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Sample records for seedlings lactuca sativa

  1. Effects of kaurane diterpene derivatives on germination and growth of Lactuca sativa seedlings.

    PubMed

    Vieira, Henriete S; Takahashi, Jacqueline A; Pimenta, Lúcia P S; Boaventura, Maria Amélia D

    2005-01-01

    Kaurenoic and grandiflorenic acid, isolated from Wedelia paludosa (Asteraceae), some derivatives from these acids (alcohols, esters, amides, lactones, oximes) and other naturally occurring kaurane diterpenes were tested for their action on the growth of radical and shoot of Lactuca sativa. Gibberellic acid, GA3, a commercially available phytohormone, belonging to the same class of diterpenes, was also tested. Some of the tested substances showed a remarkable activity either in the inhibition or in stimulation of L. sativa growth. The activity, in some cases, was even higher than that of GA3.

  2. Regulation of cell division and growth in roots of Lactuca sativa L. seedlings by the Ent-Kaurene diterpenoid rabdosin B.

    PubMed

    Ding, Lan; Jing, Hongwei; Qin, Bo; Qi, Linlin; Li, Jing; Wang, Tao; Liu, Guoan

    2010-05-01

    Rabdosin B, an ent-kaurene diterpenoid purified from the air-dried aerial parts of Isodon japonica (Burm.f) Hara var. galaucocalyx (maxin) Hara, showed a biphasic, dose-dependent effect on root growth and a strong inhibitory effect on root hair development in lettuce seedlings (Lactuca sativa L.). Lower concentrations of rabdosin B (20-80 microM) significantly promoted root growth, but its higher levels at 120-200 microM, by contrast, had inhibitory effects. Additionally, all tested concentrations (10-40 microM) inhibited root hair development of seedlings in a dose-dependent manner. Further investigations on the underlying mechanism revealed that the promotion effect of rabdosin B at the lower concentrations resulted from increasing the cell length in the mature region and enhancing the mitotic activity of meristematic cells in seedlings' root tips. In contrast, rabdosin B at higher concentrations inhibited root growth by affecting both cell length in the mature region and division of meristematic cells. Comet assay and cell cycle analysis demonstrated that the decrease of mitotic activity of root meristematic cells was due to DNA damage induced cell cycle retardation of the G(2) phase and S phase at different times.

  3. Phytotoxic effects of leukamenin E (an ent-kaurene diterpenoid) on root growth and root hair development in Lactuca sativa L. seedlings.

    PubMed

    Ding, Lan; Qi, Linlin; Jing, Hongwei; Li, Juan; Wang, Wei; Wang, Tao

    2008-11-01

    Leukamenin E, an ent-kaurene diterpenoid isolated from Isodon racemosa (Hemsl) Hara, showed phytotoxic effects on root growth and root hair development of lettuce seedlings (Lactuca sativa L.). Lower concentrations (10 microM) of leukamenin E did not affect root growth, but at concentrations higher than 50 microM, the rate was inhibited. The influence of leukamenin E on root growth rate was closely correlated with alterations in the mitotic index. A low incidence of aberrant mitosis image was observed when lettuce roots were treated with higher concentrations (100 and 200 microM) of leukamenin E. This suggests that inhibition of root growth may be due to inhibition of cell division. All tested concentrations of the diterpenoid (10 microM or more) inhibited root hair development in a dose-dependent manner. At a concentration of 80 microM, leukamenin E completely blocked root hair initiation. Application of Ag(+)-an ethylene action inhibitor-to lettuce seedlings inhibited root hair elongation similar to the diterpenoid. Enhanced root hair length was stimulated by exogenous ethephon-an ethylene-releasing agent-and could be reversed by addition of leukamenin E. This suggests that leukamenin E may act as a potential ethylene action antagonist in the inhibition of lettuce root hair development. We conclude that leukamenin E may curb root hair development by interfering with ethylene action at concentrations above 10 microM and inhibits root growth via inhibition of cell division at concentrations above 50 microM.

  4. Effects of sodium nitroprusside (SNP) pretreatment on UV-B stress tolerance in lettuce (Lactuca sativa L.) seedlings.

    PubMed

    Esringu, Aslıhan; Aksakal, Ozkan; Tabay, Dilruba; Kara, Ayse Aydan

    2016-01-01

    Ultraviolet-B (UV-B) radiation is one of the most important abiotic stress factors that could influence plant growth, development, and productivity. Nitric oxide (NO) is an important plant growth regulator involved in a wide variety of physiological processes. In the present study, the possibility of enhancing UV-B stress tolerance of lettuce seedlings by the exogenous application of sodium nitroprusside (SNP) was investigated. UV-B radiation increased the activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), peroxidase (POD) and total phenolic concentrations, antioxidant capacity, and expression of phenylalanine ammonia lyase (PAL) gene in seedlings, but the combination of SNP pretreatment and UV-B enhanced antioxidant enzyme activities, total phenolic concentrations, antioxidant capacity, and PAL gene expression even more. Moreover, UV-B radiation significantly inhibited chlorophylls, carotenoid, gibberellic acid (GA), and indole-3-acetic acid (IAA) contents and increased the contents of abscisic acid (ABA), salicylic acid (SA), malondialdehyde (MDA), hydrogen peroxide (H2O2), and superoxide radical (O2•(-)) in lettuce seedlings. When SNP pretreatment was combined with the UV-B radiation, we observed alleviated chlorophylls, carotenoid, GA, and IAA inhibition and decreased content of ABA, SA, MDA, H2O2, and O2•(-) in comparison to non-pretreated stressed seedlings.

  5. High-Throughput Growth Prediction for Lactuca sativa L. Seedlings Using Chlorophyll Fluorescence in a Plant Factory with Artificial Lighting

    PubMed Central

    Moriyuki, Shogo; Fukuda, Hirokazu

    2016-01-01

    Poorly grown plants that result from differences in individuals lead to large profit losses for plant factories that use large electric power sources for cultivation. Thus, identifying and culling the low-grade plants at an early stage, using so-called seedlings diagnosis technology, plays an important role in avoiding large losses in plant factories. In this study, we developed a high-throughput diagnosis system using the measurement of chlorophyll fluorescence (CF) in a commercial large-scale plant factory, which produces about 5000 lettuce plants every day. At an early stage (6 days after sowing), a CF image of 7200 seedlings was captured every 4 h on the final greening day by a high-sensitivity CCD camera and an automatic transferring machine, and biological indices were extracted. Using machine learning, plant growth can be predicted with a high degree of accuracy based on biological indices including leaf size, amount of CF, and circadian rhythms in CF. Growth prediction was improved by addition of temporal information on CF. The present data also provide new insights into the relationships between growth and temporal information regulated by the inherent biological clock. PMID:27242805

  6. High-Throughput Growth Prediction for Lactuca sativa L. Seedlings Using Chlorophyll Fluorescence in a Plant Factory with Artificial Lighting.

    PubMed

    Moriyuki, Shogo; Fukuda, Hirokazu

    2016-01-01

    Poorly grown plants that result from differences in individuals lead to large profit losses for plant factories that use large electric power sources for cultivation. Thus, identifying and culling the low-grade plants at an early stage, using so-called seedlings diagnosis technology, plays an important role in avoiding large losses in plant factories. In this study, we developed a high-throughput diagnosis system using the measurement of chlorophyll fluorescence (CF) in a commercial large-scale plant factory, which produces about 5000 lettuce plants every day. At an early stage (6 days after sowing), a CF image of 7200 seedlings was captured every 4 h on the final greening day by a high-sensitivity CCD camera and an automatic transferring machine, and biological indices were extracted. Using machine learning, plant growth can be predicted with a high degree of accuracy based on biological indices including leaf size, amount of CF, and circadian rhythms in CF. Growth prediction was improved by addition of temporal information on CF. The present data also provide new insights into the relationships between growth and temporal information regulated by the inherent biological clock.

  7. Pb low doses induced genotoxicity in Lactuca sativa plants.

    PubMed

    Silva, S; Silva, P; Oliveira, H; Gaivão, I; Matos, M; Pinto-Carnide, O; Santos, C

    2017-03-01

    Soil and water contamination by lead (Pb) remains a topic of great concern, particularly regarding crop production. The admissible Pb values in irrigation water in several countries range from ≈0.1 to ≈5 mg L(-1). In order to evaluate putative effects of Pb within legal doses on crops growth, we exposed Lactuca sativa seeds and seedlings to increasing doses of Pb(NO3)2 up to 20 mg L(-1). The OECD parameter seed germination and seedling/plant growth were not affected by any of the Pb-concentrations used. However, for doses higher than 5 mg L(-1) significant DNA damage was detected: Comet assay detected DNA fragmentation at ≥ 5 mg L(-1) and presence of micronuclei (MN) were detected for 20 mg L(-1). Also, cell cycle impairment was observed for doses as low as 0.05 mg L(-1) and 0.5 mg L(-1) (mostly G2 arrest). Our data show that for the low doses of Pb used, the OECD endpoints were not able to detect toxicity, while more sensitive endpoints (related with DNA damage and mitotic/interphase disorders) identified genotoxic and cytostatic effects. Furthermore, the nature of the genotoxic effect was dependent on the concentration. Finally, we recommend that MN test and the comet assay should be included as sensitive endpoints in (eco)toxicological assays.

  8. Inhibitory effect of marine green algal extracts on germination of Lactuca sativa seeds.

    PubMed

    Choi, Jae-Suk; Choi, In Soon

    2016-03-01

    The allelopathic potential of nine green seaweed species was examined based on germination and seedling growth of lettuce (Lactuca sativa L.). Out of nine methanol extracts, Capsosiphon fulvescens and Monostroma nitidum extracts completely inhibited germination of L. sativa at 4 mg/filter paper after 24 hr of treatment. Water extracts of these seaweeds generally showed low anti-germination activities than methanol extracts. Of the nine water extracts, Enteromorpha linza extract completely inhibited L. sativa germination at 16 mg/filter paper after 24 hrs. To identify the primary active compounds, C. fulvescens. powder was successively fractionated according to polarity, and the main active agents against L. sativa were determined to be lipids (0.0% germination at 0.5 mg of lipids/paper disc). According to these results, extracts of C. fulvescens can be used to develop natural herbicidal agents and manage terrestrial weeds.

  9. Initiation and elongation of lateral roots in Lactuca sativa

    NASA Technical Reports Server (NTRS)

    Zhang, N.; Hasenstein, K. H.

    1999-01-01

    Lactuca sativa cv. Baijianye seedlings do not normally produce lateral roots, but removal of the root tip or application of auxin, especially indole-butyric acid, triggered the formation of lateral roots. Primordia initiated within 9 h and were fully developed after 24 h by activating the pericycle cells opposite the xylem pole. The pericycle cells divided asymmetrically into short and long cells. The short cells divided further to form primordia. The effect of root tip removal and auxin application was reversed by 6-benzylaminopurine at concentrations >10(-8) M. The cytokinin oxidase inhibitor N1-(2chloro4pyridyl)-N2-phenylurea also suppressed auxin-induced lateral rooting. The elongation of primary roots was promoted by L-alpha-(2-aminoethoxyvinyl) glycine and silver ions, but only the latter enhanced elongation of lateral roots. The data indicate that the induction of lateral roots is controlled by basipetally moving cytokinin and acropetally moving auxin. Lateral roots appear to not produce ethylene.

  10. Allelopathic and bioherbicidal potential of Cladonia verticillaris on the germination and growth of Lactuca sativa.

    PubMed

    Tigre, R C; Silva, N H; Santos, M G; Honda, N K; Falcão, E P S; Pereira, E C

    2012-10-01

    Responses to germination and initial growth of Lactuca sativa (lettuce) submitted to organic extracts and purified compounds of Cladonia verticillaris ("salambaia") were analyzed in this work. The experiments were conducted in laboratory conditions using extracts and pure compounds at different concentrations. None of the assays showed any influence on the germination of L. sativa seeds using C. verticillaris extracts; however, modifications in leaf area and seedling hypocotyl and root development occurred. In the growth experiments, seedlings exposed to ether or acetone extract showed diminished hypocotyl growth in detriment to the root stimulus, compared to controls. Increases in extract concentrations led to the formation of abnormal seedlings. To determine the allelochemicals of C. verticillaris, its principal components, fumarprotocetraric and protocetraric acids, were isolated and then analyzed by high performance liquid chromatography (HPLC). When the seedlings were exposed to the two acids separately, presented increased leaf area at all concentrations. In contrast, hypocotyl and root stimulus was observed only in the presence of protocetraric acid at different concentrations. Fumarprotocetraric as well as protocetraric acids, isolated and purified from C. verticillaris and Parmotrema dilatatum respectively, influenced the development of L. sativa seedlings at high concentrations, indicating a possible bioherbicide potential of these acids.

  11. Yield response of head lettuce (Lactuca sativa l. ) to ozone

    SciTech Connect

    Temple, P.J.; Taylor, O.C.; Benoit, L.F.

    1986-01-01

    Head lettuce (Lactuca sativa L. cv Empire) was grown in the field and exposed in open-top chambers to proportional increments of ozone (O/sub 3/) from full charcoal filtration (CF) to twice ambient O/sub 3/ concentrations(NF x 2.0). Severe foliar injury developed on young plants exposed to O/sub 3/ concentrations 1.7 and 2.0 times greater than ambient (seasonal 7 hr means of 0.104 and 0.128 ppm, respectively). These exposure levels also reduced total head weight 13 and 35%, respectively, compared with CF plants. Marketable-sized head weight was reduced 21 and 80%, respectively.

  12. Growth promotion of Lactuca sativa in response to volatile organic compounds emitted from diverse bacterial species.

    PubMed

    Fincheira, Paola; Venthur, Herbert; Mutis, Ana; Parada, Maribel; Quiroz, Andrés

    2016-12-01

    Agrochemicals are currently used in horticulture to increase crop production. Nevertheless, their indiscriminate use is a relevant issue for environmental and legal aspects. Alternative tools for reducing fertilizers and synthetic phytohormones are being investigated, such as the use of volatile organic compounds (VOCs) as growth inducers. Some soil bacteria, such as Pseudomonas and Bacillus, stimulate Arabidopsis and tobacco growth by releasing VOCs, but their effects on vegetables have not been investigated. Lactuca sativa was used as model vegetable to investigate bacterial VOCs as growth inducers. We selected 10 bacteria strains, belonging to Bacillus, Staphylococcus and Serratia genera that are able to produce 3-hydroxy-2-butanone (acetoin), a compound with proven growth promoting activity. Two-day old-seedlings of L. sativa were exposed to VOCs emitted by the selected bacteria grown in different media cultures for 7 days. The results showed that the VOCs released from the bacteria elicited an increase in the number of lateral roots, dry weight, root growth and shoot length, depending on the media used. Three Bacillus strains, BCT53, BCT9 and BCT4, were selected according to its their growth inducing capacity. The BCT9 strain elicited the greatest increases in dry weight and primary root length when L. sativa seedlings were subjected to a 10-day experiment. Finally, because acetoin only stimulated root growth, we suggest that other volatiles could be responsible for the growth promotion of L. sativa. In conclusion, our results strongly suggest that bacteria volatiles can be used as growth-inducers as alternative or complementary strategies for application in horticulture species.

  13. Potentiating Effects of Lactuca sativa on Pentobarbital-Induced Sleep.

    PubMed

    Ghorbani, Ahmad; Rakhshandeh, Hassan; Sadeghnia, Hamid Reza

    2013-01-01

    Traditionally, Lactuca sativa (lettuce) has been recommended for its hypnotic property. The present study was planned to investigate sleep-prolonging effect of this plant. The hydro-alcoholic extract (HAE) of lettuce and its water fraction (WF), ethyl acetate fraction (EAF), and n-butanol fraction (NBF) were administrated (IP) to mice 30 min before the pentobarbital injection. Moreover, both in-vivo and in-vitro toxicity of the extracts were determined. The quality of HAE and NBF was also evaluated using HPLC fingerprint. The HAE prolonged the pentobarbital-induced sleep duration at dose of 400 mg/Kg. The NBF was the only fraction which could increase the sleep duration and decrease sleep latency. The effects of NBF were comparable to those of induced by diazepam. The LD50-value for HAE was found to be 4.8 g/Kg. No neurotoxic effect was observed either by HAE or by its fractions in cultured PC12 neuron-like cells. The results suggest that lettuce potentiates pentobarbital hypnosis without major toxic effect. The main component(s) responsible for this effect is most likely to be non-polar agent(s) which found in NBF of this plant.

  14. Phytotoxicity studies with Lactuca sativa in soil and nutrient solution

    SciTech Connect

    Hulzebos, E.M.; Dirven-van Breemen, E.M.; Dis, W.A. van; Herbold, H.A.; Hoekstra, J.A.; Baerselman, R.; Gestel, C.A.M van ); Adema, D.M.M.; Henzen, L. )

    1993-06-01

    The toxicity of 76 priority pollutants to lettuce (Lactuca sativa) was determined in soil and in nutrient solution. In the first case a static and in the latter a semistatic exposure was established. Volatile and easily degradable compounds had high EC50 values in soil. In nutrient solution, however, several of these compounds were rather toxic. Quantitative structure activity relationships (QSARs) relating EC50 values to log K[sub ow] could be described for the toxicity in nutrient solution. Generally, the toxicity of the compounds increased with increasing lipophilicity. Deviations were caused by reactivity (N-containing compounds, double bonds in compounds), low lipophilicity, and EC50 values close to solubility. To relate toxicity in soil and nutrient solution, soil EC50 values were recalculated to values in the soil pore water using calculated adsorption coefficients. Estimated pore-water EC50 values showed a good correlation with values determined in nutrient solution but were not equal to these values. The differences can be attributed to differences in exposure.

  15. Halogenated auxins affect microtubules and root elongation in Lactuca sativa

    NASA Technical Reports Server (NTRS)

    Zhang, N.; Hasenstein, K. H.

    2000-01-01

    We studied the effect of 4,4,4-trifluoro-3-(indole-3-)butyric acid (TFIBA), a recently described root growth stimulator, and 5,6-dichloro-indole-3-acetic acid (DCIAA) on growth and microtubule (MT) organization in roots of Lactuca sativa L. DCIAA and indole-3-butyric acid (IBA) inhibited root elongation and depolymerized MTs in the cortex of the elongation zone, inhibited the elongation of stele cells, and promoted xylem maturation. Both auxins caused the plane of cell division to shift from anticlinal to periclinal. In contrast, TFIBA (100 micromolar) promoted elongation of primary roots by 40% and stimulated the elongation of lateral roots, even in the presence of IBA, the microtubular inhibitors oryzalin and taxol, or the auxin transport inhibitor naphthylphthalamic acid. However, TFIBA inhibited the formation of lateral root primordia. Immunostaining showed that TFIBA stabilized MTs orientation perpendicular to the root axis, doubled the cortical cell length, but delayed xylem maturation. The data indicate that the auxin-induced inhibition of elongation and swelling of roots results from reoriented phragmoplasts, the destabilization of MTs in elongating cells, and promotion of vessel formation. In contrast, TFIBA induced promotion of root elongation by enhancing cell length, prolonging transverse MT orientation, delaying cell and xylem maturation.

  16. Potentiating Effects of Lactuca sativa on Pentobarbital-Induced Sleep

    PubMed Central

    Ghorbani, Ahmad; Rakhshandeh, Hassan; Sadeghnia, Hamid Reza

    2013-01-01

    Traditionally, Lactuca sativa (lettuce) has been recommended for its hypnotic property. The present study was planned to investigate sleep-prolonging effect of this plant. The hydro-alcoholic extract (HAE) of lettuce and its water fraction (WF), ethyl acetate fraction (EAF), and n-butanol fraction (NBF) were administrated (IP) to mice 30 min before the pentobarbital injection. Moreover, both in-vivo and in-vitro toxicity of the extracts were determined. The quality of HAE and NBF was also evaluated using HPLC fingerprint. The HAE prolonged the pentobarbital-induced sleep duration at dose of 400 mg/Kg. The NBF was the only fraction which could increase the sleep duration and decrease sleep latency. The effects of NBF were comparable to those of induced by diazepam. The LD50-value for HAE was found to be 4.8 g/Kg. No neurotoxic effect was observed either by HAE or by its fractions in cultured PC12 neuron-like cells. The results suggest that lettuce potentiates pentobarbital hypnosis without major toxic effect. The main component(s) responsible for this effect is most likely to be non-polar agent(s) which found in NBF of this plant. PMID:24250615

  17. Anxiolytic property of hydro-alcohol extract of Lactuca sativa and its effect on behavioral activities of mice.

    PubMed

    Harsha, Singapura Nagesh; Anilakumar, Kandangath Raghavan

    2013-01-01

    Lactuca sativa, belonging to the Asteraceae family, is a leafy vegetable known for its medicinal properties. This study aimed to understand the mechanism of Lactuca sativa extract with respect to pharmacological action.We investigated the anxiolytic effects of hydro-alcoholic extract of leaves of Lactuca sativa on mice. The behavioral tests performed on mice models to assess anti-anxiety properties were: open field test (OFT), elevated plus maze test (EPM), elevated T maze test, and marble burying test. Increased locomotor activity and time spent in the "open-arm" were observed in extract fed group. Malondialdehyde (MDA) and nitrite levels were decreased, catalase and glutathione levels were increased in Lactuca sativa treated mice. The data obtained in the present study suggests that the extract of Lactuca sativa can afford significant protection against anxiolytic activity.

  18. TOXICITY OF METHYL-TERT BYTYL ETHER (MTBE) TO PLANTS (AVENA SATIVA, ZEA MAYS, TRITICUM AESTIVUM, AND LACTUCA SATIVA)

    EPA Science Inventory

    Effects of Methyl tert-butyl ether (MTBE) on the germination of seeds and growth of the plant were studied in some laboratory experiments. Test plants were wild oat (Avena sative), sweet corn (Zea mays), wheat (Triticum aestivum), and lettuce (Lactuca sativa). Seed germination,...

  19. Development of genomic SSR markers for fingerprinting lettuce (Lactuca sativa L.) cultivars and mapping genes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background: Lettuce (Lactuca sativa L.) is the major vegetable from the group of leafy vegetables. Several types of molecular markers were developed that are effictively used in lettuce breeding and genetic studies. However only a very limited number of microsattelite-based markers are publicly avai...

  20. Semi-high throughput screening for potential drought-tolerance in lettuce (Lactuca sativa) germplasm collections

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This protocol describes a method by which a large collection of the leafy green vegetable lettuce (Lactuca sativa L.) germplasm was screened for likely drought-tolerance traits. Fresh water availability for agricultural use is a growing concern across the United States as well as many regions of th...

  1. SSH reveals a linkage between a senescence-associated protease and Verticillium wilt symptom development in lettuce (Lactuca sativa)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Suppression subtractive hybridization (SSH) was employed to identify lettuce (Lactuca sativa) genes that are differentially expressed in symptomatic leaves infected with Verticillium dahliae. Genes expressed only in symptomatic leaves included those with homology to pathogenesis-related (PR) protei...

  2. Reduced allelopathic inhibition of lettuce (Lactuca sativa) growth caused by velvet bean (Mucuna pruriens) under 3D-clinorotation.

    PubMed

    Tomita-Yokotani, Kaori; Fujii, Yoshiharu; Hashimoto, Hirofumi; Yamashita, Masamichi

    2003-06-01

    Allelopathy between Mucuna pruriens (velvet bean) and Lactuca sativa (lettuce) was studied under 3D-clinorotation. Growth of both roots and shoots of lettuce seedlings was suppressed by the presence of velvet bean. The degree of suppression was less on the clinostat compared to the normal static earth gravity. L-DOPA (L-3, 4-dihydroxyphenylalanine) is known to be a major substance in allelopathy of velvet bean. Amount of L-DOPA diffused out from a sintered filter paper into agar medium was compared between clinorotation and control group, and found no significant difference. It was concluded that some factors related to release, transport, and sensing phenomena of allelopathic substances may be responsible to the new findings in this study.

  3. [Analysis of the mineral elements of Lactuca sativa under the condition of different spectral components].

    PubMed

    Chen, Xiao-Li; Guo, Wen-Zhong; Xue, Xu-Zhang; Wang, Li-Chun; Li, Liang; Chen, Fei

    2013-08-01

    Mineral elements absorption and content of Lactuca sativa under different spectral component conditions were studied by ICP-AES technology. The results showed that: (1) For Lactuca sativa, the average proportion for Ca : Mg : K : Na : P was 5.5 : 2.5 : 2.3 : 1.5 : 1.0, the average proportion for Fe : Mn : Zn : Cu : B was 25.9 : 5.9 : 2.8 : 1.1 : 1.0; (2) The absorptions for K, P, Ca, Mg and B are the largest under the LED treatment R/B = 1 : 2.75, red light from fluorescent lamps and LED can both promote the absorptions of Fe and Cu; (3)The LED treatments exhibiting relatively higher content of mineral elements are R/B = 1 : 2.75 and R/W = 1 : 1 while higher dry matter accumulations are R/B = 1 : 2.75 and B/W = 1 : 1.

  4. Plastid transformation in lettuce (Lactuca sativa L.) by biolistic DNA delivery.

    PubMed

    Ruhlman, Tracey A

    2014-01-01

    The interest in producing pharmaceutical proteins in a nontoxic plant host has led to the development of an approach to express such proteins in transplastomic lettuce (Lactuca sativa L.). A number of therapeutic proteins and vaccine antigen candidates have been stably integrated into the lettuce plastid genome using biolistic DNA delivery. High levels of accumulation and retention of biological activity suggest that lettuce may provide an ideal platform for the production of biopharmaceuticals.

  5. [Effect of outer space factors on lettuce seeds (Lactuca sativa) flown on "Kosmos" biosatellites].

    PubMed

    Nevzgodina, L V; Maksimova, E N; Akatov, Iu A; Kaminskaia, E V; Marennyĭ, A M

    1990-01-01

    The effect of cosmic radiation on air-dry lettuce (Lactuca sativa) seeds was investigated. It was attempted to discriminate the effects of cosmic ionizing radiation per se and its combination with solar light radiation. It was found that the number of aberrant cells in the seeds exposed to solar light was smaller than that of cells chielded with 0.0008 to 0.0035 g/cm2 foil which could be attributed to photoreactivity.

  6. Phyotoxicity of diesel soil contamination on the germination of Lactuca sativa and Ipomoea batatas.

    PubMed

    Fatokun, Kayode; Lewu, Francis Bayo; Zharare, Godfrey Elijah

    2015-11-01

    Phytotoxic effect of diesel contaminated soil on germination rate of Lactuca sativa and Ipomoea batatas, at two concentrations ranges (0-6ml and 0-30ml), were investigated and compared. Diesel soil contamination was simulated and soil samples were taken from contaminated soil at 1, 5,10, 15, 25, 50, 75 and 100 days should be after planting. The result showed that in both plant species, diesel inhibited germination in a concentration dependent manner, Also, the influence of diesel contamination diminished with increased time duration; suggesting possible reduction in diesel toxicity over time. However, germination of lettuce was significant and negatively correlated (r2 = -0.941) with diesel contamination as compared to sweet potato (r2 = -0.638).Critical concentration of diesel in relation to seed germination of L. sativa was lower than vegetative germination of I. batatas, indicating that germination of I. batatas was less sensitive to diesel contamination as compared to L. sativa.

  7. The allelopathic effects of invasive plant Solidago canadensis on seed germination and growth of Lactuca sativa enhanced by different types of acid deposition.

    PubMed

    Wang, Congyan; Xiao, Hongguang; Zhao, Lulu; Liu, Jun; Wang, Lei; Zhang, Fei; Shi, Yanchun; Du, Daolin

    2016-04-01

    Invasive species can exhibit allelopathic effects on native species. Meanwhile, the types of acid deposition are gradually changing. Thus, the allelopathic effects of invasive species on seed germination and growth of native species may be altered or even enhanced under conditions with diversified acid deposition. This study aims to assess the allelopathic effects (using leaves extracts) of invasive plant Solidago canadensis on seed germination and growth of native species Lactuca sativa treated with five types of acid deposition with different SO4(2-) to NO3(-) ratios (1:0, sulfuric acid; 5:1, sulfuric-rich acid; 1:1, mixed acid; 1:5, nitric-rich acid; 0:1, nitric acid). Solidago canadensis leaf extracts exhibited significantly allelopathic effects on germination index, vigor index, and germination rate index of L. sativa. High concentration of S. canadensis leaf extracts also similarly exhibited significantly allelopathic effects on root length of L. sativa. This may be due to that S. canadensis could release allelochemicals and then trigger allelopathic effects on seed germination and growth of L. sativa. Acid deposition exhibited significantly negative effects on seedling biomass, root length, seedling height, germination index, vigor index, and germination rate index of L. sativa. This may be ascribed to the decreased soil pH values mediated by acid deposition which could produce toxic effects on seedling growth. Sulfuric acid deposition triggered more toxic effects on seedling biomass and vigor index of L. sativa than nitric acid deposition. This may be attributing to the difference in exchange capacity with hydroxyl groups (OH(-)) between SO4(2-) and NO3(-) as well as the fertilizing effects mediated by nitric deposition. All types of acid deposition significantly enhanced the allelopathic effects of S. canadensis on root length, germination index, vigor index, and germination rate index of L. sativa. This may be due to the negatively synergistic effects of

  8. Acinetobacter lactucae sp. nov., isolated from iceberg lettuce (Asteraceae: Lactuca sativa).

    PubMed

    Rooney, Alejandro P; Dunlap, Christopher A; Flor-Weiler, Lina B

    2016-09-01

    Strain NRRL B-41902T and three closely related strains were isolated from iceberg lettuce. The strain was found to consist of strictly aerobic, Gram-stain-negative rods that formed cocci in late stationary phase. 16S rRNA gene sequence analysis showed that strain NRRL B-41902T was most closely related to species within the genera Acinetobacter, and that a grouping of it and the three other closely related strains was most closely related to the type strain of Acinetobacter pittii, which was also confirmed through a phylogenomic analysis. Moreover, in silico DNA-DNA hybridization analysis revealed a substantial amount of genomic divergence (39.1 %) between strain NRRL B-41902T and the type strain of A. pittii, which is expected if the strains represent distinct species. Further phenotypic analysis revealed that strain NRRL B-41902T was able to utilize a combination of l-serine, citraconic acid and citramalic acid, which differentiated it from other, closely related Acinetobacter species. Therefore, strain NRRL B-41902T (=CCUG 68785T) is proposed as the type strain of a novel species, Acinetobacter lactucae sp. nov.

  9. Impact of non-functionalized and amino-functionalized multiwall carbon nanotubes on pesticide uptake by lettuce (Lactuca sativa L.).

    PubMed

    Hamdi, Helmi; De La Torre-Roche, Roberto; Hawthorne, Joseph; White, Jason C

    2015-03-01

    The effect of non-functionalized and amino-functionalized multiwall carbon nanotube (CNT) exposure, as well as the impact of CNT presence on coexistent pesticide accumulation, was investigated in lettuce (Lactuca sativa L.). Lettuce seeds were sown directly into CNT-amended vermiculite (1000 mg L(-1)) to monitor phytotoxicity during germination and growth. During growth, lettuce seedlings were subsequently exposed to chlordane (cis-chlordane [CS], trans-chlordane [TC] and trans-nonachlor [TN]) and p,p'-DDE (all at 100 ng/L) in the irrigation solution for a 19-d growth period. CNT exposure did not significantly influence seed germination (82-96%) or plant growth. Similarly, pesticide exposure had no impact on plant growth, total pigment production or tissue lipid peroxidation. After 19 d, the root content of total chlordane and p,p'-DDE was 390 and 73.8 µg g(-1), respectively; in plants not exposed to CNTs, the shoot levels were 1.58 and 0.40 µg g(-1), respectively. The presence and type of CNT significantly influenced pesticide availability to lettuce seedlings. Non-functionalized CNT decreased the root and shoot pesticide content by 88% and 78%, respectively, but amino-functionalized CNT effects were significantly more modest, with decreases of 57% in the roots and 23% in the shoots, respectively. The presence of humic acid completely reversed the reduced accumulation of pesticides induced by amino-functionalized CNT, likely due to strong competition over adsorption sites on the nanomaterial (NM). These findings have implications for food safety and for the use of engineered NMs in agriculture, especially with leafy vegetables.

  10. Toxic effects of environmental pollutants: Comparative investigation using Allium cepa L. and Lactuca sativa L.

    PubMed

    Silveira, Graciele Lurdes; Lima, Maria Gabriela Franco; Reis, Gabriela Barreto Dos; Palmieri, Marcel José; Andrade-Vieria, Larissa Fonseca

    2017-03-21

    Studies that help understand the mechanisms of action of environmental pollutants are extremely important in environmental toxicology. In this context, assays using plants as models stand out for their simplicity and low performance cost. Among the plants used for this purpose, Allium cepa L. is the model most commonly applied for cytogenotoxic tests, while Lactuca sativa L., already widely used in phytotoxic investigations, has been gaining prominence in cytotoxic analyses. The present study aimed to compare the responses of A. cepa and L. sativa via macroscopic (root growth) and microscopic analyses (cell cycle and DNA fragmentation via TdT-mediated deoxy-uracil nick and labeling (TUNEL) and comet assays) after exposure of their roots to environmental pollutants with known cytogenotoxic mechanisms. Both species presented sensitive and efficient response to the applied tests after exposure to the DNA-alkylating agent Methyl Methanesulfonate (MMS), the heavy metal Cadmium, the aluminum industry waste Spent Potliner (SPL) and the herbicide Atrazine. However, they differed regarding the responses to the evaluated endpoints. Overall, A. cepa was more efficient in detecting clastogenic changes, arising from DNA breakage, while L. sativa rather detected aneugenic alterations, related to chromosome segregation in mitosis. In the tests applied to verify DNA fragmentation (comet and TUNEL assays), A. cepa presented higher sensitivity. In conclusion, both models are efficient to evaluate toxicological risks of environmental pollutants.

  11. Phytohormone profile in Lactuca sativa and Brassica oleracea plants grown under Zn deficiency.

    PubMed

    Navarro-León, Eloy; Albacete, Alfonso; Torre-González, Alejandro de la; Ruiz, Juan M; Blasco, Begoña

    2016-10-01

    Phytohormones, structurally diverse compounds, are involved in multiple processes within plants, such as controlling plant growth and stress response. Zn is an essential micronutrient for plants and its deficiency causes large economic losses in crops. Therefore, the purpose of this study was to analyse the role of phytohormones in the Zn-deficiency response of two economically important species, i.e. Lactuca sativa and Brassica oleracea. For this, these two species were grown hydroponically with different Zn-application rates: 10 μM Zn as control and 0.1 μM Zn as deficiency treatment and phytohormone concentration was determined by U-HPLC-MS. Zn deficiency resulted in a substantial loss of biomass in L. sativa plants that was correlated with a decline in growth-promoting hormones such as indole-3-acetic acid (IAA), cytokinins (CKs), and gibberellins (GAs). However these hormones increased or stabilized their concentrations in B. oleracea and could help to maintain the biomass in this species. A lower concentration of stress-signaling hormones such as ethylene precursor aminocyclopropane-1-carboxylic acid (ACC), abscisic acid (ABA), salicylic acid (SA) and jasmonic acid (JA) and also CKs might be involved in Zn uptake in L. sativa while a rise in GA4, isopentenyl adenine (iP), and ACC and a fall in JA and SA might contribute to a better Zn-utilization efficiency (ZnUtE), as observed in B. oleracea plants.

  12. Development of EST-SSR markers for the study of population structure in lettuce (Lactuca sativa L.).

    PubMed

    Simko, Ivan

    2009-01-01

    A set of 61 simple sequence repeat (SSR) markers was developed from the 19,523 Lactuca sativa and Lactuca serriola unigenes. Approximately 4.5% of the unigenes contained a perfect SSR at least 20 bp long, corresponding to roughly 1 perfect SSR per 14.7 kb. Marker polymorphism was tested on a set comprising 96 accessions representing all major horticultural types and 3 wild species (L. serriola, Lactuca saligna, and Lactuca virosa). Both the average marker heterozygosity (UHe = 0.32) and the number of different alleles per locus (Na = 3.56) were significantly reduced in expressed sequence tag (EST)-SSRs as compared with anonymous SSRs (UHe = 0.59, Na = 5.53). Marker transfer rate to the wild species corresponded to the decreasing sexual compatibility with L. sativa and was higher for EST-SSRs (100% L. serriola, 87% L. saligna, and 75% L. virosa) than for anonymous SSRs (93%, 66%, and 42%, respectively). Assessment of population structure among 90 L. sativa cultivars with SSRs was in good agreement with classification into the horticultural types. The average marker heterozygosity was smallest in iceberg (0.097), Latin (0.140), and romaine-type (0.151) cultivars while highest in leaf (green leaf 0.208 and red leaf 0.240) lettuces. The level of marker heterozygosity is in accord with morphological variability observed in different horticultural types.

  13. 4,4,4-trifluoro-3-(indole-3-)butyric acid promotes root elongation in Lactuca sativa independent of ethylene synthesis and pH

    NASA Technical Reports Server (NTRS)

    Zhang, Nenggang; Hasenstein, Karl H.

    2002-01-01

    We studied the mode of action of 4,4,4-trifluoro-3- (indole-3-) butyric acid (TFIBA), a recently described root growth stimulator, on primary root growth of Lactuca sativa L. seedlings. TFIBA (100 micromoles) promoted elongation of primary roots by 40% in 72 h but inhibited hypocotyl growth by 35%. TFIBA induced root growth was independent of pH. TFIBA did not affect ethylene production, but reduced the inhibitory effect of ethylene on root elongation. TFIBA promoted root growth even in the presence of the ethylene biosynthesis inhibitor L-alpha-(2-aminoethoxyvinyl)glycine. TFIBA and the ethylene-binding inhibitor silver thiosulphate (STS) had a similar effect on root elongation. The results indicate that TFIBA-stimulated root elongation was neither pH-dependent nor related to inhibition of ethylene synthesis, but was possibly related to ethylene action.

  14. Toxic effects of copper-based nanoparticles or compounds to lettuce (Lactuca sativa) and alfalfa (Medicago sativa).

    PubMed

    Hong, Jie; Rico, Cyren M; Zhao, Lijuan; Adeleye, Adeyemi S; Keller, Arturo A; Peralta-Videa, Jose R; Gardea-Torresdey, Jorge L

    2015-01-01

    The increased production and use of nanoparticles (NPs) has generated concerns about their impact on living organisms. In this study, nCu, bulk Cu, nCuO, bulk CuO, Cu(OH)2 (CuPRO 2005, Kocide 3000), and CuCl2 were exposed for 15 days to 10 days-old hydroponically grown lettuce (Lactuca sativa) and alfalfa (Medicago sativa). Each compound was applied at 0, 5, 10, and 20 mg L(-1). At harvest, we measured the size of the plants and determined the concentration of Cu, macro and microelements by using ICP-OES. Catalase and ascorbate peroxidase activity was also determined. Results showed that all Cu NPs/compounds reduced the root length by 49% in both plant species. All Cu NPs/compounds increased Cu, P, and S (>100%, >50%, and >20%, respectively) in alfalfa shoots and decreased P and Fe in lettuce shoot (>50% and >50%, respectively, excluding Fe in CuCl2 treatment). Biochemical assays showed reduced catalase activity in alfalfa (root and shoot) and increased ascorbate peroxidase activity in roots of both plant species. Results suggest that Cu NPs/compounds not only reduced the size of the plants but altered nutrient content and enzyme activity in both plant species.

  15. Toxic Effects of Copper-based Nanoparticles or Compounds to Lettuce (Lactuca sativa) and Alfalfa (Medicago sativa)

    PubMed Central

    Hong, Jie; Rico, Cyren; Zhao, Lijuan; Adeleye, Adeyemi S.; Keller, Arturo A.; Peralta-Videa, Jose R.; Gardea-Torresdey, Jorge L.

    2014-01-01

    The increased production and use of nanoparticles (NPs) has generated concerns about their impact on living organisms. In this study, nCu, bulk Cu, nCuO, bulk CuO, Cu(OH)2 (CuPRO 2005, Kocide 3000), and CuCl2 were exposed for 15 days to 10 day-old hydroponically grown lettuce (Lactuca sativa) and alfalfa (Medicago sativa). Each compound was applied at 0, 5, 10, and 20 mg/L. At harvest, we measured the size of the plants and determined the concentration of Cu, macro and microelements by using ICP-OES. Catalase and ascorbate peroxidase activity was also determined. Results showed that all Cu NPs/compounds reduced the root length by 49% in both plant species. All Cu NPs/compounds increased Cu, P, and S (>100%, >50%, and >20%, respectively) in alfalfa shoots and decreased P and Fe in lettuce shoot (>50% and >50%, respectively, excluding Fe in CuCl2 treatment). Biochemical assays showed reduced catalase activity in alfalfa (root and shoot) and increased ascorbate peroxidase activity in roots of both plant species. Results suggest that Cu NPs/compounds not only reduced the size of the plants but altered nutrient content and enzyme activity in both plant species. PMID:25474419

  16. An assessment of the role of ethylene in mediating lettuce (Lactuca sativa) root growth at high temperatures.

    PubMed

    Qin, L; He, J; Lee, S K; Dodd, I C

    2007-01-01

    Growth of temperate lettuce (Lactuca sativa) plants aeroponically in tropical greenhouses under ambient root-zone temperatures (A-RZTs) exposes roots to temperatures of up to 40 degrees C during the middle of the day, and severely limits root and shoot growth. The role of ethylene in inhibiting growth was investigated with just-germinated (24-h-old) seedlings in vitro, and 10-d-old plants grown aeroponically. Compared with seedlings maintained at 20 degrees C, root elongation in vitro was inhibited by 39% and root diameter increased by 25% under a temperature regime (38 degrees C/24 degrees C for 7 h/17 h) that simulated A-RZT in the greenhouse. The effects on root elongation were partially alleviated by supplying the ethylene biosynthesis inhibitors aminooxyacetic acid (100-500 microM) or aminoisobutyric acid (5-100 microM) to the seedlings. Application of the ethylene precursor 1-aminocyclopropane-1-carboxylic acid to seedlings grown at 20 degrees C mimicked the high temperature effects on root elongation (1 microM) and root diameter (1 mM). Compared with plants grown at a constant 20 degrees C root-zone temperature, A-RZT plants showed decreased stomatal conductance, leaf relative water content, photosynthetic CO(2) assimilation, shoot and root biomass, total root length, the number of root tips, and root surface area, but increased average root diameter. Addition of 10 microM ACC to the nutrient solution of plants grown at a constant 20 degrees C root-zone temperature mimicked the effects of A-RZT on these parameters but did not influence relative water content. Addition of 30 microM aminoisobutyric acid or 100 microM aminooxyacetic acid to the nutrient solution of A-RZT plants increased stomatal conductance and relative water content and decreased average root diameter, but had no effect on other root parameters or root and shoot biomass or photosynthetic CO(2) assimilation. Although ethylene is important in regulating root morphology and elongation at A

  17. Toxicity of the effluent from an anaerobic bioreactor treating cereal residues on Lactuca sativa.

    PubMed

    Young, Brian Jonathan; Riera, Nicolás Iván; Beily, María Eugenia; Bres, Patricia Alina; Crespo, Diana Cristina; Ronco, Alicia Estela

    2012-02-01

    Effluents generated during the process of anaerobic digestion should be treated before their disposal into the environment. The aim of this study was evaluating the effectiveness of the effluent treatment system from an anaerobic bioreactor, assessing the toxicity reduction with the Lactuca sativa seed germination and root elongation inhibition test. Three sampling points were selected along the effluent treatment system: inflow into the first treatment pond, outflow from the third pond and recirculated flow to the bioreactor. Effluent dilutions tested for each sampling point were 25% and 50% (v/v), undiluted sample and controls. The pH, conductivity, temperature, dissolved oxygen, BOD₅ and COD were measured. The decrease in the organic and inorganic loads was correlated with a reduction in the phytotoxicity. The use of the seed toxicity test allows evaluating the quality and effectiveness of the studied effluent treatment system.

  18. Plastid transformation in lettuce (Lactuca sativa L.) by polyethylene glycol treatment of protoplasts.

    PubMed

    Lelivelt, Cilia L C; van Dun, Kees M P; de Snoo, C Bastiaan; McCabe, Matthew S; Hogg, Bridget V; Nugent, Jacqueline M

    2014-01-01

    A detailed protocol for PEG-mediated plastid transformation of Lactuca sativa cv. Flora, using leaf protoplasts, is described. Successful plastid transformation using protoplasts requires a large number of viable cells, high plating densities, and an efficient regeneration system. Transformation was achieved using a vector that targets genes to the trnI/trnA intergenic region of the lettuce plastid genome. The aadA gene, encoding an adenylyltransferase enzyme that confers spectinomycin resistance, was used as a selectable marker. With the current method, the expected transformation frequency is 1-2 spectinomycin-resistant cell lines per 10(6) viable protoplasts. Fertile, diploid, homoplasmic, plastid-transformed lines were obtained. Transmission of the plastid-encoded transgene to the T1 generation was demonstrated.

  19. Transfer and expression of the rabbit defensin NP-1 gene in lettuce (Lactuca sativa).

    PubMed

    Song, D; Xiong, X; Tu, W F; Yao, W; Liang, H W; Chen, F J; He, Z Q

    2017-01-23

    Lettuce (Lactuca sativa L.) is an annual plant of the daisy family, Asteraceae, with high food and medicinal value. However, the crop is susceptible to several viruses that are transmitted by aphids and is highly vulnerable to post-harvest diseases, as well as insect and mammal pests and fungal and bacterial diseases. Here, the rabbit defensin gene NP-1 was transferred into lettuce by Agrobacterium-mediated transformation to obtain a broad-spectrum disease-resistant lettuce. Transgenic lettuce plants were selected and regenerated on selective media. The presence of the NP-1 gene in these plants was confirmed by western blot analyses. Resistance tests revealed native defensin NP-1 expression conferred partial resistance to Bacillus subtilis and Pseudomonas aeruginosa, which suggests new possibilities for lettuce disease resistance.

  20. RNAseq-based transcriptome analysis of Lactuca sativa infected by the fungal necrotroph Botrytis cinerea.

    PubMed

    De Cremer, Kaat; Mathys, Janick; Vos, Christine; Froenicke, Lutz; Michelmore, Richard W; Cammue, Bruno P A; De Coninck, Barbara

    2013-11-01

    The fungal pathogen Botrytis cinerea establishes a necrotrophic interaction with its host plants, including lettuce (Lactuca sativa), causing it to wilt, collapse and eventually dry up and die, which results in serious economic losses. Global expression profiling using RNAseq and the newly sequenced lettuce genome identified a complex network of genes involved in the lettuce-B. cinerea interaction. The observed high number of differentially expressed genes allowed us to classify them according to the biological pathways in which they are implicated, generating a holistic picture. Most pronounced were the induction of the phenylpropanoid pathway and terpenoid biosynthesis, whereas photosynthesis was globally down-regulated at 48 h post-inoculation. Large-scale comparison with data available on the interaction of B. cinerea with the model plant Arabidopsis thaliana revealed both general and species-specific responses to infection with this pathogen. Surprisingly, expression analysis of selected genes could not detect significant systemic transcriptional alterations in lettuce leaves distant from the inoculation site. Additionally, we assessed the response of these lettuce genes to a biotrophic pathogen, Bremia lactucae, revealing that similar pathways are induced during compatible interactions of lettuce with necrotrophic and biotrophic pathogens.

  1. Elucidating the genetic basis of antioxidant status in lettuce (Lactuca sativa)

    PubMed Central

    Damerum, Annabelle; Selmes, Stacey L; Biggi, Gaia F; Clarkson, Graham JJ; Rothwell, Steve D; Truco, Maria José; Michelmore, Richard W; Hancock, Robert D; Shellcock, Connie; Chapman, Mark A; Taylor, Gail

    2015-01-01

    A diet rich in phytonutrients from fruit and vegetables has been acknowledged to afford protection against a range of human diseases, but many of the most popular vegetables are low in phytonutrients. Wild relatives of crops may contain allelic variation for genes determining the concentrations of these beneficial phytonutrients, and therefore understanding the genetic basis of this variation is important for breeding efforts to enhance nutritional quality. In this study, lettuce recombinant inbred lines, generated from a cross between wild and cultivated lettuce (Lactuca serriola and Lactuca sativa, respectively), were analysed for antioxidant (AO) potential and important phytonutrients including carotenoids, chlorophyll and phenolic compounds. When grown in two environments, 96 quantitative trait loci (QTL) were identified for these nutritional traits: 4 for AO potential, 2 for carotenoid content, 3 for total chlorophyll content and 87 for individual phenolic compounds (two per compound on average). Most often, the L. serriola alleles conferred an increase in total AOs and metabolites. Candidate genes underlying these QTL were identified by BLASTn searches; in several cases, these had functions suggesting involvement in phytonutrient biosynthetic pathways. Analysis of a QTL on linkage group 3, which accounted for >30% of the variation in AO potential, revealed several candidate genes encoding multiple MYB transcription factors which regulate flavonoid biosynthesis and flavanone 3-hydroxylase, an enzyme involved in the biosynthesis of the flavonoids quercetin and kaempferol, which are known to have powerful AO activity. Follow-up quantitative RT-PCR of these candidates revealed that 5 out of 10 genes investigated were significantly differentially expressed between the wild and cultivated parents, providing further evidence of their potential involvement in determining the contrasting phenotypes. These results offer exciting opportunities to improve the nutritional

  2. Elucidating the genetic basis of antioxidant status in lettuce (Lactuca sativa).

    PubMed

    Damerum, Annabelle; Selmes, Stacey L; Biggi, Gaia F; Clarkson, Graham Jj; Rothwell, Steve D; Truco, Maria José; Michelmore, Richard W; Hancock, Robert D; Shellcock, Connie; Chapman, Mark A; Taylor, Gail

    2015-01-01

    A diet rich in phytonutrients from fruit and vegetables has been acknowledged to afford protection against a range of human diseases, but many of the most popular vegetables are low in phytonutrients. Wild relatives of crops may contain allelic variation for genes determining the concentrations of these beneficial phytonutrients, and therefore understanding the genetic basis of this variation is important for breeding efforts to enhance nutritional quality. In this study, lettuce recombinant inbred lines, generated from a cross between wild and cultivated lettuce (Lactuca serriola and Lactuca sativa, respectively), were analysed for antioxidant (AO) potential and important phytonutrients including carotenoids, chlorophyll and phenolic compounds. When grown in two environments, 96 quantitative trait loci (QTL) were identified for these nutritional traits: 4 for AO potential, 2 for carotenoid content, 3 for total chlorophyll content and 87 for individual phenolic compounds (two per compound on average). Most often, the L. serriola alleles conferred an increase in total AOs and metabolites. Candidate genes underlying these QTL were identified by BLASTn searches; in several cases, these had functions suggesting involvement in phytonutrient biosynthetic pathways. Analysis of a QTL on linkage group 3, which accounted for >30% of the variation in AO potential, revealed several candidate genes encoding multiple MYB transcription factors which regulate flavonoid biosynthesis and flavanone 3-hydroxylase, an enzyme involved in the biosynthesis of the flavonoids quercetin and kaempferol, which are known to have powerful AO activity. Follow-up quantitative RT-PCR of these candidates revealed that 5 out of 10 genes investigated were significantly differentially expressed between the wild and cultivated parents, providing further evidence of their potential involvement in determining the contrasting phenotypes. These results offer exciting opportunities to improve the nutritional

  3. Acclimation to UV-B radiation and visible light in Lactuca sativa involves up-regulation of photosynthetic performance and orchestration of metabolome-wide responses.

    PubMed

    Wargent, J J; Nelson, B C W; McGhie, T K; Barnes, P W

    2015-05-01

    UV-B radiation is often viewed as a source of stress for higher plants. In particular, photosynthetic function has been described as a common target for UV-B impairment; yet as our understanding of UV-B photomorphogenesis increases, there are opportunities to expand the emerging paradigm of regulatory UV response. Lactuca sativa is an important dietary crop species and is often subjected to rapid sunlight exposure at field transfer. Acclimation to UV-B and visible light conditions in L. sativa was dissected using gas exchange and chlorophyll fluorescence measurements, in addition to non-destructive assessments of UV epidermal shielding (SUV ). After UV-B treatment, seedlings were subjected to wide-range metabolomic analysis using liquid chromatography hybrid quadrupole time-of-flight high-resolution mass spectrometry (LC-QTOF-HRMS). During the acclimation period, net photosynthetic rate increased in UV-treated plants, epidermal UV shielding increased in both subsets of plants transferred to the acclimatory conditions (UV+/UV- plants) and Fv /Fm declined slightly in UV+/UV- plants. Metabolomic analysis revealed that a key group of secondary compounds was up-regulated by higher light conditions, yet several of these compounds were elevated further by UV-B radiation. In conclusion, acclimation to UV-B radiation involves co-protection from the effects of visible light, and responses to UV-B radiation at a photosynthetic level may not be consistently viewed as damaging to plant development.

  4. Efficient and stable transformation of Lactuca sativa L. cv. Cisco (lettuce) plastids.

    PubMed

    Kanamoto, Hirosuke; Yamashita, Atsushi; Asao, Hiroshi; Okumura, Satoru; Takase, Hisabumi; Hattori, Masahira; Yokota, Akiho; Tomizawa, Ken-Ichi

    2006-04-01

    Transgenic plastids offer unique advantages in plant biotechnology, including high-level foreign protein expression. However, broad application of plastid genome engineering in biotechnology has been largely hampered by the lack of plastid transformation systems for major crops. Here we describe the development of a plastid transformation system for lettuce, Lactuca sativa L. cv. Cisco. The transforming DNA carries a spectinomycin-resistance gene (aadA) under the control of lettuce chloroplast regulatory expression elements, flanked by two adjacent lettuce plastid genome sequences allowing its targeted insertion between the rbcL and accD genes. On average, we obtained 1 transplastomic lettuce plant per bombardment. We show that lettuce leaf chloroplasts can express transgene-encoded GFP to approximately 36% of the total soluble protein. All transplastomic T0 plants were fertile and the T1 progeny uniformly showed stability of the transgene in the chloroplast genome. This system will open up new possibilities for the efficient production of edible vaccines, pharmaceuticals, and antibodies in plants.

  5. Production and characterization of cyanocobalamin-enriched lettuce (Lactuca sativa L.) grown using hydroponics.

    PubMed

    Bito, Tomohiro; Ohishi, Noriharu; Hatanaka, Yuka; Takenaka, Shigeo; Nishihara, Eiji; Yabuta, Yukinori; Watanabe, Fumio

    2013-04-24

    When lettuces (Lactuca sativa L.) grown for 30 days in hydroponic culture were treated with various concentrations of cyanocobalamin for 24 h, its content in their leaves increased significantly from nondetectable to 164.6 ± 74.7 ng/g fresh weight. This finding indicated that consumption of only two or three of these fresh leaves is sufficient to meet the Recommended Dietary Allowance for adults of 2.4 μg/day. Analyses using a cobalamin-dependent Escherichia coli 215 bioautogram and LC/ESI-MS/MS demonstrated that the cyanocobalamin absorbed from the nutrient solutions by the leaves did not alter any other compounds such as coenzymes and inactive corrinoids. Gel filtration indicated that most (86%) of the cyanocobalamin in the leaves was recovered in the free cyanocobalamin fractions. These results indicated that cyanocobalamin-enriched lettuce leaves would be an excellent source of free cyanocobalamin, particularly for strict vegetarians or elderly people with food-bound cobalamin malabsorption.

  6. An Analysis of Electrical Impedance Measurements Applied for Plant N Status Estimation in Lettuce (Lactuca sativa)

    PubMed Central

    Muñoz-Huerta, Rafael F.; de J. Ortiz-Melendez, Antonio; Guevara-Gonzalez, Ramon G.; Torres-Pacheco, Irineo; Herrera-Ruiz, Gilberto; Contreras-Medina, Luis M.; Prado-Olivarez, Juan; Ocampo-Velazquez, Rosalia V.

    2014-01-01

    Nitrogen plays a key role in crop yields. Hence, farmers may apply excessive N fertilizers to crop fields, inducing environmental pollution. Crop N monitoring methods have been developed to improve N fertilizer management, most of them based on leaf or canopy optical-property measurements. However, sensitivity to environmental interference remains an important drawback. Electrical impedance has been applied to determine the physiological and nutritional status of plant tissue, but no studies related to plant-N contents are reported. The objective of this article is to analyze how the electrical impedance response of plants is affected by their N status. Four sets of lettuce (Lactuca sativa L.) with a different N-source concentrations per set were used. Total nitrogen and electrical impedance spectra (in a 1 to 100 kHz frequency range) were measured five times per set, three times every other day. Minimum phase angles of impedance spectra were detected and analyzed, together with the frequency value in which they occurred, and their magnitude at that frequency. High and positive correlation was observed between plant N content and frequency values at minimum phase angle with no significant variations detected between days of measurement. These results suggest that electrical impedance can be sensitive to plant N status. PMID:25057134

  7. Combination of minimal processing and irradiation to improve the microbiological safety of lettuce ( Lactuca sativa, L.)

    NASA Astrophysics Data System (ADS)

    Goularte, L.; Martins, C. G.; Morales-Aizpurúa, I. C.; Destro, M. T.; Franco, B. D. G. M.; Vizeu, D. M.; Hutzler, B. W.; Landgraf, M.

    2004-09-01

    The feasibility of gamma radiation in combination with minimal processing (MP) to reduce the number of Salmonella spp. and Escherichia coli O157:H7 in iceberg lettuce ( Lactuca sativa, L.) (shredded) was studied in order to increase the safety of the product. The reduction of the microbial population during the processing, the D10-values for Salmonella spp. and E. coli O157:H7 inoculated on shredded iceberg lettuce as well as the sensory evaluation of the irradiated product were evaluated. The immersion in chlorine (200 ppm) reduced coliform and aerobic mesophilic microorganisms by 0.9 and 2.7 log, respectively. D-values varied from 0.16 to 0.23 kGy for Salmonella spp. and from 0.11 to 0.12 kGy for E. coli O157:H7. Minimally processed iceberg lettuce exposed to 0.9 kGy does not show any change in sensory attributes. However, the texture of the vegetable was affected during the exposition to 1.1 kGy. The exposition of MP iceberg lettuce to 0.7 kGy reduced the population of Salmonella spp. by 4.0 log and E. coli by 6.8 log without impairing the sensory attributes. The combination of minimal process and gamma radiation to improve the safety of iceberg lettuce is feasible if good hygiene practices begins at farm stage.

  8. Semi-High Throughput Screening for Potential Drought-tolerance in Lettuce (Lactuca sativa) Germplasm Collections.

    PubMed

    Knepper, Caleb; Mou, Beiquan

    2015-04-17

    This protocol describes a method by which a large collection of the leafy green vegetable lettuce (Lactuca sativa L.) germplasm was screened for likely drought-tolerance traits. Fresh water availability for agricultural use is a growing concern across the United States as well as many regions of the world. Short-term drought events along with regulatory intervention in the regulation of water availability coupled with the looming threat of long-term climate shifts that may lead to reduced precipitation in many important agricultural regions has increased the need to hasten the development of crops adapted for improved water use efficiency in order to maintain or expand production in the coming years. This protocol is not meant as a step-by-step guide to identifying at either the physiological or molecular level drought-tolerance traits in lettuce, but rather is a method developed and refined through the screening of thousands of different lettuce varieties. The nature of this screen is based in part on the streamlined measurements focusing on only three water-stress indicators: leaf relative water content, wilt, and differential plant growth following drought-stress. The purpose of rapidly screening a large germplasm collection is to narrow the candidate pool to a point in which more intensive physiological, molecular, and genetic methods can be applied to identify specific drought-tolerant traits in either the lab or field. Candidates can also be directly incorporated into breeding programs as a source of drought-tolerance traits.

  9. An analysis of electrical impedance measurements applied for plant N status estimation in lettuce (Lactuca sativa).

    PubMed

    Muñoz-Huerta, Rafael F; Ortiz-Melendez, Antonio de J; Guevara-Gonzalez, Ramon G; Torres-Pacheco, Irineo; Herrera-Ruiz, Gilberto; Contreras-Medina, Luis M; Prado-Olivarez, Juan; Ocampo-Velazquez, Rosalia V

    2014-06-27

    Nitrogen plays a key role in crop yields. Hence, farmers may apply excessive N fertilizers to crop fields, inducing environmental pollution. Crop N monitoring methods have been developed to improve N fertilizer management, most of them based on leaf or canopy optical-property measurements. However, sensitivity to environmental interference remains an important drawback. Electrical impedance has been applied to determine the physiological and nutritional status of plant tissue, but no studies related to plant-N contents are reported. The objective of this article is to analyze how the electrical impedance response of plants is affected by their N status. Four sets of lettuce (Lactuca sativa L.) with a different N-source concentrations per set were used. Total nitrogen and electrical impedance spectra (in a 1 to 100 kHz frequency range) were measured five times per set, three times every other day. Minimum phase angles of impedance spectra were detected and analyzed, together with the frequency value in which they occurred, and their magnitude at that frequency. High and positive correlation was observed between plant N content and frequency values at minimum phase angle with no significant variations detected between days of measurement. These results suggest that electrical impedance can be sensitive to plant N status.

  10. Ecotoxicological impact of two soil remediation treatments in Lactuca sativa seeds.

    PubMed

    Rede, Diana; Santos, Lúcia H M L M; Ramos, Sandra; Oliva-Teles, Filipe; Antão, Cristina; Sousa, Susana R; Delerue-Matos, Cristina

    2016-09-01

    Pharmaceuticals have been identified as environmental emerging pollutants and are present in different compartments, including soils. Chemical remediation showed to be a good and suitable approach for soil remediation, though the knowledge in their impact for terrestrial organisms is still limited. Therefore, in this work, two different chemical remediation treatments (Fenton oxidation and nanoremediation) were applied to a soil contaminated with an environmental representative concentration of ibuprofen (3 ng g(-1)). The phytotoxic impact of a traditional soil remediation treatment (Fenton oxidation) and of a new and more sustainable approach for soil remediation (nanoremediation using green nano-scale zero-valent iron nanoparticles (nZVIs)) was evaluated in Lactuca sativa seeds. Percentage of seed germination, root elongation, shoot length and leaf length were considered as endpoints to assess the possible acute phytotoxicity of the soil remediation treatments as well as of the ibuprofen contaminated soil. Both chemical remediation treatments showed to have a negative impact in the germination and development of lettuce seeds, exhibiting a reduction up to 45% in the percentage of seed germination and a decrease around 80% in root elongation comparatively to the contaminated soil. These results indicate that chemical soil remediation treatments could be more prejudicial for terrestrial organisms than contaminated soils.

  11. Effects of Jatropha curcas oil in Lactuca sativa root tip bioassays.

    PubMed

    Andrade-Vieira, Larissa F; Botelho, Carolina M; Laviola, Bruno G; Palmieri, Marcel J; Praça-Fontes, Milene M

    2014-03-01

    Jatropha curcas L. (Euphorbiaceae) is important for biofuel production and as a feed ingredient for animal. However, the presence of phorbol esters in the oil and cake renders the seeds toxic. The toxicity of J. curcas oil is currently assessed by testing in animals, leading to their death. The identification of toxic and nontoxic improved varieties is important for the safe use of J. curcas seeds and byproducts to avoid their environmental toxicity. Hence, the aim of this study was to propose a short-term bioassay using a plant as a model to screen the toxicity of J. curcas oil without the need to sacrifice any animals. The toxicity of J. curcas oil was evident in germination, root elongation and chromosomal aberration tests in Lactuca sativa. It was demonstrated that J. curcas seeds contain natural compounds that exert phyto-, cyto- and genotoxic effects on lettuce, and that phorbol esters act as aneugenic agents, leading to the formation of sticky chromosomes and c-metaphase cells. In conclusion, the tests applied have shown reproducibility, which is important to verify the extent of detoxification and to determine toxic doses, thus reducing the numbers of animals that would be used for toxicity tests.

  12. Trichoderma spp. alleviate phytotoxicity in lettuce plants (Lactuca sativa L.) irrigated with arsenic-contaminated water.

    PubMed

    Caporale, Antonio G; Sommella, Alessia; Lorito, Matteo; Lombardi, Nadia; Azam, Shah M G G; Pigna, Massimo; Ruocco, Michelina

    2014-09-15

    The influence of two strains of Trichoderma (T. harzianum strain T22 and T. atroviride strain P1) on the growth of lettuce plants (Lactuca sativa L.) irrigated with As-contaminated water, and their effect on the uptake and accumulation of the contaminant in the plant roots and leaves, were studied. Accumulation of this non-essential element occurred mainly into the root system and reduced both biomass development and net photosynthesis rate (while altering the plant P status). Plant growth-promoting fungi (PGPF) of both Trichoderma species alleviated, at least in part, the phytotoxicity of As, essentially by decreasing its accumulation in the tissues and enhancing plant growth, P status and net photosynthesis rate. Our results indicate that inoculation of lettuce with selected Trichoderma strains may be helpful, beside the classical biocontrol application, in alleviating abiotic stresses such as that caused by irrigation with As-contaminated water, and in reducing the concentration of this metalloid in the edible part of the plant.

  13. Phytotoxicity of 15 common pharmaceuticals on the germination of Lactuca sativa and photosynthesis of Chlamydomonas reinhardtii.

    PubMed

    Pino, Ma Rosa; Muñiz, Selene; Val, Jonatan; Navarro, Enrique

    2016-11-01

    Pharmaceuticals reach terrestrial environments through the application of treated wastewaters and biosolids to agricultural soils. We have investigated the toxicity of 15 common pharmaceuticals, classified as nonsteroidal anti-inflammatory drugs (NSAIDs), blood lipid-lowering agents, β-blockers and antibiotics, in two photosynthetic organisms. Twelve pharmaceuticals caused inhibitory effects on the radicle and hypocotyl elongation of Lactuca sativa seeds. The EC50 values obtained were in the range of 170-5656 mg L(-1) in the case of the radicle and 188-4558 mg L(-1) for the hypocotyl. Propranolol was the most toxic drug for both root and hypocotyl elongation, followed by the NSAIDs, then gemfibrozil and tetracycline. Other effects, such as root necrosis, inhibition of root growth and curly hairs, were detected. However, even at the highest concentrations tested (3000 mg L(-1)), seed germination was not affected. NSAIDs decreased the photosynthetic yield of Chlamydomonas reinhardtii, but only salicylic acid showed EC50 values below 1000 mg L(-1). The first effects detected at low concentrations, together with the concentrations found in environmental samples, indicate that the use of biosolids and wastewaters containing pharmaceuticals should be regulated and their compositions assessed in order to prevent medium- and long-term impacts on agricultural soils and crops.

  14. [The dynamic of calcium distribution during megasporegenesis of lettuce (Lactuca sativa L.)].

    PubMed

    Qiu, Yi-Lan; Liu, Ru-Shi; Xie, Chao-Tian; Yang, Yan-Hong; Ge, Li-Li; Tian, Hui-Qiao

    2005-08-01

    Potassium antimonite was used to deposit calcium in the young ovule of lettuce (Lactuca sativa L.) at megasporogenesis stage to study the relationship between calcium and megaspore degeneration. At the megaspore mother cell stage, few calcium granules were formed in the cell (Plate I-1, 2). After meiosis of megaspore mother cell and forming an arrayed tetrad in a line (Plate I-3), three megaspores degenerated one by one from the micropyle end. In the process of degeneration, the numbers of calcium granules decreased in the three megaspores. After the first megaspore degenerated, the number of calcium granules decreased in the second megaspore, which began to degenerate (Plate II-7, 8). The third megaspore also had its number of calcium granules diminishing before it degenerated (Plate III-13, 14). The fourth megaspore always accumulated many calcium granules in the cytoplasm during its development (Plate IV-17, 18) and finally becomes functional one that will develop into an embryo sac (Plate IV-20). Megaspore degeneration is a process of programmed cell death which may be closely related with change in calcium content: when a megaspore of tetrad decreases calcium content the cell begins to degenerate, and when calcium increases in the cell, it will continue to develop into a functional megaspore. This is the first report about calcium distribution in megaspores of a tetrad during megasporogenesis in higher plants and will open a door to study the physiological function of calcium in megasporogenesis.

  15. The nitrogen and nitrate economy of butterhead lettuce (Lactuca sativa var capitata L).

    PubMed

    Broadley, Martin R; Seginer, Ido; Burns, Amanda; Escobar-Gutiérrez, Abraham J; Burns, Ian G; White, Philip J

    2003-09-01

    Quantifying and simulating the relationships between crop growth, total-nitrogen (total-N) and nitrate-N (NO3--N) concentration can improve crop nutritional husbandry. In this study, the relationship between shoot relative growth rate (RGR) and shoot total-N, organic-N and NO3--N concentration of hydroponically-grown lettuce (Lactuca sativa var. capitata L. cv. Kennedy) was described and simulated. Plants were grown hydroponically for up to 74 d. Nitrogen was supplied throughout (control; T1), or removed at 35 d (T2) and 54 d (T3), respectively, after sowing. The organic-N and NO3--N concentration declined in the shoots of control plants with growth, until commercial maturity approached when organic-N and NO3--N concentration increased. There were sub-linear relationships between both total-N and organic-N concentration, and shoot RGR, in the N-limited treatments, i.e. shoot RGR approached an asymptote at high shoot N concentration. The proportional effects of total-N and organic-N concentration on shoot RGR were independent of plant age. A dynamic simulation model ('Nicolet'), derived previously under different conditions, was used to simulate the growth, dry matter content, organic-N, and NO3--N concentration of lettuce grown under the extreme N-stress conditions experienced by the plants. In view of the largely successful fitting of the model to experimental data, the model was used to interpret the results. Suggestions for model improvement are made.

  16. Use of polishing pond effluents to cultivate lettuce (Lactuca sativa) in a hydroponic system.

    PubMed

    Keller, R; Perin, K; Souza, W G; Cruz, L S; Zandonade, E; Cassini, S T A; Goncalves, R F

    2008-01-01

    The sanitary quality and productivity of hydroponic lettuce (Lactuca sativa L.) plants cultivated under greenhouse conditions and treated with effluent from anaerobic reactor + polishing pond followed by physical-chemical treatment was evaluated. Two hydroponic cultivations were performed at summer and winter time at Vitoria-ES, Brazil. The treatments for both cultivations were: T1) conventional nutrient solution, T2) effluent from physical-chemical treatment, T3) effluent from polishing pond, and T4) effluent from polishing pond with 50% dilution. The plants were evaluated for microbial contamination, productivity and nutrient content. In all cases, no significant microbial contamination of lettuce was detected and the levels of macronutrients in the shoot system were similar to those in published reports. In the experiments from summer season, the treatments T1 and T2 resulted in higher production than the T3 and T4 treatments. Plants from T3 and T4 had a less developed root system as a result of reduced oxygenation from competition with the higher algae biomass content from the polishing pond effluent. In the winter season, the effect of the algal biomass was pronounced only in the T3 treatment (undiluted effluent from polishing pond). In conclusion, hydroponic cultivation of lettuce with pond effluent is suitable as a complement to water and nutrients for plants.

  17. Uptake of perfluorinated alkyl acids by hydroponically grown lettuce (Lactuca sativa).

    PubMed

    Felizeter, Sebastian; McLachlan, Michael S; de Voogt, Pim

    2012-11-06

    An uptake study was carried out to assess the potential human exposure to perfluorinated alkyl acids (PFAAs) through the ingestion of vegetables. Lettuce (Lactuca sativa) was grown in PFAA-spiked nutrient solutions at four different concentrations, ranging from 10 ng/L to 10 μg/L. Eleven perfluorinated carboxylic acids (PFCAs) and three perfluorinated sulfonic acids (PFSAs) were analyzed by HPLC-MS/MS. At the end of the experiment, the major part of the total mass of each of the PFAAs (except the short-chain, C4-C7, PFCAs) taken up by plants appeared to be retained in the nonedible part, viz. the roots. Root concentration factors (RCF), foliage/root concentration factors (FRCF), and transpiration stream concentration factors (TSCF) were calculated. For the long chained PFAAs, RCF values were highest, whereas FRCF were lowest. This indicates that uptake by roots is likely governed by sorption of PFAAs to lipid-rich root solids. Translocation from roots to shoots is restricted and highly depending on the hydrophobicity of the compounds. Although the TSCF show that longer-chain PFCAs (e.g., perfluorododecanoic acid) get better transferred from the nutrient solution to the foliage than shorter-chain PFCAs (e.g., perfluoroheptanoic acid), the major fraction of longer-chain PFCAs is found in roots due to additional adsorption from the spiked solution. Due to the strong electron-withdrawing effect of the fluorine atoms the role of the negative charge of the dissociated PFAAs is likely insignificant.

  18. Occupational dermatitis from Lactuca sativa (lettuce) and Cichorium (endive). Simultaneous occurrence of immediate and delayed allergy as a cause of contact dermatitis.

    PubMed

    Krook, G

    1977-02-01

    Four patients with occupational contact dermatitis to Lactuca sativa had cross-sensitivity to Cichorium endivia. One of the patients also had contact urticaria to Lactuca and Cichorium, and another reacted positively to scratch tests with these plants as a sign of immediate allergy. In two cases such immediate allergy was considered the cause of a vesicular, intense itching eruption within a few minutes of contact with fresh leaves of Lactuca on previously eczematous skin. The severe chronic dermatitis of the hands of these patients is ascribed to combined delayed and immediate allergy.

  19. Phytotoxicity of three plant-based biodiesels, unmodified castor oil, and Diesel fuel to alfalfa (Medicago sativa L.), lettuce (Lactuca sativa L.), radish (Raphanus sativus), and wheatgrass (Triticum aestivum).

    PubMed

    Bamgbose, Ifeoluwa; Anderson, Todd A

    2015-12-01

    The wide use of plant-based oils and their derivatives, in particular biodiesel, have increased extensively over the past decade to help alleviate demand for petroleum products and improve the greenhouse gas emissions profile of the transportation sector. Biodiesel is regarded as a clean burning alternative fuel produced from livestock feeds and various vegetable oils. Although in theory these animal and/or plant derived fuels should have less environmental impact in soil based on their simplified composition relative to Diesel, they pose an environmental risk like Diesel at high concentrations when disposed. The aim of the present study was to ascertain the phytotoxicity of three different plant-derived biodiesels relative to conventional Diesel. For phytotoxicological analysis, we used seeds of four crop plants, Medicago sativa, Lactuca sativa, Raphanus sativus, and Triticum aestivum to analyze the germination of seeds in contaminated soil samples. The toxicological experiment was conducted with two different soil textures: sandy loam soil and silt loam soil. The studied plant-based biodiesels were safflower methyl-ester, castor methyl ester, and castor ethyl-ester. Biodiesel toxicity was more evident at high concentrations, affecting the germination and survival of small-seeded plants to a greater extent. Tolerance of plants to the biodiesels varied between plant species and soil textures. With the exception of R. sativus, all plant species were affected and exhibited some sensitivity to the fuels, such as delayed seedling emergence and slow germination (average=10 days) at high soil concentrations (0.85% for Diesel and 1.76% for the biodiesels). Tolerance of plants to soil contamination had a species-specific nature, and on average, decreased in the following order: Raphanus sativus (0-20%)>Triticum aestivum (10-40%) ≥ Medicago sativa> Lactuca sativa (80-100%). Thus, we conclude that there is some phytotoxicity associated with plant-based biodiesels. Further

  20. 4',4‴,7,7″-tetra-O-methylcupressuflavone inhibits seed germination of Lactuca sativa.

    PubMed

    DeForest, Jacob C; Du, Lin; Joyner, P Matthew

    2014-04-25

    Biflavonoids have been isolated from a wide variety of plant species, but little is known about their native biological functions. Here we report a possible ecological role for biflavonoids by describing the isolation of the biflavonoid 4',4‴,7,7″-tetra-O-methylcupressuflavone (1) from Araucaria columnaris and its inhibitory effect on seed germination. Compound 1 was isolated from needles of a single A. columnaris specimen and inhibited germination of Lactuca sativa seeds in a culture-dish assay; it was also detected in soil samples under the canopy where reduced germination was observed, but not in a location away from the canopy where germination was uninhibited.

  1. Germination and growth of lettuce (Lactuca sativa) at low atmospheric pressure

    NASA Technical Reports Server (NTRS)

    Spanarkel, Robert; Drew, Malcolm C.

    2002-01-01

    The response of lettuce (Lactuca sativa L. cv. Waldmann's Green) to low atmospheric pressure was examined during the initial 5 days of germination and emergence, and also during subsequent growth to vegetative maturity at 30 days. Growth took place inside a 66-l-volume low pressure chamber maintained at 70 kPa, and plant response was compared to that of plants in a second, matching chamber that was at ambient pressure (approximately 101 kPa) as a control. In other experiments, to determine short-term effects of low pressure transients, plants were grown at ambient pressure until maturity and then subjected to alternating periods of 24 h of low and ambient atmospheric pressures. In all treatments the partial pressure of O2 was maintained at 21 kPa (approximately the partial pressure in air at normal pressure), and the partial pressure of CO2 was in the range 66.5-73.5 Pa (about twice that in normal air) in both chambers, with the addition of CO2 during the light phase. With continuous exposure to low pressure, shoot and root growth was at least as rapid as at ambient pressure, with an overall trend towards slightly greater performance at the lower pressure. Dark respiration rates were greater at low pressure. Transient periods at low pressure decreased transpiration and increased dark respiration but only during the period of exposure to low pressure. We conclude that long-term or short-term exposure to subambient pressure (70 kPa) was without detectable detriment to vegetative growth and development.

  2. [The character of calcium distribution in developing anther of lettuce (Lactuca sativa L.)].

    PubMed

    Qiu, Yi Lan; Liu, Ru Shi; Xie, Chao Tian; Yang, Yan Hong; Xu, Qing; Tian, Hui Qiao

    2005-10-01

    Potassium antimonite was used to locate calcium in the anther of lettuce (Lactuca sativa L) during its development. At the early stage of anther development there were few calcium granules in microspore mother cells and the cells of anther wall. After meiosis of microspore mother cells, calcium granules first appeared in the tapetal cells in which some small secretive vacuoles containing many calcium granules were formed and secreted into locule. Then, the tapetal cells began to degenerate. At the late stage of microspore, tapetal cells completely degenerated and its protoplast masses moved into anther locule with many calcium granules. Few calcium granules were precipitated in the microspores just being released from tetrad, but some on the surface of exine. Then calcium granules appeared in the nucleus and cytoplasm of early microspores, as wall as in the exine. When microspores formed some small vacuoles containing some calcium granules, and then the small vacuoles fused to form a large vacuole, the calcium granules in the nucleus and cytoplasm evidently decreased, microspore developed to the late stage. The result suggested that calcium is related to the formation of large vacuole in microspores. The wall of microspore also is a main location of calcium granules during its developing. At early microspore some calcium granules began to accumulate in exine, which suggested calcium related with exine formation. At late stage of microspore, most of calcium granules were mainly deposited on the surface of exine. After the first mitosis of microspores, the large vacuole of bicellular pollen disappeared and calcium granules in the large vacuole went back to cytoplasm again. When bicellular pollen synthesized starches some calcium granules appeared on the surface of starches, which suggested calcium may regulate starch synthesis. With amount of starches increasing, calcium granules disappeared from pollen cytoplasm and only some of them located on the surface of pollen.

  3. [Calcium distribution in the egg cell, zygote and proembryo of lettuce (Lactuca sativa L.)].

    PubMed

    Qiu, Yi Lan; Liu, Ru Shi; Wei, Dong Mei; Tian, Hui Qiao

    2006-02-01

    Potassium antimonite precipitation was used to located calcium in the egg cells (before and after anthesis), zygotes and proembryos of lettuce (Lactuca sativa L.). A few calcium precipitates (ppts) were located in the small vacuoles of cytoplasm of egg cell at 3 d before anthesis, when egg cells just formed. Then the small vacuoles fused to form some bigger vacuoles in egg cell at 2d before anthesis. Calcium ppts increased evidently in the cytoplasm and nucleus of egg cells at this time. At 1d before anthesis, a biggest vacuole located at the micropyle end of the cell and its nucleus was pushed toward the chalazal end of the cell, which made an evident cellular polarity. The number of calcium ppts in the egg cell markedly decreased, suggesting that change of calcium distribution may be related to the development of egg cell. After anthesis and before fertilization, calcium ppts were still few in the egg cells, and most of them were accumulated in the nucleus, especially in the vacuoles of nucleolus. At 4h after anthesis, egg cell was fertilized and the wall at the chalazal end of egg cell was formed completely. Calcium ppts evidently increased again in egg cell, and some big ppts appeared in the karyoplasm of nucleus and abundant small ppts in the large vacuole. At 9h after anthesis, zygote completed its first division. Calcium ppts in the nucleus and cytoplasm of two-celled proembryo began to decrease, and only some ones accumulated in the vacuoles of nucleolus. At 18h after anthesis, zygote divided several times and became a multi-celled proembryo. Calcium ppts in the cells of proembryo ulteriorly diminished but there were many ppts on the surface of proembryo. The result indicates that calcium in egg cell, zygote and the cells of proembryo orderly changes its temporal and spatial position, which suggests that calcium may play a role during the development of egg cell and zygote.

  4. [Calcium distribution in the central cell of lettuce (Lactuca sativa L.) before and after pollination].

    PubMed

    Qiu, Yi Lan; Liu, Ru Shi; Ye, Lv; Tian, Hui

    2008-02-01

    Potassium antimonite precipitation was used to locate calcium in the central cell of lettuce (Lactuca sativa L.) before and after pollination. At 3d before anthesis, two polar nuclei of central cell separately located at two polarity of the cell, and few calcium precipitates (ppts) appeared in the polar nuclei and cytoplasm, but some ppts in its small vacuoles. At 2d before anthesis, two polar nuclei moved toward the middle of the cell and fused to form a secondary nucleus, and the ppts evidently increased in the nucleus and cytoplasm. At 1d before anthesis, secondary nucleus again moved toward micropylar end and located near the egg to prepare for fertilization. Calcium precipitates were mainly accumulated in the secondary nucleus. After pollination and before fertilization, the distribution of calcium ppts was similar to that before pollination. At 4h after pollination, the central cell was fertilized, and calcium ppts evidently increased in the cell and numerous were accumulated in its nucleus and cytoplasm. At 6h after pollination, the primary endosperm nucleus completed its first division and formed two dissociate endosperm nuclei, and still many calcium precipitates appeared in the nucleus and cytoplasm. With endosperm development, calcium ppts decreased in the endosperm cell. At 1d after emasculated and without pollination, the secondary nucleus of the cell still bordered on the egg and some calcium ppts appeared in the secondary nucleus. The results indicated that the temporal and spatial changes of calcium in the central cell may play an important physiological role during the development of the central cell and endosperm.

  5. Tipburn in salt-affected lettuce (Lactuca sativa L.) plants results from local oxidative stress.

    PubMed

    Carassay, Luciano R; Bustos, Dolores A; Golberg, Alberto D; Taleisnik, Edith

    2012-02-15

    Tipburn in lettuce is a physiological disorder expressed as a necrosis in the margins of young developing leaves and is commonly observed under saline conditions. Tipburn is usually attributed to Ca(2+) deficiencies, and there has very limited research on other mechanisms that may contribute to tipburn development. This work examines whether symptoms are mediated by increased reactive oxygen species (ROS) production. Two butter lettuce (Lactuca sativa L.) varieties, Sunstar (Su) and Pontina (Po), with contrasting tipburn susceptibility were grown in hydroponics with low Ca(2+) (0.5 mM), and with or without 50 mM NaCl. Tipburn symptoms were observed only in Su, and only in the saline treatment. Tipburn incidence in response to topical treatments with Ca(2+) scavengers, Ca(2+) transport inhibitors, and antioxidants was assessed. All treatments were applied before symptom expression, and evaluated later, when symptoms were expected to occur. Superoxide presence in tissues was determined with nitro blue tetrazolium (NBT) and oxidative damage as malondialdehyde (MDA) content. Superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX) activities were assayed. Under control and saline conditions, tipburn could be induced in both varieties by topical treatments with a Ca(2+) scavenger (EGTA) and Ca(2+) transport inhibitors (verapamil, LaCl(3)) and reduced by supplying Ca(2+) along with a ionophore (A 23187). Tipburn symptoms were associated with locally produced ROS. O(2)(·-) and oxidative damage significantly increased in leaf margins before symptom expression, while topical antioxidant applications (Tiron, DPI) reduced symptoms in treated leaves, but not in the rest of the plant. Antioxidant enzyme activity was higher in Po, and increased more in response to EGTA treatments, and may contribute to mitigating oxidative damage and tipburn expression in this variety.

  6. Complete genome sequence of the biofilm-forming Curtobacterium sp. strain BH-2-1-1, isolated from lettuce (Lactuca sativa) originating from a conventional field in Norway.

    PubMed

    Dees, Merete Wiken; Brurberg, May Bente; Lysøe, Erik

    2016-12-01

    Here, we present the 3,795,952 bp complete genome sequence of the biofilm-forming Curtobacterium sp. strain BH-2-1-1, isolated from conventionally grown lettuce (Lactuca sativa) from a field in Vestfold, Norway. The nucleotide sequence of this genome was deposited into NCBI GenBank under the accession CP017580.

  7. LSGermOPA, a custom OPA of 384 EST-derived SNPs for high-throughput lettuce (Lactuca sativa L.) germplasm fingerprinting

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We assessed the genetic diversity and population structure among 148 cultivated lettuce (Lactuca sativa L.) accessions using the high-throughput GoldenGate assay and 384 EST (Expressed Sequence Tag)-derived SNP (single nucleotide polymorphism) markers. A custom OPA (Oligo Pool All), LSGermOPA was fo...

  8. Differential Scanning Calorimetry as a Tool for Nondestructive Measurements of Seed Deterioration in Lettuce (Lactuca sativa, CV “Black Seeded Simpson”)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was undertaken to determine if changes in lipid phase behavior could be used to detect lost viability in lettuce (Lactuca sativa) seeds. We used seeds from the cultivar ‘Black Seeded Simpson’ that were purchased every 2-3 years since 1989 and stored in resealable plastic bags at constan...

  9. Perfluoroalkyl acid uptake in lettuce (Lactuca sativa) and strawberry (Fragaria ananassa) irrigated with reclaimed water.

    PubMed

    Blaine, Andrea C; Rich, Courtney D; Sedlacko, Erin M; Hyland, Katherine C; Stushnoff, Cecil; Dickenson, Eric R V; Higgins, Christopher P

    2014-12-16

    Using reclaimed water to irrigate food crops presents an exposure pathway for persistent organic contaminants such as perfluoroalkyl acids (PFAAs) to enter the human food chain. This greenhouse study used reclaimed water augmented with varying concentrations (0.2-40 μg/L) of PFAAs, including perfluorocarboxylates (C3F7COO(-) to C8F17COO(-)) and perfluorosulfonates (C4F9SO2O(-), C6F13SO2O(-), C8F17SO2O(-)), to investigate potential uptake and concentration-response trends in lettuce (Lactuca sativa) and strawberry (Fragaria ananassa). In addition, studies were conducted to evaluate the role of soil organic carbon concentrations on plant uptake of PFAAs. PFAA concentrations in lettuce leaves and strawberry fruit were measured for each aqueous PFAA concentration applied. PFAA plant concentrations increased linearly with the aqueous concentration for all PFAAs, with PFCAs bioaccumulating to a greater degree than PFSAs in the edible portions of the tested plants. Chain-length-dependency trends were evident in both lettuce shoot and strawberry fruit, with decreasing concentrations associated with increasing chain length. Perfluorobutanoate (PFBA) and perfluoropentanoate (PFPeA), both short-chain PFAAs (<8 carbon chain length), accumulated the most compared with other PFAAs tested in the edible parts of both lettuce and strawberry. PFAA concentrations in strawberry root and shoot were also measured at selected PFAA aqueous concentrations (0.4, 4, and 40 μg/L). Short-chain perfluorocarboxylates were the dominant fraction in the strawberry fruit and shoot compartments, whereas a more even distribution of all PFAAs appeared in the root compartment. Lettuce grown in soils with varying organic carbon contents (0.4%, 2%, 6%) was used to assess the impact of organic carbon sorption on PFAA bioaccumulation. The lettuce grown in soil with the 6% organic carbon content had the lowest bioaccumulation of PFAAs. Bioaccumulation factors for lettuce were correlated to carbon chain

  10. [Studies on the calcium distribution in developing synergids of lettuce (Lactuca sativa L.)].

    PubMed

    Qiu, Yi Lan; Liu, Ru Shi; Tian, Hui Qiao

    2007-08-01

    Potassium antimonite was used to locate calcium in the synergids of lettuce (Lactuca sativa L) during their development. The two synergids on 3d before anthesis formed evident polarity with most cytoplasm located in the micropylar end and nucleus in the middle and a big vacuole in the chalazal end. At this time, calcium precipitates were a few in both cells. Calcium precipitates in the two synergids began to increase on 2d before anthesis. Synergid wall in the micropylar end thickened on 1d before anthesis, in which many calcium precipitates located. Near anthesis, synergids formed filiform apparatus in which abundant calcium precipitates accumulated to prepare for attracting pollen tubes entering. At anthesis, the distribution of calcium precipitates between two synergids was the same. At 1h after pollination, calcium precipitates evidently increased in one synergid that seemed to degenerate, the other one was persistent and the distribution of calcium granules did not change. Two synergids kept intact at 1d after emasculated, and the distribution of calcium precipitates did not display difference, suggesting that the degeneration of one synergid was caused by approaching pollen tubes which might give some signal to induce calcium increase of the synergid. Before fusion of sperm cell with egg cell, the cytoplasm of degenerated synergid embraced the egg and formed a thin layer between the egg and the central cell. Calcium precipitates in the different parts of degenerated synergid were closely connected with the fertilization: calcium precipitates accumulated in the near chalazal end of degenerated synergid at 1h after pollination. At 2.5h after pollination, the calcium precipitates increased at the chalazal end, especially abundant in the thin layer between the egg and the central cell. However, at 4h after pollination, the fertilization had finished at this time, the distribution of calcium precipitates in degenerated synergid changed again: the precipitates

  11. Heavy metals deposited in the culture of lettuce (Lactuca sativa L.) by the influence of vehicular traffic in Pernambuco, Brazil.

    PubMed

    França, Fernanda C S S; Albuuerque, Adriana M A; Almeida, Amanda C; Silveira, Patrícia B; Filho, Crescêncio A; Hazin, Clovis A; Honorato, Eliane V

    2017-01-15

    Currently one of the main sources of atmospheric pollution identified in urban centers is derived from both industrial and motor vehicle emissions. These pollutants can be adsorbed to particulate matter which is present in the air or deposited in the soil and plants, eventually reaching the human food chain. In this context, the present study aimed to determine the concentration of metals such as Cu, Pb, Cd, Ni and Zn in two subspecies of Lactuca sativa L. and in the soil from were lettuce samples were collected. The results for the soil samples analyzed show a possible contamination by Pb with concentration values as high as 140mg.kg(-1), which are above the Brazilian standards defined by Resolution CONAMA 420/2009 (Brazilian Environmental Council). However, the values found in the lettuce itself reveal that it is still suitable for consumption.

  12. Allelopathic Activity of Extracts from Different Brazilian Peanut (Arachis hypogaea L.) Cultivars on Lettuce (Lactuca sativa) and Weed Plants

    PubMed Central

    Garcia, R.; Simas, N. K.

    2017-01-01

    Peanut (Arachis hypogaea L.) is the fourth most consumed oleaginous plant in the world, producing seeds with high contents of lipids, proteins, vitamins, and carbohydrates. Biological activities of different extracts of this species have already been evaluated by many researchers, including antioxidant, antitumoral, and antibacterial. In this work, the allelopathic activity of extracts from different Brazilian peanut cultivars against lettuce (Lactuca sativa) and two weed plants (Commelina benghalensis and Ipomoea nil) was studied. Aerial parts, roots, seeds, and seed coats were used for the preparation of crude extracts. Seed extract partitioning was performed with n-hexane, dichloromethane, ethyl acetate, n-butanol, and aqueous residue. Germination and growth of hypocotyls and rootlets were evaluated after one and five days of incubation with plant extracts, respectively. Crude seed extract and its dichloromethanic partition displayed highest allelopathic activity. These results contribute for the study of new potential natural herbicides.

  13. Analysis of bacteria, parasites, and heavy metals in lettuce (Lactuca sativa) and rocket salad (Eruca sativa L.) irrigated with treated effluent from a biological wastewater treatment plant.

    PubMed

    Nikaido, Meire; Tonani, Karina A A; Julião, Fabiana C; Trevilato, Tânia M B; Takayanagui, Angela M M; Sanches, Sérgio M; Domingo, José L; Segura-Muñoz, Susana I

    2010-06-01

    This study aimed to evaluate the viability of using treated residuary water from the Biological Wastewater Treatment Plant of Ribeirão Preto to grow vegetables, through the characterization and quantification of parasites, coliforms, and heavy metals. Three equal cultivation areas were prepared. The first was irrigated with treated/chlorinated (0.2 mg L(-1)) wastewater, the second one with treated wastewater without chlorination, and the third site with potable water, which was the control group. The presence of Hymenolepis nana, Enterobius vermicularis, nematode larvae, and Entamoeba coli was verified in lettuce (Lactuca sativa) samples. Although nematode larvae were observed in rocket salad (Eruca sativa L.), no significant differences were found between the number of parasites and type of irrigation water used. No significant differences were found between the number of fecal coliforms in vegetables and the different types of irrigation. However, the vegetables irrigated with treated effluent without chlorination showed higher levels of fecal coliforms. The risk of pathogens is reduced with bleach addition to the treated effluent at 0.2 mg/L. Concentration of heavy metals in vegetables does not mean significant risks to human health, according with the parameters recommended by the World Health Organization.

  14. Plant growth-promoting bacterium Acinetobacter calcoaceticus P23 increases the chlorophyll content of the monocot Lemna minor (duckweed) and the dicot Lactuca sativa (lettuce).

    PubMed

    Suzuki, Wakako; Sugawara, Masayuki; Miwa, Kyoko; Morikawa, Masaaki

    2014-07-01

    Acinetobacter calcoaceticus P23 is a plant growth-promoting bacterium that was isolated from the surface of duckweed (Lemna aoukikusa). The bacterium was observed to colonize on the plant surfaces and increase the chlorophyll content of not only the monocotyledon Lemna minor but also the dicotyledon Lactuca sativa in a hydroponic culture. This effect on the Lactuca sativa was significant in nutrient-poor (×1/100 dilution of H2 medium) and not nutrient-rich (×1 or ×1/10 dilutions of H2 medium) conditions. Strain P23 has the potential to play a part in the future development of fertilizers and energy-saving hydroponic agricultural technologies.

  15. Complete genome sequence of the biofilm-forming Microbacterium sp. strain BH-3-3-3, isolated from conventional field-grown lettuce (Lactuca sativa) in Norway.

    PubMed

    Dees, Merete Wiken; Brurberg, May Bente; Lysøe, Erik

    2017-03-01

    The genus Microbacterium contains bacteria that are ubiquitously distributed in various environments and includes plant-associated bacteria that are able to colonize tissue of agricultural crop plants. Here, we report the 3,508,491 bp complete genome sequence of Microbacterium sp. strain BH-3-3-3, isolated from conventionally grown lettuce (Lactuca sativa) from a field in Vestfold, Norway. The nucleotide sequence of this genome was deposited into NCBI GenBank under the accession CP017674.

  16. Comparison of sensitivity of grasses (Lolium perenne L. and Festuca rubra L.) and lettuce (Lactuca sativa L.) exposed to water contaminated with microcystins.

    PubMed

    Pereira, Silvia; Saker, Martin L; Vale, Micaela; Vasconcelos, Vitor M

    2009-07-01

    The effects of aqueous extracts from Microcysts aeruginosa strains (both microcystin-producers and non-microcystin producers) on germination and root growth were investigated for three economically important plant species: Festuca rubra L., Lolium perenne L., and Lactuca sativa L. There was a clear inhibition of root growth for L. sativa exposed to strains containing microcystins (5.9-56.4 microg L(-1)). The strain that produced the most pronounced effects contained the lowest concentration of microcystin suggesting that other cellular compounds may also affect growth.

  17. Impacts of major cations (K(+), Na (+), Ca (2+), Mg (2+)) and protons on toxicity predictions of nickel and cadmium to lettuce (Lactuca sativa L.) using exposure models.

    PubMed

    Liu, Yang; Vijver, Martina G; Peijnenburg, Willie J G M

    2014-04-01

    Biotic ligand models (BLM) explicitly accounting for hypothetical interactions with biotic ligands and bioavailability as dictated by water chemistry have been developed for various metals and different organisms. It is only recently that BLMs for plants have received increasing attention. Lettuce is one of the most important vegetable crops in the world. This study investigated the impacts of Ca(2+), Mg(2+), K(+), Na(+) and pH, on acute toxicity of Ni and Cd to butter-head lettuce seedlings (Lactuca sativa L.). 4-day assays with the root elongation inhibition (REI) as the endpoint were performed in hydroponic solutions. Magnesium was found to be the sole cation significantly enhancing the median inhibition concentration (IC50) of Ni(2+) with increasing concentration. By incorporating the competitive effects of Mg(2+), the Ni-toxicity prediction was improved significantly as compared to the total metal model (TMM) and the free ion activity model (FIAM). The conditional stability constants derived from the Ni-BLM were log K MgBL = 2.86, log K NiBL = 5.1, and f NiBL (50%)  = 0.57. A slight downtrend was observed in the 4-d IC50 of Cd(2+) at increasing H(+) concentrations, but this tendency was not consistent and statistically significant (p = 0.07) over the whole range. The overall variations of Cd-toxicity within the tested Na(+), K(+), Ca(2+) and Mg(2+) concentration ranges were relatively small and not statistically significant. 80 % of lettuce REI by Cd could be explained using both TMM and FIAM instead of BLM in the present study. Thus, the mechanistically underpinned models for soil quality guidelines should be developed on a metal-specific basis across different exposure conditions.

  18. Effects of simulated acidic rain on yields of Raphanus sativus, Lactuca sativa, Triticum aestivum and Medicago sativa

    SciTech Connect

    Evans, L.S.; Gmur, N.F.; Mancini, D.

    1982-01-01

    Experiments were performed to determine effects of simulated acidic rain on radishes (Raphanus sativus), wheat(Triticum aestivum) and alfalfa (Medicago sativa) grown under greenhouse conditions. Experimental designs allowed the detection of statistically significant differences among means that differed by less than 10%. These results suggest that the efficiency of radish foliage in increasing; root mass decreases with increased rainfall acidity since only foliage was exposed to the treatments.

  19. Effect of salicylhydroxamic acid on endosperm strength and embryo growth of Lactuca sativa L. cv Waldmann's Green seeds

    NASA Technical Reports Server (NTRS)

    Brooks, C. A.; Mitchell, C. A.

    1988-01-01

    Salicylhydroxamic acid (SHAM) stimulated germination of photosensitive lettuce (Lactuca sativa L. cv Waldmann's Green) seeds in darkness. To determine whether SHAM acts on the embryo or the endosperm, we investigated separately effects of SHAM on growth potential of isolated embryos as well as on endosperm strength. Embryo growth potential was quantified by incubating decoated embryos in various concentrations of osmoticum and measuring subsequent radicle elongation. Growth potential of embryos isolated from seeds pretreated with 4 millimolar SHAM was equal to that of untreated controls. Rupture strength of endosperm tissue excised from seeds pretreated with SHAM was 33% less than that of controls in the micropylar region. To determine if the embryo must be in contact with the endosperm of SHAM to weaken the endosperm, some endosperms were incubated with SHAM only after dissection from seeds. Rupture strength of SHAM-treated, isolated endosperms in the micropylar region was 25% less than that of untreated controls. There was no difference in rupture strength in the cotyledonary region of endosperm isolated from seeds treated with SHAM in buffer or buffer alone. SHAM therefore stimulates germination not by enhancing embryo growth potential, but by weakening the micropylar region of the endosperm enclosing the embryo.

  20. Nitrate content of lettuce (Lactuca sativa L.) after fertilization with sewage sludge and irrigation with treated wastewater.

    PubMed

    Castro, E; Mañas, M P; De Las Heras, J

    2009-02-01

    A romaine-type lettuce (Lactuca sativa L.) was cultivated over three crop seasons (spring 2005, spring 2006 and autumn-winter 2006) in six 36 m(2) plots in Alcázar de San Juan, Spain. A drip irrigation system was used to water all plots: five plots with drinking water and one plot with wastewater from the activated sludge system of a wastewater treatment plant (WWTP). One drinking water-irrigated plot was not fertilized (control). Five different treatments were applied to the soil: three organic mixtures (sewage sludge, sewage sludge mixed with pine bark and municipal solid waste with composted sludge) and a conventional fertilizer were applied to the four plots irrigated with drinking water. The last plot was irrigated with treated wastewater. The treatments were tested for their effect on plant growth and nitrate concentration in vegetable tissue. An increase in fresh weight in the lettuce was linked to the dosage of sewage sludge. The highest nitrate level was observed in the sewage sludge treatment in all crops and seasons, although, in general, all values were below the maximum limits established by the European Commission for nitrate content in fresh romaine lettuce. In the third crop season, a significant increase in nitrate content was observed in lettuce from organic treatments. Nitrate concentration in lettuce from irrigated treated wastewater was higher than control, although significant differences were not found.

  1. Physiological Mechanisms Only Tell Half Story: Multiple Biological Processes are involved in Regulating Freezing Tolerance of Imbibed Lactuca sativa Seeds

    PubMed Central

    Jaganathan, Ganesh K.; Han, Yingying; Li, Weijie; Song, Danping; Song, Xiaoyan; Shen, Mengqi; Zhou, Qiang; Zhang, Chenxue; Liu, Baolin

    2017-01-01

    The physiological mechanisms by which imbibed seeds survive freezing temperatures in their natural environment have been categorized as freezing avoidance by supercooling and freezing tolerance by extracellular freeze-desiccation, but the biochemical and molecular mechanisms conferring seed freezing tolerance is unexplored. In this study, using imbibed Lactuca sativa seeds we show that fast cooled seeds (60 °C h−1) suffered significantly higher membrane damage at temperature between −20 °C and −10 °C than slow cooled (3 °Ch−1) seeds (P < 0.05), presumably explaining viability loss during fast cooling when temperature approaches −20 °C. Total soluble sugars increase in low temperature environment, but did not differ significantly between two cooling rates (P > 0.05). However, both SOD activity and accumulation of free proline were induced significantly after slow cooling to −20 °C compared with fast cooling. RNA-seq demonstrated that multiple pathways were differentially regulated between slow and fast cooling. Real-time verification of some differentially expressed genes (DEGs) revealed that fast cooling caused mRNA level changes of plant hormone and ubiquitionation pathways at higher sub-zero temperature, whilst slow cooling caused mRNA level change of those pathways at lower sub-zero ttemperatures. Thus, we conclude that imbibed seed tolerate low temperature not only by physiological mechanisms but also by biochemical and molecular changes. PMID:28287125

  2. Foliar exposure of the crop Lactuca sativa to silver nanoparticles: evidence for internalization and changes in Ag speciation.

    PubMed

    Larue, Camille; Castillo-Michel, Hiram; Sobanska, Sophie; Cécillon, Lauric; Bureau, Sarah; Barthès, Véronique; Ouerdane, Laurent; Carrière, Marie; Sarret, Géraldine

    2014-01-15

    The impact of engineered nanomaterials on plants, which act as a major point of entry of contaminants into trophic chains, is little documented. The foliar pathway is even less known than the soil-root pathway. However, significant inputs of nanoparticles (NPs) on plant foliage may be expected due to deposition of atmospheric particles or application of NP-containing pesticides. The uptake of Ag-NPs in the crop species Lactuca sativa after foliar exposure and their possible biotransformation and phytotoxic effects were studied. In addition to chemical analyses and ecotoxicological tests, micro X-ray fluorescence, micro X-ray absorption spectroscopy, time of flight secondary ion mass spectrometry and electron microscopy were used to localize and determine the speciation of Ag at sub-micrometer resolution. Although no sign of phytotoxicity was observed, Ag was effectively trapped on lettuce leaves and a thorough washing did not decrease Ag content significantly. We provide first evidence for the entrapment of Ag-NPs by the cuticle and penetration in the leaf tissue through stomata, for the diffusion of Ag in leaf tissues, and oxidation of Ag-NPs and complexation of Ag(+) by thiol-containing molecules. Such type of information is crucial for better assessing the risk associated to Ag-NP containing products.

  3. Bioavailability of silver and silver sulfide nanoparticles to lettuce (Lactuca sativa): Effect of agricultural amendments on plant uptake.

    PubMed

    Doolette, Casey L; McLaughlin, Michael J; Kirby, Jason K; Navarro, Divina A

    2015-12-30

    Silver nanoparticles (AgNPs) can enter terrestrial systems as sulfidised AgNPs (Ag2S-NPs) through the application of biosolids to soil. However, the bioavailability of Ag2S-NPs in soils is unknown. The two aims of this study were to investigate (1) the bioavailability of Ag to lettuce (Lactuca sativa) using a soil amended with biosolids containing Ag2S-NPs and (2) the effect of commonly used agricultural fertilisers/amendments on the bioavailability of Ag, AgNPs and Ag2S-NPs to lettuce. The study used realistic AgNP exposure pathways and exposure concentrations. The plant uptake of Ag from biosolids-amended soil containing Ag2S-NPs was very low for all Ag treatments (0.02%). Ammonium thiosulfate and potassium chloride fertilisation significantly increased the Ag concentrations of plant roots and shoots. The extent of the effect varied depending on the type of Ag. Ag2S-NPs, the realistic form of AgNPs in soil, had the lowest bioavailability. The potential risk of AgNPs in soils is low; even in the plants that had the highest Ag concentrations (Ag(+)+thiosulfate), only 0.06% of added Ag was found in edible plant parts (shoots). Results from the study suggest that agricultural practises must be considered when carrying out risk assessments of AgNPs in terrestrial systems; such practises can affect AgNP bioavailability.

  4. Physiological Mechanisms Only Tell Half Story: Multiple Biological Processes are involved in Regulating Freezing Tolerance of Imbibed Lactuca sativa Seeds.

    PubMed

    Jaganathan, Ganesh K; Han, Yingying; Li, Weijie; Song, Danping; Song, Xiaoyan; Shen, Mengqi; Zhou, Qiang; Zhang, Chenxue; Liu, Baolin

    2017-03-13

    The physiological mechanisms by which imbibed seeds survive freezing temperatures in their natural environment have been categorized as freezing avoidance by supercooling and freezing tolerance by extracellular freeze-desiccation, but the biochemical and molecular mechanisms conferring seed freezing tolerance is unexplored. In this study, using imbibed Lactuca sativa seeds we show that fast cooled seeds (60 °C h(-1)) suffered significantly higher membrane damage at temperature between -20 °C and -10 °C than slow cooled (3 °Ch(-1)) seeds (P < 0.05), presumably explaining viability loss during fast cooling when temperature approaches -20 °C. Total soluble sugars increase in low temperature environment, but did not differ significantly between two cooling rates (P > 0.05). However, both SOD activity and accumulation of free proline were induced significantly after slow cooling to -20 °C compared with fast cooling. RNA-seq demonstrated that multiple pathways were differentially regulated between slow and fast cooling. Real-time verification of some differentially expressed genes (DEGs) revealed that fast cooling caused mRNA level changes of plant hormone and ubiquitionation pathways at higher sub-zero temperature, whilst slow cooling caused mRNA level change of those pathways at lower sub-zero ttemperatures. Thus, we conclude that imbibed seed tolerate low temperature not only by physiological mechanisms but also by biochemical and molecular changes.

  5. Evaluation of the toxic potential of coffee wastewater on seeds, roots and meristematic cells of Lactuca sativa L.

    PubMed

    Aguiar, Luara Louzada; Andrade-Vieira, Larissa Fonseca; de Oliveira David, José Augusto

    2016-11-01

    Coffee wastewater (CWW) is an effluent produced through wet processing of coffee containing high concentration of organic matter, nutrients, salts and also agrochemicals. It is released directly into the argillaceous soil or into decantation tanks for later disposal into soils, by fertigation, subsurface infiltration or superficial draining. However, this practice is not followed by the monitoring the toxicity potential of this effluent. In this sense, the present work aimed to evaluate the phytotoxic, cytogenotoxic and mutagenic potential of CWW on seed germination, root elongation and cell cycle alterations in the plant model Lactuca sativa L. The effluent (CWW) collected was diluted in distilled water into six concentrations solutions (1.25%, 1.66%, 2.5%, 5.0%, 10%, 20%). A solution of raw CWW (100%) was also applied. Distilled water was used as negative control), and the DNA alkylating agent, metilmetano sulfonate (4×10(-4)M) as positive control. Physico-chemical parameters of the CWW was accessed and it was found that the effluent contained total phenols and inorganic matter in amounts within the limits established by the National Environment Council (CONAMA). Nevertheless, the biologicals assays performed demonstrated the phytotoxicity and cytogenotoxicty of CWW. Seed germination was totally inhibited after exposure of raw CWW. In addition, a decrease in seed germination speed as well as in root growth dose-dependently manner was noticed. Moreover, nuclear and chromosomal alterations were observed in the cell cycle, mostly arising from aneugenic action.

  6. Construction of transplastomic lettuce (Lactuca sativa) dominantly producing astaxanthin fatty acid esters and detailed chemical analysis of generated carotenoids.

    PubMed

    Harada, Hisashi; Maoka, Takashi; Osawa, Ayako; Hattan, Jun-Ichiro; Kanamoto, Hirosuke; Shindo, Kazutoshi; Otomatsu, Toshihiko; Misawa, Norihiko

    2014-04-01

    The plastid genome of lettuce (Lactuca sativa L.) cv. Berkeley was site-specifically modified with the addition of three transgenes, which encoded β,β-carotenoid 3,3'-hydroxylase (CrtZ) and β,β-carotenoid 4,4'-ketolase (4,4'-oxygenase; CrtW) from a marine bacterium Brevundimonas sp. strain SD212, and isopentenyl diphosphate isomerase from a marine bacterium Paracoccus sp. strain N81106. Constructed transplastomic lettuce plants were able to grow on soil at a growth rate similar to that of non-transformed lettuce cv. Berkeley and generate flowers and seeds. The germination ratio of the lettuce transformants (T0) (98.8%) was higher than that of non-transformed lettuce (93.1 %). The transplastomic lettuce (T1) leaves produced the astaxanthin fatty acid (myristate or palmitate) diester (49.2% of total carotenoids), astaxanthin monoester (18.2%), and the free forms of astaxanthin (10.0%) and the other ketocarotenoids (17.5%), which indicated that artificial ketocarotenoids corresponded to 94.9% of total carotenoids (230 μg/g fresh weight). Native carotenoids were there lactucaxanthin (3.8%) and lutein (1.3 %) only. This is the first report to structurally identify the astaxanthin esters biosynthesized in transgenic or transplastomic plants producing astaxanthin. The singlet oxygen-quenching activity of the total carotenoids extracted from the transplastomic leaves was similar to that of astaxanthin (mostly esterified) from the green algae Haematococcus pluvialis.

  7. Determination of phytotoxicity of soluble elements in soils, based on a bioassay with lettuce (Lactuca sativa L.).

    PubMed

    Valerio, Marlon Escoto; García, Juan Fernández; Peinado, Francisco Martín

    2007-05-25

    In this work the different concentrations of soluble elements in soils from natural (peridotitic soils) and anthropogenic (soils affected by a pyrite-mine spill) origin, are used to determine the phytotoxicity in lettuce (Lactuca sativa L.). The solutions are obtained from soil:water extracts (1:1), having neutral pH and high concentrations of As, Pb, Zn, Mn, Co and Ni, with values exceeding the toxic level for soil solution [Bohn HL, McNeal BL, O'Connor GA. Soil Chemistry, Wiley Interscience. Wiley & Sons, New York, 1985]. The variables evaluated are: Seed Germination (SG), Root Elongation (RE), Germination Rate (GR) and Root Necrosis (RN). The most sensitive variables in the bioassay with these solutions are GR and RN, in these cases the solution causes a reduction of 44% and 67%, respectively, in relation to control (distilled water). The test using soil-water solutions is sensitive and reproducible to determine phytotoxicity in lettuce caused by potentially pollutant elements in soils.

  8. The effects of cover crop on weed control in collard (Brassica olerecea var acephala) and lettuce (Lactuca sativa L.).

    PubMed

    Mennan, H; Ngouajio, M; Isik, D; Kose, B; Kaya, E

    2006-01-01

    Leafy vegetables are not very competitive and weed interference can cause considerable yield losses in collard (Brassica olerecea var acephala) and lettuce (Lactuca sativa L.). Currently there are no pre or post emergence herbicides registered for weed control in these vegetables in Turkey. For this reason, alternative weed control strategies need to be developed. Cover crop residue could represent an alternative method of weed management in these crops. Field studies were conducted in 2004 at the Black Sea Agricultural Research Institute experimental field in Samsun, Turkey. The cover crop treatments consisted of Sorghum bicolor (L.) Moench, Sorghum vulgare Pers., Vicia villosa L., Amaranthus cruentus L., Pisum sativum L. and the bare ground with no cover crop. All cover crops were seeded by hand and incorporated into the soil on 11 May, 2004. Each plot was 10 m2 (2 x 5 m) and arranged in a randomized complete block design with four replications. All cover crops were incorporated into the soil by discing on 1 September 2004 at flowering stage of the cover crops. Broadleaved weed species were dominant in the experimental area. Most cover crops established well and S. bicolor biomass was the highest. The number of weed species emerging in all treatments was different at 14 DAD (days after desiccation). Similar results were observed at 28 and 56 DAD. Treatments with Vicia villosa residues had fewer weed species and lower total weed densities than other treatments.

  9. [The dynamics of calcium distribution in stigma and style of lettuce (Lactuca sativa L.) before and after pollination].

    PubMed

    Qiu, Yi Lan; Liu, Ru Shi; Xie, Chao Tian; Yang, Yan Hong; Gu, Li; Tian, Hui Qiao

    2005-08-01

    Potassium antimonite was used to deposit calcium in the stigma and style of lettuce (Lactuca sativa L.) before and after pollination. The stigma of lettuce is two splits. Abundant calcium granules are displayed in the wall of papillae on the receptive surface of stigma before and after pollination, which may facilitate pollen germination. However, a few calcium granules in the wall of epidermis cell on no-receptive surface. Calcium distribution in style presents a gradient in transmitting tissue and parenchyma cells from the top to the base of the style before pollination. After pollination, calcium in transmitting tissue distinctly increased and its gradient distribution became more evident. Pollen tubes grow in the intercellular gaps of transmitting tissue. When pollen tubes grew into transmitting tissue, calcium granules in parenchyma around transmitting tissue decreased, suggesting a calcium movement was controlled by pollen tubes. The calcium gradient distribution also appeared in the trachea of vascular bundle of style. In general, calcium in style displays a feature of time-special distribution: transmitting tissue doesn't need much more calcium that is only stored in the parenchyma before pollination. However, calcium in parenchyma cells may be transported to transmitting tissue and make the latter contain more calcium to form an evident calcium gradient and meet the requirement of pollen tubes directionally growing after pollination. This is the second sample of calcium gradient existing in style, which was found by using potassium antimonite method.

  10. Influence of diesel contamination in soil on growth and dry matter partitioning of Lactuca sativa and Ipomoea batatas.

    PubMed

    Fatokun, Kayode; Zharare, Godfrey Elijah

    2015-09-01

    Phytotoxic effect of diesel contaminated soil was investigated on growth and dry matter partitioning in Lactuca sativa and Ipomoea batatas in greenhouse pot experiment at two concentration range (0-30 ml and 0-6 ml diesel kg(-1) soil) for 14 weeks. The results indicated thatwhole plant biomass, stem length, root length, number of leaves and leaf chlorophyll in two plants were negatively correlated with increasing diesel concentrations. The critical concentration of diesel associated with 10% decrease in plant growth was 0.33 ml for lettuce and 1.50 ml for sweet potato. Thus, growth of lettuce in diesel contaminated soil was more sensitive than sweet potato. The pattern of dry matter partitioning between root and shoot in both plants were similar. In 0-6 ml diesel contamination range, allocation of dry matter to shoot system was favoured resulting in high shoot: root ratio of 4.54 and 12.91 for lettuce and sweet potato respectively. However, in 0-30 ml diesel contamination range, allocation of dry matter to root was favoured, which may have been an adaptive mechanism in which the root system was used for storage in addition to increasing the capacity for foraging for mineral nutrients and water. Although lettuce accumulated more metals in its tissue than sweet potato, the tissue mineral nutrients in both species did not vary to great extent. The critical diesel concentration for toxicity suggested that the cause of mortality and poor growth of sweet potato and lettuce grown in diesel contaminated soil was due to presence of hydrocarbons in diesel.

  11. Root exudation and root development of lettuce (Lactuca sativa L. cv. Tizian) as affected by different soils.

    PubMed

    Neumann, G; Bott, S; Ohler, M A; Mock, H-P; Lippmann, R; Grosch, R; Smalla, K

    2014-01-01

    Development and activity of plant roots exhibit high adaptive variability. Although it is well-documented, that physicochemical soil properties can strongly influence root morphology and root exudation, particularly under field conditions, a comparative assessment is complicated by the impact of additional factors, such as climate and cropping history. To overcome these limitations, in this study, field soils originating from an unique experimental plot system with three different soil types, which were stored at the same field site for 10 years and exposed to the same agricultural management practice, were used for an investigation on effects of soil type on root development and root exudation. Lettuce (Lactuca sativa L. cv. Tizian) was grown as a model plant under controlled environmental conditions in a minirhizotrone system equipped with root observation windows (rhizoboxes). Root exudates were collected by placing sorption filters onto the root surface followed by subsequent extraction and GC-MS profiling of the trapped compounds. Surprisingly, even in absence of external stress factors with known impact on root exudation, such as pH extremes, water and nutrient limitations/toxicities or soil structure effects (use of sieved soils), root growth characteristics (root length, fine root development) as well as profiles of root exudates were strongly influenced by the soil type used for plant cultivation. The results coincided well with differences in rhizosphere bacterial communities, detected in field-grown lettuce plants cultivated on the same soils (Schreiter et al., this issue). The findings suggest that the observed differences may be the result of plant interactions with the soil-specific microbiomes.

  12. Delineating ion-ion interactions by electrostatic modeling for predicting rhizotoxicity of metal mixtures to lettuce Lactuca sativa.

    PubMed

    Le, T T Yen; Wang, Peng; Vijver, Martina G; Kinraide, Thomas B; Hendriks, A Jan; Peijnenburg, Willie J G M

    2014-09-01

    Effects of ion-ion interactions on metal toxicity to lettuce Lactuca sativa were studied based on the electrical potential at the plasma membrane surface (ψ0 ). Surface interactions at the proximate outside of the membrane influenced ion activities at the plasma membrane surface ({M(n+)}0). At a given free Cu(2+) activity in the bulk medium ({Cu(2+)}b), additions of Na(+), K(+), Ca(2+), and Mg(2+) resulted in substantial decreases in {Cu(2+)}0. Additions of Zn(2+) led to declines in {Cu(2+)}0, but Cu(2+) and Ag(+) at the exposure levels tested had negligible effects on the plasma membrane surface activity of each other. Metal toxicity was expressed by the {M(n+)}0 -based strength coefficient, indicating a decrease of toxicity in the order: Ag(+)  > Cu(2+)  > Zn(2+). Adsorbed Na(+), K(+), Ca(2+), and Mg(2+) had significant and dose-dependent effects on Cu(2+) toxicity in terms of osmolarity. Internal interactions between Cu(2+) and Zn(2+) and between Cu(2+) and Ag(+) were modeled by expanding the strength coefficients in concentration addition and response multiplication models. These extended models consistently indicated that Zn(2+) significantly alleviated Cu(2+) toxicity. According to the extended concentration addition model, Ag(+) significantly enhanced Cu(2+) toxicity whereas Cu(2+) reduced Ag(+) toxicity. By contrast, the response multiplication model predicted insignificant effects of adsorbed Cu(2+) and Ag(+) on the toxicity of each other. These interactions were interpreted using ψ0, demonstrating its influence on metal toxicity.

  13. Experimental determinations of soil copper toxicity to lettuce (Lactuca sativa) growth in highly different copper spiked and aged soils.

    PubMed

    Christiansen, Karen S; Borggaard, Ole K; Holm, Peter E; Vijver, Martina G; Hauschild, Michael Z; Peijnenburg, Willie J G M

    2015-04-01

    Accurate knowledge about factors and conditions determining copper (Cu) toxicity in soil is needed for predicting plant growth in various Cu-contaminated soils. Therefore, effects of Cu on growth (biomass production) of lettuce (Lactuca sativa) were tested on seven selected, very different soils spiked with Cu and aged for 2 months at 35 °C. Cu toxicity was expressed as pEC50(Cu(2+)), i.e., the negative logarithm of the EC50(Cu(2+)) activity to plant growth. The determined pEC50(Cu(2+)) was significantly and positively correlated with both the analytically readily available soil pH and concentration of dissolved organic carbon [DOC] which together could explain 87% of the pEC50(Cu(2+)) variation according to the simple equation: pEC50(Cu(2+)) = 0.98 × pH + 345 × [DOC] - 0.27. Other soil characteristics, including the base cation concentrations (Na(+), K(+), Ca(2+), Mg(2+)), the cation exchange capacity at soil pH (ECEC), and at pH 7 (CEC7), soil organic carbon, clay content, and electric conductivity as well as the distribution coefficient (Kd) calculated as the ratio between total soil Cu and water-extractable Cu did not correlate significantly with pEC50(Cu(2+)). Consequently, Cu toxicity, expressed as the negative log of the Cu(2+) activity, to plant growth increases at increasing pH and DOC, which needs to be considered in future management of plant growth on Cu-contaminated soils. The developed regression equation allows identification of soil types in which the phytotoxicity potential of Cu is highest.

  14. Use of hairy roots extracts for 2,4-DCP removal and toxicity evaluation by Lactuca sativa test.

    PubMed

    Angelini, Vanina A; Agostini, Elizabeth; Medina, María I; González, Paola S

    2014-02-01

    2,4-Dichlorophenol (2,4-DCP) is widely distributed in wastewaters discharged from several industries, and it is considered as a priority pollutant due to its high toxicity. In this study, the use of different peroxidase extracts for 2,4-DCP removal from aqueous solutions was investigated. Tobacco hairy roots (HRs), wild-type (WT), and double-transgenic (DT) for tomato basic peroxidases (TPX1 and TPX2) were used to obtain different peroxidase extracts: total peroxidases (TPx), soluble peroxidases (SPx), and peroxidases ionically bound to the cell wall (IBPx). All extracts derived from DT HRs exhibited higher peroxidase activity than those obtained from WT HRs. TPx and IBPx DT extracts showed the highest catalytic efficiency values. The optimal conditions for 2,4-DCP oxidation were pH 6.5, H2O2 0.5 mM, and 200 U mL(-1) of enzyme, for all extracts analyzed. Although both TPx extracts were able to oxidize different 2,4-DCP concentrations, the removal efficiency was higher for TPx DT. Polyethylene glycol addition slightly improved 2,4-DCP removal efficiency, and it showed some protective effect on TPx WT after 2,4-DCP oxidation. In addition, using Lactuca sativa test, a reduction of the toxicity of post removal solutions was observed, for both TPx extracts. The results demonstrate that TPx extracts from both tobacco HRs appear to be promising candidate for future applications in removing 2,4-DCP from wastewaters. This is particularly true considering that these peroxidase sources are associated with low costs and are readily available. However, TPx DT has increased peroxidase activity, catalytic efficiency, and higher removal efficiency than TPx WT, probably due to the expression of TPX1 and TPX2 isoenzymes.

  15. Silencing the lettuce homologs of small rubber particle protein does not influence natural rubber biosynthesis in lettuce (Lactuca sativa).

    PubMed

    Chakrabarty, Romit; Qu, Yang; Ro, Dae-Kyun

    2015-05-01

    Natural rubber, cis-1,4-polyisoprene, is an important raw material in chemical industries, but its biosynthetic mechanism remains elusive. Natural rubber is known to be synthesized in rubber particles suspended in laticifer cells in the Brazilian rubber tree (Hevea brasiliensis). In the rubber tree, rubber elongation factor (REF) and its homolog, small rubber particle protein (SRPP), were found to be the most abundant proteins in rubber particles, and they have been implicated in natural rubber biosynthesis. As lettuce (Lactuca sativa) can synthesize natural rubber, we utilized this annual, transformable plant to examine in planta roles of the lettuce REF/SRPP homologs by RNA interference. Among eight lettuce REF/SRPP homologs identified, transcripts of two genes (LsSRPP4 and LsSRPP8) accounted for more than 90% of total transcripts of REF/SRPP homologs in lettuce latex. LsSRPP4 displays a typical primary protein sequence as other REF/SRPP, while LsSRPP8 is twice as long as LsSRPP4. These two major LsSRPP transcripts were individually and simultaneously silenced by RNA interference, and relative abundance, polymer molecular weight, and polydispersity of natural rubber were analyzed from the LsSRPP4- and LsSRPP8-silenced transgenic lettuce. Despite previous data suggesting the implications of REF/SRPP in natural rubber biosynthesis, qualitative and quantitative alterations of natural rubber could not be observed in transgenic lettuce lines. It is concluded that lettuce REF/SRPP homologs are not critically important proteins in natural rubber biosynthesis in lettuce.

  16. Cadmium uptake in above-ground parts of lettuce (Lactuca sativa L.).

    PubMed

    Tang, Xiwang; Pang, Yan; Ji, Puhui; Gao, Pengcheng; Nguyen, Thanh Hung; Tong, Yan'an

    2016-03-01

    Because of its high Cd uptake and translocation, lettuce is often used in Cd contamination studies. However, there is a lack of information on Cd accumulation in the above-ground parts of lettuce during the entire growing season. In this study, a field experiment was carried out in a Cd-contaminated area. Above-ground lettuce parts were sampled, and the Cd content was measured using a flame atomic absorption spectrophotometer (AAS). The results showed that the Cd concentration in the above-ground parts of lettuce increased from 2.70 to 3.62mgkg(-1) during the seedling stage, but decreased from 3.62 to 2.40mgkg(-1) during organogenesis and from 2.40 to 1.64mgkg(-1) during bolting. The mean Cd concentration during the seedling stage was significantly higher than that during organogenesis (a=0.05) and bolting (a=0.01). The Cd accumulation in the above-ground parts of an individual lettuce plant could be described by a sigmoidal curve. Cadmium uptake during organogenesis was highest (80% of the total), whereas that during bolting was only 4.34%. This research further reveals that for Rome lettuce: (1) the highest Cd content of above-ground parts occurred at the end of the seedling phase; (2) the best harvest time with respect to Cd phytoaccumulation is at the end of the organogenesis stage; and (3) the organogenesis stage is the most suitable time to enhance phytoaccumulation efficiency by adjusting the root:shoot ratio.

  17. Exposure studies of core-shell Fe/Fe(3)O(4) and Cu/CuO NPs to lettuce (Lactuca sativa) plants: Are they a potential physiological and nutritional hazard?

    PubMed

    Trujillo-Reyes, J; Majumdar, S; Botez, C E; Peralta-Videa, J R; Gardea-Torresdey, J L

    2014-02-28

    Iron and copper nanomaterials are widely used in environmental remediation and agriculture. However, their effects on physiological parameters and nutritional quality of terrestrial plants such as lettuce (Lactuca sativa) are still unknown. In this research, 18-day-old hydroponically grown lettuce seedlings were treated for 15 days with core-shell nanoscale materials (Fe/Fe(3)O(4), Cu/CuO) at 10 and 20mg/L, and FeSO(4)·7H(2)O and CuSO(4)·5H(2)O at 10mg/L. At harvest, Fe, Cu, micro and macronutrients were determined by ICP-OES. Also, we evaluated chlorophyll content, plant growth, and catalase (CAT) and ascorbate peroxidase (APX) activities. Our results showed that iron ions/NPs did not affect the physiological parameters with respect to water control. Conversely, Cu ions/NPs reduced water content, root length, and dry biomass of the lettuce plants. ICP-OES results showed that nano-Cu/CuO treatments produced significant accumulation of Cu in roots compared to the CuSO(4)·5H(2)O treatment. In roots, all Cu treatments increased CAT activity but decreased APX activity. In addition, relative to the control, nano-Cu/CuO altered the nutritional quality of lettuce, since the treated plants had significantly more Cu, Al and S but less Mn, P, Ca, and Mg.

  18. Effect of ozonated water treatment on microbial control and on browning of iceberg lettuce (Lactuca sativa L.).

    PubMed

    Koseki, Shigenobu; Isobe, Seiichiro

    2006-01-01

    We examined the effect of ozonated water treatment on microbial control and quality of cut iceberg lettuce (Lactuca sativa L.). Fresh-cut lettuce was washed in ozonated water (3, 5, and 10 ppm) for 5 min at ambient temperature. The native bacterial population on the lettuce declined in response to a rise in ozone concentration. However, there was no further bacterial reduction (1.4 log CFU/g) above 5 ppm ozone. Although ozonated water treatment increased the phenylalanine ammonia lyase (PAL) activity of the lettuce stored at 10 degrees C compared with the water wash treatment after 1 day of storage, the concentration of ozone did not affect PAL activity. The a* value of the residue of the lettuce methanol extracts, which reflects the extent of browning, increased dramatically in lettuce treated with 10 ppm ozonated water compared with other treatments. Treatment with 3 or 5 ppm ozonated water resulted in more rapid changes in the a* value than after the water treatment. The combined treatment of hot water (50 degrees C, 2.5 min) followed by ozonated water (5 ppm, 2.5 min) had the same bactericidal effect as treatment with ozonated water (5 ppm, 5 min) or sodium hypochlorite (NaOCl, 200 ppm, 5 min), giving a reduction in bacteria numbers of 1.2 to 1.4 log CFU/g. The ascorbic acid content of the lettuce was not affected by these treatments. The combined treatment of hot water followed by ozonated water greatly inhibited PAL activity for up to 3 days of storage at 10 degrees C. Treatment with this combination greatly suppressed increases in the a* value, thus retarding the progress of browning compared with other treatments throughout the 6-day storage. NaOCl treatment also inhibited browning for up to 3 days of storage. Bacterial populations on the lettuce treated with sanitizers were initially reduced but then showed rapid growth compared with that of the water wash treatment, which did not reduce bacterial counts initially.

  19. Remote sensing of nutrient deficiency in Lactuca sativa using neural networks for terrestrial and advanced life support applications

    NASA Astrophysics Data System (ADS)

    Sears, Edie Seldon

    2000-12-01

    A remote sensing study using reflectance and fluorescence spectra of hydroponically grown Lactuca sativa (lettuce) canopies was conducted. An optical receiver was designed and constructed to interface with a commercial fiber optic spectrometer for data acquisition. Optical parameters were varied to determine effects of field of view and distance to target on vegetation stress assessment over the test plant growth cycle. Feedforward backpropagation neural networks (NN) were implemented to predict the presence of canopy stress. Effects of spatial and spectral resolutions on stress predictions of the neural network were also examined. Visual inspection and fresh mass values failed to differentiate among controls, plants cultivated with 25% of the recommended concentration of phosphorous (P), and those cultivated with 25% nitrogen (N) based on fresh mass and visual inspection. The NN's were trained on input vectors created using reflectance and test day, fluorescence and test day, and reflectance, fluorescence, and test day. Four networks were created representing four levels of spectral resolution: 100-nm NN, 10-nm NN, 1-nm NN, and 0.1-nm NN. The 10-nm resolution was found to be sufficient for classifying extreme nitrogen deficiency in freestanding hydroponic lettuce. As a result of leaf angle and canopy structure broadband scattering intensity in the 700-nm to 1000-nm range was found to be the most useful portion of the spectrum in this study. More subtle effects of "greenness" and fluorescence emission were believed to be obscured by canopy structure and leaf orientation. As field of view was not as found to be as significant as originally believed, systems implementing higher repetitions over more uniformly oriented, i.e. smaller, flatter, target areas would provide for more discernible neural network input vectors. It is believed that this technique holds considerable promise for early detection of extreme nitrogen deficiency. Further research is recommended using

  20. Health risks resulting from contaminants transfers in soil-plants systems: case study of Atrazine in Lactuca sativa.

    NASA Astrophysics Data System (ADS)

    Mathieu, Camoin

    2015-04-01

    Food safety is presently at the center of great part of scientific and political debates. This represents a field of study in its own right of health risks, including ingestion by humans of hazardous biological, physical, chemical or radiological substances, from contaminated foods during different stages of production. Plant cultivation step is often one of the main sources of contamination, whether of voluntary (pesticide application) or accidental (nuclear, industrial waste, etc.) origin. As a result, the plants growth in an contaminated environment may increase the risk of transfer within the plant, and finally the exposure of humans. Furthermore, pesticides are among the main contaminants investigated in the frame of human health risks resulting from food intakes. However, most of these scientific works focus mainly on their occurrence and persistence in water bodies, and few of them are interested in soil/plants transfer. In this context, the understanding of the processes governing transfers of pesticides in plants is become a necessity, in particular to prevent human risks linked the ingestion of food produced in contaminated environments. This objective can be reached by studying the pollutants behavior in soils/plants transfers, and using various substances/plants couples. In our study, we selected a salad/pesticide couple as our experimental model. Atrazine was chosen as model contaminant because of its problematic presence in a large amount of environmental compartments, its physico-chemical properties and because of its long-term toxicity. Lactuca sativa has been selected as model plant because of its importance in French agriculture, and specifically in Languedoc-Roussillon. Salad has been cultivated in peats and irrigated with an atrazine spiked water solution (concentrations from 10 to 100 μg/L). Plant growth in such conditions has been compared to a growth in clean condition (irrigation with non spiked water). Measurements of atrazine contents in

  1. Influence of fine process particles enriched with metals and metalloids on Lactuca sativa L. leaf fatty acid composition following air and/or soil-plant field exposure.

    PubMed

    Schreck, Eva; Laplanche, Christophe; Le Guédard, Marina; Bessoule, Jean-Jacques; Austruy, Annabelle; Xiong, Tiantian; Foucault, Yann; Dumat, Camille

    2013-08-01

    We investigate the effect of both foliar and root uptake of a mixture of metal(loid)s on the fatty acid composition of plant leaves. Our objectives are to determine whether both contamination pathways have a similar effect and whether they interact. Lactuca sativa L. were exposed to fine process particles enriched with metal(loid)s in an industrial area. Data from a first experiment were used to conduct an exploratory statistical analysis which findings were successfully cross-validated by using the data from a second one. Both foliar and root pathways impact plant leaf fatty acid composition and do not interact. Z index (dimensionless quantity), weighted product of fatty acid concentration ratios was built up from the statistical analyses. It provides new insights on the mechanisms involved in metal uptake and phytotoxicity. Plant leaf fatty acid composition is a robust and fruitful approach to detect and understand the effects of metal(loid) contamination on plants.

  2. Performance and feeding behaviour of two biotypes of the black currant-lettuce aphid, Nasonovia ribisnigri, on resistant and susceptible Lactuca sativa near-isogenic lines.

    PubMed

    ten Broeke, Cindy J M; Dicke, Marcel; van Loon, Joop J A

    2013-10-01

    The black currant-lettuce aphid, Nasonovia ribisnigri, is an important pest of cultivated lettuce, Lactuca sativa. Since 1982, the control of this aphid on lettuce is largely based on host plant resistance, conferred by the Nr gene, introgressed from Lactuca virosa. The resistance mechanism remains to be identified. N. ribisnigri populations virulent on the Nr-based resistance in lettuce have emerged in several locations in Europe since 2007. The objective of this study was to investigate the resistance mechanism mediated by the Nr gene in lettuce by detailed studies of aphid feeding behaviour and performance. Both avirulent (Nr:0) and virulent (Nr:1)biotypes of N. ribisnigri were studied on five resistant and two susceptible near isogenic lines (NILs). In addition, survival and colony development were quantified.Nr:0 aphids showed a strong decrease in sieve element ingestion and took longer to accept a sieve element on resistant NILs compared with susceptible NILs, and no aphids survived on the resistant NIL. Nr:1 aphids fed and performed equally well on the resistant and susceptible NILs. The resistance mechanism against Nr:0 aphids encoded by the Nr gene seems to be located in the phloem, although we also observed differences in feeding behaviour during the pathway phase to the phloem. Nr:1 aphids were highly virulent to the resistance conferred by the Nr gene. The consequences of the appearance of Nr:1 aphids for control of N. ribisnigri are discussed.

  3. Benzoxazolin-2(3H)-one (BOA) induced changes in leaf water relations, photosynthesis and carbon isotope discrimination in Lactuca sativa.

    PubMed

    Hussain, M Iftikhar; González, L; Chiapusio, G; Reigosa, M J

    2011-08-01

    The effects are reported here of Benzoxazolin-2(3H)-one (BOA), an allelopathic compound, on plant water relations, growth, components of chlorophyll fluorescence, and carbon isotope discrimination in lettuce (Lactuca sativa L.). Lettuce seedlings were grown in 1:1 Hoagland solution in perlite culture medium in environmentally controlled glasshouse. After 30 days, BOA was applied at concentration of 0.1, 0.5, 1.0 and 1.5 mM and distilled water (control). BOA, in the range (0.1-1.5 mM), decreased the shoot length, root length, leaf and root fresh weight. Within this concentration range, BOA significantly reduced relative water content while leaf osmotic potential remained unaltered. Stress response of lettuce was evaluated on the basis of six days of treatment with 1.5 mM BOA by analyzing several chlorophyll fluorescence parameters determined under dark-adapted and steady state conditions. There was no change in initial fluorescence (F₀) in response to BOA treatment while maximum chlorophyll fluorescence (F(m)) was significantly reduced. BOA treatment significantly reduced variable fluorescence (F(v)) on first, second, third, fourth, fifth and sixth day. Quantum efficiency of open PSII reaction centers (F(v)/F(m)) in the dark-adapted state was significantly reduced in response to BOA treatment. Quantum yield of photosystem II (ΦPSII) electron transport was significantly reduced because of decrease in the efficiency of excitation energy trapping of PSII reaction centers. Maximum fluorescence in light-adapted leaves (F'(m)) was significantly decreased but there was no change in initial fluorescence in light-adapted state (F'₀) in response to 1.5 mM BOA treatment. BOA application significantly reduced photochemical fluorescence quenching (qP) indicating that the balance between excitation rate and electron transfer rate has changed leading to a more reduced state of PSII reaction centers. Non photochemical quenching (NPQ) was also significantly reduced by BOA

  4. Effect of SPL (Spent Pot Liner) and its main components on root growth, mitotic activity and phosphorylation of Histone H3 in Lactuca sativa L.

    PubMed

    Freitas, Aline Silva; Fontes Cunha, Isabela Martinez; Andrade-Vieira, Larissa Fonseca; Techio, Vânia Helena

    2016-02-01

    Spent Pot Liner (SPL) is a solid waste from the aluminum industry frequently disposed of in industrial landfills; it can be leached and contaminate the soil, sources of drinking water and plantations, and thus may pose a risk to human health and to ecosystems. Its composition is high variable, including cyanide, fluoride and aluminum salts, which are highly toxic and environmental pollutants. This study evaluated the effect of SPL and its main components on root growth and the mitosis of Lactuca sativa, by investigating the mechanisms of cellular and chromosomal alterations with the aid of immunolocalization. To this end, newly emerged roots of L. sativa were exposed to SPL and its main components (solutions of cyanide, fluoride and aluminum) and to calcium chloride (control) for 48h. After this, root length was measured and cell cycle was examined by means of conventional cytogenetics and immunolocalization. Root growth was inhibited in the treatments with SPL and aluminum; chromosomal and nuclear alterations were observed in all treatments. The immunolocalization evidenced normal dividing cells with regular temporal and spatial distribution of histone H3 phosphorylation at serine 10 (H3S10ph). However, SPL and its main components inhibited the phosphorylation of histone H3 at serine 10, inactivated pericentromeric regions and affected the cohesion of sister chromatids, thus affecting the arrangement of chromosomes in the metaphase plate and separation of chromatids in anaphase. In addition, these substances induced breaks in pericentromeric regions, characterized as fragile sites.

  5. Physiological and molecular level effects of silver nanoparticles exposure in rice (Oryza sativa L.) seedlings.

    PubMed

    Nair, Prakash M Gopalakrishnan; Chung, Ill Min

    2014-10-01

    The physiological and molecular level changes of silver nanoparticles (AgNPs) exposure were investigated in rice (Oryza sativa L.) seedlings. The seedlings were exposed to different concentrations of (0, 0.2, 0.5 and 1 mg L(-1)) AgNPs for one week. Significant reduction in root elongation, shoot and root fresh weights, total chlorophyll and carotenoids contents were observed. Exposure to 0.5 and 1 mg L(-1) of AgNPs caused significant increase in hydrogen peroxide formation and lipid peroxidation in shoots and roots, increased foliar proline accumulation and decreased sugar contents. AgNPs exposure resulted in a dose dependant increase in reactive oxygen species generation and also caused cytotoxicity as evidenced by increased dihydroethidium, 3'-(p-hydroxyphenyl) fluorescein and propidium iodide fluorescence. Tetramethylrhodamine methyl ester assay showed decreased mitochondrial membrane potential with increasing concentrations of AgNPs exposure in roots. Real Time PCR analysis showed differential transcription of genes related to oxidative stress tolerance viz. FSD1, MSD1, CSD1, CSD2, CATa, CATb, CATc, APXa and APXb in shoots and roots of rice seedlings. The overall results suggest that exposure to AgNPs caused significant physiological and molecular level changes, oxidative stress and also resulted in the induction oxidative stress tolerance mechanisms in rice seedlings.

  6. A chlorophyll fluorescence analysis of photosynthetic efficiency, quantum yield and photon energy dissipation in PSII antennae of Lactuca sativa L. leaves exposed to cinnamic acid.

    PubMed

    Hussain, M Iftikhar; Reigosa, Manuel J

    2011-11-01

    This study investigated the effects of cinnamic acid (CA) on growth, biochemical and physiological responses of Lactuca sativa L. CA (0.1, 0.5, 1.0 and 1.5 mM) treatments decreased plant height, root length, leaf and root fresh weight, but it did not affect the leaf water status. CA treatment (1.5 mM) significantly reduced F(v), F(m), photochemical efficiency of PSII (F(v)/F(m)) and quantum yield of PSII (ΦPSII) photochemistry in L. sativa. The photochemical fluorescence quenching (qP) and non-photochemical quenching (NPQ) were reduced after treatment with 1.5 mM CA. Fraction of photon energy absorbed by PS II antennae trapped by "open" PS II reaction centers (P) was reduced by CA (1.5 mM) while, portion of absorbed photon energy thermally dissipated (D) and photon energy absorbed by PSII antennae and trapped by "closed" PSII reaction centers (E) was increased. Carbon isotope composition ratios (δ(13)C) was less negative (-27.10) in CA (1.5 mM) treated plants as compared to control (-27.61). Carbon isotope discrimination (Δ(13)C) and ratio of intercellular CO(2) concentration (ci/ca) from leaf to air were also less in CA treated plants. CA (1.5 mM) also decreased the leaf protein contents of L. sativa as compared to control.

  7. Accumulation of nickel ions in seedlings of Vicia sativa L. and manifestations of oxidative stress.

    PubMed

    Ivanishchev, V V; Abramova, E A

    2015-05-01

    The accumulation of nickel ions in the roots and shoots of vetch seedlings (Vicia sativa L.) at increasing concentrations of nickel chloride in the medium was studied. It was shown that the accumulation of nickel in the shoots was increased when the concentration of nickel chloride in the medium was more than 50 μM. The bioconcentration factor and sustainability index for vetch seedlings were calculated under the experimental conditions. The obtained results were similar to parameters for other plants, grown on a nutrient medium or soil substrate. First, the obtained results allowed estimate the limits of nickel chloride concentrations for four of five zones, which correspond to the theoretical concept of dose-response curves in the studies on the influence of physiologically essential heavy metals on plants (Prasad 2010). Some parameters of oxidative stress caused by the presence of nickel chloride in the medium were shown. It seems that at low nickel concentrations in the medium in vetch seedlings the increase of several biochemical parameters (catalase activity and proline) caused by the high amylase activity in seeds.

  8. [Effects of copper stress on Medicago sativa seedlings leaf antioxidative system].

    PubMed

    Wang, Song-hua; Zhang, Hua; He, Qing-yuan

    2011-09-01

    This paper studied the effects of different concentration (0, 10, 30, 50, and 100 micromol x L(-1)) CuSO4 on the leaf physiological and biochemical characteristics of Medicago sativa seedlings cultured with 1/4-strength Hoagland nutrient solution. In treatments 30, 50, and 100 micromol x L(-1) of CuSO4, the leaf H2O2, OH., and MDA contents and Fe-SOD and EST activities increased, and GSH and AsA contents increased significantly. With increasing concentration Cu, the POD, GR, and APX activities increased gradually, and the CAT and G6PDH activities decreased after an initial increase. In treatments >10 micromol x L(-1) of Cu, the capacity of leaf antioxidative system in reactive oxygen species scavenging increased to prevent the injury from copper-induced oxidative stress.

  9. Supplemental Upward Lighting from Underneath to Obtain Higher Marketable Lettuce (Lactuca sativa) Leaf Fresh Weight by Retarding Senescence of Outer Leaves

    PubMed Central

    Zhang, Geng; Shen, Shanqi; Takagaki, Michiko; Kozai, Toyoki; Yamori, Wataru

    2015-01-01

    Recently, the so-called “plant factory with artificial lighting” (PFAL) approach has been developed to provide safe and steady food production. Although PFALs can produce high-yielding and high-quality plants, the high plant density in these systems accelerates leaf senescence in the bottom (or outer) leaves owing to shading by the upper (or inner) leaves and by neighboring plants. This decreases yield and increases labor costs for trimming. Thus, the establishment of cultivation methods to retard senescence of outer leaves is an important research goal to improve PFAL yield and profitability. In the present study, we developed an LED lighting apparatus that would optimize light conditions for PFAL cultivation of a leafy vegetable. Lettuce (Lactuca sativa L.) was hydroponically grown under white, red, or blue LEDs, with light provided from above (downward), with or without supplemental upward lighting from underneath the plant. White LEDs proved more appropriate for lettuce growth than red or blue LEDs, and the supplemental lighting retarded the senescence of outer leaves and decreased waste (i.e., dead or low-quality senescent leaves), leading to an improvement of the marketable leaf fresh weight. PMID:26697055

  10. Transformation of Lactuca sativa L. with rol C gene results in increased antioxidant potential and enhanced analgesic, anti-inflammatory and antidepressant activities in vivo.

    PubMed

    Ismail, Hammad; Dilshad, Erum; Waheed, Mohammad Tahir; Sajid, Moniba; Kayani, Waqas Khan; Mirza, Bushra

    2016-12-01

    Lettuce is an important edible crop which possesses various medicinal properties. In this study Lactuca sativa L. (cv Grand Rapids) was transformed by Agrobacterium-mediated transformation with rol C gene. Transgene integration and expression was confirmed through PCR and semiquantitative RT-PCR. The transformed extracts were evaluated for their in vitro antioxidant and in vivo analgesic, anti-inflammatory and antidepressant activities in rats. The transformed plants showed 53-98 % increase in total phenolic and 45-58 % increase in total flavonoid contents compared with untransformed plants. Results of total reducing power and total antioxidant capacity exhibited 90-118 and 61-75 % increase in transformed plants, respectively. In contrast to control, DPPH, lipid peroxidation and DNA protection assay showed up to 37, 20 and 50 % enhancement in transformed plants, respectively. The extracts showed similar but significant enhancement behavior in hot plate analgesic and carrageenan-induced hind paw edema test. The transformed extracts showed 72.1 and 78.5 % increase for analgesic and anti-inflammatory activities, respectively. The transformants of rol C gene exhibited prominent antidepressant activity with 64-73 % increase compared with untransformed plants. In conclusion, the present work suggests that transformation with rol C gene can be used to generate lettuce with enhanced medicinally important properties, such as antioxidant, analgesic, anti-inflammatory and antidepressant potential.

  11. Root Zone Cooling and Exogenous Spermidine Root-Pretreatment Promoting Lactuca sativa L. Growth and Photosynthesis in the High-temperature Season.

    PubMed

    Sun, Jin; Lu, Na; Xu, Hongjia; Maruo, Toru; Guo, Shirong

    2016-01-01

    Root zone high-temperature stress is a major factor limiting hydroponic plant growth during the high-temperature season. The effects of root zone cooling (RZC; at 25°C) and exogenous spermidine (Spd) root-pretreatment (SRP, 0.1 mM) on growth, leaf photosynthetic traits, and chlorophyll fluorescence characteristics of hydroponic Lactuca sativa L. grown in a high-temperature season (average temperature > 30°C) were examined. Both treatments significantly promoted plant growth and photosynthesis in the high-temperature season, but the mechanisms of photosynthesis improvement in the hydroponic grown lettuce plants were different between the RZC and SRP treatments. The former improved plant photosynthesis by increasing stoma conductance (G s) to enhance CO2 supply, thus promoting photosynthetic electron transport activity and phosphorylation, which improved the level of the photochemical efficiency of photosystem II (PSII), rather than enhancing CO2 assimilation efficiency. The latter improved plant photosynthesis by enhancing CO2 assimilation efficiency, rather than stomatal regulation. Combination of RZC and SRP significantly improved P N of lettuce plants in a high-temperature season by both improvement of G s to enhance CO2 supply and enhancement of CO2 assimilation. The enhancement of photosynthetic efficiency in both treatments was independent of altering light-harvesting or excessive energy dissipation.

  12. Evaluation of anti-inflammatory activity and fast UHPLC-DAD-IT-TOF profiling of polyphenolic compounds extracted from green lettuce (Lactuca sativa L.; var. Maravilla de Verano).

    PubMed

    Pepe, Giacomo; Sommella, Eduardo; Manfra, Michele; De Nisco, Mauro; Tenore, Gian Carlo; Scopa, Antonio; Sofo, Adriano; Marzocco, Stefania; Adesso, Simona; Novellino, Tiziana; Campiglia, Pietro

    2015-01-15

    Fresh cut vegetables represent a widely consumed food worldwide. Among these, lettuce (Lactuca sativa L.) is one of the most popular on the market. The growing interest for this "healthy" food is related to the content of bioactive compounds, especially polyphenols, that show many beneficial effects. In this study, we report the anti-inflammatory and antioxidant potential of polyphenols extracted from lettuce (var. Maravilla de Verano), in J774A.1 macrophages stimulated with Escherichia coli lipopolysaccharide (LPS). Lettuce extract significantly decreased reactive oxygen species, nitric oxide release, inducible nitric oxide synthase and cycloxygenase-2 expression. A detailed quali/quantitative profiling of the polyphenolic content was carried out, obtaining fast separation (10 min), good retention time and peak area repeatability, (RSD% 0.80 and 8.68, respectively) as well as linearity (R(2)⩾ 0.999) and mass accuracy (⩽ 5 ppm). Our results show the importance in the diet of this cheap and popular food for his healthy properties.

  13. Metallic Nanoparticle (TiO2 and Fe3O4) Application Modifies Rhizosphere Phosphorus Availability and Uptake by Lactuca sativa.

    PubMed

    Zahra, Zahra; Arshad, Muhammad; Rafique, Rafia; Mahmood, Arshad; Habib, Amir; Qazi, Ishtiaq A; Khan, Saud A

    2015-08-12

    Application of engineered nanoparticles (NPs) with respect to nutrient uptake in plants is not yet well understood. The impacts of TiO2 and Fe3O4 NPs on the availability of naturally soil-bound inorganic phosphorus (Pi) to plants were studied along with relevant parameters. For this purpose, Lactuca sativa (lettuce) was cultivated on the soil amended with TiO2 and Fe3O4 (0, 50, 100, 150, 200, and 250 mg kg(-1)) over a period of 90 days. Different techniques, such as scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), Raman, and Fourier transform infrared spectroscopy (FTIR) were used to monitor translocation and understand the possible mechanisms for phosphorus (P) uptake. The trends for P accumulation were different for roots (TiO2 > Fe3O4 > control) and shoots (Fe3O4 > TiO2 > control). Cystine and methionine were detected in the rhizosphere in Raman spectra. Affinities of NPs to adsorb phosphate ions, modifications in P speciation, and NP stress in the rhizosphere had possibly contributed to enhanced root exudation and acidification. All of these changes led to improved P availability and uptake by the plants. These promising results can help to develop an innovative strategy for using NPs for improved nutrient management to ensure food security.

  14. Production characteristics of lettuce Lactuca sativa L. in the frame of the first crop tests in the Higher Plant Chamber integrated into the MELiSSA Pilot Plant

    NASA Astrophysics Data System (ADS)

    Tikhomirova, Natalia; Lawson, Jamie; Stasiak, Michael; Dixon, Mike; Paille, Christel; Peiro, Enrique; Fossen, Arnaud; Godia, Francesc

    Micro-Ecological Life Support System Alternative (MELiSSA) is an artificial closed ecosystem that is considered a tool for the development of a bioregenerative life support system for manned space missions. One of the five compartments of MELiSSA loop -Higher Plant Chamber was recently integrated into the MELiSSA Pilot Plant facility at Universitat Aut`noma deo Barcelona. The main contributions expected by integration of this photosynthetic compartment are oxygen, water, vegetable food production and CO2 consumption. Production characteristics of Lactuca sativa L., as a MELiSSA candidate crop, were investigated in this work in the first crop experiments in the MELiSSA Pilot Plant facility. The plants were grown in batch culture and totaled 100 plants with a growing area 5 m long and 1 m wide in a sealed controlled environment. Several replicates of the experiments were carried out with varying duration. It was shown that after 46 days of lettuce cultivation dry edible biomass averaged 27, 2 g per plant. However accumulation of oxygen in the chamber, which required purging of the chamber, and decrease in the food value of the plants was observed. Reducing the duration of the tests allowed uninterrupted test without opening the system and also allowed estimation of the crop's carbon balance. Results of productivity, tissue composition, nutrient uptake and canopy photosynthesis of lettuce regardless of test duration are discussed in the paper.

  15. Particle trajectories in seeds of Lactuca sativa and chromosome aberrations after exposure to cosmic heavy ions on cosmos biosatellites 8 and 9

    NASA Astrophysics Data System (ADS)

    Facius, R.; Scherer, K.; Reitz, G.; Bücker, H.; Nevzgodina, L. V.; Maximova, E. N.

    1994-10-01

    The potentially specific importance of the heavy ions of the galactic cosmic radiation for radiation protection in manned spaceflight continues to stimulate in situ, i.e., spaceflight experiments to investigate their radiobiological properties. Chromosome aberrations as an expression of a direct assault on the genome are of particular interest in view of cancerogenesis being the primary radiation risk for man in space. In such investigations the establishment of the geometrical correlation between heavy ions' trajectories and the location of radiation sensitive biological substructures is an essential task. The overall qualitative and quantitative precision achieved for the identification of particle trajectories in the order of 2~10 μm as well as the contributing sources of uncertainties are discussed. We describe how this was achieved for seeds of Lactuca sativa as biological test organisms, whose location and orientation had to be derived from contact photographies displaying their outlines and those of the holder plates only. The incidence of chromosome aberrations in cells exposed during the COSMOS 1887 (Biosatellite 8) and the COSMOS 2044 (Biosatellite 9) mission was determined for seeds hit by cosmic heavy ions. In those seeds the incidence of both single and multiple chromosome aberrations was enhanced. The results of the Biosatellite 9 experiment, however, are confounded by spaceflight effects unrelated to the passage of heavy ions.

  16. Supplemental Upward Lighting from Underneath to Obtain Higher Marketable Lettuce (Lactuca sativa) Leaf Fresh Weight by Retarding Senescence of Outer Leaves.

    PubMed

    Zhang, Geng; Shen, Shanqi; Takagaki, Michiko; Kozai, Toyoki; Yamori, Wataru

    2015-01-01

    Recently, the so-called "plant factory with artificial lighting" (PFAL) approach has been developed to provide safe and steady food production. Although PFALs can produce high-yielding and high-quality plants, the high plant density in these systems accelerates leaf senescence in the bottom (or outer) leaves owing to shading by the upper (or inner) leaves and by neighboring plants. This decreases yield and increases labor costs for trimming. Thus, the establishment of cultivation methods to retard senescence of outer leaves is an important research goal to improve PFAL yield and profitability. In the present study, we developed an LED lighting apparatus that would optimize light conditions for PFAL cultivation of a leafy vegetable. Lettuce (Lactuca sativa L.) was hydroponically grown under white, red, or blue LEDs, with light provided from above (downward), with or without supplemental upward lighting from underneath the plant. White LEDs proved more appropriate for lettuce growth than red or blue LEDs, and the supplemental lighting retarded the senescence of outer leaves and decreased waste (i.e., dead or low-quality senescent leaves), leading to an improvement of the marketable leaf fresh weight.

  17. Genotype variations in cadmium and lead accumulations of leafy lettuce (Lactuca sativa L.) and screening for pollution-safe cultivars for food safety.

    PubMed

    Zhang, Kun; Yuan, Jiangang; Kong, Wei; Yang, Zhongyi

    2013-06-01

    Heavy-metals in polluted soils can accumulate in plants and threaten crop safety. To evaluate the risk of heavy-metal pollution in leafy lettuce (Lactuca sativa L.), two pot experiments were conducted to investigate Cd and Pb accumulation and transfer potential in 28 cultivars of lettuce and to screen for low-Cd and low-Pb accumulative cultivars. In the three treatments, 5.2-fold, 4.8-fold and 4.8-fold differences in the shoot Cd concentration were observed between the cultivars with the highest and the lowest Cd concentrations, respectively. This genotype variation was sufficiently large to identify low-Cd accumulative genotypes to reduce Cd contamination in food. Cadmium accumulation in the low-Cd accumulative genotypes was significantly positively correlated with Pb accumulation. At the cultivar level, Cd and Pb accumulation in lettuce was stable and genotype-dependent. High Pb soil levels did not affect shoot Cd accumulation in lettuce. Lettuce was concluded to be at high risk for Cd pollution and low risk for Pb pollution. Among the tested cultivars, cvs. SJGT, YLGC, N518, and KR17 had the lowest Cd and Pb accumulation abilities in shoots and are thus important parental material for breeding pollution-safe cultivars to minimize Cd and Pb accumulation.

  18. Proximate nutrient analyses of four species of submerged aquatic vegetation consumed by Florida manatee (Trichechus manatus latirostris) compared to romaine lettuce (Lactuca sativa var. longifolia).

    PubMed

    Siegal-Willott, Jessica L; Harr, Kendal; Hayek, Lee-Ann C; Scott, Karen C; Gerlach, Trevor; Sirois, Paul; Reuter, Mike; Crewz, David W; Hill, Richard C

    2010-12-01

    Free-ranging Florida manatees (Trichechus manatus latirostris) consume a variety of sea grasses and algae. This study compared the dry matter (DM) content, proximate nutrients (crude protein [CP], ether-extracted crude fat [EE], nonfiber carbohydrate [NFC], and ash), and the calculated digestible energy (DE) of sea grasses (Thalassia testudinum, Halodule wrightii, and Syringodium filiforme) collected in spring, summer, and winter, and an alga (Chara sp.) with those of romaine lettuce (Lactuca sativa var. longifolia). Neutral-detergent fiber (NDF), acid-detergent fiber (ADF), and lignin (L) measured after ash-extraction were also compared. Results of statistical tests (C = 0.01) revealed DM content was higher in aquatic vegetation than in lettuce (P = 0.0001), but NDF and ADF were up to threefold greater, EE (P = 0.00001) and CP (P = 0.00001) were 2-9 times less, and NFC (P = 0.0001) was 2-6 times lower in sea grass than in lettuce, on a DM basis. Chara was lower in NDF, ADF, L, EE, CP, and NFC relative to lettuce on a DM basis. Ash content (DM basis) was higher (P = 0.0001), and DE was 2-6 times lower in aquatic vegetation than in lettuce. Sea grass rhizomes had lower L and higher ash contents (DM basis) than sea grass leaves. Based on the nutrient analyses, romaine lettuce and sea grasses are not equivalent forages, which suggests that the current diet of captive Florida manatees should be reassessed.

  19. Root Zone Cooling and Exogenous Spermidine Root-Pretreatment Promoting Lactuca sativa L. Growth and Photosynthesis in the High-temperature Season

    PubMed Central

    Sun, Jin; Lu, Na; Xu, Hongjia; Maruo, Toru; Guo, Shirong

    2016-01-01

    Root zone high-temperature stress is a major factor limiting hydroponic plant growth during the high-temperature season. The effects of root zone cooling (RZC; at 25°C) and exogenous spermidine (Spd) root-pretreatment (SRP, 0.1 mM) on growth, leaf photosynthetic traits, and chlorophyll fluorescence characteristics of hydroponic Lactuca sativa L. grown in a high-temperature season (average temperature > 30°C) were examined. Both treatments significantly promoted plant growth and photosynthesis in the high-temperature season, but the mechanisms of photosynthesis improvement in the hydroponic grown lettuce plants were different between the RZC and SRP treatments. The former improved plant photosynthesis by increasing stoma conductance (Gs) to enhance CO2 supply, thus promoting photosynthetic electron transport activity and phosphorylation, which improved the level of the photochemical efficiency of photosystem II (PSII), rather than enhancing CO2 assimilation efficiency. The latter improved plant photosynthesis by enhancing CO2 assimilation efficiency, rather than stomatal regulation. Combination of RZC and SRP significantly improved PN of lettuce plants in a high-temperature season by both improvement of Gs to enhance CO2 supply and enhancement of CO2 assimilation. The enhancement of photosynthetic efficiency in both treatments was independent of altering light-harvesting or excessive energy dissipation. PMID:27047532

  20. Investigating the ability of Pseudomonas fluorescens UW4 to reduce cadmium stress in Lactuca sativa via an intervention in the ethylene biosynthetic pathway.

    PubMed

    Albano, Lucas J; Macfie, Sheila M

    2016-12-01

    A typical plant response to any biotic or abiotic stress, including cadmium (Cd), involves increased ethylene synthesis, which causes senescence of the affected plant part. Stressed plants can experience reduced ethylene and improved growth if they are inoculated with bacteria that have the enzyme ACC deaminase, which metabolizes the ethylene precursor ACC (1-aminocyclopropane-1-carboxylate). We investigated whether one such bacterium, Pseudomonas fluorescens UW4, reduces the production of ethylene and improves the growth of lettuce (Lactuca sativa) sown in Cd-contaminated potting material (PRO-MIX® BX). Plants were inoculated with the wild-type P. fluorescens UW4 or a mutant strain that cannot produce ACC deaminase. Cadmium-treated plants contained up to 50 times more Cd than did control plants. In noninoculated plants, Cd induced a 5-fold increase in ethylene concentration. The wild-type bacterium prevented Cd-induced reductions in root biomass but there was no relationship between Cd treatment and ethylene production in inoculated plants. In contrast, when the concentration of ethylene was plotted against the extent of bacterial colonization of the roots, increased colonization with wild-type P. fluorescens UW4 was associated with 20% less ethylene production. Ours is the first study to show that the protective effect of this bacterium is proportional to the quantity of bacteria on the root surface.

  1. Elongation growth of the leaf sheath base of Avena sativa seedlings: regulation by hormones and sucrose

    NASA Technical Reports Server (NTRS)

    Brock, T. G.; Kaufman, P. B.

    1991-01-01

    The leaf sheath base of the seedling of Avena sativa was characterized for growth response to hormones and sucrose. Six day old plants, raised under a 10:14 hr light:dark cycle, were excised at the coleoptilar node and 1 cm above the node for treatment. The growth of the leaf sheath base was promoted by gibberellic acid (GA3) and this response was dose dependent. The lag to response initiation was approximately 4 hr. Growth with or without GA3 (10 micromoles) was transient, diminishing appreciably after 48 hr. The addition of 10 mM sucrose greatly prolonged growth; the effect of GA3 and sucrose was additive. Neither indole-3-acetic acid (IAA) nor the cytokinin N6-benzyladenine (BA), alone or in combination, promoted the growth of leaf sheath bases. However, both significantly inhibited the action of GA3. The inhibitory effect of IAA was dose dependent and was not affected by the addition of BA or sucrose. These results indicate that the growth of leaf sheath bases of Avena sativa is promoted specifically by gibberellin, that this action depends on the availability of carbohydrates from outside of the leaf sheath base, and that the promotional effect of GA3 can be modified by either auxins or cytokinins.

  2. Sensitivity of salad greens (Lactuca sativa L. and Eruca sativa Mill.) exposed to crude extracts of toxic and non-toxic cyanobacteria.

    PubMed

    Bittencourt-Oliveira, M C; Hereman, T C; Macedo-Silva, I; Cordeiro-Araújo, M K; Sasaki, F F C; Dias, C T S

    2015-05-01

    We evaluated the effect of crude extracts of the microcystin-producing (MC+) cyanobacteria Microcystis aeruginosa on seed germination and initial development of lettuce and arugula, at concentrations between 0.5 μg.L(-1) and 100 μg.L(-1) of MC-LR equivalent, and compared it to crude extracts of the same species without the toxin (MC-). Crude extracts of the cyanobacteria with MC (+) and without MC (-) caused different effects on seed germination and initial development of the salad green seedlings, lettuce being more sensitive to both extracts when compared to arugula. Crude extracts of M. aeruginosa (MC+) caused more evident effects on seed germination and initial development of both species of salad greens than MC-. Concentrations of 75 μg.L(-1) and 100 μg.L(-1) of MC-LR equivalent induced a greater occurrence of abnormal seedlings in lettuce, due to necrosis of the radicle and shortening of this organ in normal seedlings, as well as the reduction in total chlorophyll content and increase in the activity of the antioxidant enzyme peroxidase (POD). The MC- extract caused no harmful effects to seed germination and initial development of seedlings of arugula. However, in lettuce, it caused elevation of POD enzyme activity, decrease in seed germination at concentrations of 75 μg.L(-1) (MC-75) and 100 μg.L(-1) (MC-100), and shortening of the radicle length, suggesting that other compounds present in the cyanobacteria extracts contributed to this result. Crude extracts of M. aeruginosa (MC-) may contain other compounds, besides the cyanotoxins, capable of causing inhibitory or stimulatory effects on seed germination and initial development of salad green seedlings. Arugula was more sensitive to the crude extracts of M. aeruginosa (MC+) and (MC-) and to other possible compounds produced by the cyanobacteria.

  3. A Lettuce (Lactuca sativa) Homolog of Human Nogo-B Receptor Interacts with cis-Prenyltransferase and Is Necessary for Natural Rubber Biosynthesis*

    PubMed Central

    Qu, Yang; Chakrabarty, Romit; Tran, Hue T.; Kwon, Eun-Joo G.; Kwon, Moonhyuk; Nguyen, Trinh-Don; Ro, Dae-Kyun

    2015-01-01

    Natural rubber (cis-1,4-polyisoprene) is an indispensable biopolymer used to manufacture diverse consumer products. Although a major source of natural rubber is the rubber tree (Hevea brasiliensis), lettuce (Lactuca sativa) is also known to synthesize natural rubber. Here, we report that an unusual cis-prenyltransferase-like 2 (CPTL2) that lacks the conserved motifs of conventional cis-prenyltransferase is required for natural rubber biosynthesis in lettuce. CPTL2, identified from the lettuce rubber particle proteome, displays homology to a human NogoB receptor and is predominantly expressed in latex. Multiple transgenic lettuces expressing CPTL2-RNAi constructs showed that a decrease of CPTL2 transcripts (3–15% CPTL2 expression relative to controls) coincided with the reduction of natural rubber as low as 5%. We also identified a conventional cis-prenyltransferase 3 (CPT3), exclusively expressed in latex. In subcellular localization studies using fluorescent proteins, cytosolic CPT3 was relocalized to endoplasmic reticulum by co-occurrence of CPTL2 in tobacco and yeast at the log phase. Furthermore, yeast two-hybrid data showed that CPTL2 and CPT3 interact. Yeast microsomes containing CPTL2/CPT3 showed enhanced synthesis of short cis-polyisoprenes, but natural rubber could not be synthesized in vitro. Intriguingly, a homologous pair CPTL1/CPT1, which displays ubiquitous expressions in lettuce, showed a potent dolichol biosynthetic activity in vitro. Taken together, our data suggest that CPTL2 is a scaffolding protein that tethers CPT3 on endoplasmic reticulum and is necessary for natural rubber biosynthesis in planta, but yeast-expressed CPTL2 and CPT3 alone could not synthesize high molecular weight natural rubber in vitro. PMID:25477521

  4. Leaf Morphology, Photosynthetic Performance, Chlorophyll Fluorescence, Stomatal Development of Lettuce (Lactuca sativa L.) Exposed to Different Ratios of Red Light to Blue Light.

    PubMed

    Wang, Jun; Lu, Wei; Tong, Yuxin; Yang, Qichang

    2016-01-01

    Red and blue light are both vital factors for plant growth and development. We examined how different ratios of red light to blue light (R/B) provided by light-emitting diodes affected photosynthetic performance by investigating parameters related to photosynthesis, including leaf morphology, photosynthetic rate, chlorophyll fluorescence, stomatal development, light response curve, and nitrogen content. In this study, lettuce plants (Lactuca sativa L.) were exposed to 200 μmol⋅m(-2)⋅s(-1) irradiance for a 16 h⋅d(-1) photoperiod under the following six treatments: monochromatic red light (R), monochromatic blue light (B) and the mixture of R and B with different R/B ratios of 12, 8, 4, and 1. Leaf photosynthetic capacity (A max) and photosynthetic rate (P n) increased with decreasing R/B ratio until 1, associated with increased stomatal conductance, along with significant increase in stomatal density and slight decrease in stomatal size. P n and A max under B treatment had 7.6 and 11.8% reduction in comparison with those under R/B = 1 treatment, respectively. The effective quantum yield of PSII and the efficiency of excitation captured by open PSII center were also significantly lower under B treatment than those under the other treatments. However, shoot dry weight increased with increasing R/B ratio with the greatest value under R/B = 12 treatment. The increase of shoot dry weight was mainly caused by increasing leaf area and leaf number, but no significant difference was observed between R and R/B = 12 treatments. Based on the above results, we conclude that quantitative B could promote photosynthetic performance or growth by stimulating morphological and physiological responses, yet there was no positive correlation between P n and shoot dry weight accumulation.

  5. Effects of microcystin-LR, cylindrospermopsin and a microcystin-LR/cylindrospermopsin mixture on growth, oxidative stress and mineral content in lettuce plants (Lactuca sativa L.).

    PubMed

    Freitas, Marisa; Azevedo, Joana; Pinto, Edgar; Neves, Joana; Campos, Alexandre; Vasconcelos, Vitor

    2015-06-01

    Toxic cyanobacterial blooms are documented worldwide as an emerging environmental concern. Recent studies support the hypothesis that microcystin-LR (MC-LR) and cylindrospermopsin (CYN) produce toxic effects in crop plants. Lettuce (Lactuca sativa L.) is an important commercial leafy vegetable that supplies essential elements for human nutrition; thus, the study of its sensitivity to MC-LR, CYN and a MC-LR/CYN mixture is of major relevance. This study aimed to assess the effects of environmentally relevant concentrations (1, 10 and 100 µg/L) of MC-LR, CYN and a MC-LR/CYN mixture on growth, antioxidant defense system and mineral content in lettuce plants. In almost all treatments, an increase in root fresh weight was obtained; however, the fresh weight of leaves was significantly decreased in plants exposed to 100 µg/L concentrations of each toxin and the toxin mixture. Overall, GST activity was significantly increased in roots, contrary to GPx activity, which decreased in roots and leaves. The mineral content in lettuce leaves changed due to its exposure to cyanotoxins; in general, the mineral content decreased with MC-LR and increased with CYN, and apparently these effects are time and concentration-dependent. The effects of the MC-LR/CYN mixture were almost always similar to the single cyanotoxins, although MC-LR seems to be more toxic than CYN. Our results suggest that lettuce plants in non-early stages of development are able to cope with lower concentrations of MC-LR, CYN and the MC-LR/CYN mixture; however, higher concentrations (100 µg/L) can affect both lettuce yield and nutritional quality.

  6. The use of nile tilapia (Oreochromis niloticus) cultivation wastewater for the production of romaine lettuce (Lactuca sativa L. var. longifolia) in water recirculation system

    NASA Astrophysics Data System (ADS)

    Effendi, Hefni; Wahyuningsih, Sri; Wardiatno, Yusli

    2016-05-01

    In the recirculation aquaponic system (RAS), fish farming waste was utilized as a nutrient for plant, minimizing the water need, reducing the waste disposal into the environment, and producing the fish and plant as well. The study aimed to examine the growth of romaine lettuce (Lactuca sativa L. var. Longifolia) in aquaponic system without the addition of artificial nutrient. The nutrient relies solely on wastewater of nile tilapia (Oreochromis niloticus) cultivation circulated continuously on the aquaponic system. The results showed that tilapia weight reached 48.49 ± 3.92 g of T3 (tilapia, romaine lettuce, and inoculated bacteria), followed by T2 (tilapia and romaine lettuce) and T1 (tilapia) of 47.80 ± 1.97 and 45.89 ± 1.10 g after 35 days of experiment. Tilapia best performance in terms of growth and production occurred at T3 of 3.96 ± 0.44 g/day, 12.10 ± 0.63 %/day, 96.11 ± 1.44 % and 1.60 ± 0.07 for GR, SGR, SR, and FCR, respectively. It is also indicated by better water quality characteristic in this treatment. Romaine lettuce harvests of T2 and T3 showed no significant difference, with the final weight of 61.87 ± 5.59 and 57.74 ± 4.35 g. Overall, the integration of tilapia fish farming and romaine lettuce is potentially a promising aquaponic system for sustainable fish and horticulture plant production.

  7. A lettuce (Lactuca sativa) homolog of human Nogo-B receptor interacts with cis-prenyltransferase and is necessary for natural rubber biosynthesis.

    PubMed

    Qu, Yang; Chakrabarty, Romit; Tran, Hue T; Kwon, Eun-Joo G; Kwon, Moonhyuk; Nguyen, Trinh-Don; Ro, Dae-Kyun

    2015-01-23

    Natural rubber (cis-1,4-polyisoprene) is an indispensable biopolymer used to manufacture diverse consumer products. Although a major source of natural rubber is the rubber tree (Hevea brasiliensis), lettuce (Lactuca sativa) is also known to synthesize natural rubber. Here, we report that an unusual cis-prenyltransferase-like 2 (CPTL2) that lacks the conserved motifs of conventional cis-prenyltransferase is required for natural rubber biosynthesis in lettuce. CPTL2, identified from the lettuce rubber particle proteome, displays homology to a human NogoB receptor and is predominantly expressed in latex. Multiple transgenic lettuces expressing CPTL2-RNAi constructs showed that a decrease of CPTL2 transcripts (3-15% CPTL2 expression relative to controls) coincided with the reduction of natural rubber as low as 5%. We also identified a conventional cis-prenyltransferase 3 (CPT3), exclusively expressed in latex. In subcellular localization studies using fluorescent proteins, cytosolic CPT3 was relocalized to endoplasmic reticulum by co-occurrence of CPTL2 in tobacco and yeast at the log phase. Furthermore, yeast two-hybrid data showed that CPTL2 and CPT3 interact. Yeast microsomes containing CPTL2/CPT3 showed enhanced synthesis of short cis-polyisoprenes, but natural rubber could not be synthesized in vitro. Intriguingly, a homologous pair CPTL1/CPT1, which displays ubiquitous expressions in lettuce, showed a potent dolichol biosynthetic activity in vitro. Taken together, our data suggest that CPTL2 is a scaffolding protein that tethers CPT3 on endoplasmic reticulum and is necessary for natural rubber biosynthesis in planta, but yeast-expressed CPTL2 and CPT3 alone could not synthesize high molecular weight natural rubber in vitro.

  8. Uptake of arsenic species by turnip (Brassica rapa L.) and lettuce (Lactuca sativa L.) treated with roxarsone and its metabolites in chicken manure.

    PubMed

    Huang, Lian Xi; Yao, Li Xian; He, Zhao Huan; Zhou, Chang Min; Li, Guo Liang; Yang, Bao Mei; Li, Ying Fen

    2013-01-01

    Roxarsone is an organoarsenic feed additive that can be metabolised to other higher toxic arsenic (As) species in animal manure such as arsenate, arsenite, monomethylarsonic acid, dimethylarsinic acid, 3-amino-4-hydroxyphenylarsonic acid and other unknown As species. The accumulation, transport and distribution of As species in turnip (Brassica rapa L.) and lettuce (Lactuca sativa L.) amended with roxarsone and its metabolites in chicken manure were investigated. Results showed arsenite was the predominant As form, followed by arsenate in turnip and lettuce plants, and a low content of dimethylarsinic acid was detected only in lettuce roots. Compared with the control plants treated with chicken manure without roxarsone and its metabolites, the treatments containing roxarsone and its metabolites increased arsenite content by 2.0-3.2% in turnip shoots, by 6.6-6.7% in lettuce shoots, by 11-44% in turnip tubers and by 18-20% in lettuce roots at two growth stages. The enhanced proportion of arsenate content in turnip shoots, turnip tubers and lettuce roots was 4.3-14%, 20-35% and 70%, respectively, while dimethylarsinic acid content in lettuce roots increased 2.4 times. Results showed that the occurrence of dimethylarsinic acid in lettuce roots might be converted from the inorganic As species and the uptake of both inorganic and organic As compounds in turnip and lettuce plants would be enhanced by roxarsone and its metabolites in chicken manure. The pathway of roxarsone metabolites introduced into the human body via roxarsone → animal → manure → soil → crop was indicated.

  9. Leaf Morphology, Photosynthetic Performance, Chlorophyll Fluorescence, Stomatal Development of Lettuce (Lactuca sativa L.) Exposed to Different Ratios of Red Light to Blue Light

    PubMed Central

    Wang, Jun; Lu, Wei; Tong, Yuxin; Yang, Qichang

    2016-01-01

    Red and blue light are both vital factors for plant growth and development. We examined how different ratios of red light to blue light (R/B) provided by light-emitting diodes affected photosynthetic performance by investigating parameters related to photosynthesis, including leaf morphology, photosynthetic rate, chlorophyll fluorescence, stomatal development, light response curve, and nitrogen content. In this study, lettuce plants (Lactuca sativa L.) were exposed to 200 μmol⋅m−2⋅s−1 irradiance for a 16 h⋅d−1 photoperiod under the following six treatments: monochromatic red light (R), monochromatic blue light (B) and the mixture of R and B with different R/B ratios of 12, 8, 4, and 1. Leaf photosynthetic capacity (Amax) and photosynthetic rate (Pn) increased with decreasing R/B ratio until 1, associated with increased stomatal conductance, along with significant increase in stomatal density and slight decrease in stomatal size. Pn and Amax under B treatment had 7.6 and 11.8% reduction in comparison with those under R/B = 1 treatment, respectively. The effective quantum yield of PSII and the efficiency of excitation captured by open PSII center were also significantly lower under B treatment than those under the other treatments. However, shoot dry weight increased with increasing R/B ratio with the greatest value under R/B = 12 treatment. The increase of shoot dry weight was mainly caused by increasing leaf area and leaf number, but no significant difference was observed between R and R/B = 12 treatments. Based on the above results, we conclude that quantitative B could promote photosynthetic performance or growth by stimulating morphological and physiological responses, yet there was no positive correlation between Pn and shoot dry weight accumulation. PMID:27014285

  10. Arabidopsis R2R3-MYB transcription factor AtMYB60 functions as a transcriptional repressor of anthocyanin biosynthesis in lettuce (Lactuca sativa)

    PubMed Central

    Park, Jong-Sug; Kim, Jung-Bong; Cho, Kang-Jin; Cheon, Choong-Ill; Sung, Mi-Kyung; Choung, Myoung-Gun

    2008-01-01

    The MYB transcription factors play important roles in the regulation of many secondary metabolites at the transcriptional level. We evaluated the possible roles of the Arabidopsis R2R3-MYB transcription factors in flavonoid biosynthesis because they are induced by UV-B irradiation but their associated phenotypes are largely unexplored. We isolated their genes by RACE-PCR, and performed transgenic approach and metabolite analyses in lettuce (Lactuca sativa). We found that one member of this protein family, AtMYB60, inhibits anthocyanin biosynthesis in the lettuce plant. Wild-type lettuce normally accumulates anthocyanin, predominantly cyanidin and traces of delphinidin, and develops a red pigmentation. However, the production and accumulation of anthocyanin pigments in AtMYB60-overexpressing lettuce was inhibited. Using RT-PCR analysis, we also identified the complete absence or reduction of dihydroflavonol 4-reductase (DFR) transcripts in AtMYB60- overexpressing lettuce (AtMYB60-117 and AtMYB60-112 lines). The correlation between the overexpression of AtMYB60 and the inhibition of anthocyanin accumulation suggests that the transcription factorAtMYB60 controls anthocyanin biosynthesis in the lettuce leaf. Clarification of the roles of the AtMYB60 transcription factor will facilitate further studies and provide genetic tools to better understand the regulation in plants of the genes controlled by the MYB-type transcription factors. Furthermore, the characterization of AtMYB60 has implications for the development of new varieties of lettuce and other commercially important plants with metabolic engineering approaches. PMID:18317777

  11. Toxicity of methyl tert butyl ether to soil invertebrates (springtails: Folsomia candida, Proisotoma minuta, and Onychiurus folsomi) and lettuce (Lactuca sativa).

    PubMed

    Dodd, Matthew; Addison, Janet A

    2010-02-01

    Experiments were conducted to assess the toxicity of methyl tert butyl ether (MTBE) to three species of Collembola (Proisotoma minuta, Folsomia candida, and Onychiurus folsomi) and lettuce (Lactuca sativa L.) using an artificial Organization for Economic Cooperation and Development (OECD) soil and field-collected sandy loam and silt loam soil samples. Soil invertebrate tests were carried out in airtight vials to prevent volatilization of MTBE out of the test units and to allow for direct head-space sampling and gas chromatography-mass spectrometry (GC-MS) analysis for residual MTBE. The use of the airtight vial protocol proved to be very successful, in that the measured MTBE concentrations at the beginning of the experiments were within 95% of nominal concentrations. The test methods used in this study could be used to test the toxicity of other volatile organic compounds to Collembola. The soil invertebrates tested had inhibitory concentration (ICx) and lethal concentration (LCx) values that ranged from 242 to 844 mg MTBE/kg dry soil. When the three test species of Collembola were tested under identical conditions in the artificial OECD soil, O. folsomi was the most sensitive collembolan, with a median inhibitory concentration (IC50; reproduction) of 296 mg MTBE/kg dry soil. The most sensitive endpoint for lettuce was an IC50 for root length of 81 mg MTBE/kg dry soil after 5 d of germination in OECD soil. Data on the loss of MTBE from the three test soils over time indicated that MTBE was retained in the silt loam soil longer than in either the sandy loam or the artificial OECD soil.

  12. Selective toxin effects on faster and slower growing individuals in the formation of hormesis at the population level - A case study with Lactuca sativa and PCIB.

    PubMed

    Belz, Regina G; Sinkkonen, Aki

    2016-10-01

    Natural plant populations have large phenotypic plasticity that enhances acclimation to local stress factors such as toxin exposures. While consequences of high toxin exposures are well addressed, effects of low-dose toxin exposures on plant populations are seldom investigated. In particular, the importance of 'selective low-dose toxicity' and hormesis, i.e. stimulatory effects, has not been studied simultaneously. Since selective toxicity can change the size distribution of populations, we assumed that hormesis alters the size distribution at the population level, and investigated whether and how these two low-dose phenomena coexist. The study was conducted with Lactuca sativa L. exposed to the auxin-inhibitor 2-(p-chlorophenoxy)-2-methylpropionic acid (PCIB) in vitro. In two separate experiments, L. sativa was exposed to 12 PCIB doses in 24 replicates (50 plants/replicate). Shoot/root growth responses at the population level were compared to the fast-growing (≥90% percentile) and the slow-growing subpopulations (≤10% percentile) by Mann-Whitney U testing and dose-response modelling. In the formation of pronounced PCIB hormesis at the population level, low-dose effects proved selective, but widely stimulatory which seems to counteract low-dose selective toxicity. The selectivity of hormesis was dose- and growth rate-dependent. Stimulation occurred at lower concentrations and stimulation percentage was higher among slow-growing individuals, but partly or entirely masked at the population level by moderate or negligible stimulation among the faster growing individuals. We conclude that the hormetic effect up to the maximum stimulation may be primarily facilitated by an increase in size of the most slow-growing individuals, while thereafter it seems that mainly the fast-growing individuals contributed to the observed hormesis at the population level. As size distribution within a population is related to survival, our study hints that selective effects on slow

  13. Effect of proline on biochemical and molecular mechanisms in lettuce (Lactuca sativa L.) exposed to UV-B radiation.

    PubMed

    Aksakal, Ozkan; Tabay, Dilruba; Esringu, Aslıhan; Icoglu Aksakal, Feyza; Esim, Nevzat

    2017-02-15

    The purpose of the present study was to evaluate the role of proline (Pro) in relieving UV-B radiation-induced oxidative stress in lettuce. Lettuce seedlings were exposed to 3.3 W m(-2) UV-B radiation for 12 h after pre-treatment sprayed with 20 mM Pro. The data for malondialdehyde (MDA), hydrogen peroxide (H2O2), endogenous Pro level, the activities of antioxidant enzymes [superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and peroxidase (POD)], total phenolic concentration, antioxidant capacity, expression of phenylalanine ammonia lyase (PAL), γ-tocopherol methyltransferase (γ-TMT) and proline dehydrogenase (ProDH) genes, phytohormone levels such as abscisic acid (ABA), gibberellic acid (GA), indole acetic acid (IAA) and salicylic acid (SA), soluble sugars and organic acids were recorded. It was found that Pro alleviated the oxidative damage in the seedlings of lettuce as demonstrated by lower lipid peroxidation and H2O2 content, increasing the endogenous Pro level, the activity of antioxidant enzymes, total phenolic concentration and the antioxidant capacity. Additionally, it was revealed that exogenous application of Pro enhanced the levels of GA, IAA, the concentrations of soluble sugars and organic acids and expressions of PAL, γ-TMT and ProDH genes as compared to the control. The results obtained in this study suggest that pre-treatment with exogenous Pro provides important contributions to the increase in the UV-B tolerance of lettuce by regulating the biochemical mechanisms of UV-B response.

  14. Assessment of the impact of Aluminum on germination, early growth and free proline content in Lactuca sativa L.

    PubMed

    Silva, Patrícia; Matos, Manuela

    2016-09-01

    Aluminum (Al) toxicity is a major problem in crop production on acid soils. The use of industrial or municipal wastewaters, which may be contaminated with metals, for irrigation in agriculture is common over the world. This action can increase the concentration of these agents in the soil and decrease crops yields. In order to evaluate the toxicological effects of recommended Al levels in irrigation water, under acidic conditions, on lettuce, seeds of two cultivars ("cv Reine de Mai" and "cv White Boston") were exposed to five different Al concentrations (0, 0.05, 0.5, 5 and 20mg/L) and germination percentage, root and shoot lengths were measured. Also, the germination rate and the vigor index were calculated, and the proline content was estimated for all concentrations. Results showed that seed germination was not negatively affected by Al, but the germination rate decreased in both cultivars. For the other factors analyzed, with the exception of 20mg/L concentration for "cv White Boston", Al induced, in general, negative effects including the content of proline that increased in the seeds that were exposed to this metal. The "cv Reine de Mai" was more sensitive for the analyzed concentrations than the other cultivar.. The results indicated that even recommended Al concentrations for irrigation, under acidic conditions, can interfere negatively in seed germination and seedling establishment and possibly with crop production.

  15. Lactucaxanthin - a potential anti-diabetic carotenoid from lettuce (Lactuca sativa) inhibits α-amylase and α-glucosidase activity in vitro and in diabetic rats.

    PubMed

    Gopal, Sowmya Shree; Lakshmi, Magisetty Jhansi; Sharavana, Gurunathan; Sathaiah, Gunaseelan; Sreerama, Yadahally N; Baskaran, Vallikannan

    2017-03-22

    Intestinal and pancreatic α-amylase and α-glucosidase inhibitors offer an approach to lower the levels of post-prandial hyperglycemia through the control of dietary starch breakdown in digestion. This study hypothesized that lactucaxanthin (Lxn) in lettuce (Lactuca sativa) inhibits the activity of α-amylase and α-glucosidase. In this study, the interaction of Lxn with α-amylase and α-glucosidase in silico and its inhibitory effect on these enzymes were studied using in vitro and STZ-induced diabetic rat models. Lxn was isolated from lettuce with 96% purity confirmed by HPLC and LCMS. The in silico analysis showed that Lxn has a lower binding energy (-6.05 and -6.34 kcal mol(-1)) with α-amylase and α-glucosidase compared to their synthetic inhibitors, acarbose (-0.21 kcal mol(-1)) and miglitol (-2.78 kcal mol(-1)), respectively. In vitro α-amylase and α-glucosidase inhibition assays revealed that Lxn had IC50 values of 435.5 μg mL(-1) and 1.84 mg mL(-1), but acarbose has values of 2.5 and 16.19 μg mL(-1). The in vivo results showed an increased activity for α-amylase and α-glucosidase in the intestine (4.7 and 1.30 fold, p < 0.05) and pancreas (1.3 and 1.48 fold, p < 0.05) of STZ induced diabetic rats compared to normal rats. Whereas the activity decreased (p < 0.05) in the Lxn fed diabetic rats, except for the intestinal α-glucosidase activity (1.69 ± 0.12 PNP per min per mg protein). This was confirmed by the low blood glucose level (239.4 ± 18.2 mg dL(-1)) in diabetic rats fed Lxn compared to the diabetic group (572.2 ± 30.5 mg dL(-1), p < 0.05). Lxn significantly inhibited (p < 0.05) the activity of α-amylase and α-glucosidase and could be of medical and nutritional relevance in the treatment of diabetes.

  16. Predawn and high intensity application of supplemental blue light decreases the quantum yield of PSII and enhances the amount of phenolic acids, flavonoids, and pigments in Lactuca sativa.

    PubMed

    Ouzounis, Theoharis; Razi Parjikolaei, Behnaz; Fretté, Xavier; Rosenqvist, Eva; Ottosen, Carl-Otto

    2015-01-01

    To evaluate the effect of blue light intensity and timing, two cultivars of lettuce [Lactuca sativa cv. "Batavia" (green) and cv. "Lollo Rossa" (red)] were grown in a greenhouse compartment in late winter under natural light and supplemental high pressure sodium (SON-T) lamps yielding 90 (±10) μmol m(-2) s(-1) for up to 20 h, but never between 17:00 and 21:00. The temperature in the greenhouse compartments was 22/11°C day/night, respectively. The five light-emitting diode (LED) light treatments were Control (no blue addition), 1B 06-08 (Blue light at 45 μmol m(-2) s(-1) from 06:00 to 08:00), 1B 21-08 (Blue light at 45 μmol m(-2) s(-1) from 21:00 to 08:00), 2B 17-19 (Blue at 80 μmol m(-2) s(-1) from 17:00 to 19:00), and 1B 17-19 (Blue at 45 μmol m(-2) s(-1) from 17:00 to 19:00). Total fresh and dry weight was not affected with additional blue light; however, plants treated with additional blue light were more compact. The stomatal conductance in the green lettuce cultivar was higher for all treatments with blue light compared to the Control. Photosynthetic yields measured with chlorophyll fluorescence showed different response between the cultivars; in red lettuce, the quantum yield of PSII decreased and the yield of non-photochemical quenching increased with increasing blue light, whereas in green lettuce no difference was observed. Quantification of secondary metabolites showed that all four treatments with additional blue light had higher amount of pigments, phenolic acids, and flavonoids compared to the Control. The effect was more prominent in red lettuce, highlighting that the results vary among treatments and compounds. Our results indicate that not only high light level triggers photoprotective heat dissipation in the plant, but also the specific spectral composition of the light itself at low intensities. However, these plant responses to light are cultivar dependent.

  17. Effect of aqueous and hydro-alcoholic extracts of lettuce (Lactuca sativa) seed on testosterone level and spermatogenesis in NMRI mice

    PubMed Central

    Ahangarpour, Akram; Oroojan, Ali Akbar; Radan, Maryam

    2014-01-01

    Background: One of the considerable uses of lettuce (Lactuca sativa) seed in traditional medicine has been to reduce semen, sperm and sexuality. Objective: The aim of this study was to investigate the effects of aqueous and hydro-alcoholic extracts of lettuce seed on testosterone level and spermatogenesis. Materials and Methods: In this experimental study 24 adult male NMRI mice weighing 20-25gr were purchased. Animals were randomly divided into 4 groups: controls, hydro-alcoholic (200 mg/kg) and aqueous extracts (50, 100mg/kg). The extracts were injected intraperitoneally once a day for 10 consecutive days. 2 weeks after the last injection, the mice were anaesthetized by ether and after laparatomy blood was collected from the heart to determine testosterone by ELISA assay kit. Then testis and cauda epididymis of all animals were removed for analyzing testis morphology and sperm count and viability. Results: Testis weight in hydro-alcoholic and aqueous extracts 100 mg/kg (p=0.001) and aqueous extract 50 mg/kg (p=0.008) groups was increased. Sperm viability in hydro-alcoholic (p=0.001) and aqueous extracts 50 (p=0.026), 100 mg/kg (p=0.045) groups was decreased, Also the results showed a significant decrease in sperm count in hydro-alcoholic (p=0.035) and aqueous extracts 50 mg/kg (p=0.006) groups in comparison with control group. Also there was a significant increase in serum level of testosterone in aqueous extract 50 mg/kg group in comparison with control (p=0.002) hydro-alcoholic (p=0.001) and aqueous extracts 100 mg/kg (p=0.003) groups. Conclusion: Present results demonstrated that hydro-alcoholic and aqueous 50 mg/kg extracts of lettuce seed have antispermatogenic effects, also aqueous extract 50 mg/kg increased serum level of testosterone in mice. Therefore we can suggest that lettuce seed could be a potential contraceptive agent. This article extracted from M.Sc. student research project. (Ali Akbar Oroojan) PMID:24799863

  18. Influence of season growth, soils and irrigation water composition on the concentration of uranium in two lettuce (Lactuca sativa L.) varieties. Field experiments

    NASA Astrophysics Data System (ADS)

    Abreu, M. M.; Neves, O.; Marcelino, M.

    2012-04-01

    Former uranium mines areas are frequently the sources of environmental radionuclides problems even many years after the closure of mining operations. A concern for inhabitants from mining areas is the use of contaminated land or irrigation water for agriculture, and the potential transfer of metals from soils to vegetables, and to humans through the food chain. The main aim of this study was to compare the uranium concentration in lettuce (Lactuca sativa L. varieties Marady and Romana) grown in different seasons (autumn and summer) and exposed to high and low uranium concentrations both in irrigation water and agricultural soil. The content of uranium in irrigation water, soil (total and available fraction) and in lettuce leaf samples was analyzed in a certified laboratory. In the field experiments, two agricultural soils were divided into two plots (four replicates each); one of them was irrigated with uranium contaminated water (0.94 to 1.14 mg/L) and the other with uncontaminated water (< 0.02 mg/L). Irrigation with contaminated water together with highest soil uranium available concentration (10 to 13 mg/kg) had negative effects on both studied lettuce varieties, namely yield reduction (up to 53% and 87% in autumn and summer experiments, respectively) and increase of uranium leaf concentration (up to 1.4 and 7 fold in autumn and summer, respectively). Effect on lettuce yield was mainly due to the high soil salinity (1.01 to 6.31 mS/cm) as a consequence of high irrigation water electrical conductivity (up to 1.82 mS/cm) and low lettuce soil salinity tolerance (1 to 3 mS/cm). The highest lettuce uranium concentration (dry weight) observed was 2.13 and 5.37 mg/kg for Marady and Romana variety, respectively. The highest uranium lettuce concentration in Romana variety was also the effect of its growing in summer season when it was subject to greatest frequency and amount of water irrigation. The consumption by an adult of the lettuce that concentrate more uranium

  19. Predawn and high intensity application of supplemental blue light decreases the quantum yield of PSII and enhances the amount of phenolic acids, flavonoids, and pigments in Lactuca sativa

    PubMed Central

    Ouzounis, Theoharis; Razi Parjikolaei, Behnaz; Fretté, Xavier; Rosenqvist, Eva; Ottosen, Carl-Otto

    2015-01-01

    To evaluate the effect of blue light intensity and timing, two cultivars of lettuce [Lactuca sativa cv. “Batavia” (green) and cv. “Lollo Rossa” (red)] were grown in a greenhouse compartment in late winter under natural light and supplemental high pressure sodium (SON-T) lamps yielding 90 (±10) μmol m−2 s−1 for up to 20 h, but never between 17:00 and 21:00. The temperature in the greenhouse compartments was 22/11°C day/night, respectively. The five light-emitting diode (LED) light treatments were Control (no blue addition), 1B 06-08 (Blue light at 45 μmol m−2 s−1 from 06:00 to 08:00), 1B 21-08 (Blue light at 45 μmol m−2 s−1 from 21:00 to 08:00), 2B 17-19 (Blue at 80 μmol m−2 s−1 from 17:00 to 19:00), and 1B 17-19 (Blue at 45 μmol m−2 s−1 from 17:00 to 19:00). Total fresh and dry weight was not affected with additional blue light; however, plants treated with additional blue light were more compact. The stomatal conductance in the green lettuce cultivar was higher for all treatments with blue light compared to the Control. Photosynthetic yields measured with chlorophyll fluorescence showed different response between the cultivars; in red lettuce, the quantum yield of PSII decreased and the yield of non-photochemical quenching increased with increasing blue light, whereas in green lettuce no difference was observed. Quantification of secondary metabolites showed that all four treatments with additional blue light had higher amount of pigments, phenolic acids, and flavonoids compared to the Control. The effect was more prominent in red lettuce, highlighting that the results vary among treatments and compounds. Our results indicate that not only high light level triggers photoprotective heat dissipation in the plant, but also the specific spectral composition of the light itself at low intensities. However, these plant responses to light are cultivar dependent. PMID:25767473

  20. Effects of silicon on Oryza sativa L. seedling roots under simulated acid rain stress.

    PubMed

    Ju, Shuming; Yin, Ningning; Wang, Liping; Zhang, Cuiying; Wang, Yukun

    2017-01-01

    Silicon (Si) has an important function in reducing the damage of environmental stress on plants. Acid rain is a serious abiotic stress factor, and Si can alleviate the stress induced by acid rain on plants. Based on these assumptions, we investigated the effects of silicon on the growth, root phenotype, mineral element contents, hydrogen peroxide (H2O2) and antioxidative enzymes of rice (Oryza sativa L.) seedling roots under simulated acid rain (SAR) stress. The results showed that the combined or single effects of Si and/or SAR on rice roots depend on the concentration of Si and the pH of the SAR. The combined or single effects of a low or moderate concentration of Si (1.0 or 2.0 mM) and light SAR (pH 4.0) enhanced the growth of rice roots, and the combined effects were stronger than those of the single treatment. A high concentration of Si (4.0 mM) or severe SAR (pH 2.0) exerted deleterious effects. The incorporation of Si (1.0, 2.0 or 4.0 mM) into SAR with pH 3.0 or 2.0 promoted the rice root growth, decreased the H2O2 content, increased the Si concentration and the superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) and ascorbate peroxidase (APX) activities, maintained the balance of mineral element (K, Ca, Mg, Fe, Zn, and Cu) concentrations in the roots of rice seedlings compared with SAR alone. The alleviatory effects observed with a moderate concentration of Si (2.0 mM) were better than the effects obtained with a low or high concentration of Si (1.0 or 4.0 mM). The observed effects were due to disruptions in the absorption and utilization of mineral nutrients and impacts on the activity of antioxidant enzymes in roots, and this conclusion suggests that the degree of rice root damage caused by acid rain might be attributed to not only acid rain but also the level of Si in the soil.

  1. Effects of silicon on Oryza sativa L. seedling roots under simulated acid rain stress

    PubMed Central

    Wang, Liping; Zhang, Cuiying; Wang, Yukun

    2017-01-01

    Silicon (Si) has an important function in reducing the damage of environmental stress on plants. Acid rain is a serious abiotic stress factor, and Si can alleviate the stress induced by acid rain on plants. Based on these assumptions, we investigated the effects of silicon on the growth, root phenotype, mineral element contents, hydrogen peroxide (H2O2) and antioxidative enzymes of rice (Oryza sativa L.) seedling roots under simulated acid rain (SAR) stress. The results showed that the combined or single effects of Si and/or SAR on rice roots depend on the concentration of Si and the pH of the SAR. The combined or single effects of a low or moderate concentration of Si (1.0 or 2.0 mM) and light SAR (pH 4.0) enhanced the growth of rice roots, and the combined effects were stronger than those of the single treatment. A high concentration of Si (4.0 mM) or severe SAR (pH 2.0) exerted deleterious effects. The incorporation of Si (1.0, 2.0 or 4.0 mM) into SAR with pH 3.0 or 2.0 promoted the rice root growth, decreased the H2O2 content, increased the Si concentration and the superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) and ascorbate peroxidase (APX) activities, maintained the balance of mineral element (K, Ca, Mg, Fe, Zn, and Cu) concentrations in the roots of rice seedlings compared with SAR alone. The alleviatory effects observed with a moderate concentration of Si (2.0 mM) were better than the effects obtained with a low or high concentration of Si (1.0 or 4.0 mM). The observed effects were due to disruptions in the absorption and utilization of mineral nutrients and impacts on the activity of antioxidant enzymes in roots, and this conclusion suggests that the degree of rice root damage caused by acid rain might be attributed to not only acid rain but also the level of Si in the soil. PMID:28291806

  2. γ-Aminobutyric acid addition alleviates ammonium toxicity by limiting ammonium accumulation in rice (Oryza sativa) seedlings.

    PubMed

    Ma, Xiaoling; Zhu, Changhua; Yang, Na; Gan, Lijun; Xia, Kai

    2016-12-01

    Excessive use of nitrogen (N) fertilizer has increased ammonium (NH4(+) ) accumulation in many paddy soils to levels that reduce rice vegetative biomass and yield. Based on studies of NH4(+) toxicity in rice (Oryza sativa, Nanjing 44) seedlings cultured in agar medium, we found that NH4(+) concentrations above 0.75 mM inhibited the growth of rice and caused NH4(+) accumulation in both shoots and roots. Use of excessive NH4(+) also induced rhizosphere acidification and inhibited the absorption of K, Ca, Mg, Fe and Zn in rice seedlings. Under excessive NH4(+) conditions, exogenous γ-aminobutyric acid (GABA) treatment limited NH4(+) accumulation in rice seedlings, reduced NH4(+) toxicity symptoms and promoted plant growth. GABA addition also reduced rhizosphere acidification and alleviated the inhibition of Ca, Mg, Fe and Zn absorption caused by excessive NH4(+) . Furthermore, we found that the activity of glutamine synthetase/NADH-glutamate synthase (GS; EC 6.3.1.2/NADH-GOGAT; EC1.4.1.14) in root increased gradually as the NH4(+) concentration increased. However, when the concentration of NH4(+) is more than 3 mM, GABA treatment inhibited NH4(+) -induced increases in GS/NADH-GOGAT activity. The inhibition of ammonium assimilation may restore the elongation of seminal rice roots repressed by high NH4(+) . These results suggest that mitigation of ammonium accumulation and assimilation is essential for GABA-dependent alleviation of ammonium toxicity in rice seedlings.

  3. Chemical composition of essential oils and in vitro antioxidant activity of fresh and dry leaves crude extracts of medicinal plant of Lactuca Sativa L. native to Sultanate of Oman

    PubMed Central

    Al Nomaani, Rahma Said Salim; Hossain, Mohammad Amzad; Weli, Afaf Mohammed; Al-Riyami, Qasim; Al-Sabahi, Jamal Nasser

    2013-01-01

    Objective To isolate and analyse the chemical composition in the essential oils and free radical scavenging activity of different crude extracts from the fresh and dry leaves of vegetable plants of Lactuca sativa L. (L. sativa). Methods The essential oils and volatile chemical constituents were isolated from the fresh and dry leaves of L. sativa (lettuce) grown in Sultanate of Oman by hydro distillation method. The antioxidant activity of the crude extracts was carried out by well established free radical scavenging activity (DPPH) method. Results About 20 chemical compounds of different concentration representing 83.07% and 79.88% respectively were isolated and identified by gas chromatography-mass spectroscopy in the essential oils isolated from the fresh and dry leaves as α-pinene (5.11% and 4.05%), γ-cymene (2.07% and 1.92%), thymol (11.55% and 10.73%), durenol (52.00% and 49.79%), α-terpinene (1.66% and 1.34%), thymol acetate (0.99% and 0.67%), caryophyllene (2.11% and 1.98%), spathulenol (3.09% and 2.98%), camphene (4.11% and 3.65%), limonene (1.28% and 1.11%) representing these major chemical compounds. However, some other minor chemical constituents were also isolated and identified from the essential oil of lettuce including β-pinene, α-terpinolene, linalool, 4-terpineol, α-terpineol, o-methylthymol, L-alloaromadendrene and viridiflorene. Conclusions The chemical constituents in the essential oils from the locally grown lettuce were identified in the following classes or groups of chemical compounds such as monoterpenes, sesquiterpenes volatile organic compounds and their oxygenated hydrocarbons. Therefore, the essential oils and the crude extracts from Omani vegetable species of lettuce are active candidates which would be used as antioxidant, antifungal or antimicrobial agents in new drugs preparation for therapy of infectious diseases. PMID:23646297

  4. Priming effect of abscisic acid on alkaline stress tolerance in rice (Oryza sativa L.) seedlings.

    PubMed

    Wei, Li-Xing; Lv, Bing-Sheng; Wang, Ming-Ming; Ma, Hong-Yuan; Yang, Hao-Yu; Liu, Xiao-Long; Jiang, Chang-Jie; Liang, Zheng-Wei

    2015-05-01

    Saline-alkaline stress is characterized by high salinity and high alkalinity (high pH); alkaline stress has been shown to be the primary factor inhibiting rice seedling growth. In this study, we investigated the potential priming effect of abscisic acid (ABA) on tolerance of rice seedlings to alkaline stress simulated by Na2CO3. Seedlings were pretreated with ABA at concentrations of 0 (control), 10, and 50 μM by root-drench for 24 h and then transferred to a Na2CO3 solution that did not contain ABA. Compared to control treatment, pretreatment with ABA substantially improved the survival rate of rice seedlings and increased biomass accumulation after 7 days under the alkaline condition. ABA application at 10 μM also alleviated the inhibitory effects of alkaline stress on the total root length and root surface area. Physiologically, ABA increased relative water content (RWC) and decreased cell membrane injury degree (MI) and Na(+)/K(+) ratios. In contrast, fluridone (an ABA biosynthesis inhibitor) decreased the RWC and increased MI in shoots under the alkaline conditions. These data suggest that ABA has a potent priming effect on the adaptive response to alkaline stress in rice and may be useful for improving rice growth in saline-alkaline paddy fields.

  5. Compartmental analysis of roots in intact rapidly-growing Spergularia marina and Lactuca sativa: partial characterization of the symplasms functional in the radial transport of Na/sup +/ and K/sup +/

    SciTech Connect

    Lazof, D.B.

    1987-01-01

    Techniques of compartmental analysis were adapted to the study of intact roots of rapidly-growing Spergularia marine and Lactuca sativa. Using large numbers of plants short time-courses of uptake and chase, /sup 42/K/sup +/ and /sup 22/Na/sup +/ transport could be resolved, even during a chase following a brief 10 minute labeling period. The use of intact plant systems allowed distinction of that portion of the isotope flux into the root, associated with the ion-conducting symplasms. A small compartment, which rapidly (t/sub .5/ < 1 min) exchanges with the external medium was implicated in the radial transport of N/sup +/, accounting for the observed obtention of linear translocation rates within minutes of transferring to labeled solution. The ion contents of this compartment varied in proportion to the external ion concentration. When K/sup +/ was at a high external concentration, labeled K/sup +/ exchanged into this same symplasm, but chasing a short pulse indicated that K/sup +/ transport to the xylem was not through a rapidly-exchanging compartment. At physiological concentrations of K/sup +/ the evidence indicated that transport of K/sup +/ across the root proceeded through a compartment which was not exchanging rapidly with the external medium. The rise to a linear rate of isotope translocation was gradual and translocation during a chase, following a brief pulse,was prolonged, indicating that this compartment retained its specific activity for a considerable period.

  6. Silicon alleviates simulated acid rain stress of Oryza sativa L. seedlings by adjusting physiology activity and mineral nutrients.

    PubMed

    Ju, Shuming; Wang, Liping; Yin, Ningning; Li, Dan; Wang, Yukun; Zhang, Cuiying

    2017-03-16

    Silicon (Si) has been a modulator in plants under abiotic stresses, such as acid rain. To understand how silicon made an effect on rice (Oryza sativa L.) exposed to simulated acid rain (SAR) stress, the growth, physiologic activity, and mineral nutrient content in leaves of rice were investigated. The results showed that combined treatments with Si (1.0, 2.0, or 4.0 mM) and SAR (pH 4.0, 3.0, or 2.0) obviously improved the rice growth compared with the single treatment with SAR. Incorporation of Si into SAR treatment decreased malondialdehyde (MDA) content; increased soluble protein and proline contents; promoted CAT, POD, SOD, and APX activity; and maintained the K, Ca, Mg, Fe, Zn, Cu content balance in leaves of rice seedlings under SAR stress. The moderate concentration of Si (2.0 mM) was better than the low and high concentration of Si (1.0 and 4.0 mM). Therefore, application of Si could be a better strategy for maintaining the crop productivity in acid rain regions.

  7. Interactive effects of different inorganic As and Se species on their uptake and translocation by rice (Oryza sativa L.) seedlings.

    PubMed

    Hu, Ying; Duan, Gui-Lan; Huang, Yi-Zong; Liu, Yun-Xia; Sun, Guo-Xin

    2014-03-01

    There is a lack of information on the interactive relationship of absorption and transformation between two inorganic arsenic (As) species and two inorganic selenium (Se) species in rice grown under hydroponic condition. Interactive effects of inorganic As (As(III)) and (As(V)) and Se (Se(IV)and Se(VI)) species on their uptake, accumulation, and translocation in rice (Oryza sativa L.) seedlings were investigated in hydroponic culture. The results clearly showed the interactive effects of inorganic As and Se on their uptake by rice. The presence of Se reduced the sum of As species in the rice shoots regardless of Se speciation. If Se is present as Se(IV), then is it is accompanied by a corresponding increase of the sum of As species, but if Se is present as Se(VI), then there is no change in the sum of As species in rice roots. These effects are observed regardless of initial As speciation. When the rice plants are exposed to Se(IV), the presence of As increases the sum of Se species in the roots, and decreases the sum of Se species in the corresponding shoots. This effect is more pronounced for As(III) than for As(V). There is no effect on Se during exposure to Se(VI). Co-existence of As also increased SeMet in rice roots.

  8. Effect of three insecticides and two herbicides on rice (Oryza sativa) seedling germination and growth.

    PubMed

    Moore, M T; Kröger, R

    2010-11-01

    Rice (Oryza sativa L.) is one of the most important food crops worldwide. However, it is also a valuable tool in assessing toxicity of organic and inorganic compounds. For more than 20 years, it has been an approved species for standardized phytotoxicity experiments. The objective of this study is to determine germination and radicle (root) and coleoptile (shoot) growth of rice seeds exposed to three insecticides and two herbicides, commonly used in the agricultural production landscape. Although no germination effects of pesticide exposure were observed, significant growth effects were noted between pesticide treatments. Coleoptile growth was significantly (p ≤ 0.05) lowered in metolachlor/atrazine mixture, diazinon, and lambda-cyhalothrin exposures when compared with controls. Radicles of fipronil-exposed seeds were significantly larger (p ≤ 0.05) when compared with controls. This research contributes to the phytotoxicity assessment database, in addition to laying the foundation for the use of rice as a phytoremediation tool for agricultural pesticide runoff.

  9. CYP94A1, a plant cytochrome P450-catalyzing fatty acid omega-hydroxylase, is selectively induced by chemical stress in Vicia sativa seedlings.

    PubMed

    Benveniste, Irène; Bronner, Roberte; Wang, Yong; Compagnon, Vincent; Michler, Pierre; Schreiber, Lukas; Salaün, Jean-Pierre; Durst, Francis; Pinot, Franck

    2005-08-01

    CYP94A1 is a cytochrome P450 (P450) catalyzing fatty acid (FA) omega-hydroxylation in Vicia sativa seedlings. To study the physiological role of this FA monooxygenase, we report here on its regulation at the transcriptional level (Northern blot). Transcripts of CYP94A1, as those of two other P450-dependent FA hydroxylases (CYP94A2 and CYP94A3) from V. sativa, are barely detectable during the early development of the seedlings. CYP94A1 transcripts, in contrast to those of the two other isoforms, are rapidly (less than 20 min) and strongly (more than 100 times) enhanced after treatment by clofibrate, an hypolipidemic drug in animals and an antiauxin (p-chlorophenoxyisobutyric acid) in plants, by auxins (2,4-dichlorophenoxyacetic acid and indole-3-acetic acid), by an inactive auxin analog (2,3-dichlorophenoxyacetic acid), and also by salicylic acid. All these compounds activate CYP94A1 transcription only at high concentrations (50-500 microM range). In parallel, these high levels of clofibrate and auxins modify seedling growth and development. Therefore, the expression of CYP94A1 under these conditions and the concomitant morphological and cytological modifications would suggest the implication of this P450 in a process of plant defense against chemical injury.

  10. Genetic characterization of quantitative resistance to Bremia lactucae, the causal organism of lettuce downy mildew

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lettuce (Lactuca sativa) is one of the most valuable vegetable crops in the United States. Downy mildew (DM), caused by Bremia lactucae, is the most important foliar disease of lettuce worldwide, which decreases the quality of the marketable portion of the crop. The use of resistant varieties carryi...

  11. Reversed-phase ultra-high-performance liquid chromatography coupled to electrospray ionization-quadrupole-time-of-flight mass spectrometry as a powerful tool for metabolic profiling of vegetables: Lactuca sativa as an example of its application.

    PubMed

    Abu-Reidah, I M; Contreras, M M; Arráez-Román, D; Segura-Carretero, A; Fernández-Gutiérrez, A

    2013-10-25

    Lettuce (Lactuca sativa), a leafy vegetal widely consumed worldwide, fresh cut or minimally processed, constitutes a major dietary source of natural antioxidants and bioactive compounds. In this study, reversed-phase ultra-high-performance liquid chromatography (RP-UHPLC) coupled to electrospray ionization-quadrupole-time-of-flight mass spectrometry (ESI-QTOF-MS) was applied for the comprehensive profiling of polar and semi-polar metabolites from three lettuce cultivars (baby, romaine, and iceberg). The UHPLC systems allowed the use of a small-particle-size C18 column (1.8 μm), with very fine resolution for the separation of up to seven isomers, and the QTOF mass analyzer enabled sensitive detection with high mass resolution and accuracy in full scan. Thus, a total of 171 compounds were tentatively identified by matching their accurate mass signals and suggested molecular formula with those previously reported in family Asteraceae. Afterwards, their structures were also corroborated by the MS/MS data provided by the QTOF analyzer. Well-known amino acids, organic acids, sesquiterpene lactones, phenolic acids and flavonoids were characterized, e.g. lactucin, lactucopicrin, caftaric acid, chlorogenic acid, caffeoylmalic acid, chicoric acid, isochlorogenic acid A, luteolin, and quercetin glycosides. For this plant species, this is the first available report of several isomeric forms of the latter polyphenols and other types of components such as nucleosides, peptides, and tryptophan-derived alkaloids. Remarkably, 10 novel structures formed by the conjugation of known amino acids and sesquiterpene lactones were also proposed. Thus, the methodology applied is a useful option to develop an exhaustive metabolic profiling of plants that helps to explain their potential biological activities and folk uses.

  12. Response of plasma membrane H+-ATPase in rice (Oryza sativa) seedlings to simulated acid rain.

    PubMed

    Liang, Chanjuan; Ge, Yuqing; Su, Lei; Bu, Jinjin

    2015-01-01

    Understanding the adaptation of plants to acid rain is important to find feasible approaches to alleviate such damage to plants. We studied effects of acid rain on plasma membrane H(+)-ATPase activity and transcription, intracellular H(+), membrane permeability, photosynthetic efficiency, and relative growth rate during stress and recovery periods. Simulated acid rain at pH 5.5 did not affect plasma membrane H(+)-ATPase activity, intracellular H(+), membrane permeability, photosynthetic efficiency, and relative growth rate. Plasma membrane H(+)-ATPase activity and transcription in leaves treated with acid rain at pH 3.5 was increased to maintain ion homeostasis by transporting excessive H(+) out of cells. Then intracellular H(+) was close to the control after a 5-day recovery, alleviating damage on membrane and sustaining photosynthetic efficiency and growth. Simulated acid rain at pH 2.5 inhibited plasma membrane H(+)-ATPase activity by decreasing the expression of H(+)-ATPase at transcription level, resulting in membrane damage and abnormal intracellular H(+), and reduction in photosynthetic efficiency and relative growth rate. After a 5-day recovery, all parameters in leaves treated with pH 2.5 acid rain show alleviated damage, implying that the increased plasma membrane H(+)-ATPase activity and its high expression were involved in repairing process in acid rain-stressed plants. Our study suggests that plasma membrane H(+)-ATPase can play a role in adaptation to acid rain for rice seedlings.

  13. Uptake, translocation and transformation of antimony in rice (Oryza sativa L.) seedlings.

    PubMed

    Cai, Fei; Ren, Jinghua; Tao, Shu; Wang, Xilong

    2016-02-01

    Antimony (Sb), as a toxic metalloid, has been gaining increasing research concerns due mainly to its severe pollution in many places. Rice has been identified to be the dominant intake route of Sb by residents close to the Sb mining areas. A hydroponic experiment was conducted to investigate the difference in uptake, translocation and transformation of Sb in rice seedlings of four cultivars exposed to 0.2 or 1.0 mg/L of Sb(V). The results showed that mass concentration of iron plaque (mg/kg FW) formed at the root surfaces of cultivar N was the highest among all tested cultivars at both low and high exposure levels of Sb(V). The accumulated Sb concentration in iron plaque significantly increased with an increase in mass concentration of iron plaque formed at the rice root. The total amount of iron plaque (mg/pot) at rice root generally increased with increasing exposed Sb(V) concentration, which was closely associated with the increasing lipid peroxidation in roots. Concentration percentage of Sb in rice root significantly reduced as the corresponding value in the iron plaque increased, suggesting that iron plaque formation strongly suppressed uptake of Sb by rice root. Sb concentration in rice tissues followed an order: root > stem, leaf. The japonica rice (cultivars N and Z) exhibited a stronger translocation tendency of Sb from root to stem than indica hybrid rice (cultivars F and G). Translocation of Sb from root of cultivar F to its stem and leaf was sharply enhanced with increasing Sb exposure concentration. Sb(V) could be reduced to Sb(III) in rice tissues, especially in stems (10-26% of the total Sb). For the sake of food safety, the difference in uptake, translocation and transformation of Sb in rice species planted in Sb-contaminated soils should be taken into consideration.

  14. Biochemical and molecular changes in rice seedlings (Oryza sativa L.) to cope with chromium stress.

    PubMed

    Kabir, A H

    2016-07-01

    Chromium (Cr) is very toxic to both humans and plants. This investigation aimed to understand the physiological and molecular responses of rice seedlings to Cr stress. Cr toxicity did not significantly affect morphological features and Cr accumulation in roots and shoots in Pokkali but not in BRRI 51, although there was a reduction in chlorophyll concentration in leaves of both genotypes. These results imply that Pokkali has mechanisms to cope with Cr supplementation. We therefore performed quantitative real-time PCR on the expression pattern of two chelator genes, OsPCS1 and OsMT1, but there were no significant changes in expression in roots and shoots of Pokkali and BRRI 51 following Cr stress. This suggests that there was no metal sequestration following heavy metal stress in roots of these genotypes. Moreover, no expression of two heavy metal transporter genes, OsHMA3 and OsNRAMP1, was induced after Cr stress in roots and shoots, suggesting that these transporter genes are not induced by Cr stress or might not be involved in Cr uptake in rice. We also performed a targeted study on the effect of Cr on Fe uptake mechanisms. Our studies showed a consistent reduction in Fe uptake, Fe reductase activity and expression of Fe-related genes (OsFRO1 and OsIRT1) under Cr stress in both roots and leaves of Pokkali. In contrast, these parameters and genes were significantly increased in Cr-sensitive BRRI 51 under Cr stress. The results confirm that limiting Fe uptake through the down-regulation of Fe reductase and Fe transporter genes is the main strategy of Cr-tolerant Pokkali to cope with Cr stress. Finally, increased CAT, POD and GR activity and elevated glutathione and proline synthesis might provide strong antioxidant defence against Cr stress in Pokkali. Taken together, our findings reveal that Cr stress tolerance in rice (Pokkali) is not related to metal sequestration but is associated with reduced Fe transport and increased antioxidant defence.

  15. Transgenic lettuce seedlings carrying hepatitis B virus antigen HBsAg.

    PubMed

    Marcondes, Jackson; Hansen, Ekkehard

    2008-12-01

    The obtainment of transgenic edible plants carrying recombinant antigens is a desired issue in search for economic alternatives viewing vaccine production. Here we report a strategy for genetic transformation of lettuce plants (Lactuca sativa L.) using the surface antigen HBsAg of hepatitis B virus. Transgenic lettuce seedlings were obtained through the application of a regulated balance of plant growth regulators. Genetic transformation process was acquired by cocultivation of cotyledons with Agrobacterium tumefaciens harboring the recombinant plasmid. It is the first description of a lettuce Brazilian variety 'Vitória de Verão' genetically modified.

  16. Importance of 'blue' photon levels for lettuce seedlings grown under red-light-emitting diodes

    NASA Technical Reports Server (NTRS)

    Hoenecke, M. E.; Bula, R. J.; Tibbitts, T. W.

    1992-01-01

    Light-emitting diodes (LEDs) with high-intensity output are being studied as a photosynthetic light source for plants. High-output LEDs have peak emission at approximately 660 nm concentrated in a waveband of +/- 30 nm. Lettuce (Lactuca sativa Grand Rapids') seedlings developed extended hypocotyls and elongated cotyledons when grown under these LEDs as a sole source of irradiance. This extension and elongation was prevented when the red LED radiation was supplemented with more than 15 micromoles m-2 s-1 of 400- to 500-nm photons from blue fluorescent lamps. Blue radiation effects were independent of the photon level of the red radiation.

  17. Methyl jasmonate induces lauric acid omega-hydroxylase activity and accumulation of CYP94A1 transcripts but does not affect epoxide hydrolase activities in vicia sativa seedlings

    PubMed

    Pinot; Benveniste; Sala n JP; Durst

    1998-12-01

    Treatment of etiolated Vicia sativa seedlings by the plant hormone methyl jasmonate (MetJA) led to an increase of cytochrome P450 content. Seedlings that were treated for 48 h in a 1 mM solution of MetJA stimulated omega-hydroxylation of 12:0 (lauric acid) 14-fold compared with the control (153 versus 11 pmol min-1 mg-1 protein, respectively). Induction was dose dependent. The increase of activity (2.7-fold) was already detectable after 3 h of treatment. Activity increased as a function of time and reached a steady level after 24 h. Northern-blot analysis revealed that the transcripts coding for CYP94A1, a fatty acid omega-hydroxylase, had already accumulated after 1 h of exposure to MetJA and was maximal between 3 and 6 h. Under the same conditions, a study of the enzymatic hydrolysis of 9,10-epoxystearic acid showed that both microsomal and soluble epoxide hydrolase activities were not affected by MetJA treatment.

  18. Synthesis and characterisation of metal nanoparticles and their effects on seed germination and seedling growth in commercially important Eruca sativa.

    PubMed

    Zaka, Mehreen; Abbasi, Bilal Haider; Rahman, Latif-Ur; Shah, Afzal; Zia, Muhammad

    2016-06-01

    The synthesis, characterisation and application of metal nanoparticles have become an important and attractive branch of nanotechnology. In current study, metallic nanoparticles of silver, copper, and gold were synthesised using environment friendly method (polyols process), and applied on medicinally important plant: Eruca sativa. Effects of application of these nanoparticles were evaluated on seed germination frequency and biochemical parameters of plant tissues. Seeds of E. sativa were germinated on Murashige and Skoog (MS) medium incorporated with various combinations of nanoparticles suspension (30 µg/ml). Phytotoxicity study showed that nanoparticles could induce stress in plants by manipulating the endogenous mechanisms. In response to these stresses, plants release various defensive compounds; known as antioxidant secondary metabolites. These plants derived secondary metabolites having a great potential in treating the common human ailments. In the authors study, small-sized nanoparticles showed higher toxicity levels and enhanced secondary metabolites production, total protein content, total flavonoids content and total phenolics content.

  19. Protective roles of nitric oxide on seed germination and seedling growth of rice (Oryza sativa L.) under cadmium stress.

    PubMed

    He, Junyu; Ren, Yanfang; Chen, Xiulan; Chen, Hui

    2014-10-01

    Nitric oxide (NO) is a bioactive molecule in plants which mediates a variety of physiological processes and responses to biotic and abiotic stresses including heavy metals. In the present study, the effects of exogenous NO donor sodium nitroprusside (SNP) on rice seed germination and seedlings growth were investigated under Cd stress and a possible mechanism was postulated. The results indicated that 100μM Cd significantly decreased rice seed germination index, vigor index, root and shoot lengths as well as fresh weight compared to control. Exogenous SNP dose-dependently attenuated the inhibition of rice seed germination and thereafter seedling growth caused by Cd. The promoting effect was most pronounced at 30μM SNP. Cd exposure caused oxidative stress by elevating hydrogen peroxide (H2O2) and malondialdehyde (MDA) contents in root and shoot of rice seedlings. 30μM SNP counteracted partly Cd toxicity by reducing the H2O2 and MDA contents of Cd-exposed seedlings. Meanwhile, application of SNP markedly stimulated the activities of superoxide dismutases (SOD), ascorbate peroxidases (APX), guaiacol peroxidase (POD) and catalases (CAT) compared with Cd treatment alone, thereby indicating the enhancement of the antioxidative capacity in the root and shoot under Cd stress. In addition, addition of 30μM SNP increased accumulation of proline in both root and shoot. The Cd accumulation in seedlings was significant reduced by SNP, implicating that the protective role of SNP was responsible for preventing Cd accumulation. However, the effects of SNP were reverted by addition of cPTIO, a NO scavenger, suggesting the protective roles of SNP might be related to the induction of NO. Furthermore, K3Fe(CN)6 and [Formula: see text] / [Formula: see text] had no similar roles as SNP. Based on these results, it can be concluded that SNP exerted an advantageous effect on alleviating the inhibitory effect of Cd on rice seed germination and seedling growth, which might interact with

  20. Photosynthesis mediated decrease in cadmium translocation protect shoot growth of Oryza sativa seedlings up on ammonium phosphate-sulfur fertilization.

    PubMed

    Sebastian, Abin; Prasad, M N V

    2014-01-01

    Cadmium (Cd) stress responses in seedlings of two Indian rice cultivars, MTU 7029 and MO 16 were investigated under ammonium-based fertilizer amendment. Cd translocation was reduced by fertilizer treatment. An increase in the production of organic acids as well as nitrogenous compounds and maintenance of nutrient status were implicated for decrease in Cd translocation which in turn promoted shoot growth. Fertilizer treatment increased photosynthetic pigments and activity of antioxidant enzymes that ensured steady photosynthetic rate during Cd stress. MO 16 showed Cd exclusion characteristics when compared with MTU 7029. Photosynthesis performance of MO 16 was not affected by Cd treatments. These findings suggest that photosynthesis influenced decrease in Cd translocation enhanced shoot growth of seedlings during ammonium phosphate-sulfur fertilizer supplementation.

  1. Comparison of globulin mobilization and cysteine proteinases in embryonic axes and cotyledons during germination and seedling growth of vetch (Vicia sativa L.).

    PubMed

    Schlereth, A; Becker, C; Horstmann, C; Tiedemann, J; Müntz, K

    2000-08-01

    Vicilin and legumin, the storage globulins of mature dry vetch (Vicia sativa L.) seeds, are found in protein bodies which are present not only in the cotyledons, but also in the radicle, axis and shoot (together, for reasons of simplicity, here called axis). When at 24 h after the start of imbibition (hai) the radicle breaks through the seed coat a major part of the globulins in the axis has already been degraded, whereas in the cotyledons globulin breakdown cannot yet be detected. Globulin mobilization starts with the degradation of vicilin. At 48 hai when globulin mobilization in the cotyledons just begins, the axis is already nearly depleted of globulins. Mobilization of storage globulin is probably brought about by a complex of different cysteine proteinases (CPRs). The papain-like CPR2 and CPR4, and the legumain-like VsPB2, together with their mRNAs, are already present in axes and cotyledons of dry seeds. This means that they must have been formed during seed maturation. Additional papain-like CPRs are formed later during germination and seedling growth. CPR4 and VsPB2 together with their corresponding mRNAs become undetectable as germination and seedling growth proceed. VsPB2 and VsPB2-mRNA are substituted by the homologous legumain-like proteinase B and its mRNA. The composition of stored and newly formed CPRs undergoes developmental changes which differ between axes and cotyledons. It is concluded that storage globulin mobilization in germinating vetch seeds is started by stored CPRs, whereas the mobilization of the bulk of globulin is predominantly mediated by CPRs which are formed de novo.

  2. Regulation of sugar metabolism in rice (Oryza sativa L.) seedlings under arsenate toxicity and its improvement by phosphate.

    PubMed

    Choudhury, Bhaskar; Mitra, Souvik; Biswas, Asok K

    2010-01-01

    The effect of arsenate with or without phosphate on the growth and sugar metabolism in rice seedlings cv. MTU 1010 was studied. Arsenate was found to be more toxic for root growth than shoot growth and water content of the seedlings gradually decreased with increasing concentrations. Arsenate exposure at 20 μM and 100 μM resulted in an increase in reducing sugar content and decrease in non-reducing sugar content. There was a small increase in starch content, the activity of starch phosphorylase was increased but α-amylase activity was found to be decreased. Arsenate toxicity also affected the activities of different carbohydrate metabolizing enzymes. The activities of sucrose degrading enzymes viz., acid invertase and sucrose synthase were increased whereas, the activity of sucrose synthesizing enzyme, viz. sucrose phosphate synthase declined. The combined application of arsenate with phosphate exhibited significant alterations of all the parameters tested under the purview of arsenate treatment alone which was congenial to better growth and efficient sugar metabolism in rice seedlings. Thus, the use of phosphorus enriched fertilizers may serve to ensure the production of healthy rice plants in arsenic contaminated soils.

  3. The effects of biochars from rice residue on the formation of iron plaque and the accumulation of Cd, Zn, Pb, As in rice (Oryza sativa L.) seedlings.

    PubMed

    Zheng, Rui-Lun; Cai, Chao; Liang, Jian-Hong; Huang, Qing; Chen, Zheng; Huang, Yi-Zong; Arp, Hans Peter H; Sun, Guo-Xin

    2012-10-01

    A historically multi-metal contaminated soil was amended with biochars produced from different parts of rice plants (straw, husk and bran) to investigate how biochar can influence the mobility of Cd, Zn, Pb and As in rice seedlings (Oryza sativa L.). Rice shoot concentrations of Cd, Zn and Pb decreased by up to 98%, 83% and 72%, respectively, due to biochar amendment, though that of As increased by up to 327%. Biochar amendments significantly decreased pore water concentrations (C(pw)) of Cd and Zn and increased that of As. For Pb it depended on the amendment. Porewater pH, dissolved organic carbon, dissolved phosphorus, silicon in pore water and iron plaque formation on root surfaces all increased significantly after the amendments. The proportions of Cd and Pb in iron plaque increased by factors 1.8-5.7 and 1.4-2.8, respectively; no increase was observed for As and Zn. Straw-char application significantly and noticeably decreased the plant transfer coefficients of Cd and Pb. This study, the first to investigate changes in metal mobility and iron plaque formation in rice plants due to amending a historically contaminated soil with biochar, indicates that biochar has a potential to decrease Cd, Zn and Pb accumulations in rice shoot but increase that of As. The main cause is likely biochar decreasing the C(pw) of Cd and Zn, increasing the C(pw) of As, and increasing the iron plaque blocking capacity for Cd and Pb.

  4. Antioxidant enzymes and DPPH-radical scavenging activity in chilled and heat-shocked rice (Oryza sativa L.) seedlings radicles.

    PubMed

    Kang, Ho-Min; Saltveit, Mikal E

    2002-01-30

    Chilling whole rice seedlings at 5 degrees C significantly increased the time needed to recover linear growth and reduced the subsequent linear rate of radicle growth. Subjecting nonchilled seedlings to a 45 degrees C heat shock for up to 20 min did not alter subsequent growth, whereas a 3 min heat shock was optimal in reducing growth inhibition caused by 2 days of chilling. The activity of five antioxidant enzymes [superoxide dismutase (EC 1.15.1.1), catalase (CAT; EC 1.11.1.6), ascorbate peroxidase (APX; EC 1.11.1.11), glutathione reductase (GR; EC 1.6.4.2), and guaiacol peroxidase (GPX; EC 1.11.1.7)] and DPPH (1,1-diphenyl-2-picrylhydrazyl)-radical scavenging activity were measured in heat-shocked and/or chilled radicles. Heat shock slightly increased the activity of CAT, APX, and GR and suppressed the increase of GR and GPX activity during recovery from chilling. Increased CAT, APX, GR, and DPPH-radical scavenging activity and protection of CAT activity during chilling appear to be correlated with heat shock-induced chilling tolerance.

  5. Effects of Seselin and Coumarin on Growth, Indoleacetic Acid Oxidase, and Peroxidase, with Special Reference to Cucumber (Cucumis sativa L.) Radicles

    PubMed Central

    Goren, Raphael; Tomer, Eliahu

    1971-01-01

    Seselin, a natural coumarin derivative isolated from citrus roots, inhibited radicle growth in seedlings of cucumber (Cucumis sativa), lettuce (Lactuca sativum), radish (Raphanus sativus), and wheat (Triticum aestivum) grown in the dark. Coumarin similarly inhibited radicle growth of cucumber seedlings. Growth retardation of the cucumber radicles was accompanied by an increased activity of peroxidase and indole-3-acetic acid oxidase. Both compounds antagonized indole-3-acetic acid-induced growth of wheat coleoptiles, whereas coumarin was much less effective than seselin in antagonizing gibberellic acid-induced release of reducing sugars from barley endosperm. It is suggested that seselin plays an important role in the regulation of root growth, and that it is the indole-3-acetic acid oxidase cofactor previously detected in citrus roots. Images PMID:16657614

  6. Low pH-induced changes of antioxidant enzyme and ATPase activities in the roots of rice (Oryza sativa L.) seedlings.

    PubMed

    Zhang, Yi-Kai; Zhu, De-Feng; Zhang, Yu-Ping; Chen, Hui-Zhe; Xiang, Jing; Lin, Xian-Qing

    2015-01-01

    Soil acidification is the main problem in the current rice production. Here, the effects of low pH on the root growth, reactive oxygen species metabolism, plasma membrane functions, and the transcript levels of the related genes were investigated in rice seedlings (Oryza sativa L.) in a hydroponic system at pH 3.5, 4.5, and 5.5. There were two hybrid rice cultivars in this trial, including Yongyou 12 (YY12, a japonica hybrid) and Zhongzheyou 1 (ZZY1, an indica hybrid). Higher H+ activity markedly decreased root length, the proportion of fine roots, and dry matter production, but induced a significant accumulation of hydrogen peroxide (H2O2), and led to serious lipid peroxidation in the roots of the two varieties. The transcript levels of copper/zinc superoxide dismutase 1 (Cu/Zn SOD1), copper/zinc superoxide dismutase 2 (Cu/Zn SOD2), catalase A (CATA) and catalase B (CATB) genes in YY12 and ZZY1 roots were significantly down-regulated after low pH exposure for two weeks. Meanwhile, a significant decrease was observed in the expression of the P-type Ca2+-ATPases in roots at pH 3.5. The activities of antioxidant enzymes (SOD, CAT) and plasma membrane (PM) Ca2+-ATPase in the two varieties were dramatically inhibited by strong rhizosphere acidification. However, the expression levels of ascorbate peroxidase 1 (APX1) and PM H+-ATPase isoform 7 were up-regulated under H+ stress compared with the control. Significantly higher activities of APX and PM H+-ATPase could contribute to the adaptation of rice roots to low pH.

  7. Mapping QTLs for traits related to salinity tolerance at seedling stage of rice (Oryza sativa L.): an agrigenomics study of an Iranian rice population.

    PubMed

    Ghomi, Khadijeh; Rabiei, Babak; Sabouri, Hossein; Sabouri, Atefeh

    2013-05-01

    Rice (Oryza sativa L.) is one of the most important food crops in the world, especially in Asian countries, and salinity is a major constraint to the sustainability and expansion of rice cultivation. Genetically improving salt tolerance of rice is a highly important objective of rice breeding programs. Traits such as salt tolerance are quantitatively inherited. Hence, mapping quantitative trait loci (QTL) with molecular markers can be very helpful to plant breeders in the field of agricultural genomics (AgriGenomics). In this investigation, QTL analysis of physiological traits related to salt tolerance was carried out using F2:4 population of rice derived from a cross between a salt-tolerant variety, Gharib (indica), and a salt-sensitive variety, Sepidroud (indica). A linkage map based on 148 F2 individuals was constructed with 131 SSR markers and 105 AFLP markers, covering 2475.7 cM of rice genome with an average distance of 10.48 cM between flanking markers. A total of 41 QTLs for twelve physiological traits under salinity stress were detected distributed on all rice chromosomes, some of them being reported for the first time. Also, overlapping of QTLs related to salt tolerance were observed in this study. Some of the identified QTLs on specific chromosomal regions explaining high phenotypic variance could be used for marker-assisted selection (MAS) programs. New QTLs retrieved in this study play an important role in growth of rice at seedling stage in an Iranian local population under high salinity conditions.

  8. Ethylene-induced inhibition of root growth requires abscisic acid function in rice (Oryza sativa L.) seedlings.

    PubMed

    Ma, Biao; Yin, Cui-Cui; He, Si-Jie; Lu, Xiang; Zhang, Wan-Ke; Lu, Tie-Gang; Chen, Shou-Yi; Zhang, Jin-Song

    2014-10-01

    Ethylene and abscisic acid (ABA) have a complicated interplay in many developmental processes. Their interaction in rice is largely unclear. Here, we characterized a rice ethylene-response mutant mhz4, which exhibited reduced ethylene-response in roots but enhanced ethylene-response in coleoptiles of etiolated seedlings. MHZ4 was identified through map-based cloning and encoded a chloroplast-localized membrane protein homologous to Arabidopsis thaliana (Arabidopsis) ABA4, which is responsible for a branch of ABA biosynthesis. MHZ4 mutation reduced ABA level, but promoted ethylene production. Ethylene induced MHZ4 expression and promoted ABA accumulation in roots. MHZ4 overexpression resulted in enhanced and reduced ethylene response in roots and coleoptiles, respectively. In root, MHZ4-dependent ABA pathway acts at or downstream of ethylene receptors and positively regulates root ethylene response. This ethylene-ABA interaction mode is different from that reported in Arabidopsis, where ethylene-mediated root inhibition is independent of ABA function. In coleoptile, MHZ4-dependent ABA pathway acts at or upstream of OsEIN2 to negatively regulate coleoptile ethylene response, possibly by affecting OsEIN2 expression. At mature stage, mhz4 mutation affects branching and adventitious root formation on stem nodes of higher positions, as well as yield-related traits. Together, our findings reveal a novel mode of interplay between ethylene and ABA in control of rice growth and development.

  9. Reactive oxygen species, ascorbate-glutathione pool, and enzymes of their metabolism in drought-sensitive and tolerant indica rice (Oryza sativa L.) seedlings subjected to progressing levels of water deficit.

    PubMed

    Pyngrope, Samantha; Bhoomika, Kumari; Dubey, R S

    2013-04-01

    Water deficit for rice is a worldwide concern, and to produce drought-tolerant varieties, it is essential to elucidate molecular mechanisms associated with water deficit tolerance. In the present study, we investigated the differential responses of nonenzymatic antioxidants ascorbate (AsA), glutathione (GSH), and their redox pool as well as activity levels of enzymes of ascorbate-glutathione cycle in seedlings of drought-sensitive rice (Oryza sativa L.) cv. Malviya-36 and drought-tolerant cv. Brown Gora subjected to water deficit treatment of -1.0 and -2.1 MPa for 24-72 h using PEG-6000 in sand cultures. Water deficit caused increased production of reactive oxygen species such as O2[Symbol: see text](-), H2O2, and HO[Symbol: see text] in the tissues, and the level of production was higher in the sensitive than the tolerant cultivar. Water deficit caused reduction in AsA and GSH and decline in their redox ratios (AsA/DHA and GSH/GSSG) with lesser decline in tolerant than the sensitive seedlings. With progressive level of water deficit, the activities of monodehydroascorbate reductase, dehydroascorbate reductase, ascorbate peroxidase (APX), and glutathione transferase increased in the seedlings of both rice cultivars, but the increased activity levels were higher in the seedlings of drought-tolerant cv. Brown Gora compared to the sensitive cv. Malviya-36. Greater accumulation of proline was observed in stressed seedlings of tolerant than the sensitive cultivar. In-gel activity staining of APX revealed varying numbers of their isoforms and their differential expression in sensitive and tolerant seedlings under water deficit. Results suggest that an enhanced oxidative stress tolerance by a well-coordinated cellular redox state of ascorbate and glutathione in reduced forms and induction of antioxidant defense system by elevated activity levels of enzymes of ascorbate-glutathione cycle is associated with water deficit tolerance in rice.

  10. Phytotoxic Activity of Ocimum tenuiflorum Extracts on Germination and Seedling Growth of Different Plant Species

    PubMed Central

    2014-01-01

    Phytotoxic activity of Ocimum tenuiflorum (Lamiaceae) plant extracts was investigated against the germination and seedling growth of cress (Lepidium sativum), lettuce (Lactuca sativa), alfalfa (Medicago sativa), Italian ryegrass (Lolium multiflorum), barnyard grass (Echinochloa crus-galli), and timothy (Phleum pratense) at four different concentrations. The plant extracts at concentrations greater than 30 mg dry weight equivalent extract mL−1 reduced significantly the total germination percent (GP), germination index (GI), germination energy (GE), speed of emergence (SE), seedling vigour index (SVI), and coefficient of the rate of germination (CRG) of all test species except barnyard grass and GP of lettuce. In contrast, time required for 50% germination (T50) and mean germination time (MGT) were increased at the same or higher than this concentration. The increasing trend of T50 and MGT and the decreasing trend of other indices indicated a significant inhibition or delay of germination of the test species by O. tenuiflorum plant extracts and vice versa. In addition, the shoot and root growth of all test species were significantly inhibited by the extracts at concentrations greater than 10 mg dry weight equivalent extract mL−1. The I50 values for shoot and root growth were ranged from 26 to 104 mg dry weight equivalent extract mL−1. Seedling growth was more sensitive to the extracts compared to seed germination. Results of this study suggest that O. tenuiflorum plant extracts have phytotoxic properties and thus contain phytotoxic substances. Isolation and characterization of those substances from this plant may act as a tool for new natural, biodegradable herbicide development to control weeds. PMID:25032234

  11. Phytotoxic activity of Ocimum tenuiflorum extracts on germination and seedling growth of different plant species.

    PubMed

    Islam, A K M Mominul; Kato-Noguchi, Hisashi

    2014-01-01

    Phytotoxic activity of Ocimum tenuiflorum (Lamiaceae) plant extracts was investigated against the germination and seedling growth of cress (Lepidium sativum), lettuce (Lactuca sativa), alfalfa (Medicago sativa), Italian ryegrass (Lolium multiflorum), barnyard grass (Echinochloa crus-galli), and timothy (Phleum pratense) at four different concentrations. The plant extracts at concentrations greater than 30 mg dry weight equivalent extract mL(-1) reduced significantly the total germination percent (GP), germination index (GI), germination energy (GE), speed of emergence (SE), seedling vigour index (SVI), and coefficient of the rate of germination (CRG) of all test species except barnyard grass and GP of lettuce. In contrast, time required for 50% germination (T 50) and mean germination time (MGT) were increased at the same or higher than this concentration. The increasing trend of T 50 and MGT and the decreasing trend of other indices indicated a significant inhibition or delay of germination of the test species by O. tenuiflorum plant extracts and vice versa. In addition, the shoot and root growth of all test species were significantly inhibited by the extracts at concentrations greater than 10 mg dry weight equivalent extract mL(-1). The I 50 values for shoot and root growth were ranged from 26 to 104 mg dry weight equivalent extract mL(-1). Seedling growth was more sensitive to the extracts compared to seed germination. Results of this study suggest that O. tenuiflorum plant extracts have phytotoxic properties and thus contain phytotoxic substances. Isolation and characterization of those substances from this plant may act as a tool for new natural, biodegradable herbicide development to control weeds.

  12. The Challenge of Peat Substitution in Organic Seedling Production: Optimization of Growing Media Formulation through Mixture Design and Response Surface Analysis.

    PubMed

    Ceglie, Francesco Giovanni; Bustamante, Maria Angeles; Ben Amara, Mouna; Tittarelli, Fabio

    2015-01-01

    Peat replacement is an increasing demand in containerized and transplant production, due to the environmental constraints associated to peat use. However, despite the wide information concerning the use of alternative materials as substrates, it is very complex to establish the best materials and mixtures. This work evaluates the use of mixture design and surface response methodology in a peat substitution experiment using two alternative materials (green compost and palm fibre trunk waste) for transplant production of tomato (Lycopersicon esculentum Mill.); melon, (Cucumis melo L.); and lettuce (Lactuca sativa L.) in organic farming conditions. In general, the substrates showed suitable properties for their use in seedling production, showing the best plant response the mixture of 20% green compost, 39% palm fibre and 31% peat. The mixture design and applied response surface methodology has shown to be an useful approach to optimize substrate formulations in peat substitution experiments to standardize plant responses.

  13. The Challenge of Peat Substitution in Organic Seedling Production: Optimization of Growing Media Formulation through Mixture Design and Response Surface Analysis

    PubMed Central

    Ceglie, Francesco Giovanni; Bustamante, Maria Angeles; Ben Amara, Mouna; Tittarelli, Fabio

    2015-01-01

    Peat replacement is an increasing demand in containerized and transplant production, due to the environmental constraints associated to peat use. However, despite the wide information concerning the use of alternative materials as substrates, it is very complex to establish the best materials and mixtures. This work evaluates the use of mixture design and surface response methodology in a peat substitution experiment using two alternative materials (green compost and palm fibre trunk waste) for transplant production of tomato (Lycopersicon esculentum Mill.); melon, (Cucumis melo L.); and lettuce (Lactuca sativa L.) in organic farming conditions. In general, the substrates showed suitable properties for their use in seedling production, showing the best plant response the mixture of 20% green compost, 39% palm fibre and 31% peat. The mixture design and applied response surface methodology has shown to be an useful approach to optimize substrate formulations in peat substitution experiments to standardize plant responses. PMID:26070163

  14. Potent endogenous allelopathic compounds in Lepidium sativum seed exudate: effects on epidermal cell growth in Amaranthus caudatus seedlings.

    PubMed

    Iqbal, Amjad; Fry, Stephen C

    2012-04-01

    Many plants exude allelochemicals--compounds that affect the growth of neighbouring plants. This study reports further studies of the reported effect of cress (Lepidium sativum) seed(ling) exudates on seedling growth in Amaranthus caudatus and Lactuca sativa. In the presence of live cress seedlings, both species grew longer hypocotyls and shorter roots than cress-free controls. The effects of cress seedlings were allelopathic and not due to competition for resources. Amaranthus seedlings grown in the presence of cress allelochemical(s) had longer, thinner hypocotyls and shorter, thicker roots--effects previously attributed to lepidimoide. The active principle was more abundant in cress seed exudate than in seedling (root) exudates. It was present in non-imbibed seeds and releasable from heat-killed seeds. Release from live seeds was biphasic, starting rapidly but then continuing gradually for 24 h. The active principle was generated by aseptic cress tissue and was not a microbial digestion product or seed-treatment chemical. Crude seed exudate affected hypocotyl and root growth at ~25 and ~450 μg ml(-1) respectively. The exudate slightly (28%) increased epidermal cell number along the length of the Amaranthus hypocotyl but increased total hypocotyl elongation by 129%; it resulted in a 26% smaller hypocotyl circumference but a 55% greater epidermal cell number counted round the circumference. Therefore, the effect of the allelochemical(s) on organ morphology was imposed primarily by regulation of cell expansion, not cell division. It is concluded that cress seeds exude endogenous substances, probably including lepidimoide, that principally regulate cell expansion in receiver plants.

  15. Effects of soil conditioners on emergence and growth of tomato-cotton, and lettuce seedlings. [Lycopersicon esculentum; Gossypium hirsutum; Lactuea sativa

    SciTech Connect

    Wallace, A.; Wallace, G.A.

    1986-05-01

    The purpose of this paper is to demonstrate the extent to which seedling emergence and plant growth can be improved with use of new soil conditioners. The early findings regarding polymeric soil conditioners are still valid today, with the exception that much lower application rates are needed today, and different application methodology is available.

  16. Marker Aided Incorporation of Saltol, a Major QTL Associated with Seedling Stage Salt Tolerance, into Oryza sativa ‘Pusa Basmati 1121’

    PubMed Central

    Babu, N. Naresh; Krishnan, S. Gopala; Vinod, K. K.; Krishnamurthy, S. L.; Singh, Vivek K.; Singh, Madan P.; Singh, Renu; Ellur, Ranjith K.; Rai, Vandna; Bollinedi, Haritha; Bhowmick, Prolay K.; Yadav, Ashutosh K.; Nagarajan, Mariappan; Singh, Nagendra K.; Prabhu, Kumble V.; Singh, Ashok K.

    2017-01-01

    Pusa Basmati 1121 (PB1121), an elite Basmati rice cultivar is vulnerable to salinity at seedling stage. A study was undertaken to impart seedling-stage salt tolerance into PB1121 by transferring a quantitative trait locus (QTL), Saltol, using FL478 as donor, through marker assisted backcrossing. Sequence tagged microsatellite site (STMS) marker RM 3412, tightly linked to Saltol was used for foreground selection. Background recovery was estimated using 90 genome-wide STMS markers. Systematic phenotypic selection helped in accelerated recovery of recurrent parent phenome (RPP). A set of 51 BC3F2 lines homozygous for Saltol were advanced to develop four improved near isogenic lines (NILs) of PB1121 with seedling stage salt tolerance. The background genome recovery in the NILs ranged from 93.3 to 99.4%. The improved NILs were either similar or better than the recurrent parent PB1121 for yield, grain and cooking quality and duration. Biochemical analyses revealed significant variation in shoot and root Na+ and K+ concentrations. Correlation between shoot and root Na+ concentration was stronger than that between root and shoot K+ concentration. The effect of QTL integration into the NILs was studied through expression profiling of OsHKT1;5, one of the genes present in the Saltol region. The NILs had significantly higher OsHKT1;5 expression than the recurrent parent PB1121, but lower than FL478 on salt exposure validating the successful introgression of Saltol in the NILs. This was also confirmed under agronomic evaluation, wherein the NILs showed greater salt tolerance at seedling stage. One of the NILs, Pusa1734-8-3-3 (NIL3) showed comparable yield and cooking quality to the recurrent parent PB1121, with high field level seedling stage salinity tolerance and shorter duration. This is the first report of successful introgression of Saltol into a Basmati rice cultivar. PMID:28184228

  17. Inhibition of root growth by narciclasine is caused by DNA damage-induced cell cycle arrest in lettuce seedlings.

    PubMed

    Hu, Yanfeng; Li, Jiaolong; Yang, Lijing; Nan, Wenbin; Cao, Xiaoping; Bi, Yurong

    2014-09-01

    Narciclasine (NCS) is an Amaryllidaceae alkaloid isolated from Narcissus tazetta bulbs. Its phytotoxic effects on plant growth were examined in lettuce (Lactuca sativa L.) seedlings. Results showed that high concentrations (0.5-5 μM) of NCS restricted the growth of lettuce roots in a dose-dependent manner. In NCS-treated lettuce seedlings, the following changes were detected: reduction of mitotic cells and cell elongation in the mature region, inhibition of proliferation of meristematic cells, and cell cycle. Moreover, comet assay and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay indicated that higher levels NCS (0.5-5 μM) induced DNA damage in root cells of lettuce. The decrease in meristematic cells and increase in DNA damage signals in lettuce roots in responses to NCS are in a dose-dependent manner. NCS-induced reactive oxygen species accumulation may explain an increase in DNA damage in lettuce roots. Thus, the restraint of root growth is due to cell cycle arrest which is caused by NCS-induced DNA damage. In addition, it was also found that NCS (0.5-5 μM) inhibited the root hair development of lettuce seedlings. Further investigations on the underlying mechanism revealed that both auxin and ethylene signaling pathways are involved in the response of root hairs to NCS.

  18. Sulfur (S)-induced enhancement of iron plaque formation in the rhizosphere reduces arsenic accumulation in rice (Oryza sativa L.) seedlings.

    PubMed

    Hu, Zheng-Yi; Zhu, Yong-Guan; Li, Min; Zhang, Li-Gan; Cao, Zhi-Hong; Smith, F Andrew

    2007-05-01

    The effects of two sulfur (S) sources (SO(4)(2-), S(0)), and three rates of S application (0, 30, 120 mgS/kg) on the formation of iron plaque in the rhizosphere, and on the root surface of rice, and As (arsenic) uptake into rice (Oryza sativa L.) were studied in a combined soil-sand culture experiment. Significant differences in As uptake into rice between +S and -S treatments were observed in relation to S sources, and rates of S application. Concentrations of As in rice shoots decreased with increasing rates of S application. The mechanism could be ascribed to sulfur, induced the formation of iron plaque, since concentrations of Fe in iron plaque on quartz sands in the rhizosphere, and on the root surface of rice increased with increasing rates of S application. The results suggest that sulfur fertilization may be important for the development approaches to reducing As accumulation in rice.

  19. Endogenous hydrogen sulfide enhances salt tolerance by coupling the reestablishment of redox homeostasis and preventing salt-induced K⁺ loss in seedlings of Medicago sativa.

    PubMed

    Lai, Diwen; Mao, Yu; Zhou, Heng; Li, Feng; Wu, Mingzhu; Zhang, Jing; He, Ziyi; Cui, Weiti; Xie, Yanjie

    2014-08-01

    Despite the external application of hydrogen sulfide (H2S) conferring plant tolerance against various environmental cues, the physiological significance of l-cysteine desulfhydrase (L-DES)-associated endogenous H2S production involved in salt-stress signaling was poorly understood. To address this gap, the participation of in planta changes of H2S homeostasis involved in alfalfa salt tolerance was investigated. The increasing concentration of NaCl (from 50 to 300 mM) progressively caused the induction of total l-DES activity and the increase of endogenous H2S production. NaCl-triggered toxicity symptoms (175 mM), including seedling growth inhibition and lipid peroxidation, were alleviated by sodium hydrosulfide (NaHS; 100 μM), a H2S donor, whereas aggravated by an inhibitor of l-DES or a H2S scavenger. A weaker or negative response was observed in lower or higher dose of NaHS. Further results showed that endogenous l-DES-related H2S modulated several genes/activities of antioxidant defence enzymes, and also regulated the contents of antioxidant compounds, thus counterbalancing the NaCl-induced lipid peroxidation. Moreover, H2S maintained K(+)/Na(+) homeostasis by preventing the NaCl-triggered K(+) efflux, which might be result form the impairment of SKOR expression. Together, our findings indicated that endogenous H2S homeostasis enhance salt tolerance by coupling the reestablishment of redox balance and restraining K(+) efflux in alfalfa seedlings.

  20. [Disinfection treatment for lettuces (Lactuca sativa) and strawberries (Fragatia Chiloensis)].

    PubMed

    López, L; Romero, J; Ureta, F

    2001-12-01

    The disinfection of vegetables and fruits is a treatment applied in order to reduce their natural contamination or processes to the product along the different steps of the food chain until its consumption. In the present work the effect of two disinfectants products was studied: grapefruit seed extract (400 ppm) for 10 min and peracetic acid (2000 ppm) for 1 min (action times assayed according to the manufacturer recommendations) and other additional times. The germicidal action was carried out against the natural contaminants of lettuces and strawberries, through the determination of the germicidal efficiency (%). Treated and untreated strawberries were also evaluated for flavor changes through a sensorial difference test, triangular test. None of the assayed products reached the 99.999% destruction of the natural contaminants according to the Chambers test. Peracetic acid was the most effective disinfectant, reaching the highest destruction percentages at a time lower than that for grapefruit seed extract. Sensory analysis showed no significant differences (p = .05) between strawberries with and without disinfection treatments, at the conditions suggested by the manufacturer.

  1. Selectivity of thiobencarb between two lettuce (Lactuca sativa, L. ) cultivars

    SciTech Connect

    Reiners, S.

    1987-01-01

    Thiobencarb (S-(4-chlorobenzyl)N,N-diethylthiocarbamate) was examined for weed control on muck grown lettuce. Weed control results were erratic though differential lettuce tolerance was observed in the field. This led to the testing of five lettuce cultivars for tolerance to the herbicide. Of the five lettuce cultivars evaluated, two were selected with the widest tolerance differences: Great Lakes 366 (GLA) (tolerant) and Dark Green Boston (BOS) (susceptible). Studies examining the mechanism of thiobencarb tolerance were conducted with these two cultivars. Within four days after the addition of thiobencarb to the nutrient solution, BOS had significant reductions in the foliar dry weight. In addition, growth abnormalities including fused leaves were observed, indicating inhibition early in leaf development. Greater amounts of /sup 14/C-thiobencarb were absorbed from nutrient solution by BOS, likely due to a significantly greater root system at the time of treatment. The greater uptake and accumulation of /sup 14/C-label in the leaves, as well as significantly greater amounts of unmetabolized /sup 14/C-thiobencarb in the foliage of BOS may account for the selectivity observed. A thiobencarb sulfoxide was not identified in these studies. This indicates that the metabolism of thiobencarb in lettuce differs from other members of the thiocarbamate family of herbicides.

  2. Growing patterns to produce 'nitrate-free' lettuce (Lactuca sativa).

    PubMed

    Croitoru, Mircea Dumitru; Muntean, Daniela-Lucia; Fülöp, Ibolya; Modroiu, Adriana

    2015-01-01

    Vegetables can contain significant amounts of nitrate and, therefore, may pose health hazards to consumers by exceeding the accepted daily intake for nitrate. Different hydroponic growing patterns were examined in this work in order to obtain 'nitrate-free lettuces'. Growing lettuces on low nitrate content nutrient solution resulted in a significant decrease in lettuces' nitrate concentrations (1741 versus 39 mg kg(-1)), however the beneficial effect was cancelled out by an increase in the ambient temperature. Nitrate replacement with ammonium was associated with an important decrease of the lettuces' nitrate concentration (from 1896 to 14 mg kg(-1)) and survival rate. An economically feasible method to reduce nitrate concentrations was the removal of all inorganic nitrogen from the nutrient solution before the exponential growth phase. This method led to lettuces almost devoid of nitrate (10 mg kg(-1)). The dried mass and calcinated mass of lettuces, used as markers of lettuces' quality, were not influenced by this treatment, but a small reduction (18%, p < 0.05) in the fresh mass was recorded. The concentrations of nitrite in the lettuces and their modifications are also discussed in the paper. It is possible to obtain 'nitrate-free' lettuces in an economically feasible way.

  3. Acinetobacter lactucae sp. nov., isolated from iceberg lettuce (Asteraceae: Lactuca sativa)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Strain NRRL B-41902 and three closely related strains were isolated from iceberg lettuce. The strain was found to consist of strictly aerobic, gram-negative rods that formed cocci in late stationary phase. Subsequent to sequencing the 16S ribosomal RNA gene, it was found that strain NRRL B-41902 was...

  4. Population Structure, Diversity and Trait Association Analysis in Rice (Oryza sativa L.) Germplasm for Early Seedling Vigor (ESV) Using Trait Linked SSR Markers

    PubMed Central

    Anandan, Annamalai; Anumalla, Mahender; Pradhan, Sharat Kumar; Ali, Jauhar

    2016-01-01

    Early seedling vigor (ESV) is the essential trait for direct seeded rice to dominate and smother the weed growth. In this regard, 629 rice genotypes were studied for their morphological and physiological responses in the field under direct seeded aerobic situation on 14th, 28th and 56th days after sowing (DAS). It was determined that the early observations taken on 14th and 28th DAS were reliable estimators to study ESV as compared to56th DAS. Further, 96 were selected from 629 genotypes by principal component (PCA) and discriminate function analyses. The selected genotypes were subjected to decipher the pattern of genetic diversity in terms of both phenotypic and genotypic by using ESV QTL linked simple sequence repeat (SSR) markers. To assess the genetic structure, model and distance based approaches were used. Genotyping of 96 rice lines using 39 polymorphic SSRs produced a total of 128 alleles with the phenotypic information content (PIC) value of 0.24. The model based population structure approach grouped the accession into two distinct populations, whereas unrooted tree grouped the genotypes into three clusters. Both model based and structure based approach had clearly distinguished the early vigor genotypes from non-early vigor genotypes. Association analysis revealed that 16 and 10 SSRs showed significant association with ESV traits by general linear model (GLM) and mixed linear model (MLM) approaches respectively. Marker alleles on chromosome 2 were associated with shoot dry weight on 28 DAS, vigor index on 14 and 28 DAS. Improvement in the rate of seedling growth will be useful for identifying rice genotypes acquiescent to direct seeded conditions through marker-assisted selection. PMID:27031620

  5. Phytotoxicity of arsenate and salinity on early seedling growth of rice (Oryza sativa L.): a threat to sustainable rice cultivation in South and South-East Asia.

    PubMed

    Rahman, M Mamunur; Rahman, M Azizur; Maki, T; Hasegawa, H

    2012-05-01

    Arsenic (As) contamination is an important environmental consequence in some parts of salinity-affected South (S) and South-East (SE) Asia. In this study, we investigated the individual and combined phytotoxicity of arsenic (As) [arsenate; As(V)] and salinity (NaCl) on early seedling growth (ESG) of saline-tolerant and non-tolerant rice varieties. Germination percentage (GP), germination speed (GS) and vigor index (VI) of both saline-tolerant and non-tolerant rice varieties decreased significantly (p > 0.01) with increasing As(V) and NaCl concentrations. The highest GP (91%) was observed for saline non-tolerant BRRI dhan28 and BRRI dhan49, while the lowest (62%) was for saline-tolerant BRRI dhan47. The ESG parameters, such as weights and relative lengths of plumule and radicle, also decreased significantly (p < 0.01) with increasing As(V) and NaCl concentrations. Relative radicle length was more affected than plumule length by As(V) and NaCl. Although VI of saline-tolerant and non-tolerant rice seedlings showed significant variation (p < 0.05), weights and lengths of plumule and radicle of different rice varieties did not show significant variation for As(V) and NaCl treatments. Results reveal that the combined phytotoxicity of As(V) and NaCl on rice seed germination and ESG are greater than their individual toxicities, and some saline-tolerant rice varieties are more resistant to the combined phytotoxicity of As(V) and NaCl than the saline non-tolerant varieties.

  6. Preillumination of lettuce seedlings with red light enhances the resistance of photosynthetic apparatus to UV-A.

    PubMed

    Kreslavski, Vladimir D; Lyubimov, Valery Yu; Shirshikova, Galina N; Shmarev, Alexander N; Kosobryukhov, Anatoly A; Schmitt, Franz-Josef; Friedrich, Thomas; Allakhverdiev, Suleyman I

    2013-05-05

    Seedlings of 10-day-old lettuce (Lactuca sativa L., cultivar Berlin) were preilluminated by low intensity red light (λmax=660 nm, 10 min, 5 μmol quanta m(-2) s(-1)) and far-red light (λmax=730 nm, 10 min, 5 μmol quanta m(-2) s(-1)) to study the effect of pre-treatment on photosynthesis, photochemical activity of photosystem II (PSII), the contents of photosynthetic and UV-A-absorbing pigments (UAPs) and H2O2, as well as total and ascorbate peroxidase activities in cotyledonary leaves of seedlings exposed to UV-A. UV radiation reduced the photosynthetic rate (Pn), the activity of PSII, and the contents of Chl a and b, carotenoids and UAPs in the leaves, but increased the content of H2O2 and the total peroxidase activity. Preillumination with red light removed these effects of UV. In turn, the illumination with red light, then far-red light removed the effect of the red light. Illumination with red light alone increased the content of UAPs, as well as peroxidase activity. It is suggested that higher resistance of the lettuce photosynthetic apparatus to UV-A radiation is associated with involvement of the active form of phytochrome B, thereby increasing peroxidase activities as well as UAPs and saving preservation of photosynthetic pigment contents due to pre-illumination with red light.

  7. The metabolism and distribution of sup 14 C-8N sup 6 -benzyladenine in lettuce seeds and seedlings

    SciTech Connect

    Seeber, R.G. Jr.

    1989-01-01

    This investigation sought to follow the uptake of the cytokinin, {sup 14}C-8N{sup 6}-benzyladenine (BAP), by lettuce seeds through time, trace the movement of the metabolites through several areas of the seedling, and identify the BAP metabolites. Lettuce seeds (Lactuca sativa L. cv. Grand Rapids) were exposed to a two hour pulse of the radioactive BAP. These seeds were harvested at 4 hour intervals from 2-48 hours. Seedlings incubated from 36-48 hours were cut in two; root, stem, shoot tip and seed coats. Each of these groups were extracted in 70% methanol and their radioactive isolated by high performance liquid chromatography. Radioactive fractions were pooled and reduced for further analysis by thin layer chromatography. The major compound identified throughout the time periods was BAP, exclusively found from 2-20 hours. BAP riboside was found in addition to BAP from 24-32 hours. The 40 and 44 hour extracts contained BAP and its riboside in the shoot and BAP in the seed coat. The 48 hours extract contained BAP and its riboside in both the shoot tip and the seed coat. This study produced information on the following points. A cytokinin exposure of 2 hours or less is needed to break dormancy in these seeds.

  8. Phytotoxic action of naphthoquinone juglone demonstrated on lettuce seedling roots.

    PubMed

    Babula, Petr; Vaverkova, Veronika; Poborilova, Zuzana; Ballova, Ludmila; Masarik, Michal; Provaznik, Ivo

    2014-11-01

    Juglone, 5-hydroxy-1,4-naphthoquinone, is the plant secondary metabolite with allelopathic properties, which was isolated especially from the plant species belonging to family Juglandaceae A. Rich. ex Kunth (walnut family). The mechanism of phytotoxic action of juglone was investigated on lettuce seedlings Lactuca sativa L. var. capitata L. cv. Merkurion by determining its effect at different levels. We have found that juglone inhibits mitosis (mitotic index 8.5 ± 0.6% for control versus 2.2 ± 0.9% for 250 μM juglone), changes mitotic phase index with accumulation of the cells in prophase (56.5 ± 2.6% for control versus 85.3 ± 5.0% for 250 μM juglone), and decreases meristematic activity in lettuce root tips (51.07 ± 3.62% for control versus 5.27 ± 2.29% for 250 μM juglone). In addition, juglone induced creation of reactive oxygen species and changed levels of reactive nitrogen species. Amount of malondialdehyde, a product of lipid peroxidation, increased from 24.0 ± 4.0 ng g(-1) FW for control to 55.5 ± 5.4 ng g(-1) FW for 250 μM juglone. We observed also changes in cellular structure, especially changes in the morphology of endoplasmic reticulum. Reactive oxygen species induced damage of plasma membrane. All these changes resulted in the disruption of the mitochondrial membrane potential, increase in free intracellular calcium ions, and DNA fragmentation and programmed cell death that was revealed by two methods, TUNEL test and DNA electrophoresis. The portion of TUNEL-positive cells increase from 0.96 ± 0.5% for control to 7.66 ± 1.5% for 250 μM juglone. Results of the study indicate complex mechanism of phytotoxic effect of juglone in lettuce root tips and may indicate mechanism of allelopathic activity of this compound.

  9. Genetic Architecture of Cold Tolerance in Rice (Oryza sativa) Determined through High Resolution Genome-Wide Analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cold temperature is an important abiotic stress which negatively affects morphological development and seed production in rice (Oryza sativa L.). At the seedling stage, cold stress causes poor germination, seedling injury and poor stand establishment; and at the reproductive stage cold decreases se...

  10. Evaluation of seedling cold tolerance in rice cultivars: a comparison of visual ratings and quantitative indicators of physiological changes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice (Oryza sativa L.) is sensitive to prolonged exposure to low temperature, which at the seedling stage can result in significant chilling injury and mortality. The objective of this study was to quantify physiological and biochemical changes in rice seedlings undergoing chilling stress and compar...

  11. Phytochemical relationship of Euphorbia helioscopia and Euphorbia pulcherrima with Lactuca sativa.

    PubMed

    Rehman, Hafiza Ayesha; Yousaf, Zubaida; Rashid, Madiha; Younas, Afifa; Arif, Ayesha; Afzal, Ismah; Akram, Waheed

    2014-01-01

    Allelopathy is an important phenomenon that modifies the ecosystem. A plant can enhance or reduce the growth of other plant due to the presence of a number of allelochemicals in its different parts. Euphorbia helioscopia and Euphorbia pulcherrima are medicinal plant species. Both these species are collected from wild resources for various purposes. To reduce the pressure on wild population, it is important to bring them into cultivation. Therefore, the allelopathic effects of E. helioscopia and E. pulcherrima on the growth of lettuce seeds were studied. Three different concentrations (2%, 4% and 6%) of five different solvents (methanol, acetone, ethyl acetate, n-hexane and distilled water) were used to estimate the allelopathic potential of the above-mentioned Euphorbia species. Results indicated a non-significant growth inhibitory effect of both plants on lettuce seeds. Different extracts reduced the growth of test plant to some extent but this inhibition was not significant. From the observed results, it was concluded that the studied Euphorbia species, being medicinally important crops, can be introduced as intercrop with other cash crops.

  12. Physiological and Molecular Responses of Lactuca sativa to Colonization by Salmonella enterica Serovar Dublin▿

    PubMed Central

    Klerks, M. M.; van Gent-Pelzer, M.; Franz, E.; Zijlstra, C.; van Bruggen, A. H. C.

    2007-01-01

    This paper describes the physiological and molecular interactions between the human-pathogenic organism Salmonella enterica serovar Dublin and the commercially available mini Roman lettuce cv. Tamburo. The association of S. enterica serovar Dublin with lettuce plants was first determined, which indicated the presence of significant populations outside and inside the plants. The latter was evidenced from significant residual concentrations after highly efficient surface disinfection (99.81%) and fluorescence microscopy of S. enterica serovar Dublin in cross sections of lettuce at the root-shoot transition region. The plant biomass was reduced significantly compared to that of noncolonized plants upon colonization with S. enterica serovar Dublin. In addition to the physiological response, transcriptome analysis by cDNA amplified fragment length polymorphism analysis also provided clear differential gene expression profiles between noncolonized and colonized lettuce plants. From these, generally and differentially expressed genes were selected and identified by sequence analysis, followed by reverse transcription-PCR displaying the specific gene expression profiles in time. Functional grouping of the expressed genes indicated a correlation between colonization of the plants and an increase in expressed pathogenicity-related genes. This study indicates that lettuce plants respond to the presence of S. enterica serovar Dublin at physiological and molecular levels, as shown by the reduction in growth and the concurrent expression of pathogenicity-related genes. In addition, it was confirmed that Salmonella spp. can colonize the interior of lettuce plants, thus potentially imposing a human health risk when processed and consumed. PMID:17513585

  13. Effects of Nitrogen Fertilizers on the Growth and Nitrate Content of Lettuce (Lactuca sativa L.)

    PubMed Central

    Liu, Cheng-Wei; Sung, Yu; Chen, Bo-Ching; Lai, Hung-Yu

    2014-01-01

    Nitrogen is an essential element for plant growth and development; however, due to environmental pollution, high nitrate concentrations accumulate in the edible parts of these leafy vegetables, particularly if excessive nitrogen fertilizer has been applied. Consuming these crops can harm human health; thus, developing a suitable strategy for the agricultural application of nitrogen fertilizer is important. Organic, inorganic, and liquid fertilizers were utilized in this study to investigate their effect on nitrate concentrations and lettuce growth. The results of this pot experiment show that the total nitrogen concentration in soil and the nitrate concentration in lettuce increased as the amount of nitrogen fertilizer increased. If the recommended amount of inorganic fertilizer (200 kg·N·ha−1) is used as a standard of comparison, lettuce augmented with organic fertilizers (200 kg·N·ha−1) have significantly longer and wider leaves, higher shoot, and lower concentrations of nitrate. PMID:24758896

  14. Nutritional value, bioactive compounds, and health benefits of lettuce (Lactuca sativa L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lettuce is one of the most popularly consumed vegetables worldwide but its nutritional value has been underestimated. Lettuce is low in calories and fat but high in fiber. Moreover, lettuce is high in potassium but low in sodium. Lettuce is also a good source of health-beneficial bioactive compounds...

  15. Characterization of volatile production during storage of lettuce (Lactuca sativa) seed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The duration that seeds stay vigorous during storage is difficult to predict but critical to seed industry and conservation communities. Production of volatile compounds from lettuce seeds during storage was investigated as a non-invasive and early detection method of seed aging rates. Over thirty...

  16. Genetic Control of Water and Nitrate Capture and Their Use Efficiency in Lettuce (Lactuca sativa L.).

    PubMed

    Kerbiriou, Pauline J; Maliepaard, Chris A; Stomph, Tjeerd Jan; Koper, Martin; Froissart, Dorothee; Roobeek, Ilja; Lammerts Van Bueren, Edith T; Struik, Paul C

    2016-01-01

    Robustness in lettuce, defined as the ability to produce stable yields across a wide range of environments, may be associated with below-ground traits such as water and nitrate capture. In lettuce, research on the role of root traits in resource acquisition has been rather limited. Exploring genetic variation for such traits and shoot performance in lettuce across environments can contribute to breeding for robustness. A population of 142 lettuce cultivars was evaluated during two seasons (spring and summer) in two different locations under organic cropping conditions, and water and nitrate capture below-ground and accumulation in the shoots were assessed at two sampling dates. Resource capture in each soil layer was measured using a volumetric method based on fresh and dry weight difference in the soil for soil moisture, and using an ion-specific electrode for nitrate. We used these results to carry out an association mapping study based on 1170 single nucleotide polymorphism markers. We demonstrated that our indirect, high-throughput phenotyping methodology was reliable and capable of quantifying genetic variation in resource capture. QTLs for below-ground traits were not detected at early sampling. Significant marker-trait associations were detected across trials for below-ground and shoot traits, in number and position varying with trial, highlighting the importance of the growing environment on the expression of the traits measured. The difficulty of identifying general patterns in the expression of the QTLs for below-ground traits across different environments calls for a more in-depth analysis of the physiological mechanisms at root level allowing sustained shoot growth.

  17. MADS-Box Genes and Gibberellins Regulate Bolting in Lettuce (Lactuca sativa L.).

    PubMed

    Han, Yingyan; Chen, Zijing; Lv, Shanshan; Ning, Kang; Ji, Xueliang; Liu, Xueying; Wang, Qian; Liu, Renyi; Fan, Shuangxi; Zhang, Xiaolan

    2016-01-01

    Bolting in lettuce is promoted by high temperature and bolting resistance is of great economic importance for lettuce production. But how bolting is regulated at the molecular level remains elusive. Here, a bolting resistant line S24 and a bolting sensitive line S39 were selected for morphological, physiological, transcriptomic and proteomic comparisons. A total of 12204 genes were differentially expressed in S39 vs. S24. Line S39 was featured with larger leaves, higher levels of chlorophyll, soluble sugar, anthocyanin and auxin, consistent with its up-regulation of genes implicated in photosynthesis, oxidation-reduction and auxin actions. Proteomic analysis identified 30 differentially accumulated proteins in lines S39 and S24 upon heat treatment, and 19 out of the 30 genes showed differential expression in the RNA-Seq data. Exogenous gibberellins (GA) treatment promoted bolting in both S39 and S24, while 12 flowering promoting MADS-box genes were specifically induced in line S39, suggesting that although GA regulates bolting in lettuce, it may be the MADS-box genes, not GA, that plays a major role in differing the bolting resistance between these two lettuce lines.

  18. Improving Water Use Efficiency of Lettuce (Lactuca sativa L.) Using Phosphorous Fertilizers.

    PubMed

    Alkhader, Asad M F; Abu Rayyan, Azmi M

    2013-01-01

    A greenhouse pot experiment was conducted to evaluate the effect of phosphorous (P) fertilizers application to an alkaline calcareous soil on the water use efficiency (WUE) of lettuce cultivar "robinson" of iceberg type. Head fresh and dry weights, total water applied and WUE were affected significantly by the P fertilizer type and rate. P fertilizers addition induced a significant enhancement in the WUE and fresh and dry weights of the crop. A local phosphate rock (PR) applied directly was found to be inferior to the other types of P fertilizers (Mono ammonium phosphate (MAP), Single superphosphate (SSP), and Di ammonium phosphate ((DAP)). MAP fertilizer at 375 and 500 kg P2O5/ha application rates recorded the highest significant values of head fresh weight and WUE, respectively.

  19. Changes in the content of free and conjugated polyamines during Lettuce (Lactuca sativa) growth.

    PubMed

    Pinto, Edgar; Ferreira, Isabel M P L V O

    2015-01-21

    Polyamines (PAs) in plant foods are relevant due to the association of these bioactive nutrients with health and disease. The scope of the present study was to monitor the content of free, conjugated, and total (free + conjugated) putrescine (Put), spermidine (Spd), and spermine (Spm) at five stages of lettuce growth in three different greenhouses. The daily intake of PAs from lettuce consumption was estimated since its consumption represents about 7.2% of vegetables intake. Results showed that the content of free Put, Spd, and Spm decreased during plant growth, while the content of conjugated Put, Spd, and Spm increased. Nevertheless, the total PA content remained fairly constant. Significant differences were observed in the PAs content in lettuces grown in different greenhouses. The conjugated fraction of PAs in mature lettuces has an important contribution to the total PAs and will certainly influence the bioavailability and/or bioactivity of dietary polyamines.

  20. Ultrastructural and developmental evidence of phytotoxicity on cos lettuce (Lactuca sativa) associated with nonylphenol exposure.

    PubMed

    de Bruin, Willeke; van der Merwe, Chris; Kritzinger, Quenton; Bornman, Riana; Korsten, Lise

    2017-02-01

    It has long been understood that the presence of endocrine disrupter chemicals (EDCs) in water can affect the reproductive, behavioural and regulatory systems of different types of mammals. Thus far, only a handful of studies have examined its impact on plant systems. Present research is limited to the potential uptake of these chemicals by plants and the general phytotoxic effects it can elicit. The aim of this study was to determine what effect an EDC has on developing plant and cell organelles and how it affects it. In this study, cos lettuce plants were exposed to different concentrations of nonylphenol (NP), an EDC, in a static hydroponic system. Changes in plant morphology, mass and length, chlorophyll content, as well as electrolyte leakage were examined. Furthermore an in-depth investigation of the plant cell ultrastructure was carried out with transmission electron microscopy. Results indicated that cos lettuce growth was severely restricted, chlorophyll content was reduced, leakage of electrolytes increased and roots were stunted especially after ≥3200 μg/l NP exposures. The structure of the rough endoplasmic reticulum, vacuole and chloroplast were also changed. This study emphasizes the importance of water quality management, since the presence of an EDC, like NP, can negatively impact the yield and internal structure of one of the world's most significant salad crops, namely lettuce.

  1. MADS-Box Genes and Gibberellins Regulate Bolting in Lettuce (Lactuca sativa L.)

    PubMed Central

    Han, Yingyan; Chen, Zijing; Lv, Shanshan; Ning, Kang; Ji, Xueliang; Liu, Xueying; Wang, Qian; Liu, Renyi; Fan, Shuangxi; Zhang, Xiaolan

    2016-01-01

    Bolting in lettuce is promoted by high temperature and bolting resistance is of great economic importance for lettuce production. But how bolting is regulated at the molecular level remains elusive. Here, a bolting resistant line S24 and a bolting sensitive line S39 were selected for morphological, physiological, transcriptomic and proteomic comparisons. A total of 12204 genes were differentially expressed in S39 vs. S24. Line S39 was featured with larger leaves, higher levels of chlorophyll, soluble sugar, anthocyanin and auxin, consistent with its up-regulation of genes implicated in photosynthesis, oxidation-reduction and auxin actions. Proteomic analysis identified 30 differentially accumulated proteins in lines S39 and S24 upon heat treatment, and 19 out of the 30 genes showed differential expression in the RNA-Seq data. Exogenous gibberellins (GA) treatment promoted bolting in both S39 and S24, while 12 flowering promoting MADS-box genes were specifically induced in line S39, suggesting that although GA regulates bolting in lettuce, it may be the MADS-box genes, not GA, that plays a major role in differing the bolting resistance between these two lettuce lines. PMID:28018414

  2. Photoprotection vs. Photoinhibition of Photosystem II in Transplastomic Lettuce (Lactuca sativa) Dominantly Accumulating Astaxanthin.

    PubMed

    Fujii, Ritsuko; Yamano, Nami; Hashimoto, Hideki; Misawa, Norihiko; Ifuku, Kentaro

    2016-07-01

    Transplastomic (chloroplast genome-modified; CGM) lettuce that dominantly accumulates astaxanthin grows similarly to a non-transgenic control with almost no accumulation of naturally occurring photosynthetic carotenoids. In this study, we evaluated the activity and assembly of PSII in CGM lettuce. The maximum quantum yield of PSII in CGM lettuce was <0.6; however, the quantum yield of PSII was comparable with that in control leaves under higher light intensity. CGM lettuce showed a lower ability to induce non-photochemical quenching (NPQ) than the control under various light intensities. The fraction of slowly recovering NPQ in CGM lettuce, which is considered to be photoinhibitory quenching (qI), was less than half that of the control. In fact, (1)O2 generation was lower in CGM than in control leaves under high light intensity. CGM lettuce contained less PSII, accumulated mostly as a monomer in thylakoid membranes. The PSII monomers purified from the CGM thylakoids bound echinenone and canthaxanthin in addition to β-carotene, suggesting that a shortage of β-carotene and/or the binding of carbonyl carotenoids would interfere with the photophysical function as well as normal assembly of PSII. In contrast, high accumulation of astaxanthin and other carbonyl carotenoids was found within the thylakoid membranes. This finding would be associated with the suppression of photo-oxidative stress in the thylakoid membranes. Our observation suggests the importance of a specific balance between photoprotection and photoinhibition that can support normal photosynthesis in CGM lettuce producing astaxanthin.

  3. Effects of nitrogen fertilizers on the growth and nitrate content of lettuce (Lactuca sativa L.).

    PubMed

    Liu, Cheng-Wei; Sung, Yu; Chen, Bo-Ching; Lai, Hung-Yu

    2014-04-22

    Nitrogen is an essential element for plant growth and development; however, due to environmental pollution, high nitrate concentrations accumulate in the edible parts of these leafy vegetables, particularly if excessive nitrogen fertilizer has been applied. Consuming these crops can harm human health; thus, developing a suitable strategy for the agricultural application of nitrogen fertilizer is important. Organic, inorganic, and liquid fertilizers were utilized in this study to investigate their effect on nitrate concentrations and lettuce growth. The results of this pot experiment show that the total nitrogen concentration in soil and the nitrate concentration in lettuce increased as the amount of nitrogen fertilizer increased. If the recommended amount of inorganic fertilizer (200 kg·N·ha⁻¹) is used as a standard of comparison, lettuce augmented with organic fertilizers (200 kg·N·ha⁻¹) have significantly longer and wider leaves, higher shoot, and lower concentrations of nitrate.

  4. Irrigation with treated wastewater: effects on soil, lettuce (Lactuca sativa L.) crop and dynamics of microorganisms.

    PubMed

    Mañas, Pilar; Castro, Elena; de Las Heras, Jorge

    2009-10-01

    The aim of this study was to evaluate the applicability of treated wastewater for horticultural crops, assess the effects of continuous use of treated water on soil and crops, and analyse the physical, chemical and biological effects of irrigation with recycled water. Two lettuce plots watered with drinking water and treated wastewater were monitored over a three year period. Nutrients, heavy metal and the dynamics of pathogen and indicator microorganism content in soil and foliar tissues were analysed. Wastewater irrigation had a high influence on soil parameters: organic matter, N, P, Ca, Al, Fe, Pb and Zn. Indicator and pathogenic microorganisms were detected in soil and plants grown in the wastewater-irrigated plot, and persisted in the soil for 27 days during the study under humid conditions. N, P, Pb and Al content were significantly higher in plant tissues of wastewater-irrigated plots than in the control after 3 years of irrigation. Harvest was significantly higher in the wastewater-irrigated plot. Wastewater can be a resource for agricultural irrigation. In any case, the possible heavy metal accumulation in soils and presence of pathogenic organisms require careful management of this alternative resource: use of a drip irrigation system, previous wastewater disinfection and a limited irrigation period are recommended.

  5. Oxidative Phosphorylation in Germinating Lettuce Seeds (Lactuca sativa) during the First Hours of Imbibition

    PubMed Central

    Hourmant, Annick; Pradet, Alain

    1981-01-01

    Experiments with lettuce seeds during the first hours of imbibition showed that oxygen is necessary to sustain high adenine nucleotide ratios and consequently, energy charge values are higher than 0.8 as is usually the case in normally metabolizing tissues. The energy charge value (0.2) of dry seeds soaked in aerated water increased to normal values (0.8) within 30 minutes. The energy charge value of seeds imbibed under cyanide or nitrogen stayed at low values, about 0.3 for 30 minutes. Nitrogen and cyanide treatment of seeds imbibed in aerated water produced a decrease of energy charge to low values within 3 minutes. During the first minutes of imbibition, the oxygen uptake is cyanide-sensitive. The effect of the uncoupler carbonyl cyanide p-trifluoromethoxyphenyl hydrazone was not as clear-cut. However, results were obtained which agree with the occurrence of oxidative phosphorylation during the first hours of imbibition. These results indicate that a normal cytochromic pathway synthesizes ATP during the first minutes and hours following the imbibition of lettuce seeds. PMID:16661970

  6. Genetic Control of Water and Nitrate Capture and Their Use Efficiency in Lettuce (Lactuca sativa L.)

    PubMed Central

    Kerbiriou, Pauline J.; Maliepaard, Chris A.; Stomph, Tjeerd Jan; Koper, Martin; Froissart, Dorothee; Roobeek, Ilja; Lammerts Van Bueren, Edith T.; Struik, Paul C.

    2016-01-01

    Robustness in lettuce, defined as the ability to produce stable yields across a wide range of environments, may be associated with below-ground traits such as water and nitrate capture. In lettuce, research on the role of root traits in resource acquisition has been rather limited. Exploring genetic variation for such traits and shoot performance in lettuce across environments can contribute to breeding for robustness. A population of 142 lettuce cultivars was evaluated during two seasons (spring and summer) in two different locations under organic cropping conditions, and water and nitrate capture below-ground and accumulation in the shoots were assessed at two sampling dates. Resource capture in each soil layer was measured using a volumetric method based on fresh and dry weight difference in the soil for soil moisture, and using an ion-specific electrode for nitrate. We used these results to carry out an association mapping study based on 1170 single nucleotide polymorphism markers. We demonstrated that our indirect, high-throughput phenotyping methodology was reliable and capable of quantifying genetic variation in resource capture. QTLs for below-ground traits were not detected at early sampling. Significant marker-trait associations were detected across trials for below-ground and shoot traits, in number and position varying with trial, highlighting the importance of the growing environment on the expression of the traits measured. The difficulty of identifying general patterns in the expression of the QTLs for below-ground traits across different environments calls for a more in-depth analysis of the physiological mechanisms at root level allowing sustained shoot growth. PMID:27064203

  7. Earthworm bioassays and seedling emergence for monitoring toxicity, aging and bioaccumulation of anthropogenic waste indicator compounds in biosolids-amended soil

    USGS Publications Warehouse

    Kinney, Chad A.; Campbell, Bryan R.; Thompson, Regina; Furlong, Edward T.; Kolpin, Dana W.; Burkhardt, Mark R.; Zaugg, Steven D.; Werner, Stephen L.; Hay, Anthony G.

    2012-01-01

    Land application of biosolids (treated sewage sludge) can be an important route for introducing xenobiotic compounds into terrestrial environments. There is a paucity of available information on the effects of biosolids amendment on terrestrial organisms. In this study, the influence of biosolids and biosolids aging on earthworm (Eisenia fetida) reproduction and survival and lettuce (Lactuca sativa) seedling emergence was investigated. Earthworms were exposed to soils amended with varying quantities of biosolids (0, 1, 2, 3, or 4% dry mass). To investigate the influence of biosolids aging, the biosolids used in the study were aged for differing lengths of time (2 or 8 weeks) prior to exposure. All of the adult earthworms survived in the biosolids–amended soils at all concentrations that were aged for 2 weeks; however, only 20% of the adults survived in the soil amended with the highest concentration of biosolids and aged for 8 weeks. Reproduction as measured by mean number of juveniles and unhatched cocoons produced per treatment correlated inversely with biosolids concentration, although the effects were generally more pronounced in the 8-week aged biosolids–soil samples. Latent seedling emergence and reduced seedling fitness correlated inversely with biosolids concentration, but these effects were tempered in the 8-week aged versus the 2-week aged soil–biosolids mixtures. Anthropogenic waste indicator compounds (AWIs) were measured in the biosolids, biosolids–soil mixtures, and earthworm samples. Where possible, bioaccumulation factors (BAFs) were calculated or estimated. A wide variety of AWIs were detected in the biosolids (51 AWIs) and earthworm samples (≤ 19 AWI). The earthworms exposed to the 8-week aged biosolids–soil mixtures tended to accumulate greater quantities of AWIs compared to the 2-week aged mixture, suggesting that the bioavailability of some AWIs was enhanced with aging. The BAFs for a given AWI varied with treatment. Notably large

  8. Occupational contact dermatitis from Cichorium (chicory, endive) and Lactuca (lettuce).

    PubMed

    Friis, B; Hjorth, N; Vail, J T; Mitchell, J C

    1975-10-01

    In two cases, occupational contact dermatitis was found to be due to chicory (Cichorium) used as a salad plant. In one of the two cases, contact sensitivity to letuce (Lactuca) was also observed. The sesquiterpene lactones of the plant may be the allergens.

  9. Infrared light-emitting diode radiation causes gravitropic and morphological effects in dark-grown oat seedlings

    NASA Technical Reports Server (NTRS)

    Johnson, C. F.; Brown, C. S.; Wheeler, R. M.; Sager, J. C.; Chapman, D. K.; Deitzer, G. F.

    1996-01-01

    Oat (Avena sativa cv Seger) seedlings were irradiated with IR light-emitting diode (LED) radiation passed through a visible-light-blocking filter. Infrared LED irradiated seedlings exhibited differences in growth and gravitropic response when compared to seedlings grown in darkness at the same temperature. Thus, the oat seedlings in this study were able to detect IR LED radiation. These findings call into question the use of IR LED as a safe-light for some photosensitive plant response experiments. These findings also expand the defined range of wavelengths involved in radiation-gravity (light-gravity) interactions to include wavelengths in the IR region of the spectrum.

  10. Using GWAS to identify SNPs associated with rice seedling cold tolerance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cold tolerance at the seedling stage is important for stand establishment when rice (Oryza sativa L.) is planted in cold water or under the cool temperatures that occur early in the growing season in temperate regions or at high elevations in the tropics. The Rice Diversity Panel 1 (RDP1) represent...

  11. N-glycan transition of the early developmental stage in Oryza sativa.

    PubMed

    Horiuchi, Risa; Hirotsu, Naoki; Miyanishi, Nobumitsu

    2016-08-26

    N-Glycosylation is one of the post-translational modifications. In animals, N-glycans linked to proteins function in cell-cell recognition, sorting, transport, and other biological phenomena. However, in plants, N-glycan-mediated biological functions remain obscure. In a previous study, we showed that the main type of N-glycan transition is from the paucimannosidic to complex type before and after germination in Oryza sativa, suggesting that transitions of N-glycan, including those of glycoproteins and glycosyltransferases, are closely associated with plant growth. To further elucidate the relationship between N-glycan structure and plant growth, we analyzed the structures of N-glycans expressed in O. sativa seedlings grown under light conditions and performed comparative analyses of the structures in the shoot and root. The analyses show that fundamental N-glycan structures are common to the shoot and root, whereas paucimannosidic-type N-glycans dramatically decreased in the root grown under light conditions. Further, to investigate the effects of light on N-glycan structures in O. sativa seedlings, we analyzed N-glycan structures in O. sativa seedlings grown in the dark. Understandably, N-glycan expression in the root was almost unaffected by light. However, despite a marked difference in phenotype, N-glycan expression in the shoot was also unaffected by light. This result suggests that the shoot and root of O. sativa have different glycoproteins and distinct N-glycan synthetic systems. Thus, we propose that the N-glycan synthetic system of the O. sativa shoot is almost unaffected by light conditions and that many photosynthesis-related proteins are not modified by N-glycans.

  12. Alcohol dehydrogenase and an inactivator from rice seedlings

    SciTech Connect

    Shimomura, S.; Beevers, H.

    1983-01-01

    Alcohol dehydrogenase (ADH) was measured in the various organs of rice seedlings (Oryza sativa) growing in air. In extracts from ungerminated seeds, the ADH is stable, but in extracts from seedlings more than 2 days old the enzyme initially present loses activity in a time- and temperature-dependent fashion, due to the presence of an inactivating component which increases with age in roots and shoots. The inactivation can be prevented completely by dithiothreitol, and when this is included in the extraction medium the apparent loss of total ADH in roots and shoots with age is not observed. In seedlings grown in N/sub 2/, ADA levels in coleoptile extracts are higher than those in air, the enzyme is stable, and no inactivator can be detected. When seedlings grown for 5 days in air were transferred to N/sub 2/ for 3 days, ADA levels increased and there was a decline in inactivator activity. Transfer back to air after 1 day in N/sub 2/ led to loss of the accumulated ADH and increase in inactivator. These reciprocal changes and the fact that the inactivator is absent from coleoptiles of seedlings grown in N/sub 2/ appear to suggest a regulator role for the inactivator in vivo. However, it is clear that high levels of inactivator and ADH can exist in cells of seedlings grown in air for long periods without loss of enzyme activity, and it is argued that they must normally be separately compartmented.

  13. RESPONSE OF OXIDATIVE STRESS DEFENSE SYSTEMS IN RICE (ORYZA SATIVA) LEAVES WITH SUPPLEMENTAL UV-B RADIATION

    EPA Science Inventory

    The impact of elevated ultraviolet-B radiation (UV-B, 280-320 nm) on membrane systems and lipid peroxidation, and possible involvement of active oxygen radicals was investigated in leaves of two UV-B susceptible rice cultivars (Oryza sativa L. cvs IR74 and Dular). Rice seedlings ...

  14. Alfalfa (Medicago sativa L.).

    PubMed

    Fu, Chunxiang; Hernandez, Timothy; Zhou, Chuanen; Wang, Zeng-Yu

    2015-01-01

    Alfalfa (Medicago sativa L.) is a high-quality forage crop widely grown throughout the world. This chapter describes an efficient protocol that allows for the generation of large number of transgenic alfalfa plants by sonication-assisted Agrobacterium-mediated transformation. Binary vectors carrying different selectable marker genes that confer resistance to phosphinothricin (bar), kanamycin (npt II), or hygromycin (hph) were used to generate transgenic alfalfa plants. Intact trifoliates collected from clonally propagated plants in the greenhouse were sterilized with bleach and then inoculated with Agrobacterium strain EHA105. More than 80 % of infected leaf pieces could produce rooted transgenic plants in 4-5 months after Agrobacterium-mediated transformation.

  15. Comparative study of Zn deficiency in L. sativa and B. oleracea plants: NH4(+) assimilation and nitrogen derived protective compounds.

    PubMed

    Navarro-León, Eloy; Barrameda-Medina, Yurena; Lentini, Marco; Esposito, Sergio; Ruiz, Juan M; Blasco, Begoña

    2016-07-01

    Zinc (Zn) deficiency is a major problem in agricultural crops of many world regions. N metabolism plays an essential role in plants and changes in their availability and their metabolism could seriously affect crop productivity. The main objective of the present work was to perform a comparative analysis of different strategies against Zn deficiency between two plant species of great agronomic interest such as Lactuca sativa cv. Phillipus and Brassica oleracea cv. Bronco. For this, both species were grown in hydroponic culture with different Zn doses: 10μM Zn as control and 0.01μM Zn as deficiency treatment. Zn deficiency treatment decreased foliar Zn concentration, although in greater extent in B. oleracea plants, and caused similar biomass reduction in both species. Zn deficiency negatively affected NO3(-) reduction and NH4(+) assimilation and enhanced photorespiration in both species. Pro and GB concentrations were reduced in L. sativa but they were increased in B. oleracea. Finally, the AAs profile changed in both species, highlighting a great increase in glycine (Gly) concentration in L. sativa plants. We conclude that L. sativa would be more suitable than B. oleracea for growing in soils with low availability of Zn since it is able to accumulate a higher Zn concentration in leaves with similar biomass reduction. However, B. oleracea is able to accumulate N derived protective compounds to cope with Zn deficiency stress.

  16. Seedling disease in Michigan

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sugar beet seedlings (24 entries of a larger genetic population constructed to dissect Rhizoctonia disease reaction in sugar beet) were screened for their response to a highly virulent isolate of Rhizoctonia solani AG 2-2. Seedlings were grown to the two-leaf stage in the greenhouse, thinned to 15 p...

  17. Effect of low temperature on ethanolic fermentation in rice seedlings.

    PubMed

    Kato-Noguchi, Hisashi; Yasuda, Yukihiro

    2007-08-01

    Rice seedlings (Oryza sativa L.) were incubated at 5-30 degrees C for 48 h and the effect of temperature on ethanolic fermentation in the seedlings was investigated in terms of low-temperature adaptation. Activities of alcohol dehydrogenase (ADH, EC 1.1.1.1) and pyruvate decarboxylase (PDC, EC 4.1.1.1) in roots and shoots of the seedlings were low at temperatures of 20-30 degrees C, whereas temperatures of 5, 7.5 and 10 degrees C significantly increased ADH and PDC activities in the roots and shoots. Temperatures of 5-10 degrees C also increased ethanol concentrations in the roots and shoots. The ethanol concentrations in the roots and shoots at 7.5 degrees C were 16- and 12-times greater than those in the roots and shoots at 25 degrees C, respectively. These results indicate that low temperatures (5-10 degrees C) induced ethanolic fermentation in the roots and shoots of the seedlings. Ethanol is known to prevent lipid degradation in plant membrane, and increased membrane-lipid fluidization. In addition, an ADH inhibitor, 4-methylpyrazole, decreased low-temperature tolerance in roots and shoots of rice seedlings and this reduction in the tolerance was recovered by exogenous applied ethanol. Therefore, production of ethanol by ethanolic fermentation may lead to low-temperature adaptation in rice plants by altering the physical properties of membrane lipids.

  18. Effect of competitive interactions between ectomycorrhizal and saprotrophic fungi on Castanea sativa performance.

    PubMed

    Pereira, Eric; Coelho, Valentim; Tavares, Rui Manuel; Lino-Neto, Teresa; Baptista, Paula

    2012-01-01

    In Northeast of Portugal, the macrofungal community associated to chestnut tree (Castanea sativa Mill.) is rich and diversified. Among fungal species, the ectomycorrhizal Pisolithus tinctorius and the saprotroph Hypholoma fasciculare are common in this habitat. The aim of the present work was to assess the effect of the interaction between both fungi on growth, nutritional status, and physiology of C. sativa seedlings. In pot experiments, C. sativa seedlings were inoculated with P. tinctorius and H. fasciculare individually or in combination. Inoculation with P. tinctorius stimulated the plant growth and resulted in increased foliar-N, foliar-P, and photosynthetic pigment contents. These effects were suppressed when H. fasciculare was simultaneously applied with P. tinctorius. This result could be related to the inhibition of ectomycorrhizal fungus root colonization as a result of antagonism or to the competition for nutrient sources. If chestnut seedlings have been previously inoculated with P. tinctorius, the subsequent inoculation of H. fasciculare 30 days later did not affect root colonization, and mycorrhization benefits were observed. This work confirms an antagonistic interaction between ectomycorrhizal and saprotrophic fungi with consequences on the ectomycorrhizal host physiology. Although P. tinctorius is effective in promoting growth of host trees by establishing mycorrhizae, in the presence of other fungi, it may not always be able to interact with host roots due to an inability to compete with certain fungi.

  19. On the biomechanics of seedling anchorage

    NASA Astrophysics Data System (ADS)

    Crouzy, Benoît; Edmaier, Katharina; Perona, Paolo

    2014-05-01

    We propose a minimal model for the response of vegetation to pullout constraints at early development stage. We try to capture both the average mechanical properties of the root system and the stochastic component of the uprooting process of seedlings. We identify a minimal set of relevant physical components in the purpose of quantifying the uprooting process: length of the root fibres, elastic response of the fibres and adhesion between the roots and the soil matrix. We present for validation a dataset extracted from Edmaier et al. (under revision), accounting for 98 uprooting experiments using Avena sativa L. seedlings (common oat), growing in non-cohesive sediment under controlled conditions. The corresponding root system has a very simple architecture, with three root fibres of different lengths. The response of the system to the constraint is however complex: the stress-strain signal presents sudden jumps followed by partial elastic recoveries. The analysis of the jumps and partial recoveries gives an insight into the resilience of the system. The anchorage of less mature seedlings rapidly collapses after the peak force has been reached, while more mature seedlings usually recover from partial failures. We explore this crossover with our validation dataset. The type of seedlings we study has been used in flume experiments investigating the feedbacks between the vegetation and the river morphodynamics (see for example Perona et al. (2012)). An understanding of the characteristics of the uprooting curve (maximal uprooting force and total uprooting work) of such vegetation reveals the ability of seedlings to withstand environmental constraints in terms of duration or intensity (see Edmaier et al., under revision), and is therefore helpful for planning future experiments. REFERENCES - P. Perona, P. Molnar, B. Crouzy, E. Perucca, Z. Jiang, S. McLelland, D. Wüthrich, K. Edmaier, R. Francis, C. Camporeale, et al., Biomass selection by floods and related timescales

  20. The secrets of cold tolerance at the seedling stage and heading in rice as revealed by association mapping

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cold stress at the seedling stage limits rice (Oryza sativa L.) production in temperate regions or at high elevations in the tropics due to poor plant stand establishment and delayed maturity. At the heading stage, cold temperature causes sterility, thus decreasing grain yield. To explore the mechan...

  1. Genetic architecture of cold tolerance in rice at the seedling stage and heading determined through genome-wide association studies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cold stress at the seedling stage limits rice (Oryza sativa L.) production in temperate regions or at high elevations in the tropics due to poor plant stand establishment and delayed maturity. At the heading stage, cold temperature causes sterility, thus decreasing grain yield. Initially, the Rice D...

  2. Chestnut, European (Castanea sativa).

    PubMed

    Corredoira, Elena; Valladares, Silvia; Vieitez, Ana M; Ballester, Antonio

    2015-01-01

    Development of a system for direct transfer of antifungal candidate genes into European chestnut (Castanea sativa) would provide an alternative approach to conventional breeding for production of chestnut trees that are tolerant to ink disease caused by Phytophthora spp. Overexpression of genes encoding PR proteins (such as thaumatin-like proteins), which display antifungal activity, may represent an important advance in control of the disease. We have used a chestnut thaumatin-like protein gene (CsTL1) isolated from European chestnut cotyledons and have achieved overexpression of the gene in chestnut somatic embryogenic lines used as target material. We have also acclimatized the transgenic plants and grown them on in the greenhouse. Here, we describe the various steps of the process, from the induction of somatic embryogenesis to the production of transgenic plants.

  3. Hemp (Cannabis sativa L.).

    PubMed

    Feeney, Mistianne; Punja, Zamir K

    2015-01-01

    Hemp (Cannabis sativa L.) suspension culture cells were transformed with Agrobacterium tumefaciens strain EHA101 carrying the binary plasmid pNOV3635. The plasmid contains a phosphomannose isomerase (PMI) selectable marker gene. Cells transformed with PMI are capable of metabolizing the selective agent mannose, whereas cells not expressing the gene are incapable of using the carbon source and will stop growing. Callus masses proliferating on selection medium were screened for PMI expression using a chlorophenol red assay. Genomic DNA was extracted from putatively transformed callus lines, and the presence of the PMI gene was confirmed using PCR and Southern hybridization. Using this method, an average transformation frequency of 31.23% ± 0.14 was obtained for all transformation experiments, with a range of 15.1-55.3%.

  4. Hemp (Cannabis sativa L.).

    PubMed

    Feeney, Mistianne; Punja, Zamir K

    2006-01-01

    Hemp (Cannabis sativa L.) suspension culture cells were transformed with Agrobacterium tumefaciens strain EHA101 carrying the binary plasmid pNOV3635. The plasmid contains a phosphomannose isomerase (PMI) selectable marker gene. Cells transformed with PMI are capable of metabolizing the selective agent, mannose, whereas cells not expressing the gene are incapable of using the carbon source and will stop growing. Callus masses proliferating on selection were screened for PMI expression using a chlorophenol red assay. Genomic DNA was extracted from putatively transformed callus lines and the presence of the PMI gene was confirmed using polymerase chain reaction and Southern hybridization. Using this method, an average transformation frequency of 31.23% +/- 0.14 was obtained for all transformation experiments, with a range of 15.1 to 55.3%.

  5. Spectrophotometric phytochrome measurements in light-grown Avena sativa L.

    PubMed

    Jabben, M; Deitzer, G F

    1978-01-01

    Phytochrome was studied spectrophotometrically in Avena sativa L. seedlings that had been grown for 6 d in continous white fluorescent light from lamps. Greening was prevented through the use of the herbicide San 9789. When placed in the light, phytochrome (Ptot) decreased with first order kinetics (τ1/2 ≈ 2 h) but reached a stable low level (≈2.5% of the dark level) after 36 h. This concentration of phytochrome remained constant in the light and during the initial hours of a subsequent dark period, but increased significantly after a prolonged dark period. Evidence suggests that the constant pool of phytochrome in the light is achieved through an equilibrium between synthesis of the red absorbing (Pr) and destruction of the far-red absorbing form (Pfr) of phytochrome. It is concluded that the phytochrome system in light-grown oat seedlings is qualitatively the same as that known from etiolated monocotyledonous seedlings, but different than that described for cauliflower florets.

  6. The influence of sulfathiazole on the macroalgae Ulva lactuca.

    PubMed

    Leston, Sara; Nunes, Margarida; Viegas, Ivan; Nebot, Carolina; Cepeda, Alberto; Pardal, Miguel Ângelo; Ramos, Fernando

    2014-04-01

    Sulfonamides (SA) are a class of antibiotics routinely found in environmental matrices and therefore their role as contaminants should be investigated in non-target organisms. With this purpose the present experimental work has evaluated the exposure of the chlorophycean Ulva lactuca L. to sulfathiazole (STZ), a SA drug commonly used in aquaculture, at two concentrations representing prophylactic (25 μg mL(-1)) and therapeutic (50 μg mL(-1)) administrations. Results showed that STZ exhibits high stability in seawater with only 18% degradation over the 5d assay at both dosages tested. Also, macroalgae demonstrated an efficient uptake capacity with constant internal concentrations after 24h regardless of the external solutions and thus should be considered as a bioindicator species in risk assessment. Both STZ concentrations induced a slight inhibition of the macroalgae growth after 96 h.

  7. GC-MS analysis of bio-active compounds in methanolic extract of Lactuca runcinata DC

    PubMed Central

    Kanthal, Lakshmi Kanta; Dey, Akalanka; Satyavathi, K.; Bhojaraju, P.

    2014-01-01

    Background: The presence of phytochemical constitutes has been reported from species of the Compositae (Asteraceae). Hitherto no reports exist on the phytochemical components and biological activity of Lactuca runcinata DC. Objective: The present study was designed to determine the bioactive compounds in the whole plant methanol extract of Lactuca runcinata. Materials and Methods: Phytochemical screening of the entire herb of Lactuca runcinata DC revealed the presence of some bio-active components. Gas chromatography-mass spectrometry (GC-MS) analysis of the whole plant methanol extract of Lactuca runcinata was performed on a GC-MS equipment (Thermo Scientific Co.) Thermo GC-TRACE ultra ver.: 5.0, Thermo MS DSQ II. Results: The phytochemical tests showed the presence of alkaloids, cardiac glycosides, flavonoids, phenols, phlobatannin, reducing sugars, saponins, steroids, tannins, terpenoids, volatile oils, carbohydrates, and protein/amino acids in methanolic extract of L. runcinata. The GC-MS analysis has shown the presence of different phytochemical compounds in the methanolic extract of Lactuca runcinata. A total of 21 compounds were identified representing 84.49% of total methanolic extract composition. Conclusion: From the results, it is evident that Lactuca runcinata contains various phytocomponents and is recommended as a plant of phytopharmaceutical importance. PMID:24497744

  8. Sativa by falcata alfalfa hybrid variety trials

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Previous research has demonstrated that alfalfa (Medicago sativa L.) subsp. sativa by subsp. falcata hybrids showed heterosis. Limited work has been done examining these hybrids in a sward situation. The objective of this study was to produce sativa by falcata hybrids using Dairyland Seed Company’...

  9. DECA: a new model for assessing the foliar uptake of atmospheric lead by vegetation, using Lactuca sativa as an example.

    PubMed

    Schreck, E; Bonnard, R; Laplanche, C; Leveque, T; Foucault, Y; Dumat, C

    2012-12-15

    In the context of peri-urban atmospheric pollution by industrial lead recycling emissions, metal can transfer to plant shoots. Home gardeners consuming their produce can therefore be exposed to metal pollution. The Human Health Risk Assessment Protocol (HHRAP) model from the United States Environmental Protection Agency (US EPA) classically used in risk assessment provides foliar metal uptake predictions for large farms but is not adapted to cultures in kitchen gardens. Thus, this study developed a new model, entitled "DECA", which includes individually measured parameters and the washing of vegetables before human consumption. Results given by DECA and HHRAP models were compared with experimental measurements of lettuce. The data calculated by the DECA model were highly correlated with the measured values; the HHRAP model overestimates foliar lead uptake. Moreover, strong influences of factor of washing and time-dependent variations of loss coefficient were highlighted. Finally, the DECA model provided important risk assessment data regarding consumption of vegetables from kitchen gardens.

  10. Mycorrhizal and non-mycorrhizal Lactuca sativa plants exhibit contrasting responses to exogenous ABA during drought stress and recovery

    PubMed Central

    Aroca, Ricardo; Vernieri, Paolo; Ruiz-Lozano, Juan Manuel

    2008-01-01

    The arbuscular mycorrhizal (AM) symbiosis enhances plant tolerance to water deficit through the alteration of plant physiology and the expression of plant genes. These changes have been postulated to be caused (among others) by different contents of abscisic acid (ABA) between AM and non-AM plants. However, there are no studies dealing with the effects of exogenous ABA on the expression of stress-related genes and on the physiology of AM plants. The aim of the present study was to evaluate the influence of AM symbiosis and exogenous ABA application on plant development, physiology, and expression of several stress-related genes after both drought and a recovery period. Results show that the application of exogenous ABA had contrasting effects on AM and non-AM plants. Only AM plants fed with exogenous ABA maintained shoot biomass production unaltered by drought stress. The addition of exogenous ABA enhanced considerably the ABA content in shoots of non-AM plants, concomitantly with the expression of the stress marker genes Lsp5cs and Lslea and the gene Lsnced. By contrast, the addition of exogenous ABA decreased the content of ABA in shoots of AM plants and did not produce any further enhancement of the expression of these three genes. AM plants always exhibited higher values of root hydraulic conductivity and reduced transpiration rate under drought stress. From plants subjected to drought, only the AM plants recovered their root hydraulic conductivity completely after the 3 d recovery period. As a whole, the results indicate that AM plants regulate their ABA levels better and faster than non-AM plants, allowing a more adequate balance between leaf transpiration and root water movement during drought and recovery. PMID:18469324

  11. Transcriptome Profiling of Caco-2 Cancer Cell Line following Treatment with Extracts from Iodine-Biofortified Lettuce (Lactuca sativa L.)

    PubMed Central

    Koronowicz, Aneta A.; Kopeć, Aneta; Master, Adam; Smoleń, Sylwester; Piątkowska, Ewa; Bieżanowska-Kopeć, Renata; Ledwożyw-Smoleń, Iwona; Skoczylas, Łukasz; Rakoczy, Roksana; Leszczyńska, Teresa; Kapusta-Duch, Joanna; Pysz, Mirosław

    2016-01-01

    Although iodization of salt is the most common method used to obtain iodine-enriched food, iodine deficiency disorders are still a global health problem and profoundly affect the quality of human life. Iodine is required for the synthesis of thyroid hormones, which are crucial regulators of human metabolism, cell growth, proliferation, apoptosis and have been reported to be involved in carcinogenesis. In this study, for the first time, we evaluated the effect of iodine-biofortified lettuce on transcriptomic profile of Caco-2 cancer cell line by applying the Whole Human Genome Microarray assay. We showed 1326 differentially expressed Caco-2 transcripts after treatment with iodine-biofortified (BFL) and non-fortified (NFL) lettuce extracts. We analysed pathways, molecular functions, biological processes and protein classes based on comparison between BFL and NFL specific genes. Iodine, which was expected to act as a free ion (KI-NFL) or at least in part to be incorporated into lettuce macromolecules (BFL), differently regulated pathways of numerous transcription factors leading to different cellular effects. In this study we showed the inhibition of Caco-2 cells proliferation after treatment with BFL, but not potassium iodide (KI), and BFL-mediated induction of mitochondrial apoptosis and/or cell differentiation. Our results showed that iodine-biofortified plants can be effectively used by cells as an alternative source of this trace element. Moreover, the observed differences in action of both iodine sources may suggest a potential of BFL in cancer treatment. PMID:26799209

  12. Transcriptome Profiling of Caco-2 Cancer Cell Line following Treatment with Extracts from Iodine-Biofortified Lettuce (Lactuca sativa L.).

    PubMed

    Koronowicz, Aneta A; Kopeć, Aneta; Master, Adam; Smoleń, Sylwester; Piątkowska, Ewa; Bieżanowska-Kopeć, Renata; Ledwożyw-Smoleń, Iwona; Skoczylas, Łukasz; Rakoczy, Roksana; Leszczyńska, Teresa; Kapusta-Duch, Joanna; Pysz, Mirosław

    2016-01-01

    Although iodization of salt is the most common method used to obtain iodine-enriched food, iodine deficiency disorders are still a global health problem and profoundly affect the quality of human life. Iodine is required for the synthesis of thyroid hormones, which are crucial regulators of human metabolism, cell growth, proliferation, apoptosis and have been reported to be involved in carcinogenesis. In this study, for the first time, we evaluated the effect of iodine-biofortified lettuce on transcriptomic profile of Caco-2 cancer cell line by applying the Whole Human Genome Microarray assay. We showed 1326 differentially expressed Caco-2 transcripts after treatment with iodine-biofortified (BFL) and non-fortified (NFL) lettuce extracts. We analysed pathways, molecular functions, biological processes and protein classes based on comparison between BFL and NFL specific genes. Iodine, which was expected to act as a free ion (KI-NFL) or at least in part to be incorporated into lettuce macromolecules (BFL), differently regulated pathways of numerous transcription factors leading to different cellular effects. In this study we showed the inhibition of Caco-2 cells proliferation after treatment with BFL, but not potassium iodide (KI), and BFL-mediated induction of mitochondrial apoptosis and/or cell differentiation. Our results showed that iodine-biofortified plants can be effectively used by cells as an alternative source of this trace element. Moreover, the observed differences in action of both iodine sources may suggest a potential of BFL in cancer treatment.

  13. Metabolomics to Detect Response of Lettuce (Lactuca sativa) to Cu(OH)2 Nanopesticides: Oxidative Stress Response and Detoxification Mechanisms.

    PubMed

    Zhao, Lijuan; Ortiz, Cruz; Adeleye, Adeyemi S; Hu, Qirui; Zhou, Hongjun; Huang, Yuxiong; Keller, Arturo A

    2016-09-06

    There has been an increasing influx of nanopesticides into agriculture in recent years. Understanding the interaction between nanopesticides and edible plants is crucial in evaluating the potential impact of nanotechnology on the environment and agriculture. Here we exposed lettuce plants to Cu(OH)2 nanopesticides (1050-2100 mg/L) through foliar spray for one month. Inductively coupled plasma-mass spectrometry (ICP-MS) results indicate that 97-99% (1353-2501 mg/kg) of copper was sequestered in the leaves and only a small percentage (1-3%) (17.5-56.9 mg/kg) was translocated to root tissues through phloem loading. Gas chromatography-time-of-flight mass spectrometry (GC-TOF-MS) based metabolomics combined with partial least squares-discriminant analysis (PLS-DA) multivariate analysis revealed that Cu(OH)2 nanopesticides altered metabolite levels of lettuce leaves. Tricarboxylic (TCA) cycle and a number of amino acid-related biological pathways were disturbed. Some antioxidant levels (cis-caffeic acid, chlorogenic acid, 3,4-dihydroxycinnamic acid, dehydroascorbic acid) were significantly decreased compared to the control, indicating that oxidative stress and a defense response occurred. Nicotianamine, a copper chelator, increased by 12-27 fold compared to the control, which may represent a detoxification mechanism. The up-regulation of polyamines (spermidine and putrescine) and potassium may mitigate oxidative stress and enhance tolerance. The data presented here provide a molecular-scale perspective on the response of plants to copper nanopesticides.

  14. Treated wastewater phytotoxicity assessment using Lactuca sativa: Focus on germination and root elongation test parameters.

    PubMed

    Priac, Anne; Badot, Pierre-Marie; Crini, Grégorio

    2017-03-01

    Sensitive and simple ecotoxicological bioassays like seed germination and root elongation tests are commonly used to evaluate the phytotoxicity of waste and industrial discharge waters. Although the tests are performed following national and international standards, various parameters such as the number of seeds per dish, the test duration or the type of support used remain variable. To be able to make a correct comparison of results from different studies, it is crucial to know which parameter(s) could affect ecotoxicological diagnosis. We tested four different control waters and three seed densities. No significant differences on either germination rate or root elongation endpoints were shown. Nevertheless, we found that the four lettuce cultivars (Appia, batavia dorée de printemps, grosse blonde paresseuse, and Kinemontepas) showed significantly different responses when watered with the same and different metal-loaded industrial discharge water. From the comparison, it is clear that a differential sensitivity scale occurs among not just species but cultivars.

  15. Effect of supplemental ultraviolet radiation on the concentration of phytonutrients in green and red leaf lettuce (Lactuca sativa) cultivars

    NASA Astrophysics Data System (ADS)

    Britz, Steven; Caldwell, Charles; Mirecki, Roman; Slusser, James; Gao, Wei

    2005-08-01

    Eight cultivars each of red and green leaf lettuce were raised in a greenhouse with supplemental UV radiation, either UV-A (wavelengths greater than ca. 315 nm) or UV-A+UV-B (wavelengths greater than ca. 290 nm; 6.4 kJ m-2 daily biologically effective UV-B), or no supplemental UV (controls). Several phytonutrients were analyzed in leaf flours to identify lines with large differences in composition and response to UV-B. Red leaf lettuce had higher levels of phenolic acid esters, flavonols and anthocyanins than green lines. Both green and red lines exposed to UV-B for 9 days showed 2-3-fold increases in flavonoids compared to controls, but only 45% increases in phenolic acid esters, suggesting these compounds may be regulated by different mechanisms. There were large differences between cultivars in levels of phenolic compounds under control conditions and also large differences in UV-B effects. Among red varieties, cv. Galactic was notable for high levels of phenolics and a large response to UV-B. Among green varieties, cvs. Black-Seeded Simpson and Simpson Elite had large increases in phenolics with UV-B exposure. Photosynthetic pigments were also analyzed. Green leaf lettuce had high levels of pheophytin, a chlorophyll degradation product. Total chlorophylls (including pheophytin) were much lower in green compared to red varieties. Lutein, a carotenoid, was similar for green and red lines. Total chlorophylls and lutein increased 2-fold under supplemental UV-B in green lines but decreased slightly under UV-B in red lines. Lettuce appears to be a valuable crop to use to study phytochemical-environment interactions.

  16. Changes in macrominerals, trace elements and pigments content during lettuce (Lactuca sativa L.) growth: influence of soil composition.

    PubMed

    Pinto, Edgar; Almeida, Agostinho A; Aguiar, Ana A R M; Ferreira, Isabel M P L V O

    2014-01-01

    Changes in macrominerals, trace elements and photosynthetic pigments were monitored at 5 stages of lettuce growth. Plants were grown in three experimental agriculture greenhouse fields (A1, A2 and A3). Soil composition was also monitored to understand its influence on lettuce composition. In general, the content of macrominerals, trace elements, chlorophylls and carotenoids decreased during lettuce growth and consequently, high nutritional value was observed at younger stages. A2 lettuces showed an increase of Fe, Al, Cr, V and Pb due to the different soil physicochemical parameters. Multiple linear regression analysis with stepwise variable selection, indicated that soil characteristics, namely, pH(CaCl2) for Fe and Cr, silt and fine-sand for Al and V, OM for Al and Pb, coarse-sand and CEC for Cr, had a key role determining element bioavailability and plant mineral content. Thus, lettuce nutritional value was strongly dependent of growth stage and soil characteristics.

  17. Nitrate content in dandelion (Taraxacum officinale) and lettuce (Lactuca sativa) from organic and conventional origin: intake assessment.

    PubMed

    Gorenjak, Alenka Hmelak; Koležnik, Urška Rizman; Cencič, Avrelija

    2012-01-01

    To estimate the actual intake of nitrate by consumption of different lettuce varieties, 52 samples of lettuce of different origins and dandelion from 15 different areas of northeast Slovenia were analysed. For determination of actual nitrate content, a continuous flow method was used. The lowest nitrate content was detected in dandelion, with a mean value of 195 mg kg(-1) (ranging 47-487 mg kg(-1)). Nitrate content in lettuce of different origins ranged 85-3237 mg kg(-1), with a mean value of 1196 mg kg(-1). The mean nitrate content in organically cultivated lettuce was 890 mg kg(-1), which was considerably lower than the nitrate level in conventionally cultivated lettuce (1298 mg kg(-1)). Consumption of 100 g of dandelion would result in a maximal nitrate intake corresponding to 22% of the acceptable daily intake (ADI), with values up to seven times higher for lettuce.

  18. Filth fly transmission of Escherichia coli O157:H7 and Salmonella enterica to lettuce, Lactuca sativa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Filth flies have been implicated in the dispersal of human disease pathogens; however, fly transmission parameters of human pathogens to plants are largely undescribed. The capacity of the black blow fly, Phormia regina, to acquire and subsequently release bacteria onto baby lettuce leaves was comp...

  19. Metabolic fate of [14C] chlorophenols in radish (Raphanus sativus), lettuce (Lactuca sativa), and spinach (Spinacia oleracea).

    PubMed

    Pascal-Lorber, Sophie; Despoux, Sabrina; Rathahao, Estelle; Canlet, Cécile; Debrauwer, Laurent; Laurent, François

    2008-09-24

    Chlorophenols are potentially harmful pollutants that are found in numerous natural and agricultural systems. Plants are a sink for xenobiotics, which occur either intentionally or not, as they are unable to eliminate them although they generally metabolize them into less toxic compounds. The metabolic fate of [ (14)C] 4-chlorophenol (4-CP), [ (14)C] 2,4-dichlorophenol (2,4-DCP), and [ (14)C] 2,4,5-trichlorophenol (2,4,5-TCP) was investigated in lettuce, spinach, and radish to locate putative toxic metabolites that could become bioavailable to food chains. Radish plants were grown on sand for four weeks before roots were dipped in a solution of radiolabeled chlorophenol. The leaves of six-week old lettuce and spinach were treated. Three weeks after treatments, metabolites from edible plant parts were extracted and analyzed by high performance liquid chromatography (HPLC) and characterized by mass spectrometry (MS), and nuclear magnetic resonance spectroscopy (NMR). Characterization of compounds highlighted the presence of complex glycosides. Upon hydrolysis in the digestive tract of animals or humans, these conjugates could return to the toxic parent compound, and this should be kept in mind for registration studies.

  20. Genetic Diversity of Lettuce (Lactuca sativa) for Resistance to Bacterial Leaf Spot Caused by Xanthomonas campestris pv. vitians.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lettuce plants were artificially inoculated with three isolates of Xanthomonas campestris pv. vitians in field and greenhouse evaluations for genetic variation in resistance to bacterial leaf spot. The cultivar Little Gem had the least amount of disease, whether evaluated for disease severity or dis...

  1. Variations in bioactive substance contents and crop yields of lettuce (Lactuca sativa L.) cultivated in soils with different fertilization treatments.

    PubMed

    Coria-Cayupán, Yanina Soledad; Sánchez de Pinto, María Ines; Nazareno, Mónica Azucena

    2009-11-11

    Changes in crop yields and bioactive substance contents were studied in lettuce crop concerning the influence of soil nutritional status as a result of compost and vermicompost additions obtained from different organic substrates. Plant productions and main pigment contents in lettuce were higher in all the fertilized soils than in the untreated soil, with the exception of the one treated with urban solid waste compost. These positive effects correlate with nitrogen level increase in soil. However, the high saline input of this compost prepared from food home wastes interferes in lettuce growth and prevents it from being higher than the control. Marked decreases in lettuce phenolic contents and antiradical activity were found in most of the treatments. Composts and vermicomposts produced through the processing of cattle manures, agro-industrial organic wastes significantly increased lettuce crop yield enriching its pigment contents, although, in some cases, antioxidant value and phenolic levels were reduced.

  2. Effect of plant growth-promoting rhizobacteria inoculation on cadmium (Cd) uptake by Eruca sativa.

    PubMed

    Kamran, Muhammad Aqeel; Syed, Jabir Hussain; Eqani, Syed Ali Musstjab Akber Shah; Munis, Muhammad Farooq Hussain; Chaudhary, Hassan Javed

    2015-06-01

    Microbe-assisted phyto-remediation approach is widely applied and appropriate choice to reduce the environmental risk of heavy metals originated from contaminated soils. The present study was designed to screen out the nested belongings of Eruca sativa plants and Pseudomonas putida (ATCC 39213) at varying cadmium (Cd) levels and their potential to deal with Cd uptake from soils. We carried out pot trial experiment by examining the soil containing E. sativa seedlings either treated with P. putida and/or untreated plants subjected to three different levels (ppm) of Cd (i.e., 150, 250, and 500). In all studied cases, we observed an increase in Cd uptake for E. sativa plants inoculated with P. putida than those of un-inoculated plants. Cd toxicity was assessed by recording different parameters including stunted shoot growth, poor rooting, and Cd residual levels in the plants that were not inoculated with P. putida. Significant difference (p < 0.05) of different growth parameters for inoculated vs non-inoculated plants was observed at all given treatments. However, among the different treatments, E. sativa exhibited increased values for different growth parameters (except proline contents) at lower Cd levels than those of their corresponding higher levels, shoot length (up to 27 %), root length (up to 32 %), whole fresh plant (up to 40 %), dry weight (up to 22 %), and chlorophyll contents (up to 26 %). Despite the hyperaccumulation of Cd in whole plant of E. sativa, P. putida improved the plant growth at varying levels of Cd supply than those of associated non-inoculated plants. Present results indicated that inoculation with P. putida enhanced the Cd uptake potential of E. sativa and favors the healthy growth under Cd stress.

  3. Pharmacology of Marihuana (Cannabis sativa)

    ERIC Educational Resources Information Center

    Maickel, Roger P.

    1973-01-01

    A detailed discussion of marihuana (Cannabis sativa) providing the modes of use, history, chemistry, and physiologic properties of the drug. Cites research results relating to the pharmacologic effects of marihuana. These effects are categorized into five areas: behavioral, cardiovascular-respiratory, central nervous system, toxicity-toxicology,…

  4. Osmotic adaptation in Ulva lactuca under fluctuating salinity regimes.

    PubMed

    Dickson, D M; Wyn Jones, R G; Davenport, J

    1982-09-01

    A study has been made of the osmotic responses of the green intertidal alga, Ulva lactuca, under two fluctuating salinity regimes; sinusoidal and square-wave fluctuations between 30 and 100% sea water in a 12 h cycle. These regimes closely resemble the tidal fluctuation of salinity encountered by the alga in its natural estuarine habitat. Data on changes in the inorganic ions, potassium, sodium, chloride and sulphate; in the organic solute, dimethylsulphoniopropionate; in the total sugar levels and estimated osmotic and turgor pressures under the two salinity regimes are reported. Significant differences in the solute responses under these different conditions were detected. In general, better control of ion fluxes appeared to be exercised under the sinusoidal conditions which also buffered changes in dimethylsulphoniopropionate levels. Influxes of potassium were highly light-dependent. Chloride levels conspicuously failed to reach the steady-state levels in the 6-h-hyper-osmotic part of either the abrupt or gradual cycle. The possible significance of these data, which may better reflect osmotic changes in the natural environment, and some of the problems encountered, particularly in accounting for charge balance under some conditions, are discussed.

  5. Metals in Ulva lactuca in Hong Kong intertidal waters

    SciTech Connect

    Ho, Y.B. )

    1990-07-01

    The levels of Mn, Fe, Ni, Cu, Zn, Cd, and Pb in Ulva lactuca collected from 24 intertidal sites around the Island of Hong Kong were determined by flame atomic absorption spectrophotometry. Twelve of the sites are in the rural southern parts of the island where the coastal waters are relatively clean. The remaining 12 sites are located in the north and within Victoria Harbor which receives, apart from industrial effluents, untreated domestic sewage from a population of some 3.5 million. The mean levels of Mn, Fe, Ni, Cu, Zn and Pb in Ulva from the urban sites were respectively 4.0, 4.6, 1.8, 2.3, 2.4, and 4.6 times those from the rural sites. However, somewhat similar levels of Cd were found in the alga among all the sites. Some locations of high levels of metal contamination have been identified in Victoria Harbor. Preliminary findings indicated that Ulva is a good indicator of Mn, Fe, Cu, Zn and Pb contamination due to its cosmopolitan distribution, simple morphology leading to ease of growth assessment, and its graded tolerance and response to pollutants. 11 refs., 3 figs., 3 tabs.

  6. Calcium Supplementation Improves Na+/K+ Ratio, Antioxidant Defense and Glyoxalase Systems in Salt-Stressed Rice Seedlings

    PubMed Central

    Rahman, Anisur; Nahar, Kamrun; Hasanuzzaman, Mirza; Fujita, Masayuki

    2016-01-01

    The present study investigates the regulatory role of exogenous calcium (Ca) in developing salt stress tolerance in rice seedlings. Hydroponically grown 13-day-old rice (Oryza sativa L. cv. BRRI dhan47) seedlings were exposed to 200 mM NaCl alone and combined with 2 mM CaCl2 and 2 mM ethylene glycol tetraacetic acid (EGTA, a Ca scavenger) for 3 days. The salt stress caused growth inhibition, chlorosis and water shortage in the rice seedlings. The salt-induced stress disrupted ion homeostasis through Na+ influx and K+ efflux, and decreased other mineral nutrient uptake. Salt stress caused oxidative stress in seedlings through lipid peroxidation, loss of plasma membrane integrity, higher reactive oxygen species (ROS) production and methylglyoxal (MG) formation. The salt-stressed seedlings supplemented with exogenous Ca recovered from water loss, chlorosis and growth inhibition. Calcium supplementation in the salt-stressed rice seedlings improved ion homeostasis by inhibition of Na+ influx and K+ leakage. Exogenous Ca also improved ROS and MG detoxification by improving the antioxidant defense and glyoxalase systems, respectively. On the other hand, applying EGTA along with salt and Ca again negatively affected the seedlings as EGTA negated Ca activity. It confirms that, the positive responses in salt-stressed rice seedlings to exogenous Ca were for Ca mediated improvement of ion homeostasis, antioxidant defense and glyoxalase system. PMID:27242816

  7. Identification of embryo proteins associated with seed germination and seedling establishment in germinating rice seeds.

    PubMed

    Liu, Shu-Jun; Xu, Heng-Heng; Wang, Wei-Qing; Li, Ni; Wang, Wei-Ping; Lu, Zhuang; Møller, Ian Max; Song, Song-Quan

    2016-06-01

    Seed germination is a critical phase in the plant life cycle, but the mechanism of seed germination is still poorly understood. In the present study, rice (Oryza sativa L. cv. Peiai 64S) seeds were sampled individually when they reached different germination stages, quiescent, germinated sensu stricto, germinated completely and seedling, and were used to study the changes in the embryo proteome. A total of 88 protein spots showed a significant change in abundance during germination in water, and the results showed an activation of metabolic processes. Cell division, cell wall synthesis, and secondary metabolism were activated at late seed germination and during preparation for subsequent seedling establishment. Cycloheximide (CHX) at 70μM inhibited seedling establishment without an apparent negative effect on seed germination, while CHX at 500μM completely blocked seed germination. We used this observation to identify the potentially important proteins involved in seed germination (coleoptile protrusion) and seedling establishment (coleoptile and radicle protrusion). Twenty-six protein spots, mainly associated with sugar/polysaccharide metabolism and energy production, showed a significant difference in abundance during seed germination. Forty-nine protein spots, mainly involved in cell wall biosynthesis, proteolysis as well as cell defense and rescue, were required for seedling establishment. The results help improve our understanding of the key events (proteins) involved in germination and seedling development.

  8. Studies on the methods of identification of irradiated food I. Seedling growth test

    NASA Astrophysics Data System (ADS)

    Qiongying, Liu; Yanhua, Kuang; Yuemei, Zheng

    1993-07-01

    A seedling growth test for the identification of gamma irradiated edible vegetable seeds was described. The identification of gamma irradiated grape and the other seeds has been investigated. The purpose of this study was to develop an easy, rapid and practical technique for the identification of irradiated edible vegetable seeds. Seven different irradiated edible vegetable seeds as: rice ( Oryza sativa), peanut ( Arachis hypogaea), maize ( Zeamays), soybean ( Glycine max), red bean ( Phaseolus angularis), mung bean ( Phaseolus aureus) and catjang cowpea ( Vigna cylindrica) were tested by using the method of seedling growth. All of the edible vegetable seeds were exposed to gamma radiation on different doses, O(CK), 0.5, 1.0, 1.5, 2.0, 3.0, 5.0 kGy. After treatment with above 1.0 kGy dose to the seeds, the seedling rate was less than 50% compared with the control. Although the seedling rate of rice seeds can reached 58%, the seedling growth was not normal and the seedling leaves appeared deformed. The results by this method were helpful to identify gamma treatment of the edible vegetable seeds with above 1.0 kGy dose.

  9. Older leaves of lettuce (Lactuca spp.) support higher levels of Salmonella enterica ser. Senftenberg attachment and show greater variation between plant accessions than do younger leaves.

    PubMed

    Hunter, Paul J; Shaw, Robert K; Berger, Cedric N; Frankel, Gad; Pink, David; Hand, Paul

    2015-06-01

    Salmonella can bind to the leaves of salad crops including lettuce and survive for commercially relevant periods. Previous studies have shown that younger leaves are more susceptible to colonization than older leaves and that colonization levels are dependent on both the bacterial serovar and the lettuce cultivar. In this study, we investigated the ability of two Lactuca sativa cultivars (Saladin and Iceberg) and an accession of wild lettuce (L. serriola) to support attachment of Salmonella enterica serovar Senftenberg, to the first and fifth to sixth true leaves and the associations between cultivar-dependent variation in plant leaf surface characteristics and bacterial attachment. Attachment levels were higher on older leaves than on the younger ones and these differences were associated with leaf vein and stomatal densities, leaf surface hydrophobicity and leaf surface soluble protein concentrations. Vein density and leaf surface hydrophobicity were also associated with cultivar-specific differences in Salmonella attachment, although the latter was only observed in the older leaves and was also associated with level of epicuticular wax.

  10. Bioaccumulation of nickel by E. sativa and role of plant growth promoting rhizobacteria (PGPRs) under nickel stress.

    PubMed

    Kamran, Muhammad Aqeel; Eqani, Syed Ali Musstjab Akber Shah; Bibi, Sadia; Xu, Ren-kou; Amna; Monis, Muhammad Farooq Hussain; Katsoyiannis, Athanasios; Bokhari, Habib; Chaudhary, Hassan Javed

    2016-04-01

    Phytoremediation potential of plants can be enhanced in association with microbes. Further, many plant growth-promoting rhizobacteria can improve growth under stress. The present study was conducted to investigate the effect of Pseudomonas putida (P. putida) on nickel (Ni) uptake and on growth of Eruca sativa (E. sativa). Three different levels of Ni (low; 150 ug/g, medium; 250 ug/g and high; 500 ug/g) were applied to the soil containing E. sativa seedlings, with or without P. putida. Ni-toxicity was measured by metamorphic parameters including shoot length, root length, biomass, chlorophyll and proline and Ni contents. Inoculation with P. putida increased 34% and 41% in root and shoot length and 38% and 24% in fresh, dry weight respectively, as compared to non-inoculated plants. Similarly, Ni uptake increased by up to 46% following P. putida inoculation as compared to non-inoculated plants. Indole acetic acid, siderophore and 1-aminocyclopropane-1-carboxylate deaminase (ACCD) activity in the growing media enhanced growth and Ni uptake in E. sativa. The present results offer insight on Plant Growth Promoting Rhizobacteria (PGPR), such as P. putida, for the potential to enhance the plant growth by inhibiting the adverse effects of Ni in E. sativa.

  11. USE OF ULVA LACTUCA TO DISTINGUISH PH DEPENDENT TOXICANTS IN MARINE WATERS AND SEDIMENTS

    EPA Science Inventory

    Ulva lactuca (sea lettuce) is a cosmopolitan marine attached green seaweed capable of sequestering high environmental levels of ammonia. Ammonia can be acutely toxic to marine organisms and is often found in dredged sediments from highly industrial areas or from areas with high c...

  12. Detection and quantification of Bremia lactucae by spore trapping and quantitative PCR

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bremia lactucae causes the characteristic vein-delimited lesions, leaf chlorosis and necrosis and adversely affects marketability of lettuce. The disease has been managed with a combination of host resistance and fungicide applications with mixed success over the years. Fungicide applications are ro...

  13. Development of an assay for rapid detection of the lettuce downy mildew pathogen, Bremia lactucae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Downy mildew of lettuce, caused by Bremia lactucae, causes chlorosis on leaves and adversely affects marketability. Though downy mildew on lettuce can be controlled by fungicide applications, it is costly to routinely apply fungicides to prevent the establishment of downy mildew. Repeated use of the...

  14. Biorefinery of the green seaweed Ulva lactuca to produce animal feed, chemicals and biofuels.

    PubMed

    Bikker, Paul; van Krimpen, Marinus M; van Wikselaar, Piet; Houweling-Tan, Bwee; Scaccia, Nazareno; van Hal, Jaap W; Huijgen, Wouter J J; Cone, John W; López-Contreras, Ana M

    2016-01-01

    The growing world population demands an increase in animal protein production. Seaweed may be a valuable source of protein for animal feed. However, a biorefinery approach aimed at cascading valorisation of both protein and non-protein seaweed constituents is required to realise an economically feasible value chain. In this study, such a biorefinery approach is presented for the green seaweed Ulva lactuca containing 225 g protein (N × 4.6) kg(-1) dry matter (DM). The sugars in the biomass were solubilised by hot water treatment followed by enzymatic hydrolysis and centrifugation resulting in a sugar-rich hydrolysate (38.8 g L(-1) sugars) containing glucose, rhamnose and xylose, and a protein-enriched (343 g kg(-1) in DM) extracted fraction. This extracted fraction was characterised for use in animal feed, as compared to U. lactuca biomass. Based on the content of essential amino acids and the in vitro N (85 %) and organic matter (90 %) digestibility, the extracted fraction seems a promising protein source in diets for monogastric animals with improved characteristics as compared to the intact U. lactuca. The gas production test indicated a moderate rumen fermentation of U. lactuca and the extracted fraction, about similar to that of alfalfa. Reduction of the high content of minerals and trace elements may be required to allow a high inclusion level of U. lactuca products in animal diets. The hydrolysate was used successfully for the production of acetone, butanol, ethanol and 1,2-propanediol by clostridial fermentation, and the rhamnose fermentation pattern was studied.

  15. Chemical characterization of new oxylipins from Cestrum parqui, and their effects on seed germination and early seedling growth.

    PubMed

    Fiorentino, Antonio; D'Abrosca, Brigida; Dellagreca, Marina; Izzo, Angelina; Natale, Angela; Pascarella, Maria Teresa; Pacifico, Severina; Zarrelli, Armando; Monaco, Pietro

    2008-09-01

    Isolation, chemical characterization, and phytotoxicity of five new oxylipins, together with seven already known related compounds, from Cestrum parqui L' Hérl. is reported. All the structures were elucidated on the basis of their spectral data, especially 1D-(1H- and 13C-NMR, DEPT) and 2D-NMR (COSY, TOCSY, HSQC, HMBC, and NOESY). The configurations of the stereogenic C-atoms were determined by the Mosher's method. The compounds have been assayed for their phytotoxicity on Lactuca sativa at concentrations ranging between 10(-4) and 10(-8) M. The results of the phytotoxicity tests on the germination and growth of the test species, obtained by a cluster analysis, showed interesting relationship between the chemical structures of the compounds and their biological effects.

  16. Growing Different Lactuca Genotypes Aeroponically within a Tropical Greenhouse—Cool Rootzone Temperatures Decreased Rootzone Ethylene Concentrations and Increased Shoot Growth

    PubMed Central

    Choong, Tsui-Wei; He, Jie; Lee, Sing K.; Dodd, Ian C.

    2016-01-01

    Temperate crops cannot grow well in the tropics without rootzone cooling. As cooling increased production costs, this experiment aimed to study the growth of various Lactuca genotypes and propose possible ways of reducing these costs, without compromising productivity. A recombinant inbred line (RIL) of lettuce and its parental lines (L. serriola and L. sativa “Salinas”) were grown aeroponically in a tropical greenhouse under 24°C cool (C) or warm fluctuating 30–36°C ambient (A) rootzone temperature (RZT). Their roots were misted with Netherlands standard nutrient solution for 1 min, at intervals of either 5 min (A5, C5) or 10 min (A10, C10) in attempting to reduce electricity consumption and production costs. Lower mortality and higher productivity were observed in all genotypes when grown in C-RZT. Higher shoot fresh weight was observed under C5 than C10, for the RIL and L. serriola. Since “Salinas” had similar shoot fresh weight at both C-RZ treatments, this may indicate it is more sensitive to RZT than water availability. Under A-RZ treatments, higher carotenoid content, with correspondingly higher nonphotochemical quenching, was observed in A10 for the RIL and “Salinas.” Further, total chlorophyll content was also highest at this RZ treatment for the RIL though photochemical quenching was contrastingly the lowest. Cumulatively, productivity was compromised at A10 as the RIL seemed to prioritize photoprotection over efficiency in photosynthesis, under conditions of higher RZT and lower water availability. Generally, higher RZ ethylene concentrations accumulated in A10 and C10 than A5 and C5, respectively—probably due to spray frequency exerting a greater effect on RZ ethylene accumulation than RZT. In the C5 RZ treatment, lowest RZ ethylene concentration corresponded with highest shoot fresh weight. As such, further research on ethylene (in)sensitivity and water use efficiency could be conducted to identify Lactuca cultivars that are better

  17. Investigation on the effects of guava (Psidium guajava L.) infusions on germination, root tips and meristematic cells of Latuca sativa.

    PubMed

    Luber, Jaquelini; Palmieri, Marcel J; Botelho, Carolina M; Rinaldo, Daniel; Andrade-Vieira, Larissa F

    2015-01-01

    Guava (Psidium guajava L.) is a plant often employed in popular medicine. Recently several studies have alerted about the toxicity of substances present in medicinal plants, which can pose risks to the human health. In this sense, the present work aimed to investigate the phytotoxic, cytotoxic and genotoxic action of three guava varieties - Paluma, Pedro Sato and Roxa ("purple") - on the plant test system Lactuca sativa L. Thus, macro- and microscopic evaluations were carried out for five infusion concentrations (2.5, 5.0, 10.0, 20.0 and 40.0 g.L(-1)) prepared from each variety. Distilled water was used as negative control. Chromatographic and spectroscopic analysis by HPLC-PAD indicated that the chemical composition of the infusion of Roxa is different than that of the infusions of the varieties Paluma and Pedro Sato. It was observed that seed germination and root growth in L. sativa exposed to infusions decreased with increasing infusion concentration, regardless of the tested cultivar. For the mitotic index, no statistical differences were observed. On the other hand, a significant increase in the frequency of cell cycle alterations was verified, especially for the highest concentrations tested. The cytogenotoxic effect was significant. Therefore, guava should not be used indiscriminately in popular medicine.

  18. Allelopatic effects of cyanobacteria extracts containing microcystins on Medicago sativa-Rhizobia symbiosis.

    PubMed

    El Khalloufi, Fatima; Oufdou, Khalid; Lahrouni, Majida; El Ghazali, Issam; Saqrane, Sanaa; Vasconcelos, Vitor; Oudra, Brahim

    2011-03-01

    The eutrophication of water leads to massive blooms of cyanobacteria potentially producers of highly toxic substances: cyanotoxins, especially microcystins (MC). The contamination of water used for irrigation by these toxins, can cause several adverse effects on plants and microorganisms. In this work, we report the phytotoxic effects of microcystins on the development of symbiosis between the leguminous plant Medicago sativa (Alfalfa) and rhizobia strains. The exposure of rhizobial strains to three different concentrations 0.01, 0.05 and 0.1 μg MC ml(-1) led to decrease on the bacteria growth. The strains of rhizobia Rh L1, Rh L2, Rh L3 and Rh L4 reduced their growth to, respectively, 20.85%, 20.80%, 33.19% and 25.65%. The chronic exposure of alfalfa seeds and seedlings to different MC concentrations affects the whole stages of plant development. The germination process has also been disrupted with an inhibition, which reaches 68.34% for a 22.24 μg MC ml(-1). Further, seedlings growth and photosynthetic process were also disrupted. The toxins reduced significantly the roots length and nodule formation and leads to an oxidative stress. Thus, the MCs contained in lake water and used for irrigation affect the development of symbiosis between M. sativa and Rhizobia.

  19. Metabolic responses in root nodules of Phaseolus vulgaris and Vicia sativa exposed to the imazamox herbicide.

    PubMed

    García-Garijo, A; Tejera, N A; Lluch, C; Palma, F

    2014-05-01

    Alterations on growth, amino acids metabolism and some antioxidant enzyme activities as result of imazamox treatment were examined in determinate and indeterminate nodules, formed by Phaseolus vulgaris and Vicia sativa, respectively. Young seedlings of both legumes were inoculated with their respective microsymbionts and grown under controlled conditions. At vegetative growth, plants were treated with imazamox (250μM) in the nutrient solution and harvested 7days after. Imazamox was mainly accumulated in V. sativa where concentrations were more than six fold higher than those detected in P. vulgaris. Nodule dry weight and total nitrogen content were reduced by the herbicide treatment: the highest decrease of nodule biomass (50%) and nitrogen content (40%) were registered in V. sativa and P. vulgaris, respectively. The concentration of branched-chain amino acids (BCAA) did not change in neither determinate nor indeterminate nodules even though the acetohydroxyacid synthase activity decreased in root and nodules of both symbioses with the herbicide application. Based on this last result and taking into account that total free amino acids increased in roots but not in nodules of common vetch, a possible BCAA translocation from root to nodule could occur. Our results suggest that the maintenance of BCAA balance in nodule become a priority for the plant in such conditions. The involvement of activities glutathione-S-transferase, guaiacol peroxidase and superoxide dismutase in the response of the symbioses to imazamox are also discussed.

  20. Basal Transcription Factor 3 Plays an Important Role in Seed Germination and Seedling Growth of Rice

    PubMed Central

    Wang, Wenyi; Xu, Mengyun; Wang, Ya

    2014-01-01

    BTF3 has been recognized to be involved in plant growth and development. But its function remains mostly unknown during seed germination and seedling stage. Here, we have analyzed OsBTF3-related sequences in Oryza sativa L. subspecies, japonica, which resembles with the conserved domain of a nascent polypeptide associated complex (NAC) with different homologs of OsBTF3 and human BTF3. Inhibition of Osj10gBTF3 has led to considerable morphological changes during seed germination and seedling growth. Germination percentage was not influenced by the application of GA3, ABA, and NaCl but all concentrations caused wild-type (WT) seeds to germinate more rapidly than the RNAi (Osj10gBTF3Ri) transgenic lines. Seedling inhibition was more severe in the Osj10gBTF3Ri seedlings compared with their WT especially when treated with 100 or 200 μM GA3; 50% reduction in shoots was observed in Osj10gBTF3Ri seedlings. The expression of Osj3g1BTF3, Osj3g2BTF3 and Osj10gBTF3 was primarily constitutive and generally modulated by NaCl, ABA, and GA3 stresses in both Osj10gBTF3Ri lines and WT at the early seedling stage, suggesting that Osj3g1BTF3 and Osj10gBTF3 are much similar but different from Osj3g2BTF3 in biological function. These results show that OsBTF3 plays an important role in seed germination and seedling growth gives a new perception demonstrating that more multifaceted regulatory functions are linked with BTF3 in plants. PMID:24971328

  1. Bioactive spirans and other constituents from the leaves of Cannabis sativa f. sativa.

    PubMed

    Guo, Tian-Tian; Zhang, Jian-Chun; Zhang, Hai; Liu, Qing-Chao; Zhao, Yong; Hou, Yu-Fei; Bai, Lu; Zhang, Li; Liu, Xue-Qiang; Liu, Xue-Ying; Zhang, Sheng-Yong; Bai, Nai-Sheng

    2016-11-16

    In this paper, 17 compounds (1-17) were isolated from the leaves of Hemp (Cannabis sativa f. sativa). Among the isolates, two were determined to be new spirans: cannabispirketal (1), and α-cannabispiranol 4'-O-β-D-glucopyranose (2) by 1D and 2D NMR spectroscopy, LC-MS, and HRESIMS. The known compounds 7, 8, 10, 13, 15, and 16 were isolated from Hemp (C. sativa f. sativa) for the first time. Furthermore, compounds 8 and 13 were isolated from the nature for the first time. All isolated compounds were evaluated for cytotoxicity on different tissue-derived passage cancer cell lines through cell viability and apoptosis assay. Among these compounds, compounds 5, 9 and 16 exhibited a broad-spectrum antitumor effect via inhibiting cell proliferation and promoting apoptosis. These results obtained have provided valuable clues to the understanding of the cytotoxic profile for these isolated compounds from Hemp (C. sativa f. sativa).

  2. Glucosinolate biosynthesis in Eruca sativa.

    PubMed

    Katsarou, Dimitra; Omirou, Michalis; Liadaki, Kalliopi; Tsikou, Daniela; Delis, Costas; Garagounis, Constantine; Krokida, Afrodite; Zambounis, Antonis; Papadopoulou, Kalliope K

    2016-12-01

    Glucosinolates (GSLs) are a highly important group of secondary metabolites in the Caparalles order, both due to their significance in plant-biome interactions and to their chemoprotective properties. This study identified genes involved in all steps of aliphatic and indolic GSL biosynthesis in Eruca sativa, a cultivated plant closely related to Arabidopsis thaliana with agronomic and nutritional value. The impact of nitrogen (N) and sulfur (S) availability on GSL biosynthetic pathways at a transcriptional level, and on the final GSL content of plant leaf and root tissues, was investigated. N and S supply had a significant and interactive effect on the GSL content of leaves, in a structure-specific and tissue-dependent manner; the metabolites levels were significantly correlated with the relative expression of the genes involved in their biosynthesis. A more complex effect was observed in roots, where aliphatic and indolic GSLs and related biosynthetic genes responded differently to the various nutritional treatments suggesting that nitrogen and sulfur availability are important factors that control plant GSL content at a transcriptional level. The biological activity of extracts derived from these plants grown under the specific nutritional schemes was examined. N and S availability were found to significantly affect the cytotoxicity of E. sativa extracts on human cancer cells, supporting the notion that carefully designed nutritional schemes can promote the accumulation of chemoprotective substances in edible plants.

  3. Biogenic nanoparticle-mediated augmentation of seed germination, growth, and antioxidant level of Eruca sativa mill. varieties.

    PubMed

    Ushahra, Jyoti; Bhati-Kushwaha, Himakshi; Malik, C P

    2014-09-01

    A study was undertaken to examine the influence of biogenic nanoparticles synthesized from Tridax procumbens on different parameters of seed germination, seedling growth, and various biochemical parameters in four Eruca sativa varieties having low percentage of germination. Seeds were treated with different concentrations (30 and 40 ppm) of biogenic nanoparticles, of which 30 ppm was found to be the most effective and was therefore used for subsequent studies. Initially, the effect of biogenic nanoparticles on germination percentage, speed of germination, coefficient of germination, mean germination time, shoot and root length, fresh and dry matter, and vigor index was studied. From the experiments performed and the results obtained, it was evident that the treatment with biogenic nanoparticles decreased the electrolyte leakage and level of malondialdehyde as compared to control. The treatment with biogenic nanoparticles enhanced the levels of proline and ascorbic acid and stimulated the antioxidant enzyme activities resulting in the reduced level of reactive oxygen species. These activities were found to be variety-dependent. The possible involvement of biogenic nanoparticles in the production of new pores in seed coat during their penetration, resulting in the influx of the nutrients inside the seed, is suggested. This accelerated seed germination is followed by rapid seedling growth. The present findings indicated that biogenic nanoparticles promote seed germination in E. sativa by overcoming the detrimental effects of reactive oxygen species (ROS) and improving the antioxidative defense system which finally result in increased seedling growth.

  4. Production of acetone, butanol, and ethanol from biomass of the green seaweed Ulva lactuca.

    PubMed

    van der Wal, Hetty; Sperber, Bram L H M; Houweling-Tan, Bwee; Bakker, Robert R C; Brandenburg, Willem; López-Contreras, Ana M

    2013-01-01

    Green seaweed Ulva lactuca harvested from the North Sea near Zeeland (The Netherlands) was characterized as feedstock for acetone, ethanol and ethanol fermentation. Solubilization of over 90% of sugars was achieved by hot-water treatment followed by hydrolysis using commercial cellulases. A hydrolysate was used for the production of acetone, butanol and ethanol (ABE) by Clostridium acetobutylicum and Clostridium beijerinckii. Hydrolysate-based media were fermentable without nutrient supplementation. C. beijerinckii utilized all sugars in the hydrolysate and produced ABE at high yields (0.35 g ABE/g sugar consumed), while C. acetobutylicum produced mostly organic acids (acetic and butyric acids). These results demonstrate the great potential of U. lactuca as feedstock for fermentation. Interestingly, in control cultures of C. beijerinckii on rhamnose and glucose, 1,2 propanediol was the main fermentation product (9.7 g/L).

  5. In vitro exposure of Ulva lactuca Linnaeus (Chlorophyta) to gasoline - Biochemical and morphological alterations.

    PubMed

    Pilatti, Fernanda Kokowicz; Ramlov, Fernanda; Schmidt, Eder Carlos; Kreusch, Marianne; Pereira, Débora Tomazi; Costa, Christopher; de Oliveira, Eva Regina; Bauer, Cláudia M; Rocha, Miguel; Bouzon, Zenilda Laurita; Maraschin, Marcelo

    2016-08-01

    Refined fuels have considerable share of pollution of marine ecosystems. Gasoline is one of the most consumed fuel worldwide, but its effects on marine benthic primary producers are poorly investigated. In this study, Ulva lactuca was chosen as a biological model due to its cosmopolitan nature and tolerance to high levels and wide range of xenobiotics and our goal was to evaluate the effects of gasoline on ultrastructure and metabolism of that seaweed. The experimental design consisted of in vitro exposure of U. lactuca to four concentrations of gasoline (0.001%, 0.01%, 0.1%, and 1.0%, v/v) over 30 min, 1 h, 12 h, and 24 h, followed by cytochemical, SEM, and biochemical analysis. Increase in the number of cytoplasmic granules, loss of cell turgor, cytoplasmic shrinkage, and alterations in the mucilage were some of the ultrastructural alterations observed in thalli exposed to gasoline. Decrease in carotenoid and polyphenol contents, as well as increase of soluble sugars and starch contents were associated with the time of exposure to the xenobiotic. In combination, the results revealed important morphological and biochemical alterations in the phenotype of U. lactuca upon acute exposure to gasoline. This seaweed contain certain metabolites assigned as candidates to biomarkers of the environmental stress investigated and it is thought to be a promise species for usage in coastal ecosystems perturbation monitoring system. In addition, the findings suggest that U. lactuca is able to metabolize gasoline hydrocarbons and use them as energy source, acting as bioremediator of marine waters contaminated by petroleum derivatives.

  6. Space Station Live: Seedling Growth

    NASA Video Gallery

    Public Affairs Officer Lori Meggs talks with Carol Jacobs, payload operations director at the Marshall Space Flight Center's POIC, about the Seedling Growth experiment talking place aboard the Inte...

  7. Cathepsin D inhibitor from Vicia sativa L.

    PubMed

    Roszkowska-Jakimiec, W; Bańkowska, A

    1998-01-01

    Specific inhibitor of cathepsin D has been shown in the extract of Vicia sativa L. seeds. This inhibitor does not inhibit the activity of other aspartic proteases. Also it does not inhibit the activity of cysteine proteases and serine proteases.

  8. Neuropharmacological effects of Nigella sativa

    PubMed Central

    Beheshti, Farimah; Khazaei, Majid; Hosseini, Mahmoud

    2016-01-01

    Nigella sativa (NS) (Ranunculaceae family) is generally utilized as a therapeutic plant all over the world. The seeds of the plant have a long history of use in different frameworks of medicines and food. In Islamic literature, it is considered as one of the greatest forms of therapeutics. It has been widely used to treat nervous system diseases such as memory impairment, epilepsy, neurotoxicity, pain, etc. Additionally, this is uncovered that the majority of therapeutic properties of this plant are due to the presence of thymoquinone (TQ) which is a major bioactive component of the essential oil. Pharmacological studies have been done to evaluate the effects of NS on the central nervous system (CNS). The present review is an effort to provide a detailed scientific literature survey about pharmacological activities of the plant on nervous system. Our literature review showed that NS and its components can be considered as promising agents in the treatment of nervous system disorders. PMID:27247928

  9. ANTI-CANCER ACTIVITY OF NIGELLA SATIVA

    PubMed Central

    Salomi, M.J.; Panikkar, K.R.; Kesavan, M.; Donata, K.; Rajagopalan, K.

    1989-01-01

    An extract of Smilax china, Hemidesmus indicus and Nigella Sativa on the ratio 3:2:1, prepared by boiling in water and concentrated could completely cure cases of oral canger diagnosed by modern methods. Cytotoxic studies with the three components showed activity in Nigella sativa at a concentration of 25 microgram equivalent of the dry powder against Dalton's lymphoma ascites cells. Animal experiments indicated the retarded growth of ascites as compared to the controls with a longivity of 90%. PMID:22557660

  10. A gene encoding an abscisic acid biosynthetic enzyme (LsNCED4) collocates with the high temperature germination locus Htg6.1 in lettuce (Lactuca sp.)

    PubMed Central

    Argyris, Jason; Truco, María José; Ochoa, Oswaldo; McHale, Leah; Dahal, Peetambar; Van Deynze, Allen; Michelmore, Richard W.

    2010-01-01

    Thermoinhibition, or failure of seeds to germinate when imbibed at warm temperatures, can be a significant problem in lettuce (Lactuca sativa L.) production. The reliability of stand establishment would be improved by increasing the ability of lettuce seeds to germinate at high temperatures. Genes encoding germination- or dormancy-related proteins were mapped in a recombinant inbred line population derived from a cross between L. sativa cv. Salinas and L. serriola accession UC96US23. This revealed several candidate genes that are located in the genomic regions containing quantitative trait loci (QTLs) associated with temperature and light requirements for germination. In particular, LsNCED4, a temperature-regulated gene in the biosynthetic pathway for abscisic acid (ABA), a germination inhibitor, mapped to the center of a previously detected QTL for high temperature germination (Htg6.1) from UC96US23. Three sets of sister BC3S2 near-isogenic lines (NILs) that were homozygous for the UC96US23 allele of LsNCED4 at Htg6.1 were developed by backcrossing to cv. Salinas and marker-assisted selection followed by selfing. The maximum temperature for germination of NIL seed lots with the UC96US23 allele at LsNCED4 was increased by 2–3°C when compared with sister NIL seed lots lacking the introgression. In addition, the expression of LsNCED4 was two- to threefold lower in the former NIL lines as compared to expression in the latter. Together, these data strongly implicate LsNCED4 as the candidate gene responsible for the Htg6.1 phenotype and indicate that decreased ABA biosynthesis at high imbibition temperatures is a major factor responsible for the increased germination thermotolerance of UC96US23 seeds. Electronic supplementary material The online version of this article (doi:10.1007/s00122-010-1425-3) contains supplementary material, which is available to authorized users. PMID:20703871

  11. Two new mountainous species of Lactuca (Cichorieae, Asteraceae) from Iran, one presenting a new, possibly myrmecochorous achene variant.

    PubMed

    Kilian, Norbert; Djavadi, Seyyedeh Bahereh; Eskandari, Majid

    2012-01-01

    It is shown that the concept of the Iranian endemic Lactuca polyclada in the sense of both its original author Boissier and its current use actually admixes two entirely different species, as was first noted by Beauverd a hundred years ago but has been neglected by later workers. One is a putative relative of Lactuca rosularis, the other was recognised by Beauverd as a member of the genus Cicerbita. The name Lactuca polyclada Boiss. is lectotypified here, maintaining its use as established by Beauverd for the Cicerbita species. Both species are morphologically delimited and mature achenes of Cicerbita polyclada are illustrated for the first time. The putative relative of Lactuca rosularis, a rare local endemic of the summit area of Kuh e-Dena, which has remained without a valid name by now, is described as a new species, Lactuca denaensis N. Kilian & Djavadi, and illustrated. A third member of the Lactuca rosularis group, Lactuca hazaranensis Djavadi & N. Kilian, discovered among a recent collection and apparently being a rare chasmophyte of the Hazaran mountain massif in the province of Kerman, Iran, is described as a species new to science, illustrated and delimited from the other two species. This new species has peculiar achenes representing a hitherto unknown variant: the body of the beaked achenes is divided into two segments by a transversal constriction in the distal third. The proximal segment contains the embryo, the distal segment is solid with a lipid-containing yellow tissue. The easily detachable pappus and the equally easily detachable beak potentially obstruct dispersal by wind. Since detachment of the beak also exposes the lipid-containing tissue of the distal segment, its potential as an elaiosome and myrmecochory as a possible mode of dispersal are discussed.

  12. Activities of nitrate reductase and glutamine synthetase in rice seedlings during cyanide metabolism.

    PubMed

    Yu, Xiao-Zhang; Zhang, Fu-Zhong

    2012-07-30

    A study was conducted to investigate activities of nitrate reductase (NR) and glutamine synthetase (GS) in plants during cyanide metabolism. Young rice seedlings (Oryza sativa L. cv. XZX 45) were grown in the nutrient solutions containing KNO(3) or NH(4)Cl and treated with free cyanide (KCN). Cyanide in solutions and in plant materials was analyzed to estimate the phyto-assimilation potential. Activities of NR and GS in different parts of rice seedlings were assayed in vivo. Seedlings grown on NH(4)(+) showed significantly higher relative growth rate than those on NO(3)(-) (p<0.05) in the presence of exogenous cyanide. The metabolic rates of cyanide by seedlings were all positively correlated to the concentrations supplied. A negligible difference was observed between the two treatments with nitrate and ammonium (p>0.05). Enzymatic assays showed that cyanide (≥0.97mg CN L(-1)) impaired NR activity significantly in both roots and shoots (p<0.05). The effect of cyanide on GS activity in roots was more evident at 1.93mg CN L(-1), suggesting that NR activity was more susceptible to change from cyanide application than GS activity. The results observed here suggest that the exogenous cyanide, which to a certain level has a beneficial role in plant nutrition.

  13. Comparison of QTLs for rice seedling morphology under different water supply conditions.

    PubMed

    Zheng, Bingsong; Yang, Ling; Mao, Chuanzao; Huang, Youjun; Wu, Ping

    2008-08-01

    The variation of seedling characteristics under different water supply conditions is strongly associated with drought resistance in rice (Oryza sativa L.) and a better elucidation of its genetics is helpful for improving rice drought resistance. Ninetysix doubled-haploid (DH) rice lines of an indica and japonica cross were grown in both flooding and upland conditions and QTLs for morphological traits at seedling stage were examined using 208 restriction fragment length polymorphism (RFLP) and 76 microsatellite (SSR) markers. A total of 32 putative QTLs were associated with the four seedling traits: average of three adventitious root lengths (ARL), shoot height (SH), shoot biomass (SW), and root to shoot dry weight ratio (RSR). Five QTLs detected were the same under control and upland conditions. The ratio between the mean value of the seedling trait under upland and flooding conditions was used for assessing drought tolerance. A total of six QTLs for drought tolerance were detected. Comparative analysis was performed for the QTLs detected in this case and those reported from two other populations with the same upland rice variety Azucena as parent. Several identical QTLs for seedling elongation across the three populations with the positive alleles from the upland rice Azucena were detected, which suggests that the alleles of Azucena might be involved in water stress-accelerated elongation of rice under different genetic backgrounds. Five cell wall-related candidate genes for OsEXP1, OsEXP2, OsEXP4, EXT, and EGase were mapped on the intervals carrying the QTLs for seedling traits.

  14. Terpene synthases from Cannabis sativa

    PubMed Central

    Booth, Judith K.; Page, Jonathan E.

    2017-01-01

    Cannabis (Cannabis sativa) plants produce and accumulate a terpene-rich resin in glandular trichomes, which are abundant on the surface of the female inflorescence. Bouquets of different monoterpenes and sesquiterpenes are important components of cannabis resin as they define some of the unique organoleptic properties and may also influence medicinal qualities of different cannabis strains and varieties. Transcriptome analysis of trichomes of the cannabis hemp variety ‘Finola’ revealed sequences of all stages of terpene biosynthesis. Nine cannabis terpene synthases (CsTPS) were identified in subfamilies TPS-a and TPS-b. Functional characterization identified mono- and sesqui-TPS, whose products collectively comprise most of the terpenes of ‘Finola’ resin, including major compounds such as β-myrcene, (E)-β-ocimene, (-)-limonene, (+)-α-pinene, β-caryophyllene, and α-humulene. Transcripts associated with terpene biosynthesis are highly expressed in trichomes compared to non-resin producing tissues. Knowledge of the CsTPS gene family may offer opportunities for selection and improvement of terpene profiles of interest in different cannabis strains and varieties. PMID:28355238

  15. Phytochemistry of Cannabis sativa L.

    PubMed

    ElSohly, Mahmoud A; Radwan, Mohamed M; Gul, Waseem; Chandra, Suman; Galal, Ahmed

    2017-01-01

    Cannabis (Cannabis sativa, or hemp) and its constituents-in particular the cannabinoids-have been the focus of extensive chemical and biological research for almost half a century since the discovery of the chemical structure of its major active constituent, Δ(9)-tetrahydrocannabinol (Δ(9)-THC). The plant's behavioral and psychotropic effects are attributed to its content of this class of compounds, the cannabinoids, primarily Δ(9)-THC, which is produced mainly in the leaves and flower buds of the plant. Besides Δ(9)-THC, there are also non-psychoactive cannabinoids with several medicinal functions, such as cannabidiol (CBD), cannabichromene (CBC), and cannabigerol (CBG), along with other non-cannabinoid constituents belonging to diverse classes of natural products. Today, more than 560 constituents have been identified in cannabis. The recent discoveries of the medicinal properties of cannabis and the cannabinoids in addition to their potential applications in the treatment of a number of serious illnesses, such as glaucoma, depression, neuralgia, multiple sclerosis, Alzheimer's, and alleviation of symptoms of HIV/AIDS and cancer, have given momentum to the quest for further understanding the chemistry, biology, and medicinal properties of this plant.This contribution presents an overview of the botany, cultivation aspects, and the phytochemistry of cannabis and its chemical constituents. Particular emphasis is placed on the newly-identified/isolated compounds. In addition, techniques for isolation of cannabis constituents and analytical methods used for qualitative and quantitative analysis of cannabis and its products are also reviewed.

  16. Differential toxic effects of Ulva lactuca (Chlorophyta) on the herbivorous gastropods, Littorina littorea and L. obtusata (Mollusca).

    PubMed

    Peckol, Paulette; Putnam, Alysha B

    2016-12-28

    Members of the genus Ulva are widespread and abundant in intertidal and shallow subtidal areas but there are conflicting data regarding susceptibility to herbivory. While some studies have documented that Ulva spp. were favored by a diversity of marine herbivores, other work has revealed herbivore deterrence. We investigated grazing and growth rates of the littorinid species, Littorina littorea and L. obtusata, when offered Fucus vesiculosus, Ascophyllum nodosum, Ulva lactuca, and Chondrus crispus, highlighting distinctive vulnerabilities to toxic effects of U. lactuca. Ulva lactuca was the preferred food of L. littorea, while L. obtusata showed no grazing on this ephemeral algal species. In contrast, F. vesiculosus was highly preferred by L. obtusata. Although L. littorea demonstrated a grazing preference for U. lactuca, growth rate of this gastropod species was nearly 3× greater when fed F. vesiculosus, suggesting a non-lethal, negative effect of U. lactuca on L. littorea with long-term exposure. Mortality of L. obtusata ranged from 0% to 100% when held in the presence of various Ulva densities for 1 week, and Ulva exudate depressed herbivory of this gastropod. We conclude that the water-soluble, toxic exudate produced by U. lactuca in response to herbivory had allelochemical properties, and may contain a cleavage product (acrylic acid) of dimethylsulfoniopropionate or reactive oxygen species (i.e., H2 O2 ). Observed differences in susceptibility to Ulva toxicity by the littorinid species may be related to generalist versus specialist feeding and habitat strategies.

  17. A Quantitative Dynamic Simulation of Bremia lactucae Airborne Conidia Concentration above a Lettuce Canopy

    PubMed Central

    Fall, Mamadou Lamine; Van der Heyden, Hervé; Carisse, Odile

    2016-01-01

    Lettuce downy mildew, caused by the oomycete Bremia lactucae Regel, is a major threat to lettuce production worldwide. Lettuce downy mildew is a polycyclic disease driven by airborne spores. A weather-based dynamic simulation model for B. lactucae airborne spores was developed to simulate the aerobiological characteristics of the pathogen. The model was built using the STELLA platform by following the system dynamics methodology. The model was developed using published equations describing disease subprocesses (e.g., sporulation) and assembled knowledge of the interactions among pathogen, host, and weather. The model was evaluated with four years of independent data by comparing model simulations with observations of hourly and daily airborne spore concentrations. The results show an accurate simulation of the trend and shape of B. lactucae temporal dynamics of airborne spore concentration. The model simulated hourly and daily peaks in airborne spore concentrations. More than 95% of the simulation runs, the daily-simulated airborne conidia concentration was 0 when airborne conidia were not observed. Also, the relationship between the simulated and the observed airborne spores was linear. In more than 94% of the simulation runs, the proportion of the linear variation in the hourly-observed values explained by the variation in the hourly-simulated values was greater than 0.7 in all years except one. Most of the errors came from the deviation from the 1:1 line, and the proportion of errors due to the model bias was low. This model is the only dynamic model developed to mimic the dynamics of airborne inoculum and represents an initial step towards improved lettuce downy mildew understanding, forecasting and management. PMID:26953691

  18. Specific accumulation of CYP94A1 transcripts after exposure to gaseous benzaldehyde: induction of lauric acid ω-hydroxylase activity in Vicia sativa exposed to atmospheric pollutants.

    PubMed

    Kastner, P E; Le Calvé, S; Diss, L; Sauveplane, V; Franke, R; Schreiber, L; Pinot, F

    2011-01-01

    The effects of air pollutants such as aldehydes, ozone, nitrogen dioxide and benzene on fatty acid ω-hydroxylase activity in Vicia sativa microsomes have been investigated. Four days old etiolated V. sativa seedlings were exposed to different concentrations of selected pollutants for varying exposure times. Growing etiolated V. sativa seedlings in air containing the gaseous benzaldehyde (150 nM) led to an 8-fold enhancement of lauric acid ω-hydroxylase activity in microsomes of treated plants compared to controls grown in pure air (96 ± 10 versus 12 ± 2 pmol/min/mg protein, respectively). The induction increased with increasing gas phase concentrations (10-1300 nM) and the maximum of activity was measured after 48 h of exposure. Northern blot analysis revealed that this induction occurred via transcriptional activation of the gene coding for CYP94A1. The absence of CYP94A2 and CYP94A3 transcription activation together with the missing effect on epoxide hydrolases activities indicate the specificity of CYP94A1 induction by benzaldehyde. Exposure to nitrogen dioxide, ozone and formaldehyde also stimulated lauric acid ω-hydroxylases activity while exposure to benzene did not show any effect.

  19. Comparison of the lipid composition of oat root and coleoptile plasma membranes. [Avena sativa L

    SciTech Connect

    Sandstrom, R.P. ); Cleland, R.E. )

    1989-07-01

    The total lipid composition of plasma membranes (PM), isolated by the phase partitioning method from two different oat (Avena sativa L.) tissues, the root and coleoptile, was compared. In general, the PM lipid composition was not conserved between these two organs of the oat seedling. Oat roots contained 50 mole % phospholipid, 25 mole % glycolipid, and 25 mole % free sterol, whereas comparable amounts in the coleoptile were 42, 39, and 19 mole %, respectively. Individual lipid components within each lipid class also showed large variations between the two tissues. Maximum specific ATPase activity in the root PM was more than double the activity in the coleoptile. Treatment of coleoptile with auxin for 1 hour resulted in no detectable changes in PM lipids or extractable ATPase activity. Differences in the PM lipid composition between the two tissues that may define the limits of ATPase activity are discussed.

  20. Beet Rust and Seedling Rust

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Beet rust, caused by Uromyces betae, can cause pustules on most beet types, and can be a problem in various beet growing areas. Seedling rust, caused by Puccinia subnitens can cause lesions on young beets, primarily on cotyledons, and does not cause economic damage. This chapter describes the dise...

  1. Cloning and functional characterization of CYP94A2, a medium chain fatty acid hydroxylase from Vicia sativa.

    PubMed

    Le Bouquin, R; Pinot, F; Benveniste, I; Salaün, J P; Durst, F

    1999-07-22

    A full length cDNA encoding a new cytochrome P450-dependent fatty acid hydroxylase (CYP94A2) was isolated from a Vicia sativa library. CYP94A2 displays 58% sequence identity with CYP94A1, a fatty acid omega-hydroxylase isolated from the same material. Heterologous expression of CYP94A2 in Saccharomyces cerevisiae yeast strain WAT11 shows that it catalyses the hydroxylation of myristic (C14) acid with a K(m(app)) of 4.0 microM and a turnover rate number of 80 min(-1). In addition, lauric (C12) and palmitic (C16) acids were hydroxylated at a ten-fold lower rate, while C18 fatty acids were not oxidized. Remarkably, the regiospecificity of hydroxylation is different for the C12, C14, and C16 fatty acids and appears to be correlated with the length of the carbon chain. Northern blot analysis showed a low level of constitutive expression of CYP94A2 in V. sativa seedlings. In contrast to CYP94A1, transcript accumulation of CYP94A2 was only weakly enhanced in seedlings treated with clofibrate or methyl jasmonate, indicating that both substrate range and gene regulation of the two fatty acid hydroxylases are different.

  2. Water deficit and aluminum interactive effects on generation of reactive oxygen species and responses of antioxidative enzymes in the seedlings of two rice cultivars differing in stress tolerance.

    PubMed

    Pandey, Poonam; Srivastava, Rajneesh Kumar; Rajpoot, Ritika; Rani, Anjana; Pandey, Akhilesh Kumar; Dubey, R S

    2016-01-01

    Aluminum (Al) is a major constraint to crop productivity in acid soils, whereas water deficit severely limits crop production in arid and semi-arid regions of the world. The objective of the present study was to examine the effects of both stresses, Al excess and water deficit, individually and in combination on the production of the reactive oxygen species (ROS) superoxide anion (O2˙(-)), hydrogen peroxide (H2O2), hydroxyl radical, and lipid peroxidation and the activity of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and guaiacol peroxidase (GPX) in the seedlings of two rice (Oryza sativa L.) cvs. Malviya-36 (sensitive to water deficit and Al) and Vandana (tolerant to water deficit and Al). When 15-day grown seedlings were exposed to water deficit (created with 15% polyethylene glycol, PEG-6000) or Al (1 mM AlCl3) treatment or both treatments together for 24-72 h, the lengths and fresh weights of root/shoot declined in the seedlings of the sensitive cultivar, whereas in the tolerant seedlings, either little or insignificant decline in these parameters was observed due to the treatments. Biochemical determinations and histochemical studies revealed that under a similar level of water deficit, Al, or combined treatment, seedlings of sensitive cultivar showed a higher level of production of O2˙(-), H2O2, hydroxyl radical, and lipid peroxides compared to the tolerant seedlings. Seedlings of tolerant cultivars, both in roots and shoots, had constitutively higher activity levels of antioxidative enzymes SOD, CAT, and GPX and showed a greater increase in activity under water deficit or Al treatment alone or in combination compared to the similarly treated seedlings of sensitive cultivar. Our results suggest that a lower constitutive level of ROS and a high antioxidative enzyme capacity are associated with tolerance to both water deficit and Al excess in rice seedlings.

  3. Expression Variations of miRNAs and mRNAs in Rice (Oryza sativa)

    PubMed Central

    Wen, Ming; Xie, Munan; He, Lian; Wang, Yushuai; Shi, Suhua; Tang, Tian

    2016-01-01

    Differences in expression levels are an important source of phenotypic variation within and between populations. MicroRNAs (miRNAs) are key players in post-transcriptional gene regulation that are important for plant development and stress responses. We surveyed expression variation of miRNAs and mRNAs of six accessions from two rice subspecies Oryza sativa L. ssp. indica and Oryza sativa L. ssp. japonica using deep sequencing. While more than half (53.7%) of the mature miRNAs exhibit differential expression between grains and seedlings of rice, only 11.0% show expression differences between subspecies, with an additional 2.2% differentiated for the development-by-subspecies interaction. Expression variation is greater for lowly conserved miRNAs than highly conserved miRNAs, whereas the latter show stronger negative correlation with their targets in expression changes between subspecies. Using a permutation test, we identified 51 miRNA–mRNA pairs that correlate negatively or positively in expression level among cultivated rice. Genes involved in various metabolic processes and stress responses are enriched in the differentially expressed genes between rice indica and japonica subspecies. Our results indicate that stabilizing selection is the major force governing miRNA expression in cultivated rice, albeit positive selection may be responsible for much of the between-subspecies expression divergence. PMID:27797952

  4. Physiological and molecular characterization of lucerne (Medicago sativa L.) germplasm with improved seedling freezing tolerance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We conducted greenhouse experiments to compare 14 alfalfa germplasms for their survival following freezing. Among these germplasms are collections adapted to the Grand River National Grasslands in South Dakota. Our hypothesis was that these collections developed tolerance to survive the frigid gro...

  5. EPOXIDE HYDROLASE ACTIVITIES IN THE MICROSOMES AND THE SOLUBLE FRACTION FROM VICIA SATIVA SEEDLINGS. (R825433)

    EPA Science Inventory

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  6. Toxicity of the amphoteric surfactant, cocamidopropyl betaine, to the marine macroalga, Ulva lactuca.

    PubMed

    Vonlanthen, Sofie; Brown, Murray T; Turner, Andrew

    2011-01-01

    The degradation of the synthetic, amphoteric surfactant, cocamidopropyl betaine (CAPB) and its toxicity to the marine macroalga, Ulva lactuca, has been evaluated using several different physiological test end-points over different periods of exposure up to 120 h. Droplet surface angle measurements revealed that, following a period of acclimation of about 24 h, CAPB began to degrade and that primary degradation was complete within 120 h. Effective quantum yield (∆F/F(m)') and relative growth rates (RGRs) were the most sensitive measures of phytotoxicity, with CAPB concentrations at and above 10 mg l(-1) eliciting irreversible, time-dependent and/or dose-dependent responses. Cell membrane damage, estimated from measurements of ion leakage, was detected only at a concentration of 40 mg l(-1) after 48 h of exposure to CAPB but by 120 h damage was evident at all measured concentrations above 10 mg l(-1). These observations suggest that both CAPB and its metabolites are intrinsically toxic to U. lactuca. The findings of this study are discussed in terms of the environmental consequences of applying CAPB to control harmful algal blooms.

  7. Calcium Mitigates Arsenic Toxicity in Rice Seedlings by Reducing Arsenic Uptake and Modulating the Antioxidant Defense and Glyoxalase Systems and Stress Markers.

    PubMed

    Rahman, Anisur; Mostofa, Mohammad Golam; Alam, Md Mahabub; Nahar, Kamrun; Hasanuzzaman, Mirza; Fujita, Masayuki

    2015-01-01

    The effect of exogenous calcium (Ca) on hydroponically grown rice seedlings was studied under arsenic (As) stress by investigating the antioxidant and glyoxalase systems. Fourteen-day-old rice (Oryza sativa L. cv. BRRI dhan29) seedlings were exposed to 0.5 and 1 mM Na2HAsO4 alone and in combination with 10 mM CaCl2 (Ca) for 5 days. Both levels of As caused growth inhibition, chlorosis, reduced leaf RWC, and increased As accumulation in the rice seedlings. Both doses of As in growth medium induced oxidative stress through overproduction of reactive oxygen species (ROS) by disrupting the antioxidant defense and glyoxalase systems. Exogenous application of Ca along with both levels of As significantly decreased As accumulation and restored plant growth and water loss. Calcium supplementation in the As-exposed rice seedlings reduced ROS production, increased ascorbate (AsA) content, and increased the activities of monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), catalase (CAT), glutathione peroxidase (GPX), superoxide dismutase (SOD), and the glyoxalase I (Gly I) and glyoxalase II (Gly II) enzymes compared with seedlings exposed to As only. These results suggest that Ca supplementation improves rice seedlings tolerance to As-induced oxidative stress by reducing As uptake, enhancing their antioxidant defense and glyoxalase systems, and also improving growth and physiological condition.

  8. Calcium Mitigates Arsenic Toxicity in Rice Seedlings by Reducing Arsenic Uptake and Modulating the Antioxidant Defense and Glyoxalase Systems and Stress Markers

    PubMed Central

    Rahman, Anisur; Mostofa, Mohammad Golam; Alam, Md. Mahabub; Nahar, Kamrun; Hasanuzzaman, Mirza; Fujita, Masayuki

    2015-01-01

    The effect of exogenous calcium (Ca) on hydroponically grown rice seedlings was studied under arsenic (As) stress by investigating the antioxidant and glyoxalase systems. Fourteen-day-old rice (Oryza sativa L. cv. BRRI dhan29) seedlings were exposed to 0.5 and 1 mM Na2HAsO4 alone and in combination with 10 mM CaCl2 (Ca) for 5 days. Both levels of As caused growth inhibition, chlorosis, reduced leaf RWC, and increased As accumulation in the rice seedlings. Both doses of As in growth medium induced oxidative stress through overproduction of reactive oxygen species (ROS) by disrupting the antioxidant defense and glyoxalase systems. Exogenous application of Ca along with both levels of As significantly decreased As accumulation and restored plant growth and water loss. Calcium supplementation in the As-exposed rice seedlings reduced ROS production, increased ascorbate (AsA) content, and increased the activities of monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR), catalase (CAT), glutathione peroxidase (GPX), superoxide dismutase (SOD), and the glyoxalase I (Gly I) and glyoxalase II (Gly II) enzymes compared with seedlings exposed to As only. These results suggest that Ca supplementation improves rice seedlings tolerance to As-induced oxidative stress by reducing As uptake, enhancing their antioxidant defense and glyoxalase systems, and also improving growth and physiological condition. PMID:26798635

  9. Purification of glucosinolates from Camelina sativa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Camelina sativa (Gold-of-pleasure or false flax) has been cultivated as an oilseed crop for centuries, and has been used as both a fuel oil and an edible oil. Current research efforts centers on its exceptionally high levels of omega-3 fatty acids which is uncommon in vegetable oils, as well as ric...

  10. Purification of glucosinolates from Camelina sativa seeds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Camelina sativa L. Crantz defatted seed press cake contains a number of phytochemicals, including the flavonoid rutin (quercetin 3-O-rutinoside), an acylated quercetin glycoside, and three glucosinolates: glucoarabin (9-(methylsulfinyl)nonyl-glucosinolate) glucocamelinin (10-(methylsulfinyl)decyl-gl...

  11. North American Continent – A new source of wild Lactuca spp. germplasm variability for future lettuce breeding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the years 2002-2008, missions were undertaken in the USA and Canada to search for wild and weedy Lactuca species. Altogether, 16 states in the USA (Arizona, California, Colorado, Idaho, Iowa, Minnesota, Montana, Nevada, New York, North Carolina, Oregon, South Dakota, Utah, Washington, Wisconsin a...

  12. Potential Antidepressant Constituents of Nigella sativa Seeds

    PubMed Central

    Elkhayat, Ehab S.; Alorainy, Mohammad S.; El-Ashmawy, Ibrahim M.; Fat’hi, Shawkat

    2016-01-01

    Background: Nigella sativa Linn. is well known seed in the Middle East, Asia, and the Far East as a natural remedy for many ailments and as a flavoring agent proclaimed medicinal usage dating back to the ancient Egyptians, Greeks, and Romans. An authentic saying of the Prophet Muhammad (Peace Be Upon Him) about black seed is also quoted in Al-Bukhari. Objective: This study was carried out to evaluate the antidepressant effect and isolate the potential antidepressant constituents of the polar extract of N. sativa seeds. Materials and Methods: The antidepressant effect was evaluated through the immobility duration in tail suspension and forced swim tests (FSTs). Albino mice were orally treated with N. sativa polar extract and its RP-18 column chromatography fractions (50 and 100 mg/kg,). Results: The polar extract and two of its sub-fractions were significantly able to decrease the immobility time of mice when subjected to both tail suspension and FSTs, the effects are comparable to standard drug (Sertraline, 5 mg/kg). However, these treatments did not affect the number of crossings and rearing in the open field test. Phytochemical investigation of the two active fractions led to the isolation of quercetin-3-O-α-L-rhamnopyranoside 1, quercetin-7-O-β-D-gluco- pyranoside 2, tauroside E 3, and sapindoside B as the potential antidepressant constituents. SUMMARY Phytochemical and biological evaluation the antidepressant constituents in Nigella sativa using the tail suspension and forced swim methods afforded the isolation and identification of quercetin-3-O-α-L rhamnopyranoside, quercetin-7-O-β-D gluco pyranoside, tauroside E, and sapindoside B as the potential antidepressant constituents in the polar extract of N. sativa. The isolated compounds were identified through extensive NMR analysis (1D, 2D, ESI MS). Abbreviations used: TST: Tail suspension test, FST: Forced swim test, OFT: An Open field test PMID:27041854

  13. Identification of Differentially Expressed Proteins and Phosphorylated Proteins in Rice Seedlings in Response to Strigolactone Treatment

    PubMed Central

    Chen, Fangyu; Jiang, Liangrong; Zheng, Jingsheng; Huang, Rongyu; Wang, Houcong; Hong, Zonglie; Huang, Yumin

    2014-01-01

    Strigolactones (SLs) are recently identified plant hormones that inhibit shoot branching and control various aspects of plant growth, development and interaction with parasites. Previous studies have shown that plant D10 protein is a carotenoid cleavage dioxygenase that functions in SL biosynthesis. In this work, we used an allelic SL-deficient d10 mutant XJC of rice (Oryza sativa L. spp. indica) to investigate proteins that were responsive to SL treatment. When grown in darkness, d10 mutant seedlings exhibited elongated mesocotyl that could be rescued by exogenous application of SLs. Soluble protein extracts were prepared from d10 mutant seedlings grown in darkness in the presence of GR24, a synthetic SL analog. Soluble proteins were separated on two-dimensional gels and subjected to proteomic analysis. Proteins that were expressed differentially and phosphoproteins whose phosphorylation status changed in response to GR24 treatment were identified. Eight proteins were found to be induced or down-regulated by GR24, and a different set of 8 phosphoproteins were shown to change their phosphorylation intensities in the dark-grown d10 seedlings in response to GR24 treatment. Analysis of these proteins revealed that they are important enzymes of the carbohydrate and amino acid metabolic pathways and key components of the cellular energy generation machinery. These proteins may represent potential targets of the SL signaling pathway. This study provides new insight into the complex and negative regulatory mechanism by which SLs control shoot branching and plant development. PMID:24699514

  14. DNA-protein cross-links involved in growth inhibition of rice seedlings exposed to Ga.

    PubMed

    Yu, Xiao-Zhang; Zhang, Xue-Hong

    2015-07-01

    Hydroponic experiments were conducted with rice seedlings (Oryza sativa L. cv. XZX45) exposed to gallium nitrate (Ga(3+)) to investigate the accumulation of Ga in plant tissues and phytotoxic responses. Results showed that phyto-transport of Ga was apparent, and roots were the dominant site for Ga accumulation. The total accumulation rates of Ga responded biphasically to Ga treatments by showing increases at low (1.06-8.52 mg Ga/L) and constants at high (8.52-15.63 mg Ga/L) concentrations, suggesting that accumulation kinetics of Ga followed a typical saturation curve. Higher amount of Ga accumulation in plant tissues led to significant inhibition in relative growth rate and water use efficiency in a dose-dependent manner. DNA-protein cross-links (DPCs) analysis revealed that overaccumulation of Ga in plant tissues positively stimulated formation of DPCs in roots. Likewise, the measure of root cell viability evaluated by Evan blue uptake showed a similar trend. These results suggested that Ga can be absorbed, transported, and accumulated in plant materials of rice seedlings. Overaccumulation of Ga in plant tissues provoked the formation of DPCs in roots, which resulted in cell death and growth inhibition of rice seedlings.

  15. Differential induction of pyruvate decarboxylase subunits and transcripts in anoxic rice seedlings.

    PubMed Central

    Rivoal, J; Thind, S; Pradet, A; Ricard, B

    1997-01-01

    In 2-d-old rice (Oryza sativa L.) seedlings subjected to anoxic stress, pyruvate decarboxylase (PDC) activity increased 9-fold during a 168-h period. A polyclonal PDC antiserum that recognized alpha- and beta-subunits was used to quantify PDC protein by an enzyme-linked immunosorbant assay and showed a 5.6-fold increase, suggesting that the anoxically induced enzyme has a higher specific activity than the PDC isoform present under normoxia. Immunoblot analysis showed that levels of both PDC subunits were induced by anoxia. Immunoprecipitation of proteins labeled in vivo during anoxic treatment demonstrated that the alpha-subunit was preferentially synthesized at the onset of anoxia. Two partial cDNAs, including a novel sequence, were cloned from a cDNA library made from seedlings subjected to anoxia for 6 h. Gene-specific probes used to quantify northern blots showed that two or three PDC mRNAs are differentially induced by anoxia in rice seedlings. Immunoprecipitation of in vitro translation products of mRNAs isolated a different times of anoxic treatment confirmed this findings Our results suggest that anoxic induction of rice PDC involves transcriptional and posttranscriptional regulation of gene expression as well as differences in enzyme characteristics. PMID:9232881

  16. Foliar application with nano-silicon alleviates Cd toxicity in rice seedlings.

    PubMed

    Wang, Shihua; Wang, Fayuan; Gao, Shuangcheng

    2015-02-01

    Nanofertilizers may be more effective than regular fertilizers in improving plant nutrition, enhancing nutrition use efficiency, and protecting plants from environmental stress. A hydroponic pot experiment was conducted to study the role of foliar application with 2.5 mM nano-silicon in alleviating Cd stress in rice seedlings (Oryza sativa L. cv Youyou 128) grown in solution added with or without 20 μM CdCl2. The results showed that Cd treatment decreased the growth and the contents of Mg, Fe, Zn, chlorophyll a, and glutathione (GSH), accompanied by a significant increase in Cd accumulation. However, foliar application with nano-Si improved the growth, Mg, Fe, and Zn nutrition, and the contents of chlorophyll a of the rice seedlings under Cd stress and decreased Cd accumulation and translocation of Cd from root to shoot. Cd treatment produced oxidative stress to rice seedlings indicated by a higher lipid peroxidation level (as malondialdehyde (MDA)) and higher activities of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), and a lower GSH content. However, those nano-Si-treated plants had lower MDA but higher GSH content and different antioxidant enzyme activities, indicating a higher Cd tolerance in them. The results suggested that nano-Si application alleviated Cd toxicity in rice by decreasing Cd accumulation, Cd partitioning in shoot and MDA level and by increasing content of some mineral elements (Mg, Fe, and Zn) and antioxidant capacity.

  17. Role of relative humidity in processing and storage of seeds and assessment of variability in storage behaviour in Brassica spp. and Eruca sativa.

    PubMed

    Suma, A; Sreenivasan, Kalyani; Singh, A K; Radhamani, J

    2013-01-01

    The role of relative humidity (RH) while processing and storing seeds of Brassica spp. and Eruca sativa was investigated by creating different levels of relative humidity, namely, 75%, 50%, 32%, and 11% using different saturated salt solutions and 1% RH using concentrated sulphuric acid. The variability in seed storage behaviour of different species of Brassica was also evaluated. The samples were stored at 40 ± 2°C in sealed containers and various physiological parameters were assessed at different intervals up to three months. The seed viability and seedling vigour parameters were considerably reduced in all accessions at high relative humidity irrespective of the species. Storage at intermediate relative humidities caused minimal decline in viability. All the accessions performed better at relative humidity level of 32% maintaining seed moisture content of 3%. On analyzing the variability in storage behaviour, B. rapa and B. juncea were better performers than B. napus and Eruca sativa.

  18. Genetic architecture of cold tolerance in rice (Oryza sativa) determined through high resolution genome-wide analysis

    PubMed Central

    Shakiba, Ehsan; Edwards, Jeremy D.; Jodari, Farman; Duke, Sara E.; Baldo, Angela M.; Korniliev, Pavel; McCouch, Susan R.; Eizenga, Georgia C.

    2017-01-01

    Cold temperature is an important abiotic stress which negatively affects morphological development and seed production in rice (Oryza sativa L.). At the seedling stage, cold stress causes poor germination, seedling injury and poor stand establishment; and at the reproductive stage cold decreases seed yield. The Rice Diversity Panel 1 (RDP1) is a global collection of over 400 O. sativa accessions representing the five major subpopulations from the INDICA and JAPONICA varietal groups, with a genotypic dataset consisting of 700,000 SNP markers. The objectives of this study were to evaluate the RDP1 accessions for the complex, quantitatively inherited cold tolerance traits at the germination and reproductive stages, and to conduct genome-wide association (GWA) mapping to identify SNPs and candidate genes associated with cold stress at these stages. GWA mapping of the germination index (calculated as percent germination in cold divided by warm treatment) revealed 42 quantitative trait loci (QTLs) associated with cold tolerance at the seedling stage, including 18 in the panel as a whole, seven in temperate japonica, six in tropical japonica, 14 in JAPONICA, and nine in INDICA, with five shared across all subpopulations. Twenty-two of these QTLs co-localized with 32 previously reported cold tolerance QTLs. GWA mapping of cold tolerance at the reproductive stage detected 29 QTLs, including seven associated with percent sterility, ten with seed weight per panicle, 14 with seed weight per plant and one region overlapping for two traits. Fifteen co-localized with previously reported QTLs for cold tolerance or yield components. Candidate gene ontology searches revealed these QTLs were associated with significant enrichment for genes related to with lipid metabolism, response to stimuli, response to biotic stimuli (suggesting cross-talk between biotic and abiotic stresses), and oxygen binding. Overall the JAPONICA accessions were more tolerant to cold stress than INDICA

  19. Mechanism of Safening Action of Dymuron and Its Two Monomethyl Analogues against Bensulfuron-methyl Injury to Rice (Oryza sativa)

    PubMed

    Omokawa; Wu; Hatzios

    1996-05-01

    The comparative efficacy and mechanism of action of the herbicide dymuron and its two optically active monomethyl analogues, (R)-1-(alpha-methylbenzyl)-3-(p-tolylurea) (R-MBTU) and S-MBTU, as safeners of rice against injury from bensulfuron-methyl were investigated. Bioassays using etiolated seedlings of rice (Oryza sativa L., cv. Lemont), grown either in agar or in liquid media containing bensulfuron-methyl, showed that this sulfonylurea herbicide is a potent inhibitor of rice root growth (I50 = 120 nM). Similar studies with the herbicide dymuron and its two optically active monomethyl analogues (R-MTBU and S-MTBU) showed that at 10 μM, dymuron and R-MBTU reduced rice root length by 25 and 17%, respectively, whereas S-MBTU had no effect on root growth of Lemont rice. Combined treatments with bensulfuron-methyl and dymuron or each of its two analogues confirmed that S-MTBU is an excellent safener of rice against bensulfuron-methyl, far more effective than either dymuron or R-MTBU. The protective action of S-MTBU appeared to result mainly from a drastic reduction in the uptake of bensulfuron-methyl by safened rice seedlings. Dymuron and R-MTBU reduced also the uptake of bensulfuron-methyl by rice seedlings, but to a lesser extent than S-MTBU. Quantitative changes in the metabolism of bensulfuron-methyl by safened rice seedlings were also observed, but did not appear to support the involvement of enhanced herbicide metabolism in the safening action of S-MBTU, R-MBTU, and dymuron. The major metabolites of bensulfuron-methyl detected in both safened and unsafened rice seedlings were tentatively identified as methyl-(4-hydroxy-6-methoxypyrimidin-2-yl-carbamoylsulfamoyl)-o-toluate; methyl-(aminosulfonyl)-o-toluate; and 1H-2,3-benzothiazin-4-(3H)-one-2,2-dioxide.

  20. Morphological and proteomic responses of Eruca sativa exposed to silver nanoparticles or silver nitrate.

    PubMed

    Vannini, Candida; Domingo, Guido; Onelli, Elisabetta; Prinsi, Bhakti; Marsoni, Milena; Espen, Luca; Bracale, Marcella

    2013-01-01

    Silver nanoparticles (AgNPs) are widely used in commercial products, and there are growing concerns about their impact on the environment. Information about the molecular interaction of AgNPs with plants is lacking. To increase our understanding of the mechanisms involved in plant responses to AgNPs and to differentiate between particle specific and ionic silver effects we determined the morphological and proteomic changes induced in Eruca sativa (commonly called rocket) in response to AgNPs or AgNO3. Seedlings were treated for 5 days with different concentrations of AgNPs or AgNO3. A similar increase in root elongation was observed when seedlings were exposed to 10 mg Ag L(1) of either PVP-AgNPs or AgNO3. At this concentration we performed electron microscopy investigations and 2-dimensional electrophoresis (2DE) proteomic profiling. The low level of overlap of differentially expressed proteins indicates that AgNPs and AgNO3 cause different plant responses. Both Ag treatments cause changes in proteins involved in the redox regulation and in the sulfur metabolism. These responses could play an important role to maintain cellular homeostasis. Only the AgNP exposure cause the alteration of some proteins related to the endoplasmic reticulum and vacuole indicating these two organelles as targets of the AgNPs action. These data add further evidences that the effects of AgNPs are not simply due to the release of Ag ions.

  1. Morphological and Proteomic Responses of Eruca sativa Exposed to Silver Nanoparticles or Silver Nitrate

    PubMed Central

    Vannini, Candida; Domingo, Guido; Onelli, Elisabetta; Prinsi, Bhakti; Marsoni, Milena; Espen, Luca; Bracale, Marcella

    2013-01-01

    Silver nanoparticles (AgNPs) are widely used in commercial products, and there are growing concerns about their impact on the environment. Information about the molecular interaction of AgNPs with plants is lacking. To increase our understanding of the mechanisms involved in plant responses to AgNPs and to differentiate between particle specific and ionic silver effects we determined the morphological and proteomic changes induced in Eruca sativa (commonly called rocket) in response to AgNPs or AgNO3. Seedlings were treated for 5 days with different concentrations of AgNPs or AgNO3. A similar increase in root elongation was observed when seedlings were exposed to 10 mg Ag L1 of either PVP-AgNPs or AgNO3. At this concentration we performed electron microscopy investigations and 2-dimensional electrophoresis (2DE) proteomic profiling. The low level of overlap of differentially expressed proteins indicates that AgNPs and AgNO3 cause different plant responses. Both Ag treatments cause changes in proteins involved in the redox regulation and in the sulfur metabolism. These responses could play an important role to maintain cellular homeostasis. Only the AgNP exposure cause the alteration of some proteins related to the endoplasmic reticulum and vacuole indicating these two organelles as targets of the AgNPs action. These data add further evidences that the effects of AgNPs are not simply due to the release of Ag ions. PMID:23874747

  2. The Medicago sativa gene index 1.2: a web-accessible gene expression atlas for investigating expression differences between Medicago sativa subspecies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alfalfa (Medicago sativa L.) is the primary forage legume crop species in the United States and plays essential economic and ecological roles in agricultural systems across the country. Modern alfalfa is the result of hybridization between tetraploid M. sativa ssp. sativa and M. sativa ssp. falcata....

  3. The complete chloroplast genomes of Cannabis sativa and Humulus lupulus.

    PubMed

    Vergara, Daniela; White, Kristin H; Keepers, Kyle G; Kane, Nolan C

    2016-09-01

    Cannabis and Humulus are sister genera comprising the entirety of the Cannabaceae sensu stricto, including C. sativa L. (marijuana, hemp), and H. lupulus L. (hops) as two economically important crops. These two plants have been used by humans for many purposes including as a fiber, food, medicine, or inebriant in the case of C. sativa, and as a flavoring component in beer brewing in the case of H. lupulus. In this study, we report the complete chloroplast genomes for two distinct hemp varieties of C. sativa, Italian "Carmagnola" and Russian "Dagestani", and one Czech variety of H. lupulus "Saazer". Both C. sativa genomes are 153 871 bp in length, while the H. lupulus genome is 153 751 bp. The genomes from the two C. sativa varieties differ in 16 single nucleotide polymorphisms (SNPs), while the H. lupulus genome differs in 1722 SNPs from both C. sativa cultivars.

  4. Inhibition of ribonuclease and protease activities in arsenic exposed rice seedlings: role of proline as enzyme protectant.

    PubMed

    Mishra, Shruti; Dubey, Rama Shanker

    2006-09-01

    When seedlings of two rice (Oryza sativa L.) cvs. Malviya-36 and Pant-12 were raised under 25 and 50 microM As2O3 in the medium an increase in the level of RNA, proteins and proline accompanied with a decline in the level of free amino acid pool was observed under arsenic supplementation compared to controls. In situ As3+ treatment caused a marked inhibition in activities of ribonuclease (RNase, EC 3.1.27.1), protease and leucine aminopeptidase (LAP, EC 3.4.11.1) whereas the activity level of carboxypeptidase (EC 3.4.16.5) was enhanced. In vitro supply of As2O3 in the enzyme assay medium beyond 400 microM resulted in gradual inhibition of RNase and beyond 5 microM inhibition of LAP activities. Addition of 1M proline in the assay medium significantly restored the loss in RNase activity due to in vitro arsenic treatment or due to osmotic stress created by incorporation of polyethylene glycol (PEG). Isoform pattern of RNase extracted from As3+ -exposed seedlings showed a significant alteration compared to its pattern in unexposed seedlings. Results suggest that arsenic exposure impairs hydrolysis of RNA and proteins in rice seedlings due to inhibition of RNase and proteases activities and that proline accumulating under As3+ toxicity appears to serve as enzyme protectant.

  5. Biosurfactant Produced by Salmonella Enteritidis SE86 Can Increase Adherence and Resistance to Sanitizers on Lettuce Leaves (Lactuca sativa L., cichoraceae).

    PubMed

    Rossi, Eliandra M; Beilke, Luniele; Kochhann, Marília; Sarzi, Diana H; Tondo, Eduardo C

    2016-01-01

    Salmonella Enteritidis SE86 is an important foodborne pathogen in Southern Brazil and it is able to produce a biosurfactant. However, the importance of this compound for the microorganism is still unknown. This study aimed to investigate the influence of the biosurfactant produced by S. Enteritidis SE86 on adherence to slices of lettuce leaves and on resistance to sanitizers. First, lettuce leaves were inoculated with S. Enteritidis SE86 in order to determine the amount of biosurfactant produced. Subsequently, lettuce leaves were inoculated with S. Enteritidis SE86 with and without the biosurfactant, and the adherence and bacterial resistance to different sanitization methods were evaluated. S. Enteritidis SE86 produced biosurfactant after 16 h (emulsification index of 11 to 52.15 percent, P < 0.05) and showed greater adherence capability and resistance to sanitization methods when the compound was present. The scanning electron microscopy demonstrated that S. Enteritidis was able to adhere, form lumps, and invade the lettuce leaves' stomata in the presence of the biosurfactant. Results indicated that the biosurfactant produced by S. Enteritidis SE86 contributed to adherence and increased resistance to sanitizers when the microorganism was present on lettuce leaves.

  6. Influence of Green, Red and Blue Light Emitting Diodes on Multiprotein Complex Proteins and Photosynthetic Activity under Different Light Intensities in Lettuce Leaves (Lactuca sativa L.)

    PubMed Central

    Muneer, Sowbiya; Kim, Eun Jeong; Park, Jeong Suk; Lee, Jeong Hyun

    2014-01-01

    The objective of this study was to investigate the response of light emitting diodes (LEDs) at different light intensities (70 and 80 for green LEDs, 88 and 238 for red LEDs and 80 and 238 μmol m−2 s−1 for blue LEDs) at three wavelengths in lettuce leaves. Lettuce leaves were exposed to (522 nm), red (639 nm) and blue (470 nm) LEDs of different light intensities. Thylakoid multiprotein complex proteins and photosynthetic metabolism were then investigated. Biomass and photosynthetic parameters increased with an increasing light intensity under blue LED illumination and decreased when illuminated with red and green LEDs with decreased light intensity. The expression of multiprotein complex proteins including PSII-core dimer and PSII-core monomer using blue LEDs illumination was higher at higher light intensity (238 μmol m−2 s−1) and was lowered with decreased light intensity (70–80 μmol m−2 s−1). The responses of chloroplast sub-compartment proteins, including those active in stomatal opening and closing, and leaf physiological responses at different light intensities, indicated induced growth enhancement upon illumination with blue LEDs. High intensity blue LEDs promote plant growth by controlling the integrity of chloroplast proteins that optimize photosynthetic performance in the natural environment. PMID:24642884

  7. A dose-response relationship for marketable yield reduction of two lettuce (Lactuca sativa L.) cultivars exposed to tropospheric ozone in Southern Europe.

    PubMed

    Marzuoli, Riccardo; Finco, Angelo; Chiesa, Maria; Gerosa, Giacomo

    2016-12-27

    The present study investigated the response to ozone (O3) of two cultivars (cv.'Romana' and cv. 'Canasta') of irrigated lettuce grown in an open-top chamber (OTC) experiment in Mediterranean conditions. Two different levels of O3 were applied, ambient O3 in non-filtered OTCs (NF-OTCs) and -40% of ambient O3 in charcoal-filtered OTCs (CF-OTCs), during four consecutive growing cycles. At the end of each growing cycle, the marketable yield (fresh biomass) was assessed while during the growing periods, measurements of the stomatal conductance at leaf level were performed and used to define a stomatal conductance model for calculation of the phytotoxic ozone dose (POD) absorbed by the plants.Results showed that O3 caused statistically significant yield reductions in the first and in the last growing cycle. In general, the marketable yield of the NF-OTC plants was always lower than the CF-OTC plants for both cultivars, with mean reductions of -18.5 and -14.5% for 'Romana' and 'Canasta', respectively. On the contrary, there was no statistically significant difference in marketable yield due to the cultivar factor or to the interaction between O3 and cultivar in any of the growing cycle performed.Dose-response relationships for the marketable relative yield based on the POD values were calculated according to different flux threshold values (Y). The best regression fit was obtained using an instantaneous flux threshold of 6 nmol O3 m(-2) s(-1) (POD6); the same value was obtained also for other crops. According to the generic lettuce dose-response relationship, an O3 critical level of 1 mmol O3 m(-2) of POD6 for a 15% of marketable yield loss was found.

  8. Effects of co-cropping Bidens pilosa (L.) and Tagetes minuta (L.) on bioaccumulation of Pb in Lactuca sativa (L.) growing in polluted agricultural soils.

    PubMed

    Cid, Carolina Vergara; Rodriguez, Judith Hebelen; Salazar, María Julieta; Blanco, Andrés; Pignata, María Luisa

    2016-09-01

    Polluted agricultural soils are a serious problem for food safety, with phytoremediation being the most favorable alternative from the environmental perspective. However, this methodology is generally time-consuming and requires the cessation of agriculture. Therefore, the purpose of this study was to evaluate two potential phytoextractor plants (the native species Bidens pilosa and Tagetes minuta) co-cropped with lettuce growing on agricultural lead-polluted soils. The concentrations of Pb, as well as of other metals, were investigated in the phytoextractors, crop species, and in soils, with the potential risk to the health of consumers being estimated. The soil parameters pH, EC, organic matter percentage and bioavailable lead showed a direct relationship with the accumulation of Pb in roots. In addition, the concentration of Pb in roots of native species was closely related to Fe (B. pilosa, r = 0.81; T. minuta r = 0.75), Cu (T. minuta, r = 0.93), Mn (B. pilosa, r = 0.89) and Zn (B. pilosa, r = 0.91; T. minuta, r = 0.91). Our results indicate that the interaction between rhizospheres increased the phytoextraction of lead, which was accompanied by an increase in the biomass of the phytoextractor species. However, the consumption of lettuce still revealed a toxicological risk from Pb in all treatments.

  9. Selection for resistance to Verticillium wilt caused by race 2 isolates of Verticillium dahliae in accessions of lettuce (Lactuca sativa L.).

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Verticillium wilt of lettuce caused by Verticillium dahliae can cause severe economic damage to lettuce producers. The pathogen exists as two races (races 1 and 2) in lettuce, and complete resistance to race 1 is known. Resistance to race 2 isolates has not been reported, and production of race 1 re...

  10. Effects of biochar and alkaline amendments on cadmium immobilization, selected nutrient and cadmium concentrations of lettuce (Lactuca sativa) in two contrasting soils.

    PubMed

    Woldetsadik, Desta; Drechsel, Pay; Keraita, Bernard; Marschner, Bernd; Itanna, Fisseha; Gebrekidan, Heluf

    2016-01-01

    To assess the efficiency of seven treatments including biochars produced from dried faecal matter and manures as stabilizing agents of cadmium (Cd)-spiked soils, lettuce was grown in glasshouse on two contrasting soils. The soils used were moderately fertile silty loam and less fertile sandy loam and the applied treatments were 7 % w/w. The reduction of bioavailable Cd (ammonium nitrate extractable) and its phytoavailability for lettuce were used as assessment criteria in the evaluation of stabilization performance of each treatment. Moreover, the agronomic values of the treatments were also investigated. Ammonium nitrate extraction results indicated that faecal matter biochar, cow manure biochar and lime significantly reduced bioavailable Cd by 84-87, 65-68 and 82-91 %, respectively, as compared to the spiked controls. Unpredictably, coffee husk biochar induced significant increment of Cd in NH4NO3 extracts. The immobilization potential of faecal matter biochar and lime were superior than the other treatments. However, lime and egg shell promoted statistically lower yield and P, K and Zn concentrations response of lettuce plants compared to the biochar treatments. The lowest Cd and highest P tissue concentrations of lettuce plants were induced by faecal matter and cow manure biochar treatments in both soils. Additionally, the greatest Cd phytoavailability reduction for lettuce was induced by poultry litter and cow manure biochars in the silty loam soil. Our results indicate that faecal matter and animal manure biochars have shown great potential to promote Cd immobilization and lettuce growth response in heavily contaminated agricultural fields.

  11. Association analysis of bacterial leaf spot resistance and SNP markers derived from expressed sequence tags (ESTs) in lettuce (Lactuca sativa L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial leaf spot of lettuce, caused by Xanthomonas campestris pv. vitians, is a devastating disease of lettuce worldwide. Since there are no chemicals available for effective control of the disease, host-plant resistance is highly desirable to protect lettuce production. A total of 179 lettuce ge...

  12. Iodine and Selenium Biofortification with Additional Application of Salicylic Acid Affects Yield, Selected Molecular Parameters and Chemical Composition of Lettuce Plants (Lactuca sativa L. var. capitata).

    PubMed

    Smoleń, Sylwester; Kowalska, Iwona; Czernicka, Małgorzata; Halka, Mariya; Kęska, Kinga; Sady, Włodzimierz

    2016-01-01

    Iodine (I) and selenium (Se) are included in the group of beneficial elements. They both play important roles in humans and other animals, particularly in the regulation of thyroid functioning. A substantial percentage of people around the world suffer from health disorders related to the deficiency of these elements in the diet. Salicylic acid (SA) is a compound similar to phytohormones and is known to improve the efficiency of I biofortification of plants. The influence of SA on Se enrichment of plants has not, however, been recognized together with its effect on simultaneous application of I and Se to plants. Two-year studies (2014-2015) were conducted in a greenhouse with hydroponic cultivation of lettuce in an NFT (nutrient film technique) system. They included the application of I (as KIO3), Se (as Na2SeO3) and SA into the nutrient solution. KIO3 was used at a dose of 5 mg I⋅dm(-3) (i.e., 39.4 μM I), while Na2SeO3 was 0.5 mg Se⋅dm(-3) (i.e., 6.3 μM Se). SA was introduced at three doses: 0.1, 1.0, and 10.0 mg⋅dm(-3) nutrient solutions, equivalent to 0.724, 7.24, and 72.4 μM SA, respectively. The tested combinations were as follows: (1) control, (2) I + Se, (3) I + Se + 0.1 mg SA⋅dm(-3), (4) I + Se + 1.0 mg SA⋅dm(-3) and (5) I + Se + 10.0 mg SA⋅dm(-3). The applied treatments had no significant impact on lettuce biomass (leaves and roots). Depending on the dose, a diverse influence of SA was noted with respect to the efficiency of I and Se biofortification; chemical composition of leaves; and mineral nutrition of lettuce plants, including the content of macro- and microelements and selenocysteine methyltransferase (SMT) gene expression. SA application at all tested doses comparably increased the level of selenomethionine (SeMet) and decreased the content of SA in leaves.

  13. Effect of abiotic elicitation on main health-promoting compounds, antioxidant activity and commercial quality of butter lettuce (Lactuca sativa L.).

    PubMed

    Złotek, Urszula; Świeca, Michał; Jakubczyk, Anna

    2014-04-01

    The study presents changes in the phytochemical levels, antiradical activity and quality of lettuce caused by different chemical elicitors: arachidonic acid (AA), jasmonic acid (JA), and abscisic acid (ABA). The application of 1 μM and 100 μM JA induced an increase in the concentration of phenolic compounds, including flavonoids and phenolic acids. Flavonoid levels were also increased after treatment with 100 μM AA and ABA. Some of the elicitor concentrations used also caused an increase in the levels of other phytochemicals, such as chlorophyll a (1 μM and 100 μM AA, 50 μM ABA); chlorophyll b (100 μM AA); carotenoids (100 μM AA, 1 μM JA and 100 μM ABA) and vitamin C (100 μM AA, 100 μM JA). The highest antiradical activity was noted after treatment with 100 μM AA, 100 μM JA. 1,1-Diphenyl-2-picrylhydrazyl (DPPH) scavenging ability was positively and significantly correlated with flavonoid, chlorophyll and carotenoid levels. These results may suggest that the antiradical activity of lettuce was determined not only by phenolics, but also by other bioactive compounds. Elicitation did not change the sensory quality of lettuce. Therefore, treatment with elicitors could be a useful tool for improving the health-promoting qualities of lettuce without the loss of sensory quality.

  14. Lettuce (Lactuca sativa L.) leaf-proteome profiles after exposure to cylindrospermopsin and a microcystin-LR/cylindrospermopsin mixture: a concentration-dependent response.

    PubMed

    Freitas, Marisa; Campos, Alexandre; Azevedo, Joana; Barreiro, Aldo; Planchon, Sébastien; Renaut, Jenny; Vasconcelos, Vitor

    2015-02-01

    The intensification of agricultural productivity is an important challenge worldwide. However, environmental stressors can provide challenges to this intensification. The progressive occurrence of the cyanotoxins cylindrospermopsin (CYN) and microcystin-LR (MC-LR) as a potential consequence of eutrophication and climate change is of increasing concern in the agricultural sector because it has been reported that these cyanotoxins exert harmful effects in crop plants. A proteomic-based approach has been shown to be a suitable tool for the detection and identification of the primary responses of organisms exposed to cyanotoxins. The aim of this study was to compare the leaf-proteome profiles of lettuce plants exposed to environmentally relevant concentrations of CYN and a MC-LR/CYN mixture. Lettuce plants were exposed to 1, 10, and 100 μg/l CYN and a MC-LR/CYN mixture for five days. The proteins of lettuce leaves were separated by two-dimensional electrophoresis (2-DE), and those that were differentially abundant were then identified by matrix-assisted laser desorption/ionization time of flight-mass spectrometry (MALDI-TOF/TOF MS). The biological functions of the proteins that were most represented in both experiments were photosynthesis and carbon metabolism and stress/defense response. Proteins involved in protein synthesis and signal transduction were also highly observed in the MC-LR/CYN experiment. Although distinct protein abundance patterns were observed in both experiments, the effects appear to be concentration-dependent, and the effects of the mixture were clearly stronger than those of CYN alone. The obtained results highlight the putative tolerance of lettuce to CYN at concentrations up to 100 μg/l. Furthermore, the combination of CYN with MC-LR at low concentrations (1 μg/l) stimulated a significant increase in the fresh weight (fr. wt) of lettuce leaves and at the proteomic level resulted in the increase in abundance of a high number of proteins. In contrast, many proteins exhibited a decrease in abundance or were absent in the gels of the simultaneous exposure to 10 and 100 μg/l MC-LR/CYN. In the latter, also a significant decrease in the fr. wt of lettuce leaves was obtained. These findings provide important insights into the molecular mechanisms of the lettuce response to CYN and MC-LR/CYN and may contribute to the identification of potential protein markers of exposure and proteins that may confer tolerance to CYN and MC-LR/CYN. Furthermore, because lettuce is an important crop worldwide, this study may improve our understanding of the potential impact of these cyanotoxins on its quality traits (e.g., presence of allergenic proteins).

  15. The effect of light and ancymidol on the metabolism of sup 14 C-ent-Kaurene in photoblastic lettuce (Lactuca sativa L. var. Grand Rapids) seeds

    SciTech Connect

    Hazebroek, J.P.; Coolbaugh, R.C. )

    1990-05-01

    The effect of light ancymidol on the metabolism of {sup 14}C-kaurene in light-requiring lettuce seeds was investigated. Seeds were soaked in a solution of {sup 14}C-kaurene in CH{sub 2}Cl{sub 2} with 0.1% Tween-20 for 24 h. The treatment did not reduce viability nor alter the light requirement. The solvent was removed and the seeds were incubated at 25{degree}C in continuous light or dark in 20% (w/v) PEG or 10 mM anycymidol. Labeled metabolites were extracted and analyzed by reverse phase HPLC. {sup 14}C-Kaurenol and {sup 14}C-kaurenal were identified in seed incubated in 20% PeG in the light, while no acid EtOAc-soluble metabolites were found in seeds incubated in the dark. In the presence of ancymidol, {sup 14}C-karuenol, {sup 14}C-kaurenal, and a polar metabolite were found in seeds exposed to light, while only a trace of {sup 14}C-kaurenol was detected in seeds incubated in the dark. These results indicate that the oxidation of kaurene is a light sensitive step in the biosynthesis of gibberellins in photoblastic lettuce seeds. Under these conditions ancymidol inhibits germination at a site different than the light sensitive kaurene oxidation step.

  16. Selected biochemical properties of polyphenol oxidase in butter lettuce leaves (Lactuca sativa L. var. capitata) elicited with dl-β-amino-n-butyric acid.

    PubMed

    Złotek, Urszula; Gawlik-Dziki, Urszula

    2015-02-01

    The study concentrated on changes in certain biochemical parameters of polyphenol oxidase (PPO) from lettuce leaves caused by dl-β-amino-n-butyric acid (BABA) elicitation. PPO from control plants demonstrated the highest affinity toward catechol, whereas PPO from BABA-elicited lettuce showed the highest affinity to 4-methylcatechol. The optimum temperature for enzymes from control plants was 35°C, whereas from plants elicited with 1mM BABA this was 25°C. PPO from plants elicited with BABA was also more sensitive to the tested inhibitors than PPO from control plants. l-Cysteine was the most effective inhibitor. Native gel stained for PPO activity in control samples showed two isoforms. However, in BABA-treated lettuce three bands visualising PPO activity were observed. The information obtained in this study will be valuable for the development of treatment technology and storage conditions to control undesirable browning reactions in elicited lettuce.

  17. Biosurfactant Produced by Salmonella Enteritidis SE86 Can Increase Adherence and Resistance to Sanitizers on Lettuce Leaves (Lactuca sativa L., cichoraceae)

    PubMed Central

    Rossi, Eliandra M.; Beilke, Luniele; Kochhann, Marília; Sarzi, Diana H.; Tondo, Eduardo C.

    2016-01-01

    Salmonella Enteritidis SE86 is an important foodborne pathogen in Southern Brazil and it is able to produce a biosurfactant. However, the importance of this compound for the microorganism is still unknown. This study aimed to investigate the influence of the biosurfactant produced by S. Enteritidis SE86 on adherence to slices of lettuce leaves and on resistance to sanitizers. First, lettuce leaves were inoculated with S. Enteritidis SE86 in order to determine the amount of biosurfactant produced. Subsequently, lettuce leaves were inoculated with S. Enteritidis SE86 with and without the biosurfactant, and the adherence and bacterial resistance to different sanitization methods were evaluated. S. Enteritidis SE86 produced biosurfactant after 16 h (emulsification index of 11 to 52.15 percent, P < 0.05) and showed greater adherence capability and resistance to sanitization methods when the compound was present. The scanning electron microscopy demonstrated that S. Enteritidis was able to adhere, form lumps, and invade the lettuce leaves’ stomata in the presence of the biosurfactant. Results indicated that the biosurfactant produced by S. Enteritidis SE86 contributed to adherence and increased resistance to sanitizers when the microorganism was present on lettuce leaves. PMID:26834727

  18. Iodine and Selenium Biofortification with Additional Application of Salicylic Acid Affects Yield, Selected Molecular Parameters and Chemical Composition of Lettuce Plants (Lactuca sativa L. var. capitata)

    PubMed Central

    Smoleń, Sylwester; Kowalska, Iwona; Czernicka, Małgorzata; Halka, Mariya; Kęska, Kinga; Sady, Włodzimierz

    2016-01-01

    Iodine (I) and selenium (Se) are included in the group of beneficial elements. They both play important roles in humans and other animals, particularly in the regulation of thyroid functioning. A substantial percentage of people around the world suffer from health disorders related to the deficiency of these elements in the diet. Salicylic acid (SA) is a compound similar to phytohormones and is known to improve the efficiency of I biofortification of plants. The influence of SA on Se enrichment of plants has not, however, been recognized together with its effect on simultaneous application of I and Se to plants. Two-year studies (2014–2015) were conducted in a greenhouse with hydroponic cultivation of lettuce in an NFT (nutrient film technique) system. They included the application of I (as KIO3), Se (as Na2SeO3) and SA into the nutrient solution. KIO3 was used at a dose of 5 mg I⋅dm-3 (i.e., 39.4 μM I), while Na2SeO3 was 0.5 mg Se⋅dm-3 (i.e., 6.3 μM Se). SA was introduced at three doses: 0.1, 1.0, and 10.0 mg⋅dm-3 nutrient solutions, equivalent to 0.724, 7.24, and 72.4 μM SA, respectively. The tested combinations were as follows: (1) control, (2) I + Se, (3) I + Se + 0.1 mg SA⋅dm-3, (4) I + Se + 1.0 mg SA⋅dm-3 and (5) I + Se + 10.0 mg SA⋅dm-3. The applied treatments had no significant impact on lettuce biomass (leaves and roots). Depending on the dose, a diverse influence of SA was noted with respect to the efficiency of I and Se biofortification; chemical composition of leaves; and mineral nutrition of lettuce plants, including the content of macro- and microelements and selenocysteine methyltransferase (SMT) gene expression. SA application at all tested doses comparably increased the level of selenomethionine (SeMet) and decreased the content of SA in leaves. PMID:27803709

  19. Influence of the temporal and spatial variation of nitrate reductase, glutamine synthetase and soil composition in the N species content in lettuce (Lactuca sativa).

    PubMed

    Pinto, Edgar; Fidalgo, Fernanda; Teixeira, Jorge; Aguiar, Ana A; Ferreira, Isabel M P L V O

    2014-04-01

    The variation of nitrate reductase (NR), glutamine synthetase (GS) and N content in lettuce was evaluated at 5 stages of lettuce growth. Soil physicochemical properties and its N content were also assessed to elucidate the soil-to-plant transfer of inorganic N and potential leaching to groundwater. A decrease of NR activity and an increase of NO3(-) and N-Kjeldahl content in lettuces were observed during plant growth, whereas GS activity and NH4(+) increased during the first few weeks of lettuce growth and then decreased. Although the temporal variation was similar in lettuces grown in different soils, quantitative differences were observed, indicating that high NO3(-) content in soil caused a higher NO3(-) accumulation in lettuce despite the higher NR activity during the initial stage of plant growth. Higher levels of NO3(-) and NH4(+) were correlated with higher levels of N-Kjeldahl in lettuce suggesting a positive effect of these N species in the biosynthesis of organic forms of N. Soil physicochemical properties influenced the mobility of inorganic N within the groundwater-soil-plant system. Sandy soils with low OM content allowed NO3(-) leaching, which was confirmed by higher NO3(-) levels in groundwater. Therefore, lettuces grown in those soils presented lower N content and the inputs of N to the environment were higher.

  20. Phylogenetic relationship and antifouling activity of bacterial epiphytes from the marine alga Ulva lactuca.

    PubMed

    Egan, S; Thomas, T; Holmström, C; Kjelleberg, S

    2000-06-01

    It is widely accepted that bacterial epiphytes can inhibit the colonization of surfaces by common fouling organisms. However, little information is available regarding the diversity and properties of these antifouling bacteria. This study assessed the antifouling traits of five epiphytes of the common green alga, Ulva lactuca. All isolates were capable of preventing the settlement of invertebrate larvae and germination of algal spores. Three of the isolates also inhibited the growth of a variety of bacteria and fungi. Their phylogenetic positions were determined by 16S ribosomal subunit DNA sequencing. All isolates showed a close affiliation with the genus Pseudoalteromonas and, in particular, with the species P. tunicata. Strains of this bacterial species also display a variety of antifouling activities, suggesting that antifouling ability may be an important trait for members of this genus to be highly successful colonizers of animate surfaces and for such species to protect their host against fouling.

  1. Genetic and biochemical evaluation of natural rubber from Eastern Washington prickly lettuce (Lactuca serriola L.).

    PubMed

    Bell, Jared L; Burke, Ian C; Neff, Michael M

    2015-01-21

    Alternative sources of natural rubber are of importance due to economic, biological, and political threats that could diminish supplies of this resource. Prickly lettuce (Lactuca serriola L.) synthesizes long-chain natural rubber and was studied to determine underlying genetic and phenotypic characteristics of rubber biosynthesis. Genotypic and phenotypic analysis of an F2 segregating population using EST-SSR markers led to the discovery of genetic regions linked to natural rubber production. Interval mapping (IM) and multiple QTL mapping (MQM) identified several QTL in the mapping population that had significance based on LOD score thresholds. The discovered QTL and the corresponding local markers are genetic resources for understanding rubber biosynthesis in prickly lettuce and could be used in marker-assisted selection (MAS) breeding. Prickly lettuce is an excellent candidate for elucidating the rubber synthesis mechanism and has potential as a crop plant for rubber production.

  2. Peroxidase activity as an indicator of exposure of wetland seedlings to metals

    SciTech Connect

    Sutton, H.D.; Klaine, S.J.

    1995-12-31

    The enzyme peroxidase has been found to increase quantitatively in several aquatic plant species in response to increasing exposure to various contaminants. In this study, a number of wetland species are tested for their usefulness as bioindicators of metal exposure using the peroxidase assay. Woody species tested include Liquidambar styraciflua (sweetgum), Fraxinus pennsylvanica (green ash), and Cephalanthus occidentalis (buttonbush), while herbaceous species include Saururus cernuus (lizard`s tail) and Sparganium americanum (bur-reed). The assay has been optimized for all of these species. In all cases the pH optimum has been found to be either 5.5 or 6.0 and the substrate optimum is 2.8 or 1.4mM hydrogen peroxide. There is considerable variation in baseline peroxidase activity among the species when tested under their optimal assay conditions. These species are being dosed with copper, nickel, and cadmium in order to determine whether a response elicited. Seedlings will be dosed using both petri dish culture conditions and test tubes filled with vermiculite and sand combinations. The peroxidase response will be compared to germination and root elongation endpoints. Lettuce (Lactuca saliva) and radish (Raphanus sativus) are being tested alongside the wetland species as reference organisms for which background data is available. The wetland species tested in the present study have rarely if ever been used in toxicological studies.

  3. Field measurement of cotton seedling evapotranspiration

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Information on cotton evapotranspiration (ET) during the seedling growth stage and under field conditions is scarce because ET is a difficult parameter to measure. Our objective was to use weighable lysimeters to measure daily values of cotton seedling ET. We designed and built plastic weighable mic...

  4. On the role of β-cyanoalanine synthase (CAS) in metabolism of free cyanide and ferri-cyanide by rice seedlings.

    PubMed

    Yu, Xiao-Zhang; Lu, Peng-Cheng; Yu, Zhen

    2012-03-01

    A study was conducted to investigate the contribution of β-cyanoalanine synthase (CAS) to the botanical metabolism of free cyanide and iron cyanides. Seedlings of rice (Oryza sativa L. cv. XZX 45) were grown hydroponically and then amended with free cyanide (KCN) or ferri-cyanide [K(3)Fe(CN)(6)] into the growth media. Total cyanide, free cyanide, and Fe(3+)/Fe(2+) in aqueous solution were analyzed to identify the speciation of K(3)Fe(CN)(6). Activity of CAS in different parts of the rice seedlings was also assayed in vivo and results indicated that dissociation of K(3)Fe(CN)(6) to free cyanide in solution was negligible. Almost all of the applied KCN was removed by rice seedlings and the metabolic rates were concentration dependent. Phyto-transport of K(3)Fe(CN)(6) was apparent, but appreciable amounts of cyanide were recovered in plant tissues. The metabolic rates of K(3)Fe(CN)(6) were also positively correlated to the concentrations supplied. Rice seedlings exposed to KCN showed a considerable increase in the CAS activity and roots had higher CAS activity than shoots, indicating that CAS plays an important role in the botanical assimilation of KCN. However, no measurable change of CAS activity in different parts of rice seedlings exposed to K(3)Fe(CN)(6) was detected, suggesting that K(3)Fe(CN)(6) is likely metabolized by rice directly through an unknown pathway rather than the β-cyanoalanine pathway.

  5. Decontamination treatments to eliminate problem biota from macroalgal tank cultures of Osmundea pinnatifida, Palmaria palmata and Ulva lactuca.

    PubMed

    Kerrison, Philip D; Le, Hau Nhu; Twigg, Gail C; Smallman, Duncan R; MacPhee, Rory; Houston, Fiona A B; Hughes, Adam D

    2016-01-01

    The effect of a range of chemical disinfectants at different concentration and exposure times was investigated on five macroalgal species and the marine gastropod Littorina spp. Palmaria palmata, Osmundea pinnatifida and Ulva lactuca are commercially valuable and are often cultivated in tanks for food or feed. Ectocarpus siliculosus and Ulva intestinalis are common epiphytes of P. palmata and O. pinnatifida cultures, whilst Littorina spp. are common herbivorous epibionts within U. lactuca culture tanks. These contaminants reduce the productivity and quality of the culture as a food. Differential tolerance to the treatments was seen between the algal species using pulse-amplitude modulation (PAM) chlorophyll a fluorescence, a few hours and a week following treatment. We identified treatments that selectively damaged the epiphyte but not the basiphyte species. Ectocarpus siliculosus had a significantly lower tolerance to 1 % sodium hypochlorite than P. palmata, and to 25 % methanol than O. pinnatifida, with a 1-5 min exposure appearing most suitable. Ulva intestinalis had a significantly lower tolerance than P. palmata and O. pinnatifida to many disinfectants: 0.1-1 % sodium hypochlorite for 10 min, 0.5 % potassium iodide for up to 10 min, and 0.25 % Kick-start (a commercial aquaculture disinfectant solution) for 1-5 min. No treatment was able to kill the gastropod snails without also damaging U. lactuca, although agitation in freshwater for an hr may cause them to detach from the basiphyte, with little to no photophysiological impact seen to U. lactuca. This experiment forms the basis for more extended commercial trials.

  6. Enhanced Salt Tolerance under Nitrate Nutrition is Associated with Apoplast Na+ Content in Canola (Brassica. napus L.) and Rice (Oryza sativa L.) Plants.

    PubMed

    Gao, Limin; Liu, Mei; Wang, Min; Shen, Qirong; Guo, Shiwei

    2016-11-01

    To analyze the effect of nitrogen form on salt stress, we studied the response of two different plant species, canola (Brassica napus L.), a dicotyledon which prefers NO3(-) nutrition, and rice (Oryza sativa L.), a monocotyledon which prefers NH4(+) nutrition, to salt stress under NO3(-) (NN) and NH4(+) (AN) nutrition. Salt stress was simulated by the addition of 150 and 100 mM NaCl to NN (NNS) and AN (ANS) in canola and rice seedlings, respectively. Salt stress induced reductions of shoot and root biomass that were more drastic under ANS. A higher Na(+) content was obtained in NNS than in ANS. The impact of Na(+) on the reduction of biomass (Δbiomass/Na(+)) was 162, 181, 230 and 245% higher in canola root, canola shoot, rice root and rice shoot in ANS than in NNS, respectively. In both canola and rice seedlings, the ratio of leaf Na(+) content in apoplasts to symplasts ([Na(+)]apo/[Na(+)]sym) was higher in NNS than in ANS. Also, in canola seedlings, the ratio of apoplast Na(+) in the leaf edge to the leaf center ([Na(+)]LE/[Na(+)]LC) was 18 times higher in NNS than in ANS. Our results illustrate that the confinement of Na(+) in the canola leaf edge, as well as the restriction of Na(+) in leaf apoplasts of canola and rice seedlings, protect cells from suffering Na(+) stress and contribute to the higher tolerance of NO3(-)-fed plants.

  7. Abiotic stresses affect differently the intron splicing and expression of chloroplast genes in coffee plants (Coffea arabica) and rice (Oryza sativa).

    PubMed

    Nguyen Dinh, Sy; Sai, Than Zaw Tun; Nawaz, Ghazala; Lee, Kwanuk; Kang, Hunseung

    2016-08-20

    Despite the increasing understanding of the regulation of chloroplast gene expression in plants, the importance of intron splicing and processing of chloroplast RNA transcripts under stress conditions is largely unknown. Here, to understand how abiotic stresses affect the intron splicing and expression patterns of chloroplast genes in dicots and monocots, we carried out a comprehensive analysis of the intron splicing and expression patterns of chloroplast genes in the coffee plant (Coffea arabica) as a dicot and rice (Oryza sativa) as a monocot under abiotic stresses, including drought, cold, or combined drought and heat stresses. The photosynthetic activity of both coffee plants and rice seedlings was significantly reduced under all stress conditions tested. Analysis of the transcript levels of chloroplast genes revealed that the splicing of tRNAs and mRNAs in coffee plants and rice seedlings were significantly affected by abiotic stresses. Notably, abiotic stresses affected differently the splicing of chloroplast tRNAs and mRNAs in coffee plants and rice seedlings. The transcript levels of most chloroplast genes were markedly downregulated in both coffee plants and rice seedlings upon stress treatment. Taken together, these results suggest that coffee and rice plants respond to abiotic stresses via regulating the intron splicing and expression of different sets of chloroplast genes.

  8. Effect of external iron and arsenic species on chelant-enhanced iron bioavailability and arsenic uptake in rice (Oryza sativa L.).

    PubMed

    Rahman, M Azizur; Rahman, M Mamunur; Kadohashi, K; Maki, T; Hasegawa, H

    2011-07-01

    This study was conducted to investigate the effect of external iron status and arsenic species on chelant-enhanced iron bioavailability and arsenic uptake. Rice seedlings (Oryza sativa L.) were used as model plant, and were grown in artificially contaminated sandy soils irrigated with Murashige and Skoog (MS) culture solution. Arsenate uptake in roots and shoots of rice seedlings were affected significantly (p>0.05) while dimethylarsinic acid (DMAA) was not by the additional iron and chelating ligand treatments. Regardless of iron concentrations in the soil solution, HIDS increased arsenic uptake for roots more than EDTA and EDDS. Chelating ligands and arsenic species also influenced iron uptake in rice roots. Irrespective of arsenic species, HIDS was found to be more effective in the increase of iron bioavailability and uptake in rice roots compared to other chelants. There was a significant positive correlation (r=0.78, p<0.05) between arsenate and iron concentrations in the roots of rice seedlings grown with or without additional iron indicating that arsenate inhibit iron uptake. In contrast, there was no correlation between iron and DMAA uptake in roots. Poor correlation between iron and arsenic in shoots indicated that iron uptake in shoots was neither affected by additional iron nor by arsenic species. Compared to the control, chelating ligands increased iron uptake in shoots of rice seedlings significantly (p<0.05). Regardless of additional iron and arsenic species, iron uptake in rice shoots did not differed among EDTA, EDDS, and HIDS treatments.

  9. Genetic mapping of agronomic traits in false flax (Camelina sativa subsp. sativa).

    PubMed

    Gehringer, A; Friedt, W; Lühs, W; Snowdon, R J

    2006-12-01

    The crucifer oilseed plant false flax (Camelina sativa subsp. sativa) possesses numerous valuable agronomic attributes that make it attractive as an alternative spring-sown crop for tight crop rotations. The oil of false flax is particularly rich in polyunsaturated C18-fatty acids, making it a valuable renewable feedstock for the oleochemical industry. Because of the minimal interest in the crop throughout the 20th century, breeding efforts have been limited. In this study, a genetic map for C. sativa was constructed, using amplified fragment length polymorphism (AFLP) markers, in a population of recombinant inbred lines that were developed, through single-seed descent, from a cross between 'Lindo' and 'Licalla', 2 phenotypically distinct parental varieties. Three Brassica simple sequence repeat (SSR) markers were also integrated into the map, and 1 of these shows linkage to oil-content loci in both C. sativa and Brassica napus. Fifty-five other SSR primer combinations showed monomorphic amplification products, indicating partial genome homoeology with the Brassica species. Using data from field trials with different fertilization treatments (0 and 80 kg N/ha) at multiple locations over 3 years, the map was used to localize quantitative trait loci (QTLs) for seed yield, oil content, 1000-seed mass, and plant height. Some yield QTLs were found only with the N0 treatment, and might represent loci contributing to the competitiveness of false flax in low-nutrient soils. The results represent a starting point for future marker-assisted breeding.

  10. First Comprehensive Proteome Analyses of Lysine Acetylation and Succinylation in Seedling Leaves of Brachypodium distachyon L.

    PubMed Central

    Zhen, Shoumin; Deng, Xiong; Wang, Jian; Zhu, Gengrui; Cao, Hui; Yuan, Linlin; Yan, Yueming

    2016-01-01

    Protein acetylation and succinylation are the most crucial protein post-translational modifications (PTMs) involved in the regulation of plant growth and development. In this study, we present the first lysine-acetylation and lysine-succinylation proteome analysis of seedling leaves in Brachypodium distachyon L (Bd). Using high accuracy nano LC-MS/MS combined with affinity purification, we identified a total of 636 lysine-acetylated sites in 353 proteins and 605 lysine-succinylated sites in 262 proteins. These proteins participated in many biology processes, with various molecular functions. In particular, 119 proteins and 115 sites were found to be both acetylated and succinylated, simultaneously. Among the 353 acetylated proteins, 148 had acetylation orthologs in Oryza sativa L., Arabidopsis thaliana, Synechocystis sp. PCC 6803, and Glycine max L. Among the 262 succinylated proteins, 170 of them were found to have homologous proteins in Oryza sativa L., Escherichia coli, Sacchayromyces cerevisiae, or Homo sapiens. Motif-X analysis of the acetylated and succinylated sites identified two new acetylated motifs (K---K and K-I-K) and twelve significantly enriched succinylated motifs for the first time, which could serve as possible binding loci for future studies in plants. Our comprehensive dataset provides a promising starting point for further functional analysis of acetylation and succinylation in Bd and other plant species. PMID:27515067

  11. Occurrence of transgenic feral alfalfa (Medicago sativa subsp. sativa L.) in alfalfa seed production areas in the United States

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genetically-engineered glyphosate-resistant alfalfa (Medicago sativa subsp. sativa) was commercialized in 2011. The potential risk of transgene dispersal into the environment is not clearly understood for alfalfa, a perennial crop that is cross-pollinated by insects. We gathered data on feral and tr...

  12. Organ-specific analysis of the anaerobic primary metabolism in rice and wheat seedlings. I: Dark ethanol production is dominated by the shoots.

    PubMed

    Mustroph, Angelika; Boamfa, Elena I; Laarhoven, Lucas J J; Harren, Frans J M; Albrecht, Gerd; Grimm, Bernhard

    2006-12-01

    During anaerobiosis in darkness the main route for ATP production in plants is through glycolysis in combination with fermentation. We compared the organ-specific anaerobic fermentation of flooding-tolerant rice (Oryza sativa) and sensitive wheat (Triticum aestivum) seedlings. A sensitive laser-based photoacoustic trace gas detection system was used to monitor emission of ethanol and acetaldehyde by roots and shoots of intact seedlings. Dark-incubated rice seedlings released 3 times more acetaldehyde and 14 times more ethanol than wheat seedlings during anaerobiosis. Ninety percent of acetaldehyde originated from shoots of both species. In comparison to wheat shoots, the high ethanol production of rice shoots correlated with larger amounts of soluble carbohydrates, and higher activities of fermentative enzymes. After 24 h of anaerobiosis in darkness rice shoots still contained 30% of aerated ATP level, which enabled seedlings to survive this period. In contrast, ATP content declined almost to zero in wheat shoots and roots, which were irreversibly damaged after a 24-h anaerobic period. When plants were anaerobically and dark incubated for 4 h and subsequently transferred back to aeration, shoots showed a transient peak of acetaldehyde release indicating prompt re-oxidation of ethanol. Post-anoxic acetaldehyde production was lower in rice seedlings than in wheat. This observation accounts for a more effective acetaldehyde detoxification system in rice. Compared to wheat the greater tolerance of rice seedlings to transient anaerobic periods is explained by a faster fermentation rate of their shoots allowing a sufficient ATP production and an efficient suppression of toxic acetaldehyde formation in the early re-aeration period.

  13. Transcriptome phase distribution analysis reveals diurnal regulated biological processes and key pathways in rice flag leaves and seedling leaves.

    PubMed

    Xu, Wenying; Yang, Rendong; Li, Meina; Xing, Zhuo; Yang, Wenqiang; Chen, Guang; Guo, Han; Gong, Xiaojie; Du, Zhou; Zhang, Zhenhai; Hu, Xingming; Wang, Dong; Qian, Qian; Wang, Tai; Su, Zhen; Xue, Yongbiao

    2011-03-02

    Plant diurnal oscillation is a 24-hour period based variation. The correlation between diurnal genes and biological pathways was widely revealed by microarray analysis in different species. Rice (Oryza sativa) is the major food staple for about half of the world's population. The rice flag leaf is essential in providing photosynthates to the grain filling. However, there is still no comprehensive view about the diurnal transcriptome for rice leaves. In this study, we applied rice microarray to monitor the rhythmically expressed genes in rice seedling and flag leaves. We developed a new computational analysis approach and identified 6,266 (10.96%) diurnal probe sets in seedling leaves, 13,773 (24.08%) diurnal probe sets in flag leaves. About 65% of overall transcription factors were identified as flag leaf preferred. In seedling leaves, the peak of phase distribution was from 2:00am to 4:00am, whereas in flag leaves, the peak was from 8:00pm to 2:00am. The diurnal phase distribution analysis of gene ontology (GO) and cis-element enrichment indicated that, some important processes were waken by the light, such as photosynthesis and abiotic stimulus, while some genes related to the nuclear and ribosome involved processes were active mostly during the switch time of light to dark. The starch and sucrose metabolism pathway genes also showed diurnal phase. We conducted comparison analysis between Arabidopsis and rice leaf transcriptome throughout the diurnal cycle. In summary, our analysis approach is feasible for relatively unbiased identification of diurnal transcripts, efficiently detecting some special periodic patterns with non-sinusoidal periodic patterns. Compared to the rice flag leaves, the gene transcription levels of seedling leaves were relatively limited to the diurnal rhythm. Our comprehensive microarray analysis of seedling and flag leaves of rice provided an overview of the rice diurnal transcriptome and indicated some diurnal regulated biological

  14. Nigella Sativa reverses osteoporosis in ovariectomized rats

    PubMed Central

    2014-01-01

    Background Osteoporosis poses a significant public health issue. It is a skeletal disorder characterized by compromised bone strength that predisposes to increased risk of fracture. There is a direct relationship between the lack of estrogen after menopause and the development of osteoporosis. About 33% of women over 50 will experience bone fractures as a result of osteoporosis. Nigella Sativa (NS) has been shown to have beneficial effects on bone and joint diseases. The present study was conducted to elucidate the protective effect of Nigella Sativa on osteoporosis produced by ovariectomy in rats. Methods Female Wistar rats aged 12–14 months were divided into three groups: sham-operated control (SHAM), ovariectomized (OVX), and ovariectomized supplemented with nigella sativa (OVX-NS) orally for 12 weeks; 4 weeks before ovariectomy and 8 weeks after. After 12 weeks, plasma levels of calcium (Ca+2), phosphorous (Pi), alkaline phosphatase (ALP), amino terminal collagen type 1 telopeptide, malondialdehyde (MDA), nitrates, nitric oxide surrogate, tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) were measured. Histological examination of the liver and the tibia was conducted. Histomorphometric analysis of the tibia was also performed. Results OVX rats showed significant decrease in plasma Ca+2, accompanied by a significant increase in plasma ALP, amino terminal collagen type 1 telopeptide, MDA, nitrates, TNF-α and IL-6. These changes were reversed by NS supplementation in OVX-NS group to be near SHAM levels. Histological examination of the tibias revealed discontinuous eroded bone trabeculae with widened bone marrow spaces in OVX rats accompanied by a significant decrease in both cortical and trabecular bone thickness compared to Sham rats. These parameters were markedly reversed in OVX-NS rats. Histological examination of the liver showed mononuclear cellular infiltration and congestion of blood vessels at the portal area in OVX rats which were not found

  15. The effects of cadmium on the biochemical and physiological parameters of Eruca sativa.

    PubMed

    Kompe, Yasemin Ozdener; Sagiroglu, Ahmet

    2016-12-01

    In this study, Eruca sativa (Rocket) seedlings were treated with different cadmium (Cd) concentrations (0, 150, 300 and 450 μg ∙ g(-1)). The effects of Cd on lipid peroxidation, enzymatic (APx, CAT, GPX, SOD) and non-enzymatic antioxidants (total ascorbate, dehydroascorbate, ascorbate, non-protein thiol), fresh and dry masses, water content were determined. Also, Cd content of the leaves and the roots were analysed. The highest cadmium accumulation of leaves was at 450 μg ∙ g(-1) Cd treatment and the accumulation was 2.62 times greater than those in the roots. The translocation factor was 3.89 at 300 μg ∙ g(-1) Cd treatment. Cd treatments caused decreases of fresh, dry mass and water content of leaves and roots. Malondialdehyde content, which is an index of lipid peroxidation, was increased in proportion with the increase in Cd. While there was not change in the activity of GPX according to control, a decrease in activities of SOD, CAT and APX were observed with the increase of cadmium concentration. Although a significant increase in the amounts of non-protein thiol groups and proline were observed in 450 μg ∙ g(-1) Cd treated plants, Cd did not lead to a significant change in AsA, DHA and total AsA contents. According to the results of the research, E. sativa may be a Cd hyperaccumulator plant and we suggest that the plant may be a candidate plant for remediation of Cd-contaminated soil.

  16. Seedling Diversity and the Homologies of Seedling Organs in the Order Poales (Monocotyledons)

    PubMed Central

    Tillich, Hans-Jürgen

    2007-01-01

    Background and Aims Seedlings of monocots are much more diverse than those of other angiosperms, often with very derived character states. This makes morphological interpretation difficult. The morphology of seedlings of most of the 16 families of the Poales alliance are only incompletely known. The present study aims first to develop an unambiguous terminology for the description of monocotyledonous seedlings. This makes possible clear morphological comparisons and the use of homologous terms for organs. Finally, plotting of well defined characters onto a molecular tree allows the polarization of character states. Method Seedlings were grown in Petri dishes on moist filter paper under permanent light conditions and analysed using light and scanning electron microscopy. Only seeds collected at natural habitats or from plants with a well documented source were used. Seedling vouchers are deposited in the alcohol collection of Monocot seedlings in the Botanische Staatssammlung München (M). Key Results Based on an unambiguous terminology, seedlings of a great number of genera are described and presented as figures, representing all families of Poales except Ecdeiocoleaceae. Seedlings of Rapateaceae, Joinvilleaceae and Mayacaceae are described for the first time. Morphological comparisons reveal a plausible interpretation of even very modified organ structures, including those of the grass seedling. Conclusions This study demonstrates that detailed studies of seedling morphology can provide interesting morphological insights and also new facts for phylogenetic analyses. However, the morphological diversity of seedlings in the monocots is as yet incompletely known, and in some, e.g. Alismatales or Zingiberales, the seedling structure is particularly poorly understood in terms of comparative morphology. PMID:17933843

  17. Identification and quantification of glucosinolates in sprouts derived from seeds of wild Eruca sativa L. (salad rocket) and Diplotaxis tenuifolia L. (wild rocket) from diverse geographical locations.

    PubMed

    Bennett, Richard N; Carvalho, Rosa; Mellon, Fred A; Eagles, John; Rosa, Eduardo A S

    2007-01-10

    The Brassicaceae rocket species Eruca sativa L. (salad rocket) and Diplotaxis tenuifolia L. (wild rocket) are consumed throughout the world in salads, predominantly the leaves but also the flowers and more recently the sprouts (seedlings). Ontogenic profiling of glucosinolates and flavonoids in plants derived from commercial seed of these species has previously been done, but no studies have been conducted to determine how geographical origin affects glucosinolate composition in rocket species. Seeds from wild E. sativa L. and D. tenuifolia L. from diverse regions of the world were obtained from gene banks and grown under controlled conditions. Sprouts were harvested when they would normally be harvested for consumption, and glucosinolates were extracted and profiled in these accessions. All of the sprouts from Italian E. sativa L. had consistently high total glucosinolate content, with only a few exceptions, and also the highest percentage contents of 4-mercaptobutylglucosinolate. In contrast, sprouts produced from Central and Eastern European seeds had a much higher percentage of 4-methylthiobutylglucosinolate. With a single exception, Tunisia, all sprouts produced from North African seeds had very high 4-methylthiobutylglucosinolate contents. The single sample from China had a high total glucosinolate content and glucosinolate profile that was very similar to the accessions from Uzbekistan and Pakistan. All of the D. tenuifolia L. sprouts had consistently high total glucosinolate contents, and a high percentage of this was 4-mercaptobutylglucosinolate. This glucosinolate variation in levels and profiles of the rockets can be used for genetic studies, selected breeding, and human intervention studies.

  18. Ostryopsis davidiana seedlings inoculated with ectomycorrhizal fungi facilitate formation of mycorrhizae on Pinus tabulaeformis seedlings.

    PubMed

    Bai, Shu-Lan; Li, Guo-Lei; Liu, Yong; Kasten Dumroese, R; Lv, Rui-Heng

    2009-08-01

    Reforestation in China is important for reversing anthropogenic activities that degrade the environment. Pinus tabulaeformis is desired for these activities, but survival and growth of seedlings can be hampered by lack of ectomycorrhizae. When outplanted in association with Ostryopsis davidiana plants on reforestation sites, P. tabulaeformis seedlings become mycorrhizal and survival and growth are enhanced; without O. davidiana, pines often remain without mycorrhizae and performance is poorer. To better understand this relationship, we initiated an experiment using rhizoboxes that restricted root and tested the hypothesis that O. davidiana seedlings facilitated ectomycorrhizae formation on P. tabulaeformis seedlings through hyphal contact. We found that without O. davidiana seedlings, inocula of five indigenous ectomycorrhizal fungi were unable to grow and associate with P. tabulaeformis seedlings. Inocula placed alongside O. davidiana seedlings, however, resulted in enhanced growth and nutritional status of O. davidiana and P. tabulaeformis seedlings, and also altered rhizosphere pH and phosphatase activity. We speculate that these species form a common mycorrhizal network and this association enhances outplanting performance of P. tabulaeformis seedlings used for forest restoration.

  19. N-glycan maturation is crucial for cytokinin-mediated development and cellulose synthesis in Oryza sativa.

    PubMed

    Fanata, Wahyu Indra Duwi; Lee, Kyoung Hwan; Son, Bo Hwa; Yoo, Jae Yong; Harmoko, Rikno; Ko, Ki Seong; Ramasamy, Nirmal Kumar; Kim, Kyung Hwa; Oh, Doo-Byoung; Jung, Hyun Suk; Kim, Jae-Yean; Lee, Sang Yeol; Lee, Kyun Oh

    2013-03-01

    To explore the physiological significance of N-glycan maturation in the plant Golgi apparatus, gnt1, a mutant with loss of N-acetylglucosaminyltransferase I (GnTI) function, was isolated in Oryza sativa. gnt1 exhibited complete inhibition of N-glycan maturation and accumulated high-mannose N-glycans. Phenotypic analyses revealed that gnt1 shows defective post-seedling development and incomplete cell wall biosynthesis, leading to symptoms such as failure in tiller formation, brittle leaves, reduced cell wall thickness, and decreased cellulose content. The developmental defects of gnt1 ultimately resulted in early lethality without transition to the reproductive stage. However, callus induced from gnt1 seeds could be maintained for periods, although it exhibited a low proliferation rate, small size, and hypersensitivity to salt stress. Shoot regeneration and dark-induced leaf senescence assays indicated that the loss of GnTI function results in reduced sensitivity to cytokinin in rice. Reduced expression of A-type O. sativa response regulators that are rapidly induced by cytokinins in gnt1 confirmed that cytokinin signaling is impaired in the mutant. These results strongly support the proposed involvement of N-glycan maturation in transport as well as in the function of membrane proteins that are synthesized via the endomembrane system.

  20. Anticancer activity of Nigella sativa (black seed) - a review.

    PubMed

    Randhawa, Mohammad Akram; Alghamdi, Mastour Safar

    2011-01-01

    Nigella sativa (N. sativa) seed has been an important nutritional flavoring agent and natural remedy for many ailments for centuries in ancient systems of medicine, e.g. Unani, Ayurveda, Chinese and Arabic Medicines. Many active components have been isolated from N. sativa, including thymoquinone, thymohydroquinone, dithymoquinone, thymol, carvacrol, nigellimine-N-oxide, nigellicine, nigellidine and alpha-hederin. In addition, quite a few pharmacological effects of N. sativa seed, its oil, various extracts and active components have been identified to include immune stimulation, anti-inflammation, hypoglycemic, antihypertensive, antiasthmatic, antimicrobial, antiparasitic, antioxidant and anticancer effects. Only a few authors have reviewed the medicinal properties of N. sativa and given some description of the anticancer effects. A literature search has revealed that a lot more studies have been recently carried out related to the anticancer activities of N. sativa and some of its active compounds, such as thymoquinone and alpha-hederin. Acute and chronic toxicity studies have recently confirmed the safety of N. sativa oil and its most abundant active component, thymoquinone, particularly when given orally. The present work is aimed at summarizing the extremely valuable work done by various investigators on the effects of N. sativa seed, its extracts and active principles against cancer. Those related to the underlying mechanism of action, derivatives of thymoquinone, nano thymoquinone and combinations of thymoquinone with the currently used cytotoxic drugs are of particular interest. We hope this review will encourage interested researchers to conduct further preclinical and clinical studies to evaluate the anticancer activities of N. sativa, its active constituents and their derivatives.

  1. Bioremediation of reject water from anaerobically digested waste water sludge with macroalgae (Ulva lactuca, Chlorophyta).

    PubMed

    Sode, Sidsel; Bruhn, Annette; Balsby, Thorsten J S; Larsen, Martin Mørk; Gotfredsen, Annemarie; Rasmussen, Michael Bo

    2013-10-01

    Phosphorus and biologically active nitrogen are valuable nutrient resources. Bioremediation with macroalgae is a potential means for recovering nutrients from waste streams. In this study, reject water from anaerobically digested sewage sludge was successfully tested as nutrient source for cultivation of the green macroalgae Ulva lactuca. Maximal growth rates of 54.57±2.16% FW d(-1) were achieved at reject water concentrations equivalent to 50 μM NH4(+). Based on the results, the growth and nutrient removal was parameterised as function of NH4(+) concentration a tool for optimisation of any similar phycoremediation system. Maximal nutrient removal rates of 22.7 mg N g DW(-1) d(-1) and 2.7 mg P g DW(-1) d(-1) were achieved at reject water concentrations equivalent to 80 and 89 μM NH4(+), respectively. A combined and integrated use of the produced biomass in a biorefinery is thought to improve the feasibility of using Ulva for bioremediation of reject water.

  2. Structure and cytotoxic activity of ulvan extracted from green seaweed Ulva lactuca.

    PubMed

    Thanh, Thi Thu Thuy; Quach, Thi Minh Thu; Nguyen, Thi Nu; Vu Luong, Dang; Bui, Minh Ly; Tran, Thi Thanh Van

    2016-12-01

    The structure of an ulvan obtained by water extraction from green seaweed Ulva lactuca was elucidated by using IR, NMR, SEC-MALL and ESIMS methods. The ulvan was also evaluated for its cytotoxic effects on three human cancer cell lines. The results showed that the ulvan was composed of rhamnose, galactose, xylose, manose, glucose (with a mole ratio of Rha: Gal: Xyl: Man: Glu equal to 1: 0.03: 0.07: 0.01: 0.06), uronic acid (21.5%) and sulfate content (18.9%) with a molecular weight of 347000. This ulvan mainly consists of disaccharide [→4)-β-d-GlcA-(1→4)-α-l-Rha3S-(1→] and other minor disaccharide β-GlcA-(1→2)-α-Xyl and β-GlcA-(→2)-α-Rha. The ulvan showed a significant cytotoxic activity against hepatocellular carcinoma (IC50 29.67±2.87μg/ml), human breast cancer (IC50 25.09±1.36μg/ml), and cervical cancer (IC50 36.33±3.84μg/ml).

  3. Isolation, biochemical characterization and antibiofilm effect of a lectin from the marine sponge Aplysina lactuca.

    PubMed

    Carneiro, Rômulo Farias; Lima, Paulo Henrique Pinheiro de; Chaves, Renata Pinheiro; Pereira, Rafael; Pereira, Anna Luísa; de Vasconcelos, Mayron Alves; Pinheiro, Ulisses; Teixeira, Edson Holanda; Nagano, Celso Shiniti; Sampaio, Alexandre Holanda

    2017-06-01

    A new lectin was isolated from the marine sponge Aplysina lactuca (ALL) by combining ammonium sulfate precipitation and affinity chromatography on guar gum matrix. ALL showed affinity for the disaccharides α-lactose, β-lactose and lactulose (Ka=12.5, 31.9 and 145.5M(-1), respectively), as well as the glycoprotein porcine stomach mucin. Its hemagglutinating activity was stable in neutral acid pH values and temperatures below 60°C. ALL is a dimeric protein formed by two covalently linked polypeptide chains. The average molecular mass, as determined by Electrospray Ionization Mass Spectrometry (ESI-MS), was 31,810±2Da. ESI-MS data also indicated the presence of three cysteines involved in one intrachain and one interchain disulfide bond. The partial amino acid sequence of ALL was determined by tandem mass spectrometry. Eight tryptic peptides presented similarity with lectin I isolated from Axinella polypoides. Its secondary structure is predominantly β-sheet, as indicated by circular dichroism (CD) spectroscopy. ALL agglutinated gram-positive and gram-negative bacterial cells, and it were able to significantly reduce the biomass of the bacterial biofilm tested at dose- dependent effect.

  4. Effect of the interaction between light and touch stimuli on inducing curling seminal roots in rice seedlings

    PubMed Central

    Kang, Chia-Hao; Chen, Hsiang-Wen

    2011-01-01

    Root development is sensitive to environmental stimuli. We have recently reported that the light signal could promote the helical growth of seminal roots and drive the wavy root morphology in rice (Oryza sativa L.) young seedlings. The light-stimulated wavy roots were mostly performed in indica-type rice varieties (e.g., Taichung Native 1; TCN1) but not in japonica rice (e.g., Tainung 67; TNG67). Here, we demonstrated that the light-driven circumutation trajectory of TCN1 seminal roots could be changed if the seedling roots were grown in the medium containing high concentration of Phytagel. The data showed the root morphology would be modulated from wavy to curling when the Phytagel concentration was increased to 2%. However, the touch-stimulated curling root phenotype could not be performed in dark. In addition, the touch-induced curling roots were not appeared in the TNG67 rice cultivar. Although touch stimuli could not induce wavy/curling root phenotype in dark, it could modify the light-promoted helical growth to conduct curling roots in TCN1 rice seedlings. Thus, it was suggested that there is a crosstalk mechanism between touching-induced root curling and light-stimulated root waving. PMID:21912213

  5. Mutation of the rice ASL2 gene encoding plastid ribosomal protein L21 causes chloroplast developmental defects and seedling death.

    PubMed

    Lin, D; Jiang, Q; Zheng, K; Chen, S; Zhou, H; Gong, X; Xu, J; Teng, S; Dong, Y

    2015-05-01

    The plastid ribosome proteins (PRPs) play important roles in plastid protein biosynthesis, chloroplast differentiation and early chloroplast development. However, the specialised functions of individual protein components of the chloroplast ribosome in rice (Oryza sativa) remain unresolved. In this paper, we identified a novel rice PRP mutant named asl2 (Albino seedling lethality 2) exhibiting an albino, seedling death phenotype. In asl2 mutants, the alteration of leaf colour was associated with chlorophyll (Chl) content and abnormal chloroplast development. Through map-based cloning and complementation, the mutated ASL2 gene was isolated and found to encode the chloroplast 50S ribosome protein L21 (RPL21c), a component of the chloroplast ribosome large subunit, which was localised in chloroplasts. ASL2 was expressed at a higher level in the plumule and leaves, implying its tissue-specific expression. Additionally, the expression of ASL2 was regulated by light. The transcript levels of the majority of genes for Chl biosynthesis, photosynthesis and chloroplast development were strongly affected in asl2 mutants. Collectively, the absence of functional ASL2 caused chloroplast developmental defects and seedling death. This report establishes the important role of RPL21c in chloroplast development in rice.

  6. Effects of low temperature on photosynthetic characteristics in the super-high-yield hybrid rice 'Liangyoupeijiu' at the seedling stage.

    PubMed

    Shi, D W; Wei, X D; Chen, G X

    2016-12-02

    To elucidate the resistance of high-yield hybrid rice (Oryza sativa L.) at the seedling stage to low temperature, photosynthetic characteristics, such as membrane lipid peroxidation, fatty acid composition, and chloroplast ultrastructure, were investigated in a newly developed super-hybrid rice ('Liangyoupeijiu') and a traditional chill-sensitive hybrid rice ('Shanyou63'), with 20°C as the control condition and 10°C as the low temperature treatment. Chlorophyll content, oxygen consumption by photosystem I, and oxygen production by photosystem II in the thylakoid membrane mainly decreased under the low-temperature treatment. The malondialdehyde content of 'Liangyoupeijiu' decreased slightly, while increases in membrane lipid peroxidation were greater in 10°C-treated than in 25°C-treated 'Shanyou63' seedlings. The index of unsaturated fatty acids increased in the two cultivars, particularly in 'Liangyoupeijiu'. No severe chloroplast ultrastructure damage was observed under cold stress, but the number of osmiophilic granules in 'Shanyou63' increased rapidly. The results indicate that compared to 'Shanyou63', 'Liangyoupeijiu' is more chill-resistant at the seedling stage.

  7. QTLs for Resistance to Major Rice Diseases Exacerbated by Global Warming: Brown Spot, Bacterial Seedling Rot, and Bacterial Grain Rot.

    PubMed

    Mizobuchi, Ritsuko; Fukuoka, Shuichi; Tsushima, Seiya; Yano, Masahiro; Sato, Hiroyuki

    2016-12-01

    In rice (Oryza sativa L.), damage from diseases such as brown spot, caused by Bipolaris oryzae, and bacterial seedling rot and bacterial grain rot, caused by Burkholderia glumae, has increased under global warming because the optimal temperature ranges for growth of these pathogens are relatively high (around 30 °C). Therefore, the need for cultivars carrying genes for resistance to these diseases is increasing to ensure sustainable rice production. In contrast to the situation for other important rice diseases such as blast and bacterial blight, no genes for complete resistance to brown spot, bacterial seedling rot or bacterial grain rot have yet been discovered. Thus, rice breeders have to use partial resistance, which is largely influenced by environmental conditions. Recent progress in molecular genetics and improvement of evaluation methods for disease resistance have facilitated detection of quantitative trait loci (QTLs) associated with resistance. In this review, we summarize the results of worldwide screening for cultivars with resistance to brown spot, bacterial seedling rot and bacterial grain rot and we discuss the identification of QTLs conferring resistance to these diseases in order to provide useful information for rice breeding programs.

  8. Modification of yield and chlorophyll content in leaf lettuce by HPS radiation and nitrogen treatments

    NASA Technical Reports Server (NTRS)

    Mitchell, Cary A.; Leakakos, Tina; Ford, Tameria L.

    1991-01-01

    The potential of realizing high photosynthetic photon flux from radiation by high-pressure sodium (HPS) lamp, alone or in combination with metal halide (MH) plus quartz iodide (QI) incandescent lamps, to support lettuce grow, with or without nitrogen supplement, was investigated. It was found that varying exposures to radiation from combined HPS, MH, and QI lamps influenced dry weight gain and photosynthetic pigment content of hydroponically grown lettuce (Lactuca sativa L.) seedlings.

  9. Cross-amplification of Vicia sativa subsp. sativa microsatellites across 22 other Vicia species.

    PubMed

    Raveendar, Sebastin; Lee, Gi-An; Jeon, Young-Ah; Lee, Yun Jeong; Lee, Jung-Ro; Cho, Gyu-Taek; Cho, Joon-Hyeong; Park, Jong-Hyun; Ma, Kyung-Ho; Chung, Jong-Wook

    2015-01-16

    The temperate and herbaceous genus Vicia L. is a member of the legume tribe Fabeae of the subfamily Papilionoideae. The genus Vicia comprises 166 annual or perennial species distributed mainly in Europe, Asia, and North America, but also extending to the temperate regions of South America and tropical Africa. The use of simple sequence repeat (SSR) markers for Vicia species has not been investigated as extensively as for other crop species. In this study, we assessed the potential for cross-species amplification of cDNA microsatellite markers developed from common vetch (Vicia sativa subsp. sativa). For cross-species amplification of the SSRs, amplification was carried out with genomic DNA isolated from two to eight accessions of 22 different Vicia species. For individual species or subspecies, the transferability rates ranged from 33% for V. ervilia to 82% for V. sativa subsp. nigra with an average rate of 52.0%. Because the rate of successful SSR marker amplification generally correlates with genetic distance, these SSR markers are potentially useful for analyzing genetic relationships between or within Vicia species.

  10. Cannflavin A and B, prenylated flavones from Cannabis sativa L.

    PubMed

    Barrett, M L; Scutt, A M; Evans, F J

    1986-04-15

    Two novel prenylated flavones, termed Cannflavin A and B, were isolated from the cannabinoid free ethanolic extract of Cannabis sativa L. Both compounds inhibited prostaglandin E2 production by human rheumatoid synovial cells in culture.

  11. [Quality standard of uygur medicine Medicago sativa seeds].

    PubMed

    Ding, Wen-Huan; Xu, Hai-Yan; Wang, Dong-Dong; Li, Jie; Tian, Shu-Ge

    2013-11-01

    In this paper, microscopic identification method was adopted to observe the microscopic characters of ten batches of Medicago sativa seeds. And M. sativa seeds were identificated by TLC method in contrast to trigonelline and stachydrine hydrochloride. The impurities, moisture, ash, sour insoluble ash were detected based on Chinese Pharmacopoeia 2010 version (Vol I ). An HPLC method was also established for determination of trigonelline in the M. sativa seeds. The contents of impurities, moisture, ash, sour insoluble ash should not exceed 5%, 10%, 6%, and 2%, respectively. The content of trigonelline should be not less than 0.795 6 mg x g(-1). The experimental methods were accurate and reliable, and can be used as the quality control of the seeds of M. sativa.

  12. Clinorotation affects soybean seedling morphology.

    PubMed

    Hilaire, E; Guikema, J A; Brown, C S

    1995-01-01

    Although spaceflight does not appear to significantly affect seed germination, it can influence subsequent plant growth. On STS-3 and SL-2, decreased growth (measured as plant length, fresh weight and dry weight) was noted for pine, oat and mung bean. In the CHROMEX-01 and -02 experiments with Haplopappus and in the CHROMEX-03 experiment with Arabidopsis, enhanced root growth was noted in the space-grown plants. In the CHROMEX-04 experiment with wheat, both leaf fresh weight and leaf area were diminished in the space-grown plants but there was no difference in total plant height (CS Brown, HG Levine, and AD Krikorian, unpublished data). These data suggest that microgravity impacts growth by whole plant partitioning of assimilates. The objective of the present study was to determine the influence of clinorotation on the growth and morphology of soybean seedlings grown in the BRIC (Biological Research In Canister) flight hardware. This experiment provided baseline data for a spaceflight experiment (BRIC-03) flown on STS-63 (Feb. 3-11, 1995).

  13. Clinorotation affects soybean seedling morphology

    NASA Technical Reports Server (NTRS)

    Hilaire, Emmanuel; Guikema, James A.; Brown, Christopher S.

    1995-01-01

    Although spaceflight does not appear to significantly affect seed germination, it can influence subsequent plant growth. On STS-3 and SL-2, decreased growth (measured as plant length, fresh weight, and dry weight) was noted for pine, oat, and mung bean. In the CHROMEX-01 and 02 experiments with Haplopappus and in the CHROMEX-03 experiment with Arabidopsis, enhanced root growth was noted in the space-grown plants. In the CHROMEX-04 experiments with wheat, both leaf fresh weight and leaf area were diminished in the space-grown plants but there was no difference in total plant height (CS Brown, HG Levine, and AD Krikorian, unpublished data). These data suggest that microgravity impacts growth by whole plant partitioning of the assimilates. The objective of the present study was to determine the influence of clinorotation on the growth and the morphology of soybean seedlings grown in the Biological Research In Canister (BRIC) flight hardware. This experiment provided baseline data for a spaceflight experiment (BRIC-3) flown on STS-63 (February 3-11, 1995).

  14. Improving Pharmaceutical Protein Production in Oryza sativa

    PubMed Central

    Kuo, Yu-Chieh; Tan, Chia-Chun; Ku, Jung-Ting; Hsu, Wei-Cho; Su, Sung-Chieh; Lu, Chung-An; Huang, Li-Fen

    2013-01-01

    Application of plant expression systems in the production of recombinant proteins has several advantages, such as low maintenance cost, absence of human pathogens, and possession of complex post-translational glycosylation capabilities. Plants have been successfully used to produce recombinant cytokines, vaccines, antibodies, and other proteins, and rice (Oryza sativa) is a potential plant used as recombinant protein expression system. After successful transformation, transgenic rice cells can be either regenerated into whole plants or grown as cell cultures that can be upscaled into bioreactors. This review summarizes recent advances in the production of different recombinant protein produced in rice and describes their production methods as well as methods to improve protein yield and quality. Glycosylation and its impact in plant development and protein production are discussed, and several methods of improving yield and quality that have not been incorporated in rice expression systems are also proposed. Finally, different bioreactor options are explored and their advantages are analyzed. PMID:23615467

  15. Chemoprevention of Diethylnitrosamine-Initiated and Phenobarbital-Promoted Hepatocarcinogenesis in Rats by Sulfated Polysaccharides and Aqueous Extract of Ulva lactuca.

    PubMed

    Hussein, Usama K; Mahmoud, Hamada M; Farrag, Asmaa G; Bishayee, Anupam

    2015-11-01

    Hepatocellular carcinoma (HCC) is one of the common cancers and lethal diseases worldwide. Both oxidative stress and chronic inflammation contribute to the pathogenesis of HCC. Because of limited treatment options and a grave prognosis of HCC, preventive management has been emphasized. The marine macroalgae Ulva lactuca (Ulvaceae) is consumed by humans and livestock because of its nutritional value. Recent studies showed that various extracts of U. lactuca possess antiviral, antiplasmodial, antinephrotoxic, antioxidant, and anti-inflammatory properties. However, very limited information is available on anticancer potential of U. lactuca with no reports on liver cancer chemopreventive efficacy of this marine algae. Accordingly, the present study was initiated to evaluate the possible antihepatocarcinogenic effects and antioxidant mechanisms of action of various U. lactuca extracts against a clinically relevant rodent model of HCC. Initiation of hepatocarcinogenesis was performed in Sprague-Dawley rats by a single injection of dietary carcinogen diethylnitrosamine (DENA, 200 mg/kg, intraperitoneally), followed by promotion with phenobarbital (0.05%) in drinking water. The rats were fed with daily oral dose (50 mg/kg) of polysaccharide sulfate or aqueous extract of U. lactuca for 2, 12, and 24 weeks. At these timepoints, blood samples were taken to measure hepatic injury markers, including alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, γ-glutamyl transferase, and bilirubin. The liver tissue was harvested for measurement of hepatic oxidative indices, including lipid peroxidation, reduced glutathione, nitric oxide, catalase, superoxide dismutase, glutathione reductase, and glutathione S-transferase. Hepatic histopathology, immunohistochemical analysis of cell proliferation and apoptosis by DNA fragmentation assay were performed. Our results clearly indicate that sulfated polysaccharides of U. lactuca exert a marked chemoprevention of DENA

  16. Genetically improved ponderosa pine seedlings outgrow nursery-run seedlings with and without competition -- Early findings

    SciTech Connect

    McDonald, P.M.; Fiddler, G.O. ); Kitzmiller, J.H. . Chico Tree Improvement Center)

    1994-04-01

    Three classes of ponderosa pine (Pinus ponderosa) seedlings (nursery-run, wind-pollinated, control-pollinated) were evaluated for stem height and diameter at the USDA Forest Service's Placerville Nursery and the Georgetown Range District in northern California. Pines in all three classes were grown with competing vegetation or maintained in a free-to-grow condition. Control-pollinated seedlings were statistically taller than nursery-run counterparts when outplanted, and after 1 and 2 growing seasons in the field with and without competition. They also had significantly larger diameters when outplanted and after 2 growing seasons in the field when free to grow. Wind-pollinated seedlings grew taller than nursery-run seedlings when free to grow. A large amount of competing vegetation [bearclover (Chamaebatia foliolosa)--29,490 plants per acre; herbaceous vegetation--11,500; hardwood sprouts--233; and whiteleaf manzanita (Arctostaphylos viscida) seedlings--100] ensure that future pine development will be tested rigorously.

  17. Pharmacological and toxicological properties of Nigella sativa.

    PubMed

    Ali, B H; Blunden, Gerald

    2003-04-01

    The seeds of Nigella sativa Linn. (Ranunculaceae), commonly known as black seed or black cumin, are used in folk (herbal) medicine all over the world for the treatment and prevention of a number of diseases and conditions that include asthma, diarrhoea and dyslipidaemia. This article reviews the main reports of the pharmacological and toxicological properties of N. sativa and its constituents. The seeds contain both fixed and essential oils, proteins, alkaloids and saponin. Much of the biological activity of the seeds has been shown to be due to thymoquinone, the major component of the essential oil, but which is also present in the fi ed oil. The pharmacological actions of the crude extracts of the seeds (and some of its active constituents, e.g. volatile oil and thymoquinone) that have been reported include protection against nephrotoxicity and hepatotoxicity induced by either disease or chemicals. The seeds/oil have antiinflammatory, analgesic, antipyretic, antimicrobial and antineoplastic activity. The oil decreases blood pressure and increases respiration. Treatment of rats with the seed extract for up to 12 weeks has been reported to induce changes in the haemogram that include an increase in both the packed cell volume (PCV) and haemoglobin (Hb), and a decrease in plasma concentrations of cholesterol, triglycerides and glucose. The seeds are characterized by a very low degree of toxicity. Two cases of contact dermatitis in two individuals have been reported following topical use. Administration of either the seed extract or its oil has been shown not to induce significant adverse effects on liver or kidney functions. It would appear that the beneficial effects of the use of the seeds and thymoquinone might be related to their cytoprotective and antioxidant actions, and to their effect on some mediators of inflammation.

  18. Influence of plant-parasitic nematodes on longleaf pine seedlings.

    PubMed

    Ruehle, J L

    1973-01-01

    Seedlings of longleaf pine (Pinus palustris) were grown in 20-cm pots for 5 to 7 months in the greenhouse following inoculation with a high or low level of one of seven species of plant-parasitic nematodes. Belonolaimus longicaudatus and Helicotylenchus dihystera had no effect on seedling growth. High inoculum densities of Hoplolaimus galeatus and Tylenchorhynchus claytoni caused a significant reduction of fresh weight of seedling roots. Root and top weights of seedlings grown in soil infested with Meloidodera floridensis or Pratylenchus brachyurus were significantly less than those of seedlings in noninfested soil. Root growth of seedlings was stimulated by the higher inoculum density of Scutellonema brachyurum.

  19. Isolation, structure, and surfactant properties of polysaccharides from Ulva lactuca L. from South China Sea.

    PubMed

    Tian, Hua; Yin, Xueqiong; Zeng, Qinghuan; Zhu, Li; Chen, Junhua

    2015-08-01

    Two polysaccharides (ULP1 and ULP2) were isolated through ultrasonic-assisted extraction from green seaweed Ulva lactuca L. which was collected from the South China Sea. The highest yield of 17.57% was obtained under the conditions of 2% NaOH, 90 °C, material/water mass ratio 1:80, liquid extraction 5h and subsequent ultrasound-assisted extraction 1h. The structure of ULPs were characterized with periodate oxidation followed by Smith degradation, (1)H NMR, (13)C NMR spectroscopy, FTIR, and GPC. The molecular weights of ULP1 and ULP2 were 189 kDa and 230 kDa, respectively. The structural characteristics of ULP1 and ULP2 were quite similar. They were composed of rhamnose, xylose, glucose, and glucuronic acid. The content of rhamnose, xylose, glucose, glucuronic acid, sulfate was 51.2%, 12.3%, 20.1%, 16.4%, 12.0% for ULP1, respectively, and 60.8%, 14.2%, 8.2%, 16.8%, 26.8%, respectively, for ULP2. Both ULP1 and ULP2 showed good surface activity. 5 mg/mL ULP1 (2.62×10(-2) mmol/L) decreased the water surface tension to 51.63 mN/m. The critical micellar concentration of ULP1 and ULP2 was 1.01 mg/mL (5.3×10(-3) mmol/L) and 1.14 mg/mL (5.0×10(-3) mmol/L), respectively.

  20. Red and blue lights induced oxidative stress tolerance promote cadmium rhizocomplexation in Oryza sativa.

    PubMed

    Sebastian, Abin; Prasad, M N V

    2014-08-01

    Cadmium (Cd) accumulation and related stress responses have been investigated in red, blue and white lights exposed Oryza sativa L. cv MTU 7029. Cd translocation was reduced significantly by red and blue lights. Increase in amount of organic acids, thiols, and nutrients in the roots that cause Cd rhizocomplexation was the reason for reduction in Cd translocation. These effects were due to higher efficiency to perform photosynthesis and transpiration under red or blue lights compare with white light during Cd stress. Increased photosynthetic assimilate turnover was witnessed as a function of sugar content. Amount of redox regulators such as glutathione and ascorbate were also increased under red and blue light exposure. Together with up regulation of antioxidant enzyme activities, these metabolites ensured redox balance in presence of reactive oxygen species produced due to Cd toxicity. Protection of photosynthesis from Cd inducible oxidative stress ensured supplies of sugar intermediates essential for the synthesis of metal chelators in roots. Therefore, it was inferred that red and blue lights promote Cd rhizocomplexation and ameliorated Cd stress in rice seedlings.

  1. Nitrogen Fixation, Nodule Development, and Vegetative Regrowth of Alfalfa (Medicago sativa L.) following Harvest 1

    PubMed Central

    Vance, Carroll P.; Heichel, Gary H.; Barnes, Donald K.; Bryan, Jeff W.; Johnson, Lois E.

    1979-01-01

    Nitrogenase-dependent acetylene reduction, nodule function, and nodule regrowth were studied during vegetative regrowth of harvested (detopped) alfalfa (Medicago sativa L.) seedlings grown in the glasshouse. Compared with controls, harvesting caused an 88% decline in acetylene reduction capacity of detached root systems within 24 hours. Acetylene reduction in harvested plants remained low for 13 days, then increased to a level comparable to the controls by day 18. Protease activity increased in nodules from harvested plants, reached a maximum at day 7 after harvest, and then declined to a level almost equal to the control by day 22 after harvest. Soluble protein and leghemoglobin decreased in nodules from harvested plants in an inverse relationship to protease activity. Nitrate reductase activity of nodules from harvested plants increased significantly within 24 hours and was inversely associated with acetylene reduction. The difference in nitrate reductase between nodules from harvested plants and control plants became less evident as shoot regrowth occurred and as acetylene reduction increased in the harvested plants. No massive loss of nodules occurred after harvest as evidenced by little net change in nodule fresh weight. There was, however, a rapid localized senescence which occurred in nodules of harvested plants. Histology of nodules from harvested plants showed that they degenerated at the proximal end after harvest. Starch in the nodule was depleted by 10 days after harvest. The meristem and vascular bundles of nodules from harvested plants remained intact. The senescent nodules began to regrow and fix nitrogen after shoot growth resumed. Images PMID:16660893

  2. Genes for iron-sulphur cluster assembly are targets of abiotic stress in rice, Oryza sativa.

    PubMed

    Liang, Xuejiao; Qin, Lu; Liu, Peiwei; Wang, Meihuan; Ye, Hong

    2014-03-01

    Iron-sulphur (Fe-S) cluster assembly occurs in chloroplasts, mitochondria and cytosol, involving dozens of genes in higher plants. In this study, we have identified 41 putative Fe-S cluster assembly genes in rice (Oryza sativa) genome, and the expression of all genes was verified. To investigate the role of Fe-S cluster assembly as a metabolic pathway, we applied abiotic stresses to rice seedlings and analysed Fe-S cluster assembly gene expression by qRT-PCR. Our data showed that genes for Fe-S cluster assembly in chloroplasts of leaves are particularly sensitive to heavy metal treatments, and that Fe-S cluster assembly genes in roots were up-regulated in response to iron toxicity, oxidative stress and some heavy metal assault. The effect of each stress treatment on the Fe-S cluster assembly machinery demonstrated an unexpected tissue or organelle specificity, suggesting that the physiological relevance of the Fe-S cluster assembly is more complex than thought. Furthermore, our results may reveal potential candidate genes for molecular breeding of rice.

  3. Enhanced salt tolerance of alfalfa (Medicago sativa) by rstB gene transformation.

    PubMed

    Zhang, Wan-Jun; Wang, Tao

    2015-05-01

    Generating salt tolerance forage plant is essential for use of the land affected by high salinity. A salt tolerance gene rstB was used as a selectable marker gene in Agrobacterium-mediated transformation of tobacco under a selective regime of 170mM NaCl. The transgenic plants showed clear improvement in salt tolerance. To improve salt tolerance of alfalfa (Medicago sativa L.), rstB gene was introduced into alfalfa genome by Agrobacterium-mediated transformation. No abnormal phenotype was observed among the transgenic plants when compared with wild type (wt) plants. Significant enhancement of resistance to salt-shock treatment was noted on the rstB transgenic (T0) plants. Transgenic second-generation (T1) seeds showed improved germination rate and seedling growth under salt-stress condition. Hindered Na(+) accumulation, but enhanced Ca(2+) accumulation was observed on the rstB T1 plants when subjected to salt-stresses. Enhanced calcium accumulation in transgenic plants was also verified by cytohistochemical localization of calcium. Under salt-stress of 50mM NaCl, about 15% of the transgenic plants finished their life-cycle but the wt plants had no flower formation. The results demonstrated that the expression of rstB gene improved salt tolerance in transgenic alfalfa.

  4. Anaerobic metabolism in Brassica seedlings

    NASA Astrophysics Data System (ADS)

    Park, Myoung-Ryoul; Hasenstein, Karl H.

    Germination typically depends on oxidative respiration. The lack of convection under space conditions may create hypoxic or conditions during seed germination. We investigated the effect of reduced oxygen on seed germination and metabolism to understand how metabolic constraints affect seed growth and responsiveness to reorientation. Germination was completely inhibited when seeds were imbibed in the absence of oxygen; germination occurred at 5% oxygen and higher levels. Adding oxygen after 72 h resulted in immediate germination (protrusion of the radicle). Hypoxia typically activates alcohol dehydrogenase (ADH, EC 1.1.1.1) and lactate dehydrogenase (LDH, EC 1.1.1.27) which produce ethanol and/or L-lactate, respectively. We report on the expression of ADH1 and LDH1, and changes in total soluble sugars, starch, pH, and L-lactate in seedlings grown at 28°C in 0, 2.5, 5, 10% and ambient (21%) oxygen conditions as controls. The highest consumption (lowest level) of sugars was seen at 0% oxygen but the lowest level of starch occurred 24 h after imbibition under ambient condition. Expression levels of ADH1 in ambient oxygen condition increased within 24 h but increased threefold under hypoxic conditions; LDH1 increased up to 8-fold under hypoxia compared to controls but ADH1 and LDH1 were less expressed as the oxygen levels increased. The intracellular pH of seeds decreased as the content of L-lactate increased for all oxygen concentrations. These results indicate that germination of Brassica is sensitive to oxygen levels and that oxygen availability during germination is an important factor for metabolic activities. (Supported by NASA grant NNX10AP91G)

  5. Seedling growth and development on space shuttle

    NASA Technical Reports Server (NTRS)

    Cowles, J.; Lemay, R.; Jahns, G.

    1994-01-01

    Young pine seedlings, and mung bean and oat seeds were flown on shuttle flights, STS-3 and STS-51F, in March, 1982 and July/August, 1985, respectively. The plant growth units built to support the two experiments functioned mechanically as anticipated and provided the necessary support data. Pine seedlings exposed to the microgravity environment of the space shuttle for 8 days continued to grow at a rate similar to ground controls. Pine stems in flight seedlings, however, averaged 10 to 12% less lignin than controls. Flight mung beans grew slower than control beans and their stems contained about 25% less lignin than control seedlings. Reduced mung bean growth in microgravity was partly due to slower germination rate. Lignin also was reduced in flight oats as compared to controls. Oats and mung beans exhibited upward growing roots which were not observed in control seedlings. Chlorophyll A/B ratios were lower in flight tissues than controls. The sealed PGCs exhibited large variations in atmospheric gas composition but the changes were similar between flight and ground controls. Ethylene was present in low concentrations in all chambers.

  6. Ecology and pathology of European chestnut (Castanea sativa) in the deciduous forests of the Caucasus Mountains in southern Russia

    USGS Publications Warehouse

    Pridnya, M.V.; Cherpakov, V.V.; Paillet, Frederick L.

    1996-01-01

    Chestnut-dominated forests of the Caucasus Mountain area of Russia are very similar to former chestnut-dominated forests in eastern North America. The distribution, pathology, and reproductive status of European chestnut (Castanea sativa) in the Caucasus are described and compared to that of American chestnut (C. dentata). Chestnut forests are distributed continuously along the southern slope of the Caucasus mountains near the Black Sea, and are found in isolated populations on the north side of the Caucasus, at elevations ranging from 200 to 1300 meters. Chestnut blight was apparently introduced into the region after 1880 and continues to destroy chestnut forests today. Chestnut in the Caucasus is also infected by several other fungal and bacterial parasites and the joint infection of blight and bacteria may be especially dangerous for chestnut trees. Chestnut-dominated forests comprise only a few percent of total forest cover in the Caucasus Biosphere Preserve, and usually occur in mountain valleys or coves with deep brown soil. The age structure and reproductive status of chestnut in the Caucasus was investigated on six study plots in the Caucasus Biosphere Forest Preserve near the upper altitudinal limit of chestnut. Although chestnut is at least 70 percent of the overstory on these sites, there are very few trees less than 50 years old, and very few recent seedlings on any of the plots. Most large chestnut trees appear to have originated as basal spouts from previously established stems. Although chestnut seed production appears adequate, we suspect that competition with shrubs and other tree seedlings, and predation by herbivores and rodents, now prevent the establishment and survival of chestnut seedlings in the Biosphere Preserve.

  7. Heterosis in rice seedlings: its relationship to gibberellin content and expression of gibberellin metabolism and signaling genes.

    PubMed

    Ma, Qian; Hedden, Peter; Zhang, Qifa

    2011-08-01

    Despite the accumulation of data on the genetic and molecular understanding of heterosis, there is little information on the regulation of heterosis at the physiological level. In this study, we performed a quantitative analysis of endogenous gibberellin (GA) content and expression profiling of the GA metabolism and signaling genes to investigate the possible relationship between GA signaling and heterosis for seedling development in rice (Oryza sativa). The materials used were an incomplete diallele set of 3 × 3 crosses and the six parents. In the growing shoots of the seedlings at 20 d after sowing, significant positive correlations between the contents of some GA species and performance and heterosis based on shoot dry mass were detected. Expression analyses of GA-related genes by real-time reverse transcription-polymerase chain reaction revealed that 13 out of the 16 GA-related genes examined exhibited significant differential expression among the F1 hybrid and its parents, acting predominantly in the modes of overdominance and positive dominance. Expression levels of nine genes in the hybrids displayed significant positive correlations with the heterosis of shoot dry mass. These results imply that GAs play a positive role in the regulation of heterosis for rice seedling development. In shoots plus root axes of 4-d-old germinating seeds that had undergone the deetiolation, mimicking normal germination in soil, the axis dry mass was positively correlated with the content of GA₂₉ but negatively correlated with that of GA₁₉. Our findings provide supporting evidence for GAs playing an important regulatory role in heterosis for rice seedling development.

  8. Changes of nucleic acids of wheat seedlings under spaceflight conditions

    NASA Technical Reports Server (NTRS)

    Sytnyk, K. M.; Musatenko, L. I.

    1983-01-01

    The effects of space flight on the growth of wheat seedlings and their nucleic acid content were studied. It was shown that both space and ground seedlings have almost the same appearance, dry weight and nucleic acid content in the root, coleoptile and leaves. The only difference found is in the RNA and DNA content, which is twice as much in the ground seedling apices as in the space-grown seedlings.

  9. Nigella sativa concoction induced sustained seroreversion in HIV patient.

    PubMed

    Onifade, Abdulfatah Adekunle; Jewell, Andrew Paul; Adedeji, Waheed Adeola

    2013-01-01

    Nigella sativa had been documented to possess many therapeutic functions in medicine but the least expected is sero-reversion in HIV infection which is very rare despite extensive therapy with highly active anti-retroviral therapy (HAART). This case presentation is to highlight the complete recovery and sero-reversion of adult HIV patient after treatment with Nigella sativa concoction for the period of six months. The patient presented to the herbal therapist with history of chronic fever, diarrhoea, weight loss and multiple papular pruritic lesions of 3 months duration. Examination revealed moderate weight loss, and the laboratory tests of ELISA (Genscreen) and western blot (new blot 1 & 2) confirmed sero-positivity to HIV infection with pre-treatment viral (HIV-RNA) load and CD4 count of 27,000 copies/ml and CD4 count of 250 cells/ mm(3) respectively. The patient was commenced on Nigella sativa concoction 10 mls twice daily for 6 months.. He was contacted daily to monitor side-effects and drug efficacy. Fever, diarrhoea and multiple pruritic lesions disappeared on 5th, 7th and 20th day respectively on Nigella sativa therapy. The CD4 count decreased to 160 cells/ mm3 despite significant reduction in viral load (≤1000 copies/ml) on 30th day on N. sativa. Repeated EIA and Western blot tests on 187th day on Nigella sativa therapy was sero-negative. The post therapy CD4 count was 650 cells/ mm(3) with undetectable viral (HIV-RNA) load. Several repeats of the HIV tests remained sero-negative, aviraemia and normal CD4 count since 24 months without herbal therapy. This case report reflects the fact that there are possible therapeutic agents in Nigella sativa that may effectively control HIV infection.

  10. Rhizoctonia seedling damping-off in sugar beet in Michigan

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia solani is an important seedling pathogen of sugar beet, causing damping-off following seedling emergence. Anastomosis group (AG)-4 has been the primary seedling pathogen reported on sugar beet, however, recent screening has found high incidence of infection by AG-2-2. Isolations of R. so...

  11. Management of seedling damping-off of alfalfa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A vigorous and productive alfalfa stand starts with strong and uniform seedling establishment. Seed rot and seedling damping-off are a significant cause of poor stand establishment in wet soils. A number of organisms cause seed rot and seedling damping-off including several species of Pythium. As a ...

  12. Seed Mucilage Improves Seedling Emergence of a Sand Desert Shrub

    PubMed Central

    Yang, Xuejun; Baskin, Carol C.; Baskin, Jerry M.; Liu, Guangzheng; Huang, Zhenying

    2012-01-01

    The success of seedling establishment of desert plants is determined by seedling emergence response to an unpredictable precipitation regime. Sand burial is a crucial and frequent environmental stress that impacts seedling establishment on sand dunes. However, little is known about the ecological role of seed mucilage in seedling emergence in arid sandy environments. We hypothesized that seed mucilage enhances seedling emergence in a low precipitation regime and under conditions of sand burial. In a greenhouse experiment, two types of Artemisia sphaerocephala achenes (intact and demucilaged) were exposed to different combinations of burial depth (0, 5, 10, 20, 40 and 60 mm) and irrigation regimes (low, medium and high, which simulated the precipitation amount and frequency in May, June and July in the natural habitat, respectively). Seedling emergence increased with increasing irrigation. It was highest at 5 mm sand burial depth and ceased at burial depths greater than 20 mm in all irrigation regimes. Mucilage significantly enhanced seedling emergence at 0, 5 and 10 mm burial depths in low irrigation, at 0 and 5 mm burial depths in medium irrigation and at 0 and 10 mm burial depths in high irrigation. Seed mucilage also reduced seedling mortality at the shallow sand burial depths. Moreover, mucilage significantly affected seedling emergence time and quiescence and dormancy percentages. Our findings suggest that seed mucilage plays an ecologically important role in successful seedling establishment of A. sphaerocephala by improving seedling emergence and reducing seedling mortality in stressful habitats of the sandy desert environment. PMID:22511952

  13. Complete mitochondrial genome of Eruca sativa Mill. (Garden rocket).

    PubMed

    Wang, Yankun; Chu, Pu; Yang, Qing; Chang, Shengxin; Chen, Jianmei; Hu, Maolong; Guan, Rongzhan

    2014-01-01

    Eruca sativa (Cruciferae family) is an ancient crop of great economic and agronomic importance. Here, the complete mitochondrial genome of Eruca sativa was sequenced and annotated. The circular molecule is 247,696 bp long, with a G+C content of 45.07%, containing 33 protein-coding genes, three rRNA genes, and 18 tRNA genes. The Eruca sativa mitochondrial genome may be divided into six master circles and four subgenomic molecules via three pairwise large repeats, resulting in a more dynamic structure of the Eruca sativa mtDNA compared with other cruciferous mitotypes. Comparison with the Brassica napus MtDNA revealed that most of the genes with known function are conserved between these two mitotypes except for the ccmFN2 and rrn18 genes, and 27 point mutations were scattered in the 14 protein-coding genes. Evolutionary relationships analysis suggested that Eruca sativa is more closely related to the Brassica species and to Raphanus sativus than to Arabidopsis thaliana.

  14. Renal injury, nephrolithiasis and Nigella sativa: A mini review

    PubMed Central

    Hayatdavoudi, Parichehr; Khajavi Rad, Abolfazl; Rajaei, Ziba; Hadjzadeh, Mousa AL-Reza

    2016-01-01

    Objective: The incidence and prevalence of kidney stone is increasing worldwide. After the first recurrence the risk of subsequent relapses is higher and the time period between relapses is shortened. Urinary stones can be severely painful and make a huge economic burden. The stone disease may increase the vulnerability of patients to other diseases such as renal failure. Medicinal herbs are rich sources of antioxidants which are increasingly consumed globally for their safety, efficacy and low price. Nigella sativa is a spice plant that is widely used for prevention and treatment of many ailments in Muslim countries and worldwide. This review aims at investigation of the effects of Nigella sativa on renal injury and stone formation. Materials and Methods: The scientific resources including PubMed, Scopus, and Google scholar were searched using key words such as: nephrolithiasis, urolithiasis, kidney/renal stone, renal injury, renal failure, urinary retention and black seed, black cumin, Nigella sativa and thymoquinone. Results: N. sativa and its main component, thymoquinone showed positive effects in prevention or curing kidney stones and renal failure through various mechanism such as antioxidative, anti-inflammatory, anti-eicosanoid and immunomodulatory effects. The putative candidate in many cases has been claimed to be thymoquinone but it seems that at least in part, particularly in kidney stones, the herbal melanin plays a role which requires further investigation to prove. Conclusion: N. sativa and its components are beneficial in prevention and curing of renal diseases including nephrolithiasis and renal damages. PMID:27247917

  15. Study of the kinetics and the adsorption isotherm of cadmium(II) from aqueous solution using green algae (Ulva lactuca) biomass.

    PubMed

    Asnaoui, H; Laaziri, A; Khalis, M

    2015-01-01

    Batch experiments were conducted to study the adsorption of hazardous cadmium onto low-cost algae biomass in aqueous solution with respect to concentration of adsorbate, adsorbent dosage, contact time, solution pH and temperature. Langmuir and Freundlich adsorption models were applied to describe the equilibrium isotherms and the isotherm constants were determined. The activation energy of adsorption was also evaluated for the adsorption of cadmium onto Ulva lactuca biomass. Experimental data were tested in terms of biosorption kinetics using pseudo-first-order and pseudo-second-order kinetic models. The results showed that the biosorption processes of Cd(II) followed well pseudo-second-order kinetics. Langmuir and Freundlich models were applied to describe the biosorption isotherm of the metal ions by Ulva lactuca biomass. Langmuir model fitted the equilibrium data better than the Freundlich isotherm. The biosorption capacity of Ulva lactuca biomass for cadmium was found to be 3.02 mg/g at pH 5.60 min equilibrium time and 20 °C. The mean free energy which was calculated was 6.24 kJ/mol for Cd(II) biosorption, which shows that the adsorption is physical. The calculated thermodynamic parameters (ΔG0, ΔH0 and ΔS0) showed that the biosorption of Cd(II) onto Ulva lactuca biomass was feasible, spontaneous and exothermic under examined conditions. The results indicate that algae Ulva lactuca could be employed as a low-cost material for the removal of metal ions from aqueous solution.

  16. Potential use of green macroalgae Ulva lactuca as a feed supplement in diets on growth performance, feed utilization and body composition of the African catfish, Clarias gariepinus

    PubMed Central

    Abdel-Warith, Abdel-Wahab A.; Younis, El-Sayed M.I.; Al-Asgah, Nasser A.

    2015-01-01

    This study aimed to evaluate the effects of diet containing the green macroalgae, Ulva lactuca, on the growth performance, feed utilization and body composition of African catfish Clarias gariepinus. Four experimental diets were formulated: D1 as a control group and D2, D3 and D4 which included 10%, 20% and 30% U. lactuca meal, respectively. 180 African catfish, weighing 9.59 ± 0.43 g, and with an average length of 11.26 ± 0.21, (mean ± SE) were divided into four groups corresponding to the different feeding regimes. The final body weight of the fish showed insignificant differences (P > 0.05) between the control and fish fed D2, whereas, there was a significant difference (P < 0.05) between these two diets compared with D3 and D4, with weights of 70.52, 60.92, 40.57 and 35.66 g recorded for D1, D2, D3 and D4, respectively. In the same trend significant differences were also evident in weight gain, specific growth rate and feed utilization. Fish fed with a diet containing 20% or 30% U. lactuca meal had poorer growth performance and feed utilization. Protein productive value, protein efficiency ratio, daily dry feed intake and total feed intake were also significantly lower in fish fed with D3 and D4 than in the control D1 and D2. Overall, the results of the experiment revealed that African catfish fed a diet with U. lactuca included at 20% and 30% levels showed poorer growth and feed utilization than the control group and fish fed diets containing 10% of U. lactuca. PMID:27081367

  17. Comparative Proteomics of Cannabis sativa Plant Tissues

    PubMed Central

    Raharjo, Tri J.; Widjaja, Ivy; Roytrakul, Sittiruk; Verpoorte, Robert

    2004-01-01

    Comparative proteomics of leaves, flowers, and glands of Cannabis sativa have been used to identify specific tissue-expressed proteins. These tissues have significantly different levels of cannabinoids. Cannabinoids accumulate primarily in the glands but can also be found in flowers and leaves. Proteins extracted from glands, flowers, and leaves were separated using two-dimensional gel electrophoresis. Over 800 protein spots were reproducibly resolved in the two-dimensional gels from leaves and flowers. The patterns of the gels were different and little correlation among the proteins could be observed. Some proteins that were only expressed in flowers were chosen for identification by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and peptide mass fingerprint database searching. Flower and gland proteomes were also compared, with the finding that less then half of the proteins expressed in flowers were also expressed in glands. Some selected gland protein spots were identified: F1D9.26-unknown prot. (Arabidopsis thaliana), phospholipase D beta 1 isoform 1a (Gossypium hirsutum), and PG1 (Hordeum vulgare). Western blotting was employed to identify a polyketide synthase, an enzyme believed to be involved in cannabinoid biosynthesis, resulting in detection of a single protein. PMID:15190082

  18. Stress responses in alfalfa (Medicago sativa L. )

    SciTech Connect

    Kessmann, H.; Edwards, R.; Dixon, R.A. ); Geno, P.W. )

    1990-09-01

    The isoflavonoid conjugates medicarpin-3-O-glucoside-6{double prime}-O-malonate (MGM), afrormosin-7-O-glucoside (AG), and afrormosin-7-O-glucoside-6{double prime}-O-malonate (AGM) were isolated and characterized from cell suspension cultures of alfalfa (Medicago sativa L.), where they were the major constitutive secondary metabolites. They were also found in alfalfa roots but not in other parts of the plant. The phytoalexin medicarpin accumulated rapidly in suspension cultured cells treated with elicitor from Colletotrichum lindemuthianum, and this was subsequently accompanied by an increase in the levels of MGM. In contrast, net accumulation of afrormosin conjugates was not affected by elicitor treatment. Labeling studies with ({sup 14}C)phenylalanine indicated that afrormosin conjugates were the major de novo synthesized isoflavonoid products in unelicited cells. During elicitation, ({sup 14}C)phenylalanine was incorporated predominantly into medicarpin, although a significant proportion of the newly synthesized medicarpin was also conjugated. Treatment of {sup 14}C-labeled, elicited cells with L-{alpha}-aminooxy-{beta}-phenylpropionic acid, a potent inhibitor of PAL activity in vivo, resulted in the initial appearance of labeled medicarpin of very low specific activity, suggesting that the phytoalexin could be released from a preformed conjugate under these conditions. Our data draw attention to the involvement of isoflavone hydroxylases during the constitutive and elicitor-induced accumulation of isoflavonoids and their conjugates in alfalfa cell cultures.

  19. Stress Responses in Alfalfa (Medicago sativa L.)

    PubMed Central

    Jorrin, Jesus; Dixon, Richard A.

    1990-01-01

    l-Phenylalanine ammonia-lyase has been purified from elicitor-treated alfalfa (Medicago sativa L.) cell suspension cultures using two protocols based on different sequences of chromatofocusing and hydrophobic interaction chromatography. Three distinct forms of the intact enzyme were separated on the basis of affinity for Octyl-Sepharose, with isoelectric points in the range pH 5.1 to 5.4. The native enzyme was a tetramer of Mr 311,000; the intact subunit Mr was about 79,000, although polypeptides of Mr 71,000, 67,000 and 56,000, probably arising from degradation of the intact subunit, were observed in all preparations. Two-dimensional gel analysis revealed the presence of several subunit isoforms of differing isoelectric points. The purified isoforms of the native enzyme had different Km values for l-phenylalanine in the range 40 to 110 micromolar, although mixtures of the forms in crude preparations exhibited apparent negative rate cooperativity. The enzyme activity was induced approximately 16-fold within 6 hours of exposure of alfalfa cells to a fungal elicitor or yeast extract. Analysis by hydrophobic interaction chromatography revealed different proportions of the different active enzyme isoforms, depending upon either time after elicitation or the elicitor used. The elicitor-induced increase in enzyme activity was associated with increased translatable phenylalanine ammonia-lyase mRNA activity in the polysomal fraction. Images Figure 4 Figure 7 PMID:16667296

  20. Stress Responses in Alfalfa (Medicago sativa L.)

    PubMed Central

    Gowri, Ganesan; Bugos, Robert C.; Campbell, Wilbur H.; Maxwell, Carl A.; Dixon, Richard A.

    1991-01-01

    S-Adenosyl-l-methionine:caffeic acid 3-O-methyltransferase (COMT, EC 2.1.1.6) catalyzes the conversion of caffeic acid to ferulic acid, a key step in the biosynthesis of lignin monomers. We have isolated a functionally active cDNA clone (pCOMT1) encoding alfalfa (Medicago sativa L.) COMT by immunoscreening a λZAPII cDNA expression library with anti-(aspen COMT) antibodies. The derived amino acid sequence of pCOMT1 is 86% identical to that of COMT from aspen. Southern blot analysis indicates that COMT in alfalfa is encoded by at least two genes. Addition of an elicitor preparation from bakers' yeast to alfalfa cell suspension cultures resulted in a rapid accumulation of COMT transcripts, which reached a maximum level around 19 hours postelicitation. Northern blot analysis of total RNA from different organs of alfalfa plants at various developmental stages showed that COMT transcripts are most abundant in roots and stems. Transcripts encoding ATP: i-methionine-S-adenosyl transferase (AdoMet synthetase, EC 2.5.1.6), the enzyme responsible for the synthesis of the methyl donor for the COMT reaction, were coinduced with COMT transcripts in elicitor-treated cells and exhibited a similar pattern of expression to that of COMT in different organs of alfalfa plants at various stages of development. ImagesFigure 3Figure 4Figure 6 PMID:16668418

  1. Effects of untreated and treated wastewater at the morphological, physiological and biochemical levels on seed germination and development of sorghum (Sorghum bicolor (L.) Moench), alfalfa (Medicago sativa L.) and fescue (Festuca arundinacea Schreb.).

    PubMed

    Rekik, Imen; Chaabane, Zayneb; Missaoui, Amara; Bouket, Ali Chenari; Luptakova, Lenka; Elleuch, Amine; Belbahri, Lassaad

    2017-03-15

    Wastewater reuse in agriculture may help mitigate water scarcity. This may be reached if high quality treatments removing harmful pollutants are applied. The aim of the present study was to compare the effect of untreated (UTW) and treated wastewater (TW) on germination and seedlings development of alfalfa (Medicago sativa L.), fescue (Festuca arundinacea Schreb.) and sorghum (Sorghum bicolor (L.) Moench). UTW presented high turbidity (130 NTU), chemical and biological oxygen demand (COD, 719mgL(-1), BOD5, 291mgL(-1)) and metal concentrations. These levels caused mortality (18% for fescue), decreased germination speed in seeds (37.5% for alfalfa) and reductions of root and stem length in seedlings (80% and 22% respectively for alfalfa). Adverse effects on seeds germination were reflected at the biochemical level by increased H2O2 levels (6 times for sorghum after 5days) and by increased Malondialdehyde (MDA) levels (more than 600 times for sorghum roots) during seedlings development. When TW was used, these parameters were close to control seeds ones. They were also dependent on plant species and developmental stage. Therefore, for efficient reclaimed wastewater reuse in irrigation, suitable crops, displaying wide tolerance to toxic contents during germination and later seedling development stages have to be selected.

  2. Rhizoctonia seedling disease on sugar beet

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia seedling damping-off can cause losses in sugar beet as well as providing inoculum for later root rot. The disease is caused by Rhizoctonia solani. The pathogen has several subgroups, anastomosis groups (AG), of which AG-4 has historically been associated with damping-off, while AG-2-2 is...

  3. Root Surface Association in Relation to Nodulation of Medicago sativa

    PubMed Central

    van Rensburg, Henri Jansen; Strijdom, Barend W.

    1982-01-01

    Nine strains of Rhizobium meliloti, ranging in competitive ability on Medicago sativa from excellent to poor in autoclaved soils, were paired in 29 combinations and used to inoculate M. sativa in a liquid rooting medium. A positive correlation (r = 0.545) between strain ratios in nodules after 28 days and root surface cell ratios after 7 days was determined. Two cell fractions from the root surface, representing loosely and firmly adhering cells, were investigated. Infectivity was linked to the more firmly adhering cells. A significant relationship was established between the cell ratios of competing strains in the two fractions. In another experiment, adherence of cells of both infective and noninfective Rhizobium strains to roots of M. sativa and Trifolium repens was demonstrated; the ratios of loosely to firmly adhering cells on the root surface were significantly narrower with the infective combinations than with noninfective strain-legume associations. PMID:16346071

  4. Effect of Nigella sativa on the kidney function in rats

    PubMed Central

    Dollah, Mohammad Aziz; Parhizkar, Saadat; Izwan, Mohammad

    2013-01-01

    Objectives: Nigella sativa (N. sativa) is an amazing herb which is used in traditional medicine for a wide range of illnesses including bronchial asthma, dysentery, gastrointestinal problems, as well as beneficial effect on blood lipids, lowering blood pressure, serum cholesterol, and triglycerides level. This study aimed to determine the toxic effect of N. sativa powder on the kidney function which was evaluated by serum urea and creatinine and through histopathological examination of kidney tissue. Methods and Materials: In this study, 24 male Sprague Dawley rats were randomly divided into four groups (six each). The rats were kept in the separate cage with three rats per cage. The treatment groups were given rat pellet containing N. sativa dose at 0.01, 0.10, and 1.00 g/kg body weight which were considered as low, normal, and high dose for five weeks while control group fed with rat chow pellet without supplementation. At the end of 35 days, the rats were sacrificed to take the blood sample and to remove the kidney organ for toxicity evaluation. Statistical analyses were done through one-way ANOVA using SPSS. Results: The finding revealed that there was no significant difference in serum urea of treatment groups compared with the control group. The results showed a significant decline in serum creatinine of high dose of Nigella sativa treated compared with low dose treated and control groups (p<0.05). Histopathological examination of kidney tissue showed normal kidney architecture with no tissue degeneration, inflammation, necrosis, and tubular dilation in all groups. Conclusion: With the evidence of normal urea and creatinine level in blood and normal kidney tissue in histology examination for all treatment groups, it is suggested that there is no toxic effect on kidney function of Nigella sativa at different doses for five-week period. PMID:25050269

  5. Postfire seedling dynamics and performance in Pinus halepensis Mill. populations

    NASA Astrophysics Data System (ADS)

    Daskalakou, Evangelia N.; Thanos, Costas A.

    2010-09-01

    Postfire dynamics of Aleppo pine seedling density, survival and growth were assessed in five burned forests of Attica, Greece (Stamata, Villia, Avlona, Kapandriti and Agios Stefanos) through the establishment of permanent experimental plots. All emerging seedlings were tagged and their survival and growth monitored at regular intervals. Seedling density dynamics show an initial, steep increase (to maximum values 2.9-4.6 seedlings m -2) followed by a gradual decrease that levels off at the second and third postfire year (1.3-3.0 seedlings m -2); similarly, postfire seedling survival more or less stabilised at 30-50%, 2-3 years after fire. On the basis of density and mortality trends as well as relevant bibliographic data, it is predicted that very dense, mature forests (10.000 trees ha -1 or more) will be reinstated within 15-20 years. During the first 5-7 postfire years, seedling/sapling annual height followed linear trends with various yearly rates, ranging mostly between 8 and 15 cm (and 27-30 cm in two exceptional, fast growing cases). Within an individual growth season, seedling height dynamics were found to follow sigmoid curves with growth increment peaks in mid-spring. The time (on a monthly basis) of seedling emergence did not affect seedling growth or survival. On the other hand, for the first time under natural conditions, it has been shown that cotyledon number per seedling, an indirect measure of both seed size and initial photosynthetic capacity, significantly affected seedling survival but not growth. Seedlings bearing a higher number of cotyledons, presumably derived from larger seeds, showed greater survival at the end of the first postfire year than seedlings with fewer cotyledons. A postfire selective pressure, favouring large seed size, is postulated to counteract with a contrasting one, which favours small seed size, expressed during fire-free conditions.

  6. Metabolite analysis of Cannabis sativa L. by NMR spectroscopy.

    PubMed

    Flores-Sanchez, Isvett Josefina; Choi, Young Hae; Verpoorte, Robert

    2012-01-01

    NMR-based metabolomics is an analytical platform, which has been used to classify and analyze Cannabis sativa L. cell suspension cultures and plants. Diverse groups of primary and secondary metabolites were identified by comparing NMR data with reference compounds and/or by structure elucidation using ¹H-NMR, J-resolved, ¹H-¹H COSY, and ¹H-¹³C HMBC spectroscopy. The direct extraction and the extraction by indirect fractionation are two suitable methods for the C. sativa sample preparation. Quantitative analyses could be performed without requiring fractionation or isolation procedures.

  7. Effects of timing and severity of salinity stress on rice (Oryza sativa L.) yield, grain composition, and starch functionality.

    PubMed

    Thitisaksakul, Maysaya; Tananuwong, Kanitha; Shoemaker, Charles F; Chun, Areum; Tanadul, Orn-u-ma; Labavitch, John M; Beckles, Diane M

    2015-03-04

    The aim of this work was to examine agronomic, compositional, and functional changes in rice (Oryza sativa L. cv. Nipponbare) grains from plants grown under low-to-moderate salinity stress in the greenhouse. Plants were grown in sodium chloride-containing soil (2 or 4 dS/m(2) electrical conductivity), which was imposed 4-weeks after transplant (called Seedling EC2 and EC4) or after the appearance of the anthers (called Anthesis EC2 and EC4). The former simulates field conditions while the latter permits observation of the isolated effect of salt on grain filling processes. Key findings of this study are the following: (i) Plants showed adaptive responses to prolonged salt treatment with no negative effects on grain weight or fertility. Seedling EC2 plants had more panicles and enhanced caryopsis dimensions, while surprisingly, Seedling EC4 plants did not differ from the control group in the agronomic parameters measured. (ii) Grain starch increased in Seedling EC4 (32.6%) and Anthesis EC2 (39%), respectively, suggesting a stimulatory effect of salt on starch accumulation. (iii) The salinity treatment of 2 dS/m(2) was better tolerated at anthesis than the 4 dS/m(2) treatment as the latter led to reduced grain weight (28.8%) and seed fertility (19.4%) and compensatory increases in protein (20.1%) and nitrogen (19.8%) contents. (iv) Although some salinity treatments led to changes in starch content, these did not alter starch fine structure, morphology, or composition. We observed no differences in reducing sugar and amylose content or starch granule size distribution among any of the treatments. The only alterations in starch were limited to small changes in thermal properties and glucan chain distribution, which were only seen in the Anthesis EC4 treatment. This similarity of compositional and functional features was supported by multivariate analysis of all variables measured, which suggested that differences due to treatments were minimal. Overall, this study

  8. [Effects of low magnesium on photosynthesis characteristics and antioxidant system in cucumber seedlings under low temperature].

    PubMed

    Zhu, Shuai; Wu, Guo-xiu; Cai, Huan; Liu, Zhang-lei; Liu, Jing; Yang, Rui; Ai, Xi-zhen

    2015-05-01

    The effects of low magnesium (30% Mg) stress on photosynthesis characteristics and antioxidant system in 'Jinyou 3' cucumber ( Cucumis sativa) seedlings under low temperature (day/ night temperature was 12 °C/8 °C) were investigated, with Hoagland nutrient solution treatment as the control. The results showed that the 30% Mg treatment showed a significantly lower Mg content in leaves, compared with the control. However, no marked difference in roots between the 30% Mg treatment and the control was found. Low temperature significantly decreased the chlorophyll content, net photosynthetic rate (Pn), stomatal conductance (g(s)), and carboxylation efficiency (CE), while increased the intercelluar CO2 concentration (Ci). The 30% Mg treatment showed significantly lower chlorophyll content, Pn, g(s) and CE, compared with the control. No marked change was found in Ci between the 30% Mg treatment and the control. Low magnesium stress resulted in a more serious damage in chloroplast membrane under low temperature, and showed lower chloroplasts, grains and lamellas, while more and larger starch grains in cucumber seedlings. Low magnesium stress also led to an increase in MDA content, while a decrease in activities of superoxide dismutase (SOD) , peroxidase (POD) , catalase ( CAT) , ascorbate peroxidase (APX) and glutathione reductase (GR). These data suggested that magnesium deficiency caused by its hindered transportation under low temperature was the main reason for the chlorosis of cucumber leaves. The decrease in Pn was mainly caused by the non-stomatal limitation. Low magnesium stress increased the influence of low temperature on Pn, and the resulting decline in Pn was caused by the stomatal limitation.

  9. Chelator-induced phytoextraction of zinc and copper by rice seedlings.

    PubMed

    Yu, Xiao-Zhang; Wang, Dun-Qiu; Zhang, Xue-Hong

    2014-05-01

    Solution culture was carried to investigate capacity of synthetic aminopolycarboxylic acids (ethylenediamine tetraacetate, N-hydroxyethylenediaminetriacetic acid, and diethylenetriamine-pentaacetate) for enhancing botanical removal and transport of heavy metals (Cu and Zn) by plants. Biodegradable organic acids (citric acid, malic acid, and oxalic acid) were also selected as alternatives to compare them with synthesized chelating agents for effectiveness. Young rice seedlings (Oryza sativa L. cv. XZX 45) were grown in nutrient solutions treated with single or combined metal solutions in presence or absence of chelating compounds. Calculation by chemical equilibrium program VISUAL MINTEQ showed that different chelating compounds had various complex potential with Cu(2+) and Zn(2+) ions, in which synthetic chelators exhibited higher complexed capability than biodegradable organic acids. All applied synthetic aminopolycarboxylic acids significantly decreased removal of metal from nutrient solution (p < 0.01), while more or less effects of organic acids supplied on biosorptive potential were observed with all treatments (p > 0.05), compared with the treatment without metal ligands. Synthetic aminopolycarboxylic acids significantly decreased metal concentrations in plant materials in all treatments (p < 0.01). However, biodegradable organic acids decreased metal concentrations in roots (p < 0.01), but enhanced them in shoots (p < 0.01). Results obtained indicated that synthetic aminopolycarboxylic acids decreased uptake of metals by rice seedlings, but translocation of metals complexed within plant materials was evident. Although exogenous biodegradable organic acids showed negligible effect on botanical removal of metals, metals complexed with organic acids was more mobile than those complexed with other chelating agents. These information collected here had important implication for the use of biodegradable metal chelators in transport of essential micronutrients in

  10. Identification and fine mapping of quantitative trait loci for seed vigor in germination and seedling establishment in rice.

    PubMed

    Xie, Lixia; Tan, Zhengwei; Zhou, Yuan; Xu, Rongbao; Feng, Laibao; Xing, Yongzhong; Qi, Xiaoquan

    2014-08-01

    Seed vigor is an index of seed quality that is used to describe the rapid and uniform germination and the establishment of strong seedlings in any environmental conditions. Strong seed vigor in low-temperature germination conditions is particularly important in direct-sowing rice production systems. However, seed vigor has not been selected as an important breeding trait in traditional breeding programs due to its quantitative inherence. In this study, we identified and mapped eight quantitative trait loci (QTLs) for seed vigor by using a recombinant inbred population from a cross between rice (Oryza sativa L. ssp. indica) cultivars ZS97 and MH63. Conditional QTL analysis identified qSV-1, qSV-5b, qSV-6a, qSV-6b, and qSV-11 influenced seedling establishment and that qSV-5a, qSV-5c, and qSV-8 influenced only germination. Of these, qSV-1, qSV-5b, qSV-6a, qSV-6b, and qSV-8 were low-temperature-specific QTLs. Two major-effective QTLs, qSV-1, and qSV-5c were narrowed down to 1.13-Mbp and 400-kbp genomic regions, respectively. The results provide tightly linked DNA markers for the marker-assistant pyramiding of multiple positive alleles for increased seed vigor in both normal and low-temperature germination environments.

  11. Synthesis, characterization and biocompatibility of silver nanoparticles synthesized from Nigella sativa leaf extract in comparison with chemical silver nanoparticles.

    PubMed

    Amooaghaie, Rayhaneh; Saeri, Mohammad Reza; Azizi, Morteza

    2015-10-01

    Despite the development potential in the field of nanotechnology, there is a concern about possible effects of nanoparticles on the environment and human health. In this study, silver nanoparticles (AgNPs) were synthesized by 'green' and 'chemical' methods. In the wet-chemistry method, sodium borohydrate, sodium citrate and silver nitrate were used as raw materials. Leaf extract of Nigella sativa was used as reducing as well as capping agent to reduce silver nitrate in the green synthesis method. In addition, toxic responses of both synthesized AgNPs were monitored on bone-building stem cells of mice as well as seed germination and seedling growth of six different plants (Lolium, wheat, bean and common vetch, lettuce and canola). In both synthesis methods, the colorless reaction mixtures turned brown and UV-visible spectra confirmed the presence of silver nanoparticles. Scanning electron microscope (SEM) observations revealed the predominance of silver nanosized crystallites and fourier transform infra-red spectroscopy (FTIR) indicated the role of different functional groups in the synthetic process. MTT assay showed cell viability of bone-building stem cells of mice was further in the green AgNPs synthesized using black cumin extract than chemical AgNPs. IC50 (inhibitory concentrations) values for seed germination, root and shoot length for 6 plants in green AgNPs exposures were higher than the chemical AgNPs. These results suggest that cytotoxicity and phytotoxicity of the green synthesized AgNPs were significantly less than wet-chemistry synthesized ones. This study indicated an economical, simple and efficient ecofriendly technique using leaves of N. sativa for synthesis of AgNPs and confirmed that green AgNPs are safer than chemically-synthesized AgNPs.

  12. [omega]-Hydroxylation of Oleic Acid in Vicia sativa Microsomes (Inhibition by Substrate Analogs and Inactivation by Terminal Acetylenes).

    PubMed Central

    Pinot, F.; Bosch, H.; Alayrac, C.; Mioskowski, C.; Vendais, A.; Durst, F.; Salaun, J. P.

    1993-01-01

    Oleic acid (18:1) is hydroxylated exclusively on the terminal methyl by a microsomal cytochrome P-450-dependent system ([omega]-OAH) from clofibrate-induced Vicia sativa L. (var minor) seedlings (F. Pinot, J.-P. Salaun, H. Bosch, A. Lesot, C. Mioskowski, F. Durst [1992] Biochem Biophys Res Commun 184: 183-193). This reaction was inactivated by two terminal acetylenes: (Z)-9-octadecen-17-ynoic acid (17-ODCYA) and the corresponding epoxide, (Z)-9,10-epoxyoctadecan-17-ynoic acid (17-EODCYA). Inactivation was mechanism-based, with an apparent binding constant of 21 and 32 [mu]M and half-lives of 16 and 19 min for 17-ODCYA and 17-EODCYA, respectively. We have investigated the participation of one or more [omega]-hydroxylase isoforms in the oxidation of fatty acids in this plant system. Lauric acid (12:0) is [omega]-hydroxylated by the cytochrome P-450 [omega]-hydroxylase [omega]-LAH (J.-P. Salaun, A. Simon, F. Durst [1986] Lipids 21: 776-779). Half-lives of [omega]-OAH and [omega]-LAH in the presence of 40 [mu]M 17-ODCYA were 23 and 41 min, respectively. Inhibition of oleic acid [omega]-hydroxylation was competitive with linoleic acid (18:2), but noncompetitive with lauric acid (12:0). In contrast, oleic acid did not inhibit [omega]-hydroxylation of lauric acid. Furthermore, 1-pentadecyltriazole inhibited [omega]-hydroxylation of oleic acid but not of lauric acid. These results suggest that distinct monooxygenases catalyze [omega]-hydroxylation of medium- and long-chain fatty acids in V. sativa microsomes. PMID:12231907

  13. Models Analyses for Allelopathic Effects of Chicory at Equivalent Coupling of Nitrogen Supply and pH Level on F. arundinacea, T. repens and M. sativa

    PubMed Central

    Wang, Quanzhen; Xie, Bao; Wu, Chunhui; Chen, Guo; Wang, Zhengwei; Cui, Jian; Hu, Tianming; Wiatrak, Pawel

    2012-01-01

    Alllelopathic potential of chicory was investigated by evaluating its effect on seed germination, soluble sugar, malondialdehyde (MDA) and the chlorophyll content of three target plants species (Festuca arundinacea, Trifolium repens and Medicago sativa). The secretion of allelochemicals was regulated by keeping the donor plant (chicory) separate from the three target plant species and using different pH and nitrogen levels. Leachates from donor pots with different pH levels and nitrogen concentrations continuously irrigated the target pots containing the seedlings. The allelopathic effects of the chicory at equivalent coupling of nitrogen supply and pH level on the three target plants species were explored via models analyses. The results suggested a positive effect of nitrogen supply and pH level on allelochemical secretion from chicory plants. The nitrogen supply and pH level were located at a rectangular area defined by 149 to 168 mg/l nitrogen supply combining 4.95 to 7.0 pH value and point located at nitrogen supply 177 mg/l, pH 6.33 when they were in equivalent coupling effects; whereas the inhibitory effects of equivalent coupling nitrogen supply and pH level were located at rectangular area defined by 125 to 131 mg/l nitrogen supply combining 6.71 to 6.88 pH value and two points respectively located at nitrogen supply 180 mg/l with pH 6.38 and nitrogen supply 166 mg/l with pH 7.59. Aqueous extracts of chicory fleshy roots and leaves accompanied by treatment at different sand pH values and nitrogen concentrations influenced germination, seedling growth, soluble sugar, MDA and chlorophyll of F. arundinacea, T. repens and M. sativa. Additionally, we determined the phenolics contents of root and leaf aqueous extracts, which were 0.104% and 0.044% on average, respectively. PMID:22384054

  14. Models analyses for allelopathic effects of chicory at equivalent coupling of nitrogen supply and pH level on F. arundinacea, T. repens and M. sativa.

    PubMed

    Wang, Quanzhen; Xie, Bao; Wu, Chunhui; Chen, Guo; Wang, Zhengwei; Cui, Jian; Hu, Tianming; Wiatrak, Pawel

    2012-01-01

    Alllelopathic potential of chicory was investigated by evaluating its effect on seed germination, soluble sugar, malondialdehyde (MDA) and the chlorophyll content of three target plants species (Festuca arundinacea, Trifolium repens and Medicago sativa). The secretion of allelochemicals was regulated by keeping the donor plant (chicory) separate from the three target plant species and using different pH and nitrogen levels. Leachates from donor pots with different pH levels and nitrogen concentrations continuously irrigated the target pots containing the seedlings. The allelopathic effects of the chicory at equivalent coupling of nitrogen supply and pH level on the three target plants species were explored via models analyses. The results suggested a positive effect of nitrogen supply and pH level on allelochemical secretion from chicory plants. The nitrogen supply and pH level were located at a rectangular area defined by 149 to 168 mg/l nitrogen supply combining 4.95 to 7.0 pH value and point located at nitrogen supply 177 mg/l, pH 6.33 when they were in equivalent coupling effects; whereas the inhibitory effects of equivalent coupling nitrogen supply and pH level were located at rectangular area defined by 125 to 131 mg/l nitrogen supply combining 6.71 to 6.88 pH value and two points respectively located at nitrogen supply 180 mg/l with pH 6.38 and nitrogen supply 166 mg/l with pH 7.59. Aqueous extracts of chicory fleshy roots and leaves accompanied by treatment at different sand pH values and nitrogen concentrations influenced germination, seedling growth, soluble sugar, MDA and chlorophyll of F. arundinacea, T. repens and M. sativa. Additionally, we determined the phenolics contents of root and leaf aqueous extracts, which were 0.104% and 0.044% on average, respectively.

  15. [Transferring the Suaeda salsa glutathione S-transferase and catalase genes enhances low temperature stress resistance in transgenic rice seedlings].

    PubMed

    Zhao, Feng-Yun; Wang, Xiao-Yun; Zhao, Yan-Xiu; Zhang, Hui

    2006-04-01

    The GST (glutathione S-transferase) and GST+CAT1 (catalase 1) of Suaeda salsa were introduced into a low temperature-sensitive rice cultivar (Oryza sativa cv. Zhonghua No.11) by Agrobacterium tumefaciens-mediated transformation under the control of cauliflower mosaic virus (CaMV) 35S promoter, and the transformed calli and plantlets were screened on Murashige and Skoog (1962) medium supplemented with hygromycin 25 microg/mL and cefotaxime 300 microg/mL. The putative primary transformants (T(0) generation) were acclimatized at 26 degrees C /22 degrees C in a greenhouse for 7 d, and then transplanted to the field, where they grew up to maturity under outdoor conditions. 25 and 14 independent transgenic lines of T(1) generation carrying the GST and GST+CAT1 genes, respectively, were identified by PCR amplification. Transgene expression was monitored by RNA-blot hybridization using total RNA samples from leaf tissues. To investigate whether expressing the Suaeda salsa GST and GST+CAT1 in transgenic rice increased low temperature stress tolerance, the T(4) 14-day-old transgenic and non-transgenic rice seedlings were transferred to a low temperature (day 7 degrees C/night 4 degrees C) growth chamber for 3-6 d. The experimental data showed that expressing the Suaeda salsa GST and GST+CAT1 enhanced low temperature stress resistance in transgenic rice seedlings. When treated with low temperature, both GST and CAT activity increased in the transformants with the time of temperature treatment. These transgenic rice plant seedlings exhibited a higher level of photosynthetic capacity than those of the non-transgenic control seedlings under low temperature treatment. Whereas, there were lower H(2)O(2) and MDA (malondialdehyde) content, and relative electrolyte leakage through the plasma membrane was also lower in transgenic rice seedlings than in the parent line under low temperature condition. The results also indicated that GST+CAT1 co-expression conferred greater level of low

  16. Seedling emergence on Sonoran desert dunes

    USGS Publications Warehouse

    Bowers, Janice E.

    1996-01-01

    Seedling emergence of psammophiles (plants restricted to active dunes) was examined with germination experiments and with field observations at the Algodones Dunes, California, U.S.A., and the Sierra del Rosario Dunes, Sonora, Mexico. In the field, perennial psammophiles germinated in response to smaller rainfall triggers (??? 10mm) than other woody desert plants (??? 16mm). In germination experiments, seedlings of three perennial psammophiles, Astragalus magdalenae var. peirsonii, Helianthus niveus subsp. tephrodes, and Palafoxia arida var. gigantea, emerged in larger numbers from greater soil depths than those of three nonpsammophiles, Cercidium microphyllum, Fouquieria splendens, and Palafoxia arida var. arida. Seed size for these six species did not correlate in any consistent fashion with emergence depth, suggesting that food reserves are not the only variable that ensures emergence of deeply buried psammophile seeds.

  17. Effects of Nigella sativa and Lepidium sativum on Cyclosporine Pharmacokinetics

    PubMed Central

    Al-Jenoobi, F. I.; Al-Suwayeh, S. A.; Muzaffar, Iqbal; Al-Kharfy, Khalid M.; Korashy, Hesham M.; Al-Mohizea, Abdullah M.; Raish, Mohd

    2013-01-01

    The present study was conducted to investigate the effects of Nigella sativa and Lepidium sativum on the pharmacokinetics of cyclosporine in rabbits. Two groups of animals were treated separately with Nigella sativa (200 mg/kg p.o.) or Lepidium sativum (150 mg/kg p.o.) for eight consecutive days. On the 8th day, cyclosporine (30 mg/kg p.o.) was administered to each group one hour after herbal treatment. Blood samples were withdrawn at different time intervals (0.0, 0.5, 1.0, 1.5, 2.0, 3.0, 4.0, 6.0, 8.0, 12, and 24 hrs) from marginal ear vein. Cyclosporine was analyzed using UPLC/MS method. The coadministration of Nigella sativa significantly decreased the Cmax and AUC0−∞ of cyclosporine; the change was observed by 35.5% and 55.9%, respectively (P ≤ 0.05). Lepidium sativum did not produce any significant change in Cmax of cyclosporine, although its absorption was significantly delayed compared with control group. A remarkable change was observed in Tmax and AUC0−t of Lepidium sativum treated group. Our findings suggest that concurrent consumption of Nigella sativa and Lepidium sativum could alter the pharmacokinetics of cyclosporine at various levels. PMID:23957013

  18. Nigella sativa: reduces the risk of various maladies.

    PubMed

    Butt, Masood Sadiq; Sultan, Muhammad Tauseef

    2010-08-01

    Coinage of terms like nutraceuticals, functional, and pharma foods has diverted the attention of human beings to where they are seeking more natural cures. Though pharmaceutical drugs have been beneficial for human health and have cured various diseases but they also impart some side effects. Numerous plants have been tested for their therapeutic potential; Nigella sativa, commonly known as black cumin, is one of them. It possesses a nutritional dense profile as its fixed oil (lipid fraction), is rich in unsaturated fatty acids while essential oil contains thymoquinone and carvacrol as antioxidants. N. sativa seeds also contain proteins, alkaloids (nigellicines and nigelledine), and saponins (alpha-hederin) in substantial amounts. Recent pharmacological investigations suggested its potential role, especially for the amelioration of oxidative stress through free radical scavenging activity, the induction of apoptosis to cure various cancer lines, the reduction of blood glucose, and the prevention of complications from diabetes. It regulates hematological and serological aspects and can be effective in dyslipidemia and respiratory disorders. Moreover, its immunopotentiating and immunomodulating role brings balance in the immune system. Evidence is available supporting the utilization of Nigella sativa and its bioactive components in a daily diet for health improvement. This review is intended to focus on the composition of Nigella sativa and to elaborate its possible therapeutic roles as a functional food to prevent an array of maladies.

  19. Phytochemistry, pharmacology, and therapeutic uses of black seed (Nigella sativa).

    PubMed

    Kooti, Wesam; Hasanzadeh-Noohi, Zahra; Sharafi-Ahvazi, Naim; Asadi-Samani, Majid; Ashtary-Larky, Damoon

    2016-10-01

    Black seed (Nigella sativa) is an annual flowering plant from Ranunculaceae family, native to southwest Asia. This plant has many food and medicinal uses. The use of its seeds and oil is common for treatment of many diseases, including rheumatoid arthritis, asthma, inflammatory diseases, diabetes and digestive diseases. The purpose of this study was to provide a comprehensive review on the scientific reports that have been published about N. sativa. The facts and statistics presented in this review article were gathered from the journals accessible in creditable databases such as Science Direct, Medline, PubMed, Scopus, EBSCO, EMBASE, SID and IranMedex. The keywords searched in Persian and English books on medicinal plants and traditional medicine, as well as the above reputable databases were "Black seed", "Nigella sativa", "therapeutic effect", and "medicinal plant". The results showed that N. sativa has many biological effects such as anti-inflammatory, anti-hyperlipidemic, anti-microbial, anti-cancer, anti-oxidant, anti-diabetic, anti-hypertensive, and wound healing activities. It also has effects on reproductive, digestive, immune and central nervous systems, such as anticonvulsant and analgesic activities. In summary, it can be used as a valuable plant for production of new drugs for treatment of many diseases.

  20. Genetic Isolation, Divergence And Gene Flow In O. sativa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Knowledge about the structure and evolutionary history of naturally occurring variation in crops and their wild relatives provides insights into the complex process of domestication and new opportunities for utilizing novel alleles in crop improvement. Domesticated Asian rice (Oryza sativa L.) is co...

  1. Early events in geotropism of seedling shoots

    NASA Technical Reports Server (NTRS)

    Pickard, B. G.

    1985-01-01

    Developments during the first ten minutes of geotropic stimulation in plant seedling shoots are reviewed. Topics include induction and curvature; early processes; the relationship between auxin, electric field, calcium, and differential growth; gravity reception leading to Went-Cholodny transport; and comparison of root and shoot. Early processes reviewed are sedimentation of amyloplasts, release of ethylene, rise of electrical and auxin asymmetry, redistribution of calcium, asymmetric vascular transport, increase in tendency to deposit callose, and simulation of putative exocytotic voltage transients.

  2. Enhancement of American chestnut somatic seedling production.

    PubMed

    Andrade, G M; Merkle, S A

    2005-08-01

    Somatic embryogenesis holds promise for mass propagation of American chestnut trees bred or genetically engineered for resistance to chestnut blight. However, low germination frequency of chestnut somatic embryos has limited somatic seedling production for this forest tree. We tested the effects of culture regime (semi-solid versus liquid), cold treatment, AC and somatic embryo morphology (i.e., cotyledon number) on germination and conversion of the somatic embryos. Cold treatment for 12 weeks was critical for conversion of chestnut somatic embryos to somatic seedlings, raising conversion frequencies for one line to 47%, compared to 7% with no cold treatment. AC improved germination and conversion frequency for one line to 77% and 59%, respectively, and kept roots from darkening. For two lines that produced embryos with one, two or three-plus cotyledons, cotyledon number did not affect germination or conversion frequency. We also established embryogenic American chestnut suspension cultures and adapted a fractionation/plating system that allowed us to produce populations of relatively synchronous somatic embryos for multiple lines. Embryos derived from suspension cultures of two lines tested had higher conversion frequencies (46% and 48%) than those from cultures maintained on semi-solid medium (7% and 30%). The improvements in manipulation of American chestnut embryogenic cultures described in this study have allowed over a 100-fold increase in somatic seedling production efficiency over what we reported previously and thus constitute a substantial advance toward the application of somatic embryogenesis for mass clonal propagation of the tree.

  3. Transcriptome Analysis of Salt Stress Responsiveness in the Seedlings of Dongxiang Wild Rice (Oryza rufipogon Griff.).

    PubMed

    Zhou, Yi; Yang, Ping; Cui, Fenglei; Zhang, Fantao; Luo, Xiangdong; Xie, Jiankun

    2016-01-01

    Dongxiang wild rice (Oryza rufipogon Griff.) is the progenitor of cultivated rice (Oryza sativa L.), and is well known for its superior level of tolerance against cold, drought and diseases. To date, however, little is known about the salt-tolerant character of Dongxiang wild rice. To elucidate the molecular genetic mechanisms of salt-stress tolerance in Dongxiang wild rice, the Illumina HiSeq 2000 platform was used to analyze the transcriptome profiles of the leaves and roots at the seedling stage under salt stress compared with those under normal conditions. The analysis results for the sequencing data showed that 6,867 transcripts were differentially expressed in the leaves (2,216 up-regulated and 4,651 down-regulated) and 4,988 transcripts in the roots (3,105 up-regulated and 1,883 down-regulated). Among these differentially expressed genes, the detection of many transcription factor genes demonstrated that multiple regulatory pathways were involved in salt stress tolerance. In addition, the differentially expressed genes were compared with the previous RNA-Seq analysis of salt-stress responses in cultivated rice Nipponbare, indicating the possible specific molecular mechanisms of salt-stress responses for Dongxiang wild rice. A large number of the salt-inducible genes identified in this study were co-localized onto fine-mapped salt-tolerance-related quantitative trait loci, providing candidates for gene cloning and elucidation of molecular mechanisms responsible for salt-stress tolerance in rice.

  4. Complex molecular mechanisms underlying seedling salt tolerance in rice revealed by comparative transcriptome and metabolomic profiling

    PubMed Central

    Wang, Wen-Sheng; Zhao, Xiu-Qin; Li, Min; Huang, Li-Yu; Xu, Jian-Long; Zhang, Fan; Cui, Yan-Ru; Fu, Bin-Ying; Li, Zhi-Kang

    2016-01-01

    To understand the physiological and molecular mechanisms underlying seedling salt tolerance in rice (Oryza sativa L.), the phenotypic, metabolic, and transcriptome responses of two related rice genotypes, IR64 and PL177, with contrasting salt tolerance were characterized under salt stress and salt+abscisic acid (ABA) conditions. PL177 showed significantly less salt damage, lower Na+/K+ ratios in shoots, and Na+ translocation from roots to shoots, attributed largely to better salt exclusion from its roots and salt compartmentation of its shoots. Exogenous ABA was able to enhance the salt tolerance of IR64 by selectively decreasing accumulation of Na+ in its roots and increasing K+ in its shoots. Salt stress induced general and organ-specific increases of many primary metabolites in both rice genotypes, with strong accumulation of several sugars plus proline in shoots and allantoin in roots. This was due primarily to ABA-mediated repression of genes for degradation of these metabolites under salt. In PL177, salt specifically up-regulated genes involved in several pathways underlying salt tolerance, including ABA-mediated cellular lipid and fatty acid metabolic processes and cytoplasmic transport, sequestration by vacuoles, detoxification and cell-wall remodeling in shoots, and oxidation–reduction reactions in roots. Combined genetic and transcriptomic evidence shortlisted relatively few candidate genes for improved salt tolerance in PL177. PMID:26512058

  5. Lanthanum regulates the reactive oxygen species in the roots of rice seedlings

    PubMed Central

    Liu, Dongwu; Zheng, Shengnan; Wang, Xue

    2016-01-01

    In this study, the effects of La3+ on the reactive oxygen species (ROS) and antioxidant metabolism were studied in the roots of rice (Oryza sativa L. cv Shengdao 16) exposed to increasing concentrations of La3+ (0.05, 0.1, 0.5, 1.0, and 1.5 mM). The level of hydrogen peroxide, superoxide anion, and malondialdehyde was increased by 0.5, 1.0 and 1.5 mM La3+, and the activity of catalase and peroxidase was increased by 0.05 and 0.1 mM La3+. However, La3+ treatments stimulated superoxide dismutase activity in the roots of rice seedlings at all tested concentrations. In addition, the probe 2′,7′-dichlorofluorescein diacetate (H2DCF-DA) was used to investigate the instantaneous change of ROS in the root cells with the laser-scanning confocal microscopy. The result indicated that ROS level was declined after treated with 0.05 mM La3+. The results showed that the appropriate concentration of La3+ decreased the level of ROS, and hormetic effects on the antioxidant metabolism were found in the roots of rice exposed to 0.05, 0.1, 0.5, 1.0, and 1.5 mM La3+. PMID:27546334

  6. Complex molecular mechanisms underlying seedling salt tolerance in rice revealed by comparative transcriptome and metabolomic profiling.

    PubMed

    Wang, Wen-Sheng; Zhao, Xiu-Qin; Li, Min; Huang, Li-Yu; Xu, Jian-Long; Zhang, Fan; Cui, Yan-Ru; Fu, Bin-Ying; Li, Zhi-Kang

    2016-01-01

    To understand the physiological and molecular mechanisms underlying seedling salt tolerance in rice (Oryza sativa L.), the phenotypic, metabolic, and transcriptome responses of two related rice genotypes, IR64 and PL177, with contrasting salt tolerance were characterized under salt stress and salt+abscisic acid (ABA) conditions. PL177 showed significantly less salt damage, lower Na(+)/K(+) ratios in shoots, and Na(+) translocation from roots to shoots, attributed largely to better salt exclusion from its roots and salt compartmentation of its shoots. Exogenous ABA was able to enhance the salt tolerance of IR64 by selectively decreasing accumulation of Na(+) in its roots and increasing K(+) in its shoots. Salt stress induced general and organ-specific increases of many primary metabolites in both rice genotypes, with strong accumulation of several sugars plus proline in shoots and allantoin in roots. This was due primarily to ABA-mediated repression of genes for degradation of these metabolites under salt. In PL177, salt specifically up-regulated genes involved in several pathways underlying salt tolerance, including ABA-mediated cellular lipid and fatty acid metabolic processes and cytoplasmic transport, sequestration by vacuoles, detoxification and cell-wall remodeling in shoots, and oxidation-reduction reactions in roots. Combined genetic and transcriptomic evidence shortlisted relatively few candidate genes for improved salt tolerance in PL177.

  7. Improvement of nitrogen accumulation and metabolism in rice (Oryza sativa L.) by the endophyte Phomopsis liquidambari.

    PubMed

    Yang, Bo; Ma, Hai-Yan; Wang, Xiao-Mi; Jia, Yong; Hu, Jing; Li, Xia; Dai, Chuan-Chao

    2014-09-01

    The fungal endophyte Phomopsis liquidambari can enhance nitrogen (N) uptake and metabolism of rice plants under hydroponic conditions. To investigate the effects of P. liquidambari on N accumulation and metabolism in rice (Oryza sativa L.) under field conditions during the entire growing season (S1, the seedling stage; S2, the tillering stage; S3, the heading stage; S4, the ripening stage), we utilized pot experiments to examine metabolic and physiological levels in both shoot and root tissues of rice, with endophyte (E+) and without endophyte (E-), in response to three different N levels. We found that under low-N treatment, P. liquidambari symbiosis increased the rice yield and N use efficiency by 12% and by 11.59%, respectively; that the total N contents in E+ rice plants at the four growth stages were separately increased by 29.05%, 14.65%, 21.06% and 18.38%, respectively; and that the activities of nitrate reductase and glutamine synthetase in E+ rice roots and shoots were significantly increased by fungal infection during the S1 to S3 stages. Moreover, P. liquidambari significantly increased the free NH4(+), NO3(-), amino acid and soluble protein contents in infected rice tissues under low-N treatment during the S1 to S3 stages. The obtained results offer novel data concerning the systemic changes induced by P. liquidambari in rice during the entire growth period and confirm the hypothesis that the rice-P. liquidambari interaction improved the N accumulation and metabolism of rice plants, consequently increasing rice N utilization in nutrient-limited soil.

  8. Silicon decreases chloride transport in rice (Oryza sativa L.) in saline conditions.

    PubMed

    Shi, Yu; Wang, Yichao; Flowers, Timothy J; Gong, Haijun

    2013-06-15

    Silicon can alleviate salt damage to plants, although the mechanism(s) still remains to be elucidated. In this paper, we report the effect of silicon on chloride transport in rice (Oryza sativa L.) seedlings in saline conditions. In the absence of salinity, silicon enhanced the growth of shoots, but not roots in three cultivars (cv. GR4, IR36, and CSR10). Salinity reduced the growth of both shoots and roots in all three genotypes. In saline conditions, addition of silicon to the culture solution again improved the growth of shoots, but not of roots. Under these saline conditions, the concentrations of chloride in the shoot were markedly decreased by adding silicon and the ratio of K(+)/Cl(-) was significantly increased, while the concentration of chloride in the roots was unchanged. The decrease in chloride concentration in the shoot was correlated with the decrease in transpirational bypass flow in rice, as shown by the transport of the apoplastic tracer trisodium-8-hydroxy-1,3,6-pyrenetrisulphonic acid (PTS). Addition of silicon increased the net photosynthetic rate, stomata conductance, and transpiration of salt-stressed plants in cv. IR36, indicating that the reduction of chloride (and sodium) uptake by silicon was not through a reduction in transpiration rate. Silicon addition also increased the instantaneous water use efficiency of salt-stressed plants, while it did not change the relative growth rate of shoots. The results suggest that silicon addition decreased transpirational bypass flow in the roots, and therefore decreased the transport of chloride to the shoot.

  9. Resistance to uprooting of Alfalfa and Avena Sativa and related importance for flume experiments

    NASA Astrophysics Data System (ADS)

    Edmaier, K.; Crouzy, B.; Burlando, P.; Perona, P.

    2012-04-01

    Vegetation influences sediment dynamics by stabilizing the alluvial sediment with its root system. Thus, vegetation engineers the riparian ecosystem by contributing to the formation and stabilization of river bars and islands. The resistance to uprooting of young plants in non-cohesive sediment depends on the competition between flow induced drag and root growth timescales. The investigation of flow-sediment-plant interactions in situ is difficult since variables cannot be controlled and material hardly be collected. In order to investigate ecomorphological processes, laboratory experiments are essential and have gained importance in the last decade. To achieve a better understanding of the dependence of resistance to uprooting on the root system (length and structure) we conducted vertical uprooting experiments with Alfalfa and Avena Sativa which are both species that have been used in flume experiments on vegetation-flow interactions (e.g. Tal and Paola, 2010; Perona et al., in press). Seeds were seeded on quartz sand and vertically uprooted with constant velocity whereat the weight force required to uproot a seedling was measured. After uprooting, roots were scanned and analyzed and the correlation of root parameters with the uprooting work was studied. Total root length was found to be the best explanatory variable, in particular the uprooting work increases following a power law with increasing root length. The impact of other root parameters (main root length, root number, tortuosity) on the uprooting work was as well analyzed. Still, not all influencing root parameters could be captured, like the angle between roots or root hair distribution. Environmental conditions like grain size and saturation were also found to have an effect on the uprooting resistance of roots. So, lower saturated sediment results in a higher uprooting work. This work is a first step to better understand the energy regime for vegetation uprooting and its dependence on various

  10. Production of high levels of poly-3-hydroxybutyrate in plastids of Camelina sativa seeds.

    PubMed

    Malik, Meghna R; Yang, Wenyu; Patterson, Nii; Tang, Jihong; Wellinghoff, Rachel L; Preuss, Mary L; Burkitt, Claire; Sharma, Nirmala; Ji, Yuanyuan; Jez, Joseph M; Peoples, Oliver P; Jaworski, Jan G; Cahoon, Edgar B; Snell, Kristi D

    2015-06-01

    Poly-3-hydroxybutyrate (PHB) production in plastids of Camelina sativa seeds was investigated by comparing levels of polymer produced upon transformation of plants with five different binary vectors containing combinations of five seed-specific promoters for expression of transgenes. Genes encoding PHB biosynthetic enzymes were modified at the N-terminus to encode a plastid targeting signal. PHB levels of up to 15% of the mature seed weight were measured in single sacrificed T1 seeds with a genetic construct containing the oleosin and glycinin promoters. A more detailed analysis of the PHB production potential of two of the best performing binary vectors in a Camelina line bred for larger seed size yielded lines containing up to 15% polymer in mature T2 seeds. Transmission electron microscopy showed the presence of distinct granules of PHB in the seeds. PHB production had varying effects on germination, emergence and survival of seedlings. Once true leaves formed, plants grew normally and were able to set seeds. PHB synthesis lowered the total oil but not the protein content of engineered seeds. A change in the oil fatty acid profile was also observed. High molecular weight polymer was produced with weight-averaged molecular weights varying between 600 000 and 1 500 000, depending on the line. Select lines were advanced to later generations yielding a line with 13.7% PHB in T4 seeds. The levels of polymer produced in this study are the highest reported to date in a seed and are an important step forward for commercializing an oilseed-based platform for PHB production.

  11. Nutrient partitioning and seedling development in the genus Leucaena

    SciTech Connect

    Dovel, R.L.

    1987-01-01

    Slow establishment of the genus Leucaena from seed has been attributed to law seedling vigor and late nodulation. Observation of early seedling growth indicated that partitioning of a large proportion of resources to the root of young Leucaena seedlings could account, in part, for the slow initial shoot growth observed in this genus. Therefore, a series of experiments were conducted to examine the partitioning of stored seed reserves, photosynthate, and nitrogen in developing Leucaena seedlings. The effects of nodulation and nitrogen fertilization on partitioning of nutrients in the seedling were also examined. Seed reserves were initially used for radicle growth in dark grown seedlings; however, partitioning soon shifted to the hypocotyl. By four days after imbibition, hypocotyl weight exceeded radicle weight in both species tested (L. leucocephala and L. retusa), at all temperatures above 20/sup 0/C. Two experiments were conducted examining the carbon partitioning of L. leucocephala cultivar K-8 using /sup 14/CO/sub 2/ pulse labeling techniques.

  12. [Adaptability of mangrove Kandelia obovata seedlings to salinity-waterlogging].

    PubMed

    You, Hui-ming

    2015-03-01

    A laboratory test on the effects of 12 salinity-waterlogging stresses on the growth of Kandelia obovata seedlings was conducted. Nine growth indexes including seedling height, stem height, basal diameter, node number, leaf number, root biomass, stem biomass, leaf biomass and total biomass were measured. The results showed that salinity and salinity-waterlogging stresses had significant effects on the growth of K. obovata seedlings, while waterlogging stress had no significant effects on the seedling height, stem height, basal diameter, node number and leaf number, but had significant effects on root biomass, stem biomass, leaf biomass and total biomass. The growth and biomass of K. obovata seedlings decreased with increasing the salinity and waterlogging time. The principal components analysis showed that K. obovata seedlings would grow best under the 7 per thousand salinity+2 h waterlogging stress, while the 21per thousand+8 h combination was a critical stress.

  13. Container Oak Seedlings for Bottomland Hardwood (BLH) Restoration

    DTIC Science & Technology

    1993-08-01

    artificial stratification, necessary to break seed dormancy . Following the stratification period, seeds should be sown directly into containers filled...when flooding extends into the growing season. Traditionally, restoration has been accomplished with bare-root seedlings or direct seeding with acorns...operators must harvest seedlings before preparation of the seed bed for next year’s crop. If planting occurs prior to flooding, seedlings must tolerate

  14. Sod cutting and soil biota effects on seedling performance

    NASA Astrophysics Data System (ADS)

    Weijtmans, Kim; Jongejans, Eelke; van Ruijven, Jasper

    2009-09-01

    Sod cutting (i.e. top soil removal) is a restoration management option for enhancing seedling establishment and for lowering the nutrient concentration in eutrophicated soils of nutrient-poor species-rich grasslands. Removal of the upper soil changes not only abiotic soil properties but may also affect the resident soil community. We investigated the effects of sod cutting on the establishment and performance of two endangered plant species ( Cirsium dissectum and Succisa pratensis) while simultaneously manipulating the interaction between seedlings and soil biota. In intact grassland and sod-cut areas at two localities, seedlings were grown in plastic tubes. Half of the tubes had a filter that excluded roots but allowed entry of fungal hyphae and soil microorganisms. The other tubes were closed (i.e. no contact with the surrounding soil). In a greenhouse experiment we studied the effect of soil solutions (with or without fungal tissue) from three grasslands and three sod-cut areas on seedling growth. Sod cutting had a positive net effect on seedling growth for S. pratensis. Access to (mycorrhizal) fungi and other soil biota resulted in a negative impact on seedling growth of both plant species, both in grassland and sod-cut areas. The greenhouse experiment confirmed that the soil biota in these meadows reduced seedling growth. Although sod cutting did not mitigate negative plant-soil feedback, it enhanced seedling growth, presumably by decreasing competition for light. Sod cutting is therefore very useful when seedling establishment needs to be stimulated.

  15. The Medicago sativa Gene Index 1.2: A web-accessible expression atlas of two Medicago sativa sub-species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alfalfa is an important crop, both financially and ecologically, in the agricultural system of the United States. Using Illumina RNA-seq technology we have developed a de-novo transcriptome assembly from two Medicago sativa sub-species, sativa (B47) and falcata (F56). These two genotypes have proven...

  16. Breeding for blast-disease-resistant and high-yield Thai jasmine rice (Oryza sativa L. cv. KDML 105) mutants using low-energy ion beams

    NASA Astrophysics Data System (ADS)

    Mahadtanapuk, S.; Teraarusiri, W.; Phanchaisri, B.; Yu, L. D.; Anuntalabhochai, S.

    2013-07-01

    Low-energy ion beam was applied on mutation induction for plant breeding of blast-disease-resistant Thai jasmine rice (Oryza sativa L. cv. KDML 105). Seeds of the wild-type rice were bombarded in vacuum by nitrogen ion beam at energy of 60-80 keV to a beam fluence range of 2 × 1016-2 × 1017 ions/cm2. The ion-bombarded rice seeds were grown in soil for 2 weeks as transplanted rice in plastic pots at 1 seedling/pot. The seedlings were then screened for blast resistance by Pyricularia grisea inoculation with 106 spores/ml concentrations. The blast-resistant rice mutant was planted up to F6 generation with the consistent phenotypic variation. The high percentage of the blast-disease-resistant rice was analyzed with DNA fingerprint. The HAT-RAPD (high annealing temperature-random amplified polymorphic DNA) marker revealed the modified polymorphism fragment presenting in the mutant compared with wild type (KDML 105). The cDNA fingerprints were investigated and the polymorphism fragment was subcloned into pGEM-T easy vector and then sequenced. The sequence of this fragment was compared with those already contained in the database, and the fragment was found to be related to the Spotted leaf protein 11 (Spl11).

  17. The emerging biofuel crop Camelina sativa retains a highly undifferentiated hexaploid genome structure.

    PubMed

    Kagale, Sateesh; Koh, Chushin; Nixon, John; Bollina, Venkatesh; Clarke, Wayne E; Tuteja, Reetu; Spillane, Charles; Robinson, Stephen J; Links, Matthew G; Clarke, Carling; Higgins, Erin E; Huebert, Terry; Sharpe, Andrew G; Parkin, Isobel A P

    2014-04-23

    Camelina sativa is an oilseed with desirable agronomic and oil-quality attributes for a viable industrial oil platform crop. Here we generate the first chromosome-scale high-quality reference genome sequence for C. sativa and annotated 89,418 protein-coding genes, representing a whole-genome triplication event relative to the crucifer model Arabidopsis thaliana. C. sativa represents the first crop species to be sequenced from lineage I of the Brassicaceae. The well-preserved hexaploid genome structure of C. sativa surprisingly mirrors those of economically important amphidiploid Brassica crop species from lineage II as well as wheat and cotton. The three genomes of C. sativa show no evidence of fractionation bias and limited expression-level bias, both characteristics commonly associated with polyploid evolution. The highly undifferentiated polyploid genome of C. sativa presents significant consequences for breeding and genetic manipulation of this industrial oil crop.

  18. Salicylic acid alleviates aluminum toxicity in rice seedlings better than magnesium and calcium by reducing aluminum uptake, suppressing oxidative damage and increasing antioxidative defense.

    PubMed

    Pandey, Poonam; Srivastava, Rajneesh Kumar; Dubey, R S

    2013-05-01

    Aluminum toxicity is a major constraint to crop production in acid soils. The present study was undertaken to examine the comparative ameliorating effects of salicylic acid, Ca and Mg on Al toxicity in rice (Oryza sativa L.) seedlings grown in hydroponics. Al treatment (0.5 mM AlCl3) caused decrease in plant vigour, loss of root plasma membrane integrity, increased contents of O 2 (∙-) , H2O2, lipid peroxidation, protein carbonyls and decline in the level of protein thiol. Al treatment caused significant changes in activity of antioxidative enzymes in rice seedlings. Exogenously added salicylic acid (60 μM), Ca (1 mM) and Mg (0.25 mM) significantly alleviated Al toxicity effects in the seedlings marked by restoration of growth, suppression of Al uptake, restoration of root plasma membrane integrity and decline in O 2 (∙-) , H2O2, lipid peroxidation and protein carbonyl contents. Salicylic acid, Ca and Mg suppressed Al-induced increase in SOD, GPX and APX activities while it elevated Al-induced decline in CAT activity. By histochemical staining of O 2 (∙-) using NBT and H2O2 using DAB, it was further confirmed that added salicylic acid, Ca or Mg decreased Al-induced accumulation of O 2 (∙-) and H2O2 in the leaf tissues. Results indicate that exogenously added salicylic acid, Ca or Mg alleviates Al toxicity in rice seedlings by suppressing Al uptake, restoring root membrane integrity, reducing ROS level and ROS induced oxidative damage and regulating the level of antioxidative enzyme activities. Further salicylic appears to be superior to Mg and Ca in alleviating Al toxicity effects in rice plants.

  19. Heterosis in Rice Seedlings: Its Relationship to Gibberellin Content and Expression of Gibberellin Metabolism and Signaling Genes1[W][OA

    PubMed Central

    Ma (马谦), Qian; Hedden, Peter; Zhang (张启发), Qifa

    2011-01-01

    Despite the accumulation of data on the genetic and molecular understanding of heterosis, there is little information on the regulation of heterosis at the physiological level. In this study, we performed a quantitative analysis of endogenous gibberellin (GA) content and expression profiling of the GA metabolism and signaling genes to investigate the possible relationship between GA signaling and heterosis for seedling development in rice (Oryza sativa). The materials used were an incomplete diallele set of 3 × 3 crosses and the six parents. In the growing shoots of the seedlings at 20 d after sowing, significant positive correlations between the contents of some GA species and performance and heterosis based on shoot dry mass were detected. Expression analyses of GA-related genes by real-time reverse transcription-polymerase chain reaction revealed that 13 out of the 16 GA-related genes examined exhibited significant differential expression among the F1 hybrid and its parents, acting predominantly in the modes of overdominance and positive dominance. Expression levels of nine genes in the hybrids displayed significant positive correlations with the heterosis of shoot dry mass. These results imply that GAs play a positive role in the regulation of heterosis for rice seedling development. In shoots plus root axes of 4-d-old germinating seeds that had undergone the deetiolation, mimicking normal germination in soil, the axis dry mass was positively correlated with the content of GA29 but negatively correlated with that of GA19. Our findings provide supporting evidence for GAs playing an important regulatory role in heterosis for rice seedling development. PMID:21693671

  20. Habitat-related variation in seedling recruitment of Gentiana pannonica

    NASA Astrophysics Data System (ADS)

    Ekrtová, Ester; Košnar, Jan

    2012-11-01

    Differences in seedling recruitment of Gentiana pannonica were investigated between the primary (relict) and the secondary (semi-natural) forest-free habitats of the Bohemian Forest (870-1200 m a.s.l.) and of the Alps (1045-1935 m a.s.l.) to understand the factors promoting the seedling recruitment of G. pannonica and their importance for species distribution, population structure, and conservation. In the communities with adult plants of G. pannonica, we recorded environmental variables (the slope, the altitude, and the covers of bare ground, litter, and rocks), estimated parameters of the vegetation (the covers of herbs, bryophytes, and dwarf shrubs), and counted the seedlings of G. pannonica. In a field experiment, we investigated seedling survival under different soil moisture regimes. We also observed seasonal dynamics of seedling recruitment in permanent plots over the course of three years. In the primary habitats of both regions, G. pannonica grew in a relatively wide range of communities, and its seedlings occurred in each area. In the secondary habitats of the Bohemian Forest, a very low frequency of the seedlings was recorded. The number of seedlings increased with the covers of the moss layer and of bare soil and decreased with the cover of the herb layer, especially of graminoids. The seedling mortality was significantly lower in the plots with higher soil moistures, and the emergence of new-born seedlings was concentrated in the spring season, when the soil received a high water supply due to melting of snow. For the successful generative reproduction of G. pannonica, our findings highlight the critical importance of the microsites with low levels of competition and of sufficient soil moisture G. pannonica. It seems that because of the long-term lack of grazing disturbances, the structures of the secondary habitats of G. pannonica in the Bohemian Forest have become unfavourable for seedling establishment and generative reproduction of this threatened

  1. CSN6, a subunit of the COP9 signalosome, is involved in early response to iron deficiency in Oryza sativa

    PubMed Central

    Tan, Song; Liu, Fang; Pan, Xiao-Xi; Zang, Yue-Peng; Jin, Fei; Zu, Wei-Xi; Qi, Xiao-Ting; Xiao, Wei; Yin, Li-Ping

    2016-01-01

    The COP9 signalosome (CSN) plays an important role in proteasome-mediated degradation by regulating CUL1 rubylation of the SCF ligase and is involved in many crucial biological processes. Here, we demonstrate a link between IDEF1 accumulation and the decline in COP9 derubylation activity in response to iron deficiency (-Fe) in rice (Oryza sativa). CSN6 expression is rapidly down-regulated during Fe depletion, contributing to reduced CSN activity, as judged by CSN5 and CUL1 expression, indicating CSN6 is involved in the early stage response of -Fe. In contrast to CSN6, the IDEF1 protein and expression of several iron uptake/utilisation-related genes are increased in response to -Fe. Thus, we constructed CSN6 transgenic sense and antisense lines and found that experimental depletion of CSN6 results in accumulation of the IDEF1 protein and up-regulation of several iron uptake/utilisation-related genes. Furthermore, IDEF1 can be decorated with K48-linked polyubiquitin and degraded via the 26S proteasome. Accumulated IDEF1 in antisense lines led to increased chlorophyll and Fe content in seedlings during -Fe. Collectively, the cellular CSN6 level is decreased during early stages of -Fe to ensure the rapid accumulation of IDEF1, which in turn up-regulates several iron uptake/utilisation-related genes to help overcome -Fe stress in rice. PMID:27137867

  2. CSN6, a subunit of the COP9 signalosome, is involved in early response to iron deficiency in Oryza sativa

    NASA Astrophysics Data System (ADS)

    Tan, Song; Liu, Fang; Pan, Xiao-Xi; Zang, Yue-Peng; Jin, Fei; Zu, Wei-Xi; Qi, Xiao-Ting; Xiao, Wei; Yin, Li-Ping

    2016-05-01

    The COP9 signalosome (CSN) plays an important role in proteasome-mediated degradation by regulating CUL1 rubylation of the SCF ligase and is involved in many crucial biological processes. Here, we demonstrate a link between IDEF1 accumulation and the decline in COP9 derubylation activity in response to iron deficiency (-Fe) in rice (Oryza sativa). CSN6 expression is rapidly down-regulated during Fe depletion, contributing to reduced CSN activity, as judged by CSN5 and CUL1 expression, indicating CSN6 is involved in the early stage response of -Fe. In contrast to CSN6, the IDEF1 protein and expression of several iron uptake/utilisation-related genes are increased in response to -Fe. Thus, we constructed CSN6 transgenic sense and antisense lines and found that experimental depletion of CSN6 results in accumulation of the IDEF1 protein and up-regulation of several iron uptake/utilisation-related genes. Furthermore, IDEF1 can be decorated with K48-linked polyubiquitin and degraded via the 26S proteasome. Accumulated IDEF1 in antisense lines led to increased chlorophyll and Fe content in seedlings during -Fe. Collectively, the cellular CSN6 level is decreased during early stages of -Fe to ensure the rapid accumulation of IDEF1, which in turn up-regulates several iron uptake/utilisation-related genes to help overcome -Fe stress in rice.

  3. Concurrent synthesis and release of nod-gene-inducing flavonoids from alfalfa roots. [Medicago sativa L. ; Rhizobium meliloti

    SciTech Connect

    Maxwell, C.A.; Phillips, D.A. )

    1990-08-01

    Flavonoid signals from alfalfa (Medicago sativa L.) induce transcription of nodulation (nod) genes in Rhizobium meliloti. Alfalfa roots release three major nod-gene inducers: 4{prime},7-dihydroxyflavanone, 4{prime},7-dihydroxyflavone, and 4,4{prime}-dihydroxy-2{prime}-methoxychalcone. The objective of the present study was to define temporal relationships between synthesis and exudation for those flavonoids. Requirements for concurrent flavonoid biosynthesis were assessed by treating roots of intact alfalfa seedlings with (U-{sup 14}C)-L-phenylalanine in the presence or absence of the phenylalanine ammonia-lyase inhibitor L-2-aminoxy-3-phenylpropionic acid (AOPP). In the absence of AOPP, each of the three flavonoids in exudates contained {sup 14}C. In the presence of AOPP, {sup 14}C labeling and release of all the exuded nod-gene inducers were reduced significantly. AOPP inhibited labeling and release of the strongest nod-gene inducer, methoxychalcone, by more than 90%. The release process responsible for exudation of nod-gene inducers appears to be specific rather than a general phenomenon such as a sloughing off of cells during root growth.

  4. Allelopathic potential of switchgrass (Panicum virgatum L.) on perennial ryegrass (Lolium perenne L.) and alfalfa (Medicago sativa L.).

    PubMed

    Shui, Junfeng; An, Yu; Ma, Yongqing; Ichizen, Nobumasa

    2010-10-01

    This study investigated allelopathy and its chemical basis in nine switchgrass (Panicum virgatum L.) accessions. Perennial ryegrass (Lolium perenne L.) and alfalfa (Medicago sativa L.) were used as test species. Undiluted aqueous extracts (5 g plant tissue in 50 ml water) from the shoots and roots of most of the switchgrass accessions inhibited the germination and growth of the test species. However, the allelopathic effect of switchgrass declined when extracts were diluted 5- or 50-fold. Seedling growth was more sensitive than seed germination as an indicator of allelopathic effect. Allelopathic effect was related to switchgrass ecotype but not related to ploidy level. Upland accessions displayed stronger allelopathic potential than lowland accessions. The aqueous extract from one switchgrass accession was separated into phenols, organic acids, neutral chemicals, and alkaloids, and then these fractions were bioassayed to test for allelopathic potential. Alkaloids had the strongest allelopathic effect among the four chemical fractions. In summary, the results indicated that switchgrass has allelopathic potential; however, there is not enough evidence to conclude that allelopathic advantage is the main factor that has contributed to the successful establishment of switchgrass on China's Loess Plateau.

  5. Chloroplast downsizing under nitrate nutrition restrained mesophyll conductance and photosynthesis in rice (Oryza sativa L.) under drought conditions.

    PubMed

    Li, Yong; Ren, Binbin; Yang, Xiuxia; Xu, Guohua; Shen, Qirong; Guo, Shiwei

    2012-05-01

    The phenomenon whereby ammonium enhances the tolerance of rice seedlings (Oryza sativa L., cv. 'Shanyou 63' hybrid indica China) to water stress has been reported in previous studies. To study the intrinsic mechanism of biomass synthesis related to photosynthesis, hydroponic experiments supplying different nitrogen (N) forms were conducted; water stress was simulated by the addition of polyethylene glycol. Water stress decreased leaf water potential (Ψ(leaf)) under nitrate nutrition, while it had no negative effect under ammonium nutrition. The decreased Ψ(leaf) under nitrate nutrition resulted in chloroplast downsizing and subsequently decreased mesophyll conductance to CO(2) (g(m)). The decreased g(m) and stomatal conductance (g(s)) under nitrate nutrition with water stress restrained the CO(2) supply to the chloroplast and Rubisco. The relatively higher distribution of leaf N to Rubisco under ammonium nutrition might also be of benefit for photosynthesis under water stress. In conclusion, chloroplast downsizing induced a decline in g(m), a relatively higher decrease in g(s) under nitrate nutrition with water stress, restrained the CO(2) supply to Rubisco and finally decreased the photosynthetic rate.

  6. Allelopathic Potential of Switchgrass ( Panicum virgatum L.) on Perennial Ryegrass ( Lolium perenne L.) and Alfalfa ( Medicago sativa L.)

    NASA Astrophysics Data System (ADS)

    Shui, Junfeng; An, Yu; Ma, Yongqing; Ichizen, Nobumasa

    2010-10-01

    This study investigated allelopathy and its chemical basis in nine switchgrass ( Panicum virgatum L.) accessions. Perennial ryegrass ( Lolium perenne L.) and alfalfa ( Medicago sativa L.) were used as test species. Undiluted aqueous extracts (5 g plant tissue in 50 ml water) from the shoots and roots of most of the switchgrass accessions inhibited the germination and growth of the test species. However, the allelopathic effect of switchgrass declined when extracts were diluted 5- or 50-fold. Seedling growth was more sensitive than seed germination as an indicator of allelopathic effect. Allelopathic effect was related to switchgrass ecotype but not related to ploidy level. Upland accessions displayed stronger allelopathic potential than lowland accessions. The aqueous extract from one switchgrass accession was separated into phenols, organic acids, neutral chemicals, and alkaloids, and then these fractions were bioassayed to test for allelopathic potential. Alkaloids had the strongest allelopathic effect among the four chemical fractions. In summary, the results indicated that switchgrass has allelopathic potential; however, there is not enough evidence to conclude that allelopathic advantage is the main factor that has contributed to the successful establishment of switchgrass on China’s Loess Plateau.

  7. Comparative biochemical and RAPD analysis in two varieties of rice (Oryza sativa) under arsenic stress by using various biomarkers.

    PubMed

    Ahmad, Mohd Anwar; Gaur, Rashmi; Gupta, Meetu

    2012-05-30

    Multiple biomarker systems have been frequently used to measure the genotoxic effects of environmental pollutants (including heavy metals) on living organisms. In this study, we used leaves of hydroponically grown 14 days old seedlings of rice (Oryza sativa) varieties (PB1 and IR64) treated with 50, 150 and 300 μM arsenite (As(III)) for 24 and 96 h duration. Reduction in seed germination, root-shoot length, chlorophyll and protein were observed with increasing As(III) concentration and duration in both varieties, being more in IR64. Increase/decrease of antioxidant enzymes and stress related parameters showed much changes at higher concentration for 24 and 96 h duration in both varieties. Eleven primers were found in RAPD analysis to produce polymorphic band pattern and produced a total of 51 (control), 79 (treated) and 42 (control) and 29 (treated) bands in PB1 and IR64 varieties, respectively. These results indicated that genomic template stability (GTS, changes in RAPD profile) was significantly affected at all tested As(III) concentration, when compared with other parameters. Differential response was observed in both varieties with PB1 being more tolerant. We concluded that DNA polymorphism detected by RAPD analysis in conjunction with other biochemical parameters could be a powerful eco-toxicological tool in bio-monitoring arsenic pollution.

  8. Molecular cloning and functional analysis of the drought tolerance gene MsHSP70 from alfalfa (Medicago sativa L.).

    PubMed

    Li, Zhenyi; Long, Ruicai; Zhang, Tiejun; Wang, Zhen; Zhang, Fan; Yang, Qingchuan; Kang, Junmei; Sun, Yan

    2017-03-01

    Heat shock proteins (HSPs) are a ubiquitously expressed class of protective proteins that play a key role in plant response to stressful conditions. This study aimed to characterize and investigate the function of an HSP gene in alfalfa (Medicago sativa). MsHSP70, which contains a 2028-bp open reading frame, was identified through homology cloning. MsHSP70 shares high sequence identity (94.47%) with HSP70 from Medicago truncatula. Expression analysis of MsHSP70 in alfalfa organs revealed a relatively higher expression level in aerial organs such as flowers, stems and leaves than in roots. MsHSP70 was induced by heat shock, abscisic acid (ABA) and hydrogen peroxide. Transgenic Arabidopsis seedlings overexpressing MsHSP70 were hyposensitive to polyethylene glycol (PEG) and ABA treatments, suggesting that exogenous expression of MsHSP70 enhanced Arabidopsis tolerance to these stresses. Examination of physiological indexes related to drought and ABA stress demonstrated that in comparison with non-transgenic plants, T3 transgenic Arabidopsis plants had an increased proline content, higher superoxide dismutase (SOD) activity, and decreased malondialdehyde (MDA) content. Furthermore, higher relative water content (RWC) was detected in transgenic plants compared with non-transgenic plants under drought stress. These findings clearly indicate that molecular manipulation of MsHSP70 in plants can have substantial effects on stress tolerance.

  9. Radiation effects on Brassica seeds and seedlings

    NASA Astrophysics Data System (ADS)

    Deoli, Naresh; Hasenstein, Karl H.

    2016-07-01

    Space radiation consists of high energy charged particles and affects biological systems, but because of its stochastic, non-directional nature is difficult to replicate on Earth. Radiation damages biological systems acutely at high doses or cumulatively at low doses through progressive changes in DNA organization. These damages lead to death or cause of mutations. While radiation biology typically focuses on mammalian or human systems, little is known as to how radiation affects plants. In addition, energetic ion beams are widely used to generate new mutants in plants considering their high-LET (Linear Energy Transfer) as compared to gamma rays and X-rays. Understanding the effect of ionizing radiation on plant provides a basis for studying effects of radiation on biological systems and will help mitigate (space) radiation damage in plants. We exposed dry and imbibed Brassica rapa seeds and seedling roots to proton beams of varying qualities and compared the theoretical penetration range of different energy levels with observable growth response. We used 1, 2 and 3 MeV protons in air at the varying fluences to investigate the effect of direct irradiation on the seeds (1012 - 1015 ions/cm2) and seedlings (1013 ions/cm2). The range of protons in the tissue was calculated using Monte-Carlo based SRIM (Stopping and Range of Ions in Matter) software. The simulation and biological results indicate that ions did not penetrate the tissue of dry or hydrated seeds at all used ion energies. Therefore the entire energy was transferred to the treated tissue. Irradiated seeds were germinated vertically under dim light and roots growth was observed for two days after imbibition. The LD50 of the germination was about 2×1014 ions/cm2 and about 5×1014 ions/cm2 for imbibed and dry seeds, respectively. Since seedlings are most sensitive to gravity, the change in gravitropic behavior is a convenient means to assess radiation damage on physiological responses other than direct tissue

  10. 2'-Deoxymugineic acid promotes growth of rice (Oryza sativa L.) by orchestrating iron and nitrate uptake processes under high pH conditions.

    PubMed

    Araki, Ryoichi; Kousaka, Kayoko; Namba, Kosuke; Murata, Yoshiko; Murata, Jun

    2015-01-01

    Poaceae plants release 2'-deoxymugineic acid (DMA) and related phytosiderophores to chelate iron (Fe), which often exists as insoluble Fe(III) in the rhizosphere, especially under high pH conditions. Although the molecular mechanisms behind the biosynthesis and secretion of DMA have been studied extensively, little information is known about whether DMA has biological roles other than chelating Fe in vivo. Here, we demonstrate that hydroponic cultures of rice (Oryza sativa) seedlings show almost complete restoration in shoot height and soil-plant analysis development (SPAD) values after treatment with 3-30 μm DMA at high pH (pH 8.0), compared with untreated control seedlings at normal pH (pH 5.8). These changes were accompanied by selective accumulation of Fe over other metals. While this enhanced growth was evident under high pH conditions, DMA application also enhanced seedling growth under normal pH conditions in which Fe was fairly accessible. Microarray and qRT-PCR analyses revealed that exogenous DMA application attenuated the increased expression levels of various genes related to Fe transport and accumulation. Surprisingly, despite the preferential utilization of ammonium over nitrate as a nitrogen source by rice, DMA application also increased nitrate reductase activity and the expression of genes encoding high-affinity nitrate transporters and nitrate reductases, all of which were otherwise considerably lower under high pH conditions. These data suggest that exogenous DMA not only plays an important role in facilitating the uptake of environmental Fe, but also orchestrates Fe and nitrate assimilation for optimal growth under high pH conditions.

  11. Nigella sativa amliorates inflammation and demyelination in the experimental autoimmune encephalomyelitis-induced Wistar rats.

    PubMed

    Noor, Neveen A; Fahmy, Heba M; Mohammed, Faten F; Elsayed, Anwar A; Radwan, Nasr M

    2015-01-01

    Multiple sclerosis (MS) is the major, immune-mediated, demyelinating neurodegenerative disease of the central nervous system (CNS). Experimental autoimmune encephalomyelitis (EAE) is a well-established animal model of MS. The aim of the present study was to investigate the protective and ameliorative effects of N. sativa seeds (2.8 g/kg body weight) in EAE-induced Wistar rats. EAE-induced rats were divided into: 1- EAE-induced rats ("EAE" group). 2- "N. sativa + EAE" group received daily oral administration of N. sativa 2 weeks prior EAE induction until the end of the experiment. 3- "EAE + N. sativa" group received daily oral administration of N. sativa after the appearance of first clinical signs until the end of the experiment. All animals were decapitated at the 28th day post EAE-induction. EAE was investigated using histopathological, immunohistochemical and ultrastructural examinations in addition to determination of some oxidative stress parameters in the cerebellum and medulla. N. sativa suppressed inflammation observed in EAE-induced rats. In addition, N. sativa enhanced remyelination in the cerebellum. Moreover, N. sativa reduced the expression of transforming growth factor beta 1 (TGF β1). N. sativa seeds could provide a promising agent effective in both the protection and treatment of EAE.

  12. Chemical characterisation of bioactive compounds in Medicago sativa growing in the desert of Oman.

    PubMed

    Hanif, Muhammad Asif; Al-Maskari, Ahmed Yahya; Al-Sabahi, Jamal Nasser; Al-Hdhrami, Ibtisam; Khan, Muhammad Mumtaz; Al-Azkawi, Ahlam; Hussain, Abdullah Ijaz

    2015-01-01

    Medicago sativa Linn growing in Omani desert were chemically characterised using flame photometry, inductively coupled plasma, gas chromatography-mass spectrometry and high performance liquid chromatographic (HPLC) analysis. HPLC analyses were performed to determine the phenolics and flavonoids present in M. sativa. The major compounds detected in M. sativa leaves were protchaechenic acid (3.22%), hydroxyl benzoic acid (1.05%), β-Phenyl caffate (0.97%) and kaempherol (0.89%). Pterostilbene, a cholesterol-lowering compound, was detected in M. sativa.

  13. Nigella sativa seed extract: 1. Enhancement of sheep macrophage immune functions in vitro.

    PubMed

    Elmowalid, Gamal; Amar, Ahmad M; Ahmad, Adel Attia M

    2013-10-01

    Nigella sativa (N. sativa) seed, Black cumin, immunomodulatory activity has been investigated in human and mice. Little is known about the immunomodulatory effect of Nigella sativa (N. sativa) seed extract on animals' immune cells, specifically, antigen presenting cells such as macrophages. This study focused on the immunomodulatory effect of N. sativa seed extract on sheep macrophage functions in vitro. Sheep peripheral blood monocytes were isolated and derived to macrophages (MDM). The MDM were cultured with N. sativa seed extract and their morphological changes, phagocytic activity, nitric oxide production, and microbicidal activity were investigated. Marked morphological changes were observed in MDM cultured with N. sativa seed extract including cell size enlargement; increase in both cytoplasmic space and cytoplasmic granules. Significant increases in phagocytic activity to Candida albicans yeast and in number of yeast engulfed per individual MDM were observed in cells cultured with seed extract. MDM capacity to produce nitric oxide was higher in the culture media of the seed extract-cultured cells compared to the control. Interestingly, prominent enhancement in MDM microbicidal activity to yeast or bacteria was observed in MDM cultured with N. sativa seed extract confirming the potent immunostimulatory effect of the extract. From this study, it could be concluded that N. sativa seed extract can enhance macrophages' important innate immune functions that could control infectious diseases and regulate adaptive immunity.

  14. Biofunctional properties of Eruca sativa Miller (rocket salad) hydroalcoholic extract.

    PubMed

    Sultan, Khushbakht; Zakir, Muhammad; Khan, Haroon; Rauf, Abdur; Akber, Noor Ul; Khan, Murad Ali

    2016-01-01

    Eruca sativa Miller is a worldwide common alimentary plant (rocket leaves). The aim of this study was to correlate the potential in vitro scavenging activity of the E. sativa hydroalcoholic extract (HAE) with its in vivo hypoglycaemic effect. In DDPH free radical (DFR) and ferric-reducing antioxidant power assays, HAE in a concentration dependent manner (25-100 μg/mL) displayed a strong scavenging activity with maximum effect of 88% and 75% at 100 μg/mL, respectively. Daily administration of HAE (50 mg/kg; p.o.) in the in vivo model of alloxan-induced diabetic rabbits for 28 days showed significant reduction in glycaemia, also supported by recovery of body weight. In conclusion, our results give preliminary information on the potential use of this plant as a nutraceutical, useful to control and/or prevent a hyperglycaemic status.

  15. Bioactive prenylogous cannabinoid from fiber hemp (Cannabis sativa).

    PubMed

    Pollastro, Federica; Taglialatela-Scafati, Orazio; Allarà, Marco; Muñoz, Eduardo; Di Marzo, Vincenzo; De Petrocellis, Luciano; Appendino, Giovani

    2011-09-23

    The waxy fraction from the variety Carma of fiber hemp (Cannabis sativa) afforded the unusual cannabinoid 4, identified as the farnesyl prenylogue of cannabigerol (CBG, 1) on the basis of its spectroscopic properties. A comparative study of the profile of 4 and 1 toward metabotropic (CB1, CB2) and ionotropic (TRPV1, TRPV2, TRPM8, TRPA1) targets of phytocannabinoids showed that prenylogation increased potency toward CB2 by ca. 5-fold, with no substantial difference toward the other end-points, except for a decreased affinity for TRPM8. The isolation of 4 suggests that C. sativa could contain yet-to-be-discovered prenylogous versions of medicinally relevant cannabinoids, for which their biological profiles could offer interesting opportunities for biomedical exploitation.

  16. Temporal patterns in seedling establishment on pocket gopher disturbances.

    PubMed

    Forbis, Tara A; Larmore, Jason; Addis, Elizabeth

    2004-01-01

    Disturbances often facilitate seedling establishment, and can change the species composition of a community by increasing recruitment of disturbance-adapted species. To understand the effects of pocket gopher disturbances on alpine seedling dynamics, we examined the gopher disturbances' effects on seedling emergence and survival on gopher disturbances 0 to 5 years old. In contrast to results from most other ecosystems, these recently created gopher mounds had lower seedling emergence and survival rates than undisturbed areas. A lack of correlation between species' abundances on gopher mounds and undisturbed sites in one of the two communities studied suggested that a suite of disturbance-adapted species recruited onto the mounds. To explain low seedling emergence on recent gopher mounds, we quantified gopher mound seed banks and studied recruitment in a site with mounds that ranged from 0 to >20 years old. Seed numbers in first-year gopher mound soils were extremely low relative to undisturbed soils, and this pattern was mirrored in seedling establishment patterns over the long term. Gopher disturbance depressed seedling emergence density for the first 5 years. Subsequently, emergence density increased until at least 20 years following the disturbance. Emergence on disturbances more than 20 years old was higher than on undisturbed sites. Therefore, gopher disturbances probably facilitate seedling establishment in alpine dry and moist meadow; however, this process takes place over decades.

  17. Evaluation of Promalin to promote growth of young mangosteen seedlings

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A major impediment to the development of a mangosteen (Garcinia mangostana L.) industry is the long pre-bearing stage that seedlings take to produce fruits. A field study was conducted to determine the effect of Promalin on the growth of mangosteen seedlings. Promalin was applied as a foliar spray...

  18. Response of Citrus Seedlings to Radopholus similis in Two Soils.

    PubMed

    O'Bannon, J H; Tomerlin, A T

    1971-07-01

    Radopholus similis was less pathogenic to greenhouse-grown citrus seedlings in Leon loamy sand than in Lakeland fine sand. This was not affected by different watering regimes. Seedling growth reduction by the burrowing nematode in either soil, compared with noninfected controls, was significant at the 1% level.

  19. Seedling diseases of sugar beet – diversity and host interactions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seedling diseases cause loss of plant stand due to pre- and post-emergence damping-off and weakened plants due to root or hypocotyl infection. Several pathogens cause seedling disease of sugar beet, including Rhizoctonia solani, Aphanomyces cochlioides, Pythium species, and Fusarium species. Differe...

  20. Competitive suppression of Quercus douglasii (Fagaceae) seedling emergence and growth.

    PubMed

    Gordon, D R; Rice, K J

    2000-07-01

    Reduced recruitment of blue oak (Quercus douglasii) seedlings in California grasslands and woodlands may result from shifts in seasonal soil water availability coincident with replacement of the native perennial herbaceous community by Mediterranean annuals. We used a combination of container and field experiments to examine the interrelationships between soil water potential, herbaceous neighborhood composition, and blue oak seedling shoot emergence and growth. Neighborhoods of exotic annuals depleted soil moisture more rapidly than neighborhoods of a perennial grass or "no-neighbor" controls. Although effects of neighborhood composition on oak seedling root elongation were not statistically significant, seedling shoot emergence was significantly inhibited in the annual neighborhoods where soil water was rapidly depleted. Seedling water status directly reflected soil water potential, which also determined the extent and duration of oak seedling growth during the first year. End-of-season seedling height significantly influenced survival and growth in subsequent years. While growth and survival of blue oak seedlings may be initially constrained by competition with herbaceous species, subsequent competition with adult blue oak trees may further contribute to reduced sapling recruitment.

  1. Coumarin pretreatment alleviates salinity stress in wheat seedlings.

    PubMed

    Saleh, Ahmed Mahmoud; Madany, M M Y

    2015-03-01

    The potentiality of COU to improve plant tolerance to salinity was investigated. Wheat grains were primed with COU (50 ppm) and then grown under different levels of NaCl (50, 100, 150 mM) for two weeks. COU pretreatment improved the growth of wheat seedling under salinity, relative to COU-untreated seedlings, due to the accumulation of osmolytes such as soluble sugars and proline. Moreover, COU treatment significantly improved K(+)/Na(+) ratio in the shoots of both salt stressed and un-stressed seedlings. However, in the roots, this ratio increased only under non-salinity. In consistent with phenylalanine ammonia lyase (PAL), phenolics and flavonoids were accumulated in COU-pretreated seedlings under the higher doses of salinity, relative to COU-untreated seedlings. COU primed seedlings showed higher content of the coumarin derivative, scopoletin, and salicylic, chlorogenic, syringic, vanillic, gallic and ferulic acids, under both salinity and non-salinity conditions. Salinity stress significantly improved the activity of peroxidase (POD) in COU-pretreated seedlings. However, the effect of COU on the total antioxidant capacity (TAC) was only obtained at the highest dose of NaCl (150 mM). The present results suggest that COU pretreatment could alleviate the adverse effect of salinity on the growth of wheat seedlings through enhancing, at least partly, the osmoregulation process and antioxidant defense system.

  2. Azospirillum brasilense and Azospirillum lipoferum Hydrolyze Conjugates of GA20 and Metabolize the Resultant Aglycones to GA1 in Seedlings of Rice Dwarf Mutants1

    PubMed Central

    Cassán, Fabricio; Bottini, Rubén; Schneider, Gernot; Piccoli, Patricia

    2001-01-01

    Azospirillum species are plant growth-promotive bacteria whose beneficial effects have been postulated to be partially due to production of phytohormones, including gibberellins (GAs). In this work, Azospirillum brasilense strain Cd and Azospirillum lipoferum strain USA 5b promoted sheath elongation growth of two single gene GA-deficient dwarf rice (Oryza sativa) mutants, dy and dx, when the inoculated seedlings were supplied with [17,17-2H2]GA20-glucosyl ester or [17,17- 2H2]GA20-glucosyl ether. Results of capillary gas chromatography-mass spectrometry analysis show that this growth was due primarily to release of the aglycone [17,17-2H2]GA20 and its subsequent 3β-hydroxylation to [17,17-2H2]GA1 by the microorganism for the dy mutant, and by both the rice plant and microorganism for the dx mutant. PMID:11299384

  3. Adenylate cyclase activity in a higher plant, alfalfa (Medicago sativa).

    PubMed Central

    Carricarte, V C; Bianchini, G M; Muschietti, J P; Téllez-Iñón, M T; Perticari, A; Torres, N; Flawiá, M M

    1988-01-01

    An adenylate cyclase activity in Medicago sativa L. (alfalfa) roots was partially characterized. The enzyme activity remains in the supernatant fluid after centrifugation at 105,000 g and shows in crude extracts an apparent Mr of about 84,000. The enzyme is active with Mg2+ and Ca2+ as bivalent cations, and is inhibited by EGTA and by chlorpromazine. Calmodulin from bovine brain or spinach leaves activates this adenylate cyclase. PMID:3128270

  4. Characterization of recombinant β-amylases from Oryza sativa.

    PubMed

    Koide, Tomojiro; Ohnishi, Yasuo; Horinouchi, Sueharu

    2011-01-01

    Four putative β-amylase genes found in the Oryza sativa cDNA sequence database (KOME) were expressed in Escherichia coli. Recombinant proteins from two of these genes showed β-amylase activity. Similarly to β-amylases from other plants, the optimum pH of the recombinant rice β-amylases was about 5.5-6.0, but they exhibited inferior heat stability to soybean β-amylase.

  5. [Therapeutic use of Cannibis Sativa L. in Arab medicine].

    PubMed

    Lozano, I

    1997-01-01

    Arab scientists were various centuries ahead of our current knowledge of the curative power of hemp (Cannabis sativa L., Cannabaceae). Modern scientific literature ignores their contribution on the subject. We review in this paper the therapeutic uses of the plant in Arabic medicine from the 8th to the 18th century. Arab physicians knew and used its diuretic, anti-emetic, anti-epileptic, anti-inflammatory, pain-killing and antipyretic properties, among others.

  6. Effects of graphene on seed germination and seedling growth

    NASA Astrophysics Data System (ADS)

    Zhang, Ming; Gao, Bin; Chen, Jianjun; Li, Yuncong

    2015-02-01

    The environmental impact of graphene has recently attracted great attention. In this work, we show that graphene at a low concentration affected tomato seed germination and seedling growth. Graphene-treated seeds germinated much faster than control seeds. Analytical results indicated that graphene penetrated seed husks. The penetration might break the husks to facilitate water uptake, resulting in faster germination and higher germination rates. At the stage of seedling growth, graphene was also able to penetrate root tip cells. Seedlings germinated from graphene-treated seeds had slightly lower biomass accumulation than the control, but exhibited significantly longer stems and roots than the control, which suggests that graphene, in contrast with other nanoparticles, had different effects on seedling growth. Taken together, our results imply that graphene played complicated roles in affecting the initial stage of seed germination and subsequent seedling growth.

  7. Evolutionary history and distance dependence control survival of dipterocarp seedlings.

    PubMed

    Bagchi, Robert; Press, Malcolm C; Scholes, Julie D

    2010-01-01

    One important hypothesis to explain tree-species coexistence in tropical forests suggests that increased attack by natural enemies near conspecific trees gives locally rare species a competitive advantage. Host ranges of natural enemies generally encompass several closely related plant taxa suggesting that seedlings should also do poorly around adults of closely related species. We investigated the effects of adult Parashorea malaanonan on seedling survival in a Bornean rain forest. Survival of P. malaanonan seedlings was highest at intermediate distances from parent trees while heterospecific seedlings were unaffected by distance. Leaf herbivores did not drive this relationship. Survival of seedlings was lowest for P. malaanonan, and increased with phylogenetic dissimilarity from this species, suggesting that survival of close relatives of common species is reduced. This study suggests that distance dependence contributes to species coexistence and highlights the need for further investigation into the role of shared plant enemies in community dynamics.

  8. The Response of Citrus limon Seedlings to a Symbiont, Glomus etunicatus, and a Pathogen, Radopholus similis.

    PubMed

    O'Bannon, J H; Nemec, S

    1979-07-01

    The influences of a vesicular-arbuscular mycorrhiza (Glomus etunicatus) and burrowing nematode (Radophohts similis), alone and in combination, on the growth of rough lemon (Citrus limon) seedlings were studied in the greenhouse. Growth of mycorrhizal seedlings was significantly greater than that of nonmycorrhizal seedlings or seedlings inoculated with R. sindlis. Mycorrhizal stimulation of seedling growth was inhibited by nematode infection. When seedlings were inoculated with G. etunicatus arid R. similis, suppression of seedling growth by R. similis was less on VAM seedlings than on nonmycorrhizal seedlings, Nonmycorrhizal seedlings infected with R. similis were significantly smaller than nonmycorrhizal seedlings free of R. similis. Vesicle formation and mycelia growth were less in nematode-infected roots.

  9. Chemiluminescence of adzuki bean and soybean seedlings.

    PubMed

    Iida, T; Kawane, M; Ashikaga, K; Yoshiki, Y; Okubo, K

    2000-01-01

    The chemiluminescence of extracts from leguminous seedlings (adzuki bean and soybean) was investigated. In an H(2)O(2)/gallic acid/water extract system, the photon intensities of adzuki bean seedlings were increased after germination and in the hypocotyls it reached a maximum level during the first 4 days of germination. On day 4 after germination, chemiluminescence in the primary leaf part exhibited the strongest intensity. Emission spectra showed a main peak at 510 nm, with shoulders at 660 nm. Mechanical injuries to the stems and cotyledons resulted in about a 1.5- and 6.8-fold increase of chemiluminescence, respectively. In an H(2)O(2)/70% EtOH extract/HRP system, photon intensities increased after germination and reached a maximum level during the first 2 days of germination. On day 4 after germination, chemiluminescence in the root and leaf area was stronger than in any other area. Emission spectra showed a main peak at around 570 nm, with shoulders at around 660 nm. The photon intensities of stems and cotyledons after mechanical injuries resulted in about an 0.72-fold decrease and an 8.8-fold increase in the presence of H(2)O(2) and acetaldehyde (MeCHO), respectively.

  10. Analgesic and anti-inflammatory actions on bradykinin route of a polysulfated fraction from alga Ulva lactuca.

    PubMed

    de Araújo, Ianna Wivianne Fernandes; Rodrigues, José Ariévilo Gurgel; Quinderé, Ana Luíza Gomes; Silva, Jane de Fátima Teixeira; Maciel, Gabrielle de Freitas; Ribeiro, Natássia Albuquerque; de Sousa Oliveira Vanderlei, Edfranck; Ribeiro, Kátia Alves; Chaves, Hellíada Vasconcelos; Pereira, Karuza Maria Alves; Bezerra, Mirna Marques; Benevides, Norma Maria Barros

    2016-11-01

    We investigated structural features of polysaccharides from Ulva lactuca and their effects on the classical models of nociception and inflammation. Crude extract was obtained by enzymatic digestion and isolated by ion exchange chromatography on DEAE-cellulose. The fraction with higher yield was used in the tests (SP-Ul). Swiss mice received SP-Ul (1, 3 or 9mg/kg; i.v.), 30min prior to injection of 0.8%-acetic acid or 1%-formalin or prior to a thermal stimulus. At same doses, SP-Ul was tested on Wistar rats on paw edema elicited by different irritants (carrageenan, dextran, bradykinin, histamine or serotonin). The results of infrared characterization indicated the presence of hydroxyl groups, sulfate, uronic acid and glycosidic linkages in all SP fractions spectrums. SP-Ul decreased significantly the antinociception in response to acetic acid or formalin (second phase), but not in the hot-plate test, suggesting that its analgesia occurs through a peripheral mechanism. SP-Ul did not reduce carrageenan-induced paw edema as supported by both histological and myeloperoxidase activity assessments. However, SP-Ul (1mg/kg; s.c.) reduced dextran-elicited edema, showing vascular anti-inflammatory effect, with bradykinin as major target because it did not reduce histamine- and serotonin-induced paw edemas. Therefore, SP-Ul acts on bradykinin pathway in its antinociceptive and anti-inflammatory responses.

  11. Process-based modeling of temperature and water profiles in the seedling recruitment zone: Part II. Seedling emergence timing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Predictions of seedling emergence timing for spring wheat are facilitated by process-based modeling of the microsite environment in the shallow seedling recruitment zone. Hourly temperature and water profiles within the recruitment zone for 60 days after planting were simulated from the process-base...

  12. Effects of flooding regime and seedling treatment on early survival and growth of nuttall oak

    USGS Publications Warehouse

    Burkett, V.R.; Draugelis-Dale, R.O.; Williams, H.M.; Schoenholtz, S.H.

    2005-01-01

    Effects of flooding on survival and growth of three different types of Nuttall oak (Quercus texana Buckl.) seedlings were observed at the end of third and fifth growing seasons at Yazoo National Wildlife Refuge, Mississippi, U.S.A. Three types of seedlings were planted in January 1995 in a split-plot design, with four replications at each of two elevations on floodprone, former cropland in Sharkey clay soil. The lower of the two planting elevations was inundated for 21 days during the first growing season, whereas the higher elevation did not flood during the 5-year period of this study. The three types of 1-0 seedlings were bareroot seedlings, seedlings grown in containers (3.8 ?? 21a??cm plastic seedling cones), and container-grown seedlings inoculated with vegetative mycelia of Pisolithus tinctorius (Pers.) Coker. Survival of all the three seedling types was greatest at the lower, intermittently flooded elevation, indicating that drought and related effects on plant competition were more limiting to seedling survival than flooding. At the lower elevation, survival of mycorrhizal-inoculated container seedlings was greater than that of noninoculated container seedlings. Survival among bareroot seedlings and inoculated container seedlings was not significantly different at either elevation. At the higher, nonflooded elevation, however, bareroot seedling survival was greater than the survival of container seedlings without inoculation. Differences were significant among the inoculated and the noninoculated container seedlings, with higher survival of inoculated seedlings at both elevations, though differences were only significant in year 3. At the end of the fifth year, height of bareroot seedlings was significantly greater than the heights of both types of container-grown seedlings at both planting elevations. Because seedlings grown in the plastic seedlings cones did not survive better than the bareroot seedlings at either planting elevation, the bareroot stock

  13. Temperature Requirements for Seed Germination and Seedling Development Determine Timing of Seedling Emergence of Three Monocotyledonous Temperate Forest Spring Geophytes

    PubMed Central

    Vandelook, Filip; Van Assche, Jozef A.

    2008-01-01

    Background and Aims The optimal period for seedling emergence depends on factors such as habitat preference, life cycle and geographical distribution. This research was performed to clarify the role of temperature in regulating processes leading to seedling emergence of the European continental Scilla bifolia and the Atlantic Narcissus pseudonarcissus and Hyacinthoides non-scripta. Methods Experiments in natural conditions were performed to examine the phenology of embryo growth, seed germination in the soil and seedling emergence. Effects of temperature conditions on embryo growth, seed germination, seedling growth and leaf formation were studied in temperature-controlled incubators. Key Results In nature, embryo growth of all three species was initiated from the moment the seeds were dispersed in spring and continued during summer. A sequence of high temperature followed by a lower temperature was required to complete embryo growth and initiate germination. Seeds of H. non-scripta and N. pseudonarcissus germinated in autumn once they attained the critical E:S ratio, while seeds of S. bifolia started germinating when temperatures were low in winter. Seedlings developed normally, but slowly, only when placed in low temperature conditions (5 or 10 °C), resulting in a time lag between the moment of radicle protrusion and seedling emergence in the field. Conclusions A continuous development of the embryo and seedlings of the three species was observed from the moment the seeds were dispersed until seedlings emerged. A sequence of high summer temperatures followed by decreasing autumn and winter temperatures was required for all developmental processes to be completed. Although a time lag occurs between radicle protrusion and seedling emergence, the term ‘epicotyl dormancy’ does not apply here, due to the absence of a period of developmental arrest. Timing of first seedling emergence differed between the three species and could be related to differences in

  14. Allelopathic effect of alfalfa (Medicago sativa) on bladygrass (Imperata cylindrica).

    PubMed

    Abdul-Rahman, A A; Habib, S A

    1989-09-01

    Greenhouse and laboratory experiments were conducted at the Agricultural and Water Resources Research Center Station, Baghdad, in 1985 and 1986 to investigate the possible allelopathic potential of alfalfa (Medicago saliva L.) and its decomposed residues on bladygrass (Imperata cylin-drica L. Beauv.), a noxious weed in Iraq, and to isolate, characterize, and quantify possible allelopathic agents in alfalfa residues and root exudates. Results indicated that decomposed alfalfa roots and their associated soil produced a 51-56% reduction in bladygrass seed germination. Root and shoot length of bladygrass seedlings were reduced by an average of 88%. Decayed and undecayed mixtures of alfalfa roots and soil at 0.015∶1 (w/w) inhibited bladygrass seedlings reproduced from rhizomes by 30 and 42%. It was found that root exudates of alfalfa seedlings caused significant reduction in shoot and root dry weights of bladygrass seedlings when alfalfa and bladygrass were grown together in nutrient culture. Caffeic, chlorogenic, isochloro-genic,p-coumaric,p-OH-benzoic, and ferulic acids were detected in alfalfa root exudates and residues. The highest amount (126 fig phenolic acids/g soil) of these compounds was found in alfalfa root residues after six months of decomposition in soil.

  15. Genetic diversity of seagrass seeds influences seedling morphology and biomass.

    PubMed

    Randall Hughes, A; Hanley, Torrance C; Schenck, Forest R; Hays, Cynthia G

    2016-12-01

    Genetic diversity can influence ecological processes throughout ontogeny, yet whether diversity at early life history stages is important in long-lived taxa with overlapping generations is unclear. Seagrass systems provide some of the best evidence for the ecological effects of genetic diversity among adult shoots, but we do not know if the genetic diversity of seeds and seedlings also influences seagrass ecology. We tested the effects of seagrass (Zostera marina) seed diversity and relatedness on germination success, seedling morphology, and seedling production by comparing experimental assemblages of seeds collected from single reproductive shoots ("monocultures") to assemblages of seeds collected from multiple reproductive shoots ("polycultures"). There was no difference in seedling emergence, yet seedlings from polycultures had larger shoots above and below ground than seedlings from monocultures at the end of the 1-yr experiment. Genetic relatedness of the seedlings predicted some aspects of shoot morphology, with more leaves and longer roots and shoots at intermediate levels of relatedness, regardless of seed diversity. Our results suggest that studies of only adult stages may underestimate the importance of genetic diversity if the benefits at early life history stages continue to accrue throughout the life cycle.

  16. Flow and scour constraints on uprooting of pioneer woody seedlings

    NASA Astrophysics Data System (ADS)

    Bywater-Reyes, Sharon; Wilcox, Andrew C.; Stella, John C.; Lightbody, Anne F.

    2015-11-01

    Scour and uprooting during flood events is a major disturbance agent that affects plant mortality rates and subsequent vegetation composition and density, setting the trajectory of physical-biological interactions in rivers. During flood events, riparian plants may be uprooted if they are subjected to hydraulic drag forces greater than their resisting force. We measured the resisting force of woody seedlings established on river bars with in situ lateral pull tests that simulated flood flows with and without substrate scour. We quantified the influence of seedling size, species (Populus and Tamarix), water-table depth, and scour depth on resisting force. Seedling size and resisting force were positively related with scour depth and water-table depth—a proxy for root length—exerting strong and opposing controls on resisting force. Populus required less force to uproot than Tamarix, but displayed a greater increase in uprooting force with seedling size. Further, we found that calculated mean velocities required to uproot seedlings were greater than modeled flood velocities under most conditions. Only when plants were either shallowly rooted or subjected to substrate scour (≥0.3 m) did the calculated velocities required for uprooting decrease to within the range of modeled flood velocities, indicating that drag forces alone are unlikely to uproot seedlings in the absence of extreme events or bar-scale sediment transport. Seedlings on river bars are most resilient to uprooting when they are large, deeply rooted, and unlikely to experience substrate scour, which has implications for ecogeomorphic evolution and river management.

  17. Growth of ponderosa pine seedlings as affected by air pollution

    NASA Astrophysics Data System (ADS)

    Momen, B.; Anderson, P. D.; Houpis, J. L. J.; Helms, J. A.

    The effect of air pollution on seedling survival and competitive ability is important to natural and artificial regeneration of forest trees. Although biochemical and physiological processes are sensitive indicators of pollution stress, the cumulative effects of air pollutants on seedling vigor and competitive ability may be assessed directly from whole-plant growth characteristics such as diameter, height, and photosynthetic area. A few studies that have examined intraspecific variation in seedling response to air pollution indicate that genotypic differences are important in assessing potential effects of air pollution on forest regeneration. Here, we studied the effects of acid rain (no-rain, pH 5.1 rain, pH 3.0 rain) and ozone (filtered, ambient, twice-ambient) in the field on height, diameter, volume, the height:diameter ratio, maximum needle length, and time to reach maximum needle length in seedlings of three families of ponderosa pine ( Pinus ponderosa Dougl. ex Laws). Seedling diameter, height, volume, and height:diameter ratio related significantly to their pre-treatment values. Twice-ambient ozone decreased seedling diameter compared with ozone-filtered air. A significant family-by-ozone interaction was detected for seedling height, as the height of only one of the three families was decreased by twice-ambient ozone compared with the ambient level. Seedling diameter was larger and the height:diameter ratio was smaller under pH 3.0 rain compared to either the no-rain or the pH 5.1-rain treatment. This suggests greater seedling vigor, perhaps due to a foliar fertilization effect of the pH 3.0 rain.

  18. Photomodulation of strigolactone biosynthesis and accumulation during sunflower seedling growth.

    PubMed

    Bharti, Niharika; Tripathi, Smita; Bhatla, Satish Chander

    2015-01-01

    Present investigations report the presence of strigolactones (SLs) and photomodulation of their biosynthesis in sunflower seedlings (roots, cotyledons and first pair of leaves) during early phase of seedling development. Qualitative analyses and characterization by HPLC, ESI-MS and FT-IR revealed the presence of more than one type of SLs. Orobanchyl acetate was detected both in roots and leaves. Five-deoxystrigol, sorgolactone and orobanchol were exclusively detected in seedling roots. Sorgomol was detectable only in leaves. HPLC eluted fraction from seedling roots and leaves co-chromatographing with GR24 (a synthetic SL) could also bring about germination in Orobanche cernua (a weed) seeds, which are established to exhibit SL - mediated germination, thereby indicating the SL identity of the eluates using this bioassay. SLs accumulation was always more in the roots of light-grown seedlings, it being maximum at 4 d stage. Although significant activity of carotenoid cleavage dioxygenase (CCD, the enzyme critical for SL biosynthesis) was detected in 2 d old seedling roots, SLs remained undetectable in cotyledons at all stages of development and also in the roots of 2 d old light and dark-grown seedlings. Roots of light-grown seedlings showed maximum CCD activity during early (2 d) stage of development, thereby confirming photomodulation of enzyme activity. These observations indicate the migration of a probable light-sensitized signaling molecule (yet to be identified) or a SL precursor from light exposed aerial parts to the seedling roots maintained in dark. Thus, a photomodulation and migration of SL precursor/s is evident from the present work.

  19. Arthropod invasion disrupts Cycas micronesica seedling recruitment.

    PubMed

    Marler, Thomas E; Terry, L Irene

    2011-11-01

    We recently described characteristics of reproductive effort for the cycad Cycas micronesica on the island of Guam. The data were serendipitously recorded just prior to the devastating invasion of the armored scale Aulacaspis yasumatsui. This invasion decimated the cycad population and after six years of infestation no recruitment is occurring among the survivors. We describe various underlying mechanisms that may explain how this homopteran insect has eliminated host recruitment among categories including plant-pollinator mutualism disruptions, direct damage to reproductive structures, population level responses to declining plant health, and failures of seedlings to establish. Our pre-invasion data on reproductive effort will serve as the benchmark for quantifying how this alien pest is endangering the endemic cycad.

  20. Storage oil hydrolysis during early seedling growth.

    PubMed

    Quettier, Anne-Laure; Eastmond, Peter J

    2009-06-01

    Storage oil breakdown plays an important role in the life cycle of many plants by providing the carbon skeletons that support seedling growth immediately following germination. This metabolic process is initiated by lipases (EC: 3.1.1.3), which catalyze the hydrolysis of triacylglycerols (TAGs) to release free fatty acids and glycerol. A number of lipases have been purified to near homogeneity from seed tissues and analysed for their in vitro activities. Furthermore, several genes encoding lipases have been cloned and characterised from plants. However, only recently has data been presented to establish the molecular identity of a lipase that has been shown to be required for TAG breakdown in seeds. In this review we briefly outline the processes of TAG synthesis and breakdown. We then discuss some of the biochemical literature on seed lipases and describe the cloning and characterisation of a lipase called SUGAR-DEPENDENT1, which is required for TAG breakdown in Arabidopsis thaliana seeds.

  1. Arborescent palm seed morphology and seedling distribution.

    PubMed

    Salm, Rodolfo

    2005-11-01

    This study examines how the seed morphology of two large arborescent palms, Attalea maripa (Aubl.) Mart. and Astrocaryum aculeatum G. Mey, may affect their seed shadow in a seasonally dry Amazonian forest. In addition to being smaller and produced in larger numbers than those of A. aculeatum, A. maripa seeds also presented a substantially lower amount of nutritional reserves available for the embryo. However, A. maripa seedlings were found in much higher numbers than those of A. aculeatum. The results suggest that, within the spatial scale considered, the seed rain of A. maripa is more restricted to the area surrounding around reproductive conspecifics than that of A. aculeatum. Furthermore, in comparison with those of A. aculeatum, the smaller seeds of A. maripa might be less attractive to scatterhoarding rodents (e.g. Dasyprocta aguti). The pattern observed emphasizes the importance of scatterhoarding rodents as dispersers of large-seeded plant species in Neotropical forests.

  2. BIM LAU-PE: Seedlings in Microgravity

    NASA Astrophysics Data System (ADS)

    Gass, S.; Pennese, R.; Chapuis, D.; Dainesi, P.; Nebuloni, S.; Garcia, M.; Oriol, A.

    2015-09-01

    The effect of gravity on plant roots is an intensive subject of research. Sounding rockets represent a costeffective platform to study this effect under microgravity conditions. As part of the upcoming MASER 13 sounding rocket campaign, two experiments on Arabidopsis thaliana seedlings have been devised: GRAMAT and SPARC. These experiments are aimed at studying (1) the genes that are specifically switched on or off during microgravity, and (2) the position of auxin-transporting proteins during microgravity. To perform these experiments, RUAG Space Switzerland site of Nyon, in collaboration with the Swedish Space Corporation (SSC) and the University of Freiburg, has developed the BIM LAU-PE (Biolology In Microgravity Late Access Unit Plant Experiment). In the following an overview of the BIM LAU-PE design is presented, highlighting specific module design features and verifications performed. A particular emphasis is placed on the parabolic flight experiments, including results of the micro-g injection system validation.

  3. Endophytic Chaetomium globosum enhances maize seedling copper stress tolerance.

    PubMed

    Abou Alhamed, M F; Shebany, Y M

    2012-09-01

    This study aims at characterisation of the impact of Chaetomium globosum on copper stress resistance of maize seedlings. Higher levels of copper treatment decreased maize dry weight and induced a marked increase in osmotic solutes, antioxidant enzyme activity and the level of lipid peroxidation. On the other hand, addition of the endophytic C. globosum alleviated the toxic effect of copper on maize growth. The combination of copper sulphate and Chaetomium increased seedling dry weight, osmotic solute content and antioxidant enzyme activity compared to copper sulphate alone, while lipid peroxidation levels were also decreased. The fungal scavenger system might be important for supporting the ability of maize seedlings to resist copper toxicity.

  4. Methanosarcina Play an Important Role in Anaerobic Co-Digestion of the Seaweed Ulva lactuca: Taxonomy and Predicted Metabolism of Functional Microbial Communities

    PubMed Central

    FitzGerald, Jamie A.; Allen, Eoin; Wall, David M.; Jackson, Stephen A.; Murphy, Jerry D.; Dobson, Alan D. W.

    2015-01-01

    Macro-algae represent an ideal resource of third generation biofuels, but their use necessitates a refinement of commonly used anaerobic digestion processes. In a previous study, contrasting mixes of dairy slurry and the macro-alga Ulva lactuca were anaerobically digested in mesophilic continuously stirred tank reactors for 40 weeks. Higher proportions of U. lactuca in the feedstock led to inhibited digestion and rapid accumulation of volatile fatty acids, requiring a reduced organic loading rate. In this study, 16S pyrosequencing was employed to characterise the microbial communities of both the weakest (R1) and strongest (R6) performing reactors from the previous work as they developed over a 39 and 27-week period respectively. Comparing the reactor communities revealed clear differences in taxonomy, predicted metabolic orientation and mechanisms of inhibition, while constrained canonical analysis (CCA) showed ammonia and biogas yield to be the strongest factors differentiating the two reactor communities. Significant biomarker taxa and predicted metabolic activities were identified for viable and failing anaerobic digestion of U. lactuca. Acetoclastic methanogens were inhibited early in R1 operation, followed by a gradual decline of hydrogenotrophic methanogens. Near-total loss of methanogens led to an accumulation of acetic acid that reduced performance of R1, while a slow decline in biogas yield in R6 could be attributed to inhibition of acetogenic rather than methanogenic activity. The improved performance of R6 is likely to have been as a result of the large Methanosarcina population, which enabled rapid removal of acetic acid, providing favourable conditions for substrate degradation. PMID:26555136

  5. The relaxant effect of Nigella sativa on smooth muscles, its possible mechanisms and clinical applications.

    PubMed

    Keyhanmanesh, Rana; Gholamnezhad, Zahra; Boskabady, Mohammad Hossien

    2014-12-01

    Nigella sativa (N. sativa) is a spice plant which has been traditionally used for culinary and medicinal purposes. Different therapeutic properties including the beneficial effects on asthma and dyspnea, digestive and gynecology disorders have been described for the seeds of N. sativa. There is evidence of the relaxant effects of this plant and some of its constituents on different types of smooth muscle including rabbit aorta, rabbit jejunum and trachea. The relaxant effect of N. sativa could be of therapeutic importance such as bronchodilation in asthma, vasodilation in hypertension and therapeutic effect on digestive or urogenital disorders. Therefore in the present article, the relaxant effects of N. sativa and its constituents on smooth muscles and its possible mechanisms as well as clinical application of this effect were reviewed.

  6. Phylogeography of Asian wild rice, Oryza rufipogon, reveals multiple independent domestications of cultivated rice, Oryza sativa.

    PubMed

    Londo, Jason P; Chiang, Yu-Chung; Hung, Kuo-Hsiang; Chiang, Tzen-Yuh; Schaal, Barbara A

    2006-06-20

    Cultivated rice, Oryza sativa L., represents the world's most important staple food crop, feeding more than half of the human population. Despite this essential role in world agriculture, the history of cultivated rice's domestication from its wild ancestor, Oryza rufipogon, remains unclear. In this study, DNA sequence variation in three gene regions is examined in a phylogeographic approach to investigate the domestication of cultivated rice. Results indicate that India and Indochina may represent the ancestral center of diversity for O. rufipogon. Additionally, the data suggest that cultivated rice was domesticated at least twice from different O. rufipogon populations and that the products of these two independent domestication events are the two major rice varieties, Oryza sativa indica and Oryza sativa japonica. Based on this geographical analysis, O. sativa indica was domesticated within a region south of the Himalaya mountain range, likely eastern India, Myanmar, and Thailand, whereas O. sativa japonica was domesticated from wild rice in southern China.

  7. Roles of hydrogen sulfide and nitric oxide in the alleviation of cadmium-induced oxidative damage in alfalfa seedling roots.

    PubMed

    Li, Le; Wang, Yanqin; Shen, Wenbiao

    2012-06-01

    Despite hydrogen sulfide (H(2)S) and nitric oxide (NO) are important endogenous signals or bioregulators involved in many vital aspects of plant growth and responses against abiotic stresses, little information was known about their interaction. In the present study, we evaluated the effects of H(2)S and NO on alfalfa (Medicago sativa L.) plants exposed to cadmium (Cd) stress. Pretreatment with an H(2)S donor sodium hydrosulfide (NaHS) and well-known NO donor sodium nitroprusside (SNP) decreased the Cd toxicity. This conclusion was supported by the decreases of lipid peroxidation as well as the amelioration of seedling growth inhibition and Cd accumulation, in comparison with the Cd-stressed alone plants. Total activities and corresponding transcripts of antioxidant enzymes, including superoxide dismutase, peroxidase and ascorbate peroxidase were modulated differentially, thus leading to the alleviation of oxidative damage. Effects of H(2)S above were reversed by 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide potassium salt (cPTIO), the specific scavenger of NO. By using laser confocal scanning microscope combined with Greiss reagent method, further results showed that NO production increased significantly after the NaHS pretreatment regardless of whether Cd was applied or not, all of which were obviously inhibited by cPTIO. These decreases of NO production were consistent with the exaggerated syndromes associated with Cd toxicity. Together, above results suggested that NO was involved in the NaHS-induced alleviation of Cd toxicity in alfalfa seedlings, and also indicated that there exists a cross-talk between H(2)S and NO responsible for the increased abiotic stress tolerance.

  8. Salt-induced subcellular kinase relocation and seedling susceptibility caused by overexpression of Medicago SIMKK in Arabidopsis.

    PubMed

    Ovečka, Miroslav; Takáč, Tomáš; Komis, George; Vadovič, Pavol; Bekešová, Slávka; Doskočilová, Anna; Šamajová, Veronika; Luptovčiak, Ivan; Samajová, Olga; Schweighofer, Alois; Meskiene, Irute; Jonak, Claudia; Křenek, Pavel; Lichtscheidl, Irene; Škultéty, L'udovít; Hirt, Heribert; Šamaj, Jozef

    2014-06-01

    Dual-specificity mitogen-activated protein kinases kinases (MAPKKs) are the immediate upstream activators of MAPKs. They simultaneously phosphorylate the TXY motif within the activation loop of MAPKs, allowing them to interact with and regulate multiple substrates. Often, the activation of MAPKs triggers their nuclear translocation. However, the spatiotemporal dynamics and the physiological consequences of the activation of MAPKs, particularly in plants, are still poorly understood. Here, we studied the activation and localization of the Medicago sativa stress-induced MAPKK (SIMKK)-SIMK module after salt stress. In the inactive state, SIMKK and SIMK co-localized in the cytoplasm and in the nucleus. Upon salt stress, however, a substantial part of the nuclear pool of both SIMKK and SIMK relocated to cytoplasmic compartments. The course of nucleocytoplasmic shuttling of SIMK correlated temporally with the dual phosphorylation of the pTEpY motif. SIMKK function was further studied in Arabidopsis plants overexpressing SIMKK-yellow fluorescent protein (YFP) fusions. SIMKK-YFP plants showed enhanced activation of Arabidopsis MPK3 and MPK6 kinases upon salt treatment and exhibited high sensitivity against salt stress at the seedling stage, although they were salt insensitive during seed germination. Proteomic analysis of SIMKK-YFP overexpressors indicated the differential regulation of proteins directly or indirectly involved in salt stress responses. These proteins included catalase, peroxiredoxin, glutathione S-transferase, nucleoside diphosphate kinase 1, endoplasmic reticulum luminal-binding protein 2, and finally plasma membrane aquaporins. In conclusion, Arabidopsis seedlings overexpressing SIMKK-YFP exhibited higher salt sensitivity consistent with their proteome composition and with the presumptive MPK3/MPK6 hijacking of the salt response pathway.

  9. [Seasonal variations of metal contents (Cd, Cu, Fe, Mn and Zn) in seaweed Ulva lactuca from the coast of El Jadida city (Morocco)].

    PubMed

    Kaimoussi, Aziz; Mouzdahir, Abdelkrim; Saih, Abdelkbir

    2004-04-01

    The quality of El Jadida Atlantic coastal water was monitored from April 1998 to March 1999 by measuring hydrological parameters (dissolved oxygen, suspended particulate matter, phosphates and nitrites) and using the seaweed Ulva lactuca as a quantitative bio-indicator of cadmium, copper, iron, manganese and zinc contamination. Metal content in seaweeds, collected every month from four stations characterized by the discharge of urban and industrial waste water, showed significant variations depending on the station and sampling period. However, the seaweed of El Jadida exhibited generally lower contents compared to those of similar species from other geographical areas.

  10. The protective effect of Nigella sativa against cisplatin-induced nephrotoxicity in rats

    PubMed Central

    Hosseinian, Sara; Khajavi Rad, Abolfazl; Hadjzadeh, Mousa-Al-Reza; Mohamadian Roshan, Nema; Havakhah, Shahrzad; Shafiee, Somayeh

    2016-01-01

    Objective: The clinical use of cisplatin is highly restricted, because of its nephrotoxicity. In this study the protective effect of Nigella sativa (N. sativa) against cisplatin-induced nephrotoxicity was investigated in rats. Materials and Methods: In the current study, the effects of the administration of aqueous-ethanolic extract of N. sativa (100 and 200 mg/kg, BW) and vitamin E (100 mg/kg, BW) against blood and urine biochemical alterations and kidney function in rats treated with cisplatin were investigated. Cisplatin was injected at a dose of 6 mg/kg, BW, on the sixth day of the experiment. Results: The results indicated significant changes in serum urea and creatinine concentration, urine glucose concentration, and urine output in cisplatin group compared with control group. Serum urea and creatinine concentration in preventive and preventive+treatment vitamin E and preventive+treatment N. sativa (200 mg/kg, BW) groups and also serum creatinine concentration in preventive+treatment N. sativa (100 mg/kg, BW) group significantly decreased compared with cisplatin group. Urine glucose concentration in preventive and preventive+treatment N. sativa groups and urine output in preventive and preventive+treatment N. sativa (200 mg/kg, BW) groups significantly decreased compared with cisplatin group.Osmolarity excretion rate in preventive and preventive+treatment vitamin E and preventive N. sativa groups was significantly higher than control group. Conclusions: The current study suggests that N. sativa extract and vitamin E in a dose- and time-dependent manner improved the serum and urine biochemical parameters and kidney function in cisplatin-induced nephrotoxicity in rats. However, it needs more investigations to determine the mechanism of N. sativa action on cisplatin-induced kidney toxicity. PMID:27247921

  11. Nigella sativa and its active constituent thymoquinone in oral health

    PubMed Central

    AlAttas, Safia A.; Zahran, Fat’heya M.; Turkistany, Shereen A.

    2016-01-01

    In this review, we summarized published reports that investigated the role of Nigella sativa (NS) and its active constituent, thymoquinone (TQ) in oral health and disease management. The literature studies were preliminary and scanty, but the results revealed that black seed plants have a potential therapeutic effect for oral and dental diseases. Such results are encouraging for the incorporation of these plants in dental therapeutics and hygiene products. However, further detailed preclinical and clinical studies at the cellular and molecular levels are required to investigate the mechanisms of action of NS and its constituents, particularly TQ. PMID:26905343

  12. Complete sequence of a cryptic virus from hemp (Cannabis sativa).

    PubMed

    Ziegler, Angelika; Matoušek, Jaroslav; Steger, Gerhard; Schubert, Jörg

    2012-02-01

    Hemp (Cannabis sativa) was found to be a useful propagation host for hop latent virus, a carlavirus. However, when virus preparations were analysed by electron microscopy, along with the expected filamentous particles, spherical particles with a diameter of around 34 nm were found. RNA from virus preparations was purified, and cDNA was prepared and cloned. Sequence information was used to search databases, and the greatest similarity was found with Primula malacoides virus 1, a putative new member of the genus Partitivirus. The full sequences of RNA 1 and RNA 2 of this new hemp cryptic virus were obtained.

  13. ARC EMCS Experiments (Seedling Growth-2) Experiment Status

    NASA Technical Reports Server (NTRS)

    Heathcote, David; Steele, Marianne

    2015-01-01

    Presentation of the status of the ARC ISS (International Space Station) Experiment, Seedling Growth-2 to the Payload Operations Investigator Working Group meeting at MSFC, Huntsville AL. The experiment employs the European Modular Cultivation System (ECMS).

  14. Limitations to seedling establishment in a mesic Hawaiian forest.

    PubMed

    Denslow, Julie S; Uowolo, Amanda L; Hughes, R Flint

    2006-05-01

    While invasive species may be visible indicators of plant community degradation, they may not constitute the only, or even the primary, limitation to stand regeneration. We used seed-augmentation and grass-removal experiments under different canopy conditions to assess the relative importance of dispersal limitation, resource availability, and competition on seedling establishment in the understory shrubs Sophora chrysophilla, Dodonea viscosa, and Pipturus albidus in a montane mesic forest in Hawaii. The study location was an Acacia koa-Metrosideros polymorpha forest at 1000-1500 m elevation on the leeward side of Hawaii Island; it is a closed-canopy forest historically subject to logging and grazing by cattle and sheep and currently dominated by the exotic grass, Ehrharta stipoides, in the herb layer. Seedling establishment after 1 and 2 years was strongly dispersal limited in Sophora and Dodonea, but not in Acacia, a non-augmented species in which abundant seedlings established, nor in Pipterus, in which only one seedling established in 2 years. Grass cover reduced seedling establishment in Acacia, Sophora, and Dodonea and, for the latter two species, seedling establishment was substantially greater in the warmer, more moist forest at the lowest elevation. Light, moisture, and resin-captured N and P were more strongly affected by elevation and canopy composition than by grass cover, but in most cases seedling establishment was not positively correlated with resource availability. Limitations to the establishment of woody seedlings in this forest-grassland mixture vary among species; however, both dispersal limitation and competition from a shade-tolerant grass are important deterrents to regeneration in these forests.

  15. Actin of Beta vulgaris seedlings under the clinorotation

    NASA Astrophysics Data System (ADS)

    Kozeko, L. Ye.

    We study the influence of altered gravity on actin expression in roots of Beta vulguris seedlings grown on the horizontal clinostat (2 rpm) from seed germination for three days. It is shown that the total actin quantity was not influenced. Three actin isoforms are revealed; a relative protein quantity of these isoforms was similar both in clinorotated seedlings and in ones grown in norm. This point to stable expression of actin under the altered gravity conditions.

  16. Translocation of Paclobutrazol, a Gibberellin Biosynthesis Inhibitor, in Apple Seedlings

    PubMed Central

    Wang, Shiow Y.; Sun, Tung; Faust, Miklos

    1986-01-01

    The [(2RS,3RS)-1-(4-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-1- yl)-pentan-3-ol] (paclobutrazol, PP333) measured in apple seedlings (`York Imperial' Malus domestica Borkh) was confirmed by gas chromatography-mass spectrometry. Data showed that paclobutrazol was taken up through roots and transported primarily in the xylem through the stems and accumulated in leaves. No detectable basipetal movement of paclobutrazol in apple seedlings was found. PMID:16664976

  17. Use of spent mushroom substrates from Agaricus subrufescens (syn. A. blazei, A. brasiliensis) and Lentinula edodes productions in the enrichment of a soil-based potting media for lettuce (Lactuca sativa) cultivation: Growth promotion and soil bioremediation.

    PubMed

    Ribas, L C C; de Mendonça, M M; Camelini, C M; Soares, C H L

    2009-10-01

    This study aimed to assess physicochemical and microbiological properties of fresh spent mushroom substrates (SMSs)--without post-crop heat treatment--from Agaricus subrufescens and Lentinula edodes production to optimize the use of these residues in the soil enrichment for lettuce growth promotion and soil remediation. Organic matter and C content of both SMSs were high. Fresh A. subrufescens SMS was a good source of N, P and K. On the other hand, L. edodes SMS presented a lower concentration of these nutrients and a high level of immaturity. Both SMSs presented high electric conductivity values (2.5-3.4 mS/cm). Microbiological analysis, based upon enumeration of culturable bacteria (thermophilic and mesophilic) and fungi, and also evolution of CO(2), showed that SMSs played higher microbial diversity than soil control. Laccase activity from A. subrufescens SMS tended to remain constant during a 2-month period, while L. edodes SMS presented low laccase activity throughout the same period. Agaricus subrufescens and L. edodes were able to grow on a PDA (Potato Dextrose Agar) media supplemented with different concentrations of atrazine (1-50 microg/ml), degraded the herbicide, attaining rates of 35% and 26%, respectively. On experiments of lettuce growth promotion using a soil-based potting media with different SMS rates, 5% and 10% (dw) rates of A. subrufescens SMS resulted in higher lettuce aerial dry weights than the rates of 25% and 40%, the chemical fertilization (NPK) and the control (soil). At 10% supplementation, lettuce aerial dry weight increased 2.2 and 1.3 times compared to the control and the NPK treatment, respectively. Protein content increased along with SMS rates. Fresh A. subrufescens SMS was an excellent supplement for lettuce growth promotion and showed potential for remediation of biocides possibly due to improved microbial diversity and enzymatic activity. Fresh L. edodes SMS was not a good fertilizer, at least under the conditions tested. However, microbiological analysis showed that promising results may be achieved when using fresh L. edodes SMS for soil remediation.

  18. Potential of a metal-organic framework as a new material for solid-phase extraction of pesticides from lettuce (Lactuca sativa), with analysis by gas chromatography-mass spectrometry.

    PubMed

    Barreto, Alysson S; da Silva, Rogério Luiz; Dos Santos Silva, Silvia Caroline G; Rodrigues, Marcelo O; de Simone, Carlos A; de Sá, Gilberto F; Júnior, Severino A; Navickiene, Sandro; de Mesquita, Maria Eliane

    2010-12-01

    The metal-organic framework (∞)[(La(0.9)Eu(0.1))(2)(DPA)(3)(H(2)O)(3)] was tested for extraction of pyrimicarb, procymidone, malathion, methyl parathion and α- and β-endosulfan from lettuce, with analysis using GC/MS in SIM mode. Experiments were carried out in triplicate at two fortification levels (0.1 and 0.5 mg/kg), and resulted in recoveries in the range of 78-107%, with RSD values between 1.6 and 8.0% for (∞)[(La(0.9)Eu(0.1))(2)(DPA)(3)(H(2)O)(3)] sorbent. Detection and quantification limits ranged from 0.02 to 0.05 mg/kg and from 0.05 to 0.10 mg/kg, respectively, for the different pesticides studied. The method developed was linear over the range tested (0.05-10.0 μg/mL), with correlation coefficients ranging from 0.9990 to 0.9997. Comparison between (∞)[(La(0.9)Eu(0.1))(2)(DPA)(3)(H(2)O)(3)] and conventional sorbent (silica gel) showed better performance of the (∞)[(La(0.9)Eu(0.1))(2)(DPA)(3)(H(2)O)(3)] polymeric sorbent for all pesticides tested.

  19. Moderate and high doses of sodium hypochlorite, neutral electrolyzed oxidizing water, peroxyacetic acid, and gaseous chlorine dioxide did not affect the nutritional and sensory qualities of fresh-cut Iceberg lettuce (Lactuca sativa Var. capitata L.) after washing.

    PubMed

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

    2009-05-27

    Besides the traditionally used sodium hypochlorite (20 and 200 mg L(-1)), alternative sanitizers such as peroxyacetic acid (80 and 250 mg L(-1)) and neutral electrolyzed oxidizing water (4.5 and 30 mg L(-1) free chlorine) as well as chlorine dioxide gas (1.54 mg L(-1)) were evaluated for their efficiency in reducing the microbial load of fresh-cut iceberg lettuce. An additional rinsing step with tap water and cooling of the sanitizing solutions, which are obvious for the fresh-cut industry, were not performed within the current study. The high doses of sodium hypochlorite and peroxyacetic acid tested within this study do not conform to the normally used concentrations within the fresh-cut industry. Neutral electrolyzed oxidizing water (30 mg L(-1)), peroxyacetic acid (250 mg L(-1)), and gaseous chlorine dioxide significantly reduced the total aerobic plate count of cut lettuce in comparison with water wash treatments alone. None of the treatments significantly affected the sensory quality of the lettuce, although small color changes were observed after colorimetric measurements. From a nutritional point of view water rinsing significantly decreased the vitamin C (maximum 35%) and phenol (maximum 17%) contents, but did not affect the carotenoid and α-tocopherol contents. Additional effects caused by adding a sanitizer to the wash water were not observed for vitamin C and phenols. Conversely, washing with 250 mg L(-1) peroxyacetic acid reduced the β-carotene content by about 30%, whereas using 200 mg L(-1) sodium hypochlorite reduced both the lactucaxanthin and the lutein contents by about 60%. Use of gaseous chlorine dioxide also had an impact on the lutein content (-18%). Furthermore, the α-tocopherol content was reduced by 19.7 and 15.4% when the two concentrations of neutral electrolyzed oxidizing water were used, respectively. These data represent the situation on day 0. In a next phase, shelf-life studies considering microbial and sensory quality and nutrient content should be conducted.

  20. A single recessive gene conferring short leaves in romaine x Latin type lettuce (Lactuca sativa L.) crosses, and its effect on plant morphology and resistance to lettuce drop caused by Sclerotinia minor Jagger.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Understanding the relationship between plant morphology and disease resistance is crucial to successful breeding, particularly resistance to lettuce drop caused by Sclerotinia minor. Latin type lettuce cultivars are small plants with upright leaves longer than they are wide, similar to romaine type...

  1. Reuse of Organomineral Substrate Waste from Hydroponic Systems as Fertilizer in Open-Field Production Increases Yields, Flavonoid Glycosides, and Caffeic Acid Derivatives of Red Oak Leaf Lettuce (Lactuca sativa L.) Much More than Synthetic Fertilizer.

    PubMed

    Dannehl, Dennis; Becker, Christine; Suhl, Johanna; Josuttis, Melanie; Schmidt, Uwe

    2016-09-28

    Effects of organic waste from a hydroponic system added with minerals (organomineral fertilizer) and synthetic fertilizer on major polyphenols of red oak leaf lettuce using HPLC-DAD-ESI-MS(3) were investigated. Interestingly, contents of the main flavonoid glycosides and caffeic acid derivatives of lettuce treated with organomineral fertilizer were equal to those synthesized without soil additives. This was found although soil nutrient concentrations, including that of nitrogen, were much lower without additives. However, lettuce treated with synthetic fertilizer showed a significant decrease in contents of caffeic acid derivatives and flavonoid glycosides up to 78.3 and 54.2%, respectively. It is assumed that a negative effect of a high yield on polyphenols as described in the growth-differentiation balance hypothesis can be counteracted by (i) a higher concentration of Mg or (ii) optimal physical properties of the soil structure. Finally, the organomineral substrate waste reused as fertilizer and soil improver resulted in the highest yield (+78.7%), a total fertilizer saving of 322 kg ha(-1) and waste reduction in greenhouses.

  2. Effects of light level, time of harvest and position within field on the variability of tissue nitrate concentration in commercial crops of lettuce (Lactuca sativa) and endive (Cichorium endiva).

    PubMed

    Weightman, R M; Dyer, C; Buxton, J; Farrington, D S

    2006-05-01

    Seven commercial crops of lettuce and one crop of endive were sampled in order to study the variability in plant tissue nitrate concentration (TNC). Assuming that an appropriate sampling pattern was employed, ten plants were sufficient to give an acceptable estimate of the mean TNC. Short-term shading (24-48 h) had no significant effects on mean TNC, unlike the increase in TNC known to occur following dull periods 10-14 days before harvest. The effect on TNC of time of day harvested was significant, but there was no obvious pattern of diurnal variation. Averaged over all experiments, the coefficient of variation for TNC was in the order of 35%. Increasing the sample size from ten to 40 plants would only be expected to decrease the standard error of measurement of TNC from 16 to 12% of the mean because of the underlying analytical error, which would remain constant.

  3. Molecular biology of Ganoderma pathogenicity and diagnosis in coconut seedlings.

    PubMed

    Kandan, A; Radjacommare, R; Ramanathan, A; Raguchander, T; Balasubramanian, P; Samiyappan, R

    2009-01-01

    The pathogenicity of Ganoderma boninense was tested on coconut seedlings under greenhouse conditions and infection confirmed by using immunological and molecular diagnostic tools. Desiccation of older leaves and the emergence of sporophores were observed from pathogen-inoculated seedlings, whereas a control seedling does not show any pathogenic symptoms. Mature sporophores were formed within 10-13 weeks after inoculation. Polyclonal antibodies raised against mycelial proteins of Ganoderma were used for detection of Ganoderma in infected field palm and seedlings through indirect enzyme-linked immunosorbent assay technique. We adopted dot-immunobinding assay for the detection of Ganoderma from greenhouse and field samples. Under nucleic-acid-based diagnosis, G. boninense (167 bp) was detected from artificially inoculated seedlings and infected field palms by polymerase chain reaction. Apart from these, histopathological studies also support the Ganoderma pathogenicity in coconut seedlings. The pathogenicity test and combination of all the three diagnostic methods for Ganoderma could be highly reliable, rapid, sensitive and effective screening of resistance in planting material in the future.

  4. Eucalyptus obliqua seedling growth in organic vs. mineral soil horizons.

    PubMed

    Barry, Karen M; Janos, David P; Nichols, Scott; Bowman, David M J S

    2015-01-01

    Eucalyptus obliqua, the most widespread timber tree in Tasmania, is a pioneer after fire which can eliminate the organic layer of forest soil, exposing the underlying mineral soil. We compared seedling growth, mycorrhiza formation, and mineral nutrient limitation in organic layer vs. mineral soil. We grew E. obliqua seedlings separately in pots of organic layer and mineral soil in a glasshouse. Additional treatments of organic soil only, involved fully crossed methyl-bromide fumigation and fertilization. Fertilization comprised chelated iron for 121 days after transplant (DAT) followed by soluble phosphorus. At 357 DAT, whole plant dry weight was three times greater in ambient organic than in mineral soil. In organic soil, fumigation halved ectomycorrhiza abundance and reduced seedling growth at 149 DAT, but by 357 DAT when negative effects of fumigation on seedling growth had disappeared, neither fumigation nor fertilization affected mycorrhiza abundance. Iron fertilization diminished seedling growth, but subsequent phosphorus fertilization improved it. E. obliqua seedlings grow much better in organic layer soil than in mineral soil, although phosphorus remains limiting. The prevalent forestry practice of burning to mineral soil after timber harvest exposes a poor growth medium likely only partially compensated by fire-induced mineral soil alterations.

  5. Considerations for evaluating controlled exposure studies of tree seedlings

    SciTech Connect

    Peterson, C.E. Jr.; Mickler, R.A.

    1994-03-01

    Tree seedling exposure studies, covering a wide range of experimental conditions in pollutant treatments, species, facilities, and exposure regimes, have been conducted during the past several years to determine acute effects and relative sensitivity of tree species in response to simulated acid precipitation and gaseous pollutants. Because of the difficulties inherent in conducting controlled exposures with mature trees (e.g., size, variability among experimental units, and costs associated with replication of treatments), seedling exposure studies have been initiated as the quickest way to address these issues. However, sufficient consideration has not been given to either the comparability of seedling studies or to their appropriate inference. The statistical power of any given analysis is rarely discussed when the outcomes are published. Appropriate and documented statistics of experimenter bias are often not reported, and variability in the exposure regime (ie., treatment target levels) and the measurement of experimental variables is assumed to be zero, rather than quantified. FInally, the populations of seedlings for which seedling experiments have inferences the extent to which seedling responses are applicable to mature trees and forest condition, and the limitations in national or regional generalizations are crucial issues often left to an individual reader`s interpretation without the benefit of adequate quantitative information presented by the authors. 31 refs., 8 figs., 1 tab.

  6. Wood formation in Abies balsamea seedlings subjected to artificial defoliation.

    PubMed

    Rossi, Sergio; Simard, Sonia; Deslauriers, Annie; Morin, Hubert

    2009-04-01

    We determined the cambial sensitivity and quantified the anatomical differences in xylem of Abies balsamea (L.) Mill. seedlings subjected to artificial defoliation to simulate spruce budworm feeding. Defoliation was performed by removing two-thirds of needles of all current-year shoots for up to four consecutive growth cycles to account for inter- and intra-annual xylem formation. In Experiment 1, xylem development was studied from May to October 2005 in seedlings defoliated at the end of June. In Experiment 2, anatomical features of the xylem were measured along the tree rings formed in 2005 and 2006 during the four cycles of growth and defoliation. Control and defoliated seedlings showed similar patterns of cambial activity and timing of xylem differentiation, although fewer enlarging cells were observed in August to September in defoliated seedlings. Tree-ring widths were similar in control and defoliated seedlings, with thinner rings produced in the greenhouse in winter. No effect of defoliation on cell lumen area was observed, and effects on radial cell diameter and wall thickness were found only occasionally. The results indicate that the A. balsamea seedlings produced all the resources required to maintain stem growth during the four cycles of defoliation.

  7. Development of Loop-Mediated Isothermal Amplification (LAMP) Assay for Rapid Detection of Cannabis sativa.

    PubMed

    Kitamura, Masashi; Aragane, Masako; Nakamura, Kou; Watanabe, Kazuhito; Sasaki, Yohei

    2016-07-01

    In many parts of the world, the possession and cultivation of Cannabis sativa L. are restricted by law. As chemical or morphological analyses cannot identify the plant in some cases, a simple yet accurate DNA-based method for identifying C. sativa is desired. We have developed a loop-mediated isothermal amplification (LAMP) assay for the rapid identification of C. sativa. By optimizing the conditions for the LAMP reaction that targets a highly conserved region of tetrahydrocannabinolic acid (THCA) synthase gene, C. sativa was identified within 50 min at 60-66°C. The detection limit was the same as or higher than that of conventional PCR. The LAMP assay detected all 21 specimens of C. sativa, showing high specificity. Using a simple protocol, the identification of C. sativa could be accomplished within 90 min from sample treatment to detection without use of special equipment. A rapid, sensitive, highly specific, and convenient method for detecting and identifying C. sativa has been developed and is applicable to forensic investigations and industrial quality control.

  8. Antiatherogenic Potential of Nigella sativa Seeds and Oil in Diet-Induced Hypercholesterolemia in Rabbits.

    PubMed

    Al-Naqeep, Ghanya; Al-Zubairi, Adel S; Ismail, Maznah; Amom, Zulkhairi Hj; Esa, Norhaizan Mohd

    2011-01-01

    Nigella sativa or Black seed (N. sativa L.) is traditionally used for several ailments in many Middle Eastern countries. It is an annual herbaceous plant that belongs to the Ranuculacea family with many beneficial properties as antitumor, antidiabetic, antihypertensive, antioxidative and antibacterial. This work attempted to study the effect of N. sativa seeds powder and oil on atherosclerosis in diet-induced hypercholesterolemic (HC) rabbits in comparison with simvastatin (ST). Twenty-five adult New Zealand male white rabbits, weighing 1.5-2.5 kg, were divided into five groups; normal group (NC, n = 5) and four hypercholesterolemic groups (n = 20): a positive control (PC) and three HC groups force fed diet supplemented with 1000 mg Kg(-1) body weight of N. sativa powder (NSP), 500 mg Kg(-1) body N. sativa oil (NSO) and 10 mg Kg(-1) ST for 8 weeks. Feeding HC rabbits with N. sativa either in powder or oil forms was shown to significantly reduce (P < .05) total cholesterol (TC) and low-density lipoprotein cholesterol (LDLC) levels and enhance high-density lipoprotein cholesterol (HDL) levels after treatment for 2, 4, 6 and 8 weeks compared to the PC group. Plaque formation was significantly inhibited while the intima: media ratio was significantly reduced in the NSP and NSO supplemented groups compared to the PC group. In conclusion, treatment of HC rabbits with N. sativa seeds powder or oil showed hypocholesterolemic and antiatherogenic cardioprotective properties.

  9. Nigella sativa ext