John P. Moore

John P. Moore
Stellenbosch University | SUN · Department of Viticulture and Oenology

PhD

About

87
Publications
24,647
Reads
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1,758
Citations
Introduction
I am an academic at the SA Grape and Wine Research Institute (Department of Viticulture and Oenology) (DVO) at Stellenbosch University in South Africa. My research interests are plant cell walls and plant polyphenols. Current research includes studying grape berry ripening, plant pathology and the effects of water deficit stress from the perspective of plant cell walls. Carbohydrate active enzymes involved in winemaking are studied. I also maintain an interest in plant desiccation tolerance.
Additional affiliations
January 2019 - present
Stellenbosch University
Position
  • Lecturer
Description
  • GVS214 2nd Year Grapevine Science BScAgric (Anatomy, Phenology, Evolution). GVS244 2nd Year Grapevine Science BScAgric (Reproduction, Flowering, Fruitset, Ripening). CP152 1st Year Crop Production (Plant Classification, Plant Hormones), WS446 4th Year Wine Science (Wine Polysaccharides)
May 2016 - present
Stellenbosch University
Position
  • Principal Investigator (Senior Researcher)
January 2008 - present
Stellenbosch University
Position
  • Lecturer
Description
  • BSc Hons Honours IWBT 771: Practical research project in Wine Biotechnology. Honours IWBT 714: Chemical and metabolic aspects of grapes and wine. Honours IWBT 774: Molecular biology and biotechnology of grapevine.

Publications

Publications (87)
Article
Chardonnay grape pomace was treated with pressurized heat followed by enzymatic hydrolysis, with commercial or pure enzymes, in buffered conditions. The pomace was unfermented as commonly found for white winemaking wastes and treatments aimed to simulate biovalorization processing. Cell wall profiling techniques showed that the pretreatment led to...
Article
Full-text available
Background and Aims Root border cells and border-like cells (BLCs), the latter originally described in Arabidopsis thaliana, have been described as cells released at the root tips of the species in which they occur. BLCs are thought to provide protection to root meristems similar to classical root border cells. In addition, four defensin peptides (...
Article
The effectiveness of enzyme-mediated-maceration in red winemaking relies on the use of an optimum combination of specific enzymes. A lack of information on the relevant enzyme activities and the corresponding polysaccharide-rich berry cell wall structure is a major limitation. This study used different combinations of purified recombinant pectinase...
Article
Full-text available
Significant intra-vineyard variation in grape berry ripening occurs within vines and between vines. However, no cell wall data is available on such variation. Here we used a chequered-board-panel-design to investigate ripening variation in pooled grape bunches for enzyme-assisted winemaking. The vineyard was dissected into defined panels which were...
Article
Full-text available
Understanding plant desiccation tolerance – a global perspective One of the most exciting and gratifying privileges of having edited this special topic on plant desiccation tolerance is that we received papers and reviews on resurrection plant species (particularly angiosperms) covering five continents, almost six, although unfortunately we did no...
Article
Full-text available
Industrial wine yeast strains expressing hydrolytic enzymes were fermented on Chardonnay pomace and were shown to unravel the cell walls of the berry tissues according to the enzyme activities. The yeasts produced a native endo-polygalacturonase (Saccharomyces cerevisiae × Saccharomyces paradoxus hybrid, named PR7) and/or a recombinant endo-glucana...
Article
Pectolytic enzyme maceration is common for producing red wines, but the effects on bitterness and astringency are not well understood. Glycan microarrays assessed polysaccharide diversity and with polyphenol analysis was correlated with sensory data on descriptors of astringency and their perceived levels in enzyme-crafted Cabernet Sauvignon wines....
Article
Phenolic composition of young red wines has been shown to play an important role in their ageing potential. Therefore, the modulation of phenolic extraction during maceration, may influence the subsequent phenolic evolution of these wines. The present work aimed to evaluate the impact of three different maceration times on the phenolic levels and e...
Article
Full-text available
Root cap–derived cells and mucilage provide the first line of defense of the plant against soil microbial pathogens. These cells form a mucilaginous root extracellular trap (RET), which also harbors a range of molecules including exDNA and defensive peptides and proteins much like the neutrophil extracellular trap (NET) of mammalians. Plant RETs re...
Article
Background and aims: The necrotrophic fungus Botrytis cinerea infects a broad range of fruit crops including domesticated grapevine Vitis vinifera cultivars. Damages caused by this pathogen are severely detrimental to the table and wine grape industries and results in substantial crop losses worldwide. The apoplast and cell wall interface is an im...
Article
Shiraz is a widely planted cultivar in many of the world’s top wine regions where it is used for the production of top-quality single varietal or blended red wines. Cell wall changes during grape ripening and over-ripening have been investigated, particularly in the context of understanding berry deconstruction thereby facilitating the release of f...
Article
Full-text available
The cell wall acts as one of the first barriers of the plant against various biotic stressors. Previous studies have shown that alterations in wall polysaccharides may influence crop disease resistance. In the grapevine family, several native species (e.g., Chinese wild grapevine) show a naturally higher resistance to microbial pathogens than culti...
Article
Full-text available
This study evaluates the capacity of four hydrolytic enzymes to limit the interactions between grape cell-walls and tannins and/or to favor tannin desorption. Adsorption and desorption tests were conducted by mixing a commercial seed tannin with purified skin cell-walls from Syrah grapes, in the presence or absence of hydrolytic enzymes, in a model...
Article
Full-text available
The expression of Vitis vinifera polygalacturonase inhibiting protein 1 (VviPGIP1) in Nicotiana tabacum has been linked to modifications at the cell wall level. Previous investigations have shown an upregulation of the lignin biosynthesis pathway and reorganisation of arabinoxyloglucan composition. This suggests cell wall tightening occurs, which m...
Chapter
Plant cell walls are composed of a number of coextensive polysaccharide-rich networks (i.e., pectin, hemicellulose, protein). Polysaccharide-rich cell walls are important in a number of biological processes including fruit ripening, plant–pathogen interactions (e.g., pathogenic fungi), fermentations (e.g., winemaking), and tissue differentiation (e...
Article
Natural Deep Eutectic Solvents (NaDES) have been proposed as designer solvents for the green extraction of bioactive products from plants. Myrothamnus flabellifolia is a desiccation-tolerant medicinal shrub that has been widely studied for its phenolic properties; however, a NaDES-based approach for the extraction of phenolics has not been tested i...
Preprint
Tannins are present in grape skins and seeds from where they are transferred into the must-wine matrix during the maceration stages of winemaking. However, tannin transfer is often incomplete. This could be due, among other reasons, to tannins becoming bound to grape cell wall polysaccharides, including soluble polymers, which are released during v...
Article
New knowledge on grape cell wall structure and the effects of maceration enzymes
Article
The first genome sequenced resurrection plant Boea hygrometrica has been shown to be able to survive rapid air-drying after experiencing a slow soil-drying acclimation phase. Weighted gene co-expression analysis was used to study B. hygrometrica transcriptomic datasets. A network containing 22 modules was constructed and seven modules were found to...
Article
The first genome sequenced resurrection plant Boea hygrometrica has been shown to be able to survive rapid air-drying after experiencing a slow soil-drying acclimation phase. Weighted gene co-expression analysis was used to study B. hygrometrica transcriptomic datasets. A network containing 22 modules was constructed and seven modules were found to...
Poster
Full-text available
Red winemaking often relies on the application of maceration enzymes, which comprise ‘cocktails’ of semi-purified fungal extracts. Until recently the ‘targets’ of these enzymes in grape tissues undergoing on-skins fermentation has been largely inferred from knowledge of enzymatic action from research performed on non-grape fruits, for example. The...
Article
Full-text available
Pectinases improve consistency in winemaking (for Wineland)
Article
The root cap releases cells that produce massive amounts of mucilage containing polysaccharides, proteoglycans, extracellular DNA (exDNA) and a variety of antimicrobial compounds. The released cells-known as border cells or border-like cells-and mucilage secretions form networks that are defined as root extracellular traps (RETs). RETs are importan...
Article
Winemaking results in a significant amount of sediments that are formed in the tanks, the vats and in the bottles before and after fermentation. Little is known about the biochemical composition of these sediments apart from the fact that they are assumed to be derived in large part from the grape matrix. Glycan microarray technology offers a relat...
Article
Full-text available
The leaves and twigs of the desiccation-tolerant medicinal shrub Myrothamnus flabellifolia are harvested for use in traditional and commercial teas and cosmetics due to their phenolic properties. The antioxidant and pharmacological value of this plant has been widely confirmed; however, previous studies typically based their findings on material co...
Article
The desiccation-tolerant shrub Myrothamnus flabellifolia has colonised a unique and harsh niche that provides little protection from the elements. It has a wide distribution range in southern Africa, occurring across an environmental gradient that is exceptionally arid in the southwest and highly mesic in the northeast. It is also harvested for use...
Article
Full-text available
Enzyme-aid maceration is carried out in most modern winemaking industries with a range of positive impacts on wine production. However, inconsistencies in enzyme efficiency are an issue complicated by unclear targets (limited information available on berry cell wall architecture of different cultivars) and the complex wine environment (i.e., fermen...
Article
Full-text available
Roots are important organs for plant survival. In recent years, clear differences between roots and shoots in their respective plant defense strategies have been highlighted. Some putative gene markers of defense responses usually used in leaves are less relevant in roots and are sometimes not even expressed. Immune responses in roots appear to be...
Article
This study evaluated the relationship between cell wall breakdown, from Shiraz grapes harvested at three different ripeness levels and the colour and phenolics extracted during alcoholic fermentation into wines. Phenolic differences between the ripeness treatments were minimal after ¼ of the fermentation was completed. However, colour and phenolic...
Article
Phenolic compounds play an important role in colour stability and sensory properties of red wine. This study evaluated berry skin cell wall composition and how this influences grape and wine phenolics at different ripeness levels (21°Brix, 23°Brix, and 25°Brix) over two consecutive vintages. The vintage effect was highly significant, especially in...
Poster
Full-text available
Phenolic compounds are important quality indicators in red wines. These compounds are extracted during the alcoholic fermentation due to grape tissue breakdown and the degradation of the grape berry cell wall structure during maceration. However, there are lot of unknowns in the relationship between phenolic compounds and cell wall polysaccharides...
Presentation
Full-text available
Summary of the Current Working Model of the Wine Grape Berry Cell Wall
Conference Paper
Full-text available
Various factors can positively or negatively affect the grape developmental and ripening processes in vineyards, which in turn results in a significant degree of intra-vineyard variation (e.g., lack of synchronicity of berry ripening). Cabernet Sauvignon is one of the most iconic wine grape cultivars and has been studied with respect to the role of e...
Article
Full-text available
Endoplasmic reticulum (ER) bodies are important organelles for root defense. However, little is known regarding the genetic control of their formation in root tissues. In the present study, Arabidopsis thaliana (L.) Heynh. roots were dissected using laser-assisted microdissection (LAM) with minimal sample preparation (no fixation or embedding steps...
Article
Full-text available
Yeast cells possess a cell wall comprising primarily glycoproteins, mannans and glucan polymers. Several yeast phenotypes relevant for fermentation, wine processing and wine quality are correlated with cell wall properties. To investigate the effect of wine fermentation on cell wall composition, a study was performed using mid-infrared (MIR) spectr...
Article
Full-text available
The unraveling of crushed grapes by maceration enzymes during winemaking is difficult to study due to the complex and rather undefined nature of both the substrate and the enzyme preparations. In this study we simplified both the substrate, by using isolated grape skin cell walls, and the enzyme preparations, by using purified enzymes in buffered c...
Article
Limited information is available on grape wall-derived polymeric structure/composition and howthis changes during fermentation. Commercial winemaking operations use enzymes that target thepolysaccharide-rich polymers of the cell walls of grape tissues to clarify musts and extract pigments dur-ing the fermentations. In this study, we have assessed c...
Conference Paper
Full-text available
Wine grapes are small and soft with thick skins whereas table grapes are larger and crisp while being thin-skinned. Wine grapes are bred for concentrated flavor and aroma, but table grapes are mainly grown for eating and so texture and berry colouring are considered more important parameters. Table grapes are also exposed to hormone (gibberellin an...
Article
Full-text available
Cell wall profiling technologies were used to follow compositional changes that occurred in the skins of grape berries (from two different ripeness levels) during fermentation and enzyme maceration. Multivariate data analysis showed that the fermentation process yielded cell walls enriched in hemicellulose components because pectin was solubilized...
Conference Paper
Full-text available
Red wines are fermented on berry-skins thus extracting pectins, while white winemaking involves pectin-clarification of pressed-juice. Many biotic and abiotic factors influence berry structure (composed of skin and pulp cell walls) which impacts the efficiency of enzyme-mediated degradation (Ortega-Regules et al, 2006). To build a better model of c...
Article
Full-text available
Background and Aims Cell wall changes in ripening grapes (Vitis vinifera) have been shown to involve re-modelling of pectin, xyloglucan and cellulose networks. Newer experimental techniques, such as molecular probes specific for cell wall epitopes, have yet to be extensively used in grape studies. Limited general information is available on the cel...
Article
Full-text available
The arabinoxylans are one of the main components of plant cell walls and are known to play major roles in plant tissues properties depending in particular on their structural features. It has been recently shown that one of the strategies developed by resurrection plants to overcome dehydration is based on cell wall composition. For this purpose, t...
Article
Vitis species include Vitis vinifera, the domesticated grapevine, used for wine and grape agriculturalproduction and considered the world’s most important fruit crop. A cell wall preparation, isolated fromfully expanded photosynthetically active leaves, was fractionated via chemical and enzymatic reagents;and the various extracts obtained were assa...
Conference Paper
Full-text available
A joint South African/French research project has been initiated with the aim to study plant-pathogen interactions with a particular focus on the plant cell wall. This focus has presented itself naturally after it was found that the grapevine polygalacturonase-inhibiting protein1 (VvPGIP1) influence cell wall properties in transgenic tobacco plants...
Article
Full-text available
Background Constitutive expression of Vitis vinifera polygalacturonase-inhibiting protein 1 (Vvpgip1) has been shown to protect tobacco plants against Botrytis cinerea. Evidence points to additional roles for VvPGIP1, beyond the classical endopolygalacturonase (ePG) inhibition mechanism, in providing protection against fungal infection. Gene expres...
Conference Paper
Full-text available
The Department of Viticulture and Oenology (DVO) and the Institute for Wine Biotechnology (IWBT) at Stellenbosch University present an ANCIENT WINE MINI-SYMPOSIUM: UNCORKING THE PAST: THE QUEST FOR WINE, BEER, AND EXTREME FERMENTED BEVERAGES to host the visit of Dr Patrick McGovern (USA)
Article
Full-text available
A variety of Southern African resurrection plants were surveyed using high-throughput cell wall profiling tools. Species evaluated were the dicotyledons, Myrothamnus flabellifolia and Craterostigma plantagineum; the monocotyledons, Xerophyta viscosa, Xerophyta schlecterii, Xerophyta humilis and the resurrection grass Eragrostis nindensis, as well a...
Chapter
Full-text available
Resurrection plants represent a remarkable group of plants possessing vegetative tissue capable of surviving water loss to an air-dry state. Many of these species grow in semiarid and arid countries, and a rich diversity is found in Southern Africa. We review the mechanisms proposed to explain how they tolerate desiccation, highlighting the process...
Chapter
Full-text available
22.1 INTRODUCTION The grapevine is the world's most important agricultural fruit crop with 7,861,000 hectares of vineyards worldwide in 2008 and about 270 million hL of wine produced annually (OIV, 2009). Wine, an alcoholic beverage that dates back thousands of years, predating the Greek and Roman empires, is currently believed to have originated i...
Article
Full-text available
The leaves, flower and stems of the southern African angiosperm resurrection plant Myrothamnus flabellifolia were investigated at the ultrastructural level to determine the source of previously reported fungal contamination. Fungal mycelia and hyphae of the genera Aspergillus and Penicillium were found localized to the hydathodes of the leaves and...
Article
Full-text available
A polyphenol-rich extract of the medicinal resurrection plant Myrothamnus flabellifolia was shown to inhibit viral (M-MLV and HIV-1) reverse transcriptases. Fractionation and purification of this extract yielded the major polyphenol, 3,4,5 tri-O-galloylquinic acid, as the main active compound. A sensitive, ethidium bromide based fluorescent assay,...
Conference Paper
Full-text available
Almost 173 years ago to the day, Charles Darwin visited Cape Town at the Cape of Good Hope (South Africa) on the last leg of his epic voyage on the H.M.S. Beagle. During the visit he embarked on an inland trip where he travelled through the Cape Winelands, visiting the the wine-farming towns of Paarl, Franschhoek and Somerset West. The remarkable g...
Article
Full-text available
Vegetative desiccation tolerance occurs in a unique group of species termed 'resurrection plants'. Here, we review the molecular genetic, physiological, biochemical, ultrastructural and biophysical studies that have been performed on a variety of resurrection plants to discover the mechanisms responsible for their tolerance. Desiccation tolerance i...
Article
Full-text available
The wine industry in South Africa is over three centuries old and over the last decade has reemerged as a significant competitor in world wine markets. The Institute for Wine Biotechnology (IWBT) was established in partnership with the Department of Viticulture and Oenology at Stellenbosch University to foster basic fundamental research in the wine...