Phospho<i>enol</i>pyruvate carboxylase in mistletoe leaves: Regulation of gene expression, protein content, and covalent modification

Li, Xuemei; Wanek, Wolfgang; Nehls, Uwe; Popp, Marianne; Hampp, Rüdiger; Rennenberg, Heinz; Einig, Werner

doi:10.1034/j.1399-3054.2001.1120307.x

Cited by 2 publications

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“…Nitrogen content of leaves and the activity of the enzyme phosphoenolpyruvate carboxylase are dependent on the host species and the season of the year (Kim et al, 2019; Li et al, 2001). Nitrogen content in leaves of V. album subsp.…”

Section: Structure and Physiologymentioning

confidence: 99%

Biological Flora of Britain and Ireland:Viscum album

et al. 2022

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This account presents information on all aspects of the biology of Viscum album L. (Mistletoe) that are relevant to understanding its ecological characteristics and behaviour. The main topics are presented within the standard framework of the Biological Flora of Britain and Ireland: distribution, habitat, communities, responses to biotic factors, responses to environment, structure and physiology, phenology, floral and seed characters, herbivores and disease, history, and conservation. Viscum album is a widespread obligate hemiparasite on a wide range of angiosperm and gymnosperm trees. Once thought to take just water and nutrients from its host via a haustorium, it is now suggested to also take carbon. Heavy infestations can reduce host vitality through prolific water use and carbon removal. Flowers are highly reduced but are primarily pollinated by flies, ants and bees. Seeds are dispersed by birds. Removal of the epicarp is necessary for successful seedling establishment, and seeds have a sticky viscin coat, adhering it to the host bark. Vegetative spread also happens under the bark of its host resulting in densities of >700 Mistletoe plants per host. Viscum album is a lowland species, most frequent in open human‐made habitats extending into woodlands in Europe. It has been widely planted for folklore use centred around Christmas. Despite conservation concerns following removal of Mistletoe‐laden old orchards, the species is thriving and needs control in some areas. Viscotoxins and lectins in leaves and shoots have been widely used in herbal medicine and now potentially in complementary cancer therapy.

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Section: Structure and Physiologymentioning

confidence: 99%

Biological Flora of Britain and Ireland:Viscum album

et al. 2022

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“…The xylem sap not only supplies water and mineral nutrients, but also varying amounts of carbon and nitrogen compounds (Seledzhanu and Galan-Fabian 1962;Sauter 1980;Ehleringer et al 1985;Marshall and Ehleringer 1990;Marshall et al 1994;Pate et al 1991), and such a variation in nitrogen content is involved in the regulation of PEPCase gene expression in leaves of mistletoes (Li et al 2000). The xylem sap not only supplies water and mineral nutrients, but also varying amounts of carbon and nitrogen compounds (Seledzhanu and Galan-Fabian 1962;Sauter 1980;Ehleringer et al 1985;Marshall and Ehleringer 1990;Marshall et al 1994;Pate et al 1991), and such a variation in nitrogen content is involved in the regulation of PEPCase gene expression in leaves of mistletoes (Li et al 2000).…”

Section: Introductionmentioning

confidence: 99%

Sucrose phosphate synthase in leaves of mistletoe: its regulation in relation to host (Abies alba) and season

Pfiz

Küppers

et al. 2003

Trees

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Sucrose-phosphate synthase (SPS; E.C. 2.4.1.14) was studied in 1-year-old leaves of the xylemparasitic mistletoe (Viscum album L.), growing on Abies alba. Glucose-6-phosphate served as an allosteric activator of mistletoe SPS, increasing the affinity for both substrates, fructose-6-phosphate and UDP-glucose. The activation state of SPS, i.e. the ratio of substrate limited versus non-limited activity, showed two clear peaks between February and July which coincided with increased rates of net photosynthesis of the parasite. Periods of decreased SPS activity were accompanied by a transient accumulation of sucrose and starch. In samples exhibiting a high activation state, activity was decreased by incubation of the extract with ATP; however, ATP did not affect SPS activity in samples exhibiting a low activation state of SPS. In parallel to the first increase of the activation state in March, pool sizes of the positive effector glucose-6-phosphate were high, whereas pool sizes of fructose-2,6-bisphosphate, an inhibitor of sucroneogenesis, were low. The decline in the activation state in April occurred in parallel with increased rates of transpiration of the parasite. This could have increased the availability of host-derived sugars, although the xylem sap of A. alba showed rather consistent concentrations of total soluble sugars throughout the vegetation period (1.1-3.9 mM). We thus speculate that sugar availability in the host xylem controls carbohydrate metabolism in the parasite.

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Phosphoenolpyruvate carboxylase in mistletoe leaves: Regulation of gene expression, protein content, and covalent modification

Cited by 2 publications

References 49 publications

Biological Flora of Britain and Ireland:Viscum album

Biological Flora of Britain and Ireland:Viscum album

Sucrose phosphate synthase in leaves of mistletoe: its regulation in relation to host (Abies alba) and season

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