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1

Prezygotic barriers to gene flow between Taraxacum ceratophorum and the invasive Taraxacum officinale (Asteraceae)  

Microsoft Academic Search

Prezygotic reproductive barriers limit interspecific gene flow between congeners. Here, I examine the strength of floral isolation\\u000a and interspecific pollen-pistil barriers between an invasive apomictic, Taraxacum officinale, and the indigenous sexual alpine dandelion, Taraxacum ceratophorum. Experimental arrays of either native inflorescences or a mixture of native and exotic inflorescences were used to examine\\u000a insect preference and to track movement of

Marcus T. Brock

2009-01-01

2

Prezygotic barriers to gene flow between Taraxacum ceratophorum and the invasive Taraxacum officinale (Asteraceae).  

PubMed

Prezygotic reproductive barriers limit interspecific gene flow between congeners. Here, I examine the strength of floral isolation and interspecific pollen-pistil barriers between an invasive apomictic, Taraxacum officinale, and the indigenous sexual alpine dandelion, Taraxacum ceratophorum. Experimental arrays of either native inflorescences or a mixture of native and exotic inflorescences were used to examine insect preference and to track movement of a pollen analog. Using hand-pollinations, conspecific and heterospecific pollen germination success on native stigmas was compared. To additionally test for interspecific pollen competition, T. ceratophorum plants received one of three possible hand-pollinations: control conspecific pollination, concomitant conspecific and heterospecific pollination (mixed), or conspecific pollen followed by heterospecific pollen 15 min later (staggered). Floral isolation was negligible as no insect preference was detected. On a presence/absence basis, florets on native inflorescences received slightly less pollen analog from heterospecific donors than from conspecific donors; however, the amount of dye particles transferred from either Taraxacum species to stigmas on recipient T. ceratophorum inflorescences was equivalent. In contrast to weak floral isolation, strong pollen germination and pollen competition barriers should reduce the potential for hybridization. Heterospecific T. officinale pollen exhibited reduced germination success on T. ceratophorum stigmas in comparison to conspecific pollen. Furthermore, a significant pollen-competition effect on the percentage of hybrid offspring was detected only when T. officinale preceded T. ceratophorum pollen by 15 min. This result indicates that conspecific pollen out-competes heterospecific pollen but further suggests that biotic and abiotic factors reducing pollen accrual rates may partially remove barriers to natural hybridization. PMID:19504127

Brock, Marcus T

2009-08-01

3

Further investigations on the resilience capacity of Taraxacum officinale Weber growing on mine soils  

NASA Astrophysics Data System (ADS)

Heavy metal accumulation produces significant physiological and biochemical responses in vascular plants. Plants growing on abandoned mine sites are of particular interest, since they are genetically tolerant to high metal concentrations. In this work we examined the effect of heavy metals (HM) on the morphology of T. officinale growing on mine soils, with the following objectives: - to determine the fate of HM within the soil-plant system; - to highlight possible damage at anatomical and cytological level; - to assess the resilience capacity of Taraxacum officinale after three years of pot cultivation. Wild specimens of Taraxacum officinale Web, with their soil clod, were gathered from four sites with different contamination levels by heavy metals (Cu, Fe, Pb, Zn) in the abandoned Imperina Valley mine (Northeast Italy). Plants were cultivated in pots at the botanical garden of the University of Florence (HBF), and appeared macroscopically not affected by toxic signals (e.g. reduced growth, leaf necrosis) possibly induced by soil HM concentration. Leaves and roots taken at the same growing season were observed by light microscopy (LM) and transmission electron microscopy (TEM). Light microscopy observations show a clear difference in the cell organization of not-contaminated and contaminated samples. The unpolluted samples present a well organized palisade tissue and spongy photosynthetic parenchyma. Samples from contaminated sites, instead, present a palisade parenchyma less organized, and a reduction of leaf thickness proportional to HM concentration. The poor structural organisations, and the reduced foliar thickness of the contaminated plants, are related to soil contamination. Differences in roots micromorphology concern the cortical parenchyma. Moreover, all the samples examined present mycorrhiza. Ultrastructure observations of the parenchyma cells show mitochondrial structure alteration, with lacking or reduced cristae of the internal membrane at increasing metal content. Instead, chloroplast organization does not present significant differences, particularly in number and compartmentalization of thylakoids. Although macromorphology does not present evidence of phytotoxicity, the recorded observations of the micromorphological characteristics of leaves and roots, show a suffering state of the plants, strictly related to HM content. Leaching reduced partly the HM content of the soil, therefore decreasing their phytotoxic effect. A gradual restoration of leaf organization suggests that somewhat resilience occurred in plants. Moreover, the presence of stress-tolerant mycorrhizal fungi could contribute to reduce metal toxicity. The resilience capacity suggests that Taraxacum could be a useful species in remediation projects. Keywords: Heavy metals • Mine soils • Plant morphology • Taraxacum officinale • Ultrastructure

Maleci, Laura; Bini, Claudio; Spiandorello, Massimo; Wahsha, Mohammad

2014-05-01

4

Phenotypic plasticity and performance of Taraxacum officinale (dandelion) in habitats of contrasting environmental heterogeneity  

Microsoft Academic Search

Ecological theory predicts a positive association between environmental heterogeneity of a given habitat and the magnitude\\u000a of phenotypic plasticity exhibited by resident plant populations. Taraxacum officinale (dandelion) is a perennial herb from Europe that has spread worldwide and can be found growing in a wide variety of habitats.\\u000a We tested whether T. officinale plants from a heterogeneous environment in terms

Marco A. Molina-Montenegro; Cristian Atala; Ernesto Gianoli

2010-01-01

5

THE POTENTIAL FOR GENETIC ASSIMILATION OF A NATIVE DANDELION SPECIES, TARAXACUM CERATOPHORUM (ASTERACEAE), BY THE EXOTIC CONGENER T. OFFICINALE1  

Microsoft Academic Search

Exotic plant species can threaten closely related native congeners through asymmetric hybridization and subsequent backcrossing, the process known as genetic assimilation. I explore the initial stages of this process in Taraxacum ceratophorum(Asteraceae), the native alpine dandelion, and the invasive apomict T. officinale . In central Colorado, seven T. ceratophorum populations all occur in sympatry with T. officinale . In one

MARCUS T. B ROCK

6

Productivity differences between dandelion ( Taraxacum officinale ; Asteraceae) clones from pollution impacted versus non-impacted soils  

Microsoft Academic Search

Common dandelions (Taraxacum officinale Weber, sensu lato; Asteraceae) introduced to North America form an assemblage of asexual (agamospermous), clonal lineages derived from Eurasian mixed sexual\\u000a and asexual populations. We investigated whether selection for more pollution tolerant clonal lineages occurs at polluted\\u000a sites and selection for more pollution intolerant lineages occurs at unpolluted sites. We tested the above hypothesis by performing

Matthew H. Collier; Brian Keane; Steven H. Rogstad

2010-01-01

7

Pancreatic lipase inhibitory activity of taraxacum officinale in vitro and in vivo  

PubMed Central

Obesity has become a worldwide health problem. Orlistat, an inhibitor of pancreatic lipase, is currently approved as an anti-obesity drug. However, gastrointestinal side effects caused by Orlistat may limit its use. In this study the inhibitory activities of dandelion (Taraxacum officinale) against pancreatic lipase in vitro and in vivo were measured to determine its possible use as a natural anti-obesity agent. The inhibitory activities of the 95% ethanol extract of T. officinale and Orlistat were measured using 4-methylumbelliferyl oleate (4-MU oleate) as a substrate at concentrations of 250, 125, 100, 25, 12.5 and 4 µg/ml. To determine pancreatic lipase inhibitory activity in vivo, mice (n=16) were orally administered with corn oil emulsion (5 ml/kg) alone or with the 95% ethanol extract of T. officinale (400 mg/kg) following an overnight fast. Plasma triglyceride levels were measured at 0, 90, 180, and 240 min after treatment and incremental areas under the response curves (AUC) were calculated. The 95% ethanol extract of T. officinale and Orlistat, inhibited, porcine pancreatic lipase activity by 86.3% and 95.7% at a concentration of 250 µg/ml, respectively. T. officinale extract showed dose-dependent inhibition with the IC50 of 78.2 µg/ml. A single oral dose of the extract significantly inhibited increases in plasma triglyceride levels at 90 and 180 min and reduced AUC of plasma triglyceride response curve (p<0.05). The results indicate that T. officinale exhibits inhibitory activities against pancreatic lipase in vitro and in vivo. Further studies to elucidate anti-obesity effects of chronic consumption of T. officinale and to identify the active components responsible for inhibitory activity against pancreatic lipase are necessary. PMID:20016719

Zhang, Jian; Kang, Min-Jung; Kim, Myung-Jin; Kim, Mi-Eun; Song, Ji-Hyun; Lee, Young-Min

2008-01-01

8

Quality control of herbs: determination of amino acids in Althaea officinalis, Matricaria chamomilla and Taraxacum officinale.  

PubMed

Analysis of raw materials and final products need reliable methods for the standardization of natural product drugs. Legal guideline also emphasizes on the qualitative and quantitative analyses of the plant constituents in an herbal product. In this study, thin layer chromatography (TLC) and amino acid analyzer was used for the determination of amino acids in plant extracts. Samples for this study were standards and aqueous extracts from Althaea officinalis, Matricaria chamomilla and Taraxacum officinale. Different amino acids in the extracts were detected through TLC. An automatic amino acid analyzer was used for the quantification of amino acids in the plant extracts under study. PMID:24811801

Qureshi, Muhammad Nasimullah; Stecher, Guenther; Bonn, Guenther Karl

2014-05-01

9

A comparison of phenotypic plasticity in the native dandelion Taraxacum ceratophorum and its invasive congener T. officinale.  

PubMed

We compared plastic responses to variation in the light environment for sympatric populations of native and exotic dandelion species, Taraxacum ceratophorum and Taraxacum officinale. Plasticity in leaf size, inflorescence height, reproductive phenology and dispersal-related traits were measured under experimentally altered light quality (red : far-red light ratio, R : FR) and light intensity (photosynthetically active radiation, PAR). To test whether differences in means and reaction norms of dispersal-related traits between species affected colonization potential, we created seed-dispersal models based on seed-fall rate and release height. Differences in plasticity between species were not systematic, but varied in direction and magnitude among traits. Taraxacum officinale produced larger leaves that exhibited greater plasticity in size under variable light intensity than T. ceratophorum. Plasticity in scape length at flowering occurred in relation to R : FR ratio in both species, but tended to be greater in T. ceratophorum. Seed-bearing scapes of T. officinale were taller and more canalized in height across light regimes than scapes of T. ceratophorum. Seeds of T. officinale were smaller than seeds of T. ceratophorum. Models predict greater dispersal in T. officinale within open and vegetated habitats. In contrast to the idea that plasticity promotes invasiveness, results suggest that the lack of plasticity in dispersal-related traits enhances the colonization potential of T. officinale. PMID:15760361

Brock, Marcus T; Weinig, Cynthia; Galen, Candace

2005-04-01

10

Metal contamination in urban street sediment in Pisa (Italy) can affect the production of antioxidant metabolites in Taraxacum officinale Weber.  

PubMed

Taraxacum officinale Weber (dandelion) is a very ubiquitous species, and it can grow in urban environments on metal-polluted sediments deposited in the gutters. This study represents a preliminary step to verify the presence of metals in sediments collected in urban streets in Pisa and to assess the alteration in dandelion metabolites in order to understand its adaptation to polluted environments. The soil and sediments were collected at three urban streets and analyzed for total and extractable Cr, Pb, Cu, Ni, and Zn. The total values of Pb and Zn in street sediments exceeded the limits for residential areas of soils. Zn was the most mobile of the metals analyzed. Floating cultivations trials were set up with dandelion seedlings and street sediments. The metals were analyzed in roots and leaves. Antioxidant power, anthocyanins, polyphenols, non-protein thiols (NP-TH) and chlorophylls were measured in dandelion leaves. The first two parameters (anthocyanins and antioxidant power) were higher in the polluted samples compared to the control; chlorophyll content was lower in the treated samples, whereas NP-TH showed no differences. NP-TH groups determined in roots were associated with the root content of Zn and Pb. These results indicate that dandelion can tolerate plant stress by altering its metabolite content. PMID:24062063

Bretzel, Francesca; Benvenuti, Stefano; Pistelli, Laura

2014-02-01

11

Kairomone from dandelion,Taraxacum officinale, attractant for scarab beetleAnomala octiescostata.  

PubMed

The attraction of the scarab beetleAnomala octiescostata to dandelion,Taraxacum officinale, was demonstrated to be chemically mediated by a mixture ofcis-3-hexenyl acetate, benzaldehyde, phenylacetaldehyde, benzyl alcohol, phenethyl alcohol, phenylacetonitrile, and benzyl benzoate, in the ratio 4:8:14:3:5:19:11. Combination of the synthetic kairomone and sex pheromone (buibuilactone + japonilure, 8:2), significantly increased the total catches ofA. octiescostata. Catches of male (but not female) beetles were significantly higher with the kairomone-pheromone blend than with kairomone alone. The synergistic effect of the kairomone from dandelion on the attractiveness did not significantly differ from that of a food-type lure, anethol, geraniol, and phenethyl propionate (9:0.5:0.5). The latter combined with the synthetic sex pheromone resulted in better attraction of female (but not male)A. octiescostata than the sex pheromone alone. PMID:24242662

Leal, W S; Ono, M; Hasegawa, M; Sawada, M

1994-07-01

12

Effect of leaf extracts of Taraxacum officinale on CCl4 induced hepatotoxicity in rats, in vivo study.  

PubMed

Taraxacum officinale L is a medicinal plant, which has enormous medicinal values against various types of liver disorders and it has traditionally been used for the treatment of liver problems by people from the South East Asia. Previously we have screened the crude methanolic extract of T. officinale against cytotoxicity induced by CCl4. Present study was designed to compare the protective effect of ethanolic and n-hexane extract of leaves in carbon tetrachloride (CCl4) induced liver toxicity in rats. The extract (200 mg/kg and 400mg/kg body weight) along with silymarin (100 mg/kg) a standard drug was administered to experimental animals. It was observed that ethanolic plant extract has significantly reduced the negative effect of CCl4 as compared to n-hexane extract and effect of extract was increased with increasing dose level. Although both leaf extracts decreased the concentration of TBARS, H2O2 and nitrite contents which enhance due to CCl4 toxicity but effect was higher in ethanolic extract. The results clearly indicated that Taraxacum officinale ethanolic leaves extract has better protective effect against CCl4 induced liver tissues toxicity. This claim was also supported by histopathological results obtained during this study and this might be due to presence of various polar phytochemicals that might be more prevent in this extract. PMID:25015447

Gulfraz, Muhammad; Ahamd, Dawood; Ahmad, Muhammad Sheeraz; Qureshi, Rehmatullah; Mahmood, Raja Tahir; Jabeen, Nyla; Abbasi, Kashif Sarfraz

2014-07-01

13

The potential for genetic assimilation of a native dandelion species, Taraxacum ceratophorum (Asteraceae), by the exotic congener T. officinale.  

PubMed

Exotic plant species can threaten closely related native congeners through asymmetric hybridization and subsequent backcrossing, the process known as genetic assimilation. I explore the initial stages of this process in Taraxacum ceratophorum (Asteraceae), the native alpine dandelion, and the invasive apomict T. officinale. In central Colorado, seven T. ceratophorum populations all occur in sympatry with T. officinale. In one large population on Pennsylvania Mountain, surveys further revealed that flowering phenologies and visiting insect taxa overlap almost completely for both Taraxacum species. Together these results indicated that heterospecific pollen transfer is likely. Crossing experiments showed that T. ceratophorum is an obligate outcrosser, and interspecific hand pollinations resulted in 37.3% seed set. However, molecular analysis of the F1 offspring indicated that only 33.2% of germinating seeds were hybrids; the remainder were selfed offspring produced from a breakdown in self-incompatibility (the mentor effect). Although the mentor effect helps reduce the production of hybrids, the asymmetrical direction of hybridization creates the potential for genetic assimilation of T. ceratophorum by T. officinale. PMID:21653420

Brock, Marcus T

2004-05-01

14

Potential of dandelion ( Taraxacum officinale) as a bioindicator of manganese arising from the use of methylcyclopentadienyl manganese tricarbonyl in unleaded gasoline  

Microsoft Academic Search

Methylcyclopentadienyl manganese tricarbonyl (MMT) is an organic manganese (Mn) compound currently added to unleaded gasoline in Canada. It has been suggested that the combustion of MMT containing Mn could cause various deleterious health effects in animals and humans at very high concentrations. This study evaluates the potential of dandelions (Taraxacum officinale) as bioindicators of Mn environmental comtamination. Samples were picked

L. Normandin; G. Kennedy; J. Zayed

1999-01-01

15

Drought tolerance in the alpine dandelion, Taraxacum ceratophorum (Asteraceae), its exotic congener T. officinale, and interspecific hybrids under natural and experimental conditions  

Microsoft Academic Search

We compared water relations and adaptations to drought stress in native and invasive exotic dandelions, Taraxacum ceratophorum and T. officinale . Photosynthesis (A), transpiration (E), and water use efficiency (WUE; carbon gained\\/water lost) were measured for the two species under extreme drought in the alpine tundra of Colorado, USA. We also subjected both species and F1 hybrids to a dry-down

M. T. Brock; CANDACE GALEN

2005-01-01

16

Drought tolerance in the alpine dandelion, Taraxacum ceratophorum (Asteraceae), its exotic congener T. officinale, and interspecific hybrids under natural and experimental conditions.  

PubMed

We compared water relations and adaptations to drought stress in native and invasive exotic dandelions, Taraxacum ceratophorum and T. officinale. Photosynthesis (A), transpiration (E), and water use efficiency (WUE; carbon gained/water lost) were measured for the two species under extreme drought in the alpine tundra of Colorado, USA. We also subjected both species and F(1) hybrids to a dry-down experiment to determine how relative physiological performance varied with water availability. Photosynthesis and transpiration in the field were low and did not differ between Taraxacum congeners; however, native T. ceratophorum had higher WUE than T. officinale. After 6 days of greenhouse drought, photosynthesis and transpiration were reduced in T. officinale compared to T. ceratophorum. Taraxacum ceratophorum maintained high WUE under control and drought treatments. Conversely, WUE in T. officinale was highly plastic between watered (low WUE) and dry-down (high WUE) treatments. Hybrids did not exhibit heterosis; instead, they were similar to T. officinale in A and E and intermediate to the parental species in WUE. Overall, results suggest that native dandelions are more drought tolerant than invasive congeners or their hybrids, but have less plasticity in WUE. Arid habitats and occasional drought in mesic sites may provide native dandelions with refugia from negative interactions with invasives. PMID:21646151

Brock, Marcus T; Galen, Candace

2005-08-01

17

Lipid peroxidation rates in Taraxacum officinale Wigg. and Vicia cracca L. from biotopes with different levels of soil pollution with heavy metals  

Microsoft Academic Search

The rates of lipid peroxidation (LPO) have been studied in Taraxacum officinale Wigg. (Asteraceae) and Vicia cracca L. (Fabaceae) from urban ecosystems with different levels of soil pollution with heavy metals (HMs), including Pb, Zn, Cu,\\u000a and Cr. The former species responds to the increased HM contents by intensification of LPO processes, with their parameters\\u000a correlating with the concentrations of

A. B. Savinov; L. N. Kurganova; Yu. I. Shekunov

2007-01-01

18

EDTA reduces lead accumulation in Symphytum officinale L. (comfrey) roots  

Microsoft Academic Search

The addition of EDTA in phytoextraction studies has been reported to increase heavy metal accumulation in above-ground parts or to have no negative impact on the overall (root\\/shoot) accumulation levels in terrestrial plants. At a purely quantitative level, this study assessed the phytoextraction potential of a previously untested high-biomass terrestrial plant, Symphytum officinale L. (comfrey), in the presence of Pb

Lily Chin; David W. M. Leung; H. Harry Taylor

2009-01-01

19

Formation of unreduced megaspores (diplospory) in apomictic dandelions (Taraxacum officinale, s.l.) is controlled by a sex-specific dominant locus.  

PubMed Central

In apomictic dandelions, Taraxacum officinale, unreduced megaspores are formed via a modified meiotic division (diplospory). The genetic basis of diplospory was investigated in a triploid (3x = 24) mapping population of 61 individuals that segregated approximately 1:1 for diplospory and meiotic reduction. This population was created by crossing a sexual diploid (2x = 16) with a tetraploid diplosporous pollen donor (4x = 32) that was derived from a triploid apomict. Six different inheritance models for diplospory were tested. The segregation ratio and the tight association with specific alleles at the microsatellite loci MSTA53 and MSTA78 strongly suggest that diplospory is controlled by a dominant allele D on a locus, which we have named DIPLOSPOROUS (DIP). Diplosporous plants have a simplex genotype, Ddd or Dddd. MSTA53 and MSTA78 were weakly linked to the 18S-25S rDNA locus. The D-linked allele of MSTA78 was absent in a hypotriploid (2n = 3x - 1) that also lacked one of the satellite chromosomes. Together these results suggest that DIP is located on the satellite chromosome. DIP is female specific, as unreduced gametes are not formed during male meiosis. Furthermore, DIP does not affect parthenogenesis, implying that several independently segregating genes control apomixis in dandelions. PMID:15020437

van Dijk, Peter J; Bakx-Schotman, J M Tanja

2004-01-01

20

Lead chelation to immobilised Symphytum officinale L. (comfrey) root tannins.  

PubMed

Reported correlations between tannin level and metal accumulation within plant tissues suggest that metal-chelating tannins may help plants to tolerate toxic levels of heavy metal contaminants. This paper supports such correlations using a new method that demonstrated the ability of plant tannins to chelate heavy metals, and showed that the relative levels of tannins in tissues were quantitatively related to lead chelation in vitro. Using this in vitro metal chelation method, we showed that immobilised tannins prepared from lateral roots of Symphytum officinale L., that contained high tannin levels, chelated 3.5 times more lead than those from main roots with lower tannin levels. This trend was confirmed using increasing concentrations of tannins from a single root type, and using purified tannins (tannic acid) from Chinese gallnuts. This study presents a new, simple, and reliable method that demonstrates direct lead-tannin chelation. In relation to phytoremediation, it also suggests that plant roots with more 'built-in' tannins may advantageously accumulate more lead. PMID:19477483

Chin, Lily; Leung, David W M; Harry Taylor, H

2009-07-01

21

Safety and efficacy of Zingiber officinale roots on fertility of male diabetic rats  

Microsoft Academic Search

The acute toxicity of methanolic and watery extracts of Zingiber officinale (ZO) roots in mice and their effects on fertility of male diabetic rats were carried out. The fertility experiment was done on six groups of male rats one of them was kept as normal control, while the others were rendered diabetic by subcutaneous injection of alloxan (120mgkg?1). One group

M. A. Shalaby; A. R. Hamowieh

2010-01-01

22

Isolation of symlandine from the roots of common comfrey (Symphytum officinale) using countercurrent chromatography.  

PubMed

Three pyrrolizidine alkaloids, symlandine, symphytine, and echimidine (1-3), were isolated from the roots of Symphytum officinale using a one-step countercurrent chromatography procedure. The structures of 1-3 were confirmed by several spectroscopic techniques including 2D NMR methods. This is the first description of the separation of symlandine (1) from its stereoisomer, symphytine (2). PMID:11430014

Kim, N C; Oberlies, N H; Brine, D R; Handy, R W; Wani, M C; Wall, M E

2001-02-01

23

Transformation of Nasturtium officinale, Barbarea verna and Arabis caucasica for hairy roots and glucosinolate-myrosinase system production.  

PubMed

Hairy roots of Nasturtium officinale, Barbarea verna and Arabis caucasica with active glucosinolate-myrosinase system were obtained after transformation with Agrobacterium rhizogenes. Hairy roots of N. officinale produced phenylalanine-derived gluconasturtiin and glucotropaeolin (max. 24 and 7 mg g(-1) DW). B. verna and A. caucasica hairy roots produced gluconasturtiin (max. 41 mg g(-1) DW) and methionine-derived glucoiberverin (max. 32 mg g(-1) DW), respectively. Treatment of the roots with amino acid precursors of glucosinolate or/and cysteine biosynthesis increased levels of glucosinolate production, combinations of phenylalanine with cysteine (for gluconasturtiin and glucotropaeolin) and methionine with o-acetylserine (for glucoiberverin) were the most effective. PMID:19229477

Wielanek, Marzena; Królicka, Aleksandra; Bergier, Katarzyna; Gajewska, Ewa; Sk?odowska, Maria

2009-06-01

24

Influence of release size on establishment and impact of a root weevil for the biocontrol of houndstongue (Cynoglossum officinale)  

Microsoft Academic Search

The root-boring weevil, Mogulones cruciger, was introduced into Canada to control the weed, houndstongue (Cynoglossum officinale). To optimise its use as a biocontrol agent, a 2-year study was performed in British Columbia, Canada to test if the number of M. cruciger released at sites predicted subsequent declines in weed populations. No, 100, 200, 300 or 400 weevils were released in

Rosemarie De Clerck-Floate; Brian Wikeem

2009-01-01

25

Costs of mass-producing the root weevil, Mogulones cruciger, a biological control agent for houndstongue ( Cynoglossum officinale L.)  

Microsoft Academic Search

The cost of rearing the root-feeding weevil, Mogulones cruciger Herbst, to control the invasive weed houndstongue (Cynoglossum officinale L.) was determined for two managed production methods. Production in an insectary setting provides control over rearing and all adult weevils that emerge can be collected, but required facility investment and high labor input. Mass-rearing in a managed ‘field crop’ setting required

Elwin G. Smith; Rosemarie A. De Clerck-Floate; Brian H. Van Hezewijk; James R. Moyer; Eva Pavlik

2009-01-01

26

The Pattern of Genetic Variability in Apomictic Clones of Taraxacum officinale Indicates the Alternation of Asexual and Sexual Histories of Apomicts  

PubMed Central

Dandelions (genus Taraxacum) comprise a group of sexual diploids and apomictic polyploids with a complicated reticular evolution. Apomixis (clonal reproduction through seeds) in this genus is considered to be obligate, and therefore represent a good model for studying the role of asexual reproduction in microevolutionary processes of apomictic genera. In our study, a total of 187 apomictic individuals composing a set of nine microspecies (sampled across wide geographic area in Europe) were genotyped for six microsatellite loci and for 162 amplified fragment length polymorphism (AFLP) markers. Our results indicated that significant genetic similarity existed within accessions with low numbers of genotypes. Genotypic variability was high among accessions but low within accessions. Clustering methods discriminated individuals into nine groups corresponding to their phenotypes. Furthermore, two groups of apomictic genotypes were observed, which suggests that they had different asexual histories. A matrix compatibility test suggests that most of the variability within accession groups was mutational in origin. However, the presence of recombination was also detected. The accumulation of mutations in asexual clones leads to the establishment of a network of clone mates. However, this study suggests that the clones primarily originated from the hybridisation between sexual and apomicts. PMID:22870257

Majesky, Lubos; Vasut, Radim J.; Kitner, Miloslav; Travnicek, Bohumil

2012-01-01

27

Improved method for isolation of lycopsamine from roots of comfrey (Symphytum officinale).  

PubMed

An improved method for the isolation and purification of pyrrolizidine alkaloids from comfrey (Symphytum officinale L.) roots was developed, introducing very fast, selective and ion residue-free reduction of N-oxides followed by ion-exchange chromatography giving a non-aqueous solution of alkaloids, from which solvents can be easily removed. With this procedure the use of large volumes of organic solvents, very slow reduction of N-oxides and input of additional impurities was avoided. Lycopsamine, which proved to be the major alkaloid, was additionally purified by preparative layer chromatography (PLC) and high performance liquid chromatography (HPLC). The identity of the alkaloid was confirmed by (I)H NMR spectroscopy and mass spectrometry. PMID:22908565

Janes, Damjan; Kalamar, Bostjan; Kreft, Samo

2012-07-01

28

Safety and efficacy of Zingiber officinale roots on fertility of male diabetic rats.  

PubMed

The acute toxicity of methanolic and watery extracts of Zingiber officinale (ZO) roots in mice and their effects on fertility of male diabetic rats were carried out. The fertility experiment was done on six groups of male rats one of them was kept as normal control, while the others were rendered diabetic by subcutaneous injection of alloxan (120 mg kg(-1)). One group was left as diabetic control, while the others were given orally either methanolic (100 and 200 mg kg(-1)) or watery extract (150 and 300 mg kg(-1)) for 65 consecutive days. The results showed that no mortalities occur when both extracts were given orally to mice in doses up to 5 g kg(-1) b.wt. Both extracts increased fertility index, sexual organs weight, serum testosterone level and sperm motility and count. Histopathological examination of the testes of diabetic rats showed mild to moderate degenerative changes of spermatogenic cells, diffuse edema and incomplete arrest of spermatogenesis. Treatment with ZO extracts caused alleviation of the testicular lesions that appeared in non-treated diabetic rats. Conclusively, extracts of ZO have high safety in mice and intake of ZO roots as a drink may be useful for diabetic patients who suffer from sexual impotency. PMID:20667464

Shalaby, M A; Hamowieh, A R

2010-10-01

29

Effect of Zingiber officinale and propolis on microorganisms and endotoxins in root canals  

PubMed Central

The purpose of this study was to evaluate the effectiveness of glycolic propolis (PRO) and ginger (GIN) extracts, calcium hydroxide (CH), chlorhexidine (CLX) gel and their combinations as ICMs (ICMs) against Candida albicans, Enterococcus faecalis, Escherichia coli and endotoxins in root canals. Material and Methods: After 28 days of contamination with microorganisms, the canals were instrumented and then divided according to the ICM: CH+saline; CLX, CH+CLX, PRO, PRO+CH; GIN; GIN+CH; saline. The antimicrobial activity and quantification of endotoxins by the chromogenic test of Limulus amebocyte lysate were evaluated after contamination and instrumentation at 14 days of ICM application and 7 days after ICM removal. Results and Conclusion: After analysis of results and application of the Kruskal-Wallis and Dunn statistical tests at 5% significance level, it was concluded that all ICMs were able to eliminate the microorganisms in the root canals and reduce their amount of endotoxins; however, CH was more effective in neutralizing endotoxins and less effective against C. albicans and E. faecalis, requiring the use of medication combinations to obtain higher success. PMID:23559108

MAEKAWA, Lilian Eiko; VALERA, Marcia Carneiro; de OLIVEIRA, Luciane Dias; CARVALHO, Claudio Antonio Talge; CAMARGO, Carlos Henrique Ribeiro; JORGE, Antonio Olavo Cardoso

2013-01-01

30

Studying allozyme variation in sexual and apomictic Taraxacum and Pilosella (Asteraceae) populations  

Microsoft Academic Search

Allozyme spectra of peroxidase, esterase, superoxid dismutase, tyrosinase, alcohol dehydrogenase, lactate dehydrogenase, and acid phosphatase were examined in populations of sexual (Taraxacum serotinum and Pilosella echioides) and apomictic (T. officinale and P. officinarum) plant species. The heterozygosity in these populations (0.455–0.620) proved to be considerably higher than the average level characteristic of plant populations (0.058–0.185). The populations examined did not

A. S. Kashin; V. E. Anfalov; Yu. A. Demochko

2005-01-01

31

Occurrence of nitriles in Taraxacum labelled honeys  

Microsoft Academic Search

Nitrile compounds, whose presence is not common in honey, have been found in the volatile fraction of a few honey types, their relative amounts being particularly high in honeys commercialized under the Taraxacum label. Among them, 2-methylpropanenitrile, 2-methylbutanenitrile, 3-methylbutanenitrile, 2-butenenitrile (cis- or trans-isomer), 3-butenenitrile and 3-methylpentanenitrile, have been identified for the first time in honeys. Melissopalynological analysis of Taraxacum labelled

Ana C. Soria; I. Martínez-Castro; C. de Lorenzo; J. Sanz

2008-01-01

32

Distribution, biosynthesis and turnover of pyrrolizidine alkaloids in Cynoglossum officinale  

Microsoft Academic Search

The facultative biennial Cynoglossum officinale contains the N-oxides of the following pyrrolizidine alkaloids (PAs): trachelanthamine, viridiflorine, 7-angeloylheliotridine, rinderine, echinatine, 3?-acetylechinatine and heliosupine. The inflorescences contain the highest levels of PAs. At the vegetative rosette stage, the youngest leaves have higher PA levels than the older leaves. Both isolated roots and isolated shoots of rosette plants were able to produce PAs

Nicole M. van Dam; Ludger Witte; Claudine Theuring; Thomas Hartmann

1995-01-01

33

Sclerotinia minor avances fruiting and reduces germination in dandelion (Taraxacum officinale)  

Microsoft Academic Search

Sclerotinia minor Jagger is a promising biocontrol agent for dandelion in turfgrass. When a flowering dandelion population was treated with S. minor, flowering accelerated to the fruiting stage within 4 days. This developmental response was 4–5 days earlier than in the control, untreated plants and was not observed in herbicide-treated plants. Seeds obtained from the fungal-treated plants were smaller, lighter

Mohammed H. Abu-Dieyeh; Jerome Bernier; Alan K. Watson

2005-01-01

34

Economics of Biological Invasion: Hound's Tongue (Cynoglossum officinale) and  

E-print Network

Economics of Biological Invasion: Hound's Tongue (Cynoglossum officinale) and Livestock Production Invasion: Hound's Tongue (Cynoglossum officinale) and Livestock Production in British Columbia Supervisory (Cynoglossum officinale) invades rangelands in British Columbia (BC) and creates economic welfare losses

35

Cynoglossum officinale toxicity in calves.  

PubMed

Six calves were given dried, ground Cynoglossum officinale daily in a dose which provided 15 (two calves) or 60 (four calves) mg per kg per day of total pyrrolizidine alkaloids. Those calves given 60 mg per kg of total pyrrolizidine alkaloids per day died following a single dose of plant material. These calves had a marked elevation of serum gamma-glutamyltransferase (GGT) and aspartate transaminase (AST) activities and serum bile acid and total bilirubin (TBili) concentrations. These four calves all had massive hepatocellular necrosis and haemorrhage of the liver. Of the two calves that were given 15 mg per kg of total pyrrolizidine alkaloids per day, one died on day 34 and the other survived until day 35 when it was painlessly killed. There were significant elevations in serum AST and GGT activities in these calves. The histological lesions of the calf surviving until 35 days were compatible with pyrrolizidine alkaloid toxicity, that is megalocytosis, karyomegaly and necrosis of hepatocytes with karyomegaly of biliary epithelium. The pyrrolizidine base present in Cynoglossum officinale (heliotridine) and its esters have a similar type of toxicity to the highly toxic and more familiar macrocyclic diester pyrrolizidine alkaloids of the pyrrolizidine base (retronecine), present in Senecio or Crotolaria species. PMID:1678752

Baker, D C; Pfister, J A; Molyneux, R J; Kechele, P

1991-05-01

36

Mutagenic effects of aqueous extracts of Symphytum officinale L. and of its alkaloidal fractions.  

PubMed

Symphytum officinale L. (Boraginaceae) is a medicinal plant widely used in therapy. It roots, described in the Polish Pharmacopoeia as Radix symphyti, are recommended as expectorants, especially for children. Aqueous solutions of three alkaloid fractions obtained from infusions of Symphytum officinale L. root were tested for their antimitotic and mutagenic activity in meristematic cells of the lateral roots of Vicia faba L., var minor. Lasiocarpine, a proven carcinogen, served as a positive control. Mutagenic effects were induced by lasiocarpine, by the alkaloidal fraction I and by diluted infusions from Radix symphyti. Fraction III had only antimitotic effect. The biological activity of the tested solutions is discussed in relation to the relevant literature. PMID:6619497

Furmanowa, M; Guzewska, J; Be?dowska, B

1983-06-01

37

Structural Diversity in the Dandelion (Taraxacum officinale) Polyphenol Oxidase Family Results in Different Responses to Model Substrates  

PubMed Central

Polyphenol oxidases (PPOs) are ubiquitous type-3 copper enzymes that catalyze the oxygen-dependent conversion of o-diphenols to the corresponding quinones. In most plants, PPOs are present as multiple isoenzymes that probably serve distinct functions, although the precise relationship between sequence, structure and function has not been addressed in detail. We therefore compared the characteristics and activities of recombinant dandelion PPOs to gain insight into the structure–function relationships within the plant PPO family. Phylogenetic analysis resolved the 11 isoenzymes of dandelion into two evolutionary groups. More detailed in silico and in vitro analyses of four representative PPOs covering both phylogenetic groups were performed. Molecular modeling and docking predicted differences in enzyme-substrate interactions, providing a structure-based explanation for grouping. One amino acid side chain positioned at the entrance to the active site (position HB2+1) potentially acts as a “selector” for substrate binding. In vitro activity measurements with the recombinant, purified enzymes also revealed group-specific differences in kinetic parameters when the selected PPOs were presented with five model substrates. The combination of our enzyme kinetic measurements and the in silico docking studies therefore indicate that the physiological functions of individual PPOs might be defined by their specific interactions with different natural substrates. PMID:24918587

Dirks-Hofmeister, Mareike E.; Singh, Ratna; Leufken, Christine M.; Inlow, Jennifer K.; Moerschbacher, Bruno M.

2014-01-01

38

THE EFFECTS OF NINE POLLEN DIETS ON BROODREARING OF HONEYBEES  

E-print Network

mustard (Lesquerella gordoni). No brood was raised on a diet of dandelion pollen (Taraxacum officinale, dandelion (Taraxacum officinale), bladderpod mustard (Lesquerella gordoni) and london rocket mustard

Paris-Sud XI, Université de

39

Early establishment and dispersal of the weevil, Mogulones cruciger (Coleoptera: Curculionidae) for biological control of houndstongue (Cynoglossum officinale) in British Columbia, Canada  

Microsoft Academic Search

First released in Canada in 1997 to control the invasive rangeland weed, houndstongue (Cynoglossum officinale), the European root weevil, Mogulones cruciger, is showing early potential as a successful biocontrol agent. Out of 22 experimental releases in southeastern British Columbia, Canada, 100% established, regardless of initial release size (range 100–400). These founding populations persisted beyond 2 years, and quickly dispersed through

R. A. De Clerck-Floate; B. Wikeem; R. S. Bourchier

2005-01-01

40

Lipids of the seeds of Cynoglossum officinale  

Microsoft Academic Search

The compositions of the lipids and fatty acids of the seeds ofCynoglossum officinale, familyBoraginaceae have been established. The bulk of the lipids consisted of netural compounds (95.2%), while the amounts of glycolipids and\\u000a phospholipids were 3.1 and 1.7%, respectively. Among the fatty acids, in addition to the usual components, acids characteristic\\u000a for theBoraginaceae family have been found: 18:3 (6, 9,

N. T. Ul'chenko; I. P. Nazarova; A. I. Glushenkova; F. F. Fatkhiev; G. A. Tolstikov

1991-01-01

41

Taraxacum sect. Erythrosperma in Moravia (Czech Republic): Taxonomic notes and the distribution of previously described species  

Microsoft Academic Search

Dandelions (Taraxacum) of the section Erythrosperma were studied in Moravia, Czech Republic, where both sexual diploid and apomictic polyploid species occur. Diploid species T. erythrospermum grows in the warmest part of southern Moravia and is confined to natural dry grasslands, whereas some apomictic species have ranges extending up to the submontane regions and prefer ruderal habits. Altogether, 21 apomictic types

R. Vasut

2003-01-01

42

Design and application of specific 16S rDNA-targeted primers for assessing endophytic diversity in Dendrobium officinale using nested PCR-DGGE.  

PubMed

Novel specific 16S rDNA-targeted primers were successfully designed and applied to the characterization of endophytic diversity in Dendrobium officinale. Using the popular universal bacterial primers 27f/1492r, the fragments of chloroplast and mitochondrion 16S/18S rDNA were amplified from D. officinale. They shared high nucleotide identity with the chloroplast 16S rDNAs (99-100 %) and with the mitochondrion 18S rDNAs (93-100 %) from various plants, respectively, and both shared 73-86 % identities with the bacterial 16S rDNA sequences in GenBank. The current bacterial universal primers, including 27f/1492r, match well with the chloroplast and mitochondrion 16S/18S rDNAs, which accordingly renders these primers not useful for endophytic diversity analysis. Novel 16S rDNA-targeted primers fM1 (5'-CCGCGTGNRBGAHGAAGGYYYT-3') and rC5 (5'-TAATCCTGTTTGCTCC CCAC-3') were designed, which show good specificity compared to the 16S/18S rDNAs of D. officinale, and perfect universality within bacteria except for Cyanobacteria. The primers fM1/rC5, together with 515f-GC/rC5, which overlaps the whole V4 region of 16S rDNA, were subjected to nested polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE) to analyze the diversity of endophytic bacteria in D. officinale from three different sources in China. The results showed diversities in roots and stems of the plants from all three locations. Altogether, 29 bands were identified as bacteria, with the dominant group being Proteobacteria and the dominant genus being Burkholderia, some of which commonly has the function of nitrogen fixation and thus may play potentially important roles in D. officinale. Therefore, the nested PCR-DGGE method based on the novel primers provides a good alternative for investigating the communities and roles of endophytes in D. officinale. PMID:24127138

Yu, Jie; Zhou, Xiao-Feng; Yang, Sui-Juan; Liu, Wen-Hong; Hu, Xiu-Fang

2013-11-01

43

Pyrrolizidine alkaloids of Cynoglossum officinale and Cynoglossum amabile (family boraginaceae)  

Microsoft Academic Search

Heliosupine, heliosupine N-oxide, 3?-acetylheliosupine, and viridiflorine were isolated and identified on the base of MS, 1H and 13C NMR from Cynoglossum officinale. Altogether 14 pyrrolizidine alkaloids were separated and identified by GLC and GLC-MS in the alkaloid extracts from different parts of Cynoglossum officinale. From Cynoglossum amabile five pyrrolizidine alkaloids were recorded: supinine, amabiline, rinderine, echinatine, and 3?-O-acetylechinatine.

A. El-Shazly; T. Sarg; A. Ateya; E. Abdel Aziz; L. Witte; M. Wink

1996-01-01

44

Chromium resistance of dandelion (Taraxacum platypecidum Diels.) and bermudagrass (Cynodon dactylon [Linn.] Pers.) is enhanced by arbuscular mycorrhiza in Cr(VI)-contaminated soils.  

PubMed

In a greenhouse pot experiment, dandelion (Taraxacum platypecidum Diels.) and bermudagrass (Cynodon dactylon[Linn.] Pers.), inoculated with and without arbuscular mycorrhizal fungus (AMF) Rhizophagus irregularis, were grown in chromium (Cr)-amended soils (0?mg/kg, 5?mg/kg, 10?mg/kg, and 20?mg/kg Cr[VI]) to test whether arbuscular mycorrhizal (AM) symbiosis can improve Cr tolerance in different plant species. The experimental results indicated that the dry weights of both plant species were dramatically increased by AM symbiosis. Mycorrhizal colonization increased plant P concentrations and decreased Cr concentrations and Cr translocation from roots to shoots for dandelion; in contrast, mycorrhizal colonization decreased plant Cr concentrations without improvement of P nutrition in bermudagrass. Chromium speciation analysis revealed that AM symbiosis potentially altered Cr species and bioavailability in the rhizosphere. The study confirmed the protective effects of AMF on host plants under Cr contaminations. PMID:24920536

Wu, Song-Lin; Chen, Bao-Dong; Sun, Yu-Qing; Ren, Bai-Hui; Zhang, Xin; Wang, You-Shan

2014-09-01

45

Growth-promoting Sphingomonas paucimobilis?ZJSH1 associated with Dendrobium officinale through phytohormone production and nitrogen fixation.  

PubMed

Growth-promoting Sphingomonas paucimobilis?ZJSH1, associated with Dendrobium officinale, a traditional Chinese medicinal plant, was characterized. At 90 days post-inoculation, strain ZJSH1 significantly promoted the growth of D.?officinale seedlings, with increases of stems by 8.6% and fresh weight by 7.5%. Interestingly, the polysaccharide content extracted from the inoculated seedlings was 0.6% higher than that of the control. Similar growth promotion was observed with the transplants inoculated with strain ZJSH1. The mechanism of growth promotion was attributed to a combination of phytohormones and nitrogen fixation. Strain ZJSH1 was found using the Kjeldahl method to have a nitrogen fixation activity of 1.15?mg?l(-1) , which was confirmed by sequencing of the nifH gene. Using high-performance liquid chromatography-mass spectrometry, strain ZJSH1 was found to produce various phytohormones, including salicylic acid (SA), indole-3-acetic acid (IAA), Zeatin and abscisic acid (ABA). The growth curve showed that strain ZJSH1 grew well in the seedlings, especially in the roots. Accordingly, much higher contents of SA, ABA, IAA and c-ZR were detected in the inoculated seedlings, which may play roles as both phytohormones and 'Systemic Acquired Resistance' drivers. Nitrogen fixation and secretion of plant growth regulators (SA, IAA, Zeatin and ABA) endow S.?paucimobilis?ZJSH1 with growth-promoting properties, which provides a potential for application in the commercial growth of D.?officinale. PMID:25142808

Yang, Suijuan; Zhang, Xinghai; Cao, Zhaoyun; Zhao, Kaipeng; Wang, Sai; Chen, Mingxue; Hu, Xiufang

2014-11-01

46

Ecological and evolutionary opportunities of apomixis: insights from Taraxacum and Chondrilla.  

PubMed Central

The ecological and evolutionary opportunities of apomixis in the short and the long term are considered, based on two closely related apomictic genera: Taraxacum (dandelion) and Chondrilla (skeleton weed). In both genera apomicts have a wider geographical distribution than sexuals, illustrating the short-term ecological success of apomixis. Allozymes and DNA markers indicate that apomictic populations are highly polyclonal. In Taraxacum, clonal diversity can be generated by rare hybridization between sexuals and apomicts, the latter acting as pollen donors. Less extensive clonal diversity is generated by mutations within clonal lineages. Clonal diversity may be maintained by frequency-dependent selection, caused by biological interactions (e.g. competitors and pathogens). Some clones are geographically widespread and probably represent phenotypically plastic 'general-purpose genotypes'. The long-term evolutionary success of apomictic clones may be limited by lack of adaptive potential and the accumulation of deleterious mutations. Although apomictic clones may be considered as 'evolutionary dead ends', the genes controlling apomixis can escape from degeneration and extinction via pollen in crosses between sexuals and apomicts. In this way, apomixis genes are transferred to a new genetic background, potentially adaptive and cleansed from linked deleterious mutations. Consequently, apomixis genes can be much older than the clones they are currently contained in. The close phylogenetic relationship between Taraxacum and Chondrilla and the similarity of their apomixis mechanisms suggest that apomixis in these two genera could be of common ancestry. PMID:12831477

van Dijk, Peter J

2003-01-01

47

Statistical downscaling of general-circulation-model- simulated average monthly air temperature to the beginning of flowering of the dandelion (Taraxacum officinale) in Slovenia  

Microsoft Academic Search

Phenological observations are a valuable source of information for investigating the relationship between climate variation and plant development. Potential climate change in the future will shift the occurrence of phenological phases. Information about future climate conditions is needed in order to estimate this shift. General circulation models (GCM) provide the best information about future climate change. They are able to

Klemen Bergant; Lu?ka Kajfež-Bogataj; Zalika ?repinšek

2002-01-01

48

An In-Situ Root-Imaging System in the Context of Surface Detection of CO2  

NASA Astrophysics Data System (ADS)

Carbon sequestration is a valuable method of spatially confining CO2 belowground. The Zero Emissions Research Technology, (ZERT), site is an experimental facility in a former agricultural field on the Montana State University campus in Bozeman, Montana, where CO2 was experimentally released at a rate of 200kg/day in 2009 into a 100 meter underground injection well running parallel to the ground surface. This injection well, or pipe, has deliberate leaks at intervals, and CO2 travels from these leaks upward to the surface of the ground. The ZERT site is a model system designed with the purpose of testing methods of surface detection of CO2. One important aspect of surface detection is the determination of the effects of CO2 on the above and belowground portions of plants growing above sequestration fields. At ZERT, these plants consist of a pre-existing mixture of herbaceous species present at the agricultural field. Species growing at the ZERT site include several grasses, Dactylis glomerata (Orchard Grass), Poa pratensis (Kentucky Bluegrass), and Bromus japonicus (Japanese Brome); the nitrogen-fixing legumes Medicago sativa, (Alfalfa), and Lotus corniculatus, (Birdsfoot trefoil); and an abundance of Taraxacum officinale, (Dandelion). Although the aboveground parts of the plants at high CO2 are stressed, as indicated by changes in hyperspectral plant signatures, leaf fluorescence and leaf chlorophyll content, we are interested in determining whether the roots are also stressed. To do so, we are combining measurements of soil conductivity and soil moisture with root imaging. We are using an in-situ root-imaging system manufactured by CID, Inc. (Camas, WA), along with image analysis software (Image-J) to analyze morphometric parameters in the images and to determine what effects, if any, the presence of leaking and subsequently upwelling CO2 has on the phenology of root growth, growth and turnover of individual fine and coarse roots, branching patterns, and root density and depth in the soil. We drilled three holes for the plexiglass root-imaging tubes in December 2008 and installed the tubes post-thaw in May 2009, with the initial set of images taken in July 2009 on the day preceding the 4-week long CO2 injection. We collected images weekly thereafter until late August 2009 by inserted a rotating camera into the tube and photographing at 10 cm intervals from the surface to a depth of 75-80 cm. By August 2009, roots were visible at 80 cm below ground. The root-imaging tubes will remain in place so that we can track the roots through the upcoming years at the ZERT site. Each year, we anticipate gathering images in the fall, winter, before the beginning of root growth in the spring, as well as during the summer injections of CO2. The information gained from these images will be useful in linking above and belowground responses of plants to CO2.

Apple, M. E.; Prince, J. B.; Bradley, A. R.; Zhou, X.; Lakkaraju, V. R.; Male, E. J.; Pickles, W.; Thordsen, J. J.; Dobeck, L.; Cunningham, A.; Spangler, L.

2009-12-01

49

Selective Seed Abortion Increases Offspring Survival in Cynoglossum officinale (Boraginaceae)  

Microsoft Academic Search

Selective embryo abortion is one of the evolutionary explanations for the surplus of ovules found in many plant species. To manipulate the level of embryo abortion, we removed ovules and applied nutrients to plants of Cynoglossum officinale(Boraginaceae) after they started to flower. From these two treatments and a control series, seeds were collected, germinated, and transplanted in the field to

Chantal Melser; Peter G. L. Klinkhamer

2001-01-01

50

Limiting factors for seed production in Cynoglossum officinale  

Microsoft Academic Search

Over three years of study, small plants of Cynoglossum officinale consistently produced more flowers per unit of dry weight than large plants. In contrast to earlier results, weight of all seeds tended to increase more than proportional to size. As a result a positive correlation existed between seed set per flower and plant size. The correlation between the mean number

Tom J. Jong; Peter G. L. Klinkhamer

1989-01-01

51

[Molecular characterization of a HMG-CoA reductase gene from a rare and endangered medicinal plant, Dendrobium officinale].  

PubMed

The 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) catalyzes the conversion of HMG-CoA to mevalonate in mavalonic acid pathway, which is the first committed step for isoprenoid biosynthesis in plants. However, it still remains unclear whether HGMR gene plays a role in the isoprenoid biosynthesis in Dendrobium officinale, an endangered epiphytic orchid species. In the present study, a HMGR encoding gene, designed as DoHMGR1 (GenBank accession JX272632), was identified from D. officinale using the reverse transcription polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE) methods, for the first time. The full length cDNA of DoHMGR1 was 2 071 bp in length and encoded a 562-aa protein with a molecular weight of 59.73 kD and an isoelectric point (pI) of 6.18. The deduced DoHMGR1 protein, like other HMGR proteins, constituted four conserved domains (63-561, 147-551, 268-383 and 124-541) and two transmembrane motifs (42-64 and 85-107). Multiple sequence alignment and phylogenetic analyses demonstrated that DoHMGR1 had high identity (67%-89%) to a number of HMGR genes from various plants and was closely related to Vanda hybrid cultivar, rice and maize monocots. Real time quantitative PCR (qPCR) analysis revealed that DoHMGR1 was expressed in the three included organs. The transcripts were the most abundant in the roots with 2.13 fold over that in the leaves, followed by that in the stems with 1.98 fold. Molecular characterization of DoHMGR1 will be useful for further functional elucidation of the gene involving in isoprenoid biosynthesis pathway in D. officinale. PMID:24961116

Zhang, Lin; Wang, Ji-Tao; Zhang, Da-Wei; Zhang, Gang; Guo, Shun-Xing

2014-03-01

52

[Allozyme variation in sexual and apomictic Taraxacum and Pilosella (Asteraceae) populations].  

PubMed

Allozyme spectra of peroxidase, esterase, superoxid dismutase, tyrosinase, alcohol dehydrogenase, lactate dehydrogenase, and acid phosphatase were examined in populations of sexual (Taraxacum serotinum and Pilosella echioides) and apomictic (T. officinalis and P. officinarum) plant species. The heterozygosity in these populations (0.455-0.620) proved to be considerably higher than the average level characteristic of plant populations (0.058-0.185). The populations examined did not differ in the mean phenotype number mu, i.e., they exhibited the same diversity (3.213-3.380). The proportion of rare phenotypes h also did not differ between the sexual and apomictic species of the same genus, whereas this parameter in the Pilosella populations (0.150-0.174) was significantly higher than in the Taraxacum ones (0.093-0.114). The populations were characterized by numerous isozyme spectra (more than 11 per populations) and displayed multiple allelism (the mean allele frequency was 3.63-4.38 per locus). They exhibited a high percentage of rare (occurring at a frequency lower than 5%) spectra (35-80%). This indicates that agamic complexes, to which these populations belong, may have a more complicated genetic structure of both apomictic and sexual populations than the species that do not belong to agamic complexes. PMID:15810610

Kashin, A S; Anfalov, V E; Demochko, Iu A

2005-02-01

53

[Molecular characterization of a mitogen-activated protein kinase gene DoMPK1 in Dendrobium officinale].  

PubMed

The mitogen-activated protein kinase (MAPK) cascade, composed of MAPK kinase kinase (MAP3K), MAPK kinase (MAP2K), and MAPK, is abundantly conserved in all eukaryotes. MAPK along with MAPK cascade plays a vital regulatory role in the plant-arbuscular mycorrhiza/rhizobium nodule symbioses. However, the biological function of MAPK in orchid mycorrhiza (OM) symbiosis remains elusive. In the present study, a MAPK gene, designated as DoMPK1 (GenBank accession No. JX297594), was identified from D. officinale roots infected by an OM fungus-Mycena sp. using the reverse transcription polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE) methods. The full length cDNA of DoMPK1 was 1 263 bp and encoded a 372 aa protein with a molecular weight of 42.61 kD and an isoelectric point (pI) of 6.07. The deduced DoMPK1 protein contained the conserved serine/threonine-protein kinase catalytic domain (39-325) and MAP kinase signature (77-177). Multiple sequence alignment and phylogenetic analysis demonstrated that DoMPK1 was highly homologous (71%-85%) to MAPK genes from various plant species and was closely related to those from monocots. Real time quantitative PCR (qPCR) analysis revealed that DoMPK1 was constitutively expressed in leaves, stems, roots and seeds, and the transcript abundance was not significantly different in the four included tissues. Furthermore, DoMPK1 transcript was markedly induced in roots at 30 d after fungal infection, with 7.91 fold compared to that of the mock inoculated roots, suggesting implication of DoMPK1 in the early D. officinale and Mycena sp. interaction and an essential role in the symbiosis. Our study characterized a MAPK gene associated with OM symbiosis for the first time, and will be helpful for further functional elucidation of DoMPK1 involving in D. officinale and Mycena sp. symbiotic interaction. PMID:23460979

Zhang, Gang; Zhao, Ming-Ming; Song, Chao; Zhang, Da-Wei; Li, Biao; Guo, Shun-Xing

2012-12-01

54

Hound's-tongue (Cynoglossum officinale) poisoning in a calf.  

PubMed

Cynoglossum officinale was believed to be responsible for the death of one calf and possibly 5 other calves in a group of 9 calves being fed chopped hay contaminated by this plant. The plant, commonly known as hound's tongue, contains pyrrolizidine alkaloids and has been determined to be toxic to horses fed contaminated hay, but was fed to cattle at the same time with no effect. PMID:2703425

Baker, D C; Smart, R A; Ralphs, M; Molyneux, R J

1989-04-01

55

Cyclooxygenase-2 inhibitors in ginger (Zingiber officinale)  

PubMed Central

Ginger roots have been used to treat inflammation and have been reported to inhibit cyclooxygenase (COX). Ultrafiltration liquid chromatography mass spectrometry was used to screen a chloroform partition of a methanol extract of ginger roots for COX-2 ligands, and 10-gingerol, 12-gingerol, 8-shogaol, 10-shogaol, 6-gingerdione, 8-gingerdione, 10-gingerdione, 6-dehydro-10-gingerol, 6-paradol, and 8-paradol bound to the enzyme active site. Purified 10-gingerol, 8-shogaol and 10-shogaol inhibited COX-2 with IC50 values of 32 ?M, 17.5 ?M and 7.5 ?M, respectively. No inhibition of COX-1 was detected. Therefore, 10-gingerol, 8-shogaol and 10-shogaol inhibit COX-2 but not COX-1, which can explain, in part, anti-inflammatory properties of ginger. PMID:20837112

van Breemen, Richard B.; Tao, Yi; Li, Wenkui

2010-01-01

56

Investigation of antioxidant properties of Nasturtium officinale (watercress) leaf extracts.  

PubMed

The objective of this study was to examine the in vitro and in vivo antioxidative properties of aqueous and ethanolic extracts of the leaf of Nasturtium officinale R. Br. (watercress). Extracts were evaluated for total antioxidant activity by ferric thiocyanate method, total reducing power by potassium ferricyanide reduction method, 1,1-diphenyl-2-picrylhydrazyl (DPPH*) radical scavenging activities, superoxide anion radical scavenging activities in vitro and lipid peroxidation in vivo. Those various antioxidant activities were compared to standards such as butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT) and alpha-tocopherol. The ethanolic extract was found as the most active in total antioxidant activity, reducing power, DPPH* radicals and superoxide anion radicals scavenging activities. Administration of the ethanol extract to rats decreased lipid peroxidation in liver, brain and kidney. These results lead to the conclusion that N. officinale extracts show relevant antioxidant activity by means of reducing cellular lipid peroxidation and increasing antioxidant activity, reducing power, free radiacal and superoxide anion radical scavenging activities. In addition, total phenolic compounds in the aqueous and ethanolic extract of N. officinale were determined as pyrocatechol. PMID:19719054

Ozen, Tevfik

2009-01-01

57

Absence of mutagenic effects of a particular Symphytum officinale L. liquid extract in the bacterial reverse mutation assay.  

PubMed

Comfrey (Symphytum officinale L.) root is traditionally used for the topical treatment of contusions, strains and sprains. Besides allantoin and rosmarinic acid, which are discussed as pharmacologically active principles, the drug contains pyrrolizidine alkaloids (PAs) known for their hepatotoxic, carcinogenic and mutagenic properties. The topical herbal medicinal products Kytta-Salbe f and Kytta-Plasma f contain a PA-free liquid extract from comfrey root as active substance. The aim of this study was to demonstrate the absence of genotoxic effects of this special extract in the bacterial reverse mutation assay (Ames test). Briefly, comfrey root liquid extract was investigated for its ability to induce gene mutations in Salmonella typhimurium strains TA 98, TA 100, TA 102, TA 1535 and TA 1537 with and without metabolic activation using the mammalian microsomal fraction S9 mix. Reference mutagens were used to check the validity of the experiments. Comfrey root fluid extract showed no biologically relevant increases in revertant colony numbers of any of the five tester strains, neither in the presence nor in the absence of metabolic activation. In conclusion, the comfrey root fluid extract contained in Kytta-Salbe f and Kytta-Plasma f was not mutagenic in the bacterial reverse mutation assay. PMID:19827020

Benedek, Birgit; Ziegler, Andreas; Ottersbach, Peter

2010-03-01

58

Growth habits of dandelion, daisy, catsear, and hawkbit in some New Zealand grasslands  

Microsoft Academic Search

dGrowth habits of four basal rosette composites, dandelion (Taraxacum officinale Weber), catsear (Hypochaeris radicata L.), hawkbit (Leontodon taraxacoides Vill. Mérat), and daisy (Bellis perennis L.). were studied in two mowed, three heavily grazed, three lightly grazed, and two uncut grasslands near Palmerston North.With increasing degree of defoliation: (1) plant radius and longest leaf decreased, (2) root length generally decreased, (3)

G. J. Struik

1967-01-01

59

Isolation and differential expression of a novel MAP kinase gene DoMPK4 in Dendrobium officinale.  

PubMed

Mitogen-activated protein kinases (MAPKs) are important signaling transduction components well conserved in eukaryotes and play essential roles in various physiological, developmental and hormonal responses in plant. In the present study, a MAPK gene, designated as DoMPK4 (GenBank accession No. JX297597), is identified from a rare endangered medicinal orchid species D. officinale using the reverse transcription polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE) methods. The full length cDNA of DoMPK4 is 1 518 bp in length and encoded a 369 aa protein with a molecular weight of 42.42 kD and an isoelectric point of 5.55. DoMPK4 protein contained a serine/threonine protein kinase active site (158-170), a MAP kinase site (71-174), and eight conserved motifs. DoMPK4 had a transmembrane (214-232) but no signal peptide. Multiple sequence alignment showed that DoMPK4 shared high identities (74.9%-80.6%) with MAPK proteins from various plants. Phylogenetic analysis demonstrated that DoMPK4 belonged to group A of the MAPK evolutionary tree, and is closely related to monocots. Real time quantitative PCR (qPCR) analysis revealed that DoMPK4 is differentially expressed among the five organs including leaf, stem, root, seed, and protocorm-like body (PLB). The transcription level of DoMPK4 is the highest in the PLBs with 17.65 fold, followed by seeds, roots, and stems with 5.84, 2.28, and 1.64 fold, respectively. The progressive enhancement of DoMPK4 transcripts in the developing PLBs compared to that in the germinating seeds, suggests a role of DoMPK4 during the development of embryogenic PLBs formation in D. officinale. PMID:25233643

Zhang, Gang; Li, Yi-Min; Hu, Ben-Xiang; Zhang, Da-Wei; Guo, Shun-Xing

2014-07-01

60

Discrimination of Dendrobium officinale and its common adulterants by combination of normal light and fluorescence microscopy.  

PubMed

The stems of Dendrobium officinale Kimura et Migo, named Tie-pi-shi-hu, is one of the most endangered and precious species in China. Because of its various pharmacodynamic effects, D. officinale is widely recognized as a high-quality health food in China and other countries in south and south-east Asia. With the rising interest of D. officinale, its products have a high price due to a limited supply. This high price has led to the proliferation of adulterants in the market. To ensure the safe use of D. officinale, a fast and convenient method combining normal and fluorescence microscopy was applied in the present study to distinguish D. officinale from three commonly used adulterants including Zi-pi-shi-hu (D. devonianum), Shui-cao-shi-hu (D. aphyllum), Guang-jie-shi-hu (D. gratiosissimum). The result demonstrated that D. officinale could be identified by the characteristic "two hat-shaped" vascular bundle sheath observed under the fluorescence microscopy and the distribution of raphides under normal light microscopy. The other three adulterants could be discriminated by the vascular bundle differences and the distribution of raphides under normal light microscopy. This work indicated that combination of normal light and fluorescence microscopy is a fast and efficient technique to scientifically distinguish D. officinale from the commonly confused species. PMID:24662084

Chu, Chu; Yin, Huimin; Xia, Li; Cheng, Dongping; Yan, Jizhong; Zhu, Lin

2014-01-01

61

[Investigation on wild resources of Dendrobium officinale distribution and ecological envirment in Anhui].  

PubMed

The wild resources of Dendrobium officinale in Anhui province were studied by textural research, data collection, interview survey and regional survey, in order to investigate the resources distribution and ecological characters and provide the reference for Anhui Dendrobium industry. In this paper, a part of producing areas of wild D. officinale in Anhui province was selected to analyze the ecological characters. As a result, we find that the wild resources of D. officinale in Anhui distributed only sporadic and the conditions of growth environment were harsh. Our findings may provide some suggestions on wild resources protection and artificial cultivation in suitable environments because the wild resources of D. officinale in Anhui are decreasing rapidly and facing an endangered situation. PMID:24791481

Jin, Yan-Yan; Fang, Cheng-Wu; Yang, Qi-Qing; Gao, Xiao-Ming; Zhang, Chuan-Biao; Zhang, Ming-Yan; Wang, Wu; Wang, Lin

2013-12-01

62

The “Raison D'être” of pyrrolizidine alkaloids in Cynoglossum officinale: Deterrent effects against generalist herbivores  

Microsoft Academic Search

In this study we tested whether pyrrolizidine alkaloids (PAs) ofCynoglossum officinale serve as antifeedants against herbivores. Total PA N-oxide extracts of the leaves significantly deterred feeding by generalist herbivores. Specialist herbivores did not discriminate between food with high and low PA levels. Three PAs fromC. officinale, heliosupine, echinatine, and 3-acetylechinatine, equally deterred feeding by the polyphagous larvae ofSpodoptera exigua. Although

Nicole M. van Dam; Lucienne W. M. Vuister; Cora Bergshoeff; Helene de Vos; ED van Der Meijden

1995-01-01

63

Zingiber officinale: A Potential Plant against Rheumatoid Arthritis  

PubMed Central

Rheumatoid arthritis (RA) is an autoimmune disease particularly affecting elderly people which leads to massive bone destruction with consequent inflammation, pain, and debility. Allopathic medicine can provide only symptomatic relief. However, Zingiber officinale is a plant belonging to the Zingiberaceae family, which has traditionally been used for treatment of RA in alternative medicines of many countries. Many of the phytochemical constituents of the rhizomes of this plant have therapeutic benefits including amelioration of RA. This review attempts to list those phytochemical constituents with their reported mechanisms of action. It is concluded that these phytochemicals can form the basis of discovery of new drugs, which not only can provide symptomatic relief but also may provide total relief from RA by stopping RA-induced bone destruction. As the development of RA is a complex process, further research should be continued towards elucidating the molecular details leading to RA and drugs that can stop or reverse these processes by phytoconstituents of ginger. PMID:24982806

Al-Nahain, Abdullah; Jahan, Rownak

2014-01-01

64

[Cloning and expression analysis of a calcium-dependent protein kinase gene in Dendrobium officinale in response to mycorrhizal fungal infection].  

PubMed

Calcium-dependent protein kinases (CDPKs) play an important regulatory role in the plantarbuscular mycorrhiza/rhizobium nodule symbiosis. However, the biological action of CDPKs in orchid mycorrhiza (OM) symbiosis remains unclear. In the present study, a CDPK encoding gene, designated as DoCPK1 (GenBank accession No. JX193703), was identified from D. officinale roots infected by an OM fungus-Mycena sp. using the reverse transcription polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE) methods, for the first time. The full length cDNA of DoCPK1 was 2137 bp in length and encoded a 534 aa protein with a molecular weight of 59.61 kD and an isoelectric point (pI) of 6.03. The deduced DoCPK1 protein contained the conserved serine/threonine-protein kinase catalytic domain and four Ca2+ binding EF hand motifs. Multiple sequence alignment demonstrated that DoCPK1 was highly homologous (85%) to the Panax ginseng PgCPK1 (ACY78680), followed by CDPKs genes from wheat, rice, and Arabidopsis (ABD98803, ADM14342, Q9ZSA2, respectively). Phylogenetic analysis showed that DoCPK1 was closely related to CDPKs genes from monocots, such as wheat, maize and rice. Real time quantitative PCR (qPCR) analysis revealed that DoCPK1 was constitutively expressed in the included tissues and the transcript levels were in the order of roots > stems > seeds > leaves. Furthermore, DoCPK1 transcripts were significantly accumulated in roots 30 d after fungal infection, with 5.16 fold compared to that of the mock roots, indicating involvement of DoCPK1 during the early interaction between D. officinale and Mycena sp., and a possible role in the symbiosis process. This study firstly provided important clues of a CDPK gene associated with OM symbiosis, and will be useful for further functional determination of the gene involving in D. officinale and Mycena sp. symbiosis. PMID:23387091

Zhang, Gang; Zhao, Ming-Ming; Li, Biao; Song, Chao; Zhang, Da-Wei; Guo, Shun-Xing

2012-11-01

65

Selective seed abortion increases offspring survival in Cynoglossum officinale (Boraginaceae).  

PubMed

Selective embryo abortion is one of the evolutionary explanations for the surplus of ovules found in many plant species. To manipulate the level of embryo abortion, we removed ovules and applied nutrients to plants of Cynoglossum officinale (Boraginaceae) after they started to flower. From these two treatments and a control series, seeds were collected, germinated, and transplanted in the field to assess the quality of the resulting offspring. Nutrient addition did not increase the number of seeds per flower significantly. Fewer embryos were aborted in the ovule removal treatment. The seeds produced in the ovule removal treatment had a significantly greater mass and significantly lower survival than the offspring from the control group. This difference in survival indicates that offspring of lower quality are selectively aborted in the control group. Offspring from the nutrient addition treatment survived longer. The offspring of the treatments did not differ significantly from the control group in growth. Simple mathematical calculations, based on the differences in offspring quality that we found, indicate that the selective abortion hypothesis can be an important factor explaining the advantage of the "surplus production" of ovules. PMID:11410467

Melser, C; Klinkhamer, P G

2001-06-01

66

Evaluation of effects of Zingiber officinale on salivation in rats.  

PubMed

There are some herbal plants in Iranian traditional system of medicine which are believed to be excellent remedies to alleviate the symptoms of xerostomia. The aim of the present study was to evaluate the effect of systemic administration of seven different herbal extracts on the rate of salivation in rats. The extracts of 7 herbs; Zingiber officinale Roscoe (Zingiberaceae), Citrus sinensis (L.) Osbeck (Rutaceae), Artemisia absinthium L. (Asteraceae), Cichorium intybus L. (Asteraceae), Pimpinella anisum L.(Apiaceae), Portulaca oleracea L.(Portulacaceae), Tribulus terrestris L. (Zygophyllaceae) were prepared. Nine groups of animals (including negative and positive control groups) were used and seven rats were tested in each group. After the injection of extracts, saliva volume was measured gravimetrically in four continuous seven-minute intervals. The results showed that after injection of ginger extracts salivation was significantly higher as compared to the negative control group and other herbal extracts in all of the four intervals (P<0.01). The peak action of the ginger was during the first 7-minute interval and following this, salivation decreased to some extent. The present study suggests that the extract of Zingiber offiicianle can increase the rate of salivation significantly in animal model. Further investigations on different constituents of ginger seem to be essential to identify the responsible constituent for stimulation of saliva secretion. PMID:21874635

Chamani, Goli; Zarei, Mohammad Reza; Mehrabani, Mitra; Taghiabadi, Yousef

2011-01-01

67

Biological activities of Zingiber officinale (Zingiberaceae) and Piper cubeba (Piperaceae) essential oils against pulse beetle, Callosobruchus chinensis (Coleoptera: Bruchidae).  

PubMed

Zingiber officinale (Zingiberaceae) and Piper cubeba (Piperaceae) was essential oils were investigated for repellent, insecticidal, antiovipositional, egg hatching, persistence of its insecticidal activities against pulse beetle, Callosobruchus chinensis (Coleoptera: Bruchidae). Essential oil vapours repelled bruchid adults significantly as oviposition was found reduced in choice oviposition assay. Z. officinale and P. cubeba essential oils caused both fumigant and contact toxicity in C. chinensis adults. In fumigation toxicity assay, median lethal concentrations (LC50) were 0.34 and 0.27 microL cm(-3) for Z. officinale and P. cubeba essential oils, respectively, while in contact toxicity assay, LC50 were 0.90 and 0.66 microL cm(-2) for Z. officinale and P. cubeba essential oils, respectively. These two essential oils reduced oviposition in C. chinensis adults when treated with sublethal concentrations by fumigation and contact method. Oviposition inhibition was more pronounced when adults come in contact than in vapours. Both essential oils significantly reduced egg hatching rate when fumigated. Persistence in insecticidal efficiency of both essential oils decreased with time. P. cubeba showed less persistence than Z. officinale essential oil because no mortality was observed in C. chinensis adults after 36 h of treatment with P. cubeba and after 48 h of treatment of Z. officinale essential oil. Fumigation with these essential oils has no effect on the germination of the cowpea seeds. Findings of the study suggest that Z. officinale and P. cubeba essential oils can be useful as promising agent in insect pest management programme. PMID:24498820

Chaubey, Mukesh Kumar

2013-06-01

68

Impact of Erysiphe cynoglossi on the Growth and Reproduction of the Rangeland Weed Cynoglossum officinale  

Microsoft Academic Search

The powdery mildew fungus, Erysiphe cynoglossi (Wallr.) E. Braun, is a commonly occurring pathogen of houndstongue (Cynoglossum officinale L.) and may have a role in the biocontrol program being developed in North America for this introduced rangeland weed. To assess the effect of E. cynoglossi on the growth and reproduction of houndstongue, field observations were conducted to relate the level

R. De Clerck-Floate

1999-01-01

69

Analysis of the Dendrobium officinale transcriptome reveals putative alkaloid biosynthetic genes and genetic markers.  

PubMed

Dendrobium officinale Kimura et Migo (Orchidaceae) is a traditional Chinese medicinal plant. The stem contains an alkaloid that is the primary bioactive component. However, the details of alkaloid biosynthesis have not been effectively explored because of the limited number of expressed sequence tags (ESTs) available in GenBank. In this study, we analyzed RNA isolated from the stem of D. officinale using a single half-run on the Roche 454 GS FLX Titanium platform to generate 553,084 ESTs with an average length of 417 bases. The ESTs were assembled into 36,407 unique putative transcripts. A total of 69.97% of the unique sequences were annotated, and a detailed view of alkaloid biosynthesis was obtained. Functional assignment based on Kyoto Encyclopedia of Genes and Genomes (KEGG) terms revealed 69 unique sequences representing 25 genes involved in alkaloid backbone biosynthesis. A series of qRT-PCR experiments confirmed that the expression levels of 5 key enzyme-encoding genes involved in alkaloid biosynthesis are greater in the leaves of D. officinale than in the stems. Cytochrome P450s, aminotransferases, methyltransferases, multidrug resistance protein (MDR) transporters and transcription factors were screened for possible involvement in alkaloid biosynthesis. Furthermore, a total of 1061 simple sequence repeat motifs (SSR) were detected from 36,407 unigenes. Dinucleotide repeats were the most abundant repeat type. Of these, 179 genes were associated with a metabolic pathway in KEGG. This study is the first to produce a large volume of transcriptome data from D. officinale. It extends the foundation to facilitate gene discovery in D. officinale and provides an important resource for the molecular genetic and functional genomic studies in this species. PMID:23756193

Guo, Xu; Li, Ying; Li, Chunfang; Luo, Hongmei; Wang, Lizhi; Qian, Jun; Luo, Xiang; Xiang, Li; Song, Jingyuan; Sun, Chao; Xu, Haibin; Yao, Hui; Chen, Shilin

2013-09-15

70

ESTs Analysis Reveals Putative Genes Involved in Symbiotic Seed Germination in Dendrobium officinale  

PubMed Central

Dendrobiumofficinale (Orchidaceae) is one of the world’s most endangered plants with great medicinal value. In nature, D. officinale seeds must establish symbiotic relationships with fungi to germinate. However, the molecular events involved in the interaction between fungus and plant during this process are poorly understood. To isolate the genes involved in symbiotic germination, a suppression subtractive hybridization (SSH) cDNA library of symbiotically germinated D. officinale seeds was constructed. From this library, 1437 expressed sequence tags (ESTs) were clustered to 1074 Unigenes (including 902 singletons and 172 contigs), which were searched against the NCBI non-redundant (NR) protein database (E-value cutoff, e-5). Based on sequence similarity with known proteins, 579 differentially expressed genes in D. officinale were identified and classified into different functional categories by Gene Ontology (GO), Clusters of orthologous Groups of proteins (COGs) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. The expression levels of 15 selected genes emblematic of symbiotic germination were confirmed via real-time quantitative PCR. These genes were classified into various categories, including defense and stress response, metabolism, transcriptional regulation, transport process and signal transduction pathways. All transcripts were upregulated in the symbiotically germinated seeds (SGS). The functions of these genes in symbiotic germination were predicted. Furthermore, two fungus-induced calcium-dependent protein kinases (CDPKs), which were upregulated 6.76- and 26.69-fold in SGS compared with un-germinated seeds (UGS), were cloned from D. officinale and characterized for the first time. This study provides the first global overview of genes putatively involved in D. officinale symbiotic seed germination and provides a foundation for further functional research regarding symbiotic relationships in orchids. PMID:23967335

Zhao, Ming-Ming; Zhang, Gang; Zhang, Da-Wei; Hsiao, Yu-Yun; Guo, Shun-Xing

2013-01-01

71

ESTs analysis reveals putative genes involved in symbiotic seed germination in Dendrobium officinale.  

PubMed

Dendrobiumofficinale (Orchidaceae) is one of the world's most endangered plants with great medicinal value. In nature, D. officinale seeds must establish symbiotic relationships with fungi to germinate. However, the molecular events involved in the interaction between fungus and plant during this process are poorly understood. To isolate the genes involved in symbiotic germination, a suppression subtractive hybridization (SSH) cDNA library of symbiotically germinated D. officinale seeds was constructed. From this library, 1437 expressed sequence tags (ESTs) were clustered to 1074 Unigenes (including 902 singletons and 172 contigs), which were searched against the NCBI non-redundant (NR) protein database (E-value cutoff, e(-5)). Based on sequence similarity with known proteins, 579 differentially expressed genes in D. officinale were identified and classified into different functional categories by Gene Ontology (GO), Clusters of orthologous Groups of proteins (COGs) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. The expression levels of 15 selected genes emblematic of symbiotic germination were confirmed via real-time quantitative PCR. These genes were classified into various categories, including defense and stress response, metabolism, transcriptional regulation, transport process and signal transduction pathways. All transcripts were upregulated in the symbiotically germinated seeds (SGS). The functions of these genes in symbiotic germination were predicted. Furthermore, two fungus-induced calcium-dependent protein kinases (CDPKs), which were upregulated 6.76- and 26.69-fold in SGS compared with un-germinated seeds (UGS), were cloned from D. officinale and characterized for the first time. This study provides the first global overview of genes putatively involved in D. officinale symbiotic seed germination and provides a foundation for further functional research regarding symbiotic relationships in orchids. PMID:23967335

Zhao, Ming-Ming; Zhang, Gang; Zhang, Da-Wei; Hsiao, Yu-Yun; Guo, Shun-Xing

2013-01-01

72

Cloning and expression of a novel cDNA encoding a mannose-binding lectin from Dendrobium officinale  

Microsoft Academic Search

Using RNA extracted from Dendrobium officinale young leaves and primers designed according to the conservative regions of orchidaceae lectins, the full-length cDNA of Dendrobium officinale agglutinin2 (DOA2) was cloned by rapid amplification of cDNA ends (RACE). The full-length cDNA of doa2 was 777bp and contained a 513bp open reading frame (ORF) encoding a lectin precursor of 170 amino acids. Through

Zhonghai Chen; Xiaofen Sun; Kexuan Tang

2005-01-01

73

Bidirectional selection on threshold size for flowering in Cynoglossum officinale (hound's-tongue)  

Microsoft Academic Search

Previous studies have demonstrated that many facultative biennials show variation in threshold size for flowering. In order to quantify the genetic variation for this character, we performed a two-way artificial selection experiment on threshold size in Cynoglossum officinale. The parental generation, established from seed from a natural population, showed large variation in threshold sizes (2.6?13.4 g). After one generation of

Renate A Wesselingh; Tom J de Jong

1995-01-01

74

Histological study of some Echium vulgare, Pulmonaria officinalis and Symphytum officinale populations.  

PubMed

Plants living in different ecological habitats can show significant variability in their histological and phytochemical characters. The main histological features of various populations of three medicinal plants from the Boraginaceae family were studied. Stems, petioles and leaves were investigated by light microscopy in vertical and transverse sections. The outline of the epidermal cells, as well as the shape and cell number of trichomes was studied in leaf surface casts. Differences were measured among the populations of Echium vulgare in the width and height of epidermis cells in the stem, petiole and leaf, as well as in the size of palisade cells in the leaves. Among the populations of Pulmonaria officinalis significant differences were found in the length of trichomes and in the slightly or strongly wavy outline of epidermal radial cell walls. Populations of Symphytum officinale showed variance in the height of epidermal cells in leaves and stems, length of palisade cells and number of intercellular spaces in leaves, and the size of the central cavity in the stem. Boraginaceae bristles were found to be longer in plants in windy/shady habitats as opposed to sunny habitats, both in the leaves and stems ofP. officinalis and S. officinale, which might be connected to varying levels of exposure to wind. Longer epidermal cells were detected in the leaves and stems of both E. vulgare and S. officinale plants living in shady habitats, compared with shorter cells in sunny habitats. Leaf mesophyll cells were shorter in shady habitats as opposed to longer cells in sunny habitats, both in E. vulgare and S. officinale. This combination of histological characters may contribute to the plant's adaptation to various amounts of sunshine. The reported data prove the polymorphism of the studied taxa, as well as their ability to adapt to various ecological circumstances. PMID:22164787

Papp, Nóra; Bencsik, Tímea; Németh, Kitti; Gyergyák, Kinga; Sulc, Alexandra; Farkas, Agnes

2011-10-01

75

Potential for biparental cytoplasmic inheritance in Jasminum officinale and Jasminum nudiflorum  

Microsoft Academic Search

Mature Jasminum officinale and J. nudiflorum pollen grains were stained with 4?,6-diamidino-2-phenylindole (DAPI) and examined by epifluorescence microscopy. The pollen\\u000a grains were found to be trinucleate, and the sperm cells in both species contained a large number of epifluorescent spots\\u000a that corresponded to cytoplasmic DNA aggregates (nucleoids). The nucleoids of J. nudiflorum were observed to be dimorphic under the epifluorescence

Sodmergen; H. H. Bai; J. X. He; H. Kuroiwa; S. Kawano; T. Kuroiwa

1998-01-01

76

Chemistry, antioxidant and antimicrobial investigations on essential oil and oleoresins of Zingiber officinale  

Microsoft Academic Search

The essential oil and oleoresins (ethanol, methanol, CCl4 and isooctane) of Zingiber officinale were extracted respectively by hydrodistillation and Soxhlet methods and subjected to GC–MS analysis. Geranial (25.9%) was the major component in essential oil; eugenol (49.8%) in ethanol oleoresin, while in the other three oleoresins, zingerone was the major component (33.6%, 33.3% and 30.5% for, methanol, CCl4 and isooctane

Gurdip Singh; I. P. S. Kapoor; Pratibha Singh; Carola S. de Heluani; Marina P. de Lampasona; Cesar A. N. Catalan

2008-01-01

77

Structural characterization of a 2- O-acetylglucomannan from Dendrobium officinale stem  

Microsoft Academic Search

A heteropolysaccharide obtained from an aqueous extract of dried stem of Dendrobium officinale Kimura and Migo by anion-exchange chromatography and gel-permeation chromatography, was investigated by chemical techniques and NMR spectroscopy, and is demonstrated to be a 2-O-acetylglucomannan, composed of mannose, glucose, and arabinose in 40.2:8.4:1 molar ratios. It has a backbone of (1?4)-linked ?-d-mannopyranosyl residues and ?-d-glucopyranosyl residues, with branches

Yun-fen Hua; Ming Zhang; Cheng-xin Fu; Zhang-hui Chen; Gilbert Yuk Sing Chan

2004-01-01

78

Essential oils of Zingiber officinale var. rubrum Theilade and their antibacterial activities  

Microsoft Academic Search

The essential oils obtained by hydrodistilation of the leaves and rhizomes of Zingiber officinale var. rubrum Theilade were analysed by capillary GC and GC–MS. Forty-six constituents were identified in the leaf oil, while 54 were identified in the oil from the rhizomes. The leaf oil was clearly dominated by ?-caryophyllene (31.7%), while the oil from the rhizomes was predominantly monoterpenoid,

Yasodha Sivasothy; Wong Keng Chong; Abdul Hamid; Ibrahim M. Eldeen; Shaida Fariza Sulaiman; Khalijah Awang

2011-01-01

79

Root hairs.  

PubMed

Roots hairs are cylindrical extensions of root epidermal cells that are important for acquisition of nutrients, microbe interactions, and plant anchorage. The molecular mechanisms involved in the specification, differentiation, and physiology of root hairs in Arabidopsis are reviewed here. Root hair specification in Arabidopsis is determined by position-dependent signaling and molecular feedback loops causing differential accumulation of a WD-bHLH-Myb transcriptional complex. The initiation of root hairs is dependent on the RHD6 bHLH gene family and auxin to define the site of outgrowth. Root hair elongation relies on polarized cell expansion at the growing tip, which involves multiple integrated processes including cell secretion, endomembrane trafficking, cytoskeletal organization, and cell wall modifications. The study of root hair biology in Arabidopsis has provided a model cell type for insights into many aspects of plant development and cell biology. PMID:24982600

Grierson, Claire; Nielsen, Erik; Ketelaarc, Tijs; Schiefelbein, John

2014-01-01

80

Effect of Zingiber officinale R. rhizomes (ginger) on pain relief in primary dysmenorrhea: a placebo randomized trial  

PubMed Central

Background Zingiber officinale R. rhizome (ginger) is a popular spice that has traditionally been used to combat the effects of various inflammatory diseases. The aim of this study was to evaluate the effects of ginger on pain relief in primary dysmenorrhea. Method This was a randomized, controlled trial. The study was based on a sample of one hundred and twenty students with moderate or severe primary dysmenorrhea. The students were all residents of the dormitories of Shahed University. They were randomly assigned into two equal groups, one for ginger and the other for placebo in two different treatment protocols with monthly intervals. The ginger and placebo groups in both protocols received 500?mg capsules of ginger root powder or placebo three times a day. In the first protocol ginger and placebo were given two days before the onset of the menstrual period and continued through the first three days of the menstrual period. In the second protocol ginger and placebo were given only for the first three days of the menstrual period. Severity of pain was determined by a verbal multidimensional scoring system and a visual analogue scale. Results There was no difference in the baseline characteristics of the two groups (placebo n?=?46, ginger n?=?56). The results of this study showed that there were significant differences in the severity of pain between ginger and placebo groups for protocol one (P?=?0.015) and protocol two (P?=?0.029). There was also significant difference in duration of pain between the two groups for protocol one (P?=?0.017) but not for protocol two (P?=?0.210). Conclusion Treatment of primary dysmenorrhea in students with ginger for 5?days had a statistically significant effect on relieving intensity and duration of pain. Trial registration IRCT201105266206N3 PMID:22781186

2012-01-01

81

Determination of carotenoids in Taraxacum formosanum by HPLC-DAD-APCI-MS and preparation by column chromatography.  

PubMed

The objectives of this study were to determine the variety and content of carotenoids in Taraxacum formosanum, a traditional Chinese herb possessing vital biological activities, by developing an HPLC-DAD-APCI-MS method and a preparative column chromatographic method for carotenoid isolation. A total of 25 carotenoids were resolved within 66 min by employing a YMC C30 column and a gradient mobile phase of methanol-acetonitrile-water (79:14:7, v/v/v) and methylene chloride (100%) with flow rate at 1.0 mL/min and detection at 450 nm. All-trans-canthaxanthin was shown to be an appropriate internal standard for quantitation, with all-trans-?-carotene and its cis isomers present in largest amount (413.6 ?g/g), followed by all-trans-violoxanthin and its cis isomers (209.5 ?g/g), all-trans-lutein and its cis isomers (212.4 ?g/g), all-trans-neoxanthin and its cis isomers (134.6 ?g/g), antheraxanthin (16.5 ?g/g), all-trans-?-cryptoxanthin and its cis isomers (5.8 ?g/g), all-trans-zeaxanthin (3.6 ?g/g) and neochrome (0.1 ?g/g). For preparative chromatography, with a glass column containing 52 g of magnesium oxide-diatomaceous earth (1:3, w/w) as adsorbent, the carotenoid fraction was eluted with 300 mL of ethyl acetate with flow rate at 10 mL/min. Some more epoxides and cis isomers of carotenoids were generated during preparative column chromatography. Nevertheless, the carotenoids isolated from T. formosanum may be used as raw material for possible production of health food in the future. PMID:22502907

Kao, T H; Loh, C H; Inbaraj, B Stephen; Chen, B H

2012-07-01

82

Activity-Guided Isolation and Purification of Three Flavonoid Glycosides from Neo-Taraxacum siphonanthum by High-Speed Counter-Current Chromatography  

Microsoft Academic Search

DPPH (1,1-diphenyl-2-picryhydrazyl) radical scavenging assay was used to screen different fractions of Neo-Taraxacum siphonanthum ethanol extracts. The potent active fraction was isolated and purified by preparative high-speed counter-current chromatography (HSCCC) with a solvent system composed of n-hexane-n-butanol-water (3:4:7, v\\/v\\/v). The flow rate was 1.5 mL\\/min and resolution speed was 800 rpm. Three flavonoid glycosides with the purity over 99% were obtained and

Xinyu Jiang; Shuyun Shi; Yuping Zhang; Xiaoqing Chen

2010-01-01

83

[SCoT differential expression of cold resistance related genes in Dendrobium officinale under low temperature stress].  

PubMed

In order to study the molecule mechanism of the differential expression in Dendrobium officinale under low temperature, the high cold resistance germplasms were used for constructing the RNA pools. SCoT markers were used to analyze the different cDNA pools transcribed from the RNA pools. 11 transcripts derived fragments from 500 cDNA amplified bands were amplified by 64 primers, and were sorted out, cloned, sequenced and analyzed. The results showed that cDNA pools with SCoT markers could be used for differential display in D. officinale under low temperature stress. Sequence analysis indicated that the transcripts derived fragments were significantly homologous in nucleotide sequence with membrane-associated proteins, osmotic regulation protein, CBF transcriptional factor, resistance protein. One left gene segments functions were still unknown, which may be related to the cold resistant gene expression in D. officinale. PMID:23713274

Li, Dong-Bin; Gao, Yan-Hui; Si, Jin-Ping

2013-02-01

84

Cynoglossum officinale (hound's-tongue)--a cause of pyrrolizidine alkaloid poisoning in horses.  

PubMed

The death of 10 horses was attributed to feeding dried grass hay containing hound's-tongue, Cynoglossum officinale. Affected horses developed weight loss, icterus, photosensitization, and hepatic encephalopathy. Histologic examination of the liver of 3 of the horses revealed megalocytosis, biliary hyperplasia, and fibrosis characteristic of pyrrolizidine alkaloid poisoning. Hound's-tongue was found to contain large quantities (0.6% to 2.1%, dry matter basis) of toxic pyrrolizidine alkaloids, which, when fed to a pony for 20 days, caused liver fibrosis and biliary hyperplasia. PMID:6490488

Knight, A P; Kimberling, C V; Stermitz, F R; Roby, M R

1984-09-15

85

Warming and Intensified Summer Drought Influence Leaf Dark Respiration and Related Plant Traits in Three Dominant Species of the Southern Oak Savanna  

E-print Network

) little or no acclimation of respiration occurred when grown at low temperatures, while other species (Ranunculus acris, Anthoxanthum odoratum, Leucanthemum alpinum, Poa pratensis, Taraxacum alpinum, T. officinale) did exhibit acclimation of respiration...) little or no acclimation of respiration occurred when grown at low temperatures, while other species (Ranunculus acris, Anthoxanthum odoratum, Leucanthemum alpinum, Poa pratensis, Taraxacum alpinum, T. officinale) did exhibit acclimation of respiration...

Lindgren, Kourtnee Marr

2011-08-08

86

American Journal of Botany 91(5): 656663. 2004. THE POTENTIAL FOR GENETIC ASSIMILATION OF A  

E-print Network

OF A NATIVE DANDELION SPECIES, TARAXACUM CERATOPHORUM (ASTERACEAE), BY THE EXOTIC CONGENER T. OFFICINALE1 the initial stages of this process in Taraxacum ceratophorum (Asteraceae), the native alpine dandelion, and the invasive apomict T. officinale. In central Colorado, seven T. ceratophorum populations all occur

Cruzan, Mitchell B.

87

Development of SCAR (sequence-characterized amplified region) markers as a complementary tool for identification of ginger (Zingiber officinale Roscoe) from crude drugs and multicomponent formulations.  

PubMed

Zingiber officinale Roscoe (common or culinary ginger) is an official drug in Ayurvedic, Indian herbal, Chinese, Japanese, African and British Pharmacopoeias. The objective of the present study was to develop DNA-based markers that can be applied for the identification and differentiation of the commercially important plant Z. officinale Roscoe from the closely related species Zingiber zerumbet (pinecone, bitter or 'shampoo' ginger) and Zingiber cassumunar [cassumunar or plai (Thai) ginger]. The rhizomes of the other two Zingiber species used in the present study are morphologically similar to that of Z. officinale Roscoe and can be used as its adulterants or contaminants. Various methods, including macroscopy, microscopy and chemoprofiling, have been reported for the quality control of crude ginger and its products. These methods are reported to have limitations in distinguishing Z. officinale from closely related species. Hence, newer complementary methods for correct identification of ginger are useful. In the present study, RAPD (random amplification of polymorphic DNA) analysis was used to identify putative species-specific amplicons for Z. officinale. These were further cloned and sequenced to develop SCAR (sequence-characterized amplified region) markers. The developed SCAR markers were tested in several non-Zingiber species commonly used in ginger-containing formulations. One of the markers, P3, was found to be specific for Z. officinale and was successfully applied for detection of Z. officinale from Trikatu, a multicomponent formulation. PMID:17868041

Chavan, Preeti; Warude, Dnyaneshwar; Joshi, Kalpana; Patwardhan, Bhushan

2008-05-01

88

Positive and negative effects of herbivory on the population dynamics of Senecio jacobaea L. and Cynoglossum officinale L  

Microsoft Academic Search

Herbivore effects were studied on populations of the biennial plant species Senecio jacobaea and Cynoglossum officinale. During a three year period (1985–1988) population characteristics (herbivory, number of seedlings, rosettes and flowering plants) were compared in-and outside exclosures, as well as parameters reflecting vegetation cover. In S. jacobaea, a strong negative effect of Tyria jacobaeae was found on seedling establishment, rosette

A. H. Prins; H. W. Nell

1990-01-01

89

Anxiolytic-like effect of combined extracts of zingiber officinale and ginkgo biloba in the elevated plus-maze  

Microsoft Academic Search

The effects of the known anxiolytic compound diazepam (DZ) on the behavior of rats in the elevated plus-maze were compared with those of zingicomb (ZC) (registered trademark of Mattern et Partner), a combination preparation of standardized extracts of ginkgo biloba and zingiber officinale. DZ was administered intraperitoneally (IP) in a reference dosage of 1 mg\\/kg 30 min before the rats

R. U. Hasenöhrl; Ch. Nichau; Ch. Frisch; M. A. De Souza Silva; J. P. Huston; C. M. Mattern; R. Häcker

1996-01-01

90

[Quantitive variation of polysaccharides and alcohol-soluble extracts in F1 generation of Dendrobium officinale].  

PubMed

Using phenol-sulfuric acid method and hot-dip method of alcohol-soluble extracts, the contents of polysaccharides and alcohol-soluble extracts in 11 F1 generations of Dendrobium officinale were determined. The results showed that the polysaccharides contents in samples collected in May and February were 32.89%-43.07% and 25.77%-35.25%, respectively, while the extracts contents were 2.81%-4.85% and 7.90%-17.40%, respectively. They were significantly different among families. The content of polysaccharides in offspring could be significantly improved by hybridization between parents with low and high polysaccharides contents, and the hybrid vigor was obvious. Cross breeding was an effective way for breeding new varieties with higher polysaccharides contents. Harvest time would significantly affect the contents of polysaccharides and alcohol-soluble extracts. The contents of polysaccharides in families collected in May were higher than those of polysaccharides in families collected in February, but the extracts content had the opposite variation. The extents of quantitative variation of polysaccharides and alcohol-soluble extracts were different among families, and each family had its own rules. It would be significant in giving full play to their role as the excellent varieties and increasing effectiveness by studying on the quantitative accumulation regularity of polysaccharides and alcohol-soluble extracts in superior families (varieties) of D. officinale to determine the best harvesting time. PMID:24494555

Zhang, Xiao-Ling; Liu, Jing-Jing; Wu, Ling-Shang; Si, Jin-Ping; Guo, Ying-Ying; Yu, Jie; Wang, Lin-Hua

2013-11-01

91

Root gravitropism  

NASA Technical Reports Server (NTRS)

When a plant root is reoriented within the gravity field, it responds by initiating a curvature which eventually results in vertical growth. Gravity sensing occurs primarily in the root tip. It may involve amyloplast sedimentation in the columella cells of the root cap, or the detection of forces exerted by the mass of the protoplast on opposite sides of its cell wall. Gravisensing activates a signal transduction cascade which results in the asymmetric redistribution of auxin and apoplastic Ca2+ across the root tip, with accumulation at the bottom side. The resulting lateral asymmetry in Ca2+ and auxin concentration is probably transmitted to the elongation zone where differential cellular elongation occurs until the tip resumes vertical growth. The Cholodny-Went theory proposes that gravity-induced auxin redistribution across a gravistimulated plant organ is responsible for the gravitropic response. However, recent data indicate that the gravity-induced reorientation is more complex, involving both auxin gradient-dependent and auxin gradient-independent events.

Masson, P. H.

1995-01-01

92

10-Shogaol, an Antioxidant from Zingiber officinale for Skin Cell Proliferation and Migration Enhancer  

PubMed Central

In this work, one of Zingiber officinale components, 10-shogaol, was tested with 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging, metal chelating ability, and reducing power to show antioxidant activity. 10-Shogaol promoted human normal epidermal keratinocytes and dermal fibroblasts cell growths. 10-Shogaol enhanced growth factor production in transforming growth factor-? (TGF-?), platelet derived growth factor-?? (PDGF-??) and vascular endothelial growth factors (VEGF) of both cells. In the in vitro wound healing assay for 12 or 24 h, with 10-shogaol, the fibroblasts and keratinocytes migrated more rapidly than the vehicle control group. Thus, this study substantiates the target compound, 10-shogaol, as an antioxidant for human skin cell growth and a migration enhancer with potential to be a novel wound repair agent. PMID:22408422

Chen, Chung-Yi; Cheng, Kuo-Chen; Chang, Andy Y; Lin, Ying-Ting; Hseu, You-Cheng; Wang, Hui-Min

2012-01-01

93

Food Value of Two Varieties of Ginger (Zingiber officinale) Commonly Consumed in Nigeria  

PubMed Central

Ginger (Zingiber officinale) is a well-known and widely used herb, which contains several interesting bioactive constituents and possesses health-promoting properties. The proximate, mineral, antinutrient, amino acid, and phytochemical components of two varieties of ginger (Zingiber officinale) were investigated. Amino acid composition was determined using standard analytical techniques. The results obtained in percentages in the two varieties of ginger (white and yellow types) were crude fibre (21.90, 8.30), fat (17.11, 9.89), carbohydrate (39.70, 58.21), crude protein (12.05, 11.65), ash (4.95, 7.45) and moisture (3.95, 4.63) contents respectively. Elemental analysis revealed that potassium (0.98?ppm and 1.38?ppm) is the most abundant, while copper (0.01?ppm) is the least. Phytochemical screening indicated that they are both rich in saponins, anthraquinones, phlobatannin and glycosides. Also, the antinutrient constituents of white ginger were lower than yellow ginger, although the levels of the antinutrient constituents in the two varieties are saved for consumption. The essential amino acids in the two varieties were almost the same, with Leu being the most abundant in both. The two ginger varieties were adequate only in Leu, Phe?+?Try, and valine based on FAO/WHO provisional pattern. Overall, the findings indicate that the two varieties of ginger are good sources of nutrients, mineral elements, amino acid, and phytochemicals which could be exploited as great potentials for drugs and/or nutritional supplements. PMID:24967255

Ajayi, Olubunmi B.; Akomolafe, Seun F.; Akinyemi, Funmilayo T.

2013-01-01

94

Zingiber Officinale Alters 3,4-methylenedioxymethamphetamine-Induced Neurotoxicity in Rat Brain  

PubMed Central

Objective: The spice Zingiber officinale or ginger possesses antioxidant activity and neuroprotective effects. The effects of this traditional herbal medicine on 3,4-methylenedioxymethamphetamine (MDMA) induced neurotoxicity have not yet been studied. The present study considers the effects of Zingiber officinale on MDMA-induced spatial memory impairment and apoptosis in the hippocampus of male rats. Materials and Methods: In this experimental study, 21 adult male Sprague Dawley rats (200-250 g) were classified into three groups (control, MDMA, and MDMA plus ginger). The groups were intraperitoneally administered 10 mg/kg MDMA, 10 mg/kg MDMA plus 100 mg/kg ginger extract, or 1 cc/kg normal saline as the control solution for one week (n=7 per group). Learning memory was assessed by Morris water maze (MWM) after the last administration. Finally, the brains were removed to study the cell number in the cornu ammonis (CA1) hippocampus by light microscope, Bcl-2 by immunoblotting, and Bax expression by reverse transcription polymerase chain reaction (RT-PCR). Data was analyzed using SPSS 16 software and a one-way ANOVA test. Results: Escape latency and traveled distances decreased significantly in the MDMA plus ginger group relative to the MDMA group (p<0.001). Cell number increased in the MDMA plus ginger group in comparison to the MDMA group. Down-regulation of Bcl-2 and up-regulation of Bax were observed in the MDMA plus ginger group in comparison to the MDMA group (p<0.05). Conclusion: Our findings suggest that ginger consumption may lead to an improvement of MDMA-induced neurotoxicity. PMID:23508562

Mehdizadeh, Mehdi; Dabaghian, Fataneh; Nejhadi, Akram; Fallah-huseini, Hassan; Choopani, Samira; Shekarriz, Nima; Molavi, Nima; Basirat, Arghavan; Mohammadzadeh Kazorgah, Farzaneh; Samzadeh-Kermani, Alireza; Soleimani Asl, Sara

2012-01-01

95

Host identity impacts rhizosphere fungal communities associated with three alpine plant species.  

PubMed

Fungal diversity and composition are still relatively unknown in many ecosystems; however, host identity and environmental conditions are hypothesized to influence fungal community assembly. To test these hypotheses, we characterized the richness, diversity, and composition of rhizosphere fungi colonizing three alpine plant species, Taraxacum ceratophorum, Taraxacum officinale, and Polemonium viscosum. Roots were collected from open meadow and willow understory habitats at treeline on Pennsylvania Mountain, Colorado, USA. Fungal small subunit ribosomal DNA was sequenced using fungal-specific primers, sample-specific DNA tags, and 454 pyrosequencing. We classified operational taxonomic units (OTUs) as arbuscular mycorrhizal (AMF) or non-arbuscular mycorrhizal (non-AMF) fungi and then tested whether habitat or host identity influenced these fungal communities. Approximately 14% of the sequences represented AMF taxa (44 OTUs) with the majority belonging to Glomus groups A and B. Non-AMF sequences represented 186 OTUs belonging to Ascomycota (58%), Basidiomycota (26%), Zygomycota (14%), and Chytridiomycota (2%) phyla. Total AMF and non-AMF richness were similar between habitats but varied among host species. AMF richness and diversity per root sample also varied among host species and were highest in T. ceratophorum compared with T. officinale and P. viscosum. In contrast, non-AMF richness and diversity per root sample were similar among host species except in the willow understory where diversity was reduced in T. officinale. Fungal community composition was influenced by host identity but not habitat. Specifically, T. officinale hosted a different AMF community than T. ceratophorum and P. viscosum while P. viscosum hosted a different non-AMF community than T. ceratophorum and T. officinale. Our results suggest that host identity has a stronger effect on rhizosphere fungi than habitat. Furthermore, although host identity influenced both AMF and non-AMF, this effect was stronger for the mutualistic AMF community. PMID:22038036

Becklin, Katie M; Hertweck, Kate L; Jumpponen, Ari

2012-04-01

96

Genes involved in ethylene and gibberellins metabolism are required for endosperm-limited germination of Sisymbrium officinale L. seeds  

Microsoft Academic Search

The rupture of the seed coat and that of the endosperm were found to be two sequential events in the germination of Sisymbrium officinale L. seeds, and radicle protrusion did not occur exactly in the micropylar area but in the neighboring zone. The germination\\u000a patterns were similar both in the presence of gibberellins (GA4+7) and in presence of ethrel. The

Raquel Iglesias-Fernández; Angel J. Matilla

2010-01-01

97

Use of Peroxyacetic Acid as Green Chemical on Yield and Sensorial Quality in Watercress (Nasturtium officinale R. Br.) Under Soilless Culture  

PubMed Central

The goal of this research was to evaluate the effect of different doses of peroxyacetic acid on the productivity of watercress (Nasturtium officinale R. Br.) cultivated hydroponically using a constant nutritive solution. Green chemistry in protected horticulture seeks compatibility with the environment through the creation of biodegradable byproducts. In hydroponics, appropriate doses of peroxyacetic mixtures deliver these byproducts while also oxygenating the roots. Watercress producers who recirculate the nutritive solution can use these mixtures in order to increase oxygenation in the hydroponic system. The experiment took place between August and December 2009, beginning with the planting of the watercress seeds and concluding with the completion of the sensory panels. A completely random design was used, including three treatments and four repetitions, with applications of 0, 20 and 40 mg L?1 of the peroxyacetic mixture. Measured variables were growth (plant height, leaf length and stem diameter), yield (weight per plant and dry matter) and organoleptic quality (color and sensory panel). The application of 40 mg L?1 of the peroxyacetic mixture had a greater effect on the growth and development of the plants, which reached an average height of 29.3 cm, stem diameter of 3.3 mm and leaf length of 7.6 cm, whereas the control group reached an average height of only 20.2 cm, stem diameter of 1.9 mm and leaf length of 5.7 cm. The application of the peroxyacetic mixtures resulted in an improvement in growth parameters as well as in yield. Individual weights achieved using the 40 mg L?1 dose were 1.3 g plant?1 in the control group and 3.4 g plant?1 in the experimental group (62% yield increase). Sensory analysis revealed no differences in organoleptic quality. PMID:22272143

Carrasco, Gilda; Moggia, Claudia; Osses, Ingrid Jennifer; Alvaro, Juan Eugenio; Urrestarazu, Miguel

2011-01-01

98

Use of peroxyacetic acid as green chemical on yield and sensorial quality in Watercress (Nasturtium officinale R. Br.) under soilless culture.  

PubMed

The goal of this research was to evaluate the effect of different doses of peroxyacetic acid on the productivity of watercress (Nasturtium officinale R. Br.) cultivated hydroponically using a constant nutritive solution. Green chemistry in protected horticulture seeks compatibility with the environment through the creation of biodegradable byproducts. In hydroponics, appropriate doses of peroxyacetic mixtures deliver these byproducts while also oxygenating the roots. Watercress producers who recirculate the nutritive solution can use these mixtures in order to increase oxygenation in the hydroponic system. The experiment took place between August and December 2009, beginning with the planting of the watercress seeds and concluding with the completion of the sensory panels. A completely random design was used, including three treatments and four repetitions, with applications of 0, 20 and 40 mg L(-1) of the peroxyacetic mixture. Measured variables were growth (plant height, leaf length and stem diameter), yield (weight per plant and dry matter) and organoleptic quality (color and sensory panel). The application of 40 mg L(-1) of the peroxyacetic mixture had a greater effect on the growth and development of the plants, which reached an average height of 29.3 cm, stem diameter of 3.3 mm and leaf length of 7.6 cm, whereas the control group reached an average height of only 20.2 cm, stem diameter of 1.9 mm and leaf length of 5.7 cm. The application of the peroxyacetic mixtures resulted in an improvement in growth parameters as well as in yield. Individual weights achieved using the 40 mg L(-1) dose were 1.3 g plant(-1) in the control group and 3.4 g plant(-1) in the experimental group (62% yield increase). Sensory analysis revealed no differences in organoleptic quality. PMID:22272143

Carrasco, Gilda; Moggia, Claudia; Osses, Ingrid Jennifer; Alvaro, Juan Eugenio; Urrestarazu, Miguel

2011-01-01

99

Nitrate-induced early transcriptional changes during imbibition in non-after-ripened Sisymbrium officinale seeds.  

PubMed

We have here demonstrated for the first time that nitrate not only accelerates testa rupture of non- AR seeds but also modifies expression pattern of the cell-wall remodeling proteins (mannanases; SoMAN6 and SoMAN7) and key genes belonging to metabolism and signaling of ABA (SoNCED6, SoNCED9, SoCYP707A2 and SoABI5) and GAs (SoGA3ox, SoGA20ox, SoGA2ox and SoRGL2). These results were obtained during Sisymbrium officinale seed imbibition in the absence of endosperm rupture. Exogenous ABA induced a notable inhibition of testa rupture in both absence and presence of nitrate being this effect sharply reversed by GA(4+7). However, nitrate was capable to provoke testa rupture in absence of ABA synthesis. The expression of SoMAN6 and SoMAN7 were positively altered by nitrate. Although ABA synthesis seems apparent at the start of non-AR seed imbibition, taken together the results of SoNCED6, SoNCED9 and SoCYP707A2 expression seem to suggest that nitrate leads to a strong net ABA decrease. Likewise, nitrate positively affected the SoABI5 expression when the SoNCED9 expression was also stimulated. By contrast, at the early and final of imbibition, nitrate clearly inhibited the SoABI5 expression. The expression of SoGA2ox6 and SoGA3ox2 are strongly inhibited by nitrate whereas of SoGA20ox6 was stimulated. On the other hand, SoRGL2 transcript level decreased in the presence of nitrate. Taken together, the results presented here suggest that the nitrate signaling is already operative during the non-AR S. officinale seeds imbibition. The nitrate, in cross-talk with the AR network likely increases the favorable molecular conditions that trigger germination. PMID:23106241

Carrillo-Barral, Nestor; Matilla, Angel J; Iglesias-Fernández, Raquel; Del Carmen Rodríguez-Gacio, María

2013-08-01

100

In vivo wound healing effects of Symphytum officinale L. leaves extract in different topical formulations.  

PubMed

The present work evaluates wound healing activity of leaves extracts of Symphytum officinale L. (comfrey) incorporated in three pharmaceutical formulations. Wound healing activity of comfrey was determined by qualitative and quantitative histological analysis of open wound in rat model, using allantoin as positive control. Three topical formulations, carbomer gel, glycero-alcoholic solution and O/W emulsion (soft lotion) were compared. The histological analysis of the healing process shows significant differences in treatment, particularly on its intensity and rate. The results indicate that emulsion containing both extracts, commercial and prepared, induced the largest and furthest repair of damaged tissue. This could be evidenced from day 3 to 28 by increase in collagen deposition from 40% to 240% and reduction on cellular inflammatory infiltrate from 3% to 46%. However, 8% prepared extract in emulsion presented the best efficacy. This work clearly demonstrates that comfrey leaves have a wound healing activity. The O/W emulsion showed to be the vehicle most effective to induce healing activity, particularly with extracts obtained from comfrey leaves collected in Minas Gerais state in Brazil. It shows the best efficacy to control the inflammatory process and to induce collagen deposition at 8% concentration. PMID:22570943

Araújo, L U; Reis, P G; Barbosa, L C O; Saúde-Guimarães, D A; Grabe-Guimarães, A; Mosqueira, V C F; Carneiro, C M; Silva-Barcellos, N M

2012-04-01

101

[Field experiment of F1 generation and superior families selection of Dendrobium officinale].  

PubMed

Based on randomized block design of experiment, agronomic traits and yields of 14 F1 generations of Dendrobium officinale were determined. The results showed that the differences in agronomic traits and yields among families were significant, and the hybrid vigor was obvious. Families of 6b x 2a, 9 x 66 and 78 x 69 were selected with the remarkable superiority of yields, agronomic traits and product customization. Correlation analysis between agronomic traits and yields showed that plant height, stem diameter, leaf number, blade length and blade width were all significantly correlated with biological yields and economic yields. Among which, stem diameter, leaf number and blade length were the most significant, and an optimal linear regression model could be established. When the number of shoots was fewer than 4.5, both biological yields and economic yields increased with the increasing number of shoots, but it could not much affect yields when the number of shoots was larger than 4.5. Shoots number, stem diameter and leaf index were basic stability when compared biennial traits to annual, which could be used for early selection. PMID:24558865

Zhang, Xiao-Ling; Si, Jin-Ping; Wu, Ling-Shang; Guo, Ying-Ying; Yu, Jie; Wang, Lin-Hua

2013-11-01

102

Total antioxidant activity and antimicrobial potency of the essential oil and oleoresin of Zingiber officinale Roscoe  

PubMed Central

Objective To compare in vitro antioxidant and antimicrobial activities of the essential oil and oleoresin of Zingiber officinale Roscoe. Methods The antioxidant activity was evaluated based on the ability of the ginger extracts to scavenge ABTS°+ free radical. The antimicrobial activity was studied by the disc diffusion method and minimal inhibitory concentration was determined by using the agar incorporation method. Results Ginger extracts exerted significant antioxidant activity and dose-depend effect. In general, oleoresin showed higher antioxidant activity [IC50=(1.820±0.034) mg/mL] when compared to the essential oil [IC50=(110.14±8.44) mg/mL]. In terms of antimicrobial activity, ginger compounds were more effective against Escherichia coli, Bacillus subtilis and Staphylococcus aureus, and less effective against Bacillus cereus. Aspergillus niger was least, whereas, Penicillium spp. was higher sensitive to the ginger extracts; minimal inhibitory concentrations of the oleoresin and essential oil were 2 mg/mL and 869.2 mg/mL, respectively. Moreover, the studied extracts showed an important antifungal activity against Candida albicans. Conclusions The study confirms the wide application of ginger oleoresin and essential oil in the treatment of many bacterial and fungal diseases.

Bellik, Yuva

2014-01-01

103

Cloning, expression, purification and characterization of recombinant (+)-germacrene D synthase from Zingiber officinale.  

PubMed

A cDNA clone encoding a sesquiterpene synthase, (+)-germacrene D synthase, has been isolated from ginger (Zingiber officinale). The full-length cDNA (AY860846) contains a 1650-bp open reading frame coding for 550 amino acids (63.8kDa) with a theoretical pI=5.59. The deduced amino acid sequence is 30-46% identical with sequences of other sesquiterpene synthases from angiosperms. The recombinant enzyme, produced in Escherichia coli, catalyzed the formation of a major product, (+)-germacrene D (50.2% of total sesquiterpenoids produced) and a co-product, germacrene B (17.1%) and a number of minor by-products. The optimal pH for the recombinant enzyme is around 7.5. Substantial (+)-germacrene D synthase activity is observed in the presence of Mg2+, Mn2+, Ni2+ or Co2+, while the enzyme is inactive when Cu2+ or Zn2+ is used. The Km- and kcat-values are 0.88 microM and 3.34 x 10(-3) s(-1), respectively. A reaction mechanism involving a double 1,2-hydride shift has been established using deuterium labeled substrates in combination with GC-MS analysis. PMID:16839518

Picaud, Sarah; Olsson, Mikael E; Brodelius, Maria; Brodelius, Peter E

2006-08-01

104

Essential oil composition of diploid and tetraploid clones of ginger (Zingiber officinale Roscoe) grown in Australia.  

PubMed

Ginger oil, obtained by steam distillation of the rhizome of Zingiber officinale Roscoe, is used in the beverage and fragrance industries. Ginger oil displays considerable compositional diversity, but is typically characterized by a high content of sesquiterpene hydrocarbons, including zingiberene, ar-curcumene, beta-bisabolene, and beta-sesquiphellandrene. Australian ginger oil has a reputation for possessing a particular "lemony" aroma, due to its high content of the isomers neral and geranial, often collectively referred to as citral. Fresh rhizomes of 17 clones of Australian ginger, including commercial cultivars and experimental tetraploid clones, were steam distilled 7 weeks post-harvest, and the resulting oils were analyzed by GC-MS. The essential oils of 16 of the 17 clones, including the tetraploid clones and their parent cultivar, were found to be of substantially similar composition. These oils were characterized by very high citral levels (51-71%) and relatively low levels of the sesquiterpene hydrocarbons typical of ginger oil. The citral levels of most of these oils exceeded those previously reported for ginger oils. The neral-to-geranial ratio was shown to be remarkably constant (0.61 +/- 0.01) across all 17 clones. One clone, the cultivar "Jamaican", yielded oil with a substantially different composition, lower citral content and higher levels of sesquiterpene hydrocarbons. Because this cultivar also contains significantly higher concentrations of pungent gingerols, it possesses unique aroma and flavor characteristics, which should be of commercial interest. PMID:16478268

Wohlmuth, Hans; Smith, Mike K; Brooks, Lyndon O; Myers, Stephen P; Leach, David N

2006-02-22

105

[Cloning and analysis of reverse transcriptase(RT) of Ty1-copia retrotransposons in Dendrobium officinale].  

PubMed

Using universal primer Ty1-copia retrotransposon RT,43 Ty1-copia like retrotransposon RT with high heterogeneity, stop codon mutation and frameshift mutation were amplified by PCR from genomic DNA of Zhejiang Lin'an (C15) and Yunnan Guangnan (A39) of Dendrobium officinale. The length of these sequences varied from 260 to 266 bp, and was rich in AT and consistency ranged from 47.1% to 97.7%. Different c/s-acting regulatory elements induced by low temperature, heat, light, all kinds of plant growth regulating substances and the starting transcription signals, corresponding to CAAT box, TATA box conserved sequences and some other regulatory elements. When being translated into amino acids, ten sequences presented stop codon mutation, five sequences presented frameshift mutation, and thirty-seven sequences presented conserved sequence "SLYGKQ" mutation. Six categories were identified through phylogenic analysis after alignment analyses of their amino acid sequences, and with other plants (eg. Triticum aestivum, Eleocharis quinqueflora) having high homology, which indicated that horizontal transmission of retrotransposon occurred among the plants in the past. PMID:24761633

Li, Cong; Si, Jin-Ping; Gao, Yan-Hui; Zhu, Yu-Qiu

2014-01-01

106

Roots and Shoots  

NSDL National Science Digital Library

In this outdoor activity, learners discover that plants aren't just shoots (stem, branches, leaves, and flowers) growing above ground, but contain plenty of roots growing undergroundâmore than half the mass of a plant can be its roots. Learners dig up "mystery" plants to investigate their root structures, and match them to different types of root systems. Learners also learn about animals found near plant roots and how humans use roots.

Science, Lawrence H.

2008-01-01

107

Genetic variation in constitutive and inducible pyrrolizidine alkaloid levels in Cynoglossum officinale L  

Microsoft Academic Search

The constitutive pyrrolizidine alkaloid (PA) concentration of both shoots and roots differed significantly between 17 selfed families. The broad-sense heritability accounted for 33–43% of the variation in PA levels. Families also differed significantly in the amount and the direction of PA induction in both shoots and roots, 24 h after punching 15 holes in the leaves. We found a significantly

Nicole M. van Dam; Klaas Vrieling

1994-01-01

108

Pyrrole detection and the pathologic progression of Cynoglossum officinale (houndstongue) poisoning in horses.  

PubMed

Houndstongue (Cynoglossum officinale), a noxious weed that contains pyrrolizidine alkaloids (PAs), infests pastures and fields in the western United States and Europe. The purpose of this study was to develop techniques to better diagnose PA poisoning and describe the progression of gross and microscopic lesions caused by houndstongue intoxication. Six horses were gavaged daily with a suspension of houndstongue containing 5 or 15 mg/kg total PA for 14 days. Two horses were treated similarly with ground alfalfa as controls. Liver biopsy samples and serum biochemical and hematologic values were evaluated biweekly. Within 7 days after dosing, horses treated with 15 mg/kg PA developed severe liver disease characterized by altered bile acid metabolism, elevated serum enzymes, and extensive hepatocellular necrosis with minimal periportal fibrosis and biliary hyperplasia. The condition of these animals continued to deteriorate, and they were euthanized. For several weeks after dosing, horses treated with 5 mg/kg PA were depressed, had transient elevations of serum enzymes and bile acids, and developed minimal periportal hepatocellular necrosis with fibrosis. The biochemical changes resolved by 6-8 weeks; however, the histologic disease persisted with extensive megalocytosis by week 14. Throughout the study, the rate of hepatocellular proliferation remained constant. Biliary cells had an increase in mitotic rate that correlated with the histologic changes. Hepatic tissue-bound pyrroles (PA metabolites) were identified in necropsy samples of treated animals using gas chromatography/mass spectrometry and photometrically with Ehrlich's reagent. These findings suggest that pyrrole extraction and identification are useful in documenting PA exposure and that houndstongue is extremely toxic to horses. PMID:9026086

Stegelmeier, B L; Gardner, D R; James, L F; Molyneux, R J

1996-01-01

109

Comfrey (Symphytum Officinale. l.) and Experimental Hepatic Carcinogenesis: A Short-term Carcinogenesis Model Study.  

PubMed

Comfrey or Symphytum officinale (L.) (Boraginaceae) is a very popular plant used for therapeutic purposes. Since the 1980s, its effects have been studied in long-term carcinogenesis studies, in which Comfrey extract is administered at high doses during several months and the neoplastic hepatic lesions are evaluated. However, the literature on this topic is very poor considering the studies performed under short-term carcinogenesis protocols, such as the 'resistant hepatocyte model' (RHM). In these studies, it is possible to observe easily the phenomena related to the early phases of tumor development, since pre-neoplastic lesions (PNLs) rise in about 1-2 months of chemical induction. Herein, the effects of chronic oral treatment of rats with 10% Comfrey ethanolic extract were evaluated in a RHM. Wistar rats were sequentially treated with N-nitrosodiethylamine (ip) and 2-acetilaminofluorene (po), and submitted to hepatectomy to induce carcinogenesis promotion. Macroscopic/microscopic quantitative analysis of PNL was performed. Non-parametric statistical tests (Mann-Whitney and ?(2)) were used, and the level of significance was set at P ? 0.05. Comfrey treatment reduced the number of pre-neoplastic macroscopic lesions up to 1 mm (P ? 0.05), the percentage of oval cells (P = 0.0001) and mitotic figures (P = 0.007), as well as the number of Proliferating Cell Nuclear Antigen (PCNA) positive cells (P = 0.0001) and acidophilic pre-neoplastic nodules (P = 0.05). On the other hand, the percentage of cells presenting megalocytosis (P = 0.0001) and vacuolar degeneration (P = 0.0001) was increased. Scores of fibrosis, glycogen stores and the number of nucleolus organizing regions were not altered. The study indicated that oral treatment of rats with 10% Comfrey alcoholic extract reduced cell proliferation in this model. PMID:18955295

Gomes, Maria Fernanda Pereira Lavieri; de Oliveira Massoco, Cristina; Xavier, José Guilherme; Bonamin, Leoni Villano

2010-06-01

110

[Effect of ABA on transcriptionally active Ty1-copia retrotransposons in Dendrobium officinale].  

PubMed

Using universal primer Tyl-copia retrotransposon RT, the conserved reverse transcriptase domain of about 260 bp was amplified by RT-PCR from the Dendrobium officinale which induced by 100 micromol x L(-1) abscisic acid (ABA), indicating these retrotransposons activated by 100 micromol x L(-1) ABA. The amplicons were recovered and cloned,then sequenced and analyzed by related bioinformatics software. Forty-two Ty1-copia like retrotransposon RT transcriptionally activated were obtained with high heterogeneity. The length of these sequences varied from 247 to 266 bp, and was rich in AT and homology ranged from 46.3% to 98.9%. The same to Ty1-copia like retrotransposon RT of genome, different c/s-acting regulatory elements induced by stress conditions and the starting transcription signals, corresponding to CAAT box, TATA box conserved sequences and some other regulatory elements. The c/s-acting regulatory elements induced by stress conditions of reverse transcriptase transcriptionally activated of Tyl-copia retrotransposons were significantly increased than that of Ty1-copia like retrotransposon RT of genome. When being translated into amino acids, fifteen sequences presented stop codon mutation, nineteen sequences presented frameshift mutation, and all sequences presented conserved sequence "SLYGKQ" mutation. Five categories were identified through phylogenic analysis after alignment analyses of their amino acid sequences, and with Ty1-copia like retrotransposon RT of genome having low homology, which indicated that reverse transcriptase transcriptionally activated of Ty1-copia retrotransposons which induced by ABA had Significantly differences with Ty1-copia like retrotransposon RT of genome. PMID:25282883

Li, Cong; Si, Jin-Ping; Gao, Yan-Hui; Zhu, Yu-Qiu; Jiang, Yuan

2014-05-01

111

Determination of Phenolic Acids and Flavonoids in Taraxacum formosanum Kitam by Liquid Chromatography-Tandem Mass Spectrometry Coupled with a Post-Column Derivatization Technique  

PubMed Central

A liquid chromatography-tandem mass spectrometry method (LC-MS/MS) was developed for the determination of phenolic acids and flavonoids in a medicinal Chinese herb Taraxacum formosanum Kitam. Initially, both phenolic acids and flavonoids were extracted with 50% ethanol in a water-bath at 60 °C for 3 h and eventually separated into acidic fraction and neutral fraction by using a C18 cartridge. A total of 29 compounds were separated within 68 min by employing a Gemini C18 column and a gradient solvent system of 0.1% formic acid and acetonitrile at a flow rate of 1.0 mL/min. Based on the retention behavior as well as absorption and mass spectra, 19 phenolic acids and 10 flavonoids were identified and quantified in T. formosanum, with the former ranging from 14.1 ?g/g to 10,870.4 ?g/g, and the latter from 9.9 ?g/g to 325.8 ?g/g. For further identification of flavonoids, a post-column derivatization method involving shift reagents such as sodium acetate or aluminum chloride was used and the absorption spectral characteristics without or with shift reagents were compared. An internal standard syringic acid was used for quantitation of phenolic acids, whereas (±) naringenin was found suitable for quantitation of flavonoids. The developed LC-MS/MS method showed high reproducibility, as evident from the relative standard deviation (RSD) values for intra-day and inter-day variability being 1.0–6.8% and 2.0–7.7% for phenolic acids and 3.7–7.4% and 1.5–8.1% for flavonoids, respectively, and thus may be applied for simultaneous determination of phenolic acids and flavonoids in Chinese herb and nutraceuticals. PMID:22312251

Chen, Hung-Ju; Inbaraj, Baskaran Stephen; Chen, Bing-Huei

2012-01-01

112

Determination of chlorophylls in Taraxacum formosanum by high-performance liquid chromatography-diode array detection-mass spectrometry and preparation by column chromatography.  

PubMed

Taraxacum formosanum, a well-known Chinese herb shown to be protective against hepatic cancer as well as liver and lung damage, may be attributed to the presence of abundant carotenoids and chlorophylls. However, the variety and content of chlorophylls remain uncertain. The objectives of this study were to develop an high-performance liquid chromatography-diode array detection-mass spectrometry method for determination of chlorophylls in T. formosanum and preparation by column chromatography. An HyPURITY C18 column and a gradient mobile phase of water (A), methanol (B), acetonitrile (C), and acetone (D) could resolve 10 chlorophylls and an internal standard Fast Green FCF within 30 min with a flow rate at 1 mL/min and detection at 660 nm. Both chlorophylls a and a' were present in the largest amount (1389.6 ?g/g), followed by chlorophylls b and b' (561.2 ?g/g), pheophytins a and a' (31.7 ?g/g), hydroxychlorophyll b (26.5 ?g/g), hydroxychlorophylls a and a' (9.8 ?g/g), and chlorophyllides a and a' (0.35 ?g/g). A glass column containing 52 g of magnesium oxide-diatomaceous earth (1:3, w/w) could elute chlorophylls with 800 mL of acetone containing 50% ethanol at a flow rate of 10 mL/min. Some new chlorophyll derivatives including chlorophyllide b, pyropheophorbide b, hydroxypheophytin a, and hydroxypheophytin a' were generated during column chromatography but accompanied by a 63% loss in total chlorophylls. Thus, the possibility of chlorophyll fraction prepared from T. formosanum as a raw material for future production of functional food needs further investigation. PMID:22656126

Loh, Chin Hoe; Inbaraj, Baskaran Stephen; Liu, Man Hai; Chen, Bing Huei

2012-06-20

113

Dietary supplementation of Zingiber officinale and Zingiber zerumbet to heat-stressed broiler chickens and its effect on heat shock protein 70 expression, blood parameters and body temperature.  

PubMed

The present study was conducted to assess the effects of dietary supplementation of Zingiber officinale and Zingiber zerumbet and to heat-stressed broiler chickens on heat shock protein (HSP) 70 density, plasma corticosterone concentration (CORT), heterophil to lymphocyte ratio (HLR) and body temperature. Beginning from day 28, chicks were divided into five dietary groups: (i) basal diet (control), (ii) basal diet +1%Z. zerumbet powder (ZZ1%), (iii) basal diet +2%Z. zerumbet powder (ZZ2%), (iv) basal diet +1%Z. officinale powder (ZO1%) and (v) basal diet +2%Z. officinale powder (ZO2%). From day 35-42, heat stress was induced by exposing birds to 38±1°C and 80% RH for 2 h/day. Irrespective of diet, heat challenge elevated HSP70 expression, CORT and HLR on day 42. On day 42, following heat challenge, the ZZ1% birds showed lower body temperatures than those of control, ZO1% and ZO2%. Neither CORT nor HLR was significantly affected by diet. The ZO2% and ZZ2% diets enhanced HSP70 expression when compared to the control groups. We concluded that dietary supplementation of Z. officinale and Z. zerumbet powder may induce HSP70 reaction in broiler chickens exposed to heat stress. PMID:22533311

Hasheimi, S R; Zulkifli, I; Somchit, M N; Zunita, Z; Loh, T C; Soleimani, A F; Tang, S C

2013-08-01

114

Bioassay Screening of the Essential Oil and Various Extracts of Fruits of Heracleum persicum Desf. and Rhizomes of Zingiber officinale Rosc. using Brine Shrimp Cytotoxicity Assay  

Microsoft Academic Search

In the present work, the bioassay screening of the essential oil and various extracts of two plants including fruits of Heracleum persicum Desf. and rhizomes of Zingiber officinale Rosc. have been studied with brine shrimp test. There is only one report about cytotoxicity of H. sphondylium in literature and so H. persicum has been used as second selection. At first

Mohammad Hassan Moshafi; Fariba Sharififar; Gholam-Reza Dehghan; Alieh Ameri

2009-01-01

115

Effect of fast CO 2 pressure changes on the yield of lovage ( Levisticum officinale Koch.) and celery ( Apium graveolens L.) extracts  

Microsoft Academic Search

The effect of pressure alterations on the yield of CO2 extracts from different anatomical parts of lovage (Levisticum officinale Koch.) and celery (Apium graveolens L.) was studied. It was found that by applying frequent pressure changes in the extraction vessel it is possible to increase the rate of the isolation of CO2 soluble materials from lovage seeds and leaves, lovage

Egidijus Daukšas; Petras Rimantas Venskutonis; Björn Sivik; Tobias Nillson

2002-01-01

116

Antibacterial effects of Myristica fragrans , Zataria multiflora Boiss, Syzygium aromaticum , and Zingiber officinale Rosci essential oils, alone and in combination with nisin on Listeria monocytogenes  

Microsoft Academic Search

Plant essential oils and their components are perceived to exhibit antimicrobial activities. In this study the antibacterial\\u000a effects of essential oil extracted from Myristica fragrans, Zataria multiflora Boiss, Syzygium aromaticum, and Zingiber officinale Rosci, alone and in combination with nisin, were evaluated against Listeria monocytogenes in brain heart infusion broth. Minimum inhibitory concentration (MIC) and minimum bacterial concentration (MBC) with

Mohammad Rahnama; Mohsen Najimi; Shahraki Ali

117

The "Raison D'être" of pyrrolizidine alkaloids inCynoglossum officinale: Deterrent effects against generalist herbivores.  

PubMed

In this study we tested whether pyrrolizidine alkaloids (PAs) ofCynoglossum officinale serve as antifeedants against herbivores. Total PA N-oxide extracts of the leaves significantly deterred feeding by generalist herbivores. Specialist herbivores did not discriminate between food with high and low PA levels. Three PAs fromC. officinale, heliosupine, echinatine, and 3'-acetylechinatine, equally deterred feeding by the polyphagous larvae ofSpodoptera exigua. Although the plants mainly contain PAs in their N-oxide form, reduced PAs deterred feeding byS. exigua more efficiently than PA N-oxides. On rosette plants, the monophagous weevilMogulones cruciger significantly consumed more of the youngest leaves, which had the highest PA level and the highest nitrogen percentage. Larvae ofEthmia bipunctella, which are oligophagous within the Boraginaceae, did not discriminate between leaves. All generalist herbivores tested significantly avoided the youngest leaves with the highest PA levels. In the field, the oldest leaves also were relatively more damaged by herbivores than the youngest leaves. It is hypothesized that the skewed distribution of PAs over the leaves of rosette plants reflects optimal defense distribution within the plant. PMID:24234247

van Dam, N M; Vuister, L W; Bergshoeff, C; de Vos, H; van Der Meijden, E

1995-05-01

118

In Vivo Evaluation of Ethanolic Extract of Zingiber officinale Rhizomes for Its Protective Effect against Liver Cirrhosis  

PubMed Central

Zingiber officinale is a traditional medicine against various disorders including liver diseases.The aim of this study was to assess the hepatoprotective activity of the ethanolic extract of rhizomes of Z. officinale (ERZO) against thioacetamide-induced hepatotoxicity in rats. Five groups of male Sprague Dawley have been used. In group 1 rats received intraperitoneal (i.p.) injection of normal saline while groups 2–5 received thioacetamide (TAA, 200?mg/kg; i.p.) for induction of liver cirrhosis, thrice weekly for eight weeks. Group 3 received 50?mg/kg of silymarin. The rats in groups 4 and 5 received 250 and 500?mg/kg of ERZO (dissolved in 10% Tween), respectively. Hepatic damage was assessed grossly and microscopically for all of the groups. Results confirmed the induction of liver cirrhosis in group 2 whilst administration of silymarin or ERZO significantly reduced the impact of thioacetamide toxicity. These groups decreased fibrosis of the liver tissues. Immunohistochemistry assessment against proliferating cell nuclear antigen did not show remarkable proliferation in the ERZO-treated rats when compared with group 2. Moreover, factions of the ERZO extract were tested on Hep-G2 cells and showed antiproliferative activity (IC50 38–60??g/mL). This study showed hepatoprotective effect of ERZO. PMID:24396831

Abdulaziz Bardi, Daleya; Halabi, Mohammed Farouq; Abdullah, Nor Azizan; Rouhollahi, Elham

2013-01-01

119

[Comparison on polysaccharide content and PMP-HPLC fingerprints of polysaccharide in stems and leaves of Dendrobium officinale].  

PubMed

In order to provide scientific basics for exploitation and sufficient application of Dendrobium officinale leaves resources, the phenol-sulfuric acid method was applied to determine the polysaccharide content. The monosaccharides were derivated by PMP and the derivatives were identified by HPLC-DAD-ESI-MS(n) and the contents of mannose and glucose were determined simultaneously. Similarity evaluation system for chromatographic fingerprint of traditional Chinese medicine (2004A) was employed to generate the mean chromatogram and similarity analysis of the samples was carried out. The results demonstrated that polysaccharide content, monosaccharide compositions and composition ratio had an obvious difference between stems and leaves. The polysaccharide content of stems was higher than that of leaves. Monosaccharide composition in leaf was significantly different from that in stem. The polysaccharide from stems was composed of mannose and glucose, however the polysaccharide of leaves was acid heteropolysaccharide and was mainly composed of five monosaccharides, including mannose, galacturonic acid, glucose, galactose and arabinose. The similarity value of the 14 batches was above 0.9, indicating that similarity of fingerprints among different samples was high. The study can provide evidence for expanding the medicinal parts of D. officinale. PMID:25204167

Zhou, Gui-Fen; Pang, Min-Xia; Chen, Su-Hong; Lv, Gui-Yuan; Yan, Mei-Qiu

2014-03-01

120

Discrete square root smoothing.  

NASA Technical Reports Server (NTRS)

The basic techniques applied in the square root least squares and square root filtering solutions are applied to the smoothing problem. Both conventional and square root solutions are obtained by computing the filtered solutions, then modifying the results to include the effect of all measurements. A comparison of computation requirements indicates that the square root information smoother (SRIS) is more efficient than conventional solutions in a large class of fixed interval smoothing problems.

Kaminski, P. G.; Bryson, A. E., Jr.

1972-01-01

121

Analysis of antioxidant flavonoids from asteraceae and moraceae plants by capillary electrophoresis  

Microsoft Academic Search

Summary  Antioxidant flavonoids from the plantsSolidago gigantea Ait.,Taraxacum officinale Wiggers and Webers (Asteraceae) andMorus nigra L. (Moraceae) have been analysed by capillary electrophoresis (CE).Solidago gigantea was investigated because of its diuretic, spasmolytic, antiphlogistic, and wound-healing effect,Taraxacum officinale because it has been shown to have good diuretic and choleretic activity, andMorus nigra because it is also widely regarded as a diuretic and

Sz. T. Kristó; K. Ganzler; P. Apáti; É. Sz?ke; Á. Kéry

2002-01-01

122

Stomatal response to carbon dioxide: aperature and chloroplast structure  

E-print Network

). Heath and Mansfield (1962), however, discovered an increased stomatal sensitivity to CO during early stages of water stress in Taraxacum officinale. Stalfelt (1957; 1959) noted that stomatal closing movements in response to water stress were gr eater...). Heath and Mansfield (1962), however, discovered an increased stomatal sensitivity to CO during early stages of water stress in Taraxacum officinale. Stalfelt (1957; 1959) noted that stomatal closing movements in response to water stress were gr eater...

Spence, Richard Douglas

2012-06-07

123

Medicinal plants and their role in the dooryard gardens of Bryan, Texas  

E-print Network

Name Scientific Name Catnip Chamomile Nepeta cataria L. Matricaria chamomilla L. Rose Hips Dandelion Fennel Castor Bean Rosa rugose Juss. Taraxacum officinale Wiggers Foeniculum vulgare Mill. Ricinus communis L. Com&ey Willow Calendula... Name Scientific Name Catnip Chamomile Nepeta cataria L. Matricaria chamomilla L. Rose Hips Dandelion Fennel Castor Bean Rosa rugose Juss. Taraxacum officinale Wiggers Foeniculum vulgare Mill. Ricinus communis L. Com&ey Willow Calendula...

Elbaum, Nora Renee

2012-06-07

124

WHY ROOTING FAILS.  

SciTech Connect

I explore the origins of the unphysical predictions from rooted staggered fermion algorithms. Before rooting, the exact chiral symmetry of staggered fermions is a flavored symmetry among the four 'tastes.' The rooting procedure averages over tastes of different chiralities. This averaging forbids the appearance of the correct 't Hooft vertex for the target theory.

CREUTZ,M.

2007-07-30

125

[Molecular cloning and characterization of S-adenosyl-L-methionine decarboxylase gene (DoSAMDC1) in Dendrobium officinale].  

PubMed

S-Adenosyl-L-methionine decarboxylase (SAMDC) is a key enzyme in the polyamines biosynthesis, thus is essential for basic physiological and biochemical processes in plant. In the present study, a full length cDNA of DoSAMDC1 gene was obtained from symbiotic germinated seeds of an endangered medicinal orchid species Dendrobium officinale, using the rapid amplification of cDNA ends (RACE)-PCR technique for the first time. The full length cDNA was 1 979 bp, with three open reading frames, i.e. tiny-uORF, small-uORF and main ORF (mORF). The mORF was deduced to encode a 368 amino acid (aa) protein with a molecular mass of 40.7 kD and a theoretical isoelectric point of 5.2. The deduced DoSAMDC1 protein, without signal peptide, had two highly conserved function domains (proenzyme cleavage site and PEST domain) and a 22-aa transmembrane domain (89-110). Multiple sequence alignments and phylogenetic relationship analyses revealed DoSAMDC1 had a higher level of sequence similarity to monocot SAMDCs than those of dicot. Expression patterns using qRT-PCR analyses showed that DoSAMDC1 transcripts were expressed constitutively without significant change in the five tissues (not infected with fungi). While in the symbiotic germinated seeds, the expression level was enhanced by 2.74 fold over that in the none-germinated seeds, indicating possible involvement of the gene in symbiotic seed germination of D. officinale. PMID:23984533

Zhao, Ming-Ming; Zhang, Gang; Zhang, Da-Wei; Guo, Shun-Xing

2013-06-01

126

Dual Effect of Light on the Gibberellin- and Nitrate-Stimulated Seed Germination of Sisymbrium officinale and Arabidopsis thaliana  

PubMed Central

Red light (R) has a dual effect on the seed germination of the two related species Arabidopsis thaliana and Sisymbrium officinale. The two species provide different means to separate the light-effects. In S. officinale, stimulation of germination by R depends on the stimultaneous presence of nitrate (light-effect I). The effect of both factors is completely blocked by tetcyclacis, an inhibitor of gibberellin (GA)-biosynthesis. Addition of a mixture of gibberellins A4 and A7 (GA4+7) antagonizes the inhibition. In the absence of nitrate, R shifts germination to lower GA-requirement (light-effect II). In A. thaliana a similar second light-effect is seen on the GA-requirement of GA-deficient ga-1 mutant seeds. R stimulates germination of wild type seeds in water (light-effect I). For both species, light-effect I shows a fluence threshold value of approximately 10?5 moles per square meter, which is independent of the nitrate concentration. Increasing nitrate concentrations narrow the fluence-range required for maximal germination whereby the product of nitrate concentration and fluence value determines the germination level, indicating a multiplicative interaction between R and nitrate. Fluence-response curves for light-effect II are similar for both species. Germination occurs in the range of 10?6 to 10?2 moles per square meter fluence. The maximal level of germination is determined by the level of dark-germination and light-effect II. Increasing GA4+7 concentrations induce a shift to lower fluence values. It is shown that in the second effect the co-action of R and exogenous GA4+7 is clearly additive. It is concluded that light-effect I induces a chain of events leading to GA biosynthesis. Light-effect II seems to enhance the sensitivity of the seeds to GAs. PMID:16665951

Hilhorst, Henk W. M.; Karssen, Cees M.

1988-01-01

127

Gastroprotective Effect of Ginger Rhizome (Zingiber officinale) Extract: Role of Gallic Acid and Cinnamic Acid in H+ ,K +ATPase\\/H. pylori Inhibition and Anti-oxidative Mechanism  

Microsoft Academic Search

Zinger officinale has been used as a traditional source against gastric disturbances from time immemorial. The ulcer-preventive properties of aqueous extract of ginger rhizome (GRAE) belonging to the family Zingiberceae is reported in the present study. GRAE at 200 mg kg? 1 b.w. protected up to 86% and 77% for the swim stress-\\/ethanol stress-induced ulcers with an ulcer index (UI)

Siddaraju M. Nanjundaiah; Harish Nayaka; Mysore Annaiah; Shylaja M. Dharmesh

128

Irrational Square Roots  

ERIC Educational Resources Information Center

If students are presented the standard proof of irrationality of [square root]2, can they generalize it to a proof of the irrationality of "[square root]p", "p" a prime if, instead of considering divisibility by "p", they cling to the notions of even and odd used in the standard proof?

Misiurewicz, Michal

2013-01-01

129

ROOT Statistical Software  

E-print Network

Advanced mathematical and statistical computational methods are required by the LHC experiments for analyzing their data. Some of these methods are provided by the ROOT project, a C++ Object Oriented framework for large scale data handling applications. We review the current mathematical and statistical classes present in ROOT, emphasizing the recent developments.

Moneta, Lorenzo; Brun, R; Kreshuk, Anna

2008-01-01

130

TPCP: Armillaria Root Rot ARMILLARIA ROOT ROT  

E-print Network

. Armillaria root rot usually becomes apparent when indigenous forests are cleared for afforestation to the fact that indigenous forests are uncommon and few plantations have been established on stands where unsuccessful. It has been found that infection centres apparently disappear after a number of pine rotations

131

Root nutrient foraging.  

PubMed

During a plant's lifecycle, the availability of nutrients in the soil is mostly heterogeneous in space and time. Plants are able to adapt to nutrient shortage or localized nutrient availability by altering their root system architecture to efficiently explore soil zones containing the limited nutrient. It has been shown that the deficiency of different nutrients induces root architectural and morphological changes that are, at least to some extent, nutrient specific. Here, we highlight what is known about the importance of individual root system components for nutrient acquisition and how developmental and physiological responses can be coupled to increase nutrient foraging by roots. In addition, we review prominent molecular mechanisms involved in altering the root system in response to local nutrient availability or to the plant's nutritional status. PMID:25082891

Giehl, Ricardo F H; von Wirén, Nicolaus

2014-10-01

132

Root hydrotropism: an update.  

PubMed

While water shortage remains the single-most important factor influencing world agriculture, there are very few studies on how plants grow in response to water potential, i.e., hydrotropism. Terrestrial plant roots dwell in the soil, and their ability to grow and explore underground requires many sensors for stimuli such as gravity, humidity gradients, light, mechanical stimulations, temperature, and oxygen. To date, extremely limited information is available on the components of such sensors; however, all of these stimuli are sensed in the root cap. Directional growth of roots is controlled by gravity, which is fixed in direction and intensity. However, other environmental factors, such as water potential gradients, which fluctuate in time, space, direction, and intensity, can act as a signal for modifying the direction of root growth accordingly. Hydrotropism may help roots to obtain water from the soil and at the same time may participate in the establishment of the root system. Current genetic analysis of hydrotropism in Arabidopsis has offered new players, mainly AHR1, NHR1, MIZ1, and MIZ2, which seem to modulate how root caps sense and choose to respond hydrotropically as opposed to other tropic responses. Here we review the mechanism(s) by which these genes and the plant hormones abscisic acid and cytokinins coordinate hydrotropism to counteract the tropic responses to gravitational field, light or touch stimuli. The biological consequence of hydrotropism is also discussed in relation to water stress avoidance. PMID:23258371

Cassab, Gladys I; Eapen, Delfeena; Campos, María Eugenia

2013-01-01

133

Ginger (Zingiber Officinale Roscoe) Prevents Morphine-Induced Addictive Behaviors in Conditioned Place Preference Test in Rats  

PubMed Central

Background Consumption of chronic morphine induces neuro-inflammation and addictive seeking behavior. Ginger (Zingiber Officinale Roscoe), a well-known spice plant, has been used traditionally in the treatment of a wide variety of ailments. It has been shown that ginger has anti-inflammatory, anti-oxidative and antinociceptive properties. However, its influences on morphine-induced addictive behaviors have not yet been clarified. The aim of the present study was the inhibition of exploratory behavior of morphine addiction in the conditioned place preference test in male desert rats through ginger. Methods For conditioning to the morphine, the male Wistar rats received morphine (12 mg/kg intraperitoneally or i.p.) for 6 consecutive days and treatment groups were given different doses of ginger (25, 50 and 100 mg/kg intragastrically or i.g.) 30 min before morphine injection. For investigating addictive seeking behavior, conditioned place preference test (CPP) was used. Findings Our result demonstrated that injection of morphine for 6 days induces dependency to morphine and creates addictive seeking behavior and ginger (100 mg/kg) could decrease time spend in conditioning box (addictive seeking behavior). Conclusion The data indicated that ginger extract has a potential anti-addictive property against chronic usage of morphine. PMID:25140219

Torkzadeh-Mahani, Shima; Nasri, Sima; Esmaeili-Mahani, Saeed

2014-01-01

134

Insect growth inhibition, antifeedant and antifungal activity of compounds isolated/derived from Zingiber officinale Roscoe (ginger) rhizomes.  

PubMed

Fresh rhizomes of Zingiber officinale (ginger), when subjected to steam distillation, yielded ginger oil in which curcumene was found to be the major constituent. The thermally labile zingiberene-rich fraction was obtained from its diethyl ether extract. Column chromatography of ginger oleoresin furnished a fraction from which [6]-gingerol was obtained by preparative TLC. Naturally occurring [6]-dehydroshogaol was synthesised following condensation of dehydrozingerone with hexanal, whereas zingerone and 3-hydroxy-1-(4-hydroxy-3-methoxyphenyl)butane were obtained by hydrogenation of dehydrozingerone with 10% Pd/C. The structures of the compounds were established by 1H NMR, 13C NMR and mass (EI-MS and ES-MS) spectral analysis. The test compounds exhibited moderate insect growth regulatory (IGR) and antifeedant activity against Spilosoma obliqua, and significant antifungal activity against Rhizoctonia solani. Among the various compounds, [6]-dehydroshogaol exhibited maximum IGR activity (EC50 3.55 mg ml-1), while dehydrozingerone imparted maximum antifungal activity (EC50 86.49 mg litre-1). PMID:11455660

Agarwal, M; Walia, S; Dhingra, S; Khambay, B P

2001-03-01

135

Evaluation of Chloropicrin as a Soil Fumigant against Ralstonia solanacarum in Ginger (Zingiber officinale Rosc.) Production in China  

PubMed Central

Background Chloropicrin (Pic) offers a potential alternative to methyl bromide (MB) against Ralstonia solanacarum in ginger (Zingiber officinale Rosc.) production. MB is scheduled to be withdrawn from routine use by 2015 in developing countries. Methods Pic treatments were evaluated in a laboratory study and in three commercial ginger fields. Results Laboratory studies showed that the EC50 value and EC80 value of Pic were 2.7 and 3.7 mg a.i. kg?1 soil, respectively. Field trials in highly infested soil revealed that treatments of Pic at the dose of 50 g m?2 covered with totally impermeable film (TIF) or polyethylene film (PE) sharply reduced Ralstonia solanacarum and maintained high ginger yields. Both of the Pic treatments provided results similar to, or in some cases slightly lower than, MB with respect to Ralstonia solanacarum control, plant survival, plant growth and yield. All of the fumigant treatments were significantly better than the non-treated control. Conclusions The present study confirms that the Pic is a promising alternative with good efficacy against Ralstonia solanacarum for ginger production and could be used in integrated pest management programs in China. PMID:24618853

Ma, Taotao; Liu, Pengfei; Shen, Jin; Li, Yuan; Ouyang, Canbin; Guo, Meixia; Cao, Aocheng

2014-01-01

136

Selection of endophytic fungi from comfrey (Symphytum officinale L.) for in vitro biological control of the phytopathogen Sclerotinia sclerotiorum (Lib.)  

PubMed Central

Biological control consists of using one organism to attack another that may cause economic damage to crops. Integrated Pest Management (IPM) is a very common strategy. The white mold produced by Sclerotinia sclerotiorum (Lib.) causes considerable damage to bean crops. This fungus is a soil inhabitant, the symptoms of which are characterized by water-soaked lesions covered by a white cottony fungal growth on the soil surface and/or the host plant. Possible biological control agents taken from plants are being investigated as phytopathogen inhibitors. These are endophytic microorganisms that inhabit the intercellular spaces of vegetal tissues and are often responsible for antimicrobial production. The objective of the present study was to select endophytic fungi isolated from comfrey (Symphytum officinale L.) leaves with in vitro antagonist potential against the phytopathogenic fungus S. sclerotiorum. Twelve isolates of endophytic fungi and a pathogenic strain of S. sclerotiorum were used in the challenge method. With the aid of this method, four endophytes with the best antagonistic activity against S. sclerotiorum were selected. Pathogen growth inhibition zones were considered indicative of antibiosis. The percentages of pathogenic mycelia growth were measured both with and without the antagonist, resulting in growth reductions of 46.7% to 50.0% for S. sclerotiorum. These analyses were performed by evaluating the endophytic/pathogenic mycelia growth in mm/day over an eight-day period of antagonistic tests. PMID:24031320

Rocha, Rafaeli; da Luz, Daniela Eleuterio; Engels, Cibelle; Pileggi, Sonia Alvim Veiga; de Souza Jaccoud Filho, David; Matiello, Rodrigo Rodrigues; Pileggi, Marcos

2009-01-01

137

Roots and Extremal Points  

NASA Astrophysics Data System (ADS)

In computational physics very often roots and local extrema of a function have to be determined. In one dimension bisection is a very robust but rather inefficient root finding method. If a good starting point close to the root is available and the function is smooth enough, the Newton-Raphson method converges much faster. Special strategies are necessary to find roots of not so well behaved functions or higher order roots. The combination of bisection and interpolation as by the methods of Dekker, Brent and more recently Chandrupatla provides generally applicable algorithms. In multidimensions Quasi-Newton methods are a good choice. Whereas local extrema can be found as the roots of the gradient, at least in principle, direct optimization can be more efficient. In one dimension the ternary search method or Brent's more efficient golden section search method can be used. In multidimensions the class of direction set search methods is very popular which includes the methods of steepest descent and conjugate gradients, the Newton-Raphson method and, if calculation of the full Hessian matrix is too expensive, the Quasi-Newton methods.

Scherer, Philipp O. J.

138

Modeling root reinforcement using root-failure Weibull survival function  

NASA Astrophysics Data System (ADS)

Root networks contribute to slope stability through complicated interactions that include mechanical compression and tension. Due to the spatial heterogeneity of root distribution and the dynamic of root turnover, the quantification of root reinforcement on steep slope is challenging and consequently the calculation of slope stability as well. Although the considerable advances in root reinforcement modeling, some important aspect remain neglected. In this study we address in particular to the role of root strength variability on the mechanical behaviors of a root bundle. Many factors may contribute to the variability of root mechanical properties even considering a single class of diameter. This work presents a new approach for quantifying root reinforcement that considers the variability of mechanical properties of each root diameter class. Using the data of laboratory tensile tests and field pullout tests, we calibrate the parameters of the Weibull survival function to implement the variability of root strength in a numerical model for the calculation of root reinforcement (RBMw). The results show that, for both laboratory and field datasets, the parameters of the Weibull distribution may be considered constant with the exponent equal to 2 and the normalized failure displacement equal to 1. Moreover, the results show that the variability of root strength in each root diameter class has a major influence on the behavior of a root bundle with important implications when considering different approaches in slope stability calculation. Sensitivity analysis shows that the calibration of the tensile force and the elasticity of the roots are the most important equations, as well as the root distribution. The new model allows the characterization of root reinforcement in terms of maximum pullout force, stiffness, and energy. Moreover, it simplifies the implementation of root reinforcement in slope stability models. The realistic quantification of root reinforcement for tensile, shear and compression behavior allows the consideration of the stabilization effects of root networks on steep slopes and the influence that this has on the triggering of shallow landslides.

Schwarz, M.; Giadrossich, F.; Cohen, D.

2013-03-01

139

Root architecture impacts on root decomposition rates in switchgrass  

NASA Astrophysics Data System (ADS)

Roots strongly contribute to soil organic carbon accrual, but the rate of soil carbon input via root litter decomposition is still uncertain. Root systems are built up of roots with a variety of different diameter size classes, ranging from very fine to very coarse roots. Since fine roots have low C:N ratios and coarse roots have high C:N ratios, root systems are heterogeneous in quality, spanning a range of different C:N ratios. Litter decomposition rates are generally well predicted by litter C:N ratios, thus decomposition of roots may be controlled by the relative abundance of fine versus coarse roots. With this study we asked how root architecture (i.e. the relative abundance of fine versus coarse roots) affects the decomposition of roots systems in the biofuels crop switchgrass (Panicum virgatum L.). To understand how root architecture affects root decomposition rates, we collected roots from eight switchgrass cultivars (Alamo, Kanlow, Carthage, Cave-in-Rock, Forestburg, Southlow, Sunburst, Blackwell), grown at FermiLab (IL), by taking 4.8-cm diameter soil cores from on top of the crown and directly next to the crown of individual plants. Roots were carefully excised from the cores by washing and analyzed for root diameter size class distribution using WinRhizo. Subsequently, root systems of each of the plants (4 replicates per cultivar) were separated in 'fine' (0-0.5 mm), 'medium' (0.5-1 mm) and 'coarse' roots (1-2.5 mm), dried, cut into 0.5 cm (medium and coarse roots) and 2 mm pieces (fine roots), and incubated for 90 days. For each of the cultivars we established five root-treatments: 20g of soil was amended with 0.2g of (1) fine roots, (2) medium roots, (3) coarse roots, (4) a 1:1:1 mixture of fine, medium and coarse roots, and (5) a mixture combining fine, medium and coarse roots in realistic proportions. We measured CO2 respiration at days 1, 3, 7, 15, 30, 60 and 90 during the experiment. The 13C signature of the soil was -26‰, and the 13C signature of plants was -12‰, enabling us to differentiate between root-derived C and native SOM-C respiration. We found that the relative abundance of fine, medium and coarse roots were significantly different among cultivars. Root systems of Alamo, Kanlow and Cave-in-Rock were characterized by a large abundance of coarse-, relative to fine roots, whereas Carthage, Forestburg and Blackwell had a large abundance of fine, relative to coarse roots. Fine roots had a 28% lower C:N ratio than medium and coarse roots. These differences led to different root decomposition rates. We conclude that root architecture should be taken into account when predicting root decomposition rates; enhanced understanding of the mechanisms of root decomposition will improve model predictions of C input to soil organic matter.

de Graaff, M.; Schadt, C.; Garten, C. T.; Jastrow, J. D.; Phillips, J.; Wullschleger, S. D.

2010-12-01

140

Soil-root mechanical interactions within bundles of roots  

NASA Astrophysics Data System (ADS)

Root-soil mechanical interactions play an important role in strength and force redistribution in rooted soil. Recent advances in root reinforcement modeling implement detailed representation of root geometry and mechanical properties as well as root-soil mechanical interactions. Nevertheless, root-soil mechanical interactions are often considered at the single root scale ignoring interactions between neighboring roots and root bundles known to play important role in similar applications such as engineered composite material reinforcement. The objective was to quantify mechanical interactions among neighboring roots or roots network using pullout laboratory experiments and modeling. We focus on the on effects of such interactions on global pull out force of a bundle of roots via better understanding of transmission of radial stresses to soil matrix due to the friction at the interface soil-root. Additionally, we wish to predict how cumulative friction changes along a single root axis with and without branching points during the slipping out. Analytical models of fiber reinforced materials show the magnitude of bonded friction depends on three key parameters: bond modulus, maximal bond strength and difference between the Young moduli of fiber and Young moduli of matrix. Debonded friction is calculated assuming failure follows Coulomb failure that includes apparent cohesion, effective normal stress and residual root soil friction angle. We used a pullout device to measure displacement and force of individual roots and for the bundle of roots. Additionally, we monitored and detected activation of root-soil friction by six acoustic emission sensors placed on waveguide in contact with the soil matrix. Results from experiments with parallel and crossing roots demonstrated the importance of considering factors such as distance of root axis, branching points, crossing of roots and roots diameter for the behavior of bundle of roots and inclined roots during pullout. Acoustic emission measurements provided interesting insights into progressive activation of root-soil friction. These results enhance understanding of root reinforcement mechanism and enable more realistic implementation of root reinforcement modeling for stability calculation of vegetated slopes.

Giadrossich, Filippo; Schwarz, Massimiliano; Preti, Federico; Or, Dani

2010-05-01

141

The "Green" Root Beer Laboratory  

ERIC Educational Resources Information Center

No, your students will not be drinking green root beer for St. Patrick's Day--this "green" root beer laboratory promotes environmental awareness in the science classroom, and provides a venue for some very sound science content! While many science classrooms incorporate root beer-brewing activities, the root beer lab presented in this article has…

Clary, Renee; Wandersee, James

2010-01-01

142

Developmental Changes in Peanut Root Structure during Root Growth and Root-structure Modification by Nodulation  

PubMed Central

Background and Aims Basic information about the root and root nodule structure of leguminous crop plants is incomplete, with many aspects remaining unresolved. Peanut (Arachis hypogaea) forms root nodules in a unique process. Structures of various peanut root types were studied with emphasis on insufficiently characterized lateral roots, changes in roots during their ontogenesis and root modification by nodule formation. Methods Peanut plants were grown in the field, in vermiculite or in filter paper. The taproot, first-order and second-order lateral roots and root nodules were analysed using bright-field and fluorescence microscopy with hand sections and resin sections. Key Results Three root categories were recognized. The primary seminal root was thick, exhibiting early and intensive secondary thickening mainly on its base. It was tetrarch and contained broad pith. First-order lateral roots were long and thin, with limited secondary thickening; they contained no pith. Particularly different were second- and higher-order lateral roots, which were anatomically simple and thin, with little or no secondary growth. Unusual wall ingrowths were visible in the cells of the central part of the cortex in the first-order and second-order lateral roots. The nodule body was formed at the junction of the primary and lateral roots by the activity of proliferating cells derived originally from the pericycle. Conclusions Two morphologically and anatomically distinct types of lateral roots were recognized: long, first-order lateral roots, forming the skeleton of the root system, and thin and short second- and higher-order lateral roots, with an incomplete second state of endodermal development, which might be classified as peanut ‘feeder roots’. Formation of root nodules at the base of the lateral roots was the result of proliferating cell divisions derived originally from the pericycle. PMID:18256023

Tajima, Ryosuke; Abe, Jun; Lee, O. New; Morita, Shigenori; Lux, Alexander

2008-01-01

143

Synthesis of Analogues of Gingerol and Shogaol, the Active Pungent Principles from the Rhizomes of Zingiber officinale and Evaluation of Their Anti-Platelet Aggregation Effects  

PubMed Central

The present study was aimed at discovering novel biologically active compounds based on the skeletons of gingerol and shogaol, the pungent principles from the rhizomes of Zingiber officinale. Therefore, eight groups of analogues were synthesized and examined for their inhibitory activities of platelet aggregation induced by arachidonic acid, collagen, platelet activating factor, and thrombin. Among the tested compounds, [6]-paradol (5b) exhibited the most significant anti-platelet aggregation activity. It was the most potent candidate, which could be used in further investigation to explore new drug leads. PMID:24599082

Shih, Hung-Cheng; Chern, Ching-Yuh; Kuo, Ping-Chung; Wu, You-Cheng; Chan, Yu-Yi; Liao, Yu-Ren; Teng, Che-Ming; Wu, Tian-Shung

2014-01-01

144

Cytoskeleton and Root Hair Growth  

Microsoft Academic Search

\\u000a Root hairs are long tubular outgrowths of root epidermis cell that form to increase the root surface in order to assist in\\u000a the uptake of water and nutrients from soil. Root hair development consists of two distinct processes: root hair initiation\\u000a and tip growth. During both events, the dynamic organization of the cytoskeleton translates local signaling events into a\\u000a focused

Eunsook Park; Andreas Nebenführ

145

The Roots of Reading.  

ERIC Educational Resources Information Center

This newsletter covers educational issues affecting schools in the Western Regional Educational Laboratory's 4-state region (Arizona, California, Nevada, and Utah) and nationwide. The following articles appear in the Volume 4, Number 1 issue: (1) "The Roots of Reading"; (2) "Breaking the Code: Reading Literacy in K-3"; (3) "Improving Secondary…

Montoya, Colleen, Ed.

2002-01-01

146

Lotka's Roots under Rescalings  

Microsoft Academic Search

In the mathematical theory of stable populations, when the net maternity function is scaled by a constant divisor, changing its level without changing its shape, the rates of attrition of transient waves in the age structure of the population as it converges toward stability are altered. The attrition rates are specified by the real parts of the complex roots of

Kenneth W. Wachter

1984-01-01

147

Root Canal Irrigants  

Microsoft Academic Search

Local wound debridement in the diseased pulp space is the main step in root canal treatment to prevent the tooth from being a source of infection. In this review article, the specifics of the pulpal microenvironment and the resulting requirements for irrigating solutions are spelled out. Sodium hypochlorite solutions are recommended as the main irrigants. This is because of their

Matthias Zehnder

2006-01-01

148

PESTICIDE ROOT ZONE MODEL  

EPA Science Inventory

PRZM3 is a modeling system that links two subordinate models - PRZM and VADOFT to predict pesticide transport and transformation down through the crop root and unsaturated zone. PRZM3 includes modeling capabilities for such phenomena as soil temperature simulation, vo...

149

Great Plains Roots.  

ERIC Educational Resources Information Center

Sandy White Hawk, Sicangu Lakota, was adopted by white missionaries as an infant and suffered child abuse. After 33 years, she found her birth family and formed First Nations Orphans Association, which uses songs and ceremonies to help adoptees return to their roots. Until the 1970s, federal agencies and welfare organizations facilitated removal…

Frey, Jennifer

2001-01-01

150

Unit Root Testing  

Microsoft Academic Search

A frequent criticism of unit root tests concerns the poor power and size properties that many such tests exhibit. However, during the past decade or so intensive research has been conducted to alleviate these problems and great advances have been made. The present paper provides a selective survey of recent contributions to improve upon both the size and power of

Niels Haldrup; Michael Jansson

151

Genetic Diversity of the Endemic and Medicinally Important Plant Rheum officinale as Revealed by Inter-Simpe Sequence Repeat (ISSR) Markers  

PubMed Central

Rheum officinale Baill., an important but endangered medicinal herb, is endemic to China. Inter-simple sequence repeat (ISSR) markers were employed to investigate the genetic diversity and differentiation of 12 populations of R. officinale. Thirteen selected primers yielded 189 bright and discernible bands, with an average of 14.54 per primer. The genetic diversity was low at the population level, but pretty high at the species level (H = 0.1008, I = 0.1505, PPB = 28.95% vs. H = 0.3341, I = 0.5000, PPB = 95.24%, respectively) by POPGENE analysis. Analysis of molecular variance (AMOVA) showed that the genetic variation was found mainly among populations (74.38%), in line with the limited gene flow (Nm = 0.2766) among populations. Mantel test revealed a significant correlation between genetic and geographic distances (r = 0.5381, P = 0.002), indicating the role of geographic isolation in shaping the present population genetic structure. Both Bayesian analysis and UPGMA cluster analysis demonstrated the similar results. Our results imply that the conservation efforts should aim to preserve all the extant populations of this endangered species, and cultivation is proposed in this study. PMID:22489188

Wang, Xu-Mei; Hou, Xiao-Qi; Zhang, Yu-Qu; Yang, Rui; Feng, Shi-Fang; Li, Yan; Ren, Yi

2012-01-01

152

Rooting of blue honeysuckle microshoots  

Microsoft Academic Search

Rooting of axillary shoots of two blue honeysuckle forms, Lonicera caerulea f. caerulea and L. caerulea f. edulis, was studied.\\u000a Both in vitro and ex vitro rooting procedures were used, and the effects of mineral and auxin concentrations of the rooting\\u000a media were tested. Reduced mineral nutrient concentrations of modified MS medium allowed more root elongation but did not\\u000a affect

Saila T. Karhu

1997-01-01

153

A rapid cleanup method for the isolation and concentration of pyrrolizidine alkaloids in comfrey root.  

PubMed

Preparations from comfrey (Symphytum officinale and S. x uplandicum) root and leaf contain varying levels of the hepatotoxic pyrrolizidine alkaloids (PAs). Reference compounds for comfrey are not commercially available, and there is currently no rapid extraction or analytical method capable of determining low levels in raw materials or as adulterants in commercially available extracts. A solid-phase extraction (SPE) method was developed using an Ergosil cleanup column that specifically binds the PAs. With this method, powdered comfrey root was extracted by sonication and shaking with basic chloroform. The extract was applied to the cleanup column under vacuum, washed with 2 mL acetone-chloroform (8 + 2, v/v) followed by 2 mL petroleum ether to remove excess chloroform. The column was dried under vacuum, and the PAs were eluted with 2 successive 1 mL aliquots methanol. Percent recoveries of the PAs following Ergosil SPE had an overall average of 96.8%, with RSD of 3.8% over a range of 1.0 to 25.0 g extracted in 100 mL. Average precision of the method (n = 3 over 4 extraction concentrations) gave an overall RSD of 6.0% for the 5 alkaloids, with a range of 0.8% (5 g in 100 mL) to 11.2% (25 g in 100 mL). Recovery optimization testing showed that 1.0 g comfrey root extracted in 100 mL yielded the greatest recovery (% dry weight) of the PAs, with an extraction efficiency and accuracy of 94.2%, and RSD of 1.7% (n = 9). The unique properties of the Ergosil cleanup column provide rapid sample cleanup, volume reduction, and concentration of PAs from comfrey extracts, and allow the eluant to be analyzed directly by traditional chromatographic methods. PMID:15493660

Gray, Dean E; Porter, Andrew; O'Neill, Terry; Harris, Roger K; Rottinghaus, George E

2004-01-01

154

Strigolactones Effects on Root Growth  

NASA Astrophysics Data System (ADS)

Strigolactones (SLs) were defined as a new group of plant hormones that suppress lateral shoot branching. Our previous studies suggested SLs to be regulators of root development. SLs were shown to alter root architecture by regulating lateral root formation and to affect root hair elongation in Arabidopsis. Another important effect of SLs on root growth was shown to be associated with root directional growth. Supplementation of SLs to roots led to alterations in root directional growth, whereas associated mutants showed asymmetrical root growth, which was influenced by environmental factors. The regulation by SLs of root development was shown to be conducted via a cross talk of SLs with other plant hormones, including auxin. SLs were shown to regulate auxin transport, and to interfere with the activity of auxin-efflux carriers. Therefore, it might be that SLs are regulators of root directional growth as a result of their ability to regulated auxin transport. However, other evidences suggest a localized effect of SLs on cell division, which may not necessarily be associated with auxin efflux. These and other, recent hypothesis as to the SLs mode of action and the associated root perception and response to environmental factors will be discussed.

Koltai, Hinanit

2012-07-01

155

Lesson 24: Roots and Radicals  

NSDL National Science Digital Library

Exponential notation for Nth roots and radicals is introduced. A short discussion about Nth roots and irrational numbers follows before symbolic manipulation of fractional exponents and solving equations is presented. Power functions and solving radical equations are presented before the lesson concludes with roots of negative numbers.

2011-01-01

156

Springback in root gravitropism  

NASA Technical Reports Server (NTRS)

Conditions under which a gravistimulus of Merit corn roots (Zea mays L.) is withdrawn result in a subsequent loss of gravitropic curvature, an effect which we refer to as springback.' This loss of curvature begins within 1 to 10 minutes after removal of the gravistimulus. It occurs regardless of the presence or absence of the root cap. It is insensitive to inhibitors of auxin transport (2,3,5-triiodobenzoic acid, naphthylphthalamic [correction of naphthylphthalmaic] acid) or to added auxin (2,4-dichlorophenoxyacetic acid). Springback is prevented if a clinostat treatment is interjected to neutralize gravistimulation during germination, which suggests that the change in curvature is a response to a memory' effect carried over from a prior gravistimulation.

Leopold, A. C.; Wettlaufer, S. H.

1989-01-01

157

Mathematica with ROOT  

E-print Network

We present an open-source Mathematica importer for CERN ROOT files. Taking advantage of Mathematica's import/export plug-in mechanism, the importer offers a simple, unified interface that cleanly wraps around its MathLink-based core that links the ROOT libraries with Mathematica. Among other tests for accuracy and efficiency, the importer has also been tested on a large (~5 Gbyte) file structure, D3PD, used by the ATLAS experiment for offline analysis without problems. In addition to describing the installation and usage of the importer, we discuss how the importer may be further improved and customized. A link to the package can be found at: http://library.wolfram.com/infocenter/Articles/7793/ and a related presentation is at: http://cd-docdb.fnal.gov/cgi-bin/DisplayMeeting?conferenceid=522

Ken Hsieh; Thomas G. Throwe; Sebastian White

2011-02-24

158

Cotton Root-rot.  

E-print Network

excelsa, Pinus sylvestri.s, Strobw, P. Laricio, Larix Europoea, Acer platanoides. Fagus. This disease manifests itself by the blackening of the roots and rootlets. The Cotylcdons have a spotted appearance. Warm and moist weather causes the fungus... is a case of symbiosis, and Kamien- ski holds that symbiosis cannot be applied to all the ~Kycorhiza forms described by Frank; that in case of Carpinzn Betulus and Pinus Sylvestris the niycelium of the fungns causes hyper- trophy of the tissues. Dr...

Pammel, L. H. (Louis Herman)

1889-01-01

159

Effect of CO2 Enrichment on Synthesis of Some Primary and Secondary Metabolites in Ginger (Zingiber officinale Roscoe)  

PubMed Central

The effect of two different CO2 concentrations (400 and 800 ?mol mol?1) on the photosynthesis rate, primary and secondary metabolite syntheses and the antioxidant activities of the leaves, stems and rhizomes of two Zingiber officinale varieties (Halia Bentong and Halia Bara) were assessed in an effort to compare and validate the medicinal potential of the subterranean part of the young ginger. High photosynthesis rate (10.05 ?mol CO2 m?2s?1 in Halia Bara) and plant biomass (83.4 g in Halia Bentong) were observed at 800 ?mol mol?1 CO2. Stomatal conductance decreased and water use efficiency increased with elevated CO2 concentration. Total flavonoids (TF), total phenolics (TP), total soluble carbohydrates (TSC), starch and plant biomass increased significantly (P ? 0.05) in all parts of the ginger varieties under elevated CO2 (800 ?mol mol?1). The order of the TF and TP increment in the parts of the plant was rhizomes > stems > leaves. More specifically, Halia Bara had a greater increase of TF (2.05 mg/g dry weight) and TP (14.31 mg/g dry weight) compared to Halia Bentong (TF: 1.42 mg/g dry weight; TP: 9.11 mg/g dry weight) in average over the whole plant. Furthermore, plants with the highest rate of photosynthesis had the highest TSC and phenolics content. Significant differences between treatments and species were observed for TF and TP production. Correlation coefficient showed that TSC and TP content are positively correlated in both varieties. The antioxidant activity, as determined by the ferric reducing/antioxidant potential (FRAP) activity, increased in young ginger grown under elevated CO2. The FRAP values for the leaves, rhizomes and stems extracts of both varieties grown under two different CO2 concentrations (400 and 800 ?mol mol?1) were significantly lower than those of vitamin C (3107.28 ?mol Fe (II)/g) and ?-tocopherol (953 ?mol Fe (II)/g), but higher than that of BHT (74.31 ?mol Fe (II)/g). These results indicate that the plant biomass, primary and secondary metabolite synthesis, and following that, antioxidant activities of Malaysian young ginger varieties can be enhanced through controlled environment (CE) and CO2 enrichment. PMID:21541046

Ghasemzadeh, Ali; Jaafar, Hawa Z. E.

2011-01-01

160

iRootHair: a comprehensive root hair genomics database.  

PubMed

The specialized root epidermis cells of higher plants produce long, tubular outgrowths called root hairs. Root hairs play an important role in nutrient and water uptake, and they serve as a valuable model in studies of plant cell morphogenesis. More than 1,300 articles that describe the biological processes of these unique cells have been published to date. As new fields of root hair research are emerging, the number of new papers published each year and the volumes of new relevant data are continuously increasing. Therefore, there is a general need to facilitate studies on root hair biology by collecting, presenting, and sharing the available information in a systematic, curated manner. Consequently, in this paper, we present a comprehensive database of root hair genomics, iRootHair, which is accessible as a Web-based service. The current version of the database includes information about 153 root hair-related genes that have been identified to date in dicots and monocots along with their putative orthologs in higher plants with sequenced genomes. In order to facilitate the use of the iRootHair database, it is subdivided into interrelated, searchable sections that describe genes, processes of root hair formation, root hair mutants, and available references. The database integrates bioinformatics tools with a focus on sequence identification and annotation. iRootHair is a unique resource for root hair research that integrates the large volume of data related to root hair genomics in a single, curated, and expandable database that is freely available at www.iroothair.org. PMID:23129204

Kwasniewski, Miroslaw; Nowakowska, Urszula; Szumera, Jakub; Chwialkowska, Karolina; Szarejko, Iwona

2013-01-01

161

Roots Engage in Underground Chemical Warfare  

NSF Publications Database

... plant roots secrete a wide variety of compounds that affect other nearby roots, as well as insects ... from Arabidopsis roots kill a wide range of bacteria, confirming that roots are not always ...

162

Differential control of growth, apoptotic activity and gene expression in human colon cancer cells by extracts derived from medicinal herbs, Rhazya stricta and Zingiber officinale and their combination  

PubMed Central

AIM: To investigate the effects of extracts from Rhazya stricta (R. stricta) and Zingiber officinale (Z. officinale) on human colorectal cancer cells. METHODS: Human colorectal cancer cells (HCT116) were subjected to increasing doses of crude alkaloid extracts from R. stricta (CAERS) and crude flavonoid extracts from Z. officinale (CFEZO). Cells were then harvested after 24, 48 or 72 h and cell viability was examined by trypan blue exclusion dye test; clonogenicity and soft agar colony-forming assays were also carried out. Nuclear stain (Hoechst 33342), acridine orange/ethidium bromide double staining, agarose gel electrophoresis and comet assays were performed to assess pro-apoptotic potentiality of the extracts. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR), using gene-specific primers and Western blot analyses were performed to assess the impact of CAERS and CFEZO on the expression levels of key regulatory proteins in HCT116 cells. RESULTS: Treatment with a combination of CAERS and CFEZO synergistically suppressed the proliferation, colony formation and anchorage-independent growth of HCT116 cells. Calculated IC50, after 24, 48 and 72 h, were 70, 90 and 130 ?g/mL for CAERS, 65, 85 and 120 ?g/mL for CFEZO and 20, 25 and 45 ?g/mL for both agents, respectively. CAERS- and CFEZO-treated cells exhibited morphologic and biochemical features of apoptotic cell death. The induction of apoptosis was associated with the release of mitochondrial cytochrome c, an increase in the Bax/Bcl-2 ratio, activation of caspases 3 and 9 and cleavage of poly ADP-ribose polymerase. CAERS and CFEZO treatments downregulated expression levels of anti-apoptotic proteins including Bcl-2, Bcl-X, Mcl-1, survivin and XIAP, and upregulated expression levels of proapoptotic proteins such as Bad and Noxa. CAERS and CFEZO treatments elevated expression levels of the oncosuppressor proteins, p53, p21 and p27, and reduced levels of the oncoproteins, cyclin D1, cyclin/cyclin-dependent kinase-4 and c-Myc. CONCLUSION: These data suggest that a combination of CAERS and CFEZO is a promising treatment for the prevention of colon cancer. PMID:25386076

Elkady, Ayman I; Hussein, Rania Abd El Hamid; Abu-Zinadah, Osama A

2014-01-01

163

Philosophical Roots of Cosmology  

NASA Astrophysics Data System (ADS)

We shall consider the philosophical roots of cosmology in the earlier Greek philosophy. Our goal is to answer the question: Are earlier Greek theories of pure philosophical-mythological character, as often philosophers cited it, or they have scientific character. On the bases of methodological criteria, we shall contend that the latter is the case. In order to answer the question about contemporary situation of the relation philosophy-cosmology, we shall consider the next question: Is contemporary cosmology completely independent of philosophical conjectures? The answer demands consideration of methodological character about scientific status of contemporary cosmology. We also consider some aspects of the relation contemporary philosophy-cosmology.

Ivanovic, M.

2008-10-01

164

Microtubules in root hairs.  

PubMed

The microtubules of root hairs of Raphanus sativus, Lepidium sativum, Equisetum hyemale, Limnobium stoloniferum, Ceratopteris thalictroides, Allium sativum and Urtica dioica were investigated using immunofluorescence and electron microscopy. Arrays of cortical microtubules were observed in all hairs. The microtubules in the hairs show net axial orientations, but in Allium and Urtica helical microtubule patterns are also present. Numerical parameters of microtubules in Raphanus, Equisetum and Limnobium were determined from dry-cleave preparations. The results are discussed with respect to cell wall deposition and cell morphogenesis. PMID:4066793

Traas, J A; Braat, P; Emons, A M; Meekes, H; Derksen, J

1985-06-01

165

Matching roots to their environment  

PubMed Central

Background Plants form the base of the terrestrial food chain and provide medicines, fuel, fibre and industrial materials to humans. Vascular land plants rely on their roots to acquire the water and mineral elements necessary for their survival in nature or their yield and nutritional quality in agriculture. Major biogeochemical fluxes of all elements occur through plant roots, and the roots of agricultural crops have a significant role to play in soil sustainability, carbon sequestration, reducing emissions of greenhouse gasses, and in preventing the eutrophication of water bodies associated with the application of mineral fertilizers. Scope This article provides the context for a Special Issue of Annals of Botany on ‘Matching Roots to Their Environment’. It first examines how land plants and their roots evolved, describes how the ecology of roots and their rhizospheres contributes to the acquisition of soil resources, and discusses the influence of plant roots on biogeochemical cycles. It then describes the role of roots in overcoming the constraints to crop production imposed by hostile or infertile soils, illustrates root phenotypes that improve the acquisition of mineral elements and water, and discusses high-throughput methods to screen for these traits in the laboratory, glasshouse and field. Finally, it considers whether knowledge of adaptations improving the acquisition of resources in natural environments can be used to develop root systems for sustainable agriculture in the future. PMID:23821619

White, Philip J.; George, Timothy S.; Gregory, Peter J.; Bengough, A. Glyn; Hallett, Paul D.; McKenzie, Blair M.

2013-01-01

166

RootNav: navigating images of complex root architectures.  

PubMed

We present a novel image analysis tool that allows the semiautomated quantification of complex root system architectures in a range of plant species grown and imaged in a variety of ways. The automatic component of RootNav takes a top-down approach, utilizing the powerful expectation maximization classification algorithm to examine regions of the input image, calculating the likelihood that given pixels correspond to roots. This information is used as the basis for an optimization approach to root detection and quantification, which effectively fits a root model to the image data. The resulting user experience is akin to defining routes on a motorist's satellite navigation system: RootNav makes an initial optimized estimate of paths from the seed point to root apices, and the user is able to easily and intuitively refine the results using a visual approach. The proposed method is evaluated on winter wheat (Triticum aestivum) images (and demonstrated on Arabidopsis [Arabidopsis thaliana], Brassica napus, and rice [Oryza sativa]), and results are compared with manual analysis. Four exemplar traits are calculated and show clear illustrative differences between some of the wheat accessions. RootNav, however, provides the structural information needed to support extraction of a wider variety of biologically relevant measures. A separate viewer tool is provided to recover a rich set of architectural traits from RootNav's core representation. PMID:23766367

Pound, Michael P; French, Andrew P; Atkinson, Jonathan A; Wells, Darren M; Bennett, Malcolm J; Pridmore, Tony

2013-08-01

167

Comparison of the Transcriptomes of Ginger (Zingiber officinale Rosc.) and Mango Ginger (Curcuma amada Roxb.) in Response to the Bacterial Wilt Infection  

PubMed Central

Bacterial wilt in ginger (Zingiber officinale Rosc.) caused by Ralstonia solanacearum is one of the most important production constraints in tropical, sub-tropical and warm temperature regions of the world. Lack of resistant genotype adds constraints to the crop management. However, mango ginger (Curcuma amada Roxb.), which is resistant to R. solanacearum, is a potential donor, if the exact mechanism of resistance is understood. To identify genes involved in resistance to R. solanacearum, we have sequenced the transcriptome from wilt-sensitive ginger and wilt-resistant mango ginger using Illumina sequencing technology. A total of 26387032 and 22268804 paired-end reads were obtained after quality filtering for C. amada and Z. officinale, respectively. A total of 36359 and 32312 assembled transcript sequences were obtained from both the species. The functions of the unigenes cover a diverse set of molecular functions and biological processes, among which we identified a large number of genes associated with resistance to stresses and response to biotic stimuli. Large scale expression profiling showed that many of the disease resistance related genes were expressed more in C. amada. Comparative analysis also identified genes belonging to different pathways of plant defense against biotic stresses that are differentially expressed in either ginger or mango ginger. The identification of many defense related genes differentially expressed provides many insights to the resistance mechanism to R. solanacearum and for studying potential pathways involved in responses to pathogen. Also, several candidate genes that may underline the difference in resistance to R. solanacearum between ginger and mango ginger were identified. Finally, we have developed a web resource, ginger transcriptome database, which provides public access to the data. Our study is among the first to demonstrate the use of Illumina short read sequencing for de novo transcriptome assembly and comparison in non-model species of Zingiberaceae. PMID:24940878

Prasath, Duraisamy; Karthika, Raveendran; Habeeba, Naduva Thadath; Suraby, Erinjery Jose; Rosana, Ottakandathil Babu; Shaji, Avaroth; Eapen, Santhosh Joseph; Deshpande, Uday; Anandaraj, Muthuswamy

2014-01-01

168

A Split-Root Technique for Measuring Root Water Potential  

PubMed Central

Water encounters various resistances in moving along a path of decreasing potential energy from the soil through the plant to the atmosphere. The reported relative magnitudes of these pathway resistances vary widely and often these results are conflicting. One reason for such inconsistency is the difficulty in measuring the potential drop across various segments of the soil-plant-atmosphere continuum. The measurement of water potentials at the soil-root interface and in the root xylem of a transpiring plant remains a challenging problem. In the divided root experiment reported here, the measured water potential of an enclosed, nonabsorbing branch of the root system of young corn (Bonanza) plants to infer the water potential of the remaining roots growing in soil was used. The selected root branch of the seedling was grown in a specially constructed Teflon test tube into which a screen-enclosed thermocouple psychrometer was inserted and sealed to monitor the root's water potential. The root and its surrounding atmosphere were assumed to be in vapor equilibrium. Images PMID:16661886

Adeoye, Kingsley B.; Rawlins, Stephen L.

1981-01-01

169

Osmolarity and root canal antiseptics.  

PubMed

Antiseptics used in endodontics for disinfection purposes include root canal dressings and irrigants. Osmotic shock is known to cause the alteration of microbial cell viability and might have a role in the mechanism of action of root canal antiseptics. The aim of this review was to determine the role of osmolarity on the performance of antiseptics in root canal treatment. A literature search using the Medline electronic database was conducted up to 30 May 2013 using the following search terms and combinations: 'osmolarity AND root canal or endodontic or antiseptic or irrigation or irrigant or medication or dressing or biofilm; osmolality AND root canal or endodontic or antiseptic or irrigation or irrigant or medication or dressing or biofilm; osmotic AND root canal or endodontic or antiseptic or irrigation or irrigant or medication or dressing or biofilm; osmosis AND root canal or endodontic or antiseptic or irrigation or irrigant or medication or dressing or biofilm; sodium chloride AND root canal or endodontic or antiseptic or irrigation or irrigant or medication or dressing or biofilm'. Publications were included if the effects of osmolarity on the clinical performance of antiseptics in root canal treatment were stated, if preparations with different osmolarities values were compared and if they were published in English. A hand search of articles published online, 'in press' and 'early view', and in the reference list of the included papers was carried out following the same criteria. A total of 3274 publications were identified using the database, and three were included in the review. The evidence available in endodontics suggests a possible role for hyperosmotic root canal medicaments as disinfectants, and that there is no influence of osmolarity on the tissue dissolution capacity of sodium hypochlorite. There are insufficient data to obtain a sound conclusion regarding the role of hypo-osmosis in root canal disinfection, or osmosis in any further desirable ability. PMID:23889531

Rossi-Fedele, G; Guastalli, A R

2014-04-01

170

Energetics of Yellow-Bellied Marmot Populations  

E-print Network

to the Festuca thurberi community type (Langenheim 1956, 1962), dominated by Bromus richardsonii, Bromus porteri, and Poa spp. (primarily secunda and alpina). Also abundant is Potentilla gracilis, Taraxacum of- ficinale, Stipa lettermanii, Achillea... was provided known amounts of Potentilla gracilis, Taraxacum officinale, Agoseris glauca, and Bromus richardsonii, in various combinations, twice daily. A sample of each plant species fed on a particular day was weighed, dried to a constant weight...

Kilgore, Delbert L.; Armitage, Kenneth

1978-01-01

171

The "Green" Root Beer Laboratory  

NSDL National Science Digital Library

No, your students will not be drinking green root beer for St. Patrick's Day--this "green" root beer laboratory promotes environmental awareness in the science classroom, and provides a venue for some very sound science content! While many science classroo

Wandersee, James; Clary, Renee

2010-02-01

172

Theon's Ladder for Any Root  

ERIC Educational Resources Information Center

Theon's ladder is an ancient algorithm for calculating rational approximations for the square root of 2. It features two columns of integers (called a ladder), in which the ratio of the two numbers in each row is an approximation to the square root of 2. It is remarkable for its simplicity. This algorithm can easily be generalized to find rational…

Osler, Thomas J.; Wright, Marcus; Orchard, Michael

2005-01-01

173

Gut and Root Microbiota Commonalities  

PubMed Central

Animal guts and plant roots have absorption roles for nutrient uptake and converge in harboring large, complex, and dynamic groups of microbes that participate in degradation or modification of nutrients and other substances. Gut and root bacteria regulate host gene expression, provide metabolic capabilities, essential nutrients, and protection against pathogens, and seem to share evolutionary trends. PMID:23104406

Ramirez-Puebla, Shamayim T.; Servin-Garciduenas, Luis E.; Jimenez-Marin, Berenice; Bolanos, Luis M.; Rosenblueth, Monica; Martinez, Julio; Rogel, Marco Antonio; Ormeno-Orrillo, Ernesto

2013-01-01

174

Project Work on Plant Roots.  

ERIC Educational Resources Information Center

Methods of investigating plant root growth developed for research purposes can be adopted for student use. Investigations of the effect of water table level and of ethylene concentration are described, and techniques of measuring root growth are explained. (Author/ML)

Devonald, V. G.

1986-01-01

175

Vetiver Root System : Search for the Ideotype  

Microsoft Academic Search

Vetiver roots have a tufted vertically growing root structure. The roots are one of the most important organizational systems that make vetiver a miracle grass for its multifarious applications in soil and water conservation, soil health, and raw material for vetiver root handicrafts, environmental and perfumery products. A lot of diversity is found in vetiver root system in nature, and

Seshu Lavania

176

Parameterizing complex root water uptake models - the arrangement of root hydraulic properties within the root architecture affects dynamics and efficiency of root water uptake  

NASA Astrophysics Data System (ADS)

Detailed three-dimensional models of root water uptake have become increasingly popular for investigating the process of root water uptake. However they suffer from a lack of information in important parameters, especially distribution of root hydraulic properties. In this paper we explore the role that arrangement of root hydraulic properties and root system topology play for modelled uptake dynamics. We apply microscopic models of single root structures to investigate the mechanisms shaping uptake dynamics and demonstrate the effects in a complex three dimensional root water uptake model. We introduce two efficiency indices, for (a) overall plant resistance and (b) water stress and show that an appropriate arrangement of root hydraulic properties can increase modelled efficiency of root water uptake in single roots, branched roots and entire root systems. The average uptake depth of the complete root system was not influenced by parameterization. However, other factors such as evolution of collar potential, which is related to the plant resistance, root bleeding and redistribution patterns were strongly affected by the parameterization. Root systems are more efficient when they are assembled of different root types, allowing for separation of root function in uptake (short young) roots and transport (longer mature) roots. Results become similar, as soon as this composition is accounted for to some degree (between 40 and 80% of young uptake roots). Overall resistance to root water uptake was decreased up to 40% and total transpiration was increased up to 25% in these composed root systems, compared to homogenous root systems. Also, one parameterization (homogenous young root system) was characterized by excessive bleeding (hydraulic lift), which was accompanied by lowest efficiency. We conclude that heterogeneity of root hydraulic properties is a critical component of complex three dimensional uptake models. Efficiency measures together with information on critical xylem potentials may be useful in parameterizing root property distribution.

Bechmann, M.; Schneider, C.; Carminati, A.; Vetterlein, D.; Attinger, S.; Hildebrandt, A.

2014-01-01

177

Responses of Cotton to 2,4-D.  

E-print Network

in cotton plant under action of 2,4-dichlorophe11oxyacetic acid. Doklady Akad. Nauk. S.S.S.R. 60: 1073-5. 1948. 15. Rasmussen, L. A. The physiological action of 2,4-dichlorophenoxyacetic acid on dandelion, Taraxacum officinale. Plant Physiol. 22: 377... in cotton plant under action of 2,4-dichlorophe11oxyacetic acid. Doklady Akad. Nauk. S.S.S.R. 60: 1073-5. 1948. 15. Rasmussen, L. A. The physiological action of 2,4-dichlorophenoxyacetic acid on dandelion, Taraxacum officinale. Plant Physiol. 22: 377...

Dunlap, A. A. (Albert Atkinson); Ergle, David R. (David Ramsey)

1949-01-01

178

Gravisensing in roots  

NASA Astrophysics Data System (ADS)

The mode of gravisensing in higher plants is not yet elucidated. Although, it is generally accepted that the amyloplasts (statoliths) in the root cap cells (statocytes) are responsible for susception of gravity. However, the hypothesis that the whole protoplast acts as gravisusceptor cannot be dismissed. The nature of the sensor that is able to transduce and amplify the mechanical energy into a biochemical factor is even more controversial. Several cell structures could potentially serve as gravireceptors: the endoplasmic reticulum, the actin network, the plasma membrane, or the cytoskeleton associated with this membrane. The nature of the gravisusceptors and gravisensors is discussed by taking into account the characteristics of the gravitropic reaction with respect to the presentation time, the threshold acceleration, the reciprocity rule, the deviation from the sine rule, the movement of the amyloplasts, the pre-inversion effect, the response of starch free and intermediate mutants and the effects of cytochalasin treatment. From this analysis, it can be concluded that both the amyloplasts and the protoplast could be the gravisusceptors, the former being more efficient than the latter since they can focus pressure on limited areas. The receptor should be located in the plasma membrane and could be a stretch-activated ion channel.

Perbal, G.

1999-01-01

179

Hypocotyl adventitious root organogenesis differs from lateral root development  

PubMed Central

Wound-induced adventitious root (AR) formation is a requirement for plant survival upon root damage inflicted by pathogen attack, but also during the regeneration of plant stem cuttings for clonal propagation of elite plant varieties. Yet, adventitious rooting also takes place without wounding. This happens for example in etiolated Arabidopsis thaliana hypocotyls, in which AR initiate upon de-etiolation or in tomato seedlings, in which AR initiate upon flooding or high water availability. In the hypocotyl AR originate from a cell layer reminiscent to the pericycle in the primary root (PR) and the initiated AR share histological and developmental characteristics with lateral roots (LRs). In contrast to the PR however, the hypocotyl is a determinate structure with an established final number of cells. This points to differences between the induction of hypocotyl AR and LR on the PR, as the latter grows indeterminately. The induction of AR on the hypocotyl takes place in environmental conditions that differ from those that control LR formation. Hence, AR formation depends on differentially regulated gene products. Similarly to AR induction in stem cuttings, the capacity to induce hypocotyl AR is genotype-dependent and the plant growth regulator auxin is a key regulator controlling the rooting response. The hormones cytokinins, ethylene, jasmonic acid, and strigolactones in general reduce the root-inducing capacity. The involvement of this many regulators indicates that a tight control and fine-tuning of the initiation and emergence of AR exists. Recently, several genetic factors, specific to hypocotyl adventitious rooting in A. thaliana, have been uncovered. These factors reveal a dedicated signaling network that drives AR formation in the Arabidopsis hypocotyl. Here we provide an overview of the environmental and genetic factors controlling hypocotyl-born AR and we summarize how AR formation and the regulating factors of this organogenesis are distinct from LR induction. PMID:25324849

Verstraeten, Inge; Schotte, Sebastien; Geelen, Danny

2014-01-01

180

Root hairs improve root penetration, root-soil contact, and phosphorus acquisition in soils of different strength.  

PubMed

Root hairs are a key trait for improving the acquisition of phosphorus (P) by plants. However, it is not known whether root hairs provide significant advantage for plant growth under combined soil stresses, particularly under conditions that are known to restrict root hair initiation or elongation (e.g. compacted or high-strength soils). To investigate this, the root growth and P uptake of root hair genotypes of barley, Hordeum vulgare L. (i.e. genotypes with and without root hairs), were assessed under combinations of P deficiency and high soil strength. Genotypes with root hairs were found to have an advantage for root penetration into high-strength layers relative to root hairless genotypes. In P-deficient soils, despite a 20% reduction in root hair length under high-strength conditions, genotypes with root hairs were also found to have an advantage for P uptake. However, in fertilized soils, root hairs conferred an advantage for P uptake in low-strength soil but not in high-strength soil. Improved root-soil contact, coupled with an increased supply of P to the root, may decrease the value of root hairs for P acquisition in high-strength, high-P soils. Nevertheless, this work demonstrates that root hairs are a valuable trait for plant growth and nutrient acquisition under combined soil stresses. Selecting plants with superior root hair traits is important for improving P uptake efficiency and hence the sustainability of agricultural systems. PMID:23861547

Haling, Rebecca E; Brown, Lawrie K; Bengough, A Glyn; Young, Iain M; Hallett, Paul D; White, Philip J; George, Timothy S

2013-09-01

181

Root Absorption and Xylem Translocation  

NSDL National Science Digital Library

Overview: Herbicides must be absorbed into plants inorder to be effective. Plant roots and below ground shoots have fewbarriers to herbicide absorption; however, interactions with soilparticles and soil organic matter have significant impacts on theamount of herbicide available for plant absorption. Plant roots andbelow ground shoots (hypocotyls or coleoptiles) are lipophilic bynature and do not have thick, waxy cuticles like leaves. Lipophilic andhydrophilic herbicides reach the root surface by bulk transport in soilwater; however, there are a few examples of herbicides that reach theroot as a vapor or gas. Soil-applied herbicides can translocate to theshoot or remain in the root system. Soil-applied herbicides translocateto the shoot in the xylem and tend to accumulate in mature leaves thattranspire the most water. The lipophilic/hydrophilic nature of theherbicide will determine if the herbicide translocates to the shoot.Absorption and translocation of phloem-mobile herbicides will bediscussed in another lesson.

182

Urolithiasis and phytotherapy  

Microsoft Academic Search

The effects of seven plants with suspected application to prevent and treat stone kidney formation (Verbena officinalis, Lithospermum officinale, Taraxacum officinale, Equisetum arvense. Arctostaphylos uva-ursi, Arctium lappa andSilene saxifraga) have been studied using female Wistar rats. Variations of the main urolithiasis risk factors (citraturia, calciuria, phosphaturia,\\u000a pH and diuresis) have been evaluated. It can be concluded that beneficial effects caused

F. Grases; G. Melero; A. Costa-Bauzá; R. Prieto; J. G. March

1994-01-01

183

Organic parasite control for poultry and rabbits in British Columbia, Canada.  

PubMed

Plants used for treating endo- and ectoparasites of rabbits and poultry in British Columbia included Arctium lappa (burdock), Artemisia sp. (wormwood), Chenopodium album (lambsquarters) and C. ambrosioides (epazote), Cirsium arvense (Canada thistle), Juniperus spp. (juniper), Mentha piperita (peppermint), Nicotiana sp. (tobacco), Papaver somniferum (opium poppy), Rubus spp. (blackberry and raspberry relatives), Symphytum officinale (comfrey), Taraxacum officinale (common dandelion), Thuja plicata (western redcedar) and Urtica dioica (stinging nettle). PMID:21756341

Lans, Cheryl; Turner, Nancy

2011-01-01

184

Organic parasite control for poultry and rabbits in British Columbia, Canada  

PubMed Central

Plants used for treating endo- and ectoparasites of rabbits and poultry in British Columbia included Arctium lappa (burdock), Artemisia sp. (wormwood), Chenopodium album (lambsquarters) and C. ambrosioides (epazote), Cirsium arvense (Canada thistle), Juniperus spp. (juniper), Mentha piperita (peppermint), Nicotiana sp. (tobacco), Papaver somniferum (opium poppy), Rubus spp. (blackberry and raspberry relatives), Symphytum officinale (comfrey), Taraxacum officinale (common dandelion), Thuja plicata (western redcedar) and Urtica dioica (stinging nettle). PMID:21756341

2011-01-01

185

Nerve and Nerve Root Biomechanics  

Microsoft Academic Search

\\u000a Together, the relationship between the mechanical response of neural tissues and the related mechanisms of injury provide\\u000a a foundation for defining relevant thresholds for injury. The nerves and nerve roots are biologic structures with specific\\u000a and important functions, and whose response to mechanical loading can have immediate, long-lasting and widespread consequences.\\u000a In particular, when nerves or nerve roots are mechanically

Kristen J. Nicholson; Beth A. Winkelstein

186

Effect of parameter choice in root water uptake models - the arrangement of root hydraulic properties within the root architecture affects dynamics and efficiency of root water uptake  

NASA Astrophysics Data System (ADS)

Detailed three-dimensional models of root water uptake have become increasingly popular for investigating the process of root water uptake. However, they suffer from a lack of information on important parameters, particularly on the spatial distribution of root axial and radial conductivities, which vary greatly along a root system. In this paper we explore how the arrangement of those root hydraulic properties and branching within the root system affects modelled uptake dynamics, xylem water potential and the efficiency of root water uptake. We first apply a simple model to illustrate the mechanisms at the scale of single roots. By using two efficiency indices based on (i) the collar xylem potential ("effort") and (ii) the integral amount of unstressed root water uptake ("water yield"), we show that an optimal root length emerges, depending on the ratio between roots axial and radial conductivity. Young roots with high capacity for radial uptake are only efficient when they are short. Branching, in combination with mature transport roots, enables soil exploration and substantially increases active young root length at low collar potentials. Second, we investigate how this shapes uptake dynamics at the plant scale using a comprehensive three-dimensional root water uptake model. Plant-scale dynamics, such as the average uptake depth of entire root systems, were only minimally influenced by the hydraulic parameterization. However, other factors such as hydraulic redistribution, collar potential, internal redistribution patterns and instantaneous uptake depth depended strongly on the arrangement on the arrangement of root hydraulic properties. Root systems were most efficient when assembled of different root types, allowing for separation of root function in uptake (numerous short apical young roots) and transport (longer mature roots). Modelling results became similar when this heterogeneity was accounted for to some degree (i.e. if the root systems contained between 40 and 80% of young uptake roots). The average collar potential was cut to half and unstressed transpiration increased by up to 25% in composed root systems, compared to homogenous ones. Also, the least efficient root system (homogenous young root system) was characterized by excessive bleeding (hydraulic lift), which seemed to be an artifact of the parameterization. We conclude that heterogeneity of root hydraulic properties is a critical component for efficient root systems that needs to be accounted for in complex three-dimensional root water uptake models.

Bechmann, M.; Schneider, C.; Carminati, A.; Vetterlein, D.; Attinger, S.; Hildebrandt, A.

2014-10-01

187

[Accident report: animal nutrition in veterinary medicine--actual cases: houndstongue (Cynoglossum officinale) in pasture--a health hazard for horses].  

PubMed

Meteorism and colics were observed in horses after grazing on young pasture. The botanical analysis of a sample as taken by the owner revealed a great diversity of grasses, herbs and legumes. Houndstongue (Cynoglossum officinale) in its rosette stage was identified in amounts of 1% of the total sample, although this cannot be regarded as representative for the composition of the green fodder. This plant has been reported to be highly toxic for horses and other species, mainly during the early growth stadium due to its contents of pyrrolizidin alkaloids with a strong hepatotoxic activity. In the present case it remained unclear, whether the horses actually ingested this poisonous plant in relevant amounts. In general it has to be emphasised, that a contamination especially of hay or silage bears a severe risk for horses. The contamination of green fodder with houndstongue can be a serious problem for the feeding practice in certain regions (dry grassland, loess or shell lime soil, extensive management). PMID:10609417

Zentek, J; Aboling, S; Kamphues, J

1999-11-01

188

A biophysical model for water movement in roots: Root exudation and root pressure  

Microsoft Academic Search

Abbreviations: CeX: the osmotic concentration of the xylem exudate (osmolm 3), Cex(px): CeX as a function of root pressure px (osmol m-3). ci: the osmotic concentration in the symplast (osmol m-3), Cs(x): the osmotic concentration of absorbable solute in the canal at x (osmolm-3), Cs(x, px): C~(x) as a function of root pressure (osmolm 3), C~V: the average of Cs(x)

Kiyoshi Katou; Takehide Taura; Muneyoshi Furumoto

1988-01-01

189

Effects of root diameter and root nitrogen concentration on in situ root respiration among different seasons and tree species  

Microsoft Academic Search

Knowledge of root respiration is a prerequisite for a better understanding of ecosystem carbon budget and carbon allocation.\\u000a However, there are not many relevant data in the literature on direct measurements of in situ root respiration by root chamber\\u000a method. Furthermore, few studies have been focused on the effects of root diameter (D\\u000a r) and root nitrogen concentration (N\\u000a r)

Dima Chen; Lixia Zhou; Xingquan Rao; Yongbiao Lin; Shenglei Fu

2010-01-01

190

Root plasticity in Mediterranean herbaceous species  

Microsoft Academic Search

Root plasticity has been largely studied on herbaceous species of north European temperate flora and is defined as the ratio between root depth in dry soils and root depth in wet soils. In summer dry habitats such as Mediterranean environments, the soil water deficit is a common feature to which root systems of plant species should adapt to improve their

M. De Lillis; F. Manes; F. Tufaro

2005-01-01

191

Biotechnological Induction of Rooting in Arbutus menziesii  

Microsoft Academic Search

This work tests the ability of the bacterium hairy-root (Agrobacterium rhizogenes) to induce the formation of adventitious roots on Pacific mad- rone (Arbutus menziesii) stems and cuttings. Madrone stems 6, 9, 12 and 18 months of age are innoculated at different seasons of the year and tested for the production of adventitious roots. Successful rooting of stems with endogenously produced

Barbara Selemon; Toby Bradshaw

192

Genetic Dissection of Root Formation in Maize (Zea mays) Reveals Root?type Specific Developmental Programmes  

PubMed Central

• Background Maize (Zea mays) forms a complex root system comprising embryonic and post?embryonic roots. The embryonically formed root system is made up of the primary root and a variable number of seminal roots. Later in development the post?embryonic shoot?borne root system becomes dominant and is responsible together with its lateral roots for the major portion of water and nutrient uptake. Although the anatomical structure of the different root?types is very similar they are initiated from different tissues during embryonic and post?embryonic development. Recently, a number of mutants specifically affected in maize root development have been identified. These mutants indicate that various root?type specific developmental programmes are involved in the establishment of the maize root stock. • Scope This review summarizes these genetic data in the context of the maize root morphology and anatomy and gives an outlook on possible perspectives of the molecular analysis of maize root formation. PMID:14980975

HOCHHOLDINGER, FRANK; WOLL, KATRIN; SAUER, MICHAELA; DEMBINSKY, DIANA

2004-01-01

193

Root status and future developments  

SciTech Connect

In this talk the authors review the major additions and improvements made to the ROOT system in the last 18 months and present their plans for future developments. The additions and improvements range from modifications to the I/O sub-system to allow users to save and restore objects of classes that have not been instrumented by special ROOT macros, to the addition of a geometry package designed for building, browsing, tracking and visualizing detector geometries. Other improvements include enhancements to the quick analysis sub-system (TTree::Draw()), the addition of classes that allow inter-file object references (TRef, TRefArray), better support for templates and STL classes, amelioration of the Automatic Script Compiler and the incorporation of new fitting and mathematical tools. Efforts have also been made to increase the modularity of the ROOT system with the introduction of more abstract interfaces and the development of a plug-in manager. In the near future, they intend to continue the development of PROOF and its interfacing with GRID environments. They plan on providing an interface between Geant3, Geant4 and Fluka and the new geometry package. The ROOT-GUI classes will finally be available on Windows and they plan to release a GUI inspector and builder. In the last year, ROOT has drawn the endorsement of additional experiments and institutions. It is now officially supported by CERN and used as key I/O component by the LCG project.

Rene Brun et al.

2003-10-01

194

Root gravitropism and root hair development constitute coupled developmental responses regulated by auxin homeostasis in the Arabidopsis root apex.  

PubMed

Active polar transport establishes directional auxin flow and the generation of local auxin gradients implicated in plant responses and development. Auxin modulates gravitropism at the root tip and root hair morphogenesis at the differentiation zone. Genetic and biochemical analyses provide evidence for defective basipetal auxin transport in trh1 roots. The trh1, pin2, axr2 and aux1 mutants, and transgenic plants overexpressing PIN1, all showing impaired gravity response and root hair development, revealed ectopic PIN1 localization. The auxin antagonist hypaphorine blocked root hair elongation and caused moderate agravitropic root growth, also leading to PIN1 mislocalization. These results suggest that auxin imbalance leads to proximal and distal developmental defects in Arabidopsis root apex, associated with agravitropic root growth and root hair phenotype, respectively, providing evidence that these two auxin-regulated processes are coupled. Cell-specific subcellular localization of TRH1-YFP in stele and epidermis supports TRH1 engagement in auxin transport, and hence impaired function in trh1 causes dual defects of auxin imbalance. The interplay between intrinsic cues determining root epidermal cell fate through the TTG/GL2 pathway and environmental cues including abiotic stresses modulates root hair morphogenesis. As a consequence of auxin imbalance in Arabidopsis root apex, ectopic PIN1 mislocalization could be a risk aversion mechanism to trigger root developmental responses ensuring root growth plasticity. PMID:23252740

Rigas, Stamatis; Ditengou, Franck Anicet; Ljung, Karin; Daras, Gerasimos; Tietz, Olaf; Palme, Klaus; Hatzopoulos, Polydefkis

2013-03-01

195

Efficient hydraulic properties of root systems  

NASA Astrophysics Data System (ADS)

Understanding the mechanisms of ecosystem root water uptake (RWU) is paramount for parameterizing hydrological models. With the increase in computational power it is possible to calculate RWU explicitly up to the single plant scale using physical models. However, application of these models for increasing our understanding of ecosystem root water uptake is hindered by the deficit in knowledge about the detailed hydraulic parameter distribution within root systems. However, those physical models may help us to identify efficient parameterizations and to describe the influence of these hydraulic parameters on RWU profiles. In this research, we investigated the combined influence of root hydraulic parameters and different root topologies on shaping efficient root water uptake. First, we use a conceptual model of simple branching structures to understand the influence of branching location and transitions in root hydraulic properties on the RWU patterns in typical sub root structures. Second, we apply a physical model called "aRoot" to test our conclusions on complex root system architectures of single plants. aRoot calculates the distribution of xylem potential within arbitrary root geometries to satisfy a given water demand depending on the available water in the soil. Redistribution of water within the bulk soil is calculated using the Richards equation. We analyzed results using a measure of uptake efficiency, which describes the effort necessary for transpiration. Simulations with the conceptual model showed that total transpiration in sub root structures is independent of root hydraulic properties over a wide range of hydraulic parameters. On the other hand efficiency of root water uptake depends crucially on distribution hydraulic parameters in line with root topology. At the same time, these parameters shape strongly the distribution of RWU along the roots, and its evolution in time, thus leading to variable individual root water uptake profiles. Calculating RWU of three dimensional root architectures unveiled that the same effects can be observed at the single plant scale. Total transpiration is almost independent of root hydraulic properties. On the other hand, the arrangement of hydraulic properties significantly influences RWU efficiency. Furthermore the vertical root water uptake profiles are governed by the different root properties. They result from two combined re-distribution patterns over time: One within a rooting branch similar to the results mentioned above, and a second one between the different rooting branches within the root system. This leads to complex vertical uptake profiles, which cannot be predicted from a combination of root abundance and soil moisture, and depend strongly on the individual morphology.

Bechmann, Marcel; Schneider, Christoph; Carminati, Andrea; Hildebrandt, Anke

2013-04-01

196

Root growth, secondary root formation and root gravitropism in carotenoid-deficient seedlings of Zea mays L  

NASA Technical Reports Server (NTRS)

The effect of ABA on root growth, secondary-root formation and root gravitropism in seedlings of Zea mays was investigated by using Fluridone-treated seedlings and a viviparous mutant, both of which lack carotenoids and ABA. Primary roots of seedlings grown in the presence of Fluridone grew significantly slower than those of control (i.e. untreated) roots. Elongation of Fluridone-treated roots was inhibited significantly by the exogenous application of 1 mM ABA. Exogenous application of 1 micromole and 1 nmole ABA had either no effect or only a slight stimulatory effect on root elongation, depending on the method of application. The absence of ABA in Fluridone-treated plants was not an important factor in secondary-root formation in seedlings less than 9-10 d old. However, ABA may suppress secondary-root formation in older seedlings, since 11-d-old control seedlings had significantly fewer secondary roots than Fluridone-treated seedlings. Roots of Fluridone-treated and control seedlings were graviresponsive. Similar data were obtained for vp-9 mutants of Z. mays, which are phenotypically identical to Fluridone-treated seedlings. These results indicate that ABA is necessary for neither secondary-root formation nor for positive gravitropism by primary roots.

Ng, Y. K.; Moore, R.

1985-01-01

197

A method to separate plant roots from soil and analyze root surface area  

Microsoft Academic Search

Analysis of the effects of soil management practices on crop production requires knowledge of these effects on plant roots.\\u000a Much time is required to wash plant roots from soil and separate the living plant roots from organic debris and previous years’\\u000a roots. We developed a root washer that can accommodate relatively large soil samples for washing. The root washer has

J. G. Benjamin; D. C. Nielsen

2004-01-01

198

STIMULATING ROOT REGENERATION OF LANDSCAPE-SIZE RED OAK WITH AUXIN ROOT SPRAYS  

Microsoft Academic Search

Sprays of 3000 ppm indole-3-butyric acid (IBA) and napthaleneacetic acid (NAA), applied to freshly cut roots of 250-300 cm tall red oaks (Quercus rubra L) dug by tree spade, increased the number of roots regenerated from medium (5-1 5 mm) and large (15-25 mm) diameter roots. IBA stimulated more new roots than NAA on large roots only. As root diameter

Glen P. Lumis

199

The Global Biogeography of Roots  

Microsoft Academic Search

Studies in global plant biogeography have almost exclusively analyzed re- lationships of abiotic and biotic factors with the distribution and structure of vegetation aboveground. The goal of this study was to extend such analyses to the belowground structure of vegetation by determining the biotic and abiotic factors that influence vertical root distributions in the soil, including soil, climate, and plant

H. Jochen Schenk; Robert B. Jackson

2002-01-01

200

Lesson 10: Extraction of Roots  

NSDL National Science Digital Library

This lesson introduces quadratic equations and graphs. Equations of the form ax^2 + c = 0 are solved via extraction of roots. Later application problems involving volume and surface area and compound interest (problems of the form a(x - p)^2 = q ) are presented.

2011-01-01

201

Squares, Diagonals, and Square Roots  

NSDL National Science Digital Library

In this lesson, students measure the sides of many squares and their diagonals, then consider the ratio of diagonal length to side length. They can note that in all cases the ratio hovers near 1.4 or the square root of 2. The very complete lesson plan contains handouts, questions for discussion, and problems for applying the new learning.

Johnston, Christopher

2000-01-01

202

Cutting the Roots of Violence.  

ERIC Educational Resources Information Center

Violence is rooted in obedience to authority and in comparisons--foundations of our institutions of parenting and schooling. Obedience brings reward and punishment, comparison perpetuates a cycle of competition and conflict. Television violence is especially harmful because children easily understand visual images. The Reality Research approach to…

Koziey, Paul W.

1996-01-01

203

Investigation of VEGGIE Root Mat  

NASA Technical Reports Server (NTRS)

VEGGIE is a plant growth facility that utilizes the phenomenon of capillary action as its primary watering system. A cloth made of Meta Aramid fiber, known as Nomex is used to wick water up from a reservoir to the bottom of the plants roots. This root mat system is intended to be low maintenance with no moving parts and requires minimal crew interface time. Unfortunately, the water wicking rates are inconsistent throughout the plant life cycle, thus causing plants to die. Over-wicking of water occurs toward the beginning of the cycle, while under-wicking occurs toward the middle. This inconsistency of wicking has become a major issue, drastically inhibiting plant growth. The primary objective is to determine the root cause of the inconsistent wicking through experimental testing. Suspect causes for the capillary water column to break include: a vacuum effect due to a negative pressure gradient in the water reservoir, contamination of material due to minerals in water and back wash from plant fertilizer, induced air bubbles while using syringe refill method, and material limitations of Nomex's ability to absorb and retain water. Experimental testing will be conducted to systematically determine the cause of under and over-wicking. Pressure gages will be used to determine pressure drop during the course of the plant life cycle and during the water refill process. A debubbler device will be connected to a root mat in order to equalize pressure inside the reservoir. Moisture and evaporation tests will simultaneously be implemented to observe moisture content and wicking rates over the course of a plant cycle. Water retention tests will be performed using strips of Nomex to determine materials wicking rates, porosity, and absorptivity. Through these experimental tests, we will have a better understanding of material properties of Nomex, as well as determine the root cause of water column breakage. With consistent test results, a forward plan can be achieved to resolve the issue and give valuable insight for the next generation of VEGGIE.

Subbiah, Arun M.

2013-01-01

204

Image analysis from root system pictures  

NASA Astrophysics Data System (ADS)

Root research has been hampered by a lack of good methods and by the amount of time involved in making measurements. In general the studies from root system are made with either monolith or minirhizotron method which is used as a quantitative tool but requires comparison with conventional destructive methods. This work aimed to analyze roots systems images, obtained from a root atlas book, to different crops in order to find the root length and root length density and correlate them with the literature. Five crops images from Zea mays, Secale cereale, Triticum aestivum, Medicago sativa and Panicum miliaceum were divided in horizontal and vertical layers. Root length distribution was analyzed for horizontal as well as vertical layers. In order to obtain the root length density, a cuboidal volume was supposed to correspond to each part of the image. The results from regression analyses showed root length distributions according to horizontal or vertical layers. It was possible to find the root length distribution for single horizontal layers as a function of vertical layers, and also for single vertical layers as a function of horizontal layers. Regression analysis showed good fits when the root length distributions were grouped in horizontal layers according to the distance from the root center. When root length distributions were grouped according to soil horizons the fits worsened. The resulting root length density estimates were lower than those commonly found in literature, possibly due to (1) the fact that the crop images resulted from single plant situations, while the analyzed field experiments had more than one plant; (2) root overlapping may occur in the field; (3) root experiments, both in the field and image analyses as performed here, are subject to sampling errors; (4) the (hand drawn) images used in this study may have omitted some of the smallest roots.

Casaroli, D.; Jong van Lier, Q.; Metselaar, K.

2009-04-01

205

SOME BROADLEAF HERBICIDES USED IN MIXTURES WITH GLYPHOSATE MAY HINDER THE GROWTH OF NARROW-LEAFED LUPIN  

Microsoft Academic Search

In southern Chile, glyphosate is often complemented with broadleaf herbicides to improve the control of weeds like Taraxacum officinale Weber ex F. H. Wigg., Hypochaeris radicata L., Plantago lanceolata L., Raphanus raphanistrum L., Veronica persica Poiret , and Trifolium repens L. prior to sowing lupin or canola. The broadleaf herbicides may persist in the soil for unpredictable periods, depending on

Nelson Espinoza; Mario Mer

206

[Chicoric and chlorogenic acids in various plants growing in Georgia].  

PubMed

Chicoric acid was isolated from dandelion (Taraxacum officinale Wigg.) leaves by column chromatography. Conditions for HPLC analysis of chicoric and chlorogenic acids were optimized. These acids were assayed in some plants growing in Georgia. The optimum conservation temperature for the preservation of chicoric and chlorogenic acids in leaves of dandelion and bilberry (Vaccinium arctostaphylos L.) was determined. PMID:11357428

Chkhikvishvili, I D; Kharebava, G I

2001-01-01

207

Quantifying individual feeding variability: implications for mollusc feeding experiments  

Microsoft Academic Search

Summary 1. In order to quantify the level of variability in seedling consumption displayed by individual molluscs, we placed one snail ( Helix aspersa ) in each of 51 trays containing (7-day-old) Taraxacum officinale seedlings for 7 days. 2. Initially, individual snails displayed considerable variability in their consumption of seedlings; however, this variability declined with time. The consumption of seedlings

M. E. Hanley; M. T. Bulling; M. Fenner

2003-01-01

208

A Sensitive Bioassay for Gibberellins based on Retardation of Leaf Senescence in Rumex obtusifolius (L.)  

Microsoft Academic Search

THE senescence and yellowing of detached leaves and leaf disks of many plants are retarded by low concentrations of kinetin. Gibberellic acid (GA) and indolyl-3-acetic acid (IAA) may also induce a similar response, depending on the age of the leaf and the species. Thus, mature leaves of dandelion (Taraxacum officinale) respond to low concentrations of kinetin and GA, but scarcely

Pamela Whyte; L. C. Luckwill

1966-01-01

209

Effect of ‘antidiabetis’ herbal preparation on serum glucose and fructosamine in NOD mice  

Microsoft Academic Search

The antihyperglycemic effect of the Antidiabetis herbal preparation ((Myrtilli folium (Vaccinium myrtillus L.), Taraxaci radix (Taraxacum officinale Web.), Cichorii radix (Cichorium intybus L.), Juniperi fructus (Juniperus communis L.), Centaurii herba (Centaurium umbellatum Gilib.), Phaseoli pericarpium (Phaseolus vulgaris), Millefollii herba (Achillea millefolium L.), Morii folium (Morus nigra L.), Valeriane radix (Valleriana officinalis L.), Urticae herba et radix (Urtica dioica L.)), patent

R. Petlevski; M. Hadžija; M. Slijep?evi?; D. Jureti?

2001-01-01

210

Spatial and Temporal Distribution of Zeatin and Zeatin Riboside during the Period of the Egg-Cell Activity in the Ovaries of Amphimictic and Apomictic Plants  

Microsoft Academic Search

Spatial and temporal distribution of zeatin and zeatin riboside was studied in the ovaries of amphimictic (Triticum aestivum L.) and apomictic (Taraxacum officinale Web.) species during the period from the quiescence release of the egg cell to its first division. This period was divided into three stages: (1) no signs of division of the central cell, (2) division of the

M. A. Gusakovskaya; A. N. Blintsov

2004-01-01

211

Appendix 4. Supplementary Electronic Material -A list of all of the plant species from each community included in the analyses, together with the predicted pollinator [Euclidean distances to  

E-print Network

Aster occidentalis bee butterfly X Calyptridium umbellatum fly butterfly fly Castilleja miniata bird longipes fly X Symphoricarpos rotundifolius fly butterfly X Taraxacum officinale bee butterfly X Tragopogon alpinus butterfly X Castilleja miniata bird bird X Castilleja occidentalis bee bird X Castilleja

Northampton, University of

212

TOTAL PHENOLIC CONTENT, ANTIOXIDANT AND ANTIMICROBIAL ACTIVITIES OF SOME MEDICINAL PLANTS  

Microsoft Academic Search

Crude extracts from Inula aucherana, Fumaria officinalis, Crocus sativus, Vicum album, Tribulus terestris, Polygonatum multiflorum, Alkanna tinctoria and Taraxacum officinale were screened for their in vitro antioxidant and antimicrobial properties. Total phenolic content of extracts from these plants were also determined. ?-carotene bleaching assay and Folin-Ciocalteu reagent were used to determine total antioxidant activity and total phenols of plant extracts.

MEMNUNE SENGUL; HILAL YILDIZ; NEVA GUNGOR; BULENT CETIN; ZEYNEP ESER; SEZAI ERCISLI

213

Modelling Root Systems Using Oriented Density Distributions  

NASA Astrophysics Data System (ADS)

Root architectural models are essential tools to understand how plants access and utilize soil resources during their development. However, root architectural models use complex geometrical descriptions of the root system and this has limitations to model interactions with the soil. This paper presents the development of continuous models based on the concept of oriented density distribution function. The growth of the root system is built as a hierarchical system of partial differential equations (PDEs) that incorporate single root growth parameters such as elongation rate, gravitropism and branching rate which appear explicitly as coefficients of the PDE. Acquisition and transport of nutrients are then modelled by extending Darcy's law to oriented density distribution functions. This framework was applied to build a model of the growth and water uptake of barley root system. This study shows that simplified and computer effective continuous models of the root system development can be constructed. Such models will allow application of root growth models at field scale.

Dupuy, Lionel X.

2011-09-01

214

Healthy Roots By: Shelly Van Landingham, Forester  

E-print Network

(tree food) produced by the leaves. About 85% of a tree's roots are within the top 18 inches of the soil the trunk two to three times the height of the tree! Figure 1: Area of Root Distribution vs. Crown

215

EFFECTS OF OZONE ON ROOT PROCESSES  

EPA Science Inventory

Ozone alters root growth and root processes by first reducing photosynthesis and altering foliar metabolic pathways. The alteration in foliar metabolism is reflected in lowered carbohydrate levels in the roots. This can reduce key metabolic processes such as mineral uptake and sy...

216

Root Cap and the Perception of Gravity  

Microsoft Academic Search

DURING investigations into the fine structure of apical meristems under the electron microscope, one of us (S. G.) discovered that it was possible, in maize and barley, to detach the intact root cap cleanly from the rest of the root tip. This is shown in Fig. 1. The roots of grasses are characterized by having a discrete cap meristem and,

B. E. Juniper; Suzanne Groves; BRURIA LANDAU-SCHACHAR; L. J. AUDUS

1966-01-01

217

Eight nerve, root nucleus Dolores E. Lpez  

E-print Network

of the CRNs #12;Motoneurons Cochlear Root Neurons PnC Muscles Auditory Startle reflex Cochlear Root Neurons of the CRNs explain its role in the ASR #12;AUDITORY STARTLE REFLEX Sudden and loud sounds (> 90 dB) Rapid. · They can be immunostained and visualized with the protein calbindin Cochlear Root Neurons - Characteristics

Oliver, Douglas L.

218

How Roots Perceive and Respond to Gravity.  

ERIC Educational Resources Information Center

Discusses graviperception and gravitropism by plant roots. Indicates that graviperception occurs via sedimentation of amyloplasts in columella cells of the root cap and that the minimal graviresponsiveness of lateral roots may be due to the intensity of their caps to establish a concentration gradient of inhibitor(s) sufficient to affect…

Moore, Randy

1984-01-01

219

Root Cause Analysis: Methods and Mindsets.  

ERIC Educational Resources Information Center

This instructional unit is intended for use in training operations personnel and others involved in scram analysis at nuclear power plants in the techniques of root cause analysis. Four lessons are included. The first lesson provides an overview of the goals and benefits of the root cause analysis method. Root cause analysis techniques are covered…

Kluch, Jacob H.

220

FOREST PATHOLOGY Root and Butt Rot Diseases  

E-print Network

. Indeed, root and butt rots cause more economic damage to commercial forestry in the temperate world thanFOREST PATHOLOGY Root and Butt Rot Diseases M Garbelotto, University of California ­ Berkeley Diseases caused by root rots figure prominently amongst the most-studied pathologies of forest trees

California at Berkeley, University of

221

The rhizosphere revisited: root microbiomics  

PubMed Central

The rhizosphere was defined over 100 years ago as the zone around the root where microorganisms and processes important for plant growth and health are located. Recent studies show that the diversity of microorganisms associated with the root system is enormous. This rhizosphere microbiome extends the functional repertoire of the plant beyond imagination. The rhizosphere microbiome of Arabidopsis thaliana is currently being studied for the obvious reason that it allows the use of the extensive toolbox that comes with this model plant. Deciphering plant traits that drive selection and activities of the microbiome is now a major challenge in which Arabidopsis will undoubtedly be a major research object. Here we review recent microbiome studies and discuss future research directions and applicability of the generated knowledge. PMID:23755059

Bakker, Peter A. H. M.; Berendsen, Roeland L.; Doornbos, Rogier F.; Wintermans, Paul C. A.; Pieterse, Corné M. J.

2013-01-01

222

Archimedes' calculations of square roots  

E-print Network

We reconsider Archimedes' evaluations of several square roots in 'Measurement of a Circle'. We show that several methods proposed over the last century or so for his evaluations fail one or more criteria of plausibility. We also provide internal evidence that he probably used an interpolation technique. The conclusions are relevant to the precise calculations by which he obtained upper and lower bounds on pi.

Davies, E B

2011-01-01

223

Modeling root reinforcement using a root-failure Weibull survival function  

NASA Astrophysics Data System (ADS)

Root networks contribute to slope stability through complex interactions with soil that include mechanical compression and tension. Due to the spatial heterogeneity of root distribution and the dynamics of root turnover, the quantification of root reinforcement on steep slopes is challenging and consequently the calculation of slope stability also. Although considerable progress has been made, some important aspects of root mechanics remain neglected. In this study we address specifically the role of root-strength variability on the mechanical behavior of a root bundle. Many factors contribute to the variability of root mechanical properties even within a single class of diameter. This work presents a new approach for quantifying root reinforcement that considers the variability of mechanical properties of each root diameter class. Using the data of laboratory tensile tests and field pullout tests, we calibrate the parameters of the Weibull survival function to implement the variability of root strength in a numerical model for the calculation of root reinforcement (RBMw). The results show that, for both laboratory and field data sets, the parameters of the Weibull distribution may be considered constant with the exponent equal to 2 and the normalized failure displacement equal to 1. Moreover, the results show that the variability of root strength in each root diameter class has a major influence on the behavior of a root bundle with important implications when considering different approaches in slope stability calculation. Sensitivity analysis shows that the calibration of the equations of the tensile force, the elasticity of the roots, and the root distribution are the most important steps. The new model allows the characterization of root reinforcement in terms of maximum pullout force, stiffness, and energy. Moreover, it simplifies the implementation of root reinforcement in slope stability models. The realistic quantification of root reinforcement for tensile, shear and compression behavior allows for the consideration of the stabilization effects of root networks on steep slopes and the influence that this has on the triggering of shallow landslides.

Schwarz, M.; Giadrossich, F.; Cohen, D.

2013-11-01

224

Auxin fluxes in the root apex co-regulate gravitropism and lateral root1 initiation2  

E-print Network

1 Auxin fluxes in the root apex co-regulate gravitropism and lateral root1 initiation2 Running title: Co-regulation of root gravitropism and branching by auxin3 transport4 Lucas, M.1,2 , Godin, C.2 and root5 gravitropism, two processes that are regulated by auxin, are co-regulated in6 Arabidopsis. We

Paris-Sud XI, Université de

225

Development of extracellular electric pattern around Lepidium roots: its possible role in root growth and gravitropism  

Microsoft Academic Search

Summary Using a vibrating probe technique, four distinct electric patterns around growing cress roots were observed. The growth rate of the root with a particular one of them was apparently faster than that with the others. No direct correlation between the intensity of electric field and the root growth rate could be found. When gravistimulation was applied to the root,

Akira Iwabuchi; Masafumi Yano; Hiroshi Shimizu

1989-01-01

226

Hydraulic lift: water efflux from upper roots improves effectiveness of water uptake by deep roots  

Microsoft Academic Search

Deuterated water absorbed by deep roots of Artemisia tridentata appeared in the stem water of neighboring Agropyron desertorum tussocks. This supports the hypothesis that water absorbed by deep roots in moist soil moves through the roots, is released in the upper soil profile at night, and is stored there until it is resorbed by roots the following day. This phenomenon

M. M. Caldwell; J. H. Richards

1989-01-01

227

The pattern of secondary root formation in curving roots of Arabidopsis thaliana (L.) Heynh  

NASA Technical Reports Server (NTRS)

A gravitational stimulus was used to induce the curvature of the main root of Arabidopsis thaliana. The number of secondary roots increased on the convex side and decreased on the concave side of any curved main root axes in comparison with straight roots used as the control. The same phenomenon was observed with the curved main roots of plants grown on a clinostat and of mutant plants exhibiting random root orientation. The data suggest that the pattern of lateral root formation is associated with curvature but is independent of the environmental stimuli used to induce curvature.

Fortin, M. C.; Pierce, F. J.; Poff, K. L.

1989-01-01

228

Linking root morphology, longevity and function to root branch order: a case study in three shrubs  

Microsoft Academic Search

Root branching order supports a powerful approach to understanding complex root systems; however, how the pattern of root\\u000a morphological characteristics, tissue carbon (C) and nitrogen (N) concentrations, and root lifespan are related to anatomical\\u000a features of variable root orders for mature shrubs (?19 years old) in sandy habitats is still unclear. In this study, these\\u000a relationships were investigated for three typical

Gang Huang; Xue-yong Zhao; Ha-lin Zhao; Ying-xin Huang; Xiao-an Zuo

2010-01-01

229

Shoot regeneration capacity from roots and transgenic hairy roots of tomato cultivars and wild related species  

Microsoft Academic Search

The organogenetic competence of roots and Agrobacterium rhizogenes-induced hairy roots of twelve Lycopersicon genotypes was investigated. Both roots and hairy roots of L. peruvianum, L. chilense, L. hirsutum and two L. peruvianum-derived genotypes regenerated shoots after 2–4 weeks of incubation on zeatin-contained medium. Anatomical analysis showed\\u000a that shoot regeneration in roots could be direct or indirect, depending on the genotype

Lázaro E. P. Peres; Patrícia G. Morgante; Cláudia Vecchi; Jane E. Kraus; Marie-Anne van Sluys

2001-01-01

230

Induction of branch roots by cutting method in t Hyoscyamus niger root culture  

Microsoft Academic Search

Root tips of Hyoscyamus niger were cultivated on agar or in liquid medium, and patterns of elongation and branching were investigated.\\u000a The elongation of roots compared to branching, particularly tertiary root branching, was more effective in liquid medium than\\u000a on agar medium. The number (0.06 per cm) of tertiary roots which branched out from secondary roots was far less than

Seung Han Woo; Jong Moon Park; Ji-Won Yang

1997-01-01

231

Bioavailable concentrations of germanium and rare earth elements in soil as affected by low molecular weight organic acids and root exudates  

NASA Astrophysics Data System (ADS)

Availability of elements in soil to plant is generally dependent on the solubility and mobility of elements in soil solution which is controlled by soil, elemental properties and plant-soil interactions. Low molecular organic acids or other root exudates may increase mobility and availability of certain elements for plants as an effect of lowering pH in the rhizosphere and complexation. However, these processes take place in a larger volume in soil, therefore to understand their nature, it is also important to know in which layers of the soil what factors modify these processes. In this work the influence of citric acid and root exudates of white lupin (Lupinus albus L.) on bioavailable concentrations of germanium, lanthan, neodymium, gadolinium and erbium in soil solution and uptake in root and shoot of rape (Brassica napus L.), comfrey (Symphytum officinale L.), common millet (Panicum milliaceum L.) and oat (Avena sativa L.) was investigated. Two different pot experiments were conducted: (1) the mentioned plant species were treated with nutrient solutions containing various amount of citric acid; (2) white lupin was cultivated in mixed culture (0 % lupin, 33 % lupin) with oat (Avena sativa L.) and soil solution was obtained by plastic suction cups placed at various depths. As a result, addition of citric acid significantly increased germanium concentrations in plant tissue of comfrey and rape and increased translocation of germanium, lanthan, neodymium, gadolinium and erbium from root to shoot. The cultivation of white lupin in mixed culture with oat led to significantly higher concentrations of germanium and increasing concentrations of lanthan, neodymium, gadolinium and erbium in soil solution and aboveground plant tissue. In these pots concentrations of citric acid in soil solution were significantly higher than in the control. The results show, that low molecular organic acids exuded by plant roots are of great importance for the mobilization of germanium, lanthan, neodymium, gadolinium and erbium in the rhizosphere and therefore the enhancement of bioavailability of the mentioned elements to plants. Based on the suction cup experiment we conclude that in vertical soil profile the bioavailable germanium is heavily affected by the activity of exudates, as the complexation processes of germanium take place at the root zone and below affected by the interplay of the infiltration of citric acid solutions and the actually produced exudates. These studies have been carried out in the framework of the PhytoGerm project, financed by the Federal Ministry of Education and Research, Germany. BS contributed as an Alexander von Humboldt Research Fellow. The authors are grateful to students and laboratory assistants contributing in the field work and sample preparation.

Wiche, Oliver; Székely, Balázs; Kummer, Nicolai-Alexeji; Heinemann, Ute; Tesch, Silke; Heilmeier, Hermann

2014-05-01

232

Plant responsiveness to root-root communication of stress cues  

PubMed Central

Background and Aims Phenotypic plasticity is based on the organism's ability to perceive, integrate and respond to multiple signals and cues informative of environmental opportunities and perils. A growing body of evidence demonstrates that plants are able to adapt to imminent threats by perceiving cues emitted from their damaged neighbours. Here, the hypothesis was tested that unstressed plants are able to perceive and respond to stress cues emitted from their drought- and osmotically stressed neighbours and to induce stress responses in additional unstressed plants. Methods Split-root Pisum sativum, Cynodon dactylon, Digitaria sanguinalis and Stenotaphrum secundatum plants were subjected to osmotic stress or drought while sharing one of their rooting volumes with an unstressed neighbour, which in turn shared its other rooting volume with additional unstressed neighbours. Following the kinetics of stomatal aperture allowed testing for stress responses in both the stressed plants and their unstressed neighbours. Key Results In both P. sativum plants and the three wild clonal grasses, infliction of osmotic stress or drought caused stomatal closure in both the stressed plants and in their unstressed neighbours. While both continuous osmotic stress and drought induced prolonged stomatal closure and limited acclimation in stressed plants, their unstressed neighbours habituated to the stress cues and opened their stomata 3–24 h after the beginning of stress induction. Conclusions The results demonstrate a novel type of plant communication, by which plants might be able to increase their readiness to probable future osmotic and drought stresses. Further work is underway to decipher the identity and mode of operation of the involved communication vectors and to assess the potential ecological costs and benefits of emitting and perceiving drought and osmotic stress cues under various ecological scenarios. PMID:22408186

Falik, Omer; Mordoch, Yonat; Ben-Natan, Daniel; Vanunu, Miriam; Goldstein, Oron; Novoplansky, Ariel

2012-01-01

233

Hydrogenase in actinorhizal root nodules and root nodule homogenates.  

PubMed

Hydrogenases were measured in intact actinorhizal root nodules and from disrupted nodules of Alnus glutinosa, Alnus rhombifolia, Alnus rubra, and Myrica pensylvanica. Whole nodules took up H2 in an O2-dependent reaction. Endophyte preparations oxidized H2 through the oxyhydrogen reaction, but rates were enhanced when hydrogen uptake was coupled to artificial electron acceptors. Oxygen inhibited artifical acceptor-dependent H2 uptake. The hydrogenase system from M. pensylvanica had a different pattern of coupling to various electron acceptors than the hydrogenase systems from the alders; only the bayberry system evolved H2 from reduced viologen dyes. PMID:6989799

Benson, D R; Arp, D J; Burris, R H

1980-04-01

234

Wilt\\/root rot diseases of chickpea in Ethiopia  

Microsoft Academic Search

Research work on wilt\\/root rot diseases of chickpea (Cicer arietinum L.) in Ethiopia is reviewed. The five important wilt\\/root rot diseases in Ethiopia are wilt, dry root rot, wet root rot, black root rot and collar rot, which are caused by Fusarium oxysporum f. sp. ciceri, Rhizoctonia bataticola, R. solani, F. solani and Sclerotium rolfsii respectively. Of these, dry root

S. P. S. Beniwal; S. Ahmed; D. Gorfu

1992-01-01

235

ROOT GROWTH: HOMOGENIZATION IN DOMAINS WITH TIME DEPENDENT PARTIAL PERFORATIONS  

E-print Network

distributed cylindrical roots. The growth direction of the root is dictated by gravity, therefore fixed a macroscopic model for the root growth, in presence of many roots. We assume that the roots are planted an effective model for the root growth and for the nutrient concentration when tends to zero. The motivation

Rheinisch-Westfälische Technische Hochschule Aachen (RWTH)

236

Root cause analysis guidance document  

SciTech Connect

DOE Order 5000.3A, Occurrence Reporting and Processing of Operations Information,'' requires the investigation and reporting of occurrences (including the performance of root cause analysis) and the selection, implementation, and follow-up of corrective actions. The level of effort expended should be based on the significance attached to the occurrence. Most off-normal occurrences need only a scaled-down effort while most emergency occurrences should be investigated using on or more of the formal analytical models. A discussion of methodologies, instructions, and worksheets in this document guides the analysis of occurrences as specified by DOE Order 5000.3A.

Not Available

1992-02-01

237

The root cap and control of root elongation in Zea mays L. seedlings exposed to white light  

Microsoft Academic Search

Light-induced inhibition of the elongation of primary roots of Zea mays seedlings is dependent upon the perception of light by the root cap. Separate exposure of detached root caps and roots from which root caps have been removed (i.e. decapped roots) to white light or darkness has shown that the elongation of a dark-exposed root to which a light-exposed root

Henry Wilkins; R. L. Wain

1974-01-01

238

Foraging strategies in trees of different root morphology: the role of root lifespan.  

PubMed

Resource exploitation of patches is influenced not simply by the rate of root production in the patches but also by the lifespan of the roots inhabiting the patches. We examined the effect of sustained localized nitrogen (N) fertilization on root lifespan in four tree species that varied widely in root morphology and presumed foraging strategy. The study was conducted in a 12-year-old common garden in central Pennsylvania using a combination of data from minirhizotron and root in-growth cores. The two fine-root tree species, Acer negundo L. and Populus tremuloides Michx., exhibited significant increases in root lifespan with local N fertilization; no significant responses were observed in the two coarse-root tree species, Sassafras albidum Nutt. and Liriodendron tulipifera L. Across species, coarse-root tree species had longer median root lifespan than fine-root tree species. Localized N fertilization did not significantly increase the N concentration or the respiration of the roots growing in the N-rich patch. Our results suggest that some plant species appear to regulate the lifespan of different portions of their root system to improve resource acquisition while other species do not. Our results are discussed in the context of different strategies of foraging of nutrient patches in species of different root morphology. PMID:24128849

Adams, Thomas S; McCormack, M Luke; Eissenstat, David M

2013-09-01

239

Nitrate and glutamate sensing by plant roots.  

PubMed

The architecture of a root system plays a major role in determining how efficiently a plant can capture water and nutrients from the soil. Growth occurs at the root tips and the process of exploring the soil volume depends on the behaviour of large numbers of individual root tips at different orders of branching. Each root tip is equipped with a battery of sensory mechanisms that enable it to respond to a range of environmental signals, including nutrients, water potential, light, gravity and touch. We have previously identified a MADS (MCM1, agamous, deficiens and SRF) box gene (ANR1) in Arabidopsis thaliana that is involved in modulating the rate of lateral root growth in response to changes in the external NO(3)(-) supply. Transgenic plants have been generated in which a constitutively expressed ANR1 protein can be post-translationally activated by treatment with dexamethasone (DEX). When roots of these lines are treated with DEX, lateral root growth is markedly stimulated but there is no effect on primary root growth, suggesting that one or more components of the regulatory pathway that operate in conjunction with ANR1 in lateral roots may be absent in the primary root tip. We have recently observed some very specific effects of low concentrations of glutamate on root growth, resulting in significant changes in root architecture. Experimental evidence suggests that this response involves the sensing of extracellular glutamate by root tip cells. We are currently investigating the possible role of plant ionotropic glutamate receptors in this sensory mechanism. PMID:15667327

Filleur, S; Walch-Liu, P; Gan, Y; Forde, B G

2005-02-01

240

A statistical approach to root system classification  

PubMed Central

Plant root systems have a key role in ecology and agronomy. In spite of fast increase in root studies, still there is no classification that allows distinguishing among distinctive characteristics within the diversity of rooting strategies. Our hypothesis is that a multivariate approach for “plant functional type” identification in ecology can be applied to the classification of root systems. The classification method presented is based on a data-defined statistical procedure without a priori decision on the classifiers. The study demonstrates that principal component based rooting types provide efficient and meaningful multi-trait classifiers. The classification method is exemplified with simulated root architectures and morphological field data. Simulated root architectures showed that morphological attributes with spatial distribution parameters capture most distinctive features within root system diversity. While developmental type (tap vs. shoot-borne systems) is a strong, but coarse classifier, topological traits provide the most detailed differentiation among distinctive groups. Adequacy of commonly available morphologic traits for classification is supported by field data. Rooting types emerging from measured data, mainly distinguished by diameter/weight and density dominated types. Similarity of root systems within distinctive groups was the joint result of phylogenetic relation and environmental as well as human selection pressure. We concluded that the data-define classification is appropriate for integration of knowledge obtained with different root measurement methods and at various scales. Currently root morphology is the most promising basis for classification due to widely used common measurement protocols. To capture details of root diversity efforts in architectural measurement techniques are essential. PMID:23914200

Bodner, Gernot; Leitner, Daniel; Nakhforoosh, Alireza; Sobotik, Monika; Moder, Karl; Kaul, Hans-Peter

2013-01-01

241

The role of root system architecture and root hairs in promoting anchorage against uprooting forces in Allium cepa and root mutants of Arabidopsis thaliana  

Microsoft Academic Search

The role played by lateral roots and root hairs in promoting plant anchorage, and specifically resist- ance to vertical uprooting forces has been deter- mined experimentally. Two species were studied, Allium cepa (onion) which has a particularly simple root system and two mutants of Arabidopsis thaliana, one without root hairs (rhd 2-1) and another with reduced lateral root branching (axr

Peter H. J. Bailey; J. D. Currey; A. H. Fitter

2002-01-01

242

Thermotropism by primary roots of maize  

SciTech Connect

Sensing in the roots of higher plants has long been recognized to be restricted mainly to gravitropism and thigmotropism. However, root responses to temperature gradients have not been extensively studied. We have designed experiments under controlled conditions to test if and how root direction of maize can be altered by thermal gradients perpendicular to the gravity vector. Primary roots of maize grown on agar plates exhibit positive thermotropism (curvature toward the warmer temperature) when exposed to gradients of 0.5 to 4.2{degree}C cm{sup {minus}1}. The extent of thermotropism depends on the temperature gradient and the temperature at which the root is placed within the gradient. The curvature cannot be accounted for by differential growth as a direct effect of temperature on each side of the root.

Fortin, M.-C.; Poff, K.L. (MSU-DOE Plant Research Laboratory, East Lansing, MI (USA))

1990-05-01

243

Cell death after dorsal root injury  

Microsoft Academic Search

Flow cytometry and terminal deoxynucleotidyl transferase-mediated biotinylated uridine triphosphate nick end-labelling (TUNEL) immunohistochemistry have been used to assess cell death in the dorsal root ganglia (DRG) or spinal cord 1, 2 or 14 days after multiple lumbar dorsal root rhizotomy or dorsal root avulsion injury in adult rats. Neither injury induced significant cell death in the DRG compared to sham-operated

Daniel J. Chew; Veronica H. L. Leinster; Mathuri Sakthithasan; Lesley G. Robson; Thomas Carlstedt; Peter J. Shortland

2008-01-01

244

Root-knot Nematodes and Giant Cells  

Microsoft Academic Search

\\u000a Of all the economically important plant parasitic nematodes, root-knot nematodes (Meloidogyne species) are amongst the most widespread, the best recognized and most widely studied. This is partly because infected roots\\u000a develop galls where the nematodes feed, which with severe infection give roots a ‘knotted’ appearance. They have a remarkably\\u000a wide host range, and are ubiquitous especially in tropical and sub-tropical

Michael G. K. Jones; Derek B. Goto

245

Root Doctors as Providers of Primary Care  

PubMed Central

Physicians in primary care recognize that as many as 65 percent of the patients seen in their offices are there for psychological reasons. In any southern town with a moderate population of blacks, there are at least two “root doctors.” These root doctors have mastered the power of autosuggestion and are treating these patients with various forms of medication and psychological counseling. This paper updates the practicing physician on root doctors who practice primary care. PMID:6887277

Stitt, Van J.

1983-01-01

246

Ecology of Root Colonizing Massilia (Oxalobacteraceae)  

Microsoft Academic Search

BackgroundEcologically meaningful classification of bacterial populations is essential for understanding the structure and function of bacterial communities. As in soils, the ecological strategy of the majority of root-colonizing bacteria is mostly unknown. Among those are Massilia (Oxalobacteraceae), a major group of rhizosphere and root colonizing bacteria of many plant species.Methodology\\/Principal FindingsThe ecology of Massilia was explored in cucumber root and

Maya Ofek; Yitzhak Hadar; Dror Minz

2012-01-01

247

Mechanized instrumentation of root canals oscillating systems.  

PubMed

Cleaning and shaping are important steps in the root canal treatment. Despite the technological advances in endodontics, K and Hedstroen files are still widely used. In an attempt to be more effective in preparing the root canals, faster and more cutting efficient kinematic, alloys and design alternatives utilizing mechanically oscillating or rotary files are proposed. Even with all these technological innovating alternatives, the preparation of root canals remains a challenge. PMID:23579914

Leonardo, Renato de Toledo; Puente, Carlos Garcia; Jaime, Alejandro; Jent, Carol

2013-01-01

248

Maximum Bounded Rooted-Tree Packing Problem  

E-print Network

Given a graph and a root, the Maximum Bounded Rooted-Tree Packing (MBRTP) problem aims at finding K rooted-trees that span the largest subset of vertices, when each vertex has a limited outdegree. This problem is motivated by peer-to-peer streaming overlays in under-provisioned systems. We prove that the MBRTP problem is NP-complete. We present two polynomial-time algorithms that computes an optimal solution on complete graphs and trees respectively.

Kerivin, Herve; Simon, Gwendal; Zhou, Fen

2011-01-01

249

Water Transport in Maize Roots 1  

PubMed Central

A root pressure probe has been used to measure the root pressure (Pr) exerted by excised main roots of young maize plants (Zea Mays L.). Defined gradients of hydrostatic and osmotic pressure could be set up between root xylem and medium to induce radial water flows across the root cylinder in both directions. The hydraulic conductivity of the root (Lpr) was evaluated from root pressure relaxations. When permeating solutes were added to the medium, biphasic root pressure relaxations were observed with water and solute phases and root pressure minima (maxima) which allowed the estimation of permeability (PSr) and reflection coefficients (?sr) of roots. Reflection coefficients were: ethanol, 0.27; mannitol, 0.74; sucrose, 0.54; PEG 1000, 0.82; NaCl, 0.64; KNO3, 0.67, and permeability coefficients (in 10?8 meters per second): ethanol, 4.7; sucrose, 1.6; and NaCl, 5.7. Lpr was very different for osmotic and hydrostatic gradients. For hydrostatic gradients Lpr was 1·10?7 meters per second per megapascal, whereas in osmotic experiments the hydraulic conductivity was found to be an order of magnitude lower. For hydrostatic gradients, the exosmotic Lpr was about 15% larger than the endosmotic, whereas in osmotic experiments the polarity in the water movement was reversed. These results either suggest effects of unstirred layers at the osmotic barrier in the root, an asymmetrical barrier, and/or mechanical effects. Measurements of the hydraulic conductivity of individual root cortex cells revealed an Lp similar to Lpr (hydrostatic). It is concluded that, in the presence of external hydrostatic gradients, water moves primarily in the apoplast, whereas in the presence of osmotic gradients this component is much smaller in relation to the cell-to-cell component (symplasmic plus transcellular transport). PMID:16665588

Steudle, Ernst; Oren, Ram; Schulze, Ernst-Detlef

1987-01-01

250

Cluster Roots: A Curiosity in Context  

Microsoft Academic Search

Cluster roots are an adaptation for nutrient acquisition from nutrient-poor soils. They develop on root systems of a range\\u000a of species belonging to a number of different families (e.g., Proteaceae, Casuarinaceae, Fabaceae and Myricaceae) and are\\u000a also found on root systems of some crop species (e.g., albus, Macadamia integrifoliaandCucurbita pepo). Their morphology is variable but typically, large numbers of determinate

Michael W. Shane; Hans Lambers

2005-01-01

251

Root-to-Root Travel of the Beneficial Bacterium Azospirillum brasilense†  

PubMed Central

The root-to-root travel of the beneficial bacterium Azospirillum brasilense on wheat and soybean roots in agar, sand, and light-textured soil was monitored. We used a motile wild-type (Mot+) strain and a motility-deficient (Mot-) strain which was derived from the wild-type strain. The colonization levels of inoculated roots were similar for the two strains. Mot+ cells moved from inoculated roots (either natural or artificial roots in agar, sand, or light-textured soil) to noninoculated roots, where they formed a band-type colonization composed of bacterial aggregates encircling a limited part of the root, regardless of the plant species. The Mot- strain did not move toward noninoculated roots of either plant species and usually stayed at the inoculation site and root tips. The effect of attractants and repellents was the primary factor governing the motility of Mot+ cells in the presence of adequate water. We propose that interroot travel of A. brasilense is an essential preliminary step in the root-bacterium recognition mechanism. Bacterial motility might have a general role in getting Azospirillum cells to the site where firmer attachment favors colonization of the root system. Azospirillum travel toward plants is a nonspecific active process which is not directly dependent on nutrient deficiency but is a consequence of a nonspecific bacterial chemotaxis, influenced by the balance between attractants and possibly repellents leaked by the root. PMID:16349297

Bashan, Yoav; Holguin, Gina

1994-01-01

252

Genetic ablation of root cap cells in Arabidopsis  

NASA Technical Reports Server (NTRS)

The root cap is increasingly appreciated as a complex and dynamic plant organ. Root caps sense and transmit environmental signals, synthesize and secrete small molecules and macromolecules, and in some species shed metabolically active cells. However, it is not known whether root caps are essential for normal shoot and root development. We report the identification of a root cap-specific promoter and describe its use to genetically ablate root caps by directing root cap-specific expression of a diphtheria toxin A-chain gene. Transgenic toxin-expressing plants are viable and have normal aerial parts but agravitropic roots, implying loss of root cap function. Several cell layers are missing from the transgenic root caps, and the remaining cells are abnormal. Although the radial organization of the roots is normal in toxin-expressing plants, the root tips have fewer cytoplasmically dense cells than do wild-type root tips, suggesting that root meristematic activity is lower in transgenic than in wild-type plants. The roots of transgenic plants have more lateral roots and these are, in turn, more highly branched than those of wild-type plants. Thus, root cap ablation alters root architecture both by inhibiting root meristematic activity and by stimulating lateral root initiation. These observations imply that the root caps contain essential components of the signaling system that determines root architecture.

Tsugeki, R.; Fedoroff, N. V.

1999-01-01

253

Genotypic recognition and spatial responses by rice roots  

PubMed Central

Root system growth and development is highly plastic and is influenced by the surrounding environment. Roots frequently grow in heterogeneous environments that include interactions from neighboring plants and physical impediments in the rhizosphere. To investigate how planting density and physical objects affect root system growth, we grew rice in a transparent gel system in close proximity with another plant or a physical object. Root systems were imaged and reconstructed in three dimensions. Root–root interaction strength was calculated using quantitative metrics that characterize the extent to which the reconstructed root systems overlap each other. Surprisingly, we found the overlap of root systems of the same genotype was significantly higher than that of root systems of different genotypes. Root systems of the same genotype tended to grow toward each other but those of different genotypes appeared to avoid each other. Shoot separation experiments excluded the possibility of aerial interactions, suggesting root communication. Staggered plantings indicated that interactions likely occur at root tips in close proximity. Recognition of obstacles also occurred through root tips, but through physical contact in a size-dependent manner. These results indicate that root systems use two different forms of communication to recognize objects and alter root architecture: root-root recognition, possibly mediated through root exudates, and root-object recognition mediated by physical contact at the root tips. This finding suggests that root tips act as local sensors that integrate rhizosphere information into global root architectural changes. PMID:23362379

Fang, Suqin; Clark, Randy T.; Zheng, Ying; Iyer-Pascuzzi, Anjali S.; Weitz, Joshua S.; Kochian, Leon V.; Edelsbrunner, Herbert; Liao, Hong; Benfey, Philip N.

2013-01-01

254

Transcriptional Networks in Root Cell Fate Specification  

PubMed Central

Summary Cell fate in the Arabidopsis root is determined by positional information mediated by plant hormones and interpreted by transcriptional networks. In this review, we summarize recent advances in our understanding of the regulatory networks that control cell fate within the root meristem, and in the interplay of these networks with phytohormones. Recent work describing the importance of chromatin organization in tissue patterning is also highlighted. A new, high resolution root expression map detailing the transciptome of nearly all cell types in the Arabidopsis root across developmental timepoints will provide a framework for understanding these networks. PMID:18973837

Iyer-Pascuzzi, Anjali S.; Benfey, Philip N.

2009-01-01

255

Take-All Root Rot of Turfgrass  

E-print Network

the growing season, Take-all Root Rot of Turfgrass Joseph P. Krausz* L-5170 4-05 *Professor and Extension Program Leader for Plant Pathology, The Texas A&M University System. Characteristic infection pads (hypho - podia) of the take-all root rot fungus... the growing season, Take-all Root Rot of Turfgrass Joseph P. Krausz* L-5170 4-05 *Professor and Extension Program Leader for Plant Pathology, The Texas A&M University System. Characteristic infection pads (hypho - podia) of the take-all root rot fungus...

Krausz, Joseph P.

2005-04-21

256

OZONE DECREASES SPRING ROOT GROWTH AND ROOT CARBOHYDRATE CONTENT IN PONDEROSA PINE THE YEAR FOLLOWING EXPOSURE  

EPA Science Inventory

Storage carbohydrates are extremely important for new shoot and root development following dormancy or during periods of high stress. he hypothesis that ozone decreases carbohydrate storage and decreases new root growth during the year following exposure was investigated. eedling...

257

Detection of tree roots and determination of root diameters by ground penetrating radar under optimal conditions.  

PubMed

A tree's root system accounts for between 10 and 65% of its total biomass, yet our understanding of the factors that cause this proportion to vary is limited because of the difficulty encountered when studying tree root systems. There is a need to develop new sampling and measuring techniques for tree root systems. Ground penetrating radar (GPR) offers the potential for direct nondestructive measurements of tree root biomass and root distributions to be made. We tested the ability of GPR, with 500 MHz, 800 MHz and 1 GHz antennas, to detect tree roots and determine root size by burying roots in a 32 m3 pit containing damp sand. Within this test bed, tree roots were buried in two configurations: (1) roots of various diameters (1-10 cm) were buried at a single depth (50 cm); and (2) roots of similar diameter (about 5 cm) were buried at various depths (15-155 cm). Radar antennas were drawn along transects perpendicular to the buried roots. Radar profile normalization, filtration and migration were undertaken based on standard algorithms. All antennas produced characteristic reflection hyperbolas on the radar profiles allowing visual identification of most root locations. The 800 MHz antenna resulted in the clearest radar profiles. An unsupervised, maximum-convexity migration algorithm was used to focus information contained in the hyperbolas back to a point. This resulted in a significant gain in clarity with roots appearing as discrete shapes, thereby reducing confusion due to overlapping of hyperbolas when many roots are detected. More importantly, parameters extracted from the resultant waveform through the center of a root correlated well with root diameter for the 500 MHz antenna, but not for the other two antennas. A multiple regression model based on the extracted parameters was calibrated on half of the data (R2 = 0.89) and produced good predictions when tested on the remaining data. Root diameters were predicted with a root mean squared error of 0.6 cm, allowing detection and quantification of roots as small as 1 cm in diameter. An advantage of this processing technique is that it produces results independently of signal strength. These waveform parameters represent a major advance in the processing of GPR profiles for estimating root diameters. We conclude that enhanced data analysis routines combined with improvements in GPR hardware design could make GPR a valuable tool for studying tree root systems. PMID:15465695

Barton, Craig V M; Montagu, Kelvin D

2004-12-01

258

ROOT CAUSE ANALYSIS PROGRAM MANUAL  

SciTech Connect

Root Cause Analysis (RCA) identifies the cause of an adverse condition that, if corrected, will preclude recurrence or greatly reduce the probability of recurrence of the same or similar adverse conditions and thereby protect the health and safety of the public, the workers, and the environment. This procedure sets forth the requirements for management determination and the selection of RCA methods and implementation of RCAs that are a result of significant findings from Price-Anderson Amendments Act (PAAA) violations, occurrences/events, Significant Adverse Conditions, and external oversight Corrective Action Requests (CARs) generated by the Office of Enforcement (PAAA headquarters), the U.S. Environmental Protection Agency, and other oversight entities against Lawrence Berkeley National Laboratory (LBNL). Performance of an RCA may result in the identification of issues that should be reported in accordance with the Issues Management Program Manual.

Gravois, Melanie C.

2007-05-02

259

Root-growth-inhibiting sheet  

DOEpatents

In accordance with this invention, a porous sheet material is provided at intervals with bodies of a polymer which contain a 2,6-dinitroaniline. The sheet material is made porous to permit free passage of water. It may be either a perforated sheet or a woven or non-woven textile material. A particularly desirable embodiment is a non-woven fabric of non-biodegradable material. This type of material is known as a "geotextile" and is used for weed control, prevention of erosion on slopes, and other landscaping purposes. In order to obtain a root repelling property, a dinitroaniline is blended with a polymer which is attached to the geotextile or other porous material.

Burton, Frederick G. (Stansbury Park, UT); Cataldo, Dominic A. (Kennewick, WA); Cline, John F. (Prosser, WA); Skiens, W. Eugene (Wilsonville, OR); Van Voris, Peter (Richland, WA)

1993-01-01

260

Variations of fine root diameter with root order in Manchurian ash and Dahurian larch plantations  

Microsoft Academic Search

Fine root lifespan and turnover play an important role in carbon allocation and nutrient cycling in forest ecosystems. Fine\\u000a roots are typically defined as less than 1 or 2 mm in diameter. However, when categorizing roots by this diameter size, the\\u000a position of an individual root on the complex lateral branching pattern has often been ignored, and our knowledge about

Xiangrong Wang; Zhengquan Wang; Youzhi Han; Jiacun Gu; Dali Guo; Li Mei

2007-01-01

261

Chemical root pruning and its effects on water relations and root morphology of photinia  

E-print Network

CHEMICAL ROOT PRUNING AND ITS EFFECTS ON WATER RELATIONS AND ROOT MORPHOLOGY OF PHOT1IVIA A Thesis by DIPTISH RAMESH VARTAK Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE December 1993 Major Subject: Agricultural Engineering CHEMICAL ROOT PRUNING AND ITS EFFECTS ON WATER RELATIONS AND ROOT MORPHOLOGY OF PHOTJIVIA A Thesis by DIPTISH RAMESH VARTAK Submitted to Texas A&M University...

Vartak, Diptish Ramesh

2012-06-07

262

The occurrence and potential relevance of post-release, nontarget attack by Mogulones cruciger, a biocontrol agent for Cynoglossum officinale in Canada  

Microsoft Academic Search

Reports on nontarget attack by introduced biological control agents have caused debate over the safety of biological control of weeds. One outcome of this dialogue is the importance of monitoring for nontarget attack and its effects as part of post-release assessments. This is particularly vital in the case of the root-mining weevil Mogulones cruciger, which was approved and released in

Jennifer Elizabeth Andreas; Mark Schwarzländer; Rosemarie De Clerck-Floate

2008-01-01

263

Root functioning in tropical high-elevation forests: Environmental vs. biological control of root water absorption  

Microsoft Academic Search

Lowered temperatures may reduce the root water uptake of tropical trees at high elevations through several mechanisms; however, field studies to test their relevance are lacking. We measured sap flux density (J) in small-diameter tree roots across a 2000-m elevation transect in a tropical mountain forest for quantifying the effects of temperature (Ta), VPD and soil moisture (?) on root

Sophie Graefe; Christoph Leuschner; Heinz Coners; Dietrich Hertel

2011-01-01

264

Root-gel interactions and the root waving behavior of Arabidopsis.  

PubMed

Arabidopsis roots grown on inclined agarose gels exhibit a sinusoidal growth pattern known as root waving. While root waving has been attributed to both intrinsic factors (e.g. circumnutation) and growth responses to external signals such as gravity, the potential for physical interactions between the root and its substrate to influence the development of this complex phenotype has been generally ignored. Using a rotating stage microscope and time-lapse digital imaging, we show that (1) root tip mobility is impeded by the gel surface, (2) this impedance causes root tip deflections by amplifying curvature in the elongation zone in a way that is distinctly nontropic, and (3) root tip impedance is augmented by normal gravitropic pressure applied by the root tip against the gel surface. Thus, both lateral corrective bending near the root apex and root tip impedance could be due to different vector components of the same graviresponse. Furthermore, we speculate that coupling between root twisting and bending is a mechanical effect resulting from root tip impedance. PMID:15247406

Thompson, Matthew V; Holbrook, N Michele

2004-07-01

265

EFFECTS OF HEDGING ON MATURATION IN LOBLOLLY PINE: ROOTING CAPACITY AND ROOT FORMATION  

E-print Network

and clonal forestry systems are reviewed. Three quantitative rooting experiments were conductedi EFFECTS OF HEDGING ON MATURATION IN LOBLOLLY PINE: ROOTING CAPACITY AND ROOT FORMATION By Andreas State University of New York College of Environmental Science and Forestry Syracuse, New York January

Hamann, Andreas

266

The Root and Root Canal Morphology of the Human Mandibular First Premolar: A Literature Review  

Microsoft Academic Search

The purpose of this study was to undertake a comprehensive literature review of the root and root canal morphology of the mandibular first premolar. Published studies citing the anatomy and morphology of mandibular premolars report data for over 6,700 teeth. These studies were divided into anatomical studies reporting number of roots, number of canals, and apical morphology. Variations because of

Blaine M. Cleghorn; William H. Christie; Cecilia C. S. Dong

2007-01-01

267

Enhanced Phenanthrene Biodegradation in Soil by Slender Oat Root Exudates and Root Debris  

Microsoft Academic Search

mineralization enhancement of 23% compared with ace- tate-fed controls (Burken and Schnoor, 1996). Parathion To investigate the mechanisms by which slender oat (Avena barbata mineralization was also stimulated in soils amended with Pott ex Link) enhances phenanthrene biodegradation, we analyzed the impacts of root exudates and root debris on phenanthrene biodeg- root exudates, but greater stimulation resulted from the radation

Ryan K. Miya; Mary K. Firestone

2001-01-01

268

Gravitropism and Autotropism in Cress Roots  

NASA Technical Reports Server (NTRS)

The overall purpose of this experiment was to study how cress roots respond to a withdrawal of a gravity stimulus i.e. when and how much the roots straighten (autotropism) after curving (gravitropism). This question was studied both in extensive ground-based research and in microgravity on BioRack.

Sack, Fred D.

1998-01-01

269

ADVANCING FINE ROOT RESEARCH WITH MINIRHIZOTRONS  

EPA Science Inventory

Minirhizotrons provide a nondestructive, in situ method for directly viewing and studying fine roots. Although many insights into fine roots have been gained using minirhizotrons, it is clear from the literature that there is still wide variation in how minirhizotrons and minirhi...

270

Compounds from the roots of Jasminum sambac.  

PubMed

Four new compounds (+)-jasminoids A, B, C, and D, together with seven known compounds, were isolated from the roots of Jasminum sambac. Their structures were identified using spectroscopic methods. This study provides a better understanding to the chemical composition of J. sambac roots that have been thought to be one ingredient of an ancient prescription 'Ma-Fei-San'. PMID:23134371

Zeng, Lin-Hong; Hu, Min; Yan, Yong-Ming; Lu, Qing; Cheng, Yong-Xian

2012-01-01

271

ACETOGENIC BACTERIA ASSOCIATED WITH SEAGRASS ROOTS  

EPA Science Inventory

Seagrasses are adapted to being rooted in reduced, anoxic sediments with high rates of sulfate reduction. During the day, an oxygen gradient is generated around the roots, becoming anoxic at night. Thus, obligate anaerobic bacteria in the rhizosphere have to tolerate elevated oxy...

272

Topographic and ecologic controls on root reinforcement  

Microsoft Academic Search

Shallow landslides are a significant hazard in steep, soil-mantled landscapes. During intense rainfall events, the distribution of shallow landslides is controlled by variations in landscape gradient, the frictional and cohesive properties of soil and roots, and the subsurface hydrologic response. While gradients can be estimated from digital elevation models, information on soil and root properties remains sparse. We investigated whether

T. C. Hales; C. R. Ford; T. Hwang; J. M. Vose; L. E. Band

2009-01-01

273

Testing for unit roots in heterogeneous panels  

Microsoft Academic Search

This paper proposes unit root tests for dynamic heterogeneous panels based on the mean of individual unit root statistics. In particular it proposes a standardized t-bar test statistic based on the (augmented) Dickey–Fuller statistics averaged across the groups. Under a general setting this statistic is shown to converge in probability to a standard normal variate sequentially with T (the time

Kyung So Im; M. Hashem Pesaran; Yongcheol Shin

2003-01-01

274

Root Kits - An Operating Systems Viewpoint  

Microsoft Academic Search

Root Kits are tool boxes containing a collection of highly skilled tools for attacking computer systems. Their algorithms and databases contain professional knowledge about methods and mecha- nisms for completely automated attacks both over a network as well as from within a system. Root kits attack by maneuvering a system into executing a script with supervisor privileges. Once having g~ned

Winfried E. Kfihnhauser

275

Root Kits: an operating systems viewpoint  

Microsoft Academic Search

Root Kits are tool boxes containing a collection of highly skilled tools for attacking computer systems. Their algorithms and databases contain professional knowledge about methods and mechanisms for completely automated attacks both over a network as well as from within a system. Root kits attack by maneuvering a system into executing a script with supervisor privileges. Once having gained full

Winfried E. Kfihnhauser

2004-01-01

276

Square Root SAM Simultaneous Localization and Mapping  

E-print Network

Square Root SAM Simultaneous Localization and Mapping via Square Root Information Smoothing Frank Solving the SLAM problem is one way to enable a robot to explore, map, and navigate in a previously of these methods as an alternative to EKF-based approaches. 1 Introduction The problem of simultaneous localization

Leonard, John J.

277

Cytological and ultrastructural studies on root tissues  

NASA Technical Reports Server (NTRS)

The anatomy and fine structure of roots from oat and mung bean seedlings, grown under microgravity conditions for 8 days aboard the Space Shuttle, was examined and compared to that of roots from ground control plants grown under similar conditions. Roots from both sets of oat seedlings exhibited characteristic monocotyledonous tissue organization and normal ultrastructural features, except for cortex cell mitochondria, which exhibited a 'swollen' morphology. Various stages of cell division were observed in the meristematic tissues of oat roots. Ground control and flight-grown mung bean roots also showed normal tissue organization, but root cap cells in the flight-grown roots were collapsed and degraded in appearance, especially at the cap periphery. At the ultrastructural level, these cells exhibited a loss of organelle integrity and a highly-condensed cytoplasm. This latter observation perhaps suggests a differing tissue sensitivity for the two species to growth conditions employed in space flight. The basis for abnormal root cap cell development is not understood, but the loss of these putative gravity-sensing cells holds potential significance for long term plant growth orientation during space flight.

Slocum, R. D.; Gaynor, J. J.; Galston, A. W.

1984-01-01

278

Plant root research: the past, the present and the future  

PubMed Central

This special issue is dedicated to root biologists past and present who have been exploring all aspects of root structure and function with an extensive publication record going over 100 years. The content of the Special Issue on Root Biology covers a wide scale of contributions, spanning interactions of roots with microorganisms in the rhizosphere, the anatomy of root cells and tissues, the subcellular components of root cells, and aspects of metal accumulation and stresses on root function and structure. We have organized the papers into three topic categories: (1) root ecology, interactions with microbes, root architecture and the rhizosphere; (2) experimental root biology, root structure and physiology; and (3) applications of new technology to study root biology. Finally, we will speculate on root research for the future. PMID:22966495

Lux, Alexander; Rost, Thomas L.

2012-01-01

279

Branching out in roots: uncovering form, function, and regulation.  

PubMed

Root branching is critical for plants to secure anchorage and ensure the supply of water, minerals, and nutrients. To date, research on root branching has focused on lateral root development in young seedlings. However, many other programs of postembryonic root organogenesis exist in angiosperms. In cereal crops, the majority of the mature root system is composed of several classes of adventitious roots that include crown roots and brace roots. In this Update, we initially describe the diversity of postembryonic root forms. Next, we review recent advances in our understanding of the genes, signals, and mechanisms regulating lateral root and adventitious root branching in the plant models Arabidopsis (Arabidopsis thaliana), maize (Zea mays), and rice (Oryza sativa). While many common signals, regulatory components, and mechanisms have been identified that control the initiation, morphogenesis, and emergence of new lateral and adventitious root organs, much more remains to be done. We conclude by discussing the challenges and opportunities facing root branching research. PMID:25136060

Atkinson, Jonathan A; Rasmussen, Amanda; Traini, Richard; Voß, Ute; Sturrock, Craig; Mooney, Sacha J; Wells, Darren M; Bennett, Malcolm J

2014-10-01

280

Gene for a protein capable of enhancing lateral root formation.  

PubMed

Analysis of genes preferentially expressed in hairy roots caused by infection with Agrobacterium rhizogenes has provided insights into the regulation of lateral root formation. A hairy root preferential cDNA, HR7, has been cloned from hairy roots of Hyoscyamus niger. HR7 encodes a novel protein partially homologous to a metallocarboxypeptidase inhibitor and is expressed exclusively in the primordium and base of lateral roots in hairy roots. Overexpression of HR7 in transgenic roots of H. niger dramatically enhances the frequency of lateral root formation. The results of this study indicate that expression of HR7 plays a critical role in initiating lateral root formation. PMID:10356981

Mikami, Y; Horiike, G; Kuroyanagi, M; Noguchi, H; Shimizu, M; Niwa, Y; Kobayashi, H

1999-05-14

281

GiA Roots: software for the high throughput analysis of plant root system architecture  

PubMed Central

Background Characterizing root system architecture (RSA) is essential to understanding the development and function of vascular plants. Identifying RSA-associated genes also represents an underexplored opportunity for crop improvement. Software tools are needed to accelerate the pace at which quantitative traits of RSA are estimated from images of root networks. Results We have developed GiA Roots (General Image Analysis of Roots), a semi-automated software tool designed specifically for the high-throughput analysis of root system images. GiA Roots includes user-assisted algorithms to distinguish root from background and a fully automated pipeline that extracts dozens of root system phenotypes. Quantitative information on each phenotype, along with intermediate steps for full reproducibility, is returned to the end-user for downstream analysis. GiA Roots has a GUI front end and a command-line interface for interweaving the software into large-scale workflows. GiA Roots can also be extended to estimate novel phenotypes specified by the end-user. Conclusions We demonstrate the use of GiA Roots on a set of 2393 images of rice roots representing 12 genotypes from the species Oryza sativa. We validate trait measurements against prior analyses of this image set that demonstrated that RSA traits are likely heritable and associated with genotypic differences. Moreover, we demonstrate that GiA Roots is extensible and an end-user can add functionality so that GiA Roots can estimate novel RSA traits. In summary, we show that the software can function as an efficient tool as part of a workflow to move from large numbers of root images to downstream analysis. PMID:22834569

2012-01-01

282

Long-term control of root growth  

DOEpatents

A method and system for long-term control of root growth without killing the plants bearing those roots involves incorporating a 2,6-dinitroaniline in a polymer and disposing the polymer in an area in which root control is desired. This results in controlled release of the substituted aniline herbicide over a period of many years. Herbicides of this class have the property of preventing root elongation without translocating into other parts of the plant. The herbicide may be encapsulated in the polymer or mixed with it. The polymer-herbicide mixture may be formed into pellets, sheets, pipe gaskets, pipes for carrying water, or various other forms. The invention may be applied to other protection of buried hazardous wastes, protection of underground pipes, prevention of root intrusion beneath slabs, the dwarfing of trees or shrubs and other applications. The preferred herbicide is 4-difluoromethyl-N,N-dipropyl-2,6-dinitro-aniline, commonly known as trifluralin.

Burton, Frederick G. (West Richland, WA); Cataldo, Dominic A. (Kennewick, WA); Cline, John F. (Prosser, WA); Skiens, W. Eugene (Richland, WA)

1992-05-26

283

Effect of lead on root growth  

PubMed Central

Lead (Pb) is one of the most widespread heavy metal contaminant in soils. It is highly toxic to living organisms. Pb has no biological function but can cause morphological, physiological, and biochemical dysfunctions in plants. Plants have developed a wide range of tolerance mechanisms that are activated in response to Pb exposure. Pb affects plants primarily through their root systems. Plant roots rapidly respond either (i) by the synthesis and deposition of callose, creating a barrier that stops Pb entering (ii) through the uptake of large amounts of Pb and its sequestration in the vacuole accompanied by changes in root growth and branching pattern or (iii) by its translocation to the aboveground parts of plant in the case of hyperaccumulators plants. Here we review the interactions of roots with the presence of Pb in the rhizosphere and the effect of Pb on the physiological and biochemical mechanisms of root development. PMID:23750165

Fahr, Mouna; Laplaze, Laurent; Bendaou, Najib; Hocher, Valerie; Mzibri, Mohamed El; Bogusz, Didier; Smouni, Abdelaziz

2013-01-01

284

How roots perceive and respond to gravity  

NASA Technical Reports Server (NTRS)

Graviperception by plant roots is believed to occur via the sedimentation of amyloplasts in columella cells of the root cap. This physical stimulus results in an accumulation of calcium on the lower side of the cap, which in turn induces gravicurvature. In this paper we present a model for root gravitropism integrating gravity-induced changes in electrical potential, cytochemical localization of calcium in cells of gravistimulated roots, and the interdependence of calcium and auxin movement. Key features of the model are that 1) gravity-induced redistribution of calcium is an early event in the transduction mechanism, and 2) apoplastic movement of calcium through the root-cap mucilage may be an important component of the pathway for calcium movement.

Moore, R.; Evans, M. L.

1986-01-01

285

Systems approaches to study root architecture dynamics  

PubMed Central

The plant root system is essential for providing anchorage to the soil, supplying minerals and water, and synthesizing metabolites. It is a dynamic organ modulated by external cues such as environmental signals, water and nutrients availability, salinity and others. Lateral roots (LRs) are initiated from the primary root post-embryonically, after which they progress through discrete developmental stages which can be independently controlled, providing a high level of plasticity during root system formation. Within this review, main contributions are presented, from the classical forward genetic screens to the more recent high-throughput approaches, combined with computer model predictions, dissecting how LRs and thereby root system architecture is established and developed. PMID:24421783

Cuesta, Candela; Wabnik, Krzysztof; Benkova, Eva

2013-01-01

286

Long-term control of root growth  

SciTech Connect

A method and system for long-term control of root growth without killing the plants bearing those roots involves incorporating a 2,6-dinitroaniline in a polymer and disposing the polymer in an area in which root control is desired. This results in controlled release of the substituted aniline herbicide over a period of many years. Herbicides of this class have the property of preventing root elongation without translocating into other parts of the plant. The herbicide may be encapsulated in the polymer or mixed with it. The polymer-herbicide mixture may be formed into pellets, sheets, pipe gaskets, pipes for carrying water, or various other forms. The invention may be applied to other protection of buried hazardous wastes, protection of underground pipes, prevention of root intrusion beneath slabs, the dwarfing of trees or shrubs and other applications. The preferred herbicide is 4-difluoromethyl-N,N-dipropyl-2,6-dinitro-aniline, commonly known as trifluralin. 7 figs.

Burton, F.G.; Cataldo, D.A.; Cline, J.F.; Skiens, W.E.

1992-05-26

287

The origin and early evolution of roots.  

PubMed

Geological sites of exceptional fossil preservation are becoming a focus of research on root evolution because they retain edaphic and ecological context, and the remains of plant soft tissues are preserved in some. New information is emerging on the origins of rooting systems, their interactions with fungi, and their nature and diversity in the earliest forest ecosystems. Remarkably well-preserved fossils prove that mycorrhizal symbionts were diverse in simple rhizoid-based systems. Roots evolved in a piecemeal fashion and independently in several major clades through the Devonian Period (416 to 360 million years ago), rapidly extending functionality and complexity. Evidence from extinct arborescent clades indicates that polar auxin transport was recruited independently in several to regulate wood and root development. The broader impact of root evolution on the geochemical carbon cycle is a developing area and one in which the interests of the plant physiologist intersect with those of the geochemist. PMID:25187527

Kenrick, Paul; Strullu-Derrien, Christine

2014-10-01

288

Root gravitropism: a complex response to a simple stimulus?  

Microsoft Academic Search

Roots avoid depleting their immediate environment of essential nutrients by continuous growth. Root growth is directed by environmental cues, including gravity. Gravity sensing occurs mainly in the columella cells of the root cap. Upon reorientation within the gravity field, the root-cap amyloplasts sediment, generating a physiological signal that promotes the development of a curvature at the root elongation zones. Recent

Elizabeth Rosen; Rujin Chen; Patrick H Masson

1999-01-01

289

Mechanical properties of tree roots for soil reinforcement models  

Microsoft Academic Search

Evidence from forestry has shown that part of the forest floor bearing capacity is delivered by tree roots. The beneficial effect however varies and diminishes with increasing number of vehicle passes. Roots potential for reinforcing the soil is known to depend among others on root mechanical properties, distribution, morphology, etc. Rooting intensity and root patterns of forest trees are complicated,

P. Cofie

2001-01-01

290

Bud Initiation in Excised Roots of Linaria vulgaris  

Microsoft Academic Search

VEGETATIVE reproduction in Linaria vulgaris is effected by the formation of root-buds at the junction of the parent and some of the lateral roots. Up to four buds may be formed in the superficial layers of the lateral root within the cortex of the parent root1 (Fig. 1), though parent and lateral root tissues are often not separately recognizable in

W. A. Charlton

1965-01-01

291

Root phenology at Harvard Forest and beyond  

NASA Astrophysics Data System (ADS)

Roots are hidden from view and heterogeneously distributed making them difficult to study in situ. As a result, the causes and timing of root production are not well understood. Researchers have long assumed that above and belowground phenology is synchronous; for example, most parameterizations of belowground carbon allocation in terrestrial biosphere models are based on allometry and represent a fixed fraction of net C uptake. However, using results from metaanalysis as well as empirical data from oak and hemlock stands at Harvard Forest, we show that synchronous root and shoot growth is the exception rather than the rule. We collected root and shoot phenology measurements from studies across four biomes (boreal, temperate, Mediterranean, and subtropical). General patterns of root phenology varied widely with 1-5 production peaks in a growing season. Surprisingly, in 9 out of the 15 studies, the first root production peak was not the largest peak. In the majority of cases maximum shoot production occurred before root production (Offset>0 in 32 out of 47 plant sample means). The number of days offset between maximum root and shoot growth was negatively correlated with median annual temperature and therefore differs significantly across biomes (ANOVA, F3,43=9.47, p<0.0001). This decline in offset with increasing temperature may reflect greater year-round coupling between air and soil temperature in warm biomes. Growth form (woody or herbaceous) also influenced the relative timing of root and shoot growth. Woody plants had a larger range of days between root and shoot growth peaks as well as a greater number of growth peaks. To explore the range of phenological relationships within woody plants in the temperate biome, we focused on above and belowground phenology in two common northeastern tree species, Quercus rubra and Tsuga canadensis. Greenness index, rate of stem growth, root production and nonstructural carbohydrate content were measured beginning in April 2012 through August 2013 at the Harvard Forest in Petersham, MA, USA. Greenness and stem growth were highest in late May and early June with one clear maximum growth period. In contrast, root growth was characterized by multiple production peaks. Q. rubra root growth experienced many small flushes around day of year (DOY) 156 (early June) and one large peak on 234 (late August). T. canadensis root growth peaked on DOY 188 (early July), 234.5 (late August) and 287 (mid-October). However, particular phenological patterns varied widely from site to site. Despite large spatial heterogeneity, it appears that Q. rubra experiences greater overall root production as well as more allocation to roots during the growing season. The storage pool of nonstructural carbohydrates experiences a mid-summer drawdown in Q. rubra but not T. canadensis roots. Timing of belowground C allocation to root growth and nonstructural carbohydrate accumulation may be regulated by climate factors as well as endogenous factors such as vessel size, growth form, or tradeoffs in C allocated between plant organs. Plant roots supply substrate to microbial communities and hence their production feeds back to other plant and soil processes that affect ecosystem C fluxes.

Abramoff, R. Z.; Finzi, A.

2013-12-01

292

iRootHair: A Comprehensive Root Hair Genomics Database1[W  

PubMed Central

The specialized root epidermis cells of higher plants produce long, tubular outgrowths called root hairs. Root hairs play an important role in nutrient and water uptake, and they serve as a valuable model in studies of plant cell morphogenesis. More than 1,300 articles that describe the biological processes of these unique cells have been published to date. As new fields of root hair research are emerging, the number of new papers published each year and the volumes of new relevant data are continuously increasing. Therefore, there is a general need to facilitate studies on root hair biology by collecting, presenting, and sharing the available information in a systematic, curated manner. Consequently, in this paper, we present a comprehensive database of root hair genomics, iRootHair, which is accessible as a Web-based service. The current version of the database includes information about 153 root hair-related genes that have been identified to date in dicots and monocots along with their putative orthologs in higher plants with sequenced genomes. In order to facilitate the use of the iRootHair database, it is subdivided into interrelated, searchable sections that describe genes, processes of root hair formation, root hair mutants, and available references. The database integrates bioinformatics tools with a focus on sequence identification and annotation. iRootHair is a unique resource for root hair research that integrates the large volume of data related to root hair genomics in a single, curated, and expandable database that is freely available at www.iroothair.org. PMID:23129204

Kwasniewski, Miroslaw; Nowakowska, Urszula; Szumera, Jakub; Chwialkowska, Karolina; Szarejko, Iwona

2013-01-01

293

Root growth inhibition by NH4 in Arabidopsis is mediated  

E-print Network

produce lat- erals along the length of the primary root (Deak & Malamy 2005); hence, the developing root a rudimentary embryonic root, and most growth and differentiation is post-embryonic (Deak & Malamy 2005). During

Kronzucker, Herbert J.

294

76 FR 51430 - Roots Pharmaceuticals, Inc.; Revocation of Registration  

Federal Register 2010, 2011, 2012, 2013

...Drug Enforcement Administration Roots Pharmaceuticals, Inc.; Revocation of Registration...issued an Order to Show Cause to Roots Pharmaceuticals, Inc. (Registrant), of American...Registration BR9610571, issued to Roots Pharmaceuticals, Inc., be, and it hereby...

2011-08-18

295

Ecology of Root Colonizing Massilia (Oxalobacteraceae)  

PubMed Central

Background Ecologically meaningful classification of bacterial populations is essential for understanding the structure and function of bacterial communities. As in soils, the ecological strategy of the majority of root-colonizing bacteria is mostly unknown. Among those are Massilia (Oxalobacteraceae), a major group of rhizosphere and root colonizing bacteria of many plant species. Methodology/Principal Findings The ecology of Massilia was explored in cucumber root and seed, and compared to that of Agrobacterium population, using culture-independent tools, including DNA-based pyrosequencing, fluorescence in situ hybridization and quantitative real-time PCR. Seed- and root-colonizing Massilia were primarily affiliated with other members of the genus described in soil and rhizosphere. Massilia colonized and proliferated on the seed coat, radicle, roots, and also on hyphae of phytopathogenic Pythium aphanidermatum infecting seeds. High variation in Massilia abundance was found in relation to plant developmental stage, along with sensitivity to plant growth medium modification (amendment with organic matter) and potential competitors. Massilia absolute abundance and relative abundance (dominance) were positively related, and peaked (up to 85%) at early stages of succession of the root microbiome. In comparison, variation in abundance of Agrobacterium was moderate and their dominance increased at later stages of succession. Conclusions In accordance with contemporary models for microbial ecology classification, copiotrophic and competition-sensitive root colonization by Massilia is suggested. These bacteria exploit, in a transient way, a window of opportunity within the succession of communities within this niche. PMID:22808103

Ofek, Maya; Hadar, Yitzhak; Minz, Dror

2012-01-01

296

Meniscal root tears: significance, diagnosis, and treatment.  

PubMed

Meniscal root tears, less common than meniscal body tears and frequently unrecognized, are a subset of meniscal injuries that often result in significant knee joint disorders. The meniscus root attachment aids meniscal function by securing the meniscus in place and allowing for optimal shock-absorbing function in the knee. With root tears, meniscal extrusion often occurs, and the transmission of circumferential hoop stresses is impaired. This alters knee biomechanics and kinematics and significantly increases tibiofemoral contact pressure. In recent years, meniscal root tears, which by definition include direct avulsions off the tibial plateau or radial tears adjacent to the root itself, have attracted attention because of concerns that significant meniscal extrusion dramatically inhibits normal meniscal function, leading to a condition biomechanically similar to a total meniscectomy. Recent literature has highlighted the importance of early diagnosis and treatment; fortunately, these processes have been vastly improved by advances in magnetic resonance imaging and arthroscopy. This article presents a review of the clinically relevant anatomic, biomechanical, and functional descriptions of the meniscus root attachments, as well as current strategies for accurate diagnosis and treatment of common injuries to these meniscus root attachments. PMID:24623276

Bhatia, Sanjeev; LaPrade, Christopher M; Ellman, Michael B; LaPrade, Robert F

2014-12-01

297

Adventitious root induction in Arabidopsis thaliana as a model for in vitro root organogenesis.  

PubMed

Adventitious root formation, the development of roots on non-root tissue (e.g. leaves, hypocotyls and stems) is a critical step during micropropagation. Although root induction treatments are routinely used for a large number of species micropropagated in vitro as well as for in vivo cuttings, the mechanisms controlling adventitious rooting are still poorly understood. Researchers attempt to gain better insight into the molecular aspects by studying adventitious rooting in Arabidopsis thaliana. The existing assay involves etiolation of seedlings and measurements of de novo formed roots on the elongated hypocotyl. The etiolated hypocotyls express a novel auxin-controlled signal transduction pathway in which auxin response factors (ARFs), microRNAs and environmental conditions that drive adventitious rooting are integrated. An alternative assay makes use of so-called thin cell layers (TCL), excised strips of cells from the inflorescence stem of Arabidopsis thaliana. However, both the etiolated seedling system and the TCL assay are only distantly related to industrial rooting processes in which roots are induced on adult stem tissue. Here, we describe an adventitious root induction system that uses segments of the inflorescence stems of Arabidopsis thaliana, which have a histological structure similar to cuttings or in vitro micropropagated shoots. The system allows multiple treatments with chemicals as well as the evaluation of different environmental conditions on a large number of explants. It is therefore suitable for high throughput chemical screenings and experiments that require numerous data points for statistical analysis. Using this assay, the adventitious root induction capacity of classical auxins was evaluated and a differential response to the different auxins could be demonstrated. NAA, IBA and IAA stimulated adventitious rooting on the stem segment, whereas 2,4-D and picloram did not. Light conditions profoundly influenced the root induction capacity of the auxins. Additionally to the environmental control of adventitious root formation, we also investigated the spatial and temporal aspects of stem-based adventitious root organogenesis. To determine the cells involved in de novo root initiation on the adult stems, we adopted scanning electron microscopy, which allows the visualization of the auxin responsive stem tissue. Using this technique, direct (without callus interface) and indirect (with intermediate callus phase) organogenesis was readily distinguished. The described micro-stem segment system is also suitable for other non-woody species and it is a valuable tool to perform fast evaluations of different treatments to study adventitious root induction. PMID:23299674

Verstraeten, Inge; Beeckman, Tom; Geelen, Danny

2013-01-01

298

BOREAS TE-2 Root Respiration Data  

NASA Technical Reports Server (NTRS)

The BOREAS TE-2 team collected several data sets in support of its efforts to characterize and interpret information on the respiration of the foliage, roots, and wood of boreal vegetation. This data set includes means of tree root respiration measurements on roots having diameters ranging from 0 to 2 mm conducted in the NSA during the growing season of 1994. The data are stored in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

Ryan, Michael G.; Lavigne, Michael; Hall, Forrest G. (Editor); Papagno, Andrea (Editor)

2000-01-01

299

Plant roots use a patterning mechanism to position lateral root branches toward available water.  

PubMed

The architecture of the branched root system of plants is a major determinant of vigor. Water availability is known to impact root physiology and growth; however, the spatial scale at which this stimulus influences root architecture is poorly understood. Here we reveal that differences in the availability of water across the circumferential axis of the root create spatial cues that determine the position of lateral root branches. We show that roots of several plant species can distinguish between a wet surface and air environments and that this also impacts the patterning of root hairs, anthocyanins, and aerenchyma in a phenomenon we describe as hydropatterning. This environmental response is distinct from a touch response and requires available water to induce lateral roots along a contacted surface. X-ray microscale computed tomography and 3D reconstruction of soil-grown root systems demonstrate that such responses also occur under physiologically relevant conditions. Using early-stage lateral root markers, we show that hydropatterning acts before the initiation stage and likely determines the circumferential position at which lateral root founder cells are specified. Hydropatterning is independent of endogenous abscisic acid signaling, distinguishing it from a classic water-stress response. Higher water availability induces the biosynthesis and transport of the lateral root-inductive signal auxin through local regulation of tryptophan aminotransferase of Arabidopsis 1 and PIN-formed 3, both of which are necessary for normal hydropatterning. Our work suggests that water availability is sensed and interpreted at the suborgan level and locally patterns a wide variety of developmental processes in the root. PMID:24927545

Bao, Yun; Aggarwal, Pooja; Robbins, Neil E; Sturrock, Craig J; Thompson, Mark C; Tan, Han Qi; Tham, Cliff; Duan, Lina; Rodriguez, Pedro L; Vernoux, Teva; Mooney, Sacha J; Bennett, Malcolm J; Dinneny, José R

2014-06-24

300

Rooting depths of plants relative to biological and environmental factors  

SciTech Connect

In 1981 to 1982 an extensive bibliographic study was completed to document rooting depths of native plants in the United States. The data base presently contains 1034 citations with approximately 12,000 data elements. In this paper the data were analyzed for rooting depths as related to life form, soil type, geographical region, root type, family, root depth to shoot height ratios, and root depth to root lateral ratios. Average rooting depth and rooting frequencies were determined and related to present low-level waste site maintenance.

Foxx, T S; Tierney, G D; Williams, J M

1984-11-01

301

Asymptotic unbounded root loci - Formulas and computation  

NASA Technical Reports Server (NTRS)

A new geometric way of computing the asymptotic behavior of unbounded root loci of a strictly proper linear time-invariant control system as loop gain goes to infinity is presented. Properties of certain restricted linear maps and nested restrictions of linear maps are developed, and formulas are obtained for the leading coefficient of the asymptotic values of the unbounded multivariable root loci are obtained in terms of eigenvalues of those maps. Published results and a certain simple null structure assumption are used to relate these asymptotic values to the structure at infinity of the Smith-McMillan form of the open loop transfer function. Explicit matrix formulas for the more abstract derived formulas are given and additional geometric insights are developed with orthogonal projections and singular value decomposition. Formulas for the pivots of the unbounded root loci are calculated and shown to have the same form as the coefficients of the unbounded asymptotic root loci.

Sastry, S. S.; Desoer, C. A.

1983-01-01

302

Auxin metabolism in the root apical meristem.  

PubMed

Within the root meristem of flowering plants is a group of mitotically inactive cells designated the quiescent center (QC). Recent work links the quiescent state to high levels of the growth regulator auxin that accumulates in the QC via polar transport. This in turn results in elevated levels of the enzyme ascorbic acid oxidase (AAO), resulting in a reduction of ascorbic acid (AA) within the QC and mitotic quiescence. We present evidence for additional interactions between auxin, AAO, and AA, and report that, in vitro, AAO oxidatively decarboxylates auxin, suggesting a mechanism for regulating auxin levels within the QC. We also report that oxidative decarboxylation occurs at the root tip and that an intact root cap must be present for this metabolic event to occur. Finally, we consider how interaction between auxin and AAO may influence root development by regulating the formation of the QC. PMID:10712557

Kerk, N M; Jiang, K; Feldman, L J

2000-03-01

303

Plant Structure--Leaves, Stems, and Roots  

NSDL National Science Digital Library

Page one consists of a full color illustration of an idealized plant, showing various leaf, stem and root features. Page two illustrates various adaptations of plant flowers, leaves and stems. All illustrations are accompanied by explanations of the structures' functions.

2000-01-01

304

Roots of the identity operator and optics  

NASA Astrophysics Data System (ADS)

Fresnel diffraction and lens transformations can be combined to implement optical transformations corresponding to operators that are roots of the identity operator I . Since their nature remains invariant under unitary transformations, new roots can be obtained by Fresnel diffraction. A correspondence is established with ray matrices in periodic lens systems with unit magnification. Consecutive powers of particular roots of I form groups from which the projectors can be obtained by means of optical discrete Fourier transforms (DFT's), conveniently performed by networks of beam splitters and mirrors. One can then obtain additional roots of I from the projectors by reassigning eigenvalues among them, which is done by introducing suitable phase shifts, and reusing the DFT network backward.

Marhic, M. E.

1995-07-01

305

Root gravitropism in maize and Arabidopsis  

NASA Technical Reports Server (NTRS)

Research during the period 1 March 1992 to 30 November 1993 focused on improvements in a video digitizer system designed to automate the recording of surface extension in plants responding to gravistimulation. The improvements included modification of software to allow detailed analysis of localized extension patterns in roots of Arabidopsis. We used the system to analyze the role of the postmitotic isodiametric growth zone (a region between the meristem and the elongation zone) in the response of maize roots to auxin, calcium, touch and gravity. We also used the system to analyze short-term auxin and gravitropic responses in mutants of Arabidopsis with reduced auxin sensitivity. In a related project, we studied the relationship between growth rate and surface electrical currents in roots by examining the effects of gravity and thigmostimulation on surface potentials in maize roots.

Evans, Michael L.

1993-01-01

306

[Measurement of mesiodistal root angulation for panoramic images and the effect of buccolingual root angulation].  

PubMed

Panoramic images were taken from an anatomically correct phantom with three different buccolingual angulations for each tooth (Original, 10 degrees buccal root torque, and 10 degrees lingual root torque). The true mesiodistal angulation of each tooth was determined with a three-dimensional coordinate measurement machine. Each tooth had at least one angle measurement that was statistically different from the other mesiodistal angles with different buccolingual orientations. Roots with buccal root orientations were projected more distally than they were in reality; and the roots lingually positioned were projected more mesially. The canine and premolars in both arches were most affected and the phenomenon was more pronounced in the maxilla than the mandible. Buccolingual orientation changes did not affect the root angulation expression on the incisor area. PMID:20303900

Garcia-Figueroa, Mariano A; Raboud, Donald W; Lam, Ernest W; Heo, Giseon; Major, Paul W

2009-03-01

307

Euphorbia escula L. Root and Root Bud Indole-3-Acetic Acid Levels at Three Phenologic Stages.  

PubMed

Endogenous indoleacetic acid (IAA) levels of Euphorbia esula L. primary root and root buds were examined at three phenologic stages. High performance liquid chromatography coupled with fluorescence detection and gas chromatography-mass spectrometry, using (13)C(6)[benzene ring]-indole-3-acetic acid as internal standard, were used to measure root bud free and bound IAA levels in vegetative, full flower, and post-flower plants. Highest levels of free IAA (103 nanograms per gram fresh weight) were found in root buds during full flower. Esterified and amide IAA increased significantly in root buds of full flower and post-flower plants, but were not detectable in root buds of vegetative plants. Primary rootfree IAA was highest in vegetative and full flower plants (34.5 nanograms per gram fresh weight) and decreased by 50% in post-flower plants. PMID:16665432

Nissen, S J; Foley, M E

1987-06-01

308

Capillary-Effect Root-Environment System  

NASA Technical Reports Server (NTRS)

Capillary-effect root-environment system (CERES) is experimental apparatus for growing plants in nutrient solutions. Solution circulated at slight tension in cavity filled with plastic screen and covered by porous plastic membrane. By adsorptive attraction, root draws solution through membrane. Conceived for use in microgravity of space, also finds terrestrial application in germinating seedlings, because it protects them from extremes of temperature, moisture, and soil pH and from overexposure to fertilizers and herbicides.

Wright, Bruce D.

1991-01-01

309

Anatomical aspects of angiosperm root evolution  

PubMed Central

Background and Aims Anatomy had been one of the foundations in our understanding of plant evolutionary trends and, although recent evo-devo concepts are mostly based on molecular genetics, classical structural information remains useful as ever. Of the various plant organs, the roots have been the least studied, primarily because of the difficulty in obtaining materials, particularly from large woody species. Therefore, this review aims to provide an overview of the information that has accumulated on the anatomy of angiosperm roots and to present possible evolutionary trends between representatives of the major angiosperm clades. Scope This review covers an overview of the various aspects of the evolutionary origin of the root. The results and discussion focus on angiosperm root anatomy and evolution covering representatives from basal angiosperms, magnoliids, monocots and eudicots. We use information from the literature as well as new data from our own research. Key Findings The organization of the root apical meristem (RAM) of Nymphaeales allows for the ground meristem and protoderm to be derived from the same group of initials, similar to those of the monocots, whereas in Amborellales, magnoliids and eudicots, it is their protoderm and lateral rootcap which are derived from the same group of initials. Most members of Nymphaeales are similar to monocots in having ephemeral primary roots and so adventitious roots predominate, whereas Amborellales, Austrobaileyales, magnoliids and eudicots are generally characterized by having primary roots that give rise to a taproot system. Nymphaeales and monocots often have polyarch (heptarch or more) steles, whereas the rest of the basal angiosperms, magnoliids and eudicots usually have diarch to hexarch steles. Conclusions Angiosperms exhibit highly varied structural patterns in RAM organization; cortex, epidermis and rootcap origins; and stele patterns. Generally, however, Amborellales, magnoliids and, possibly, Austrobaileyales are more similar to eudicots, and the Nymphaeales are strongly structurally associated with the monocots, especially the Acorales. PMID:23299993

Seago, James L.; Fernando, Danilo D.

2013-01-01

310

Aortic root dilation after the Ross procedure.  

PubMed

This study evaluated changes in neoaortic root geometry in patients who underwent the Ross procedure. Serial postoperative echocardiographic measurements of the neoaortic root indexed to the square root of body surface area (centimeters divided by meters) were obtained from 30 patients (age range 3.1 to 31.4 years) and compared with paired preoperative and immediate postoperative values. Normal aortic root diameter Z scores were derived from root dimensions obtained from 217 healthy controls. Compared with preoperative values, an immediate stretch of the neoaortic versus pulmonary root (annulus and sinuses of valsalva) was observed at a mean follow-up period of 1 week. Additional aortic annular dilation from baseline prehospital discharge values was observed at 2 to 12 months (baseline vs follow-up annulus Z score: 1.4 vs 2.6, p <0.01, n = 16) and at 16 to 33 months follow-up (0.8 vs 2.0, p <0.05, n = 12). In a similar fashion, there was additional enlargement of the aortic sinus from its stretched state at hospital discharge at 2 to 12 months (baseline vs follow-up sinus Z score: 2.0 vs 3.3, p <0.01, n = 17) and at 16 to 33 months (1.7 vs 3.0, p <0.01, n = 13). There were no differences in root size between 2 to 12 and 16 to 33 months after surgery. There was a decrease in left ventricular size with no alteration in blood pressure or degree of aortic valve regurgitation. Thus, aortic root dilation occurs up to the first year after the Ross procedure but does not appear to progress beyond this time. PMID:10190409

Tantengco, M V; Humes, R A; Clapp, S K; Lobdell, K W; Walters, H L; Hakimi, M; Epstein, M L

1999-03-15

311

The Cytoskeleton and Root Growth Behavior  

Microsoft Academic Search

\\u000a The roots of many plant species develop complex growth behaviors when germinated on hard surfaces, and scientists have learned\\u000a to use this experimental set-up to study the structure and dynamics of cytoskeletal arrays. Our knowledge of the elements\\u000a that lead to anisotropic cell expansion in rapidly elongating cells has increased by finding mutants with altered root growth\\u000a behavior as well

Laura M. Vaughn; Katherine L. Baldwin; Gengxiang Jia; Julian C. Verdonk; Allison K. Strohm; Patrick H. Masson

312

Distribution of Pb, Cd and Ba in soils and plants of two contaminated sites.  

PubMed

Evaluation of metal accumulation in soils and plants is of environmental importance due to their health effects on humans and other biota. Soil material and plant tissue were collected along transects in two heavily contaminated facilities, a Superfund site and a lead-acid battery dump, and analyzed for metal content. Soil lead (Pb), cadmium (Cd) and barium (Ba) concentrations for the Superfund site averaged 55,480, 8.5 and 132.3 mg/kg, respectively. Soil Pb occurred primarily in the carbonate, sulfide/residual and organic chemical fractions (41.6, 28.6 and 16.7%, respectively). Soil Pb, Cd and Ba concentrations for the dump site averaged 29,400, 3.9 and 1130 mg/kg, respectively. Soil Pb occurred mostly in the organic and carbonate fractions as 48.5 and 42.5%, respectively. Pb uptake in the two sites ranged from non-detectable (Agrostemma githago, Plantago rugelii, Alliaria officinalis shoots), to 1800 mg/kg (Agrostemma githago root). Cd uptake was maximal in Taraxacum officinale at 15.4 mg/kg (Superfund site). In the majority > or =65%) of the plants studied, root Pb and Cd content was higher than that for the shoots. Tissue Pb correlated slightly with exchangeable and soluble soil Pb; however, tissue Cd was poorly correlated with soil Cd species. None of the sampled plants accumulated measurable amounts of Ba. Those plants that removed most Pb and Cd were predominantly herbaceous species, some of which produce sufficient biomass to be practical for phytoremediation technologies. Growth chamber studies demonstrated the ability of T. officinale and Ambrosia artemisiifolia to successfully remove soil Pb and Cd during repeated croppings. Tissue Pb was correlated with exchangeable soil Pb at r(2)=0.68 in Ambrosia artemisiifolia. PMID:15092867

Pichtel, J; Kuroiwa, K; Sawyerr, H T

2000-10-01

313

Root size and shoot\\/root ratio as influenced by light environment of the shoot  

Microsoft Academic Search

The light environment of a plant shoot can affect its root size and the shoot\\/root biomass ratio. Photoperiodic influence on shoot\\/root ratios of first?year biennial sweetclover (Melilotus alba Desr.) plants was related to phytochrome measurement of day length and its regulation of photosynthate partitioning to favor successful completion of the life cycle. Short photoperiods alternated with long, uninterrupted nights resulted

M. J. Kasperbauer; P. G. Hunt

1992-01-01

314

Sequential rooting media and rooting capacity of Sequoiadendron giganteum in vitro. Peroxidase activity as a marker  

Microsoft Academic Search

The rooting capacities of tips of seedling, juvenile and mature shoots of Sequoiadendron giganteum were compared on different rooting media (inductive and expressive media) after passage on an elongating medium. None of the cuttings rooted when continuously kept on medium containing the auxin NAA and vitamin D2. Peroxidase activity of all those cuttings on NAA+D2 first increased during the 7–9

J. Y. Berthon; N. Boyer; Th. Gaspar

1987-01-01

315

Attractiveness of CO 2 released by root respiration fades on the background of root exudates  

Microsoft Academic Search

Plants are endangered at their roots by soil-dwelling rhizophagous insects. These below-ground living herbivores may orient to the source of carbon dioxide (CO2), an ubiquitous volatile released by respiring plant roots. Here, we studied the interaction of CO2 and other plant root-derived chemical stimuli with regard to the chemical orientation of the polyphagous larvae of Melolontha melolontha L. (Scarabaeidae). A

Andreas Reinecke; Frank Müller; Monika Hilker

2008-01-01

316

Modeling vegetation rooting strategies on a hillslope  

NASA Astrophysics Data System (ADS)

The manner in which water and energy is partitioned and redistributed along a hillslope is the result of complex coupled ecohydrological interactions between the climatic, soils, topography and vegetation operating over a wide range of spatiotemporal scales. Distributed process based modeling creates a framework through which the interaction of vegetation with the subtle differences in the spatial and temporal dynamics of soil moisture that arise under localized abiotic conditions along a hillslope can be simulated and examined. One deficiency in the current dynamic vegetation models is the one sided manner in which vegetation responds to soil moisture dynamics. Above ground, vegetation is given the freedom to dynamically evolve through alterations in fractional vegetation cover and/or canopy height and density; however below ground rooting profiles are simplistically represented and often held constant in time and space. The need to better represent the belowground role of vegetation through dynamic rooting strategies is fundamental in capturing the magnitude and timing of water and energy fluxes between the atmosphere and land surface. In order to allow vegetation to adapt to gradients in soil moisture a dynamic rooting scheme was incorporated into tRIBS+VEGGIE (a physically based distributed ecohydrological model). The dynamic rooting scheme allows vegetation the freedom to adapt their rooting depth and distribution in response abiotic conditions in a way that more closely mimics observed plant behavior. The incorporation of this belowground plasticity results in vegetation employing a suite of rooting strategies based on soil texture, climatic conditions and location on the hillslope.

Sivandran, G.; Bras, R. L.

2011-12-01

317

Roots of Dehn twists about separating curves  

E-print Network

Let $C$ be a curve in a closed orientable surface $F$ of genus $g \\geq 2$ that separates $F$ into subsurfaces $\\widetilde {F_i}$ of genera $g_i$, for $i = 1,2$. We study the set of roots in $\\Mod(F)$ of the Dehn twist $t_C$ about $C$. All roots arise from pairs of $C_{n_i}$-actions on the $\\widetilde{F_i}$, where $n=\\lcm(n_1,n_2)$ is the degree of the root, that satisfy a certain compatibility condition. The $C_{n_i}$ actions are of a kind that we call nestled actions, and we classify them using tuples that we call data sets. The compatibility condition can be expressed by a simple formula, allowing a classification of all roots of $t_C$ by compatible pairs of data sets. We use these data set pairs to classify all roots for $g = 2$ and $g = 3$. We show that there is always a root of degree at least $2g^2+2g$, while $n \\leq 4g^2+2g$. We also give some additional applications.

Rajeevsarathy, Kashyap

2011-01-01

318

Defining the core Arabidopsis thaliana root microbiome  

PubMed Central

Land plants associate with a root microbiota distinct from the complex microbial community present in surrounding soil. The microbiota colonizing therhizosphere(immediately surroundingthe root) and the endophytic compartment (within the root) contribute to plant growth, productivity, carbon sequestration and phytoremediation1-3. Colonization of the root occurs despite a sophisticated plant immune system4,5, suggesting finely tuned discrimination of mutualists and commensals from pathogens. Genetic principles governing the derivation of host-specific endophyte communities from soil communities are poorly understood. Here we report the pyrosequencing of the bacterial 16S ribosomal RNA gene of more than 600 Arabidopsis thaliana plants to test the hypotheses that the root rhizosphere and endophytic compartment microbiota of plants grown under controlled conditions in natural soils are sufficiently dependent on the host to remain consistent across different soil types and developmental stages, and sufficiently dependent on host genotype to vary between inbred Arabidopsis accessions. We describe different bacterial communities in two geochemically distinct bulk soils and in rhizosphere and endophytic compartments prepared from roots grown in these soils. The communities in each compartment are strongly influenced by soil type. Endophytic compartments from both soils feature overlapping, low-complexity communities that are markedly enriched in Actinobacteria and specific families from other phyla, notably Proteobacteria. Some bacteria vary quantitatively between plants of different developmental stage and genotype. Our rigorous definition of an endophytic compartment microbiome should facilitate controlled dissection of plantmicrobe interactions derived from complex soil communities. PMID:22859206

Gehring, Jase; Malfatti, Stephanie; Tremblay, Julien; Engelbrektson, Anna; Kunin, Victor; del Rio, Tijana Glavina; Edgar, Robert C.; Eickhorst, Thilo; Ley, Ruth E.; Hugenholtz, Philip; Tringe, Susannah Green; Dangl, Jeffery L.

2014-01-01

319

Competing neighbors: light perception and root function.  

PubMed

Plant responses to competition have often been described as passive consequences of reduced resource availability. However, plants have mechanisms to forage for favorable conditions and anticipate competition scenarios. Despite the progresses made in understanding the role of light signaling in modulating plant-plant interactions, little is known about how plants use and integrate information gathered by their photoreceptors aboveground to regulate performance belowground. Given that the phytochrome family of photoreceptors plays a key role in the acquisition of information about the proximity of neighbors and canopy cover, it is tempting to speculate that changes in the red:far-red (R:FR) ratio perceived by aboveground plant parts have important implications shaping plant behavior belowground. Exploring data from published experiments, we assess the neglected role of light signaling in the control of root function. The available evidence indicates that plant exposure to low R:FR ratios affects root growth and morphology, root exudate profiles, and interactions with beneficial soil microorganisms. Although dependent on species identity, signals perceived aboveground are likely to affect root-to-root interactions. Root systems could also be guided to deploy new growth predominantly in open areas by light signals perceived by the shoots. Studying interactions between above- and belowground plant-plant signaling is expected to improve our understanding of the mechanisms of plant competition. PMID:24894371

Gundel, Pedro E; Pierik, Ronald; Mommer, Liesje; Ballaré, Carlos L

2014-09-01

320

Vertical root fractures and their management  

PubMed Central

Vertical root fractures associated with endodontically treated teeth and less commonly in vital teeth represent one of the most difficult clinical problems to diagnose and treat. In as much as there are no specific symptoms, diagnosis can be difficult. Clinical detection of this condition by endodontists is becoming more frequent, where as it is rather underestimated by the general practitioners. Since, vertical root fractures almost exclusively involve endodontically treated teeth; it often becomes difficult to differentiate a tooth with this condition from an endodontically failed one or one with concomitant periodontal involvement. Also, a tooth diagnosed for vertical root fracture is usually extracted, though attempts to reunite fractured root have been done in various studies with varying success rates. Early detection of a fractured root and extraction of the tooth maintain the integrity of alveolar bone for placement of an implant. Cone beam computed tomography has been shown to be very accurate in this regard. This article focuses on the diagnostic and treatment strategies, and discusses about predisposing factors which can be useful in the prevention of vertical root fractures. PMID:24778502

Khasnis, Sandhya Anand; Kidiyoor, Krishnamurthy Haridas; Patil, Anand Basavaraj; Kenganal, Smita Basavaraj

2014-01-01

321

Astroculture™ Root Metabolism and Cytochemical Analysis  

NASA Astrophysics Data System (ADS)

Physiology of the root system is dependent upon oxygen availability and tissue respiration. During hypoxia nutrient and water acquisition may be inhibited, thus affecting the overall biochemical and physiological status of the plant. For the Astroculture™ plant growth hardware, the availability of oxygen in the root zone was measured by examining the changes in alcohol dehydrogenase (ADH) activity within the root tissue. ADH activity is a sensitive biochemical indicator of hypoxic conditions in plants and was measured in both spaceflight and control roots. In addition to the biochemical enzyme assays, localization of ADH in the root tissue was examined cytochemically. The results of these analyses showed that ADH activity increased significantly as a result of spaceflight exposure. Enzyme activity increased 248% to 304% in dwarf wheat when compared with the ground controls and Brassica showed increases between 334% and 579% when compared with day zero controls. Cytochemical staining revealed no differences in ADH tissue localization in any of the dwarf wheat treatments. These results show the importance of considering root system oxygenation in designing and building nutrient delivery hardware for spaceflight plant cultivation and confirm previous reports of an ADH response associated with spaceflight exposure

Porterfield, D. M.; Barta, D. J.; Ming, D. W.; Morrow, R. C.; Musgrave, M. E.

322

Natural H+ Currents Traverse Growing Roots and Root Hairs of Barley (Hordeum vulgare L.) 1  

PubMed Central

With the aid of an extracellular vibrating electrode, natural electric fields were detected and measured in the medium near growing roots and root hairs of barley seedlings. An exploration of these fields indicates that both the root as a whole, as well as individual root hairs, drive large steady currents through themselves. Current consistently enters both the main elongation zone of the root as well as the growing tips of elongating root hairs; it leaves the surface of the root beneath the root hairs. These currents enter with a density of about 2 microamperes per square centimeter, leave with a density of about 0.5 to 1 microampere per square centimeter, and total about 30 nanoamperes. Responses of the natural fields to changes in the ionic composition of the medium as well as observations of the pH pattern in the medium near the roots (made with bromocresol purple) together indicate that much of the current consists of hydrogen ions. Altogether, H+ ions seem to leak into growing cells or cell parts and to be pumped out of nongrowing ones. Images PMID:16661000

Weisenseel, Manfred H.; Dorn, Alfred; Jaffe, Lionel F.

1979-01-01

323

Capturing Arabidopsis Root Architecture Dynamics with root-fit Reveals Diversity in Responses to Salinity.  

PubMed

The plant root is the first organ to encounter salinity stress, but the effect of salinity on root system architecture (RSA) remains elusive. Both the reduction in main root (MR) elongation and the redistribution of the root mass between MRs and lateral roots (LRs) are likely to play crucial roles in water extraction efficiency and ion exclusion. To establish which RSA parameters are responsive to salt stress, we performed a detailed time course experiment in which Arabidopsis (Arabidopsis thaliana) seedlings were grown on agar plates under different salt stress conditions. We captured RSA dynamics with quadratic growth functions (root-fit) and summarized the salt-induced differences in RSA dynamics in three growth parameters: MR elongation, average LR elongation, and increase in number of LRs. In the ecotype Columbia-0 accession of Arabidopsis, salt stress affected MR elongation more severely than LR elongation and an increase in LRs, leading to a significantly altered RSA. By quantifying RSA dynamics of 31 different Arabidopsis accessions in control and mild salt stress conditions, different strategies for regulation of MR and LR meristems and root branching were revealed. Different RSA strategies partially correlated with natural variation in abscisic acid sensitivity and different Na(+)/K(+) ratios in shoots of seedlings grown under mild salt stress. Applying root-fit to describe the dynamics of RSA allowed us to uncover the natural diversity in root morphology and cluster it into four response types that otherwise would have been overlooked. PMID:25271266

Julkowska, Magdalena M; Hoefsloot, Huub C J; Mol, Selena; Feron, Richard; de Boer, Gert-Jan; Haring, Michel A; Testerink, Christa

2014-11-01

324

RootNav: Navigating Images of Complex Root Architectures1[C][W  

PubMed Central

We present a novel image analysis tool that allows the semiautomated quantification of complex root system architectures in a range of plant species grown and imaged in a variety of ways. The automatic component of RootNav takes a top-down approach, utilizing the powerful expectation maximization classification algorithm to examine regions of the input image, calculating the likelihood that given pixels correspond to roots. This information is used as the basis for an optimization approach to root detection and quantification, which effectively fits a root model to the image data. The resulting user experience is akin to defining routes on a motorist’s satellite navigation system: RootNav makes an initial optimized estimate of paths from the seed point to root apices, and the user is able to easily and intuitively refine the results using a visual approach. The proposed method is evaluated on winter wheat (Triticum aestivum) images (and demonstrated on Arabidopsis [Arabidopsis thaliana], Brassica napus, and rice [Oryza sativa]), and results are compared with manual analysis. Four exemplar traits are calculated and show clear illustrative differences between some of the wheat accessions. RootNav, however, provides the structural information needed to support extraction of a wider variety of biologically relevant measures. A separate viewer tool is provided to recover a rich set of architectural traits from RootNav’s core representation. PMID:23766367

Pound, Michael P.; French, Andrew P.; Atkinson, Jonathan A.; Wells, Darren M.; Bennett, Malcolm J.; Pridmore, Tony

2013-01-01

325

Effects of Nutrient Heterogeneity and Competition on Root Architecture of Spruce Seedlings: Implications for an Essential Feature of Root Foraging  

PubMed Central

Background We have limited understanding of root foraging responses when plants were simultaneously exposed to nutrient heterogeneity and competition, and our goal was to determine whether and how plants integrate information about nutrients and neighbors in root foraging processes. Methodology/Principal Findings The experiment was conducted in split-containers, wherein half of the roots of spruce (Picea asperata) seedlings were subjected to intraspecific root competition (the vegetated half), while the other half experienced no competition (the non-vegetated half). Experimental treatments included fertilization in the vegetated half (FV), the non-vegetated half (FNV), and both compartments (F), as well as no fertilization (NF). The root architecture indicators consisted of the number of root tips over the root surface (RTRS), the length percentage of diameter-based fine root subclasses to total fine root (SRLP), and the length percentage of each root order to total fine root (ROLP). The target plants used novel root foraging behaviors under different combinations of neighboring plant and localized fertilization. In addition, the significant increase in the RTRS of 0–0.2 mm fine roots after fertilization of the vegetated half alone and its significant decrease in fertilizer was applied throughout the plant clearly showed that plant root foraging behavior was regulated by local responses coupled with systemic control mechanisms. Conclusions/Significance We measured the root foraging ability for woody plants by means of root architecture indicators constructed by the roots possessing essential nutrient uptake ability (i.e., the first three root orders), and provided new evidence that plants integrate multiple forms of environmental information, such as nutrient status and neighboring competitors, in a non-additive manner during the root foraging process. The interplay between the responses of individual root modules (repetitive root units) to localized environmental signals and the systemic control of these responses may well account for the non-additive features of the root foraging process. PMID:23762405

Nan, Hongwei; Liu, Qing; Chen, Jinsong; Cheng, Xinying; Yin, Huajun; Yin, Chunying; Zhao, Chunzhang

2013-01-01

326

microRNA profiling of root tissues and root forming explant cultures in Medicago truncatula.  

PubMed

Plant root architecture is regulated by the initiation and modulation of cell division in regions containing pluripotent stem cells known as meristems. In roots, meristems are formed early in embryogenesis, in the case of the root apical meristem (RAM), and during organogenesis at the site of lateral root or, in legumes, nodule formation. Root meristems can also be generated in vitro from leaf explants cultures supplemented with auxin. microRNAs (miRNAs) have emerged as regulators of many key biological functions in plants including root development. To identify key miRNAs involved in root meristem formation in Medicago truncatula, we used deep sequencing to compare miRNA populations. Comparisons were made between: (1) the root tip (RT), containing the RAM and the elongation zone (EZ) tissue and (2) root forming callus (RFC) and non-root forming callus (NRFC). We identified 83 previously reported miRNAs, 24 new to M. truncatula, in 44 families. For the first time in M. truncatula, members of conserved miRNA families miR165, miR181 and miR397 were found. Bioinformatic analysis identified 38 potential novel miRNAs. Selected miRNAs and targets were validated using Taqman miRNA assays and 5' RACE. Many miRNAs were differentially expressed between tissues, particularly RFC and NRFC. Target prediction revealed a number of miRNAs to target genes previously shown to be differentially expressed between RT and EZ or RFC and NRFC and important in root development. Additionally, we predict the miRNA/target relationships for miR397 and miR160 to be conserved in M. truncatula. Amongst the predictions, were AUXIN RESPONSE FACTOR 10, targeted by miR160 and a LACCASE-like gene, targeted by miR397, both are miRNA/target pairings conserved in other species. PMID:23572382

Eyles, Rodney P; Williams, Philip H; Ohms, Stephen J; Weiller, Georg F; Ogilvie, Huw A; Djordjevic, Michael A; Imin, Nijat

2013-07-01

327

Comparative root morphology of some pasture grasses and clovers  

Microsoft Academic Search

Root systems of three clovers and five pasture grasses grown in sand culture during summer and in soil during winter were examined at two stages of growth.There were large differences in shoot\\/root ratio between harvests, but no consistent differences among species. In general grasses had longer, thinner, more finely branched roots than clovers, but had similar root surface areas per

P. S. Evans

1977-01-01

328

Seasonal soil–water availability influences snakeweed root dynamics  

Microsoft Academic Search

We tested a hypothesis that variable precipitation may induce altered rooting patterns. A nursery study was conducted over 2 years to evaluate the effect of seasonally variable soil moisture on the rooting pattern of shallow-rooted shrub broom snakeweed (Gutierrezia sarothrae Britt and Rusby). Plants irrigated during the spring–summer, but grown under rainout shelters in the winter (S) produced more roots

Changgui Wan; Ibrahim Yilmaz; Ronald E. Sosebee

2002-01-01

329

The dynamic interplay between roots and soil moisture  

Microsoft Academic Search

Although water uptake by roots in the soil has been investigated in numerous studies, it is still not clear which is the main factor controlling the uptake, especially under non-uniform soil moisture distribution or intermediately wet soil. Root activity or root compensation factors are frequently used to adjust 1-D root water uptake models to observations. However, they are fitting parameters,

Sarah Garre; Jan Vanderborght; Mathieu Javaux; Harry Vereecken

2010-01-01

330

Fine Root Architecture of Nine North American Trees  

Microsoft Academic Search

The fine roots of trees are concentrated on lateral branches that arise from perennial roots. They are important in the acquisition of water and essential nutrients, and at the ecosystem level, they make a significant contribution to biogeochemical cycling. Fine roots have often been studied according to arbitrary size classes, e.g., all roots less than 1 or 2 mm in

Kurt S. Pregitzer; Jared L. DeForest; Andrew J. Burton; Michael F. Allen; Roger W. Ruess; Ronald L. Hendrick

2002-01-01

331

ROOTBOX FOR QUANTITATIVE OBSERVATIONS ON INTACT ENTIRE ROOT SYSTEMS  

EPA Science Inventory

A rootbox is described which allows observation of an intact, entire root system. oots are sandwiched against a plexiglass surface by a nylon mesh that is impermeable to roots, but permeable to water and nutrients. o quantify root growth non-destructively, roots of different size...

332

Root hairs confer a competitive advantage under low phosphorus availability  

Microsoft Academic Search

Root hairs are presumably important in the acquisition of immobile soil resources such as phosphorus. The density and length of root hairs vary substantially within and between species, and are highly regulated by soil phosphorus availability, which suggests that at high nutrient availability, root hairs may have a neutral or negative impact on fitness. We used a root-hairless mutant of

Terence R. Bates; Jonathan P. Lynch

2001-01-01

333

Production of scopolamine by normal root culture of Hyoscyamus niger  

Microsoft Academic Search

Normal root of Hyoscyamus niger was cultivated in various nutrient conditions to optimize root growth and scopolamine production. Nitrate or phosphate concentration had little effect on root growth, while the low levels of nitrate or phosphate enhanced specific scopolamine content by 44% and 39%, respectively. Glucose or fructose was not adequate for the root culture as a carbon source, while

Seung Han Woo; Jong Moon Park; Ji-Won Yang

1995-01-01

334

Endophytic colonization of plant roots by nitrogen-fixing bacteria  

Microsoft Academic Search

Nitrogen-fixing bacteria are able to enter into roots from the rhizosphere, particularly at the base of emerging lateral roots, between epidermal cells and through root hairs. In the rhizosphere growing root hairs play an important role in symbiotic recognition in legume crops. Nodulated legumes in endosymbiosis with rhizobia are amongst the most prominent nitrogen-fixing systems in agriculture. The inoculation of

Edward C. Cocking

2003-01-01

335

The evolution of root hairs and rhizoids  

PubMed Central

Background Almost all land plants develop tip-growing filamentous cells at the interface between the plant and substrate (the soil). Root hairs form on the surface of roots of sporophytes (the multicellular diploid phase of the life cycle) in vascular plants. Rhizoids develop on the free-living gametophytes of vascular and non-vascular plants and on both gametophytes and sporophytes of the extinct rhyniophytes. Extant lycophytes (clubmosses and quillworts) and monilophytes (ferns and horsetails) develop both free-living gametophytes and free-living sporophytes. These gametophytes and sporophytes grow in close contact with the soil and develop rhizoids and root hairs, respectively. Scope Here we review the development and function of rhizoids and root hairs in extant groups of land plants. Root hairs are important for the uptake of nutrients with limited mobility in the soil such as phosphate. Rhizoids have a variety of functions including water transport and adhesion to surfaces in some mosses and liverworts. Conclusions A similar gene regulatory network controls the development of rhizoids in moss gametophytes and root hairs on the roots of vascular plant sporophytes. It is likely that this gene regulatory network first operated in the gametophyte of the earliest land plants. We propose that later it functioned in sporophytes as the diploid phase evolved a free-living habit and developed an interface with the soil. This transference of gene function from gametophyte to sporophyte could provide a mechanism that, at least in part, explains the increase in morphological diversity of sporophytes that occurred during the radiation of land plants in the Devonian Period. PMID:22730024

Jones, Victor A.S.; Dolan, Liam

2012-01-01

336

How can science education foster students' rooting?  

NASA Astrophysics Data System (ADS)

The question of how to foster rooting in science education points towards a double challenge; efforts to prevent (further) uprooting and efforts to promote rooting/re-rooting. Wolff-Michael Roth's paper discusses the uprooting/rooting pair of concepts, students' feeling of alienation and loss of fundamental sense of the earth as ground, and potential consequences for teaching science in a rooted manner. However, the argumentation raises a number of questions which I try to answer. My argumentation rests on Husserl's critique of science and the "ontological reversal", an ontological position where abstract models from science are considered as more real than the everyday reality itself, where abstract, often mathematical, models are taken to be the real causes behind everyday experiences. In this paper, measures towards an "ontological re-reversal" are discussed by drawing on experiences from phenomenon-based science education. I argue that perhaps the most direct and productive way of promoting rooting in science class is by intentionally cultivating the competencies of sensing and aesthetic experience. An aesthetic experience is defined as a precognitive, sensuous experience, an experience that is opened up for through sensuous perception. Conditions for rooting in science education is discussed against three challenges: Restoring the value of aesthetic experience, allowing time for open inquiry and coping with curriculum. Finally, I raise the question whether dimensions like "reality" or "nature" are self-evident for students. In the era of constructivism, with its focus on cognition and knowledge building, the inquiry process itself has become more important than the object of inquiry. I argue that as educators of science teachers we have to emphasize more explicitly "the nature of nature" as a field of exploration.

Østergaard, Edvin

2014-06-01

337

The best for the guest: high Andean nurse cushions of Azorella madreporica enhance arbuscular mycorrhizal status in associated plant species.  

PubMed

Positive interactions between cushion plant and associated plants species in the high Andes of central Chile should also include the effects of fungal root symbionts. We hypothesized that higher colonization by arbuscular mycorrhizal (AM) fungi exists in cushion-associated (nursling) plants compared with conspecific individuals growing on bare ground. We assessed the AM status of Andean plants at two sites at different altitudes (3,200 and 3,600 ma.s.l.) in 23 species, particularly in cushions of Azorella madreporica and five associated plants; additionally, AM fungal spores were retrieved from soil outside and beneath cushions. 18 of the 23 examined plant species presented diagnostic structures of arbuscular mycorrhiza; most of them were also colonized by dark-septate endophytes. Mycorrhization of A. madreporica cushions showed differences between both sites (68% and 32%, respectively). In the native species Hordeum comosum, Nastanthus agglomeratus, and Phacelia secunda associated to A. madreporica, mycorrhization was six times higher than in the same species growing dispersed on bare ground at 3,600 ma.s.l., but mycorrhiza development was less cushion dependent in the alien plants Cerastium arvense and Taraxacum officinale at both sites. The ratio of AM fungal spores beneath versus outside cushions was also 6:1. The common and abundant presence of AM in cushion communities at high altitudes emphasizes the importance of the fungal root symbionts in such situations where plant species benefit from the microclimatic conditions generated by the cushion and also from well-developed mycorrhizal networks. PMID:21384201

Casanova-Katny, M Angélica; Torres-Mellado, Gustavo Adolfo; Palfner, Goetz; Cavieres, Lohengrin A

2011-10-01

338

Rapid Plant Identification Using Species- and Group-Specific Primers Targeting Chloroplast DNA  

PubMed Central

Plant identification is challenging when no morphologically assignable parts are available. There is a lack of broadly applicable methods for identifying plants in this situation, for example when roots grow in mixture and for decayed or semi-digested plant material. These difficulties have also impeded the progress made in ecological disciplines such as soil- and trophic ecology. Here, a PCR-based approach is presented which allows identifying a variety of plant taxa commonly occurring in Central European agricultural land. Based on the trnT-F cpDNA region, PCR assays were developed to identify two plant families (Poaceae and Apiaceae), the genera Trifolium and Plantago, and nine plant species: Achillea millefolium, Fagopyrum esculentum, Lolium perenne, Lupinus angustifolius, Phaseolus coccineus, Sinapis alba, Taraxacum officinale, Triticum aestivum, and Zea mays. These assays allowed identification of plants based on size-specific amplicons ranging from 116 bp to 381 bp. Their specificity and sensitivity was consistently high, enabling the detection of small amounts of plant DNA, for example, in decaying plant material and in the intestine or faeces of herbivores. To increase the efficacy of identifying plant species from large number of samples, specific primers were combined in multiplex PCRs, allowing screening for multiple species within a single reaction. The molecular assays outlined here will be applicable manifold, such as for root- and leaf litter identification, botanical trace evidence, and the analysis of herbivory. PMID:22253728

Staudacher, Karin; Schallhart, Nikolaus; Mitterrutzner, Evi; Steiner, Eva-Maria; Thalinger, Bettina; Traugott, Michael

2012-01-01

339

Induction of hairy roots in Gmelina arborea Roxb. and production of verbascoside in hairy roots  

Microsoft Academic Search

Seedling tissues of Gmelina arborea, a medicinally important tree species, were infected with wild type Agrobacterium rhizogenes strain ATTCC 15834, which led to the induction of hairy roots from 32% of the explants. Transgenic status of the roots was confirmed by PCR using rolB specific primers, and subsequently, by Southern analysis of the PCR products. Six transformed clones of hairy

Shrutika Dhakulkar; T. R. Ganapathi; Sujata Bhargava; V. A. Bapat

2005-01-01

340

Update on Root Chemical Defenses In Defense of Roots: A Research Agenda for Studying  

E-print Network

biology, namely, the chemistry of plant defense against belowground herbivores. Focusing on secondaryUpdate on Root Chemical Defenses In Defense of Roots: A Research Agenda for Studying Plant (Bezemer and van Dam, 2005). When attacked by herbivores, plants defend themselves through a continuum

Agrawal, Anurag

341

ROOT FUNCTIONAL ARCHITECTURE: A FRAMEWORK FOR MODELLING THE INTERPLAY BETWEEN ROOTS AND SOIL  

E-print Network

biological activity and associated processes are concentrated in the soil located around living plant roots of soil life forms, plants play a dominant role in the regulation of many soil processes. In this paper consider how the response of root systems to their environment affects resource acquisition by plants

Paris-Sud XI, Université de

342

Seeking roots and tracing lineages: constructing a framework of reference for roots and genealogical tourism  

Microsoft Academic Search

Travel for the purpose of seeking roots, or roots tourism, is understood to be focused on the descendants of a diaspora living in contemporary multicultural societies and travelling to ancestral homelands in search of identity and belongingness. It is an almost negligible niche segment of heritage tourism due to an obscure amalgam of contextual concepts. The primary purpose of this

Gregory Higginbotham

2012-01-01

343

Effect of root canal preparation, type of endodontic post and mechanical cycling on root fracture strength  

PubMed Central

Objective To evaluate the impact of the type of root canal preparation, intraradicular post and mechanical cycling on the fracture strength of roots. Material and Methods eighty human single rooted teeth were divided into 8 groups according to the instruments used for root canal preparation (manual or rotary instruments), the type of intraradicular post (fiber posts- FRC and cast post and core- CPC) and the use of mechanical cycling (MC) as follows: Manual and FRC; Manual, FRC and MC; Manual and CPC; Manual, CPC and MC; Rotary and FRC; Rotary, FRC and MC; Rotary and CPC; Rotary, CPC and MC. The filling was performed by lateral compactation. All root canals were prepared for a post with a 10 mm length, using the custom #2 bur of the glass fiber post system. For mechanical cycling, the protocol was applied as follows: an angle of incidence of 45°, 37°C, 88 N, 4 Hz, 2 million pulses. All groups were submitted to fracture strength test in a 45° device with 1 mm/ min cross-head speed until failure occurred. Results The 3-way ANOVA showed that the root canal preparation strategy (p<0.03) and post type (p<0.0001) affected the fracture strength results, while mechanical cycling (p=0.29) did not. Conclusion The root canal preparation strategy only influenced the root fracture strength when restoring with a fiber post and mechanical cycling, so it does not seem to be an important factor in this scenario. PMID:25025556

RIPPE, Marilia Pivetta; SANTINI, Manuela Favarin; BIER, Carlos Alexandre Souza; BALDISSARA, Paolo; VALANDRO, Luiz Felipe

2014-01-01

344

Identification of coniferous fine roots to species using ribosomal PCR products of pooled root samples  

EPA Science Inventory

Background/Question/Methods To inform an individual-based forest stand model emphasizing belowground competition, we explored the potential of using the relative abundances of ribosomal PCR products from pooled and milled roots, to allocate total root biomass to each of the thre...

345

The SHORT-ROOT Gene Controls Radial Patterning of the Arabidopsis Root through Radial Signaling  

Microsoft Academic Search

Asymmetric cell divisions play an important role in the establishment and propagation of the cellular pattern of plant tissues. The SHORT-ROOT (SHR) gene is required for the asymmetric cell division responsible for formation of ground tissue (endodermis and cortex) as well as specification of endodermis in the Arabidopsis root. We show that SHR encodes a putative transcription factor with homology

Yrjo Helariutta; Hidehiro Fukaki; Joanna Wysocka-Diller; Keiji Nakajima; Jee Jung; Giovanni Sena; Marie-Theres Hauser; Philip N. Benfey

2000-01-01

346

Enhanced phenanthrene biodegradation in soil by slender oat root exudates and root debris.  

PubMed

To investigate the mechanisms by which slender oat (Avena barbata Pott ex Link) enhances phenanthrene biodegradation, we analyzed the impacts of root exudates and root debris on phenanthrene biodegradation and degrader community dynamics. Accelerated phenanthrene biodegradation rates occurred in soils amended with slender oat root exudates as well as combined root debris + root exudate as compared with unamended controls. Root exudates significantly enhanced phenanthrene biodegradation in rhizosphere soils, either by increasing contaminant bioavailability and/or increasing microbial population size and activity. A modified most probable number (MPN) method was used to determine quantitative shifts in heterotrophic and phenanthrene degrader communities. During the first 4 to 6 d of treatment, heterotrophic populations increased in all amended soils. Both root debris-amended and exudate-amended soil then maintained larger phenanthrene degrader populations than in control soils later in the experiment after much of the phenanthrene had been utilized. Thus, root amendments had a greater impact over time on phenanthrene degraders than heterotrophs resulting in selective maintenance of degrader populations in amended soils compared with controls. PMID:11789996

Miya, R K; Firestone, M K

2001-01-01

347

Unleashing the potential of the root hair cell as a single plant cell type model in root systems biology  

PubMed Central

Plant root is an organ composed of multiple cell types with different functions. This multicellular complexity limits our understanding of root biology because -omics studies performed at the level of the entire root reflect the average responses of all cells composing the organ. To overcome this difficulty and allow a more comprehensive understanding of root cell biology, an approach is needed that would focus on one single cell type in the plant root. Because of its biological functions (i.e., uptake of water and various nutrients; primary site of infection by nitrogen-fixing bacteria in legumes), the root hair cell is an attractive single cell model to study root cell response to various stresses and treatments. To fully study their biology, we have recently optimized procedures in obtaining root hair cell samples. We culture the plants using an ultrasound aeroponic system maximizing root hair cell density on the entire root systems and allowing the homogeneous treatment of the root system. We then isolate the root hair cells in liquid nitrogen. Isolated root hair yields could be up to 800 to 1000~mg of plant cells from 60 root systems. Using soybean as a model, the purity of the root hair was assessed by comparing the expression level of genes previously identified as soybean root hair specific between preparations of isolated root hair cells and stripped roots, roots devoid in root hairs. Enlarging our tests to include other plant species, our results support the isolation of large quantities of highly purified root hair cells which is compatible with a systems biology approach. PMID:24324480

Qiao, Zhenzhen; Libault, Marc

2013-01-01

348

Imaging tree root systems in situ  

NASA Astrophysics Data System (ADS)

Predictions of global energy use in this century suggest a continued increase in carbon emissions and rising concentrations of carbon dioxide (CO2) in the atmosphere. This represents a serious environmental problem and contributes significantly to greenhouse gases that affect global warming. Terrestrial ecosystems are a huge natural biological scrubber for CO2 currently sequestering, directly from the atmosphere, about 25% (approximately 2 GtC) of the 7.4 Gt of anthropogenic carbon emitted annually into the atmosphere. The major carbon pathways into soil are through plant litter and roots. Presently, there are no means by which root morphology, distribution, and mass can be measured without serious sampling artifacts that alter these properties. The current methods are destructive and labor intensive. Preliminary results using a high frequency, 1.5 Ghz, impulse Ground Penetrating Radar (GPR) for nondestructive imaging of tree root systems in situ are presented. The 3D reconstructed image is used to assess root morphology and dimensions. The constraints, limitations, and potential solutions for using GPR for tree root systems imaging and analysis are discussed.

Wielopolski, Lucian; Hendrey, George; Daniels, Jeffrey J.; McGuigan, Michael

2000-04-01

349

Broad compatibility in fungal root symbioses.  

PubMed

Plants associate with a wide range of beneficial fungi in their roots which facilitate plant mineral nutrient uptake in exchange for carbohydrates and other organic metabolites. These associations play a key role in shaping terrestrial ecosystems and are widely believed to have promoted the evolution of land plants. To establish compatibility with their host, root-associated fungi have evolved diverse colonization strategies with distinct morphological, functional and genomic specializations as well as different degrees of interdependence. They include obligate biotrophic arbuscular mycorrhizal (AM), and facultative biotrophic ectomycorrhizal (ECM) interactions but are not restricted to these well-characterized symbioses. There is growing evidence that root endophytic associations, which due to their inconspicuous nature have been often overlooked, can be of mutualistic nature and represent important players in natural and managed environments. Recent research into the biology and genomics of root associations revealed fascinating insight into the phenotypic and trophic plasticity of these fungi and underlined genomic traits associated with biotrophy and saprotrophy. In this review we will consider the commonalities and differences of AM and ECM associations and contrast them with root endophytes. PMID:24929298

Zuccaro, Alga; Lahrmann, Urs; Langen, Gregor

2014-08-01

350

Organochlorine (chlordecone) uptake by root vegetables.  

PubMed

Chlordecone, an organochlorine insecticide, continues to pollute soils in the French West Indies. The main source of human exposure to this pollutant is food. Root vegetables, which are staple foods in tropical regions, can be highly contaminated and are thus a very effective lever for action to reduce consumer exposure. We analyzed chlordecone contamination in three root vegetables, yam, dasheen and sweet potato, which are among the main sources of chlordecone exposure in food in the French West Indies. All soil types do not have the same potential for the contamination of root vegetables, allophanic andosols being two to ten times less contaminating than non-allophanic nitisols and ferralsols. This difference was only partially explained by the higher OC content in allophanic soils. Dasheen corms were shown to accumulate more chlordecone than yam and sweet potato tubers. The physiological nature of the root vegetable may explain this difference. Our results are in good agreement with the hypothesis that chlordecone uptake by root vegetables is based on passive and diffusive processes and limited by transport and dilution during growth. PMID:25043888

Florence, Clostre; Philippe, Letourmy; Magalie, Lesueur-Jannoyer

2015-01-01

351

The importance of root gravitropism for inter-root competition and phosphorus acquisition efficiency: results from a geometric simulation model  

Microsoft Academic Search

We have observed that low soil phosphorus availability alters the gravitropic response of basal roots in common bean (Phaseolus vulgaris L.), resulting in a shallower root system. In this study we use a geometric model to test the hypotheses that a shallower\\u000a root system is a positive adaptive response to low soil P availability by (1) concentrating root foraging in

Zhenyang Ge; Gerardo Rubio; Jonathan P Lynch

2000-01-01

352

Variability of Root Traits in Spring Wheat Germplasm  

PubMed Central

Root traits influence the amount of water and nutrient absorption, and are important for maintaining crop yield under drought conditions. The objectives of this research were to characterize variability of root traits among spring wheat genotypes and determine whether root traits are related to shoot traits (plant height, tiller number per plant, shoot dry weight, and coleoptile length), regions of origin, and market classes. Plants were grown in 150-cm columns for 61 days in a greenhouse under optimal growth conditions. Rooting depth, root dry weight, root: shoot ratio, and shoot traits were determined for 297 genotypes of the germplasm, Cultivated Wheat Collection (CWC). The remaining root traits such as total root length and surface area were measured for a subset of 30 genotypes selected based on rooting depth. Significant genetic variability was observed for root traits among spring wheat genotypes in CWC germplasm or its subset. Genotypes Sonora and Currawa were ranked high, and genotype Vandal was ranked low for most root traits. A positive relationship (R2?0.35) was found between root and shoot dry weights within the CWC germplasm and between total root surface area and tiller number; total root surface area and shoot dry weight; and total root length and coleoptile length within the subset. No correlations were found between plant height and most root traits within the CWC germplasm or its subset. Region of origin had significant impact on rooting depth in the CWC germplasm. Wheat genotypes collected from Australia, Mediterranean, and west Asia had greater rooting depth than those from south Asia, Latin America, Mexico, and Canada. Soft wheat had greater rooting depth than hard wheat in the CWC germplasm. The genetic variability identified in this research for root traits can be exploited to improve drought tolerance and/or resource capture in wheat. PMID:24945438

Narayanan, Sruthi; Mohan, Amita; Gill, Kulvinder S.; Prasad, P. V. Vara

2014-01-01

353

The integration of whole-root and cellular hydraulic conductivities in cereal roots.  

PubMed

The hydraulic conductivities of excised whole root systems of wheat (Triticum aestivum L. cv. Atou) and of single excised roots of wheat and maize (Zea mays L. cv. Passat) were measured using an osmotically induced back-flow technique. Ninety minutes after excision the values for single excised roots ranged from 1.6·10(-8) to 5.5·10(-8) m·s(-1)·MPa(-1) in wheat and from 0.9·10(-8) to 4.8·10(-8) m·s(-1)·MPa(-1) in maize. The main source of variation was a decrease in the value as root length increased. The hydraulic conductivities of whole root systems, but not of single excised roots, were smaller 15 h after excision. This was not caused by occlusion of the xylem at the cut end of the coleoptile. The hydraulic conductivities of epidermal, cortical and endodermal cells were measured using a pressure probe. Epidermal and cortical cells of both wheat and maize roots gave mean values of 1.2·10(-7) m·s(-1)·MPa(-1) but in endodermal cells (measured only in wheat) the mean value was 0.5·10(-7) m·s(-1)·MPa(-1). The cellular hydraulic conductivities were used to calculate the root hydraulic conductivities expected if water flow across the root was via transcellular (vacuole-to-vacuole), apoplasmic or symplasmic pathways. The results indicate that, in freshly excised roots, the bulk of water flow is unlikely to be via the transcellular pathway. This is in contrast to our previous conclusion (H. Jones, A.D. Tomos, R.A. Leigh and R.G. Wyn Jones 1983, Planta 158, 230-236) which was based on results obtained with whole root systems of wheat measured 14-15 h after excision and which probably gave artefactually low values for root hydraulic conductivity. It is now concluded that, near the root tip, water flow could be through a symplasmic pathway in which the only substantial resistances to water flow are provided by the outer epidermal and the inner endodermal plasma membranes. Further from the tip, the measured hydraulic conductivities of the roots are consistent with flow either through the symplasmic or apoplasmic pathways. PMID:24221410

Jones, H; Leigh, R A; Wyn Jones, R G; Tomos, A D

1988-04-01

354

Rapid analysis of the essential oils from dried Illicium verum Hook. f. and Zingiber officinale Rosc. by improved solvent-free microwave extraction with three types of microwave-absorption medium.  

PubMed

A new method of extracting essential oils from dried plant materials has been studied. By adding a microwave-absorption medium (MAM) to a reactor, solvent-free microwave extraction (SFME) was improved and can be used to extract essential oils from dried plant material without pretreatment. With a microwave irradiation power of 85 W it took only approximately 30 min to extract the essential oils completely. The whole extraction process is simple, rapid, and economical. Three types of MAM, iron carbonyl powder (ICP), graphite powder (GP), and activated carbon powder (ACP), and two types of dried plant material, Illicium verum Hook. f. and Zingiber officinale Rosc., were studied. The results were compared with those obtained by use of conventional SFME, microwave-assisted hydrodistillation (MAHD), and conventional hydrodistillation (HD), and the conclusion drawn was that improved SFME was a feasible means of extracting essential oils from dried plant materials, because there were few differences between the composition of the essential oils extracted by improved SFME and by the other methods. PMID:17047940

Wang, Ziming; Wang, Lu; Li, Tiechun; Zhou, Xin; Ding, Lan; Yu, Yong; Yu, Aimin; Zhang, Hanqi

2006-11-01

355

The effect of the volatile oil from ginger rhizomes (Zingiber officinale), its fractions and isolated compounds on the 5-HT3 receptor complex and the serotoninergic system of the rat ileum.  

PubMed

A contribution of the volatile oil from ginger rhizomes (Zingiber officinale Roscoe) on inhabiting the 5-HT3 receptor complex had been shown. In the present study a possible interaction of some compounds of the volatile oil with the 5-HT3 receptor system expressed in N1E-115 cells and with the serotoninergic system of the rat ileum was investigated. The volatile oil was obtained by steam distillation and fractionated using a silica gel column resulting in five fractions. Compounds of the fractions were identified by GC-MS. The influence of the volatile oil, its fractions and pure components on serotonin-induced [14C]guanidinium influx into N1E-115 cells was measured indicating the inhibitory interaction with the 5-HT3 receptor channel system. Most potent inhibitors of cation influx were the volatile oil, fraction 4, beta-pinene, terpinolene, alpha-copaene and alpha-phellandrene. The volatile oil and fractions 1 and 4 were not able to significantly influence either serotonin (10 microM)-induced maximum contraction of the rat ileum or the second phase of the biphasic contraction 2.5 min after serotonin addition. However, beta-pinene, terpinolene and alpha-phellandrene reduced both contractions. In conclusion, the volatile oil and distinct compounds such as terpinolene, beta-pinene and alpha-phellandrene interact with 5-HT3 receptor channel system and possess an antispasmodic effect at the rat ileum. PMID:17511060

Riyazi, A; Hensel, A; Bauer, K; Geissler, N; Schaaf, S; Verspohl, E J

2007-04-01

356

Origin and development of the root cap in rice.  

PubMed

The tip of the root is covered by a thimble-shaped root cap that is the site of perception and transduction for many environmental stimuli. Until now, little was known about how the root cap of rice (Oryza sativa) develops and functions to regulate the adaptive behavior of the root. To address this, we examined the formation of the rice root cap during embryogenesis and characterized the anatomy and structure of the rice radicle root cap. We further investigated the role of the quiescent center in the de novo origin of the root cap. At the molecular level, we found that shoot-derived auxin was absolutely needed to trigger root cap regeneration when the quiescent center was removed. Our time-course analysis of transcriptomic dynamics during the early phases of root cap regeneration indicated that changes in auxin signaling and appropriate levels of cytokinin are critical for root cap regeneration after the removal of the root cap. Moreover, we identified 152 genes that produce root cap-specific transcripts in the rice root tip. These findings together offer, to our knowledge, new mechanistic insights into the cellular and molecular events inherent in the formation and development of the root cap in rice and provide a basis for future research on the developmental and physiological function of the root cap of monocot crops. PMID:24958716

Wang, Likai; Chu, Huangwei; Li, Zhiyong; Wang, Juan; Li, Jintao; Qiao, Yang; Fu, Yanru; Mou, Tongmin; Chen, Chunli; Xu, Jian

2014-10-01

357

Effect of medications for root canal treatment on bonding to root canal dentin.  

PubMed

Use of resin-based restorative materials recently has become widely accepted for treatment of endodontically treated teeth. However, some solutions routinely used during endodontic treatment procedures may have an effect on bond strengths of adhesive materials to root canal dentin. The purpose of this in vitro study was to evaluate the effect of various medications on microtensile bond strength to root canal dentin. Fourteen extracted human single-rooted teeth were used. The crowns and the pulp tissues were removed. The root canals were then instrumented and widened to the same size. The teeth were randomly divided into seven groups of two teeth each. The root canal dentin walls of the roots were treated with 5% sodium hypochloride (NaOCI), 3% hydrogen peroxide (H2O2), the combination of H2O2 and NaOCl, or 0.2% chlorhexidine gluconate for 60 s; or calcium hydroxide or formocresol for 24 h. The teeth in control group were irrigated with water. The root canals were obturated using C&B Metabond. After 24 h of storage in distilled water, serial 1-mm-thick cross-sections were cut, and approximately 12 samples were obtained from each group. Microtensile bond strengths to root canal dentin were then measured by using an Instron machine. The data were recorded and expressed as MPa. The results indicated that NaOCI, H2O2, or a combination of NaOCl and H2O2 treatment decreased bond strength to root canal dentin significantly (p < 0.05). The teeth treated with chlorhexidine solution showed the highest bond strength values (p < 0.05). In conclusion, chlorhexidine is an appropriate irrigant solution for root canal treatment before adhesive post core applications. PMID:14977310

Erdemir, Ali; Ari, Hale; Güngüne?, Hakan; Belli, Sema

2004-02-01

358

Vertical root fracture: prevalence, etiology, and diagnosis.  

PubMed

A vertical root fracture (VRF) is a frustrating complication that may occur following root canal treatment, and in almost every case leads to the extraction of the affected tooth. This type of fracture is usually diagnosed by secondary symptoms that develop some time after primary treatment, often when prosthodontic restoration has already been completed. The fracture line itself is often not directly visible, and therefore clinical and radiographic signs and symptoms indicate the diagnosis indirectly. Knowledge of the condition and pathogenesis of VRF is required in order to avoid hopeless trials of periodontal and/or endodontic therapy. Several etiologic factors are discussed that make teeth susceptible to VRF, such as the loss of substance due to restorative and endodontic therapy and stress factors associated with root canal debridement, and filling. PMID:23757466

Haueisen, Helga; Gärtner, Kathrin; Kaiser, Lea; Trohorsch, Dominik; Heidemann, Detlef

2013-07-01

359

Relationship between Shoot-rooting and Root-sprouting Abilities and the Carbohydrate and Nitrogen Reserves of Mediterranean Dwarf Shrubs  

PubMed Central

Background and Aims This study analysed the differences in nitrogen (N), non-structural carbohydrates (NSC) and biomass allocation to the roots and shoots of 18 species of Mediterranean dwarf shrubs with different shoot-rooting and resprouting abilities. Root N and NSC concentrations of strict root-sprouters and species resprouting from the base of the stems were also compared. Methods Soluble sugars (SS), starch and N concentrations were assessed in roots and shoots. The root : shoot ratio of each species was obtained by thorough root excavations. Cross-species analyses were complemented by phylogenetically independent contrasts (PICs). Key Results Shoot-rooting species showed a preferential allocation of starch to shoots rather than roots as compared with non-shoot-rooting species. Resprouters displayed greater starch concentrations than non-sprouters in both shoots and roots. Trends were maintained after PICs analyses, but differences became weak when root-sprouters versus non-root-sprouters were compared. Within resprouters, strict root-sprouters showed greater root concentrations and a preferential allocation of starch to the roots than stem-sprouters. No differences were found in the root : shoot ratio of species with different rooting and resprouting abilities. Conclusions The shoot-rooting ability of Mediterranean dwarf shrubs seems to depend on the preferential allocation of starch and SS to shoots, though alternative C-sources such as current photosynthates may also be involved. In contrast to plants from other mediterranean areas of the world, the resprouting ability of Mediterranean dwarf shrubs is not related to a preferential allocation of N, NSC and biomass to roots. PMID:17728338

Palacio, Sara; Maestro, Melchor; Montserrat-Marti, Gabriel

2007-01-01

360

Influence of root structure on root survivorship: an analysis of 18 tree species using a minirhizotron method  

Microsoft Academic Search

Fine root survivorship is an important aspect of root ecology and is known to be influenced by a suite of covariates. However,\\u000a the relative importance of each covariate on root survivorship is not clear. Here, we used minirhizotron-based data from 18\\u000a woody species to evaluate the relative strength of influence on root survivorship by root diameter, branch order, soil depth,

Jiacun GuShuiqiang; Shuiqiang Yu; Yue Sun; Zhengquan Wang; Dali Guo

361

Cotton Root-Rot and Its Control.  

E-print Network

and sweet potatoes, but also trees such as elms and chinaberries, and ornamental shrubs and flowers such as the privet, rose, and chrysan- themum. In the areas where it is serious, root-rot thus concerns the farmer, the truck grower, the nurseryman..., during dry weather. Eithcr of these estrcme soil-moisture conclitions ericlently is unfarorable to the fungus. With resistaiit plants s~zcli as the Turk's-cap Hibiscus and the pomegranate, the yo~~i~g plant!: become infectecl ~rith root-rot hut nre...

Taubenhaus, J. J. (Jacob Joseph); Ezekiel, (Walter Naphtali) Walter N.

1931-01-01

362

Apical organization of the roots of dicotyledons  

Microsoft Academic Search

Summary and Conclusions  The root apical organisation of nine species of dicotyledons belonging to some primitive and some advanced families has been\\u000a investigated.\\u000a \\u000a The structural configurations of these species fall under three types: (i) with four superimposed tiers, a common tier for\\u000a the dermatogen and the peripheral region of the root-cap—the dermocalyptrogen—hypodermis, periblem and plerome, (ii) with\\u000a three tiers of initials,

S. K. Pillai; P. Vijayalekshmi; Omana M. George

1965-01-01

363

Quantification of exudation from sorghum roots  

E-print Network

by Hartin to assess exudation from both sterile and non-sterile roots grown in soil (25, 27, 28). Data from wheat, clover, and ryegrass indicated that leachates plus root free soil contained from 2. 8-5. 7% of the total C02 (27). Later experiments on 14... wheat gave much higher values (5). From 7-18/ of the assimilated 14C was exuded in sterile and non-sterile soils respectively. Barley yielded still higher percentages of 13-25/. Differences in quantity of exudation between sterile and non-sterile...

Kennedy, Lynne Susan

2012-06-07

364

Mycorrhizal fungi in roots of Texas crops  

E-print Network

were y 1. '1 t G~t~l( ht hyhd h ypi 1 thick outer wall and thin inner membrane (Fig. 14, p. 31) . Blackberry (Rubus sp. ) Root and Soil Material The blackberry sample was collected at Stephenville, Texas. Four different spore types were found... were y 1. '1 t G~t~l( ht hyhd h ypi 1 thick outer wall and thin inner membrane (Fig. 14, p. 31) . Blackberry (Rubus sp. ) Root and Soil Material The blackberry sample was collected at Stephenville, Texas. Four different spore types were found...

Yeh, May-Wei Mavix

2012-06-07

365

Analysis of root reinforcement of vegetated riprap  

NASA Astrophysics Data System (ADS)

Riprap is a traditional engineering solution used to protect riverbanks against erosion on developed riparian corridors. However, the traditional riprap does not provide adequate fish and wildlife habitat within the riparian zone, which is normally provided by naturally vegetated stream banks. An innovative approach, which mitigates this issue and at the same time provides stream bank erosion control, is the vegetated riprap technique. This solution, which combines rocks and native vegetation in the form of live cuttings, has been designed and implemented by Terra Erosion Control Ltd for the past 7 years. The aim of this work was to study the effect of the vegetation, in particular the root system, on the stability of the riprap. This analysis was carried out in the late spring of 2013 on the vegetated riprap installation located along the Columbia River riverbank, adjacent to the Teck Metals Ltd. smelter in Trail, British Columbia, Canada. An excavation perpendicular to the river was performed in order to investigate the root system development within the vegetated riprap structure. This excavation exposed one of the Salix bebbiana cuttings installed in 2006. The cutting was 2.3 m long and was set with an inclination of 35° with respect to the horizontal plane: the first 0.3 m was exposed, 1 m was buried within the riprap rocks (which had an average diameter of 30 cm) and the remaining 1.0 m was in the soil matrix below the rocks. The diameter of the roots growing along the cutting were measured in order to obtain the root density at various depths and tensile strength tests were carried out on the Salix bebbiana roots with diameters of up to 9 mm. The aim was to quantitatively estimate the additional cohesion given by the roots. The additional root cohesion was more effective in the deeper soil layer where the soil matrix predominates. In the upper soil layer, where the particle size is significantly higher, roots do not increase the cohesion but act as a network which ties the rocks of the riprap structure together. The uprooting resistance was also tested with a pullout test, which demonstrated that the force necessary to uproot a Salix bebianna cutting, grown in the riprap along the riverbank, was higher if compared with the same species grown in a natural environment.

Tron, Stefania; Raymond, Pierre

2014-05-01

366

Parthenolide: from plant shoots to cancer roots.  

PubMed

Parthenolide (PTL), a sesquiterpene lactone (SL) originally purified from the shoots of feverfew (Tanacetum parthenium), has shown potent anticancer and anti-inflammatory activities. It is currently being tested in cancer clinical trials. Structure-activity relationship (SAR) studies of parthenolide revealed key chemical properties required for biological activities and epigenetic mechanisms, and led to the derivatization of an orally bioavailable analog, dimethylamino-parthenolide (DMAPT). Parthenolide is the first small molecule found to be selective against cancer stem cells (CSC), which it achieves by targeting specific signaling pathways and killing cancer from its roots. In this review, we highlight the exciting journey of parthenolide, from plant shoots to cancer roots. PMID:23688583

Ghantous, Akram; Sinjab, Ansam; Herceg, Zdenko; Darwiche, Nadine

2013-09-01

367

The isolation of Actinomyces naeslundii from sound root surfaces and root carious lesions.  

PubMed

The isolation of Actinomyces naeslundii from sound, exposed root surfaces (n = 56) and soft and leathery root carious lesions (n = 71) was investigated. Root carious lesions were sampled after the removal of overlying plaque. Supragingival plaque or carious dentine was sampled using a sterile excavator, the samples were disaggregated and cultured on both selective and non-selective media. A. naeslundii isolates were identified to the genospecies using specific antisera. Significantly greater numbers and proportions of A. naeslundii genospecies 2 than A. naeslundii genospecies 1 were isolated from all sites sampled. There was no significant difference between the numbers and proportions of the two genospecies isolated from leathery and soft lesions. The relationship between the presence of A. naeslundii genospecies and aciduric and acidogenic organisms was investigated. Those sound exposed root surfaces from which A. naeslundii genospecies 1 and/or 2 were isolated yielded significantly lower numbers of lactobacilli and yeasts than the surfaces from which A. naeslundii were not isolated. This difference was also found in leathery lesions but not soft root carious lesions. The microflora of soft root carious lesions was found to comprise primarily gram-positive pleomorphic rods which formed 70+/-7.8% of the flora, while in plaque from exposed root surfaces and in infected dentine from leathery lesions the gram-positive pleomorphic rods represented only 35% of the flora. PMID:9544857

Brailsford, S R; Lynch, E; Beighton, D

1998-01-01

368

Arabidopsis alcohol dehydrogenase expression in both shoots and roots is conditioned by root growth environment  

NASA Technical Reports Server (NTRS)

It is widely accepted that the Arabidopsis Adh (alcohol dehydrogenase) gene is constitutively expressed at low levels in the roots of young plants grown on agar media, and that the expression level is greatly induced by anoxic or hypoxic stresses. We questioned whether the agar medium itself created an anaerobic environment for the roots upon their growing into the gel. beta-Glucuronidase (GUS) expression driven by the Adh promoter was examined by growing transgenic Arabidopsis plants in different growing systems. Whereas roots grown on horizontal-positioned plates showed high Adh/GUS expression levels, roots from vertical-positioned plates had no Adh/GUS expression. Additional results indicate that growth on vertical plates closely mimics the Adh/GUS expression observed for soil-grown seedlings, and that growth on horizontal plates results in induction of high Adh/GUS expression that is consistent with hypoxic or anoxic conditions within the agar of the root zone. Adh/GUS expression in the shoot apex is also highly induced by root penetration of the agar medium. This induction of Adh/GUS in shoot apex and roots is due, at least in part, to mechanisms involving Ca2+ signal transduction.

Chung, H. J.; Ferl, R. J.

1999-01-01

369

Allometry of root branching and its relationship to root morphological and functional traits in three range grasses.  

PubMed

The study of proportional relationships between size, shape, and function of part of or the whole organism is traditionally known as allometry. Examination of correlative changes in the size of interbranch distances (IBDs) at different root orders may help to identify root branching rules. Root morphological and functional characteristics in three range grasses {bluebunch wheatgrass [Pseudoroegneria spicata (Pursh) Löve], crested wheatgrass [Agropyron desertorum (Fisch. ex Link) Schult.×A. cristatum (L.) Gaert.], and cheatgrass (Bromus tectorum L.)} were examined in response to a soil nutrient gradient. Interbranch distances along the main root axis and the first-order laterals as well as other morphological and allocation root traits were determined. A model of nutrient diffusivity parameterized with root length and root diameter for the three grasses was used to estimate root functional properties (exploitation efficiency and exploitation potential). The results showed a significant negative allometric relationship between the main root axis and first-order lateral IBD (P ? 0.05), but only for bluebunch wheatgrass. The main root axis IBD was positively related to the number and length of roots, estimated exploitation efficiency of second-order roots, and specific root length, and was negatively related to estimated exploitation potential of first-order roots. Conversely, crested wheatgrass and cheatgrass, which rely mainly on root proliferation responses, exhibited fewer allometric relationships. Thus, the results suggested that species such as bluebunch wheatgrass, which display slow root growth and architectural root plasticity rather than opportunistic root proliferation and rapid growth, exhibit correlative allometry between the main axis IBD and morphological, allocation, and functional traits of roots. PMID:21868398

Arredondo, J Tulio; Johnson, Douglas A

2011-11-01

370

Allometry of root branching and its relationship to root morphological and functional traits in three range grasses  

PubMed Central

The study of proportional relationships between size, shape, and function of part of or the whole organism is traditionally known as allometry. Examination of correlative changes in the size of interbranch distances (IBDs) at different root orders may help to identify root branching rules. Root morphological and functional characteristics in three range grasses {bluebunch wheatgrass [Pseudoroegneria spicata (Pursh) Löve], crested wheatgrass [Agropyron desertorum (Fisch. ex Link) Schult.×A. cristatum (L.) Gaert.], and cheatgrass (Bromus tectorum L.)} were examined in response to a soil nutrient gradient. Interbranch distances along the main root axis and the first-order laterals as well as other morphological and allocation root traits were determined. A model of nutrient diffusivity parameterized with root length and root diameter for the three grasses was used to estimate root functional properties (exploitation efficiency and exploitation potential). The results showed a significant negative allometric relationship between the main root axis and first-order lateral IBD (P ?0.05), but only for bluebunch wheatgrass. The main root axis IBD was positively related to the number and length of roots, estimated exploitation efficiency of second-order roots, and specific root length, and was negatively related to estimated exploitation potential of first-order roots. Conversely, crested wheatgrass and cheatgrass, which rely mainly on root proliferation responses, exhibited fewer allometric relationships. Thus, the results suggested that species such as bluebunch wheatgrass, which display slow root growth and architectural root plasticity rather than opportunistic root proliferation and rapid growth, exhibit correlative allometry between the main axis IBD and morphological, allocation, and functional traits of roots. PMID:21868398

Arredondo, J. Tulio; Johnson, Douglas A.

2011-01-01

371

Functional traits and root morphology of alpine plants  

PubMed Central

Background and Aims Vegetation has long been recognized to protect the soil from erosion. Understanding species differences in root morphology and functional traits is an important step to assess which species and species mixtures may provide erosion control. Furthermore, extending classification of plant functional types towards root traits may be a useful procedure in understanding important root functions. Methods In this study, pioneer data on traits of alpine plant species, i.e. plant height and shoot biomass, root depth, horizontal root spreading, root length, diameter, tensile strength, plant age and root biomass, from a disturbed site in the Swiss Alps are presented. The applicability of three classifications of plant functional types (PFTs), i.e. life form, growth form and root type, was examined for above- and below-ground plant traits. Key Results Plant traits differed considerably among species even of the same life form, e.g. in the case of total root length by more than two orders of magnitude. Within the same root diameter, species differed significantly in tensile strength: some species (Geum reptans and Luzula spicata) had roots more than twice as strong as those of other species. Species of different life forms provided different root functions (e.g. root depth and horizontal root spreading) that may be important for soil physical processes. All classifications of PFTs were helpful to categorize plant traits; however, the PFTs according to root type explained total root length far better than the other PFTs. Conclusions The results of the study illustrate the remarkable differences between root traits of alpine plants, some of which cannot be assessed from simple morphological inspection, e.g. tensile strength. PFT classification based on root traits seems useful to categorize plant traits, even though some patterns are better explained at the individual species level. PMID:21795278

Pohl, Mandy; Stroude, Raphael; Buttler, Alexandre; Rixen, Christian

2011-01-01

372

New spermidine alkaloids from Capparis spinosa roots  

Microsoft Academic Search

Three new spermidine alkaloids capparispine (1), capparispine 26-O-?-d-glucoside (2) and cadabicine 26-O-?-d-glucoside hydrochloride (3) were isolated from the roots of Capparis spinosa. Their structures were established on the basis of spectroscopic analysis, including 1D and 2D NMR experiments (1H–1H COSY, HSQC, HMBC).

Xiao Pu Fu; Tao Wu; Miriban Abdurahim; Zhen Su; Xue Ling Hou; Haji Akber Aisa; Hankui Wu

2008-01-01

373

Gene expression in physically impeded maize roots  

E-print Network

PIIGI contains 678 hp with an open reading frame which specifies a polypeptide of 129 amino acid residues which showed 97% similarity at the nucleic acid level to maize root cortical cell delineating protein. Northern analysis with cDNA PIIGI as a probe...

Huang, Ying-Fei

2012-06-07

374

Getting to the Root of Things  

ERIC Educational Resources Information Center

This article introduces a new "perspective" on the typical landscape painting. It is an opportunity for art students to study the local ecosystem and native trees in their community. Other aspects of this assignment are the study of Symbolism and a new focus on the natural designs created by exposed tree roots. (Contains 1 web link.)

Lott, Debra

2008-01-01

375

Towards Understanding the Roots of Reflective Inquiry.  

ERIC Educational Resources Information Center

Curricula involving reflective inquiry are always dynamic, have a problem orientation, afford introspection, require personal decisions, and recognize that living socially is a basic human condition. Such a curriculum, which views education as a liberating force, has its roots in humanism and existentialism. (RM)

Parsons, James B.

1983-01-01

376

Challenging Cancer at the Grass Roots.  

ERIC Educational Resources Information Center

The National Cancer Institute created the Appalachia Leadership Initiative on Cancer, composed of four similar projects that focus on increasing screening for cervical and breast cancer among low-income, older women. The program relies on community coalitions that develop innovative grass roots methods to spread the message about the importance of…

Casto, James E.

1997-01-01

377

Tapping Ancient Roots: Plaited Paper Baskets  

ERIC Educational Resources Information Center

With ancient roots, basket making has been practiced since the earliest civilizations, and according to textile experts, probably pre-dates pottery. This is partly conjecture since few baskets remain. It is through evidence found in clay impressions that the earliest baskets reveal themselves. Basically, basketry construction is like flat weaving.…

Patrick, Jane

2011-01-01

378

[The Historical Roots of Developmental Education.  

ERIC Educational Resources Information Center

The historical roots of developmental education are traced in a three-part article extending across three serial issues. "Educating All the Nation's People," by Hunter R. Boylan and William G. White, Jr., reviews the historical antecedents of developmental education, focusing on efforts in the 17th century to prepare English-speaking American…

Boylan, Hunter R.; And Others

1988-01-01

379

Iridoids in roots of Pedicularis chinensis  

Microsoft Academic Search

Four new iridoids, the glucosides 3?-butoxy-3,4-dihydroaucubin, 6-O-butyl-aucubin and 6-O-butyl-epiaucubin, together with pedicularis-lactone were isolated from roots of pedicularis chinensis. In addition, the known glucosides aucubin and bartsioside and a known iridoid lactone were also isolated. The compounds were identified mainly by spectral evidence.

Yang Li; Wang Changzeng; Jia Zhongjian

1995-01-01

380

Reclaiming our Roots: Accomplishments and Challenges  

Microsoft Academic Search

Best practices for Native Americans are rooted in culture. However, reclaiming best practices is a challenge given the genocidal policies that outlawed Native culture. Despite this challenge Native people have proven resilient in restoring culture. The Native American Health Center in Oakland, California, has made cultural interventions an option for an urban, intertribal and sometimes multiracial Native American population to

Janet King

2011-01-01

381

Resistance to Fungal Pathogens of Tree Roots  

Microsoft Academic Search

The two wood-rotting basidiomycetes Armillaria mellea and Fomes annosus are chosen to illustrate observations and experiments on resistance phenomena. The degree of suppression and position in a stand affect resistance of trees to these root parasites, competition for light and water being important factors. Resistance to killing tends to increase with age and often leads to stabilization of disease gaps.

J. Rishbeth

1972-01-01

382

Auxin Metabolism in the Root Apical Meristem  

Microsoft Academic Search

Within the root meristem of flowering plants is a group of mitot- ically inactive cells designated the quiescent center (QC). Recent work links the quiescent state to high levels of the growth regulator auxin that accumulates in the QC via polar transport. This in turn results in elevated levels of the enzyme ascorbic acid oxidase (AAO), resulting in a reduction

Nancy M. Kerk; Keni Jiang; Lewis J. Feldman

2000-01-01

383

Plant Disease Lesson: Root-knot nematode  

NSDL National Science Digital Library

This plant disease lesson on Root-knot nematode (caused by Meloidogyne ) includes information on symptoms and signs, pathogen biology, disease cycle and epidemiology, disease management, and the significance of the disease. Selected references are listed and a glossary is also available for use with this resource.

Nathaniel A. Mitkowski (University of Rhode Island;); George S. Abawi (NYSAES-Cornell University;)

2003-09-17

384

Rooted staggered fermions: good, bad or ugly?  

E-print Network

I give a status report on the validity of the so-called ``fourth-root trick'', i.e. the procedure of representing the determinant for a single fermion by the fourth root of the staggered fermion determinant. This has been used by the MILC collaboration to create a large ensemble of lattices using which many quantities of physical interest have been and are being calculated. It is also used extensively in studies of QCD thermodynamics. The main question is whether the theory so defined has the correct continuum limit. There has been significant recent progress towards answering this question. After recalling the issue, and putting it into a broader context of results from statistical mechanics, I critically review the new work. I also address the related issue of the impact of treating valence and sea quarks differently in rooted simulations, discuss whether rooted simulations at finite temperature and density are subject to additional concerns, and briefly update results for quark masses using the MILC configurations. An answer to the question in the title is proposed in the summary.

Stephen R. Sharpe

2006-10-15

385

Learning, Judgment, and the Rooted Particular  

ERIC Educational Resources Information Center

This article begins by acknowledging the general worry that scholarship in the humanities lacks the rigor and objectivity of other scholarly fields. In considering the validity of that criticism, I distinguish two models of learning: the covering law model exemplified by the natural sciences, and the model of rooted particularity that…

McCabe, David

2012-01-01

386

Plant growth: roots in the cell cycle.  

PubMed

Overexpression in transgenic plants of a B-type cyclin--thought to regulate cell-cycle progression to mitosis--causes structures such as roots to grow faster than normal, indicating that the rate of cell division may be a constraint on plant growth. PMID:8805285

Doonan, J

1996-07-01

387

Diagnosis of brachial root and plexus lesions  

Microsoft Academic Search

The diagnosis and management of lesions of the brachial roots and of the brachial plexus is improved by appropriate investigation, both in acute and chronic disorders. The choice of investigation should be determined by the clinical problem. Since they are relatively non-invasive, electrophysiological investigations are particularly useful. In this review the role of these investigations is considered in relation to

M. Swash

1986-01-01

388

Unit root tests for panel data  

Microsoft Academic Search

This paper develops unit root tests for panel data. These tests are devised under more general assumptions than the tests previously proposed. First, the number of groups in the panel data is assumed to be either finite or infinite. Second, each group is assumed to have different types of nonstochastic and stochastic components. Third, the time series spans for the

In Choi

2001-01-01

389

On Nth roots of positive operators  

NASA Technical Reports Server (NTRS)

A bounded operator A on a Hilbert space H was positive. These operators were symmetric, and as such constitute a natural generalization of nonnegative real diagonal matrices. The following result is thus both well known and not surprising: A positive operator has a unique positive square root (under operator composition).

Brown, D. R.; Omalley, M. J.

1978-01-01

390

Plant Disease Lesson: Brown root rot  

NSDL National Science Digital Library

This plant disease lesson on brown root rot (caused by the fungus Phellinus noxius) includes information on symptoms and signs, pathogen biology, disease cycle and epidemiology, disease management, and the significance of the disease. Selected references are listed and a glossary is also available for use with this resource.

Fred Brooks (American Samoa Community College Land Grant Program;)

2002-09-23

391

Stimulation of adventitious rooting of Taxus species by thiamine.  

PubMed

Results obtained from using root inducing compounds on Taxus species cuttings suggested that rooting could be significantly enhanced by the presence of thiamine. This observation was verified using a root inducing solution containing a set concentration of IBA (0.2%), NAA (0.1%), and supplemented with various concentrations of thiamine. The best rooting response for Taxus cuspidata stem cuttings was found using this solution supplemented with 0.08% thiamine. Rooted cuttings were easily established and developed into vigorous plants. In addition, Taxus brevifolia shoots obtained from tissue cultures via in vitro organogenesis also responded favorably to this 0.08% thiamine supplemented rooting solution. PMID:24186706

Chee, P P

1995-10-01

392

Water Transport across Maize Roots 1  

PubMed Central

A double pressure probe technique was used to measure simultaneously water flows and hydraulic parameters of individual cells and of excised roots of young seedlings of maize (Zea mays L.) in osmotic experiments. By following initial flows of water at the cell and root level and by estimating the profiles of driving forces (water potentials) across the root, the hydraulic conductivity of individual cell layers was evaluated. Since the hydraulic conductivity of the cell-to-cell path was determined separately, the hydraulic conductivity of the cell wall material could be evaluated as well (Lpcw = 0.3 to 6.10?9 per meter per second per megapascal). Although, for radial water flow across the cortex and rhizodermis, the apoplasmic path was predominant, the contribution of the hydraulic conductance of the cell-to-cell path to the overall conductance increased significantly from the first layer of the cortex toward the inner layers from 2% to 23%. This change was mainly due to an increase of the hydraulic conductivity of the cell membranes which was Lp = 1.9.10?7 per meter per second per megapascal in the first layer and Lp = 14 to 9.10?7 per meter per second per megapascal in the inner layers of the cortex. The hydraulic conductivity of entire roots depended on whether hydrostatic or osmotic forces were used to induce water flows. Hydrostatic Lpr was 1.2 to 2.3.10?7 per meter per second per megapascal and osmotic Lpr = 1.6 to 2.8.10?8 per meter per second per megapascal. The apparent reflection coefficients of root cells (?s) of nonpermeating solutes (KCI, PEG 6000) decreased from values close to unity in the rhizodermis to about 0.7 to 0.8 in the cortex. In all cases, however, ?s was significantly larger than the reflection coefficient of entire roots (?sr). For KCI and PEG 6000, ?sr was 0.53 and 0.64, respectively. The results are discussed in terms of a composite membrane model of the root. PMID:16667970

Zhu, Guo Li; Steudle, Ernst

1991-01-01

393

ON THE ORIGINS OF DORSAL ROOT POTENTIALS  

PubMed Central

The "dorsal root potential" consists of five successive deflections designated for convenience, D.R.I, II, III, IV, and V. Of these, D.R.V alone constitutes the dorsal root potential of prior description. A study has been made of the general properties of those deflections not previously described. Dorsal root potentials are electrotonic extensions into the extramedullary root segment, the result of electrical interactions within the cord comparable to those that have been studied in peripheral nerve. Although the anatomical and electrical conditions of interaction are infinitely more complex in the cord than in nerve, it is seen that the fact of parallel distribution of primary afferent fibers pertaining to neighboring dorsal roots provides a sufficient anatomical basis for qualitative analysis in the first approximation of dorsal root potentials. An extension of the theory of interaction between neighboring nerve fibers has been made to include an especial case of interaction between fibers orientated at right angles to one another. The predictions have been tested in a nerve model and found correct. Given this elaboration, and the stated anatomical propositions, existing knowledge of interaction provides an adequate theoretical basis for an elementary understanding of dorsal root potentials. The study of general properties and the analysis of dorsal root potentials have led to the formulation of certain conclusions that follow. D.R.I, II, and III record the electrotonic spread of polarization resulting from the external field of impulses conducted in the intramedullary segment and longitudinal trajects of primary afferent fibers. D.R.IV arises in part as the result of activity in primary afferent fibers, and in part as the result of activity in secondary neurons. In either case the mode of production is the same, and the responsible agent is residual negativity in the active collaterals, or, more precisely, the external field of current flow about the collaterals during the period of residual negativity. Current flow about active primary afferent collaterals during the period of residual negativity is the agent for residual facilitation of monosynaptic reflex pathways. Since the changes in reflex threshold follow the course of residual negativity there is no need to postulate especial properties for prolonging action at regions the threshold of which is measured by means of monosynaptic test reflexes. D.R.V results from polarization of primary afferent fibers by current flow about secondary neurons. There is indication that somata rather than axons of secondary neurons generate the polarizing currents. Similarity between D.R.V and the positive intermediary potential further indicates that soma gradients established during the recovery cycle are responsible for D.R.V. Little or no net polarization of primary afferent fibers results from activity confined to the contralateral gray substance, the dorsal root potentials in contralateral recording resulting from interaction in the dorsal column or in the ipsilateral gray substance following decussation of contralaterally evoked activity. During the course of asphyxia the initial defect in reflex pathways is the failure of secondary neurons to respond to primary impulses. Subsequently block is established at the branching zone of primary afferent fibers. A relation exists between the sequence of dorsal root potentials and the cord potential sequence, the major departure from exact correspondence occurring in the region of D.R.IV and the negative intermediary potential and being of a nature to suggest that different aspects of internuncial activity are emphasized by the two methods of leading. PMID:18114558

Lloyd, David P. C.; McIntyre, A. K.

1949-01-01

394

Why fine tree roots are stronger than thicker roots: The role of cellulose and lignin in relation to slope stability  

NASA Astrophysics Data System (ADS)

Plant roots help to reinforce the soil, increase slope stability and decrease water erosion. Root tensile strength plays an important role in soil reinforcement and slope stabilization. The relationship between tensile strength and internal chemical composition of roots is unknown due to limited studies. Thus, it is difficult to determine why root tensile strength tends to decrease with increasing root diameter. In this study, biomechanical and biochemical tests were performed on the roots of Chinese pine (Pinus tabulaeformis) to determine the relationships among tensile strength and the contents of the main chemical composition: cellulose, alpha-cellulose and lignin in the roots with different diameters. Our results confirmed that the tensile strength of Chinese pine roots decreased with increasing root diameter, and this relationship might be a power function. The chemical contents of the roots and root diameter were also related to each other with significant power regression. With increasing root diameter, the cellulose content and alpha-cellulose content increased, but the lignin content decreased. In addition, the lignin content exhibited a significantly positive relationship with tensile strength. Furthermore, the ratios of lignin/cellulose and lignin/alpha-cellulose decreased with increasing root diameter following significant power regressions, and they also demonstrated a positive relationship with tensile strength. Taken together, these results may be useful for studies on root tensile strength, soil reinforcement and slope stability.

Zhang, Chao-Bo; Chen, Li-Hua; Jiang, Jing

2014-02-01

395

Anatomical responses of root tips to boron deficiency I. Effects of boron deficiency on elongation of root tips and their morphological characteristics  

Microsoft Academic Search

Effects of boron deficiency on the elongation of root tips of tomato and sunflower seedlings were investigated and the morphological responses of root tips were discussed.The primary effect of boron deficiency was the rapid cessation of root elongation followed by browning and some morphological changes in the root tips, such as abnormal enlargement and dense appearance of lateral roots. Root

Hiroshi Kouchi; Kikuo Kumazawa

1975-01-01

396

Root traits contributing to plant productivity under drought.  

PubMed

Geneticists and breeders are positioned to breed plants with root traits that improve productivity under drought. However, a better understanding of root functional traits and how traits are related to whole plant strategies to increase crop productivity under different drought conditions is needed. Root traits associated with maintaining plant productivity under drought include small fine root diameters, long specific root length, and considerable root length density, especially at depths in soil with available water. In environments with late season water deficits, small xylem diameters in targeted seminal roots save soil water deep in the soil profile for use during crop maturation and result in improved yields. Capacity for deep root growth and large xylem diameters in deep roots may also improve root acquisition of water when ample water at depth is available. Xylem pit anatomy that makes xylem less "leaky" and prone to cavitation warrants further exploration holding promise that such traits may improve plant productivity in water-limited environments without negatively impacting yield under adequate water conditions. Rapid resumption of root growth following soil rewetting may improve plant productivity under episodic drought. Genetic control of many of these traits through breeding appears feasible. Several recent reviews have covered methods for screening root traits but an appreciation for the complexity of root systems (e.g., functional differences between fine and coarse roots) needs to be paired with these methods to successfully identify relevant traits for crop improvement. Screening of root traits at early stages in plant development can proxy traits at mature stages but verification is needed on a case by case basis that traits are linked to increased crop productivity under drought. Examples in lesquerella (Physaria) and rice (Oryza) show approaches to phenotyping of root traits and current understanding of root trait genetics for breeding. PMID:24204374

Comas, Louise H; Becker, Steven R; Cruz, Von Mark V; Byrne, Patrick F; Dierig, David A

2013-01-01

397

Root traits contributing to plant productivity under drought  

PubMed Central

Geneticists and breeders are positioned to breed plants with root traits that improve productivity under drought. However, a better understanding of root functional traits and how traits are related to whole plant strategies to increase crop productivity under different drought conditions is needed. Root traits associated with maintaining plant productivity under drought include small fine root diameters, long specific root length, and considerable root length density, especially at depths in soil with available water. In environments with late season water deficits, small xylem diameters in targeted seminal roots save soil water deep in the soil profile for use during crop maturation and result in improved yields. Capacity for deep root growth and large xylem diameters in deep roots may also improve root acquisition of water when ample water at depth is available. Xylem pit anatomy that makes xylem less “leaky” and prone to cavitation warrants further exploration holding promise that such traits may improve plant productivity in water-limited environments without negatively impacting yield under adequate water conditions. Rapid resumption of root growth following soil rewetting may improve plant productivity under episodic drought. Genetic control of many of these traits through breeding appears feasible. Several recent reviews have covered methods for screening root traits but an appreciation for the complexity of root systems (e.g., functional differences between fine and coarse roots) needs to be paired with these methods to successfully identify relevant traits for crop improvement. Screening of root traits at early stages in plant development can proxy traits at mature stages but verification is needed on a case by case basis that traits are linked to increased crop productivity under drought. Examples in lesquerella (Physaria) and rice (Oryza) show approaches to phenotyping of root traits and current understanding of root trait genetics for breeding. PMID:24204374

Comas, Louise H.; Becker, Steven R.; Cruz, Von Mark V.; Byrne, Patrick F.; Dierig, David A.

2013-01-01

398

Plant roots and spectroscopic methods - analyzing species, biomass and vitality.  

PubMed

In order to understand plant functioning, plant community composition, and terrestrial biogeochemistry, it is decisive to study standing root biomass, (fine) root dynamics, and interactions belowground. While most plant taxa can be identified by visual criteria aboveground, roots show less distinctive features. Furthermore, root systems of neighboring plants are rarely spatially segregated; thus, most soil horizons and samples hold roots of more than one species necessitating root sorting according to taxa. In the last decades, various approaches, ranging from anatomical and morphological analyses to differences in chemical composition and DNA sequencing were applied to discern species' identity and biomass belowground. Among those methods, a variety of spectroscopic methods was used to detect differences in the chemical composition of roots. In this review, spectroscopic methods used to study root systems of herbaceous and woody species in excised samples or in situ will be discussed. In detail, techniques will be reviewed according to their usability to discern root taxa, to determine root vitality, and to quantify root biomass non-destructively or in soil cores holding mixtures of plant roots. In addition, spectroscopic methods which may be able to play an increasing role in future studies on root biomass and related traits are highlighted. PMID:24130565

Rewald, Boris; Meinen, Catharina

2013-01-01

399

Plant roots and spectroscopic methods - analyzing species, biomass and vitality  

PubMed Central

In order to understand plant functioning, plant community composition, and terrestrial biogeochemistry, it is decisive to study standing root biomass, (fine) root dynamics, and interactions belowground. While most plant taxa can be identified by visual criteria aboveground, roots show less distinctive features. Furthermore, root systems of neighboring plants are rarely spatially segregated; thus, most soil horizons and samples hold roots of more than one species necessitating root sorting according to taxa. In the last decades, various approaches, ranging from anatomical and morphological analyses to differences in chemical composition and DNA sequencing were applied to discern species’ identity and biomass belowground. Among those methods, a variety of spectroscopic methods was used to detect differences in the chemical composition of roots. In this review, spectroscopic methods used to study root systems of herbaceous and woody species in excised samples or in situ will be discussed. In detail, techniques will be reviewed according to their usability to discern root taxa, to determine root vitality, and to quantify root biomass non-destructively or in soil cores holding mixtures of plant roots. In addition, spectroscopic methods which may be able to play an increasing role in future studies on root biomass and related traits are highlighted. PMID:24130565

Rewald, Boris; Meinen, Catharina

2013-01-01

400

Time to shift: from scaling and root planing to root surface debridement.  

PubMed

Non-surgical periodontal treatment has traditionally been based on the notion that bacterial plaque (dental biofilm) penetrates and infects dental cementum. Removal of this infected cementum via scaling and root planing (SRP) was considered essential for re-establishing periodontal health. In the 1980s the concept of SRP was questioned because several in vitro studies showed that the biofilm was superficially located on the root surface and its disruption and removal could be relatively easily achieved by ultrasonic instrumentation of the root surface (known as root surface debridement (RSD). Subsequent in vivo studies corroborated the in vitro findings. There is now sufficient clinical evidence to substantiate the concept that the deliberate removal of cementum by SRP is no longer warranted or justified, and that the more gentle and conservative approach of RSD should be implemented in daily periodontal practice. PMID:25198637

Ciantar, Marilou

2014-08-01

401

1-Aminocyclopropane-1-carboxylic acid (ACC) concentration and ACC synthase expression in soybean roots, root tips, and soybean cyst nematode (Heterodera glycines)-infected roots.  

PubMed

Colonization of plant roots by root knot and cyst nematodes requires a functional ethylene response pathway. However, ethylene plays many roles in root development and whether its role in nematode colonization is direct or indirect, for example lateral root initiation or root hair growth, is not known. The temporal requirement for ethylene and localized synthesis of ethylene during the life span of soybean cyst nematode (SCN) on soybean roots was further investigated. Although a significant increase in ethylene evolution was not detected from SCN-colonized roots, the concentration of the immediate precursor to ethylene, 1-aminocyclopropane-1-carboxylic acid (ACC), was higher in SCN-colonized root pieces and root tips than in other parts of the root. Moreover, expression analysis of 17 ACC synthase (ACS) genes indicated that a select set of ACS genes is expressed in SCN-colonized root pieces that is clearly different from the set of genes expressed in non-colonized roots or root tips. Semi-quantitative real-time PCR indicated that ACS transcript accumulation correlates with the high concentration of ACC in root tips. In addition, an ACS-like sequence was found in the public SCN nucleotide database. Acquisition of a full-length sequence for this mRNA (accession GQ389647) and alignment with transcripts for other well-characterized ACS proteins indicated that the nematode sequence is missing a key element required for ACS activity and therefore probably is not a functional ACS. Moreover, no significant amount of ACC was found in any growth stage of SCN that was tested. PMID:19861652

Tucker, Mark L; Xue, Ping; Yang, Ronghui

2010-01-01

402

Nitrogen in shoot litter, root litter and root exudates from nitrogen-fixing Alnus incana  

Microsoft Academic Search

Summary A pot experiment withAlnus incana (L.) Moench growing in sand was set up to compare the amounts of nitrogen released from plants shoot litter with that released below ground as root litter and\\/or root exudation. No nitrogen fixation by free-living microorganisms was found in the sand and the increased nitrogen content of the plant + soil system was therefore

Kerstin Huss-Danell

1986-01-01

403

Rooting greenwood tip cuttings of several Populus clones hydroponically (hydroponic rooting of Populus cuttings)  

Microsoft Academic Search

Greenwood cuttings of several Populus clones were successfully rooted with a relatively simple hydroponic method. Indolebutyric acid and naphthaleneacetic acid at concentrations of 500 to 5000 ppM applied as a quick dip to the cutting bases, a complete nutrient solution at 20 to 40% of full strength, and a solution temperature between 27 and 30°C generally produced the best rooting

Howard M. Phipps; Edward A. Hansen; David N. Tolsted

1980-01-01

404

Carbon unloading in roots in relation to root senescence in Cercis chinensis seedlings under drought stress  

Microsoft Academic Search

When Cercis chinensis seedlings suffered from drought treatment, net photosynthetic rates had been significantly reduced at the end of the drought\\u000a treatment. Compared with the control, the activities of acid invertases in roots had increased 5 and 11 days after drought\\u000a treatment. Seventeen days after drought treatment, the activities of acid invertases in roots were significantly decreased,\\u000a while activities of

Cai-xia Gan; Chu Wu

2009-01-01

405

Antioxidation responses of maize roots and leaves to partial root-zone irrigation  

Microsoft Academic Search

Antioxidation responses of maize roots and leaves to water deficit and rewatering under partial root-zone irrigation (PRI) were investigated using a pot system. Plants were cultured using three irrigation methods, i.e. conventional irrigation (CI), alternate PRI (APRI) and fixed PRI (FPRI) with three different water regimes including W1 (70% field capacity, FC), W2 (50% FC) and W3 (35% FC). Compared

Tiantian Hu; Lina Yuan; Jinfeng Wang; Shaozhong Kang; Fusheng Li

2010-01-01

406

Nitrate-reducing capacity of roots and nodules of Alnus rubra and roots of Pseudotsuga menziesii  

Microsoft Academic Search

Summary Nitrate-reducing capability was demonstrated for root segments of red alder and, at more than twice that rate, for alder nodules. Root segments of Douglas-fir failed to reduce nitrate despite various treatments designed to induce such activity. The reported response of Douglas-fir to nitrate fertilizer may be ascribed either to microbial assimilation of nitrate ions with subsequent liberation of ammonium

C. Y. Li; K. C. Lu; J. M. Trappe; W. B. Bollen

1972-01-01

407

Effect of heavy metals on root growth and peroxidase activity in barley root tip  

Microsoft Academic Search

In the present work, we investigated the alteration of oxidative and peroxidative activities of peroxidases (PODs) along the\\u000a longitudinal root axis of barley seedlings during heavy metal (HM; e.g., Cd, Cu, Hg, Ni, Pb) treatment. Analysis of the individual\\u000a root segments revealed that all of the analyzed HMs caused an increase of guaiacol-POD activity, however to a different extent\\u000a and

L’ubica Halušková; Katarína Valentovi?ová; Jana Huttová; Igor Mistrík; Ladislav Tamás

2010-01-01

408

Growth of hybrid poplar as affected by dandelion and quackgrass competition  

Microsoft Academic Search

A pot experiment was conducted in a growth chamber to investigate the effects of dandelion (Taraxacum officinale) and quackgrass (Elymus repens) on the growth of hybrid poplar (Populus deltoides?×?Populus?×?petrowskyana var. Walker). Single hybrid poplar seedlings were grown in pots either alone (SHP) or with four or eight dandelion plants\\u000a per pot or with one or three quackgrass plants per pot

Bachitter S. Kabba; J. Diane Knight; Ken C. J. Van Rees

2007-01-01

409

New Group 16SrIII Phytoplasma Lineages in Lithuania Exhibit rRNA Interoperon Sequence Heterogeneity  

Microsoft Academic Search

Previously undescribed phytoplasmas were detected in diseased plants of dandelion (Taraxacum officinale) exhibiting virescence of flowers, thistle (Cirsium arvense) exhibiting symptoms of white leaf, and a Gaillardia sp. exhibiting symptoms of stunting and phyllody in Lithuania. On the basis of restriction fragment length polymorphism (RFLP) analysis of 16S rDNA amplified in PCR, the dandelion virescence (DanVir), cirsium whiteleaf (CirWL), and

R. Jomantiene; R. E. Davis; D. Valiunas; A. Alminaite

2002-01-01

410

Rate of Change in Dormancy Level and Light Requirement in Weed Seeds During Stratification  

Microsoft Academic Search

The rate of change in dormancy level and light requirement, induced during stratification at 3.2 °C, was investigated in seeds ofStellaria media, Cerastium fontanum, Veronica agrestisandTaraxacum officinale.Two stratification environments, soil and wet filter paper in petri-dishes, were used. On nine occasions during a 6 week stratification period, germination was tested under three light conditions at 3.5\\/18.5 °C: (1) darkness; (2)

ANGELA NORONHA; LARS ANDERSSON; PER MILBERG

1997-01-01

411

A new algorithm for automatic Rumex obtusifolius detection in digital images using colour and texture features and the influence of image resolution  

Microsoft Academic Search

In Gebhardt et al. (2006) an object-oriented image classification algorithm was introduced for detecting Rumex obtusifolius (RUMOB) and other weeds in mixed grassland swards, based on shape, colour and texture features. This paper describes a new\\u000a algorithm that improves classification accuracy. The leaves of the typical grassland weeds (RUMOB, Taraxacum officinale, Plantago major) and other homogeneous regions were segmented automatically in

Steffen Gebhardt; Walter Kühbauch

2007-01-01

412

An Apomixis-Gene’s View on Dandelions  

Microsoft Academic Search

\\u000a In asexual organisms, the clone constitutes a level above the individual. Most dandelions (Taraxacum officinale\\u000a s.l.) reproduce asexually through apomixis, asexual reproduction through seeds. A clone can be seen as a superorganism that is\\u000a born, that growths, degenerates and eventually dies. Apomixis in dandelions is controlled by a few dominant genes, the so\\u000a called apomixis-genes. This implies that there should

Peter Van Dijk; Hans de Jong; Kitty Vijverberg; Arjen Biere

2010-01-01

413

Spatial and temporal distribution of free and bound ABA in wheat and dandelion ovaries in the period of egg-cell activity  

Microsoft Academic Search

We quantified endogenous free and bound ABA in ovaries of the apomictic Taraxacum officinale Web. (dandelion) and amphimictic Triticum aestivum L. (wheat) species. ABA distribution was assessed in four ovary sections and during three developmental stages: from the\\u000a quiescence release of the egg-cell until its first division (the period of egg-cell activity). ABA content was determined\\u000a by the novel modification

M. A. Gusakovskaya; A. N. Blintsov

2006-01-01

414

Amyloplast Distribution Directs a Root Gravitropic Reaction  

NASA Astrophysics Data System (ADS)

Immobile higher plants are oriented in the gravitational field due to gravitropim that is a physiological growth reaction and consists of three phases: reception of a gravitational signal by statocytes, its transduction to the elongation zone, and finally the organ bending. As it is known, roots are characterized with positive gravitropism, i. e. they grow in the direction of a gravitational vector, stems - with negative gravitropism, i. e. they grow in the direction opposite to a gravitational vector. According to the Nemec’s and Haberlandt’s starch-statolith hypothesis, amyloplasts in diameter of 1.5 - 3 ? in average, which appear to act as gravity sensors and fulfill a statolythic function in the specialized graviperceptive cells - statocytes, sediment in the direction of a gravitational vector in the distal part of a cell, while a nucleus is in the proximal one. There are reasonable data that confirm the amyloplasts-statoliths participation in gravity perception: 1) correlation between the statoliths localization and the site of gravity sensing, 2) significant redistribution (sedimentation) of amyloplasts in statocytes under gravistimulation in comparison with other cell organelles, 3) root decreased ability to react on gravity under starch removal from amyloplasts, 4) starchless Arabidopsis thaliana mutants are agravitropic, 5) amyloplasts-statoliths do not sediment in the absence of the gravitational vector and are in different parts or more concentrated in the center of statocytes. Plant tropisms have been intensively studied for many decades and continue to be investigated. Nevertheless, the mechanisms by which plants do so is still not clearly explained and many questions on gravisensing and graviresponse remain unanswered. Even accepted hypotheses are now being questioned and recent data are critically evaluated. Although the available data show the Ca2+ and cytoskeleton participation in graviperception and signal transduction, the clear evidence with regard to the participation of calcium ions and cytoskeletal elements in these processes is therefore substantial but still circumstantial and requires new experimental data. Using a new model - weak combined magnetic fields (CMFs), which elicit a variety of responses in plants, growth rate and fresh weight, seed germination, Ca2+ concentration, membrane permeability, with a frequency resonance to cyclotron frequency of calcium ions, we firstly showed that a root positive gravitropic reaction changes on a negative one. In this case, the paradoxical displacement of amylopasts-statoliths to the upper longitudinal cell wall of statocytes occurred in the direction opposite to a gravitational vector. Displacement of amyloplasts, which contain the abundance of free Ca2+ in the stroma, was accompanied with Ca2+ redistribution in the same direction in the cytosol and increasing around amyloplasts in comparison with the state magnetic field. In the elongation zone, calcium ions accumulated in the upper site of a gravistimulated root unlike a positive gravitropic reaction, and a root is bending in the same direction in which amyloplasts are displacing. It seems that a root gravitropic reaction, if it began, occurs by an usual physiological way resulting in root bending with an opposite sign. It is of a special interest that a root is bending to the same direction with displacing of amyloplasts: in positive gravitropism - downwards, in negative gravitropism - upwards. Peculiarities of calcium ion redistribution in statocytes under gravistimulation in such combined magnetic field are a new additional evidence of a Ca2+ ion significant role in gravitropism. Thus, our data support the starch-statolith hypothesis but also pose the question as to which forces displace amyloplasts against the gravity vector? We hope that these data will stimulate new research to better understand the mechanisms of plant graviperception and graviresponse. Gravistimulation of a root in the CMF with the frequency resonance to the cyclotron frequency of Ca2+ ions is an effective model for future

Kordyum, Elizabeth

415

Assessment of the wetting behavior of three different root canal sealers on root canal dentin  

PubMed Central

Aim: The objective of the present study was to evaluate and compare the wetting behavior of three different root canal sealers on the root canal dentin surface treated with irrigants and their combination. Materials and Methods: Decoronation and apical third resections of 27 extracted single-rooted human mandibular premolars were done. The roots were then split longitudinally into two halves, and randomly assigned into three treatment groups (n=18). The root dentin surfaces in Group1, Group 2 and Group 3 were treated with 17% ethylene diamine tetra acetic acid (EDTA), 3% sodium hypochlorite (NaOCl) and combination of 17% EDTA and 3% NaOCl, respectively. Each group was subdivided into three subgroups of 6 specimens each, depending on the the sealer used, i.e. sub group A. zinc oxide (ZnOE), sub group B. AH plus, subgroup C. Guttaflow sealer, respectively. The contact angle was measured using First Ten Angstroms (FTA) 200 dynamic contact angle analyzer. Results: The contact angle values for AH Plus sealer were significantly lower when compared to the other two sealer groups. Conclusion: The wettability of AH Plus sealer on the root surface dentin was found to be better than Gutta-Flow and ZnOE sealer. PMID:22557805

Tummala, Muralidhar; Chandrasekhar, Veeramachaneni; Rashmi, A Shashi; Kundabala, M; Ballal, Vasudev

2012-01-01

416

Root Hair-Specific EXPANSIN A7 Is Required for Root Hair Elongation in Arabidopsis  

PubMed Central

Expansins are non-hydrolytic cell wall-loosening proteins that are involved in the cell wall modifications that underlie many plant developmental processes. Root hair growth requires the accumulation of cell wall materials and dynamic cell wall modification at the tip region. Although several lines of indirect evidence support the idea that expansin-mediated wall modification occurs during root hair growth, the involvement of these proteins remains to be demonstrated in vivo. In this study, we used RNA interference (RNAi) to examine the biological function of Arabidopsis thaliana EXPANSIN A7 (AtEXPA7), which is expressed specifically in the root hair cell. The root hairspecific AtEXPA7 promoter was used to drive RNAi expression, which targeted two independent regions in the AtEXPA7 transcript. Quantitative reverse transcriptase- PCR analyses were used to examine AtEXPA7 transcript levels. In four independent RNAi transformant lines, RNAi expression reduced AtEXPA7 transcript levels by 25-58% compared to controls. Accordingly, the root hairs of RNAi transformant lines were 25-48% shorter than control plants and exhibited a broader range of lengths than the controls. Our results provide in vivo evidence that expansins are required for root hair tip growth. PMID:21359675

Lin, Changfa; Choi, Hee-Seung; Cho, Hyung-Taeg

2011-01-01

417

Distribution and speciation of Mn in hydrated roots of cowpea at levels inhibiting root growth.  

PubMed

The phytotoxicity of Mn is important globally due to its increased solubility in acid or waterlogged soils. Short-term (?24 h) solution culture studies with 150 µM Mn were conducted to investigate the in situ distribution and speciation of Mn in apical tissues of hydrated roots of cowpea [Vigna unguiculata (L.) Walp. cv. Red Caloona] using synchrotron-based techniques. Accumulation of Mn was rapid; exposure to 150 µM Mn for only 5 min resulting in substantial Mn accumulation in the root cap and associated mucigel. The highest tissue concentrations of Mn were in the root cap, with linear combination fitting of the data suggesting that??80% of this Mn(II) was associated with citrate. Interestingly, although the primary site of Mn toxicity is typically the shoots, concentrations of Mn in the stele of the root were not noticeably higher than in the surrounding cortical tissues in the short-term (?24 h). The data provided here from the in situ analyses of hydrated roots exposed to excess Mn are, to our knowledge, the first of this type to be reported for Mn and provide important information regarding plant responses to high Mn in the rooting environment. PMID:22892034

Kopittke, Peter M; Lombi, Enzo; McKenna, Brigid A; Wang, Peng; Donner, Erica; Webb, Richard I; Blamey, F Pax C; de Jonge, Martin D; Paterson, David; Howard, Daryl L; Menzies, Neal W

2013-04-01

418

Natural variation of root traits: from development to nutrient uptake.  

PubMed

The root system has a crucial role for plant growth and productivity. Due to the challenges of heterogeneous soil environments, diverse environmental signals are integrated into root developmental decisions. While root growth and growth responses are genetically determined, there is substantial natural variation for these traits. Studying the genetic basis of the natural variation of root growth traits can not only shed light on their evolution and ecological relevance but also can be used to map the genes and their alleles responsible for the regulation of these traits. Analysis of root phenotypes has revealed growth strategies and root growth responses to a variety of environmental stimuli, as well as the extent of natural variation of a variety of root traits including ion content, cellular properties, and root system architectures. Linkage and association mapping approaches have uncovered causal genes underlying the variation of these traits. PMID:25104725

Ristova, Daniela; Busch, Wolfgang

2014-10-01

419

In Vitro Cytotoxicity Evaluation of a Novel Root Repair Material  

E-print Network

gingival fibroblast, MTA Various materials have been used for root repair, including silver amalgam, zinc for the special conditions and requirements of root repair. For instance, silver amalgam has concerns associated

Zheng, Yufeng

420

Root-derived auxin contributes to the phosphorus-deficiency-induced cluster-root formation in white lupin (Lupinus albus).  

PubMed

Formation of cluster roots is a typical morphological response to phosphorus (P) deficiency in white lupin (Lupinus albus), but its physiological and molecular mechanisms are still unclear. We investigated the role of auxin in the initiation of cluster roots by distinguishing the sources of auxin, measuring the longitudinal distribution patterns of free indole-3-acetic acid (IAA) along the root and the related gene expressions responsible for polar auxin transport (PAT) in different developmental stages of cluster roots. We found that removal of shoot apex or primary root apex and application of auxin-influx or -efflux transport inhibitors, 3-chloro-4-hydroxyphenylacetic acid, N-1-naphthylphthalamic acid and 2,3,5-triiodobenzoic acid, to the stem did not affect the number of cluster roots and the free-IAA concentration in the roots of P-deficient plants, but when these inhibitors were applied directly to the growth media, the cluster-root formation was greatly suppressed, suggesting the fundamental role of root-derived IAA in cluster-root formation. The concentration of free IAA in the roots was higher in P-deficient plants than in P-adequate ones, and the highest in the lateral-root apex and the lowest in the mature cluster roots. Meanwhile the expression patterns of LaAUX1, LaPIN1 and LaPIN3 transcripts related to PAT was consistent with concentrations of free IAA along the lateral root, indicating the contribution of IAA redistribution in the cluster-root development. We proposed that root-derived IAA plays a direct and important role in the P-deficiency-induced formation of cluster roots. PMID:23067249

Meng, Zhi Bin; You, Xue Di; Suo, Dong; Chen, Yun Long; Tang, Caixian; Yang, Jian Li; Zheng, Shao Jian

2013-08-01

421

Root Carbon Dioxide Fixation by Phosphorus-Deficient Lupinus albus (Contribution to Organic Acid Exudation by Proteoid Roots).  

PubMed Central

When white lupin (Lupinus albus L.) is subjected to P deficiency lateral root development is altered and densely clustered, tertiary lateral roots (proteoid roots) are initiated. These proteoid roots exude large amounts of citrate, which increases P solubilization. In the current study plants were grown with either 1 mM P (+P-treated) or without P (-P-treated). Shoots or roots of intact plants from both P treatments were labeled independently with 14CO2 to compare the relative contribution of C fixed in each with the C exuded from roots as citrate and other organic acids. About 25-fold more acid-stable 14C, primarily in citrate and malate, was recovered in exudates from the roots of -P-treated plants compared with +P-treated plants. The rate of in vivo C fixation in roots was about 4-fold higher in -P-treated plants than in +P-treated plants. Evidence from labeling intact shoots or roots indicates that synthesis of citrate exuded by -P-treated roots is directly related to nonphotosynthetic C fixation in roots. C fixed in roots of -P-treated plants contributed about 25 and 34% of the C exuded as citrate and malate, respectively. Nonphotosynthetic C fixation in white lupin roots is an integral component in the exudation of large amounts of citrate and malate, thus increasing the P available to the plant. PMID:12226371

Johnson, J. F.; Allan, D. L.; Vance, C. P.; Weiblen, G.

1996-01-01

422

Visualization of root water uptake: quantification of deuterated water transport in roots using neutron radiography and numerical modeling.  

PubMed

Our understanding of soil and plant water relations is limited by the lack of experimental methods to measure water fluxes in soil and plants. Here, we describe a new method to noninvasively quantify water fluxes in roots. To this end, neutron radiography was used to trace the transport of deuterated water (D2O) into roots. The results showed that (1) the radial transport of D2O from soil to the roots depended similarly on diffusive and convective transport and (2) the axial transport of D2O along the root xylem was largely dominated by convection. To quantify the convective fluxes from the radiographs, we introduced a convection-diffusion model to simulate the D2O transport in roots. The model takes into account different pathways of water across the root tissue, the endodermis as a layer with distinct transport properties, and the axial transport of D2O in the xylem. The diffusion coefficients of the root tissues were inversely estimated by simulating the experiments at night under the assumption that the convective fluxes were negligible. Inverse modeling of the experiment at day gave the profile of water fluxes into the roots. For a 24-d-old lupine (Lupinus albus) grown in a soil with uniform water content, root water uptake was higher in the proximal parts of lateral roots and decreased toward the distal parts. The method allows the quantification of the root properties and the regions of root water uptake along the root systems. PMID:25189533

Zarebanadkouki, Mohsen; Kroener, Eva; Kaestner, Anders; Carminati, Andrea

2014-10-01

423

A role for the root cap in root branching revealed by the non-auxin probe naxillin  

PubMed Central

The acquisition of water and nutrients by plant roots is a fundamental aspect of agriculture and strongly depends on root architecture. Root branching and expansion of the root system is achieved through the development of lateral roots and is to a large extent controlled by the plant hormone auxin. However, the pleiotropic effects of auxin or auxin-like molecules on root systems complicate the study of lateral root development. Here we describe a small-molecule screen in Arabidopsis thaliana that identified naxillin as what is to our knowledge the first non-auxin-like molecule that promotes root branching. By using naxillin as a chemical tool, we identified a new function for root cap-specific conversion of the auxin precursor indole-3-butyric acid into the active auxin indole-3-acetic acid and uncovered the involvement of the root cap in root branching. Delivery of an auxin precursor in peripheral tissues such as the root cap might represent an important mechanism shaping root architecture. PMID:22885787

De Rybel, Bert; Audenaert, Dominique; Xuan, Wei; Overvoorde, Paul; Strader, Lucia C; Kepinski, Stefan; Hoye, Rebecca; Brisbois, Ronald; Parizot, Boris; Vanneste, Steffen; Liu, Xing; Gilday, Alison; Graham, Ian A; Nguyen, Long; Jansen, Leentje; Njo, Maria Fransiska; Inze, Dirk; Bartel, Bonnie; Beeckman, Tom

2013-01-01

424

Stored carbon partly fuels fine-root respiration but is not used for production of new fine roots  

SciTech Connect

The relative use of new photosynthate compared to stored C for the production and maintenance of fine roots, and the rate of C turnover in heterogeneous fine-root populations, are poorly understood. We followed the relaxation of a 13C tracer in fine roots in a Liquidambar styraciflua plantation at the conclusion of a free-air CO2 enrichment experiment. Goals included quantifying the relative fractions of new photosynthate versus stored C used in root growth and root respiration, as well as the turnover rate of fine-root C fixed during [CO2] fumigation. New fine-root growth was largely from recent photosynthate, while nearly one-quarter of respired C was from a storage pool. Changes in the isotopic composition of the fine-root population over two full growing seasons indicated heterogeneous C pools; less than 10% of root C had a residence time < 3 months, while a majority of root C had a residence time > 2 years. Compared to a 1-pool model, a 2-pool model for C turnover in fine roots (with 5 and 0.37 yr-1 turnover times) doubles the fine-root contribution to forest NPP (9-13%) and supports the 50% root-to-soil transfer rate often used in models.

Lynch, Douglas J [ORNL; Matamala-Paradeda, Roser [ORNL; Iversen, Colleen M [ORNL; Norby, Richard J [ORNL; Gonzalez-Meler, Miguel A [ORNL

2013-01-01

425

Root Hair Initiation Is Coupled to a Highly Localized Increase of Xyloglucan Endotransglycosylase Action in Arabidopsis Roots1  

PubMed Central

Root hairs are formed by two separate processes: initiation and subsequent tip growth. Root hair initiation is always accompanied by a highly localized increase in xyloglucan endotransglycosylase (XET) action at the site of future bulge formation, where the trichoblast locally loosens its cell wall. This suggests an important role of XET in the first stages of root hair initiation. The tip of growing root hairs is not marked by localized high XET action. Experiments in which root hair initiation was modulated and observations on root hair mutants support this view. The ethylene precursor 1-aminocyclopropane-1-carboxylic acid shifts both root hair initiation and the local increase in XET action toward the root tip. On the other hand, roots treated with the ethylene inhibitor aminoethoxyvinyl-glycine, as well as roots of mutants affected in root hair initiation (rhl1, rhd6-1, and axr2-1) revealed no localized increases of XET action at all and consequently did not initiate root hairs. Disruption of actin and microtubules did not prevent the localized increase in XET action. Also, the temporal and spatial pattern of action as the specific pH dependence suggest that different isoforms of XET act in different processes of root development. PMID:11706192

Vissenberg, Kris; Fry, Stephen C.; Verbelen, Jean-Pierre

2001-01-01