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Sample records for roots daucus carota

  1. Identification and characterization of terpene synthases potentially involved in the formation of volatile terpenes in carrot (Daucus carota L.) roots

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plants produce numerous volatile organic compounds, which are important in determining the quality and nutraceutical properties of fruit and root crops, including the taste and the aroma of carrots (Daucus carota L.). A combined chemical, biochemical and molecular study was conducted to evaluate the...

  2. Regulation of ascorbic acid biosynthesis and recycling during root development in carrot (Daucus carota L.).

    PubMed

    Wang, Guang-Long; Xu, Zhi-Sheng; Wang, Feng; Li, Meng-Yao; Tan, Guo-Fei; Xiong, Ai-Sheng

    2015-09-01

    Ascorbic acid (AsA), also known as vitamin C, is an essential nutrient in fruits and vegetables. The fleshy root of carrot (Daucus carota L.) is a good source of AsA for humans. However, the metabolic pathways and molecular mechanisms involved in the control of AsA content during root development in carrot have not been elucidated. To gain insights into the regulation of AsA accumulation and to identify the key genes involved in the AsA metabolism, we cloned and analyzed the expression of 21 related genes during carrot root development. The results indicate that AsA accumulation in the carrot root is regulated by intricate pathways, of which the l-galactose pathway may be the major pathway for AsA biosynthesis. Transcript levels of the genes encoding l-galactose-1-phosphate phosphatase and l-galactono-1,4-lactone dehydrogenase were strongly correlated with AsA levels during root development. Data from this research may be used to assist breeding for improved nutrition, quality, and stress tolerance in carrots.

  3. Combating photooxidative stress in green hairy roots of Daucus carota cultivated under light irradiation.

    PubMed

    Mukherjee, Chiranjit; Sircar, Debabrata; Chatterjee, Moniya; Das, Sampa; Mitra, Adinpunya

    2014-01-15

    The light-dependent generation of active oxygen species, which can disrupt normal metabolic process of plant, is termed as photo-oxidative stress. Plants are equipped with enzymatic and non-enzymatic antioxidative defence system to reduce the effect of such stress. Hairy root culture of Daucus carota when cultivated under continuous illumination (250 μmol m(-2)s(-1)) turned green. To know the reason behind that and photo-oxidative stress response in green hairy roots, activities of several antioxidant enzymes were measured. When compared with normal hairy roots, green hairy roots showed an enhanced superoxide dismutase (SOD) activity. Treatment with a SOD inhibitor diethyldithiocarbamate led to suppression of SOD activity in a concentration-dependent manner in green hairy roots. Interestingly, SOD-suppressed root showed three-fold enhanced caffeic acid glucoside accumulation in the soluble fraction as compared to untreated ones. While ascorbate peroxidase activity showed marginal increase in green hairy roots, a decrease in the activities of guaiacol peroxidase and catalase were observed. SDS-PAGE of crude protein profile from green hairy roots showed a distinct band, which was absent in normal hairy roots. MALDI-TOF-MS/MS analysis of the extracted protein confirmed it as the large subunit of RuBisCO. RT-PCR based expression analysis of betaine aldehyde dehydrogenase showed enhanced transcript levels in green hairy roots as compared to normal hairy roots, whereas reverse trends were observed with the transcripts accumulation for phenylalanine ammonia-lyase and chalcone synthase. These findings corroborate with the in vitro BADH activities in hairy roots, and thus indicate an important role of this stress enzyme in combating photo-oxidative stress in green hairy roots upon continuous light exposure.

  4. Identification and Characterization of Terpene Synthases Potentially Involved in the Formation of Volatile Terpenes in Carrot (Daucus carota L.) Roots.

    PubMed

    Yahyaa, Mosaab; Tholl, Dorothea; Cormier, Guy; Jensen, Roderick; Simon, Philipp W; Ibdah, Mwafaq

    2015-05-20

    Plants produce an excess of volatile organic compounds, which are important in determining the quality and nutraceutical properties of fruit and root crops, including the taste and aroma of carrots (Daucus carota L.). A combined chemical, biochemical, and molecular study was conducted to evaluate the differential accumulation of volatile terpenes in a diverse collection of fresh carrots (D. carota L.). Here, we report on a transcriptome-based identification and functional characterization of two carrot terpene synthases, the sesquiterpene synthase, DcTPS1, and the monoterpene synthase, DcTPS2. Recombinant DcTPS1 protein produces mainly (E)-β-caryophyllene, the predominant sesquiterpene in carrot roots, and α-humulene, while recombinant DcTPS2 functions as a monoterpene synthase with geraniol as the main product. Both genes are differentially transcribed in different cultivars and during carrot root development. Our results suggest a role for DcTPS genes in carrot aroma biosynthesis.

  5. Alternative oxidase (AOX) and phenolic metabolism in methyl jasmonate-treated hairy root cultures of Daucus carota L.

    PubMed

    Sircar, Debabrata; Cardoso, Hélia G; Mukherjee, Chiranjit; Mitra, Adinpunya; Arnholdt-Schmitt, Birgit

    2012-05-01

    Methyl-jasmonate (MJ)-treated hairy roots of Daucus carota L. were used to study the influence of alternative oxidase (AOX) in phenylpropanoid metabolism. Phenolic acid accumulation, as well as total flavonoids and lignin content of the MJ-treated hairy roots were decreased by treatment with salicylhydroxamic acid (SHAM), a known inhibitor of AOX. The inhibitory effect of SHAM was concentration dependent. Treatment with propyl gallate (PG), another inhibitor of AOX, also had a similar inhibitory effect on accumulation of phenolic acid, total flavonoids and lignin. The transcript levels of two DcAOX genes (DcAOX2a and DcAOX1a) were monitored at selected post-elicitation time points. A notable rise in the transcript levels of both DcAOX genes was observed preceding the MJ-induced enhanced accumulation of phenolics, flavonoids and lignin. An appreciable increase in phenylalanine ammonia-lyase (PAL) transcript level was also observed prior to enhanced phenolics accumulation. Both DcAOX genes showed differential transcript accumulation patterns after the onset of elicitation. The transcript levels of DcAOX1a and DcAOX2a attained peak at 6hours post elicitation (hpe) and 12hpe, respectively. An increase in the transcript levels of both DcAOX genes preceding the accumulation of phenylpropanoid-derivatives and lignin showed a positive correlation between AOX activity and phenylpropanoid biosynthesis. The results provide important new insight about the influence of AOX in phenylpropanoid biosynthesis.

  6. Accumulation of p-hydroxybenzoic acid in hairy roots of Daucus carota 2: confirming biosynthetic steps through feeding of inhibitors and precursors.

    PubMed

    Sircar, Debabrata; Mitra, Adinpunya

    2009-09-01

    Biosynthesis of hydroxybenzoates even at enzymatic level is poorly understood. In this report, effect of feeding of putative biosynthetic precursors and pathway-specific enzyme inhibitors of early phenylpropanoid pathway on p-hydroxybenzoic acid accumulation in chitosan-elicited hairy roots of Daucus carota was studied. Three selective metabolic inhibitors of plant phenylpropanoid pathway, namely, aminooxyacetic acid (AOAA), piperonylic acid (PIP) and 3,4-methylenedioxycinnamic acid (MDCA), which are known to inhibit phenylalanine ammonia-lyase (PAL), cinnamate-4-hydroxylase (C4H) and 4-coumarate-CoA ligase (4CL) respectively, the three early enzymes of phenylpropanoid metabolism, were chosen with the anticipation that selective inhibition of these enzymes in vivo may provide information on the metabolic route to p-hydroxybenzoic acid formation. Supplementation of AOAA (0.2-1.0 mM) and PIP (0.2-1.0 mM) resulted in the reduced accumulation of p-hydroxybenzoic acid in the wall-bound fraction. However, addition of MDCA (0.2-1.25 mM), did not suppress p-hydroxybenzoic acid accumulation but suppressed lignin and total flavonoid accumulation, suggesting that 4CL enzyme activity is not required for p-hydroxybenzoic acid formation. Feeding of elicited hairy roots with phenylalanine, coumaric acid and p-hydroxybenzaldehyde had a stimulatory effect on p-hydroxybenzoic acid accumulation; however, maximum stimulatory effect was shown by p-hydroxybenzaldehyde. This suggests that p-hydroxybenzaldehyde might be the immediate precursor in p-hydroxybenzoic acid biosynthesis. Finally, in vitro conversion of p-coumaric acid to p-hydroxybenzoic acid with p-hydroxybenzaldehyde as intermediate using cell-free extract provided an unequivocal support for CoA-independent and non-beta-oxidative route of p-hydroxybenzoic acid biosynthesis in Daucus carota.

  7. Content of carotenoids in roots of seventeen cultivars of Daucus carota L.

    PubMed

    Mech-Nowak, Aleksandra; Swiderski, Adam; Kruczek, Michał; Luczak, Irena; Kostecka-Gugała, Anna

    2012-01-01

    The aim of this study was to compare the content of carotenoids in seventeen cultivars of carrots grown in Poland. Conventional orange cultivars with rarely grown were compared: white, yellow and purple with yellow core cultivars. To determine the content of carotenoids, extracts from lyophilized carrot roots were prepared and analyzed by spectrophotometric as well as HPLC methods with DAD detector. The highest content of carotenoids was found in cultivars: 'Korund F(1)' (48 mg/100g of fresh weight) and 'Salsa F(1)' (36 mg/100g of fresh weight). The antioxidant properties of selected cultivars were compared using the DPPH method.

  8. Genome-wide association of the domestication syndrome in carrot (Daucus carota L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Carrots (Daucus carota L.) were domesticated over 1,000 years ago in Central Asia. Two traits selected during domestication were increased carotenoid accumulation (white -> yellow -> orange root color) and decreased lateral root formation. While some preliminary research has been conducted on the un...

  9. Formation of norisoprenoid flavor compounds in carrot (Daucus carota L.) roots: characterization of a cyclic-specific carotenoid cleavage dioxygenase 1 gene

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Carotenoids are isoprenoid pigments that upon oxidative cleavage lead to the production of norisoprenoids that have profound effect on flavor and aromas of agricultural produce. The biosynthetic pathway to norisoprenoids in carrots (Daucus carota L.) is still widely unknown. We found that geranial i...

  10. Diversity Arrays Technology (DArT) platform for genotyping and mapping in carrot (Daucus carota L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Carrot is one of the most important root vegetable crops grown worldwide on more than one million hectares. Its progenitor, wild Daucus carota, is a weed commonly occurring across continents in the temperate climatic zone. Diversity Array Technology (DArT) is a microarray-based molecular marker syst...

  11. Analysis of the use of microcystin-contaminated water in the growth and nutritional quality of the root-vegetable, Daucus carota.

    PubMed

    Machado, J; Azevedo, J; Freitas, M; Pinto, E; Almeida, A; Vasconcelos, V; Campos, A

    2017-01-01

    Toxic cyanobacterial blooms are often observed in freshwaters and may reflect the increased eutrophication of these environments and alterations in climate. Cyanotoxins, such as microcystins (MCs), are an effective threat to many life forms, ranging from plants to humans. Despite the research conducted to date on cyanotoxins, the risks associated to the use of contaminated water in agriculture require further elucidation. To tackle this aim, a research was conducted with the root-vegetable Daucus carota. The specific aims of this work were the following: (i) to evaluate the effects of MC-LR on the plant growth and photosynthesis; (ii) to evaluate the nutritional quality of carrot roots; and (iii) to measure bioaccumulation. To this purpose, young carrots were grown in soil during 1 month in natural conditions and exposed to Mycrocystis aeruginosa aqueous extracts containing environmentally realistic concentrations of MC-LR (10 and 50 MC-LR μg/L). The results showed that MC-LR may decrease root growth after 28 days of exposure to 50 μg/L and increase photosynthetic efficiency. We also observed changes in mineral and vitamin content in carrots as a result of the exposure to contaminated water. Moreover, MC-LR was detected in carrot roots by ELISA at very low concentration 5.23 ± 0.47 ng MC eq./g FW. The soil retained 52.7 % of the toxin potentially available for plants. This result could be attributed to MC-LR adsorption by soil particles or due to microbial degradation of the toxin. We conclude that the prolonged use of MC-LR-contaminated water may affect crop growth, alter the nutritional value of vegetable products, and potentiate contamination.

  12. Polyamine Metabolism in Embryogenic Cells of Daucus carota

    PubMed Central

    Montague, Michael J.; Koppenbrink, Joan W.; Jaworski, Ernest G.

    1978-01-01

    Changes in the metabolism of polyamines, which seem to be involved in transcription and translation in animal systems, have been studied in cultured cells of Daucus carota (carrot) undergoing embryogenesis. Putrescine levels were elevated by as much as 2-fold over the control within 24 hours after transfer of the cells to embryogenic medium. Spermidine levels were elevated also but spermine levels appeared to be lower in embryogenic cells. Embryogenic cells incorporated [14C]arginine into putrescine at two times the rate of control cells. These changes suggest that polyamines may be involved in cellular differentiation during embryogenesis. PMID:16660531

  13. Determination of polyacetylenes in carrot roots (Daucus carota L.) by high-performance liquid chromatography coupled with diode array detection.

    PubMed

    Christensen, Lars P; Kreutzmann, Stine

    2007-03-01

    A new high-performance liquid chromatographic method with diode array detection was developed for the separation and simultaneous determination of the carrot polyacetylenes falcarindiol (FaDOH), falcarindiol 3-acetate (FaDOAc) and falcarinol (FaOH) in carrot root extracts. The optimal chromatographic conditions were achieved on a C18 column with a linear gradient elution of water and acetonitrile as mobile phases, at the flow rate of 1.0 mL/min. All calibration curves of the three carrot polyacetylenes showed good linear regression (R2 > 0.998) within the test ranges. The developed method showed good precision for quantification of all polyacetylenes with overall intraday and interday variation of less than 3.3% and with average recovery rates of 99.2, 96.8 and 99.7% for FaDOH, FaDOAc and FaOH, respectively. The LOD (S/N = 3) and LOQ (S/N = 10) were less than 0.19 and 0.42 microg/mL, respectively, for all analytes. The established method was successfully used to determine the spatial distribution of FaDOH, FaDOAc and FaOH in six carrot genotypes (Bolero, Independent, Line 1, Mello Yello, Purple Haze and Tornado) by analysing peeled carrots and the corresponding peels for these polyacetylenes.

  14. Formation of norisoprenoid flavor compounds in carrot (Daucus carota L.) roots: characterization of a cyclic-specific carotenoid cleavage dioxygenase 1 gene.

    PubMed

    Yahyaa, Mosaab; Bar, Einat; Dubey, Neeraj Kumar; Meir, Ayala; Davidovich-Rikanati, Rachel; Hirschberg, Joseph; Aly, Radi; Tholl, Dorothea; Simon, Philipp W; Tadmor, Yaakov; Lewinsohn, Efraim; Ibdah, Mwafaq

    2013-12-18

    Carotenoids are isoprenoid pigments that upon oxidative cleavage lead to the production of norisoprenoids that have profound effect on flavor and aromas of agricultural products. The biosynthetic pathway to norisoprenoids in carrots (Daucus carota L.) is still largely unknown. We found the volatile norisoprenoids farnesylacetone, α-ionone, and β-ionone accumulated in Nairobi, Rothild, and Purple Haze cultivars but not in Yellowstone and Creme de Lite in a pattern reflecting their carotenoid content. A cDNA encoding a protein with carotenoid cleavage dioxygenase activity, DcCCD1, was identified in carrot and was overexpressed in Escherichia coli strains previously engineered to produce different carotenoids. The recombinant DcCCD1 enzyme cleaves cyclic carotenes to generate α- and β-ionone. No cleavage products were found when DcCCD1 was co-expressed in E. coli strains accumulating non-cyclic carotenoids, such as phytoene or lycopene. Our results suggest a role for DcCCD1 in carrot flavor biosynthesis.

  15. Genetic structure and domestication of carrot (Daucus carota subsp. sativus)(Apiaceae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We investigated domestication and genetic structure in wild and open pollinated cultivated carrots (Daucus carota L.) with 3481 SNPs developed from carrot transcriptome sequences. Phylogenetic analysis revealed a clear genetic separation between wild and cultivated carrot accessions. Among the wild ...

  16. Genotyping-by-sequencing provides the discriminating power to investigate the subspecies of Daucus carota (Apiaceae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Premise of study: Premise of study: The taxonomic classification of the subspecies of Daucus carota is unresolved. Intercrosses among traditionally recognized subspecies has been well-documented, as have intercrosses with other Daucus species containing 2n = 18 chromosomes (D. sahariensis and D. syr...

  17. Genotyping-by-sequencing provides insights into the classification of the subspecies of Daucus carota

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Premise of study: Premise of study: The taxonomic classification of the subspecies of Daucus carota is unresolved. Intercrosses among traditionally recognized subspecies has been well-documented, as have intercrosses with other Daucus species containing 2n = 18 chromosomes (D. sahariensis and D. syr...

  18. Reassessment of practical subspecies identifications of the USDA Daucus carota L. germplasm collection: Morphological data

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The genus Daucus includes about 20 species. The most widespread and economically important species, Daucus carota L., occurs on almost every continent. Cultivated carrot, subsp. sativus (Hoffm.) Schubl. & G. Martens, has been selected from wild populations that are extremely diverse, especially in t...

  19. New Claims for Wild Carrot (Daucus carota subsp. carota) Essential Oil

    PubMed Central

    Alves-Silva, Jorge M.; Zuzarte, Mónica; Gonçalves, Maria José; Cavaleiro, Carlos; Cruz, Maria Teresa; Cardoso, Susana M.

    2016-01-01

    The essential oil of Daucus carota subsp. carota from Portugal, with high amounts of geranyl acetate (29.0%), α-pinene (27.2%), and 11αH-himachal-4-en-1β-ol (9.2%), was assessed for its biological potential. The antimicrobial activity was evaluated against several Gram-positive and Gram-negative bacteria, yeasts, dermatophytes, and Aspergillus strains. The minimal inhibitory concentration (MIC) and minimal lethal concentration (MLC) were evaluated showing a significant activity towards Gram-positive bacteria (MIC = 0.32–0.64 μL/mL), Cryptococcus neoformans (0.16 μL/mL), and dermatophytes (0.32–0.64 μL/mL). The inhibition of the germ tube formation and the effect of the oil on Candida albicans biofilms were also unveiled. The oil inhibited more than 50% of filamentation at concentrations as low as 0.04 μL/mL (MIC/128) and decreased both biofilm mass and cell viability. The antioxidant capacity of the oil, as assessed by two in chemico methods, was not relevant. Still, it seems to exhibit some anti-inflammatory potential by decreasing nitric oxide production around 20% in LPS-stimulated macrophages, without decreasing macrophages viability. Moreover, the oils safety profile was assessed on keratinocytes, alveolar epithelial cells, macrophages, and hepatocytes. Overall, the oil demonstrated a safety profile at concentrations below 0.64 μL/mL. The present work highlights the bioactive potential of D. carota subsp. carota suggesting its industrial exploitation. PMID:26981143

  20. Investigating the performance of in situ quantitative nuclear magnetic resonance analysis and applying the method to determine the distribution of saccharides in various parts of carrot roots (Daucus carota L.).

    PubMed

    Bauchard, Elsa; This, Hervé

    2015-01-01

    In order to explore the performance of the analytical method called in situ quantitative nuclear magnetic resonance spectroscopy - is q NMR - the distribution of glucose, fructose and sucrose in various parts of a carrot root (Daucus carota L.) - primary xylem, secondary xylem, phloem, cortex; top part and lower part - was determined. The influence on the quality of spectra of drying samples before analysis was studied, as well as the influence of the length of strips of tissue used in analysis. Finally samples as small as 240 mm(3) could be studied directly, with minimum prior treatment (only drying), along with deuterated water for locking and a sealed capillary tube containing a solution of 0.5% of the sodium salt of (trimethylsilyl)propionic-2,2,3,3-d4 acid, used both as an internal reference and for quantification. With optimized parameters, the coefficients of variation for measurements were observed to have an average value of 0.038, with a standard deviation of 0.047.

  1. Levels of Lycopene β-Cyclase 1 Modulate Carotenoid Gene Expression and Accumulation in Daucus carota

    PubMed Central

    Moreno, Juan Camilo; Pizarro, Lorena; Fuentes, Paulina; Handford, Michael; Cifuentes, Victor; Stange, Claudia

    2013-01-01

    Plant carotenoids are synthesized and accumulated in plastids through a highly regulated pathway. Lycopene β-cyclase (LCYB) is a key enzyme involved directly in the synthesis of α-carotene and β-carotene through the cyclization of lycopene. Carotenoids are produced in both carrot (Daucus carota) leaves and reserve roots, and high amounts of α-carotene and β-carotene accumulate in the latter. In some plant models, the presence of different isoforms of carotenogenic genes is associated with an organ-specific function. D. carota harbors two Lcyb genes, of which DcLcyb1 is expressed in leaves and storage roots during carrot development, correlating with an increase in carotenoid levels. In this work, we show that DcLCYB1 is localized in the plastid and that it is a functional enzyme, as demonstrated by heterologous complementation in Escherichia coli and over expression and post transcriptional gene silencing in carrot. Transgenic plants with higher or reduced levels of DcLcyb1 had incremented or reduced levels of chlorophyll, total carotenoids and β-carotene in leaves and in the storage roots, respectively. In addition, changes in the expression of DcLcyb1 are accompanied by a modulation in the expression of key endogenous carotenogenic genes. Our results indicate that DcLcyb1 does not possess an organ specific function and modulate carotenoid gene expression and accumulation in carrot leaves and storage roots. PMID:23555569

  2. Levels of lycopene β-cyclase 1 modulate carotenoid gene expression and accumulation in Daucus carota.

    PubMed

    Moreno, Juan Camilo; Pizarro, Lorena; Fuentes, Paulina; Handford, Michael; Cifuentes, Victor; Stange, Claudia

    2013-01-01

    Plant carotenoids are synthesized and accumulated in plastids through a highly regulated pathway. Lycopene β-cyclase (LCYB) is a key enzyme involved directly in the synthesis of α-carotene and β-carotene through the cyclization of lycopene. Carotenoids are produced in both carrot (Daucus carota) leaves and reserve roots, and high amounts of α-carotene and β-carotene accumulate in the latter. In some plant models, the presence of different isoforms of carotenogenic genes is associated with an organ-specific function. D. carota harbors two Lcyb genes, of which DcLcyb1 is expressed in leaves and storage roots during carrot development, correlating with an increase in carotenoid levels. In this work, we show that DcLCYB1 is localized in the plastid and that it is a functional enzyme, as demonstrated by heterologous complementation in Escherichia coli and over expression and post transcriptional gene silencing in carrot. Transgenic plants with higher or reduced levels of DcLcyb1 had incremented or reduced levels of chlorophyll, total carotenoids and β-carotene in leaves and in the storage roots, respectively. In addition, changes in the expression of DcLcyb1 are accompanied by a modulation in the expression of key endogenous carotenogenic genes. Our results indicate that DcLcyb1 does not possess an organ specific function and modulate carotenoid gene expression and accumulation in carrot leaves and storage roots.

  3. Alternative oxidase involvement in Daucus carota somatic embryogenesis.

    PubMed

    Frederico, António Miguel; Campos, Maria Doroteia; Cardoso, Hélia Guerra; Imani, Jafargholi; Arnholdt-Schmitt, Birgit

    2009-12-01

    Plant alternative oxidase (AOX) is a mitochondrial inner membrane enzyme involved in alternative respiration. The critical importance of the enzyme during acclimation upon stress of plant cells is not fully understood and is still an issue of intensive research and discussion. Recently, a role of AOX was suggested for the ability of plant cells to change easily its fate upon stress. In order to get new insights about AOX involvement in cell reprogramming, quantitative real-time polymerase chain reaction (PCR) and inhibitor studies were performed during cell redifferentiation and developmental stages of Daucus carota L. somatic embryogenesis. Transcript level analysis shows that D. carota AOX genes (DcAOX1a and DcAOX2a) are differentially expressed during somatic embryogenesis. DcAOX1a shows lower expression levels, being mainly down-regulated, whereas DcAOX2a presented a large up-regulation during initiation of the realization phase of somatic embryogenesis. However, when globular embryos start to develop, both genes are down-regulated, being this state transient for DcAOX2a. In addition, parallel studies were performed using salicylhydroxamic acid (SHAM) in order to inhibit AOX activity during the realization phase of somatic embryogenesis. Embryogenic cells growing in the presence of the inhibitor were unable to develop embryogenic structures and its growth rate was diminished. This effect was reversible and concentration dependent. The results obtained contribute to the hypothesis that AOX activity supports metabolic reorganization as an essential part of cell reprogramming and, thus, enables restructuring and de novo cell differentiation.

  4. Polyamine Metabolism in Embryogenic Cells of Daucus carota

    PubMed Central

    Montague, Michael J.; Armstrong, Toni A.; Jaworski, Ernest G.

    1979-01-01

    Embryogenic cultured cells of Daucus carota have been shown to synthesize putrescine from exogenously supplied [14C]arginine at twice the rate of control nonembryogenic cells. In the present paper, the activity of arginine decarboxylase (arginine carboxy-lyase, EC 4.1.1.19), an important enzyme in the synthesis of putrescine, was assayed and also found to be elevated by as much as 2-fold in embryogenic cells. This difference between embryogenic and nonembryogenic cells was observed as early as 6 hours after the induction of embryogenesis and appeared not to result from the presence of a diffusible inhibitor or activator. It seemed to be dependent upon concomitant RNA and protein synthesis, as judged using 6-methyl-purine and cycloheximide. After cycloheximide addition to the culture medium, arginine decarboxylase activity declined with a half-time of about 30 minutes in both embryogenic and nonembryogenic cells. It is suggested that elevated arginine decarboxylase activity is involved in the mechanism leading to elevated putrescine levels in these cells and hence may play a role in the embryogenic process. PMID:16660725

  5. Genetic structure and domestication of carrot (Daucus carota subsp. sativus L.) (Apiaceae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Analyses of genetic structure and phylogenetic relationships illuminate the origin and domestication of modern crops. Despite being an important world-wide vegetable, the genetic structure and domestication of carrot (Daucus carota L.) is poorly understood. We provide the first such study using a la...

  6. The next generation of carotenoid studies in carrot (Daucus carota L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Orange carrot (Daucus carota L.) is one of the richest sources of naturally occurring ß-carotene while red and yellow carrot varieties contain large quantities of lycopene and lutein. The human body utilizes carotenoids, particularly ß-carotene (provitamin A) as a precursor for the production of ret...

  7. Essential-oil composition of Daucus carota ssp. major (Pastinocello Carrot) and nine different commercial varieties of Daucus carota ssp. sativus fruits.

    PubMed

    Flamini, Guido; Cosimi, Elena; Cioni, Pier Luigi; Molfetta, Ilaria; Braca, Alessandra

    2014-07-01

    The chemical composition of the essential oils obtained by hydrodistillation from the pastinocello carrot, Daucus carota ssp. major (Vis.) Arcang. (flowers and achenes), and from nine different commercial varieties of D. carota L. ssp. sativus (achenes) was investigated by GC/MS analyses. Selective breeding over centuries of a naturally occurring subspecies of the wild carrot, D. carota L. ssp. sativus, has produced the common garden vegetable with reduced bitterness, increased sweetness, and minimized woody core. On the other hand, the cultivation of the pastinocello carrot has been abandoned, even if, recently, there has been renewed interest in the development of this species, which risks genetic erosion. The cultivated carrot (D. carota ssp. sativus) and the pastinocello carrot (D. carota ssp. major) were classified as different subspecies of the same species. This close relationship between the two subspecies urged us to compare the chemical composition of their essential oils, to evaluate the differences. The main essential-oil constituents isolated from the pastinocello fruits were geranyl acetate (34.2%), α-pinene (12.9%), geraniol (6.9%), myrcene (4.7%), epi-α-bisabolol (4.5%), sabinene (3.3%), and limonene (3.0%). The fruit essential oils of the nine commercial varieties of D. carota ssp. sativus were very different from that of pastinocello, as also confirmed by multivariate statistical analyses.

  8. [Influence of arbuscular mycorrhizal inoculation on growth and phoxim residue of carrot (Daucus carota L.)].

    PubMed

    Wang, Fa-Yuan; Chen, Xin; Sun, Xian-Ming; Shi, Zhao-Yong

    2010-12-01

    A pot culture experiment was carried out to study the influence of arbuscular mycorrhizal (AM) fungi on the growth and phoxim residue of carrot (Daucus carota L). Four levels of phoxim (0, 200, 400, 800 mg x L(-1)) and two AM fungal inocula, Glomus intraradices BEG 141(141), Glomus mosseae BEG 167 (167),and one nonmycorrhizal inoculum (CK), were applied to the sterilized soil. The plants were harvested after 5 months of growth and phoxim was irrigated into the root zone 14 d before plant harvest. Although decreasing with the increase of phoxim dosage, root infection rates of all the mycorrhizal plants were higher than 70%. Phoxim showed no significant dose effect on shoot wet weights and root yields, which were all increased by AM inoculation at four phoxim dosages. Phoxim residues in shoots and roots increased with the increase of phoxim dosage, but decreased by AM inoculation. In general, Glomus intraradices BEG 141 showed more pronounced effects on the growth and phoxim residue of carrot than Glomus mosseae BEG 167 did. Our results show a promising potential of AM fungi in carrot production and controlling pesticide residues.

  9. Eating Quality of Carrots (Daucus carota L.) Grown in One Conventional and Three Organic Cropping Systems over Three Years.

    PubMed

    Bach, Vibe; Kidmose, Ulla; Kristensen, Hanne L; Edelenbos, Merete

    2015-11-11

    The eating quality of carrots (Daucus carota L.) was investigated to evaluate the impact of cropping systems (one conventional and three organic systems) and growing years (2007, 2008, and 2009) on root size, chemical composition, and sensory quality. The content of dry matter, sugars, polyacetylenes, and terpenes as well as the sensory quality and root size were related to the climate during the three growing years. A higher global radiation and a higher temperature sum in 2009 as compared to 2007 and 2008 resulted in larger roots, higher contents of dry matter, sucrose, total sugars, and total polyacetylenes, and lower contents of terpenes, fructose, and glucose. No differences were found between conventional and organic carrots with regard to the investigated parameters. This result shows that organically grown carrots have the same eating quality as conventionally grown carrots, while being produced in a more sustainable way.

  10. Molecular phylogeny of Daucus (Apiaceae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We studied the phylogeny of 22 accessions of Daucus: D. broteri, D. capillifolius, D. carota, D. carota subsp. carota, D. carota subsp. commutatus, D. carota subsp. commutatus, D. carota subsp. drepanensis, D. carota subsp. gadecaei, D. carota subsp. gummifer, D. carota subsp. halophilius, D. carota...

  11. Carrot (Daucus carota L.): Nephroprotective against gentamicin-induced nephrotoxicity in rats

    PubMed Central

    Sodimbaku, Vamsi; Pujari, Latha; Mullangi, Raviteja; Marri, Saisudheer

    2016-01-01

    Objectives: Daucus carota L.(DC) commonly known as carrot, folkorically used as ethnomedicine to treat nephrosis and other urinary disorders. Hence, the present study was aimed to investigate the nephroprotective effects of ethanolic root extract of DC against gentamicin-induced nephrotoxicity in Albino Wistar rats. Methods: Nephrotoxicity in rats was induced by intraperitoneal administration of gentamicin (100 mg/kg/day) for 8 days. Rats of either sex were divided into four groups (n = 6). Group 1 served as control that received normal saline (i.p.) whereas Group 2 (GM) was treated with gentamicin which served as gentamicin-intoxicated group. Group 3–4 (DC200, DC 400) were pretreated with DC at doses of 200 mg/kg and 400 mg/kg (p.o.), respectively, 1 h before the gentamicin intoxication. Following treatment, the nephroprotective effects of DC were evaluated by using serum levels of urea, blood urea nitrogen (BUN), uric acid, and creatinine levels; change in body weight and wet kidney weight along with the histological observations among the experimental groups. Results: Gentamicin intoxication induced elevated serum urea, BUN, uric acid, and creatinine levels which was found to be significantly (P < 0.01) decreased in a dose-dependent manner in groups received DC which was also evidenced by the histological observations. Conclusion: DC showed a significant nephroprotective effect in a dose-dependent manner by ameliorating the gentamicin-induced nephrotoxicity and thus authenticates its ethnomedicinal use. PMID:27127313

  12. Freeze Preservation of Somatic Embryos and Clonal Plantlets of Carrot (Daucus carota L) 1

    PubMed Central

    Withers, Lyndsey A.

    1979-01-01

    Cell suspensions of carrot (Daucus carota L.) can be cryopreserved by slow freezing (about 2 C per minute) in medium containing dimethylsulfoxide as a cryoprotectant. After storage in liquid nitrogen and thawing they demonstrate a high viability and are able to resume growth. Such a method entirely fails to preserve clonal plantlets; somatic embryos cease organized development at the time of freezing and recover growth only by secondary embryogenesis. Modification of the procedure, involving the removal of superficial moisture from cryoprotectant-treated embryos and plantlets and enclosing them in a foil envelope before freezing, greatly improves their survival potential. The use of dimethylsulfoxide at levels between 2.5 and 20% (v/v) and freezing at rates between 1 and 5 C per minute yielded viable preparations under appropriate thawing conditions. In general, treatments which increased tissue dehydration before or during freezing were most successful when followed by relatively slow thawing. Conversely where dehydration to a lesser degree was achieved, more rapid thawing was advantageous. Postthawing washing or inoculation into liquid media was inhibitory to recovery. On semisolid regrowth medium, somatic embryos resumed normal development, whereas in plantlets the root and shoot meristem regions gave rise to new growth. In both cases, inclusion of activated charcoal in the medium promoted organized growth. Images PMID:16660748

  13. Influence of cultivar and harvest year on the volatile profiles of leaves and roots of carrots (Daucus carota spp. sativus Hoffm.).

    PubMed

    Ulrich, Detlef; Nothnagel, Thomas; Schulz, Hartwig

    2015-04-08

    The focus of the present work centers on the diversity of volatile patterns of carrots. In total 15 main volatiles were semiquantified in leaves and roots using isolation by headspace solid phase microextraction followed by gas chromatography with FID and MS detection. Significant differences in the main number of compounds were detected between the cultivars as well as the years. Genotype-environment interactions (G × E) are discussed. The most abundant metabolites, β-myrcene (leaves) and terpinolene (roots), differ in the sum of all interactions (cultivar × harvest year) by a factor of 22 and 62, respectively. A statistical test indicates significant metabolic differences between cultivars for nine volatiles in leaves and 10 in roots. In contrast to others the volatiles α-pinene, γ-terpinene, limonene, and myristicine in leaves as well as β-pinene, humulene, and bornyl acetate in roots are relatively stable over years. A correlation analysis shows no strict clustering regarding root color. While the biosynthesis in leaves and roots is independent between these two organs for nine of the 15 volatiles, a significant correlation of the myristicine content between leaves and roots was determined, which suggests the use of this compound as a bitter marker in carrot breeding.

  14. Effects of Chrysosporum (Aphanizomenon) ovalisporum extracts containing cylindrospermopsin on growth, photosynthetic capacity, and mineral content of carrots (Daucus carota).

    PubMed

    Guzmán-Guillén, Remedios; Campos, Alexandre; Machado, Joana; Freitas, Marisa; Azevedo, Joana; Pinto, Edgar; Almeida, Agostinho; Cameán, Ana M; Vasconcelos, Vitor

    2017-01-01

    Natural toxins produced by freshwater cyanobacteria, such as cylindrospermopsin, have been regarded as an emergent environmental threat. Despite the risks for food safety, the impact of these water contaminants in agriculture is not yet fully understood. Carrots (Daucus carota) are root vegetables, extensively consumed worldwide with great importance for human nourishment and economy. It is, therefore, important to evaluate the possible effects of using water contaminated with cyanotoxins on carrot cultivation. The aim of this work was to investigate cylindrospermopsin effects on D. carota grown in soil and irrigated for 30 days, with a Chrysosporum ovalisporum extract containing environmentally relevant concentrations of cylindrospermopsin (10 and 50 μg/L). The parameters evaluated were plant growth, photosynthetic capacity, and nutritional value (mineral content) in roots of carrots, as these are the edible parts of this plant crop. The results show that, exposure to cylindrospermopsin did not have a clear negative effect on growth or photosynthesis of D. carota, even leading to an increase of both parameters. However, alterations in mineral contents were detected after exposure to crude extracts of C. ovalisporum containing cylindrospermopsin. A general decline was observed for most minerals (Ca, Mg, Na, Fe, Mn, Zn, Mo, and P), although an increase was shown in the case of K and Cu, pointing to a possible interference of the cyanobacterial extract in mineral uptake. This study is the first to evaluate the effects of C. ovalisporum extracts on a root vegetable, however, more research is necessary to understand the effects of this toxin in environmentally relevant scenarios.

  15. Inhibitory Activity and Chemical Characterization of Daucus carota subsp. maximus Essential Oils.

    PubMed

    Gaglio, Raimondo; Barbera, Marcella; Aleo, Aurora; Lommatzsch, Ines; Mantia, Tommaso La; Settanni, Luca

    2017-02-07

    The essential oils (EOs) of green seeds from Daucus carota subsp. maximus growing wild in Pantelleria island (Sicily, Italy) were characterised. EOs were extracted by steam distillation, examined for their inhibitory properties against food-borne Gram positive and Gram negative bacteria and analysed for the chemical composition by gas chromatography (GC) and mass spectrometry (MS). Undiluted EOs showed a large inhibition spectrum against Gram positive strains and also vs Acinetobacter spp. and Stenotrophomonas maltophilia. The minimum inhibition concentration (MIC) was in the range 1.25 - 2.50 μl/ml for the most sensitive strains. The chemical analysis indicated that D. carota subsp. maximus EOs included 34 compounds (5 monoterpene hydrocarbons, 6 oxygenated monoterpenes, 14 sesquiterpene hydrocarbons, 4 oxygenated sesquiterpenes, camphorene and 4 other compounds), accounting for 95.48% of the total oil, and that the major chemicals were carotol, β-bisabolene and isoelemicin. This article is protected by copyright. All rights reserved.

  16. Two new eudesmane-type glucopyranosides from the fruits of Daucus carota L.

    PubMed

    Xu, Jin-Ke; Lu, Xiang-Hong; Zhu, Wei; Yang, Bing-Xian; Zhang, Lin; Tian, Jing-Kui

    2015-01-01

    Two new eudesmane-type glucopyranosides have been isolated from the fruits of Daucus carota L. On the basis of their spectroscopic and chemical evidence, the new compounds were elucidated as daucucarotol-10-O-β-D-glucopyranoside (1) and decahydro-7-[(2-O-β-D-glucopyranosyl)-isopropyl]-1β,4aα-dimethyl-(1α,4α,8aβ)-naphthalenetriol (2). Compounds 1 and 2 showed moderate antitumour activity against human ECA-109 and gave IC50 values of 23.22 and 26.76 μM, respectively.

  17. Complete plastid genome sequence of Daucus carota: Implications for biotechnology and phylogeny of angiosperms

    PubMed Central

    Ruhlman, Tracey; Lee, Seung-Bum; Jansen, Robert K; Hostetler, Jessica B; Tallon, Luke J; Town, Christopher D; Daniell, Henry

    2006-01-01

    Background Carrot (Daucus carota) is a major food crop in the US and worldwide. Its capacity for storage and its lifecycle as a biennial make it an attractive species for the introduction of foreign genes, especially for oral delivery of vaccines and other therapeutic proteins. Until recently efforts to express recombinant proteins in carrot have had limited success in terms of protein accumulation in the edible tap roots. Plastid genetic engineering offers the potential to overcome this limitation, as demonstrated by the accumulation of BADH in chromoplasts of carrot taproots to confer exceedingly high levels of salt resistance. The complete plastid genome of carrot provides essential information required for genetic engineering. Additionally, the sequence data add to the rapidly growing database of plastid genomes for assessing phylogenetic relationships among angiosperms. Results The complete carrot plastid genome is 155,911 bp in length, with 115 unique genes and 21 duplicated genes within the IR. There are four ribosomal RNAs, 30 distinct tRNA genes and 18 intron-containing genes. Repeat analysis reveals 12 direct and 2 inverted repeats ≥ 30 bp with a sequence identity ≥ 90%. Phylogenetic analysis of nucleotide sequences for 61 protein-coding genes using both maximum parsimony (MP) and maximum likelihood (ML) were performed for 29 angiosperms. Phylogenies from both methods provide strong support for the monophyly of several major angiosperm clades, including monocots, eudicots, rosids, asterids, eurosids II, euasterids I, and euasterids II. Conclusion The carrot plastid genome contains a number of dispersed direct and inverted repeats scattered throughout coding and non-coding regions. This is the first sequenced plastid genome of the family Apiaceae and only the second published genome sequence of the species-rich euasterid II clade. Both MP and ML trees provide very strong support (100% bootstrap) for the sister relationship of Daucus with Panax in the

  18. Mitochondrial gene diversity associated with the atp9 stop codon in natural populations of wild carrot (Daucus carota ssp. carota).

    PubMed

    Mandel, Jennifer R; McAssey, Edward V; Roland, Katherine M; McCauley, David E

    2012-01-01

    Mitochondrial genomes extracted from the wild populations of Daucus carota have been used as a genetic resource by breeders of cultivated carrot, yet little is known concerning the extent of their diversity in nature. Of special interest is an SNP in the putative stop codon of the mitochondrial gene atp9 that has been associated previously with male-sterile and male-fertile phenotypic variants. In this study, either the sequence or PCR/RFLP genotypes were obtained from the mitochondrial genes atp1, atp9, and cox1 found in D. carota individuals collected from 24 populations in the eastern United States. More than half of the 128 individuals surveyed had a CAA or AAA, rather than TAA, genotype at the position usually thought to function as an atp9 stop codon in this species. We also found no evidence for mitochondrial RNA editing (Cytosine to Uridine) of the CAA stop codon in either floral or leaf tissue. Evidence for intragenic recombination, as opposed to the more common intergenic recombination in plant mitochondrial genomes, in our data set is presented. Indel and SNP variants elsewhere in atp9, and in the other 2 genes surveyed, were nonrandomly associated with the 3 atp9 stop codon variants, though further analysis suggested that multilocus genotypic diversity had been enhanced by recombination. Overall the mitochondrial genetic diversity was only modestly structured among populations with an F(ST) of 0.34.

  19. Development of a high-throughput SNP resource to advance genomic, genetic and breeding research in carrot (Daucus carota L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The rapid advancement in high-throughput SNP genotyping technologies along with next generation sequencing (NGS) platforms has decreased the cost, improved the quality of large-scale genome surveys, and allowed specialty crops with limited genomic resources such as carrot (Daucus carota) to access t...

  20. Enantioselective Reduction by Crude Plant Parts: Reduction of Benzofuran-2-yl Methyl Ketone with Carrot ("Daucus carota") Bits

    ERIC Educational Resources Information Center

    Ravia, Silvana; Gamenara, Daniela; Schapiro, Valeria; Bellomo, Ana; Adum, Jorge; Seoane, Gustavo; Gonzalez, David

    2006-01-01

    The use of biocatalysis and biotransformations are important tools in green chemistry. The enantioselective reduction of a ketone by crude plant parts, using carrot ("Daucus carota") as the reducing agent is presented. The experiment introduces an example of a green chemistry procedure that can be tailored to fit in a regular laboratory session.…

  1. Structure determination of bisacetylenic oxylipins in carrots (Daucus carota L.) and enantioselective synthesis of falcarindiol.

    PubMed

    Schmiech, Ludger; Alayrac, Carole; Witulski, Bernhard; Hofmann, Thomas

    2009-11-25

    Although bisacetylenic oxylipins have been demonstrated to exhibit diverse biological activities, the chemical structures of many representatives of this class of phytochemicals still remain elusive. As carrots play an important role in our daily diet and are known as a source of bisacetylenes, an extract made from Daucus carota L. was screened for bisacetylenic oxylipins, and, after isolation, their structures were determined by means of LC-MS and 1D/2D NMR spectroscopy. Besides the previously reported falcarinol, falcarindiol, and falcarindiol 3-acetate, nine additional bisacetylenes were identified, among which six derivatives are reported for the first time in literature and three compounds were previously not identified in carrots. To determine the absolute stereochemistry of falcarindiol in carrots, the (3R,8R)-, (3R,8S)-, (3S,8R)-, and (3S,8S)-stereoisomers of falcarindiol were synthesized according to a novel 10-step total synthesis involving a Cadiot-Chodkiewicz cross-coupling reaction of (S)- and (R)-trimethylsilanyl-4-dodecen-1-yn-3-ol and (R)- and (S)-5-bromo-1-penten-4-yn-3-ol, respectively. Comparative chiral HPLC analysis of the synthetic stereoisomers with the isolated phytochemical led to the unequivocal assignment of the (Z)-(3R,8S)-configuration for falcarindiol in carrot extracts from Daucus carota L.

  2. [Spontaneous spectinomycin resistance mutations of the chloroplast rrn16 gene in Daucus carota callus lines].

    PubMed

    Filipenko, E A; Sidorchuk, Iu V; Deĭneko, E V

    2011-01-01

    Bioballistic transformation of carrot Daucus carota L. callus cultures with a plasmid containing the aadA (aminoglycoside 3'-adenyltransferase) gene and subsequent selection oftransformants on a selective medium containing spectinomycin (100-500 mg/l) yielded ten callus lines resistant to this antibiotic. PCR analysis did not detect exogenous DNA in the genomes of spectinomycin-resistant calluses. Resistance proved to be due to spontaneous mutations that occurred in two different regions of the chloroplast rrn16 gene, which codes for the 16S rRNA. Six lines displayed the G > T or G > C transverions in position 1012 of the rrn16 gene, and three lines had the A > G transition in position 1138 of the gene. Chloroplast mutations arising during passages of callus cultures in the presence of spectinomycin were described in D. carota for the first time. The cause of spectinomycin resistance was not identified in one line. The mutations observed in the D. carota plastid genome occurred in the region that is involved in the formation of a double-stranded region at the 3' end of the 16S rRNA and coincided in positions with the nucleotide substitutions found in spectinomycin-resistant plants of tobacco Nicotiana tabacum L. and bladderpod Lesquerella fendleri L.

  3. In vivo antioxidant and hepatoprotective activity of methanolic extracts of Daucus carota seeds in experimental animals

    PubMed Central

    Singh, Kamlesh; Singh, Nisha; Chandy, Anish; Manigauha, Ashish

    2012-01-01

    Objective To assess the In vivo antioxidFant and hepatoprotective activity of methanolic extract of Daucus carota (D. carota) seeds in experimental animals. Methods Methanolic extracts of D. carota seeds is used for hepatoprotection assessment. Oxidative stress were induced in rats by thioacetamide 100 mg/kg s.c, in four groups of rats (two test, standard and toxic control). Two test groups received D. carota seeds extract (DCSE) at doses of 200 mg/kg and 400 mg/kg. Standard group received silymarin (25 mg/kg) and toxic control received only thioacetamide. Control group received only vehicle. On the 8th day animals were sacrificed and liver enzyme like serum glutamic pyruvic transaminase (SGPT), serum glutamic-oxaloacetic transaminase (SGOT) and alkaline phosphatase (ALP) were estimated in blood serum and antioxidant enzyme like superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GRD), glutathione peroxidase (GPX), glutathione-S-transferase (GST) and lipid peroxidation (LPO) were estimated in liver homogenate. Results A significant decrease in SGPT, SGOT and ALP levels was observed in all drug treated groups as compared to thioacetamide group (P < 0.001) and in case of antioxidant enzyme a significant (P < 0.001) increase in SOD, CAT, GRD, GPX and GST was observed in all drug treated groups as compared with thioacetamide group. But in case of LPO a significant (P < 0.001) reduction was observed as compared to toxic control group. Conclusions DCSE has contributed to the reduction of oxidative stress and the protection of liver in experimental rats. PMID:23569935

  4. Quantifying biochemical quality parameters in carrots (Daucus carota L.) - FT-Raman spectroscopy as efficient tool for rapid metabolite profiling.

    PubMed

    Krähmer, Andrea; Böttcher, Christoph; Rode, Andrea; Nothnagel, Thomas; Schulz, Hartwig

    2016-12-01

    Application of FT-Raman spectroscopy for simultaneous quantification of carotenoids, carbohydrates, polyacetylenes and phenylpropanoids with high bioactive potential was investigated in storage roots of Daucus carota. Within single FT-Raman experiment carbohydrates, carotenoids, and polyacetylenes could be reliably quantified with high coefficients of determination of R(2)>0.91. The most abundant individual representatives of each compound class could be quantified with comparably high quality resulting in R(2)=0.97 and 0.96 for α-carotene and β-carotene, in R(2)=0.90 for falcarindiol (FaDOH), R(2)=0.99, 0.98 and 0.96 for fructose, glucose and sucrose. In contrast, application of FT-Raman spectroscopy for quantification of two laserine-type phenylpropanoids was investigated but failed due to low concentration and Raman response. Furthermore, evaluation of metabolic profiles by principle component analysis (PCA) revealed metabolic variety of carrot root composition depending on root color and botanical relationship.

  5. Bioactive C₁₇-Polyacetylenes in Carrots (Daucus carota L.): Current Knowledge and Future Perspectives.

    PubMed

    Dawid, Corinna; Dunemann, Frank; Schwab, Wilfried; Nothnagel, Thomas; Hofmann, Thomas

    2015-10-28

    C17-polyacetylenes (PAs) are a prominent group of oxylipins and are primarily produced by plants of the families Apiaceae, Araliaceae, and Asteraceae, respectively. Recent studies on the biological activity of polyacetylenes have indicated their potential to improve human health due to anticancer, antifungal, antibacterial, anti-inflammatory, and serotogenic effects. These findings suggest targeting vegetables with elevated levels of bisacetylenic oxylipins, such as falcarinol, by breeding studies. Due to the abundant availability, high diversity of cultivars, worldwide experience, and high agricultural yields, in particular, carrot (Daucus carota L.) genotypes are a very promising target vegetable. This paper provides a review on falcarinol-type C17-polyacetylenes in carrots and a perspective on their potential as a future contributor to improving human health and well-being.

  6. Myo-Inositol trisphosphate mobilizes calcium from fusogenic carrot (Daucus carota L. ) protoplasts

    SciTech Connect

    Rincon, M.; Boss, W.F.

    1987-02-01

    To determine whether or not inositol trisphosphate (IP/sub 3/) mobilizes calcium in higher plant cells; they investigated the effect of IP/sub 3/ on Ca/sup 2 +/ fluxes in fusogenic carrot (Daucus carota L.) protoplasts. The protoplasts were incubated in /sup 45/Ca/sup 2 +/-containing medium and the /sup 45/Ca/sup 2 +/ associated with the protoplasts was monitored with time. Addition of IP/sub 3/ (20 micromolar) caused a 17% net loss of the accumulated /sup 45/Ca/sup 2 +/ within 4 minutes. There was a reuptake of /sup 45/Ca/sup 2 +/ and the protoplasts recovered to their initial value by 10 minutes. Phytic acid (IP/sub 6/), also stimulated /sup 45/Ca/sup 2 +/ efflux from the protoplasts. Both the IP/sub 3/- and the IP/sub 6/-induced /sup 45/Ca/sup 2 +/ efflux were inhibited by the calmodulin antagonist, trifluoperazine.

  7. Morphological markers for the detection of introgression from cultivated into wild carrot (Daucus carota L.) reveal dominant domestication traits.

    PubMed

    Grebenstein, C; Kos, S P; de Jong, T J; Tamis, W L M; de Snoo, G R

    2013-05-01

    Hybridisation and subsequent introgression have recently received much attention in the context of genetically modified crops. But crop-wild hybrid detection in the field can be difficult, as most domestication traits seem to be recessive, and the hybrid phenotype may also depend on the direction of the cross or environmental factors. Our aim was to develop a reliable set of morphological markers that differ between two wild and 13 cultivated carrots (Daucus carota L.) and to evaluate their inheritance in hybrid lines. We then examined these morphological markers in four F1 hybrids obtained by fertilising plants from the two wild accessions with pollen from two common carrot cultivars. Of the 16 traits that differed between the two carrot subspecies, three took intermediate values in the hybrids, eight resembled the cultivar parent (dominant domestication traits), two resembled the wild parent (domestication traits recessive), and three were not significant or growth condition-dependent. Root:shoot ratio was seven times higher for cultivars than for wild plants, while still attaining equivalent total dry weight, which shows that dry matter production by the shoot is much higher in cultivars than in wild plants. High root:shoot ratios were also present in the hybrids. While we found no maternal effects, the type of cultivar used for pollination had an impact on hybrid characteristics. The morphological markers developed here provide insights into the mode of inheritance of ecologically relevant traits and can be useful for pre-screening wild populations for hybrid detection prior to genetic analysis.

  8. Survival and flowering of hybrids between cultivated and wild carrots (Daucus carota) in Danish grasslands.

    PubMed

    Hauser, Thure P; Shim, Sang In

    2007-01-01

    Many crop species are able to hybridize with related weedy or wild relatives, which could lead to transfer of cultivar genes, and among them transgenes, into wild populations. It is not clear, however, whether the hybrids and their descendants are able to survive and reproduce in natural habitats, as inherited cultivar traits may be maladaptive under such conditions. To test this, we produced hybrid (F(1)) seeds by controlled crosses between wild [see text for formula] and cultivated carrots (Daucus carota ssp. carota and ssp. sativa, respectively) and sowed them into three Danish grasslands of different age, in parallel with seeds of wild carrots. Replicate plots were sown in fall and spring. Survival and flowering of the emerging plants were monitored for the following three years. Both hybrid and wild carrots survived and flowered in highest frequency at a recently disturbed site, and much less at two older sites. Hybrids emerged in higher proportions than wild carrots in the first year and survived to similar or slightly lower frequencies at the end of the experiment. Hybrids flowered as frequently or slightly less frequently than wild plants, and developed fewer and smaller umbels. Despite a somewhat lower reproductive potential compared to wild carrots, first generation hybrids between cultivated and wild carrots are likely to survive and produce offspring in natural grasslands in Denmark. This, together with other studies, suggests that cultivar genes may transfer relatively easily into wild carrot populations.

  9. Expression of rabies virus G protein in carrots (Daucus carota).

    PubMed

    Rojas-Anaya, Edith; Loza-Rubio, Elizabeth; Olivera-Flores, Maria Teresa; Gomez-Lim, Miguel

    2009-12-01

    Antigens derived from various pathogens can readily be synthesized at high levels in plants in their authentic forms. Such antigens administered orally can induce an immune response and, in some cases, result in protection against a subsequent challenge. We here report the expression of rabies virus G protein into carrots. The G gene was subcloned into the pUCpSSrabG vector and then used to transform carrot embryogenic cells by particle bombardment. The carrot cells were selected in liquid medium, a method previously unreported. The presence of the transgene was verified by PCR, and by RT-PCR. By western blot, G protein transgene was identified in 93.3% of adult carrot roots. The G protein was quantified by densitometric analysis (range 0.4-1.2%). The expressed protein was antigenic in mice. This confirms that the carrot is an adequate system for antigen expression.

  10. Profiling of the Terpene Metabolome in Carrot Fruits of Wild (Daucus carota L. ssp. carota) Accessions and Characterization of a Geraniol Synthase.

    PubMed

    Yahyaa, Mosaab; Ibdah, Muhammad; Marzouk, Sally; Ibdah, Mwafaq

    2016-10-06

    Fruits from wild carrot (Daucus carota L. ssp. carota) have been used for medicinal purposes since ancient times. The oil of its seeds, with their abundant monoterpenes and sesquiterpenes, has drawn attention in recent years because of its potential pharmaceutical application. A combined chemical, biochemical, and molecular study was conducted to evaluate the differential accumulation of terpene volatiles in carrot fruits of wild accessions. This work reports a similarity-based cloning strategy identification and functional characterization of one carrot monoterpene terpene synthase, WtDcTPS1. Recombinant WtDcTPS1 protein produces mainly geraniol, the predominant monoterpene in carrot seeds of wild accession 23727. The results suggest a role for the WtDcTPS1 gene in the biosynthesis of carrot fruit aroma and flavor compounds.

  11. Fluorescent in situ hybridization with arbitrarily amplified DNA fragments differentiates carrot (Daucus carota L.) chromosomes.

    PubMed

    Nowicka, Anna; Grzebelus, Ewa; Grzebelus, Dariusz

    2012-03-01

    Carrot (Daucus carota L.) chromosomes are small and poorly differentiated in size and morphology. Here we demonstrate that fluorescent in situ hybridization (FISH) signals derived from arbitrary PCR probes can be used for chromosome identification in carrot. To prepare probes, we searched for nonpolymorphic products abundantly amplified with arbitrary decamer primers in a group of accessions representing carrot genetic diversity. As a result, 13 fragments ranging in size from 517 to 1758 bp were selected, sequenced, and used as probes for fluorescent in situ hybridization. Four of these probes produced clear and reproducible hybridization signals. The sequences showed similarity to a number of carrot BAC-end sequences, indicating their repetitive character. Three of them were similar to internal portions of gypsy and copia LTR retrotransposons previously identified in plants. Hybridization signals for the four probes were observed as dotted tracks on chromosomes, differing in distribution and intensity. Generally, they were present in pericentromeric and (or) interstitial localizations on chromosome arms. The use of the four probes allowed discrimination of chromosome pairs and construction of more detailed karyotypes and idiograms of carrot.

  12. Abscisic acid regulation of DC8, a carrot embryonic gene. [Daucus carota

    SciTech Connect

    Hatzopoulos, P.; Fong, F.; Sung, Z.R. Texas A M Univ., College Station )

    1990-10-01

    DC8 encodes a hydrophylic 66 kilodalton protein located in the cytoplasm and cell walls of carrot (Daucus carota) embryo and endosperm. During somatic embryogenesis, the levels of DC8 mRNA and protein begin to increase 5 days after removal of auxin. To study the role of abscisic acid (ABA) in the regulation of DC8 gene, fluridone, 1-methyl-3-phenyl,-5(3-trifluoro-methyl-phenyl)-4(1H)-pyridinone, was used to inhibit the endogenous ABA content of the embryos. Fluridone, 50 micrograms per milliliter, effectively inhibits the accumulation of ABA in globular-tage embryos. Western and Northern analysis show that when fluridone is added to the culture medium DC8 protein and mRNA decrease to very low levels. ABA added to fluridone supplemented culture media restores the DC8 protein and mRNA to control levels. Globular-stage embryos contain 0.9 to 1.4 {times} 10{sup {minus}7} molar ABA while 10{sup {minus}6} molar exogenously supplied ABA is the optimal concentration for restoration of DC8 protein accumulation in fluridone-treated embryos. The mRNA level is increased after 15 minutes of ABA addition and reaches maximal levels by 60 minutes. Evidence is presented that, unlike other ABA-regulated genes, DC8 is not induced in nonembryonic tissues via desiccation nor addition of ABA.

  13. Calcium transport in vesicles from carrot cells: Stimulation by calmodulin and phosphatidylserine. [Daucus carota cv. Danvers

    SciTech Connect

    Wenling Hsieh; Sze, Heven )

    1991-05-01

    The transport properties of Ca-pumping ATPases from carrot (Daucus carota cv. Danvers) tissue culture cells were studied. ATP dependent Ca transport in vesicles that comigrated with an ER marker, was stimulated 3-4 fold by calmodulin. Cyclopiazonic acid (a specific inhibitor of the sarcoplasmic/endoplasmic reticulum Ca-ATPase) partially inhibited oxalate-stimulated Ca transport activity; however, it had little or not effect on calmodulin-stimulated Ca uptake. The results suggested the presence of two types of Ca ATPases, and ER- and a plasma membrane-type. Incubation of membranes with (gamma{sup 32}P)ATP resulted in the formation of a single acyl ({sup 32}P) phosphoprotein of 120 kDa. Formation of this phosphoprotein was dependent on Ca, and enhanced by La {sup 3+}, characteristic of the plasma membrane CaATPase. Acidic phospholipids, like phosphatidylserine, stimulated Ca transport, similar to their effect on the erythrocyte plasma membrane CaATPase. These results would indicate that the calmodulin-stimulated Ca transport originated in large part from a plasma membrane-type Ca pump of 120 kDa.

  14. Actinorugispora endophytica gen. nov., sp. nov., an actinomycete isolated from Daucus carota.

    PubMed

    Liu, Min-Jiao; Zhu, Wen-Yong; Li, Jie; Zhao, Guo-Zhen; Xiong, Zhi; Park, Dong-Jin; Hozzein, Wael N; Kim, Chang-Jin; Li, Wen-Jun

    2015-08-01

    An actinomycete strain, designated YIM 690008T, was isolated from Daucus carota collected from South Korea and its taxonomic position was investigated by using a polyphasic approach. The strain grew well on most media tested and no diffusible pigment was produced. The aerial mycelium formed wrinkled single spores and short spore chains, some of which were branched. The whole-cell hydrolysates contained meso-diaminopimelic acid, glucose, mannose, ribose, galactose and rhamnose. The predominant menaquinones were MK-10(H4), MK-10(H6), MK-10(H8) and MK-10(H2). The polar lipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylinositol, phosphatidylinositol mannosides, some unknown phospholipids, glycolipids and polar lipids. The major fatty acids were i-C16 : 0, ai-C17 : 0 and C18 : 1ω9c. The DNA G+C content of the genomic DNA was 63.1 mol%. Phylogenetic analysis indicated that the isolate belongs to the family Nocardiopsaceae. However, based on phenotypic, chemotaxonomic and genotypic data, it was concluded that strain YIM 690008T represents a novel genus and novel species of the family Nocardiopsaceae, for which the name Actinorugispora endophytica gen. nov., sp. nov. (type strain YIM 690008T = DSM 46770T = JCM 30099T = KCTC 29480T) is proposed.

  15. Daucus carota Pentane/Diethyl Ether Fraction Inhibits Motility and Reduces Invasion of Cancer Cells.

    PubMed

    Zgheib, Perla; Daher, Costantine F; Mroueh, Mohamad; Nasrallah, Anita; Taleb, Robin I; El-Sibai, Mirvat

    2014-01-01

    Daucus carota (DC) is a herb used in folklore medicine in Lebanon to treat numerous diseases including cancer. Recent studies in our laboratory on DC oil and its fractions revealed potent anticancer activities in vitro and in vivo. The present study aims to investigate the effect of the most potent DC fraction, pentane/diethyl ether (50:50), on lung, skin, breast and glioblastoma cancer cell motility and invasion. Upon treatment, a pronounced decrease in cancer cell motility was observed in the 4 cell lines. The treatment also led to a decrease in cancer cell invasion and an increased cell adhesion. Additionally, the DC fraction caused a decrease in the activation of the ρ-GTPases Rac and CDC42, a finding that may partially explain the treatment-induced decrease in cell motility. The current study demonstrates a crucial effect of the DC pentane/diethyl ether fraction on cancer cell motility and metastasis, making it a potential candidate for cancer therapy specifically targeting cancer motility and metastasis.

  16. Nutritional Content and Antioxidant Properties of Pulp Waste from Daucus carota and Beta vulgaris.

    PubMed

    Shyamala, B N; Jamuna, P

    2010-12-01

    This study reports the chemical composition and antioxidant potential of pulp waste from two vegetables, carrot (Daucus carota) and beetroot (Beta vulgaris). Different in vitro assays used for determining antioxidant potential of extracts of pulp wastes were: 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity, reducing power and total antioxidant activity by phosphomolybdenum method. Total polyphenols, tannins and antioxidative components such as vitamin C, total carotenoids and β-carotene were analysed in the samples. The moisture content of samples ranged from 79 - 84%. The protein content was high in beetroot (13.23 mg/100g) and low in carrot (6.21mg/100g). Total polyphenols were higher in methanol extracts of samples (220-250 mg/100g) compared to ethanol and aqueous extracts. The antioxidant activity determined by the DPPH method exhibited 40% and 78% activity in methanol extracts of carrot and beetroot pulp waste (20 mg) respectively. Overall, the results suggest that carrot and beetroot pulp wastes can be exploited for their nutrients and antioxidant components and used for value addition in food formulations. Hence, these results pave the way for utilisation of bio-wastes from the food industry.

  17. Synthesis and Accumulation of Calmodulin in Suspension Cultures of Carrot (Daucus carota L.) 1

    PubMed Central

    Perera, Imara Y.; Zielinski, Raymond E.

    1992-01-01

    The expression of calmodulin mRNA and protein were measured during a growth cycle of carrot (Daucus carota L.) cells grown in suspension culture. A full-length carrot calmodulin cDNA clone isolated from a λgt10 library was used to measure steady-state calmodulin mRNA levels. During the exponential phase of culture growth when mitotic activity and oxidative respiration rates were maximal, calmodulin mRNA levels were 4- to 5-fold higher than they were during the later stages of culture growth, when respiration rates were lower and growth was primarily by cell expansion. Net calmodulin polypeptide synthesis, as measured by pulse-labeling in vivo with [35S]methionine, paralleled the changes in calmodulin steady-state mRNA level during culture growth. As a consequence, net calmodulin polypeptide synthesis declined 5- to 10-fold during the later stages of culture growth. The qualitative spectrum of polypeptides synthesized and accumulated by the carrot cells during the course of a culture cycle, however, remained largely unchanged. Calmodulin polypeptide levels, in contrast to its net synthesis, remained relatively constant during the exponential phases of the culture growth cycle and increased during the later stages of culture growth. Our data are consistent with increased calmodulin polypeptide turnover associated with periods of rapid cell proliferation and high levels of respiration. Images Figure 1 Figure 2 Figure 4 PMID:16653062

  18. Effects of bioactive compounds from carrots (Daucus carota L.), polyacetylenes, beta-carotene and lutein on human lymphoid leukaemia cells.

    PubMed

    Zaini, Rana G; Brandt, Kirsten; Clench, Malcolm R; Le Maitre, Christine L

    2012-07-01

    New therapies for leukaemia are urgently needed. Carrots have been suggested as a potential treatment for leukaemia in traditional medicine and have previously been studied in other contexts as potential sources of anticancer agents. Indicating that carrots may contain bioactive compounds, which may show potential in leukaemia therapies. This study investigated the effects of five fractions from carrot juice extract (CJE) on human lymphoid leukaemia cell lines, together with five purified bioactive compounds found in Daucus carota L, including: three polyacetylenes (falcarinol, falcarindiol and falcarindiol-3-acetate) and two carotenoids (beta-carotene and lutein). Their effects on induction of apoptosis using Annexin V/PI and Caspase 3 activity assays analysed via flow cytometry and inhibition of cellular proliferation using Cell Titer Glo assay and cell cycle analysis were investigated. Treatment of all three lymphoid leukaemia cell lines with the fraction from carrot extracts which contained polyacetylenes and carotenoids was significantly more cytotoxic than the 4 other fractions. Treatments with purified polyacetylenes also induced apoptosis in a dose and time responsive manner. Moreover, falcarinol and falcarindiol-3-acetate isolated from Daucus carota L were more cytotoxic than falcarindiol. In contrast, the carotenoids showed no significant effect on either apoptosis or cell proliferation in any of the cells investigated. This suggests that polyacetylenes rather than beta-carotene or lutein are the bioactive components found in Daucus carota L and could be useful in the development of new leukemic therapies. Here, for the first time, the cytotoxic effects of polyacetylenes have been shown to be exerted via induction of apoptosis and arrest of cell cycle.

  19. Characterization of a Genomic Region under Selection in Cultivated Carrot (Daucus carota subsp. sativus) Reveals a Candidate Domestication Gene

    PubMed Central

    Macko-Podgórni, Alicja; Machaj, Gabriela; Stelmach, Katarzyna; Senalik, Douglas; Grzebelus, Ewa; Iorizzo, Massimo; Simon, Philipp W.; Grzebelus, Dariusz

    2017-01-01

    Carrot is one of the most important vegetables worldwide, owing to its capability to develop fleshy, highly nutritious storage roots. It was domesticated ca. 1,100 years ago in Central Asia. No systematic knowledge about the molecular mechanisms involved in the domestication syndrome in carrot are available, however, the ability to form a storage root is undoubtedly the essential transition from the wild Daucus carota to the cultivated carrot. Here, we expand on the results of a previous study which identified a polymorphism showing a significant signature for selection upon domestication. We mapped the region under selection to the distal portion of the long arm of carrot chromosome 2, confirmed that it had been selected, as reflected in both the lower nucleotide diversity in the cultivated gene pool, as compared to the wild (πw/πc = 7.4 vs. 1.06 for the whole genome), and the high FST (0.52 vs. 0.12 for the whole genome). We delimited the region to ca. 37 kb in length and identified a candidate domestication syndrome gene carrying three non-synonymous single nucleotide polymorphisms and one indel systematically differentiating the wild and the cultivated accessions. This gene, DcAHLc1, belongs to the AT-hook motif nuclear localized (AHL) family of plant regulatory genes which are involved in the regulation of organ development, including root tissue patterning. AHL genes work through direct interactions with other AHL family proteins and a range of other proteins that require intercellular protein movement. Based on QTL data on root thickening we speculate that DcAHLc1 might be involved in the development of the carrot storage root, as the localization of the gene overlapped with one of the QTLs. According to haplotype information we propose that the ‘cultivated’ variant of DcAHLc1 has been selected from wild Central Asian carrot populations upon domestication and it is highly predominant in the western cultivated carrot gene pool. However, some primitive

  20. Characterisation of polyacetylenes isolated from carrot (Daucus carota) extracts by negative ion tandem mass spectrometry.

    PubMed

    Rai, Dilip K; Brunton, Nigel P; Koidis, Anastasios; Rawson, Ashish; McLoughlin, Padraig; Griffiths, William J

    2011-08-15

    The potential use of negative electrospray ionisation mass spectrometry (ESI-MS) in the characterisation of the three polyacetylenes common in carrots (Daucus carota) has been assessed. The MS scans have demonstrated that the polyacetylenes undergo a modest degree of in-source decomposition in the negative ionisation mode while the positive ionisation mode has shown predominantly sodiated ions and no [M+H](+) ions. Tandem mass spectrometric (MS/MS) studies have shown that the polyacetylenes follow two distinct fragmentation pathways: one that involves cleavage of the C3-C4 bond and the other with cleavage of the C7-C8 bond. The cleavage of the C7-C8 bond generated product ions m/z 105.0 for falcarinol, m/z 105/107.0 for falcarindiol, m/z 147.0/149.1 for falcarindiol-3-acetate. In addition to these product ions, the transitions m/z 243.2 → 187.1 (falcarinol), m/z 259.2 → 203.1 (falcarindiol), m/z 301.2 → 255.2/203.1 (falcarindiol-3-acetate), mostly from the C3-C4 bond cleavage, can form the basis of multiple reaction monitoring (MRM)-quantitative methods which are poorly represented in the literature. The 'MS(3) ' experimental data confirmed a less pronounced homolytic cleavage site between the C11-C12 bond in the falcarinol-type polacetylenes. The optimised liquid chromatography (LC)/MS conditions have achieved a baseline chromatographic separation of the three polyacetylenes investigated within 40 min total run-time.

  1. Calcium transport in tonoplast and endoplasmic reticulum vesicles isolated from cultured carrot cells. [Daucus carota Danvers

    SciTech Connect

    Bush, D.R.; Sze, H.

    1986-02-01

    Two active calcium (Ca/sup 2 +/) transport systems have been identified and partially characterized in membrane vesicles isolated from cultured carrot cells (Daucus carota Danvers). Both transport systems required MgATP for activity and were enhanced by 10 millimolar oxalate. Ca/sup 2 +/ transport in membrane vesicles derived from isolated vacuoles equilibrated at 1.10 grams per cubic centimeter and comigrated with Cl/sup -/-stimulated, NO/sub 3//sup -/-inhibited ATPase activity on sucrose density gradients. Ca/sup 2 +/ transport in this system was insensitive to vanadate, but was inhibited by nitrate, carbonyl cyanide-m-chlorophenylhydrazone (CCCP), N,N'-dicyclohexylcarbodiimide (DCCD), and 4,4-diisothiocyano-2,2'-stilbene disulfonic acid (DIDS). The K/sub m/ for MgATP and Ca/sup 2 +/ were 0.1 mM and 21 micromolar, respectively. The predominant Ca/sup 2 +/ transport system detectable in microsomal membrane preparations equilibrated at a density of 1.13 grams per cubic centimeter and comigrated with the endoplasmic reticulum (ER) marker, antimycin A-insensitive NADH-dependent cytochrome c reductase. Ca/sup 2 +/ transport activity and the ER marker also shifted in parallel in ER shifting experiments. This transport system was inhibited by vanadate (I/sub 50/ = 12 micromolar) and was insensitive to nitrate, CCCP, DCCD, and DIDS. Transport exhibited cooperative MgATP dependent kinetics. Ca/sup 2 +/ dependent kinetics were complex with an apparent K/sub m/ ranging from 0.7 to 2 micromolar. We conclude that the vacuolar-derived system is a Ca/sup 2 +//H/sup +/ antiport located on the tonoplast and that the microsomal transport system is a Ca,Mg-ATPase enriched on the ER. These two Ca/sup 2 +/ transport systems are proposed to restore and maintain cytoplasmic Ca/sup 2 +/ homeostasis under changing cellular and environmental conditions.

  2. Nutritional, physical, and sensory evaluation of hydroponic carrots (Daucus carota L.) from different nutrient delivery systems.

    PubMed

    Gichuhi, P N; Mortley, D; Bromfield, E; Bovell-Benjamin, A C

    2009-01-01

    Carrot (Daucus carota L.) has the highest carotenoid content among foods and is consumed in large quantities worldwide, while at the same time its market demand continues to increase. Carotenoids have also been associated with protective effects against cancer and other chronic diseases. The most predominant carotenoids in carrots are beta- and alpha-carotenes. Moisture, ash, fat, texture, color, carotene content, and consumer acceptance of carrots grown in a hydroponic system with nutrient film technique (NFT) and microporous tube membrane system (MTMS) were evaluated. The moisture contents of the NFT- and MTMS-grown carrots ranged from 86.8 +/- 0.13% to 92.2 +/- 2.25% and 80.9 +/- 0.31% to 91.6 +/- 1.01%, respectively. Fat and ash contents of the carrots were negligible. NFT-grown Oxheart had the most beta-carotene (9900 +/- 20 microg/100 g) while Juwaroot had the least (248 +/- 10 microg/100 g). However, the beta-carotene content of Juwaroot from the NFT batch II carrots was 3842 +/- 6 microg/100 g. MTMS-grown carrots had less variation in the total beta-carotene contents (2434 +/- 89 to 10488 +/- 8 microg/100 g) than those from NFT. Overall, Nantes Touchan (4.8 +/- 2.3) and Nevis-F (7 +/- 1.4) from NFT were the least and most preferred by consumers. Mignon was also acceptable to consumers, and significantly (P < 0.05) more preferred than the other carrots in that NFT batch. MTMS-grown Kinko and Paramex, which were significantly (P < 0.05) more preferred than Nandrin-F and the commercial field-grown carrot, were equally liked by consumers. Nevis-F, Mignon (NFT), Paramex, and Kinko (MTMS) are potentially good cultivars to be included in NASA's food system.

  3. Patterns of Gene Flow between Crop and Wild Carrot, Daucus carota (Apiaceae) in the United States

    PubMed Central

    Mandel, Jennifer R.; Ramsey, Adam J.; Iorizzo, Massimo; Simon, Philipp W.

    2016-01-01

    Studies of gene flow between crops and their wild relatives have implications for both management practices for cultivation and understanding the risk of transgene escape. These types of studies may also yield insight into population dynamics and the evolutionary consequences of gene flow for wild relatives of crop species. Moreover, the comparison of genetic markers with different modes of inheritance, or transmission, such as those of the nuclear and chloroplast genomes, can inform the relative risk of transgene escape via pollen versus seed. Here we investigate patterns of gene flow between crop and wild carrot, Daucus carota (Apiaceae) in two regions of the United States. We employed 15 nuclear simple sequence repeat (SSR) markers and one polymorphic chloroplast marker. Further, we utilized both conventional population genetic metrics along with Shannon diversity indices as the latter have been proposed to be more sensitive to allele frequency changes and differentiation. We found that populations in both regions that were proximal to crop fields showed lower levels of differentiation to the crops than populations that were located farther away. We also found that Shannon measures were more sensitive to differences in both genetic diversity and differentiation in our study. Finally, we found indirect evidence of paternal transmission of chloroplast DNA and accompanying lower than expected levels of chloroplast genetic structure amongst populations as might be expected if chloroplast DNA genes flow through both seed and pollen. Our findings of substantial gene flow for both nuclear and chloroplast markers demonstrate the efficiency of both pollen and seed to transfer genetic information amongst populations of carrot. PMID:27603516

  4. Patterns of Gene Flow between Crop and Wild Carrot, Daucus carota (Apiaceae) in the United States.

    PubMed

    Mandel, Jennifer R; Ramsey, Adam J; Iorizzo, Massimo; Simon, Philipp W

    2016-01-01

    Studies of gene flow between crops and their wild relatives have implications for both management practices for cultivation and understanding the risk of transgene escape. These types of studies may also yield insight into population dynamics and the evolutionary consequences of gene flow for wild relatives of crop species. Moreover, the comparison of genetic markers with different modes of inheritance, or transmission, such as those of the nuclear and chloroplast genomes, can inform the relative risk of transgene escape via pollen versus seed. Here we investigate patterns of gene flow between crop and wild carrot, Daucus carota (Apiaceae) in two regions of the United States. We employed 15 nuclear simple sequence repeat (SSR) markers and one polymorphic chloroplast marker. Further, we utilized both conventional population genetic metrics along with Shannon diversity indices as the latter have been proposed to be more sensitive to allele frequency changes and differentiation. We found that populations in both regions that were proximal to crop fields showed lower levels of differentiation to the crops than populations that were located farther away. We also found that Shannon measures were more sensitive to differences in both genetic diversity and differentiation in our study. Finally, we found indirect evidence of paternal transmission of chloroplast DNA and accompanying lower than expected levels of chloroplast genetic structure amongst populations as might be expected if chloroplast DNA genes flow through both seed and pollen. Our findings of substantial gene flow for both nuclear and chloroplast markers demonstrate the efficiency of both pollen and seed to transfer genetic information amongst populations of carrot.

  5. Differential Contribution of the First Two Enzymes of the MEP Pathway to the Supply of Metabolic Precursors for Carotenoid and Chlorophyll Biosynthesis in Carrot (Daucus carota)

    PubMed Central

    Simpson, Kevin; Quiroz, Luis F.; Rodriguez-Concepción, Manuel; Stange, Claudia R.

    2016-01-01

    Carotenoids and chlorophylls are photosynthetic pigments synthesized in plastids from metabolic precursors provided by the methylerythritol 4-phosphate (MEP) pathway. The first two steps in the MEP pathway are catalyzed by the deoxyxylulose 5-phosphate synthase (DXS) and reductoisomerase (DXR) enzymes. While DXS has been recently shown to be the main flux-controlling step of the MEP pathway, both DXS and DXR enzymes have been proven to be able to promote an increase in MEP-derived products when overproduced in diverse plant systems. Carrot (Daucus carota) produces photosynthetic pigments (carotenoids and chlorophylls) in leaves and in light-exposed roots, whereas only carotenoids (mainly α- and β-carotene) accumulate in the storage root in darkness. To evaluate whether DXS and DXR activities influence the production of carotenoids and chlorophylls in carrot leaves and roots, the corresponding Arabidopsis thaliana genes were constitutively expressed in transgenic carrot plants. Our results suggest that DXS is limiting for the production of both carotenoids and chlorophylls in roots and leaves, whereas the regulatory role of DXR appeared to be minor. Interestingly, increased levels of DXS (but not of DXR) resulted in higher transcript abundance of endogenous carrot genes encoding phytoene synthase, the main rate-determining enzyme of the carotenoid pathway. These results support a central role for DXS on modulating the production of MEP-derived precursors to synthesize carotenoids and chlorophylls in carrot, confirming the pivotal relevance of this enzyme to engineer healthier, carotenoid-enriched products. PMID:27630663

  6. Modeling the transfer of arsenic from soil to carrot (Daucus carota L.)--a greenhouse and field-based study.

    PubMed

    Ding, Changfeng; Zhou, Fen; Li, Xiaogang; Zhang, Taolin; Wang, Xingxiang

    2015-07-01

    Reliable empirical models describing arsenic (As) transfer in soil-plant systems are needed to estimate the human As burden from dietary intake. A greenhouse experiment was conducted in parallel with a field trial located at three sites through China to develop and validate soil-plant transfer models to predict As concentrations in carrot (Daucus carota L.). Stepwise multiple linear regression relationships were based on soil properties and the pseudo total (aqua regia) or available (0.5 M NaHCO3) soil As fractions. Carrot As contents were best predicted by the pseudo total soil As concentrations in combination with soil pH and Fe oxide, with the percentage of variation explained being up to 70 %. The constructed prediction model was further validated and improved to avoid overprotection using data from the field trial. The final obtained model is of great practical relevance to the prediction of As uptake under field conditions.

  7. Differences in protodermal cell wall structure in zygotic and somatic embryos of Daucus carota (L.) cultured on solid and in liquid media.

    PubMed

    Dobrowolska, Izabela; Majchrzak, Oliwia; Baldwin, Timothy C; Kurczynska, Ewa U

    2012-01-01

    The ultrastructure, cuticle, and distribution of pectic epitopes in outer periclinal walls of protodermal cells of Daucus carota zygotic and somatic embryos from solid and suspension culture were investigated. Lipid substances were present as a continuous layer in zygotic and somatic embryos cultured on solid medium. Somatic embryos from suspension cultures were devoid of cuticle. The ultrastructure of the outer walls of protodermis of embryos was similar in zygotic and somatic embryos from solid culture. Fibrillar material was observed on the surface of somatic embryos. In zygotic embryos, in cotyledons and root pectic epitopes recognised by the antibody JIM5 were observed in all cell walls. In hypocotyls of these embryos, these pectic epitopes were not present in the outer periclinal and anticlinal walls of the protodermis. In somatic embryos from solid media, distribution of pectic epitopes recognised by JIM5 was similar to that described for their zygotic counterparts. In somatic embryos from suspension culture, pectic epitopes recognised by JIM5 were detected in all cell walls. In the cotyledons and hypocotyls, a punctate signal was observed on the outside of the protodermis. Pectic epitopes recognised by JIM7 were present in all cell walls independent of embryo organs. In zygotic embryos, this signal was punctate; in somatic embryos from both cultures, this signal was uniformly distributed. In embryos from suspension cultures, a punctate signal was detected outside the surface of cotyledon and hypocotyl. These data are discussed in light of current models for embryogenesis and the influence of culture conditions on cell wall structure.

  8. Influence of variation in soil copper on the yield and nutrition of carrots grown in microplots on two organic soils. [Daucus carota

    SciTech Connect

    Mathur, S.P.; Belanger, A.

    1987-01-01

    Carrots (Daucus carota L. cv. Gold Pak 128) were grown in microplots of two organic soils at site A (a peat), and site B (a muck) in the summer of 1984. The soil surface (0 to 20 cm) varied in total Cu from 13 to 1659, and 81 to 1745 ..mu..g/g at sites A and B, respectively, mainly due to three levels of applications of CuSO/sub 4/ x 5H/sub 2/O in 1978. Neither the yield nor the nutrition (P, K, Ca, Mg, Fe, Mn, Zn, Cu, Mo and B) of the carrot crop was significantly adversely affected by the copper applications or the resultant total soil copper levels at both sites A and B. There were decreases in some foliar nutrient levels due to dilution effects attributable to the significant positive correlations between both root and leaf yields and total soil copper at site B. At both sites A and B, the copper additions appeared to have increased the availability of soil Mn, in accord with earlier evidence.

  9. Daucus carota Pentane-Based Fractions Suppress Proliferation and Induce Apoptosis in Human Colon Adenocarcinoma HT-29 Cells by Inhibiting the MAPK and PI3K Pathways.

    PubMed

    Shebaby, Wassim N; Bodman-Smith, K B; Mansour, Anthony; Mroueh, Mohamad; Taleb, Robin I; El-Sibai, Mirvat; Daher, Costantine F

    2015-07-01

    Daucus carota L. ssp. carota (Apiacea, wild carrot, Queen Anne's lace) has been used in folk medicine throughout the world and recently was shown to possess anticancer and antioxidant activities. This study aims to determine the anticancer activity of the pentane fraction (F1) and the 1:1 pentane:diethyl ether fraction (F2) of the Daucus Carota oil extract (DCOE) against human colon adenocarcinoma cell lines (HT-29 and Caco-2). Treatment of cells with various concentrations of F1 or F2 fractions produced a dose-dependent inhibition of cell proliferation. Flow cytometric analysis indicated that both fractions induced sub-G1 phase accumulation and increased apoptotic cell death. Western blot revealed the activation of caspase-3, PARP cleavage, and a considerable increase in Bax and p53 levels, and a decrease in Bcl-2 level. Treatment of HT-29 cells with either fraction markedly decreased the levels of both phosphorylated Erk and Akt. Furthermore, the combined treatment of F1 or F2 with wortmannin showed no added inhibition of cell survival suggesting an effect of F1 or F2 through the phosphatidyl inositol 3-kinase (PI3K) pathway. This study proposes that DCOE fractions (F1 and F2) inhibit cell proliferation by inducing cell cycle arrest and apoptosis in HT-29 cells through the suppression of mitogen-activated protein kinase (MAPK)/Erk and PI3K/Akt pathways.

  10. Enhanced accumulation of phytosterols and phenolic compounds in cyclodextrin-elicited cell suspension culture of Daucus carota.

    PubMed

    Miras-Moreno, Begoña; Almagro, Lorena; Pedreño, M A; Sabater-Jara, Ana Belén

    2016-09-01

    In this work, suspension-cultured cells of Daucus carota were used to evaluate the effect of β-cyclodextrins on the production of isoprenoid and phenolic compounds. The results showed that the phytosterols and phenolic compounds were accumulated in the extracellular medium (15100μgL(-1) and 477.46μgL(-1), respectively) in the presence of cyclodextrins. Unlike the phytosterol and phenolic compound content, β-carotene (1138.03μgL(-1)), lutein (25949.54μgL(-1)) and α-tocopherol (8063.82μgL(-1)) chlorophyll a (1625.13μgL(-1)) and b (9.958 (9958.33μgL(-1)) were mainly accumulated inside the cells. Therefore, cyclodextrins were able to induce the cytosolic mevalonate pathway, increasing the biosynthesis of phytosterols and phenolic compounds, and accumulate them outside the cells. However, in the absence of these cyclic oligosaccharidic elicitors, carrot cells mainly accumulated carotenoids through the methylerythritol 4-phosphate pathway. Therefore, the use of cyclodextrins would allow the extracellular accumulation of both phytosterols and phenolic compounds by diverting the carbon flux towards the cytosolic mevalonate/phenylpropanoid pathway.

  11. Intra-population genetic diversity of cultivated carrot (Daucus carota L.) assessed by analysis of microsatellite markers.

    PubMed

    Maksylewicz, Anna; Baranski, Rafal

    2013-01-01

    Intra-population variation of 18 cultivated carrot (Daucus carota L. ssp. sativus) populations of diverse origins was evaluated using codominant microsatellite (SSR) markers. Using 27 genomic and EST-derived SSR markers, 253 alleles were identified with a mean 9.4 alleles per marker. Most of the alleles (60.5%) were rare i.e., with the frequency ≤ 0.05 while only 3.95% of alleles occurred with frequency > 0.6. EST-derived SSR markers were less polymorphic than genomic SSR markers. Differences in allele occurrence allowed 16 out of 18 populations to be assigned to either the Western or Asian carrot gene pools with high probability. Populations could be also discriminated due to the presence of private alleles (25.3% of all alleles). Most populations had excess of alleles in the homozygous state indicating their inbreeding, although heterozygous loci were common in F1 hybrids. Genetic diversity was due to allelic variation among plants within populations (62% of total variation) and between populations (38%). Accessions originating from continental Asia and Europe had more allelic variants and higher diversity than those from Japan and USA. Also, allelic richness and variability in landraces was higher than in F1 hybrids and open-pollinated cultivars.

  12. Reinvestigation of the bitter compounds in carrots (Daucus carota L.) by using a molecular sensory science approach.

    PubMed

    Schmiech, Ludger; Uemura, Daisuke; Hofmann, Thomas

    2008-11-12

    In order to reinvestigate the key molecules inducing bitter off-taste of carrots ( Daucus carota L.), a sensory-guided fractionation approach was applied to bitter carrot extracts. Besides the previously reported bitter compounds, 6-methoxymellein (1), falcarindiol (2), falcarinol (3), and falcarindiol-3-acetate (4), the following compounds were identified for the first time as bitter compounds in carrots with low bitter recognition thresholds between 8 and 47 micromol/L: vaginatin (5), isovaginatin (6), 2-epilaserine oxide (7), laserine oxide (8), laserine (14), 2-epilaserine (15), 6,8-O-ditigloyl- (9), 6-O-angeloyl-, 8-O-tigloyl- (10), 6-O-tigloyl-, 8-O-angeloyl- (11), and 6-, 8-O-diangeloyl-6 ss,8alpha,11-trihydroxygermacra-1(10) E,4 E-diene (12), as well as 8-O-angeloyl-tovarol (13) and alpha-angeloyloxy-latifolone (16). Among these bitter molecules, compounds 9, 10, 13, and 16 were not previously identified in carrots and compounds 6, 11, and 12 were yet not reported in the literature.

  13. Transfer model of lead in soil-carrot (Daucus carota L.) system and food safety thresholds in soil.

    PubMed

    Ding, Changfeng; Li, Xiaogang; Zhang, Taolin; Wang, Xingxiang

    2015-09-01

    Reliable empirical models describing lead (Pb) transfer in soil-plant systems are needed to improve soil environmental quality standards. A greenhouse experiment was conducted to develop soil-plant transfer models to predict Pb concentrations in carrot (Daucus carota L.). Soil thresholds for food safety were then derived inversely using the prediction model in view of the maximum allowable limit for Pb in food. The 2 most important soil properties that influenced carrot Pb uptake factor (ratio of Pb concentration in carrot to that in soil) were soil pH and cation exchange capacity (CEC), as revealed by path analysis. Stepwise multiple linear regression models were based on soil properties and the pseudo total (aqua regia) or extractable (0.01 M CaCl2 and 0.005 M diethylenetriamine pentaacetic acid) soil Pb concentrations. Carrot Pb contents were best explained by the pseudo total soil Pb concentrations in combination with soil pH and CEC, with the percentage of variation explained being up to 93%. The derived soil thresholds based on added Pb (total soil Pb with the geogenic background part subtracted) have the advantage of better applicability to soils with high natural background Pb levels. Validation of the thresholds against data from field trials and literature studies indicated that the proposed thresholds are reasonable and reliable.

  14. Purple carrot (Daucus carota L.) polyacetylenes decrease lipopolysaccharide-induced expression of inflammatory proteins in macrophage and endothelial cells.

    PubMed

    Metzger, Brandon T; Barnes, David M; Reed, Jess D

    2008-05-28

    Carrots ( Daucus carota L.) contain phytochemicals including carotenoids, phenolics, polyacetylenes, isocoumarins, and sesquiterpenes. Purple carrots also contain anthocyanins. The anti-inflammatory activity of extracts and phytochemicals from purple carrots was investigated by determining attenuation of the response to lipopolysaccharide (LPS). A bioactive chromatographic fraction (Sephadex LH-20) reduced LPS inflammatory response. There was a dose-dependent reduction in nitric oxide production and mRNA of pro-inflammatory cytokines (IL-6, IL-1beta, TNF-alpha) and iNOS in macrophage cells. Protein secretions of IL-6 and TNF-alpha were reduced 77 and 66% in porcine aortic endothelial cells treated with 6.6 and 13.3 microg/mL of the LH-20 fraction, respectively. Preparative liquid chromatography resulted in a bioactive subfraction enriched in the polyacetylene compounds falcarindiol, falcarindiol 3-acetate, and falcarinol. The polyacetylenes were isolated and reduced nitric oxide production in macrophage cells by as much as 65% without cytotoxicity. These results suggest that polyacetylenes, not anthocyanins, in purple carrots are responsible for anti-inflammatory bioactivity.

  15. Isolation and Properties of Deoxyribonucleic Acid from Protoplasts of Cell Suspension Cultures of Ammi visnaga and Carrot (Daucus carota) 1

    PubMed Central

    Ohyama, K.; Gamborg, O. L.; Miller, R. A.

    1972-01-01

    A procedure is described for the isolation of native DNA from protoplasts of ammi (Ammi visnaga) and carrot (Daucus carota) cells. Protoplasts were produced from 40 grams of fresh cells by enzyme hydrolysis and lysed with sodium dodecyl sulfate. The DNA was purified by treatment with pronase and ribonuclease. Final isolation was achieved by sucrose density gradient centrifugation. The melting temperature of ammi and carrot DNA in 0.15 m NaCl and 15 mm trisodium citrate buffer, pH 7.0, was 84.0 C and 84.5 C, respectively. The molecular weight for ammi DNA was 1.43 × 108, and for carrot DNA it was 1.56 × 108. Ammi DNA exhibited a single band at 1.690 grams per cubic centimeter in CsCl, whereas carrot DNA showed two bands, one at 1.693 grams per cubic centimeter and another at 1.706 grams per cubic centimeter. Ammi DNA consisted of a doublestranded form, since denaturation of the DNA caused a complete upward shift of 0.020 grams per cubic centimeter. PMID:16658166

  16. Daucus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The existing collections of Daucus genetic resources have recently been significantly enriched in the germplasm originating from the Mediterranean, the Middle East, Central Asia and Northern Africa. The need for thorough evaluation and valorization of these resources is urgent, as they can provide a...

  17. Assessment and Accessibility of Phenotypic and Genotypic Diversity of Carrot (Daucus carota L. var. sativus) Cultivars Commercially Available in the United States

    PubMed Central

    Luby, Claire H.; Dawson, Julie C.; Goldman, Irwin L.

    2016-01-01

    Increased use of intellectual property rights over plant germplasm has led to a complicated landscape for exchange among plant breeders. Our goal was to examine phenotypic and genotypic diversity present in commercially available carrot (Daucus carota L. var. sativus) germplasm in relation to the freedom to operate—the ability for plant breeders to access and use crop genetic diversity. A collection of 140 commercially available carrot cultivars were grown in replicated field trials in the Madison, WI area in 2013 and 2014. Phenotypic measurements were recorded for leaf and root characteristics. Illumina sequencing was used to conduct genotyping by sequencing analysis on all cultivars to understand the range of genetic diversity present. Additionally, the intellectual property rights associated with each cultivar was noted to determine the freedom to operate. We found that although one-third of the commercially available US carrot cultivars in our study are restricted through some form of intellectual property rights, the genetic and phenotypic variability of the protected cultivars does not represent a completely separate group from the available material. Phenotypic analyses including ANOVA and principal components analysis, suggest that many of the traits differed significantly based on market class, but not by whether the cultivar had freedom to operate. The principal components and Fst analyses on the genotyping by sequencing data revealed that carrot market classes (Fst = 0.065) and freedom to operate classes (Fst = 0.023) were not genetically distinct, and that principle components 1 and 2 account for only 10.1% of the total genotypic variation, implying that cultivated carrot germplasm in the US forms an unstructured population. Our findings suggest that the genetic diversity present in carrot cultivars that have freedom to operate is potentially large enough to support carrot breeding efforts in most market classes given present levels of intellectual

  18. Characterising genes associated with flowering time in carrot (Daucus carota L.) using transcriptome analysis.

    PubMed

    Ou, C-G; Mao, J-H; Liu, L-J; Li, C-J; Ren, H-F; Zhao, Z-W; Zhuang, F-Y

    2017-03-01

    Carrot is generally regarded as a biennial plant with an obligatory vernalization requirement. Early spring cultivation makes plants vulnerable to premature bolting, which results in a loss of commercial value. However, our knowledge of flowering time genes and flowering mechanisms in carrot remain limited. Bolting behavior of D. carota ssp. carota 'Songzi', a wild species sensitive to flower induction by vernalization and photoperiod, and orange cultivar 'Amsterdam forcing', and their offspring were investigated in different growing conditions. We performed RNA-seq to identify the flowering time genes, and digital gene expression (DGE) analysis to examine their expression levels. The circadian patterns of related genes were identified by qPCR. The results showed bolting behavior of carrot was influenced by low temperature, illumination intensity and photoperiod. A total of 45 flowering time-related unigenes were identified, which were classified into five categories including photoperiod, vernalization, autonomous and gibberellin pathway, and floral integrators. Homologs of LATE ELONGATED HYPOCOTYL (LHY) and CONSTANS-LIKE 2 (COL2) were more highly expressed under short day condition than under long day condition. Homologs of COL2, CONSTANS-LIKE 5 (COL5), SUPPRESSION OF OVEREXPRESSION OF CONSTANS 1 (SOC1), FLOWERING LOCUS C (FLC) and GIBBERELLIC ACID INSENSITIVE (GAI) were differentially expressed between 'Songzi' and 'Amsterdam forcing'. The homolog of COL2 (Dct43207) was repressed by light, but that of COL5 (Dct20940) was induced. A preliminary model of genetic network controlling flowering time was constructed by associating the results of DGE analysis with correlation coefficients between genes. This study provides useful information for further investigating the genetic mechanism of flowering in carrot.

  19. Prediction model for cadmium transfer from soil to carrot (Daucus carota L.) and its application to derive soil thresholds for food safety.

    PubMed

    Ding, Changfeng; Zhang, Taolin; Wang, Xingxiang; Zhou, Fen; Yang, Yiru; Huang, Guifeng

    2013-10-30

    At present, soil quality standards used for agriculture do not fully consider the influence of soil properties on cadmium (Cd) uptake by crops. This study aimed to develop prediction models for Cd transfer from a wide range of Chinese soils to carrot (Daucus carota L.) using soil properties and the total or available soil Cd content. Path analysis showed soil pH and organic carbon (OC) content were the two most significant properties exhibiting direct effects on Cd uptake factor (ratio of Cd concentration in carrot to that in soil). Stepwise multiple linear regression analysis also showed that total soil Cd, pH, and OC were significant variables contributing to carrot Cd concentration, explaining 90% of the variance across the 21 soils. Soil thresholds for carrot (cultivar New Kuroda) cropping based on added or total Cd were then derived from the food safety standard and were presented as continuous or scenario criteria.

  20. Suboptimal temperature favors reserve formation in biennial carrot (Daucus carota) plants.

    PubMed

    González, María V; Sadras, Victor O; Equiza, María A; Tognetti, Jorge A

    2009-09-01

    In response to suboptimal temperatures, temperate annual plants often increase root:shoot ratios, build-up carbohydrates and display typical morphological and anatomical changes. We know less about the responses of biennials such as carrot. As a model plant, carrot has the additional feature of two functionally and morphologically distinct root parts: the taproot, which stores carbohydrate and other compounds, and the fibrous root system involved in acquisition of water and nutrients. Here, we analyze the effects of temperature (12 vs 25°C) on growth, carbohydrate accumulation and whole-plant morphology in two carrot cultivars. Our working hypothesis is that suboptimal temperature favors active formation of reserve structures, rather than passive accumulation of storage carbohydrates. In comparison with plants grown at 25°C, plants grown at 12°C had: (1) higher fibrous root:shoot ratio (13%) , (2) thicker (10-15%) and smaller (up to two- to three-fold) leaves, (3) lower leaf cuticular permeance (two- to four-fold), (4) higher taproot:shoot ratio (two-fold), (5) higher phloem:xylem ratios in taproot (two- to six-fold), (6) unchanged percentage dry matter content (%DMC) in leaves, petioles or fibrous roots and (7) higher %DMC in taproot (20%). However, %DMC of individual taproot tissues (phloem and xylem) was unaffected by temperatures and was consistently higher in the phloem (up to 30%). Therefore, the higher %DMC of whole taproots at 12°C was attributed solely to the increased development of phloem tissue. Carrot, therefore, shares many of the most conspicuous elements of temperate plant responses to low temperatures. Consistently with our hypothesis, however, carrots grown at suboptimal temperature promoted reserve structures, rather than the increase in carbohydrate concentration typical of most temperate annual species and woody perennials.

  1. Variation of the chemical composition and antimicrobial activity of the essential oils of natural populations of Tunisian Daucus carota L. (Apiaceae).

    PubMed

    Rokbeni, Nesrine; M'rabet, Yassine; Dziri, Salma; Chaabane, Hedia; Jemli, Marwa; Fernandez, Xavier; Boulila, Abdennacer

    2013-12-01

    The essential oils of Daucus carota L. (Apiaceae) seeds sampled from ten wild populations spread over northern Tunisia were characterized by GC-FID and GC/MS analyses. In total, 36 compounds were identified in the D. carota seed essential oils, with a predominance of sesquiterpene hydrocarbons in most samples (22.63-89.93% of the total oil composition). The main volatile compounds identified were β-bisabolene (mean content of 39.33%), sabinene (8.53%), geranyl acetate (7.12%), and elemicin (6.26%). The volatile composition varied significantly across the populations, even for oils of populations harvested in similar areas. The chemometric principal component analysis and the hierarchical clustering identified four groups, each corresponding to a composition-specific chemotype. The in vitro antimicrobial activity of the isolated essential oils was preliminarily evaluated, using the disk-diffusion method, against one Gram-positive (Staphylococcus aureus) and two Gram-negative bacteria (Escherichia coli and Salmonella typhimurium), as well as against a pathogenic yeast (Candida albicans). All tested essential oils exhibited interesting antibacterial and antifungal activities against the assayed microorganisms.

  2. A tRNA gene mapping within the chloroplast rDNA cluster is differentially expressed during the development of Daucus carota.

    PubMed Central

    Manna, F; Massardo, D R; Wolf, K; Luccarini, G; Carlomagno, M S; Rivellini, F; Alifano, P; Del Giudice, L

    1994-01-01

    In vivo analysis of expression of the chloroplast rDNA cluster during somatic embryogenesis of Daucus carota (D.carota) was performed by Northern-blot analysis with different DNA probes, spanning both the 16S rRNA gene, the 16S-23S rRNA spacer, which contains the two mosaic tRNA genes tRNA(Ile) and tRNA(Ala), and the region upstream of the 16S rRNA gene, where a tRNA(Val) maps. We show that expression both of the spacer tRNAs tRNA(Ile) and tRNA(Ala) is not significantly regulated during development whereas the amount of the transcript corresponding to tRNA(Val) is not detectable during early embryonic stages and progressively accumulates during late phases. Multiple transcription start sites have been identified upstream of the tRNA(Val) gene by S1 mapping analysis, which are activated late during the embryogenesis. These data indicate that developmental control mechanisms act on plastid gene expression during embryogenesis in carrot. Images PMID:8202376

  3. Biofortification of Carrot (Daucus carota L.) with Iodine and Selenium in a Field Experiment.

    PubMed

    Smoleń, Sylwester; Skoczylas, Łukasz; Ledwożyw-Smoleń, Iwona; Rakoczy, Roksana; Kopeć, Aneta; Piątkowska, Ewa; Bieżanowska-Kopeć, Renata; Koronowicz, Aneta; Kapusta-Duch, Joanna

    2016-01-01

    The low content of iodine (I) and selenium (Se) forms available to plants in soil is one of the main causes of their insufficient transfer in the soil-plant-consumer system. Their deficiency occurs in food in the majority of human and farm animal populations around the world. Both elements are classified as beneficial elements. However, plant response to simultaneous fertilization with I and Se has not been investigated in depth. The study (conducted in 2012-2014) included soil fertilization of carrot cv. "Kazan F1" in the following combinations: (1) Control; (2) KI; (3) KIO3; (4) Na2SeO4; (5) Na2SeO3; (6) KI+Na2SeO4; (7) KIO3+Na2SeO4; (8) KI+Na2SeO3; (9) KIO3+Na2SeO3. I and Se were applied twice: before sowing and as top-dressing in a total dose of 5 kg I⋅ha(-1) and 1 kg Se⋅ha(-1). No negative effects of I and Se fertilization were noted with respect to carrot yield. Higher accumulation and the uptake by leaves and storage roots of I and Se were obtained after the application of KI than KIO3, as well as of Na2SeO4 than Na2SeO3, respectively. Transfer factor values for leaves and roots were about a dozen times higher for Se than for I. Selenomethionine content in carrot was higher after fertilization with Na2SeO4 than with Na2SeO3. However, it was the application of Na2SeO3, KI+Na2SeO3 and KIO3+Na2SeO3 that resulted in greater evenness within the years and a higher share of Se from selenomethionine in total Se in carrot plants. Consumption of 100 g f.w. of carrots fertilized with KI+Na2SeO3 and KIO3+Na2SeO3 can supply approximately or slightly exceed 100% of the Recommended Daily Allowance for I and Se. Moreover, the molar ratio of I and Se content in carrot fertilized with KI+Na2SeO3 and KIO3+Na2SeO3 was the best among the research plots.

  4. Biofortification of Carrot (Daucus carota L.) with Iodine and Selenium in a Field Experiment

    PubMed Central

    Smoleń, Sylwester; Skoczylas, Łukasz; Ledwożyw-Smoleń, Iwona; Rakoczy, Roksana; Kopeć, Aneta; Piątkowska, Ewa; Bieżanowska-Kopeć, Renata; Koronowicz, Aneta; Kapusta-Duch, Joanna

    2016-01-01

    The low content of iodine (I) and selenium (Se) forms available to plants in soil is one of the main causes of their insufficient transfer in the soil-plant-consumer system. Their deficiency occurs in food in the majority of human and farm animal populations around the world. Both elements are classified as beneficial elements. However, plant response to simultaneous fertilization with I and Se has not been investigated in depth. The study (conducted in 2012–2014) included soil fertilization of carrot cv. “Kazan F1” in the following combinations: (1) Control; (2) KI; (3) KIO3; (4) Na2SeO4; (5) Na2SeO3; (6) KI+Na2SeO4; (7) KIO3+Na2SeO4; (8) KI+Na2SeO3; (9) KIO3+Na2SeO3. I and Se were applied twice: before sowing and as top-dressing in a total dose of 5 kg I⋅ha-1 and 1 kg Se⋅ha-1. No negative effects of I and Se fertilization were noted with respect to carrot yield. Higher accumulation and the uptake by leaves and storage roots of I and Se were obtained after the application of KI than KIO3, as well as of Na2SeO4 than Na2SeO3, respectively. Transfer factor values for leaves and roots were about a dozen times higher for Se than for I. Selenomethionine content in carrot was higher after fertilization with Na2SeO4 than with Na2SeO3. However, it was the application of Na2SeO3, KI+Na2SeO3 and KIO3+Na2SeO3 that resulted in greater evenness within the years and a higher share of Se from selenomethionine in total Se in carrot plants. Consumption of 100 g f.w. of carrots fertilized with KI+Na2SeO3 and KIO3+Na2SeO3 can supply approximately or slightly exceed 100% of the Recommended Daily Allowance for I and Se. Moreover, the molar ratio of I and Se content in carrot fertilized with KI+Na2SeO3 and KIO3+Na2SeO3 was the best among the research plots. PMID:27303423

  5. Polyacetylenes from carrots (Daucus carota) improve glucose uptake in vitro in adipocytes and myotubes.

    PubMed

    El-Houri, Rime B; Kotowska, Dorota; Christensen, Kathrine B; Bhattacharya, Sumangala; Oksbjerg, Niels; Wolber, Gerhard; Kristiansen, Karsten; Christensen, Lars P

    2015-07-01

    A dichloromethane (DCM) extract of carrot roots was found to stimulate insulin-dependent glucose uptake (GU) in adipocytes in a dose dependent manner. Bioassay-guided fractionation of the DCM extract resulted in the isolation of the polyacetylenes falcarinol and falcarindiol. Both polyacetylenes were able to significantly stimulate basal and/or insulin-dependent GU in 3T3-L1 adipocytes and porcine myotube cell cultures in a dose-dependent manner. Falcarindiol increased peroxisome proliferator-activated receptor (PPAR)γ-mediated transactivation significantly at concentrations of 3, 10 and 30 μM, while PPARγ-mediated transactivation by falcarinol was only observed at 10 μM. Docking studies accordingly indicated that falcarindiol binds to the ligand binding domain of PPARγ with higher affinity than falcarinol and that both polyacetylenes exhibit characteristics of PPARγ partial agonists. Falcarinol was shown to inhibit adipocyte differentiation as evident by gene expression studies and Oil Red O staining, whereas falcarindiol did not inhibit adipocyte differentiation, which indicates that these polyacetylenes have distinct modes of action. The results of the present study suggest that falcarinol and falcarindiol may represent scaffolds for novel partial PPARγ agonists with possible antidiabetic properties.

  6. Correlations between Polyacetylene Concentrations in Carrot (Daucus carota L.) and Various Soil Parameters.

    PubMed

    Kjellenberg, Lars; Johansson, Eva; Gustavsson, Karl-Erik; Granstedt, Artur; Olsson, Marie E

    2016-08-31

    This study assessed the concentrations of three falcarinol-type polyacetylenes (falcarinol, falcarindiol, falcarindiol-3-acetate) in carrots and the correlations between these and different soil traits. A total of 144 carrot samples, from three different harvests taken a single season, were analysed in terms of their polyacetylene concentrations and root development. On one of the harvesting occasions, 48 soil samples were also taken and analysed. The chemical composition of the soil was found to influence the concentrations of falcarinol-type polyacetylenes in carrots. When the total soil potassium level was 200 mg/100 g soil, the concentration of falcarindiol (FaDOH) in the carrot samples was 630 μg/g DW, but when carrots were grown in soil with a total potassium level of 300 mg/100 g soil, the FaDOH concentration in the carrots fell to 445 μg/g DW. Carrots grown in soils generally low in available phosphorus exhibited higher levels of falcarindiol if the soil was also low in available magnesium and calcium. The concentrations of polyacetylenes in carrots were positively correlated with total soil phosphorus level, but negatively correlated with total soil potassium level. Of the three polyacetylenes analysed, FaDOH concentrations were influenced most by changes in soil chemical composition.

  7. Correlations between Polyacetylene Concentrations in Carrot (Daucus carota L.) and Various Soil Parameters

    PubMed Central

    Kjellenberg, Lars; Johansson, Eva; Gustavsson, Karl-Erik; Granstedt, Artur; Olsson, Marie E.

    2016-01-01

    This study assessed the concentrations of three falcarinol-type polyacetylenes (falcarinol, falcarindiol, falcarindiol-3-acetate) in carrots and the correlations between these and different soil traits. A total of 144 carrot samples, from three different harvests taken a single season, were analysed in terms of their polyacetylene concentrations and root development. On one of the harvesting occasions, 48 soil samples were also taken and analysed. The chemical composition of the soil was found to influence the concentrations of falcarinol-type polyacetylenes in carrots. When the total soil potassium level was 200 mg/100 g soil, the concentration of falcarindiol (FaDOH) in the carrot samples was 630 μg/g DW, but when carrots were grown in soil with a total potassium level of 300 mg/100 g soil, the FaDOH concentration in the carrots fell to 445 μg/g DW. Carrots grown in soils generally low in available phosphorus exhibited higher levels of falcarindiol if the soil was also low in available magnesium and calcium. The concentrations of polyacetylenes in carrots were positively correlated with total soil phosphorus level, but negatively correlated with total soil potassium level. Of the three polyacetylenes analysed, FaDOH concentrations were influenced most by changes in soil chemical composition. PMID:28231155

  8. Carrot (Daucus carota L.).

    PubMed

    Wally, Owen S D; Punja, Zamir K

    2015-01-01

    Plants are susceptible to infection by a broad range of fungal pathogens. A range of proteins have been evaluated that can enhance tolerance to these pathogens by heterologous expression in transgenic carrot tissues. The protocols for carrot transformation with Arabidopsis NPR1 (Non-Expressor of Pathogenesis-Related Proteins 1) are described in this chapter, using the herbicide resistance gene bar, which encodes phosphinothricin acetyltransferase, as a selectable marker. In this protocol, petiole segments (0.5-1.0 cm long) from aseptically grown carrot seedlings are exposed to Agrobacterium tumefaciens strain LBA4404 for 10-30 min and cocultivated for 2-3 days. Herbicide selection is then imposed for 8-12 weeks on a series of different tissue culture media until embryogenic calli are produced. The transfer of the embryogenic calli to hormone-free medium results in embryo development which eventually gives rise to transgenic plantlets. Embryogenic calli can also be propagated in suspension cultures. This protocol has yielded transgenic carrot plants with defined T-DNA inserts at the rate of between 1 and 3 Southern-positive independent events out of 100.

  9. Induction of extracellular defense-related proteins in suspension cultured-cells of Daucus carota elicited with cyclodextrins and methyl jasmonate.

    PubMed

    Sabater-Jara, Ana B; Almagro, Lorena; Pedreño, María A

    2014-04-01

    Suspension cultured-cells (SCC) of Daucus carota were used to evaluate the effect of methyl jasmonate and cyclodextrins, separately or in combination, on the induction of defense responses, particularly the accumulation of pathogenesis-related proteins. A comparative study of the extracellular proteome (secretome) between control and elicited carrot SCC pointed to the presence of amino acid sequences homologous to glycoproteins which have inhibitory activity against the cell-wall-degrading enzymes secreted by pathogens and/or are induced when carrot cells are exposed to a pathogen elicitor. Other amino acid sequences were homologous to Leucine-Rich Repeat domain-containing proteins, which play an essential role in defense against pathogens, as well as in the recognition of microorganisms, making them important players in the innate immunity of this plant. Also, some tryptic peptides were shown to be homologous to a thaumatin-like protein, showing high specificity to abiotic stress and to different reticuline oxidase-like proteins that displayed high levels of antifungal activity, suggesting that methyl jasmonate and cyclodextrins could play a role in mediating defense-related gene product expression in SCC of D. carota. Apart from these elicitor-inducible proteins, we observed the presence of PR-proteins in both control and elicited carrot SCC, suggesting that their expression is mainly constitutive. These PR-proteins are putative class IV chitinases, which also have inhibitory activity against pathogen growth and the class III peroxidases that participate in response to environmental stress (e.g. pathogen attack and oxidative), meaning that they are involved in defense responses triggered by both biotic and abiotic factors.

  10. Identification and characterization of DcUCGalT1, a galactosyltransferase responsible for anthocyanin galactosylation in purple carrot (Daucus carota L.) taproots.

    PubMed

    Xu, Zhi-Sheng; Ma, Jing; Wang, Feng; Ma, Hong-Yu; Wang, Qiu-Xia; Xiong, Ai-Sheng

    2016-06-06

    Purple carrots (Daucus carota ssp. sativus var. atrorubens Alef.) accumulate large amounts of cyanidin-based anthocyanins in their taproots. Cyanidin can be glycosylated with galactose, xylose, and glucose in sequence by glycosyltransferases resulting in cyanidin 3-xylosyl (glucosyl) galactosides in purple carrots. The first step in the glycosylation of cyanidin is catalysis by UDP-galactose: cyanidin galactosyltransferase (UCGalT) transferring the galactosyl moiety from UDP-galactose to cyanidin. In the present study, a gene from 'Deep purple' carrot, DcUCGalT1, was cloned and heterologously expressed in E. coli BL21 (DE3). The recombinant DcUCGalT1 galactosylated cyanidin to produce cyanidin-3-O-galactoside and showed optimal activity for cyanidin at 30 °C and pH 8.6. It showed lower galactosylation activity for peonidin, pelargonidin, kaempferol and quercetin. It accepted only UDP-galactose as a glycosyl donor when cyanidin was used as an aglycone. The expression level of DcUCGalT1 was positively correlated with anthocyanin biosynthesis in carrots. The enzyme extractions from 'Deep purple' exhibited galactosylation activity for cyanidin, peonidin and pelargonidin, while those from 'Kuroda' (a non-purple cultivar) did not.

  11. Apparent inhibition of. beta. -fructosidase secretion by tunicamycin may be explained by breakdown of the unglycosylated protein during secretion. [Daucus carota

    SciTech Connect

    Faye, L. ); Chrispeels, M.J. )

    1989-03-01

    Suspension-cultured carrot (Daucus carota) cells synthesize and secrete {beta}-fructosidase, a glycoprotein with asparagine-linked glycans. Treatment of the cells with tunicamycin completely inhibits the apparent secretion of {beta}-fructosidase as measured by the accumulation of the {sup 35}S-labelled protein in the cell wall or the culture medium. In the past, such a result has been interpreted as an inhibition of secretion by tunicamycin, but we suggest another explanation based on the following results. In the presence of tunicamycin, unglycosylated {beta}-fructosidase is synthesized and is associated with an endoplasmic-reticulum-rich microsomal fraction. Pulse-chase experiments show that the unglycosylated {beta}-fructosidase does not remain in the cells and appears to be secreted in the same way as glycosylated {beta}-fructosidase; however, no radioactive, unglycosylated {beta}-fructosidase accumulates extracellularly (cell wall or medium). Protoplasts obtained from carrot cells secrete {beta}-fructosidase protein and activity, and treatment of the protoplasts with tunicamycin results in the synthesis of unglycosylated {beta}-fructosidase. In the presence of tunicamycin, there is no accumulation of {beta}-fructosidase activity or unglycosylated {beta}-fructosidase polypeptide in the protoplast incubation medium. These results are consistent with the interpretation that the glycans of {beta}-fructosidase are necessary for its stability, and that in these suspension-cultured cells, the unglycosylated enzyme is degraded during the last stage(s) of secretion, or immediately after its arrival in the wall.

  12. A novel chimeric MOMP antigen expressed in Escherichia coli, Arabidopsis thaliana, and Daucus carota as a potential Chlamydia trachomatis vaccine candidate.

    PubMed

    Kalbina, Irina; Wallin, Anita; Lindh, Ingrid; Engström, Peter; Andersson, Sören; Strid, Ke

    2011-12-01

    The major outer membrane protein (MOMP) of Chlamydia trachomatis is a highly antigenic and hydrophobic transmembrane protein. Our attempts to express the full-length protein in a soluble form in Escherichia coli and in transgenic plants failed. A chimeric gene construct of C. trachomatis serovar E MOMP was designed in order to increase solubility of the MOMP protein but with retained antigenicity. The designed construct was successfully expressed in E. coli, in Arabidopsis thaliana, and in Daucus carota. The chimeric MOMP expressed in and purified from E. coli was used as antigen for production of antibodies in rabbits. The anti-chimeric MOMP antibodies recognized the corresponding protein in both E. coli and in transgenic plants, as well as in inactivated C. trachomatis elementary bodies. Transgenic Arabidopsis and carrots were characterized for the number of MOMP chimeric genetic inserts and for protein expression. Stable integration of the transgene and the corresponding protein expression were demonstrated in Arabidopsis plants over at least six generations. Transgenic carrots showed a high level of expression of the chimeric MOMP - up to 3% of TSP.

  13. Chlorogenic acid biosynthesis: characterization of a light-induced microsomal 5-O-(4-coumaroyl)-D-quinate/shikimate 3'-hydroxylase from carrot (Daucus carota L. ) cell suspension cultures

    SciTech Connect

    Kuehnl, T.K.; Koch, U.; Heller, W.; Wellmann, E.

    1987-10-01

    Microsomal preparations from carrot (Daucus carota L.) cell suspension cultures catalyze the formation of trans-5-O-caffeoyl-D-quinate (chlorogenate) from trans-5-O-(4-coumaroyl)-D-quinate. trans-5-O-(4-Coumaroyl)shikimate is converted to about the same extent to trans-5-O-caffeoylshikimate. trans-4-O-(4-Coumaroyl)-D-quinate, trans-3-O-(4-coumaroyl)-D-quinate, trans-4-coumarate, and cis-5-O-(4-coumaroyl)-D-quinate do not act as substrates. The reaction is strictly dependent on molecular oxygen and on NADPH as reducing cofactor. NADH and ascorbic acid cannot substitute for NADPH. Cytochrome c, Tetcyclacis, and carbon monoxide inhibit the reaction suggesting a cytochrome P-450-dependent mixed-function monooxygenase. Competition experiments as well as induction and inhibition phenomena indicate that there is only one enzyme species which is responsible for the hydroxylation of the 5-O-(4-coumaric) esters of both D-quinate and shikimate. The activity of this enzyme is greatly increased by in vivo irradiation of the cells with blue/uv light. We conclude that the biosynthesis of the predominant caffeic acid conjugates in carrot cells occurs via the corresponding 4-coumaric acid esters. Thus, in this system, 5-O-(4-coumaroyl)-D-quinate can be seen as the final intermediate in the chlorogenic acid pathway.

  14. Identification and characterization of DcUCGalT1, a galactosyltransferase responsible for anthocyanin galactosylation in purple carrot (Daucus carota L.) taproots

    PubMed Central

    Xu, Zhi-Sheng; Ma, Jing; Wang, Feng; Ma, Hong-Yu; Wang, Qiu-Xia; Xiong, Ai-Sheng

    2016-01-01

    Purple carrots (Daucus carota ssp. sativus var. atrorubens Alef.) accumulate large amounts of cyanidin-based anthocyanins in their taproots. Cyanidin can be glycosylated with galactose, xylose, and glucose in sequence by glycosyltransferases resulting in cyanidin 3-xylosyl (glucosyl) galactosides in purple carrots. The first step in the glycosylation of cyanidin is catalysis by UDP-galactose: cyanidin galactosyltransferase (UCGalT) transferring the galactosyl moiety from UDP-galactose to cyanidin. In the present study, a gene from ‘Deep purple’ carrot, DcUCGalT1, was cloned and heterologously expressed in E. coli BL21 (DE3). The recombinant DcUCGalT1 galactosylated cyanidin to produce cyanidin-3-O-galactoside and showed optimal activity for cyanidin at 30 °C and pH 8.6. It showed lower galactosylation activity for peonidin, pelargonidin, kaempferol and quercetin. It accepted only UDP-galactose as a glycosyl donor when cyanidin was used as an aglycone. The expression level of DcUCGalT1 was positively correlated with anthocyanin biosynthesis in carrots. The enzyme extractions from ‘Deep purple’ exhibited galactosylation activity for cyanidin, peonidin and pelargonidin, while those from ‘Kuroda’ (a non-purple cultivar) did not. PMID:27264613

  15. Identification of candidates for interacting partners of the tail domain of DcNMCP1, a major component of the Daucus carota nuclear lamina-like structure.

    PubMed

    Mochizuki, Ryota; Tsugama, Daisuke; Yamazaki, Michihiro; Fujino, Kaien; Masuda, Kiyoshi

    2017-02-01

    NMCP/CRWN (NUCLEAR MATRIX CONSTITUENT PROTEIN/CROWDED NUCLEI) is a major component of a protein fibrous meshwork (lamina-like structure) on the plant inner nuclear membrane. NMCP/CRWN contributes to regulating nuclear shape and nuclear functions. An NMCP/CRWN protein in Daucus carota (DcNMCP1) is localized to the nuclear periphery in interphase cells, and surrounds chromosomes in cells in metaphase and anaphase. The N-terminal region and the C-terminal region of DcNMCP1 are both necessary for localizing DcNMCP1 to the nuclear periphery. Here candidate interacting partners of the amino acid position 975-1053 of DcNMCP1 (T975-1053), which is present in the C-terminal region and contains a conserved sequence that plays a role in localizing DcNMCP1 to the nuclear periphery, are screened for. Arabidopsis thaliana nuclear proteins were subjected to far-Western blotting with GST-fused T975-1053 as a probe, and signals were detected at the positions corresponding to ∼70, ∼40, and ∼18 kDa. These ∼70, ∼40, and ∼18 kDa nuclear proteins were identified by mass spectrometry, and subjected to a yeast 2-hybrid (Y2H) analysis with T975-1053 as bait. In this analysis, the ∼40 kDa protein ARP7, which is a nuclear actin-related protein possibly involved in regulating chromatin structures, was confirmed to interact with T975-1053. Independently of the far-Western blotting, a Y2H screen was performed using T975-1053 as bait. Targeted Y2H assays confirmed that 3 proteins identified in the screen, MYB3, SINAT1, and BIM1, interact with T975-1053. These proteins might have roles in NMCP/CRWN protein-mediated biologic processes.

  16. Genome-wide analysis of AP2/ERF transcription factors in carrot (Daucus carota L.) reveals evolution and expression profiles under abiotic stress.

    PubMed

    Li, Meng-Yao; Xu, Zhi-Sheng; Huang, Ying; Tian, Chang; Wang, Feng; Xiong, Ai-Sheng

    2015-12-01

    AP2/ERF is a large transcription factor family that regulates plant physiological processes, such as plant development and stress response. Carrot (Daucus carota L.) is an important economical crop with a genome size of 480 Mb; the draft genome sequencing of this crop has been completed by our group. However, little is known about the AP2/ERF factors in carrot. In this study, a total of 267 putative AP2/ERF factors were identified from the whole-genome sequence of carrot. These AP2/ERF proteins were phylogenetically clustered into five subfamilies based on their similarity to the amino acid sequences from Arabidopsis. The distribution and comparative genome analysis of the AP2/ERF factors among plants showed the AP2/ERF factors had expansion during the evolutionary process, and the AP2 domain was highly conserved during evolution. The number of AP2/ERF factors in land plants expanded during their evolution. A total of 60 orthologous and 145 coorthologous AP2/ERF gene pairs between carrot and Arabidopsis were identified, and the interaction network of orthologous genes was constructed. The expression patterns of eight AP2/ERF family genes from each subfamily (DREB, ERF, AP2, and RAV) were related to abiotic stresses. Yeast one-hybrid and β-galactosidase activity assays confirmed the DRE and GCC box-binding activities of DREB subfamily genes. This study is the first to identify and characterize the AP2/ERF transcription factors in carrot using whole-genome analysis, and the findings may serve as references for future functional research on the transcription factors in carrot.

  17. Effect of endogenous ascorbic acid oxidase activity and stability on vitamin C in carrots (Daucus carota subsp. sativus) during thermal treatment.

    PubMed

    Leong, Sze Ying; Oey, Indrawati

    2012-10-15

    The purpose of this research was to study the effect of endogenous ascorbic acid oxidase (AAO) on vitamin C in carrots (Daucus carota subsp. sativus), namely Nantes, Egmont Gold and baby carrots during thermal treatment. Enzyme-substrate reaction kinetics of AAO were described using Michaelis-Menten equation. The estimated K(m) and V(max) values of AAO ranged from 50.34 to 63.54 μM and 23.70 to 26.82 μmol/min, respectively. Nantes carrots had the lowest AAO activity. On the other hand, Egmont Gold had the highest V(max). AAO activity in all carrot cultivars was stable up to 50 °C and inactivated above 50 °C. Irreversible thermal inactivation of AAO followed first order kinetics (55-70 °C) and the estimated activation energy of the three carrot cultivars situated between 114.33 and 191.45 kJ/mol. Regarding vitamin C stability, thermal treatment at 60-70 °C has resulted in total conversion of l-AA to DHAA due to residual AAO activity; a complete AAO inactivation was found in 80 °C-treated carrots with high vitamin C retention predominantly in l-AA form, up to 90%. On average, the carrots had a total vitamin C content amounting from 368.24 to 379.87 μg/g dry matter and the Nantes carrots had the highest vitamin C content. The effectiveness of rapid inactivation of endogenous AAO via heating (>80 °C, 10 min) prior to matrix disruption gave protection to l-AA towards enzymatic oxidation, thus resulted in a higher vitamin C content and stability in carrots.

  18. Effect of pulsed electric field treatment on enzyme kinetics and thermostability of endogenous ascorbic acid oxidase in carrots (Daucus carota cv. Nantes).

    PubMed

    Leong, Sze Ying; Oey, Indrawati

    2014-03-01

    The objective of this research was to study the enzyme kinetics and thermostability of endogenous ascorbic acid oxidase (AAO) in carrot purée (Daucus carota cv. Nantes) after being treated with pulsed electric field (PEF) processing. Various PEF treatments using electric field strength between 0.2 and 1.2kV/cm and pulsed electrical energy between 1 and 520kJ/kg were conducted. The enzyme kinetics and the kinetics of AAO thermal inactivation (55-70°C) were described using Michaelis-Menten model and first order reaction model, respectively. Overall, the estimated Vmax and KM values were situated in the same order of magnitude as the untreated carrot purée after being exposed to pulsed electrical energy between 1 and 400kJ/kg, but slightly changed at pulsed electrical energy above 500kJ/kg. However, AAO presented different thermostability depending on the electric field strength applied. After PEF treatment at the electric field strength between 0.2 and 0.5kV/cm, AAO became thermolabile (i.e. increase in inactivation rate (k value) at reference temperature) but the temperature dependence of k value (Ea value) for AAO inactivation in carrot purée decreased, indicating that the changes in k values were less temperature dependent. It is obvious that PEF treatment affects the temperature stability of endogenous AAO. The changes in enzyme kinetics and thermostability of AAO in carrot purée could be related to the resulting carrot purée composition, alteration in intracellular environment and the effective concentration of AAO released after being subjected to PEF treatment.

  19. Daucus for the flora of North America

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Flora of North America Project will treat more than 20,000 species of plants native or naturalized in North America north of Mexico, about 7% of the world's total. This contribution presents a floristic account of the two species of wild carrots (Daucus) occurring in North America, Daucus carota...

  20. A plasma membrane-type Ca[sup 2+]-ATPase of 120 kilodaltons on the endoplasmic reticulum from carrot (Daucus carota) cells

    SciTech Connect

    Chen, F.H.; Ratterman, D.M.; Sze, H. )

    1993-06-01

    Cytosolic Ca[sup 2+] levels are regulated in part by Ca[sup 2+]-pumping ATPases that export Ca[sup 2+] from the cytoplasm; The types and properties of Ca[sup 2+] pumps in plants are not well understood. The kinetic properties of a 120-kD phosphoenzyme (PE) intermediate formed during the reaction cycle of a Ca[sup 2+]-ATPase from suspension-cultured carrot (Daucus carota) cells are characterized. Only one Ca[sup 2+]-dependent phosphoprotein was formed when carrot membrane vesicles were incubated with [[gamma]-[sup 32]P]ATP. Formation of this 120-kD phosphoprotein was inhibited by vanadate, enhanced by La[sup 3+], and decreased by hydroxylamine, confirming its identification as an intermediate of a phosphorylated-type Ca[sup 2+]-translocating ATPase. The 120-kD Ca[sup 2+]-ATPase was most abundant in endoplasmic reticulum-enriched fractions, in which the Ca[sup 2+]-ATPase was estimated to be 0.1% of membrane protein. Direct quantitation of Ca[sup 2+]-dependent phosphoprotein was used to examine the kinetics of PE formation. PE formation exhibited a K[sub m] for Ca[sup 2+] of 1 to 2 [mu]m and a K[sub m] for ATP of 67 nm. Relative affinities of substrates, determined by competition experiments, were 0.075 [mu]m for ATP, 1 [mu]m for ADP, 100 [mu]m for ITP, and 250 [mu]m for GTP. Thapsigargin and cyclopiazonic acid, specific inhibitors of animal sarcoplasmic/endoplasmic reticulum Ca[sup 2+]-ATPase, had no effect on PE formation; erythrosin B inhibited with 50% inhibition at <0.1 [mu]m. Calmodulin (1 [mu]m) stimulated PE formation by 25%. The results indicate that the carrot 120-kD Ca[sup 2+]-ATPase is similar but not identical to animal plasma membrane-type Ca[sup 2+]-ATPase and yet is located on endomembranes, such as the endoplasmic reticulum. This type of Ca[sup 2+] pump may reside on the cortical endoplasmic reticulum, thought to play a major role in anchoring the cytoskeleton and in facilitating secretion. 34 refs., 9 figs., 3 tabs.

  1. Projected Dietary Intake of Zinc, Copper, and Cerium from Consumption of Carrot (Daucus carota) Exposed to Metal Oxide Nanoparticles or Metal Ions.

    PubMed

    Ebbs, Stephen D; Bradfield, Scott J; Kumar, Pawan; White, Jason C; Ma, Xingmao

    2016-01-01

    The expanding production and use of engineered nanomaterials (ENMs) have raised concerns about the potential risk of those materials to food safety and human health. In a prior study, the accumulation of Zn, Cu, and Ce from ZnO, CuO, or CeO2, respectively, was examined in carrot (Daucus carota L.) grown in sand culture in comparison to accumulation from exposure to equivalent concentrations of ionic Zn(2+), Cu(2+), or Ce(4+). The fresh weight concentration data for peeled and unpeeled carrots were used to project dietary intake of each metal by seven age-mass classes from child to adult based on consumption of a single serving of carrot. Dietary intake was compared to the oral reference dose (oral RfD) for chronic toxicity for Zn or Cu and estimated mean and median oral RfD values for Ce based on nine other rare earth elements. Reverse dietary intake calculations were also conducted to estimate the number of servings of carrot, the mass of carrot consumed, or the tissue concentration of Zn, Cu, or Ce that would cause the oral RfD to be exceeded upon consumption. The projections indicated for Zn and Cu, the oral RfD would be exceeded in only a few highly unrealistic scenarios of exceedingly high Zn or Cu concentrations in the substrate from ZnO or CuO or consumption of excessive amounts of unpeeled carrot. The implications associated with the presence of Ce in the carrot tissues depended upon whether the mean or median oral RfD value from the rare earth elements was used as a basis for comparison. The calculations further indicated that peeling carrots reduced the projected dietary intake by one to two orders of magnitude for both ENM- and ionic-treated carrots. Overall in terms of total metal concentration, the results suggested no specific impact of the ENM form on dietary intake. The effort here provided a conservative view of the potential dietary intake of these three metals that might result from consumption of carrots exposed to nanomaterials (NMs) and how

  2. Projected Dietary Intake of Zinc, Copper, and Cerium from Consumption of Carrot (Daucus carota) Exposed to Metal Oxide Nanoparticles or Metal Ions

    PubMed Central

    Ebbs, Stephen D.; Bradfield, Scott J.; Kumar, Pawan; White, Jason C.; Ma, Xingmao

    2016-01-01

    The expanding production and use of engineered nanomaterials (ENMs) have raised concerns about the potential risk of those materials to food safety and human health. In a prior study, the accumulation of Zn, Cu, and Ce from ZnO, CuO, or CeO2, respectively, was examined in carrot (Daucus carota L.) grown in sand culture in comparison to accumulation from exposure to equivalent concentrations of ionic Zn2+, Cu2+, or Ce4+. The fresh weight concentration data for peeled and unpeeled carrots were used to project dietary intake of each metal by seven age-mass classes from child to adult based on consumption of a single serving of carrot. Dietary intake was compared to the oral reference dose (oral RfD) for chronic toxicity for Zn or Cu and estimated mean and median oral RfD values for Ce based on nine other rare earth elements. Reverse dietary intake calculations were also conducted to estimate the number of servings of carrot, the mass of carrot consumed, or the tissue concentration of Zn, Cu, or Ce that would cause the oral RfD to be exceeded upon consumption. The projections indicated for Zn and Cu, the oral RfD would be exceeded in only a few highly unrealistic scenarios of exceedingly high Zn or Cu concentrations in the substrate from ZnO or CuO or consumption of excessive amounts of unpeeled carrot. The implications associated with the presence of Ce in the carrot tissues depended upon whether the mean or median oral RfD value from the rare earth elements was used as a basis for comparison. The calculations further indicated that peeling carrots reduced the projected dietary intake by one to two orders of magnitude for both ENM- and ionic-treated carrots. Overall in terms of total metal concentration, the results suggested no specific impact of the ENM form on dietary intake. The effort here provided a conservative view of the potential dietary intake of these three metals that might result from consumption of carrots exposed to nanomaterials (NMs) and how peeling

  3. Characterization of a genomic region under selection in cultivated carrot (Daucus carota subsp. sativus) reveals a candidate domestication gene

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Carrot is one of the most important vegetables worldwide, owing to its capability to develop fleshy, highly nutritious storage roots. It was domesticated ca. 1,100 years ago in Central Asia. No systematic knowledge about the molecular mechanisms involved in the domestication syndrome in carrot are a...

  4. Genomic identification of WRKY transcription factors in carrot (Daucus carota) and analysis of evolution and homologous groups for plants

    PubMed Central

    Li, Meng-Yao; Xu, Zhi-Sheng; Tian, Chang; Huang, Ying; Wang, Feng; Xiong, Ai-Sheng

    2016-01-01

    WRKY transcription factors belong to one of the largest transcription factor families. These factors possess functions in plant growth and development, signal transduction, and stress response. Here, we identified 95 DcWRKY genes in carrot based on the carrot genomic and transcriptomic data, and divided them into three groups. Phylogenetic analysis of WRKY proteins from carrot and Arabidopsis divided these proteins into seven subgroups. To elucidate the evolution and distribution of WRKY transcription factors in different species, we constructed a schematic of the phylogenetic tree and compared the WRKY family factors among 22 species, which including plants, slime mold and protozoan. An in-depth study was performed to clarify the homologous factor groups of nine divergent taxa in lower and higher plants. Based on the orthologous factors between carrot and Arabidopsis, 38 DcWRKY proteins were calculated to interact with other proteins in the carrot genome. Yeast two-hybrid assay showed that DcWRKY20 can interact with DcMAPK1 and DcMAPK4. The expression patterns of the selected DcWRKY genes based on transcriptome data and qRT-PCR suggested that those selected DcWRKY genes are involved in root development, biotic and abiotic stress response. This comprehensive analysis provides a basis for investigating the evolution and function of WRKY genes. PMID:26975939

  5. Enhanced disease resistance in transgenic carrot (Daucus carota L.) plants over-expressing a rice cationic peroxidase.

    PubMed

    Wally, O; Punja, Z K

    2010-10-01

    Plant class III peroxidases are involved in numerous responses related to pathogen resistance including controlling hydrogen peroxide (H(2)O(2)) levels and lignin formation. Peroxidases catalyze the oxidation of organic compounds using H(2)O(2) as an oxidant. We examined the mechanisms of disease resistance in a transgenic carrot line (P23) which constitutively over-expresses the rice cationic peroxidase OsPrx114 (previously known as PO-C1) and which exhibits enhanced resistance to necrotrophic foliar pathogens. OsPrx114 over-expression led to a slight enhancement of constitutive transcript levels of pathogenesis-related (PR) genes. These transcript levels were dramatically increased in line P23 compared to controls [GUS construct under the control of 35S promoter (35S::GUS)] when tissues were treated with cell wall fragments of the fungal pathogen Sclerotinia sclerotiorum (SS-walls), and to a lesser extent with 2,6-dichloroisonicotinic acid. There was no basal increase in basal H(2)O(2) levels in tissues of the line P23. However, during an oxidative burst response elicited by SS-walls, H(2)O(2) accumulation was reduced in line P23 despite, typical media alkalinization associated with oxidative burst responses was observed, suggesting that OsPrx114 was involved in rapid H(2)O(2) consumption during the oxidative burst response. Tap roots of line P23 had increased lignin formation in the outer periderm tissues, which was further increased during challenge inoculation with Alternaria radicina. Plant susceptibility to a biotrophic pathogen, Erysiphe heraclei, was not affected. Disease resistance to necrotrophic pathogens in carrot as a result of OsPrx114 over-expression is manifested through increased PR transcript accumulation, rapid removal of H(2)O(2) during oxidative burst response and enhanced lignin formation.

  6. Thermal Time Model for Egyptian Broomrape (Phelipanche aegyptiaca) Parasitism Dynamics in Carrot (Daucus carota L.): Field Validation

    PubMed Central

    Cochavi, Amnon; Rubin, Baruch; Achdari, Guy; Eizenberg, Hanan

    2016-01-01

    Carrot, a highly profitable crop in Israel, is severely damaged by Phelipanche aegyptiaca parasitism. Herbicides can effectively control the parasite and prevent damage, but for optimal results, knowledge about the soil–subsurface phenological stage of the parasite is essential. Parasitism dynamics models have been successfully developed for the parasites P. aegyptiaca, Orobanche cumana, and Orobanche minor in the summer crops, tomato, sunflower, and red clover, respectively. However, these models, which are based on a linear relationship between thermal time and the parasitism dynamics, may not necessarily be directly applicable to the P. aegyptiaca–carrot system. The objective of the current study was to develop a thermal time model to predict the effect of P. aegyptiaca parasitism dynamics on carrot growth. For development and validation of the models, data was collected from a temperature-controlled growth experiment and from 13 plots naturally infested with P. aegyptiaca in commercial carrot fields. Our results revealed that P. aegyptiaca development is related to soil temperature. Moreover, unlike P. aegyptiaca parasitism in sunflower and tomato, which could be predicted both a linear model, P. aegyptiaca parasitism dynamics on carrot roots required a nonlinear model, due to the wider range of growth temperatures of both the carrot and the parasite. Hence, two different nonlinear models were developed for optimizing the prediction of P. aegyptiaca parasitism dynamics. Both models, a beta function model and combined model composed of a beta function and a sigmoid curve, were able to predict first P. aegyptiaca attachment. However, overall P. aegyptiaca dynamics was described more accurately by the combined model (RMSE = 14.58 and 10.79, respectively). The results of this study will complement previous studies on P. aegyptiaca management by herbicides to facilitate optimal carrot growth and handling in fields infested with P. aegyptiaca. PMID:28018371

  7. Production of the p24 capsid protein from HIV-1 subtype C in Arabidopsis thaliana and Daucus carota using an endoplasmic reticulum-directing SEKDEL sequence in protein expression constructs.

    PubMed

    Lindh, Ingrid; Wallin, Anita; Kalbina, Irina; Sävenstrand, Helena; Engström, Peter; Andersson, Sören; Strid, Ake

    2009-07-01

    An optimized gene expression construct was designed in order to increase the accumulation of the HIV-1 subtype C p24 protein in Arabidopsis thaliana and carrot (Daucus carota) plants. An ER retention signal was introduced into the genetic construct generating a p24 protein containing a SEKDEL amino acid sequence at its C-terminus. Mature A. thaliana plants and carrot cells were transformed using Agrobacterium tumefaciens carrying the improved pGreen0229/p24_SEKDEL vector. Several transgenic plant lines were obtained from both plant species by growth on selective medium and confirmed by PCR. Transformed lines were analyzed for p24 protein content by western blotting using anti-p24-specific antibodies and by Southern blotting to establish the number of copies of the insert in the plant nuclear genome. To estimate the accumulation levels of p24 protein in the plants, ELISA was run using soluble plant extracts. By comparing these results with our previous findings, the ER retention signal increased the level of p24 protein fivefold in the A. thaliana plants. In carrot taproot, the content of p24_SEKDEL protein was approximately half of that in Arabidopsis on a fresh weight basis and was stable in planta for several months. However, on a total soluble protein basis, carrots produced considerable higher levels of the p24_SEKDEL protein than Arabidopsis.

  8. Dissimilarity of contemporary and historical gene flow in a wild carrot (Daucus carota) metapopulation under contrasting levels of human disturbance: implications for risk assessment and management of transgene introgression

    PubMed Central

    Rong, Jun; Xu, Shuhua; Meirmans, Patrick G.; Vrieling, Klaas

    2013-01-01

    Background and Aims Transgene introgression from crops into wild relatives may increase the resistance of wild plants to herbicides, insects, etc. The chance of transgene introgression depends not only on the rate of hybridization and the establishment of hybrids in local wild populations, but also on the metapopulation dynamics of the wild relative. The aim of the study was to estimate gene flow in a metapopulation for assessing and managing the risks of transgene introgression. Methods Wild carrots (Daucus carota) were sampled from 12 patches in a metapopulation. Eleven microsatellites were used to genotype wild carrots. Genetic structure was estimated based on the FST statistic. Contemporary (over the last several generations) and historical (over many generations) gene flow was estimated with assignment and coalescent methods, respectively. Key Results The genetic structure in the wild carrot metapopulation was moderate (FST = 0·082) and most of the genetic variation resided within patches. A pattern of isolation by distance was detected, suggesting that most of the gene flow occurred between neighbouring patches (≤1 km). The mean contemporary gene flow was 5 times higher than the historical estimate, and the correlation between them was very low. Moreover, the contemporary gene flow in roadsides was twice that in a nature reserve, and the correlation between contemporary and historical estimates was much higher in the nature reserve. Mowing of roadsides may contribute to the increase in contemporary gene flow. Simulations demonstrated that the higher contemporary gene flow could accelerate the process of transgene introgression in the metapopulation. Conclusions Human disturbance such as mowing may alter gene flow patterns in wild populations, affecting the metapopulation dynamics of wild plants and the processes of transgene introgression in the metapopulation. The risk assessment and management of transgene introgression and the control of weeds need to

  9. The influence of the fungal pathogen Mycocentrospora acerina on the proteome and polyacetylenes and 6-methoxymellein in organic and conventionally cultivated carrots (Daucus carota) during post harvest storage.

    PubMed

    Louarn, Sébastien; Nawrocki, Arkadiusz; Edelenbos, Merete; Jensen, Dan F; Jensen, Ole N; Collinge, David B; Jensen, Birgit

    2012-01-04

    Many carrots are discarded during post harvest cold storage due to development of fungal infections, caused by, e.g., Mycocentrospora acerina (liquorice rot). We compared the susceptibility of carrots grown under conventional and organic agricultural practices. In one year, organically cultivated carrots showed 3× to 7× more symptoms than conventionally cultivated, when studying naturally occurring disease at 4 and 6 months, respectively. On the other hand, we have developed a bioassay for infection studies of M. acerina on carrots and observed that organic roots were more susceptible after one month of storage than conventional ones, but no differences were apparent after four or six months storage. Levels of polyacetylenes (falcarinol, falcarindiol and falcarindiol-3-acetate) did not change, whereas the isocoumarin phytoalexin (6-methoxymellein) accumulated in infected tissue as well as in healthy tissue opposite the infection. The proteomes of carrot and M. acerina were characterized, the intensity of 33 plant protein spots was significantly changed in infected roots including up regulation of defence and stress response proteins but also a decrease of proteins involved in energy metabolism. This combined metabolic and proteomic study indicates that roots respond to fungal infection through altered metabolism: simultaneous induction of 6-methoxymellein and synthesis of defence related proteins.

  10. Characterization of centromeric histone H3 (CENH3) variants in cultivated and wild carrots (Daucus sp.).

    PubMed

    Dunemann, Frank; Schrader, Otto; Budahn, Holger; Houben, Andreas

    2014-01-01

    In eukaryotes, centromeres are the assembly sites for the kinetochore, a multi-protein complex to which spindle microtubules are attached at mitosis and meiosis, thereby ensuring segregation of chromosomes during cell division. They are specified by incorporation of CENH3, a centromere specific histone H3 variant which replaces canonical histone H3 in the nucleosomes of functional centromeres. To lay a first foundation of a putative alternative haploidization strategy based on centromere-mediated genome elimination in cultivated carrots, in the presented research we aimed at the identification and cloning of functional CENH3 genes in Daucus carota and three distantly related wild species of genus Daucus varying in basic chromosome numbers. Based on mining the carrot transcriptome followed by a subsequent PCR-based cloning, homologous coding sequences for CENH3s of the four Daucus species were identified. The ORFs of the CENH3 variants were very similar, and an amino acid sequence length of 146 aa was found in three out of the four species. Comparison of Daucus CENH3 amino acid sequences with those of other plant CENH3s as well as their phylogenetic arrangement among other dicot CENH3s suggest that the identified genes are authentic CENH3 homologs. To verify the location of the CENH3 protein in the kinetochore regions of the Daucus chromosomes, a polyclonal antibody based on a peptide corresponding to the N-terminus of DcCENH3 was developed and used for anti-CENH3 immunostaining of mitotic root cells. The chromosomal location of CENH3 proteins in the centromere regions of the chromosomes could be confirmed. For genetic localization of the CENH3 gene in the carrot genome, a previously constructed linkage map for carrot was used for mapping a CENH3-specific simple sequence repeat (SSR) marker, and the CENH3 locus was mapped on the carrot chromosome 9.

  11. Isolation, Purification and Characterization of Two Laccases from Carrot (Daucus carota L.) and Their Response to Abiotic and Metal Ions Stresses.

    PubMed

    Ma, Jing; Xu, Zhi-Sheng; Wang, Feng; Xiong, Ai-Sheng

    2015-12-01

    Laccases, which belong to the blue copper oxidase enzyme family, oxidize many organic and inorganic compounds. The laccase-encoding genes DcLac1 and DcLac2 were isolated from the economically important tuberous root carrot, and their proteins were successfully expressed and purified using the Escherichia coli expression system BL21(DE3). DcLac1 and DcLac2 had molecular masses of approximately 64 and 61.9 kDa, respectively. With 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulfonate acid) as the substrate, DcLac1 and DcLac2 had K m values of 3.9043 and 1.255 mM, respectively, and V max values of 54.0832 and 81.7996 μM mg(-1) min(-1), respectively. Moreover, DcLac1 and DcLac2 had optimal pH values of 2.8 and 2.6, respectively, and optimal temperatures of 45 and 40 °C, respectively. The activities of the two enzymes were promoted by Ca(2+), Mg(2+), Cu(2+), and Na(+) but inhibited by Fe(2+), Zn(2+), Mn(2+), K(+), SDS, and EDTA. Expression profiles showed that the two DcLac genes had almost identical responses to high and low temperature stresses but different responses to salt, drought, and metal stresses. This study provided insights into the characteristics and tolerance response mechanisms of laccase in carrot.

  12. Broad-spectrum disease resistance to necrotrophic and biotrophic pathogens in transgenic carrots (Daucus carota L.) expressing an Arabidopsis NPR1 gene.

    PubMed

    Wally, Owen; Jayaraj, Jayaraman; Punja, Zamir K

    2009-12-01

    The development of transgenic plants highly resistant to a range of pathogens using traditional signal gene expression strategies has been largely ineffective. Modification of systemic acquired resistance (SAR) through the overexpression of a controlling gene such as NPR1 (non-expressor of PR genes) offers an attractive alternative for augmenting the plants innate defense system. The Arabidopsis (At) NPR1 gene was successfully introduced into 'Nantes Coreless' carrot under control of a CaMV 35S promoter and two independent transgenic lines (NPR1-I and NPR1-XI) were identified by Southern and Northern blot hybridization. Both lines were phenotypically normal compared with non-transformed carrots. Northern analysis did not indicate constitutive or spontaneous induction in carrot cultures of SAR-related genes (DcPR-1, 2, 4, 5 or DcPAL). The duration and intensity of expression of DcPR-1, 2 and 5 genes were greatly increased compared with controls when the lines were treated with purified cell wall fragments of Sclerotinia sclerotiorum as well as with 2,6-dichloroisonicotinic acid. The two lines were challenged with the necrotrophic pathogens Botrytis cinerea, Alternaria radicina and S. sclerotiorum on the foliage and A. radicina on the taproots. Both lines exhibited 35-50% reduction in disease symptoms on the foliage and roots when compared with non-transgenic controls. Leaves challenged with the biotrophic pathogen Erysiphe heraclei or the bacterial pathogen Xanthomonas hortorum exhibited 90 and 80% reduction in disease development on the transgenic lines, respectively. The overexpression of the SAR controlling master switch in carrot tissues offers the ability to control a wide range of different pathogens, for which there is currently little genetic resistance available.

  13. Effect of Hot Water Blanching Time and Drying Temperature on the Thin Layer Drying Kinetics of and Anthocyanin Degradation in Black Carrot (Daucus carota L.) Shreds

    PubMed Central

    Garba, Umar; Gurumayum, Sushma; Rasane, Prasad

    2015-01-01

    Summary This study was conducted to investigate the effect of blanching treatment (98 °C for 3 and 6 min) and air drying temperature of 40, 50 and 60 °C on the thin layer drying characteristics such as drying time, drying rate constant, effective moisture diffusivity and activation energy, as well as on anthocyanin content of black carrot shreds. It was observed that drying temperature affected the drying rate but blanching did not have an effect on drying time. Three thin layer drying models, i.e. Page, Lewis and Henderson-Pabis were evaluated. The goodness of these models was evaluated based on the coefficient of determination (R2), root mean square error, reduced chi square (χ2) and standard error. Page model showed the best fit to the drying data. The effective diffusivity ranges of 1.4·10–9 to 2.6·10–9 m2/s, 1.3·10–9 to 2.1·10–9 m2/s and 1.5·10–9 to 2.2·10–9 m2/s after 3 or 6 min of blanching and control samples respectively were calculated using Fick’s second law. The activation energy of 37.5, 26.0 and 34.6 kJ/(mol·K) of the control samples and samples blanched for 3 or 6 min respectively was determined from the Arrhenius plot. The blanching treatment affected the anthocyanin content to a great extent. The anthocyanin content of (231.7±2.9) and (278.8±7.8) mg per 100 g was recorded in samples blanched for 3 and 6 min and then dried at 60 °C, and (153.0±4.3) and (247.0±5.5) mg per 100 g was recorded at 40 °C as compared to the control of (580.1±1.3) at 60 °C and (466.7±1.1) mg per 100 g at 40 °C. PMID:27904364

  14. [Granulated carrots (Daucus carota) in dog nutrition].

    PubMed

    Zentek, J; Meyer, H

    1993-01-01

    In feeding and balance trials with dogs (4) dried, ground carrots were tested in addition (30%) to a basic dry food (rice, corn gluten, fish meal and supplements). The palatability of both mixtures was good: fecal water losses were increased after feeding the carrots. Apparent digestibilities of organic and inorganic matter, especially sodium and potassium (not phosphorus), decreased. Digestibility of carrots was calculated to reach 70% with 1.2 MJ of digestible energy per 100 g dry matter. Reduced fecal pH (6.9-->6.1), higher lactate concentrations and increasing excretion of volatile fatty acids were seen as results of the stimulated bacterial metabolism in the colon. Diurnal pattern of breath hydrogen exhalation was similar in both periods: renal excretions of phenol, indican, and nitrogen were significantly reduced after supplementation with carrots as compared to control period.

  15. Stress-Induced Accumulation of DcAOX1 and DcAOX2a Transcripts Coincides with Critical Time Point for Structural Biomass Prediction in Carrot Primary Cultures (Daucus carota L.)

    PubMed Central

    Campos, M. Doroteia; Nogales, Amaia; Cardoso, Hélia G.; Kumar, Sarma R.; Nobre, Tânia; Sathishkumar, Ramalingam; Arnholdt-Schmitt, Birgit

    2016-01-01

    Stress-adaptive cell plasticity in target tissues and cells for plant biomass growth is important for yield stability. In vitro systems with reproducible cell plasticity can help to identify relevant metabolic and molecular events during early cell reprogramming. In carrot, regulation of the central root meristem is a critical target for yield-determining secondary growth. Calorespirometry, a tool previously identified as promising for predictive growth phenotyping has been applied to measure the respiration rate in carrot meristem. In a carrot primary culture system (PCS), this tool allowed identifying an early peak related with structural biomass formation during lag phase of growth, around the 4th day of culture. In the present study, we report a dynamic and correlated expression of carrot AOX genes (DcAOX1 and DcAOX2a) during PCS lag phase and during exponential growth. Both genes showed an increase in transcript levels until 36 h after explant inoculation, and a subsequent down-regulation, before the initiation of exponential growth. In PCS growing at two different temperatures (21°C and 28°C), DcAOX1 was also found to be more expressed in the highest temperature. DcAOX genes’ were further explored in a plant pot experiment in response to chilling, which confirmed the early AOX transcript increase prior to the induction of a specific anti-freezing gene. Our findings point to DcAOX1 and DcAOX2a as being reasonable candidates for functional marker development related to early cell reprogramming. While the genomic sequence of DcAOX2a was previously described, we characterize here the complete genomic sequence of DcAOX1. PMID:26858746

  16. Spectroscopic studies on bioactive polyacetylenes and other plant components in wild carrot root.

    PubMed

    Roman, Maciej; Dobrowolski, Jan Cz; Baranska, Malgorzata; Baranski, Rafal

    2011-08-26

    Polyacetylenes and other common plant components, such as starch, pectin, cellulose, and lignin, were studied in roots of the wild carrot (Daucus carota) subspecies D. carota subsp. gummifer and D. carota subsp. maximus by Raman spectroscopy. The components were measured in situ, directly in the plant tissue and without any preliminary sample preparation. The analysis was performed on the basis of the intense and characteristic key bands observed in the Raman spectrum. The two main carrot polyacetylenes falcarinol (1) and falcarindiol (2) have similar molecular structures, but their Raman spectra exhibit a small band shift in the symmetric -C≡C-C≡C- mode from 2258 cm⁻¹ to 2252 cm⁻¹. Quantum chemical calculations confirmed that the differences observed between the samples may be due to conformational and environmental changes. The polyacetylenes were also detected by Raman mapping, which visualized the distribution of the compounds across sections of carrot roots. The mapping technique was also applied to assess the distribution of lignin and polysaccharide compounds. The results showed the tissue-specific accumulation of starch and cell wall components such as lignin, pectin, and cellulose.

  17. Characterization of inositol phosphates in carrot (Daucus carota L. ) cells

    SciTech Connect

    Rincon, M.; Chen, Q.; Boss, W.F. )

    1989-01-01

    We have shown previously that inositol-1,4,5-trisphosphate (IP{sub 3}) stimulates an efflux of {sup 45}Ca{sup 2+} from fusogenic carrot protoplasts. In light of these results, we suggested that IP{sub 3} might serve as a second messenger for the mobilization of intracellular Ca{sup 2+} in higher plant cells. To determine whether or not IP{sub 3} and other inositol phosphates were present in the carrot cells, the cells were labeled with myo-(2-{sup 3}H)inositol for 18 hours and extracted with ice-cold 10% trichloroacetic acid. The inositol metabolites were separated by anion exchange chromatography and by paper electrophoresis. We found that ({sup 3}H)inositol metabolites coeluted with inositol bisphosphate (IP{sub 2}) and IP{sub 3} when separated by anion exchange chromatography. However, we could not detect IP{sub 2} or IP{sub 3} when the inositol metabolites were analyzed by paper electrophoresis even though the polyphosphoinositides, which are the source of IP{sub 2} and IP{sub 3}, were present in these cells. Thus, ({sup 3}H)inositol metabolites other than IP{sub 2} and IP{sub 3} had coeluted on the anion exchange columns. The data indicate that either IP{sub 3} is rapidly metabolized or that it is not present at a detectable level in the carrot cells.

  18. Inositol trisphosphate metabolism in carrot (Daucus carota L. ) cells

    SciTech Connect

    Memon, A.R.; Rincon, M.; Boss, W.F. )

    1989-10-01

    The metabolism of exogenously added D-myo-(1-{sup 3}H)inositol 1,4,5-trisphosphate (IP{sub 3}) has been examined in microsomal membrane and soluble fractions of carrot cells grown in suspension culture. When ({sup 3}H)IP{sub 3} was added to a microsomal membrane fraction, ({sup 3}H)IP{sub 2} was the primary metabolite consisting of approximately 83% of the total recovered ({sup 3}H) by electrophoresis. ({sup 3}H)IP was only 6% of the ({sup 3}H) recovered, and 10% of the ({sup 3}H)IP{sub 3} was not further metabolized. In contrast, when ({sup 3}H)IP{sub 3} was added to the soluble fraction, approximately equal amounts of ({sup 3}H)IP{sub 2} and ({sup 3}H)IP were recovered. Ca{sup 2+} (100 micromolar) tended to enhance IP{sub 3} dephosphorylation but inhibited the IP{sub 2} dephosphorylation in the soluble fraction by about 20%. MoO{sub 4}{sup 2{minus}} (1 millimolar) inhibited the dephosphorylation of IP{sub 3} by the microsomal fraction and the dephosphorylation of IP{sub 2} by the soluble fraction. MoO{sub 4}{sup 2{minus}}, however, did not inhibit the dephosphorylation of IP{sub 3} by the soluble fraction. Li{sup +} (10 and 50 millimolar) had no effect on IP{sub 3} metabolism in either the soluble or membrane fraction; however, Li{sup +} (50 millimolar) inhibited IP{sub 2} dephosphorylation in the soluble fraction about 25%.

  19. Effect of acidification on carrot (Daucus carota) juice cloud stability.

    PubMed

    Schultz, Alison K; Barrett, Diane M; Dungan, Stephanie R

    2014-11-26

    Effects of acidity on cloud stability in pasteurized carrot juice were examined over the pH range of 3.5-6.2. Cloud sedimentation, particle diameter, and ζ potential were measured at each pH condition to quantify juice cloud stability and clarification during 3 days of storage. Acidification below pH 4.9 resulted in a less negative ζ potential, an increased particle size, and an unstable cloud, leading to juice clarification. As the acidity increased, clarification occurred more rapidly and to a greater extent. Only a weak effect of ionic strength was observed when sodium salts were added to the juice, but the addition of calcium salts significantly reduced the cloud stability.

  20. Obtaining carrot (Daucus carota L.) plants in isolated microspore cultures.

    PubMed

    Górecka, K; Kowalska, U; Krzyzanowska, D; Kiszczak, W

    2010-01-01

    Microspores were cultured on the modified B5 liquid medium containing 2.4D (0.1 mg L(-1)), NAA (0.1 mg L(-1)), L-glutamine (500 mg L(-1), L-serine (100 mg L(-1)), and sucrose (100 g L(-1)). The developmental stages of microspores and divisions were observed. Initially, the formation of binuclear and multicellular structures was noticed. Plants regenerated in the cultures in which the tetrad stage of microsporogenesis had predominated. Embryoids were still forming 24 weeks after the cultures were set up. Six weeks after the transfer of androgenetic embryos onto the B5 regeneration medium, they were converted into complete plants. Out of 90 androgenetic plants planted in a growth chamber, 42 plants adapted to the new conditions. All of those plants proved to be diploids in cytometric analysis.

  1. Pervasive Mitochondrial Sequence Heteroplasmy in Natural Populations of Wild Carrot, Daucus carota spp. carota L.

    PubMed

    Mandel, Jennifer R; McCauley, David E

    2015-01-01

    Exceptions to the generally accepted rules that plant mitochondrial genomes are strictly maternally inherited and that within-individual sequence diversity in those genomes, i.e., heteroplasmy, should be minimal are becoming increasingly apparent especially with regard to sequence-level heteroplasmy. These findings raise questions about the potential significance of such heteroplasmy for plant mitochondrial genome evolution. Still studies quantifying the amount and consequences of sequence heteroplasmy in natural populations are rare. In this study, we report pervasive sequence heteroplasmy in natural populations of wild carrot, a close relative of the cultivated crop. In order to assay directly for this heteroplasmy, we implemented a quantitative PCR assay that can detect and quantify intra-individual SNP variation in two mitochondrial genes (Cox1 and Atp9). We found heteroplasmy in > 60% of all wild carrot populations surveyed and in > 30% of the 140 component individuals that were genotyped. Heteroplasmy ranged from a very small proportion of the total genotype (e.g., 0.995:0.005) to near even mixtures (e.g., 0.590:0.410) in some individuals. These results have important implications for the role of intra-genomic recombination in the generation of plant mitochondrial genome genotypic novelty. The consequences of such recombination are evident in the results of this study through analysis of the degree of linkage disequilibrium (LD) between the SNP sites at the two genes studied.

  2. Morphogenetic responses of cultured totipotent cells of carrot /Daucus carota var. carota/ at zero gravity

    NASA Technical Reports Server (NTRS)

    Krikorian, A. D.; Steward, F. C.

    1978-01-01

    An experiment designed to test whether embryos capable of developing from isolated somatic carrot cells could do so under conditions of weightlessness in space was performed aboard the unmanned Soviet biosatellite Kosmos 782 under the auspices of the joint United States-Soviet Biological Satellite Mission. Space flight and weightlessness seem to have had no adverse effects on the induction of embryoids or on the development of their organs. A portion of the crop of carrot plantlets originated in space and grown to maturity were not morphologically different from controls.

  3. Radiosensitivity of different tissues from carrot root at different phases of growth in culture

    SciTech Connect

    Degani, N.; Pickholtz, D.

    1980-09-01

    The present work compares the effect of ..gamma..-radiation dose and time in culture on the growth of cambium and phloem carrot (Daucus carota) root explants. It was found that the phloem is more radiosensitive than the cambium and that both tissues were more radiosensitive when irradiated on excision at the G/sub 1/ phase rather than at the end of the lag phase on the ninth day of growth in culture when cells were predominantly at the G/sub 2/ phase. The nuclear volumes of cells from both tissues were similar but were larger at the end of the more radioresistant lag phase than those of the G/sub 1/ phase on excision. However, nuclear volume could not account for the differences in radiosensitivity between either the tissues or irradiation times in culture.

  4. In situ simultaneous analysis of polyacetylenes, carotenoids and polysaccharides in carrot roots.

    PubMed

    Baranska, Malgorzata; Schulz, Hartwig; Baranski, Rafal; Nothnagel, Thomas; Christensen, Lars P

    2005-08-24

    This paper presents an approach to simultaneously analyze polyacetylenes, carotenoids, and polysaccharides in carrot (Daucus carota L.) roots by means of Raman spectroscopy. The components were measured in situ in the plant tissue without any preliminary sample preparation. The analysis is based on the intensive and characteristic key bands observed in the Raman spectrum of carrot root. The molecular structures of the main carrot polyacetylenes, falcarinol and falcarindiol, are similar, but their Raman spectra exhibit specific differences demonstrated by the shift of their -C[triple bond]C- mode from 2258 to 2252 cm(-)(1), respectively. Carotenoids can be identified by -C=C- stretching vibrations (about 1520 and 1155 cm(-)(1)) of the conjugated system of their polyene chain, whereas the characteristic Raman band at 478 cm(-)(1) indicates the skeletal vibration mode of starch molecule. The other polysaccharide, pectin, can be identified by the characteristic band at 854 cm(-)(1), which is due to the -C-O-C- skeletal mode of alpha-anomer carbohydrates. The Raman mapping technique applied here has revealed detailed information regarding the relative distribution of polyacetylenes, carotenoids, starch, and pectin in the investigated plant tissues. The distribution of these components varies among various carrot cultivars, and especially a significant difference can be seen between cultivated carrot and the wild relative D. carota ssp. maritimus.

  5. Effects of ten antibiotics on seed germination and root elongation in three plant species.

    PubMed

    Hillis, Derek G; Fletcher, James; Solomon, Keith R; Sibley, Paul K

    2011-02-01

    We applied a screening-level phytotoxicity assay to evaluate the effects of 10 antibiotics (at concentrations ranging from 1 to 10,000 μg/L) on germination and early plant growth using three plant species: lettuce (Lactuca sativa), alfalfa (Medicago sativa), and carrot (Daucus carota). The range of phytotoxicity of the antibiotics was large, with EC₂₅s ranging from 3.9 μg/L to >10,000 μg/L. Chlortetracycline, levofloxacin, and sulfamethoxazole were the most phytotoxic antibiotics. D. carota was the most sensitive plant species, often by an order of magnitude or more, followed by L. sativa and then M. sativa. Plant germination was insensitive to the antibiotics, with no significant decreases up to the highest treatment concentration of 10,000 μg/L. Compared with shoot and total length measurements, root elongation was consistently the most sensitive end point. Overall, there were few instances where measured soil concentrations, if available in the publicly accessible literature, would be expected to exceed the effect concentrations of the antibiotics evaluated in this study. The use of screening assays as part of a tiered approach for evaluating environmental impacts of antibiotics can provide insight into relative species sensitivity and serve as a basis by which to screen the potential for toxic effects of novel compounds to plants.

  6. Control of Heterodera carotae, Ditylenchus dipsaci, and Meloidogyne javanica with Fumigant and Nonfumigant Nematicides.

    PubMed

    Greco, N; Elia, F; Brandonisio, A

    1986-07-01

    Five field trials were conducted in Italy in 1983 and 1984 to test the efficacy of isazofos and benfuracarb in controlling Heterodera carotae on carrot, Ditylenchus dipsaci on onion, and Meloidogyne javanica on tomato. Methyl isothiocyanate (MIT) was tested against H. carotae and M. javanica. Single (10 kg a.i./ha) and split (5 + 5 kg a.i./ha) applications of isazofos gave yield increases of carrot and onion similar to those obtained with DD (300 liters/ha) and aldicarb (10 kg a.i./ha). Population densities of H. carotae in carrot roots at harvest and of M. javanica in tomato roots 2 months after transplanting were also suppressed by isazofos. Benfuracarb (10 kg a.i./ha increased onion yields in a field infested with D. dipsaci, but it was not effective against H. carotae or M. javanica. The efficacy of MIT at 400 and 600 liters/ha was similar to that of MIT + DD (Di-Trapex) at 300 liters/ha. Both nematicides inhibited hatch of H. carotae eggs and decreased the soil population density of M. javanica.

  7. Arbuscular mycorrhizal hyphopodia and germinated spore exudates trigger Ca2+ spiking in the legume and nonlegume root epidermis.

    PubMed

    Chabaud, Mireille; Genre, Andrea; Sieberer, Björn J; Faccio, Antonella; Fournier, Joëlle; Novero, Mara; Barker, David G; Bonfante, Paola

    2011-01-01

    • The aim of this study was to investigate Ca(2+) responses to endosymbiotic arbuscular mycorrhizal (AM) fungi in the host root epidermis following pre-infection hyphopodium formation in both legumes and nonlegumes, and to determine to what extent these responses could be mimicked by germinated fungal spore exudate. • Root organ cultures of both Medicago truncatula and Daucus carota, expressing the nuclear-localized cameleon reporter NupYC2.1, were used to monitor AM-elicited Ca(2+) responses in host root tissues. • Ca(2+) spiking was observed in cells contacted by AM hyphopodia for both hosts, with highest frequencies correlating with the epidermal nucleus positioned facing the fungal contact site. Treatment with AM spore exudate also elicited Ca(2+) spiking within the AM-responsive zone of the root and, in both cases, spiking was dependent on the M. truncatula common SYM genes DMI1/2, but not on the rhizobial Nod factor perception gene NFP. • These findings support the conclusion that AM fungal root penetration is preceded by a SYM pathway-dependent oscillatory Ca(2+) response, whose evolutionary origin predates the divergence between asterid and rosid clades. Our results further show that fungal symbiotic signals are already generated during spore germination, and that cameleon-expressing root organ cultures represent a novel AM-specific bio-assay for such signals.

  8. Carotenoid profiles and consumer sensory evaluation of specialty carrots (Daucus carota, L.) of various colors.

    PubMed

    Surles, Rebecca L; Weng, Ning; Simon, Philipp W; Tanumihardjo, Sherry A

    2004-06-02

    Five different colored carrots were analyzed for their carotenoid profile and underwent sensory evaluation to determine consumer acceptance (n = 96). Four major carotenoids were identified and quantified by use of HPLC methods. High beta-carotene orange carrots were found to contain the greatest concentration of total carotenoids. Except for the white, all the carrots are a significant source of bioavailable carotenoids. Sensory evaluation showed the high beta-carotene orange and white carrots to be favored over the yellow, red, and purple carrots in both blind and nonblind treatments (P < 0.01). However, all the carrots were well accepted by the consumer panel. With this information, carrot growers should be encouraged to cultivate specialty carrots to provide sources of both vitamin A precursors and phytochemicals.

  9. Bioactive chemicals from carrot (Daucus carota) juice extracts for the treatment of leukemia.

    PubMed

    Zaini, Rana; Clench, Malcolm R; Le Maitre, Christine L

    2011-11-01

    Overwhelming evidence indicates that consumption of fruits and vegetables with antioxidant properties correlates with reduced risk for cancers, including leukemia. Carrots contain beneficial agents, such as β-carotene and polyacetylenes, which could be effective in the treatment of leukemia. This study investigated the effect of carrot juice extracts on myeloid and lymphoid leukemia cell lines together with normal hematopoietic stem cells. Leukemia cell lines and nontumor control cells were treated with carrot juice extracts for up to 72 hours in vitro. Induction of apoptosis was investigated by using annexin V/propidium iodide staining followed by flow cytometric analysis, and results were confirmed by using 4'-6-diamidino-2-phenylindole morphology. Effects on cellular proliferation were investigated via cell cycle analysis and cell counts. Treatment of leukemia cell lines with carrot juice extract induced apoptosis and inhibited progression through the cell cycle. Lymphoid cell lines were affected to a greater extent than were myeloid cell lines, and normal hematopoietic stem cells were less sensitive than most cell lines. This study has shown that extracts from carrots can induce apoptosis and cause cell cycle arrest in leukemia cell lines. The findings suggest that carrots may be an excellent source of bioactive chemicals for the treatment of leukemia.

  10. Bioaccessibility of Polyphenols from Plant-Processing Byproducts of Black Carrot (Daucus carota L.).

    PubMed

    Kamiloglu, Senem; Capanoglu, Esra; Bilen, Fatma Damla; Gonzales, Gerard Bryan; Grootaert, Charlotte; Van de Wiele, Tom; Van Camp, John

    2016-03-30

    Plant-processing byproducts of black carrot represent an important disposal problem for the industry; however, they are also promising sources of polyphenols, especially anthocyanins. The present study focused on the changes in polyphenols from black carrot, peel, and pomace during in vitro gastrointestinal digestion. Total phenolic content (TPC), total monomeric anthocyanin content (TMAC), and total antioxidant capacity (TAC) were determined using spectrophotometric methods, whereas identification and quantification of polyphenols were carried out using UPLC-ESI-MS(E) and HPLC-DAD, respectively. TPC, TMAC, and TAC significantly decreased (23-82%) as a result of in vitro gastrointestinal digestion. Nevertheless, the amount of pomace anthocyanins released at all stages of in vitro gastrointestinal digestion was higher than black carrot anthocyanins, suggesting that pomace may be a better source of bioaccessible anthocyanins. Overall, the current study highlighted black carrot byproducts as substantial sources of polyphenols, which may be used to enrich food products.

  11. Effects of harvesting date and storage on the amounts of polyacetylenes in carrots, Daucus carota.

    PubMed

    Kjellenberg, Lars; Johansson, Eva; Gustavsson, Karl-Erik; Olsson, Marie E

    2010-11-24

    The amounts of three main polyacetylenes in carrots; falcarinol, falcarindiol, and falcarindiol-3-acetate, were determined by HPLC, during three seasons, in carrots harvested several times per season and at different locations in Sweden. The amounts of falcarindiol first decreased from a relatively high level and then increased later in the harvest season. The amounts of falcarindiol-3-acetate showed similar variations, whereas the amounts of falcarinol did not exhibit any significant variation during the harvest season. During storage the amount of polyacetylenes leveled off, increasing in samples initially low and decreasing in samples initially high in polyacetylenes. The amounts of all polyacetylenes varied significantly due to external factors and between stored and fresh samples. This variation opens up possibilities to achieve a chemical composition of polyacetylenes at harvest that minimizes the risk of bitter off-taste and maximizes the positive health effects reported in connection with polyacetylenes in carrots.

  12. Polyacetylene diversity and bioactivity in orange market and locally grown colored carrots (Daucus carota L.).

    PubMed

    Metzger, Brandon T; Barnes, David M

    2009-12-09

    Carrots contain a wide array of phytochemicals such as carotenoids, phenolics, alpha-tocopherol, and polyacetylenes. Carrots are most known for their pro-vitamin A carotenoids but also contain other phytochemicals with documented health benefits. The phytochemicals in colored carrots present a challenge and opportunity due to the wide diversity of potent bioactive compounds. Two commercial carrots, 1 wild carrot, and 13 colored carrot varieties were characterized phytochemically. The carrots were screened in an anti-inflammatory model of lipopolysaccharide-induced nitric oxide production. Deep Purple carrot had the highest concentration of total polyacetylenes, alpha-tocopherol, and total phenolics. Commercial fresh market and baby orange carrots both had high concentrations of pro-vitamin A carotenoids. Purple carrots had higher antioxidant capacity values due to their anthocyanin content. Only seven carrot varieties had inhibitory activity (IC(25) = 257-1321 microg/mL) in macrophage cells. Among the varieties tested during the selected growing season, Deep Purple had the highest polyacetylene content and other important antioxidant phytochemicals. Further work is needed to identify other potential anti-inflammatory phytochemicals in colored carrots on the basis of this research.

  13. Sensory and health properties of steamed and boiled carrots (Daucus carota ssp. sativus).

    PubMed

    Bongoni, Radhika; Stieger, Markus; Dekker, Matthijs; Steenbekkers, Bea; Verkerk, Ruud

    2014-11-01

    This study examined the influences of domestic processing conditions applied by consumers on firmness, colour and amount of phytochemicals and liking and sensory attributes intensity rating of carrots. The aim was to identify a cooking method and time that yields carrots with higher amount of β-carotene while maintaining consumer liking. Instrumentally measured firmness and colour showed comparable degradation trends between cooking methods. While boiling showed a significant decrease in the amount β-carotene after 20 min (-19%), steaming maintained the amount (+40%). Cooking method did not show a significant effect on liking and intensity ratings for the majority of the sensory attributes. Medium firm carrots were liked the most and low firm carrots the least. This study demonstrates that for optimum liking, carrots should be in the range of medium firmness. This can be obtained through either cooking methods but steamed carrots possess a higher amount of β-carotene and maintains liking.

  14. Assessing the impact of geogenic chromium uptake by carrots (Daucus carota) grown in Asopos river basin.

    PubMed

    Lilli, Maria A; Syranidou, Evdokia; Palliou, Andriana; Nikolaidis, Nikolaos P; Karatzas, George; Kalogerakis, Nicolas

    2017-01-01

    A methodology was developed to assess the impact of geogenic origin hexavalent chromium uptake by carrots, and the risk of human consumption of carrots grown in Asopos River basin in Greece. A field scale experiment was conducted with carrots cultivated in treatment plots, with and without compost amendment, in order to assess the impact of carbon in the mobility and uptake of chromium by plants. The results suggested that there is a trend for chromium mobilization and uptake in the surface and the leaves of the carrots cultivated in the treatment plot with the higher carbon addition, but not in the core of the carrots. Limited mobility of hexavalent chromium in the soil-plant-water system is presented due to the affinity of chromium to be retained in the solid phase and be uptaken by plants. Hexavalent chromium tolerant bacterial strains were isolated from the carrots. These endophytic bacteria, present in all parts of the plant, were able to reduce hexavalent chromium to trivalent form to levels below the detection limit. Finally, a site-specific risk assessment analysis suggested no adverse effects to human health due to the consumption of carrots. These findings are of particular importance since they confirm that carrots grown in soils with geogenic origin chromium does not pose any adverse risk for human consumption, but could also have the beneficial effect of the micronutrient trivalent chromium.

  15. Antioxidant phytochemicals and antioxidant capacity of biofortified carrots (Daucus carota L.) of various colors.

    PubMed

    Sun, Ting; Simon, Philipp W; Tanumihardjo, Sherry A

    2009-05-27

    Antioxidants and antioxidant capacity of seven colored carrots were determined. Five anthocyanins, chlorogenic acid, caffeic acid, and four carotenoids were quantified by HPLC. Total phenolic content was determined according to the Folin-Ciocalteu method. Antioxidant capacities of the hydrophilic and hydrophobic fractions were determined by using the 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2'-diphenyl-1-picrylhydrazyl (DPPH) methods. The relative antioxidant capacity index was determined. Anthocyanins were the major antioxidants in purple-yellow and purple-orange carrots, and chlorogenic acid was a major antioxidant in all carrots. Carotenoids did not contribute to total antioxidant capacity, but correlated with antioxidant capacity of hydrophobic extracts. Both the DPPH and ABTS assays showed that the hydrophilic extract had higher antioxidant capacity than the hydrophobic extract. Purple-yellow carrots had the highest antioxidant capacity, followed by purple-orange carrots, and the other carrots did not significantly differ. This information is useful for consumers and may help horticulturists develop carrots with higher antioxidant capacity.

  16. Antioxidants and Antioxidant Capacity of Biofortified Carrots (Daucus Carota, L.) of Various Colors

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Antioxidants and antioxidant capacity of seven colored carrots were determined. Five anthocyanins, chlorogenic acid, caffeic acid, and four carotenoids, were quantified by HPLC. Total phenolic content was determined by the Folin-Ciocalteau method. Antioxidant capacities of the hydrophilic and hyd...

  17. Effect of pectin methylesterase on carrot (Daucus carota) juice cloud stability.

    PubMed

    Schultz, Alison K; Anthon, Gordon E; Dungan, Stephanie R; Barrett, Diane M

    2014-02-05

    To determine the effect of residual enzyme activity on carrot juice cloud, 0 to 1 U/g pectin methylesterase (PME) was added to pasteurized carrot juice. Cloud stability and particle diameters were measured to quantify juice cloud stability and clarification for 56 days of storage. All levels of PME addition resulted in clarification; higher amounts had a modest effect in causing more rapid clarification, due to a faster increase in particle size. The cloud initially exhibited a trimodal distribution of particle sizes. For enzyme-containing samples, particles in the smallest-sized mode initially aggregated to merge with the second peak over 5-10 days. This larger population then continued to aggregate more slowly over longer times. This observation of a more rapid destabilization process initially, followed by slower subsequent changes in the cloud, was also manifested in measurements of sedimentation extent and in turbidity tests. Optical microscopy showed that aggregation created elongated, fractal particle structures over time.

  18. Patterns of gene flow between crop and wild carrot, Daucus carota (Apiaceae) in the United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Studies of gene flow between crops and their wild relatives have implications for both management practices for farming and breeding as well as understanding the risk of transgene escape. These types of studies may also yield insight into population dynamics and the evolutionary consequences of gene...

  19. Daucus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The mission of the Oregon Flora Project is to serve as a comprehensive resource for the vascular plants of Oregon that grow without cultivation, and to foster effective use of this knowledge by all citizens. This contribution presents a floristic account of the two species of wild carrots occurring ...

  20. Root-Uptake of C-14 Acetic Acid by Various Plants and C-14 Dynamics Surrounding the Experimental Tessera

    SciTech Connect

    Ogiyama, S.; Takeda, H.; Uchida, S.; Suzuki, H.; Inubushi, K.

    2008-07-01

    Carbon-14 (C-14, t{sub 1/2} = 5.73x10{sup 3} yrs) from radioactive waste is one of the most important radioactive nuclides for environmental assessment in the context of geological disposal, and understanding the transfer of radioactive elements to plants is essential for public health safety. In order to obtain fundamental knowledge, culture experiments using marigold (Tagetes patula L.), tall fescue (Festuca arundinacea S.), paddy rice (Oryza sativa L.), radish (Raphanus sativus L.), and carrot (Daucus carota L.) plants were conducted to examine root-uptake and dynamics of C-14 in the laboratory. The C-14 radioactivity in each plant part (e.g. shoot, root, edible part, etc.), medium (e.g. culture solution, sand, etc.), and air was determined. The distribution of C-14 in the plants was visualized using autoradiography. For a comparison, autoradiography was also done using Na-22. Results of the present study indicated that C-14 labeled CO{sub 2} gas was released from the culture solution to the atmosphere. Clear autoradiography images were observed in plants for the shoots and lower roots which were soaked in the culture solution. The upper roots which were not soaked in the culture solution were not clearly imaged. In the radiotracer experiment using Na-22, a clear image was observed for the whole carrot seedling, even including the upper root, on the autoradiography. However, the amounts of C-14 acetic acid absorbed by all the plants through their roots were considered to be very small. Inorganic carbon transformed from C-14 acetic acid would be taken up by plants through the roots, and some fraction of C-14 would be assimilated into the shoots by photosynthesis. (authors)

  1. A novel K+ channel expressed in carrot roots with a low susceptibility toward metal ions.

    PubMed

    Paganetto, A; Bregante, M; Downey, P; Lo Schiavo, F; Hoth, S; Hedrich, R; Gambale, F

    2001-02-01

    Kdc1 is a novel K+-channel gene cloned from carrot roots, and which is also present in cultured carrot cells. We investigated the characteristics of the ionic current elicited in Xenopus oocytes coinjected with KDC1 (K+-Daucus carota 1) and KAT1 (from Arabidopsis thaliana) RNA. Expressed heteromeric channels displayed inward-rectifying potassium currents whose kinetics, voltage characteristics, and inhibition by metal ions depended on KDC1:KAT1 ratios. At low KDC1:KAT1 ratios, Zn2+ inhibition of heteromeric K+ current was less pronounced compared to homomeric KAT1 channels, while at higher KDC1:KAT1 ratios, the addition of Zn2+ even produced an increase in current. Under the same conditions, the Ni2+ inhibition of the current was also reduced, but no current increase was observed. These effects might be explained by the unusual amino acid composition of the KDC1 protein in terms of histidine residues that are absent in the pore region, but abundant (four per subunit) in the proximity of the pore entrance. Channels like KDC1 could be at least partially responsible for the higher resistance of carrot cells in the presence of metals.

  2. Phylogenomics of the carrot genus (Daucus, Apiaceae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Molecular phylogenetics of genome-scale data sets (phylogenomics) often produces phylogenetic trees with unprecedented resolution. We here explore the utility of multiple nuclear orthologs for the taxonomic resolution of a wide variety of Daucus species and outgroups. We studied the phylogeny of 89 ...

  3. Integrated molecular and morphological studies of Daucus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ninety-four nuclear orthologs were used to analyze phylogenetic structure in 92 accessions of 13 species and two subspecies of Daucus, and 15 accessions of related genera. A near parallel set of accessions was used for morphological analyses of germplasm. Reiterative analyses examined data of both a...

  4. Integrated molecular and morphological studies of Daucus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ninety-four nuclear orthologs were used to analyze phylogenetic structure in 89 accessions of 13 species and two subspecies of Daucus, and an additional ten accessions of related genera. A near parallel set of accessions were used for morphological analyses of germplasm planted in a common garden in...

  5. Cadmium-sulfide crystallites in Cd-. gamma. -glutamyl peptide complexes from Lycopersicon and Daucus

    SciTech Connect

    Reese, R.N. ); Winge, D.R. )

    1989-04-01

    Hydroponically-grown tomato plants (Lycopersicon esculentum P. Mill. cv stone) and suspension-cultured carrot cells (Daucus carota L.) exposed to 100 {mu}M cadmium salts produced metal-{gamma}-glutamyl peptide complexes containing acid labile sulfur. The properties of the complexes resemble the Cd-{gamma}-glutamyl complexes from Schizosaccharomyces pombe and Candida glabrata, known to contain a CdS crystallite core. The crystallite core is stabilized by a coating of peptides of the general structure ({gamma}-Glu-Cys){sub n}-Gly. The Cd-peptide complexes contain predominantly peptides of n{sub 2}, n{sub 3}, n{sub 4} and n{sub 3}desGly. Zn-peptide complexes were also isolated from carrot cultures grown in MS medium supplemented with 2 mM Zn and cysteine. Results of preliminary characterization of these complexes are consistent with the presence of a colloidal particle similar to that of the Cd-complexes.

  6. Biological activities and volatile constituents of Daucus muricatus L. from Algeria

    PubMed Central

    2012-01-01

    Background In order to find new bioactive natural products, the antimicrobial and antioxidant activities of essential oil components extracted from the separated organs of the Algerian medicinal and aromatic plant Daucus muricatus L. were studied. Results The chemical composition of essential oils obtained by hydrodistillation (HD) was investigated using Gas Chromatography–Retention Indices (GC-RI) and GC–Mass Spectrometry (GC-MS). Two types of essential oils were produced by D. muricatus: (i) The oil from roots is mainly composed by nonterpenic oxygenated compounds (59.8 g/100 g), and (ii) the aerial part oils (i.e., the leaves, stems, flowers, and umbels) was mainly composed by terpenic hydrocarbon compounds (62.3–72.2 g/100 g). The chemical composition of the volatile fraction isolated from different organs of Daucus muricatus were studied by HS–SPME/GC–RI and GC–MS after optimization of Solid Phase MicroExtraction parameters. For all organs studied, the main volatiles emitted by the plant were hydrocarbon compounds (60.7–82.2 g/100 g). Only quantitative differences between the volatiles of the separated organs studied were observed. In addition, the activity of the oil of D. muricatus against eight bacterial strains and one yeast was investigated. The oil from roots revealed active against S. aureus, while the essential oil obtained from the aerial parts was active against the yeast C. albicans. Conclusions Daucus muricatus essential oil seems be a promising source of natural products with potential antimicrobial activity. PMID:22647252

  7. Morphometrics of Daucus (Apiaceae): A counterpart to a phylogenomic study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Molecular phylogenetics of genome-scale data sets (phylogenomics) often produces phylogenetic trees with unprecedented resolution. A companion phylogenomics analysis of Daucus (carrots) using 94 conserved nuclear orthologs supported many of the traditional species but showed unexpected results that ...

  8. Multivariate analysis of morphological diversity among closely related Daucus species and subspecies in Tunisia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The genus Daucus includes about 20-25 species worldwide. Northern Africa represents a major center of diversity of Daucus, with Tunisia thought to contain 11 species and seven subspecies. We assessed morphological diversity from a Daucus germplasm collection of 103 accessions at the National Gene Ba...

  9. Combined effects of gamma irradiation and modified atmosphere packaging on bacterial resistance in grated carrots ( Daucus carota)

    NASA Astrophysics Data System (ADS)

    Lacroix, M.; Lafortune, R.

    2004-09-01

    The present study was conducted to evaluate the efficiency of gamma irradiation combined with modified atmosphere packaging as an alternative treatment to ensure the innocuity and the shelf life extension of pre-cured vegetables. Grated carrots were inoculated with Escherichia coli (10 6 CFU/g) and packed under air or under MAP condition (60% O 2, 30% CO 2 and 10% N 2). The packages were then, gamma irradiated at doses from 0.15 to 0.9 kGy and stored at 4±1°C. E. coli counts were periodically evaluated during 50 days of storage. Results showed that at day 1, an irradiation treatment at a dose of 0.15 kGy reduced by 3 and 4 log the microbial level representing a level of 3 and 2 log CFU/g when samples were irradiated under air and under MAP respectively. However, a level of 3 log CFU/g was detected in both treated samples after 7 days of storage. When samples were irradiated at doses ⩾0.3 kGy no E.coli were detected during the whole storage in samples treated under MAP. However, when samples were treated under air, a level of 1-2 log CFU/g of E.coli was detected after 5 days of storage.

  10. Ultraviolet-C light effect on physicochemical, bioactive, microbiological, and sensorial characteristics of carrot (Daucus carota) beverages.

    PubMed

    Hernández-Carranza, Paola; Ruiz-López, Irving Israel; Pacheco-Aguirre, Francisco Manuel; Guerrero-Beltrán, José Ángel; Ávila-Sosa, Raúl; Ochoa-Velasco, Carlos Enrique

    2016-09-01

    The aim of this research was to evaluate the effect of ultraviolet-C light on physicochemical, bioactive, microbial, and sensory characteristics of carrot beverages. Beverages were formulated with different concentrations of carrot juice (60, 80, and 100% [v/v]) and treated with ultraviolet-C light at different flow rates (0, 0.5, 3.9, and 7.9 mL s(-1)) and times (5, 10, 15, 20, and 30 min), equivalent to ultraviolet-C dosages of 13.2, 26.4, 39.6, 52.8, and 79.2 J cm(-2) Total soluble solids, pH, and titratable acidity were not affected by the ultraviolet-C light treatment. Ultraviolet-C light significantly affected (p < 0.05) color parameters of pure juice; however, at low concentration of juice, total color change was slightly affected (ΔE = 2.0 ± 0.7). Phenolic compounds (4.1 ± 0.1, 5.2 ± 0.2, and 8.6 ± 0.3 mg of GAE 100 mL(-1) of beverage with 60, 80, and 100% of juice, respectively) and antioxidant capacity (6.1 ± 0.4, 8.5 ± 0.4, and 9.4 ± 0.3 mg of Trolox 100 mL(-1) of beverage with 60, 80, and 100% of juice, respectively) of carrot beverages were not affected by ultraviolet-C light treatment. Microbial kinetics showed that mesophiles were mostly reduced at high flow rates in carrot beverages with 60% of juice. Maximum logarithmic reductions for mesophiles and total coliforms were 3.2 ± 0.1 and 2.6 ± 0.1, respectively, after 30 min of ultraviolet-C light processing. Beverages were well accepted (6-7) by judges who did not perceive the difference between untreated and Ultraviolet-C light treated beverages.

  11. Effect of storage and cooking on beta-carotene isomers in carrots ( Daucus carota L. cv. 'Stefano').

    PubMed

    Imsic, Michael; Winkler, Sonja; Tomkins, Bruce; Jones, Rod

    2010-04-28

    Carrots are one of the highest dietary sources of beta-carotene and are naturally high in the (all-E)-beta-carotene isomer, which has higher bioavailability, provitamin A activity, and antioxidant capacity compared to Z (cis) isomers. The objectives of the present study were to investigate the effects of storage temperature, time, and cooking (boiling for 15 min) on the levels of carotene isomers in 'Stefano' carrots. Storing carrots at either 4 degrees C to simulate long-term storage or 20 degrees C to simulate marketing practices resulted in increases in (all-E)-beta-carotene of 20.3% after 3 days at 4 degrees C and 34.4% after 14 days at 20 degrees C, respectively. The levels of Z isomers in raw carrots were low with (13Z)-beta-carotene and (9Z)-beta-carotene accounting for less that 1.8% of the total beta-carotene present. Levels of (9Z)-beta-carotene decreased during storage at either temperature, whereas storage at 4 degrees C resulted in a 109% increase in (13Z)-beta-carotene after 56 days. Cooking significantly increased the levels of (13Z)-beta-carotene and (9Z)-beta-carotene and resulted in the production of (15Z)-beta-carotene, which was absent in raw carrots. Storage at 4 degrees C for 15 days or more prior to cooking reduced the susceptibility of (all-E)-beta-carotene to thermal isomerization during cooking, resulting in lower levels of all three Z-beta-carotene isomers being generated, while storage at 20 degrees C for up to 21 days resulted in significantly higher levels of (all-E)-beta-carotene before and after cooking but had no effect on Z-isomer production during cooking. Consequently, we conclude that, for the greatest health benefit, fresh carrots can be stored for up to 21 days at 20 degrees C or at 4 degrees C for up to 56 days without significant reduction in (all-E)-beta-carotene and should be consumed raw or boiled for less than 15 min to limit Z-beta-carotene isomer formation.

  12. Effect of decontamination agents on the microbial population, sensorial quality, and nutrient content of grated carrots (Daucus carota L.).

    PubMed

    Vandekinderen, Isabelle; Van Camp, John; Devlieghere, Frank; Veramme, Kim; Denon, Quenten; Ragaert, Peter; De Meulenaer, Bruno

    2008-07-23

    Several decontamination agents including water, sodium hypochlorite, peroxyacetic acid, neutral electrolyzed oxidizing water, and chlorine dioxide gas were tested for their effectiveness to reduce the natural microflora on grated carrots. Microbial reductions of the total aerobic count obtained after the different treatments varied between 0.11 and 3.29 log colony-forming units (cfu)/g. Whether or not a decontamination step induced significant changes in the sensory attributes of grated carrots is highly dependent on the type and concentration of disinfectant. To maintain the nutritional value, the influence of the decontamination agents on carotenoid content, alpha-tocopherol content, total phenols, and antioxidant capacity was studied. Besides the part of the nutrients that was leached away from the cutting areas by water, the nutrient losses caused by adding sanitizers were rather limited. Compared with the untreated carrots alpha-tocopherol content was, however, significantly reduced when 250 ppm of peroxyacetic acid (-80%) or 200 ppm of sodium hypochlorite (-59%) was used. Additional losses in carotenoid content were caused by contact with chlorine dioxide gas (-9%). On the condition of an optimized decontamination process toward time and concentration, the microbial quality of fresh-cut carrots could be improved without negatively influencing their sensory quality and nutrient content.

  13. In vitro bioaccessibility of β-carotene, Ca, Mg and Zn in landrace carrots (Daucus carota, L.).

    PubMed

    Zaccari, Fernanda; Cabrera, María Cristina; Ramos, Ana; Saadoun, Ali

    2015-01-01

    Four landrace carrots ("Becaria", "CRS", "González" and "Rodríguez") and two marketable cultivars (Kuroda and Brasilia), raw and steamed, were characterised by the total content of β-carotene Ca, Mg and Zn, in vitro bioaccessibility and by colour and were evaluated to determine the effect of particle size in nutrient bioaccessibility. Steaming increased the content of β-carotene extracted from "CRS" and Brasilia (29% and 75%) and decreased the content of β-carotene extracted from "CRS" by 23% in "Rodríguez." In addition, steaming caused a loss of Ca (21%) but did not change the amount of Mg and Zn. The bioaccessibility of β-carotene in raw and pulped carrots was very low (<0.5%). Furthermore, steaming and a smaller particle size increased the bioaccessibility of β-carotene by 3-16 times. Additionally, cooking increased the in vitro bioaccessibility of Ca and Zn but had no effect on Mg. Moreover, homogenisation increased the bioaccessibility by 20% in Ca, 17% in Mg, and 10% in Zn compared to pulping.

  14. Clarification and pasteurisation effects on monomeric anthocyanins and percent polymeric colour of black carrot (Daucus carota L.) juice.

    PubMed

    Türkyılmaz, Meltem; Yemiş, Oktay; Ozkan, Mehmet

    2012-09-15

    Black carrots (BCs) are a rich source of stable anthocyanins (ACNs). The purpose of this study was to evaluate the effects of clarification and pasteurisation on ACNs of black carrot juice (BCJ). Monomeric ACNs, ACN profile and percent polymeric colour were determined during processing of BCJ. While depectinisation and bentonite treatments resulted in 7% and 20% increases in monomeric ACN content of BCJ, respectively, gelatine-kieselsol treatment and pasteurisation resulted in 10% and 3-16% reduction. Percent polymeric colour decreased after clarification, but substantially increased in samples subjected to heat. ACNs of BCJ samples were identified by HPLC-MS. Unclarified BCJ contained cyanidin-3-galactoside-xyloside-glucoside-ferulic acid as the major ACN, followed by cyanidin-3-galactoside-xyloside-glucoside-coumaric acid, and cyanidin-3-galactoside-xyloside-glucoside. After depectinisation, two more ACNs (cyanidin-3-galactoside-xyloside and cyanidin-3-galactoside-xyloside-glucoside-sinapic acid) were also identified. These results indicated that depectinisation and bentonite treatment had positive effect on the colour of BCJ, while gelatin-kieselsol treatment and pasteurisation had negative effect.

  15. Multiple nuclear ortholog next generation sequencing phylogeny of Daucus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Next generation sequencing is helping to solve the data insufficiency problem hindering well-resolved dominant gene phylogenies. We used Roche 454 technology to obtain DNA sequences from 93 nuclear orthologs, dispersed throughout all linkage groups of Daucus. Of these 93 orthologs, ten were designed...

  16. Meloidogyne incognita nematode resistance QTL in carrot

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Root-knot nematodes (Meloidogyne spp.) are major pests attacking carrots (Daucus carota) worldwide, causing galling and forking of the storage roots, rendering them unacceptable for market. Genetic resistance could significantly reduce the need for broad-spectrum soil fumigants in carrot production....

  17. Bioactive phenylpropanoids from Daucus crinitus Desf. from Algeria.

    PubMed

    Lanfranchi, Don-Antoine; Laouer, Hocine; El Kolli, Meriem; Prado, Soizic; Maulay-Bailly, Christine; Baldovini, Nicolas

    2010-02-24

    The volatile constituents of Daucus crinitus Desf. from Algeria were analyzed by GC and GC-MS, The main constituent was isochavicol isobutyrate (39.0%), an uncommon phenylpropanoid. By synthesis of a series of homologous esters, it was also possible to determine the presence of small amounts of isochavicol propionate, which has never been described previously as a natural product. The antibacterial and antifungal activities of the whole essential oil, of these two esters, and of isochavicol itself were investigated against a wide range of bacteria and fungi. Additionally, their antimalarial and antiradical properties were also evaluated, showing an interesting antiplasmodial activity of isochavicol.

  18. First report of 'Candidatus Liberibacter solanacearum' on carrot in Africa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In March of 2014, carrot plants (Daucus carota L. var. Mascot) exhibiting symptoms of yellowing, purpling, and curling of leaves, proliferation of shoots, formation of hairy secondary roots, general stunting and plant decline were observed in commercial fields in the Gharb region of Morocco. The sym...

  19. First report of ‘Candidatus Liberibacter solanacearum’ associated with the Psyllid Bactericera trigonica Hodkinson on carrots in northern Africa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Carrot plants (Daucus carota L.) exhibiting symptoms of yellowing, purpling, and curling of leaves, proliferation of shoots, formation of hairy secondary roots, and plant decline were observed in March 2014 and February 2015 in commercial fields in the Gharb region of Morocco. The symptoms resembled...

  20. Combined effects of antimicrobial coating, modified atmosphere packaging, and gamma irradiation on Listeria innocua present in ready-to-use carrots (Daucus carota).

    PubMed

    Caillet, S; Millette, M; Salmiéri, S; Lacroix, M

    2006-01-01

    The objective of this study was to evaluate the effect of an edible antimicrobial coating combined with modified atmosphere (MA) packaging (60% O2, 30% CO2, and 10% N2) and gamma irradiation on peeled minicarrots inoculated with Listeria innocua. Carrots were inoculated with L. innocua (10(3) CFU/g) and then coated with an antimicrobial coating based on calcium caseinate containing trans-cinnamaldehyde. The same formulation without trans-cinnamaldehyde was used as an inactive coating. Coated and uncoated carrots were packed under the MA or under air, irradiated at 0.25 or 0.5 kGy, and stored at 4 +/- 1 degrees C for 21 days. Samples were evaluated periodically for enumeration of L. innocua. Unirradiated carrots stored under air had the highest concentrations of L. innocua after 21 days of storage: 2.23 CFU/g in the uncoated samples and 2.26 CFU/ g in samples coated with the inactive coating. These results suggest that the inactive coating did not have any antimicrobial effect against L. innocua. However, the addition of the antimicrobial coating resulted in a 1.29-log reduction in the concentration of L. innocua in carrots packed under air after 21 days of storage and a 1.08-log reduction in carrots packed under MA after 7 days of storage. After 7 days of storage, no L. innocua was detected in samples treated at 0.5 kGy under air or in samples treated at 0.25 kGy under MA. A complete inhibition of L. innocua was also observed during all storage periods in uncoated and coated samples treated at 0.5 kGy under MA. These results indicate that the combination of irradiation and MA conditions play an important role in the radiosensitization of L. innocua.

  1. Metabolic fingerprinting reveals differences between shoots of wild and cultivated carrot (Daucus carota L.) and suggests maternal inheritance or wild trait dominance in hybrids.

    PubMed

    Grebenstein, C; Choi, Y H; Rong, J; de Jong, T J; Tamis, W L M

    2011-08-01

    Differences between the metabolic content of cultivars and their related wild species not only have implications for breeding and food quality, but also for the increasingly studied area of crop to wild introgression. Wild and cultivated western carrots belong to the same outcrossing species and hybridize under natural conditions. The metabolic fingerprinting of Dutch wild carrot and of western orange carrot cultivar shoots using (1)H NMR showed only quantitative differences in chemical content, indicating relatively low divergence after domestication. Main differences reside in the primary metabolite content and in the concentrations of chlorogenic acid and feruloyl quinic acid in the shoots of the different carrot types. Wild×cultivar hybrids cannot be distinguished from wild plants based on the metabolome, suggesting maternal, maternal environment, or dominance effects, and indicating high hybrid fitness in wild conditions. Considering these similarities, introgression is a real possibility in carrots, but understanding its consequences would require further studies using backcrosses in a multiple environments.

  2. Combined effects of coating, modified atmosphere packaging, and gamma irradiation on quality maintenance of ready-to-use carrots (Daucus carota).

    PubMed

    Lafortune, R; Caillet, S; Lacroix, M

    2005-02-01

    The objective of this study was to evaluate the effect of an edible coating combined with modified atmosphere (MA; 60% O2, 30% CO2, and 10% N2) packaging and gamma irradiation on the microbiological stability and physicochemical quality of minimally processed carrots. A coating based on calcium caseinate and whey protein isolates was used. Coated and uncoated peeled minicarrots were packed under the MA or air (78.1% N2, 20.9% O2, and 0.036% CO2), irradiated at 0.5 or 1 kGy, and stored at 4 +/- 1 degrees C for 21 days. Samples were evaluated periodically for aerobic plates counts (APCs) and physicochemical properties (firmness, white discoloration, and whiteness index). Gamma irradiation did not significantly affect the physicochemical properties of the carrots (P > 0.05). Microbiological analysis revealed that for uncoated carrots irradiation at 0.5 and 1 kGy under air and MA reduced the APCs by 3.5 and 4 log CFU/g and by 4 and 4.5 log CFU/g, respectively. For coated carrots, irradiation at 0.5 and 1 kGy under air and MA reduced the APCs by 4 and 4.5 log CFU/g and by 3 and 4.25 log CFU/g, respectively. The coating was able to protect carrots against dehydration during storage under air. Coating and irradiation at 1 kGy were also able to protect carrot firmness during storage under air. MA packaging retarded whitening of uncoated carrots but had a detrimental effect on firmness. The edible coating used in this study did not significantly inhibit (P > 0.05) microbial growth on carrots.

  3. The impact of fermentation with exopolysaccharide producing lactic acid bacteria on rheological, chemical and sensory properties of pureed carrots (Daucus carota L.).

    PubMed

    Juvonen, Riikka; Honkapää, Kaisu; Maina, Ndegwa H; Shi, Qiao; Viljanen, Kaarina; Maaheimo, Hannu; Virkki, Liisa; Tenkanen, Maija; Lantto, Raija

    2015-08-17

    Fermentation with lactic acid bacteria (LAB) offers a natural means to modify technological and nutritional properties of foods and food ingredients. This study explored the impact of fermentation with different exopolysaccharide (EPS) producing LAB on rheological, chemical and sensory properties of puréed carrots in water, as a vegetable model, with the focus on texture formation. The screening of 37 LAB strains for starter selection revealed 16 Lactobacillus, Leuconostoc and Weissella strains capable of EPS (dextran, levan, and/or β-glucan) production in the carrot raw material. Fermentations with five out of six selected EPS producers modified perceived texture of the liquid carrot model (p<0.05). The formation of low-branched dextran correlated with perceived thickness, whereas the production of β-glucan correlated with perceived elasticity. Low-branched dextran producing Weissella confusa and Leuconostoc lactis strains produced thick texture accompanied by pleasant odour and flavour. The fermentation with the selected EPS-producing LAB strains is a promising clean label approach to replace hydrocolloid additives as texturizers in vegetable containing products, not only carrot.

  4. Anthocyanins in purple-orange carrots (Daucus carota L.) do not influence the bioavailability of beta-carotene in young women.

    PubMed

    Arscott, Sara A; Simon, Philipp W; Tanumihardjo, Sherry A

    2010-03-10

    Purple carrots contain anthocyanins in addition to the provitamin A carotenoids in typical orange carrots. Simultaneous consumption of these phytochemicals in carrots may affect the bioavailability of carotenoids. The bioavailability of beta-carotene in humans was assessed from an acute feeding of orange (OC) and purple (PC) carrots with white (WC) as a control. Carrot smoothies were served to female subjects (n = 5, aged 21-26 years) for breakfast after 1 week on a low carotenoid diet and overnight fast. OC and PC smoothies were equalized to 10.3 mg of all-trans beta-carotene. Plasma beta-carotene was measured for 144 h following treatments. Peak plasma concentrations of OC and PC treatments did not differ. The PC treatment 0-144 h area-under-the-curve for beta-carotene was 76% of the OC treatment (P < 0.05). However, when the first 24 h were compared, OC and PC treatments did not differ, suggesting that anthocyanins in purple carrots do not affect the absorption of beta-carotene postprandially.

  5. Fractionation of Plant Bioactives from Black Carrots (Daucus carota subspecies sativus varietas atrorubens Alef.) by Adsorptive Membrane Chromatography and Analysis of Their Potential Anti-Diabetic Activity.

    PubMed

    Esatbeyoglu, Tuba; Rodríguez-Werner, Miriam; Schlösser, Anke; Liehr, Martin; Ipharraguerre, Ignacio; Winterhalter, Peter; Rimbach, Gerald

    2016-07-27

    Black and purple carrots have attracted interest as colored extracts for coloring food due to their high content of anthocyanins. This study aimed to investigate the polyphenol composition of black carrots. Particularly, the identification and quantification of phenolic compounds of the variety Deep Purple carrot (DPC), which presents a very dark color, was performed by HPLC-PDA and HPLC-ESI-MS(n) analyses. The separation of polyphenols from a DPC XAD-7 extract into an anthocyanin fraction (AF) and co-pigment fraction (CF; primarily phenolic acids) was carried out by membrane chromatography. Furthermore, possible anti-diabetic effects of the DPC XAD-7 extract and its AF and CF were determined. DPC samples (XAD-7, CF, and AF) inhibited α-amylase and α-glucosidase in a dose-dependent manner. Moreover, DPC XAD-7 and chlorogenic acid, but not DPC CF and DPC AF, caused a moderate inhibition of intestinal glucose uptake in Caco-2 cells. However, DPC samples did not affect glucagon-like peptide-1 (GLP-1) secretion and dipeptidyl peptidase IV (DPP-4) activity. Overall, DPC exhibits an inhibitory effect on α-amylase and α-glucosidase activity and on cellular glucose uptake indicating potential anti-diabetic properties.

  6. Analysis of the Thermal Degradation of the Individual Anthocyanin Compounds of Black Carrot (Daucus carota L.): A New Approach Using High-Resolution Proton Nuclear Magnetic Resonance Spectroscopy.

    PubMed

    Iliopoulou, Ioanna; Thaeron, Delphine; Baker, Ashley; Jones, Anita; Robertson, Neil

    2015-08-12

    The black carrot dye is a mixture of cyanidin molecules, the nuclear magnetic resonance (NMR) spectrum of which shows a highly overlapped aromatic region. In this study, the (1)H NMR (800 MHz) aromatic chemical shifts of the mixture were fully assigned by overlaying them with the characterized (1)H NMR chemical shifts of the separated compounds. The latter were isolated using reverse-phase high-performance liquid chromatography (RP-HPLC), and their chemical shifts were identified using (1)H and two-dimensional (2D) correlation spectroscopy (COSY) NMR spectroscopy. The stability of the black carrot mixture to heat exposure was investigated at pH 3.6, 6.8, and 8.0 by heat-treating aqueous solutions at 100 °C and the powdered material at 180 °C. From integration of high-resolution (1)H NMR spectra, it was possible to follow the relative degradation of each compound, offering advantages over the commonly used ultraviolet/visible (UV/vis) and HPLC approaches. UV/vis spectroscopy and CIE color measurements were used to determine thermally induced color changes, under normal cooking conditions.

  7. Diversity, genetic mapping, and signatures of domestication in the carrot (Daucus carota L.) genome, as revealed by Diversity Arrays Technology (DArT) markers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Carrot is one of the most economically important vegetables worldwide, however, genetic and genomic resources supporting carrot breeding remain limited. We developed a Diversity Arrays Technology (DArT) platform for wild and cultivated carrot and used it to investigate genetic diversity and to devel...

  8. Increased Nicotiana tabacum fitness through positive regulation of carotenoid, gibberellin and chlorophyll pathways promoted by Daucus carota lycopene β-cyclase (Dclcyb1) expression.

    PubMed

    Moreno, J C; Cerda, A; Simpson, K; Lopez-Diaz, I; Carrera, E; Handford, M; Stange, C

    2016-04-01

    Carotenoids, chlorophylls and gibberellins are derived from the common precursor geranylgeranyl diphosphate (GGPP). One of the enzymes in carotenoid biosynthesis is lycopene β-cyclase (LCYB) that catalyzes the conversion of lycopene into β-carotene. In carrot, Dclcyb1 is essential for carotenoid synthesis in the whole plant. Here we show that when expressed in tobacco, increments in total carotenoids, β-carotene and chlorophyll levels occur. Furthermore, photosynthetic efficiency is enhanced in transgenic lines. Interestingly, and contrary to previous observations where overexpression of a carotenogenic gene resulted in the inhibition of the synthesis of gibberellins, we found raised levels of active GA4 and the concommitant increases in plant height, leaf size and whole plant biomass, as well as an early flowering phenotype. Moreover, a significant increase in the expression of the key carotenogenic genes, Ntpsy1, Ntpsy2 and Ntlcyb, as well as those involved in the synthesis of chlorophyll (Ntchl), gibberellin (Ntga20ox, Ntcps and Ntks) and isoprenoid precursors (Ntdxs2 and Ntggpps) was observed. These results indicate that the expression of Dclcyb1 induces a positive feedback affecting the expression of isoprenoid gene precursors and genes involved in carotenoid, gibberellin and chlorophyll pathways leading to an enhancement in fitness measured as biomass, photosynthetic efficiency and carotenoid/chlorophyll composition.

  9. Influence of thermal processing on hydrolysis and stability of folate poly-gamma-glutamates in broccoli (Brassica oleracea var. italica), carrot (Daucus carota) and tomato (Lycopersicon esculentum).

    PubMed

    Munyaka, Ann Wambui; Verlinde, Philippe; Mukisa, Ivan Muzira; Oey, Indrawati; Van Loey, Ann; Hendrickx, Marc

    2010-04-14

    The folate poly-gamma-glutamate profile, their concentrations, and hydrolysis by endogenous gamma-glutamyl hydrolase (GGH) were evaluated in broccoli, carrot and tomato. Further studies on the effect of time and temperature on folate poly-gamma-glutamate hydrolysis and stability were carried out in broccoli since this vegetable showed the highest long-chain and total folate poly-gamma-glutamate concentration. The evolution of l-ascorbic acid, total phenols and Trolox equivalent antioxidant capacity (TEAC) values was evaluated in parallel. Upon thermal inactivation of GGH prior to crushing, it was observed that broccoli, carrot and tomato contained poly-gamma-glutamates with one to seven glutamate residues but differed in the predominant poly-gamma-glutamates. Crushing of raw broccoli, carrot and tomato resulted in significant poly-gamma-glutamate profile changes in broccoli and carrot (indicating GGH-catalyzed hydrolysis) but not in tomato. In this study, the actual crushing of raw broccoli matrix had a greater effect on folate poly-gamma-glutamate hydrolysis than incubation conditions (0-30 min at 25-55 degrees C). During treatments at 25-140 degrees C, folate retention was higher at 80 and 100 degrees C than at the other temperatures. A similar trend in thermal stability was observed for folates, vitamin C, total phenols and TEAC value, an indication that conditions that result in endogenous antioxidants degradation might also result in folate degradation.

  10. Radiation processing to ensure safety of minimally processed carrot (Daucus carota) and cucumber (Cucumis sativus): optimization of dose for the elimination of Salmonella Typhimurium and Listeria monocytogenes.

    PubMed

    Dhokane, V S; Hajare, S; Shashidhar, R; Sharma, A; Bandekar, J R

    2006-02-01

    Minimally processed vegetables are in demand, because they offer convenience to consumers. However, these products are often unsafe because of possible contamination with pathogens, such as Salmonella, Escherichia coli O157:H7, and Shigella species. Therefore, this study was carried out to optimize the radiation dose necessary to ensure the safety of precut carrot and cucumber. Decimal reduction doses (D-values) of Salmonella Typhimurium MTCC 98 were ca. 0.164 kGy in carrot samples and 0.178 kGy in cucumber samples. D-values of Listeria monocytogenes were determined to be 0.312 and 0.345 kGy in carrot and cucumber samples, respectively. Studies of inoculated, packaged, minimally processed carrot and cucumber samples showed that treatment with a 1-kGy dose of gamma radiation eliminated up to 4 log CFU/g of Salmonella Typhimurium and 3 log CFU/g of L. monocytogenes. However, treatment with a 2-kGy dose was necessary to eliminate these pathogens by 5 log CFU/g. Storage studies showed that both Salmonella Typhimurium and L. monocytogenes were able to grow at 10 degrees C in inoculated control samples. Neither of these pathogens could be recovered from radiation-processed samples after storage for up to 8 days.

  11. Development and Characterization of Novel SSR Markers in Carrot (Daucus Carota L.) and Their Application for Mapping and Diversity Analysis in Apiaceae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genomic resources in carrot and other Apiaceae are relatively underdeveloped. The availability of a large set of pcr-based codominant markers, such as simple sequence repeats (SSR), would allow integration of the different carrot genetic maps constructed to date (mainly using anonymous dominant mark...

  12. Structural and sensory characterization of compounds contributing to the bitter off-taste of carrots (Daucus carota L.) and carrot puree.

    PubMed

    Czepa, Andreas; Hofmann, Thomas

    2003-06-18

    Sequential application of solvent extraction, gel permeation chromatography, and HPLC in combination with taste dilution analyses revealed that not a sole compound but a multiplicity of bitter tastants contribute to the bitter off-taste of cold-stored carrots and commercial carrot puree, respectively. Among these bitter compounds, 3-methyl-6-methoxy-8-hydroxy-3,4-dihydroisocoumarin (6-methoxymellein), 5-hydroxy-7-methoxy-2-methylchromone (eugenin), 2,4,5-trimethoxybenzaldehyde (gazarin), (Z)-heptadeca-1,9-diene-4,6-diin-3,8-diol (falcarindiol), (Z)-heptadeca-1,9-diene-4,6-diin-3-ol (falcarinol), and (Z)-3-acetoxy-heptadeca-1,9-diene-4,6-diin-8-ol (falcarindiol 3-acetate) could be identified on the basis of MS as well as 1D- and 2D-NMR experiments. Due to the low concentrations of <0.1 mg/kg and the high taste thresholds found for eugenin and gazarin, these compounds could be unequivocally excluded as important contributors to the bitter taste of carrots. Calculation of bitter activity values as the ratio of their concentration to their bitter detection threshold clearly demonstrated that neither in fresh and stored carrots nor in commercial carrot puree did 6-methoxymellein contribute to the bitter off-taste. In contrast, the concentrations of falcarindiol in stored carrots and, even more pronounced, in carrot puree were found to be 9- and 13-fold above its low bitter detection concentration of 0.04 mmol/kg, thus demonstrating that this acetylenic diol significantly contributes to the bitter taste of the carrot products investigated.

  13. Increased Nicotiana tabacum fitness through positive regulation of carotenoid, gibberellin and chlorophyll pathways promoted by Daucus carota lycopene β-cyclase (Dclcyb1) expression

    PubMed Central

    Moreno, J.C.; Cerda, A.; Simpson, K.; Lopez-Diaz, I.; Carrera, E; Handford, M.; Stange, C.

    2016-01-01

    Carotenoids, chlorophylls and gibberellins are derived from the common precursor geranylgeranyl diphosphate (GGPP). One of the enzymes in carotenoid biosynthesis is lycopene β-cyclase (LCYB) that catalyzes the conversion of lycopene into β-carotene. In carrot, Dclcyb1 is essential for carotenoid synthesis in the whole plant. Here we show that when expressed in tobacco, increments in total carotenoids, β-carotene and chlorophyll levels occur. Furthermore, photosynthetic efficiency is enhanced in transgenic lines. Interestingly, and contrary to previous observations where overexpression of a carotenogenic gene resulted in the inhibition of the synthesis of gibberellins, we found raised levels of active GA4 and the concommitant increases in plant height, leaf size and whole plant biomass, as well as an early flowering phenotype. Moreover, a significant increase in the expression of the key carotenogenic genes, Ntpsy1, Ntpsy2 and Ntlcyb, as well as those involved in the synthesis of chlorophyll (Ntchl), gibberellin (Ntga20ox, Ntcps and Ntks) and isoprenoid precursors (Ntdxs2 and Ntggpps) was observed. These results indicate that the expression of Dclcyb1 induces a positive feedback affecting the expression of isoprenoid gene precursors and genes involved in carotenoid, gibberellin and chlorophyll pathways leading to an enhancement in fitness measured as biomass, photosynthetic efficiency and carotenoid/chlorophyll composition. PMID:26893492

  14. Nuclear DNA content variation within the genus Daucus (Apiaceae) determined by flow cytometry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The genus Daucus (Apiaceae) comprises species from around the world, covering a wide climatic range, and showing great morphological plasticity. Both cultivated and wild forms are described within the genus. The aim of the present study was to estimate the genome size variability in the collection o...

  15. Fruit morphological descriptors as a tool for discrimination of Daucus L. germplasm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Morphological diversity of a Daucus L. germplasm collection maintained at the National Gene Bank of Tunisia was assessed using fourteen morphological descriptors related to mature fruits. Quantification of variability for each character was investigated using the standardized Shannon-Weaver Diversit...

  16. Characterization of volatile compounds of Daucus crinitus Desf. Headspace Solid Phase Microextraction as alternative technique to Hydrodistillation

    PubMed Central

    2010-01-01

    Background Traditionally, the essential oil of aromatic herbs is obtained using hydrodistillation (HD). Because the emitted volatile fraction plays a fundamental role in a plant's life, various novel techniques have been developed for its extraction from plants. Among these, headspace solid phase microextraction (HS-SPME) can be used to obtain a rapid fingerprint of a plant's headspace. Daucus crinitus Desf. is a wild plant that grows along the west coast of Algeria. Only a single study has dealt with the chemical composition of the aerial part oils of Algerian D. crinitus, in which isochavicol isobutyrate (39.0%), octyl acetate (12.3%), and β-caryophyllene (5.4%) were identified. Using GC-RI and GC-MS analysis, the essential oils and the volatiles extracted from separated organs of D. crinitus Desf. were studied using HS-SPME. Results GC-RI and GC-MS analysis identified 72 and 79 components in oils extracted using HD and in the volatile fractions extracted using SPME, respectively. Two types of essential oils were produced by the plant: the root oils had aliphatic compounds as the main component (87.0%-90.1%), and the aerial part oils had phenylpropanoids as the main component (43.1%-88.6%). HS-SPME analysis showed a more precise distribution of compounds in the organs studied: oxygenated aliphatic compounds were well represented in the roots (44.3%-84.0%), hydrocarbon aliphatic compounds were in the leaves and stems (22.2%-87.9%), and phenylpropanoids were in the flowers and umbels (47.9%-64.2%). Moreover, HS-SPME allowed the occurrence of isochavicol (29.6 - 34.7%) as main component in D. crinitus leaves, but it was not detected in the oils, probably because of its solubility in water. Conclusions This study demonstrates that HD and HS-SPME modes could be complimentary extraction techniques in order to obtain the complete characterization of plant volatiles. PMID:20858266

  17. Entire plastid phylogeny of the carrot genus (Daucus, Apiaceae):Concordance with nuclear data and mitochondrial and nuclear DNA insertions to the plastid

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We explored the phylogenetic utility of entire plastid DNA sequences in Daucus and compared the results to prior phylogenetic results using plastid, nuclear, and mitochondrial DNA sequences. We obtained, using Illumina sequencing, full plastid sequences of 37 accessions of 20 Daucus taxa and outgrou...

  18. Lectotype designation for seven species names in the Daucus guttatus complex (Apiaceae) from the central and eastern Mediterranean basin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Daucus guttatus complex includes 2-4 species growing from central and northern Italy to the Middle East. They are characterized by being usually annuals up to 50 cm high; and the primary umbels up to 7 cm in diameter with less than 25(35) rays. Discolored umbels are frequent, bearing one to seve...

  19. Bioactive Terpenoids and Flavonoids from Daucus littoralis Smith subsp. hyrcanicus Rech.f, an Endemic Species of Iran

    PubMed Central

    2014-01-01

    Background Daucus littoralis Smith subsp. hyrcanicus Rech.f. (Apiaceae) is an endemic species in northern parts of Iran where it is commonly named Caspian carrot. The fruits have been used as condiment. Methods In a series of in vitro assays, antioxidant (DPPH and FRAP assays), cytotoxic and antimicrobial activities of different extracts of roots and fruits were evaluated for the first time. The separation and purification of the compounds were carried out on the most potent extracts using various chromatographic methods and identified by spectroscopic data (1H and 13C NMR). Results The results showed that among the extracts only fruit methanol extract (FME) has significant antioxidant activity (IC50 = 145.93 μg.ml-1 in DPPH assay and 358 ± 0.02 mmol FeII/g dry extract in FRAP assay). The radical scavenging activity of FME at 400 μg.ml-1 was comparable with α-tocopherol (40 μg.ml-1) and with BHA (100 μg.ml-1) (p > 0.05). FME did not show any toxicity against cancerous and normal cell lines. Fruit ethyl acetate extract (FEE) had cytotoxic activity against breast carcinoma and hepatocellular carcinoma cells (IC50 168.4 and 185 μg.ml-1, respectively), while it did not possess antioxidant activity in comparison with α-tocopherol and BHA as standard compounds. Ethyl acetate and methanol extract of fruits showed antimicrobial activity against Staphylococcus aureus (MIC: 3.75 mg.ml-1) and Candida albicans (MIC: 15.6 and 7.8 mg.ml-1, respectively). Four terpenoids were isolated form FEE including: β-sitosterol (1), stigmasterol (2), caryophyllene oxide (3), β-amyrin (4). Also, three flavonoids namely quercetin 3-O-β-glucoside (5), quercetin 3-O-β-galactoside (6) and luteolin (7) were isolated from FME. Conclusion This study showed that FEE and FME of D. littoralis Smith subsp. hyrcanicus Rech.f. had the highest biological activities which may be correlated with in vitro cytotoxic, antimicrobial and antioxidant activities of terpenoids and

  20. Determination of kinetic and equilibrium parameters of the batch adsorption of Mn(II), Co(II), Ni(II) and Cu(II) from aqueous solution by black carrot (Daucus carota L.) residues.

    PubMed

    Güzel, Fuat; Yakut, Hakan; Topal, Giray

    2008-05-30

    In this study, the effect of temperature on the adsorption of Mn(II), Ni(II), Co(II) and Cu(II) from aqueous solution by modified carrot residues (MCR) was investigated. The equilibrium contact times of adsorption process for each heavy metals-MCR systems were determined. Kinetic data obtained for each heavy metal by MCR at different temperatures were applied to the Lagergren equation, and adsorption rate constants (kads) at these temperatures were determined. These rate constants related to the adsorption of heavy metal by MCR were applied to the Arrhenius equation, and activation energies (Ea) were determined. In addition, the isotherms for adsorption of each heavy metal by MCR at different temperatures were also determined. These isothermal data were applied to linear forms of isotherm equations that they fit the Langmuir adsorption isotherm, and the Langmuir constants (qm and b) were calculated. b constants determined at different temperatures were applied to thermodynamic equations, and thermodynamic parameters such as enthalpy (Delta H), free energy (Delta G), and entropy (Delta S) were calculated and these values show that adsorption of heavy metal on MCR was an endothermic process and process of adsorption was favoured at high temperatures.

  1. Influence of field attack by carrot psyllid (Trioza apicalis Förster) on sensory quality, antioxidant capacity and content of terpenes, falcarindiol and 6-methoxymellein of carrots (Daucus carota L.).

    PubMed

    Seljåsen, Randi; Vogt, Gjermund; Olsen, Elisabeth; Lea, Per; Høgetveit, Lars Arne; Tajet, Torgeir; Meadow, Richard; Bengtsson, Gunnar B

    2013-03-20

    The effect of different degrees of attack by carrot psyllid (Trioza apicalis) on quality parameters of carrots was studied in field experiments for two years. Treatments were different degrees of physical insect protection by floating row cover. An increasing attack level of psyllids showed an enhancement effect on the antioxidant capacity (ORAC), content of falcarindiol, 6-methoxymellein, and terpenes, and scores for bitter taste, chemical flavor, terpene flavor, and toughness. Carrot psyllid attack decreased the yield, total sugar, fructose, glucose, and sensory attributes sweet taste, color hue, color strength, crispiness, and juiciness. Carrot plants at 8-10 weeks of age tolerated attack by psyllids at low levels (2% leaves with curling or discoloration).

  2. Development and in-house validation of allergen-specific ELISA tests for the quantification of Dau c 1.01, Dau c 1.02 and Dau c 4 in carrot extracts (Daucus carota).

    PubMed

    Foetisch, Kay; Dahl, Lotte; Jansen, Baerbel; Becker, Wolf-Meinhard; Lidholm, Jonas; van Ree, Ronald; Broll, Hermann; Kaul, Susanne; Vieths, Stefan; Holzhauser, Thomas

    2011-01-01

    Even though carrot allergy is common in Europe, the amount of different allergens in carrots is still unknown due to a lack of methods for quantitative allergen measurements. The current study aimed at the development of quantitative ELISA tests for the known carrot allergens, namely Dau c 1.01, Dau c 1.02, and Dau c 4 in pure carrot extracts. Monoclonal antibodies targeting the major carrot allergen isoforms Dau c 1.01 and Dau c 1.02 were generated and combined in sandwich ELISA with rabbit antisera against Api g 1, the celery homologue of Dau c 1. A competitive ELISA for the carrot profilin Dau c 4 was based on a polyclonal rabbit antiserum. The three ELISA tests were allergen-specific and displayed detection limits between 0.4 and 6 ng allergen/ml of carrot extract. The mean coefficient of variation (CV) as a means of intraassay variability of the Dau c 1.01, Dau c 1.02 and Dau c 4 ELISA tests was 8.1%, 6.9%, and 11.9%, and the mean interassay CV 13.3%, 37.1% and 15.6%, respectively. Target recovery ranged between 93 and 113%. In conclusion, the specific, accurate and reproducible quantification of three important carrot allergens may help to identify less allergenic carrot varieties, as well as to standardize the amount of allergens in extracts used for carrot allergy diagnosis.

  3. Carryover of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) from soil to plant and distribution to the different plant compartments studied in cultures of carrots (Daucus carota ssp. Sativus), potatoes (Solanum tuberosum), and cucumbers (Cucumis Sativus).

    PubMed

    Lechner, Mareike; Knapp, Holger

    2011-10-26

    A vegetation study was carried out to investigate the carryover of Perfluorooctanoic Acid (PFOA) and Perfluorooctane Sulfonate (PFOS) from soil mixed with contaminated sewage sludge to potato, carrot, and cucumber plants. Analysis was done by liquid-extraction using acetonitrile with dispersive SPE cleanup and subsequent HPLC-MS/MS. In order to assess the transfer potential from soil, transfer factors (TF) were calculated for the different plant compartments: TF = [PFC](plant (wet substance))/[PFC](soil (dry weight)). The highest TF were found for the vegetative plant compartments with average values for PFOS below those for PFOA: cucumber, 0.17 (PFOS), 0.88 (PFOA); potato, 0.36 (PFOS), 0.40 (PFOA); carrot, 0.38 (PFOS), 0.53 (PFOA). Transfer of PFOA and PFOS into potato peelings (average values of TF: PFOA 0.03, PFOS 0.04) exceeded the carryover to the peeled tubers (PFOA 0.01, PFOS < 0.01). In carrots, this difference did not occur (average values of TF: PFOA 0.04, PFOS 0.04). Transfer of PFOS into the unpeeled cucumbers was low and comparable to that of peeled potatoes (TF < 0.01). For PFOA, it was higher (TF: 0.03).

  4. Chemical Composition Variability of Essential Oils of Daucus gracilis Steinh. from Algeria.

    PubMed

    Benyelles, Batoul; Allali, Hocine; El Amine Dib, Mohamed; Djabou, Nassim; Paolini, Julien; Costa, Jean

    2017-02-17

    The chemical compositions of 20 Algerian Daucus gracilis essential oils were investigated using GC-FID, GC/MS, and NMR analyses. Altogether, 47 compounds were identified, accounting for 90-99% of the total oil compositions. The main components were linalool (18; 12.5-22.6%), 2-methylbutyl 2-methylbutyrate (20; 9.2-20.2%), 2-methylbutyl isobutyrate (10; 4.2-12.2%), ammimajane (47; 2.6-37.1%), (E)-β-ocimene (15; 0.2-12.8%) and 3-methylbutyl isovalerate (19; 3.3-9.6%). The chemical composition of the essential oils obtained from separate organs was also studied. GC and GC/MS analysis of D. gracilis leaves and flowers allowed identifying 47 compounds, amounting to 92.3% and 94.1% of total oil composition, respectively. GC and GC/MS analysis of D. gracilis leaf and flower oils allowed identifying linalool (22.7%), 2-methylbutyl 2-methylbutyrate (18.9%), 2-methylbutyl isovalerate (13.6%), ammimajane (10.4%), 3-methylbutyl isovalerate (10.3%), (E)-β-ocimene (8.4%) and isopentyl 2-methylbutyrate (8.1%) as main components. The chemical variability of the Algerian oil samples was studied using statistical analysis, which allowed the discrimination of three main Groups. A direct correlation between the altitudes, nature of soils and the chemical compositions of the D. gracilis essential oils was evidenced. This article is protected by copyright. All rights reserved.

  5. Root Hairs

    PubMed Central

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

    2014-01-01

    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

  6. EPR as an analytical tool in assessing the mineral nutrients and irradiated food products-vegetables

    NASA Astrophysics Data System (ADS)

    Prasuna, C. P. Lakshmi; Chakradhar, R. P. S.; Rao, J. L.; Gopal, N. O.

    2008-12-01

    EPR spectral investigations of some commonly available vegetables in south India, which are of global importance like Daucus carota (carrot), Cyamopsis tetragonoloba (cluster beans), Coccinia indica (little gourd) and Beta vulgaris (beet root) have been carried out. In all the vegetable samples a free radical corresponding to cellulose radical is observed. Almost all the samples under investigation exhibit Mn ions in different oxidation states. The temperature variation EPR studies are done and are discussed in view of the paramagnetic oxidation states. The radiation-induced defects have also been assessed by using the EPR spectra of such irradiated food products.

  7. 21 CFR 182.20 - Essential oils, oleoresins (solvent-free), and natural extractives (including distillates).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) Elettaria cardamomum Maton. Carob bean Ceratonia siliqua L. Carrot Daucus carota L. Cascarilla bark Croton... limon (L.) Burm. f. Lime Citrus aurantifolia Swingle. Linden flowers Tilia spp. Locust bean...

  8. Biological Survey, Buffalo River and Outer Harbor of Buffalo, New York. Volume II. Data Report.

    DTIC Science & Technology

    1982-06-01

    lTorsalm artichoke ) Sn’ilacina stellata (L.) Desf.2 (starry false *;soonns seal)2 Solidago canadensis L. 3 3 Ioldenrod) Daucus Carota L. 44 laee Anne’s lace...hispida Push. Hedge nettle *Helianthus tuberosus L. Jerusalem artichoke Oxybaphus nctagineus (Michx.) Sweet. Umbrella wort Aster sp. Aster Polygonatum...Jerusalem artichoke Guem laciniatum Murr. Avens Daucus Carota L. Queen Ann’s lace Cichorium Intybus L. Chicory Asclepias syriaca L. Common milkweed

  9. Environmental Assessment/Baseline Survey to Establish New Drop Zone (DZ) in Cadiz, Ohio

    DTIC Science & Technology

    2009-03-01

    consists primarily of grasses and legumes (e.g., clover, vetch) with some other forbs, including Aster sp., Queen Anne’s lace (Daucus carota), chicory ...legumes (clover, vetch), and other herbaceous plants (e.g., chicory , aster, queen anne’s lace, goldenrod, teasel). • There is a “puddle” near the...with some other forbs, including Aster sp., Queen Anne’s lace (Daucus carota), chicory (Cichorium intybus), goldenrod (Solidago canadensis), and

  10. Environmental Assessment/Baseline Survey to Establish New Drop Zone (DZ) in Cadiz, Ohio, Pittsburgh Air Reserve Station, Coraopolis, Pennsylvania

    DTIC Science & Technology

    2009-03-01

    with some other forbs, including Aster sp., Queen Anne’s lace (Daucus carota), chicory (Cichorium intybus), goldenrod (Solidago sp.), and teasel... chicory , aster, queen anne’s lace, goldenrod, teasel). • There is a “puddle” near the center of the circular drop zone. It was dry during the site visit...forbs, including Aster sp., Queen Anne’s lace (Daucus carota), chicory (Cichorium intybus), goldenrod (Solidago canadensis), and teasel (Dipsacus

  11. Automated Root Tracking with "Root System Analyzer"

    NASA Astrophysics Data System (ADS)

    Schnepf, Andrea; Jin, Meina; Ockert, Charlotte; Bol, Roland; Leitner, Daniel

    2015-04-01

    Crucial factors for plant development are water and nutrient availability in soils. Thus, root architecture is a main aspect of plant productivity and needs to be accurately considered when describing root processes. Images of root architecture contain a huge amount of information, and image analysis helps to recover parameters describing certain root architectural and morphological traits. The majority of imaging systems for root systems are designed for two-dimensional images, such as RootReader2, GiA Roots, SmartRoot, EZ-Rhizo, and Growscreen, but most of them are semi-automated and involve mouse-clicks in each root by the user. "Root System Analyzer" is a new, fully automated approach for recovering root architectural parameters from two-dimensional images of root systems. Individual roots can still be corrected manually in a user interface if required. The algorithm starts with a sequence of segmented two-dimensional images showing the dynamic development of a root system. For each image, morphological operators are used for skeletonization. Based on this, a graph representation of the root system is created. A dynamic root architecture model helps to determine which edges of the graph belong to an individual root. The algorithm elongates each root at the root tip and simulates growth confined within the already existing graph representation. The increment of root elongation is calculated assuming constant growth. For each root, the algorithm finds all possible paths and elongates the root in the direction of the optimal path. In this way, each edge of the graph is assigned to one or more coherent roots. Image sequences of root systems are handled in such a way that the previous image is used as a starting point for the current image. The algorithm is implemented in a set of Matlab m-files. Output of Root System Analyzer is a data structure that includes for each root an identification number, the branching order, the time of emergence, the parent

  12. Natural genetic transformation by agrobacterium rhizogenes . Annual flowering in two biennials, belgian endive and carrot

    PubMed

    Limami; Sun; Douat; Helgeson; Tepfer

    1998-10-01

    Genetic transformation of Belgian endive (Cichorium intybus) and carrot (Daucus carota) by Agrobacterium rhizogenes resulted in a transformed phenotype, including annual flowering. Back-crossing of transformed (R1) endive plants produced a line that retained annual flowering in the absence of the other traits associated with A. rhizogenes transformation. Annualism was correlated with the segregation of a truncated transferred DNA (T-DNA) insertion. During vegetative growth, carbohydrate reserves accumulated normally in these annuals, and they were properly mobilized prior to anthesis. The effects of individual root-inducing left-hand T-DNA genes on flowering were tested in carrot, in which rolC (root locus) was the primary promoter of annualism and rolD caused extreme dwarfism. We discuss the possible adaptive significance of this attenuation of the phenotypic effects of root-inducing left-hand T-DNA.

  13. Comparisons of Pathological Responses in Carrot to Root-knot Nematodes

    PubMed Central

    Seo, Yunhee; Kim, Yong Su; Park, Yong; Kim, Young Ho

    2015-01-01

    Carrot (Dacus carota var. sativus) is one of the top-ten most economically important vegetable crops produced worldwide, and the root-knot nematodes, Meloidogyne spp., are one of the most important pests in the carrot. In Korea, M. hapla and M. incognita are presumed to be the major root-knot nematodes distributing mostly in open carrot fields and greenhouses, respectively. In our study, currently-developed and commercial carrot cultivars and the parental lines were examined for their pathological responses to M. incognita and M. hapla 7 weeks after inoculation with about 1,000 second-stage juveniles (J2) of the nematodes. All the carrot cultivars and lines showed susceptible responses to both nematodes with the gall index (GI) of 2.4–4.4, which were always higher on the carrot plants infected with M. incognita than M. hapla. Gall sizes were remarkably larger with more serious reduction of the root growths in the plants infected with M. incognita than M. hapla, suggesting the carrot lines examined in our study were more susceptible to the former than the latter. In the infection sites of the root tissues, giant cells were more extensively formed, occupying larger stellar regions with the prominent destruction of adjacent xylem vessels by M. incognita than M. hapla. All of these results suggest M. incognita affect more seriously on the carrot plants that are grown in greenhouses, compared to M. hapla that has a major distribution in open carrot fields, which would be used for determining cropping systems based on target nematode species, their damage and pathological characteristics. PMID:26675114

  14. Genome sequencing and comparative analysis of the carrot bacterial blight pathogen, Xanthomonas hortorum pv. carotae M081, for insights into pathogenicity and applications in molecular diagnostics.

    PubMed

    Kimbrel, Jeffrey A; Givan, Scott A; Temple, Todd N; Johnson, Kenneth B; Chang, Jeff H

    2011-08-01

    Xanthomonas hortorum pv. carotae (Xhc) is an economically important pathogen of carrots. Its ability to epiphytically colonize foliar surfaces and infect seeds can result in bacterial blight of carrots when grown in warm and humid regions. We used high-throughput sequencing to determine the genome sequence of isolate M081 of Xhc. The short reads were de novo assembled and the resulting contigs were ordered using a syntenic reference genome sequence from X. campestris pv. campestris ATCC 33913. The improved, high-quality draft genome sequence of Xhc M081 is the first for its species. Despite its distance from other sequenced xanthomonads, Xhc M081 still shared a large inventory of orthologous genes, including many clusters of virulence genes common to other foliar pathogenic species of Xanthomonas. We also mined the genome sequence and identified at least 21 candidate type III effector genes. Two were members of the avrBs2 and xopQ families that demonstrably elicit effector-triggered immunity. We showed that expression in planta of these two type III effectors from Xhc M081 was sufficient to elicit resistance gene-mediated hypersensitive responses in heterologous plants, indicating a possibility for resistance gene-mediated control of Xhc. Finally, we identified regions unique to the Xhc M081 genome sequence, and demonstrated their potential in the design of molecular diagnostics for this pathogen.

  15. Using Square Roots

    ERIC Educational Resources Information Center

    Wilson, William Wynne

    1976-01-01

    This article describes techniques which enable the user of a comparatively simple calculator to perform calculations of cube roots, nth roots, trigonometric, and inverse trigonometric functions, logarithms, and exponentials. (DT)

  16. The Root Pressure Phenomenon

    ERIC Educational Resources Information Center

    Marsh, A. R.

    1972-01-01

    Describes experiments demonstrating that root pressure in plants is probably controlled by a circadian rhythm (biological clock). Root pressure phenomenon plays significant part in water transport in contradiction with prevalent belief. (PS)

  17. Corky root rot

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Corky root rot (corchosis) was first reported in Argentina in 1985, but the disease was presumably present long before that. The disease occurs in most alfalfa-growing areas of Argentina but is more common in older stands. In space-planted alfalfa trials scored for root problems, corky root rot was ...

  18. WHY ROOTING FAILS.

    SciTech Connect

    CREUTZ,M.

    2007-07-30

    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.

  19. Rooting gene trees without outgroups: EP rooting.

    PubMed

    Sinsheimer, Janet S; Little, Roderick J A; Lake, James A

    2012-01-01

    Gene sequences are routinely used to determine the topologies of unrooted phylogenetic trees, but many of the most important questions in evolution require knowing both the topologies and the roots of trees. However, general algorithms for calculating rooted trees from gene and genomic sequences in the absence of gene paralogs are few. Using the principles of evolutionary parsimony (EP) (Lake JA. 1987a. A rate-independent technique for analysis of nucleic acid sequences: evolutionary parsimony. Mol Biol Evol. 4:167-181) and its extensions (Cavender, J. 1989. Mechanized derivation of linear invariants. Mol Biol Evol. 6:301-316; Nguyen T, Speed TP. 1992. A derivation of all linear invariants for a nonbalanced transversion model. J Mol Evol. 35:60-76), we explicitly enumerate all linear invariants that solely contain rooting information and derive algorithms for rooting gene trees directly from gene and genomic sequences. These new EP linear rooting invariants allow one to determine rooted trees, even in the complete absence of outgroups and gene paralogs. EP rooting invariants are explicitly derived for three taxon trees, and rules for their extension to four or more taxa are provided. The method is demonstrated using 18S ribosomal DNA to illustrate how the new animal phylogeny (Aguinaldo AMA et al. 1997. Evidence for a clade of nematodes, arthropods, and other moulting animals. Nature 387:489-493; Lake JA. 1990. Origin of the metazoa. Proc Natl Acad Sci USA 87:763-766) may be rooted directly from sequences, even when they are short and paralogs are unavailable. These results are consistent with the current root (Philippe H et al. 2011. Acoelomorph flatworms are deuterostomes related to Xenoturbella. Nature 470:255-260).

  20. Effectiveness of different EDU concentrations in ameliorating ozone stress in carrot plants.

    PubMed

    Tiwari, Supriya; Agrawal, Madhoolika

    2010-07-01

    Ethylenediurea (EDU) is suggested for use to evaluate plant response under ambient ozone (O(3)) concentrations. Four EDU treatments, viz. 0 (non-EDU), 150, 300 and 450 mg L(-1), applied as soil drench at 10 days interval to carrot (Daucus carota L. var. Pusa Kesar), grown at a tropical suburban site of Varanasi experiencing mean O(3) concentration of 36.1 ppb during the experimental period. EDU treated plants showed significantly higher antioxidative defense, assimilation capability and reduced membrane lipid peroxidation, which led to better growth and significant yield increments compared to non-EDU treated ones. The magnitude of positive responses was highest at 150 mg L(-1) EDU treatment at 60 DAG, representing the metabolically most active phase of root filling in carrot. This study suggests that the lowest EDU concentration was sufficient to provide protection against negative effects of O(3).

  1. Carrot cells: a pioneering platform for biopharmaceuticals production.

    PubMed

    Rosales-Mendoza, Sergio; Tello-Olea, Marlene Anahí

    2015-03-01

    Carrot (Daucus carota L.) is of importance in the molecular farming field as it constitutes the first plant species approved to produce biopharmaceuticals for human use. In this review, features that make carrot an advantageous species in the molecular farming field are analyzed and a description of the developments achieved with this crop thus far is presented. A guide for genetic transformation procedures is also included. The state of the art comprises ten vaccine prototypes against Measles virus, Hepatitis B virus, Human immunodeficiency virus, Yersinia pestis, Chlamydia trachomatis, Mycobacterium tuberculosis, enterotoxigenic Escherichia coli, Corynebacterium diphtheria/Clostridium tetani/Bordetella pertussis, and Helicobacter pylori; as well as the case of the glucocerebrosidase, an enzyme used for replacement therapy, and other therapeutics. Perspectives for these developments are envisioned and innovations are proposed such as the use of transplastomic technologies-, hairy roots-, and viral expression-based systems to improve yields and develop new products derived from this advantageous plant species.

  2. Root canal irrigants

    PubMed Central

    Kandaswamy, Deivanayagam; Venkateshbabu, Nagendrababu

    2010-01-01

    Successful root canal therapy relies on the combination of proper instrumentation, irrigation, and obturation of the root canal. Of these three essential steps of root canal therapy, irrigation of the root canal is the most important determinant in the healing of the periapical tissues. The primary endodontic treatment goal must thus be to optimize root canal disinfection and to prevent reinfection. In this review of the literature, various irrigants and the interactions between irrigants are discussed. We performed a Medline search for English-language papers published untill July 2010. The keywords used were ‘root canal irrigants’ and ‘endodontic irrigants.’ The reference lists of each article were manually checked for additional articles of relevance. PMID:21217955

  3. Trees and Roots.

    ERIC Educational Resources Information Center

    Jones, Lethonee A.

    Constructing a family history can be significant in helping persons understand and appreciate the root system that supports and sustains them. Oral history can be a valuable resource in family research as Alex Haley demonstrated in writing "Roots." The major difficulty of using oral tradition in tracing a family history is that family…

  4. Irrational Square Roots

    ERIC Educational Resources Information Center

    Misiurewicz, Michal

    2013-01-01

    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?

  5. The Roots of Literacy.

    ERIC Educational Resources Information Center

    Goodman, Yetta M.

    This review of research with children aged two to six on their reading, writing, and oral language development speaks of five roots of a tree of literate life that require nourishment in the soil of a written language environment. The roots discussed are the development of print awareness in situational contexts, the development of print awareness…

  6. Root Nutrient Foraging1

    PubMed Central

    Giehl, Ricardo F.H.; von Wirén, Nicolaus

    2014-01-01

    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

  7. Root nutrient foraging.

    PubMed

    Giehl, Ricardo F H; von Wirén, Nicolaus

    2014-10-01

    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.

  8. Root hydrotropism: an update.

    PubMed

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

    2013-01-01

    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.

  9. Economic strategies of plant absorptive roots vary with root diameter

    NASA Astrophysics Data System (ADS)

    Kong, D. L.; Wang, J. J.; Kardol, P.; Wu, H. F.; Zeng, H.; Deng, X. B.; Deng, Y.

    2016-01-01

    Plant roots typically vary along a dominant ecological axis, the root economics spectrum, depicting a tradeoff between resource acquisition and conservation. For absorptive roots, which are mainly responsible for resource acquisition, we hypothesized that root economic strategies differ with increasing root diameter. To test this hypothesis, we used seven plant species (a fern, a conifer, and five angiosperms from south China) for which we separated absorptive roots into two categories: thin roots (thickness of root cortex plus epidermis < 247 µm) and thick roots. For each category, we analyzed a range of root traits related to resource acquisition and conservation, including root tissue density, different carbon (C), and nitrogen (N) fractions (i.e., extractive, acid-soluble, and acid-insoluble fractions) as well as root anatomical traits. The results showed significant relationships among root traits indicating an acquisition-conservation tradeoff for thin absorptive roots while no such trait relationships were found for thick absorptive roots. Similar results were found when reanalyzing data of a previous study including 96 plant species. The contrasting economic strategies between thin and thick absorptive roots, as revealed here, may provide a new perspective on our understanding of the root economics spectrum.

  10. Quantitative measurements of root water uptake and root hydraulic conductivities

    NASA Astrophysics Data System (ADS)

    Zarebanadkouki, Mohsen; Javaux, Mathieu; Meunier, Felicien; Couvreur, Valentin; Carminati, Andrea

    2016-04-01

    How is root water uptake distributed along the root system and what root properties control this distribution? Here we present a method to: 1) measure root water uptake and 2) inversely estimate the root hydraulic conductivities. The experimental method consists in using neutron radiography to trace deuterated water (D2O) in soil and roots. The method was applied to lupines grown aluminium containers filled with a sandy soil. When the lupines were 4 weeks old, D2O was locally injected in a selected soil regions and its transport was monitored in soil and roots using time-series neutron radiography. By image processing, we quantified the concentration of D2O in soil and roots. We simulated the transport of D2O into roots using a diffusion-convection numerical model. The diffusivity of the roots tissue was inversely estimated by simulating the transport of D2O into the roots during night. The convective fluxes (i.e. root water uptake) were inversely estimating by fitting the experiments during day, when plants were transpiring, and assuming that root diffusivity did not change. The results showed that root water uptake was not uniform along the roots. Water uptake was higher at the proximal parts of the lateral roots and it decreased by a factor of 10 towards the distal parts. We used the data of water fluxes to inversely estimate the profile of hydraulic conductivities along the roots of transpiring plants growing in soil. The water fluxes in the lupine roots were simulated using the Hydraulic Tree Model by Doussan et al. (1998). The fitting parameters to be adjusted were the radial and axial hydraulic conductivities of the roots. The results showed that by using the root architectural model of Doussan et al. (1998) and detailed information of water fluxes into different root segments we could estimate the profile of hydraulic conductivities along the roots. We also found that: 1) in a tap-rooted plant like lupine water is mostly taken up by lateral roots; (2) water

  11. Root lattices and quasicrystals

    NASA Astrophysics Data System (ADS)

    Baake, M.; Joseph, D.; Kramer, P.; Schlottmann, M.

    1990-10-01

    It is shown that root lattices and their reciprocals might serve as the right pool for the construction of quasicrystalline structure models. All noncrystallographic symmetries observed so far are covered in minimal embedding with maximal symmetry.

  12. Root lattices and quasicrystals

    NASA Astrophysics Data System (ADS)

    Baake, M.; Joseph, D.; Kramer, P.; Schlottmann, M.

    1990-10-01

    It is shown how root lattices and their reciprocals might serve as the right pool for the construction of quasicrystalline structure models. All non-periodic symmetries observed so far are covered in minimal embedding with maximal symmetry.

  13. Relationships between root diameter, root length and root branching along lateral roots in adult, field-grown maize

    PubMed Central

    Wu, Qian; Pagès, Loïc; Wu, Jie

    2016-01-01

    Background and Aims Root diameter, especially apical diameter, plays an important role in root development and function. The variation in diameter between roots, and along roots, affects root structure and thus the root system’s overall foraging performance. However, the effect of diameter variation on root elongation, branching and topological connections has not been examined systematically in a population of high-order roots, nor along the roots, especially for mature plants grown in the field. Methods A method combining both excavation and analysis was applied to extract and quantify root architectural traits of adult, field-grown maize plants. The relationships between root diameter and other root architectural characteristics are analysed for two maize cultivars. Key Results The basal diameter of the lateral roots (orders 1–3) was highly variable. Basal diameter was partly determined by the diameter of the bearing segment. Basal diameter defined a potential root length, but the lengths of most roots fell far short of this. This was explained partly by differences in the pattern of diameter change along roots. Diameter tended to decrease along most roots, with the steepness of the gradient of decrease depending on basal diameter. The longest roots were those that maintained (or sometimes increased) their diameters during elongation. The branching density (cm–1) of laterals was also determined by the diameter of the bearing segment. However, the location of this bearing segment along the mother root was also involved – intermediate positions were associated with higher densities of laterals. Conclusions The method used here allows us to obtain very detailed records of the geometry and topology of a complex root system. Basal diameter and the pattern of diameter change along a root were associated with its final length. These relationships are especially useful in simulations of root elongation and branching in source–sink models. PMID:26744490

  14. Barcoding melting curve analysis for rapid, sensitive, and discriminating authentication of saffron (Crocus sativus L.) from its adulterants.

    PubMed

    Jiang, Chao; Cao, Liang; Yuan, Yuan; Chen, Min; Jin, Yan; Huang, Luqi

    2014-01-01

    Saffron (Crocus sativus L.) is one of the most important and expensive medicinal spice products in the world. Because of its high market value and premium price, saffron is often adulterated through the incorporation of other materials, such as Carthamus tinctorius L. and Calendula officinalis L. flowers, Hemerocallis L. petals, Daucus carota L. fleshy root, Curcuma longa L. rhizomes, Zea may L., and Nelumbo nucifera Gaertn. stigmas. To develop a straightforward, nonsequencing method for rapid, sensitive, and discriminating detection of these adulterants in traded saffron, we report here the application of a barcoding melting curve analysis method (Bar-MCA) that uses the universal chloroplast plant DNA barcoding region trnH-psbA to identify adulterants. When amplified at DNA concentrations and annealing temperatures optimized for the curve analysis, peaks were formed at specific locations for saffron (81.92°C) and the adulterants: D. carota (81.60°C), C. tinctorius (80.10°C), C. officinalis (79.92°C), Dendranthema morifolium (Ramat.) Tzvel. (79.62°C), N. nucifera (80.58°C), Hemerocallis fulva (L.) L. (84.78°C), and Z. mays (84.33°C). The constructed melting curves for saffron and its adulterants have significantly different peak locations or shapes. In conclusion, Bar-MCA could be a faster and more cost-effective method to authenticate saffron and detect its adulterants.

  15. First Report of 'Candidatus Liberibacter solanacearum' in Carrots in Europe

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Carrot (Daucus carota) plants exhibiting symptoms that resembled those of carrot psyllid (Trioza apicalis) damage were observed in commercial fields in southern Finland in August 2008. Carrot psyllid is a serious pest of carrots in northern and central Europe, where it can cause up to 100% yield los...

  16. Association of 'Candidatus Liberibacter solanacearum' with the Psyllid, Trioza apicalis (Hemiptera: Triozidae) in Europe

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Carrot psyllid (Trioza apicalis Förster) is a serious pest of carrots (Daucus carota L.) in northern and central Europe. Carrots exhibiting symptoms of psyllid damage were observed in commercial fields in southern Finland in 2008. Symptoms in affected plants included leaf curling, yellow and purple ...

  17. Survey of 'Candidatus Liberibacter solanacearum' in carrot crops affected by the psyllid Trioza apicalis (Hemiptera: Triozidae) in Norway

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The carrot psyllid Trioza apicalis Förster (Hemiptera: Triozidae) is a serious insect pest of carrot (Daucus carota L.) in northern Europe, where it can cause up to 100% crop loss. Although it was long believed that T. apicalis causes damage to carrot by injection of toxins into the plant, it was re...

  18. First report of 'Candidatus Liberibacter solanacearum' associated with psyllid-affected carrots in Norway

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Carrot (Daucus carota) plants with symptoms resembling those associated with the carrot psyllid Trioza apicalis and the bacterium “Candidatus Liberibacter solanacearum” were observed in 70-80% of commercial fields and experimental plots in southeastern Norway from late July to mid-September 2011; al...

  19. First report of 'Candidatus Liberibacter solanacearum' associated with psyllid-affected carrots in Sweden

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Carrot (Daucus carota) plants with symptoms resembling those of the carrot psyllid Trioza apicalis and “Candidatus Liberibacter solanacearum” damage were observed in 70% of commercial fields in southern Sweden in August 2011; all cultivars grown were affected, at about 1 to 45% symptomatic plants pe...

  20. Stimulation of short-term plant growth by glycerol applied as foliar sprays and drenches under greenhouse conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Foliar and drench applications of glycerol were tested at 0, 0.1, 5, 10, 25, and 50 ml.l-1 on ‘Chantenay’ carrot (Daucus carota L.) family Apiaceae. Certain glycerol levels, especially the 1 to 10 ml.L-1 treatments, substantially increased fresh and dry weights of carrots sprayed twice over a 60-day...

  1. 21 CFR 73.300 - Carrot oil.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 1 2011-04-01 2011-04-01 false Carrot oil. 73.300 Section 73.300 Food and Drugs... ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.300 Carrot oil. (a) Identity. (1) The color additive carrot... extraction of edible carrots (Daucus carota L.) with subsequent removal of the hexane by vacuum...

  2. 21 CFR 73.300 - Carrot oil.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false Carrot oil. 73.300 Section 73.300 Food and Drugs... ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.300 Carrot oil. (a) Identity. (1) The color additive carrot... extraction of edible carrots (Daucus carota L.) with subsequent removal of the hexane by vacuum...

  3. 21 CFR 73.300 - Carrot oil.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 1 2014-04-01 2014-04-01 false Carrot oil. 73.300 Section 73.300 Food and Drugs... ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.300 Carrot oil. (a) Identity. (1) The color additive carrot... extraction of edible carrots (Daucus carota L.) with subsequent removal of the hexane by vacuum...

  4. Molecular detection of aster yellows phytoplasma and 'Candidatus Liberibacter solanacearum' in carrots affected by the psyllid Trioza apicalis (Hemiptera: triozidae) in Finland

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Carrot psyllid (Trioza apicalis Förster) causes considerable damage to carrot (Daucus carota L.) in many parts of Europe. It was recently established that the new bacterium “Candidatus Liberibacter solanacearum” is associated with carrot psyllid and plants affected by this insect pest. No other path...

  5. A high-quality carrot genome assembly provides new insights into carotenoid accumulation and asterid genome evolution

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We report a chromosome-scale assembly and analysis of the Daucus carota genome, an important source of provitamin A in the human diet and the first sequenced genome among members of the Euasterid II clade. We characterized two new polyploidization events, both occurring after the divergence of carro...

  6. Optimization of flat plate drying of carrot pomace (abstract)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Carrot (Daucus carota var. sativus) pomace is a co-product of the carrot juice and cut-carrot industry; it has high nutritional value but is currently underutilized. Drum drying is one method that could be used to dry and stabilize carrot pomace. However, optimum conditions for the dryer surface tem...

  7. The "Green" Root Beer Laboratory

    ERIC Educational Resources Information Center

    Clary, Renee; Wandersee, James

    2010-01-01

    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…

  8. How roots respond to gravity.

    PubMed

    Evans, M L; Moore, R; Hasenstein, K H

    1986-12-01

    Current knowledge about the mechanisms of plant root response to gravity is reviewed. The roles of the columella region and amyloplasts in the root cap are examined. Results of experiments related to gravistimulation in corn roots with and without root caps are explained. The role of auxin, abscisic acid, and calcium also are examined.

  9. Root architecture and root and tuber crop productivity.

    PubMed

    Villordon, Arthur Q; Ginzberg, Idit; Firon, Nurit

    2014-07-01

    It is becoming increasingly evident that optimization of root architecture for resource capture is vital for enabling the next green revolution. Although cereals provide half of the calories consumed by humans, root and tuber crops are the second major source of carbohydrates globally. Yet, knowledge of root architecture in root and tuber species is limited. In this opinion article, we highlight what is known about the root system in root and tuber crops, and mark new research directions towards a better understanding of the relation between root architecture and yield. We believe that unraveling the role of root architecture in root and tuber crop productivity will improve global food security, especially in regions with marginal soil fertility and low-input agricultural systems.

  10. Nerve root replantation.

    PubMed

    Carlstedt, Thomas

    2009-01-01

    Traumatic avulsion of nerve roots from the spinal cord is a devastating event that usually occurs in the brachial plexus of young adults following motor vehicle or sports accidents or in newborn children during difficult childbirth. A strategy to restore motor function in the affected arm by reimplanting into the spinal cord the avulsed ventral roots or autologous nerve grafts connected distally to the avulsed roots has been developed. Surgical outcome is good and useful recovery in shoulder and proximal arm muscles occurs. Pain is alleviated with motor recovery but sensory improvement is poor when only motor conduits have been reconstructed. In experimental studies, restoration of sensory connections with general improvement in the outcome from this surgery is pursued.

  11. Assessment of allelopathic properties of Aloe ferox Mill. on turnip, beetroot and carrot.

    PubMed

    Arowosegbe, Sunday; Afolayan, Anthony J

    2012-01-01

    Turnip (Brassica rapa var. rapa L.), beetroot (Beta vulgaris L.) and carrot (Daucus carota L.) are common vegetables in South Africa. The allelopathic potential of aqueous leaf and root extracts of Aloe ferox Mill.- a highly valued medicinal plant- was evaluated against seed germination and seedling growth of the three vegetables in Petri dish experiments. The extracts were tested at concentrations of 2, 4, 6, 8, and 10 mg/mL. Leaf extract concentrations above 4 mg/mL inhibited the germination of all the crops, while the root extract had no significant effect on germination irrespective of concentration. Interestingly, the lowest concentration of leaf extract stimulated root length elongation of beetroot by 31.71%. Other concentrations significantly inhibited both root and shoot growth of the vegetable crops except the turnip shoot. The most sensitive crop was carrot, with percentage inhibition ranging from 29.15 to 100% for root and shoot lengths. Lower percentage inhibition was observed for the root extract than the leaf extract against shoot growth of beetroot and carrot. The results from this study suggested the presence of allelochemicals mostly in the leaves of A. ferox that could inhibit the growth of the turnip, beetroot and carrot.

  12. Grass Roots Project Evaluation.

    ERIC Educational Resources Information Center

    Wick, John W.

    Some aspects of a grass roots evaluation training program are presented. The program consists of two elements: (1) a series of 11 slide/tape individualized self-paced units, and (2) a six-week summer program. Three points of view on this program are: (1) University graduate programs in quantitative areas are usually consumed by specialists; (2)…

  13. The Roots of Reading.

    ERIC Educational Resources Information Center

    Montoya, Colleen, Ed.

    2002-01-01

    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)…

  14. Root hair sweet growth

    PubMed Central

    Velasquez, Silvia M; Iusem, Norberto D

    2011-01-01

    Root hairs are single cells specialized in the absorption of water and nutrients from the soil. Growing root hairs require intensive cell-wall changes to accommodate cell expansion at the apical end by a process known as tip or polarized growth. We have recently shown that cell wall glycoproteins such as extensins (EXTs) are essential components of the cell wall during polarized growth. Proline hydroxylation, an early posttranslational modification of cell wall EXTs that is catalyzed by prolyl 4-hydroxylases (P4Hs), defines the subsequent O-glycosylation sites in EXTs. Biochemical inhibition or genetic disruption of specific P4Hs resulted in the blockage of polarized growth in root hairs. Our results demonstrate that correct hydroxylation and also further O-glycosylation on EXTs are essential for cell-wall self-assembly and, hence, root hair elongation. The changes that O-glycosylated cell-wall proteins like EXTs undergo during cell growth represent a starting point to unravel the entire biochemical pathway involved in plant development. PMID:21918376

  15. Great Plains Roots.

    ERIC Educational Resources Information Center

    Frey, Jennifer

    2001-01-01

    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…

  16. The Roots Of Alienation

    ERIC Educational Resources Information Center

    Bronfenbrenner, Urie

    1973-01-01

    Alienation in our society takes several forms--withdrawal, hostility, or efforts to reform. The author traces the roots of alienation to our neglect of many of the needs of children, particularly their need for interaction with adults. Among his many recommendations are: modified work schedules to permit more time with children and systems for…

  17. Advances in root reinforcement experiments

    NASA Astrophysics Data System (ADS)

    Giadrossich, Filippo; Schwarz, Massimiliano; Niedda, Marcello

    2013-04-01

    Root reinforcement is considered in many situations an important effect of vegetation for slope stability. In the past 20 years many studies analyzed root reinforcement in laboratory and field experiments, as well as through modeling frameworks. Nearby the important contribution of roots to shear strength, roots are recognized to impart stabilization also through lateral (parallel to slope) redistribution of forces under tension. Lateral root reinforcement under tensile solicitations (such as in the upper part of a shallow landslide) was documented and discussed by some studies. The most common method adopted to measure lateral root reinforcement are pullout tests where roots (single or as bundle) are pulled out from a soil matrix. These conditions are indeed representative for the case where roots within the mass of a landslide slip out from the upper stable part of the slope (such in a tension crack). However, there is also the situation where roots anchored at the upper stable part of the slope slip out from the sliding soil mass. In this last case it is difficult to quantify root reinforcement and no study discussed this mechanism so far. The main objective of this study is to quantify the contribution of roots considering the two presented cases of lateral root reinforcement discussed above - roots slipping out from stable soil profile or sliding soil matrix from anchored roots-, and discuss the implication of the results for slope stability modeling. We carried out a series of laboratory experiments for both roots pullout and soil sliding mechanisms using a tilting box with a bundle of 15 roots. Both Douglas (Pseudotsuga menziesii) roots and soil were collected from the study area in Sardinia (Italy), and reconstructed in laboratory, filling the root and soil layer by layer up to 0.4 meter thickness. The results show that the ratio between pullout force and force transferred to the root during soil sliding range from 0.5 to 1. This results indicate that

  18. Angles of multivariable root loci

    NASA Technical Reports Server (NTRS)

    Thompson, P. M.; Stein, G.; Laub, A. J.

    1982-01-01

    A generalized eigenvalue problem is demonstrated to be useful for computing the multivariable root locus, particularly when obtaining the arrival angles to finite transmission zeros. The multivariable root loci are found for a linear, time-invariant output feedback problem. The problem is then employed to compute a closed-loop eigenstructure. The method of computing angles on the root locus is demonstrated, and the method is extended to a multivariable optimal root locus.

  19. Diagravitropism in corn roots

    NASA Technical Reports Server (NTRS)

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

    1988-01-01

    The diagravitropic behavior of Merit corn (Zea mays L.) roots grown in darkness provides an opportunity for comparison of two qualitatively different gravitropic systems. As with positive gravitropism, diagravitropism is shown to require the presence of the root cap, have a similar time course for the onset of curvature, and a similar presentation time. In contrast with positive gravitropism, diagravitropism appears to have a more limited requirement for calcium, for it is insensitive to the elution of calcium by EGTA and insensitive to the subsequent addition of a calcium/EGTA complex. These results are interpreted as indicating that whereas the same sensing system is shared by the two types of gravitropism, separate transductive systems are involved, one for diagravitropism, which is relatively independent of calcium, and one for positive gravitropism, which is markedly dependent on calcium.

  20. Springback in root gravitropism

    NASA Technical Reports Server (NTRS)

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

    1989-01-01

    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.

  1. Aquaporins and root water relations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water is one of the most critical resources limiting plant growth and crop productivity, and root water uptake is an important aspect of plant physiology governing plant water use and stress tolerance. Pathways of root water uptake are complex and are affected by root structure and physiological res...

  2. Nurturing the Roots of Literacy.

    ERIC Educational Resources Information Center

    Blass, Rosanne J.

    Reflecting the work of Yetta Goodman on child language development, this paper examines Goodman's five "roots of literacy" and offers suggestions on classroom techniques for nurturing these roots. The first half of the paper explains how Goodman identified the roots of literacy and describes each of them, including (1) print awareness in…

  3. Strigolactones Effects on Root Growth

    NASA Astrophysics Data System (ADS)

    Koltai, Hinanit

    2012-07-01

    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.

  4. Philosophical Roots of Cosmology

    NASA Astrophysics Data System (ADS)

    Ivanovic, M.

    2008-10-01

    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.

  5. Rooting an Android Device

    DTIC Science & Technology

    2015-09-01

    this feature on an Android device, go to “Settings” and then “About Phone ” or “About tablet”. Find “Build Number”, then tab on the “Build Number” 7...flag, which should not affect phone operation. Ensure that the phone or tablet is on and active while the rooting process is underway, and monitor...the Android device and host computer for progress of the script to determine whether the installation succeeded or failed. Do not unplug the phone

  6. The Roots of Beowulf

    NASA Technical Reports Server (NTRS)

    Fischer, James R.

    2014-01-01

    The first Beowulf Linux commodity cluster was constructed at NASA's Goddard Space Flight Center in 1994 and its origins are a part of the folklore of high-end computing. In fact, the conditions within Goddard that brought the idea into being were shaped by rich historical roots, strategic pressures brought on by the ramp up of the Federal High-Performance Computing and Communications Program, growth of the open software movement, microprocessor performance trends, and the vision of key technologists. This multifaceted story is told here for the first time from the point of view of NASA project management.

  7. Matching roots to their environment

    PubMed Central

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

    2013-01-01

    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

  8. Morphometric analysis of root shape.

    PubMed

    Grabov, A; Ashley, M K; Rigas, S; Hatzopoulos, P; Dolan, L; Vicente-Agullo, F

    2005-02-01

    Alterations in the root shape in plant mutants indicate defects in hormonal signalling, transport and cytoskeleton function. To quantify the root shape, we introduced novel parameters designated vertical growth index (VGI) and horizontal growth index (HGI). VGI was defined as a ratio between the root tip ordinate and the root length. HGI was the ratio between the root tip abscissa and the root length. To assess the applicability of VGI and HGI for quantification of root shape, we analysed root development in agravitropic Arabidopsis mutants. Statistical analysis indicated that VGI is a sensitive morphometric parameter enabling detection of weak gravitropic defects. VGI dynamics were qualitatively similar in auxin-transport mutants aux1, pin2 and trh1, but different in the auxin-signalling mutant axr2. Analysis of VGI and HGI of roots grown on tilted plates showed that the trh1 mutation affected downstream cellular responses rather than perception of the gravitropic stimulus. All these tests indicate that the VGI and HGI analysis is a versatile and sensitive method for the study of root morphology.

  9. Geophysical Imaging of Root Architecture and Root-soil Interaction

    NASA Astrophysics Data System (ADS)

    Wu, Y.; Dafflon, B.; Hubbard, S. S.

    2015-12-01

    Roots play a critical role in controlling water and nutrient uptake, soil biogeochemical processes, as well as the physical anchorage for plants. While important processes, such as root hydraulic redistribution for optimal growth and survival have been recognized, representation of roots in climate models, e.g. its carbon storage, carbon resilience, root biomass, and role in regulating water and carbon fluxes across the rhizosphere and atmosphere interface is still challenging. Such a challenge is exacerbated because of the large variations of root architecture and function across species and locations due to both genetic and environmental controls and the lack of methods for quantifying root mass, distribution, dynamics and interaction with soils at field scales. The scale, complexity and the dynamic nature of plant roots call for minimally invasive methods capable of providing quantitative estimation of root architecture, dynamics over time and interactions with the soils. We present a study on root architecture and root-soil interactions using geophysical methods. Parameters and processes of interests include (1) moisture dynamics around root zone and its interaction with plant transpiration and environmental controls and (2) estimation of root structure and properties based on geophysical signals. Both pot and field scale studies were conducted. The pot scale experiments were conducted under controlled conditions and were monitored with cross-well electrical resistivity tomography (ERT), TDR moisture sensors and temperature probes. Pots with and without a tree were compared and the moisture conditions were controlled via a self regulated pumping system. Geophysical monitoring revealed interactions between roots and soils under dynamic soil moisture conditions and the role of roots in regulating the response of the soil system to changes of environmental conditions, e.g. drought and precipitation events. Field scale studies were conducted on natural trees using

  10. Perennial roots to immortality.

    PubMed

    Munné-Bosch, Sergi

    2014-10-01

    Maximum lifespan greatly varies among species, and it is not strictly determined; it can change with species evolution. Clonal growth is a major factor governing maximum lifespan. In the plant kingdom, the maximum lifespans described for clonal and nonclonal plants vary by an order of magnitude, with 43,600 and 5,062 years for Lomatia tasmanica and Pinus longaeva, respectively. Nonclonal perennial plants (those plants exclusively using sexual reproduction) also present a huge diversity in maximum lifespans (from a few to thousands of years) and even more interestingly, contrasting differences in aging patterns. Some plants show a clear physiological deterioration with aging, whereas others do not. Indeed, some plants can even improve their physiological performance as they age (a phenomenon called negative senescence). This diversity in aging patterns responds to species-specific life history traits and mechanisms evolved by each species to adapt to its habitat. Particularities of roots in perennial plants, such as meristem indeterminacy, modular growth, stress resistance, and patterns of senescence, are crucial in establishing perenniality and understanding adaptation of perennial plants to their habitats. Here, the key role of roots for perennial plant longevity will be discussed, taking into account current knowledge and highlighting additional aspects that still require investigation.

  11. A Split-Root Technique for Measuring Root Water Potential

    PubMed Central

    Adeoye, Kingsley B.; Rawlins, Stephen L.

    1981-01-01

    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

  12. Maximum-rank root subsystems of hyperbolic root systems

    SciTech Connect

    Tumarkin, P V

    2004-02-28

    A Kac-Moody algebra is said to be hyperbolic if it corresponds to a generalized Cartan matrix of hyperbolic type. Root subsystems of root systems of algebras of this kind are studied. The main result of the paper is the classification of the maximum-rank regular hyperbolic subalgebras of hyperbolic Kac-Moody algebras.

  13. The roots of predictivism.

    PubMed

    Barnes, Eric Christian

    2014-03-01

    In The Paradox of Predictivism (2008, Cambridge University Press) I tried to demonstrate that there is an intimate relationship between predictivism (the thesis that novel predictions sometimes carry more weight than accommodations) and epistemic pluralism (the thesis that one important form of evidence in science is the judgments of other scientists). Here I respond to various published criticisms of some of the key points from Paradox from David Harker, Jarret Leplin, and Clark Glymour. Foci include my account of predictive novelty (endorsement novelty), the claim that predictivism has two roots, the prediction per se and predictive success, and my account of why Mendeleev's predictions carried special weight in confirming the Periodic Law of the Elements.

  14. Lumbosacral nerve root avulsion.

    PubMed

    Chin, C H; Chew, K C

    1997-01-01

    Lumbosacral nerve root avulsion is a rare clinical entity. Since the first description in 1955, only 35 cases have been reported. It is often associated with pelvic fractures and may be missed in the initial clinical examination as these patients usually present with multiple injuries. We present three such cases with clinical and radiological findings. These patients were involved in road traffic accidents. Two had fractures of the sacroiliac joint with diastasis of the symphysis pubis (Tile type C 1.2) and one had fractures of the public rami (Tile type B 2.1). All three had various degrees of sensory and motor deficit of the lower limbs. Lumbar myelogram shows characteristic pseudomeningoceles in the affected lumboscral region. Magnetic resonance (MR) imaging provides an additional non-invasive modality to diagnose this condition.

  15. New roots for agriculture: exploiting the root phenome.

    PubMed

    Lynch, Jonathan P; Brown, Kathleen M

    2012-06-05

    Recent advances in root biology are making it possible to genetically design root systems with enhanced soil exploration and resource capture. These cultivars would have substantial value for improving food security in developing nations, where yields are limited by drought and low soil fertility, and would enhance the sustainability of intensive agriculture. Many of the phenes controlling soil resource capture are related to root architecture. We propose that a better understanding of the root phenome is needed to effectively translate genetic advances into improved crop cultivars. Elementary, unique root phenes need to be identified. We need to understand the 'fitness landscape' for these phenes: how they affect crop performance in an array of environments and phenotypes. Finally, we need to develop methods to measure phene expression rapidly and economically without artefacts. These challenges, especially mapping the fitness landscape, are non-trivial, and may warrant new research and training modalities.

  16. New roots for agriculture: exploiting the root phenome

    PubMed Central

    Lynch, Jonathan P.; Brown, Kathleen M.

    2012-01-01

    Recent advances in root biology are making it possible to genetically design root systems with enhanced soil exploration and resource capture. These cultivars would have substantial value for improving food security in developing nations, where yields are limited by drought and low soil fertility, and would enhance the sustainability of intensive agriculture. Many of the phenes controlling soil resource capture are related to root architecture. We propose that a better understanding of the root phenome is needed to effectively translate genetic advances into improved crop cultivars. Elementary, unique root phenes need to be identified. We need to understand the ‘fitness landscape’ for these phenes: how they affect crop performance in an array of environments and phenotypes. Finally, we need to develop methods to measure phene expression rapidly and economically without artefacts. These challenges, especially mapping the fitness landscape, are non-trivial, and may warrant new research and training modalities. PMID:22527403

  17. Osmolarity and root canal antiseptics.

    PubMed

    Rossi-Fedele, G; Guastalli, A R

    2014-04-01

    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

  18. Compensatory Root Water Uptake of Overlapping Root Systems

    NASA Astrophysics Data System (ADS)

    Agee, E.; Ivanov, V. Y.; He, L.; Bisht, G.; Shahbaz, P.; Fatichi, S.; Gough, C. M.; Couvreur, V.; Matheny, A. M.; Bohrer, G.

    2015-12-01

    Land-surface models use simplified representations of root water uptake based on biomass distributions and empirical functions that constrain water uptake during unfavorable soil moisture conditions. These models fail to capture the observed hydraulic plasticity that allows plants to regulate root hydraulic conductivity and zones of active uptake based on local gradients. Recent developments in root water uptake modeling have sought to increase its mechanistic representation by bridging the gap between physically based microscopic models and computationally feasible macroscopic approaches. It remains to be demonstrated whether bulk parameterization of microscale characteristics (e.g., root system morphology and root conductivity) can improve process representation at the ecosystem scale. We employ the Couvreur method of microscopic uptake to yield macroscopic representation in a coupled soil-root model. Using a modified version of the PFLOTRAN model, which represents the 3-D physics of variably saturated soil, we model a one-hectare temperate forest stand under natural and synthetic climatic forcing. Our results show that as shallow soil layers dry, uptake at the tree and stand level shift to deeper soil layers, allowing the transpiration stream demanded by the atmosphere. We assess the potential capacity of the model to capture compensatory root water uptake. Further, the hydraulic plasticity of the root system is demonstrated by the quick response of uptake to rainfall pulses. These initial results indicate a promising direction for land surface models in which significant three-dimensional information from large root systems can be feasibly integrated into the forest scale simulations of root water uptake.

  19. Gut and Root Microbiota Commonalities

    PubMed Central

    Ramírez-Puebla, Shamayim T.; Servín-Garcidueñas, Luis E.; Jiménez-Marín, Berenice; Bolaños, Luis M.; Rosenblueth, Mónica; Martínez, Julio; Rogel, Marco Antonio; Ormeño-Orrillo, Ernesto

    2013-01-01

    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

  20. The root as a drill

    PubMed Central

    Santisree, Parankusam; Nongmaithem, Sapana; Sreelakshmi, Yellamaraju; Ivanchenko, Maria; Sharma, Rameshwar

    2012-01-01

    Plant roots forage the soil for water and nutrients and overcome the soil’s physical compactness. Roots are endowed with a mechanism that allows them to penetrate and grow in dense media such as soil. However, the molecular mechanisms underlying this process are still poorly understood. The nature of the media in which roots grow adds to the difficulty to in situ analyze the mechanisms underlying root penetration. Inhibition of ethylene perception by application of 1-methyl cyclopropene (1-MCP) to tomato seedlings nearly abolished the root penetration in Soilrite. The reversal of this process by auxin indicated operation of an auxin-ethylene signaling pathway in the regulation of root penetration. The tomato pct1–2 mutant that exhibits an enhanced polar transport of auxin required higher doses of 1-MCP to inhibit root penetration, indicating a pivotal role of auxin transport in this process. In this update we provide a brief review of our current understanding of molecular processes underlying root penetration in higher plants. PMID:22415043

  1. Light-Sensing in Roots

    PubMed Central

    Rabenold, Jessica J; Liscum, Emmanuel

    2007-01-01

    Light gradients in the soil have largely been overlooked in understanding plant responses to the environment. However, roots contain photoreceptors that may receive ambient light through the soil or piped light through the vascular cylinder. In recent experiments we demonstrated linkages between phototropin-1 photoreceptor production, root growth efficiency, and drought tolerance, suggesting that root plasticity in response to light signals contributes to the ecological niche of A. thaliana. However, the availability of light cues in natural soil environments is poorly understood, raising questions about the relevance of light-mediated root growth for fitness in nature. Additionally, photoreceptor expression is characterized by pleiotropy so unique functions cannot be clearly ascribed to root vs. shoot sensory mechanisms. These considerations show that challenges exist for resolving the contribution of light-sensing by roots to plant adaptation. We suggest that blue-light sensing in roots of A. thaliana provides a model system for addressing these challenges. By calibrating blue light gradients in soils of diverse A. thaliana habitats and comparing fitness of phot1 mutant and wild-type controls when grown in presence or absence of soil light cues, it should be possible to elucidate the ecological significance of light-mediated plasticity in roots. PMID:19704750

  2. Theon's Ladder for Any Root

    ERIC Educational Resources Information Center

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

    2005-01-01

    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…

  3. Project Work on Plant Roots.

    ERIC Educational Resources Information Center

    Devonald, V. G.

    1986-01-01

    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)

  4. Descendant root volume varies as a function of root type: estimation of root biomass lost during uprooting in Pinus pinaster.

    PubMed

    Danjon, Frédéric; Caplan, Joshua S; Fortin, Mathieu; Meredieu, Céline

    2013-01-01

    Root systems of woody plants generally display a strong relationship between the cross-sectional area or cross-sectional diameter (CSD) of a root and the dry weight of biomass (DWd) or root volume (Vd) that has grown (i.e., is descendent) from a point. Specification of this relationship allows one to quantify root architectural patterns and estimate the amount of material lost when root systems are extracted from the soil. However, specifications of this relationship generally do not account for the fact that root systems are comprised of multiple types of roots. We assessed whether the relationship between CSD and Vd varies as a function of root type. Additionally, we sought to identify a more accurate and time-efficient method for estimating missing root volume than is currently available. We used a database that described the 3D root architecture of Pinus pinaster root systems (5, 12, or 19 years) from a stand in southwest France. We determined the relationship between CSD and Vd for 10,000 root segments from intact root branches. Models were specified that did and did not account for root type. The relationships were then applied to the diameters of 11,000 broken root ends to estimate the volume of missing roots. CSD was nearly linearly related to the square root of Vd, but the slope of the curve varied greatly as a function of root type. Sinkers and deep roots tapered rapidly, as they were limited by available soil depth. Distal shallow roots tapered gradually, as they were less limited spatially. We estimated that younger trees lost an average of 17% of root volume when excavated, while older trees lost 4%. Missing volumes were smallest in the central parts of root systems and largest in distal shallow roots. The slopes of the curves for each root type are synthetic parameters that account for differentiation due to genetics, soil properties, or mechanical stimuli. Accounting for this differentiation is critical to estimating root loss accurately.

  5. Cassava root membrane proteome reveals activities during storage root maturation.

    PubMed

    Naconsie, Maliwan; Lertpanyasampatha, Manassawe; Viboonjun, Unchera; Netrphan, Supatcharee; Kuwano, Masayoshi; Ogasawara, Naotake; Narangajavana, Jarunya

    2016-01-01

    Cassava (Manihot esculenta Crantz) is one of the most important crops of Thailand. Its storage roots are used as food, feed, starch production, and be the important source for biofuel and biodegradable plastic production. Despite the importance of cassava storage roots, little is known about the mechanisms involved in their formation. This present study has focused on comparison of the expression profiles of cassava root proteome at various developmental stages using two-dimensional gel electrophoresis and LC-MS/MS. Based on an anatomical study using Toluidine Blue, the secondary growth was confirmed to be essential during the development of cassava storage root. To investigate biochemical processes occurring during storage root maturation, soluble and membrane proteins were isolated from storage roots harvested from 3-, 6-, 9-, and 12-month-old cassava plants. The proteins with differential expression pattern were analysed and identified to be associated with 8 functional groups: protein folding and degradation, energy, metabolism, secondary metabolism, stress response, transport facilitation, cytoskeleton, and unclassified function. The expression profiling of membrane proteins revealed the proteins involved in protein folding and degradation, energy, and cell structure were highly expressed during early stages of development. Integration of these data along with the information available in genome and transcriptome databases is critical to expand knowledge obtained solely from the field of proteomics. Possible role of identified proteins were discussed in relation with the activities during storage root maturation in cassava.

  6. Root development during soil genesis: effects of root-root interactions, mycorrhizae, and substrate

    NASA Astrophysics Data System (ADS)

    Salinas, A.; Zaharescu, D. G.

    2015-12-01

    A major driver of soil formation is the colonization and transformation of rock by plants and associated microbiota. In turn, substrate chemical composition can also influence the capacity for plant colonization and development. In order to better define these relationships, a mesocosm study was set up to analyze the effect mycorrhizal fungi, plant density and rock have on root development, and to determine the effect of root morphology on weathering and soil formation. We hypothesized that plant-plant and plant-fungi interactions have a stronger influence on root architecture and rock weathering than the substrate composition alone. Buffalo grass (Bouteloua dactyloides) was grown in a controlled environment in columns filled with either granular granite, schist, rhyolite or basalt. Each substrate was given two different treatments, including grass-microbes and grass-microbes-mycorrhizae and incubated for 120, 240, and 480 days. Columns were then extracted and analyzed for root morphology, fine fraction, and pore water major element content. Preliminary results showed that plants produced more biomass in rhyolite, followed by schist, basalt, and granite, indicating that substrate composition is an important driver of root development. In support of our hypothesis, mycorrhizae was a strong driver of root development by stimulating length growth, biomass production, and branching. However, average root length and branching also appeared to decrease in response to high plant density, though this trend was only present among roots with mycorrhizal fungi. Interestingly, fine fraction production was negatively correlated with average root thickness and volume. There is also slight evidence indicating that fine fraction production is more related to substrate composition than root morphology, though this data needs to be further analyzed. Our hope is that the results of this study can one day be applied to agricultural research in order to promote the production of crops

  7. Adaptation of plants to altered shoot orientation relative to the gravity vector.

    PubMed

    Smolyanina, S O; Berkovich, Yu A; Ivanov, V B

    2004-07-01

    Wheat Triticum aestivum L., carrots Daucus carota L., Chinese cabbage Brassica pekinensis Rupr., and African marigold Tagetes patula L. were grown at natural and inverted orientation in the Earth gravitational field. Light vector was set unidirectional or opposite directional relative to the gravity vector. Shoot orientation relative to the gravity vector was set natural or invert. Plants grew in the special pots furnished with plane or cylindrical hydrophilic porous membranes. The membrane allowed to stabilize a water potential in the root zone at the fixed level. Seeds were put into a fiber ion-exchange artificial soil overlaying horizontal hydrophilic plates of porous titanium or anchored to porous metal-ceramic tubes. Plants grew at the PPF level 550 +/- 20 micromoles/(m2 s) during 24-hr lighting and at the water potential level at the membrane surface (-1.00) +/- 0.08 kPa. Normal plants were obtained both at the natural and at the inverse shoot orientation in the all experiments. The wheat plants were yielded healthy germinating seeds no matter plant orientation. In the inverse orientation, no negative influence for plant biomass accruing was marked, but the increasing of shoot to root mass ratio was considerable. However carrot root crop mass decreasing was not revealed in the inverse orientation. The results demonstrated substantial dependence of morphological and physiological characteristics of higher plants on the gravity factor.

  8. IAA transport in corn roots includes the root cap

    SciTech Connect

    Hasenstein, K.H. )

    1989-04-01

    In earlier reports we concluded that auxin is the growth regulator that controls gravicurvature in roots and that the redistribution of auxin occurs within the root cap. Since other reports did not detect auxin in the root cap, we attempted to confirm the IAA does move through the cap. Agar blocks containing {sup 3}H-IAA were applied to the cut surface of 5 mm long apical segments of primary roots of corn (mo17xB73). After 30 to 120 min radioactivity (RA) of the cap and root tissue was determined. While segments suspended in water-saturated air accumulated very little RA in the cap, application of 0.5 {mu}1 of dist. water to the cap (=controls) increased RA of the cap dramatically. Application to the cap of 0.5 {mu}1 of sorbitol or the Ca{sup 2+} chelator EGTA reduced cap RA to 46% and 70% respectively compared to water, without affecting uptake. Control root segments gravireacted faster than non-treated or osmoticum or EGTA treated segments. The data indicate that both the degree of hydration and calcium control the amount of auxin moving through the cap.

  9. Underground tuning: quantitative regulation of root growth.

    PubMed

    Satbhai, Santosh B; Ristova, Daniela; Busch, Wolfgang

    2015-02-01

    Plants display a high degree of phenotypic plasticity that allows them to tune their form and function to changing environments. The plant root system has evolved mechanisms to anchor the plant and to efficiently explore soils to forage for soil resources. Key to this is an enormous capacity for plasticity of multiple traits that shape the distribution of roots in the soil. Such root system architecture-related traits are determined by root growth rates, root growth direction, and root branching. In this review, we describe how the root system is constituted, and which mechanisms, pathways, and genes mainly regulate plasticity of the root system in response to environmental variation.

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

    PubMed

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

    2013-09-01

    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.

  11. Power and Roots by Recursion.

    ERIC Educational Resources Information Center

    Aieta, Joseph F.

    1987-01-01

    This article illustrates how questions from elementary finance can serve as motivation for studying high order powers, roots, and exponential functions using Logo procedures. A second discussion addresses a relatively unknown algorithm for the trigonometric exponential and hyperbolic functions. (PK)

  12. Swarming behavior in plant roots.

    PubMed

    Ciszak, Marzena; Comparini, Diego; Mazzolai, Barbara; Baluska, Frantisek; Arecchi, F Tito; Vicsek, Tamás; Mancuso, Stefano

    2012-01-01

    Interactions between individuals that are guided by simple rules can generate swarming behavior. Swarming behavior has been observed in many groups of organisms, including humans, and recent research has revealed that plants also demonstrate social behavior based on mutual interaction with other individuals. However, this behavior has not previously been analyzed in the context of swarming. Here, we show that roots can be influenced by their neighbors to induce a tendency to align the directions of their growth. In the apparently noisy patterns formed by growing roots, episodic alignments are observed as the roots grow close to each other. These events are incompatible with the statistics of purely random growth. We present experimental results and a theoretical model that describes the growth of maize roots in terms of swarming.

  13. Crenarchaeota colonize terrestrial plant roots.

    PubMed

    Simon, H M; Dodsworth, J A; Goodman, R M

    2000-10-01

    Microorganisms that colonize plant roots are recruited from, and in turn contribute substantially to, the vast and virtually uncharacterized phylogenetic diversity of soil microbiota. The diverse, but poorly understood, microorganisms that colonize plant roots mediate mineral transformations and nutrient cycles that are central to biosphere functioning. Here, we report the results of epifluorescence microscopy and culture-independent recovery of small subunit (SSU) ribosomal RNA (rRNA) gene sequences showing that members of a previously reported clade of soil Crenarchaeota colonize both young and senescent plant roots at an unexpectedly high frequency, and are particularly abundant on the latter. Our results indicate that non-thermophilic members of the Archaea inhabit an important terrestrial niche on earth and direct attention to the need for studies that will determine their possible roles in mediating root biology.

  14. 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)

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

    2014-10-01

    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

  15. How Can Science Education Foster Students' Rooting?

    ERIC Educational Resources Information Center

    Østergaard, Edvin

    2015-01-01

    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…

  16. Root anatomical phenes predict root penetration ability and biomechanical properties in maize (Zea Mays)

    PubMed Central

    Chimungu, Joseph G.; Loades, Kenneth W.; Lynch, Jonathan P.

    2015-01-01

    The ability of roots to penetrate hard soil is important for crop productivity but specific root phenes contributing to this ability are poorly understood. Root penetrability and biomechanical properties are likely to vary in the root system dependent on anatomical structure. No information is available to date on the influence of root anatomical phenes on root penetrability and biomechanics. Root penetration ability was evaluated using a wax layer system. Root tensile and bending strength were evaluated in plant roots grown in the greenhouse and in the field. Root anatomical phenes were found to be better predictors of root penetrability than root diameter per se and associated with smaller distal cortical region cell size. Smaller outer cortical region cells play an important role in stabilizing the root against ovalization and reducing the risk of local buckling and collapse during penetration, thereby increasing root penetration of hard layers. The use of stele diameter was found to be a better predictor of root tensile strength than root diameter. Cortical thickness, cortical cell count, cortical cell wall area and distal cortical cell size were stronger predictors of root bend strength than root diameter. Our results indicate that root anatomical phenes are important predictors for root penetrability of high-strength layers and root biomechanical properties. PMID:25903914

  17. MES Buffer Affects Arabidopsis Root Apex Zonation and Root Growth by Suppressing Superoxide Generation in Root Apex

    PubMed Central

    Kagenishi, Tomoko; Yokawa, Ken; Baluška, František

    2016-01-01

    In plants, growth of roots and root hairs is regulated by the fine cellular control of pH and reactive oxygen species (ROS). MES, 2-(N-morpholino)ethanesulfonic acid as one of the Good’s buffers has broadly been used for buffering medium, and it is thought to suit for plant growth with the concentration at 0.1% (w/v) because the buffer capacity of MES ranging pH 5.5–7.0 (for Arabidopsis, pH 5.8). However, many reports have shown that, in nature, roots require different pH values on the surface of specific root apex zones, namely meristem, transition zone, and elongation zone. Despite the fact that roots always grow on a media containing buffer molecule, little is known about impact of MES on root growth. Here, we have checked the effects of different concentrations of MES buffer using growing roots of Arabidopsis thaliana. Our results show that 1% of MES significantly inhibited root growth, the number of root hairs and length of meristem, whereas 0.1% promoted root growth and root apex area (region spanning from the root tip up to the transition zone). Furthermore, superoxide generation in root apex disappeared at 1% of MES. These results suggest that MES disturbs normal root morphogenesis by changing the ROS homeostasis in root apex. PMID:26925066

  18. Magnetophoretic Induction of Root Curvature

    NASA Technical Reports Server (NTRS)

    Hasenstein, Karl H.

    1997-01-01

    The last year of the grant period concerned the consolidation of previous experiments to ascertain that the theoretical premise apply not just to root but also to shoots. In addition, we verified that high gradient magnetic fields do not interfere with regular cellular activities. Previous results have established that: (1) intracellular magnetophoresis is possible; and (2) HGMF lead to root curvature. In order to investigate whether HGMF affect the assembly and/or organization of structural proteins, we examined the arrangement of microtubules in roots exposed to HGMF. The cytoskeletal investigations were performed with fomaldehyde-fixed, nonembedded tissue segments that were cut with a vibratome. Microtubules (MTs) were stained with rat anti-yeast tubulin (YOL 1/34) and DTAF-labeled antibody against rat IgG. Microfilaments (MFs) were visualized by incubation in rhodamine-labeled phalloidin. The distribution and arrangement of both components of the cytoskeleton were examined with a confocal microscope. Measurements of growth rates and graviresponse were done using a video-digitizer. Since HGMF repel diamagnetic substances including starch-filled amyloplasts and most The second aspect of the work includes studies of the effect of cytoskeletal inhibitors on MTs and MFs. The analysis of the effect of micotubular inhibitors on the auxin transport in roots showed that there is very little effect of MT-depolymerizing or stabilizing drugs on auxin transport. This is in line with observations that application of such drugs is not immediately affecting the graviresponsiveness of roots.

  19. Biostimulation of PAH degradation with plants containing high concentrations of linoleic acid.

    PubMed

    Yi, Haakrho; Crowley, David E

    2007-06-15

    Many plant species enhance the biodegradation of polycyclic aromatic hydrocarbons (PAHs), but there is little understanding of the mechanisms by which this occurs. This research identified phytochemicals that stimulate pyrene degradation using crushed roottissues from 43 plants that were screened in soil spiked with 100 ppm pyrene. Among the plants tested, root tissues from Apium graveolens (celery), Raphanus sativus (radish), Solanum tuberosum (potato), and Daucus carota (carrot) were most effective for promoting disappearance of pyrene within 40 days. Experiments with A. graveolens showed that plant culture in soil contaminated with pyrene or benzo[a]pyrene was as effective as addition of crushed root tissues. Comparison of the chemical compositions of the effective plants suggested that linoleic acid was the major substance that stimulated PAH degradation. This hypothesis was supported in experiments examining degradation of pyrene and benzo[a]pyrene in soil amended with linoleate, whereas linolenic and palmitic acids did not stimulate degradation within a 20 day period. Antibiotic inhibitor studies implicated gram positive bacteria as a predominant group responding to linoleic acid. These findings provide insight into the mechanisms by which plants enhance degradation of PAHs, and have practical application for remediation of PAH contaminated soils.

  20. Ambispora granatensis, a new arbuscular mycorrhizal fungus, associated with Asparagus officinalis in Andalucia (Spain).

    PubMed

    Palenzuela, Javier; Barea, José-Miguel; Ferrol, Nuria; Oehl, Fritz

    2011-01-01

    A new dimorphic fungal species in the arbuscular mycorrhiza-forming Glomeromycota, Ambispora granatensis, was isolated from an agricultural site in the province of Granada (Andalucía, Spain) growing in the rhizosphere of Asparagus officinalis. It was propagated in pot cultures with Trifolium pratense and Sorghum vulgare. The fungus also colonized Ri T-DNA transformed Daucus carota roots but did not form spores in these root organ cultures. The spores of the acaulosporoid morph are 90-150 μm diam and hyaline to white to pale yellow. They have three walls and a papillae-like rough irregular surface on the outer surface of the outer wall. The irregular surface might become difficult to detect within a few hours in lactic acid-based mountings but are clearly visible in water. The structural central wall layer of the outer wall is only 0.8-1.5 μm thick. The glomoid spores are formed singly or in small, loose spore clusters of 2-10 spores. They are hyaline to pale yellow, (25)40-70 μm diam and have a bilayered spore wall without ornamentation. Nearly full length sequences of the 18S and the ITS regions of the ribosomal gene place the new fungus in a separate clade next to Ambispora fennica and Ambispora gerdemannii. The acaulosporoid spores of the new fungus can be distinguished easily from all other spores in genus Ambispora by the conspicuous thin outer wall.

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

    PubMed

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

    2013-03-01

    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.

  2. New theories of root growth modelling

    NASA Astrophysics Data System (ADS)

    Landl, Magdalena; Schnepf, Andrea; Vanderborght, Jan; Huber, Katrin; Javaux, Mathieu; Bengough, A. Glyn; Vereecken, Harry

    2016-04-01

    In dynamic root architecture models, root growth is represented by moving root tips whose line trajectory results in the creation of new root segments. Typically, the direction of root growth is calculated as the vector sum of various direction-affecting components. However, in our simulations this did not reproduce experimental observations of root growth in structured soil. We therefore developed a new approach to predict the root growth direction. In this approach we distinguish between, firstly, driving forces for root growth, i.e. the force exerted by the root which points in the direction of the previous root segment and gravitropism, and, secondly, the soil mechanical resistance to root growth or penetration resistance. The latter can be anisotropic, i.e. depending on the direction of growth, which leads to a difference between the direction of the driving force and the direction of the root tip movement. Anisotropy of penetration resistance can be caused either by microscale differences in soil structure or by macroscale features, including macropores. Anisotropy at the microscale is neglected in our model. To allow for this, we include a normally distributed random deflection angle α to the force which points in the direction of the previous root segment with zero mean and a standard deviation σ. The standard deviation σ is scaled, so that the deflection from the original root tip location does not depend on the spatial resolution of the root system model. Similarly to the water flow equation, the direction of the root tip movement corresponds to the water flux vector while the driving forces are related to the water potential gradient. The analogue of the hydraulic conductivity tensor is the root penetrability tensor. It is determined by the inverse of soil penetration resistance and describes the ease with which a root can penetrate the soil. By adapting the three dimensional soil and root water uptake model R-SWMS (Javaux et al., 2008) in this way

  3. Root branching: mechanisms, robustness, and plasticity.

    PubMed

    Dastidar, Mouli Ghosh; Jouannet, Virginie; Maizel, Alexis

    2012-01-01

    Plants are sessile organisms that must efficiently exploit their habitat for water and nutrients. The degree of root branching impacts the efficiency of water uptake, acquisition of nutrients, and anchorage. The root system of plants is a dynamic structure whose architecture is determined by modulation of primary root growth and root branching. This plasticity relies on the continuous integration of environmental inputs and endogenous developmental programs controlling root branching. This review focuses on the cellular and molecular mechanisms involved in the regulation of lateral root distribution, initiation, and organogenesis with the main focus on the root system of Arabidopsis thaliana. We also examine the mechanisms linking environmental changes to the developmental pathways controlling root branching. Recent progress that emphasizes the parallels to the formation of root branches in other species is discussed.

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

    NASA Technical Reports Server (NTRS)

    Ng, Y. K.; Moore, R.

    1985-01-01

    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.

  5. Four cuspal maxillary second premolar with single root and three root canals: Case report

    PubMed Central

    Bansal, Parul; Nikhil, Vineeta; Goyal, Ayush; Singh, Ritu

    2016-01-01

    Traditional configuration of maxillary second premolars has been described to have two cusps, one root and one or two root canals. The endodontic literature reports considerable anatomic aberrations in the root canal morphology of maxillary second premolar but the literature available on the variation in cuspal anatomy and its relationship to the root canal anatomy is sparse. The purpose of this clinical report was to describe the root and root canal configuration of a maxillary second premolar with four cusps. PMID:27563190

  6. Psoralen production in hairy roots and adventitious roots cultures of Psoralea coryfolia.

    PubMed

    Baskaran, P; Jayabalan, N

    2009-07-01

    Psoralea corylifolia is an endangered plant producing various compounds of medical importance. Adventitious roots and hairy roots were induced in cultures prepared from hypocotyl explants. Psoralen content was evaluated in both root types grown either in suspension cultures or on agar solidified medium. Psoralen content was approximately 3 mg g(-1) DW in suspension grown hairy roots being higher than in solid grown hairy roots and in solid and suspension-grown adventitious roots.

  7. Disease notes - Bacterial root rot

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial root rot initiated by lactic acid bacteria, particularly Leuconostoc, occurs every year in Idaho sugarbeet fields. Hot fall weather seems to make the problem worse. Although Leuconostoc initiates the rot, other bacteria and yeast frequently invade the tissue as well. The acetic acid bac...

  8. Cutting the Roots of Violence.

    ERIC Educational Resources Information Center

    Koziey, Paul W.

    1996-01-01

    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…

  9. Excising the Root from STEM

    ERIC Educational Resources Information Center

    Lock, Roger

    2009-01-01

    There are a number of well-intentioned STEM initiatives, some designed to improve the recruitment and retention of science teachers. Sometimes it appears that the initiators are remote from direct contact with the "grass roots" issues that feed the "stem" on which the blossoms of young enthusiastic recruits to the science teaching profession are…

  10. Rhizoctonia root rot of lentil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia root rot is a soilborne disease of lentil caused by the fungal pathogen Rhizoctonia solani, and is favored by cool (11-19 C or 52 - 66 F) and wet soil conditions. The disease starts as reddish or dark brown lesions on lentil plants near the soil line, and develops into sunken lesions an...

  11. Roots: An Asian American Reader.

    ERIC Educational Resources Information Center

    Tachiki, Amy, Ed.; And Others

    A documentary collection of the experiences of Asian Americans from a multitude of perspectives, including a scholarly focus and also containing contemporary expressions, comprises "Roots: An Asian American Reader." The volume is said to be designed to meet the needs of Asian Americans by providing a compilation of materials in readily…

  12. Dry root rot of chickpea

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dry root rot of chickpea is a serious disease under dry hot summer conditions, particularly in the semi-arid tropics of Ethiopia, and in central and southern India. It usually occurs at reproductive stages of the plant. Symptoms include drooping of petioles and leaflets of the tips, but not the low...

  13. [Effects nutrients on the seedlings root hair development and root growth of Poncirus trifoliata under hydroponics condition].

    PubMed

    Cao, Xiu; Xia, Ren-Xue; Zhang, De-Jian; Shu, Bo

    2013-06-01

    Ahydroponics experiment was conducted to study the effects of nutrients (N, P, K, Ca, Mg, Fe, and Mn) deficiency on the length of primary root, the number of lateral roots, and the root hair density, length, and diameter on the primary root and lateral roots of Poncirus trifoliata seedlings. Under the deficiency of each test nutrient, root hair could generate, but was mainly concentrated on the root base and fewer on the root tip. The root hair density on lateral roots was significantly larger than that on primary root, but the root hair length was in adverse. The deficiency of each test nutrient had greater effects on the growth and development of root hairs, with the root hair density on primary root varied from 55.0 to 174.3 mm(-2). As compared with the control, Ca deficiency induced the significant increase of root hair density and length on primary root, P deficiency promoted the root hair density and length on the base and middle part of primary root and on the lateral roots significantly, Fe deficiency increased the root hair density but decreased the root hair length on the tip of primary root significantly, K deficiency significantly decreased the root hair density, length, and diameter on primary root and lateral roots, whereas Mg deficiency increased the root hair length of primary root significantly. In all treatments of nutrient deficiency, the primary root had the similar growth rate, but, with the exceptions of N and Mg deficiency, the lateral roots exhibited shedding and regeneration.

  14. Strigolactones fine-tune the root system.

    PubMed

    Rasmussen, Amanda; Depuydt, Stephen; Goormachtig, Sofie; Geelen, Danny

    2013-10-01

    Strigolactones were originally discovered to be involved in parasitic weed germination, in mycorrhizal association and in the control of shoot architecture. Despite their clear role in rhizosphere signaling, comparatively less attention has been given to the belowground function of strigolactones on plant development. However, research has revealed that strigolactones play a key role in the regulation of the root system including adventitious roots, primary root length, lateral roots, root hairs and nodulation. Here, we review the recent progress regarding strigolactone regulation of the root system and the antagonism and interplay with other hormones.

  15. Strigolactones are regulators of root development.

    PubMed

    Koltai, Hinanit

    2011-05-01

    Strigolactones (SLs) have been defined as a new group of plant hormones or their derivatives that suppress lateral shoot branching. Recently, a new role for SLs was discovered, in the regulation of root development. Strigolactones were shown to alter root architecture and affect root-hair elongation. Here, I review the recent findings regarding the effects of SLs on root growth and development, and their association with changes in auxin flux. The networking between SLs and other plant hormones that regulate root development is also presented. Strigolactone regulation of plant development suggests that they are coordinators of shoot and root development and mediators of plant responses to environmental conditions.

  16. Investigation of VEGGIE Root Mat

    NASA Technical Reports Server (NTRS)

    Subbiah, Arun M.

    2013-01-01

    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

  17. Characterizing pathways by which gravitropic effectors could move from the root cap to the root of primary roots of Zea mays

    NASA Technical Reports Server (NTRS)

    Moore, R.; McClelen, C. E.

    1989-01-01

    Plasmodesmata linking the root cap and root in primary roots Zea mays are restricted to approx. 400 protodermal cells bordering approx. 110000 microns2 of the calyptrogen of the root cap. This area is less than 10% of the cross-sectional area of the root-tip at the cap junction. Therefore, gravitropic effectors moving from the root cap to the root can move symplastically only through a relatively small area in the centre of the root. Decapped roots are non-responsive to gravity. However, decapped roots whose caps are replaced immediately after decapping are strongly graviresponsive. Thus, gravicurvature occurs only when the root cap contacts the root, and symplastic continuity between the cap and root is not required for gravicurvature. Completely removing mucilage from the root tip renders the root non-responsive to gravity. Taken together, these data suggest that gravitropic effectors move apoplastically through mucilage from the cap to the root.

  18. Image analysis from root system pictures

    NASA Astrophysics Data System (ADS)

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

    2009-04-01

    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.

  19. Nicotiana Roots Recruit Rare Rhizosphere Taxa as Major Root-Inhabiting Microbes.

    PubMed

    Saleem, Muhammad; Law, Audrey D; Moe, Luke A

    2016-02-01

    Root-associated microbes have a profound impact on plant health, yet little is known about the distribution of root-associated microbes among different root morphologies or between rhizosphere and root environments. We explore these issues here with two commercial varieties of burley tobacco (Nicotiana tabacum) using 16S rRNA gene amplicon sequencing from rhizosphere soil, as well as from primary, secondary, and fine roots. While rhizosphere soils exhibited a fairly rich and even distribution, root samples were dominated by Proteobacteria. A comparison of abundant operational taxonomic units (OTUs) between rhizosphere and root samples indicated that Nicotiana roots select for rare taxa (predominantly Proteobacteria, Verrucomicrobia, Actinobacteria, Bacteroidetes, and Acidobacteria) from their corresponding rhizosphere environments. The majority of root-inhabiting OTUs (~80 %) exhibited habitat generalism across the different root morphological habitats, although habitat specialists were noted. These results suggest a specific process whereby roots select rare taxa from a larger community.

  20. Dynamics of heterorhizic root systems: protoxylem groups within the fine-root system of Chamaecyparis obtusa.

    PubMed

    Hishi, Takuo; Takeda, Hiroshi

    2005-08-01

    To understand the physiology of fine-root functions in relation to soil organic sources, the heterogeneity of individual root functions within a fine-root system requires investigation. Here the heterogeneous dynamics within fine-root systems are reported. The fine roots of Chamaecyparis obtusa were sampled using a sequential ingrowth core method over 2 yr. After color categorization, roots were classified into protoxylem groups from anatomical observations. The root lengths with diarch and triarch groups fluctuated seasonally, whereas the tetrarch root length increased. The percentage of secondary root mortality to total mortality increased with increasing amounts of protoxylem. The carbon : nitrogen ratio indicated that the decomposability of primary roots might be greater than that of secondary roots. The position of diarch roots was mostly apical, whereas tetrarch roots tended to be distributed in basal positions within the root architecture. We demonstrate the heterogeneous dynamics within a fine-root system of C. obtusa. Fine-root heterogeneity should affect soil C dynamics. This heterogeneity is determined by the branching position within the root architecture.

  1. Root anatomy, morphology, and longevity among root orders in Vaccinium corymbosum (Ericaceae).

    PubMed

    Valenzuela-Estrada, Luis R; Vera-Caraballo, Vivianette; Ruth, Leah E; Eissenstat, David M

    2008-12-01

    Understanding root processes at the whole-plant or ecosystem scales requires an accounting of the range of functions within a root system. Studying root traits based on their branching order can be a powerful approach to understanding this complex system. The current study examined the highly branched root system of the ericoid plant, Vaccinium corymbosum L. (highbush blueberry) by classifying its root orders with a modified version of the morphometric approach similar to that used in hydrology for stream classification. Root anatomy provided valuable insight into variation in root function across orders. The more permanent portion of the root system occurred in 4th- and higher-order roots. Roots in these orders had radial growth; the lowest specific root length, N:C ratios, and mycorrhizal colonization; the highest tissue density and vessel number; and the coarsest root diameter. The ephemeral portion of the root system was mainly in the first three root orders. First- and 2nd-order roots were nearly anatomically identical, with similar mycorrhizal colonization and diameter, and also, despite being extremely fine, median lifespans were not very short (115-120 d; estimated with minirhizotrons). Our research underscores the value of examining root traits by root order and its implications to understanding belowground processes.

  2. Brassinosteroids Regulate Root Growth, Development, and Symbiosis.

    PubMed

    Wei, Zhuoyun; Li, Jia

    2016-01-04

    Brassinosteroids (BRs) are natural plant hormones critical for growth and development. BR deficient or signaling mutants show significantly shortened root phenotypes. However, for a long time, it was thought that these phenotypes were solely caused by reduced cell elongation in the mutant roots. Functions of BRs in regulating root development have been largely neglected. Nonetheless, recent detailed analyses, revealed that BRs are not only involved in root cell elongation but are also involved in many aspects of root development, such as maintenance of meristem size, root hair formation, lateral root initiation, gravitropic response, mycorrhiza formation, and nodulation in legume species. In this review, current findings on the functions of BRs in mediating root growth, development, and symbiosis are discussed.

  3. Environmental Control of Root System Biology.

    PubMed

    Rellán-Álvarez, Rubén; Lobet, Guillaume; Dinneny, José R

    2016-04-29

    The plant root system traverses one of the most complex environments on earth. Understanding how roots support plant life on land requires knowing how soil properties affect the availability of nutrients and water and how roots manipulate the soil environment to optimize acquisition of these resources. Imaging of roots in soil allows the integrated analysis and modeling of environmental interactions occurring at micro- to macroscales. Advances in phenotyping of root systems is driving innovation in cross-platform-compatible methods for data analysis. Root systems acclimate to the environment through architectural changes that act at the root-type level as well as through tissue-specific changes that affect the metabolic needs of the root and the efficiency of nutrient uptake. A molecular understanding of the signaling mechanisms that guide local and systemic signaling is providing insight into the regulatory logic of environmental responses and has identified points where crosstalk between pathways occurs.

  4. The Physiology of Adventitious Roots1

    PubMed Central

    Steffens, Bianka; Rasmussen, Amanda

    2016-01-01

    Adventitious roots are plant roots that form from any nonroot tissue and are produced both during normal development (crown roots on cereals and nodal roots on strawberry [Fragaria spp.]) and in response to stress conditions, such as flooding, nutrient deprivation, and wounding. They are important economically (for cuttings and food production), ecologically (environmental stress response), and for human existence (food production). To improve sustainable food production under environmentally extreme conditions, it is important to understand the adventitious root development of crops both in normal and stressed conditions. Therefore, understanding the regulation and physiology of adventitious root formation is critical for breeding programs. Recent work shows that different adventitious root types are regulated differently, and here, we propose clear definitions of these classes. We use three case studies to summarize the physiology of adventitious root development in response to flooding (case study 1), nutrient deficiency (case study 2), and wounding (case study 3). PMID:26697895

  5. The role of strigolactones in root development.

    PubMed

    Sun, Huwei; Tao, Jinyuan; Gu, Pengyuan; Xu, Guohua; Zhang, Yali

    2016-01-01

    Strigolactones (SLs) and their derivatives were recently defined as novel phytohormones that orchestrate shoot and root growth. Levels of SLs, which are produced mainly by plant roots, increase under low nitrogen and phosphate levels to regulate plant responses. Here, we summarize recent work on SL biology by describing their role in the regulation of root development and hormonal crosstalk during root deve-lopment. SLs promote the elongation of seminal/primary roots and adventitious roots (ARs) and they repress lateral root formation. In addition, auxin signaling acts downstream of SLs. AR formation is positively or negatively regulated by SLs depending largely on the plant species and experimental conditions. The relationship between SLs and auxin during AR formation appears to be complex. Most notably, this hormonal response is a key adaption that radically alters rice root architecture in response to nitrogen- and phosphate-deficient conditions.

  6. Endoplasmic Reticulum Stress Response in Arabidopsis Roots

    PubMed Central

    Cho, Yueh; Kanehara, Kazue

    2017-01-01

    Roots are the frontier of plant body to perceive underground environmental change. Endoplasmic reticulum (ER) stress response represents circumvention of cellular stress caused by various environmental changes; however, a limited number of studies are available on the ER stress responses in roots. Here, we report the tunicamycin (TM) -induced ER stress response in Arabidopsis roots by monitoring expression patterns of immunoglobulin-binding protein 3 (BiP3), a representative marker for the response. Roots promptly responded to the TM-induced ER stress through the induction of similar sets of ER stress-responsive genes. However, not all cells responded uniformly to the TM-induced ER stress in roots, as BiP3 was highly expressed in root tips, an outer layer in elongation zone, and an inner layer in mature zone of roots. We suggest that ER stress response in roots has tissue specificity. PMID:28298914

  7. Rhizosphere biophysics and root water uptake

    NASA Astrophysics Data System (ADS)

    Carminati, Andrea; Zarebanadkouki, Mohsen; Ahmed, Mutez A.; Passioura, John

    2016-04-01

    The flow of water into the roots and the (putative) presence of a large resistance at the root-soil interface have attracted the attention of plant and soil scientists for decades. Such resistance has been attributed to a partial contact between roots and soil, large gradients in soil matric potential around the roots, or accumulation of solutes at the root surface creating a negative osmotic potential. Our hypothesis is that roots are capable of altering the biophysical properties of the soil around the roots, the rhizosphere, facilitating root water uptake in dry soils. In particular, we expect that root hairs and mucilage optimally connect the roots to the soil maintaining the hydraulic continuity across the rhizosphere. Using a pressure chamber apparatus we measured the relation between transpiration rate and the water potential difference between soil and leaf xylem during drying cycles in barley mutants with and without root hairs. The samples were grown in well structured soils. At low soil moistures and high transpiration rates, large drops in water potential developed around the roots. These drops in water potential recovered very slowly, even after transpiration was severely decreased. The drops in water potential were much bigger in barley mutants without root hairs. These mutants failed to sustain high transpiration rates in dry conditions. To explain the nature of such drops in water potential across the rhizosphere we performed high resolution neutron tomography of the rhizosphere of the barleys with and without root hairs growing in the same soil described above. The tomograms suggested that the hydraulic contact between the soil structures was the highest resistance for the water flow in dry conditions. The tomograms also indicate that root hairs and mucilage improved the hydraulic contact between roots and soil structures. At high transpiration rates and low water contents, roots extracted water from the rhizosphere, while the bulk soil, due its

  8. Root proliferation in decaying roots and old root channels: A nutrient conservation mechanism in oligotrophic mangrove forests?

    USGS Publications Warehouse

    McKee, K.L.

    2001-01-01

    1. In oligotrophic habitats, proliferation of roots in nutrient-rich microsites may contribute to overall nutrient conservation by plants. Peat-based soils on mangrove islands in Belize are characterized by the presence of decaying roots and numerous old root channels (0.1-3.5 cm diameter) that become filled with living and highly branched roots of Rhizophora mangle and Avicennia germinans. The objectives of this study were to quantify the proliferation of roots in these microsites and to determine what causes this response. 2. Channels formed by the refractory remains of mangrove roots accounted for only 1-2% of total soil volume, but the proportion of roots found within channels varied from 9 to 24% of total live mass. Successive generations of roots growing inside increasingly smaller root channels were also found. 3. When artificial channels constructed of PVC pipe were buried in the peat for 2 years, those filled with nutrient-rich organic matter had six times more roots than empty or sand-filled channels, indicating a response to greater nutrient availability rather than to greater space or less impedance to root growth. 4. Root proliferation inside decaying roots may improve recovery of nutrients released from decomposing tissues before they can be leached or immobilized in this intertidal environment. Greatest root proliferation in channels occurred in interior forest zones characterized by greater soil waterlogging, which suggests that this may be a strategy for nutrient capture that minimizes oxygen losses from the whole root system. 5. Improved efficiency of nutrient acquisition at the individual plant level has implications for nutrient economy at the ecosystem level and may explain, in part, how mangroves persist and grow in nutrient-poor environments.

  9. Doubling bialgebras of rooted trees

    NASA Astrophysics Data System (ADS)

    Mohamed, Mohamed Belhaj; Manchon, Dominique

    2017-01-01

    The vector space spanned by rooted forests admits two graded bialgebra structures. The first is defined by Connes and Kreimer using admissible cuts, and the second is defined by Calaque, Ebrahimi-Fard and the second author using contraction of trees. In this article, we define the doubling of these two spaces. We construct two bialgebra structures on these spaces which are in interaction, as well as two related associative products obtained by dualization. We also show that these two bialgebras verify a commutative diagram similar to the diagram verified Calaque, Ebrahimi-Fard and the second author in the case of rooted trees Hopf algebra, and by the second author in the case of cycle-free oriented graphs.

  10. The rhizosphere revisited: root microbiomics

    PubMed Central

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

    2013-01-01

    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

  11. How Roots Perceive and Respond to Gravity.

    ERIC Educational Resources Information Center

    Moore, Randy

    1984-01-01

    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…

  12. Sonic instruments in root canal therapy.

    PubMed

    Waplington, M; Lumley, P J; Walmsley, A D

    1995-10-01

    Although hand instrumentation is considered the most acceptable method of preparing root canals, sonic instruments may be useful additions to the endodontic armamentarium. Sonic instrumentation may be incorporated as an adjunct to traditional techniques for shaping the root canal. The use of such instruments may assist the practitioner during root canal treatment in general practice.

  13. The removal of root surface deposits.

    PubMed

    Eaton, K A; Kieser, J B; Davies, R M

    1985-02-01

    The importance of adequate root surface instrumentation has received increasing emphasis. The purpose of this study was to determine the extent to which root planning could produce surfaces free of stainable deposits. Initial laboratory investigations on extracted, periodontally involved roots demonstrated that after meticulous root preparation, totally non-stainable surfaces could be obtained. These surfaces were shown to consist of either thin cementum or dentine. The efficacy of instrumenting periodontally involved buccal root surfaces on the anterior teeth of 33 patients, undergoing routine periodontal flap surgery was then evaluated. Root surfaces were instrumented either before or after the reflection of surgical flaps. Remaining bacterial deposits were disclosed with a gentian violet solution and the root surfaces then photographed. Further root planing, disclosure and photography were then carried out. These photographic slides were analysed for stainable deposits on the root surfaces using an image analysis system, based on densitometric principles, to measure the areas of stainable root surface deposits. The findings revealed that root planning under direct vision at the time of surgery was more effective than blind instrumentation. However, in no instance was any root surface found to be completely free of stainable deposits.

  14. Phenotyping jasmonate regulation of root growth.

    PubMed

    Kellermeier, Fabian; Amtmann, Anna

    2013-01-01

    Root architecture is a complex and highly plastic feature of higher plants. Direct treatments with jasmonates and alterations in jasmonate signaling have been shown to elicit a range of root phenotypes. Here, we describe a fast, noninvasive, and semiautomatic method to monitor root architectural responses to environmental stimuli using plant tissue culture and the software tool EZ-RHIZO.

  15. Root functioning modifies seasonal climate.

    PubMed

    Lee, Jung-Eun; Oliveira, Rafael S; Dawson, Todd E; Fung, Inez

    2005-12-06

    Hydraulic redistribution (HR), the nocturnal vertical transfer of soil water from moister to drier regions in the soil profile by roots, has now been observed in Amazonian trees. We have incorporated HR into an atmospheric general circulation model (the National Center for Atmospheric Research Community Atmospheric Model Version 2) to estimate its impact on climate over the Amazon and other parts of the globe where plants displaying HR occur. Model results show that photosynthesis and evapotranspiration increase significantly in the Amazon during the dry season when plants are allowed to redistribute soil water. Plants draw water up and deposit it into the surface layers, and this water subsidy sustains transpiration at rates that deep roots alone cannot accomplish. The water used for dry season transpiration is from the deep storage layers in the soil, recharged during the previous wet season. We estimate that HR increases dry season (July to November) transpiration by approximately 40% over the Amazon. Our model also indicates that such an increase in transpiration over the Amazon and other drought-stressed regions affects the seasonal cycles of temperature through changes in latent heat, thereby establishing a direct link between plant root functioning and climate.

  16. Root-cubing and general root-powering methods for finding the zeros of polynomials

    NASA Technical Reports Server (NTRS)

    Bareiss, E. H.

    1969-01-01

    Mathematical analysis technique generalizes a root squaring and root cubing method into a general root powering method. The introduction of partitioned polynomials into this general root powering method simplifies the coding of the polynomial transformations into input data suitable for processing by computer. The method includes analytic functions.

  17. Estimate of fine root production including the impact of decomposed roots in a Bornean tropical rainforest

    NASA Astrophysics Data System (ADS)

    Katayama, Ayumi; Khoon Koh, Lip; Kume, Tomonori; Makita, Naoki; Matsumoto, Kazuho; Ohashi, Mizue

    2016-04-01

    Considerable carbon is allocated belowground and used for respiration and production of roots. It is reported that approximately 40 % of GPP is allocated belowground in a Bornean tropical rainforest, which is much higher than those in Neotropical rainforests. This may be caused by high root production in this forest. Ingrowth core is a popular method for estimating fine root production, but recent study by Osawa et al. (2012) showed potential underestimates of this method because of the lack of consideration of the impact of decomposed roots. It is important to estimate fine root production with consideration for the decomposed roots, especially in tropics where decomposition rate is higher than other regions. Therefore, objective of this study is to estimate fine root production with consideration of decomposed roots using ingrowth cores and root litter-bag in the tropical rainforest. The study was conducted in Lambir Hills National Park in Borneo. Ingrowth cores and litter bags for fine roots were buried in March 2013. Eighteen ingrowth cores and 27 litter bags were collected in May, September 2013, March 2014 and March 2015, respectively. Fine root production was comparable to aboveground biomass increment and litterfall amount, and accounted only 10% of GPP in this study site, suggesting most of the carbon allocated to belowground might be used for other purposes. Fine root production was comparable to those in Neotropics. Decomposed roots accounted for 18% of fine root production. This result suggests that no consideration of decomposed fine roots may cause underestimate of fine root production.

  18. Root canal treatment of a maxillary second premolar with two palatal roots: A case report

    PubMed Central

    George, Gingu Koshy; Varghese, Anju Mary; Devadathan, Aravindan

    2014-01-01

    Anatomical variations in root canal morphology are an enigma and it is this variability, which is often a complicating factor in a successful root canal treatment. To achieve success in endodontic therapy it is imperative that all the canals are located, cleaned and shaped and obturated three dimensionally. Maxillary first premolar having three separate roots has an incidence of 0.5-6%. Even rarer are reported clinical case reports of maxillary second premolar with three separate roots and three canals. This case report describes the endodontic management of maxillary second premolar with two palatal roots and one buccal root having three root canals PMID:24944457

  19. Light as stress factor to plant roots - case of root halotropism.

    PubMed

    Yokawa, Ken; Fasano, Rossella; Kagenishi, Tomoko; Baluška, František

    2014-01-01

    Despite growing underground, largely in darkness, roots emerge to be very sensitive to light. Recently, several important papers have been published which reveal that plant roots not only express all known light receptors but also that their growth, physiology and adaptive stress responses are light-sensitive. In Arabidopsis, illumination of roots speeds-up root growth via reactive oxygen species-mediated and F-actin dependent process. On the other hand, keeping Arabidopsis roots in darkness alters F-actin distribution, polar localization of PIN proteins as well as polar transport of auxin. Several signaling components activated by phytohormones are overlapping with light-related signaling cascade. We demonstrated that the sensitivity of roots to salinity is altered in the light-grown Arabidopsis roots. Particularly, light-exposed roots are less effective in their salt-avoidance behavior known as root halotropism. Here we discuss these new aspects of light-mediated root behavior from cellular, physiological and evolutionary perspectives.

  20. Conserved and diverse mechanisms in root development.

    PubMed

    Hochholdinger, Frank; Zimmermann, Roman

    2008-02-01

    The molecular basis of root formation and growth is being analyzed in more and more detail in the dicot model organism Arabidopsis. However, considerable progress has also been made in the molecular and genetic dissection of root system development in the monocot species rice and maize. This review will highlight some recent molecular data that allow for the comparison of cereal and Arabidopsis root development. Members of the COBRA, GRAS, and LOB domain gene families and a gene encoding a subunit of the exocyst complex are associated with root development. Analyses of these genes revealed some common and distinct molecular principles and functions in cereal versus Arabidopsis root formation.

  1. Hydrogenase in actinorhizal root nodules and root nodule homogenates.

    PubMed Central

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

    1980-01-01

    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

  2. Optimal root arrangement of cereal crops

    NASA Astrophysics Data System (ADS)

    Jung, Yeonsu; Park, Keunhwan; Kim, Ho-Young

    2015-11-01

    The plant root absorbs water from the soil and supplies it to the rest part of the plant. It consists of a number of root fibers, through whose surfaces water uptake occurs. There is an intriguing observation that for most of cereal crops such as maize and wheat, the volume density of root in the soil declines exponentially as a function of depth. To understand this empirical finding, we construct a theoretical model of root water uptake, where mass transfer into root surface is modeled just as heat flux around a fin. Agreement between the theoretically predicted optimal root distribution in vertical direction and biological data supports the hypothesis that the plant root has evolved to achieve the optimal water uptake in competition with neighbors. This study has practical implication in the agricultural industry as well as optimal design of water transport networks in both micro- and macroscales. Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul 08826, Korea.

  3. Hydraulic responses of whole vines and individual roots of kiwifruit (Actinidia chinensis) following root severance.

    PubMed

    Black, Marykate Z; Patterson, Kevin J; Minchin, Peter E H; Gould, Kevin S; Clearwater, Michael J

    2011-05-01

    Whole vine (K(plant)) and individual root (K(root)) hydraulic conductances were measured in kiwifruit (Actinidia chinensis Planch. var. chinensis 'Hort16A') vines to observe hydraulic responses following partial root system excision. Heat dissipation and compensation heat pulse techniques were used to measure sap flow in trunks and individual roots, respectively. Sap flux and measurements of xylem pressure potential (Ψ) were used to calculate K(plant) and K(root) in vines with zero and ∼80% of roots severed. Whole vine transpiration (E), Ψ and K(plant) were significantly reduced within 24 h of root pruning, and did not recover within 6 weeks. Sap flux in intact roots increased within 24 h of root pruning, driven by an increase in the pressure gradient between the soil and canopy and without any change in root hydraulic conductance. Photosynthesis (A) and stomatal conductance (g(s)) were reduced, without significant effects on leaf internal CO(2) concentration (c(i)). Shoot growth rates were maintained; fruit growth and dry matter content were increased following pruning. The woody roots of kiwifruit did not demonstrate a rapid dynamic response to root system damage as has been observed previously in monocot seedlings. Increased sap flux in intact roots with no change in K(root) and only a moderate decline in shoot A suggests that under normal growing conditions root hydraulic conductance greatly exceeds requirements for adequate shoot hydration.

  4. Patterns of variability in the diameter of lateral roots in the banana root system.

    PubMed

    Lecompte, François; Pagès, Loïc; Ozier-Lafontaine, Harry

    2005-09-01

    The relative importance of root system structure, plant carbon status and soil environment in the determination of lateral root diameter remains unclear, and was investigated in this study. Banana (Musa acuminata) plants were grown at various moderate levels of soil compaction in two distinct experiments, in a field experiment (FE) and in a glasshouse experiment (GE). Radiant flux density was 5 times lower in GE. The distribution of root diameter was measured for several root branching orders. Root diameters ranged between 0.09 and 0.52 mm for secondary roots and between 0.06 and 0.27 mm for tertiary roots. A relationship was found between the diameter of the parent bearing root and the median diameter of its laterals, which appears to be valid for a wide range of species. Mean lateral root diameter increased with distance to the base of the root and decreased with branching density [number of lateral roots per unit length of bearing root (cm(-1))]. Typical symptoms of low light availability were observed in GE. In this case, lateral root diameter variability was reduced. Although primary root growth was affected by soil compaction, no effects on lateral root diameter were observed.

  5. Evaluation of phytotoxicity effect on selected crops using treated and untreated wastewater from different configurative domestic wastewater plants.

    PubMed

    Ravindran, B; Kumari, S K Sheena; Stenstrom, T A; Bux, F

    2016-01-01

    This study investigated the phytotoxicity effect of untreated and treated wastewater collected from two different configurations of domestic wastewater treatment plants in South Africa. The phytotoxicity effect on vegetable seed growth was studied in terms of germination index (GI), relative seed germination (RSG) and relative root elongation (RRE) using four commercial crop varieties, viz., tomato (Lycopersicon esculentum), radish (Raphanus sativus), carrot (Daucus carota) and onion (Allium cepa). According to phyototoxicity limits, 80% germination and above is regarded as non-toxic and less than 50% GI is regarded as highly toxic and not suitable for agricultural purposes. In our study, seeds were irrigated with concentrations of 25%, 50%, 75%, 100% of treated effluent (TE) and untreated effluent (UTE). The TE results were best with the highest GI (%) recorded as tomato, 177; carrot, 158.5; onion, 132; and lettuce, 124. The results of this study indicate that TE showed no phytotoxicty effects and recorded above 80% GI. The UTE irrigated crops reached a GI of only 50% and above which is clear evidence of the beneficial effect of waste water treatment. The overall results confirmed that treated wastewater has a beneficial effect on agricultural crops and can be used as a liquid fertilizer.

  6. Selecting iodine-enriched vegetables and the residual effect of iodate application to soil.

    PubMed

    Dai, Jiu-Lan; Zhu, Yong-Guan; Zhang, Min; Huang, Yi-Zhong

    2004-12-01

    A greenhouse pot experiment was conducted to select vegetables for iodine uptake. The residual effect of iodate fertilization on the growth of and iodine uptake by spinach plants were also investigated. Six vegetables, including leafy vegetables (pakchoi [Brassica chinensis L.], spinach [Spinacia oleracea L.]), tuber vegetables (onion [Allium cepa L.]), shoot vegetables (water spinach [Ipomoea aquatica Forsk.], celery [Apium graveolens L.]), and root vegetables (carrot [Daucus carota var. sativa DC.]) were examined. Results showed that the concentrations of iodate in soil had significant effect on the biomass of edible parts of pakchoi and spinach (p<0.01), whereas the concentrations of iodate in soil had no significant effect on that of carrots, water spinach, celery, and onion. Iodine concentrations in edible parts of vegetables and the transfer factors (TFedible parts) of soil-to-edible parts of vegetables significantly increased with increasing iodine concentrations in soil (p<0.001), and iodine concentrations in edible parts and TFedible parts of spinach were much higher than those of other vegetables at any treatment. Both transfer coefficients for edible parts (TCedible parts) and for aerial parts (TCaerial parts) of vegetables changed differently with increasing iodine concentrations in the soil, and TCedible parts and TCaerial parts of spinach were higher than those of other vegetables. Therefore, spinach was considered as an efficient vegetable for iodine biofortification. Further experiment showed that there is considerable residual effect of soil fertilization with iodate.

  7. Xanthones from Garcinia propinqua Roots.

    PubMed

    Meesakul, Pornphimol; Pansanit, Acharavadee; Maneerat, Wisanu; Sripisut, Tawanun; Ritthiwigrom, Thunwadee; Machana, Theeraphan; Cheenpracha, Sarot; Laphookhieo, Surat

    2016-01-01

    Phytochemical investigation of Garcinia propinqua roots led to the isolation and identification of a new xanthone, doitunggarcinone D (1), together with 15 known compounds (2-16). Their structures were elucidated by intensive analysis of spectroscopic data. Compounds 3, 6, 7, 14, 15 and 16 exhibited strong antibacterial activity against Bacillus subtilis TISTR 088 with MIC values in the range of 1-4 µg/mL. Compounds 3, 7, 10 and 14 also showed good antibacterial activity against B. cereus TISTR 688 with MIC values ranging from 4-8 µg/mL.

  8. Flavonoids from Caragana pruinosa roots.

    PubMed

    Peng, Wei; Wang, Liang; Qiu, Xu-Hui; Jiang, Yi-Ping; Pan, Lan; Jia, Xiao-Guang; Qin, Lu-Ping; Zheng, Cheng-Jian

    2016-10-01

    A new pterocarpan derivative, pruinosanone D (1), a new isoflavonoid, pruinosanone E (2), and a new chalcone, pruinosanone F (3), were isolated from Caragana pruinosa roots, along with four known analogues (4-7), identified as 2,4-dihydroxy-3'-methoxy-4'-ethoxychalcone, 7,4-dihydroxyflavanone, butin and scutellaprostin C, respectively. Their structures were elucidated by detailed analyses of NMR, IR, and MS data. The ability of the isolated compounds to prevent nitric oxide (NO) production by LPS-stimulated RAW 264.7 macrophages was also studied. Compound 1 were among the most potent NO production inhibitor, with IC50 value of 0.62μM.

  9. Metabolic engineering of novel ketocarotenoid production in carrot plants.

    PubMed

    Jayaraj, Jayaraman; Devlin, Robert; Punja, Zamir

    2008-08-01

    Carotenoids constitute a vast group of pigments that are ubiquitous throughout nature. Carrot (Daucus carota L.) roots provide an important source of dietary beta-carotene (provitamin A), alpha-carotene and lutein. Ketocarotenoids, such as canthaxanthin and astaxanthin, are produced by some algae and cyanobacteria but are rare in plants. Ketocarotenoids are strong antioxidants that are chemically synthesized and used as dietary supplements and pigments in the aquaculture and neutraceutical industries. We engineered the ketocarotenoid biosynthetic pathway in carrot tissues by introducing a beta-carotene ketolase gene isolated from the alga Haematococcus pluvialis. Gene constructs were made with three promoters (double CaMV 35S, Arabidopsis-ubiquitin, and RolD from Agrobacterium rhizogenes). The pea Rubisco small sub-unit transit peptide was used to target the enzyme to plastids in leaf and root tissues. The phosphinothricin acetyl transferase (bar) gene was used as a selectable marker. Following Agrobacterium-mediated transformation, 150 plants were regenerated and grown in a glasshouse. All three promoters provided strong root expression, while the double CaMV 35S and Ubiquitin promoters also had strong leaf expression. The recombinant ketolase protein was successfully targeted to the chloroplasts and chromoplasts. Endogenous expression of carrot beta-carotene hydroxylases was up-regulated in transgenic leaves and roots, and up to 70% of total carotenoids was converted to novel ketocarotenoids, with accumulation up to 2,400 microg/g root dry weight. Astaxanthin, adonirubin, and canthaxanthin were most prevalent, followed by echinenone, adonixanthin and beta-cryptoxanthin. Our results show that carrots are suitable for biopharming ketocarotenoid production for applications to the functional food, neutraceutical and aquaculture industries.

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

    PubMed

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

    2013-09-01

    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.

  11. Measuring tree root respiration using (13)C natural abundance: rooting medium matters.

    PubMed

    Cheng, Weixin; Fu, Shenglei; Susfalk, Richard B; Mitchell, Robert J

    2005-07-01

    Tree root respiration utilizes a major portion of the primary production in forests and is an important process in the global carbon cycle. Because of the lack of ecologically relevant methods, tree root respiration in situ is much less studied compared with above-ground processes such as photosynthesis and leaf respiration. This study introduces a new (13)C natural tracer method for measuring tree root respiration in situ. The method partitions tree root respiration from soil respiration in buried root chambers. Rooting media substantially influenced root respiration rates. Measured in three media, the fine root respiration rates of longleaf pine were 0.78, 0.27 and 0.18 mg CO(2) carbon mg(-1) root nitrogen d(-1) at 25 degrees C in the native soil, tallgrass prairie soil, and sand-vermiculite mixture, respectively. Compared with the root excision method, the root respiration rate of longleaf pine measured by the field chamber method was 18% higher when using the native soil as rooting medium, was similar in the prairie soil, but was 42% lower if in the sand-vermiculite medium. This natural tracer method allows the use of an appropriate rooting medium and is capable of measuring root respiration nondestructively in natural forest conditions.

  12. PATTERNS IN SOIL FERTILITY AND ROOT HERBIVORY INTERACT TO INFLUENCE FINE-ROOT DYNAMICS.

    SciTech Connect

    Stevens, Glen, N.; Jones, Robert, H.

    2006-03-01

    Fine-scale soil nutrient enrichment typically stimulates root growth, but it may also increase root herbivory, resulting in trade-offs for plant species and potentially influencing carbon cycling patterns. We used root ingrowth cores to investigate the effects of microsite fertility and root herbivory on root biomass in an aggrading upland forest in the coastal plain of South Carolina, USA. Treatments were randomly assigned to cores from a factorial combination of fertilizer and insecticide. Soil, soil fauna, and roots were removed from the cores at the end of the experiment (8–9 mo), and roots were separated at harvest into three diameter classes. Each diameter class responded differently to fertilizer and insecticide treatments. The finest roots (,1.0 mm diameter), which comprised well over half of all root biomass, were the only ones to respond significantly to both treatments, increasing when fertilizer and when insecticide were added (each P , 0.0001), with maximum biomass found where the treatments were combined (interaction term significant, P , 0.001). These results suggest that root-feeding insects have a strong influence on root standing crop with stronger herbivore impacts on finer roots and within more fertile microsites. Thus, increased vulnerability to root herbivory is a potentially significant cost of root foraging in nutrient-rich patches.

  13. Inhibition of auxin movement from the shoot into the root inhibits lateral root development in Arabidopsis

    NASA Technical Reports Server (NTRS)

    Reed, R. C.; Brady, S. R.; Muday, G. K.

    1998-01-01

    In roots two distinct polar movements of auxin have been reported that may control different developmental and growth events. To test the hypothesis that auxin derived from the shoot and transported toward the root controls lateral root development, the two polarities of auxin transport were uncoupled in Arabidopsis. Local application of the auxin-transport inhibitor naphthylphthalamic acid (NPA) at the root-shoot junction decreased the number and density of lateral roots and reduced the free indoleacetic acid (IAA) levels in the root and [3H]IAA transport into the root. Application of NPA to the basal half of or at several positions along the root only reduced lateral root density in regions that were in contact with NPA or in regions apical to the site of application. Lateral root development was restored by application of IAA apical to NPA application. Lateral root development in Arabidopsis roots was also inhibited by excision of the shoot or dark growth and this inhibition was reversible by IAA. Together, these results are consistent with auxin transport from the shoot into the root controlling lateral root development.

  14. A statistical approach to root system classification

    PubMed Central

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

    2013-01-01

    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

  15. Root hairs aid soil penetration by anchoring the root surface to pore walls

    PubMed Central

    Bengough, A. Glyn; Loades, Kenneth; McKenzie, Blair M.

    2016-01-01

    The physical role of root hairs in anchoring the root tip during soil penetration was examined. Experiments using a hairless maize mutant (Zea mays: rth3–3) and its wild-type counterpart measured the anchorage force between the primary root of maize and the soil to determine whether root hairs enabled seedling roots in artificial biopores to penetrate sandy loam soil (dry bulk density 1.0–1.5g cm−3). Time-lapse imaging was used to analyse root and seedling displacements in soil adjacent to a transparent Perspex interface. Peak anchorage forces were up to five times greater (2.5N cf. 0.5N) for wild-type roots than for hairless mutants in 1.2g cm−3 soil. Root hair anchorage enabled better soil penetration for 1.0 or 1.2g cm−3 soil, but there was no significant advantage of root hairs in the densest soil (1.5g cm−3). The anchorage force was insufficient to allow root penetration of the denser soil, probably because of less root hair penetration into pore walls and, consequently, poorer adhesion between the root hairs and the pore walls. Hairless seedlings took 33h to anchor themselves compared with 16h for wild-type roots in 1.2g cm−3 soil. Caryopses were often pushed several millimetres out of the soil before the roots became anchored and hairless roots often never became anchored securely.The physical role of root hairs in anchoring the root tip may be important in loose seed beds above more compact soil layers and may also assist root tips to emerge from biopores and penetrate the bulk soil. PMID:26798027

  16. A rooted net of life.

    PubMed

    Williams, David; Fournier, Gregory P; Lapierre, Pascal; Swithers, Kristen S; Green, Anna G; Andam, Cheryl P; Gogarten, J Peter

    2011-09-21

    Phylogenetic reconstruction using DNA and protein sequences has allowed the reconstruction of evolutionary histories encompassing all life. We present and discuss a means to incorporate much of this rich narrative into a single model that acknowledges the discrete evolutionary units that constitute the organism. Briefly, this Rooted Net of Life genome phylogeny is constructed around an initial, well resolved and rooted tree scaffold inferred from a supermatrix of combined ribosomal genes. Extant sampled ribosomes form the leaves of the tree scaffold. These leaves, but not necessarily the deeper parts of the scaffold, can be considered to represent a genome or pan-genome, and to be associated with members of other gene families within that sequenced (pan)genome. Unrooted phylogenies of gene families containing four or more members are reconstructed and superimposed over the scaffold. Initially, reticulations are formed where incongruities between topologies exist. Given sufficient evidence, edges may then be differentiated as those representing vertical lines of inheritance within lineages and those representing horizontal genetic transfers or endosymbioses between lineages.

  17. Roots at the percolation threshold.

    PubMed

    Kroener, Eva; Ahmed, Mutez Ali; Carminati, Andrea

    2015-04-01

    The rhizosphere is the layer of soil around the roots where complex and dynamic interactions between plants and soil affect the capacity of plants to take up water. The physical properties of the rhizosphere are affected by mucilage, a gel exuded by roots. Mucilage can absorb large volumes of water, but it becomes hydrophobic after drying. We use a percolation model to describe the rewetting of dry rhizosphere. We find that at a critical mucilage concentration the rhizosphere becomes impermeable. The critical mucilage concentration depends on the radius of the soil particle size. Capillary rise experiments with neutron radiography prove that for concentrations below the critical mucilage concentration water could easily cross the rhizosphere, while above the critical concentration water could no longer percolate through it. Our studies, together with former observations of water dynamics in the rhizosphere, suggest that the rhizosphere is near the percolation threshold, where small variations in mucilage concentration sensitively alter the soil hydraulic conductivity. Is mucilage exudation a plant mechanism to efficiently control the rhizosphere conductivity and the access to water?

  18. Roots at the percolation threshold

    NASA Astrophysics Data System (ADS)

    Kroener, Eva; Ahmed, Mutez Ali; Carminati, Andrea

    2015-04-01

    The rhizosphere is the layer of soil around the roots where complex and dynamic interactions between plants and soil affect the capacity of plants to take up water. The physical properties of the rhizosphere are affected by mucilage, a gel exuded by roots. Mucilage can absorb large volumes of water, but it becomes hydrophobic after drying. We use a percolation model to describe the rewetting of dry rhizosphere. We find that at a critical mucilage concentration the rhizosphere becomes impermeable. The critical mucilage concentration depends on the radius of the soil particle size. Capillary rise experiments with neutron radiography prove that for concentrations below the critical mucilage concentration water could easily cross the rhizosphere, while above the critical concentration water could no longer percolate through it. Our studies, together with former observations of water dynamics in the rhizosphere, suggest that the rhizosphere is near the percolation threshold, where small variations in mucilage concentration sensitively alter the soil hydraulic conductivity. Is mucilage exudation a plant mechanism to efficiently control the rhizosphere conductivity and the access to water?

  19. A Rooted Net of Life

    PubMed Central

    2011-01-01

    Abstract Phylogenetic reconstruction using DNA and protein sequences has allowed the reconstruction of evolutionary histories encompassing all life. We present and discuss a means to incorporate much of this rich narrative into a single model that acknowledges the discrete evolutionary units that constitute the organism. Briefly, this Rooted Net of Life genome phylogeny is constructed around an initial, well resolved and rooted tree scaffold inferred from a supermatrix of combined ribosomal genes. Extant sampled ribosomes form the leaves of the tree scaffold. These leaves, but not necessarily the deeper parts of the scaffold, can be considered to represent a genome or pan-genome, and to be associated with members of other gene families within that sequenced (pan)genome. Unrooted phylogenies of gene families containing four or more members are reconstructed and superimposed over the scaffold. Initially, reticulations are formed where incongruities between topologies exist. Given sufficient evidence, edges may then be differentiated as those representing vertical lines of inheritance within lineages and those representing horizontal genetic transfers or endosymbioses between lineages. Reviewers W. Ford Doolittle, Eric Bapteste and Robert Beiko. PMID:21936906

  20. Springback and diagravitropism in Merit corn roots

    NASA Technical Reports Server (NTRS)

    Kelly, M. O.; Leopold, A. C.

    1992-01-01

    Dark-treated Merit corn (Zea mays L.) roots are diagravitropic and lose curvature upon withdrawal of the gravity stimulus (springback). Springback was not detected in a variety of corn that is orthogravitropic in the dark, nor in Merit roots in which tropistic response was enhanced either with red light or with abscisic acid. A possible interpretation is that springback may be associated with a weak growth response of diagravitropic roots.

  1. Temperature sensing by primary roots of maize

    NASA Technical Reports Server (NTRS)

    Poff, K. L.

    1990-01-01

    Zea mays L. seedlings, grown on agar plates at 26 degrees C, reoriented the original vertical direction of their primary root when exposed to a thermal gradient applied perpendicular to the gravity vector. The magnitude and direction of curvature can not be explained simply by either a temperature or a humidity effect on root elongation. It is concluded that primary roots of maize sense temperature gradients in addition to sensing the gravitational force.

  2. Behavioral response of grape root borer (Lepidoptera: Sesiidae) neonates to grape root volatiles.

    PubMed

    Rijal, J P; Zhang, A; Bergh, J C

    2013-12-01

    Grape root borer, Vitacea polistiformis (Harris), is an oligophagous and potentially destructive pest of grape in commercial vineyards throughout much of the eastern United States. Larvae feed on vine roots, although little is known about their below-ground interactions with host plants. The behavioral response of groups of grape root borer neonates to stimuli from host and nonhost roots was evaluated in single and paired stimuli bioassays in which stimuli were presented in opposing wells attached to the bottom of petri dish arenas. Stimulus sources included root pieces and root headspace volatiles from 3309 and 420-A grape rootstocks (host) and apple (nonhost) and ethanol-based extracts of 3309 and 420-A roots. In single stimulus assays, significantly more larvae were recovered from wells containing grape roots, apple roots, grape extracts, and grape root volatiles than from control wells, but there was no significant response to volatiles collected from the headspace of apple roots. In paired stimuli assays, significantly more larvae were recovered from wells containing grape than apple roots. There was no difference in larval distribution between wells when 420-A and 3309 roots were presented simultaneously, although a significantly greater response to 3309 than 420-A root extract was recorded. When soil was added to the assays, significantly more larvae were recovered from wells containing grape roots than from those containing only soil, but this response was not detected in assays using buried apple roots. These results are discussed in relation to the plant-insect interactions between grape root borer larvae and their Vitaceae hosts.

  3. Cytokinins act directly on lateral root founder cells to inhibit root initiation.

    PubMed

    Laplaze, Laurent; Benkova, Eva; Casimiro, Ilda; Maes, Lies; Vanneste, Steffen; Swarup, Ranjan; Weijers, Dolf; Calvo, Vanessa; Parizot, Boris; Herrera-Rodriguez, Maria Begoña; Offringa, Remko; Graham, Neil; Doumas, Patrick; Friml, Jiri; Bogusz, Didier; Beeckman, Tom; Bennett, Malcolm

    2007-12-01

    In Arabidopsis thaliana, lateral roots are formed from root pericycle cells adjacent to the xylem poles. Lateral root development is regulated antagonistically by the plant hormones auxin and cytokinin. While a great deal is known about how auxin promotes lateral root development, the mechanism of cytokinin repression is still unclear. Elevating cytokinin levels was observed to disrupt lateral root initiation and the regular pattern of divisions that characterizes lateral root development in Arabidopsis. To identify the stage of lateral root development that is sensitive to cytokinins, we targeted the expression of the Agrobacterium tumefaciens cytokinin biosynthesis enzyme isopentenyltransferase to either xylem-pole pericycle cells or young lateral root primordia using GAL4-GFP enhancer trap lines. Transactivation experiments revealed that xylem-pole pericycle cells are sensitive to cytokinins, whereas young lateral root primordia are not. This effect is physiologically significant because transactivation of the Arabidopsis cytokinin degrading enzyme cytokinin oxidase 1 in lateral root founder cells results in increased lateral root formation. We observed that cytokinins perturb the expression of PIN genes in lateral root founder cells and prevent the formation of an auxin gradient that is required to pattern lateral root primordia.

  4. Characterization of Pearl Millet Root Architecture and Anatomy Reveals Three Types of Lateral Roots

    PubMed Central

    Passot, Sixtine; Gnacko, Fatoumata; Moukouanga, Daniel; Lucas, Mikaël; Guyomarc’h, Soazig; Ortega, Beatriz Moreno; Atkinson, Jonathan A.; Belko, Marème N.; Bennett, Malcolm J.; Gantet, Pascal; Wells, Darren M.; Guédon, Yann; Vigouroux, Yves; Verdeil, Jean-Luc; Muller, Bertrand; Laplaze, Laurent

    2016-01-01

    Pearl millet plays an important role for food security in arid regions of Africa and India. Nevertheless, it is considered an orphan crop as it lags far behind other cereals in terms of genetic improvement efforts. Breeding pearl millet varieties with improved root traits promises to deliver benefits in water and nutrient acquisition. Here, we characterize early pearl millet root system development using several different root phenotyping approaches that include rhizotrons and microCT. We report that early stage pearl millet root system development is characterized by a fast growing primary root that quickly colonizes deeper soil horizons. We also describe root anatomical studies that revealed three distinct types of lateral roots that form on both primary roots and crown roots. Finally, we detected significant variation for two root architectural traits, primary root lenght and lateral root density, in pearl millet inbred lines. This study provides the basis for subsequent genetic experiments to identify loci associated with interesting early root development traits in this important cereal. PMID:27379124

  5. Measurements of water uptake of maize roots: the key function of lateral roots

    NASA Astrophysics Data System (ADS)

    Ahmed, M. A.; Zarebanadkouki, M.; Kroener, E.; Kaestner, A.; Carminati, A.

    2014-12-01

    Maize (Zea mays L.) is one of the most important crop worldwide. Despite its importance, there is limited information on the function of different root segments and root types of maize in extracting water from soils. Therefore, the aim of this study was to investigate locations of root water uptake in maize. We used neutron radiography to: 1) image the spatial distribution of maize roots in soil and 2) trace the transport of injected deuterated water (D2O) in soil and roots. Maizes were grown in aluminum containers (40×38×1 cm) filled with a sandy soil. When the plants were 16 days old, we injected D2O into selected soil regions containing primary, seminal and lateral roots. The experiments were performed during the day (transpiring plants) and night (not transpiring plants). The transport of D2O into roots was simulated using a new convection-diffusion numerical model of D2O transport into roots. By fitting the observed D2O transport we quantified the diffusional permeability and the water uptake of the different root segments. The maize root architecture consisted of a primary root, 4-5 seminal roots and many lateral roots connected to the primary and seminal roots. Laterals emerged from the proximal 15 cm of the primary and seminal roots. Water uptake occurred primarily in lateral roots. Lateral roots had the highest diffusional permeability (9.4×10-7), which was around six times higher that the diffusional permeability of the old seminal segments (1.4×10-7), and two times higher than the diffusional permeability of the young seminal segments (4.7×10-7). The radial flow of D2O into the lateral (6.7×10-5 ) was much higher than in the young seminal roots (1.1×10-12). The radial flow of D2O into the old seminal was negligible. We concluded that the function of the primary and seminal roots was to collect water from the lateral roots and transport it to the shoot. A maize root system with lateral roots branching from deep primary and seminal roots would be

  6. New stopping criteria for iterative root finding

    PubMed Central

    Nikolajsen, Jorgen L.

    2014-01-01

    A set of simple stopping criteria is presented, which improve the efficiency of iterative root finding by terminating the iterations immediately when no further improvement of the roots is possible. The criteria use only the function evaluations already needed by the root finding procedure to which they are applied. The improved efficiency is achieved by formulating the stopping criteria in terms of fractional significant digits. Test results show that the new stopping criteria reduce the iteration work load by about one-third compared with the most efficient stopping criteria currently available. This is achieved without compromising the accuracy of the extracted roots. PMID:26064544

  7. Genetic ablation of root cap cells in Arabidopsis

    NASA Technical Reports Server (NTRS)

    Tsugeki, R.; Fedoroff, N. V.

    1999-01-01

    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.

  8. Root-growth-inhibiting sheet

    DOEpatents

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

    1993-01-26

    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.

  9. Root-growth-inhibiting sheet

    DOEpatents

    Burton, Frederick G.; Cataldo, Dominic A.; Cline, John F.; Skiens, W. Eugene; Van Voris, Peter

    1993-01-01

    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.

  10. ROOT CAUSE ANALYSIS PROGRAM MANUAL

    SciTech Connect

    Gravois, Melanie C.

    2007-05-02

    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.

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

    PubMed

    Barton, Craig V M; Montagu, Kelvin D

    2004-12-01

    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

  12. Piriformospora indica root colonization triggers local and systemic root responses and inhibits secondary colonization of distal roots.

    PubMed

    Pedrotti, Lorenzo; Mueller, Martin J; Waller, Frank

    2013-01-01

    Piriformosporaindica is a basidiomycete fungus colonizing roots of a wide range of higher plants, including crop plants and the model plant Arabidopsis thaliana. Previous studies have shown that P. indica improves growth, and enhances systemic pathogen resistance in leaves of host plants. To investigate systemic effects within the root system, we established a hydroponic split-root cultivation system for Arabidopsis. Using quantitative real-time PCR, we show that initial P. indica colonization triggers a local, transient response of several defense-related transcripts, of which some were also induced in shoots and in distal, non-colonized roots of the same plant. Systemic effects on distal roots included the inhibition of secondary P. indica colonization. Faster and stronger induction of defense-related transcripts during secondary inoculation revealed that a P. indica pretreatment triggers root-wide priming of defense responses, which could cause the observed reduction of secondary colonization levels. Secondary P. indica colonization also induced defense responses in distant, already colonized parts of the root. Endophytic fungi therefore trigger a spatially specific response in directly colonized and in systemic root tissues of host plants.

  13. Malformations of the tooth root in humans

    PubMed Central

    Luder, Hans U.

    2015-01-01

    The most common root malformations in humans arise from either developmental disorders of the root alone or disorders of radicular development as part of a general tooth dysplasia. The aim of this review is to relate the characteristics of these root malformations to potentially disrupted processes involved in radicular morphogenesis. Radicular morphogenesis proceeds under the control of Hertwig's epithelial root sheath (HERS) which determines the number, length, and shape of the root, induces the formation of radicular dentin, and participates in the development of root cementum. Formation of HERS at the transition from crown to root development appears to be very insensitive to adverse effects, with the result that rootless teeth are extremely rare. In contrast, shortened roots as a consequence of impaired or prematurely halted apical growth of HERS constitute the most prevalent radicular dysplasia which occurs due to trauma and unknown reasons as well as in association with dentin disorders. While odontoblast differentiation inevitably stops when growth of HERS is arrested, it seems to be unaffected even in cases of severe dentin dysplasias such as regional odontodysplasia and dentin dysplasia type I. As a result radicular dentin formation is at least initiated and progresses for a limited time. The only condition affecting cementogenesis is hypophosphatasia which disrupts the formation of acellular cementum through an inhibition of mineralization. A process particularly susceptible to adverse effects appears to be the formation of the furcation in multirooted teeth. Impairment or disruption of this process entails taurodontism, single-rooted posterior teeth, and misshapen furcations. Thus, even though many characteristics of human root malformations can be related to disorders of specific processes involved in radicular morphogenesis, precise inferences as to the pathogenesis of these dysplasias are hampered by the still limited knowledge on root formation

  14. Root-soil relationships and terroir

    NASA Astrophysics Data System (ADS)

    Tomasi, Diego

    2015-04-01

    Soil features, along with climate, are among the most important determinants of a succesful grape production in a certain area. Most of the studies, so far, investigated the above-ground vine response to differente edaphic and climate condition, but it is clearly not sufficient to explain the vine whole behaviour. In fact, roots represent an important part of the terroir system (soil-plant-atmosphere-man), and their study can provide better comprehension of vine responses to different environments. The root density and distribution, the ability of deep-rooting and regenerating new roots are good indicators of root well-being, and represents the basis for an efficient physiological activity of the root system. Root deepening and distribution are strongly dependent and sensitive on soil type and soil properties, while root density is affected mostly by canopy size, rootstock and water availability. According to root well-being, soil management strategies should alleviate soil impediments, improving aeration and microbial activity. Moreover, agronomic practices can impact root system performance and influence the above-ground growth. It is well known, for example, that the root system size is largely diminished by high planting densities. Close vine spacings stimulate a more effective utilization of the available soil, water and nutrients, but if the competition for available soil becomes too high, it can repress vine growth, and compromise vineyard longevity, productivity and reaction to growing season weather. Development of resilient rootstocks, more efficient in terms of water and nutrient uptake and capable of dealing with climate and soil extremes (drought, high salinity) are primary goals fore future research. The use of these rootstocks will benefit a more sustainable use of the soil resources and the preservation and valorisation of the terroir.

  15. Root susceptibility and inoculum production from roots of Eastern United States oak species to Phytophthora ramorum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Little is known about root susceptibility of eastern U.S. tree species to Phytophthora ramorum. In this study, we examined root susceptibility and inoculum production from roots. Sprouted acorns of Q. rubra, Q. palustrus, Q. coccinia, Q. alba, Q. michauxii and Q. prinus were exposed to motile zoos...

  16. Effect of Root Moisture Content and Diameter on Root Tensile Properties

    PubMed Central

    Yang, Yuanjun; Chen, Lihua; Li, Ning; Zhang, Qiufen

    2016-01-01

    The stabilization of slopes by vegetation has been a topical issue for many years. Root mechanical characteristics significantly influence soil reinforcement; therefore it is necessary to research into the indicators of root tensile properties. In this study, we explored the influence of root moisture content on tensile resistance and strength with different root diameters and for different tree species. Betula platyphylla, Quercus mongolica, Pinus tabulaeformis, and Larix gmelinii, the most popular tree species used for slope stabilization in the rocky mountainous areas of northern China, were used in this study. A tensile test was conducted after root samples were grouped by diameter and moisture content. The results showedthat:1) root moisture content had a significant influence on tensile properties; 2) slightly loss of root moisture content could enhance tensile strength, but too much loss of water resulted in weaker capacity for root elongation, and consequently reduced tensile strength; 3) root diameter had a strong positive correlation with tensile resistance; and4) the roots of Betula platyphylla had the best tensile properties when both diameter and moisture content being controlled. These findings improve our understanding of root tensile properties with root size and moisture, and could be useful for slope stabilization using vegetation. PMID:27003872

  17. RootScan: Software for high-throughput analysis of root anatomical traits

    Technology Transfer Automated Retrieval System (TEKTRAN)

    RootScan is a program for semi-automated image analysis of anatomical phenes in root cross-sections. RootScan uses pixel value thresholds to separate the cross-section from its background and to visually dissect it into tissue regions. Area measurements and object counts are performed within various...

  18. Anatomical evaluation of the root canal diameter and root thickness on the apical third of mesial roots of molars.

    PubMed

    Martos, Josué; Tatsch, Gustavo Henrique; Tatsch, Augusto César; Silveira, Luiz Fernando Machado; Ferrer-Luque, Carmen María

    2011-09-01

    The purpose was to determine the diameter of the main root canal and wall thickness in the apical dentin in mesial roots of maxillary and mandibular molars. Forty mesiobuccal and mesial root specimens were sectioned horizontally at 1, 2 and 3 mm from the apex, and measured at each top surface by using optical microscopy to an accuracy of ×20 magnification. The anatomical parameters were established as the following points of reference: AB, two points connected by a line from the outer edge of the mesial wall to the outer edge of the distal one through the center of the root canal to measure the thickness of the root and mesiodistal diameter of the root canal (CD). A second line (EF) was designed to evaluate the diameter of the root canal in the buccolingual direction. All data were summarized, and values were assessed statistically by ANOVA and Bonferroni multiple comparisons. The buccolingual (BL) root canal diameters at 1, 2 and 3 mm in the mandibular and maxillary molars were greater than in the mesiodistal (MD), showing statistically significant differences (p < 0.05). The MD root thicknesses at 1, 2 and 3 mm in mandibular and maxillary molars were statistically significant (p < 0.05). The lowest value to 1 mm from the apex in the mandibular molars was 1.219 mm and the highest at 3 mm from the root apex in maxillary molars was 1.741 mm. The BL diameters in maxillary and mandibular molars were higher than the MD diameter. The thickness (MD) of maxillary and mandibular molars decreased as a function of apical proximity.

  19. Coupling root architecture and pore network modeling - an attempt towards better understanding root-soil interactions

    NASA Astrophysics Data System (ADS)

    Leitner, Daniel; Bodner, Gernot; Raoof, Amir

    2013-04-01

    Understanding root-soil interactions is of high importance for environmental and agricultural management. Root uptake is an essential component in water and solute transport modeling. The amount of groundwater recharge and solute leaching significantly depends on the demand based plant extraction via its root system. Plant uptake however not only responds to the potential demand, but in most situations is limited by supply form the soil. The ability of the plant to access water and solutes in the soil is governed mainly by root distribution. Particularly under conditions of heterogeneous distribution of water and solutes in the soil, it is essential to capture the interaction between soil and roots. Root architecture models allow studying plant uptake from soil by describing growth and branching of root axes in the soil. Currently root architecture models are able to respond dynamically to water and nutrient distribution in the soil by directed growth (tropism), modified branching and enhanced exudation. The porous soil medium as rooting environment in these models is generally described by classical macroscopic water retention and sorption models, average over the pore scale. In our opinion this simplified description of the root growth medium implies several shortcomings for better understanding root-soil interactions: (i) It is well known that roots grow preferentially in preexisting pores, particularly in more rigid/dry soil. Thus the pore network contributes to the architectural form of the root system; (ii) roots themselves can influence the pore network by creating preferential flow paths (biopores) which are an essential element of structural porosity with strong impact on transport processes; (iii) plant uptake depend on both the spatial location of water/solutes in the pore network as well as the spatial distribution of roots. We therefore consider that for advancing our understanding in root-soil interactions, we need not only to extend our root models

  20. Novel mechanism of modulating natural antioxidants in functional foods: involvement of plant growth promoting Rhizobacteria NRRL B-30488.

    PubMed

    Nautiyal, Chandra Shekhar; Govindarajan, Raghavan; Lavania, Meeta; Pushpangadan, Palpu

    2008-06-25

    The significance of plant growth-promoting rhizobacteria (PGPR) mediated increase in antioxidant potential in vegetables is yet unknown. The plant growth-promoting bacterium Bacillus lentimorbus NRRL B-30488 (B-30488) mediated induction of dietary antioxidant in vegetables ( Trigonella foenum-graecum, Lactuca sativa, Spinacia oleracea, and Daucus carota) and fruit ( Citrus sinensis) after minimal processing (fresh, boiled, and frozen) was tested by estimating the total phenol content, level of antioxidant enzymes, and 1,1-diphenyl-2-picrylhydrazyl (DPPH) and superoxide scavenging activities along with integral radical scavenging capacity by photochemiluminescence assay and inhibition of lipid peroxidation. Minimal processing of vegetables showed that T. foenum-graecum had the highest phenol content in B-30488-treated plants followed by L. sativa, D. carota, and S. oleracea. Thermally treated vegetables T. foenum-graecum (26-114.5 GAE microg mg (-1)) had an exceptionally high total phenolic content, followed by D. carota (25.27-101.32 GAE microg mg (-1)), L. sativa (23.22-101.10 GAE microg mg (-1)), and S. oleracea (21.87-87.57 GAE microg mg (-1)). Among the vegetables and fruit used in this study for enzymatic estimation, induction of antioxidant enzymes, namely, polyphenol oxidase (PPO), ascorbate peroxidase (APX), catalase (CAT), and superoxidase dismutase (SOD), was observed in edible parts of T. foenum-graecum, L. sativa, S. oleracea, and D. carota, after inoculation with B-30488. The scavenging capacity of the vegetables treated with B-30488 against DPPH and superoxide anion radical activity was found to be significantly high as compared to nontreated control. Mild food processing had no adverse effect on radical scavenging capacity. Photochemiluminescence also ascertains the above findings. The ability of the plant extracts to protect against lipid peroxidation and its ability to prevent oxidation of reduced glutathione (GSH) was measured in rat liver

  1. Effect of Root System Morphology on Root-sprouting and Shoot-rooting Abilities in 123 Plant Species from Eroded Lands in North-east Spain

    PubMed Central

    GUERRERO-CAMPO, JOAQUÍN; PALACIO, SARA; PÉREZ-RONTOMÉ, CARMEN; MONTSERRAT-MARTÍ, GABRIEL

    2006-01-01

    • Background and Aims The objective of this study was to test whether the mean values of several root morphological variables were related to the ability to develop root-borne shoots and/or shoot-borne roots in a wide range of vascular plants. • Methods A comparative study was carried out on the 123 most common plant species from eroded lands in north-east Spain. After careful excavations in the field, measurements were taken of the maximum root depth, absolute and relative basal root diameter, specific root length (SRL), and the root depth/root lateral spread ratio on at least three individuals per species. Shoot-rooting and root-sprouting were observed in a large number of individuals in many eroded and sedimentary environments. The effect of life history and phylogeny on shoot-rooting and root-sprouting abilities was also analysed. • Key Results The species with coarse and deep tap-roots tended to be root-sprouting and those with fine, fasciculate and long main roots (which generally spread laterally), tended to be shoot-rooting. Phylogeny had an important influence on root system morphology and shoot-rooting and root-sprouting capacities. However, the above relations stood after applying analyses based on phylogenetically independent contrasts (PICs). • Conclusions The main morphological features of the root system of the study species are related to their ability to sprout from their roots and form roots from their shoots. According to the results, such abilities might only be functionally viable in restricted root system morphologies and ecological strategies. PMID:16790468

  2. Root phenotypic characterization of lesquerella genetic resources

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Root systems are crucial for optimizing plant growth and productivity. There has been a push to better understand root morphological and architectural traits and their plasticity because these traits determine the capacity of plants to effectively acquire available water and soil nutrients in the so...

  3. Purely extradural spinal nerve root hemangioblastomas

    PubMed Central

    Aytar, Murat Hamit; Yener, Ulaş; Ekşi, Murat Şakir; Kaya, Behram; Özgen, Serdar; Sav, Aydin; Alanay, Ahmet

    2016-01-01

    Spinal nerve root hemangioblastomas present mostly as intradural-extradurally. Purely extradural spinal nerve root hemangioblastoma is a very rare entity. In this study, we aimed to analyze epidemiological perspectives of purely extradural spinal nerve root hemangioblastomas presented in English medical literature in addition to our own exemplary case. PubMed/MEDLINE was searched using the terms “hemangioblastoma,” “extradural,” “spinal,” and “nerve root.” Demographical variables of age, gender, concomitant presence of von Hippel–Lindau (VHL) disease; spinal imaging and/or intraoperative findings for tumor location were surveyed from retrieved articles. There are 38 patients with purely extradural spinal nerve root hemangioblastoma. The median age is 45 years (range = 24–72 years). Female:male ratio is 0.6. Spinal levels for purely extradural spinal nerve root hemangioblastomas, in order of decreasing frequency, are thoracic (48.6%), cervical (13.5%), lumbar (13.5%), lumbosacral (10.8%), sacral (8.1%), and thoracolumbar (5.4%). Concomitant presence of VHL disease is 45%. Purely extradural spinal nerve root hemangioblastomas are very rare and can be confused with other more common extradural spinal cord tumors. Concomitant presence of VHL disease is observed in less than half of the patients with purely extradural spinal nerve root hemangioblastomas. Surgery is the first-line treatment in these tumors. PMID:27891027

  4. Cytological and ultrastructural studies on root tissues

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

    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.

  5. 33 CFR 117.1095 - Root River.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Root River. 117.1095 Section 117.1095 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Wisconsin § 117.1095 Root River. (a) The draw of the Main...

  6. 33 CFR 117.1095 - Root River.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Root River. 117.1095 Section 117.1095 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Wisconsin § 117.1095 Root River. (a) The draw of the Main...

  7. 33 CFR 117.1095 - Root River.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Root River. 117.1095 Section 117.1095 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Wisconsin § 117.1095 Root River. (a) The draw of the Main...

  8. 33 CFR 117.1095 - Root River.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Root River. 117.1095 Section 117.1095 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Wisconsin § 117.1095 Root River. (a) The draw of the Main...

  9. 33 CFR 117.1095 - Root River.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Root River. 117.1095 Section 117.1095 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Wisconsin § 117.1095 Root River. (a) The draw of the Main...

  10. Rapid phenotyping of alfalfa root system architecture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Root system architecture (RSA) influences the capacity of an alfalfa plant for symbiotic nitrogen fixation, nutrient uptake and water use efficiency, resistance to frost heaving, winterhardiness, and some pest and pathogen resistance. However, we currently lack a basic understanding of root system d...

  11. Graphing Powers and Roots of Complex Numbers.

    ERIC Educational Resources Information Center

    Embse, Charles Vonder

    1993-01-01

    Using De Moivre's theorem and a parametric graphing utility, examines powers and roots of complex numbers and allows students to establish connections between the visual and numerical representations of complex numbers. Provides a program to numerically verify the roots of complex numbers. (MDH)

  12. Method for Constructing Standardized Simulated Root Canals.

    ERIC Educational Resources Information Center

    Schulz-Bongert, Udo; Weine, Franklin S.

    1990-01-01

    The construction of visual and manipulative aids, clear resin blocks with root-canal-like spaces, for simulation of root canals is explained. Time, materials, and techniques are discussed. The method allows for comparison of canals, creation of any configuration of canals, and easy presentation during instruction. (MSE)

  13. Sporulation on plant roots by Phytophthora ramorum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phytophthora ramorum has been shown to infect the roots of many of the pathogen’s foliar hosts. Methods of detecting inoculum in runoff and of quantifying root colonization were tested using Viburnum tinus, Camellia oleifera, Quercus prinus, Umbellularia californica, and Epilobium ciliatum. Plants...

  14. Roots as a source of food.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Numerous plant species produce edible roots that are an important source of calories and that contribute to human nutrition. This book chapter discusses the origin and domestication, production aspects and nutritional aspects of a number of root crops including; cassava (Manioc), sweetpotato (Ipomo...

  15. Compounds from the roots of Jasminum sambac.

    PubMed

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

    2012-01-01

    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'.

  16. Enhancing Students' Understanding of Square Roots

    ERIC Educational Resources Information Center

    Wiesman, Jeff L.

    2015-01-01

    Students enrolled in a middle school prealgebra or algebra course often struggle to conceptualize and understand the meaning of radical notation when it is introduced. For example, although it is important for students to approximate the decimal value of a number such as [square root of] 30 and estimate the value of a square root in the form of…

  17. 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...

  18. 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...

  19. Branching Out in Roots: Uncovering Form, Function, and Regulation1

    PubMed Central

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

    2014-01-01

    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

  20. Tissue engineering in endodontics: root canal revascularization.

    PubMed

    Palit Madhu Chanda; Hegde, K Sundeep; Bhat, Sham S; Sargod, Sharan S; Mantha, Somasundar; Chattopadhyay, Sayan

    2014-01-01

    Root canal revascularization attempts to make necrotic tooth alive by the use of certain simple clinical protocols. Earlier apexification was the treatment of choice for treating and preserving immature permanent teeth that have lost pulp vitality. This procedure promoted the formation of apical barrier to seal the root canal of immature teeth and nonvital filling materials contained within root canal space. However with the success of root canal revascularization to regenerate the pulp dentin complex of necrotic immature tooth has made us to rethink if apexification is at the beginning of its end. The objective of this review is to discuss the new concepts of tissue engineering in endodontics and the clinical steps of root canal revascularization.

  1. Microleakage of root-end filling materials.

    PubMed

    Fogel, H M; Peikoff, M D

    2001-07-01

    The purpose of this study was to evaluate the microleakage of various root-end filling materials using a fluid filtration system. Sixty extracted human single-rooted teeth were used. The crowns were removed, the canals prepared, and root-end fillings placed. The samples were divided into two control and five experimental groups. The root-end filling materials tested were: amalgam, Intermediate Restorative Material (IRM), a dentin-bonded resin, Super-EBA, and mineral trioxide aggregate. The results showed that amalgam root-end fillings demonstrated significantly more microleakage than Super-EBA, dentin-bonded resin, or mineral trioxide aggregate. There was no significant difference between amalgam and IRM. However IRM was also not significantly different from the other three groups. There were no significant differences between the other three groups.

  2. Long-term control of root growth

    DOEpatents

    Burton, Frederick G.; Cataldo, Dominic A.; Cline, John F.; Skiens, W. Eugene

    1992-05-26

    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.

  3. Effect of lead on root growth

    PubMed Central

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

    2013-01-01

    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

  4. Management of Six Root Canals in Mandibular First Molar

    PubMed Central

    Gomes, Fabio de Almeida; Sousa, Bruno Carvalho

    2015-01-01

    Success in root canal treatment is achieved after thorough cleaning, shaping, and obturation of the root canal system. This clinical case describes conventional root canal treatment of an unusual mandibular first molar with six root canals. The prognosis for endodontic treatment in teeth with abnormal morphology is unfavorable if the clinician fails to recognize extra root canals. PMID:25685156

  5. Root Canal Treatment of a Maxillary Second Premolar with Two Palatal Root Canals: A Case Report

    PubMed Central

    Golmohammadi, Maryam; Jafarzadeh, Hamid

    2016-01-01

    Accurate diagnosis of the root canal morphology and anatomy is essential for thorough shaping and cleaning of the entire root canal system and consequent successful treatment. This report describes a case of maxillary second premolar with two roots and three root canals (two mesial and distal palatal canals). The case report underlines the importance of complete knowledge about root canal morphology and possible variations, coupled with clinical and radiographic examination in order to increase the ability of clinicians to treat difficult cases. PMID:27471538

  6. Lateral root initiation in Marsilea quadrifolia. I. Origin and histogensis of lateral roots

    NASA Technical Reports Server (NTRS)

    Lin, B. L.; Raghavan, V.

    1991-01-01

    In Marsilea quadrifolia, lateral roots arise from modified single cells of the endodermis located opposite the protoxylem poles within the meristematic region of the parent root. The initial cell divides in four specific planes to establish a five-celled lateral root primordium, with a tetrahedral apical cell in the centre and the oldest merophytes and the root cap along the sides. The cells of the merophyte divide in a precise pattern to give rise to the cells of the cortex, endodermis, pericycle, and vascular tissues of the emerging lateral root. Although the construction of the parent root is more complicated than that of lateral roots, patterns of cell division and tissue formation are similar in both types of roots, with the various tissues being arranged in similar positions in relation to the central axis. Vascular connection between the lateral root primordium and the parent root is derived from the pericycle cells lying between the former and the protoxylem members of the latter. It is proposed that the central axis of the root is not only a geometric centre, but also a physiological centre which determines the fate of the different cell types.

  7. RootGraph: a graphic optimization tool for automated image analysis of plant roots.

    PubMed

    Cai, Jinhai; Zeng, Zhanghui; Connor, Jason N; Huang, Chun Yuan; Melino, Vanessa; Kumar, Pankaj; Miklavcic, Stanley J

    2015-11-01

    This paper outlines a numerical scheme for accurate, detailed, and high-throughput image analysis of plant roots. In contrast to existing root image analysis tools that focus on root system-average traits, a novel, fully automated and robust approach for the detailed characterization of root traits, based on a graph optimization process is presented. The scheme, firstly, distinguishes primary roots from lateral roots and, secondly, quantifies a broad spectrum of root traits for each identified primary and lateral root. Thirdly, it associates lateral roots and their properties with the specific primary root from which the laterals emerge. The performance of this approach was evaluated through comparisons with other automated and semi-automated software solutions as well as against results based on manual measurements. The comparisons and subsequent application of the algorithm to an array of experimental data demonstrate that this method outperforms existing methods in terms of accuracy, robustness, and the ability to process root images under high-throughput conditions.

  8. RootGraph: a graphic optimization tool for automated image analysis of plant roots

    PubMed Central

    Cai, Jinhai; Zeng, Zhanghui; Connor, Jason N.; Huang, Chun Yuan; Melino, Vanessa; Kumar, Pankaj; Miklavcic, Stanley J.

    2015-01-01

    This paper outlines a numerical scheme for accurate, detailed, and high-throughput image analysis of plant roots. In contrast to existing root image analysis tools that focus on root system-average traits, a novel, fully automated and robust approach for the detailed characterization of root traits, based on a graph optimization process is presented. The scheme, firstly, distinguishes primary roots from lateral roots and, secondly, quantifies a broad spectrum of root traits for each identified primary and lateral root. Thirdly, it associates lateral roots and their properties with the specific primary root from which the laterals emerge. The performance of this approach was evaluated through comparisons with other automated and semi-automated software solutions as well as against results based on manual measurements. The comparisons and subsequent application of the algorithm to an array of experimental data demonstrate that this method outperforms existing methods in terms of accuracy, robustness, and the ability to process root images under high-throughput conditions. PMID:26224880

  9. GLO-Roots: an imaging platform enabling multidimensional characterization of soil-grown root systems

    PubMed Central

    Rellán-Álvarez, Rubén; Lobet, Guillaume; Lindner, Heike; Pradier, Pierre-Luc; Sebastian, Jose; Yee, Muh-Ching; Geng, Yu; Trontin, Charlotte; LaRue, Therese; Schrager-Lavelle, Amanda; Haney, Cara H; Nieu, Rita; Maloof, Julin; Vogel, John P; Dinneny, José R

    2015-01-01

    Root systems develop different root types that individually sense cues from their local environment and integrate this information with systemic signals. This complex multi-dimensional amalgam of inputs enables continuous adjustment of root growth rates, direction, and metabolic activity that define a dynamic physical network. Current methods for analyzing root biology balance physiological relevance with imaging capability. To bridge this divide, we developed an integrated-imaging system called Growth and Luminescence Observatory for Roots (GLO-Roots) that uses luminescence-based reporters to enable studies of root architecture and gene expression patterns in soil-grown, light-shielded roots. We have developed image analysis algorithms that allow the spatial integration of soil properties, gene expression, and root system architecture traits. We propose GLO-Roots as a system that has great utility in presenting environmental stimuli to roots in ways that evoke natural adaptive responses and in providing tools for studying the multi-dimensional nature of such processes. DOI: http://dx.doi.org/10.7554/eLife.07597.001 PMID:26287479

  10. Root phenology at Harvard Forest and beyond

    NASA Astrophysics Data System (ADS)

    Abramoff, R. Z.; Finzi, A.

    2013-12-01

    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

  11. Scalable encryption using alpha rooting

    NASA Astrophysics Data System (ADS)

    Wharton, Eric J.; Panetta, Karen A.; Agaian, Sos S.

    2008-04-01

    Full and partial encryption methods are important for subscription based content providers, such as internet and cable TV pay channels. Providers need to be able to protect their products while at the same time being able to provide demonstrations to attract new customers without giving away the full value of the content. If an algorithm were introduced which could provide any level of full or partial encryption in a fast and cost effective manner, the applications to real-time commercial implementation would be numerous. In this paper, we present a novel application of alpha rooting, using it to achieve fast and straightforward scalable encryption with a single algorithm. We further present use of the measure of enhancement, the Logarithmic AME, to select optimal parameters for the partial encryption. When parameters are selected using the measure, the output image achieves a balance between protecting the important data in the image while still containing a good overall representation of the image. We will show results for this encryption method on a number of images, using histograms to evaluate the effectiveness of the encryption.

  12. Auxin-induced inhibition of lateral root initiation contributes to root system shaping in Arabidopsis thaliana.

    PubMed

    Ivanchenko, Maria G; Napsucialy-Mendivil, Selene; Dubrovsky, Joseph G

    2010-12-01

    The hormone auxin is known to inhibit root elongation and to promote initiation of lateral roots. Here we report complex effects of auxin on lateral root initiation in roots showing reduced cell elongation after auxin treatment. In Arabidopsis thaliana, the promotion of lateral root initiation by indole-3-acetic acid (IAA) was reduced as the IAA concentration was increased in the nanomolar range, and IAA became inhibitory at 25 nM. Detection of this unexpected inhibitory effect required evaluation of root portions that had newly formed during treatment, separately from root portions that existed prior to treatment. Lateral root initiation was also reduced in the iaaM-OX Arabidopsis line, which has an endogenously increased IAA level. The ethylene signaling mutants ein2-5 and etr1-3, the auxin transport mutants aux1-7 and eir1/pin2, and the auxin perception/response mutant tir1-1 were resistant to the inhibitory effect of IAA on lateral root initiation, consistent with a requirement for intact ethylene signaling, auxin transport and auxin perception/response for this effect. The pericycle cell length was less dramatically reduced than cortical cell length, suggesting that a reduction in the pericycle cell number relative to the cortex could occur with the increase of the IAA level. Expression of the DR5:GUS auxin reporter was also less effectively induced, and the AXR3 auxin repressor protein was less effectively eliminated in such root portions, suggesting that decreased auxin responsiveness may accompany the inhibition. Our study highlights a connection between auxin-regulated inhibition of parent root elongation and a decrease in lateral root initiation. This may be required to regulate the spacing of lateral roots and optimize root architecture to environmental demands.

  13. Variation of the Linkage of Root Function with Root Branch Order

    PubMed Central

    Chen, Zhengxia; Zeng, Hui

    2013-01-01

    Mounting evidence has shown strong linkage of root function with root branch order. However, it is not known whether this linkage is consistent in different species. Here, root anatomic traits of the first five branch order were examined in five species differing in plant phylogeny and growth form in tropical and subtropical forests of south China. In Paramichelia baillonii, one tree species in Magnoliaceae, the intact cortex as well as mycorrhizal colonization existed even in the fifth-order root suggesting the preservation of absorption function in the higher-order roots. In contrast, dramatic decreases of cortex thickness and mycorrhizal colonization were observed from lower- to higher-order roots in three other tree species, Cunninghamia lanceolata, Acacia auriculiformis and Gordonia axillaries, which indicate the loss of absorption function. In a fern, Dicranopteris dichotoma, there were several cortex layers with prominently thickened cell wall and no mycorrhizal colonization in the third- and fourth-order roots, also demonstrating the loss of absorptive function in higher-order roots. Cluster analysis using these anatomic traits showed a different classification of root branch order in P. baillonii from other four species. As for the conduit diameter-density relationship in higher-order roots, the mechanism underpinning this relationship in P. baillonii was different from that in other species. In lower-order roots, different patterns of coefficient of variance for conduit diameter and density provided further evidence for the two types of linkage of root function with root branch order. These linkages corresponding to two types of ephemeral root modules have important implication in the prediction of terrestrial carbon cycling, although we caution that this study was pseudo-replicated. Future studies by sampling more species can test the generality of these two types of linkage. PMID:23451168

  14. Variation of the linkage of root function with root branch order.

    PubMed

    Long, Yingqian; Kong, Deliang; Chen, Zhengxia; Zeng, Hui

    2013-01-01

    Mounting evidence has shown strong linkage of root function with root branch order. However, it is not known whether this linkage is consistent in different species. Here, root anatomic traits of the first five branch order were examined in five species differing in plant phylogeny and growth form in tropical and subtropical forests of south China. In Paramichelia baillonii, one tree species in Magnoliaceae, the intact cortex as well as mycorrhizal colonization existed even in the fifth-order root suggesting the preservation of absorption function in the higher-order roots. In contrast, dramatic decreases of cortex thickness and mycorrhizal colonization were observed from lower- to higher-order roots in three other tree species, Cunninghamia lanceolata, Acacia auriculiformis and Gordonia axillaries, which indicate the loss of absorption function. In a fern, Dicranopteris dichotoma, there were several cortex layers with prominently thickened cell wall and no mycorrhizal colonization in the third- and fourth-order roots, also demonstrating the loss of absorptive function in higher-order roots. Cluster analysis using these anatomic traits showed a different classification of root branch order in P. baillonii from other four species. As for the conduit diameter-density relationship in higher-order roots, the mechanism underpinning this relationship in P. baillonii was different from that in other species. In lower-order roots, different patterns of coefficient of variance for conduit diameter and density provided further evidence for the two types of linkage of root function with root branch order. These linkages corresponding to two types of ephemeral root modules have important implication in the prediction of terrestrial carbon cycling, although we caution that this study was pseudo-replicated. Future studies by sampling more species can test the generality of these two types of linkage.

  15. Do ectomycorrhizal and arbuscular mycorrhizal temperate tree species systematically differ in root order-related fine root morphology and biomass?

    PubMed Central

    Kubisch, Petra; Hertel, Dietrich; Leuschner, Christoph

    2015-01-01

    While most temperate broad-leaved tree species form ectomycorrhizal (EM) symbioses, a few species have arbuscular mycorrhizas (AM). It is not known whether EM and AM tree species differ systematically with respect to fine root morphology, fine root system size and root functioning. In a species-rich temperate mixed forest, we studied the fine root morphology and biomass of three EM and three AM tree species from the genera Acer, Carpinus, Fagus, Fraxinus, and Tilia searching for principal differences between EM and AM trees. We further assessed the evidence of convergence or divergence in root traits among the six co-occurring species. Eight fine root morphological and chemical traits were investigated in root segments of the first to fourth root order in three different soil depths and the relative importance of the factors root order, tree species and soil depth for root morphology was determined. Root order was more influential than tree species while soil depth had only a small effect on root morphology All six species showed similar decreases in specific root length and specific root area from the 1st to the 4th root order, while the species patterns differed considerably in root tissue density, root N concentration, and particularly with respect to root tip abundance. Most root morphological traits were not significantly different between EM and AM species (except for specific root area that was larger in AM species), indicating that mycorrhiza type is not a key factor influencing fine root morphology in these species. The order-based root analysis detected species differences more clearly than the simple analysis of bulked fine root mass. Despite convergence in important root traits among AM and EM species, even congeneric species may differ in certain fine root morphological traits. This suggests that, in general, species identity has a larger influence on fine root morphology than mycorrhiza type. PMID:25717334

  16. Transcript profiling of early lateral root initiation.

    PubMed

    Himanen, Kristiina; Vuylsteke, Marnik; Vanneste, Steffen; Vercruysse, Steven; Boucheron, Elodie; Alard, Philippe; Chriqui, Dominique; Van Montagu, Marc; Inzé, Dirk; Beeckman, Tom

    2004-04-06

    At the onset of lateral root initiation in Arabidopsis thaliana, the phytohormone auxin activates xylem pole pericycle cells for asymmetric cell division. However, the molecular events leading from auxin to lateral root initiation are poorly understood, in part because the few responsive cells in the process are embedded in the root and are thus difficult to access. A lateral root induction system, in which most xylem pole pericycle cells were synchronously activated by auxin transport inhibition followed by auxin application, was used for microarray transcript profiling. Of 4,600 genes analyzed, 906 significantly differentially regulated genes were identified that could be grouped into six major clusters. Basically, three major patterns were discerned representing induced, repressed, and transiently expressed genes. Analysis of the coregulated genes, which were specific for each time point, provided new insight into the molecular regulation and signal transduction preceding lateral root initiation in Arabidopsis. The reproducible expression profiles during a time course allowed us to define four stages that precede the cell division in the pericycle. These early stages were characterized by G1 cell cycle block, auxin perception, and signal transduction, followed by progression over G1/S transition and G2/M transition. All these processes took place within 6 h after transfer from N-1-naphthylphthalamic acid to 1-naphthalene acetic acid. These results indicate that this lateral root induction system represents a unique synchronized system that allows the systematic study of the developmental program upstream of the cell cycle activation during lateral root initiation.

  17. How to bond to root canal dentin

    NASA Astrophysics Data System (ADS)

    Nica, Luminita; Todea, Carmen; Furtos, Gabriel; Baldea, Bogdan

    2014-01-01

    Bonding to root canal dentin may be difficult due to various factors: the structural characteristic of the root canal dentin, which is different from that of the coronal dentin; the presence of the organic tissue of the dental pulp inside the root canal, which has to be removed during the cleaning-shaping of the root canal system; the smear-layer resulted after mechanical instrumentation, which may interfere with the adhesion of the filling materials; the type of the irrigants used in the cleaning protocol; the type of the sealer and core material used in the obturation of the endodontic space; the type of the materials used for the restoration of the endodontically treated teeth. The influence of the cleaning protocol, of the root canal filling material, of the type of the adhesive system used in the restoration of the treated teeth and of the region of the root canal, on the adhesion of several filling and restorative materials to root canal dentin was evaluated in the push-out bond strength test on 1-mm thick slices of endodontically treated human teeth. The results showed that all these factors have a statistically significant influence on the push-out bond strength. Formation of resin tags between radicular dentin and the investigated materials was observed in some of the samples at SEM analysis.

  18. Ecology of Root Colonizing Massilia (Oxalobacteraceae)

    PubMed Central

    Ofek, Maya; Hadar, Yitzhak; Minz, Dror

    2012-01-01

    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

  19. A thermodynamic formulation of root water uptake

    NASA Astrophysics Data System (ADS)

    Hildebrandt, Anke; Kleidon, Axel; Bechmann, Marcel

    2016-08-01

    By extracting bound water from the soil and lifting it to the canopy, root systems of vegetation perform work. Here we describe how root water uptake can be evaluated thermodynamically and demonstrate that this evaluation provides additional insights into the factors that impede root water uptake. We derive an expression that relates the energy export at the base of the root system to a sum of terms that reflect all fluxes and storage changes along the flow path in thermodynamic terms. We illustrate this thermodynamic formulation using an idealized setup of scenarios with a simple model. In these scenarios, we demonstrate why heterogeneity in soil water distribution and rooting properties affect the impediment of water flow even though the mean soil water content and rooting properties are the same across the scenarios. The effects of heterogeneity can clearly be identified in the thermodynamics of the system in terms of differences in dissipative losses and hydraulic energy, resulting in an earlier start of water limitation in the drying cycle. We conclude that this thermodynamic evaluation of root water uptake conveniently provides insights into the impediments of different processes along the entire flow path, which goes beyond resistances and also accounts for the role of heterogeneity in soil water distribution.

  20. 10. PHOTOCOPY OF 'P. H. & F. M. ROOTS FOUNDARY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. PHOTOCOPY OF 'P. H. & F. M. ROOTS FOUNDARY MANUFACTURERS OF ROOTS BLOWERS' FROM INDIANAPOLIS STAR, June 13, 1926, Gravure Section, p. 2 - P. H. & F. M. Roots Company, Eastern Avenue, Connersville, Fayette County, IN

  1. Bitter Root Irrigation district canal, looking east, typical section (canal ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Bitter Root Irrigation district canal, looking east, typical section (canal full) - Bitter Root Irrigation Project, Bitter Root Irrigation Canal, Heading at Rock Creek Diversion Dam, West of U.S. Highway 93, Darby, Ravalli County, MT

  2. Bitter Root Irrigation district canal, looking east, typical section and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Bitter Root Irrigation district canal, looking east, typical section and crossing - Bitter Root Irrigation Project, Bitter Root Irrigation Canal, Heading at Rock Creek Diversion Dam, West of U.S. Highway 93, Darby, Ravalli County, MT

  3. A thermodynamic formulation of root water uptake

    NASA Astrophysics Data System (ADS)

    Hildebrandt, A.; Kleidon, A.; Bechmann, M.

    2015-12-01

    By extracting bound water from the soil and lifting it to the canopy, root systems of vegetation perform work. Here we describe how the energetics involved in root water uptake can be quantified. The illustration is done using a simple, four-box model of the soil-root system to represent heterogeneity and a parameterization in which root water uptake is driven by the xylem potential of the plant with a fixed flux boundary condition. We use this approach to evaluate the effects of soil moisture heterogeneity and root system properties on the dissipative losses and export of energy involved in root water uptake. For this, we derive an expression that relates the energy export at the root collar to a sum of terms that reflect all fluxes and storage changes along the flow path in thermodynamic terms. We conclude that such a thermodynamic evaluation of root water uptake conveniently provides insights into the impediments of different processes along the entire flow path and explicitly accounting not only for the resistances along the flow path and those imposed by soil drying but especially the role of heterogenous soil water distribution. The results show that least energy needs to be exported and dissipative losses are minimized by a root system if it extracts water uniformly from the soil. This has implications for plant water relations in forests where canopies generate heterogenous input patterns. Our diagnostic in the energy domain should be useful in future model applications for quantifying how plants can evolve towards greater efficiency in their structure and function, particularly in heterogenous soil environments. Generally, this approach may help to better describe heterogeneous processes in the soil in a simple, yet physically-based way.

  4. Root type matters: measurements of water uptake by seminal, crown and lateral roots of maize

    NASA Astrophysics Data System (ADS)

    Ahmed, Mutez Ali; Zarebanadkouki, Mohsen; Kaestner, Anders; Carminati, Andrea

    2016-04-01

    Roots play a key role in water acquisition and are a significant component of plant adaptation to different environmental conditions. Although maize (Zea mays L.) is one of the most important crops worldwide, there is limited information on the function of different root segments and types in extracting water from soils. Aim of this study was to investigate the location of root water uptake in mature maize. We used neutron radiography to image the spatial distribution of maize roots and trace the transport of injected deuterated water (D2O) in soil and roots. Maize plants were grown in aluminum containers filled with a sandy soil that was kept homogeneously wet throughout the experiment. When the plants were five weeks-old, we injected D2O into selected soil regions. The transport of D2O was simulated using a diffusion-convection numerical model. By fitting the observed D2O transport we quantified the diffusion coefficient and the water uptake of the different root segments. The model was initially developed and tested with two weeks-old maize (Ahmed et. al. 2015), for which we found that water was mainly taken up by lateral roots and the water uptake of the seminal roots was negligible. Here, we used this method to measure root water uptake in a mature maize root system. The root architecture of five weeks-old maize consisted of primary and seminal roots with long laterals and crown (nodal) roots that emerged from the above ground part of the plant two weeks after planting. The crown roots were thicker than the seminal roots and had fewer and shorter laterals. Surprisingly, we found that the water was mainly taken up by the crown roots and their laterals, while the lateral roots of seminal roots, which were the main location of water uptake of younger plants, stopped to take up water. Interestingly, we also found that in contrast to the seminal roots, the crown roots were able to take up water also from their distal segments. We conclude that for the two weeks

  5. Pullout tests of root analogs and natural root bundles in soil: Experiments and modeling

    NASA Astrophysics Data System (ADS)

    Schwarz, M.; Cohen, D.; Or, D.

    2011-06-01

    Root-soil mechanical interactions are key to soil stability on steep hillslopes. Motivated by new advances and applications of the Root Bundle Model (RBM), we conducted a series of experiments in the laboratory and in the field to study the mechanical response of pulled roots. We systematically quantified the influence of different factors such as root geometry and configuration, soil type, and soil water content considering individual roots and root bundles. We developed a novel pullout apparatus for strain-controlled field and laboratory tests of up to 13 parallel roots measured individually and as a bundle. Results highlight the importance of root tortuosity and root branching points for prediction of individual root pullout behavior. Results also confirm the critical role of root diameter distribution for realistic prediction of global pullout behavior of a root bundle. Friction between root and soil matrix varied with soil type and water content and affected the force-displacement behavior. Friction in sand varied from 1 to 17 kPa, with low values obtained in wet sand at a confining pressure of 2 kPa and high values obtained in dry sand with 4.5 kPa confining pressure. In a silty soil matrix, friction ranged between 3 kPa under wet and low confining pressure (2 kPa) and 6 kPa in dry and higher confining pressure (4.5 kPa). Displacement at maximum pullout force increased with increasing root diameter and with tortuosity. Laboratory experiments were used to calibrate the RBM that was later validated using six field measurements with natural root bundles of Norway spruce (Picea abies L.). These tests demonstrate the progressive nature of root bundle failure under strain-controlled pullout force and provide new insights regarding force-displacement behavior of root reinforcement, highlighting the importance of considering displacement in slope stability models. Results show that the magnitude of maximum root pullout forces (1-5 kPa) are important for slope

  6. THttpServer class in ROOT

    NASA Astrophysics Data System (ADS)

    Adamczewski-Musch, Joern; Linev, Sergey

    2015-12-01

    The new THttpServer class in ROOT implements HTTP server for arbitrary ROOT applications. It is based on Civetweb embeddable HTTP server and provides direct access to all objects registered for the server. Objects data could be provided in different formats: binary, XML, GIF/PNG, and JSON. A generic user interface for THttpServer has been implemented with HTML/JavaScript based on JavaScript ROOT development. With any modern web browser one could list, display, and monitor objects available on the server. THttpServer is used in Go4 framework to provide HTTP interface to the online analysis.

  7. Complex root networks of Chinese characters

    NASA Astrophysics Data System (ADS)

    Lee, Po-Han; Chen, Jia-Ling; Wang, Po-Cheng; Chi, Ting-Ting; Xiao, Zhi-Ren; Jhang, Zih-Jian; Yeh, Yeong-Nan; Chen, Yih-Yuh; Hu, Chin-Kun

    There are several sets of Chinese characters still available today, including Oracle Bone Inscriptions (OBI) in Shang Dynasty, Chu characters (CC) used in Chu of Warring State Period, Small Seal Script in dictionary Shuowen Jiezi (SJ) in Eastern Han Dynasty, and Kangxi Dictionary (KD) in Qing Dynasty. Such as Chinese characters were all constructed via combinations of meaningful patterns, called roots. Our studies for the complex networks of all roots indicate that the roots of the characters in OBI, CC, SJ and KD have characteristics of small world networks and scale-free networks.

  8. BOREAS TE-2 Root Respiration Data

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

    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).

  9. Getting to the roots of it: Genetic and hormonal control of root architecture

    PubMed Central

    Jung, Janelle K. H.; McCouch, Susan

    2013-01-01

    Root system architecture (RSA) – the spatial configuration of a root system – is an important developmental and agronomic trait, with implications for overall plant architecture, growth rate and yield, abiotic stress resistance, nutrient uptake, and developmental plasticity in response to environmental changes. Root architecture is modulated by intrinsic, hormone-mediated pathways, intersecting with pathways that perceive and respond to external, environmental signals. The recent development of several non-invasive 2D and 3D root imaging systems has enhanced our ability to accurately observe and quantify architectural traits on complex whole-root systems. Coupled with the powerful marker-based genotyping and sequencing platforms currently available, these root phenotyping technologies lend themselves to large-scale genome-wide association studies, and can speed the identification and characterization of the genes and pathways involved in root system development. This capability provides the foundation for examining the contribution of root architectural traits to the performance of crop varieties in diverse environments. This review focuses on our current understanding of the genes and pathways involved in determining RSA in response to both intrinsic and extrinsic (environmental) response pathways, and provides a brief overview of the latest root system phenotyping technologies and their potential impact on elucidating the genetic control of root development in plants. PMID:23785372

  10. Ethylene signaling pathway modulates attractiveness of host roots to the root-knot nematode Meloidogyne hapla.

    PubMed

    Fudali, Sylwia L; Wang, Congli; Williamson, Valerie M

    2013-01-01

    Infective juveniles of the root-knot nematode Meloidogyne hapla are attracted to the zone of elongation of roots where they invade the host but little is known about what directs the nematode to this region of the root. We found that Arabidopsis roots exposed to an ethylene (ET)-synthesis inhibitor attracted significantly more nematodes than control roots and that ET-overproducing mutants were less attractive. Arabidopsis seedlings with ET-insensitive mutations were generally more attractive whereas mutations resulting in constitutive signaling were less attractive. Roots of the ET-insensitive tomato mutant Never ripe (Nr) were also more attractive, indicating that ET signaling also modulated attraction of root-knot nematodes to this host. ET-insensitive mutants have longer roots due to reduced basipetal auxin transport. However, assessments of Arabidopsis mutants that differ in various aspects of the ET response suggest that components of the ET-signaling pathway directly affecting root length are not responsible for modulating root attractiveness and that other components of downstream signaling result in changes in levels of attractants or repellents for M. hapla. These signals may aid in directing this pathogen to an appropriate host and invasion site for completing its life cycle.

  11. Root System Architecture and Abiotic Stress Tolerance: Current Knowledge in Root and Tuber Crops

    PubMed Central

    Khan, M. A.; Gemenet, Dorcus C.; Villordon, Arthur

    2016-01-01

    The challenge to produce more food for a rising global population on diminishing agricultural land is complicated by the effects of climate change on agricultural productivity. Although great progress has been made in crop improvement, so far most efforts have targeted above-ground traits. Roots are essential for plant adaptation and productivity, but are less studied due to the difficulty of observing them during the plant life cycle. Root system architecture (RSA), made up of structural features like root length, spread, number, and length of lateral roots, among others, exhibits great plasticity in response to environmental changes, and could be critical to developing crops with more efficient roots. Much of the research on root traits has thus far focused on the most common cereal crops and model plants. As cereal yields have reached their yield potential in some regions, understanding their root system may help overcome these plateaus. However, root and tuber crops (RTCs) such as potato, sweetpotato, cassava, and yam may hold more potential for providing food security in the future, and knowledge of their root system additionally focuses directly on the edible portion. Root-trait modeling for multiple stress scenarios, together with high-throughput phenotyping and genotyping techniques, robust databases, and data analytical pipelines, may provide a valuable base for a truly inclusive ‘green revolution.’ In the current review, we discuss RSA with special reference to RTCs, and how knowledge on genetics of RSA can be manipulated to improve their tolerance to abiotic stresses. PMID:27847508

  12. Root System Architecture and Abiotic Stress Tolerance: Current Knowledge in Root and Tuber Crops.

    PubMed

    Khan, M A; Gemenet, Dorcus C; Villordon, Arthur

    2016-01-01

    The challenge to produce more food for a rising global population on diminishing agricultural land is complicated by the effects of climate change on agricultural productivity. Although great progress has been made in crop improvement, so far most efforts have targeted above-ground traits. Roots are essential for plant adaptation and productivity, but are less studied due to the difficulty of observing them during the plant life cycle. Root system architecture (RSA), made up of structural features like root length, spread, number, and length of lateral roots, among others, exhibits great plasticity in response to environmental changes, and could be critical to developing crops with more efficient roots. Much of the research on root traits has thus far focused on the most common cereal crops and model plants. As cereal yields have reached their yield potential in some regions, understanding their root system may help overcome these plateaus. However, root and tuber crops (RTCs) such as potato, sweetpotato, cassava, and yam may hold more potential for providing food security in the future, and knowledge of their root system additionally focuses directly on the edible portion. Root-trait modeling for multiple stress scenarios, together with high-throughput phenotyping and genotyping techniques, robust databases, and data analytical pipelines, may provide a valuable base for a truly inclusive 'green revolution.' In the current review, we discuss RSA with special reference to RTCs, and how knowledge on genetics of RSA can be manipulated to improve their tolerance to abiotic stresses.

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

    PubMed Central

    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.

    2014-01-01

    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

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

    PubMed

    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

    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.

  15. Rooting depths of plants relative to biological and environmental factors

    SciTech Connect

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

    1984-11-01

    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.

  16. Understanding plant root system influences on soil strength and stability

    NASA Astrophysics Data System (ADS)

    Bengough, A. Glyn; Brown, Jennifer L.; Loades, Kenneth W.; Knappett, Jonathan A.; Meijer, Gertjan; Nicoll, Bruce

    2016-04-01

    Keywords: root growth, soil reinforcement, tensile strength Plant roots modify and reinforce the soil matrix, stabilising it against erosion and shallow landslides. Roots mechanically bind the soil particles together and modify the soil hydrology via water uptake, creation of biopores, and modification of the soil water-release characteristic. Key to understanding the mechanical reinforcement of soil by roots is the relation between root strength and root diameter measured for roots in any given soil horizon. Thin roots have frequently been measured to have a greater tensile strength than thick roots, but their strength is also often much more variable. We consider the factors influencing this strength-diameter relationship, considering relations between root tensile strength and root dry density, root water content, root age, and root turnover in several woody and non-woody species. The role of possible experimental artefacts and measurement techniques will be considered. Tensile strength increased generally with root age and decreased with thermal time after excision as a result of root decomposition. Single factors alone do not appear to explain the strength-diameter relationship, and both strength/stiffness and dry density may vary between different layers of tissue within a single root. Results will be discussed to consider how we can achieve a more comprehensive understanding of the variation in root biomechanical properties, and its consequences for soil reinforcement. Acknowledgements: The James Hutton Institute receives funding from the Scottish Government. AGB and JAK acknowledge part funding from EPSRC (EP/M020355/1).

  17. Host-specific races in the holoparasitic angiosperm Orobanche minor: implications for speciation in parasitic plants

    PubMed Central

    Thorogood, C. J.; Rumsey, F. J.; Hiscock, S. J.

    2009-01-01

    Background and Aims Orobanche minor is a root-holoparasitic angiosperm that attacks a wide range of host species, including a number of commonly cultivated crops. The extent to which genetic divergence among natural populations of O. minor is influenced by host specificity has not been determined previously. Here, the host specificity of natural populations of O. minor is quantified for the first time, and evidence that this species may comprise distinct physiological races is provided. Methods A tripartite approach was used to examine the physiological basis for the divergence of populations occurring on different hosts: (1) host–parasite interactions were cultivated in rhizotron bioassays in order to quantify the early stages of the infection and establishment processes; (2) using reciprocal-infection experiments, parasite races were cultivated on their natural and alien hosts, and their fitness determined in terms of biomass; and (3) the anatomy of the host–parasite interface was investigated using histochemical techniques, with a view to comparing the infection process on different hosts. Key Results Races occurring naturally on red clover (Trifolium pratense) and sea carrot (Daucus carota ssp. gummifer) showed distinct patterns of host specificity: parasites cultivated in cross-infection studies showed a higher fitness on their natural hosts, suggesting that races show local adaptation to specific hosts. In addition, histological evidence suggests that clover and carrot roots vary in their responses to infection. Different root anatomy and responses to infection may underpin a physiological basis for host specificity. Conclusions It is speculated that host specificity may isolate races of Orobanche on different hosts, accelerating divergence and ultimately speciation in this genus. The rapid life cycle and broad host range of O. minor make this species an ideal model with which to study the interactions of parasitic plants with their host associates. PMID

  18. Effect of two contemporary root canal sealers on root canal dentin microhardness

    PubMed Central

    2017-01-01

    Background Successful root canal treatment depends on proper cleaning, disinfecting and shaping of the root canal space. Pulpless teeth have lower dentin microhardness value compared to that of vital teeth. A material which can cause change in dentin composition may affect the microhardness. Thus the aim of this study was to evaluate and compare the effect of two root canal sealers on dentin microhardness. Material and Methods Forty two single rooted teeth were selected and divided into 3 equal groups; Apexit, iRootSP and control groups (n=14) Each group was then divided into 2 subgroups according to the post evaluation period; 1 week and 2 months (n=7). Root canal procedure was done in the experimental groups and obturation was made using either; Apexit, iRootSP or left unprepared and unobturated in the control group. Roots were sectioned transversely into cervical, middle and apical segments. The three sections of each root were mounted in a plastic chuck with acrylic resin. The coronal dentin surfaces of the root segments werepolished. Microhardness of each section was measured at 500 µm and 1000 µm from the canal lumen. Results Four way-ANOVA revealed that different tested sealer materials, canal third, measuring distance from the pulp and time as independent variables had statistically non significant effect on mean microhardness values (VHN) at p≤0.001. Among iRootSP groups there was a statistically significant difference between iRoot SP at coronal root portion (87.79±17.83) and iRoot SP at apical root portion (76.26±9.33) groups where (p=0.01). IRoot SP at coronal canal third had higher statistically significant mean microhardness value (87.79±17.83) compared to Apexit at coronal third (73.61±13.47) where (p=0.01). Conclusions Root canal sealers do not affect dentin microhardness. Key words:Root canal, dentin, sealers, microhardness, bioceramic. PMID:28149466

  19. "Roots" Touched Children: Planned or Not

    ERIC Educational Resources Information Center

    Greathouse, Betty

    1977-01-01

    Explores children's reactions to the televised version of Alex Haley's "Roots" through interviews with thirty 8-year-old third-graders (10 Black, 10 Mexican-American, 10 White) from two classrooms in South Phoenix, Arizona. (BF/JH)

  20. DMA thermal analysis of yacon tuberous roots

    NASA Astrophysics Data System (ADS)

    Blahovec, J.; Lahodová, M.; Kindl, M.; Fernández, E. C.

    2013-12-01

    Specimens prepared from yacon roots in first two weeks after harvest were tested by dynamic mechanical analysis thermal analysis at temperatures between 30 and 90°C. No differences between different parts of roots were proved. There were indicated some differences in the test parameters that were caused by short time storage of the roots. One source of the differences was loss of water during the roots storage. The measured modulus increased during short time storage. Detailed study of changes of the modulus during the specimen dynamic mechanical analysis test provided information about different development of the storage and loss moduli during the specimen heating. The observed results can be caused by changes in cellular membranes observed earlier during vegetable heating, and by composition changes due to less stable components of yacon like inulin.

  1. Dechlorodauricumine from cultured roots of Menispermum dauricum.

    PubMed

    Sugimoto, Yukihiro; Matsui, Miharu; Takikawa, Hirosato; Sasaki, Mitsuru; Kato, Masako

    2005-11-01

    Dechlorodauricumine, a possible organic substrate for biochlorination, was isolated from cultured roots of Menispermum dauricum, a rich source of chlorinated alkaloids. Its structure was established by spectroscopic and chemical methods.

  2. Hairy root cultures for secondary metabolites production.

    PubMed

    Pistelli, Laura; Giovannini, Annalisa; Ruffoni, Barbara; Bertoli, Alessandra; Pistelli, Luisa

    2010-01-01

    Hairy roots (HRs) are differentiated cultures of transformed roots generated by the infection of wounded higher plants with Agrobacterium rhizogenes. This pathogen causes the HR disease leading to the neoplastic growth of roots that are characterized by high growth rate in hormone free media and genetic stability. HRs produce the same phytochemicals pattern of the corresponding wild type organ. High stability and productivity features allow the exploitation of HRs as valuable biotechnological tool for the production of plant secondary metabolites. In addition, several elicitation methods can be used to further enhance their accumulation in both small and large scale production. However, in the latter case, cultivation in bioreactors should be still optimized. HRs can be also utilised as biological farm for the production of recombinant proteins, hence holding additional potential for industrial use. HR technology has been strongly improved by increased knowledge of molecular mechanisms underlying their development. The present review summarizes updated aspects of the hairy root induction, genetics and metabolite production.

  3. Asymptotic unbounded root loci - Formulas and computation

    NASA Technical Reports Server (NTRS)

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

    1983-01-01

    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.

  4. Root gravitropism in maize and Arabidopsis

    NASA Technical Reports Server (NTRS)

    Evans, Michael L.

    1993-01-01

    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.

  5. Irregular sesquiterpenoids from Ligusticum grayi roots

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Root oil of Ligusticum grayi (Apiaceae) contains numerous irregular sesquiterpenoids. In addition to the known acyclic sesquilavandulol and a new sesquilavandulyl aldehyde, two thapsanes, one epithapsane, and fourteen sesquiterpenoids representing eight novel carbon skeletons were found. The new sk...

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

    PubMed

    Berthon, J Y; Boyer, N; Gaspar, T

    1987-10-01

    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 first days and decreased in the days after. Rooting was obtained by transfer of the cuttings after periods longer than 7-9 days from the NAA+D2 inductive medium to a basal medium supplemented or not with rutin (expressive medium). The rooting capacity was emphasized by rutin treatment and was in correlation with the peroxidase peak reached on the NAA+D2 medium. Seedlings, characterised by the highest peroxidase activity, were most performing in rooting.

  7. Anatomical aspects of angiosperm root evolution

    PubMed Central

    Seago, James L.; Fernando, Danilo D.

    2013-01-01

    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

  8. Capillary-Effect Root-Environment System

    NASA Technical Reports Server (NTRS)

    Wright, Bruce D.

    1991-01-01

    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.

  9. Development of Machine Learning Tools in ROOT

    NASA Astrophysics Data System (ADS)

    Gleyzer, S. V.; Moneta, L.; Zapata, Omar A.

    2016-10-01

    ROOT is a framework for large-scale data analysis that provides basic and advanced statistical methods used by the LHC experiments. These include machine learning algorithms from the ROOT-integrated Toolkit for Multivariate Analysis (TMVA). We present several recent developments in TMVA, including a new modular design, new algorithms for variable importance and cross-validation, interfaces to other machine-learning software packages and integration of TMVA with Jupyter, making it accessible with a browser.

  10. Relationships between root respiration rate and root morphology, chemistry and anatomy in Larix gmelinii and Fraxinus mandshurica.

    PubMed

    Jia, Shuxia; McLaughlin, Neil B; Gu, Jiacun; Li, Xingpeng; Wang, Zhengquan

    2013-06-01

    Tree roots are highly heterogeneous in form and function. Previous studies revealed that fine root respiration was related to root morphology, tissue nitrogen (N) concentration and temperature, and varied with both soil depth and season. The underlying mechanisms governing the relationship between root respiration and root morphology, chemistry and anatomy along the root branch order have not been addressed. Here, we examined these relationships of the first- to fifth-order roots for near surface roots (0-10 cm) of 22-year-old larch (Larix gmelinii L.) and ash (Fraxinus mandshurica L.) plantations. Root respiration rate at 18 °C was measured by gas phase O2 electrodes across the first five branching order roots (the distal roots numbered as first order) at three times of the year. Root parameters of root diameter, specific root length (SRL), tissue N concentration, total non-structural carbohydrates (starch and soluble sugar) concentration (TNC), cortical thickness and stele diameter were also measured concurrently. With increasing root order, root diameter, TNC and the ratio of root TNC to tissue N concentration increased, while the SRL, tissue N concentration and cortical proportion decreased. Root respiration rate also monotonically decreased with increasing root order in both species. Cortical tissue (including exodermis, cortical parenchyma and endodermis) was present in the first three order roots, and cross sections of the cortex for the first-order root accounted for 68% (larch) and 86% (ash) of the total cross section of the root. Root respiration was closely related to root traits such as diameter, SRL, tissue N concentration, root TNC : tissue N ratio and stele-to-root diameter proportion among the first five orders, which explained up to 81-94% of variation in the rate of root respiration for larch and up to 83-93% for ash. These results suggest that the systematic variations of root respiration rate within tree fine root system are possibly due to the

  11. Adaptive significance of root grafting in trees

    SciTech Connect

    Loehle, C.; Jones, R.

    1988-12-31

    Root grafting has long been observed in forest trees but the adaptive significance of this trait has not been fully explained. Various authors have proposed that root grafting between trees contributes to mechanical support by linking adjacent root systems. Keeley proposes that this trait would be of greatest advantage in swamps where soils provide poor mechanical support. He provides as evidence a greenhouse study of Nyssa sylvatica Marsh in which seedlings of swamp provenance formed between-individual root grafts more frequently than upland provenance seedlings. In agreement with this within-species study, Keeley observed that arid zone species rarely exhibit grafts. Keeley also demonstrated that vines graft less commonly than trees, and herbs never do. Since the need for mechanical support coincides with this trend, these data seem to support his model. In this paper, the authors explore the mechanisms and ecological significance of root grafting, leading to predictions of root grafting incidence. Some observations support and some contradict the mechanical support hypothesis.

  12. ASTROCULTURE (TM) root metabolism and cytochemical analysis

    NASA Technical Reports Server (NTRS)

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

    2000-01-01

    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 (TM) 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.

  13. Gene expression regulation in roots under drought.

    PubMed

    Janiak, Agnieszka; Kwaśniewski, Mirosław; Szarejko, Iwona

    2016-02-01

    Stress signalling and regulatory networks controlling expression of target genes are the basis of plant response to drought. Roots are the first organs exposed to water deficiency in the soil and are the place of drought sensing. Signalling cascades transfer chemical signals toward the shoot and initiate molecular responses that lead to the biochemical and morphological changes that allow plants to be protected against water loss and to tolerate stress conditions. Here, we present an overview of signalling network and gene expression regulation pathways that are actively induced in roots under drought stress. In particular, the role of several transcription factor (TF) families, including DREB, AP2/ERF, NAC, bZIP, MYC, CAMTA, Alfin-like and Q-type ZFP, in the regulation of root response to drought are highlighted. The information provided includes available data on mutual interactions between these TFs together with their regulation by plant hormones and other signalling molecules. The most significant downstream target genes and molecular processes that are controlled by the regulatory factors are given. These data are also coupled with information about the influence of the described regulatory networks on root traits and root development which may translate to enhanced drought tolerance. This is the first literature survey demonstrating the gene expression regulatory machinery that is induced by drought stress, presented from the perspective of roots.

  14. Defining the core Arabidopsis thaliana root microbiome

    PubMed Central

    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

    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

  15. Acid protease production in fungal root endophytes.

    PubMed

    Mayerhofer, Michael S; Fraser, Erica; Kernaghan, Gavin

    2015-01-01

    Fungal endophytes are ubiquitous in healthy root tissue, but little is known about their ecosystem functions, including their ability to utilize organic nutrient sources such as proteins. Root-associated fungi may secrete proteases to access the carbon and mineral nutrients within proteins in the soil or in the cells of their plant host. We compared the protein utilization patterns of multiple isolates of the root endophytes Phialocephala fortinii s.l., Meliniomyces variabilis and Umbelopsis isabellina with those of two ectomycorrhizal (ECM) fungi, Hebeloma incarnatulum and Laccaria bicolor, and the wood-decay fungus Irpex lacteus at pH values of 2-9 on liquid BSA media. We also assessed protease activity using a fluorescently labeled casein assay and gelatin zymography and characterized proteases using specific protease inhibitors. I. lacteus and U. isabellina utilized protein efficiently, while the ECM fungi exhibited poor protein utilization. ECM fungi secreted metallo-proteases and had pH optima above 4, while other fungi produced aspartic proteases with lower pH optima. The ascomycetous root endophytes M. variabilis and P. fortinii exhibited intermediate levels of protein utilization and M. variabilis exhibited a very low pH optimum. Comparing proteolytic profiles between fungal root endophytes and fungi with well defined ecological roles provides insight into the ecology of these cryptic root associates.

  16. [Apical root pins of high-karat gold alloys for resected roots].

    PubMed

    Handtmann, S; Lindemann, W; Sculte, W

    1989-02-01

    Following earlier studies on corrosion of silver pins in the root canal experience will be presented with the use of high-karat gold pins for apical closure of root amputations. The commercially available standardized Ackermann silver pins were replaced by high-karat gold pins of similar Vicker hardness and inserted in 218 patients with 264 root amputations since 1986. A clinical and radiological follow-up demonstrated a success rate of over 90%.

  17. Lectin Binding to the Root and Root Hair Tips of the Tropical Legume Macroptilium atropurpureum Urb

    PubMed Central

    Ridge, R. W.; Rolfe, B. G.

    1986-01-01

    Ten fluorescein isothiocyanate-labeled lectins were tested on the roots of the tropical legume Macroptilium atropurpureum Urb. Four of these (concanavalin A, peanut agglutinin, Ricinis communis agglutinin I [RCA-I], wheat germ agglutinin) were found to bind to the exterior of root cap cells, the root cap slime, and the channels between epidermal cells in the root elongation zone. One of these lectins, RCA-I, bound to the root hair tips in the mature and emerging hair zones and also to sites at which root hairs were only just emerging. There was no RCA-I binding to immature trichoblasts. Preincubation of these lectins with their hapten sugars eliminated all types of root cell binding. By using a microinoculation technique, preincubation of the root surface with RCA-I lectin was found to inhibit infection and nodulation by Rhizobium spp. Preincubation of the root surface with the RCA-I hapten β-d-galactose or a mixture of RCA-I lectin and its hapten failed to inhibit nodulation. Application of RCA-I lectin to the root surface caused no apparent detrimental effects to the root hair cells and did not prevent the growth of root hairs. The lectin did not prevent Rhizobium sp. motility or viability even after 24 h of incubation. It was concluded that the RCA-I lectin-specific sugar β-d-galactose may be involved in the recognition or early infection stages, or both, in the Rhizobium sp. infection of M. atropurpureum. Images PMID:16346989

  18. Modulation of root branching by a coumarin derivative.

    PubMed

    Li, Xiang; Gao, Ming-Jun

    2011-11-01

    A healthy root system is crucial to plant growth and survival. To maintain efficiency of root function, plants have to dynamically modulate root system architecture through various adaptive mechanisms such as lateral root formation to respond to a changing and diversified soil environment. Exogenous application of a coumarin derivative, 4-methylumbelliferone (4-MU), in Arabidopsis thaliana inhibits seed germination by mainly reducing primary root growth. UDP-glycosyltransferases play an integral role in the biochemical mechanism of 4-MU detoxification in plant roots.1 However, 4-MU treatment also dramatically led to increased lateral root initiation, elongation and density. Moreover, marked root bending at the root-hypocotyl junction and auxin redistribution appeared to contribute to the 4-MU-mediated lateral root formation. We propose that 4-MU would serve as a useful chemical tool to study auxin-mediated root branching.

  19. Modulation of root branching by a coumarin derivative

    PubMed Central

    Li, Xiang; Gao, Ming-Jun

    2011-01-01

    A healthy root system is crucial to plant growth and survival. To maintain efficiency of root function, plants have to dynamically modulate root system architecture through various adaptive mechanisms such as lateral root formation to respond to a changing and diversified soil environment. Exogenous application of a coumarin derivative, 4-methylumbelliferone (4-MU), in Arabidopsis thaliana inhibits seed germination by mainly reducing primary root growth. UDP-glycosyltransferases play an integral role in the biochemical mechanism of 4-MU detoxification in plant roots.1 However, 4-MU treatment also dramatically led to increased lateral root initiation, elongation and density. Moreover, marked root bending at the root-hypocotyl junction and auxin redistribution appeared to contribute to the 4-MU-mediated lateral root formation. We propose that 4-MU would serve as a useful chemical tool to study auxin-mediated root branching. PMID:22057336

  20. New insights to lateral rooting: Differential responses to heterogeneous nitrogen availability among maize root types.

    PubMed

    Yu, Peng; White, Philip J; Li, Chunjian

    2015-01-01

    Historical domestication and the "Green revolution" have both contributed to the evolution of modern, high-performance crops. Together with increased irrigation and application of chemical fertilizers, these efforts have generated sufficient food for the growing global population. Root architecture, and in particular root branching, plays an important role in the acquisition of water and nutrients, plant performance, and crop yield. Better understanding of root growth and responses to the belowground environment could contribute to overcoming the challenges faced by agriculture today. Manipulating the abilities of crop root systems to explore and exploit the soil environment could enable plants to make the most of soil resources, increase stress tolerance and improve grain yields, while simultaneously reducing environmental degradation. In this article it is noted that the control of root branching, and the responses of root architecture to nitrate availability, differ between root types and between plant species. Since the control of root branching depends upon both plant species and root type, further work is urgently required to determine the appropriate genes to manipulate to improve resource acquisition by specific crops.

  1. Melatonin promotes seminal root elongation and root growth in transgenic rice after germination.

    PubMed

    Park, Sangkyu; Back, Kyoungwhan

    2012-11-01

    The effect of melatonin on root growth after germination was examined in transgenic rice seedlings expressing sheep serotonin N-acetyltransferase (NAT). Enhanced melatonin levels were found in T(3) homozygous seedlings because of the ectopic overexpression of sheep NAT, which is believed to be the rate-limiting enzyme in melatonin biosynthesis in animals. Compared with wild-type rice seeds, the transgenic rice seeds showed enhanced seminal root growth and an analogous number of adventitious roots 4 and 10 days after seeding on half-strength Murashige and Skoog medium. The enhanced initial seminal root growth in the transgenic seedlings matched their increased root biomass well. We also found that treatment with 0.5 and 1 μM melatonin promoted seminal root growth of the wild type under continuous light. These results indicate that melatonin plays an important role in regulating both seminal root length and root growth after germination in monocotyledonous rice plants. This is the first report on the effects of melatonin on root growth in gain-of-function mutant plants that produce high levels of melatonin.

  2. Ozone decreases spring root growth and root carbohydrate content in ponderosa pine the year following exposure

    SciTech Connect

    Andersen, C.P.; Hogsett, W.E.; Wessling, R.; Plocher, M.

    1991-01-01

    Storage carbohydrates are extremely important for new shoot and root development following dormancy or during periods of high stress. The hypothesis that ozone decreases carbohydrate storage and decreases new root growth during the year following exposure was investigated. The results suggest that (1) ponderosa pine seedlings exposed to 122 and 169 ppm hrs ozone for one season have significantly less root starch reserves available just prior to and during bud break the following year, and (2) spring root growth is decreased following ozone exposure. The carry-over effects of ozone stress may be important in long-lived perennial species which are annually subjected to ozone.

  3. Cadmium translocation by contractile roots differs from that in regular, non-contractile roots

    PubMed Central

    Lux, Alexander; Lackovič, Andrej; Van Staden, Johannes; Lišková, Desana; Kohanová, Jana; Martinka, Michal

    2015-01-01

    Background and Aims Contractile roots are known and studied mainly in connection with the process of shrinkage of their basal parts, which acts to pull the shoot of the plant deeper into the ground. Previous studies have shown that the specific structure of these roots results in more intensive water uptake at the base, which is in contrast to regular root types. The purpose of this study was to find out whether the basal parts of contractile roots are also more active in translocation of cadmium to the shoot. Methods Plants of the South African ornamental species Tritonia gladiolaris were cultivated in vitro for 2 months, at which point they possessed well-developed contractile roots. They were then transferred to Petri dishes with horizontally separated compartments of agar containing 50 µmol Cd(NO3)2 in the region of the root base or the root apex. Seedlings of 4-d-old maize (Zea mays) plants, which do not possess contractile roots, were also transferred to similar Petri dishes. The concentrations of Cd in the leaves of the plants were compared after 10 d of cultivation. Anatomical analyses of Tritonia roots were performed using appropriately stained freehand cross-sections. Key Results The process of contraction required specific anatomical adaptation of the root base in Tritonia, with less lignified and less suberized tissues in comparison with the subapical part of the root. These unusual developmental characteristics were accompanied by more intensive translocation of Cd ions from the basal part of contractile roots to the leaves than from the apical–subapical root parts. The opposite effects were seen in the non-contractile roots of maize, with higher uptake and transport by the apical parts of the root and lower uptake and transport by the basal part. Conclusions The specific characteristics of contractile roots may have a significant impact on the uptake of ions, including toxic metals from the soil surface layers. This may be important for plant

  4. Root cortical senescence decreases root respiration, nutrient content, and radial water and nutrient transport in barley.

    PubMed

    Schneider, Hannah M; Wojciechowski, Tobias; Postma, Johannes A; Brown, Kathleen M; Lücke, Andreas; Zeisler, Viktoria; Schreiber, Lukas; Lynch, Jonathan P

    2017-02-06

    The functional implications of root cortical senescence (RCS) are poorly understood. We tested the hypotheses that RCS in barley: (1) reduces the respiration and nutrient content of root tissue; (2) decreases radial water and nutrient transport; (3) is accompanied by increased suberization to protect the stele. Genetic variation for RCS exists between modern germplasm and landraces. Nitrogen and phosphorus deficiency increased the rate of RCS. Maximal RCS, defined as the disappearance of the entire root cortex, reduced root nitrogen content by 66%, phosphorus content by 63%, and respiration by 87% compared to root segments with no RCS. Roots with maximal RCS had 90%, 92%, and 84% less radial water, nitrate, and phosphorus transport, respectively compared to segments with no RCS. The onset of RCS coincided with 30% greater aliphatic suberin in the endodermis. These results support the hypothesis that RCS reduces root carbon and nutrient costs and may therefore have adaptive significance for soil resource acquisition. By reducing root respiration and nutrient content, RCS could permit greater root growth, soil resource acquisition, and resource allocation to other plant processes. RCS merits investigation as a trait for improving the performance of barley, wheat, triticale, and rye under edaphic stress.

  5. Root Branching Is a Leading Root Trait of the Plant Economics Spectrum in Temperate Trees.

    PubMed

    Liese, Rebecca; Alings, Katrin; Meier, Ina C

    2017-01-01

    Global vegetation models use conceived relationships between functional traits to simulate ecosystem responses to environmental change. In this context, the concept of the leaf economics spectrum (LES) suggests coordinated leaf trait variation, and separates species which invest resources into short-lived leaves with a high expected energy return rate from species with longer-lived leaves and slower energy return. While it has been assumed that being fast (acquisitive) or slow (conservative) is a general feature for all organ systems, the translation of the LES into a root economics spectrum (RES) for tree species has been hitherto inconclusive. This may be partly due to the assumption that the bulk of tree fine roots have similar uptake functions as leaves, despite the heterogeneity of their environments and resources. In this study we investigated well-established functional leaf and stature traits as well as a high number of fine root traits (14 traits split by different root orders) of 13 dominant or subdominant temperate tree species of Central Europe, representing two phylogenetic groups (gymnosperms and angiosperms) and two mycorrhizal associations (arbuscular and ectomycorrhizal). We found reflected variation in leaf and lower-order root traits in some (surface areas and C:N) but not all (N content and longevity) traits central to the LES. Accordingly, the LES was not mirrored belowground. We identified significant phylogenetic signal in morphological lower-order root traits, i.e., in root tissue density, root diameter, and specific root length. By contrast, root architecture (root branching) was influenced by the mycorrhizal association type which developed independent from phylogeny of the host tree. In structural equation models we show that root branching significantly influences both belowground (direct influence on root C:N) and aboveground (indirect influences on specific leaf area and leaf longevity) traits which relate to resource investment and

  6. Ultrasonography Evaluation of Vulnerable Vessels Around Cervical Nerve Roots During Selective Cervical Nerve Root Block

    PubMed Central

    2017-01-01

    Objective To evaluate the prevalence of vulnerable blood vessels around cervical nerve roots before cervical nerve root block in the clinical setting. Methods This retrospective study included 74 patients with cervical radiculopathy who received an ultrasonography-guided nerve block at an outpatient clinic from July 2012 to July 2014. Before actual injection of the steroid was performed, we evaluated the vulnerable blood vessels around each C5, C6, and C7 nerve root of each patient's painful side, with Doppler ultrasound. Results Out of 74 cases, the C5 level had 2 blood vessels (2.7%), the C6 level had 4 blood vessels (5.45%), and the C7 level had 6 blood vessels (8.11%) close to each targeted nerve root. Moreover, the C5 level had 2 blood vessels (2.7%), the C6 level 5 blood vessels (6.75%), and the C7 level had 4 blood vessels (5.45%) at the site of an imaginary needle's projected pathway to the targeted nerve root, as revealed by axial transverse ultrasound imaging with color Doppler imaging. In total, the C5 level had 4 blood vessels (5.45%), the C6 level 9 blood vessels (12.16%), and the C7 level 10 had blood vessels (13.51%) either at the targeted nerve root or at the site of the imaginary needle's projected pathway to the targeted nerve root. There was an unneglectable prevalence of vulnerable blood vessels either at the targeted nerve root or at the site of the needle' projected pathway to the nerve root. Also, it shows a higher prevalence of vulnerable blood vessels either at the targeted nerve root or at the site of an imaginary needle's projected pathway to the nerve root as the spinal nerve root level gets lower. Conclusion To prevent unexpected critical complications involving vulnerable blood vessel injury during cervical nerve root block, it is recommended to routinely evaluate for the presence of vulnerable blood vessels around each cervical nerve root using Doppler ultrasound imaging before the cervical nerve root block, especially for the lower

  7. Root Branching Is a Leading Root Trait of the Plant Economics Spectrum in Temperate Trees

    PubMed Central

    Liese, Rebecca; Alings, Katrin; Meier, Ina C.

    2017-01-01

    Global vegetation models use conceived relationships between functional traits to simulate ecosystem responses to environmental change. In this context, the concept of the leaf economics spectrum (LES) suggests coordinated leaf trait variation, and separates species which invest resources into short-lived leaves with a high expected energy return rate from species with longer-lived leaves and slower energy return. While it has been assumed that being fast (acquisitive) or slow (conservative) is a general feature for all organ systems, the translation of the LES into a root economics spectrum (RES) for tree species has been hitherto inconclusive. This may be partly due to the assumption that the bulk of tree fine roots have similar uptake functions as leaves, despite the heterogeneity of their environments and resources. In this study we investigated well-established functional leaf and stature traits as well as a high number of fine root traits (14 traits split by different root orders) of 13 dominant or subdominant temperate tree species of Central Europe, representing two phylogenetic groups (gymnosperms and angiosperms) and two mycorrhizal associations (arbuscular and ectomycorrhizal). We found reflected variation in leaf and lower-order root traits in some (surface areas and C:N) but not all (N content and longevity) traits central to the LES. Accordingly, the LES was not mirrored belowground. We identified significant phylogenetic signal in morphological lower-order root traits, i.e., in root tissue density, root diameter, and specific root length. By contrast, root architecture (root branching) was influenced by the mycorrhizal association type which developed independent from phylogeny of the host tree. In structural equation models we show that root branching significantly influences both belowground (direct influence on root C:N) and aboveground (indirect influences on specific leaf area and leaf longevity) traits which relate to resource investment and

  8. Earliest rooting system and root : shoot ratio from a new Zosterophyllum plant.

    PubMed

    Hao, Shougang; Xue, Jinzhuang; Guo, Dali; Wang, Deming

    2010-01-01

    The enhanced chemical weathering by rooted vascular plants during the Silurian-Devonian period played a crucial role in altering global biogeochemical cycles and atmospheric environments; however, the documentation of early root morphology and physiology is scarce because the existing fossils are mostly incomplete. Here, we report an entire, uprooted specimen of a new Zosterophyllum Penhallow, named as Z. shengfengense, from the Early Devonian Xitun Formation (Lochkovian, c. 413 Myr old) of Yunnan, south China. This plant has the most ancient known record of a rooting system. The plant consists of aerial axes of 98 mm in height, showing a tufted habit, and a rhizome bearing a fibrous-like rooting system, c. 20 mm in length. The rhizome shows masses of branchings, which produce upwardly directed aerial axes and downwardly directed root-like axes. The completeness of Z. shengfengense made it possible to estimate the biomass allocation and root : shoot ratio. The root : shoot ratio of this early plant is estimated at a mean value of 0.028, and the root-like axes constitute only c. 3% of the total biomass. Zosterophyllum shengfengense was probably a semi-aquatic plant with efficient water use or a strong uptake capacity of the root-like axes.

  9. Exogenous nitrate induces root branching and inhibits primary root growth in Capsicum chinense Jacq.

    PubMed

    Celis-Arámburo, Teresita de Jesús; Carrillo-Pech, Mildred; Castro-Concha, Lizbeth A; Miranda-Ham, María de Lourdes; Martínez-Estévez, Manuel; Echevarría-Machado, Ileana

    2011-12-01

    The effects of nitrate (NO₃⁻) on the root system are complex and depend on several factors, such as the concentration available to the plant, endogenous nitrogen status and the sensitivity of the species. Though these effects have been widely documented on Arabidopsis and cereals, no reports are available in the Capsicum genus. In this paper, we have determined the effect of an exogenous in vitro application of this nutrient on root growth in habanero pepper (Capsicum chinense Jacq.). Exposure to NO₃⁻ inhibited primary root growth in both, dose- and time-dependent manners. The highest inhibition was attained with 0.1 mM NO₃⁻ between the fourth and fifth days of treatment. Inhibition of primary root growth was observed by exposing the root to both homogeneous and heterogeneous conditions of the nutrient; in contrast, ammonium was not able to induce similar changes. NO₃⁻-induced inhibition of primary root growth was reversed by treating the roots with IAA or NPA, a polar auxin transport inhibitor. Heterogeneous NO₃⁻ application stimulated the formation and elongation of lateral roots in the segment where the nutrient was present, and this response was influenced by exogenous phytohormones. These results demonstrate that habanero pepper responds to NO₃⁻ in a similar fashion to other species with certain particular differences. Therefore, studies in this model could help to elucidate the mechanisms by which roots respond to NO₃⁻ in fluctuating soil environments.

  10. Plant root tortuosity: an indicator of root path formation in soil with different composition and density

    PubMed Central

    Popova, Liyana; van Dusschoten, Dagmar; Nagel, Kerstin A.; Fiorani, Fabio; Mazzolai, Barbara

    2016-01-01

    Background and Aims Root soil penetration and path optimization are fundamental for root development in soil. We describe the influence of soil strength on root elongation rate and diameter, response to gravity, and root-structure tortuosity, estimated by average curvature of primary maize roots. Methods Soils with different densities (1·5, 1·6, 1·7 g cm−3), particle sizes (sandy loam; coarse sand mixed with sandy loam) and layering (monolayer, bilayer) were used. In total, five treatments were performed: Mix_low with mixed sand low density (three pots, 12 plants), Mix_medium - mixed sand medium density (three pots, 12 plants), Mix_high - mixed sand high density (three pots, ten plants), Loam_low sandy loam soil low density (four pots, 16 plants), and Bilayer with top layer of sandy loam and bottom layer mixed sand both of low density (four pots, 16 plants). We used non-invasive three-dimensional magnetic resonance imaging to quantify effects of these treatments. Key Results Roots grew more slowly [root growth rate (mm h–1); decreased 50 %] with increased diameters [root diameter (mm); increased 15 %] in denser soils (1·7 vs. 1·5 g cm–3). Root response to gravity decreased 23 % with increased soil compaction, and tortuosity increased 10 % in mixed sand. Response to gravity increased 39 % and tortuosity decreased 3 % in sandy loam. After crossing a bilayered–soil interface, roots grew more slowly, similar to roots grown in soil with a bulk density of 1·64 g cm–3, whereas the actual experimental density was 1·48±0·02 g cm–3. Elongation rate and tortuosity were higher in Mix_low than in Loam_low. Conclusions The present study increases our existing knowledge of the influence of physical soil properties on root growth and presents new assays for studying root growth dynamics in non-transparent media. We found that root tortuosity is indicative of root path selection, because it could result from both mechanical deflection and

  11. Capturing Arabidopsis root architecture dynamics with ROOT-FIT reveals diversity in responses to salinity.

    PubMed

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

    2014-11-01

    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.

  12. Modelling water uptake efficiency of root systems

    NASA Astrophysics Data System (ADS)

    Leitner, Daniel; Tron, Stefania; Schröder, Natalie; Bodner, Gernot; Javaux, Mathieu; Vanderborght, Jan; Vereecken, Harry; Schnepf, Andrea

    2016-04-01

    Water uptake is crucial for plant productivity. Trait based breeding for more water efficient crops will enable a sustainable agricultural management under specific pedoclimatic conditions, and can increase drought resistance of plants. Mathematical modelling can be used to find suitable root system traits for better water uptake efficiency defined as amount of water taken up per unit of root biomass. This approach requires large simulation times and large number of simulation runs, since we test different root systems under different pedoclimatic conditions. In this work, we model water movement by the 1-dimensional Richards equation with the soil hydraulic properties described according to the van Genuchten model. Climatic conditions serve as the upper boundary condition. The root system grows during the simulation period and water uptake is calculated via a sink term (after Tron et al. 2015). The goal of this work is to compare different free software tools based on different numerical schemes to solve the model. We compare implementations using DUMUX (based on finite volumes), Hydrus 1D (based on finite elements), and a Matlab implementation of Van Dam, J. C., & Feddes 2000 (based on finite differences). We analyse the methods for accuracy, speed and flexibility. Using this model case study, we can clearly show the impact of various root system traits on water uptake efficiency. Furthermore, we can quantify frequent simplifications that are introduced in the modelling step like considering a static root system instead of a growing one, or considering a sink term based on root density instead of considering the full root hydraulic model (Javaux et al. 2008). References Tron, S., Bodner, G., Laio, F., Ridolfi, L., & Leitner, D. (2015). Can diversity in root architecture explain plant water use efficiency? A modeling study. Ecological modelling, 312, 200-210. Van Dam, J. C., & Feddes, R. A. (2000). Numerical simulation of infiltration, evaporation and shallow

  13. D-Root: a system for cultivating plants with the roots in darkness or under different light conditions.

    PubMed

    Silva-Navas, Javier; Moreno-Risueno, Miguel A; Manzano, Concepción; Pallero-Baena, Mercedes; Navarro-Neila, Sara; Téllez-Robledo, Bárbara; Garcia-Mina, Jose M; Baigorri, Roberto; Gallego, Francisco Javier; del Pozo, Juan C

    2015-10-01

    In nature roots grow in the dark and away from light (negative phototropism). However, most current research in root biology has been carried out with the root system grown in the presence of light. Here, we have engineered a device, called Dark-Root (D-Root), to grow plants in vitro with the aerial part exposed to the normal light/dark photoperiod while the roots are in the dark or exposed to specific wavelengths or light intensities. D-Root provides an efficient system for cultivating a large number of seedlings and easily characterizing root architecture in the dark. At the morphological level, root illumination shortens root length and promotes early emergence of lateral roots, therefore inducing expansion of the root system. Surprisingly, root illumination also affects shoot development, including flowering time. Our analyses also show that root illumination alters the proper response to hormones or abiotic stress (e.g. salt or osmotic stress) and nutrient starvation, enhancing inhibition of root growth. In conclusion, D-Root provides a growing system closer to the natural one for assaying Arabidopsis plants, and therefore its use will contribute to a better understanding of the mechanisms involved in root development, hormonal signaling and stress responses.

  14. β-2-himachalen-6-ol: A novel anticancer sesquiterpene unique to the Lebanese wild carrot.

    PubMed

    Taleb, Robin I; Najm, Paul; Shebaby, Wassim; Boulos, Joelle C; Demirdjian, Sally; Hariri, Essa; El-Sibai, Mirvat; Daher, Costantine; Mroueh, Mohamad

    2016-08-22

    Daucus carota ssp. carota, also known as wild carrot, is a commonly used herb in Lebanese folk medicine to treat several ailments including cancer. Previous studies in our laboratories showed that the Daucus carota oil extract (DCOE) and subsequent fractions exhibit antioxidant, anti-inflammatory and anti-cancer activities. In this study, we report the isolation and identification of the major compound responsible for the anti-cancer activity of DCOE along with the mechanism of action involved. GC-MS and NMR spectroscopy revealed the identity of the major compound as β-2-himachalen-6-ol, a novel sesquiterpene unique to the Lebanese wild carrot. β-2-Himachalen-6-ol demonstrated potent anti-cancer activity against B16F-10, Caco-2, MB-MDA-231, A549 and SF-268 cancer cells (IC50 13-4µg/ml; 58-18µM), with SF-268 cells being the most sensitive. The sesquiterpene was shown to induce cell death through apoptosis (flow cytometry), decrease 2D cell motility (wound healing assay) and 3D invasion, as well as increase cell adhesion in SF-268 cells. Additionally, β-2-himachalen-6-ol showed very low toxicity in mice with an LD50>6000mg/kg body weight. In conclusion, the present data demonstrate that β-2-himachalen-6-ol is a potential multi-mechanistic chemotherapeutic drug with high potency and safety.

  15. Root exudates from grafted-root watermelon showed a certain contribution in inhibiting Fusarium oxysporum f. sp. niveum.

    PubMed

    Ling, Ning; Zhang, Wenwen; Wang, Dongsheng; Mao, Jiugeng; Huang, Qiwei; Guo, Shiwei; Shen, Qirong

    2013-01-01

    Grafting watermelon onto bottle gourd rootstock is commonly used method to generate resistance to Fusarium oxysporum f. sp. niveum (FON), but knowledge of the effect of the root exudates of grafted watermelon on this soil-borne pathogen in rhizosphere remains limited. To investigate the root exudate profiles of the own-root bottle gourd, grafted-root watermelon and own-root watermelon, recirculating hydroponic culture system was developed to continuously trap these root exudates. Both conidial germination and growth of FON were significantly decreased in the presence of root exudates from the grafted-root watermelon compared with the own-root watermelon. HPLC analysis revealed that the composition of the root exudates released by the grafted-root watermelon differed not only from the own-root watermelon but also from the bottle gourd rootstock plants. We identified salicylic acid in all 3 root exudates, chlorogenic acid and caffeic acid in root exudates from own-root bottle gourd and grafted-root watermelon but not own-root watermelon, and abundant cinnamic acid only in own-root watermelon root exudates. The chlorogenic and caffeic acid were candidates for potentiating the enhanced resistance of the grafted watermelon to FON, therefore we tested the effects of the two compounds on the conidial germination and growth of FON. Both phenolic acids inhibited FON conidial germination and growth in a dose-dependent manner, and FON was much more susceptible to chlorogenic acid than to caffeic acid. In conclusion, the key factor in attaining the resistance to Fusarium wilt is grafting on the non-host root stock, however, the root exudates profile also showed some contribution in inhibiting FON. These results will help to better clarify the disease resistance mechanisms of grafted-root watermelon based on plant-microbe communication and will guide the improvement of strategies against Fusarium-mediated wilt of watermelon plants.

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

    PubMed Central

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

    2013-01-01

    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

  17. Disentangling root system responses to neighbours: identification of novel root behavioural strategies

    PubMed Central

    Belter, Pamela R.; Cahill, James F.

    2015-01-01

    Plants live in a social environment, with interactions among neighbours a ubiquitous aspect of life. Though many of these interactions occur in the soil, our understanding of how plants alter root growth and the patterns of soil occupancy in response to neighbours is limited. This is in contrast to a rich literature on the animal behavioural responses to changes in the social environment. For plants, root behavioural changes that alter soil occupancy patterns can influence neighbourhood size and the frequency or intensity of competition for soil resources; issues of fundamental importance to understanding coexistence and community assembly. Here we report a large comparative study in which individuals of 20 species were grown with and without each of two neighbour species. Through repeated root visualization and analyses, we quantified many putative root behaviours, including the extent to which each species altered aspects of root system growth (e.g. rooting breadth, root length, etc.) in response to neighbours. Across all species, there was no consistent behavioural response to neighbours (i.e. no general tendencies towards root over-proliferation nor avoidance). However, there was a substantial interspecific variation showing a continuum of behavioural variation among the 20 species. Multivariate analyses revealed two novel and predominant root behavioural strategies: (i) size-sensitivity, in which focal plants reduced their overall root system size in response to the presence of neighbours, and (ii) location-sensitivity, where focal plants adjusted the horizontal and vertical placement of their roots in response to neighbours. Of these, size-sensitivity represents the commonly assumed response to competitive encounters—reduced growth. However, location sensitivity is not accounted for in classic models and concepts of plant competition, though it is supported from recent work in plant behavioural ecology. We suggest that these different strategies could have

  18. How can science education foster students' rooting?

    NASA Astrophysics Data System (ADS)

    Østergaard, Edvin

    2015-06-01

    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.

  19. Roots: evolutionary origins and biogeochemical significance.

    PubMed

    Raven, J A; Edwards, D

    2001-03-01

    Roots, as organs distinguishable developmentally and anatomically from shoots (other than by occurrence of stomata and sporangia on above-ground organs), evolved in the sporophytes of at least two distinct lineages of early vascular plants during their initial major radiation on land in Early Devonian times (c. 410-395 million years ago). This was some 15 million years after the appearance of tracheophytes and c. 50 million years after the earliest embryophytes of presumed bryophyte affinity. Both groups are known initially only from spores, but from comparative anatomy of extant bryophytes and later Lower Devonian fossils it is assumed that, during these times, below-ground structures (if any) other than true roots fulfilled the functions of anchorage and of water and nutrient acquisition, despite lacking an endodermis (as do the roots of extant Lycopodium spp.). By 375 million years ago root-like structures penetrated almost a metre into the substratum, greatly increasing the volume of mineral matter subject to weathering by the higher than atmospheric CO(2) levels generated by plant and microbial respiration in material with restricted diffusive contact with the atmosphere. Chemical weathering consumes CO(2) in converting silicates into bicarbonate and Si(OH)(4). The CO(2) consumed in weathering ultimately came from atmospheric CO(2) via photosynthesis and respiration; this use of CO(2) probably accounts for most of the postulated 10-fold decrease in atmospheric CO(2) from 400-350 million years ago, with significant effects on shoot evolution. Subsequent evolution of roots has yielded much-branched axes down to 40 microm diameter, a lower limit set by long-distance transport constraints. Finer structures involved in the uptake of nutrients of low diffusivity in soil evolved at least 400 million years ago as arbuscular mycorrhizas or as evaginations of "roots" ("root hairs").

  20. The evolution of root hairs and rhizoids

    PubMed Central

    Jones, Victor A.S.; Dolan, Liam

    2012-01-01

    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

  1. Potassium Transport in Corn Roots 1

    PubMed Central

    Kochian, Leon V.; Lucas, William J.

    1985-01-01

    It has recently been reported that plasmalemma electron transport may be involved in the generation of H+ gradients and the uptake of ions into root tissue. We report here on the influence of extracellular NADH and ferricyanide on K+ (86Rb+) influx, K+ (86Rb+) efflux, net apparent H+ efflux, and O2 consumption in 2-centimeter corn (Zea mays [A632 × Oh43]) root segments and intact corn roots. In freshly excised root segments, NADH had no effect on O2 consumption and K+ uptake. However, after the root segments were given a 4-hour wash in aerated salt solution, NADH elicited a moderate stimulation in O2 consumption but caused a dramatic inhibition of K+ influx. Moreover, net apparent H+ efflux was significantly inhibited following NADH exposure in 4-hour washed root segments. Exogenous ferricyanide inhibited K+ influx in a similar fashion to that caused by NADH, but caused a moderate stimulation of net H+ efflux. Additionally, both reagents substantially altered K+ efflux at both the plasmalemma and tonoplast. These complex results do not lend themselves to straightforward interpretation and are in contradiction with previously published results. They suggest that the interaction between cell surface redox reactions and membrane transport are more complex than previously considered. Indeed, more than one electron transport system may operate in the plasmalemma to influence, or regulate, a number of transport functions and other cellular processes. The results presented here suggest that plasmalemma redox reactions may be involved in the regulation of ion uptake and the `wound response' exhibited by corn roots. PMID:16664070

  2. 21 CFR 872.3810 - Root canal post.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Root canal post. 872.3810 Section 872.3810 Food... DEVICES DENTAL DEVICES Prosthetic Devices § 872.3810 Root canal post. (a) Identification. A root canal... of the platinum group intended to be cemented into the root canal of a tooth to stabilize and...

  3. 21 CFR 872.3810 - Root canal post.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Root canal post. 872.3810 Section 872.3810 Food... DEVICES DENTAL DEVICES Prosthetic Devices § 872.3810 Root canal post. (a) Identification. A root canal... of the platinum group intended to be cemented into the root canal of a tooth to stabilize and...

  4. 21 CFR 872.3810 - Root canal post.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Root canal post. 872.3810 Section 872.3810 Food... DEVICES DENTAL DEVICES Prosthetic Devices § 872.3810 Root canal post. (a) Identification. A root canal... of the platinum group intended to be cemented into the root canal of a tooth to stabilize and...

  5. 21 CFR 872.3810 - Root canal post.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Root canal post. 872.3810 Section 872.3810 Food... DEVICES DENTAL DEVICES Prosthetic Devices § 872.3810 Root canal post. (a) Identification. A root canal... of the platinum group intended to be cemented into the root canal of a tooth to stabilize and...

  6. 21 CFR 872.3810 - Root canal post.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Root canal post. 872.3810 Section 872.3810 Food... DEVICES DENTAL DEVICES Prosthetic Devices § 872.3810 Root canal post. (a) Identification. A root canal... of the platinum group intended to be cemented into the root canal of a tooth to stabilize and...

  7. Cold temperature delays wound healing in postharvest sugarbeet roots

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Storage temperature affects the rate and extent of wound-healing in a number of root and tuber crops. The effect of storage temperature on wound-healing in sugarbeet (Beta vulgaris L.) roots, however, is largely unknown. Wound-healing of sugarbeet roots was investigated using surface-abraded roots s...

  8. Root cortical burden influences drought tolerance in maize

    PubMed Central

    Jaramillo, Raúl E.; Nord, Eric A.; Chimungu, Joseph G.; Brown, Kathleen M.; Lynch, Jonathan P.

    2013-01-01

    Background and Aims Root cortical aerenchyma (RCA) increases water and nutrient acquisition by reducing the metabolic costs of soil exploration. In this study the hypothesis was tested that living cortical area (LCA; transversal root cortical area minus aerenchyma area and intercellular air space) is a better predictor of root respiration, soil exploration and, therefore, drought tolerance than RCA formation or root diameter. Methods RCA, LCA, root respiration, root length and biomass loss in response to drought were evaluated in maize (Zea mays) recombinant inbred lines grown with adequate and suboptimal irrigation in soil mesocosms. Key Results Root respiration was highly correlated with LCA. LCA was a better predictor of root respiration than either RCA or root diameter. RCA reduced respiration of large-diameter roots. Since RCA and LCA varied in different parts of the root system, the effects of RCA and LCA on root length were complex. Greater crown-root LCA was associated with reduced crown-root length relative to total root length. Reduced LCA was associated with improved drought tolerance. Conclusions The results are consistent with the hypothesis that LCA is a driver of root metabolic costs and may therefore have adaptive significance for water acquisition in drying soil. PMID:23618897

  9. Shoot-derived abscisic acid promotes root growth.

    PubMed

    McAdam, Scott A M; Brodribb, Timothy J; Ross, John J

    2016-03-01

    The phytohormone abscisic acid (ABA) plays a major role in regulating root growth. Most work to date has investigated the influence of root-sourced ABA on root growth during water stress. Here, we tested whether foliage-derived ABA could be transported to the roots, and whether this foliage-derived ABA had an influence on root growth under well-watered conditions. Using both application studies of deuterium-labelled ABA and reciprocal grafting between wild-type and ABA-biosynthetic mutant plants, we show that both ABA levels in the roots and root growth in representative angiosperms are controlled by ABA synthesized in the leaves rather than sourced from the roots. Foliage-derived ABA was found to promote root growth relative to shoot growth but to inhibit the development of lateral roots. Increased root auxin (IAA) levels in plants with ABA-deficient scions suggest that foliage-derived ABA inhibits root growth through the root growth-inhibitor IAA. These results highlight the physiological and morphological importance, beyond the control of stomata, of foliage-derived ABA. The use of foliar ABA as a signal for root growth has important implications for regulating root to shoot growth under normal conditions and suggests that leaf rather than root hydration is the main signal for regulating plant responses to moisture.

  10. Functional genomics of root growth and development in Arabidopsis.

    PubMed

    Iyer-Pascuzzi, Anjali; Simpson, June; Herrera-Estrella, Luis; Benfey, Philip N

    2009-04-01

    Roots are vital for the uptake of water and nutrients, and for anchorage in the soil. They are highly plastic, able to adapt developmentally and physiologically to changing environmental conditions. Understanding the molecular mechanisms behind this growth and development requires knowledge of root transcriptomics, proteomics, and metabolomics. Genomics approaches, including the recent publication of a root expression map, root proteome, and environment-specific root expression studies, are uncovering complex transcriptional and post-transcriptional networks underlying root development. The challenge is in further capitalizing on the information in these datasets to understand the fundamental principles of root growth and development. In this review, we highlight progress researchers have made toward this goal.

  11. [Dimensional fractal of post-paddy wheat root architecture].

    PubMed

    Chen, Xin-xin; Ding, Qi-shuo; Li, Yi-nian; Xue, Jin-lin; Lu, Ming-zhou; Qiu, Wei

    2015-06-01

    To evaluate whether crop rooting system was directionally dependent, a field digitizer was used to measure post-paddy wheat root architectures. The acquired data was transferred to Pro-E, in which virtual root architecture was reconstructed and projected to a series of planes each separated in 10° apart. Fractal dimension and fractal abundance of root projections in all the 18 planes were calculated, revealing a distinctive architectural distribution of wheat root in each direction. This strongly proved that post-paddy wheat root architecture was directionally dependent. From seedling to turning green stage, fractal dimension of the 18 projections fluctuated significantly, illustrating a dynamical root developing process in the period. At the jointing stage, however, fractal indices of wheat root architecture resumed its regularity in each dimension. This wheat root architecture recovered its dimensional distinctness. The proposed method was applicable for precision modeling field state root distribution in soil.

  12. Triterpene and Flavonoid Biosynthesis and Metabolic Profiling of Hairy Roots, Adventitious Roots, and Seedling Roots of Astragalus membranaceus.

    PubMed

    Park, Yun Ji; Thwe, Aye Aye; Li, Xiaohua; Kim, Yeon Jeong; Kim, Jae Kwang; Arasu, Mariadhas Valan; Al-Dhabi, Naif Abdullah; Park, Sang Un

    2015-10-14

    Astragalus membranaceus is an important traditional Chinese herb with various medical applications. Astragalosides (ASTs), calycosin, and calycosin-7-O-β-d-glucoside (CG) are the primary metabolic components in A. membranaceus roots. The dried roots of A. membranaceus have various medicinal properties. The present study aimed to investigate the expression levels of genes related to the biosynthetic pathways of ASTs, calycosin, and CG to investigate the differences between seedling roots (SRs), adventitious roots (ARs), and hairy roots (HRs) using quantitative real-time polymerase chain reaction (qRT-PCR). qRT-PCR study revealed that the transcription level of genes involved in the AST biosynthetic pathway was lowest in ARs and showed similar patterns in HRs and SRs. Moreover, most genes involved in the synthesis of calycosin and CG exhibited the highest expression levels in SRs. High-performance liquid chromatography (HPLC) analysis indicated that the expression level of the genes correlated with the content of ASTs, calycosin, and CG in the three different types of roots. ASTs were the most abundant in SRs. CG accumulation was greater than calycosin accumulation in ARs and HRs, whereas the opposite was true in SRs. Additionally, 40 metabolites were identified using gas chromatography-time-of-flight mass spectrometry (GC-TOF-MS). Principal component analysis (PCA) documented the differences among SRs, ARs, and HRs. PCA comparatively differentiated among the three samples. The results of PCA showed that HRs were distinct from ARs and SRs on the basis of the dominant amounts of sugars and clusters derived from closely similar biochemical pathways. Also, ARs had a higher concentration of phenylalanine, a precursor for the phenylpropanoid biosynthetic pathway, as well as CG. TCA cycle intermediates levels including succinic acid and citric acid indicated a higher amount in SRs than in the others.

  13. Root transcriptome of two contrasting indica rice cultivars uncovers regulators of root development and physiological responses

    PubMed Central

    Singh, Alka; Kumar, Pramod; Gautam, Vibhav; Rengasamy, Balakrishnan; Adhikari, Bijan; Udayakumar, Makarla; Sarkar, Ananda K.

    2016-01-01

    The huge variation in root system architecture (RSA) among different rice (Oryza sativa) cultivars is conferred by their genetic makeup and different growth or climatic conditions. Unlike model plant Arabidopsis, the molecular basis of such variation in RSA is very poorly understood in rice. Cultivars with stable variation are valuable resources for identification of genes involved in RSA and related physiological traits. We have screened for RSA and identified two such indica rice cultivars, IR-64 (OsAS83) and IET-16348 (OsAS84), with stable contrasting RSA. OsAS84 produces robust RSA with more crown roots, lateral roots and root hairs than OsAS83. Using comparative root transcriptome analysis of these cultivars, we identified genes related to root development and different physiological responses like abiotic stress responses, hormone signaling, and nutrient acquisition or transport. The two cultivars differ in their response to salinity/dehydration stresses, phosphate/nitrogen deficiency, and different phytohormones. Differential expression of genes involved in salinity or dehydration response, nitrogen (N) transport, phosphate (Pi) starvation signaling, hormone signaling and root development underlies more resistance of OsAS84 towards abiotic stresses, Pi or N deficiency and its robust RSA. Thus our study uncovers gene-network involved in root development and abiotic stress responses in rice. PMID:28000793

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

    PubMed

    Miya, R K; Firestone, M K

    2001-01-01

    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.

  15. A PLANT ROOT SYSTEM ARCHITECTURAL TAXONOMY: A FRAMEWORK FOR ROOT NOMENCLATURE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Research into root system morphology over the last two centuries, has developed a diverse set of terminologies that are difficult to apply consistently across species and research specialties. In response to a need for better communication, a workshop held by the International Society for Root Rese...

  16. Deep rooting conferred by DEEPER ROOTING 1 enhances rice yield in paddy fields

    PubMed Central

    Arai-Sanoh, Yumiko; Takai, Toshiyuki; Yoshinaga, Satoshi; Nakano, Hiroshi; Kojima, Mikiko; Sakakibara, Hitoshi; Kondo, Motohiko; Uga, Yusaku

    2014-01-01

    To clarify the effect of deep rooting on grain yield in rice (Oryza sativa L.) in an irrigated paddy field with or without fertilizer, we used the shallow-rooting IR64 and the deep-rooting Dro1-NIL (a near-isogenic line homozygous for the Kinandang Patong allele of DEEPER ROOTING 1 (DRO1) in the IR64 genetic background). Although total root length was similar in both lines, more roots were distributed within the lower soil layer of the paddy field in Dro1-NIL than in IR64, irrespective of fertilizer treatment. At maturity, Dro1-NIL showed approximately 10% higher grain yield than IR64, irrespective of fertilizer treatment. Higher grain yield of Dro1-NIL was mainly due to the increased 1000-kernel weight and increased percentage of ripened grains, which resulted in a higher harvest index. After heading, the uptake of nitrogen from soil and leaf nitrogen concentration were higher in Dro1-NIL than in IR64. At the mid-grain-filling stage, Dro1-NIL maintained higher cytokinin fluxes from roots to shoots than IR64. These results suggest that deep rooting by DRO1 enhances nitrogen uptake and cytokinin fluxes at late stages, resulting in better grain filling in Dro1-NIL in a paddy field in this study. PMID:24988911

  17. White lupin cluster root acclimation to phosphorus deficiency and root hair development involve unique glycerophosphodiester phosphodiesterases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    White lupin (Lupinus albus L.) is a phosphate (Pi) deficiency tolerant legume which develops short, densely clustered tertiary lateral roots (cluster/proteoid roots) in response to Pi limitation. In this report we characterize two glycerophosphodiester phosphodiesterase (GPX-PDE) genes (GPX-PDE1 and...

  18. Response of grape root borer (lepidoptera: sesiidae) neonates to root extracts from vitaceae species and rootstocks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Observations at regular intervals of the location of newly hatched grape root borer larvae moving freely within Petri dish bioassays were used to measure and compare their response to filter paper discs treated with ethanol- and hexane-based extracts of roots from known and potential Vitaceae hosts ...

  19. Roots Withstanding their Environment: Exploiting Root System Architecture Responses to Abiotic Stress to Improve Crop Tolerance

    PubMed Central

    Koevoets, Iko T.; Venema, Jan Henk; Elzenga, J. Theo. M.; Testerink, Christa

    2016-01-01

    To face future challenges in crop production dictated by global climate changes, breeders and plant researchers collaborate to develop productive crops that are able to withstand a wide range of biotic and abiotic stresses. However, crop selection is often focused on shoot performance alone, as observation of root properties is more complex and asks for artificial and extensive phenotyping platforms. In addition, most root research focuses on development, while a direct link to the functionality of plasticity in root development for tolerance is often lacking. In this paper we review the currently known root system architecture (RSA) responses in Arabidopsis and a number of crop species to a range of abiotic stresses, including nutrient limitation, drought, salinity, flooding, and extreme temperatures. For each of these stresses, the key molecular and cellular mechanisms underlying the RSA response are highlighted. To explore the relevance for crop selection, we especially review and discuss studies linking root architectural responses to stress tolerance. This will provide a first step toward understanding the relevance of adaptive root development for a plant’s response to its environment. We suggest that functional evidence on the role of root plasticity will support breeders in their efforts to include root properties in their current selection pipeline for abiotic stress tolerance, aimed to improve the robustness of crops. PMID:27630659

  20. 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...

  1. Investigating Whole Root Systems: Advances in Root Quantification Tools and Techniques

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The efficient quantification of root traits remains a critical factor in exploiting many genetic resources during the study of root function and development. This is particularly true for the high throughput phenotyping of large populations for acid soil tolerance, including aluminum (Al) tolerance...

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

    PubMed Central

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

    2014-01-01

    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

  3. Root system markup language: toward a unified root architecture description language.

    PubMed

    Lobet, Guillaume; Pound, Michael P; Diener, Julien; Pradal, Christophe; Draye, Xavier; Godin, Christophe; Javaux, Mathieu; Leitner, Daniel; Meunier, Félicien; Nacry, Philippe; Pridmore, Tony P; Schnepf, Andrea

    2015-03-01

    The number of image analysis tools supporting the extraction of architectural features of root systems has increased in recent years. These tools offer a handy set of complementary facilities, yet it is widely accepted that none of these software tools is able to extract in an efficient way the growing array of static and dynamic features for different types of images and species. We describe the Root System Markup Language (RSML), which has been designed to overcome two major challenges: (1) to enable portability of root architecture data between different software tools in an easy and interoperable manner, allowing seamless collaborative work; and (2) to provide a standard format upon which to base central repositories that will soon arise following the expanding worldwide root phenotyping effort. RSML follows the XML standard to store two- or three-dimensional image metadata, plant and root properties and geometries, continuous functions along individual root paths, and a suite of annotations at the image, plant, or root scale at one or several time points. Plant ontologies are used to describe botanical entities that are relevant at the scale of root system architecture. An XML schema describes the features and constraints of RSML, and open-source packages have been developed in several languages (R, Excel, Java, Python, and C#) to enable researchers to integrate RSML files into popular research workflow.

  4. Fate map of Medicago truncatula root nodules.

    PubMed

    Xiao, Ting Ting; Schilderink, Stefan; Moling, Sjef; Deinum, Eva E; Kondorosi, Eva; Franssen, Henk; Kulikova, Olga; Niebel, Andreas; Bisseling, Ton

    2014-09-01

    Legume root nodules are induced by N-fixing rhizobium bacteria that are hosted in an intracellular manner. These nodules are formed by reprogramming differentiated root cells. The model legume Medicago truncatula forms indeterminate nodules with a meristem at their apex. This organ grows by the activity of the meristem that adds cells to the different nodule tissues. In Medicago sativa it has been shown that the nodule meristem is derived from the root middle cortex. During nodule initiation, inner cortical cells and pericycle cells are also mitotically activated. However, whether and how these cells contribute to the mature nodule has not been studied. Here, we produce a nodule fate map that precisely describes the origin of the different nodule tissues based on sequential longitudinal sections and on the use of marker genes that allow the distinction of cells originating from different root tissues. We show that nodule meristem originates from the third cortical layer, while several cell layers of the base of the nodule are directly formed from cells of the inner cortical layers, root endodermis and pericycle. The latter two differentiate into the uninfected tissues that are located at the base of the mature nodule, whereas the cells derived from the inner cortical cell layers form about eight cell layers of infected cells. This nodule fate map has then been used to re-analyse several mutant nodule phenotypes. This showed, among other things, that intracellular release of rhizobia in primordium cells and meristem daughter cells are regulated in a different manner.

  5. How tree roots respond to drought

    PubMed Central

    Brunner, Ivano; Herzog, Claude; Dawes, Melissa A.; Arend, Matthias; Sperisen, Christoph

    2015-01-01

    The ongoing climate change is characterized by increased temperatures and altered precipitation patterns. In addition, there has been an increase in both the frequency and intensity of extreme climatic events such as drought. Episodes of drought induce a series of interconnected effects, all of which have the potential to alter the carbon balance of forest ecosystems profoundly at different scales of plant organization and ecosystem functioning. During recent years, considerable progress has been made in the understanding of how aboveground parts of trees respond to drought and how these responses affect carbon assimilation. In contrast, processes of belowground parts are relatively underrepresented in research on climate change. In this review, we describe current knowledge about responses of tree roots to drought. Tree roots are capable of responding to drought through a variety of strategies that enable them to avoid and tolerate stress. Responses include root biomass adjustments, anatomical alterations, and physiological acclimations. The molecular mechanisms underlying these responses are characterized to some extent, and involve stress signaling and the induction of numerous genes, leading to the activation of tolerance pathways. In addition, mycorrhizas seem to play important protective roles. The current knowledge compiled in this review supports the view that tree roots are well equipped to withstand drought situations and maintain morphological and physiological functions as long as possible. Further, the reviewed literature demonstrates the important role of tree roots in the functioning of forest ecosystems and highlights the need for more research in this emerging field. PMID:26284083

  6. Distribution of expansins in graviresponding maize roots

    NASA Technical Reports Server (NTRS)

    Zhang, N.; Hasenstein, K. H.

    2000-01-01

    To test if expansins, wall loosening proteins that disrupt binding between microfibrils and cell wall matrix, participate in the differential elongation of graviresponding roots, Zea mays L. cv. Merit roots were gravistimulated and used for immunolocalization with anti-expansin. Western blots showed cross-reaction with two proteins of maize, one of the same mass as cucumber expansin (29 kDa), the second slightly larger (32 kDa). Maize roots contained mainly the larger protein, but both were found in coleoptiles. The expansin distribution in cucumber roots and hypocotyls was similar to the distribution in maize. Roots showed stronger expansin signals on the expanding convex side than the concave flank as early as 30 min after gravistimulation. Treatment with brefeldin A, a vesicle transport inhibitor, or the auxin transport inhibitor, naphthylphthalamic acid, showed delayed graviresponse and the appearance of differential staining. Our results indicate that expansins may be transported and secreted to cell walls via vesicles and function in wall expansion.

  7. Protein synthesis in geostimulated root caps

    NASA Technical Reports Server (NTRS)

    Feldman, L. J.

    1982-01-01

    A study is presented of the processes occurring in the root cap of corn which are requisite for the formation of root cap inhibitor and which can be triggered or modulated by both light and gravity. The results of this study indicate the importance of protein synthesis for light-induced gravitropic bending in roots. Root caps in which protein synthesis is prevented are unable to induce downward bending. This suggests that light acts by stimulating proteins which are necessary for the translation of the gravitropic stimulus into a growth response (downward bending). The turnover of protein with time was also examined in order to determine whether light acts by stimulating the synthesis of unique proteins required for downward growth. It is found that auxin in combination with light allows for the translation of the gravitropic stimulus into a growth response at least in part through the modification of protein synthesis. It is concluded that unique proteins are stimulated by light and are involved in promoting the downward growth in roots which are responding to gravity.

  8. an evaluation of techniques for root observations

    NASA Astrophysics Data System (ADS)

    Mohamed, Awaz; Monnier, Yogan; Stokes, Alexia

    2015-04-01

    An evaluation of techniques for root observations Below-ground processes play an essential role in ecosystem nutrient cycling and the global carbon budget (C) cycle because they regulate storage of large quantities of carbon. Quantifying root dynamics, that is, production, longevity, mortality and decomposition, is crucial to the understanding of ecosystem structure and function, and in predicting how ecosystems respond to climate variability. The necessity for accumulating information about root system growth is thus clear. However, we have a relatively poor understanding of the best method of observation, especially in the natural soil environment. The objective of this study is to compare four techniques of root observation, that is, manual scanner, smartphone scanner, flatbed scanner and classical observations, for determining the best technique. Root growth dynamics were measured in Rhizotrons. The project involves several field-sites situated in agroforests comprising hybrid walnut trees and pasture/crops along a climatic gradient in France. The results of this project will provide data allowing researchers to facilitate the choice of the most suitable observation method for their research.

  9. The role of hysteresis in modeling root water uptake, both for single root and root system models.

    NASA Astrophysics Data System (ADS)

    de Willigen, P.; Heinen, M.

    2009-04-01

    The water retention curve obtained by progressive extraction of water from an initially saturated soil (desorption) differs from that obtained by gradual addition of water to air-dry soil (absorption). This phenomenon is called hysteresis (Koorevaar et al., 1983). Common as its occurrence is, it is often neglected in the modeling of root water uptake. We will present here a model for the transport of water to a single root. The model solves Richard's equation in cylindrical coordinates where the water uptake rate is a function of the root water potential. The occurrence of hysteresis is accounted for by application of the modified dependent domain model developed by Mualem (1984) and used by Kool and Parker (1987). We will discuss the differences in results due to the inclusion of the hysteresis subroutine, when alternate wetting and drying cycles occur. The influence of soil type and transpiration reduction function will be discussed. The findings obtained for the single root model were used to upscale root water uptake to a root system. This is a part of the FUSSIM2 model of Heinen and de Willigen (1998) and Heinen (2001), where water transport in a soil profile is calculated. We will use an example for a soil profile where the root length density decreases exponentially with depth, and where again wetting and drying cycles alternate. References Heinen M., 2001. FUSSIM2: brief description of the simulation model and application to fertigation scenarios. Agronomie 21: 285-296. Heinen, M., and P. de Willigen, 1998. FUSSIM2 A two-dimensional simulation model for water flow, solute transport and root uptake of water and nutrients in partly unsaturated porous media, QASA No. 20, AB-DLO, Wageningen, The Netherlands, 140 p. Kool J.B. and J.C. Parker, 1987. Development and evaluation of closed form expressions for hysteretic soil hydraulic properties. Water Resour. Res. 23: 105 114. Koorevaar P., G. Menelik and C. Dirksen, 1983. Elements of soil physics. Elsevier

  10. Developmental anatomy and branching of roots of four Zeylanidium species (podostemaceae), with implications for evolution of foliose roots.

    PubMed

    Hiyama, Y; Tsukamoto, I; Imaichi, R; Kato, M

    2002-12-01

    Podostemaceae have markedly specialized and diverse roots that are adapted to extreme habitats, such as seasonally submerged or exposed rocks in waterfalls and rapids. This paper describes the developmental anatomy of roots of four species of Zeylanidium, with emphasis on the unusual association between root branching and root-borne adventitious shoots. In Z. subulatum and Z. lichenoides with subcylindrical or ribbon-like roots, the apical meristem distal (exterior) to a shoot that is initiated within the meristem area reduces and loses meristematic activity. This results in a splitting into two meristems that separate the parental root and lateral root (anisotomous dichotomy). In Z. olivaceum with lobed foliose roots, shoots are initiated in the innermost zone of the marginal meristem, and similar, but delayed, meristem reduction usually occurs, producing a parenchyma exterior to shoots located between root lobes. In some extreme cases, due to meristem recovery, root lobing does not occur, so the margin is entire. In Z. maheshwarii with foliose roots, shoots are initiated proximal to the marginal meristem and there is no shoot-root lobe association. Results suggest that during evolution from subcylindrical or ribbon-like roots to foliose roots, reduction of meristem exterior to a shoot was delayed and then arrested as a result of inward shifting of the sites of shoot initiation. The evolutionary reappearance of a protective tissue or root cap in Z. olivaceum and Z. maheshwarii in the Zeylanidium clade is implied, taking into account the reported molecular phylogeny and root-cap development in Hydrobryum.

  11. Root-soil air gap and resistance to water flow at the soil-root interface of Robinia pseudoacacia.

    PubMed

    Liu, X P; Zhang, W J; Wang, X Y; Cai, Y J; Chang, J G

    2015-12-01

    During periods of water deficit, growing roots may shrink, retaining only partial contact with the soil. In this study, known mathematical models were used to calculate the root-soil air gap and water flow resistance at the soil-root interface, respectively, of Robinia pseudoacacia L. under different water conditions. Using a digital camera, the root-soil air gap of R. pseudoacacia was investigated in a root growth chamber; this root-soil air gap and the model-inferred water flow resistance at the soil-root interface were compared with predictions based on a separate outdoor experiment. The results indicated progressively greater root shrinkage and loss of root-soil contact with decreasing soil water potential. The average widths of the root-soil air gap for R. pseudoacacia in open fields and in the root growth chamber were 0.24 and 0.39 mm, respectively. The resistance to water flow at the soil-root interface in both environments increased with decreasing soil water potential. Stepwise regression analysis demonstrated that soil water potential and soil temperature were the best predictors of variation in the root-soil air gap. A combination of soil water potential, soil temperature, root-air water potential difference and soil-root water potential difference best predicted the resistance to water flow at the soil-root interface.

  12. Variability of Root Traits in Spring Wheat Germplasm

    PubMed Central

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

    2014-01-01

    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

  13. Analysis of peptide uptake and location of root hair-promoting peptide accumulation in plant roots.

    PubMed

    Matsumiya, Yoshiki; Taniguchi, Rikiya; Kubo, Motoki

    2012-03-01

    Peptide uptake by plant roots from degraded soybean-meal products was analyzed in Brassica rapa and Solanum lycopersicum. B. rapa absorbed about 40% of the initial water volume, whereas peptide concentration was decreased by 75% after 24 h. Analysis by reversed-phase HPLC showed that number of peptides was absorbed by the roots during soaking in degraded soybean-meal products for 24 h. Carboxyfluorescein-labeled root hair-promoting peptide was synthesized, and its localization, movement, and accumulation in roots were investigated. The peptide appeared to be absorbed by root hairs and then moved to trichoblasts. Furthermore, the peptide was moved from trichoblasts to atrichoblasts after 24 h. The peptide was accumulated in epidermal cells, suggesting that the peptide may have a function in both trichoblasts and atrichoblasts.

  14. Cyanogen Metabolism in Cassava Roots: Impact on Protein Synthesis and Root Development

    PubMed Central

    Zidenga, Tawanda; Siritunga, Dimuth; Sayre, Richard T.

    2017-01-01

    Cassava (Manihot esculenta Crantz), a staple crop for millions of sub-Saharan Africans, contains high levels of cyanogenic glycosides which protect it against herbivory. However, cyanogens have also been proposed to play a role in nitrogen transport from leaves to roots. Consistent with this hypothesis, analyses of the distribution and activities of enzymes involved in cyanide metabolism provides evidence for cyanide assimilation, derived from linamarin, into amino acids in cassava roots. Both β-cyanoalanine synthase (CAS) and nitrilase (NIT), two enzymes involved in cyanide assimilation to produce asparagine, were observed to have higher activities in roots compared to leaves, consistent with their proposed role in reduced nitrogen assimilation. In addition, rhodanese activity was not detected in cassava roots, indicating that this competing means for cyanide metabolism was not a factor in cyanide detoxification. In contrast, leaves had sufficient rhodanese activity to compete with cyanide assimilation into amino acids. Using transgenic low cyanogen plants, it was shown that reducing root cyanogen levels is associated with elevated root nitrate reductase activity, presumably to compensate for the loss of reduced nitrogen from cyanogens. Finally, we overexpressed Arabidopsis CAS and NIT4 genes in cassava roots to study the feasibility of enhancing root cyanide assimilation into protein. Optimal overexpression of CAS and NIT4 resulted in up to a 50% increase in root total amino acids and a 9% increase in root protein accumulation. However, plant growth and morphology was altered in plants overexpressing these enzymes, demonstrating a complex interaction between cyanide metabolism and hormonal regulation of plant growth. PMID:28286506

  15. Hormone interactions during lateral root formation.

    PubMed

    Fukaki, Hidehiro; Tasaka, Masao

    2009-03-01

    Lateral root (LR) formation, the production of new roots from parent roots, is a hormone- and environmentally-regulated developmental process in higher plants. Physiological and genetic studies using Arabidopsis thaliana and other plant species have revealed the roles of several plant hormones in LR formation, particularly the role of auxin in LR initiation and primordium development, resulting in much progress toward understanding the mechanisms of auxin-mediated LR formation. However, hormone interactions during LR formation have been relatively underexamined. Recent studies have shown that the plant hormones, cytokinin and abscisic acid negatively regulate LR formation whereas brassinosteroids positively regulate LR formation. On the other hand, ethylene has positive and negative roles during LR formation. This review summarizes recent findings on hormone-regulated LR formation in higher plants, focusing on auxin as a trigger and on the other hormones in LR formation, and discusses the possible interactions among plant hormones in this developmental process.

  16. Aortic Root Enlargement or Sutureless Valve Implantation?

    PubMed Central

    Baikoussis, Nikolaos G.; Dedeilias, Panagiotis; Argiriou, Michalis

    2016-01-01

    Aortic valve replacement (AVR) in patients with a small aortic annulus is a challenging issue. The importance of prosthesis–patient mismatch (PPM) post aortic valve replacement (AVR) is controversial but has to be avoided. Many studies support the fact that PPM has a negative impact on short and long term survival. In order to avoid PPM, aortic root enlargement may be performed. Alternatively and keeping in mind that often some comorbidities are present in old patients with small aortic root, the Perceval S suturelles valve implantation could be a perfect solution. The Perceval sutureless bioprosthesis provides reasonable hemodynamic performance avoiding the PPM and providing the maximum of aortic orifice area. We would like to see in the near future the role of the aortic root enlargement techniques in the era of surgical implantation of the sutureless valve (SAVR) and the transcatheter valve implantation (TAVI). PMID:28028424

  17. Two stage surgical procedure for root coverage.

    PubMed

    George, Anjana Mary; Rajesh, K S; Hegde, Shashikanth; Kumar, Arun

    2012-07-01

    Gingival recession may present problems that include root sensitivity, esthetic concern, and predilection to root caries, cervical abrasion and compromising of a restorative effort. When marginal tissue health cannot be maintained and recession is deep, the need for treatment arises. This literature has documented that recession can be successfully treated by means of a two stage surgical approach, the first stage consisting of creation of attached gingiva by means of free gingival graft, and in the second stage, a lateral sliding flap of grafted tissue to cover the recession. This indirect technique ensures development of an adequate width of attached gingiva. The outcome of this technique suggests that two stage surgical procedures are highly predictable for root coverage in case of isolated deep recession and lack of attached gingiva.

  18. Roots Air Management System with Integrated Expander

    SciTech Connect

    Stretch, Dale; Wright, Brad; Fortini, Matt; Fink, Neal; Ramadan, Bassem; Eybergen, William

    2016-07-06

    PEM fuel cells remain an emerging technology in the vehicle market with several cost and reliability challenges that must be overcome in order to increase market penetration and acceptance. The DOE has identified the lack of a cost effective, reliable, and efficient air supply system that meets the operational requirements of a pressurized PEM 80kW fuel cell as one of the major technological barriers that must be overcome. This project leveraged Roots positive displacement development advancements and demonstrated an efficient and low cost fuel cell air management system. Eaton built upon its P-Series Roots positive displacement design and shifted the peak efficiency making it ideal for use on an 80kW PEM stack. Advantages to this solution include: • Lower speed of the Roots device eliminates complex air bearings present on other systems. • Broad efficiency map of Roots based systems provides an overall higher drive cycle fuel economy. • Core Roots technology has been developed and validated for other transportation applications. Eaton modified their novel R340 Twin Vortices Series (TVS) Roots-type supercharger for this application. The TVS delivers more power and better fuel economy in a smaller package as compared to other supercharger technologies. By properly matching the helix angle with the rotor’s physical aspect ratio, the supercharger’s peak efficiency can be moved to the operating range where it is most beneficial for the application. The compressor was designed to meet the 90 g/s flow at a pressure ratio of 2.5, similar in design to the P-Series 340. A net shape plastic expander housing with integrated motor and compressor was developed to significantly reduce the cost of the system. This integrated design reduced part count by incorporating an overhung expander and motor rotors into the design such that only four bearings and two shafts were utilized.

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

    PubMed Central

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

    2007-01-01

    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

  20. Composite Cucurbita pepo plants with transgenic roots as a tool to study root development

    PubMed Central

    Ilina, Elena L.; Logachov, Anton A.; Laplaze, Laurent; Demchenko, Nikolay P.; Pawlowski, Katharina; Demchenko, Kirill N.

    2012-01-01

    Background and Aims In most plant species, initiation of lateral root primordia occurs above the elongation zone. However, in cucurbits and some other species, lateral root primordia initiation and development takes place in the apical meristem of the parental root. Composite transgenic plants obtained by Agrobacterium rhizogenes-mediated transformation are known as a suitable model to study root development. The aim of the present study was to establish this transformation technique for squash. Methods The auxin-responsive promoter DR5 was cloned into the binary vectors pKGW-RR-MGW and pMDC162-GFP. Incorporation of 5-ethynyl-2′-deoxyuridine (EdU) was used to evaluate the presence of DNA-synthesizing cells in the hypocotyl of squash seedlings to find out whether they were suitable for infection. Two A. rhizogenes strains, R1000 and MSU440, were used. Roots containing the respective constructs were selected based on DsRED1 or green fluorescent protein (GFP) fluorescence, and DR5::Egfp-gusA or DR5::gusA insertion, respectively, was verified by PCR. Distribution of the response to auxin was visualized by GFP fluorescence or β-glucuronidase (GUS) activity staining and confirmed by immunolocalization of GFP and GUS proteins, respectively. Key Results Based on the distribution of EdU-labelled cells, it was determined that 6-day-old squash seedlings were suited for inoculation by A. rhizogenes since their root pericycle and the adjacent layers contain enough proliferating cells. Agrobacterium rhizogenes R1000 proved to be the most virulent strain on squash seedlings. Squash roots containing the respective constructs did not exhibit the hairy root phenotype and were morphologically and structurally similar to wild-type roots. Conclusions The auxin response pattern in the root apex of squash resembled that in arabidopsis roots. Composite squash plants obtained by A. rhizogenes-mediated transformation are a good tool for the investigation of root apical meristem