Plants (Total 139242 Papers Found)

Small RNAs, including microRNAs (miRNAs) and short interfering RNAs (siRNAs), are key components of an evolutionarily conserved system of RNA-based gene regulation in eukaryotes. They are involved in many molecular interactions, including defense against viruses and regulation of gene expression during development. miRNAs interfere with expression of messenger RNAs encoding factors that control developmental timing, stem cell maintenance, and other developmental and physiological processes in pl ...
Six members of a multigene family encoding polypeptide constituents of the fucoxanthin, chlorophyll a/c protein complex from female gametophytes of the brown alga Macrocystis pyrifera have been cloned and characterized. The deduced amino acid sequences are very similar to those of fucoxanthin chlorophyll binding proteins (Fcp) from the diatom Phaeodactylum tricornutum and exhibit limited homology to chlorophyll a/b binding (Cab) polypeptides from higher plants. The primary translation products f ...
In order to maximize their use of light energy in photosynthesis, plants have molecules that act as light-harvesting antennae, which collect light quanta and deliver them to the reaction centres, where energy conversion into a chemical form takes place. The functioning of the antenna responds to the extreme changes in the intensity of sunlight encountered in nature. In shade, light is efficiently harvested in photosynthesis. However, in full sunlight, much of the energy absorbed is not needed an ...
Genetic analysis of host specificity in the rice blast fungus (Magnaporthe grisea) identified a single gene, PWL2 (for Pathogenicity toward Weeping Lovegrass), that exerts a major effect on the ability of this fungus to infect weeping lovegrass (Eragrostis curvula). The allele of the PWL2 gene conferring nonpathogenicity was genetically unstable, with the frequent appearance of spontaneous pathogenic mutants. PWL2 was cloned based on its map position. Large deletions detected in pathogenic mutan ...
Among the three subunits of [beta]-conglycinin, the 7S seed storage protein of soybean (Glycine max [L.] Merr.), expression of the [beta] subunit gene is unique. Accumulation of the [beta] subunit is enhanced in sulfate-deficient soybean plants, and its mRNA levels increase when abscisic acid (ABA) is added to the in vitro cotyledon culture medium. Transgenic Arabidopsis thaliana lines carrying a gene encoding the [beta] subunit was constructed and grown under sulfate deficiency. Accumulation of ...
The use of medicinal plants for the prevention and treatment of gastro-intestinal parasitism has its origin in ethnoveterinary medicine. Although until recently the majority of the evidence on the antiparasitic activity of medicinal plants was anecdotal and lacked scientific validity, there is currently an increasing number of controlled experimental studies that aim to verify and quantify such plant activity. There are indeed a large number of plants whose anthelmintic activity has been demonst ...
The accumulation of free lysine in tobacco seed triggers the stimulation of lysine-ketoglutarate reductase, an enzyme that acts in lysine catabolism. The mechanism of lysine-ketoglutarate reductase stimulation was studied in two different systems: (1) developing seeds of wild-type plants in which the low basal lysine-ketoglutarate reductase activity can be stimulated by the exogenous addition of lysine; and (2) developing seeds of transgenic tobacco plants expressing a bacterial dihydrodipicolin ...
We have constructed three tobacco mosaic virus (TMV) cDNA derivatives by modification of the full-length cDNA clone from which infectious TMV-RNA can be transcribed in vitro. A coatless TMV construct lacks most of the coat protein gene and chimeric TMV constructs retain the bacterial chloramphenicol acetyltransferase (CAT) gene in place of the coat protein gene. When in vitro transcripts from these cDNA derivatives were inoculated on the local lesion tobacco plants, TMV-specific lesions were pro ...
To characterize the mechanism through which myosin XI-K attaches to its principal endomembrane cargo, a yeast two-hybrid library of Arabidopsis thaliana cDNAs was screened using the myosin cargo binding domain as bait. This screen identified two previously uncharacterized transmembrane proteins (hereinafter myosin binding proteins or MyoB1/2) that share a myosin binding, conserved domain of unknown function 593 (DUF593). Additional screens revealed that MyoB1/2 also bind myosin XI-1, whereas myo ...
To depolymerize plant pectin, the phytopathogenic enterobacterium Erwinia chrysanthemi produces a series of enzymes which include a pectin-methyl-esterase encoded by the pem gene and five isoenzymes of pectate lyases encoded by the five genes pelA, pelB, pelC, pelD, and pelE. We have constructed transcriptional fusions between the pectinase gene promoters and the uidA gene, encoding beta-glucuronidase, to study the regulation of these E. chrysanthemi pectinase genes individually. The transcripti ...
A new phenylpropanoid glycoside, pedicularioside A, and five known glycosides, acteoside, isoacteoside, decaffeoylacteoside, echinacoside and 8-acetylharpagide, were isolated from whole plants of Pedicularis striata. On the basis of spectral and chemical evidence, pedicularioside A was shown to be 1'-O-beta-D-(3,4-dihydroxy-beta-phenyl)-ethyl-4'-O-caffeoyl-beta-D -apiosyl-(1----3')-alpha-L-rhamnosyl-(1----6')-glucopyranosi de. ...
This work studied the antinociceptive, antiinflammatory and bronchodilator activities of hydroalcoholic extracts (HAEs) from Torresea cearensis, Justicia pectoralis, Eclipta alba, Pterodon polygaliflorus and Hybanthus ipecacuanha. These plants are largely used in north-eastern Brazil for respiratory tract diseases, and have in common coumarin, one of their active principles. The antinociceptive effects of all HAEs in mice were similar, and the inhibition of the acetic acid-induced writhing was 3 ...
The mutualistic basidiomycete Piriformospora indica colonizes roots of mono- and dicotyledonous plants, and thereby improves plant health and yield. Given the capability of P. indica to colonize a broad range of hosts, it must be anticipated that the fungus has evolved efficient strategies to overcome plant immunity and to establish a proper environment for nutrient acquisition and reproduction. Global gene expression studies in barley identified various ethylene synthesis and signaling componen ...
The colonization pattern of Vitis vinifera L. by Burkholderia phytofirmans strain PsJN was determined using grapevine fruiting cuttings with emphasis on putative inflorescence colonization under nonsterile conditions. Two-week-old rooted plants harbouring flower bud initials, grown in nonsterile soil, were inoculated with PsJN:gfp2x. Plant colonization was subsequently monitored at various times after inoculation with plate counts and epifluorescence and/or confocal microscopy. Strain PsJN was c ...
We monitored the last remaining Pennsylvania population of the regal fritillary butterfly (Speyeria idalia) for 8 years (1997–2005) at Fort Indiantown Gap, a National Guard training facility located in south-central Pennsylvania, USA. We observed demes of this population in five grassland areas, four of which received limited protection from anthropogenic military activities (i.e., motorized vehicles were prohibited). The Pollard walk technique allowed us to make estimates of butterfly densit ...
Filipendula ulmaria (L.) Maxim (meadowsweet) is a medicinal plant that is claimed to have several biological activities, including anti-tumor, anti-carcinogenic, anti-oxidant, anti-coagulant, anti-ulcerogenic, anti-microbial, anti-arthritic, and immunomodulatory properties. This report describes, for the first time, an efficient plant regeneration system for F. ulmaria via adventitious shoot development from leaf, petiole, and root explants cultured on Murashige and Skoog’s minimal organics me ...
Vacuoles were isolated from different plant cell cultures and the transport mechanism for alkaloid uptake at the tonoplast membrane, as well as the compartmentation of enzymes and products inside the cells were investigated. While serpentine, the major alkaloid of Catharanthus roseus cells, is definitely located inside the vacuole, two key enzymes of the indole-alkaloid pathway, strictosidine synthase and a specific glucosidase, are located in the cytosol. Transport of alkaloids across the tonop ...
Mahonia bealei (Berberidaceae) is a frequently-used traditional Chinese medicinal plant with efficient anti-inflammatory ability. This plant is one of the sources of berberine, a new cholesterol-lowering drug with anti-diabetic activity. We have sequenced the complete nucleotide sequence of the chloroplast (cp) genome of M. bealei. The complete cp genome of M. bealei is 164,792 bp in length, and has a typical structure with large (LSC 73,052 bp) and small (SSC 18,591 bp) single-copy regions sepa ...
An analysis is introduced, based on the decomposition of relative growth rates, to examine the mode of competition (i.e. whether competition is symmetric or asymmetric), the size-dependence of growth, and their interdependence. In particular, the basis for two commonly held views is examined: (1) that the type of resource limitation determines the mode of competition, and (2) that asymmetric competition always leads to size-divergence between unequal competitors. It is shown that in field-grown ...
Cymbopogon citratus and Eucalyptus citriodora are widely used herbs/plants as a source of ethnomedicines in tropical regions of the world. In this work, we studied the anti-inflammatory and gastroprotective effects of C. citratus and E. citriodora essential oils on formol-induced edema, and acetic acid induced abdominal cramps in Wistar rats. To fully understand the chemically induced anti-inflammatory properties of these plants, we first analyzed the chemical composition of the essential oils. ...
Thermal energy storage can enhance the utility of parabolic trough solar power plants by providing the ability to match electrical output to peak demand periods. An important component of thermal energy storage system optimization is selecting the working fluid used as the storage media and/or heat transfer fluid. Large quantities of the working fluid are required for power plants at the scale of 100-MW, so maximizing heat transfer fluid performance while minimizing material cost is important. T ...
Interspecific F1 hybrids were obtained from a cross between Cucumis sativus L. (2n = 2x = 14) and C. hystrix Chakr. (2n = 2x = 24). Controlled crossing resulted in fruit containing embryos which were excised and rescued on a Murashige and Skoog solid medium. A total of 59 vigorous plants were obtained from a fruit containing 159 embryos (37.3% regeneration rate). Hybrid plants were morphologically uniform. The multiple branching habit, densely brown hairs (especially on corolla and pistil), oran ...
The purpose of this study was to investigate effects of N nutrition and water stress on stomatal behavior and CO(2) exchange rate in wheat (Triticum aestivum L. cv Olaf). Wheat plants were grown hydroponically with high (100 milligrams per liter) and low (10 milligrams per liter) N. When plants were 38 days old, a 24-day water stress cycle was begun. A gradual increase in nutrient solution osmotic pressure from 0.03 to 1.95 mega Pascals was achieved by incremental additions of PEG-6,000. Plants ...
Studies on the fine structure of green algal cells in the 1970s fundamentally revised theories on the evolution of green algae (Division Chlorophyta) and their relation to higher and drier green plants (i.e. embryophytes or land plants). Recent molecular phylogenetic work has largely confirmed some rather unorthodox proposals about which of the green algae represent the closest living relatives of higher plants. Resolution of the most ancient divergences on the green algal-land plant lineage rem ...
The carbohydrate moieties of arabinogalactan proteins (AGPs) are essential for their physiological functions and undergo rapid turnover in vivo. Degradation of the carbohydrate moieties of AGPs seems to occur by concerted action of several glycosidases, among them a-L-arabinofuranosidase, b-Dgalactosidase, and b-D-glucuronidase. Here, a bifunctional a-L-arabinofuranosidase/b-D-xylosidase from immature seeds of radish (Raphanus sativus L.), which hydrolyses a-L-arabinofuranosyl residues of the ca ...
Phototropic and gravitropic curvature by hypocotyls of Arabidopsis thaliana is minimal when the side of the hook with the cotyledons attached is positioned toward the direction of tropistic curvature, and maximal when that side of the hook is positioned away from the direction of tropistic curvature. Based on these data, it is proposed that the position of the hook with attached cotyledons affects curvature and not stimulus perception. A randomly oriented population of plants exhibited conside ...
The mortality and morbidity rates of pancreatic cancer are high because of its extremely invasive and metastatic nature. Its lack of symptoms, late diagnosis and chemo-resistance and the ineffective treatment modalities warrant the development of new chemo-therapeutic agents for pancreatic cancer. Agents from medicinal plants have demonstrated therapeutic benefits in various human cancers. Nimbolide, an active molecule isolated from Azadirachta indica, has been reported to exhibit several medici ...
Drought-induced forest dieback appears to have increased in frequency over the last decade (Van Mantgem et al. 2009; Allen et al. 2010; Peng et al. 2011). These diebacks have occurred across a wide diversity of forest types, suggesting that no forest biome is invulnerable to climate change (Choat et al. 2012). However, drought-influenced mortality rates differ substantially between species growing at the same site (Breshears et al. 2005) and populations within the species’ distribution range ( ...
The rice genome contains at least 28 EXPA (α-expansin) genes. We have obtained near full-length cDNAs from the previously uncharacterized genes. Analysis of these newly identified clones together with the 12 identified earlier showed that the EXPA genes contain up to two introns and encode proteins of 240 to 291 amino acid residues. The EXPA proteins contain three conserved motifs: eight cysteine residues at the N-terminus, four tryptophan residues at the C-terminus, and a histidinephenylalanin ...
Chepang, inhabiting the rugged terrain of Mahabharat and Churia range in central Nepal, is a group of indigenous people suffering from severe food insecurity. Their ancestors lived a semi-nomadic life up to one and half century back. To a large extent, Chepang still continue their traditional way of living, which includes collection of wild tubers (‘kandamul’), hunting and fishing. Chepangs are especially connected with the tubers of Dioscorea spp. Wild and cultivated species of Dioscorea ar ...
DNA was isolated from clover proliferation (CP) mycoplasmalike organism (MLO)-diseased periwinkle plants (Catharanthus roseus (L.) G. Don.) and cloned into pSP6 plasmid vectors. CP MLO-specific recombinant DNA clones were biotin labeled and used as probes in dot hybridization and restriction fragment length polymorphism analyses to study the genetic interrelatedness among CP MLO and other MLOs, including potato witches'-broom (PWB) MLO. Results from dot hybridization analyses indicated that both ...
In this study, a colorimetric whole-cell biosensor for cadmium (Cd) was designed using a genetically engineered red pigment producing bacterium, Deinococcus radiodurans. Based on the previous microarray data, putative promoter regions of highly Cd-inducible genes (DR_0070, DR_0659, DR_0745, and DR_2626) were screened and used for construction of lacZ reporter gene cassettes. The resultant reporter cassettes were introduced into D. radiodurans R1 to evaluate promoter activity and specificity. Amo ...
Biochemical and genetic studies have identified peptides that play crucial roles in plant defense, growth, and development. The number of known, functionally active, peptides is currently small, but genome sequencing has revealed many potential peptide-encoding genus. A major challenge of the post-genomic era is to determine the function of these molecules. ...
Leaf demography, seasonal changes in leaf quality and leaf-beetle herbivory of a herbaceous perennial plant, Sanguisorba tenuifolia, were compared between low- and high-elevation sites. Leaf nitrogen concentration was higher and leaf mass per area (LMA) was lower at the higher site than at the lower one. At the lower site, with a long growth period, plants produced many leaf cohorts and leaves emerged throughout the growing season. At the higher site, with a short growth period, however, leaf em ...
The purpose of this study is to determine the flowering requirements of Polymnia canadensis and how they correspond to the occurrence of winter annuals, biennials, and short-lived monocarpic perennials in this species. Polymnia canadensis has a vernalization requirement for flowering, and even very small plants (i.e., those with one pair of leaves) can be vernalized. Vernalized plants can flower under both long- and short days. However, to flower plants must attain a minimum postvernalization si ...
The glucosinolate(GS)-myrosinase system of Brassicaceae, including the model plant Arabidopsis thaliana (L.), comprises a defence which is effective especially against generalist herbivores. Based on their side chain structure GS are grouped into aliphatic, aromatic, and indolyl GS. Indolyl GS are widely distributed among A. thaliana ecotypes and the Brassicaceae family, but the presence of aliphatic GS is variable and under strong genetic control. We investigated the effect of AOP gene expressi ...
Sixty-two partial formyltetrahydrofolate synthetase (FTHFS) structural gene sequences were recovered from roots of salt marsh plants, including Spartina alterniflora, Salicornia virginica, and Juncus roemerianus. Only S. alterniflora roots yielded sequences grouping with FTHFS sequences from known acetogens. Most other FTHFS or FTHFS-like sequences grouped with those from sulfate-reducing bacteria. Several sequences that grouped with Sphingomonas paucimobilis ligH were also recovered. ...
SIGNIFICANCE Reactive oxygen species (ROS), important signaling molecules in plants, are involved in developmental control and stress adaptation. ROS production can trigger broad transcriptional changes; however, it is not clear how specificity in transcriptional regulation is achieved. RECENT ADVANCES A large collection of public transcriptome data from the model plant Arabidopsis thaliana is available for analysis. These data can be used for the analysis of biological processes that are asso ...
The leaf is the main photosynthetic organ of plants and its development a complex process governed by a combination of environmental factors and intrinsic and genetically regulated signals (Van Lijsebettens & Clarke, 1998). Usually, leaf ontogeny includes an early phase of increasing photosynthetic rates while the leaf is actively expanding, a mature phase where such rates peak and a senescence phase where they decline (Gepstein, 1988; Miller et al., 2000). During early development, the leaf is ...
ETHNOPHARMACOLOGICAL RELEVANCE Medicinal plant complexes of different species sharing vernacular names, morphological and aromatic characteristics and uses are common in traditional medicine of different cultures. A quantitative methodology as a tool for ethnopharmacological studies is presented for systematically analyzing morphological and therapeutic features shared by several species integrating such complexes. AIM OF THE STUDY The aim of this paper is to apply a novel methodology to deter ...
Ectopic expression of viral movement proteins (MPs) has previously been shown to alter plasmodesmata (PD) function and carbon partitioning in transgenic plants, giving rise to the view of PD being dynamic and highly regulated structures that allow resource allocation to be adapted to environmental and developmental needs. However, most work has been restricted to solanaceous species and the potential use of MP expression to improve biomass and yield parameters has not been addressed in detail. H ...
The discovery of a gene that encodes a cotton (Gossypium hirsutum) cellulose synthase (Pear et al., 1996) revolutionized and invigorated the plant cell wall community to find the genes that encode the machinery of cell wall polysaccharide synthesis. The landscape was framed by the completion of the genome sequence of Arabidopsis (Arabidopsis thaliana; Arabidopsis Genome Initiative, 2000), which gave a complete gene inventory for a model plant species, but one with many genes yet to be annotated ...
Tropical forests have a mitigating effect on man-made climate change by acting as a carbon sink. For that effect to continue, tropical trees will have to acclimate to rising temperatures, but it is currently unknown whether they have this capacity. We grew seedlings of three tropical tree species over a range of temperature regimes (TGrowth = 25, 30, 35 °C) and measured the temperature response of photosynthetic CO2 uptake. All species showed signs of acclimation: the temperature-response curve ...
Endophytic fungi are major contributors to fungal diversity and an important component of plant microbiota. Plants growing in biodiversity hotspots and having ethnobotanical utility are often explored for the presence of endophytic fungi with bioactive potential. Western Ghat mountains of India are one of the ten famous biodiversity hotspots in the world. Hence, in the present study, we investigated the diversity of endophytic fungi associated with tissues of Nothapodytes foetida (a tree), Hyper ...
The Glossy2 (Gl2) locus of maize is required for the formation of the epicuticular wax layer of young plants. gl2 mutant seedlings can be visually identified because of their glossy leaf surface which is different from the dull surface of wild-type seedlings. The Gl2 locus was isolated by transposon tagging. Seven unstable mutations, gl2-m2 to gl2-m8, were induced in a parental strain carrying an active transposable Activator (Ac) element in the unstable wx-m7 allele. Genetic tests on the gl2-m2 ...
Holoparasitic plants such as Orobanche spp. have lost their photosynthetic ability, so photoresponses to optimize photosynthesis are not necessary in these plants. Photoresponses are also involved in the regulation of plant development but the photoresponses of holoparasites have not been characterized in detail. In this study, the phytochrome (phy)-related photoresponse of Orobanche minor was investigated. Its photoreceptor, phytochrome A (OmphyA), was also characterized. Light effects on germi ...
BACKGROUND AND AIMS Trithuria is the sole genus of Hydatellaceae, a family of the early-divergent angiosperm lineage Nymphaeales (water-lilies). In this study different arabinogalactan protein (AGP) epitopes in T. submersa were evaluated in order to understand the diversity of these proteins and their functions in flowering plants. METHODS Immunolabelling of different AGPs and pectin epitopes in reproductive structures of T. submersa at the stage of early seed development was achieved by immun ...