Papers by Christopher Ford
Molecular Genetics and Genomics, Jun 14, 2009
Peach and almond have been considered as model species for the family Rosaceae and other woody pl... more Peach and almond have been considered as model species for the family Rosaceae and other woody plants. Consequently, mapping and characterisation of genes in these species has important implications. High-resolution melting (HRM) analysis is a recent development in the detection of SNPs and other markers, and proved to be an eYcient and cost-eVective approach. In this study, we aimed to map genes corresponding to known proteins in other species using the HRM approach. Prunus unigenes were searched and compared with known proteins in the public databases. We developed single-nucleotide polymorphism (SNP) markers, polymorphic in a mapping population produced from a cross between the cloned cultivars Nonpareil and Lauranne. A total of 12 SNP-anchored putative genes were genotyped in the population using HRM, and mapped to an existing linkage map. These genes were mapped on six linkage groups, and the predicted proteins were compared to putative orthologs in other species. Amongst those genes, four were abiotic stress-responsive genes, which can provide a starting point for construction of an abiotic resistance map. Two allergy and detoxiWcation related genes, respectively, were also mapped and analysed. Most of the investigated genes had high similarities to sequences from closely related species such as apricot, apple and other eudicots, and these are putatively orthologous. In addition, it was shown that HRM can be an eVective means of genotyping populations for the purpose of constructing a linkage map. Our work provides basic genomic information for the 12 genes, which can be used for further genetic and functional studies.
HortScience
The response of grape berries at a cellular level to environmental change was explored with parti... more The response of grape berries at a cellular level to environmental change was explored with particular emphasis on physiological changes such as weight, sugar content, and the biosynthesis of organic acids. Three levels of light were used: highly exposed, moderately exposed, and light-excluding boxes (1% ambient with no change in temperature effect). Berry weight was significantly lower in light-excluding boxes than in exposed bunch treatments. Organic acid content and berry development were followed throughout the growing season. Light exclusion resulted in a significant reduction of both tartaric acid and oxalic acid compared with highly exposed fruit, suggesting that in this experiment, light irradiance influenced accumulation of these metabolites. In contrast, malic acid was broken down postveraison at a dramatically slower rate in light exclusion treatments. The sink properties of grape berries appear to change according to the light received by the bunch. These data imply that...
Frontiers in microbiology, 2018
Wine yeast breeding programs utilizing interspecific hybridization deliver cost-effective tools t... more Wine yeast breeding programs utilizing interspecific hybridization deliver cost-effective tools to winemakers looking to differentiate their wines through the development of new wine styles. The addition of a non- genome to a commercial wine yeast can generate novel phenotypes ranging from wine flavor and aroma diversity to improvements in targeted fermentation traits. In the current study we utilized a novel approach to screen isolates from an evolving population for increased fitness in a × interspecific hybrid previously generated to incorporate the targeted phenotype of lower volatile acidity production. Sequential grape-juice fermentations provided a selective environment from which to screen isolates. Chromosomal markers were used in a novel approach to identify isolates with potential increased fitness. A strain with increased fitness relative to its parents was isolated from an early timepoint in the evolving population, thereby minimizing the risk of introducing collateral ...
The effect of methyl jasmonate and light irradiation treatments on the stilbenoid biosynthetic pathway in Vitis vinifera cell suspension cultures
Natural Product Research
Grape stilbenes are a well-known family of plant polyphenolics that have been confirmed to have m... more Grape stilbenes are a well-known family of plant polyphenolics that have been confirmed to have many biological activities in relation to health benefits. In the present study, we investigated the effect of methyl jasmonate (MeJA) elicitor at four different concentrations (25, 50, 100 and 200 μM) in combination or not with high-level light irradiation (10,000 LUX) on a cell line obtained from the pulp of Vitis vinifera cv. Shahani. Our results showed that the stilbene synthesis pathway is inhibited by high-light conditions. A concentration of 50 μM MeJA was optimum for efficient production and high accumulation of total phenolics and total flavonoids as well as total stilbenoids. Furthermore, we showed that there is a significant negative correlation between the production of these metabolites and cell growth. These data provide valuable information for the future scale-up of cell cultures for the production of these very high value compounds in bioreactor system.
The outcomes of extended maceration in red winemaking: winemakers' perspectives
Australian and New Zealand Grapegrower and Winemaker, 2006
Unravelling the outcomes of extended maceration in red winemaking
Australian and New Zealand Grapegrower and Winemaker, 2005
Composition of red wines made using periods of pre-and post-ferment extended maceration was compa... more Composition of red wines made using periods of pre-and post-ferment extended maceration was compared with those of conventionally made control wines. Differences in wine colour were observed for some extended maceration treatments; these were related to changes in ...
Pollination requirements for five major olive cultivars
Applied Microbiology and Biotechnology, 2009
Volatile phenols are produced by Dekkera yeasts and are of organoleptic importance in alcoholic b... more Volatile phenols are produced by Dekkera yeasts and are of organoleptic importance in alcoholic beverages.
Compatible olive varieties
New research to identify compatible olive varieties
Journal of Experimental Botany, 2015
Rotundone was initially identified as a grape-derived compound responsible for the peppery aroma ... more Rotundone was initially identified as a grape-derived compound responsible for the peppery aroma of Shiraz wine varieties. It has subsequently been found in black and white pepper and several other spices. Because of its potent aroma, the molecular basis for rotundone formation is of particular relevance to grape and wine scientists and industry. We have identified and functionally characterized in planta a sesquiterpene synthase, VvGuaS, from developing grape berries, and have demonstrated that it produces the precursor of rotundone, α-guaiene, as its main product. The VvGuaS enzyme is a novel allele of the sesquiterpene synthase gene, VvTPS24, which has previously been reported to encode VvPNSeInt, an enzyme that produces a variety of selinene-type sesquiterpenes. This newly discovered VvTPS24 allele encodes an enzyme 99.5% identical to VvPNSeInt, with the differences comprising just 6 out of the 561 amino acid residues. Molecular modelling of the enzymes revealed that two of these residues, T414 and V530, are located in the active site of VvGuaS within 4 Å of the binding-site of the substrate, farnesyl pyrophosphate. Mutation of these two residues of VvGuaS into the corresponding polymorphisms in VvPNSeInt results in a complete functional conversion of one enzyme into the other, while mutation of each residue individually produces an intermediate change in the product profile. We have therefore demonstrated that VvGuaS, an enzyme responsible for production of the rotundone precursor, α-guaiene, is encoded by a novel allele of the previously characterized grapevine gene VvTPS24 and that two specific polymorphisms are responsible for functional differences between VvTPS24 alleles.
Plant physiology, Jan 22, 2015
Anthocyanins are flavonoid compounds responsible for red/purple colours in the leaves, fruit and ... more Anthocyanins are flavonoid compounds responsible for red/purple colours in the leaves, fruit and flowers of many plant species. They are produced through a multistep pathway which is controlled by MYB transcription factors. VvMYBA1 and VvMYBA2 activate anthocyanin biosynthesis in grapevine (Vitis vinifera) and are non-functional in white grapevine cultivars. In this study, transgenic grapevines with altered VvMYBA gene expression were developed, and transcript analysis was carried out on berries using a microarray technique. The results showed that VvMYBA is a positive regulator of the later stages of anthocyanin synthesis, modification and transport in Shiraz. One up-regulated gene ANTHOCYANIN 3-O-GLUCOSIDE-6"-O-ACYLTRANSFERASE (Vv3AT) encodes a BAHD acyltransferase protein, belonging to a clade separate from most anthocyanin acyltransferases. Functional studies (in planta and in vitro) show that Vv3AT has a broad anthocyanin substrate specificity and can also utilise both ali...
BMC Plant Biology, 2015
Background: Sorbitol dehydrogenase (SDH, EC 1.1.1.14) is the key enzyme involved in sorbitol meta... more Background: Sorbitol dehydrogenase (SDH, EC 1.1.1.14) is the key enzyme involved in sorbitol metabolism in higher plants. SDH genes in some Rosaceae species could be divided into two groups. L-idonate-5-dehydrogenase (LIDH, EC 1.1.1.264) is involved in tartaric acid (TA) synthesis in Vitis vinifera and is highly homologous to plant SDHs. Despite efforts to understand the biological functions of plant SDH, the evolutionary history of plant SDH genes and their phylogenetic relationship with the V. vinifera LIDH gene have not been characterized.
Journal of Wine Research, 2014
Retailing is continually evolving with different strategies used over time. In this era of custom... more Retailing is continually evolving with different strategies used over time. In this era of customer relationships building, this study investigated an innovation gap; about Australian consumers' willingness to pay (WTP) a premium for the expert service of wine retailers. The study objectives were to evaluate factors that influence WTPs of wine retailers and to measure WTPs. A 2099 usable survey was obtained Australia-wide. The contingent valuation method was used to elicit the willingness of consumers. The data were analysed using the ordered probit model. On average, the premium respondents indicated WTP was $0.60 for the expert service of wine retailers. This study found that consumers are willing to pay for the expert service of wine retailers, and that consumers rely on the use of risk reduction strategy not only because of their perception of risk but they are also more desirous of wine knowledge and are willing to acquire it, even at a cost. This makes a strong case for the development and provision strategies of store dynamic elements such as expert service. The study has limitation as it is exploratory and cross-sectional. Confirmatory and longitudinal surveys amongst others are recommended.
The Environmental Benefits of Organic Wine: Exploring Consumer Willingness-to-Pay Premiums?
Journal of Food Products Marketing, 2014
ABSTRACT
BMC Plant Biology, 2014
Background: The genus Citrus encompasses major cultivated plants such as sweet orange, mandarin, ... more Background: The genus Citrus encompasses major cultivated plants such as sweet orange, mandarin, lemon and grapefruit, among the world's most economically important fruit crops. With increasing volumes of transcriptomics data available for these species, Gene Co-expression Network (GCN) analysis is a viable option for predicting gene function at a genome-wide scale. GCN analysis is based on a "guilt-by-association" principle whereby genes encoding proteins involved in similar and/or related biological processes may exhibit similar expression patterns across diverse sets of experimental conditions. While bioinformatics resources such as GCN analysis are widely available for efficient gene function prediction in model plant species including Arabidopsis, soybean and rice, in citrus these tools are not yet developed. Results: We have constructed a comprehensive GCN for citrus inferred from 297 publicly available Affymetrix Genechip Citrus Genome microarray datasets, providing gene co-expression relationships at a genome-wide scale (33,000 transcripts). The comprehensive citrus GCN consists of a global GCN (condition-independent) and four condition-dependent GCNs that survey the sweet orange species only, all citrus fruit tissues, all citrus leaf tissues, or stress-exposed plants. All of these GCNs are clustered using genome-wide, gene-centric (guide) and graph clustering algorithms for flexibility of gene function prediction. For each putative cluster, gene ontology (GO) enrichment and gene expression specificity analyses were performed to enhance gene function, expression and regulation pattern prediction. The guide-gene approach was used to infer novel roles of genes involved in disease susceptibility and vitamin C metabolism, and graph-clustering approaches were used to investigate isoprenoid/ phenylpropanoid metabolism in citrus peel, and citric acid catabolism via the GABA shunt in citrus fruit.
A method for determination of fruit-derived ascorbic, tartaric, oxalic and malic acids, and its application to the study of ascorbic acid catabolism in grapevines
... Hancock and Viola 2005), as is interest in manipulating the Asc content of edible plants (Jai... more ... Hancock and Viola 2005), as is interest in manipulating the Asc content of edible plants (Jain and Nessler 2000, Agius et al. ... Organic acids were separated on an Agilent 1100 series HPLC (Agilent Technologies, Santa Clara, CA, USA) equipped with a photodiode array detector ...
Phytochemistry, 2009
Organic acids are present in all plants, supporting numerous and varied facets of cellular metabo... more Organic acids are present in all plants, supporting numerous and varied facets of cellular metabolism. The type of organic acid found, and the levels to which they accumulate are extremely variable between species, developmental stages and tissue types. Acidity plays important roles in the organoleptic properties of plant tissues, where examples of both enhanced and reduced palatability can be ascribed to the presence of specific organic acids. In fruits, sourness is generally attributed to proton release from acids such as citric, malic, oxalic, quinic, succinic and tartaric, while the anion forms each contribute a distinct taste. Acidity imposes a strong influence on crop quality, and is an important factor in deciding the harvest date, particularly for fruits where acidity is important for further processing, as in wine grapes. In the grape, as for many other fruits, malate is one of the most prevalent acids, and is an important participant in numerous cellular functions. The accumulation of malate is thought to be due in large part to de novo synthesis in fruits such as the grape, through metabolism of assimilates translocated from leaf tissues, as well as photosynthetic activity within the fruit itself. During ripening, the processes through which malate is catabolised are of interest for advancing metabolic understanding, as well as for potential crop enhancement through agricultural or molecular practices. A body of literature describes research that has begun to unravel the regulatory mechanisms of enzymes involved in malate metabolism during fruit development, through exploration of protein and gene transcript levels. Datasets derived from a series of recent microarray experiments comparing transcript levels at several stages of grape berry development have been revisited, and are presented here with a focus on transcripts associated with malate metabolism. Developmental transcript patterns for enzymes potentially involved in grape malate metabolism have shown that some flux may occur through pathways that are less commonly regarded in ripening fruit, such as aerobic ethanol production. The data also suggest pyruvate as an important intermediate during malate catabolism in fruit. This review will combine an analysis of microarray data with information available on protein and enzyme activity patterns in grapes and other fruits, to explore pathways through which malate is conditionally metabolised, and how these may be controlled in response to developmental and climatic changes. Currently, an insufficient understanding of the complex pathways through which malate is degraded, and how these are regulated, prevents targeted genetic manipulation aimed at modifying fruit malate metabolism in response to environmental conditions.
ChemInform Abstract: Regulation of Malate Metabolism in Grape Berry and Other Developing Fruits
ChemInform, 2009
Annals of Botany, 2007
Background and Aims L-Ascorbate (vitamin C) has well-documented roles in many aspects of redox co... more Background and Aims L-Ascorbate (vitamin C) has well-documented roles in many aspects of redox control and anti-oxidant activity in plant cells. This Botanical Briefing highlights recent developments in another aspect of L-ascorbate metabolism: its function as a precursor for specific processes in the biosynthesis of organic acids. † Scope The Briefing provides a summary of recent advances in our understanding of L-ascorbate metabolism, covering biosynthesis, translocation and functional aspects. The role of L-ascorbate as a biosynthetic precursor in the formation of oxalic acid, L-threonic acid and L-tartaric acid is described, and progress in elaborating the mechanisms of the formation of these acids is reviewed. The potential conflict between the two roles of L-ascorbate in plant cells, functional and biosynthetic, is highlighted. † Conclusions Recent advances in the understanding of L-ascorbate catabolism and the formation of oxalic and L-tartaric acids provide compelling evidence for a major role of L-ascorbate in plant metabolism. Combined experimental approaches, using classic biochemical and emerging 'omics' technologies, have provided recent insight to previously under-investigated areas.
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Papers by Christopher Ford