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Proteomic profiling of wheat and barley grain for cultivar and provenance identification

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posted on 28.03.2022, 15:12 by Paul Worden
The proteomes of wheat and barley grain cultivars have evolved through genetic variability and environmental factors. The ability to identify different cultivars, farm origin, and quality of wheat and barley grain are becoming increasingly important to farmers, processors, and food manufacturers. This will help them to diversify into higher value boutique products, or just to add value through security and traceability to bulk grain or flour exports. This project aims to use modern proteomic techniques and transcriptomics to discover proteins that can be used as biomarkers in wheat and barley grain to identify crop cultivars, grain provenance (farm origin) and possibly grain quality. Firstly, several protein extraction methods were assessed for optimal protein yield and diversity. This was important for maximising the discovery of potential protein biomarkers through proteomic analysis. By applying Tandem Mass Tags (TMTs) labelled shotgun proteomics, a subset of grain proteins was detected from wheat and barley that show statistically significant differential expression between different cultivars and different farm locations. Indeed, serpin and chitinase proteins (observed to be involved in stress response) were found to be differentially expressed in the wheat and barley sample proteomes. The results also indicated that the differentially expressed proteins from wheat and barley grain have the potential to be used as biomarkers for probable quality traits. The assigned protein biomarkers between cultivars or a particular cultivar from a different environment (farm location) have almost identical functional summaries (gene ontology [GO] Slims). Investigations into wheat mRNA expression between cultivars showed GO Slims that were analogous to the proteomic results. Further experiments involving proteomics and common traditional quality testing such as, 1000-kernel weight, farinograph, extensograph, baking tests and falling number, are needed to answer this question, and is beyond the scope of this project. Protein-based tests to identify cultivar, farm origin, and grain quality have the potential to address these needs in a manner that would be faster relative to existing quality controls.


Table of Contents

Chapter 1. Introduction -- Chapter 2. Optimisation and comparison of two common protein extraction methods for maximum yield and diversity of wheat grain proteins for high-throughput proteomic analysis -- Chapter 3. Proteomic analysis of barley grain for the discovery of putative protein biomarkers to identify cultivar and farm origin -- Chapter 4. Proteomic analysis of wheat grain for the discovery of putative protein biomarkers to identify cultivar and farm origin -- Chapter 5. Detection of differentially transcribed mRNA transcripts in wheat grain for putative protein biomarker discovery and comparison with proteomic analysis -- Chapter 6. Conclusion and future directions -- Appendices -- References.


Empirical thesis. Bibliography: pages 311-331

Awarding Institution

Macquarie University

Degree Type

Thesis PhD


PhD, Macquarie University, Faculty of Science and Engineering, Department of Molecular Sciences

Department, Centre or School

Department of Molecular Sciences

Year of Award


Principal Supervisor

Robert Willows

Additional Supervisor 1

Brian Atwell


Copyright Paul Worden 2018. Copyright disclaimer: http://mq.edu.au/library/copyright




1 online resource (331 pages) illustrations (some colour)

Former Identifiers

mq:72130 http://hdl.handle.net/1959.14/1281687