Nigel Paul

Lancaster University, Lancaster Environment Centre, Faculty Member

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Ultraviolet radiation causes leaf warming due to partial stomatal closure

Variation in solar ultraviolet (UV) radiation induces a wide-range of plant responses from the ce... more Variation in solar ultraviolet (UV) radiation induces a wide-range of plant responses from the cellular to whole-plant scale. We demonstrate here for the first time that partial stomatal closure caused by UV exposure significantly increases leaf temperature independently of any increase in incident energy on the leaves. Significant leaf warming in response to UV radiation was consistent in tomato (Solanum lycopersicum L. ) across different experimental approaches. Exposure to UV radiation significantly decreased stomatal conductance and increased leaf temperature by up to 2°C in field experiments where solar UV was attenuated using filters. Smaller but significant increases in leaf temperature due to decreases in stomatal conductance occurred in multi-day controlled environment (CE) growth room experiments and in short-term (< 2 hours) irradiance response experiments, both using fluorescent lamps to provide UV treatments. We show that leaf warming due to partial stomatal closure is independent of any direct warming effects of UV manipulations. We discuss the implications of UV-induced warming both for crop production and understanding broader plant and ecosystem responses to UV radiation.

A novel formulation technology for baculoviruses protects biopesticide from degradation by ultraviolet radiation

Scientific Reports

Biopesticides are biological pest control agents that are viewed as safer alternatives to the syn... more Biopesticides are biological pest control agents that are viewed as safer alternatives to the synthetic chemicals that dominate the global insecticide market. A major constraint on the wider adoption of biopesticides is their susceptibility to the ultraviolet (UV: 290–400 nm) radiation in sunlight, which limits their persistence and efficacy. Here, we describe a novel formulation technology for biopesticides in which the active ingredient (baculovirus) is micro-encapsulated in an ENTOSTAT wax combined with a UV absorbant (titanium dioxide, TiO2). Importantly, this capsule protects the sensitive viral DNA from degrading in sunlight, but dissolves in the alkaline insect gut to release the virus, which then infects and kills the pest. We show, using simulated sunlight, in both laboratory bioassays and trials on cabbage and tomato plants, that this can extend the efficacy of the biopesticide well beyond the few hours of existing virus formulations, potentially increasing the spray inter...

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Effects of elevated UV-B radiation on cuticular water permeability of ivy grown under natural or artificial light

Ozone depletion: a view from the grass roots

Early failures occurred with two sizes of wheel bolts used for attaching front wheels and dual re... more Early failures occurred with two sizes of wheel bolts used for attaching front wheels and dual rear wheels to heavy truck hubs. Failure resulted in fracture of the bolts, and was a response to the material and process specification which produced a steel microstructure highly susceptible to hydrogen-assisted stress cracking. The microstructure resulted from an alloy steel that was carburized, heat treated, and then zinc plated. This combination of material and processing produced a high-strength SAE Grade 8 bolt (equivalent to an ISO 10.9 grade) with a hard, brittle case and an anodic zinc coating. A slight misalignment of the wheel bolt coupled with a ball seat mounting design for the wheel nuts created a combined axial and bending stress that exceeded the threshold for hydrogen-assisted stress cracking.

The green tea polyphenol, epigallocatechin-3-gallate (EGCG), protects against the oxidative cellular and genotoxic effects of UVA radiation

Improvements In and Relating to Plant Protection (Patent for International Application Number: PCT/GB2007/002611, International Publication Number: WO 2008/007100(a2), Filing date : July 12, 2007)

ABSTRACT The invention provides seed treatment compositions as well as their use, methods for tre... more ABSTRACT The invention provides seed treatment compositions as well as their use, methods for treating seeds, methods of protecting plants against pests and also treated seeds and plants. In one embodiment there is provided a method of treating a seed with a seed treatment composition to induce a plant resistance mechanism against one or more pests in a plant grown from said seed.

The direct effects of UVB radiation (290-315nm) on Betula pubescens litter decomposting at four European field sites

A co-ordinated series of field experiments were conducted to consider the effects of elevated UV-... more A co-ordinated series of field experiments were conducted to consider the effects of elevated UV-B radiation applied directly to decomposing plant litter. Betula pubescens was decomposed under ambient and elevated UV-B (simulating a 15% ozone depletion) using outdoor irradiation facilities at Adventdalen, Norway (78° N), Abisko, Sweden (68° N), Amsterdam, The Netherlands (52° N,) and Patras, Greece (38° N). There was no significant effect of treatment on mass loss for samples collected after 2, 12 and 14 months decomposition at Amsterdam, or after 4 months decomposition at Adventdalen. Significant reductions in the mass loss of litter decomposing under elevated UV-B compared to ambient were found at the other 2 sites. The only effect of treatment on litter chemistry during decomposition was a significant reduction in the N concentration of material at Abisko and a significant increase in C:N at Patras for litter decomposing under elevated UV-B. Significant differences were found in the structure of the fungal community decomposing litter in Sweden, the only site to be tested. These data, and the few published studies of the response of decomposition to UV-B incident on litter suggest that, in the ecosystems and climates that have been studied, such direct effects are typically confined to the initial stages of decomposition, and are rather small in magnitude.

Uv Supplementation for Growth Regulation and Disease Control

Acta Horticulturae, 2006

... MATERIALS AND METHODS Lettuce (Lactuca sativa L.) cultivar &amp;amp;amp;#x27;Rex&amp;... more ... MATERIALS AND METHODS Lettuce (Lactuca sativa L.) cultivar &amp;amp;amp;#x27;Rex&amp;amp;amp;#x27; seedlings were propagated in 40 cell tray inserts with Levington M3 compost under ... The UV treatments were provided much as we have described before (Paul et al 2005), with a daily UV photoperiod of 12hr ...

Disease and decomposition: Contrasting aspects of UV-B effects on microbes

Increased UVB radiation, arising from stratospheric ozone depletion may influence crops and nativ... more Increased UVB radiation, arising from stratospheric ozone depletion may influence crops and native vegetation by altering a range of plant-microbe interactions, including disease and decomposition. Such effects of UVB may result from direct effects on micro-organisms or indirect effects, mediated via changes in the host plant. The responses of plant diseases to increased UVB reflect both direct and indirect effects. However, our studies of Septoria tritici infecting wheat highlight the role of direct UVB effects on the fungus in this system. In controlled environment experiments infection was significantly decreased by elevated UVB after inoculation, but UVB prior to inoculation had no effect. Field experiments using a modulated UVB supplement also showed significant reductions in natural S. tritici of a wheat crop, but such reductions were transient. appeared to be dependent on weather conditions. and resulted in no change in crop yield. The responses of microbial decomposition to increased UVB also reflect both direct and indirect effects. For example, we have shown highly marked interspecific variation in the response of decomposer fungi to direct UVB exposure. and changes in the fungal decomposer community following decomposition under increased UVB conditions. lndirect UVB effects on decomposition also occur, and are evident in altered patterns of microbial respiration. Such responses may reflect changes in host nitrogen concentration, and may have their greatest ecological effects via changes in nutrient cycling.

After 30 years of protecting the ozone layer, some reasons to be cheerful

Note. This is the manuscript of the piece published in The Conversation at () The policy of The C... more Note. This is the manuscript of the piece published in The Conversation at () The policy of The Conversation is as follows "We believe in the free flow of information. We use a Creative Commons license, so you can republish our articles for free, online or in print.". If you wish to re-use this material, please follow the instructions set-out by the Conversation. Reasons to be cheerful: thirty years of protecting the ozone layer As the UN announces that the ozone layer is beginning to recover Professor Nigel Paul reflects on why this is good news for everyone on the planet.

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UV-B impacts on decomposition and biogeochemical cycling

Increased occurrence of pesticide residues on crops grown in protected environments compared to crops grown in open field conditions

Chemosphere, 2015

Crops grown under plastic-clad structures or in greenhouses may be prone to an increased frequenc... more Crops grown under plastic-clad structures or in greenhouses may be prone to an increased frequency of pesticide residue detections and higher concentrations of pesticides relative to equivalent crops grown in the open field. To test this we examined pesticide data for crops selected from the quarterly reports (2004-2009) of the UK's Pesticide Residue Committee. Five comparison crop pairs were identified whereby one crop of each pair was assumed to have been grown primarily under some form of physical protection ('protected') and the other grown primarily in open field conditions ('open'). For each pair, the number of detectable pesticide residues and the proportion of crop samples containing pesticides were statistically compared (n=100 s samples for each crop). The mean concentrations of selected photolabile pesticides were also compared. For the crop pairings of cabbage ('open') vs. lettuce ('protected') and 'berries' ('open') vs...

Interference Between Healthy and Rusted Groundsel (Senecio-Vulgaris L) Within Mixed Populations of Different Densities and Proportions

New Phytologist, 1986

ABSTRACT

The system management approach of biological weed control: Some theoretical considerations and aspects of application

Biocontrol, 2001

Theoretical considerations behind the system management approach of biological weed control are p... more Theoretical considerations behind the system management approach of biological weed control are presented. These include, a part describing and explaining the effects of parasitic fungi on crop -weed competition, a part describing and explaining the epidemic spread of parasitic fungi on weeds, and a part relating crop -weed competition at the population level to epidemics. The theoretical framework developed may also provide a basis for the use of other natural enemies, like insects, for biological weed control following the system management approach. Aspects of application are discussed using data of the interaction between the annual weed Senecio vulgaris and the rust fungus Puccinia lagenophorae.

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The green tea polyphenol, epigallocatechin-3-gallate, protects against the oxidative cellular and genotoxic damage of UVA radiation

International Journal of Cancer, 2002

A number of biological activities have been ascribed to the major green tea polyphenol epigalloca... more

Underwater ultraviolet - Response

Trends in Ecology & Evolution, 2003

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Rust pustules support invasion of ramsons by Botrytis cinerea

Mycologist, 1989

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Effects of UV-B Radiation on Wax Biosynthesis

Air Pollutants and the Leaf Cuticle, 1994

Barnes J, Paul N, Percy K, Broadbent P, McLaughlin C, Mullineaux P, Creissen G, Wellburn A. 1994 ... more

Effects of rust infection of Senecio vulgaris on competition with lettuce

Weed Research, 1987

The effects of rust (Puccinia lagenophorae) on competition between groundsel (Senecio rutgaris L.... more The effects of rust (Puccinia lagenophorae) on competition between groundsel (Senecio rutgaris L.) and leltuee were investigated. In small tubs in a glasshouse environment, rust infeetion redueed the dry weight yield of groundsel both in monoeultures and mixtures with lettuce at lotal densities from 35 to c. 1100 plants m"^. While rust did not affect the relative mixture response of groundsel it resulted in a signifieant deerease in the relative mixture response of lettuee. Indeed. the yield-density relationship of lettuee in mixture with rusted groundsel was not significantly dilTerent from that of lettuce in monoculture. At 1120 groundsel plants m-, lettuee yield in mixture with uninoeulated groundsel was inhibited by c. 50% when the ratio of lettuce:groundsel (L:G) was 1:3, By contrast, in mixture with rusted groundsel, lettuce yield per tub was not changed by varying L:G, eight leltuee with 24 groundsel yielding no less than 32 in monoculture. Although the severity of rust did not appear to differ, infeetion inhibited groundsel yield and modified eompetitive interaetions only when L: G was low. In a field experiment the fresh weight yield of lettuce was significantly inhibited by interference from uninoeuialed groundsel at all sowing densities from 250 to 65 000 seed m"^. Conversely, lettuee yield was not significantly * To whom correspondence should be addressed.

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The system management approach of biological weed control: some theoretical considerations and aspects of application

BioControl, 2001

Theoretical considerations behind the system management approach of biological weed control are p... more Theoretical considerations behind the system management approach of biological weed control are presented. These include, a part describing and explaining the effects of parasitic fungi on crop-weed competition, a part describing and explaining the epidemic spread of parasitic fungi on weeds, and a part relating crop-weed competition at the population level to epidemics. The theoretical framework developed may also provide a basis for the use of other natural enemies, like insects, for biological weed control following the system management approach. Aspects of application are discussed using data of the interaction between the annual weed Senecio vulgaris and the rust fungus Puccinia lagenophorae.

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