Regulation of the Juvenile-Adult developmental phase transition

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2 Οκτ 2013 (πριν από 3 χρόνια και 10 μήνες)

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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:

Regula
tion 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 r
epression 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 a
dult Arabidopsis plants
;

F
urthermore 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 juvenil
e 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 t
ested in other crop plants
such as Antirrhinum.



Key
experimental skill
s

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:




if applies

Chemicals


high toxicity and category 1 or 2 substances



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 an
d 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)