category 1 or 2 substances
√ if applies
✔
Organo-phosphate or carbamate pesticides
✔
Skin or respiratory sensitising agents (e.g. insect parts, organic
dusts from animals, spores, pollen, antibiotics, fibres, chemical
sensitisers, wood dust etc)
Radionuclides
✔
Significant manual handling
Mechanical repetition where the frequency and duration are
significant
Working in areas where there are temperature extremes
Driving vehicles (tractors, fork lifts, ATVs etc)
Crop planting, harvesting, recording or grading
Working in close proximity to bees or other stinging insects
Working at height [>2 m] (using various types of access
equipment)
Working with noisy or vibrating equipment
Working at night (between 11.00pm and 6.00am)
Food handling
Other significant hazards (specify)
✔