Dr Alan Little

Alan Little
Senior Research Scientist
School of Agriculture, Food and Wine
Faculty of Sciences

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.

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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.

cover2014Detailed 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.

 

cover 2016Identification 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.

Appointments

Date Position Institution name
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

Education

Date Institution name Country Title
2004 The University of Adelaide Australia PhD CSIRO Plant Industry
The University of Adelaide Australia Bachelor of Science (Honours), Biochemistry

Keywords

Mycology, Plant Cell and Molecular Biology, Plant Pathology, Plant Physiology

Journals

Date Citation
2017 Chowdhury,J, Lück,S, Rajaraman,J, Douchkov,D, Shirley,N, Schwerdt,J, Schweizer,P, Fincher,G, Burton,R, Little,A et al, 2017, Altered expression of genes implicated in xylan biosynthesis affects penetration resistance against powdery mildew, Frontiers in Plant Science, 8, 445-1-445-12 10.3389/fpls.2017.00445
2016 Douchkov,D, Lueck,S, Hensel,G, Kumlehn,J, Rajaraman,J, Johrde,A, Doblin,M, Beahan,C, Kopischke,M, Fuchs,R et al, 2016, The barley (Hordeum vulgare) cellulose synthase-like D2 gene (HvCslD2) mediates penetration resistance to host-adapted and nonhost isolates of the powdery mildew fungus, New Phytologist, 212, 2, 421-433 10.1111/nph.14065
2016 Cu,S, Collins,H, Betts,N, March,T, Janusz,A, Stewart,D, Skadhauge,B, Eglinton,J, Kyriacou,B, Little,A et al, 2016, Water uptake in barley grain: physiology; genetics and industrial applications, Plant Science, 242, 260-269 10.1016/j.plantsci.2015.08.009
2016 Chowdhury,J, Schober,M, Shirley,N, Singh,R, Jacobs,A, Douchkov,D, Schweizer,P, Fincher,G, Burton,R, Little,A et al, 2016, Down-regulation of the glucan synthase-like 6 gene (HvGsl6) in barley leads to decreased callose accumulation and increased cell wall penetration by Blumeria graminis f. sp. hordei, New Phytologist, 212, 2, 434-443 10.1111/nph.14086
2016 Zhang,R, Tucker,M, Burton,R, Shirley,N, Little,A, Morris,J, Milne,L, Houston,K, Hedley,P, Waugh,R et al, 2016, The dynamics of transcript abundance during cellularization of developing barley endosperm, Plant Physiology, 170, 3, 1549-1565 10.1104/pp.15.01690
2016 Dimitroff,G, Little,A, Lahnstein,J, Schwerdt,J, Srivastava,V, Bulone,V, Burton,R, Fincher,G, 2016, (1,3;1,4)-β-glucan biosynthesis by the CSLF6 enzyme: position and flexibility of catalytic residues influence product fine structure, Biochemistry, 55, 13, 2054-2061 10.1021/acs.biochem.5b01384
2016 Houston,K, Tucker,M, Chowdhury,J, Shirley,N, Little,A, 2016, The plant cell wall: a complex and dynamic structure as revealed by the responses of genes under stress conditions, Frontiers in Plant Science, 7, AUG2016, 1-18 10.3389/fpls.2016.00984
2015 Wong,S, Shirley,N, Little,A, Khoo,K, Schwerdt,J, Fincher,G, Burton,R, Mather,D, 2015, Differential expression of the HvCslF6 gene late in grain development may explain quantitative differences in (1,3;1,4)-β-glucan concentration in barley, Molecular Breeding, 35, 1, 20-1-20-12 10.1007/s11032-015-0208-6
2014 Schreiber,M, Wright,F, MacKenzie,K, Hedley,P, Schwerdt,J, Little,A, Burton,R, Fincher,G, Marshall,D, Waugh,R et al, 2014, The barley genome sequence assembly reveals three additional members of the CslF (1,3;1,4)-β-glucan synthase gene family, PLoS One, 9, 3, e90888-1-e90888-9 10.1371/journal.pone.0090888
2014 Chowdhury,M, Henderson,M, Schweizer,P, Burton,R, Fincher,G, Little,A, 2014, Differential accumulation of callose, arabinoxylan and cellulose in nonpenetrated versus penetrated papillae on leaves of barley infected with Blumeria graminis f. sp. hordei, New Phytologist, 204, 3, 650-660 10.1111/nph.12974
2008 Lightfoot,D, Boettcher,A, Little,A, Shirley,N, Able,A, 2008, Identification and characterisation of barley (Hordeum vulgare) respiratory burst oxidase homologue family members, Functional Plant Biology, 35, 5, 347-359 10.1071/FP08109
2007 Habili,N, Kominek,P, Little,A, 2007, Grapevine leafroll-associated virus 1 as a common grapevine pathogen, Plant Viruses, April, 63-68
2006 Little,A, Rezaian,M, 2006, Improved detection of grapevine leafroll-associated virus 1 by magnetic capture hybridisation RT-PCR on a conserved region of viral RNA, Archives of Virology, 151, 4, 753-761 10.1007/s00705-005-0649-z
2001 Little,A, Fazeli,C, Rezaian,M, 2001, Hypervariable genes in Grapevine leafroll associated virus 1, Virus Research, 80, 01-Feb, 109-116 10.1016/S0168-1702(01)00343-4

Book Chapters

Date Citation
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

Conference Papers

Date Citation
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

Ali Hassan

Ali

Trang Pham

Trang

Completed PhD Students

Jamil Chowdhury

Jamil

George Dimitroff

George

Completed Honours/Masters Students

Jamil Chowdhury

Jamil

George Dimitroff

George

Ali Hassan

Ali

Die Hu (Alice)

Alice

Basheer Jasim

Basheer

Lee Farrand

Lee

Memberships

Date Role Membership Country
2017 Member Australian Society of Plant Scientists Australia
2015 Member Australasian Plant Pathology Society Australia
Position
Senior Research Scientist
Phone
83137260
Fax
8313 7116
Campus
Waite
Building
Wine Innovation Central
Room Number
4 25
Org Unit
School of Agriculture, Food and Wine

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