Download Defining the role of cellulose-synthase

Defining the role of cellulose-synthase-like genes in barley root
development
Supervisory team: University of Adelaide: Vincent Bulone and Matthew Tucker (ARC CoE in Plant
Cell Walls) University of Nottingham: Malcolm Bennett and Leah Band (Centre for Plant Integrative
Biology)
Contacts: [email protected]; [email protected]
Primary University where the student will be based: University of Adelaide
Applications: Please apply online at: http://www.adelaide.edu.au/graduatecentre/admission/ using the
domestic (Australian Permanent Residents/ Citizens) or international application as appropriate; please
upload a covering letter indicating the specific project that you wish to apply for, your interests and
why you are applying together with your CV.
Project description: Several genes belonging to the cellulose-synthase-like (Csl) family are known to
play a role in root hair development (Favery et al., 2001; Wang et al., 2001). However, the mode of
action of the corresponding gene products and their biochemical activity are unknown in most
instances. For example, members of the CslD family have been shown to play a key role in root
elongation and morphogenesis in different species, including Arabidopsis (Bernal et al., 2008; Galway
et al., 2011; Wang et al., 2011) and rice (Li et al., 2009), but their biochemical activity and the type of
polysaccharide they deposit in the cell wall remain controversial, with two reports pointing toward
glucan and mannan synthase activities, respectively (Park et al., 2011; Yin et al., 2011). Expression
profiling in barley roots suggests that CslF genes (specific to monocots) play a similar role in root tip
growth as some CslD genes in Arabidopsis. The expression profile of CslF3 and CslF9 is significantly
higher at the tip of the roots, suggesting a role in elongation, whereas CslF4 and CslF6 show a higher
level of expression in differentiated subapical parts of the barley roots, which points toward a role in
the biosynthesis and dynamics of mature cell walls. The main objectives of this project are to:
1- Determine the role of barley CslF3/F9 and CslF4/F6 in root growth; 2- Demonstrate the catalytic activity of the Csl proteins that are differentially expressed along
the root and infer their function in cell wall formation and the type of polysaccharide they
synthesise; 3- Develop comparative studies between Arabidopsis tip growth (CslD genes) and barley tip
growth (CslF genes); 4- Develop comparative mathematical and computational models of root growth and
development in barley and Arabidopsis based on mutant characterisation and kinematic
analysis 5- Develop biomechanical models of the wild-type and mutant cell walls to predict how the
activity of Csl proteins affects cell wall properties Approaches: gene expression profiling using laser capture microdissection of root tissues in barley;
mutant phenotyping using micro-computed tomography; cell biology; complementation of Arabidopsis
CslD mutants with barley CslF genes and reciprocal experiments, coupled to phenotyping, including
cell wall carbohydrate analyses and in situ imaging with specific probes; mathematical and
computational modelling of root growth; biochemical characterisation of the target genes after
heterologous expression in planta and/or yeast and in vitro assays.
References: Bernal AJ, Yoo CM, Mutwil M, Jensen JK, Hou G, Blaukopf C, Sørensen I, Blancaflor EB, Scheller HV,
Willats WG (2008) Functional
analysis of the cellulose synthase-like genes CSLD1, CSLD2, and CSLD4 in tip-growing Arabidopsis cells. Plant Physiol
148(3):1238-53. Favery B, Ryan E, Foreman J, Linstead P, Boudonck K, Steer M, Shaw P, Dolan L (2001) KOJAK
encodes a cellulose synthase-like protein
required for root hair cell morphogenesis in Arabidopsis. Genes Dev 15(1):79-89.
Galway ME, Eng RC, Schiefelbein JW,
Wasteneys GO (2011) Root hair-specific disruption of cellulose and xyloglucan in AtCSLD3
mutants, and factors affecting the post-rupture resumption of mutant root hair growth. Planta 233(5):985-99.
Li M, Xiong
G, Li R, Cui J, Tang D, Zhang B, Pauly M, Cheng Z, Zhou Y (2009) Rice cellulose synthase-like D4 is essential for normal
cellwall biosynthesis and plant growth. Plant J 60(6):1055-69.
Park S, Szumlanski AL, Gu F, Guo F, Nielsen E (2011) A role
for CSLD3 during cell-wall synthesis in apical plasma membranes of tipgrowing root-hair cells. Nat Cell Biol 3(8):973-80.
Wang W, Wang L, Chen C, Xiong G, Tan XY, Yang KZ, Wang ZC,
Zhou Y, Ye D, Chen LQ (2011) Arabidopsis CSLD1 and CSLD4 are required
for cellulose deposition and normal growth of pollen tubes. J Exp Bot 62(14):5161-77.
Wang X, Cnops G, Vanderhaeghen
R, De Block S, Van Montagu M, Van Lijsebettens M (2001) AtCSLD3, a cellulose synthase-like gene
important for root hair growth in arabidopsis. Plant Physiol 126(2):575-86.
Yin L, Verhertbruggen Y, Oikawa A, Manisseri C, Knierim B, Prak L, Jensen JK, Knox JP, Auer M, Willats WG, Scheller
HV (2011) The cooperative activities of CSLD2, CSLD3, and CSLD5 are required for normal Arabidopsis development.
Mol Plant 4(6):1024-37.