Biochemical effects of tropospheric ozone in transgenic plants

Broadbent, P.; Creissen, Gary; Wellburn, Florence A. M.; Mullineaux, Philip M.; Wellburn, A. R.

doi:10.1042/bst0221020

“…Analagous to the case for animals, it can be expected that much will be learned about plant antioxidant processes in the next decade via extensive experimental applications of transgenic plant technology (71,72). For example, if 03 yields H202 in the aqueous phase of the apoplast, peroxidases found there or in the outer cell wall material, which is rich in peroxidases involved in lignin synthesis, could be protective via direct utilization of H202 (8).…”

Section: Structural Considerationsmentioning

confidence: 99%

“…When extrapolations are made from data generated in such clean systems as in vitro primary, secondary, and immortalized cell culture systems exposed to environmental oxidants, allowances must be made for the contributions of extracellular agents at the environment-biosystem boundary under in vivo conditions. Finally, there is no doubt that studies of the effects of environmental oxidants on plant (71,72) and animal transgenics (170) in which components of antioxidant defense systems have been over-or underexpressed will contribute to the understanding of mechanisms of oxidative stress at plant and animal biosurfaces.…”

Section: Respiratory Tract Lining Fluidsmentioning

confidence: 99%

Oxidative stress and antioxidants at biosurfaces: plants, skin, and respiratory tract surfaces.

Cross

¹

,

Vliet

²

,

Louie

³

et al. 1998

Environ Health Perspect

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Atmospheric pollutants represent an important source of oxidative and nitrosative stress to both terrestrial plants and to animals. The exposed biosurfaces of plants and animals are directly exposed to these pollutant stresses. Not surprisingly, living organisms have developed complex integrated extracellular and intracellular defense systems against stresses related to reactive oxygen and nitrogen species (ROS, RNS), including 03 and NO2. Plant and animal epithelial surfaces and respiratory tract surfaces contain antioxidants that would be expected to provide defense against environmental stress caused by ambient ROS and RNS, thus ameliorating their injurious effects on more delicate underlying cellular constituents. Parallelisms among these surfaces with regard to their antioxidant constituents and environmental oxidants are presented. The reactive substances at these biosurfaces not only represent an important protective system against oxidizing environments, but products of their reactions with ROS/RNS may also serve as biomarkers of environmental oxidative stress. Moreover, the reaction products may also induce injury to underlying cells or cause cell activation, resulting in production of proinflammatory substances including cytokines. In this review we discuss antioxidant defense systems against environmental toxins in plant cell wall/apoplastic fluids, dead keratinized cells/interstitial fluids of stratum corneum (the outermost skin layer), and mucus/respiratory tract lining fluids.-Environ Health Perspect 1 06(Suppl 5): 1241-1251 (1998 The aim of this review is to highlight certain parallels between the antioxidant mechanisms responsible for protecting diverse environmentally exposed biosurfaces. Although there are numerous other environmental oxidants that contribute to surface oxidative stress (e.g., oxides of nitrogen, cigarette smoke, radiation), our focus will be on 03 as a representative environmental oxidant and on the antioxidants with which it can be expected to react at plant, skin, and respiratory tract surfaces. Although in most circumstances the oxidant can be expected to be neutralized, products of reactions with constituents of the extracellular fluids, e.g., cytotoxic aldehydes produced by reactions of 03 with extracellular lipids (12-14), may be largely responsible for cell or tissue injury by environmental toxins. Structural ConsiderationsThe similarities of the interfaces between the environment and plant and animal tissues are simplistically depicted in Figure 1. In plants, uptake of environmental toxins can be expected to occur mainly at the cell wall surface and, via the stomata, within the extracellular apoplastic fluids (15-17). The skin and the respiratory tract are the animal organs most direcdy exposed to oxidant air pollutants. Although numerous studies have documented the effects of oxidants on lungs, and have to some extent directed attention to the importance of the respiratory tract lining fluids (RTLFs) (18)(19)(20)(21)(22), only a few studies have described possible oxi...

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“…In addition to ascorbate, the apoplastic compartment contains a variety of other potential reactants for 03 and its reactive products, including phenolic compounds and peroxidases. Analagous to the case for animals, it can be expected that much will be learned about plant antioxidant processes in the next decade via extensive experimental applications of transgenic plant technology (71,72). For example, if 03 yields H202 in the aqueous phase of the apoplast, peroxidases found there or in the outer cell wall material, which is rich in peroxidases involved in lignin synthesis, could be protective via direct utilization of H202 (8).…”

Section: Extracellular Antioxidants Of Plantsmentioning

confidence: 99%

Oxidative Stress and Antioxidants at Biosurfaces: Plants, Skin, and Respiratory Tract Surfaces

Cross¹,

Vliet²,

Louie³

et al. 1998

Environmental Health Perspectives

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Atmospheric pollutants represent an important source of oxidative and nitrosative stress to both terrestrial plants and to animals. The exposed biosurfaces of plants and animals are directly exposed to these pollutant stresses. Not surprisingly, living organisms have developed complex integrated extracellular and intracellular defense systems against stresses related to reactive oxygen and nitrogen species (ROS, RNS), including O3 and NO2. Plant and animal epithelial surfaces and respiratory tract surfaces contain antioxidants that would be expected to provide defense against environmental stress caused by ambient ROS and RNS, thus ameliorating their injurious effects on more delicate underlying cellular constituents. Parallelisms among these surfaces with regard to their antioxidant constituents and environmental oxidants are presented. The reactive substances at these biosurfaces not only represent an important protective system against oxidizing environments, but products of their reactions with ROS/RNS may also serve as biomarkers of environmental oxidative stress. Moreover, the reaction products may also induce injury to underlying cells or cause cell activation, resulting in production of proinflammatory substances including cytokines. In this review we discuss antioxidant defense systems against environmental toxins in plant cell wall/apoplastic fluids, dead keratinized cells/interstitial fluids of stratum corneum (the outermost skin layer), and mucus/respiratory tract lining fluids.

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Variable patterns of antioxidant protection but similar ethene emission differences in several ozone‐sensitive and ozone‐tolerant plant selections

Wellburn

¹

,

Wellburn

²

1996

Plant Cell & Environment

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Six pairs of O3‐sensitive and O3‐tolerant cultivars, clones or populations of different plants (tobacco, plantain, clover, radish, poplar and loblolly pine) were taken through identical but short episodic exposures to O3 in a controlled‐environment fumigation system. Emissions of ethene and concentrations of polyamines, total phenols and ascorbate as well as levels of reduced glutathione and ascorbate in fumigated and clean air controls were determined in these various cultivars, clones and populations. A large number of significant differences were detected between the various sensitive and tolerant pairs, but it is clear that different sequences of response involving these parameters occur in these various plant pairs to account for their individual O3 sensitivity or tolerance. Some O3‐tolerant plants have increased polyamines, others total phenols and some appear to be able to form reduced ascorbate and glutathione more rapidly. In the case of ethene emissions, however, all O3‐sensitive selections produce more ethene when fumigated while O3‐tolerant ones either reduce their rates of emissions below those of clean air‐grown controls or at least keep them at the same level.

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Biochemical effects of tropospheric ozone in transgenic plants

Cited by 3 publications

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Oxidative stress and antioxidants at biosurfaces: plants, skin, and respiratory tract surfaces.

Oxidative stress and antioxidants at biosurfaces: plants, skin, and respiratory tract surfaces.

Oxidative Stress and Antioxidants at Biosurfaces: Plants, Skin, and Respiratory Tract Surfaces

Variable patterns of antioxidant protection but similar ethene emission differences in several ozone‐sensitive and ozone‐tolerant plant selections

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