Dr Alan Little
Dr Alan Little is a Postdoctoral Research Scientist in the ARC Centre of Excellence in Plant Cell Walls based at the University of Adelaide node. He is a plant pathologist with expertise in molecular biology, plant cell walls and plant-pathogen interactions. His major area of interest is the synthesis and composition of fungal and plant cell walls. The association of cell wall polysaccharides with basal host resistance provides new targets for the generation of novel crop lines with greater disease resistance.
Detailed composition of the carbohydrate content of the barley papillae and their association with penetration resistance
(Chowdhury et al., New Phytologist, 2014,)
In this paper, we reported on the cell wall polysaccharide composition of effective and ineffective papillae produced in response to infection by Blumeria graminis f. sp. hordei, the causal agent of powdery mildew in barley. This is significant because the research over the last 40 years into the composition of cell wall appositions and their role in fungal penetration resistance has led to a belief that callose is the main polysaccharide component of papillae. The work in this paper utilizes the available collections of polysaccharide-specific antibodies that can be used to examine papillae for other polysaccharides that have been previously overlooked. In this study, we have shown that the major polysaccharides found in barley papillae are callose, arabinoxylan and cellulose. In addition to this we demonstrated that effective papillae that are successful in preventing the penetration attempts of Bgh contain significantly higher concentrations of callose, arabinoxylan and cellulose.
Identification of genes involved in the synthesis of the components found within barley papillae
(Tucker et al., FIPS, 2016; Chowdhury et al., New Phytologist, 2016; Douchkov et al., New Phytologist, 2016; Chowdhury et al., FIPS, 2017)
The association of arabinoxylan and cellulose with penetration resistance provided new targets for the improvement of papillae composition and for the generation of novel crop lines with greater disease resistance. In this series of papers we presented the identification of the key genes responsible for the biosynthesis of callose, cellulose and arabinoxylan in the barley papillae. Comparative genomics and reverse genetics approaches were used to identify candidate genes with particular attention given to glycosyltransferase families previously linked to the synthesis of the papillae polysaccharide components. Modulation of the candidate genes allowed the modification of papillae composition and this was reflected in the ability of the papillae to block fungal penetration attempts. The identification of the genes involved in the biosynthesis of each papilla component will aid the generation of novel crop lines with greater disease resistance.
Detailed composition of the fungal cell walls and annotation of the cell wall synthetic machinery
Fungal cell walls contain several vital polysaccharides that are not observed in plants and/or animals, and are thus the Achilles heel for the fungus. The enzymes involved in the synthesis of the cell wall components represent ideal targets of antifungal drugs for disease control. However, rational design of new efficient inhibitors requires a better understanding of cell wall structure and biosynthesis in pathogenic fungi. Fungal cell walls have been understudied in past years due to the general assumption that they are globally homogeneous in structure throughout the kingdom Fungi. As a consequence, a comprehensive treatise linking the biochemical architecture of fungal cell walls to the genomic repertoire of the corresponding lineages is lacking. In collaboration with Adelaide Glycomics we have performed a detailed characterisation of fungal cell walls isolated from in vitro grown cultures. The information gained is complemented with transcriptomics to establish a comprehensive map of the fungal cell wall synthetic machinery in vitro and during plant infection. Our approach to characterize the cell wall of plant pathogenic fungi and connect their composition to the expression of biosynthetic machinery has identified a number of potential targets for the generation of antifungal molecules.
|2011||Senior Research Fellow||University of Adelaide|
|2010 - 2011||Senior Research Scientist||University of Adelaide|
|2010||Member||Project Leadership Team within the ARC Centre of Excellence in Plant Cell Walls|
|2007 - 2010||SA Account Manager||Invitrogen - Life Technologies|
|2004 - 2007||Postdoctoral Reseach Fellow||University of Adelaide|
|2004||The University of Adelaide||Australia||PhD CSIRO Plant Industry|
|The University of Adelaide||Australia||Bachelor of Science (Honours), Biochemistry|
|2015||Little,A, Rezaian,MA, 2015, Grapevine Viroids and Viroid Diseases, APS Press, pp. 136-138|
|2003||Little,A, Rezaian,MA, 2003, Grapevine Viroids, CSIRO PUBLISHING|
|2005||Little,A, Sarpeleh,A, Craig,A, Boettcher,A, Stonor,J, Able,A, 2005, Understanding how barley interacts with Rhynchosporium secalis and Pyrenophora teres as a basis for improving disease resistance to necrotrophic fungal pathogens, Australian Barley Technical Symposium (Hobart, Tasmania), Hobart, Tasmania|
Alan teaches into the Masters in Biotechnology (Plant Biotechnology) program.
Current PhD Students
Completed PhD Students
Completed Honours/Masters Students
Die Hu (Alice)
|2017||Member||Australian Society of Plant Scientists||Australia|
|2015||Member||Australasian Plant Pathology Society||Australia|