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At least 19 recordsLinked to original sources
PubMed2002

Complexities in ETS-domain transcription factor function and regulation: lessons from the TCF (ternary complex factor) subfamily. The Colworth Medal Lecture.

The ETS-domain transcription factor family can be divided into a series of subfamilies. Elk-1 represents the founding member of the ternary complex factor (TCF) subfamily. By focusing on the TCF subfamily, we can demonstrate the complexities that exist in the function and regulation of ETS-domain transcription factors. This article focuses on Elk-1 in detail and summarizes the functions of other TCFs. The key themes covered include the domain structure of the TCFs, the mechanisms of complex formation with serum response factor, regulation of TCFs by mitogen-activated protein kinase cascades, and transcriptional regulatory properties of the TCFs. Finally, the emerging role of the TCFs in vivo is discussed. A picture is developing indicating that, while these proteins exhibit significant sequence and functional conservation, key differences in their structure and regulation are being identified which may relate to unique functions of these proteins in vivo.

Amino Acid Sequence↗
PubMed1999

Parasitic plant responses to host plant signals: a model for subterranean plant-plant interactions.

The ability of plants to fulfill nutritional needs by parasitizing neighboring plants has originated several times in angiosperm evolution. Molecular tools are now being exploited to investigate the evolutionary origins of plant parasitism and to dissect the genetic mechanisms governing parasitic plant-host plant interactions. Investigating the nature of signal exchanges between parasitic plants and their hosts serves as a tractable system for understanding how plants in general communicate in the environment. This work should also lead to the development of novel strategies for minimizing the devastation caused by parasitic weeds in international agriculture.

Biological Evolution↗
PubMed2001

[Studies on original plant of traditional Chinese drug "bai zhi" (radix Angelicae Dahuricae) and its closely related wild plants. IV. Discussion on original plant and cultivation history of traditional Chinese drug "bai zhi" and evolution of its closely related wild plants].

OBJECTIVE: To confirm the original plant of traditional Chinese drug "Bai Zhi" and to inquire into the cultivation history of "Bai Zhi" and evolution of closely related wild plants of "Bai Zhi". METHOD: Various research results obtained were synthesized and discussed according to historical and current data. RESULT: Obtained research results, historical and current data showed almost no difference. CONCLUSION: 1. Angelica dahurica var. formosana must be the original plant of traditional Chinese drug "Bai Zhi". 2. A. porphyrocaulis should be treated as a variety of A. dahurica, named as A. dahurica var. porphyrocaulis. 3. 4 sorts of Chinese traditional drug "Bai Zhi" (Chuang Bai Zhi, Hang Bai Zhi, Qi Bai Zhi and Yu Bai Zhi) should not be taxonomically distinguished. The history of utilization and cultivation of "Bai Zhi", and the evolutional relation of the closely related wild plants of "Bai Zhi" (A. dahurica, A. dahurica var. formosana, and A. dahurica var. porphyrocaulis) were also discussed.

Angelica↗
PubMed1999

Environmental behavior of explosives in groundwater from the Milan Army Ammunition Plant in aquatic and wetland plant treatments. Uptake and fate of TNT and RDX in plants.

Uptake and fate of TNT and RDX by three aquatic and four wetland plants were studied using hydroponic, batch, incubations in explosives-contaminated groundwater amended with [U-14C]-TNT or [U-14C]-RDX in the laboratory. Substrates in which the plants were rooted were also tested. Plants and substrates were collected from a small-scale wetland constructed for explosives removal, and groundwater originated from a local aquifer at the Milan Army Ammunition Plant. This study demonstrated rapid uptake of [U-14C]-TNT derived 14C, concentration at the uptake sites and limited transport in all plants. Per unit of mass, uptake was higher in submersed than in emergent species. Biotransformation of TNT had occurred in all plant treatments after 7-day incubation in 1.6 to 3.4 mg TNT L-i, with labeled amino-dinitrotoluenes (ADNTs), three unidentified compounds unique for plants, and mostly polar products as results. Biotransformation occurred also in the substrates, yielding labeled ADNT, one unidentified compound unique for substrates, and polar products. TNT was not recovered by HPLC in plants and substrates after incubation. Uptake of [U-14C]-RDX derived 14C in plants was slower than that of TNT, transport was substantial, and concentration occurred at sites where new plant material was synthesized. As for TNT, uptake per unit of mass was higher in submersed than in emergent species. Biotransformation of RDX had occurred in all plant treatments after 13-day incubation in 1.5 mg RDX L-1, with one unidentified compound unique for plants, and mostly polar products as results. Biotransformation had occurred also in the substrates, but to a far lower extent than in plants. Substrates and plants had one unidentified 14C-RDX metabolite in common. HPLC analysis confirmed the presence of RDX in most plants and in three out of four substrates at the end of the incubation period.

Autoradiography↗
PubMed2003

Plant stress signalling: understanding and exploiting plant-plant interactions.

When plants are attacked by insects, volatile chemical signals can be released, not only from the damaged parts, but also systemically from other parts of the plant and this continues after cessation of feeding by the insect. These signals are perceived by olfactory sensory mechanisms in both the herbivorous insects and their parasites. Molecular structures involved can be characterized by means of electrophysiological assays, using the insect sensory system linked to chemical analysis. Evidence is mounting that such signals can also affect neighbouring intact plants, which initiate defence by the induction of further signalling systems, such as those that increase parasitoid foraging. Furthermore, insect electrophysiology can be used in the identification of plant compounds having effects on the plants themselves. It has been found recently that certain plants can release stress signals even when undamaged, and that these can cause defence responses in intact plants. These discoveries provide the basis for new crop protection strategies, that are either delivered by genetic modification of plants or by conventionally produced plants to which the signal is externally applied. Delivery can also be made by means of mixed seed strategies in which the provoking and recipient plants are grown together. Related signalling discoveries within the rhizosphere seem set to extend these approaches into new ways of controlling weeds, by exploiting the elusive potential of allelopathy, but through signalling rather than by direct physiological effects.

Animals↗
PubMed2002

[Plants and plant produce--about plants as cause of diseases].

BACKGROUND: Plants and plant products may lead to a variety of skin disorders, commonly referred to as phytodermatoses. MATERIAL AND METHODS: On the basis of literature studies and on the author's own experience, this article discusses the main groups of phytodermatoses, focusing on Norwegian plants that may cause skin disorders. RESULTS: A small number of plant families account for more than 95% of the phytodermatoses. Contact allergy to plants of the Compositae family is an important cause of skin disorder. Phytodermatoses are commonly related to the patient's occupation. INTERPRETATION: Doctors should be familiar with the term phytodermatoses and be aware of plants and plant products as possible causes of skin disorder.

Asteraceae↗
PubMed1992

Interactions of plant zinc and plant species on the bioavailability of plant cadmium to Japanese quail fed lettuce and spinach.

Many cadmium-contaminated environments contain high levels of zinc. The effects of plant Zn and plant species on plant Cd bioavailability were tested in Japanese quail fed lettuce and spinach. Four groups of birds received 10% of their diets as lettuce or spinach leaves intrinsically labeled with 109Cd and containing low or high intrinsic Zn. Two other groups were fed control diets containing 109Cd as CdSO4 and low or high Zn as ZnCO3. Cadmium concentrations in diets ranged from 0.857 to 1.05 micrograms/g dry wt. Zinc concentrations in low-Zn diets ranged from 21.2 to 22.8, and in high-Zn diets from 56.0 to 63.3 micrograms/g dry wt. Increased lettuce and spinach Zn decreased plant Cd retention in kidney, liver, and jejunum-ileum of Japanese quail. Spinach Cd was less absorbed than lettuce Cd at both Zn levels. Inorganic Zn produced a lesser decrease in Cd retention in kidney, liver, and jejunum-ileum than did plant Zn. We conclude that (1) crops that transport Zn and Cd readily into edible tissues show lower Cd bioavailability when grown in Zn-Cd contaminated environments than in Cd-only polluted sites, (2) plant species differ in Cd bioavailability for identical concentrations of Zn and Cd in edible tissues, and (3) toxicological studies with animals exposed to Cd salts and Zn supplements do not assess Cd bioavailability of Zn-Cd contaminated crops.

Absorption↗
PubMed2001

[Studies on original plant of traditional Chinese drug "bai zhi" (radix Angelicae Dahuricae) and its closely related wild plants. II. Karyological and pollen morphological studies on "bai zhi" and closely related wild plants].

OBJECTIVE: To supplement cytobiological and pollen morphological data for confirming the original plant of traditional Chinese drug "Bai Zhi". METHOD: Karyological study and pollen observation were made on "Bai Zhi" and its closely related wild plants. RESULT: Similarities and differences of "Bai Zhi" and its closely related wild plants were found. CONCLUSION: 1. 4 cultivated breeds of "Bai Zhi", Angelica dahurica, A. dahurica var. formosana, A. porphyrocaulis are really closely related plants. 2. A. dahurica var. formosana is closer to traditional Chinese drug "Bai Zhi" than others.

Angelica↗
PubMed1990

How plants respond to stimuli. The Ninth Annual Symposium on Current Topics in Plant Biochemistry and Physiology sponsored by the University of Missouri Interdisciplinary Program in Plant Biochemistry and Physiology, the US Department of Agriculture, and the National Science Foundation, Columbia, MO, USA, April 4-7, 1990.

With the rapid progress in the identification of the molecular components of calcium and protein kinase regulatory systems, it is presently an exciting time for those studying plant signal transduction. A clear message that was conveyed at the meeting was the need for an interdisciplinary approach to the problems currently facing researchers in this area. Thus, while the powerful methods of plant molecular biology allow for rapid advances in the identification of new molecules, this approach needs to be combined with careful biochemical and physiological analyses. This was exemplified by the large number of protein kinases described at the meeting but the surprisingly few reports of physiological function of phosphorylation. Similarly, while calcium has emerged as a major regulatory molecule in plants, little is known regarding the exact molecular mechanisms of calcium and calcium-modulatory protein action. These are clearly areas for future study that should reveal the elusive pathways that lie between stimuli and responses in the plant cell.

Calcium↗
PubMed2001

[Studies on original plant of traditional Chinese drug "bai zhi" (radix Angelicae Dahuricae) and its closely related wild plants. III. Comparison of coumarins of "bai zhi" with those of closely related wild plants].

OBJECTIVE: To provide chemical data for confirming the original plant of traditional Chinese drug "Bai Zhi". METHOD: Coumarins of 4 cultivated breeds of "Bai Zhi" and 3 closely related wild plants, together with other 2 Angelica plants were compared by HPLC. RESULT: According to coumarin patterns, 4 cultivated breeds of "Bai Zhi" and 3 closely related wild plants could be divided into 3 groups: 1. 4 cultivated breeds of "Bai Zhi" ("Chuan Bai Zhi", "Hang Bai Zhi", "Qi Bai Zhi" and "Yu Bai Zhi") and Angelica dahurica var. formosana; 2. A. dahurica; 3. A. porphyrocaulis. CONCLUSION: In point of the coumarin components, A. dahurica var. formosana is closer to traditional Chinese drug "Bai Zhi" than the others.

Angelica↗
PubMed2002

Impact of grazing on plant species richness, plant biomass, plant attribute, and soil physical and hydrological properties of vertisol in East African highlands.

Understanding the problems of grazing land in vertisol areas and seeking long-lasting solutions is the central point where mixed crop livestock is the second stay for the majority of the population. In order to understand this, the current study was conducted at two sites, one with 0-4% slope and the other with 4--8% slope at Ginchi watershed, 80 km west of Addis Ababa, Ethiopia. The specific objectives of the study were to quantify changes in plant species richness, biomass, plant cover, and soil physical and hydrological properties. The grazing regimes were: moderate grazing (regulated), heavy grazing (free grazing), and no grazing (closed to any grazing), which was considered the control treatment. The results showed that the biomass yield in nongrazed plots was higher than in the grazed plots. However, the biomass yield in grazed plots improved over the years. Species richness and percentage of dominant species attributes were better in medium grazed plots than the other treatments. Soil compaction was higher in very heavily grazed plots than in nongrazed and medium-grazed plots. In contrast to that, the soil water content and infiltration rate were better in nongrazed plots than in grazed plots. Soil loss in grazed plots decreased with the increase of biomass yields and as the soil was more compacted by livestock trampling during the wet season. Finally since the medium stocking rate is better in species richness and plant attributes, and lies between nongrazed and heavily grazed plots in the rest of the measured parameters, it could be the appropriate stocking rate to practice by the smallholder farmer.

Africa, Eastern↗
PubMed2001

[Studies on original plant of traditional Chinese drug "bai zhi" (radix Angelicae Dahuricae) and its closely related wild plants. I. Morphological and anatomical studies on "bai zhi" and closely related wild plants].

OBJECTIVE: To supplement morphological and anatomical data for confirming the original plant of traditional Chinese drug "Bai Zhi" (Radix Angelicae Dahuricae). METHOD: Morphologocal observation and anatomical study were made on 4 cultivated breeds and closely related wild plants of "Bai Zhi". RESULT: According to morphological and anatomical characteristics discovered in this paper, 7 samples noted above could be divided into 3 groups: 1. 4 breeds ("Chuan Bai Zhi", "Hang Bai Zhi", "Qi Bai Zhi" and "Yu Bai Zhi") and Angelica dahurica var. formosana; 2. A. dahurica; 3. A. porphyrocaulis. CONCLUSION: In the morphological and anatomical point of view, A. dahurica var. formosana is closer to traditional Chinese drug "Bai Zhi" than others.

Angelica↗
PubMed2001

Small plants, large plants: the importance of plant size for the physiological ecology of vascular epiphytes.

Recently, a number of publications have reported that many physiological properties of vascular epiphytes are a function of plant size. This short review will summarize what is known to date about this phenomenon, describe the possible mechanism and will discuss the consequences for the present understanding of epiphyte biology. Size-related changes are also known from other plant groups and it is argued that close attention should be paid to the size of the organisms under study in order to understand the performance and survival of a species in the field. In the light of these findings, the results of many earlier studies on epiphyte ecophysiology are now difficult to interpret because essential information on the size of the specimens used is missing.

Adaptation, Physiological↗
PubMed1999

Environmental behavior of explosives in groundwater from the Milan Army Ammunition Plant in aquatic and wetland plant treatments. Removal, mass balances and fate in groundwater of TNT and RDX.

Phytoremediation of 2,4,6-trinitrotoluene (TNT) and hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) in groundwater using constructed wetlands is a potentially economical remediation alternative. To evaluate Explosives removal and fate was evaluated using hydroponic batch incubations of plant and substrate treatments with explosives-contaminated groundwater amended with [U-14C]-TNT or [U-14C]-RDX. Plants and substrates were collected from a small-scale wetland constructed for explosives removal, and groundwater originated from a local aquifer at the Milan Army Ammunition Plant. The study surveyed three aquatic, four wetland plant species and two substrates in independent incubations of 7 days with TNT and 13 days with RDX. Parent compounds and transformation products were followed using 14C and chemical (HPLC) analyses. Mass balance of water, plants, substrates and air was determined. It was demonstrated that TNT disappeared completely from groundwater incubated with plants, although growth of most plants except parrot-feather was low in groundwater amended to contain 1.6 to 3.4 mg TNT L-1. Highest specific removal rates were found in submersed plants in water star-grass and in all emergent plants except wool-grass. TNT declined less with substrates, and least in controls without plants. Radiolabel was present in all plants after incubation. Mineralization to 14CO2 was very low, and evolution into 14C-volatile organics negligible. RDX disappeared less rapidly than TNT from groundwater. Growth of submersed plants was normal, but that of emergent plants reduced in groundwater amended to contain 1.5 mg RDX L-1. Highest specific RDX removal rates were found in submersed plants in elodea, and in emergent plants in reed canary grass. RDX failed to disappear with substrates. Mineralization to 14CO2 was low, but relatively higher than in the TNT experiment. Evolution into 14C-volatile organics was negligible. Important considerations for using certain aquatic and wetland plants in constructed wetlands aimed at removing explosives from water are: (1) plant persistence at the explosives level to which it is exposed, (2) specific plant-mass based explosives removal rates, (3) plant productivity, and (4) fate of parent compounds and transformation products in water, plants, and sediments.

Environmental Pollution↗
PubMed2000

Expression of the plant cyclin-dependent kinase inhibitor ICK1 affects cell division, plant growth and morphology.

The plant CDK inhibitor ICK1 was identified previously from Arabidopis thaliana with its inhibitory activity characterized in vitro. ICK1 displayed several structural and functional features that are distinct from known animal CDK inhibitors. Despite the initial characterization, there is no information on the functions of any plant CDK inhibitor in plants. To gain insight into ICK1 functions in vivo and the role of cell division during plant growth and development, transgenic plants were generated expressing ICK1 driven by the cauliflower mosaic virus 35S promoter. In comparison to control plants, growth was significantly inhibited in transgenic 35S-ICK1 plants, with some plants weighing <10% of wild-type plants at the 3 week stage. Most organs of 35S-ICK1 plants were smaller. There were also modifications in plant morphology such as shape and serration of leaves and petals. The changes were so drastic that 35S-ICK1 plants with strong phenotype no longer resembled wild-type plants morphologically. Analyses showed that increased ICK1 expression resulted in reduced CDK activity and reduced the number of cells in these plants. Cells in 35S-ICK1 plants were larger than corresponding cells in control plants. These results demonstrate that ICK1 acts as a CDK inhibitor in the plant, and the inhibition of cell division by ICK1 expression has profound effects on plant growth and development. They also suggest that alterations of plant organ shape can be achieved by restriction of cell division.

Arabidopsis↗
PubMed2000

Plants experiencing chronic internal exposure to ionizing radiation exhibit higher frequency of homologous recombination than acutely irradiated plants.

Ionizing radiation (IR) is a known mutagen responsible for causing DNA strand breaks in all living organisms. Strand breaks thus created can be repaired by different mechanisms, including homologous recombination (HR), one of the key mechanisms maintaining genome stability [A. Britt, DNA damage and repair in plants, Annu. Rev. Plant. Phys. Plant Mol. Biol., 45 (1996) 75-100; H. Puchta, B. Hohn, From centiMorgans to basepairs: homologous recombination in plants, Trends Plant Sci., 1 (1996) 340-348.]. Acute or chronic exposure to IR may have different influences on the genome integrity. Although in a radioactively contaminated environment plants are mostly exposed to chronic pollution, evaluation of both kinds of influences is important. Estimation of the frequency of HR in the exposed plants may serve as an indication of genome stability. We used previously generated Arabidopsis thaliana and Nicotiana tabacum plants, transgenic for non-active versions of the beta-glucoronidase gene (uidA) [P. Swoboda, S. Gal, B. Hohn, H. Puchta, Intrachromosomal homologous recombination in whole plants, EMBO J., 13 (1994) 484-489; H. Puchta, P. Swoboda, B. Hohn, Induction of homologous DNA recombination in whole plants, Plant, 7 (1995) 203-210.] serving as a recombination substrate, to study the influence of acute and chronic exposure to IR on the level of HR as example of genome stability in plants. Exposure of seeds and seedlings to 0.1 to 10.0 Gy 60Co resulted in increased HR frequency, although the effect was more pronounced in seedlings. For the study of the influence of chronic exposure to IR, plants were grown on two chemically different types of soils, each artificially contaminated with equal amounts of 137Cs. We observed a strong and significant correlation between the frequency of HR in plants, the radioactivity of the soil samples and the doses of radiation absorbed by plants (in all cases r0.9, n=6, P<0.05). In addition, we noted that plants grown in soils with different chemical composition, but equal radioactivity, exhibited different levels of HR, dependent upon the absorbed dose of radiation. Remarkably, we observed a much higher frequency of HR in plants exposed to chronic irradiation when compared to acutely irradiated plants. Although acute application of 0.1-0.5 Gy did not lead to an increase of frequency of HR, the chronic exposure of the plants to several orders of magnitude lower dose of 200 muGy led to a 5-6-fold induction of the frequency of HR as compared to the control.

DNA Damage↗
PubMed2002

Plant-to-plant communication mediating in-flight orientation of Aphidius ervi.

Broad bean plants (Viciafaba) infested by the pea aphid, Acyrthosiphonpisum, play akey role in the in-flightorientation of the parasitoidAphidius ervi, by producing host-induced synomones (HIS). These volatiles are herbivore-specific and are systemically released from insect-free parts of an infested plant, suggesting the existence of an elicitor circulating throughout the plant. This study was designed to investigate whether the plant metabolic changes, leading to HIS biosynthesis and emission, can in some way trigger similar responses in neighboring plants through aerial and/or root communication. Uninfested broad bean plants maintained in the same pot together with plants infested by A. pisum became more attractive towards A. ervi females when tested in a wind-tunnel bioassay. This change was not observed when root contact was prevented among plants that had their aerial parts in close proximity, suggesting that an exudate from the roots of the infested plant may cause the induction of the attractive volatiles in uninfested plants. Broad bean plants grown hydroponically also produce pea aphid induced signals that attract A. ervi. When an intact (uninfested) plant was placed in a hydroponic solution previously used to grow a pea aphid-infested plant, it became attractive to parasitoids, while an intact plant placed in a solution previously used to grow an intact plant did not undergo such a change. These results indicate that plant-to-plant signaling in this tritrophic system may occur at the rhizosphere level and is most likely mediated by a systemically translocated elicitor.

Animals↗
PubMed2001

Systemic spread of an RNA insect virus in plants expressing plant viral movement protein genes.

Flock house virus (FHV), a single-stranded RNA insect virus, has previously been reported to cross the kingdom barrier and replicate in barley protoplasts and in inoculated leaves of several plant species [Selling, B. H., Allison, R. F. & Kaesberg, P. (1990) Proc. Natl. Acad. Sci. USA 87, 434-438]. There was no systemic movement of FHV in plants. We tested the ability of movement proteins (MPs) of plant viruses to provide movement functions and cause systemic spread of FHV in plants. We compared the growth of FHV in leaves of nontransgenic and transgenic plants expressing the MP of tobacco mosaic virus or red clover necrotic mosaic virus (RCNMV). Both MPs mobilized cell-to-cell and systemic movement of FHV in Nicotiana benthamiana plants. The yield of FHV was more than 100-fold higher in the inoculated leaves of transgenic plants than in the inoculated leaves of nontransgenic plants. In addition, FHV accumulated in the noninoculated upper leaves of both MP-transgenic plants. RCNMV MP was more efficient in mobilizing FHV to noninoculated upper leaves. We also report here that FHV replicates in inoculated leaves of six additional plant species: alfalfa, Arabidopsis, Brassica, cucumber, maize, and rice. Our results demonstrate that plant viral MPs cause cell-to-cell and long-distance movement of an animal virus in plants and offer approaches to the study of the evolution of viruses and mechanisms governing mRNA trafficking in plants as well as to the development of promising vectors for transient expression of foreign genes in plants.

Biological Transport↗