Use of miRNAs as tools to control flowering time and plant ...

Principal Supervisor
:

Stephen Jackson (Life Sciences)


Second Supervisor
s
:

Andrea Howard (Life Sciences)
, Yiguo Hong (Hangzhou University, China)


Where will
the student be based
?

Warwick School of Life Sciences


PhD project title:

Use of
miRNAs as tools to control flowering time and plant development


Project description
:

It is known that miRNAs control many aspects of plant development, including the
juvenile
-
adult developmental phase change and also the

induction of flowering by miR156
and miR172 respectively. Such miRNAs are mobile and travel via the phloem throughout the
plant acting as intercellular signaling molecules

(
Brosnan
& Voinnet,
2011)
. We will
investigate the possibility of using exogenous a
pplication of these mobile signaling molecules
to control plant development, in particular flowering time.

We have a virus
-
based expression system which we have already used successfully
to induce flowering in tobacco plants

by infecting plants with this
virus vector expressing the
FLOWERING LOCUS T (FT) floral inducing protein (Li et al. 2009). This, however, only
worked with an infectious virus particle that could move around the plant. We have a non
-
infectious virus vector in which the coat protein has
been deleted so that it can’t spread and
move around the plant. The aim of this project is to develop the system using this non
-
infectious virus vector to express the mobile miRNAs which themselves can move around the
plant to control flowering time and pl
ant development.
Other means of getting the miRNAs
into the plant, such as through the use of nanoparticles, will also be investigated in the
project.

Our collaborators at Hangzhou University are using a technique that enables
visualization of RNA localiza
tion within the plant using fluorescence, we will use this to
visualise the miRNAs movemant

once they are in the plant. As we have been awarded a
BBSRC China
-
Partnering Award there will be the possibility of spending some time at
Hangzhou University during

the course of the project for the successful applicant.


Key
experimental skill
s

involved
:

P
lant p
hysiological assay
s (flowering time, etc.)


Molecular
biological techniques


miRNA and g
ene expression analysis (real
-
time PCR)

Bioinformatics


References:


Brosnan CA, Voinnet O (2011) Cell
-
to
-
cell and long
-
distance siRNA movement in plants:
mechanisms and biological implications. Curr Opin Plant Biol 14: 580
–
587

Li, C., Zhang, K., Zeng ,X.,
Jackson, S
., Zhou, Y., and Y. Hong (2009).

A
cis
-
element within
FLOWERING LOCUS T
mRNA determines its mobility and facilitates trafficking of
heterologous viral RNA. J.Virology
83
:3540
-
3548.


Contact details for application enquiries:

Dr Stephen Jackson

School of Life Sciences

Gibbet Hill campus

Warwick University

Coventry CV4 7AL


Keywords:

Gene expression, molecular biology, plants,
miRNA,
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 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)