A5019606031- Plant biochemistry and biosynthesis
- Plant-Microbe Interactions and Immunity
- Natural product bioactivities and synthesis
- Photosynthetic Processes and Mechanisms
- Mycobacterium research and diagnosis
- Plant Disease Resistance and Genetics
- Tuberculosis Research and Epidemiology
- Plant Pathogens and Fungal Diseases
- Bacteriophages and microbial interactions
- Plant pathogens and resistance mechanisms
- Plant tissue culture and regeneration
- RNA and protein synthesis mechanisms
- Microbial Natural Products and Biosynthesis
- Plant Gene Expression Analysis
- Phytochemical compounds biological activities
- Wheat and Barley Genetics and Pathology
- Genomics and Phylogenetic Studies
- Bacterial Genetics and Biotechnology
- Antibiotic Resistance in Bacteria
- Plant Reproductive Biology
- Plant Pathogenic Bacteria Studies
- Plant nutrient uptake and metabolism
- Ocular Infections and Treatments
- Data Visualization and Analytics
- Aquaculture disease management and microbiota
John Innes Centre
2004-2025
Norwich Research Park
1994-2021
Georgia Institute of Technology
2005
Sainsbury Laboratory
1998-2004
DuPont (United States)
2001-2004
University of East Anglia
1998
Albert Einstein College of Medicine
1988-1990
Howard Hughes Medical Institute
1990
Yeshiva University
1988-1989
Summary Recent development of vectors and methodologies to introduce recombinant DNA into members the genus Mycobacterium has provided new approaches for investigating these important bacteria. While most pathogenic mycobacteria are slow‐growing, smegmatis is a fast‐growing, non‐pathogenic species that been used many years as host mycobacteriophage propagation and, recently, introduction DNA. Its use cloning analysis mycobacterial genes limited by its inability be efficiently transformed...
Saponins are glycosylated plant secondary metabolites found in many major food crops [Price, K. R., Johnson, I. T. & Fenwick, G. R. (1987) CRC Crit. Rev. Food Sci. Nutr. 26, 27-133]. Because saponins have potent antifungal properties and present healthy plants high concentrations, these molecules may act as preformed chemical barriers to fungal attack. The isolation of mutants defective saponin biosynthesis represents a powerful strategy for evaluating the importance compounds defense. oat...
Requisite to a detailed understanding of the molecular basis bacterial pathogenesis is genetic system that allows for transfer, mutation, and expression specific genes. Because continuing importance tuberculosis leprosy worldwide, we initiated studies develop in mycobacteria here report use two complementary strategies introduce express selectable markers. First, an Escherichia coli cosmid was inserted into temperate mycobacteriophage L1, generating shuttle phasmids replicating as plasmids...
The evolution of the ability to synthesize specialized metabolites is likely have been key for survival and diversification different plant species. Oats ( Avena spp.) produce antimicrobial triterpenoids (avenacins) that protect against disease. oat β-amyrin synthase gene AsbAS1 , which encodes first committed enzyme in avenacin biosynthetic pathway, clearly distinct from other synthases. Here we show has arisen by duplication divergence a cycloartenol synthase-like gene, its properties...
CYP51 sterol demethylases are the only cytochrome P450 enzymes with a conserved function across animal, fungal, and plant kingdoms (in synthesis of essential sterols). These highly enzymes, which important targets for cholesterol-lowering drugs, antifungal agents, herbicides, regarded as most ancient member family. Here we present report enzyme that has acquired different function. We show AsCYP51H10 is dispensable sterols been recruited production antimicrobial compounds (avenacins) confer...
Abstract Serine carboxypeptidase-like (SCPL) proteins have recently emerged as a new group of plant acyltransferases. These enzymes share homology with peptidases but lack protease activity and instead are able to acylate natural products. Several SCPL acyltransferases been characterized date from dicots, including an enzyme required for the synthesis glucose polyesters that may contribute insect resistance in wild tomato (Solanum pennellii) sinapate esters associated UV protection...
Members of the cytochromes P450 superfamily (P450s) catalyze a huge variety oxidation reactions in microbes and higher organisms. Most families are highly divergent, but contrast cytochrome 14α-sterol demethylase (CYP51) family is one most ancient conserved, catalyzing sterol 14α-demethylase required for essential synthesis across fungal, animal, plant kingdoms. Oats (Avena spp.) produce antimicrobial compounds, avenacins, that provide protection against disease. Avenacins synthesized from...
Abstract Operon-like gene clusters are an emerging phenomenon in the field of plant natural products. The genes encoding some best-characterized secondary metabolite biosynthetic pathways scattered across genomes. However, increasing number synthesis diverse products have recently been reported These arisen through neo-functionalization and relocation existing within genome, not by horizontal transfer from microbes. reasons for clustering yet clear, although this form organization is likely...
Abstract Non-random gene organization in eukaryotes plays a significant role genome evolution. Here, we investigate the origin of biosynthetic cluster for production defence compounds oat—the avenacin cluster. We elucidate structure and organisation this 12-gene cluster, characterise last two missing pathway steps, reconstitute entire tobacco by transient expression. show that has formed de novo since divergence oats subtelomeric region lacks homology with other grasses, order is...
Many plants synthesize antimicrobial secondary metabolites as part of their normal program growth and development, often sequestering them in tissues where they may protect against microbial attack. These include glycosylated triterpenoids (saponins), natural products that are exploited by man for a variety purposes including use drugs [Hostettmann, K. & Marston, A. (1995) Saponins (Cambridge Univ. Press, Cambridge, U.K.)]. Very little is known about the genes required synthesis this...
The use of multivariate information visualization techniques is intrinsically difficult because the multidimensional nature data cannot be effectively presented and understood on real-world displays, which have limited dimensionalities. However, necessity to these in daily life increasing as amount complexity grows explosively age. Thus, that are easier understand more accessible needed for general population. In order meet this need, present paper proposes Dust & Magnet, a technique...
Abstract Avenacins are antimicrobial triterpene glycosides that produced by oat (Avena) roots. These compounds confer broad-spectrum resistance to soil pathogens. Avenacin A-1, the major avenacin oats, is strongly UV fluorescent and accumulates in root epidermal cells. We previously defined nine loci required for synthesis, eight of which clustered. Mutants affected at seven these (including Saponin-deficient1 [Sad1], gene first committed enzyme pathway) have normal morphology but reduced...
Significance Sterols and triterpenes are complex molecules that synthesized from the isoprenoid pathway. The functions of sterols in plants have been studied extensively, but role is less well understood. Here we investigate triterpene synthesis regulation diploid oat. We show genes for regulated by an ancient root development process conserved across diverse plants. further mutants which metabolism most common plant triterpene, β-amyrin, blocked undergo a change early epidermis leads to...
Significance The triterpenes are a large and highly diverse group of plant natural products. They synthesized by cyclization the linear isoprenoid 2,3-oxidosqualene into different triterpene scaffolds enzymes known as synthases. This process is one most complex enzymatic reactions only poorly understood. Here, we identify conserved amino acid residue that critical for both product substrate specificity in synthases from species. Our results shed new light on mechanisms plants open up...
Glycosylation of small molecules is critical for numerous biological processes in plants, including hormone homeostasis, neutralization xenobiotics, and synthesis storage specialized metabolites. plant natural products usually performed by uridine diphosphate-dependent glycosyltransferases (UGTs). Triterpene glycosides (saponins) are a large family that determine important agronomic traits such as disease resistance flavor have pharmaceutical applications. Most characterized product UGTs...
Plants produce diverse specialized metabolites with important ecological functions. It has recently become apparent that the genes for many of these pathways are not dispersed in plant genomes, but rather arranged like beads on a string biosynthetic gene clusters (BGCs). Pathways encoded by BGCs as rule dedicated linear do form parts wider metabolic networks. In contrast, biosynthesis widely distributed more ancestral such carotenoids and anthocyanins clustered. Little is known about how...
Plants produce an array of natural products with important ecological functions. These compounds are often decorated oligosaccharide groups that influence bioactivity, but the biosynthesis such sugar chains is not well understood. Triterpene glycosides (saponins) a large family plant determine agronomic traits, as exemplified by avenacins, antimicrobial defense produced oats. Avenacins have branched trisaccharide moiety consisting l-arabinose linked to 2 d-glucose molecules critical for...
Many plants produce constitutive antifungal molecules belonging to the saponin family of secondary metabolites, which have been implicated in plant defense. Successful pathogens these must presumably some means combating chemical defenses their hosts. In oat root pathogen Gaeumannomyces graminis, saponin-detoxifying enzyme avenacinase has shown be essential for pathogenicity. A number other phytopathogenic fungi also saponin-degrading enzymes, although significance resistance and...
Summary Oats produce avenacins, antifungal triterpenes that are synthesized in the roots and provide protection against take‐all other soilborne diseases. Avenacins acylated at carbon‐21 position of triterpene scaffold, a modification critical for activity. We have previously characterized several steps avenacin pathway, including those required acylation. However, transfer acyl group to scaffold requires C‐21β be oxidized first, by an as yet uncharacterized enzyme. mined oat transcriptome...
1. Abstract To meet the challenge of feeding a growing population, breeders and scientists are continuously looking for ways to increase genetic gain in crop breeding. One way this can be achieved is through “speed breeding” (SB), which shortens breeding cycle accelerates research studies rapid generation advancement. The SB method carried out number ways, one involves extending duration plant’s daily exposure light (photoperiod) combined with early seed harvest order quickly from seed,...
The anti-fungal, steroidal, glycoalkaloid saponin, α-tomatine, is present in uninfected tomato plants substantial concentrations, and may contribute to the protection of against attack by phytopathogenic fungi. In general, successful fungal pathogens are more resistant α-tomatine vitro than fungi that do not infect this plant. For a number pathogens, resistance has been associated with ability detoxify through action enzymes known as tomatinases. contrast, biotrophic pathogen Cladosporium...