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Sample records for early plant growth

  1. Film coating of seeds with Bacillus cereus RS87 spores for early plant growth enhancement.

    PubMed

    Jetiyanon, Kanchalee; Wittaya-Areekul, Sakchai; Plianbangchang, Pinyupa

    2008-10-01

    The plant growth-promoting rhizobacterium Bacillus cereus RS87 was previously reported to promote plant growth in various crops in both greenhouse and field trials. To apply as a plant growth promoting agent with practical use, it is essential to ease the burden of routine preparation of a fresh suspension of strain RS87 in laboratory. The objectives of this study were to investigate the feasibility of film-coating seeds with B. cereus RS87 spores for early plant growth enhancement and to reveal the indoleacetic acid (IAA) production released from strain RS87. The experiment consisted of the following 5 treatments: nontreated seeds, water-soaked seeds, film-coated seeds, seeds soaked with vegetative cells of strain RS87, and film-coated seeds with strain RS87 spores. Three experiments were conducted separately to assess seed emergence, root length, and plant height. Results showed that both vegetative cells and spores of strain RS87 significantly promoted (P < or = 0.05) seed emergence, root length and plant height over the control treatments. The strain RS87 also produced IAA. In conclusion, the film coating of seeds with spores of B. cereus RS87 demonstrated early plant growth enhancement as well as seeds using their vegetative cells. IAA released from strain RS87 would be one of the mechanisms for plant growth enhancement.

  2. Effects of Foliar Fertilizer and Mepiquat Penteborate on Early Planted Cotton Growth and Lint Production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Multiple growth regulators and foliar fertilizers are currently marketed for use in cotton (Gossypium hirsutum L.) with varying effectiveness in promoting yield improvement. This research addressed the effectiveness of these products in a cotton early planting production system with its higher yiel...

  3. Plant species differ in early seedling growth and tissue nutrient responses to arbuscular and ectomycorrhizal fungi.

    PubMed

    Holste, Ellen K; Kobe, Richard K; Gehring, Catherine A

    2017-04-01

    Experiments with plant species that can host both arbuscular mycorrhizal fungi (AMF) and ectomycorrhizal fungi (EMF) are important to separating the roles of fungal type and plant species and understanding the influence of the types of symbioses on plant growth and nutrient acquisition. We examined the effects of mycorrhizal fungal type on the growth and tissue nutrient content of two tree species (Eucalyptus grandis and Quercus costaricensis) grown under four nutrient treatments (combinations of low versus high nitrogen (N) and phosphorus (P) with different N:P ratios) in the greenhouse. Trees were inoculated with unidentified field mixtures of AMF or EMF species cultivated on root fragments of AMF- or EMF-specific bait plants. In E. grandis, inoculation with both AMF and EMF positively affected belowground plant dry weight and negatively affected aboveground dry weight, while only inoculation with AMF increased tissue nutrient content. Conversely, Q. costaricensis dry weight and nutrient content did not differ significantly among inoculation treatments, potentially due to its dependence on cotyledon reserves for growth. Mineral nutrition of both tree species differed with the ratio of N to P applied while growth did not. Our results demonstrate that both tree species' characteristics and the soil nutrient environment can affect how AMF and EMF interact with their host plants. This research highlights the importance of mycorrhizal fungal-tree-soil interactions during early seedling growth and suggests that differences between AMF and EMF associations may be crucial to understanding forest ecosystem functioning.

  4. Early vs. asymptotic growth responses of herbaceous plants to elevated CO[sub 2

    SciTech Connect

    Thomas, S.C.; Jasienski, M.; Bazzaz, F.A. . Dept. of Organismic and Evolutionary Biology)

    1999-07-01

    Although many studies have examined the effects of elevated carbon dioxide on plant growth,'' the dynamics of growth involve at least two parameters, namely, an early rate of exponential size increase and an asymptotic size reached late in plant ontogeny. The common practice of quantifying CO[sub 2] responses as a single response ratio thus obscures two qualitatively distinct kinds of effects. The present experiment examines effects of elevated CO[sub 2] on both early and asymptotic growth parameters in eight C[sub 3] herbaceous plant species (Abutilon theophrasti, Cassia obtusifolia, Plantago major, Rumex crispus, Taraxacum officinale, Dactylis glomerata, Lolium multiflorum, and Panicum dichotomoflorum). Plants were grown for 118--172 d in a factorial design of CO[sub 2] (350 and 700 [micro]L/L) and plant density (individually grown vs. high-density monocultures) under edaphic conditions approximating those of coastal areas in Massachusetts. For Abutilon theophrasti, intraspecific patterns of plant response were also assessed using eight genotypes randomly sampled from a natural population and propagated as inbred lines.

  5. Rapeseed-legume intercrops: plant growth and nitrogen balance in early stages of growth and development.

    PubMed

    Génard, Thaïs; Etienne, Philippe; Diquélou, Sylvain; Yvin, Jean-Claude; Revellin, Cécile; Laîné, Philippe

    2017-03-01

    In this study we tested whether legumes can improve the growth and N and S nutrition of rapeseed in an intercropping system and compared the effect of mixtures on legume N-fixation and soil N-resources. Rapeseed was cultivated in low N conditions in monocrops using one (R) or two plants (RR) per pot and in mixtures with lupine, clover or vetch. The R monocrop was the most relevant control, intraspecific competition inducing a significant growth delay resulting in a significantly lower leaf number, in RR monocrop compared to R and the three mixtures considered. Plant biomass, and the N and S contents of rapeseed grown in mixtures were the same than those measured in R monocrop. Compared to the monocrop, the proportion of N derived from the atmosphere was increased by 34, 140 and 290% in lupine, clover and vetch, respectively when intercropped with rapeseed. In mixture with clover and lupine, the soil N pool at harvest was higher than in other treatments, while N export by crop was constant. Legumes suffered from competition for soil S resulting in a decrease of 40% in their S content compared to the monocrop. Compared to rapeseeds grown in R monocrop and in mixture with lupine and vetch, rapeseed mixed with clover showed significantly higher SPAD values in old leaves. In our conditions, mixing legumes with rapeseed is relevant to reduce N fertilization and improve nutrition and growth of rapeseed.

  6. Soil temperature and plant growth stage influence nitrogen uptake and amino acid concentration of apple during early spring growth.

    PubMed

    Dong, S; Scagel, C F; Cheng, L; Fuchigami, L H; Rygiewicz, P T

    2001-05-01

    In spring, nitrogen (N) uptake by apple roots begins about 3 weeks after bud break. We used 1-year-old 'Fuji' Malus domestica Borkh on M26 bare-root apple trees to determine whether the onset of N uptake in spring is dependent solely on the growth stage of the plant or is a function of soil temperature. Five times during early season growth, N uptake and total amino acid concentration were measured in trees growing at aboveground day/night temperatures of 23/15 degrees C and belowground temperatures of 8, 12, 16 or 20 degrees C. We used (15NH4)(15NO3) to measure total N uptake and rate of uptake and found that both were significantly influenced by both soil temperature and plant growth stage. Rate of uptake of 15N increased with increasing soil temperature and changed with plant growth stage. Before bud break, 15N was not detected in trees growing in the 8 degrees C soil treatment, whereas 15N uptake increased with increasing soil temperatures between 12 and 20 degrees C. Ten days after bud break, 15N was still not detected in trees growing in the 8 degrees C soil treatment, although total 15N uptake and uptake rate continued to increase with increasing soil temperatures between 12 and 20 degrees C. Twenty-one days after bud break, trees in all temperature treatments were able to acquire 15N from the soil, although the amount of uptake increased with increasing soil temperature. Distribution of 15N in trees changed as plants grew. Most of the 15N absorbed by trees before bud break (approximately 5% of 15N supplied per tree) remained in the roots. Forty-six days after bud break, approximately one-third of the 15N absorbed by the trees in the 12-20 degrees C soil temperature treatments remained in the roots, whereas the shank, stem and new growth contained about two-thirds of the 15N taken up by the roots. Total amino acid concentration and distribution of amino acids in trees changed with plant growth stage, but only the amino acid concentration in new growth and

  7. Spaceflight hardware for conducting plant growth experiments in space: the early years 1960-2000

    NASA Technical Reports Server (NTRS)

    Porterfield, D. M.; Neichitailo, G. S.; Mashinski, A. L.; Musgrave, M. E.

    2003-01-01

    The best strategy for supporting long-duration space missions is believed to be bioregenerative life support systems (BLSS). An integral part of a BLSS is a chamber supporting the growth of higher plants that would provide food, water, and atmosphere regeneration for the human crew. Such a chamber will have to be a complete plant growth system, capable of providing lighting, water, and nutrients to plants in microgravity. Other capabilities include temperature, humidity, and atmospheric gas composition controls. Many spaceflight experiments to date have utilized incomplete growth systems (typically having a hydration system but lacking lighting) to study tropic and metabolic changes in germinating seedlings and young plants. American, European, and Russian scientists have also developed a number of small complete plant growth systems for use in spaceflight research. Currently we are entering a new era of experimentation and hardware development as a result of long-term spaceflight opportunities available on the International Space Station. This is already impacting development of plant growth hardware. To take full advantage of these new opportunities and construct innovative systems, we must understand the results of past spaceflight experiments and the basic capabilities of the diverse plant growth systems that were used to conduct these experiments. The objective of this paper is to describe the most influential pieces of plant growth hardware that have been used for the purpose of conducting scientific experiments during the first 40 years of research. c2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved.

  8. Spaceflight hardware for conducting plant growth experiments in space: the early years 1960-2000.

    PubMed

    Porterfield, D M; Neichitailo, G S; Mashinski, A L; Musgrave, M E

    2003-01-01

    The best strategy for supporting long-duration space missions is believed to be bioregenerative life support systems (BLSS). An integral part of a BLSS is a chamber supporting the growth of higher plants that would provide food, water, and atmosphere regeneration for the human crew. Such a chamber will have to be a complete plant growth system, capable of providing lighting, water, and nutrients to plants in microgravity. Other capabilities include temperature, humidity, and atmospheric gas composition controls. Many spaceflight experiments to date have utilized incomplete growth systems (typically having a hydration system but lacking lighting) to study tropic and metabolic changes in germinating seedlings and young plants. American, European, and Russian scientists have also developed a number of small complete plant growth systems for use in spaceflight research. Currently we are entering a new era of experimentation and hardware development as a result of long-term spaceflight opportunities available on the International Space Station. This is already impacting development of plant growth hardware. To take full advantage of these new opportunities and construct innovative systems, we must understand the results of past spaceflight experiments and the basic capabilities of the diverse plant growth systems that were used to conduct these experiments. The objective of this paper is to describe the most influential pieces of plant growth hardware that have been used for the purpose of conducting scientific experiments during the first 40 years of research.

  9. Heterologous expression of chloroplast-localized geranylgeranyl pyrophosphate synthase confers fast plant growth, early flowering and increased seed yield.

    PubMed

    Tata, Sandeep Kumar; Jung, Jihye; Kim, Yoon-Ha; Choi, Jun Young; Jung, Ji-Yul; Lee, In-Jung; Shin, Jeong Sheop; Ryu, Stephen Beungtae

    2016-01-01

    Geranylgeranyl pyrophosphate synthase (GGPS) is a key enzyme for a structurally diverse class of isoprenoid biosynthetic metabolites including gibberellins, carotenoids, chlorophylls and rubber. We expressed a chloroplast-targeted GGPS isolated from sunflower (Helianthus annuus) under control of the cauliflower mosaic virus 35S promoter in tobacco (Nicotiana tabacum). The resulting transgenic tobacco plants expressing heterologous GGPS showed remarkably enhanced growth (an increase in shoot and root biomass and height), early flowering, increased number of seed pods and greater seed yield compared with that of GUS-transgenic lines (control) or wild-type plants. The gibberellin levels in HaGGPS-transgenic plants were higher than those in control plants, indicating that the observed phenotype may result from increased gibberellin content. However, in HaGGPS-transformant tobacco plants, we did not observe the phenotypic defects such as reduced chlorophyll content and greater petiole and stalk length, which were previously reported for transgenic plants expressing gibberellin biosynthetic genes. Fast plant growth was also observed in HaGGPS-expressing Arabidopsis and dandelion plants. The results of this study suggest that GGPS expression in crop plants may yield desirable agronomic traits, including enhanced growth of shoots and roots, early flowering, greater numbers of seed pods and/or higher seed yield. This research has potential applications for fast production of plant biomass that provides commercially valuable biomaterials or bioenergy.

  10. Impact of hydrocarbons from a diesel fuel on the germination and early growth of subantarctic plants.

    PubMed

    Macoustra, Gabriella K; King, Catherine K; Wasley, Jane; Robinson, Sharon A; Jolley, Dianne F

    2015-07-01

    Special Antarctic Blend (SAB) is a diesel fuel dominated by aliphatic hydrocarbons that is commonly used in Antarctic and subantarctic regions. The past and present use of SAB fuel at Australia's scientific research stations has resulted in multiple spills, contaminating soils in these pristine areas. Despite this, no soil quality guidelines or remediation targets have been developed for the region, primarily due to the lack of established indigenous test species and subsequent biological effects data. In this study, twelve plant species native to subantarctic regions were collected from Macquarie Island and evaluated to determine their suitably for use in laboratory-based toxicity testing, using germination success and seedling growth (shoot and root length) as endpoints. Two soil types (low and high organic carbon (OC)) were investigated to reflect the variable OC content found in soils on Macquarie Island. These soils were spiked with SAB fuel and aged for 14 days to generate a concentration series of SAB-contaminated soils. Exposure doses were quantified as the concentration of total petroleum hydrocarbons (TPH, nC9-nC18) on a soil dry mass basis. Seven species successfully germinated on control soils under laboratory conditions, and four of these species (Colobanthus muscoides Hook.f., Deschampsia chapmanii Petrie, Epilobium pendunculare A.Cunn. and Luzula crinita Hook.f.) showed a dose-dependent inhibition of germination when exposed to SAB-contaminated soils. Contaminated soils with low OC were generally more toxic to plants than high organic carbon soils. Increasing soil-TPH concentrations significantly inhibited shoot and root growth, and root length was identified as the most sensitive endpoint. Although the test species were tolerant to SAB-contaminated soils in germination assays, development of early life stages (up to 28 days) were generally more sensitive indicator of exposure effects, and may be more useful endpoints for future testing.

  11. Iron partitioning at an early growth stage impacts iron deficiency responses in soybean plants (Glycine max L.).

    PubMed

    Santos, Carla S; Roriz, Mariana; Carvalho, Susana M P; Vasconcelos, Marta W

    2015-01-01

    Iron (Fe) deficiency chlorosis (IDC) leads to leaf yellowing, stunted growth and drastic yield losses. Plants have been differentiated into 'Fe-efficient' (EF) if they resist to IDC and 'Fe-inefficient' (IN) if they do not, but the reasons for this contrasting efficiency remain elusive. We grew EF and IN soybean plants under Fe deficient and Fe sufficient conditions and evaluated if gene expression and the ability to partition Fe could be related to IDC efficiency. At an early growth stage, Fe-efficiency was associated with higher chlorophyll content, but Fe reductase activity was low under Fe-deficiency for EF and IN plants. The removal of the unifoliate leaves alleviated IDC symptoms, increased shoot:root ratio, and trifoliate leaf area. EF plants were able to translocate Fe to the aboveground plant organs, whereas the IN plants accumulated more Fe in the roots. FRO2-like gene expression was low in the roots; IRT1-like expression was higher in the shoots; and ferritin was highly expressed in the roots of the IN plants. The efficiency trait is linked to Fe partitioning and the up-regulation of Fe-storage related genes could interfere with this key process. This work provides new insights into the importance of mineral partitioning among different plant organs at an early growth stage.

  12. Iron partitioning at an early growth stage impacts iron deficiency responses in soybean plants (Glycine max L.)

    PubMed Central

    Santos, Carla S.; Roriz, Mariana; Carvalho, Susana M. P.; Vasconcelos, Marta W.

    2015-01-01

    Iron (Fe) deficiency chlorosis (IDC) leads to leaf yellowing, stunted growth and drastic yield losses. Plants have been differentiated into ‘Fe-efficient’ (EF) if they resist to IDC and ‘Fe-inefficient’ (IN) if they do not, but the reasons for this contrasting efficiency remain elusive. We grew EF and IN soybean plants under Fe deficient and Fe sufficient conditions and evaluated if gene expression and the ability to partition Fe could be related to IDC efficiency. At an early growth stage, Fe-efficiency was associated with higher chlorophyll content, but Fe reductase activity was low under Fe-deficiency for EF and IN plants. The removal of the unifoliate leaves alleviated IDC symptoms, increased shoot:root ratio, and trifoliate leaf area. EF plants were able to translocate Fe to the aboveground plant organs, whereas the IN plants accumulated more Fe in the roots. FRO2-like gene expression was low in the roots; IRT1-like expression was higher in the shoots; and ferritin was highly expressed in the roots of the IN plants. The efficiency trait is linked to Fe partitioning and the up-regulation of Fe-storage related genes could interfere with this key process. This work provides new insights into the importance of mineral partitioning among different plant organs at an early growth stage. PMID:26029227

  13. Phosphoproteome Dynamics Upon Changes in Plant Water Status Reveal Early Events Associated With Rapid Growth Adjustment in Maize Leaves*

    PubMed Central

    Bonhomme, Ludovic; Valot, Benoît; Tardieu, François; Zivy, Michel

    2012-01-01

    Plant growth adjustment during water deficit is a crucial adaptive response. The rapid fine-tuned control achieved at the post-translational level is believed to be of considerable importance for regulating early changes in plant growth reprogramming. Aiming at a better understanding of early responses to contrasting plant water statuses, we carried out a survey of the protein phosphorylation events in the growing zone of maize leaves upon a range of water regimes. In this study, the impact of mild and severe water deficits were evaluated in comparison with constant optimal watering and with recovery periods lasting 5, 10, 20, 30, 45, and 60 min. Using four biological replicates per treatment and a robust quantitative phosphoproteomic methodology based on stable-isotope labeling, we identified 3664 unique phosphorylation sites on 2496 proteins. The abundance of nearly 1250 phosphorylated peptides was reproducibly quantified and profiled with high confidence among treatments. A total of 138 phosphopeptides displayed highly significant changes according to water regimes and enabled to identify specific patterns of response to changing plant water statuses. Further quantification of protein amounts emphasized that most phosphorylation changes did not reflect protein abundance variation. During water deficit and recovery, extensive changes in phosphorylation status occurred in critical regulators directly or indirectly involved in plant growth and development. These included proteins influencing epigenetic control, gene expression, cell cycle-dependent processes and phytohormone-mediated responses. Some of the changes depended on stress intensity whereas others depended on rehydration duration, including rapid recoveries that occurred as early as 5 or 10 mins after rewatering. By combining a physiological approach and a quantitative phosphoproteomic analysis, this work provides new insights into the in vivo early phosphorylation events triggered by rapid changes in

  14. Phosphoproteome dynamics upon changes in plant water status reveal early events associated with rapid growth adjustment in maize leaves.

    PubMed

    Bonhomme, Ludovic; Valot, Benoît; Tardieu, François; Zivy, Michel

    2012-10-01

    Plant growth adjustment during water deficit is a crucial adaptive response. The rapid fine-tuned control achieved at the post-translational level is believed to be of considerable importance for regulating early changes in plant growth reprogramming. Aiming at a better understanding of early responses to contrasting plant water statuses, we carried out a survey of the protein phosphorylation events in the growing zone of maize leaves upon a range of water regimes. In this study, the impact of mild and severe water deficits were evaluated in comparison with constant optimal watering and with recovery periods lasting 5, 10, 20, 30, 45, and 60 min. Using four biological replicates per treatment and a robust quantitative phosphoproteomic methodology based on stable-isotope labeling, we identified 3664 unique phosphorylation sites on 2496 proteins. The abundance of nearly 1250 phosphorylated peptides was reproducibly quantified and profiled with high confidence among treatments. A total of 138 phosphopeptides displayed highly significant changes according to water regimes and enabled to identify specific patterns of response to changing plant water statuses. Further quantification of protein amounts emphasized that most phosphorylation changes did not reflect protein abundance variation. During water deficit and recovery, extensive changes in phosphorylation status occurred in critical regulators directly or indirectly involved in plant growth and development. These included proteins influencing epigenetic control, gene expression, cell cycle-dependent processes and phytohormone-mediated responses. Some of the changes depended on stress intensity whereas others depended on rehydration duration, including rapid recoveries that occurred as early as 5 or 10 mins after rewatering. By combining a physiological approach and a quantitative phosphoproteomic analysis, this work provides new insights into the in vivo early phosphorylation events triggered by rapid changes in

  15. Tillage and planting date effects on weed dormancy, emergence, and early growth in organic corn

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Weed management is a major constraint to adoption of reduced-tillage practices for organic grain production. Tillage, cover crop management, and crop planting date are all factors that influence the periodicity and growth potential of important weed species in these systems. Therefore, we assessed...

  16. Effects of silver nanoparticle exposure on germination and early growth of eleven wetland plants.

    PubMed

    Yin, Liyan; Colman, Benjamin P; McGill, Bonnie M; Wright, Justin P; Bernhardt, Emily S

    2012-01-01

    The increasing commercial production of engineered nanoparticles (ENPs) has led to concerns over the potential adverse impacts of these ENPs on biota in natural environments. Silver nanoparticles (AgNPs) are one of the most widely used ENPs and are expected to enter natural ecosystems. Here we examined the effects of AgNPs on germination and growth of eleven species of common wetland plants. We examined plant responses to AgNP exposure in simple pure culture experiments (direct exposure) and for seeds planted in homogenized field soils in a greenhouse experiment (soil exposure). We compared the effects of two AgNPs-20-nm polyvinylpyrrolidine-coated silver nanoparticles (PVP-AgNPs) and 6-nm gum arabic coated silver nanoparticles (GA-AgNPs)-to the effects of AgNO(3) exposure added at equivalent Ag concentrations (1, 10 or 40 mg Ag L(-1)). In the direct exposure experiments, PVP-AgNP had no effect on germination while 40 mg Ag L(-1) GA-AgNP exposure significantly reduced the germination rate of three species and enhanced the germination rate of one species. In contrast, 40 mg Ag L(-1) AgNO(3) enhanced the germination rate of five species. In general root growth was much more affected by Ag exposure than was leaf growth. The magnitude of inhibition was always greater for GA-AgNPs than for AgNO(3) and PVP-AgNPs. In the soil exposure experiment, germination effects were less pronounced. The plant growth response differed by taxa with Lolium multiflorum growing more rapidly under both AgNO(3) and GA-AgNP exposures and all other taxa having significantly reduced growth under GA-AgNP exposure. AgNO(3) did not reduce the growth of any species while PVP-AgNPs significantly inhibited the growth of only one species. Our findings suggest important new avenues of research for understanding the fate and transport of NPs in natural media, the interactions between NPs and plants, and indirect and direct effects of NPs in mixed plant communities.

  17. Dynamics of Seed-Borne Rice Endophytes on Early Plant Growth Stages

    PubMed Central

    Hardoim, Pablo R.; Hardoim, Cristiane C. P.; van Overbeek, Leonard S.; van Elsas, Jan Dirk

    2012-01-01

    Bacterial endophytes are ubiquitous to virtually all terrestrial plants. With the increasing appreciation of studies that unravel the mutualistic interactions between plant and microbes, we increasingly value the beneficial functions of endophytes that improve plant growth and development. However, still little is known on the source of established endophytes as well as on how plants select specific microbial communities to establish associations. Here, we used cultivation-dependent and -independent approaches to assess the endophytic bacterrial community of surface-sterilized rice seeds, encompassing two consecutive rice generations. We isolated members of nine bacterial genera. In particular, organisms affiliated with Stenotrophomonas maltophilia and Ochrobactrum spp. were isolated from both seed generations. PCR-based denaturing gradient gel electrophoresis (PCR-DGGE) of seed-extracted DNA revealed that approximately 45% of the bacterial community from the first seed generation was found in the second generation as well. In addition, we set up a greenhouse experiment to investigate abiotic and biotic factors influencing the endophytic bacterial community structure. PCR-DGGE profiles performed with DNA extracted from different plant parts showed that soil type is a major effector of the bacterial endophytes. Rice plants cultivated in neutral-pH soil favoured the growth of seed-borne Pseudomonas oryzihabitans and Rhizobium radiobacter, whereas Enterobacter-like and Dyella ginsengisoli were dominant in plants cultivated in low-pH soil. The seed-borne Stenotrophomonas maltophilia was the only conspicuous bacterial endophyte found in plants cultivated in both soils. Several members of the endophytic community originating from seeds were observed in the rhizosphere and surrounding soils. Their impact on the soil community is further discussed. PMID:22363438

  18. How Does Your Garden Grow? Early Conceptualization of Seeds and Their Place in the Plant Growth Cycle.

    ERIC Educational Resources Information Center

    Hickling, Anne K.; Gelman, Susan A.

    1995-01-01

    Examined young children's understanding of seed origins and growth preconditions and the stages of plant growth. Found that, by 4.5 years, children realized that natural causal mechanisms underlie plant growth and appreciated the relationship of seeds to plants. Results suggest that preschoolers hold theory-like understandings of plants similar to…

  19. S-methylmethionine is involved in the salinity tolerance of Arabidopsis thaliana plants at germination and early growth stages.

    PubMed

    Ogawa, Saori; Mitsuya, Shiro

    2012-01-01

    Methionine (Met) is biosynthesized by the activated methyl cycle and S-methylmethionine (SMM) cycle in one-carbon (C1) metabolism in plants. It is converted to S-adenosylmethionine (SAM) which serves as a precursor for many metabolites including glycinebetaine, methylated polyols, polyamines and ethylene which accumulate in plants in response to salinity. We have investigated how the Met biosynthetic pathway is regulated under saline conditions at the transcriptional level in Arabidopsis thaliana plants. Within Met biosynthesis-related genes, the expression of homocysteine methyltransferase (HMT) and methionine methyltransferase (MMT) genes in SMM cycle had altered toward increasing Met production by the presence of NaCl. We have determined the salinity tolerance of an Arabidopsis mmt mutant with an insertional mutation in the single copy of the AtMMT gene. Although the mmt mutant showed comparable germination and shoot growth with wild type under normal conditions, NaCl treatment caused severe repression of germination rate and shoot growth in the mmt mutant compared with in the wild type. These results indicate that the utilization of SMM is important for the salinity tolerance of Arabidopsis plants at the germination and early growth stages.

  20. Plant Growth Regulators.

    ERIC Educational Resources Information Center

    Nickell, Louis G.

    1978-01-01

    Describes the effect of "plant growth regulators" on plants, such as controlling the flowering, fruit development, plant size, and increasing crop yields. Provides a list of plant growth regulators which includes their chemical, common, and trade names, as well as their different use(s). (GA)

  1. Modelling primary and secondary growth processes in plants: a summary of the methodology and new data from an early lignophyte.

    PubMed Central

    Speck, Thomas; Rowe, Nick P

    2003-01-01

    A mathematical method, based on polar coordinates that allow modelling of primary and secondary growth processes in stems of extant and fossil plants, is summarized and its potential is discussed in comparison with numerical methods using digitizing tablets or electronic image analysing systems. As an example, the modelling of tissue distribution in the internode of an extant sphenopsid (Equisetum hyemale) is presented. In the second half of the paper we present new data of a functional analysis of stem structure and biomechanics of the early lignophyte Tetraxylopteris schmidtii (Middle Devonian) using the polar coordinate method for modelling the tissue distribution in stems of different ontogenetic age. Calculations of the mechanical properties of the stems, based on the modelling of the tissue arrangement, indicate that there is no increase in structural bending modulus throughout the entire development of the plant. The oldest ontogenetic stage has a significantly smaller bending elastic modulus than the intermediate ontogenetic stage, a 'mechanical signal', which is not consistent with a self-supporting growth form. These results, and the ontogenetic variations of the contributions of different stem tissues to the flexural stiffness of the entire stem, are discussed in the evolutionary context of cambial secondary growth. PMID:14561338

  2. [Plant hormones, plant growth regulators].

    PubMed

    Végvári, György; Vidéki, Edina

    2014-06-29

    Plants seem to be rather defenceless, they are unable to do motion, have no nervous system or immune system unlike animals. Besides this, plants do have hormones, though these substances are produced not in glands. In view of their complexity they lagged behind animals, however, plant organisms show large scale integration in their structure and function. In higher plants, such as in animals, the intercellular communication is fulfilled through chemical messengers. These specific compounds in plants are called phytohormones, or in a wide sense, bioregulators. Even a small quantity of these endogenous organic compounds are able to regulate the operation, growth and development of higher plants, and keep the connection between cells, tissues and synergy between organs. Since they do not have nervous and immume systems, phytohormones play essential role in plants' life.

  3. Weed management practices for organic production of trailing blackberry. I. Plant growth and early fruit production

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Weed management practices were evaluated in a new field of trailing blackberry established in western Oregon. The field was planted in May 2010 and certified organic in May 2012. Treatments included two cultivars, ‘Marion’ and ‘Black Diamond’, grown in 1) non-weeded plots, where weeds were cut to th...

  4. Degradation of seed mucilage by soil microflora promotes early seedling growth of a desert sand dune plant.

    PubMed

    Yang, Xuejun; Baskin, Carol C; Baskin, Jerry M; Zhang, Wenhao; Huang, Zhenying

    2012-05-01

    In contrast to the extensive understanding of seed mucilage biosynthesis, much less is known about how mucilage is biodegraded and what role it plays in the soil where seeds germinate. We studied seed mucilage biodegradation by a natural microbial community. High-performance anion-exchange chromatography (HPAEC) was used to determine monosaccharide composition in achene mucilage of Artemisia sphaerocephala. Mucilage degradation by the soil microbial community from natural habitats was examined by monosaccharide utilization tests using Biolog plates, chemical assays and phospholipid fatty acid (PLFA) analysis. Glucose (29.4%), mannose (20.3%) and arabinose (19.5%) were found to be the main components of achene mucilage. The mucilage was biodegraded to CO(2) and soluble sugars, and an increase in soil microbial biomass was observed during biodegradation. Fluorescence microscopy showed the presence of mucilage (or its derivatives) in seedling tissues after growth with fluorescein isothiocyanate (FITC)-labelled mucilage. The biodegradation also promoted early seedling growth in barren sand dunes, which was associated with a large soil microbial community that supplies substances promoting seedling establishment. We conclude that biodegradation of seed mucilage can play an ecologically important role in the life cycles of plants especially in harsh desert environments to which A. sphaerocephala is well-adapted.

  5. Increased sedoheptulose-1,7-bisphosphatase activity in transgenic tobacco plants stimulates photosynthesis and growth from an early stage in development.

    PubMed

    Lefebvre, Stephane; Lawson, Tracy; Zakhleniuk, Oksana V; Lloyd, Julie C; Raines, Christine A; Fryer, Mike

    2005-05-01

    Activity of the Calvin cycle enzyme sedoheptulose-1,7-bisphosphatase (SBPase) was increased by overexpression of an Arabidopsis (Arabidopsis thaliana) cDNA in tobacco (Nicotiana tabacum) plants. In plants with increased SBPase activity, photosynthetic rates were increased, higher levels of Suc and starch accumulated during the photoperiod, and an increase in leaf area and biomass of up to 30% was also evident. Light saturated photosynthesis increased with increasing SBPase activity and analysis of CO2 response curves revealed that this increase in photosynthesis could be attributed to an increase in ribulose 1,5-bisphosphate regenerative capacity. Seedlings with increased SBPase activity had an increased leaf area at the 4 to 5 leaf stage when compared to wild-type plants, and chlorophyll fluorescence imaging of these young plants revealed a higher photosynthetic capacity at the whole plant level. Measurements of photosynthesis, made under growth conditions integrated over the day, showed that mature plants with increased SBPase activity fixed 6% to 12% more carbon than equivalent wild-type leaves, with the young leaves having the highest rates. In this paper, we have shown that photosynthetic capacity per unit area and plant yield can be increased by overexpressing a single native plant enzyme, SBPase, and that this gives an advantage to the growth of these plants from an early phase of vegetative growth. This work has also shown that it is not necessary to bypass the normal regulatory control of SBPase, exerted by conditions in the stroma, to achieve improvements in carbon fixation.

  6. Plant growth promoting rhizobacterium

    DOEpatents

    Doktycz, Mitchel John; Pelletier, Dale A.; Schadt, Christopher Warren; Tuskan, Gerald A.; Weston, David

    2015-08-11

    The present invention is directed to the Pseudomonas fluorescens strain GM30 deposited under ATCC Accession No. PTA-13340, compositions containing the GM30 strain, and methods of using the GM30 strain to enhance plant growth and/or enhance plant resistance to pathogens.

  7. The method for detecting biological parameter of rice growth and early planting of paddy crop by using multi temporal remote sensing data

    NASA Astrophysics Data System (ADS)

    Domiri, D. D.

    2017-01-01

    Rice crop is the most important food crop for the Asian population, especially in Indonesia. During the growth of rice plants have four main phases, namely the early planting or inundation phase, the vegetative phase, the generative phase, and bare land phase. Monitoring the condition of the rice plant needs to be conducted in order to know whether the rice plants have problems or not in its growth. Application of remote sensing technology, which uses satellite data such as Landsat 8 and others which has a spatial and temporal resolution is high enough for monitoring the condition of crops such as paddy crop in a large area. In this study has been made an algorithm for monitoring rapidly of rice growth condition using Maximum of Vegetation Index (EVI Max). The results showed that the time of early planting can be estimated if known when EVI Max occurred. The value of EVI Max and when it occured can be known by trough spatial analysis of multitemporal EVI Landsat 8 or other medium spatial resolution satellites.

  8. Plant Growth Facility (PGF)

    NASA Technical Reports Server (NTRS)

    1998-01-01

    In a microgravity environment aboard the Space Shuttle Columbia Life and Microgravity Mission STS-78, compression wood formation and hence altered lignin deposition and cell wall structure, was induced upon mechanically bending the stems of the woody gymnosperms, Douglas fir (Pseudotsuga menziesii) and loblolly pine (Pinus taeda). Although there was significant degradation of many of the plant specimens in space-flight due to unusually high temperatures experienced during the mission, it seems evident that gravity had little or no effect on compression wood formation upon bending even in microgravity. Instead, it apparently results from alterations in the stress gradient experienced by the plant itself during bending under these conditions. This preliminary study now sets the stage for long-term plant growth experiments to determine whether compression wood formation can be induced in microgravity during phototropic-guided realignment of growing woody plant specimens, in the absence of any externally provided stress and strain.

  9. Effects of fluoride on germination, early growth and antioxidant enzyme activities of legume plant species Prosopis juliflora.

    PubMed

    Saini, Poonam; Khan, Suphiya; Baunthiyal, Mamta; Sharma, Vinay

    2013-03-01

    Prosopis juliflora (Mimosoideae) is a fast growing and drought resistant tree of semi-arid region of India where fluoride (F) toxicity is a common problem. In the present investigations this species was fluoride tested to check their capacity as bioindicator plant and its efficiency to accumulate. To achieve this aim, P. juliflora seedlings grown in hydroponic culture containing different concentrations of F were analyzed for germination percentage together with some biochemical parameters viz, antioxidant enzyme activities, total chlorophyll and accumulation of F in different plant parts. After 15 days of treatment, root growth (r = -0.928, p < 0.01), shoot growth (r = -0.976, p < 0.01), vigor index (r = -0.984, p < 0.01) were in decreasing trend with increasing concentration of NaF. Both catalase (3.2 folds) and peroxidase (2.7 folds) enzymes activity increased with increase in F concentration. Plant accumulated larger portion of the F in the roots (1024.63 microg g(-1) d.wt.) followed by shoot (492.30 microg g(-1) d.wt.). As P. juliflora did not show any morphological changes (marginal and tip chlorosis of leaf portions, necrosis and together these features are referred to as leaf "tip-burn") therefore, this species may be used as suitable bioindicator species for potentially F affected areas. Further, higher accumulation of F in roots indicates that P. juliflora is a suitable species for the removal of F in phytoremediation purposes.

  10. Unraveling the effect of structurally different classes of insecticide on germination and early plant growth of soybean [Glycine max (L.) Merr].

    PubMed

    Dhungana, Sanjeev Kumar; Kim, Il-Doo; Kwak, Hwa-Sook; Shin, Dong-Hyun

    2016-06-01

    Although a considerable number of studies about the effect of different insecticides on plant physiology and metabolism have been carried out, research work about the comparative action of structurally different classes of insecticide on physiological and biochemical properties of soybean seed germination and early growth has not been found. The objective of this study was to investigate the effect of different classes of insecticides on soybean seed germination and early plant growth. Soybean seeds of Bosuk cultivar were soaked for 24h in distilled water or recommended dose (2mLL(-1), 1mLL(-1), 0.5gL(-1), and 0.5gL(-1) water for insecticides Mepthion, Myungtaja, Actara, and Stonate, respectively) of pesticide solutions of four structurally different classes of insecticides - Mepthion (fenitrothion; organophosphate), Myungtaja (etofenprox; pyrethroid), Actara (thiamethoxam; neonicotinoid), and Stonate (lambda-cyhalothrin cum thiamethoxam; pyrethroid cum neonicotinoid) - which are used for controlling stink bugs in soybean crop. Insecticides containing thiamethoxam and lamda-cyhalothrin cum thiamethoxam showed positive effects on seedling biomass and content of polyphenol and flavonoid, however fenitrothion insecticide reduced the seed germination, seed and seedling vigor, and polyphenol and flavonoid contents in soybean. Results of this study reveal that different classes of insecticide have differential influence on physiologic and metabolic actions like germination, early growth, and antioxidant activities of soybean and this implies that yield and nutrient content also might be affected with the application of different types of insecticide.

  11. EARLY ENTRANCE COPRODUCTION PLANT

    SciTech Connect

    John S. Abughazaleh; Mushtaq Ahmed; Ashok Anand; John H. Anderson; Charles Benham; Fred D. Brent; Thomas E. Chance; William K. Davis; Raymond F. Drnevich; Larry Hall; Ming He; Stephen A. Lang; Jimmy O. Ong; Sarah J. Patel; George Potoczniak; Adela G. Sanchez; Charles H. Schrader; Lalit S. Shah; Phil J. Shires; Rae Song

    2000-10-26

    The overall objective of this project is the three phase development of an Early Entrance Coproduction Plant (EECP) which produces at least one product from at least two of the following three categories: (1) electric power (or heat), (2) fuels, and (3) chemicals. The objective is to have these products produced by technologies capable of using synthesis gas derived from coal and/or other carbonaceous feedstock. The objective of Phase I is to determine the feasibility and define the concept for the EECP located at a specific site and to develop a Research, Development, and Testing Plan (RD and T) for implementation in Phase II. The objective of Phase II is to implement the RD and T as outlined in the Phase I RD and T Plan to enhance the development and commercial acceptance of coproduction technology that produces high-value products, particularly those that are critical to our domestic fuel and power requirements. The project will resolve critical knowledge and technology gaps on the integration of gasification and downstream processing to coproduce some combination of power, fuels, and chemicals from coal and other feedstocks. The objective of Phase III is to develop an engineering design package and a financing plan for an EECP located at a specific site. The project's intended result is to provide the necessary technical, economic, and environmental information that will be needed to move the EECP forward to detailed design, construction, and operation by industry.

  12. EARLY ENTRANCE COPRODUCTION PLANT

    SciTech Connect

    John S. Abughazaleh; Mushtaq Ahmed; Ashok Anand; John H. Anderson; Charles Benham; Fred D. Brent; Thomas E. Chance; William K. Davis; Raymond F. Drnevich; Larry Hall; Ming He; Stephen A. Lang; David Mintner; Wendy Moore; Jimmy O. Ong; George Potoczniak; Adela G. Sanchez; Charles H. Schrader; Lalit S. Shah; Kalapi D. Sheth; Phil J. Shires; Rae Song

    2001-05-17

    The overall objective of this project is the three-phase development of an Early Entrance Coproduction Plant (EECP) that produces at least one product from at least two of the following three categories: Electric power (or heat); Fuels; and Chemicals. The objective is to have these products produced by technologies capable of using synthesis gas derived from coal and/or some other carbonaceous feedstock, such as petroleum coke. The objective of Phase I was to determine the feasibility and define the concept for the EECP located at a specific site and to develop a Research, Development, and Testing (RD and T) Plan for implementation in Phase II. This objective has now been accomplished. A specific site, Motiva Refinery in Port Arthur, Texas, has been selected as the location best suited for the EECP. The accomplishments of Phase I are discussed in detail in this Phase I Concept Report. A RD and T Plan and a preliminary project financing plan have been developed and are submitted separately from this report.

  13. EARLY ENTRANCE COPRODUCTION PLANT

    SciTech Connect

    Mushtaq Ahmed; John H. Anderson; Charles Benham; Earl R. Berry; Fred Brent; Belma Demirel; Ming He; Troy Raybold; Manuel E. Quintana; Lalit S. Shah; Kenneth A. Yackly

    2003-06-09

    The overall objective of this project is the three phase development of an Early Entrance Coproduction Plant (EECP) which produces at least one product from at least two of the following three categories: (1) electric power (or heat), (2) fuels, and (3) chemicals. The objective is to have these products produced by technologies capable of using synthesis gas derived from coal and/or other carbonaceous feedstocks. The objectives of Phase I were to determine the feasibility and define the concept for the EECP located at a specific site; develop a Research, Development, and Testing (RD&T) Plan for implementation in Phase II; and prepare a Preliminary Project Financing Plan. The objective of Phase II is to implement the work as outlined in the Phase I RD&T Plan to enhance the development and commercial acceptance of coproduction technology that produces high-value products, particularly those that are critical to our domestic fuel and power requirements. The project will resolve critical knowledge and technology gaps on the integration of gasification and downstream processing to coproduce some combination of power, fuels, and chemicals from coal and/or other carbonaceous feedstocks. The objective of Phase III is to develop an engineering design package and a financing and testing plan for an EECP located at a specific site. The project's intended result is to provide the necessary technical, economic, and environmental information needed by industry to move the EECP forward to detailed design, construction, and operation.

  14. Effects of dust-caused early snowmelt on soil moisture, soil carbon and nitrogen, and plant growth and reproductive output in a snow manipulation experiment

    NASA Astrophysics Data System (ADS)

    Conner, L. G.; Gill, R. A.

    2014-12-01

    Regional climate forecasts for the western United States predict slightly more snow accumulation during the winter but warmer springs and earlier spring snowmelt. Snowmelt will be further advanced by radiative forcing from dust and black carbon deposition on mountain snowpack. We expect earlier snowmelt to reduce regional water supplies (Painter et al., 2010) and suspect that it may also lead to drier soil conditions which could impact nutrient cycling and plant growth and reproduction in alpine and subalpine environments. Our snow manipulation experiment included 12 sites at two elevations in paired forest and meadow sites. We added dust to the snow surface during spring ablation. The dust treatment reduced snowpack by 20 to 40% and advanced the snowfree date by 9 to 14 days. Following snowmelt, there was a temporary difference in soil moisture in the upper 0-15 cm of soil between the treatment and control plots. Following snowmelt, the temporary differences in soil moisture quickly converged during soil drydown to a lower limit determined by the soil characteristics specific to each site. This brief window of differences in soil moisture may have temporary impacts on ecosystem processes; however, the impacts are mediated by plant and microbial phenology. Some of the plants and microbes in seasonally-snow-covered environments are adapted to take advantage of the early season environments which include low temperatures and frequent freezing, while other plants and microbes have evolved to avoid this transition period through prolonged dormancy. These adaptations, and the transient nature of environmental differences caused by early snowmelt, may limit the impacts of early snowmelt on carbon and nitrogen cycling and on plant growth and reproduction in subalpine forest and meadows.

  15. EARLY ENTRANCE COPRODUCTION PLANT

    SciTech Connect

    John H. Anderson; William K. Davis; Thomas W. Sloop

    2001-03-21

    As part of the Department of Energy's (DOE) Gasification Technologies and Transportation Fuels and Chemicals programs, DOE and Texaco are partners through Cooperative Agreement DE-FC26-99FT40658 to determine the feasibility of developing, constructing and operating an Early Entrance Coproduction Plant (EECP). The overall objective of the project is the three-phase development of an EECP that produces at least one product from at least two of the following three categories: Electric power (or heat); Fuels; and Chemicals. The objective is to have these products produced by technologies capable of using synthesis gas derived from coal and/or some other carbonaceous feedstock, such as petroleum coke. The objective of Phase I was to determine the feasibility and define the concept for the EECP located at a specific site and to develop a Research, Development, and Testing (RD and T) Plan for implementation in Phase II. This objective has now been accomplished. A specific site, Motiva Refinery in Port Arthur, Texas, has been selected as the location best suited for the EECP. The specific work requirements of Phase I included: Prepare an EECP Preliminary Concept Report covering Tasks 2-8 specified in the Cooperative Agreement; Develop a Research, Development, and Testing (RD and T) Plan as specified in Task 9 of the Cooperative Agreement for implementation in Phase II; and Develop a Preliminary Project Financing Plan for the EECP Project as specified in Task 10 of the Cooperative Agreement. This document is the Preliminary Project Financing Plan for the design, construction, and operation of the EECP at the Motiva Port Arthur Refinery.

  16. α2-COP is involved in early secretory traffic in Arabidopsis and is required for plant growth.

    PubMed

    Gimeno-Ferrer, Fátima; Pastor-Cantizano, Noelia; Bernat-Silvestre, César; Selvi-Martínez, Pilar; Vera-Sirera, Francisco; Gao, Caiji; Perez-Amador, Miguel Angel; Jiang, Liwen; Aniento, Fernando; Marcote, María Jesús

    2016-12-26

    COP (coat protein) I-coated vesicles mediate intra-Golgi transport and retrograde transport from the Golgi to the endoplasmic reticulum. These vesicles form through the action of the small GTPase ADP-ribosylation factor 1 (ARF1) and the COPI heptameric protein complex (coatomer), which consists of seven subunits (α-, β-, β'-, γ-, δ-, ε- and ζ-COP). In contrast to mammals and yeast, several isoforms for coatomer subunits, with the exception of γ and δ, have been identified in Arabidopsis. To understand the role of COPI proteins in plant biology, we have identified and characterized a loss-of-function mutant of α2-COP, an Arabidopsis α-COP isoform. The α2-cop mutant displayed defects in plant growth, including small rosettes, stems and roots and mislocalization of p24δ5, a protein of the p24 family containing a C-terminal dilysine motif involved in COPI binding. The α2-cop mutant also exhibited abnormal morphology of the Golgi apparatus. Global expression analysis of the α2-cop mutant revealed altered expression of plant cell wall-associated genes. In addition, a strong upregulation of SEC31A, which encodes a subunit of the COPII coat, was observed in the α2-cop mutant; this also occurs in a mutant of a gene upstream of COPI assembly, GNL1, which encodes an ARF-guanine nucleotide exchange factor (GEF). These findings suggest that loss of α2-COP affects the expression of secretory pathway genes.

  17. EARLY ENTRANCE COPRODUCTION PLANT

    SciTech Connect

    David Storm; Govanon Nongbri; Steve Decanio; Ming He; Lalit Shah; Charles Schrader; Earl Berry; Peter Ricci; Belma Demirel; Charles Benham; Mark Bohn

    2004-01-12

    The overall objective of this project is the three phase development of an Early Entrance Coproduction Plant (EECP) which uses petroleum coke to produce at least one product from at least two of the following three categories: (1) electric power (or heat), (2) fuels, and (3) chemicals using ChevronTexaco's proprietary gasification technology. The objective of Phase I is to determine the feasibility and define the concept for the EECP located at a specific site; develop a Research, Development, and Testing (RD&T) Plan to mitigate technical risks and barriers; and prepare a Preliminary Project Financing Plan. The objective of Phase II is to implement the work as outlined in the Phase I RD&T Plan to enhance the development and commercial acceptance of coproduction technology. The objective of Phase III is to develop an engineering design package and a financing and testing plan for an EECP located at a specific site. The project's intended result is to provide the necessary technical, economic, and environmental information needed by industry to move the EECP forward to detailed design, construction, and operation. The partners in this project are Texaco Energy Systems LLC or TES (a subsidiary of ChevronTexaco), General Electric (GE), Praxair, and Kellogg Brown & Root (KBR) in addition to the U.S. Department of Energy (DOE). TES is providing gasification technology and Fischer-Tropsch (F-T) technology developed by Rentech, Inc., GE is providing combustion turbine technology, Praxair is providing air separation technology, and KBR is providing engineering. During Phase I, a design basis for the Fischer-Tropsch Synthesis section was developed based on limited experience with the specified feed gas and operating conditions. The objective of this Task in Phase II RD&T work was to confirm the performance of the F-T reactor at the set design conditions. Although much of the research, development, and testing work were done by TES outside of this project, several important

  18. EARLY ENTRANCE COPRODUCTION PLANT

    SciTech Connect

    Fred D. Brent; Lalit Shah; Earl Berry; Charles H. Schrader; John Anderson; Ming He; James F. Stevens; Centha A. Davis; Michael Henley; Jerome Mayer; Harry Tsang; Jimell Erwin; Jennifer Adams; Michael Tillman; Chris Taylor; Marjan J. Roos; Robert F. Earhart

    2004-01-27

    The overall objective of this project is the three phase development of an Early Entrance Coproduction Plant (EECP) which uses petroleum coke to produce at least one product from at least two of the following three categories: (1) electric power (or heat), (2) fuels, and (3) chemicals using ChevronTexaco's proprietary gasification technology. The objective of Phase I is to determine the feasibility and define the concept for the EECP located at a specific site; develop a Research, Development, and Testing (RD&T) Plan to mitigate technical risks and barriers; and prepare a Preliminary Project Financing Plan. The objective of Phase II is to implement the work as outlined in the Phase I RD&T Plan to enhance the development and commercial acceptance of coproduction technology. The objective of Phase III is to develop an engineering design package and a financing and testing plan for an EECP located at a specific site. The project's intended result is to provide the necessary technical, economic, and environmental information needed by industry to move the EECP forward to detailed design, construction, and operation. The partners in this project are Texaco Energy Systems LLC or TES (a subsidiary of ChevronTexaco), General Electric (GE), Praxair, and Kellogg Brown & Root (KBR) in addition to the U.S. Department of Energy (DOE). TES is providing gasification technology and Fischer-Tropsch (F-T) technology developed by Rentech, GE is providing combustion turbine technology, Praxair is providing air separation technology, and KBR is providing engineering. Each of the EECP subsystems was assessed for technical risks and barriers. A plan was developed to mitigate the identified risks (Phase II RD&T Plan, October 2000). The potential technical and economic risks to the EECP from Task 2.5 can be mitigated by demonstrating that the end-use products derived from the upgrading of the F-T synthesis total liquid product can meet or exceed current specifications for the manufacture

  19. EARLY ENTRANCE COPRODUCTION PLANT

    SciTech Connect

    John Anderson; Charles Schrader

    2004-01-26

    In 1999, the U. S. Department of Energy (DOE) awarded a Cooperative Agreement to Texaco Energy Systems Inc. to provide a preliminary engineering design of an Early Entrance Coproduction Plant (EECP). Since the award, continuous and diligent work has been undertaken to achieve the design of an economical facility that makes strides toward attaining the goal of DOE's Vision 21 Program. The objective of the EECP is to convert coal and/or petroleum coke to power while coproducing transportation fuels, chemicals, and useful utilities such as steam. This objective is being pursued in a three-phase effort through the partnership of the DOE with prime contractor Texaco Energy Systems, LLC. (TES), the successor to Texaco Energy Systems, Inc. The key subcontractors to TES include General Electric (GE), Praxair, and Kellogg Brown and Root. ChevronTexaco provided gasification technology and Rentech Inc.'s Fischer-Tropsch (F-T) technology that has been developed for non-natural gas sources. GE provided gas turbine technology for the combustion of low energy content gas. Praxair provided air separation technology and KBR provided engineering to integrate the facility. A conceptual design was completed in Phase I and the report was accepted by the DOE in May 2001. The Phase I work identified risks and critical research, development, and testing that would improve the probability of technical success of the EECP. The objective of Phase II was to mitigate the risks by executing research, development, and testing. Results from the Phase II work are the subject of this report. As the work of Phase II concluded, it became evident that sufficient, but not necessarily complete, technical information and data would be available to begin Phase III - Preliminary Engineering Design. Work in Phase II requires additional technical development work to correctly apply technology at a specific site. The project's intended result is to provide the necessary technical, economic, and environmental

  20. EARLY ENTRANCE COPRODUCTION PLANT

    SciTech Connect

    Charles Benham; Mark Bohn; John Anderson; Earl Berry; Fred Brent; Ming He; Randy Roberts; Lalit Shah; Marjan Roos

    2003-09-15

    The 1999 U. S. Department of Energy (DOE) award to Texaco Energy Systems Inc. (presently Texaco Energy Systems LLC, a subsidiary of ChevronTexaco) was made to provide a Preliminary Engineering Design of an Early Entrance Coproduction Plant (EECP). Since the award presentation, work has been undertaken to achieve an economical concept design that makes strides toward the DOE Vision 21 goal. The objective of the EECP is to convert coal and/or petroleum coke to electric power plus transportation fuels, chemicals and useful utilities such as steam. The use of petroleum coke was added as a fuel to reduce the cost of feedstock and also to increase the probability of commercial implementation of the EECP concept. This objective has been pursued in a three phase effort through the partnership of the DOE with prime contractor Texaco Energy Systems LLC and subcontractors General Electric (GE), Praxair, and Kellogg Brown and Root (KBR). ChevronTexaco is providing gasification technology and Rentech's Fischer-Tropsch technology that has been developed for non-natural gas feed sources. GE is providing gas turbine technology for the combustion of low energy content gas. Praxair is providing air separation technology, and KBR is providing engineering to integrate the facility. The objective of Phase I was to determine the feasibility and define the concept for the EECP located at a specific site; develop a Research, Development, and Testing (RD&T) Plan to mitigate technical risks and barriers; and prepare a Preliminary Project Financing Plan. The objective of Phase II is to implement the work as outlined in the Phase I RD&T Plan to enhance the development and commercial acceptance of coproduction technology. The objective of Phase III is to develop an engineering design package and a financing and testing plan for an EECP located at a specific site. Phase I Preliminary Concept Report was completed in 2000. The Phase I Preliminary Concept Report was prepared based on making

  1. EARLY ENTRANCE COPRODUCTION PLANT

    SciTech Connect

    John H. Anderson; Charles Benham; Earl R. Berry; Ming He; Charles H. Schrader; Lalit S. Shah; O.O. Omatete; T.D. Burchell

    2004-01-12

    The overall objective of this project is the three phase development of an Early Entrance Coproduction Plant (EECP) which uses petroleum coke to produce at least one product from at least two of the following three categories: (1) electric power (or heat), (2) fuels, and (3) chemicals using ChevronTexaco's proprietary gasification technology. The objective of Phase I is to determine the feasibility and define the concept for the EECP located at a specific site; develop a Research, Development, and Testing (RD&T) Plan to mitigate technical risks and barriers; and prepare a Preliminary Project Financing Plan. The objective of Phase II is to implement the work as outlined in the Phase I RD&T Plan to enhance the development and commercial acceptance of coproduction technology. The objective of Phase III is to develop an engineering design package and a financing and testing plan for an EECP located at a specific site. The project's intended result is to provide the necessary technical, economic, and environmental information needed by industry to move the EECP forward to detailed design, construction, and operation. The partners in this project are Texaco Energy Systems LLC or TES (a subsidiary of ChevronTexaco), General Electric (GE), Praxair, and Kellogg Brown & Root (KBR) in addition to the U.S. Department of Energy (DOE). TES is providing gasification technology and Fischer-Tropsch (F-T) technology developed by Rentech, GE is providing combustion turbine technology, Praxair is providing air separation technology, and KBR is providing engineering. During Phase I the team identified several potential methods to reduce or minimize the environmental impact of the proposed EECP. The EECP Project Team identified F-T catalyst disposal, beneficial gasifier slag usage (other than landfill), and carbon dioxide recovery for the gas turbine exhaust for study under this task. Successfully completing the Task 2.10 RD&T provides additional opportunities for the EECP to meet the

  2. Students' Ideas about Plants and Plant Growth

    ERIC Educational Resources Information Center

    Barman, Charles R.; Stein, Mary; McNair, Shannan; Barman, Natalie S.

    2006-01-01

    Because the National Science Education Standards (1996) outline specific things K-8 students should know about plants, and previous data indicated that elementary students had difficulty understanding some major ideas about plants and plant growth, the authors of this article thought it appropriate to initiate an investigation to determine the…

  3. EARLY ENTRANCE COPRODUCTION PLANT

    SciTech Connect

    Fred D. Brent; Lalit Shah; Earl Berry; Charles H. Schrader; John Anderson; J. Erwin; Matthew G. Banks; Terry L. Ullman

    2004-01-12

    The overall objective of this project is the three phase development of an Early Entrance Coproduction Plant (EECP) which uses petroleum coke to produce at least one product from at least two of the following three categories: (1) electric power (or heat), (2) fuels, and (3) chemicals using ChevronTexaco's proprietary gasification technology. The objective of Phase I is to determine the feasibility and define the concept for the EECP located at a specific site; develop a Research, Development, and Testing (RD&T) Plan to mitigate technical risks and barriers; and prepare a Preliminary Project Financing Plan. The objective of Phase II is to implement the work as outlined in the Phase I RD&T Plan to enhance the development and commercial acceptance of coproduction technology. The objective of Phase III is to develop an engineering design package and a financing and testing plan for an EECP located at a specific site. The project's intended result is to provide the necessary technical, economic, and environmental information needed by industry to move the EECP forward to detailed design, construction, and operation. The partners in this project are Texaco Energy Systems LLC or TES (a subsidiary of ChevronTexaco), General Electric (GE), Praxair, and Kellogg Brown & Root (KBR) in addition to the U.S. Department of Energy (DOE). TES is providing gasification technology and Fischer-Tropsch (F-T) technology developed by Rentech, GE is providing combustion turbine technology, Praxair is providing air separation technology, and KBR is providing engineering. Each of the EECP subsystems was assessed for technical risks and barriers. A plan was developed to mitigate the identified risks (Phase II RD&T Plan, October 2000). Phase II RD&T Task 2.6 identified as potential technical risks to the EECP the fuel/engine performance and emissions of the F-T diesel fuel products. Hydrotreating the neat F-T diesel product reduces potentially reactive olefins, oxygenates, and acids levels

  4. Biotic elicitation of isoflavone metabolism with plant growth promoting rhizobacteria in early stages of development in Glycine max var. Osumi.

    PubMed

    Ramos-Solano, Beatriz; Algar, Elena; García-Villaraco, Ana; García-Cristóbal, Jorge; Lucas García, J Antonio; Gutierrez-Mañero, F Javier

    2010-02-10

    Nine plant growth-promoting rhizobacteria from different backgrounds were assayed on Glycine max var. Osumi to evaluate their potential as biotic elicitors to increase isoflavone (IF) levels. Strains were inoculated on 2 day old pregerminated seeds. Six days after inoculation, the seedlings were harvested. Biometric parameters were registered, and IFs were determined. Although only one strain (N21.4) increased total IF contents and only one (M84) caused significant decreases in total IF, five different behaviors were detected when the daidzein and genistein families were analyzed separately. All strains triggered IF metabolism so further studies have to be developed since the different beneficial effects of IF through the diet may be due to the different IF profiles. These are encouraging results from two points of view: (1) N21.4 increases IF in seedlings, and (2) all other beneficial strains trigger IF metabolism differentially; hence, both facts could be used to prepare food supplements or as enriched standardized foods after full development of the biotechnological procedure.

  5. Early effects of altered gravity environments on plant cell growth and cell proliferation: Characterization of morphofunctional nucleolar types in an Arabidopsis cell culture system

    NASA Astrophysics Data System (ADS)

    Manzano, Ana Isabel; Herranz, Raul; Manzano, Aránzazu; Van Loon, Jack; Medina, Francisco Javier

    2016-02-01

    Changes in the cell growth rate of an in vitro cellular system in Arabidopsis thaliana induced by short exposure to an altered gravity environment have been estimated by a novel approach. The method consisted of defining three structural nucleolar types which are easy and reliable indicators of the ribosome biogenesis activity and, consequently, of protein biosynthesis, a parameter strictly correlated to cell growth in this cellular system. The relative abundance of each nucleolar type was statistically assessed in different conditions of gravity. Samples exposed to simulated microgravity for 200 min showed a significant decrease in nucleolar activity compared to 1g controls, whereas samples exposed to hypergravity (2g) for the same period showed nucleolar activity slightly increased,. These effects could be considered as an early cellular response to the environmental alteration, given the short duration of the treatment. The functional significance of the structural data was validated by a combination of several different well-known parameters, using microscopical, flow cytometry, qPCR and proteomic approaches, which showed that the decreased cell growth rate was decoupled from an increased cell proliferation rate under simulated microgravity, and the opposite trend was observed under hypergravity. Actually, not all parameters tested showed the same quantitative changes, indicating that the response to the environmental alteration is time-dependent. These results are in agreement with previous observations in root meristematic cells and they show the ability of plant cells to produce a response to gravity changes, independently of their integration into plant organs.

  6. Phytotoxicity assessment on corn stover biochar, derived from fast pyrolysis, based on seed germination, early growth, and potential plant cell damage.

    PubMed

    Li, Yang; Shen, Fei; Guo, Haiyan; Wang, Zhanghong; Yang, Gang; Wang, Lilin; Zhang, Yanzong; Zeng, Yongmei; Deng, Shihuai

    2015-06-01

    The potential phytotoxicity of water extractable toxicants in a typical corn stover biochar, the product of fast pyrolysis, was investigated using an aqueous biochar extract on a soil-less bioassay with tomato plants. The biochar dosage of 0.0-16.0 g beaker(-1) resulted in an inverted U-shaped dose-response relationship between biochar doasage and seed germination/seedling growth. This indicated that tomato growth was slightly stimulated by low dosages of biochar and inhibited with higher dosages of biochar. Additionally, antioxidant enzyme activities in the roots and leaves were enhanced at lower dosages, but rapidly decreased with higher dosages of biochar. With the increased dosages of biochar, the malondialdehyde content in the roots and leaves increased, in addition with the observed morphology of necrotic root cells, suggesting that serious damage to tomato seedlings occurred. EC50 of root length inhibition occurred with biochar dosages of 9.2 g beaker(-1) (3.5th day) and 16.7 g beaker(-1) (11th day) (equivalent to 82.8 and 150.3 t ha(-1), respectively), which implied that toxicity to the early growth of tomato can potentially be alleviated as the plant grows.

  7. Germination and early plant development of ten plant species ...

    EPA Pesticide Factsheets

    Ten agronomic plant species were exposed to different concentrations of nano titanium dioxide (nTiO2) or nano cerium oxide (nCeO2) (0, 250, 500 and 1000 mg/L) to examine potential effects on germination and early seedling development. We modified a standard test protocol developed for soluble chemicals (OPPTS 850.4200) to determine if such an approach might be useful for screening engineered nanomaterials (ENMs) and whether there were differences in response across a range of commercially important plant species to two common metal oxide ENMs. Eight of 10 species responded to nTiO2, and 5 species responded to nCeO2. Overall, it appeared that early root growth may be a more sensitive indicator of potential effects from ENM exposure than germination. The observed effects did not always relate to the exposure concentration, indicating that mass-based concentration may not fully explain developmental effects of these two ENMs. The results suggest that nTiO2 and nCeO2 have different effects on early plant growth of agronomic species, which may alter the timing of specific developmental events during their life cycle. In addition, standard germination tests, which are commonly used for toxicity screening of new materials, may not detect the subtle but potentially more important changes associated with early growth and development in terrestrial plants. Engineered nanoparticles (ENMs) have been recognized as valuable components of new technologies and are current

  8. Plant growth chamber M design

    NASA Technical Reports Server (NTRS)

    Prince, R. P.; Knott, W. M.

    1986-01-01

    Crop production is just one of the many processes involved in establishing long term survival of man in space. The benefits of integrating higher plants into the overall plan was recognized early by NASA through the Closed Ecological Life Support System (CELSS) program. The first step is to design, construct, and operate a sealed (gas, liquid, and solid) plant growth chamber. A 3.6 m diameter by 6.7 m high closed cylinder (previously used as a hypobaric vessel during the Mercury program) is being modified for this purpose. The chamber is mounted on legs with the central axis vertical. Entrance to the chamber is through an airlock. This chamber will be devoted entirely to higher plant experimentation. Any waste treatment, food processing or product storage studies will be carried on outside of this chamber. Its primary purpose is to provide input and output data on solids, liquids, and gases for single crop species and multiple species production using different nutrient delivery systems.

  9. Effects of 60 Hz electromagnetic fields on early growth in three plant species and a replication of previous results

    SciTech Connect

    Davis, M.S.

    1996-05-01

    In an attempt to replicate the findings of Smith et al., seeds of Raphanus sativus L. (radish), Sinapsis alba L. (mustard), and Hordeum vulgare L. (barley) were grown for between 9 and 21 days in continuous electromagnetic fields (EMFs) at ion-cyclotron resonance conditions for stimulation of Ca{sup 2+} (B{sub H} = 78.3 {micro}T, B{sub HAC} = 40 {micro}T peak-peak at 60 Hz, B{sub v} = 0). On harvesting, radish showed results similar to those of Smith et al. Dry stem weight and plant height were both significantly greater (Mann-Whitney tests, Ps < 0.05) in EMF-exposed plants than in control plants in each EMF experiment. Wet root weight was significantly greater in EMF-exposed plants in two out of three experiments, as were dry leaf weight, dry whole weight, and stem diameter. Dry root weight, wet leaf weight, and wet whole weight were significantly greater in EMF-exposed plants in one of three experiments. All significant differences indicated an increase in weight or size in the EMF-exposed plants. In each of the sham experiments, no differences between exposed and control plants were evident. Mustard plants failed to respond to the EMFs in any of the plant parameters measured. In one experiment, barley similarly failed to respond; but in another showed significantly greater wet root weight and significantly smaller stem diameter and dry seed weight at the end of the experiment in exposed plants compared to control plants. Although these results give no clue about the underlying bioelectromagnetic mechanism, they demonstrate that, at least for one EMF-sensitive biosystem, results can be independently replicated in another laboratory. Such replication is crucial in establishing the validity of bioelectromagnetic science.

  10. Effects of 60 Hz electromagnetic fields on early growth in three plant species and a replication of previous results.

    PubMed

    Davies, M S

    1996-01-01

    In an attempt to replicate the findings of Smith et al., seeds of Raphanus sativus L. (radish), Sinapsis alba L. (mustard), and Hordeum vulgare L. (barley) were grown for between 9 and 21 days in continuous electromagnetic fields (EMFs) at "ion-cyclotron resonance" conditions for stimulation of Ca(2+) (B(H) = 78.3 mu T, B(HAC) = 40 mu T peak-peak at 60 Hz, B(V) = 0). On harvesting, radish showed results similar to those of Smith et al. Dry stem weight and plant height were both significantly greater (Mann-Whitney tests, Ps < 0.05) in EMF-exposed plants than in control plants in each EMF experiment. Wet root weight was significantly greater in EMF-exposed plants in two out of three experiments, as were dry leaf weight, dry whole weight, and stem diameter. Dry root weight, wet leaf weight, and wet whole weight were significantly greater in EMF-exposed plants in one of three experiments. All significant differences indicated an increase in weight or size in the EMF-exposed plants. In each of the sham experiments, no differences between exposed and control plants were evident. Mustard plants failed to respond to the EMFs in any of the plant parameters measured. In one experiment, barley similarly failed to respond; but in another showed significantly greater wet root weight and significantly smaller stem diameter and dry seed weight at the end of the experiment in exposed plants compared to control plants. Although these results give no clue about the underlying bioelectromagnetic mechanism, they demonstrate that, at least for one EMF-sensitive biosystem, results can be independently replicated in another laboratory. Such replication is crucial in establishing the validity of bioelectromagnetic science.

  11. Chemical Control of Plant Growth.

    ERIC Educational Resources Information Center

    Agricultural Research Center (USDA), Beltsville, MD.

    Seven experiments are presented in this Science Study Aid to help students investigate the control of plant growth with chemicals. Plant growth regulators, weed control, and chemical pruning are the topics studied in the experiments which are based on investigations that have been and are being conducted at the U. S. Agricultural Research Center,…

  12. Plant-growth-promoting rhizobacteria.

    PubMed

    Lugtenberg, Ben; Kamilova, Faina

    2009-01-01

    Several microbes promote plant growth, and many microbial products that stimulate plant growth have been marketed. In this review we restrict ourselves to bacteria that are derived from and exert this effect on the root. Such bacteria are generally designated as PGPR (plant-growth-promoting rhizobacteria). The beneficial effects of these rhizobacteria on plant growth can be direct or indirect. This review begins with describing the conditions under which bacteria live in the rhizosphere. To exert their beneficial effects, bacteria usually must colonize the root surface efficiently. Therefore, bacterial traits required for root colonization are subsequently described. Finally, several mechanisms by which microbes can act beneficially on plant growth are described. Examples of direct plant growth promotion that are discussed include (a) biofertilization, (b) stimulation of root growth, (c) rhizoremediation, and (d) plant stress control. Mechanisms of biological control by which rhizobacteria can promote plant growth indirectly, i.e., by reducing the level of disease, include antibiosis, induction of systemic resistance, and competition for nutrients and niches.

  13. Phytochrome, plant growth and flowering

    NASA Technical Reports Server (NTRS)

    King, R. W.; Bagnall, D. J.

    1994-01-01

    Attempts to use artificially lit cabinets to grow plants identical to those growing in sunlight have provided compelling evidence of the importance of light quality for plant growth. Changing the balance of red (R) to far-red (FR) radiation, but with a fixed photosynthetic input can shift the phytochrome photoequilibrium in a plant and generate large differences in plant growth. With FR enrichment the plants elongate, and may produce more leaf area and dry matter. Similar morphogenic responses are also obtained when light quality is altered only briefly (15-30 min) at the end-of-the-day. Conversely, for plants grown in natural conditions the response of plant form to selective spectral filtering has again shown that red and far-red wavebands are important as found by Kasperbauer and coworkers. Also, where photosynthetic photon flux densities (PPFD) of sunlight have been held constant, the removal of far-red alone alters plant growth. With FR depletion plants grown in sunlight are small, more branched and darker green. Here we examine the implications for plant growth and flowering when the far-red composition of incident radiation in plant growth chambers is manipulated.

  14. Flooding and Plant Growth

    PubMed Central

    VISSER, E. J. W.; VOESENEK, L. A. C. J.; VARTAPETIAN, B. B.; JACKSON, M. B.

    2003-01-01

    This Special Issue is based on the 7th Conference of the International Society for Plant Anaerobiosis (ISPA), held in Nijmegen, The Netherlands, 12–16 June 2001. The papers describe and analyse many of the responses that plants display when subjected to waterlogging of the soil or deeper submergence. These responses may be injurious or adaptive, and are discussed at various levels of organizational complexity ranging from ecosystem processes, through individual plants to single cells. The research incorporates molecular biology and genetics, cell physiology, biochemistry, hormone physiology, whole plant physiology, plant demography and ecology. The study of the damage to young rice plants caused by submergence, especially as experienced in the rainfed lowlands of Asia, is comprehensively addressed. This work integrates various specialized approaches ranging from agronomy to molecular genetics, and demonstrates how plant biology can be harnessed to improve stress tolerance in an important crop species while simultaneously improving basic understanding of tolerance mechanisms and plant processes.

  15. Lead (Pb)-induced regulation of growth, photosynthesis, and mineral nutrition in maize (Zea mays L.) plants at early growth stages.

    PubMed

    Ahmad, Muhammad Sajid Aqeel; Ashraf, Muhammad; Tabassam, Qaisra; Hussain, Mumtaz; Firdous, Humaira

    2011-12-01

    The phytotoxic effects of lead (Pb) on seed germinability, seedling growth, photosynthetic performance, and nutrient accumulation (K(+) and Cu(2+)) in two maize genotypes (EV-1098 and EV-77) treated with varying levels of PbSO(4) (0.01, 0.1, and 1.0 mg L(-1)) were appraised in this study. In the seed germination experiment, lead stress significantly reduced seed germination percentage and index, plumule and radicle lengths as well as fresh and dry weights in both genotypes. In the second experiment, lengths and fresh and dry weights of shoots and roots decreased due to Pb in both genotypes with increase in plant age. Higher Pb levels also decreased photosynthetic rate (A), water use efficiency (A/E), and intrinsic water use efficiency (A/g(s)), but increased transpiration rate (E) and C(i)/C(a) ratio as a result of increase in stomatal conductance (g(s)). The concentrations of K(+) and Cu(2+) decreased in root, stem, and leaves of both genotypes, which could be a direct consequence of multifold increase in Pb concentration in these tissues. Overall, cv. EV-1098 had better Pb tolerance potential than EV-77 because the former genotype showed less reduction in seed germinability parameters, photosynthetic performance, and K(+) and Cu(2+) accumulation in shoot and root under lead stress.

  16. Bean Plants: A Growth Experience

    ERIC Educational Resources Information Center

    West, Donna

    2004-01-01

    Teaching plant growth to seventh-grade life science students has been interesting for the author because she grew up in a rural area and always had to help in the garden. She made many assumptions about what her rural and suburban students knew. One year she decided to have them grow plants to observe the roots, stems, leaves, flowers, and fruit…

  17. Effects of drought stress on the seed germination and early seedling growth of the endemic desert plant Eremosparton songoricum (Fabaceae)

    PubMed Central

    Li, Haiyan; Li, Xiaoshuang; Zhang, Daoyuan; Liu, Huiliang; Guan, Kaiyun

    2013-01-01

    Eremosparton songoricum (Litv.) Vass. is an endemic and extremely drought-resistant desert plant with populations that are gradually declining due to the failure of sexual recruitment. The effects of drought stress on the seed germination and physiological characteristics of seeds and seedlings were investigated. The results showed that the germination percentage decreased with an increase of polyethylene glycol 6000 (PEG) concentration: -0.3 MPa (5 % PEG) had a promoting effect on seed germination, -0.9 MPa (15 % PEG) dramatically reduced germination, and -1.8 MPa (30 % PEG) was the threshold for E. songoricum germination. However, the contents of proline and soluble sugars and the activity of CAT increased with increasing PEG concentrations. At the young seedling stage, the proline content and CAT, SOD and POD activities all increased at 2 h and then decreased; except for a decrease at 2 h, the MDA content also increased compared to the control (0 h). These results indicated that 2 h may be a key response time point for E. songoricum to resist drought stress. The above results demonstrate that drought stress can suppress and delay the germination of E. songoricum and that the seeds accumulate osmolytes and augment the activity of antioxidative enzymes to cope with drought injury. E. songoricum seedlings are sensitive to water stress and can quickly respond to drought but cannot tolerate drought for an extended period. Although such physiological and biochemical changes are important strategies for E. songoricum to adapt to a drought-prone environment, they may be, at least partially, responsible for the failure of sexual reproduction under natural conditions. PMID:26417219

  18. Plant growth strategies are remodeled by spaceflight

    PubMed Central

    2012-01-01

    Background Arabidopsis plants were grown on the International Space Station within specialized hardware that combined a plant growth habitat with a camera system that can capture images at regular intervals of growth. The Imaging hardware delivers telemetric data from the ISS, specifically images received in real-time from experiments on orbit, providing science without sample return. Comparable Ground Controls were grown in a sister unit that is maintained in the Orbital Environment Simulator at Kennedy Space Center. One of many types of biological data that can be analyzed in this fashion is root morphology. Arabidopsis seeds were geminated on orbit on nutrient gel Petri plates in a configuration that encouraged growth along the surface of the gel. Photos were taken every six hours for the 15 days of the experiment. Results In the absence of gravity, but the presence of directional light, spaceflight roots remained strongly negatively phototropic and grew in the opposite direction of the shoot growth; however, cultivars WS and Col-0 displayed two distinct, marked differences in their growth patterns. First, cultivar WS skewed strongly to the right on orbit, while cultivar Col-0 grew with little deviation away from the light source. Second, the Spaceflight environment also impacted the rate of growth in Arabidopsis. The size of the Flight plants (as measured by primary root and hypocotyl length) was uniformly smaller than comparably aged Ground Control plants in both cultivars. Conclusions Skewing and waving, thought to be gravity dependent phenomena, occur in spaceflight plants. In the presence of an orienting light source, phenotypic trends in skewing are gravity independent, and the general patterns of directional root growth typified by a given genotype in unit gravity are recapitulated on orbit, although overall growth patterns on orbit are less uniform. Skewing appears independent of axial orientation on the ISS – suggesting that other tropisms (such as

  19. INTERACTIONS BETWEEN SOIL TEMPERATURE AND PLANT GROWTH STAGE ON NITROGEN UPTAKE AND AMINO ACID CONTENT OF APPLE NURSERY STOCK DURING EARLY SPRING GROWTH

    EPA Science Inventory

    In the spring, nitrogen (N) uptake by apple roots is known to be delayed about three weeks after bud break. We used one-year-old 'Fuji' (Malus domestica Borkh) on M26 bare-root apple trees to determine whether timing of N uptake in the spring is dependant solely on the growth st...

  20. Improvement of growth, fruit weight and early blight disease protection of tomato plants by rhizosphere bacteria is correlated with their beneficial traits and induced biosynthesis of antioxidant peroxidase and polyphenol oxidase.

    PubMed

    Narendra Babu, Anupama; Jogaiah, Sudisha; Ito, Shin-Ichi; Kestur Nagaraj, Amruthesh; Tran, Lam-Son Phan

    2015-02-01

    Five plant growth promoting rhizobacteria (PGPRs) of different genera, newly isolated from healthy tomato rhizosphere, were characterized with phosphate solubilizing and root colonizing ability. Treatment with these isolates recorded a significant increase in seed germination and seedling vigor as well as tomato growth and fruit weight which might be partly attributed to the ability of the PGPRs to produce IAA and enhance nutrient uptake and chlorophyll content in treated plants. More importantly, a strong protection against early blight disease was observed in PGPR-pretreated tomato plants infected with Alternaria solani which is in accordance with the presence of siderophores, HCN, chitinase and glucanase in the isolated PGPRs. Additionally, a significantly enhanced accumulation of antioxidant peroxidase (POX) and polyphenol oxidase (PPO) enzymes was observed in the PGPR-pretreated plants with or without pathogen infection in comparison with water or pathogen control. Notably, the highest increase in POX and PPO accumulations was recorded in tomato plants raised from seeds primed with TN_Vel-35 strain. A significant upregulation of POX and PPO in tomato plants subjected to similar treatment with TN_Vel-35 versus respective control was also noticed, further strengthening that the PGPR-induced POX and PPO biosyntheses also contribute to PGPR-mediated protection against early blight disease in tomato plants.

  1. [Early childhood growth and development].

    PubMed

    Arce, Melitón

    2015-01-01

    This article describes and discusses issues related to the process of childhood growth and development, with emphasis on the early years, a period in which this process reaches critical speed on major structures and functions of the human economy. We reaffirm that this can contribute to the social availability of a generation of increasingly better adults, which in turn will be able to contribute to building a better world and within it a society that enjoys greater prosperity. In the first chapter, we discuss the general considerations on the favorable evolution of human society based on quality of future adults, meaning the accomplishments that today’s children will gain. A second chapter mentions the basics of growth and development in the different fields and the various phenomena that occur in it. In the third we refer to lost opportunities and negative factors that can affect delaying the process and thereby result in not obtaining the expected accomplishments. In the fourth, conclusions and recommendations are presented confirming the initial conception that good early child care serves to build a better society and some recommendations are formulated to make it a good practice.

  2. Sequential Transphosphorylation of the BRI1/BAK1 Receptor Kinase Pair Regulates Early Events of the Brassinosteriod Signaling Pathway Promoting Plant Growth and Development

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Brassinosteroids (BRs) regulate multiple aspects of plant growth and development through a signal transduction pathway that is initiated by BR binding to the transmembrane receptor kinase BRI1. Activated BRI1 heterodimerizes with a second receptor kinase, BAK1, leading to enhanced signaling output. ...

  3. Plant growth-promoting bacterial endophytes.

    PubMed

    Santoyo, Gustavo; Moreno-Hagelsieb, Gabriel; Orozco-Mosqueda, Ma del Carmen; Glick, Bernard R

    2016-02-01

    Bacterial endophytes ubiquitously colonize the internal tissues of plants, being found in nearly every plant worldwide. Some endophytes are able to promote the growth of plants. For those strains the mechanisms of plant growth-promotion known to be employed by bacterial endophytes are similar to the mechanisms used by rhizospheric bacteria, e.g., the acquisition of resources needed for plant growth and modulation of plant growth and development. Similar to rhizospheric plant growth-promoting bacteria, endophytic plant growth-promoting bacteria can act to facilitate plant growth in agriculture, horticulture and silviculture as well as in strategies for environmental cleanup (i.e., phytoremediation). Genome comparisons between bacterial endophytes and the genomes of rhizospheric plant growth-promoting bacteria are starting to unveil potential genetic factors involved in an endophytic lifestyle, which should facilitate a better understanding of the functioning of bacterial endophytes.

  4. Phenotypic and genetic dissection of component traits for early vigour in rice using plant growth modelling, sugar content analyses and association mapping

    PubMed Central

    Rebolledo, M. C.; Dingkuhn, M.; Courtois, B.; Gibon, Y.; Clément-Vidal, A.; Cruz, D. F.; Duitama, J.; Lorieux, M.; Luquet, D.

    2015-01-01

    Early vigour of rice, defined as seedling capacity to accumulate shoot dry weight (SDW) rapidly, is a complex trait. It depends on a genotype propensity to assimilate, store, and/or use non-structural carbohydrates (NSC) for producing large and/or numerous leaves, involving physiological trade-offs in the expression of component traits and, possibly, physiological and genetic linkages. This study explores a plant-model-assisted phenotyping approach to dissect the genetic architecture of rice early vigour, applying the Genome Wide Association Study (GWAS) to morphological and NSC measurements, as well as fitted parameters for the functional–structural plant model, Ecomeristem. Leaf size, number, SDW, and source-leaf NSC concentration were measured on a panel of 123 japonica accessions. The data were used to estimate Ecomeristem genotypic parameters driving organ appearance rate, size, and carbon dynamics. GWAS was performed based on 12 221 single-nucleotide polymorphisms (SNP). Twenty-three associations were detected at P <1×10–4 and 64 at P <5×10–4. Associations for NSC and model parameters revealed new regions related to early vigour that had greater significance than morphological traits, providing additional information on the genetic control of early vigour. Plant model parameters were used to characterize physiological and genetic trade-offs among component traits. Twelve associations were related to loci for cloned genes, with nine related to organogenesis, plant height, cell size or cell number. The potential use of these associations as markers for breeding is discussed. PMID:26022255

  5. Plant perceptions of plant growth-promoting Pseudomonas.

    PubMed Central

    Preston, Gail M

    2004-01-01

    Plant-associated Pseudomonas live as saprophytes and parasites on plant surfaces and inside plant tissues. Many plant-associated Pseudomonas promote plant growth by suppressing pathogenic micro-organisms, synthesizing growth-stimulating plant hormones and promoting increased plant disease resistance. Others inhibit plant growth and cause disease symptoms ranging from rot and necrosis through to developmental dystrophies such as galls. It is not easy to draw a clear distinction between pathogenic and plant growth-promoting Pseudomonas. They colonize the same ecological niches and possess similar mechanisms for plant colonization. Pathogenic, saprophytic and plant growth-promoting strains are often found within the same species, and the incidence and severity of Pseudomonas diseases are affected by environmental factors and host-specific interactions. Plants are faced with the challenge of how to recognize and exclude pathogens that pose a genuine threat, while tolerating more benign organisms. This review examines Pseudomonas from a plant perspective, focusing in particular on the question of how plants perceive and are affected by saprophytic and plant growth-promoting Pseudomonas (PGPP), in contrast to their interactions with plant pathogenic Pseudomonas. A better understanding of the molecular basis of plant-PGPP interactions and of the key differences between pathogens and PGPP will enable researchers to make more informed decisions in designing integrated disease-control strategies and in selecting, modifying and using PGPP for plant growth promotion, bioremediation and biocontrol. PMID:15306406

  6. Water-Conserving Plant-Growth System

    NASA Technical Reports Server (NTRS)

    Dreschel, Thomas W.; Brown, Christopher S.

    1993-01-01

    Report presents further information about plant-growth apparatus described in "Tubular Membrane Plant-Growth Unit" (KSC-11375). Apparatus provides nutrient solution to roots of seedlings without flooding. Conserves water by helping to prevent evaporation from plant bed. Solution supplied only as utilized by seedlings. Device developed for supporting plant growth in space, also has applications for growing plants with minimum of water, such as in arid environments.

  7. LED Systems Target Plant Growth

    NASA Technical Reports Server (NTRS)

    2010-01-01

    To help develop technologies for growing edible biomass (food crops) in space, Kennedy Space Center partnered with Orbital Technologies Corporation (ORBITEC), of Madison, Wisconsin, through the Small Business Innovation Research (SBIR) program. One result of this research was the High Efficiency Lighting with Integrated Adaptive Control (HELIAC) system, components of which have been incorporated into a variety of agricultural greenhouse and consumer aquarium lighting features. The new lighting systems can be adapted to a specific plant species during a specific growth stage, allowing maximum efficiency in light absorption by all available photosynthetic tissues.

  8. (Plant growth with limited water)

    SciTech Connect

    Not Available

    1991-01-01

    The work supported by DOE in the last year built on our earlier findings that stem growth in soybean subjected to limited water is inhibited first by a physical limitation followed in a few hours by metabolic changes that reduce the extensibility of the cell walls. With time, there is modest recovery in extensibility and a 28kD protein accumulates in the walls of the growth-affected cells. A 31kD protein that was 80% similar in amino acid sequence also was present but did not accumulate in the walls of the stem cells. Explorations of the mRNA for these proteins showed that the mRNA for the 28kD protein increased in the shoot in response to water deprivation but the mRNA for the 31kD protein did not accumulate. In contrast, the roots continued to grow and the mRNA for the 31kD protein accumulated but the mRNA for the 28kD protein was undetectable. We also explored how growth occurs in the absence of an external water supply. We found that, under these conditions, internal water is mobilized from surrounding nongrowing or slowly growing tissues and is used by rapidly growing cells. We showed that a low water potential is normally present in the enlarging tissues and is the likely force that extracts water from the surrounding tissues. We found that it involved a gradient in water potential that extended from the xylem to the outlying cells in the enlarging region and was not observed in the slowly growing basal tissue of the stems of the same plant. The gradient was measured directly with single cell determinations of turgor and osmotic potential in intact plants. The gradient may explain instances of growth inhibition with limited water when there is no change in the turgor of the enlarging cells. 17 refs.

  9. Agriculture on Mars: Soils for Plant Growth

    NASA Technical Reports Server (NTRS)

    Ming, D. W.

    2016-01-01

    Robotic rovers and landers have enabled the mineralogical, chemical, and physical characterization of loose, unconsolidated materials on the surface of Mars. Planetary scientists refer to the regolith material as "soil." NASA is currently planning to send humans to Mars in the mid 2030s. Early missions may rely on the use of onsite resources to enable exploration and self-sufficient outposts on Mars. The martian "soil" and surface environment contain all essential plant growth elements. The study of martian surface materials and how they might react as agricultural soils opens a new frontier for researchers in the soil science community. Other potential applications for surface "soils" include (i) sources for extraction of essential plant-growth nutrients, (ii) sources of O2, H2, CO2, and H2O, (iii) substrates for microbial populations in the degradation of wastes, and (iv) shielding materials surrounding outpost structures to protect humans, plants, and microorganisms from radiation. There are many challenges that will have to be addressed by soil scientists prior to human exploration over the next two decades.

  10. Early recognition of growth abnormalities permitting early intervention

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Normal growth is a sign of good health. Monitoring for growth disturbances is fundamental to children's health care. Early detection and diagnosis of the causes of short stature allows management of underlying medical conditions, optimizing attainment of good health and normal adult height. This rev...

  11. Rapid growth and early flowering in an invasive plant, purple loosestrife ( Lythrum salicaria L.) during an El Niño spring.

    PubMed

    Dech, J P; Nosko, P

    2004-09-01

    Phenological shifts may play a role in the success of invasive species, especially in association with climatic variability. We studied the response of a North American population of the invasive plant, Lythrum salicaria L., to changes in local climate associated with the El Niño/Southern Oscillation Event (ENSO) of 1997-1998. For L. salicaria plants at two wetland sites near North Bay, Ontario, Canada, we made weekly observations of flowering phenology and monthly measurements of aboveground biomass during the 1997 and 1998 growing seasons (April-October). Reproductive output was measured as cumulative length and biomass of inflorescences at the end of the growing season. Temperature and precipitation during the 1997 growing season were typical for the region and provided good baseline data for comparison to the full effects of the ENSO event in 1998, which increased spring temperatures and reduced precipitation in the study area. In response to these conditions, populations of L. salicaria began to flower 14 days earlier (Julian day = 181 +/- 10) in 1998 than in 1997 (Julian day = 195 +/- 12), and accumulated more aboveground biomass early in the growing season (P < 0.05). However, by the end of the growing season, there were no significant differences between years in aboveground biomass or total inflorescence lengths, and senescence of plants occurred at similar times for both growing seasons. Advances in spring phenology during ENSO events offer several potential advantages to L. salicaria, and could have a significant impact on biological control programs initiated for this species in North America.

  12. Complementarity among plant growth promoting traits in rhizospheric bacterial communities promotes plant growth.

    PubMed

    Singh, Mangal; Awasthi, Ashutosh; Soni, Sumit K; Singh, Rakshapal; Verma, Rajesh K; Kalra, Alok

    2015-10-27

    An assessment of roles of rhizospheric microbial diversity in plant growth is helpful in understanding plant-microbe interactions. Using random combinations of rhizospheric bacterial species at different richness levels, we analysed the contribution of species richness, compositions, interactions and identity on soil microbial respiration and plant biomass. We showed that bacterial inoculation in plant rhizosphere enhanced microbial respiration and plant biomass with complementary relationships among bacterial species. Plant growth was found to increase linearly with inoculation of rhizospheric bacterial communities with increasing levels of species or plant growth promoting trait diversity. However, inoculation of diverse bacterial communities having single plant growth promoting trait, i.e., nitrogen fixation could not enhance plant growth over inoculation of single bacteria. Our results indicate that bacterial diversity in rhizosphere affect ecosystem functioning through complementary relationship among plant growth promoting traits and may play significant roles in delivering microbial services to plants.

  13. The microfossil record of early land plants.

    PubMed Central

    Wellman, C H; Gray, J

    2000-01-01

    Dispersed microfossils (spores and phytodebris) provide the earliest evidence for land plants. They are first reported from the Llanvirn (Mid-Ordovician). More or less identical assemblages occur from the Llanvirn (Mid-Ordovician) to the late Llandovery (Early Silurian), suggesting a period of relative stasis some 40 Myr in duration. Various lines of evidence suggest that these early dispersed microfossils derive from parent plants that were bryophyte-like if not in fact bryophytes. In the late Llandovery (late Early Silurian) there was a major change in the nature of dispersed spore assemblages as the separated products of dyads (hilate monads) and tetrads (trilete spores) became relatively abundant. The inception of trilete spores probably represents the appearance of vascular plants or their immediate progenitors. A little later in time, in the Wenlock (early Late Silurian), the earliest unequivocal land plant megafossils occur. They are represented by rhyniophytoids. It is only from the Late Silurian onwards that the microfossil/ megafossil record can be integrated and utilized in interpretation of the flora. Dispersed microfossils are preserved in vast numbers, in a variety of environments, and have a reasonable spatial and temporal fossil record. The fossil record of plant megafossils by comparison is poor and biased, with only a dozen or so known pre-Devonian assemblages. In this paper, the early land plant microfossil record, and its interpretation, are reviewed. New discoveries, novel techniques and fresh lines of inquiry are outlined and discussed. PMID:10905606

  14. The microfossil record of early land plants.

    PubMed

    Wellman, C H; Gray, J

    2000-06-29

    Dispersed microfossils (spores and phytodebris) provide the earliest evidence for land plants. They are first reported from the Llanvirn (Mid-Ordovician). More or less identical assemblages occur from the Llanvirn (Mid-Ordovician) to the late Llandovery (Early Silurian), suggesting a period of relative stasis some 40 Myr in duration. Various lines of evidence suggest that these early dispersed microfossils derive from parent plants that were bryophyte-like if not in fact bryophytes. In the late Llandovery (late Early Silurian) there was a major change in the nature of dispersed spore assemblages as the separated products of dyads (hilate monads) and tetrads (trilete spores) became relatively abundant. The inception of trilete spores probably represents the appearance of vascular plants or their immediate progenitors. A little later in time, in the Wenlock (early Late Silurian), the earliest unequivocal land plant megafossils occur. They are represented by rhyniophytoids. It is only from the Late Silurian onwards that the microfossil/ megafossil record can be integrated and utilized in interpretation of the flora. Dispersed microfossils are preserved in vast numbers, in a variety of environments, and have a reasonable spatial and temporal fossil record. The fossil record of plant megafossils by comparison is poor and biased, with only a dozen or so known pre-Devonian assemblages. In this paper, the early land plant microfossil record, and its interpretation, are reviewed. New discoveries, novel techniques and fresh lines of inquiry are outlined and discussed.

  15. Spiral Growth in Plants: Models and Simulations

    ERIC Educational Resources Information Center

    Allen, Bradford D.

    2004-01-01

    The analysis and simulation of spiral growth in plants integrates algebra and trigonometry in a botanical setting. When the ideas presented here are used in a mathematics classroom/computer lab, students can better understand how basic assumptions about plant growth lead to the golden ratio and how the use of circular functions leads to accurate…

  16. Modeling plant growth and development.

    PubMed

    Prusinkiewicz, Przemyslaw

    2004-02-01

    Computational plant models or 'virtual plants' are increasingly seen as a useful tool for comprehending complex relationships between gene function, plant physiology, plant development, and the resulting plant form. The theory of L-systems, which was introduced by Lindemayer in 1968, has led to a well-established methodology for simulating the branching architecture of plants. Many current architectural models provide insights into the mechanisms of plant development by incorporating physiological processes, such as the transport and allocation of carbon. Other models aim at elucidating the geometry of plant organs, including flower petals and apical meristems, and are beginning to address the relationship between patterns of gene expression and the resulting plant form.

  17. The plant pathogenic fungus Gaeumannomyces graminis var. tritici improves bacterial growth and triggers early gene regulations in the biocontrol strain Pseudomonas fluorescens Pf29Arp.

    PubMed

    Barret, M; Frey-Klett, P; Boutin, M; Guillerm-Erckelboudt, A-Y; Martin, F; Guillot, L; Sarniguet, A

    2009-01-01

    In soil, some antagonistic rhizobacteria contribute to reduce root diseases caused by phytopathogenic fungi. Direct modes of action of these bacteria have been largely explored; however, commensal interaction also takes place between these microorganisms and little is known about the influence of filamentous fungi on bacteria. An in vitro confrontation bioassay between the pathogenic fungus Gaeumannomyces graminis var. tritici (Ggt) and the biocontrol bacterial strain Pseudomonas fluorescens Pf29Arp was set up to analyse bacterial transcriptional changes induced by the fungal mycelium at three time-points of the interaction before cell contact and up until contact. For this, a Pf29Arp shotgun DNA microarray was constructed. Specifity of Ggt effect was assessed in comparison with one of two other filamentous fungi, Laccaria bicolor and Magnaporthe grisea. During a commensal interaction, Ggt increased the growth rate of Pf29Arp. Before contact, Ggt induced bacterial genes involved in mycelium colonization. At contact, genes encoding protein of stress response and a patatin-like protein were up-regulated. Among all the bacterial genes identified, xseB was specifically up-regulated at contact by Ggt but down-regulated by the other fungi. Data showed that the bacterium sensed the presence of the fungus early, but the main gene alteration occurred during bacterial-fungal cell contact.

  18. Tuning plant signaling and growth to survive salt.

    PubMed

    Julkowska, Magdalena M; Testerink, Christa

    2015-09-01

    Salinity is one of the major abiotic factors threatening food security worldwide. Recently, our understanding of early processes underlying salinity tolerance has expanded. In this review, early signaling events, such as phospholipid signaling, calcium ion (Ca(2+)) responses, and reactive oxygen species (ROS) production, together with salt stress-induced abscisic acid (ABA) accumulation, are brought into the context of long-term salt stress-specific responses and alteration of plant growth. Salt-induced quiescent and recovery growth phases rely on modification of cell cycle activity, cell expansion, and cell wall extensibility. The period of initial growth arrest varies among different organs, leading to altered plant morphology. Studying stress-induced changes in growth dynamics can be used for screening to discover novel genes contributing to salt stress tolerance in model species and crops.

  19. Plant photomorphogenesis and canopy growth

    NASA Technical Reports Server (NTRS)

    Ballare, Carlos L.; Scopel, Ana L.

    1994-01-01

    An important motivation for studying photomorphogenesis is to understand the relationships among plant photophysiology in canopies, canopy productivity, and agronomic yield. This understanding is essential to optimize lighting systems used for plant farming in controlled environments (CE) and for the design of genetically engineered crop strains with altered photoresponses. This article provides an overview of some basic principles of plant photomorphogenesis in canopies and discusses their implications for (1) scaling up information on plant photophysiology from individual plants in CE to whole canopies in the field, and (2) designing lighting conditions to increase plant productivity in CE used for agronomic purposes (e.g. space farming in CE Life Support Systems). We concentrate on the visible (lambda between 400 and 700 nm) and far-infrared (FR; lambda greater than 700 nm) spectral regions, since the ultraviolet (UV; 280 to 400 nm) is covered by other authors in this volume.

  20. Increasing rice plant growth by Trichoderma sp.

    NASA Astrophysics Data System (ADS)

    Doni, Febri; Isahak, Anizan; Zain, Che Radziah Che Mohd; Sulaiman, Norela; Fathurahman, F.; Zain, Wan Nur Syazana Wan Mohd.; Kadhimi, Ahsan A.; Alhasnawi, Arshad Naji; Anhar, Azwir; Yusoff, Wan Mohtar Wan

    2016-11-01

    Trichoderma sp. is a plant growth promoting fungi in many crops. Initial observation on the ability to enhance rice germination and vigor have been reported. In this study, the effectiveness of a local isolate Trichoderma asprellum SL2 to enhance rice seedling growth was assessed experimentally under greenhouse condition using a completely randomized design. Results showed that inoculation of rice plants with Trichoderma asprellum SL2 significantly increase rice plants height, root length, wet weight, leaf number and biomass compared to untreated rice plants (control). The result of this study can serve as a reference for further work on the application of beneficial microorganisms to enhance rice production.

  1. Nitric oxide (NO) and phytohormones crosstalk during early plant development.

    PubMed

    Sanz, Luis; Albertos, Pablo; Mateos, Isabel; Sánchez-Vicente, Inmaculada; Lechón, Tamara; Fernández-Marcos, María; Lorenzo, Oscar

    2015-05-01

    During the past two decades, nitric oxide (NO) has evolved from a mere gaseous free radical to become a new messenger in plant biology with an important role in a plethora of physiological processes. This molecule is involved in the regulation of plant growth and development, pathogen defence and abiotic stress responses, and in most cases this is achieved through its interaction with phytohormones. Understanding the role of plant growth regulators is essential to elucidate how plants activate the appropriate set of responses to a particular developmental stage or a particular stress. The first task to achieve this goal is the identification of molecular targets, especially those involved in the regulation of the crosstalk. The nature of NO targets in these growth and development processes and stress responses remains poorly described. Currently, the molecular mechanisms underlying the effects of NO in these processes and their interaction with other plant hormones are beginning to unravel. In this review, we made a compilation of the described interactions between NO and phytohormones during early plant developmental processes (i.e. seed dormancy and germination, hypocotyl elongation and root development).

  2. Mechanical stress regulation of plant growth and development

    NASA Technical Reports Server (NTRS)

    Mitchell, C. A.; Myers, P. N.

    1995-01-01

    The authors introduce the chapter with a discussion of lessons from nature, agriculture, and landscapes; terms and definitions; and an historical perspective of mechanical stress regulation of plant growth and development. Topics include developmental responses to mechanical stress; mechanical stress-environment interactions; metabolic, productivity, and compositional changes; hormonal involvement; mechanoperception and early transduction mechanisms; applications in agriculture; and research implications. The discussion of hormonal involvement in mechanical stress physiology includes ethylene, auxin, gibberellins, and other phytohormones. The discussion of applications in agriculture examines windbreaks, nursery practices, height control and conditioning, and enhancement of growth and productivity. Implications for research are related to handling plant materials, space biology, and future research needs.

  3. How Plants Make Light Work of Growth.

    ERIC Educational Resources Information Center

    Kendrick, R. E.

    1981-01-01

    Presented is one of a series of articles designed to help science teachers keep current on ideas in specific areas in biology. Contained is information on how plants use light for growth, seed germination, and flowering. (PB)

  4. Sealed Plant-Growth Chamber For Clinostat

    NASA Technical Reports Server (NTRS)

    Brown, Christopher S.; Dreschel, Thomas W.

    1993-01-01

    Laboratory chamber for growing plants used to measure photosynthesis and respiration in simulated microgravity. Holds plant specimens while rotated on clinostat, see article, "Clinostat Delivers Power To Plant-Growth Cabinets" (KSC-11537). Provides way of comparing gas-exchange rates of plants rotated horizontally on clinostat with those of stationary or vertically rotated plants. Gas extracted for analysis without stopping clinostat. Chamber includes potlike base and cylindrical cover, both made of transparent acrylic pipe. Gasket forms seal between cover and bottom plate of base. Cover bolted to pot baseplate, which in turn bolted to clinostat.

  5. Rotary plant growth accelerating apparatus. [weightlessness

    NASA Technical Reports Server (NTRS)

    Dedolph, R. D. (Inventor)

    1975-01-01

    Rotary plant growth accelerating apparatus for increasing plant yields by effectively removing the growing plants from the constraints of gravity and increasing the plant yield per unit of space is described. The apparatus is comprised of cylindrical plant beds supported radially removed from a primary axis of rotation, with each plant bed being driven about its own secondary axis of rotation and simultaneously moved in a planetary path about the primary axis of rotation. Each plant bed is formed by an apertured outer cylinder, a perforated inner cylinder positioned coaxially, and rooting media disposed in the space between. A rotatable manifold distributes liquid nutrients and water to the rooting media through the perforations in the inner cylinders as the plant beds are continuously rotated by suitable drive means.

  6. Effect of microgravity on plant growth

    NASA Technical Reports Server (NTRS)

    Lewis, Norman G.

    1994-01-01

    The overall goal of this research is to determine the effect of microgravity proper on plant growth (metabolism and cell wall formation). In addressing this goal, the work conducted during this grant period was divided into three components: analyses of various plant tissues previously grown in space aboard MIR Space Station; analyses of wheat tissues grown on Shuttle flight STS-51; and Phenylpropanoid metabolism and plant cell wall synthesis (earth-based investigations).

  7. Plant Growth Module (PGM) conceptual design

    NASA Technical Reports Server (NTRS)

    Schwartzkopf, Steven H.; Rasmussen, Daryl

    1987-01-01

    The Plant Growth Module for the Controlled Ecological Life Support System (CELSS), designed to answer basic science questions related to growing plants in closed systems, is described functionally with artist's conception drawings. Subsystems are also described, including enclosure and access; data acquisition and control; gas monitor and control; heating, ventilation, and air conditioning; air delivery; nutrient monitor and control; microbial monitoring and control; plant support and nutrient delivery; illumination; and internal operations. The hardware development plan is outlined.

  8. Contour Instabilities in Early Tumor Growth Models

    NASA Astrophysics Data System (ADS)

    Ben Amar, M.; Chatelain, C.; Ciarletta, P.

    2011-04-01

    Recent tumor growth models are often based on the multiphase mixture framework. Using bifurcation theory techniques, we show that such models can give contour instabilities. Restricting to a simplified but realistic version of such models, with an elastic cell-to-cell interaction and a growth rate dependent on diffusing nutrients, we prove that the tumor cell concentration at the border acts as a control parameter inducing a bifurcation with loss of the circular symmetry. We show that the finite wavelength at threshold has the size of the proliferating peritumoral zone. We apply our predictions to melanoma growth since contour instabilities are crucial for early diagnosis. Given the generality of the equations, other relevant applications can be envisaged for solving problems of tissue growth and remodeling.

  9. A continuous growth model for plant tissue

    NASA Astrophysics Data System (ADS)

    Bozorg, Behruz; Krupinski, Pawel; Jönsson, Henrik

    2016-12-01

    Morphogenesis in plants and animals involves large irreversible deformations. In plants, the response of the cell wall material to internal and external forces is determined by its mechanical properties. An appropriate model for plant tissue growth must include key features such as anisotropic and heterogeneous elasticity and cell dependent evaluation of mechanical variables such as turgor pressure, stress and strain. In addition, a growth model needs to cope with cell divisions as a necessary part of the growth process. Here we develop such a growth model, which is capable of employing not only mechanical signals but also morphogen signals for regulating growth. The model is based on a continuous equation for updating the resting configuration of the tissue. Simultaneously, material properties can be updated at a different time scale. We test the stability of our model by measuring convergence of growth results for a tissue under the same mechanical and material conditions but with different spatial discretization. The model is able to maintain a strain field in the tissue during re-meshing, which is of particular importance for modeling cell division. We confirm the accuracy of our estimations in two and three-dimensional simulations, and show that residual stresses are less prominent if strain or stress is included as input signal to growth. The approach results in a model implementation that can be used to compare different growth hypotheses, while keeping residual stresses and other mechanical variables updated and available for feeding back to the growth and material properties.

  10. Transgenic plants with enhanced growth characteristics

    DOEpatents

    Unkefer, Pat J.; Anderson, Penelope S.; Knight, Thomas J.

    2016-09-06

    The invention relates to transgenic plants exhibiting dramatically enhanced growth rates, greater seed and fruit/pod yields, earlier and more productive flowering, more efficient nitrogen utilization, increased tolerance to high salt conditions, and increased biomass yields. In one embodiment, transgenic plants engineered to over-express both glutamine phenylpyruvate transaminase (GPT) and glutamine synthetase (GS) are provided. The GPT+GS double-transgenic plants of the invention consistently exhibit enhanced growth characteristics, with T0 generation lines showing an increase in biomass over wild type counterparts of between 50% and 300%. Generations that result from sexual crosses and/or selfing typically perform even better, with some of the double-transgenic plants achieving an astounding four-fold biomass increase over wild type plants.

  11. (Plant growth with limited water)

    SciTech Connect

    Not Available

    1992-01-01

    When water is in short supply, soybean stem growth is inhibited by a physical limitation followed in a few hours by metabolic changes that reduce the extensibility of the cell walls. The extensibility then becomes the main limitation. With time, there is a modest recovery in extensibility along with an accumulation of a 28kD protein in the walls of the growth-affected cells. A 3lkD protein that was 80% similar in amino acid sequence also was present but did not accumulate in the walls of the stem cells. In the stem, growth was inhibited and the mRNA for the 28kD protein increased in response to water deprivation but the mRNA for the 3 1 kD protein did not. The roots continued to grow and the mRNA for the 28kD protein did not accumulate but the mRNA for the 3lkD protein did. Thus, there was a tissuespecific response of gene expression that correlated with the contrasting growth response to low water potential in the same seedlings. Further work using immunogold labeling, fluorescence labeling, and western blotting gave evidence that the 28kD protein is located in the cell wall as well as several compartments in the cytoplasm. Preliminary experiments indicate that the 28kD protein is a phosphatase.

  12. Plant Growth Modelling and Applications: The Increasing Importance of Plant Architecture in Growth Models

    PubMed Central

    Fourcaud, Thierry; Zhang, Xiaopeng; Stokes, Alexia; Lambers, Hans; Körner, Christian

    2008-01-01

    Background Modelling plant growth allows us to test hypotheses and carry out virtual experiments concerning plant growth processes that could otherwise take years in field conditions. The visualization of growth simulations allows us to see directly and vividly the outcome of a given model and provides us with an instructive tool useful for agronomists and foresters, as well as for teaching. Functional–structural (FS) plant growth models are nowadays particularly important for integrating biological processes with environmental conditions in 3-D virtual plants, and provide the basis for more advanced research in plant sciences. Scope In this viewpoint paper, we ask the following questions. Are we modelling the correct processes that drive plant growth, and is growth driven mostly by sink or source activity? In current models, is the importance of soil resources (nutrients, water, temperature and their interaction with meristematic activity) considered adequately? Do classic models account for architectural adjustment as well as integrating the fundamental principles of development? Whilst answering these questions with the available data in the literature, we put forward the opinion that plant architecture and sink activity must be pushed to the centre of plant growth models. In natural conditions, sinks will more often drive growth than source activity, because sink activity is often controlled by finite soil resources or developmental constraints. PMA06 This viewpoint paper also serves as an introduction to this Special Issue devoted to plant growth modelling, which includes new research covering areas stretching from cell growth to biomechanics. All papers were presented at the Second International Symposium on Plant Growth Modeling, Simulation, Visualization and Applications (PMA06), held in Beijing, China, from 13–17 November, 2006. Although a large number of papers are devoted to FS models of agricultural and forest crop species, physiological and genetic

  13. Concerted gene recruitment in early plant evolution

    PubMed Central

    Huang, Jinling; Gogarten, J Peter

    2008-01-01

    Background Horizontal gene transfer occurs frequently in prokaryotes and unicellular eukaryotes. Anciently acquired genes, if retained among descendants, might significantly affect the long-term evolution of the recipient lineage. However, no systematic studies on the scope of anciently acquired genes and their impact on macroevolution are currently available in eukaryotes. Results Analyses of the genome of the red alga Cyanidioschyzon identified 37 genes that were acquired from non-organellar sources prior to the split of red algae and green plants. Ten of these genes are rarely found in cyanobacteria or have additional plastid-derived homologs in plants. These genes most likely provided new functions, often essential for plant growth and development, to the ancestral plant. Many remaining genes may represent replacements of endogenous homologs with a similar function. Furthermore, over 78% of the anciently acquired genes are related to the biogenesis and functionality of plastids, the defining character of plants. Conclusion Our data suggest that, although ancient horizontal gene transfer events did occur in eukaryotic evolution, the number of acquired genes does not predict the role of horizontal gene transfer in the adaptation of the recipient organism. Our data also show that multiple independently acquired genes are able to generate and optimize key evolutionary novelties in major eukaryotic groups. In light of these findings, we propose and discuss a general mechanism of horizontal gene transfer in the macroevolution of eukaryotes. PMID:18611267

  14. A nondestructive method for continuously monitoring plant growth

    NASA Technical Reports Server (NTRS)

    Schwartzkopf, S. H.

    1985-01-01

    In the past, plant growth generally has been measured using destructive methods. This paper describes a nondestructive technique for continuously monitoring plant growth. The technique provides a means of directly and accurately measuring plant growth over both short and long time intervals. Application of this technique to the direct measurement of plant growth rates is illustrated using corn (Zea mays L.) as an example.

  15. Growth and physiological responses of Chinese cabbage cv. 'Chungwang' to different irradiances during early-to-middle growth stages

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Changes of the growth and morphology of Chinese cabbage cv. ‘Chungwang’ in response to five different irradiance treatments were investigated during the early and middle stages of growth. Seedlings were transplanted to 15 liter pots at the fourth leaf stage and plants were grown in controlled enviro...

  16. Lunar base agriculture: Soils for plant growth

    NASA Technical Reports Server (NTRS)

    Ming, Douglas W. (Editor); Henninger, Donald L. (Editor)

    1989-01-01

    This work provides information on research and experimentation concerning various aspects of food production in space and particularly on the moon. Options for human settlement of the moon and Mars and strategies for a lunar base are discussed. The lunar environment, including the mineralogical and chemical properties of lunar regolith are investigated and chemical and physical considerations for a lunar-derived soil are considered. It is noted that biological considerations for such a soil include controlled-environment crop production, both hydroponic and lunar regolith-based; microorganisms and the growth of higher plants in lunar-derived soils; and the role of microbes to condition lunar regolith for plant cultivation. Current research in the controlled ecological life support system (CELSS) project is presented in detail and future research areas, such as the growth of higher research plants in CELSS are considered. Optimum plant and microbiological considerations for lunar derived soils are examined.

  17. Dynamical scaling analysis of plant callus growth

    NASA Astrophysics Data System (ADS)

    Galeano, J.; Buceta, J.; Juarez, K.; Pumariño, B.; de la Torre, J.; Iriondo, J. M.

    2003-07-01

    We present experimental results for the dynamical scaling properties of the development of plant calli. We have assayed two different species of plant calli, Brassica oleracea and Brassica rapa, under different growth conditions, and show that their dynamical scalings share a universality class. From a theoretical point of view, we introduce a scaling hypothesis for systems whose size evolves in time. We expect our work to be relevant for the understanding and characterization of other systems that undergo growth due to cell division and differentiation, such as, for example, tumor development.

  18. Developmental Stages in Dynamic Plant Growth Models

    NASA Astrophysics Data System (ADS)

    Maclean, Heather; Dochain, Denis; Waters, Geoff; Stasiak, Michael; Dixon, Mike; Van Der Straeten, Dominique

    2011-09-01

    During the growth of red beet plants in a closed environment plant growth chamber, a change in metabolism was observed (decreasing photosynthetic quotient) which was not predicted by a previously developed simple dynamic model of photosynthesis and respiration reactions. The incorporation of developmental stages into the model allowed for the representation of this change in metabolism without adding unnecessary complexity. Developmental stages were implemented by dividing the model into two successive sub-models with independent yields. The transition between the phases was detected based on online measurements. Results showed an accurate prediction of carbon dioxide and oxygen fluxes.

  19. Regulation of plant growth by cytokinin

    PubMed Central

    Werner, Tomáš; Motyka, Václav; Strnad, Miroslav; Schmülling, Thomas

    2001-01-01

    Cytokinins are a class of plant-specific hormones that play a central role during the cell cycle and influence numerous developmental programs. Because of the lack of biosynthetic and signaling mutants, the regulatory roles of cytokinins are not well understood. We genetically engineered cytokinin oxidase expression in transgenic tobacco plants to reduce their endogenous cytokinin content. Cytokinin-deficient plants developed stunted shoots with smaller apical meristems. The plastochrone was prolonged, and leaf cell production was only 3–4% that of wild type, indicating an absolute requirement of cytokinins for leaf growth. In contrast, root meristems of transgenic plants were enlarged and gave rise to faster growing and more branched roots. These results suggest that cytokinins are an important regulatory factor of plant meristem activity and morphogenesis, with opposing roles in shoots and roots. PMID:11504909

  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. Auxins as one of the factors of plant growth improvement by plant growth promoting rhizobacteria.

    PubMed

    Ahmed, Ambreen; Hasnain, Shahida

    2014-01-01

    Plant growth promoting rhizobacteria (PGPR) promote plant growth by various mechanisms such as phytohormone production, enhanced water and nutrient uptake, improved nitrogen availability in the soil, production of ACC-deaminase for ethylene breakdown, phosphate solubilization, siderophore production etc. Microbial auxin production is the major factor not only responsible for strengthening the plant-microbe relationship but it also promotes plant growth and development in a positive manner. Thus, bacterial auxin production potential can be exploited for plant growth improvement that may be effective in reducing the hazardous effects of chemical fertilizers on the ecosystem used to obtain higher yields. The present review gives a better understanding of various factors and mechanisms involved in auxin production by PGPR that may be helpful in proper exploitation of these natural resources in a beneficial way.

  2. Importance of Gravity for Plant Growth and Behavior

    NASA Technical Reports Server (NTRS)

    Brown, A. H.

    1985-01-01

    Flight experiments on the importance of gravity to plant growth and behavior are reported. The following studies were undertaken: (1) hyperastic responses to incremental changes of an axially imposed centripetal force; (2) Spacelab-1 experiments, methods for preparing soil in flight hardware containers were impound, to ensure desired moisture content and minimal contamination probability; (3) mesocotyl growth patterns were established by Avena lore exposure to red light during early seedling outogency; (4) the development of flight hardware; (5) choice of member of seedlings in each cube; (6) data processing and reduction; (7) clinostat validation; circummutation in space was more vigorous than on Earth based clinostat.

  3. Plant growth responses to polypropylene--biocontainers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The influence of bio-fillers incorporated into polypropylene (PP) on the growth of plants was evaluated. Biocontainers were created by injection molding of PP with 25-40% by weight of Osage orange tree, Paulownia tree, coffee tree wood or dried distillers grain and 5% by weight of maleated polypropy...

  4. Static Magnetic Field and Plant Growth

    NASA Astrophysics Data System (ADS)

    Maharramov, Akif A.

    2007-04-01

    In the conditions of stable existence of Static Magnetic Field (SMF) the growth processes of some plants' (chickpeas, beans and lentils) seeds have been investigated in different temperatures of microenvironment. It has been established that the rate of the plant growths is affected (speeded up) by SMF that is intimately related to environmental temperature, any other environmental parameters (humidity, illumination, soil chemical state, etc) being under control. At the same time, the highest rate of growth has been observed in beans at a range of 30, 0 +/- 2, 0 °C. Special experiments and analyses of the data obtained, testified that the plants roots occurred the main target for SMF to be affected to get increasing rate. In order to standardize experimental conditions, the SMF have been created by magnetic bars of the intensity of B, equal that of the Earth at a distance of 23 cm from a pole of a bar magnet on the line passing along the both of its poles. Taking as a basis the results, it may be concluded that SMF can affect plant growth process, being regarded as an environmental factor of ecological importance.

  5. Ethylene production throughout growth and development of plants

    NASA Technical Reports Server (NTRS)

    Wheeler, Raymond M.; Peterson, Barbara V.; Stutte, Gary W.

    2004-01-01

    Ethylene production by 10 or 20 m2 stands of wheat, soybean, lettuce, potato, and tomato was monitored throughout growth and development in an atmospherically closed plant chamber. Chamber ethylene levels varied among species and rose during periods of canopy expansion and rapid growth for all species. Following this, ethylene levels either declined during seed fill and maturation for wheat and soybean, or remained relatively constant for potato and tomato (during flowering and early fruit development). Lettuce plants were harvested during rapid growth and peak ethylene production. Chamber ethylene levels increased rapidly during tomato ripening, reaching concentrations about 10 times that measured during vegetative growth. The highest ethylene production rates during vegetative growth ranged from 1.6 to 2.5 nmol m-2 d-1 during rapid growth of lettuce and wheat stands, or about 0.3 to 0.5 nmol g-1 fresh weight per hour. Estimates of stand ethylene production during tomato ripening showed that rates reached 43 nmol m-2 d-1 in one study and 93 nmol m-2 d-1 in a second study with higher lighting, or about 50x that of the rate during vegetative growth of tomato. In a related test with potato, the photoperiod was extended from 12 to 24 hours (continuous light) at 58 days after planting (to increase tuber yield), but this change in the environment caused a sharp increase in ethylene production from the basal rate of 0.4 to 6.2 nmol m-2 d-1. Following this, the photoperiod was changed back to 12 h at 61 days and ethylene levels decreased. The results suggest three separate categories of ethylene production were observed with whole stands of plants: 1) production during rapid vegetative growth, 2) production during climacteric fruit ripening, and 3) production from environmental stress.

  6. Ethylene production throughout growth and development of plants.

    PubMed

    Wheeler, Raymond M; Peterson, Barbara V; Stutte, Gary W

    2004-12-01

    Ethylene production by 10 or 20 m2 stands of wheat, soybean, lettuce, potato, and tomato was monitored throughout growth and development in an atmospherically closed plant chamber. Chamber ethylene levels varied among species and rose during periods of canopy expansion and rapid growth for all species. Following this, ethylene levels either declined during seed fill and maturation for wheat and soybean, or remained relatively constant for potato and tomato (during flowering and early fruit development). Lettuce plants were harvested during rapid growth and peak ethylene production. Chamber ethylene levels increased rapidly during tomato ripening, reaching concentrations about 10 times that measured during vegetative growth. The highest ethylene production rates during vegetative growth ranged from 1.6 to 2.5 nmol m-2 d-1 during rapid growth of lettuce and wheat stands, or about 0.3 to 0.5 nmol g-1 fresh weight per hour. Estimates of stand ethylene production during tomato ripening showed that rates reached 43 nmol m-2 d-1 in one study and 93 nmol m-2 d-1 in a second study with higher lighting, or about 50x that of the rate during vegetative growth of tomato. In a related test with potato, the photoperiod was extended from 12 to 24 hours (continuous light) at 58 days after planting (to increase tuber yield), but this change in the environment caused a sharp increase in ethylene production from the basal rate of 0.4 to 6.2 nmol m-2 d-1. Following this, the photoperiod was changed back to 12 h at 61 days and ethylene levels decreased. The results suggest three separate categories of ethylene production were observed with whole stands of plants: 1) production during rapid vegetative growth, 2) production during climacteric fruit ripening, and 3) production from environmental stress.

  7. Water vapor recovery from plant growth chambers

    NASA Technical Reports Server (NTRS)

    Ray, R. J.; Newbold, D. D.; Colton, R. H.; Mccray, S. B.

    1991-01-01

    NASA is investigating the use of plant growth chambers (PGCs) for space missions and for bases on the moon and Mars. Key to successful development of PGCs is a system to recover and reuse the water vapor that is transpired from the leaves of the plants. A design is presented for a simple, reliable, membrane-based system that allows the recovery, purification, and reuse of the transpired water vapor through control of temperature and humidity levels in PGCs. The system is based on two membrane technologies: (1) dehumidification membrane modules to remove water vapor from the air, and (2) membrane contactors to return water vapor to the PGC (and, in doing so, to control the humidity and temperature within the PGC). The membrane-based system promises to provide an ideal, stable growth environment for a variety of plants, through a design that minimizes energy usage, volume, and mass, while maximizing simplicity and reliability.

  8. The vascular plants: open system of growth.

    PubMed

    Basile, Alice; Fambrini, Marco; Pugliesi, Claudio

    2017-03-01

    What is fascinating in plants (true also in sessile animals such as corals and hydroids) is definitely their open and indeterminate growth, as a result of meristematic activity. Plants as well as animals are characterized by a multicellular organization, with which they share a common set of genes inherited from a common eukaryotic ancestor; nevertheless, circa 1.5 billion years of evolutionary history made the two kingdoms very different in their own developmental biology. Flowering plants, also known as angiosperms, arose during the Cretaceous Period (145-65 million years ago), and up to date, they count around 235,000 species, representing the largest and most diverse group within the plant kingdom. One of the foundations of their success relies on the plant-pollinator relationship, essentially unique to angiosperms that pushed large speciation in both plants and insects and on the presence of the carpel, the structure devoted to seed enclosure. A seed represents the main organ preserving the genetic information of a plant; during embryogenesis, the primary axis of development is established by two groups of pluripotent cells: the shoot apical meristem (SAM), responsible for gene rating all aboveground organs, and the root apical meristem (RAM), responsible for producing all underground organs. During postembryonic shoot development, axillary meristem (AM) initiation and outgrowth are responsible for producing all secondary axes of growth including inflorescence branches or flowers. The production of AMs is tightly linked to the production of leaves and their separation from SAM. As leaf primordia are formed on the flanks of the SAM, a region between the apex and the developing organ is established and referred to as boundary zone. Interaction between hormones and the gene network in the boundary zone is fundamental for AM initiation. AMs only develop at the adaxial base of the leaf; thus, AM initiation is also strictly associated with leaf polarity. AMs

  9. Mechanical regulation of plant growth and development

    NASA Technical Reports Server (NTRS)

    Mitchell, C. A.

    1984-01-01

    Soybean and eggplant grown and shaken in a greenhouse exhibited decreased internode length, internode diameter, leaf area, and fresh and dry weight of roots and shoots in much the same way as outdoor-exposed plants. Perhaps more important than decreased dimensions of plant parts resulting from periodic seismic treatment is the inhibition of photosynthetic productivity that accompanies this stress. Soybeam plants briefly shaken or rubbed twice daily experienced a decrease in relative as well as absolute growth rate compared to that of undisturbed controls. Growth dynamics analysis revealed that virtually all of the decline in relative growth rate (RGR) was due to a decline in net assimilation rate (NAR), but not in leaf area ratio (LAR). Lower NAR suggests that the stress-induced decrease in dry weight gain is due to a decline in photosynthetic efficiency. Possible effects on stomatal aperture was investigated by measuring rates of whole plant transpiration as a function of seismo-stress, and a transitory decrease followed by a gradual, partial recovery was detected.

  10. Bacterial Ammonia Causes Significant Plant Growth Inhibition

    PubMed Central

    Weise, Teresa; Kai, Marco; Piechulla, Birgit

    2013-01-01

    Many and complex plant-bacteria inter-relationships are found in the rhizosphere, since plants release a variety of photosynthetic exudates from their roots and rhizobacteria produce multifaceted specialized compounds including rich mixtures of volatiles, e.g., the bouquet of Serratia odorifera 4Rx13 is composed of up to 100 volatile organic and inorganic compounds. Here we show that when growing on peptone-rich nutrient medium S. odorifera 4Rx13 and six other rhizobacteria emit high levels of ammonia, which during co-cultivation in compartmented Petri dishes caused alkalization of the neighboring plant medium and subsequently reduced the growth of A. thaliana. It is argued that in nature high-protein resource degradations (carcasses, whey, manure and compost) are also accompanied by bacterial ammonia emission which alters the pH of the rhizosphere and thereby influences organismal diversity and plant-microbe interactions. Consequently, bacterial ammonia emission may be more relevant for plant colonization and growth development than previously thought. PMID:23691060

  11. Condensate Recycling in Closed Plant Growth Chambers

    NASA Technical Reports Server (NTRS)

    Bledsoe, J. O.; Sager, J. C.; Fortson, R. E.

    1994-01-01

    Water used in the the Controlled Ecological Life Support System (CELSS) Breadboard Project at the Kennedy Space Center is being recycled. Condensation is collected in the air ducts, filtered and deionized, and resupplied to the system for nutrient solutions, supplemental humidification, solvents and diluents. While the system functions well from a process control standpoint, precise and accurate tracking of water movement through the system to answer plant physiological questions is not consistent. Possible causes include hardware errors, undetected vapor loss from chamber leakage, and unmeasured changes in water volume in the plant growth trays.

  12. 22-Oxocholestanes as plant growth promoters.

    PubMed

    Zeferino-Diaz, Reyna; Hilario-Martinez, J Ciciolil; Rodriguez-Acosta, Maricela; Sandoval-Ramirez, Jesus; Fernandez-Herrera, Maria A

    2015-06-01

    The spirostanic steroidal side-chain of diosgenin and hecogenin was modified to produce 22-oxocholestane derivatives. This type of side-chain was obtained in good yields through a straightforward four-step pathway. These compounds show potent brassinosteroid-like growth promoting activity evaluated via the rice lamina joint inclination bioassay. This is the first report of steroidal skeletons bearing the 22-oxocholestane side-chain and preserving the basic structure (A-D rings) from their corresponding parent compounds acting as plant growth promoters.

  13. Klebsiella pneumoniae inoculants for enhancing plant growth

    DOEpatents

    Triplett, Eric W.; Kaeppler, Shawn M.; Chelius, Marisa K.

    2008-07-01

    A biological inoculant for enhancing the growth of plants is disclosed. The inoculant includes the bacterial strains Herbaspirillum seropedicae 2A, Pantoea agglomerans P101, Pantoea agglomerans P102, Klebsiella pneumoniae 342, Klebsiella pneumoniae zmvsy, Herbaspirillum seropedicae Z152, Gluconacetobacter diazotrophicus PA15, with or without a carrier. The inoculant also includes strains of the bacterium Pantoea agglomerans and K. pneumoniae which are able to enhance the growth of cereal grasses. Also disclosed are the novel bacterial strains Herbaspirillum seropedicae 2A, Pantoea agglomerans P101 and P102, and Klebsiella pneumoniae 342 and zmvsy.

  14. Clonal growth and plant species abundance

    PubMed Central

    Herben, Tomáš; Nováková, Zuzana; Klimešová, Jitka

    2014-01-01

    Background and Aims Both regional and local plant abundances are driven by species' dispersal capacities and their abilities to exploit new habitats and persist there. These processes are affected by clonal growth, which is difficult to evaluate and compare across large numbers of species. This study assessed the influence of clonal reproduction on local and regional abundances of a large set of species and compared the predictive power of morphologically defined traits of clonal growth with data on actual clonal growth from a botanical garden. The role of clonal growth was compared with the effects of seed reproduction, habitat requirements and growth, proxied both by LHS (leaf–height–seed) traits and by actual performance in the botanical garden. Methods Morphological parameters of clonal growth, actual clonal reproduction in the garden and LHS traits (leaf-specific area – height – seed mass) were used as predictors of species abundance, both regional (number of species records in the Czech Republic) and local (mean species cover in vegetation records) for 836 perennial herbaceous species. Species differences in habitat requirements were accounted for by classifying the dataset by habitat type and also by using Ellenberg indicator values as covariates. Key Results After habitat differences were accounted for, clonal growth parameters explained an important part of variation in species abundance, both at regional and at local levels. At both levels, both greater vegetative growth in cultivation and greater lateral expansion trait values were correlated with higher abundance. Seed reproduction had weaker effects, being positive at the regional level and negative at the local level. Conclusions Morphologically defined traits are predictive of species abundance, and it is concluded that simultaneous investigation of several such traits can help develop hypotheses on specific processes (e.g. avoidance of self-competition, support of offspring) potentially

  15. Operational development of small plant growth systems

    NASA Technical Reports Server (NTRS)

    Scheld, H. W.; Magnuson, J. W.; Sauer, R. L.

    1986-01-01

    The results of a study undertaken on the first phase of an empricial effort in the development of small plant growth chambers for production of salad type vegetables on space shuttle or space station are discussed. The overall effort is visualized as providing the underpinning of practical experience in handling of plant systems in space which will provide major support for future efforts in planning, design, and construction of plant-based (phytomechanical) systems for support of human habitation in space. The assumptions underlying the effort hold that large scale phytomechanical habitability support systems for future space stations must evolve from the simple to the complex. The highly complex final systems will be developed from the accumulated experience and data gathered from repetitive tests and trials of fragments or subsystems of the whole in an operational mode. These developing system components will, meanwhile, serve a useful operational function in providing psychological support and diversion for the crews.

  16. Early interactions during the encounter of plants, aphids and arboviruses.

    PubMed

    Bak, Aurélie; Martinière, Alexandre; Blanc, Stéphane; Drucker, Martin

    2013-06-01

    Aphids infest many plants and cause damage by depriving them of nutrients and by transmitting many viral diseases. Aphid infestation and arbovirus transmission are controlled by establishment (or not) of a compatible reaction between the insects and the plants. This reaction is the result of defense reactions of the plant and counter-defense reactions of the parasite. Contrarily to plant-bacteria, plant-fungi and plant-herbivorous insects pathosystems, the plant-aphid pathosystem is understudied, although recent advances have begun to uncover some of its details. Especially the very early steps in plant-aphid interactions are hardly known. We here resume the present knowledge of these interactions. We discuss further how an aphid-transmitted plant virus that is transmitted during the first moments of the plant-aphid encounter, might help to study the very early plant aphid interactions.

  17. Mechanisms of the early phases of plant gravitropism

    NASA Technical Reports Server (NTRS)

    Kiss, J. Z.

    2000-01-01

    Gravitropism is directed growth of a plant or plant organ in response to gravity and can be divided into the following temporal sequence: perception, transduction, and response. This article is a review of the research on the early events of gravitropism (i.e., phenomena associated with the perception and transduction phases). The two major hypotheses for graviperception are the protoplast-pressure and starch-statolith models. While most researchers support the concept of statoliths, there are suggestions that plants have multiple mechanisms of perception. Evidence supports the hypothesis that the actin cytoskeleton is involved in graviperception/transduction, but the details of these mechanisms remain elusive. A number of recent developments, such as increased use of the molecular genetic approach, magnetophoresis, and laser ablation, have facilitated research in graviperception and have allowed for refinement of the current models. In addition, the entire continuum of acceleration forces from hypo- to hyper-gravity have been useful in studying perception mechanisms. Future interdisciplinary molecular approaches and the availability of sophisticated laboratories on the International Space Station should help to develop new insights into mechanisms of gravitropism in plants.

  18. [Review on application of plant growth retardants in medicinal plants cultivation].

    PubMed

    Zhai, Yu-Yao; Guo, Bao-Lin; Cheng, Ming

    2013-09-01

    Plant growth retardants are widely used in cultivation of medicinal plant, but there is still lack of scientific guidance. In order to guide the use of plant growth retardants in medicinal plant cultivation efficiently and reasonably, this paper reviewed the mechanism, function characteristic, plant and soil residue of plant growth retardants, such as chlorocholine chloride, mepiquat chloride, paclobutrazol, unicnazle and succinic acid, and summarized the application of plant growth retardants in medicinal plants cultivation in recent years, with focus on the effect of growth and yield of the officinal organs and secondary metabolites.

  19. The growth and form of plant shoots

    NASA Astrophysics Data System (ADS)

    Chelakkot, Raghunath; Mahadevan, L.

    2015-03-01

    Growing plant stems and shoots exhibit a variety of shapes that embody growth in response to various stimuli. We provide a quantitative biophysical theory for these shapes by accounting for the inherent observed passive and active effects: (i) the passive elastic deflection of the shoot due to its own weight, and (ii) the active controllable growth response of the shoot in response to its orientation relative to gravity, and (iii) proprioception, the shoot's growth response to its own observable shape, which is itself determined by its elasticity and weight. A morphospace diagram in terms of two dimensionless parameters representing a scaled local active gravitropic sensitivity, and a scaled passive elastic sag shows how a variety of observed transient and steady morphologies with effective positive, negative and even oscillatory gravitropic behaviors arise in a sentient growing filament naturally, without the need for ad-hoc complex spatio-temporal control strategies.

  20. Redox control of plant growth and development.

    PubMed

    Kocsy, Gábor; Tari, Irma; Vanková, Radomíra; Zechmann, Bernd; Gulyás, Zsolt; Poór, Péter; Galiba, Gábor

    2013-10-01

    Redox changes determined by genetic and environmental factors display well-organized interactions in the control of plant growth and development. Diurnal and seasonal changes in the environmental conditions are important for the normal course of these physiological processes and, similarly to their mild irregular alterations, for stress adaptation. However, fast or large-scale environmental changes may lead to damage or death of sensitive plants. The spatial and temporal redox changes influence growth and development due to the reprogramming of metabolism. In this process reactive oxygen and nitrogen species and antioxidants are involved as components of signalling networks. The control of growth, development and flowering by reactive oxygen and nitrogen species and antioxidants in interaction with hormones at organ, tissue, cellular and subcellular level will be discussed in the present review. Unsolved problems of the field, among others the need for identification of new components and interactions in the redox regulatory network at various organization levels using systems biology approaches will be also indicated.

  1. Earlier snowmelt and warming lead to earlier but not necessarily more plant growth

    PubMed Central

    Livensperger, Carolyn; Steltzer, Heidi; Darrouzet-Nardi, Anthony; Sullivan, Patrick F.; Wallenstein, Matthew; Weintraub, Michael N.

    2016-01-01

    Climate change over the past ∼50 years has resulted in earlier occurrence of plant life-cycle events for many species. Across temperate, boreal and polar latitudes, earlier seasonal warming is considered the key mechanism leading to earlier leaf expansion and growth. Yet, in seasonally snow-covered ecosystems, the timing of spring plant growth may also be cued by snowmelt, which may occur earlier in a warmer climate. Multiple environmental cues protect plants from growing too early, but to understand how climate change will alter the timing and magnitude of plant growth, experiments need to independently manipulate temperature and snowmelt. Here, we demonstrate that altered seasonality through experimental warming and earlier snowmelt led to earlier plant growth, but the aboveground production response varied among plant functional groups. Earlier snowmelt without warming led to early leaf emergence, but often slowed the rate of leaf expansion and had limited effects on aboveground production. Experimental warming alone had small and inconsistent effects on aboveground phenology, while the effect of the combined treatment resembled that of early snowmelt alone. Experimental warming led to greater aboveground production among the graminoids, limited changes among deciduous shrubs and decreased production in one of the dominant evergreen shrubs. As a result, we predict that early onset of the growing season may favour early growing plant species, even those that do not shift the timing of leaf expansion. PMID:27075181

  2. Plant growth conditions alter phytolith carbon

    PubMed Central

    Gallagher, Kimberley L.; Alfonso-Garcia, Alba; Sanchez, Jessica; Potma, Eric O.; Santos, Guaciara M.

    2015-01-01

    Many plants, including grasses and some important human food sources, accumulate, and precipitate silica in their cells to form opaline phytoliths. These phytoliths contain small amounts of organic matter (OM) that are trapped during the process of silicification. Previous work has suggested that plant silica is associated with compounds such as proteins, lipids, lignin, and carbohydrate complexes. It is not known whether these compounds are cellular components passively encapsulated as the cell silicifies, polymers actively involved in the precipitation process or random compounds assimilated by the plant and discarded into a “glass wastebasket.” Here, we used Raman spectroscopy to map the distribution of OM in phytoliths, and to analyze individual phytoliths isolated from Sorghum bicolor plants grown under different laboratory treatments. Using mapping, we showed that OM in phytoliths is distributed throughout the silica and is not related to dark spots visible in light microscopy, previously assumed to be the repository for phytolith OM. The Raman spectra exhibited common bands indicative of C-H stretching modes of general OM, and further more diagnostic bands consistent with carbohydrates, lignins, and other OM. These Raman spectra exhibited variability of spectral signatures and of relative intensities between sample treatments indicating that differing growth conditions altered the phytolith carbon. This may have strong implications for understanding the mechanism of phytolith formation, and for use of phytolith carbon isotope values in dating or paleoclimate reconstruction. PMID:26442066

  3. Plant growth conditions alter phytolith carbon.

    PubMed

    Gallagher, Kimberley L; Alfonso-Garcia, Alba; Sanchez, Jessica; Potma, Eric O; Santos, Guaciara M

    2015-01-01

    Many plants, including grasses and some important human food sources, accumulate, and precipitate silica in their cells to form opaline phytoliths. These phytoliths contain small amounts of organic matter (OM) that are trapped during the process of silicification. Previous work has suggested that plant silica is associated with compounds such as proteins, lipids, lignin, and carbohydrate complexes. It is not known whether these compounds are cellular components passively encapsulated as the cell silicifies, polymers actively involved in the precipitation process or random compounds assimilated by the plant and discarded into a "glass wastebasket." Here, we used Raman spectroscopy to map the distribution of OM in phytoliths, and to analyze individual phytoliths isolated from Sorghum bicolor plants grown under different laboratory treatments. Using mapping, we showed that OM in phytoliths is distributed throughout the silica and is not related to dark spots visible in light microscopy, previously assumed to be the repository for phytolith OM. The Raman spectra exhibited common bands indicative of C-H stretching modes of general OM, and further more diagnostic bands consistent with carbohydrates, lignins, and other OM. These Raman spectra exhibited variability of spectral signatures and of relative intensities between sample treatments indicating that differing growth conditions altered the phytolith carbon. This may have strong implications for understanding the mechanism of phytolith formation, and for use of phytolith carbon isotope values in dating or paleoclimate reconstruction.

  4. Gravitational effects on plant growth hormone concentration

    NASA Technical Reports Server (NTRS)

    Bandurski, R. S.; Schulze, A.

    1983-01-01

    Dolk's (1936) finding that more growth hormone diffuses from the lower side of a gravity-stimulated plant shoot than from the upper side is presently confirmed by means of both an isotope dilution assay and selected ion monitoring-gas chromatography-mass spectrometry, and it is established that the asymmetrically distributed hormone is indole-3-acetic acid (IAA). This is the first physicochemical demonstration that there is more IAA on the lower sides of a geostimulated plant shoot. It is also found that free IAA primarily occurs in the conductive vascular tissues of the shoot, while IAA esters predominate in the growing cortical cells. A highly sensitive gas chromatographic isotope dilution assay shows that the hormone asymmetry also occurs in the nonvascular tissue.

  5. Phytotoxicity assessment of atrazine on growth and physiology of three emergent plants.

    PubMed

    Wang, Qinghai; Que, Xiaoe; Zheng, Ruilun; Pang, Zuo; Li, Cui; Xiao, Bo

    2015-07-01

    The emergent plants Acorus calamus, Lythrum salicaria, and Scirpus tabernaemontani were exposed to atrazine for 15, 30, 45, and 60 days in a hydroponic system. Effects were evaluated investigating plant growth, chlorophyll (Chl) content, peroxidase (POD) activity, and malondialdehyde (MDA) content. Results showed that selected plants survived in culture solution with atrazine ≤8 mg L(-1), but relative growth rates decreased significantly in the first 15-day exposure. Chla content decreased, but MDA increased with increasing atrazine concentration. S. tabernaemontani was the most insensitive species, followed by A. calamus and L.salicaria. The growth indicators exhibited significant changes in the early stage of atrazine exposure; subsequently, the negative impacts weakened and disappeared. Plant growth may be more representative of emergent plant fitness than physiological endpoints in toxicity assessment of herbicides to emergent plants.

  6. A natural plant growth promoter calliterpenone from a plant Callicarpa macrophylla Vahl improves the plant growth promoting effects of plant growth promoting rhizobacteria (PGPRs).

    PubMed

    Maji, Deepamala; Barnawal, Deepti; Gupta, Aakansha; King, Shikha; Singh, A K; Kalra, A

    2013-05-01

    Experiments were conducted to evaluate the efficacy of calliterpenone, a natural plant growth promoter from a shrub Callicarpa macrophylla Vahl., in enhancing the growth and yield promoting effects of plant growth promoting rhizobacteria (PGPRs), in menthol mint (Mentha arvensis L).This study is based on our previous results indicating the microbial growth promotion by calliterpenone and assumption that application of calliterpenone along with PGPRs will improve the population of PGPRs resulting in higher impacts on plant growth and yield. Of the 15 PGPRs (identified as potent ones in our laboratory), 25 μl of 0.01 mM calliterpenone (8.0 μg/100 ml) was found to be useful in improving the population of nine PGPRs in culture media. The five selected strains of PGPRs exhibiting synergy with calliterpenone in enhancing growth of maize compared to PGPR or calliterpenone alone were selected and tested on two cultivars (cvs. Kosi and Kushal) of M. arvensis. Of the five strains, Bacillus subtilis P-20 (16S rDNA sequence homologous to Accession No NR027552) and B. subtilis Daz-26 (16SrDNA sequence homologuos to Accession No GU998816) were found to be highly effective in improving the herb and essential oil yield in the cultivars Kushal and Kosi respectively when co-treated with calliterpenone. The results open up the possibilities of using a natural growth promoter along with PGPRs as a bio-agri input for sustainable and organic agriculture.

  7. Gravitational effects on plant growth hormone concentration

    NASA Astrophysics Data System (ADS)

    Bandurski, Robert S.; Schulze, Aga

    Numerous studies, particularly those of H. Dolk in the 1930's, established by means of bio-assay, that more growth hormone diffused from the lower, than from the upper side of a gravity-stimulated plant shoot. Now, using an isotope dilution assay, with 4,5,6,7 tetradeutero indole-3-acetic acid as internal standard, and selected ion monitoring-gas chromatography-mass spectrometry as the method of determination, we have confirmed Dolk's finding and established that the asymmetrically distributed hormone is, in fact, indole-3-acetic acid (IAA). This is the first physico-chemical demonstration that there is more free IAA on the lower sides of a geo-stimulated plant shoot. We have also shown that free IAA occurs primarily in the conductive vascular tissues of the shoot, whereas IAA esters predominate in the growing cortical cells. Now, using an especially sensitive gas chromatographic isotope dilution assay we have found that the hormone asymmetry also occurs in the non-vascular tissue. Currently, efforts are directed to developing isotope dilution assays, with picogram sensitivity, to determine how this asymmetry of IAA distribution is attained so as to better understand how the plant perceives the geo-stimulus.

  8. Mechanical forces in plant growth and development.

    PubMed

    Fisher, D D; Cyr, R J

    2000-06-01

    Plant cells perceive forces that arise from the environment and from the biophysics of plant growth. These forces provide meaningful cues that can affect the development of the plant. Seedlings of Arabidopsis thaliana were used to examine the cytoplasmic tensile character of cells that have been implicated in the gravitropic response. Laser-trapping technology revealed that the starch-containing statoliths of the central columella cells in root caps are held loosely within the cytoplasm. In contrast, the peripheral cells have starch granules that are relatively resistant to movement. The role of the actin cytoskeleton in affecting the tensile character of these cells is discussed. To explore the role that biophysical forces might play in generating developmental cues, we have developed an experimental model system in which protoplasts, embedded in a synthetic agarose matrix, are subjected to stretching or compression. We have found that protoplasts subjected to these forces from five minutes to two hours will subsequently elongate either at right angles or parallel to the tensive or compressive force vector. Moreover, the cortical microtubules are found to be organized either at right angles or parallel to the tensive or compressive force vector. We discuss these results in terms of an interplay of information between the extracellular matrix and the underlying cytoskeleton.

  9. Mechanical forces in plant growth and development

    NASA Technical Reports Server (NTRS)

    Fisher, D. D.; Cyr, R. J.

    2000-01-01

    Plant cells perceive forces that arise from the environment and from the biophysics of plant growth. These forces provide meaningful cues that can affect the development of the plant. Seedlings of Arabidopsis thaliana were used to examine the cytoplasmic tensile character of cells that have been implicated in the gravitropic response. Laser-trapping technology revealed that the starch-containing statoliths of the central columella cells in root caps are held loosely within the cytoplasm. In contrast, the peripheral cells have starch granules that are relatively resistant to movement. The role of the actin cytoskeleton in affecting the tensile character of these cells is discussed. To explore the role that biophysical forces might play in generating developmental cues, we have developed an experimental model system in which protoplasts, embedded in a synthetic agarose matrix, are subjected to stretching or compression. We have found that protoplasts subjected to these forces from five minutes to two hours will subsequently elongate either at right angles or parallel to the tensive or compressive force vector. Moreover, the cortical microtubules are found to be organized either at right angles or parallel to the tensive or compressive force vector. We discuss these results in terms of an interplay of information between the extracellular matrix and the underlying cytoskeleton.

  10. Instrumentation for plant health and growth

    NASA Astrophysics Data System (ADS)

    Schlager, K. J.

    1994-11-01

    Comprehensive spectroscopic monitoring of plant health and growth in bioregenerative life support system environments is possible using a variety of spectrometric technologies. Absorption spectrometry and atomic emission spectrometry in combination allow for direct, on-line, reagentless monitoring of plant nutrients from nitrate and potassium to micronutrients such as copper and zinc. Fluorometric spectrometry is ideal for the on-line detection, identification and quantification of bacteria and fungi. Liquid Atomic Emission Spectrometry (LAES) is a new form of spectrometry that allows for direct measurement of atomic emission spectra in liquids. An electric arc is generated by a pair of electrodes in the liquid to provide the energy necessary to break molecular bonds and reduce the substance to atomic form. With a fiber probe attached to the electrodes, spectral light can be transmitted to a photodiode array spectrometer for light dispersion and analysis. Ultraviolet (UV) absorption spectrometry is a long-established technology, but applications typically have required specific reagents to produce an analyte-specific absorption. Nitrate and iron nutrients have native UV absorption spectra that have been used to accurately determine nutrient concentrations at the +/- 5% level. Fluorescence detection and characterization of microbes is based upon the native fluorescent signatures of most microbiological species. Spectral and time-resolved fluorometers operating with remote fiber-optic probes will be used for on-line microbial monitoring in plant nutrient streams.

  11. Biomass Production System (BPS) Plant Growth Unit

    NASA Astrophysics Data System (ADS)

    Morrow, R. C.; Crabb, T. M.

    The Biomass Production System (BPS) was developed under the Small Business Innovative Research (SBIR) program to meet science, biotechnology and commercial plant growth needs in the Space Station era. The BPS is equivalent in size to a double middeck locker, but uses it's own custom enclosure with a slide out structure to which internal components mount. The BPS contains four internal growth chambers, each with a growing volume of more than 4 liters. Each of the growth chambers has active nutrient delivery, and independent control of temperature, humidity, lighting, and CO2 set-points. Temperature control is achieved using a thermoelectric heat exchanger system. Humidity control is achieved using a heat exchanger with a porous interface which can both humidify and dehumidify. The control software utilizes fuzzy logic for nonlinear, coupled temperature and humidity control. The fluorescent lighting system can be dimmed to provide a range of light levels. CO2 levels are controlled by injecting pure CO2 to the system based on input from an infrared gas analyzer. The unit currently does not scrub CO2, but has been designed to accept scrubber cartridges. In addition to providing environmental control, a number of features are included to facilitate science. The BPS chambers are sealed to allow CO2 and water vapor exchange measurements. The plant chambers can be removed to allow manipulation or sampling of specimens, and each chamber has gas/fluid sample ports. A video camera is provided for each chamber, and frame-grabs and complete environmental data for all science and hardware system sensors are stored on an internal hard drive. Data files can also be transferred to 3.5-inch disks using the front panel disk drive

  12. Biomass Production System (BPS) plant growth unit.

    PubMed

    Morrow, R C; Crabb, T M

    2000-01-01

    The Biomass Production System (BPS) was developed under the Small Business Innovative Research (SBIR) program to meet science, biotechnology and commercial plant growth needs in the Space Station era. The BPS is equivalent in size to a double middeck locker, but uses its own custom enclosure with a slide out structure to which internal components mount. The BPS contains four internal growth chambers, each with a growing volume of more than 4 liters. Each of the growth chambers has active nutrient delivery, and independent control of temperature, humidity, lighting, and CO2 set-points. Temperature control is achieved using a thermoelectric heat exchanger system. Humidity control is achieved using a heat exchanger with a porous interface which can both humidify and dehumidify. The control software utilizes fuzzy logic for nonlinear, coupled temperature and humidity control. The fluorescent lighting system can be dimmed to provide a range of light levels. CO2 levels are controlled by injecting pure CO2 to the system based on input from an infrared gas analyzer. The unit currently does not scrub CO2, but has been designed to accept scrubber cartridges. In addition to providing environmental control, a number of features are included to facilitate science. The BPS chambers are sealed to allow CO2 and water vapor exchange measurements. The plant chambers can be removed to allow manipulation or sampling of specimens, and each chamber has gas/fluid sample ports. A video camera is provided for each chamber, and frame-grabs and complete environmental data for all science and hardware system sensors are stored on an internal hard drive. Data files can also be transferred to 3.5-inch disks using the front panel disk drive.

  13. Ammonia And Ethylene Optrodes For Research On Plant Growth

    NASA Technical Reports Server (NTRS)

    Zhou, Quan; Tabacco, Mary Beth

    1995-01-01

    Fiber-optic sensors developed for use in measuring concentrations of ammonia and ethylene near plants during experiments on growth of plants in enclosed environments. Developmental fiber-optic sensors satisfy need to measure concentrations as low as few parts per billion (ppb) and expected to contribute to research on roles of ethylene and ammonia in growth of plants.

  14. Plant Growth Under Light Emitting Diode Irradiation.

    NASA Astrophysics Data System (ADS)

    Tennessen, Daniel John

    Plant growth under light emitting diodes (LEDs) was investigated to determine if LEDs would be useful to provide radiant energy for two plant processes, photosynthesis and photomorphogenesis. Photosynthesis of tomato (Lycopersicon esculentum L.) and Kudzu (Pueraria lobata (Willd) Ohwi.) was measured using photons from LEDs to answer the following: (1) Are leaves able to use red LED light for photosynthesis? and (2) Is the efficiency of photosynthesis in pulsed light equal to that of continuous light? In 175 Pa CO _2, or in response to changes in CO _2,<=af photosynthesis and ATP status were the same in LED as in white xenon arc light. In 35 Pa CO_2, photosynthesis was 10% lower in LED than in xenon arc light due to lowered stomatal conductance. The quantum efficiency of photosynthesis in pulsed light was equal to continuous light, even when pulses were twice as bright as sunlight. Xanthophyll pigments were not affected by these bright pulses. Photomorphogenesis of tobacco (Nicotiana tabacum L.), tomato (Lycopersicon esculentum Mill.) and transformed tobacco and tomato (expressing oat phytochrome-A) was assessed by growing plants under red LED lamps in an attempt to answer the following: (1) What is the developmental response of non-transformed and transformed tobacco to red LED light? and (2) Can tomato plants that grow tall and spindly in red LED light be made to grow short by increasing the amount of phytochrome-A? The short phenotype of transformed tobacco was not evident when plants were grown in LED light. Addition of photons of far-red or blue light to red light resulted in short transformed tobacco. Tomato plants grew three times as tall and lacked leaf development in LED versus white light, but transformed tomato remained short and produced fruit under LED light. I have determined that the LED photons are useful for photosynthesis and that the photon efficiency of photosynthesis is the same in pulsed as in continuous light. From responses of tobacco, I

  15. Professional Growth Reconceptualized: Early Childhood Staff Searching for Meaning.

    ERIC Educational Resources Information Center

    Fleet, Alma; Patterson, Catherine

    2001-01-01

    This paper challenges traditional perspectives of professional development through a reconceptualization of early childhood professional growth. A review of the early childhood professional development literature reveals the problematic nature of the linear perspectives and deficit models of staff development prevalent in the early childhood…

  16. Martian Soil Plant Growth Experiment: The Effects of Adding Nitrogen, Bacteria, and Fungi to Enhance Plant Growth

    NASA Technical Reports Server (NTRS)

    Kliman, D. M.; Cooper, J. B.; Anderson, R. C.

    2000-01-01

    Plant growth is enhanced by the presence of symbiotic soil microbes. In order to better understand how plants might prosper on Mars, we set up an experiment to test whether symbiotic microbes function to enhance plant growth in a Martian soil simulant.

  17. Demonstrating the Effects of Light Quality on Plant Growth.

    ERIC Educational Resources Information Center

    Whitesell, J. H.; Garcia, Maria

    1977-01-01

    Describes a lab demonstration that illustrates the effect of different colors or wavelengths of visible light on plant growth and development. This demonstration is appropriate for use in college biology, botany, or plant physiology courses. (HM)

  18. Sugar signals and the control of plant growth and development.

    PubMed

    Lastdrager, Jeroen; Hanson, Johannes; Smeekens, Sjef

    2014-03-01

    Sugars have a central regulatory function in steering plant growth. This review focuses on information presented in the past 2 years on key players in sugar-mediated plant growth regulation, with emphasis on trehalose 6-phosphate, target of rapamycin kinase, and Snf1-related kinase 1 regulatory systems. The regulation of protein synthesis by sugars is fundamental to plant growth control, and recent advances in our understanding of the regulation of translation by sugars will be discussed.

  19. Isolation and characterization of plant growth-promoting rhizobacteria from wheat rhizosphere and their effect on plant growth promotion

    PubMed Central

    Majeed, Afshan; Hameed, Sohail; Imran, Asma; Rahim, Nasir

    2015-01-01

    The present study was conducted to characterize the native plant growth promoting (PGP) bacteria from wheat rhizosphere and root-endosphere in the Himalayan region of Rawalakot, Azad Jammu and Kashmir (AJK), Pakistan. Nine bacterial isolates were purified, screened in vitro for PGP characteristics and evaluated for their beneficial effects on the early growth of wheat (Triticum aestivum L.). Among nine bacterial isolates, seven were able to produce indole-3- acetic acid in tryptophan-supplemented medium; seven were nitrogen fixer, and four were able to solubilize inorganic phosphate in vitro. Four different morphotypes were genotypically identified based on IGS-RFLP fingerprinting and representative of each morphotype was identified by 16S rRNA gene sequencing analysis except Gram-positive putative Bacillus sp. Based on 16S rRNA gene sequence analysis, bacterial isolates AJK-3 and AJK-9 showing multiple PGP-traits were identified as Stenotrophomonas spp. while AJK-7 showed equal homologies to Acetobacter pasteurianus and Stenotrophomonas specie. Plant inoculation studies indicated that these Plant growth-promoting rhizobacteria (PGPR) strains provided a significant increase in shoot and root length, and shoot and root biomass. A significant increase in shoot N contents (up to 76%) and root N contents (up to 32%) was observed over the un-inoculated control. The study indicates the potential of these PGPR for inoculums production or biofertilizers for enhancing growth and nutrient content of wheat and other crops under field conditions. The study is the first report of wheat associated bacterial diversity in the Himalayan region of Rawalakot, AJK. PMID:25852661

  20. Plant growth-promoting hormones activate mammalian guanylate cyclase activity.

    PubMed

    Vesely, D L; Hudson, J L; Pipkin, J L; Pack, L D; Meiners, S E

    1985-05-01

    In vivo injections of plant growth-promoting hormones increase the growth of animals as well as plants. Plant growth-promoting hormones and positive plant growth regulators are known to increase RNA and protein synthesis. Since cyclic GMP also increases RNA and protein synthesis, the object of the present investigation was to determine whether physiological levels of plant growth-promoting hormones and positive plant growth regulators have part of their mechanism(s) of action through stimulation of the guanylate cyclase (EC 4.6.1.2)-cyclic GMP system. Representatives of the three classes of growth-promoting hormones were investigated. Thus, auxins (indole-3-acetic acid, indole-3-butyric acid, beta-naphthoxyacetic acid, and 2,4,5-trichlorophenoxy acetic acid), gibberellins (gibberellic acid), and cytokinins [N6-benzyl adenine, kinetin (6-furfuryl aminopurine), and beta-(2-furyl) acrylic acid] all increased rat lung, small intestine, liver, and renal cortex guanylate cyclase activity 2- to 4-fold at the 1 microM concentration. Dose response curves revealed that maximal stimulation of guanylate cyclase by these plant growth regulators was at 1 microM; there was no augmented cyclase activity at 1 nM. The guanylate cyclase cationic cofactor manganese was not essential for augmentation of guanylate cyclase by these plant growth-promoting regulators. The antioxidant butylated hydroxytoluene did not block the enhancement of guanylate cyclase by these plant growth-promoting factors. These data suggest that guanylate cyclase may play a role in the mechanism of action of plant growth-promoting hormones and even of positive plant regulators at the cellular level.

  1. Planet formation - Mechanism of early growth

    NASA Technical Reports Server (NTRS)

    Hartmann, W. K.

    1978-01-01

    Experiments in vacuum (approx. 0.5 to 1 mbar) and in air quantify mechanics of collisions, rebound, and fragmentation at low velocities (1-50 m/sec), under the conditions usually postulated for the preplanetary environment in the primitive solar nebula. Such collisions have been little studied experimentally. Contrary to widespread assumptions, accretionary growth of the largest meteoroid- and asteroid-sized bodies in a given swarm results spontaneously from the simple mechanics of these collisions, without other ad hoc sticking mechanisms. The smaller bodies in the swarm are less likely to grow. Granular surfaces form, either by gravitational collapse of dust swarms or by rapid formation of regolith surfaces on solid planetesimals; these surfaces strongly promote further growth by retarding rebound. Growth of large bodies increases modal collision velocities, causing fragmentation of smaller bodies and eventual production of interstellar dust as a by-product of planetesimal interactions.

  2. [Early growth of phytoplankton community in Dianshan Lake].

    PubMed

    Cheng, Xi; Li, Xiao-Ping

    2011-11-01

    Seasonal variation of phytoplankton community biomass (Chla) in Dianshan Lake was simulated based on data of 2004-2009. The result showed that early growths of the phytoplankton community in spring and summer seasons could be well described by the Logistic growth model. General speaking, phytoplankton community dominated by diatom and green algae may enter its exponential phase in the late February, doubling its density within 18 days, and reaching its maximum growth rate of 29.4 microg x (L x month) (-1) in the middle of March, blooming in June. Phytoplankton community dominated by blue green algae may enter its exponential phase in the middle June, doubling its density within 26 days, and reaching its maximum growth rate of 22.8 microg x (L x month) (-1) in the middle of July, blooming during August-September. The general pattern of early growth of phytoplankton community may offer sound information for early warning and prevention of algal bloom.

  3. The Arabidopsis TOR kinase links plant growth, yield, stress resistance and mRNA translation.

    PubMed

    Deprost, Dorothée; Yao, Lei; Sormani, Rodnay; Moreau, Manon; Leterreux, Guillaume; Nicolaï, Maryse; Bedu, Magali; Robaglia, Christophe; Meyer, Christian

    2007-09-01

    Plants, unlike animals, have plastic organ growth that is largely dependent on environmental information. However, so far, little is known about how this information is perceived and transduced into coherent growth and developmental decisions. Here, we report that the growth of Arabidopsis is positively correlated with the level of expression of the TARGET OF RAPAMYCIN (TOR) kinase. Diminished or augmented expression of the AtTOR gene results in a dose-dependent decrease or increase, respectively, in organ and cell size, seed production and resistance to osmotic stress. Strong downregulation of AtTOR expression by inducible RNA interference also leads to a post-germinative halt in growth and development, which phenocopies the action of the plant hormone abscisic acid, to an early senescence and to a reduction in the amount of translated messenger RNA. Thus, we propose that the AtTOR kinase is one of the contributors to the link between environmental cues and growth processes in plants.

  4. Parametric study of potential early commercial MHD power plants

    NASA Technical Reports Server (NTRS)

    Hals, F. A.

    1979-01-01

    Three different reference power plant configurations were considered with parametric variations of the various design parameters for each plant. Two of the reference plant designs were based on the use of high temperature regenerative air preheaters separately fired by a low Btu gas produced from a coal gasifier which was integrated with the power plant. The third reference plant design was based on the use of oxygen enriched combustion air preheated to a more moderate temperature in a tubular type metallic recuperative heat exchanger which is part of the bottoming plant heat recovery system. Comparative information was developed on plant performance and economics. The highest net plant efficiency of about 45 percent was attained by the reference plant design with the use of a high temperature air preheater separately fired with the advanced entrained bed gasifier. The use of oxygen enrichment of the combustion air yielded the lowest cost of generating electricity at a slightly lower plant efficiency. Both of these two reference plant designs are identified as potentially attractive for early MHD power plant applications.

  5. Plant growth-promoting bacteria as inoculants in agricultural soils

    PubMed Central

    de Souza, Rocheli; Ambrosini, Adriana; Passaglia, Luciane M.P.

    2015-01-01

    Abstract Plant-microbe interactions in the rhizosphere are the determinants of plant health, productivity and soil fertility. Plant growth-promoting bacteria (PGPB) are bacteria that can enhance plant growth and protect plants from disease and abiotic stresses through a wide variety of mechanisms; those that establish close associations with plants, such as the endophytes, could be more successful in plant growth promotion. Several important bacterial characteristics, such as biological nitrogen fixation, phosphate solubilization, ACC deaminase activity, and production of siderophores and phytohormones, can be assessed as plant growth promotion (PGP) traits. Bacterial inoculants can contribute to increase agronomic efficiency by reducing production costs and environmental pollution, once the use of chemical fertilizers can be reduced or eliminated if the inoculants are efficient. For bacterial inoculants to obtain success in improving plant growth and productivity, several processes involved can influence the efficiency of inoculation, as for example the exudation by plant roots, the bacterial colonization in the roots, and soil health. This review presents an overview of the importance of soil-plant-microbe interactions to the development of efficient inoculants, once PGPB are extensively studied microorganisms, representing a very diverse group of easily accessible beneficial bacteria. PMID:26537605

  6. Plant growth-promoting bacteria as inoculants in agricultural soils.

    PubMed

    Souza, Rocheli de; Ambrosini, Adriana; Passaglia, Luciane M P

    2015-12-01

    Plant-microbe interactions in the rhizosphere are the determinants of plant health, productivity and soil fertility. Plant growth-promoting bacteria (PGPB) are bacteria that can enhance plant growth and protect plants from disease and abiotic stresses through a wide variety of mechanisms; those that establish close associations with plants, such as the endophytes, could be more successful in plant growth promotion. Several important bacterial characteristics, such as biological nitrogen fixation, phosphate solubilization, ACC deaminase activity, and production of siderophores and phytohormones, can be assessed as plant growth promotion (PGP) traits. Bacterial inoculants can contribute to increase agronomic efficiency by reducing production costs and environmental pollution, once the use of chemical fertilizers can be reduced or eliminated if the inoculants are efficient. For bacterial inoculants to obtain success in improving plant growth and productivity, several processes involved can influence the efficiency of inoculation, as for example the exudation by plant roots, the bacterial colonization in the roots, and soil health. This review presents an overview of the importance of soil-plant-microbe interactions to the development of efficient inoculants, once PGPB are extensively studied microorganisms, representing a very diverse group of easily accessible beneficial bacteria.

  7. Plant growth promotion in cereal and leguminous agricultural important plants: from microorganism capacities to crop production.

    PubMed

    Pérez-Montaño, F; Alías-Villegas, C; Bellogín, R A; del Cerro, P; Espuny, M R; Jiménez-Guerrero, I; López-Baena, F J; Ollero, F J; Cubo, T

    2014-01-01

    Plant growth-promoting rhizobacteria (PGPR) are free-living bacteria which actively colonize plant roots, exerting beneficial effects on plant development. The PGPR may (i) promote the plant growth either by using their own metabolism (solubilizing phosphates, producing hormones or fixing nitrogen) or directly affecting the plant metabolism (increasing the uptake of water and minerals), enhancing root development, increasing the enzymatic activity of the plant or "helping" other beneficial microorganisms to enhance their action on the plants; (ii) or may promote the plant growth by suppressing plant pathogens. These abilities are of great agriculture importance in terms of improving soil fertility and crop yield, thus reducing the negative impact of chemical fertilizers on the environment. The progress in the last decade in using PGPR in a variety of plants (maize, rice, wheat, soybean and bean) along with their mechanism of action are summarized and discussed here.

  8. Singlet oxygen signaling links photosynthesis to translation and plant growth.

    PubMed

    Reinbothe, Christiane; Pollmann, Stephan; Reinbothe, Steffen

    2010-09-01

    Translation is a major target of metabolic and growth control in animals and plants. Changes in the phosphorylation status of ribosomal protein S6 are responsible for rapid adjustments in the growth pattern of higher plants in response to changes in the environment. In this review, we illuminate some common and unique aspects of translational control in animals and plants and discuss recent studies that link photosynthesis to growth via specific signal transduction cascades, one of which relies on singlet oxygen and the plant growth regulator jasmonic acid (JA). It is the aim of this review to discuss the role of the target of rapamycin (TOR) signaling network in plants and what mechanisms could contribute to growth control in response to the changing environment.

  9. Early plant embryogenesis-dark ages or dark matter?

    PubMed

    Bayer, Martin; Slane, Daniel; Jürgens, Gerd

    2017-02-01

    In nearly all flowering plants, the basic body plan is laid down during embryogenesis. In Arabidopsis, the crucial cell types are established extremely early as reflected in the stereotypic sequence of oriented cell divisions in the developing young embryo. Research into early embryogenesis was especially focused on the role of the infamous tryptophan derivative auxin in establishing embryo polarity and generating the main body axis. However, it is becoming obvious that the mere link to auxin does not provide any mechanistic understanding of early embryo patterning. Taking recent research into account, we discuss mechanisms underlying early embryonic patterning from an evolutionary perspective.

  10. The regulation of plant growth by the circadian clock.

    PubMed

    Farré, E M

    2012-05-01

    Circadian regulated changes in growth rates have been observed in numerous plants as well as in unicellular and multicellular algae. The circadian clock regulates a multitude of factors that affect growth in plants, such as water and carbon availability and light and hormone signalling pathways. The combination of high-resolution growth rate analyses with mutant and biochemical analysis is helping us elucidate the time-dependent interactions between these factors and discover the molecular mechanisms involved. At the molecular level, growth in plants is modulated through a complex regulatory network, in which the circadian clock acts at multiple levels.

  11. Transcriptomic profile of leg muscle during early growth in chicken

    PubMed Central

    Zhang, Genxi; Li, Tingting; Ling, Jiaojiao; Zhang, Xiangqian; Wang, Jinyu

    2017-01-01

    The early growth pattern, especially the age of peak growth, of broilers affects the time to market and slaughter weight, which in turn affect the profitability of the poultry industry. However, the underlying mechanisms regulating chicken growth and development have rarely been studied. This study aimed to identify candidate genes involved in chicken growth and investigated the potential regulatory mechanisms of early growth in chicken. RNA sequencing was applied to compare the transcriptomes of chicken muscle tissues at three developmental stages during early growth. In total, 978 differentially expressed genes (DEGs) (fold change ≥ 2; false discovery rate < 0.05) were detected by pairwise comparison. Functional analysis showed that the DEGs are mainly involved in the processes of cell growth, muscle development, and cellular activities (such as junction, migration, assembly, differentiation, and proliferation). Many of the DEGs are well known to be related to chicken growth, such as MYOD1, GH, IGF2BP2, IGFBP3, SMYD1, CEBPB, FGF2, and IGFBP5. KEGG pathway analysis identified that the DEGs were significantly enriched in five pathways (P < 0.1) related to growth and development: extracellular matrix–receptor interaction, focal adhesion, tight junction, insulin signaling pathway, and regulation of the actin cytoskeleton. A total of 42 DEGs assigned to these pathways are potential candidate genes inducing the difference in growth among the three developmental stages, such as MYH10, FGF2, FGF16, FN1, CFL2, MAPK9, IRS1, PHKA1, PHKB, and PHKG1. Thus, our study identified a series of genes and several pathways that may participate in the regulation of early growth in chicken. These results should serve as an important resource revealing the molecular basis of chicken growth and development. PMID:28291821

  12. TCP Transcription Factors at the Interface between Environmental Challenges and the Plant's Growth Responses.

    PubMed

    Danisman, Selahattin

    2016-01-01

    Plants are sessile and as such their reactions to environmental challenges differ from those of mobile organisms. Many adaptions involve growth responses and hence, growth regulation is one of the most crucial biological processes for plant survival and fitness. The plant-specific TEOSINTE BRANCHED 1, CYCLOIDEA, PCF1 (TCP) transcription factor family is involved in plant development from cradle to grave, i.e., from seed germination throughout vegetative development until the formation of flowers and fruits. TCP transcription factors have an evolutionary conserved role as regulators in a variety of plant species, including orchids, tomatoes, peas, poplar, cotton, rice and the model plant Arabidopsis. Early TCP research focused on the regulatory functions of TCPs in the development of diverse organs via the cell cycle. Later research uncovered that TCP transcription factors are not static developmental regulators but crucial growth regulators that translate diverse endogenous and environmental signals into growth responses best fitted to ensure plant fitness and health. I will recapitulate the research on TCPs in this review focusing on two topics: the discovery of TCPs and the elucidation of their evolutionarily conserved roles across the plant kingdom, and the variety of signals, both endogenous (circadian clock, plant hormones) and environmental (pathogens, light, nutrients), TCPs respond to in the course of their developmental roles.

  13. Ethylene signaling and regulation in plant growth and stress responses.

    PubMed

    Wang, Feifei; Cui, Xiankui; Sun, Yue; Dong, Chun-Hai

    2013-07-01

    Gaseous phytohormone ethylene affects many aspects of plant growth and development. The ethylene signaling pathway starts when ethylene binds to its receptors. Since the cloning of the first ethylene receptor ETR1 from Arabidopsis, a large number of studies have steadily improved our understanding of the receptors and downstream components in ethylene signal transduction pathway. This article reviews the regulation of ethylene receptors, signal transduction, and the posttranscriptional modulation of downstream components. Functional roles and importance of the ethylene signaling components in plant growth and stress responses are also discussed. Cross-reactions of ethylene with auxin and other phytohormones in plant organ growth will be analyzed. The studies of ethylene signaling in plant growth, development, and stress responses in the past decade greatly advanced our knowledge of how plants respond to endogenous signals and environmental factors.

  14. Magnetic fields: how is plant growth and development impacted?

    PubMed

    da Silva, Jaime A Teixeira; Dobránszki, Judit

    2016-03-01

    This review provides detailed insight on the effects of magnetic fields on germination, growth, development, and yield of plants focusing on ex vitro growth and development and discussing the possible physiological and biochemical responses. The MFs considered in this review range from the nanoTesla (nT) to geomagnetic levels, up to very strong MFs greater than 15 Tesla (T) and also super-weak MFs (near 0 T). The theoretical bases of the action of MFs on plant growth, which are complex, are not discussed here and thus far, there is limited mathematical background about the action of MFs on plant growth. MFs can positively influence the morphogenesis of several plants which allows them to be used in practical situations. MFs have thus far been shown to modify seed germination and affect seedling growth and development in a wide range of plants, including field, fodder, and industrial crops; cereals and pseudo-cereals; grasses; herbs and medicinal plants; horticultural crops (vegetables, fruits, ornamentals); trees; and model crops. This is important since MFs may constitute a non-residual and non-toxic stimulus. In addition to presenting and summarizing the effects of MFs on plant growth and development, we also provide possible physiological and biochemical explanations for these responses including stress-related responses of plants, explanations based on dia-, para-, and ferromagnetism, oriented movements of substances, and cellular and molecular changes.

  15. Effects of the Plant Growth-Promoting Bacterium Burkholderia phytofirmans PsJN throughout the Life Cycle of Arabidopsis thaliana

    PubMed Central

    Poupin, María Josefina; Timmermann, Tania; Vega, Andrea; Zuñiga, Ana; González, Bernardo

    2013-01-01

    Plant growth-promoting rhizobacteria (PGPR) induce positive effects in plants, such as increased growth or reduced stress susceptibility. The mechanisms behind PGPR/plant interaction are poorly understood, as most studies have described short-term responses on plants and only a few studies have analyzed plant molecular responses under PGPR colonization. Here, we studied the effects of the PGPR bacterial model Burkholderiaphytofirmans PsJN on the whole life cycle of Arabidopsis thaliana plants. We reported that at different plant developmental points, strain PsJN can be found in the rhizosphere and also colonizing their internal tissues. In early ontogeny, strain PsJN increased several growth parameters and accelerated growth rate of the plants. Also, an Arabidopsis transcriptome analysis revealed that 408 genes showed differential expression in PsJN-inoculated plants; some of these genes are involved in stress response and hormone pathways. Specifically, genes implicated in auxin and gibberellin pathways were induced. Quantitative transcriptional analyses of selected genes in different developmental stages revealed that the beginning of these changes could be evidenced early in development, especially among the down-regulated genes. The inoculation with heat-killed bacteria provoked a more severe transcriptional response in plants, but was not able to induce plant growth-promotion. Later in ontogeny, the growth rates of inoculated plants decreased with respect to the non-inoculated group and, interestingly, the inoculation accelerated the flowering time and the appearance of senescence signs in plants; these modifications correlate with the early up-regulation of flowering control genes. Then, we show that a single inoculation with a PGPR could affect the whole life cycle of a plant, accelerating its growth rate and shortening its vegetative period, both effects relevant for most crops. Thus, these findings provide novel and interesting aspects of these relevant

  16. Effects of the plant growth-promoting bacterium Burkholderia phytofirmans PsJN throughout the life cycle of Arabidopsis thaliana.

    PubMed

    Poupin, María Josefina; Timmermann, Tania; Vega, Andrea; Zuñiga, Ana; González, Bernardo

    2013-01-01

    Plant growth-promoting rhizobacteria (PGPR) induce positive effects in plants, such as increased growth or reduced stress susceptibility. The mechanisms behind PGPR/plant interaction are poorly understood, as most studies have described short-term responses on plants and only a few studies have analyzed plant molecular responses under PGPR colonization. Here, we studied the effects of the PGPR bacterial model Burkholderiaphytofirmans PsJN on the whole life cycle of Arabidopsis thaliana plants. We reported that at different plant developmental points, strain PsJN can be found in the rhizosphere and also colonizing their internal tissues. In early ontogeny, strain PsJN increased several growth parameters and accelerated growth rate of the plants. Also, an Arabidopsis transcriptome analysis revealed that 408 genes showed differential expression in PsJN-inoculated plants; some of these genes are involved in stress response and hormone pathways. Specifically, genes implicated in auxin and gibberellin pathways were induced. Quantitative transcriptional analyses of selected genes in different developmental stages revealed that the beginning of these changes could be evidenced early in development, especially among the down-regulated genes. The inoculation with heat-killed bacteria provoked a more severe transcriptional response in plants, but was not able to induce plant growth-promotion. Later in ontogeny, the growth rates of inoculated plants decreased with respect to the non-inoculated group and, interestingly, the inoculation accelerated the flowering time and the appearance of senescence signs in plants; these modifications correlate with the early up-regulation of flowering control genes. Then, we show that a single inoculation with a PGPR could affect the whole life cycle of a plant, accelerating its growth rate and shortening its vegetative period, both effects relevant for most crops. Thus, these findings provide novel and interesting aspects of these relevant

  17. Early intestinal growth and development in poultry.

    PubMed

    Lilburn, M S; Loeffler, S

    2015-07-01

    While there are many accepted "facts" within the field of poultry science that are in truth still open for discussion, there is little debate with respect to the tremendous genetic progress that has been made with commercial broilers and turkeys (Havenstein et al., 2003, 2007). When one considers the changes in carcass development in poultry meat strains, these genetic "improvements" have not always been accompanied by correlated changes in other physiological systems and this can predispose some birds to developmental anomalies (i.e. ascites; Pavlidis et al., 2007; Wideman et al., 2013). Over the last decade, there has been increased interest in intestinal growth/health as poultry nutritionists have attempted to adopt new approaches to deal with the broader changes in the overall nutrition landscape. This landscape includes not only the aforementioned genetic changes but also a raft of governmental policies that have focused attention on the environment (phosphorus and nitrogen excretion), consumer pressure on the use of antibiotics, and renewable biofuels with its consequent effects on ingredient costs. Intestinal morphology has become a common research tool for assessing nutritional effects on the intestine but it is only one metric among many that can be used and histological results can often be interpreted in a variety of ways. This study will address the broader body of research on intestinal growth and development in commercial poultry and will attempt to integrate the topics of the intestinal: microbial interface and the role of the intestine as an immune tissue under the broad umbrella of intestinal physiology.

  18. [Effects of early growth stage shading on rice flag leaf physiological characters and grain growth at grain-filling stage].

    PubMed

    Liu, Qi-hua; Zhou, Xue-biao; Yang, Lian-qun; Li, Tian; Zhang, Jian-jun

    2009-09-01

    In a pot experiment, rice plants were shaded during the period from transplanting to booting, aimed to study the effects of early growth stage shading on the rice growth at grain-filling stage. Comparing with the control, early growth stage shading decreased the tiller number by 26.72%, but increased the flag leaf area and soluble sugar content by 33.86% and 30.23%, respectively. The filled-grain number per panicle, 1000-grain mass, ultimate brown rice mass, and maximum and average grain-filling rates decreased by 8.65%, 4.81%, 9.74%, 20.22%, and 19.13%, and the effective panicle number and grain yield declined by 25.26% and 39.56%, respectively. The peak time of grain-filling rate (Tm) advanced 1.66 days, while the grain-filling time (T99) prolonged 6.80 days. For shading-tolerance variety, its flag leaf Chl a, Chl b, and Chl (a + b) contents at early and mid grain-filling stages, and the protein N and soluble sugar contents and Chl a/b in its flag leaves at grain-filling stage all increased under early growth stage shading, and the ultimate brown rice mass and 1000-grain mass maintained at the similar levels as the control. Consequently, its grain yield reduction rate was lower than that of shading-sensitive variety.

  19. Hyperspectral remote sensing for advanced detection of early blight (Alternaria solani) disease in potato (Solanum tuberosum) plants

    NASA Astrophysics Data System (ADS)

    Atherton, Daniel

    Early detection of disease and insect infestation within crops and precise application of pesticides can help reduce potential production losses, reduce environmental risk, and reduce the cost of farming. The goal of this study was the advanced detection of early blight (Alternaria solani) in potato (Solanum tuberosum) plants using hyperspectral remote sensing data captured with a handheld spectroradiometer. Hyperspectral reflectance spectra were captured 10 times over five weeks from plants grown to the vegetative and tuber bulking growth stages. The spectra were analyzed using principal component analysis (PCA), spectral change (ratio) analysis, partial least squares (PLS), cluster analysis, and vegetative indices. PCA successfully distinguished more heavily diseased plants from healthy and minimally diseased plants using two principal components. Spectral change (ratio) analysis provided wavelengths (490-510, 640, 665-670, 690, 740-750, and 935 nm) most sensitive to early blight infection followed by ANOVA results indicating a highly significant difference (p < 0.0001) between disease rating group means. In the majority of the experiments, comparisons of diseased plants with healthy plants using Fisher's LSD revealed more heavily diseased plants were significantly different from healthy plants. PLS analysis demonstrated the feasibility of detecting early blight infected plants, finding four optimal factors for raw spectra with the predictor variation explained ranging from 93.4% to 94.6% and the response variation explained ranging from 42.7% to 64.7%. Cluster analysis successfully distinguished healthy plants from all diseased plants except for the most mildly diseased plants, showing clustering analysis was an effective method for detection of early blight. Analysis of the reflectance spectra using the simple ratio (SR) and the normalized difference vegetative index (NDVI) was effective at differentiating all diseased plants from healthy plants, except for the

  20. Plant growth regulators enhance gold uptake in Brassica juncea.

    PubMed

    Kulkarni, Manoj G; Stirk, Wendy A; Southway, Colin; Papenfus, Heino B; Swart, Pierre A; Lux, Alexander; Vaculík, Marek; Martinka, Michal; Van Staden, Johannes

    2013-01-01

    The use of plant growth regulators is well established and they are used in many fields of plant science for enhancing growth. Brassica juncea plants were treated with 2.5, 5.0 and 7.5 microM auxin indole-3-butyric acid (IBA), which promotes rooting. The IBA-treated plants were also sprayed with 100 microM gibberellic acid (GA3) and kinetin (Kin) to increase leaf-foliage. Gold (I) chloride (AuCl) was added to the growth medium of plants to achieve required gold concentration. The solubilizing agent ammonium thiocyanate (1 g kg(-1)) (commonly used in mining industries to solubilize gold) was added to the nutrient solution after six weeks of growth and, two weeks later, plants were harvested. Plant growth regulators improved shoot and root dry biomass of B. juncea plants. Inductively Coupled Plasma Optical Emission Spectrometry analysis showed the highest Au uptake for plants treated with 5.0 microM IBA. The average recovery of Au with this treatment was significantly greater than the control treatment by 45.8 mg kg(-1) (155.7%). The other IBA concentrations (2.5 and 7.5 microM) also showed a significant increase in Au uptake compared to the control plants by 14.7 mg kg(-1) (50%) and 42.5 mg kg(-1) (144.5%) respectively. A similar trend of Au accumulation was recorded in the roots of B. juncea plants. This study conducted in solution culture suggests that plant growth regulators can play a significant role in improving phytoextraction of Au.

  1. Plant Growth-Promoting Rhizobacteria Stimulate Vegetative Growth and Asexual Reproduction of Kalanchoe daigremontiana.

    PubMed

    Park, Yong-Soon; Park, Kyungseok; Kloepper, Joseph W; Ryu, Choong-Min

    2015-09-01

    Certain bacterial species associate with plant roots in soil. The plant growth-promoting rhizobacteria (PGPR) stimulate plant growth and yield in greenhouse and field. Here, we examined whether application of known bacilli PGPR strains stimulated growth and asexual reproduction in the succulent plant Kalanchoe daigremontiana. Four PGPR strains B. amyloliquefaciens IN937a, B. cereus BS107, B. pumilus INR7, and B. subtilis GB03 were applied to young plantlets by soil-drenching, and plant growth and development was monitored for three months. Aerial growth was significantly stimulated in PGPR-inoculated plants, which was observed as increases in plant height, shoot weight, and stem width. The stimulated growth influenced plant development by increasing the total number of leaves per plant. Treatment with bacilli also increased the total root biomass compared with that of control plants, and led to a 2-fold increase in asexual reproduction and plantlet formation on the leaf. Collectively, our results firstly demonstrate that Bacillus spp. promote vegetative development of K. daigremontiana, and the enhanced growth stimulates asexual reproduction and plantlet formation.

  2. Plant growth and architectural modelling and its applications

    PubMed Central

    Guo, Yan; Fourcaud, Thierry; Jaeger, Marc; Zhang, Xiaopeng; Li, Baoguo

    2011-01-01

    Over the last decade, a growing number of scientists around the world have invested in research on plant growth and architectural modelling and applications (often abbreviated to plant modelling and applications, PMA). By combining physical and biological processes, spatially explicit models have shown their ability to help in understanding plant–environment interactions. This Special Issue on plant growth modelling presents new information within this topic, which are summarized in this preface. Research results for a variety of plant species growing in the field, in greenhouses and in natural environments are presented. Various models and simulation platforms are developed in this field of research, opening new features to a wider community of researchers and end users. New modelling technologies relating to the structure and function of plant shoots and root systems are explored from the cellular to the whole-plant and plant-community levels. PMID:21638797

  3. Tubular Membrane Plant-Growth Unit

    NASA Technical Reports Server (NTRS)

    Dreschel, Thomas W.

    1992-01-01

    Hydroponic system controls nutrient solution for growing crops in space. Pump draws nutrient solution along inside of tubular membrane in pipe from reservoir, maintaining negative pressure in pipe. Roots of plants in slot extract nutrient through membrane within pipe. Crop plants such as wheat, rice, lettuce, tomatoes, soybeans, and beans grown successfully with system.

  4. Early growth and development of later life metabolic disorders.

    PubMed

    Foo, Joo-Pin; Mantzoros, Christos

    2013-01-01

    Growth is effected via a complex interaction of genetic, nutritional, environmental and growth factors. Hormonal factors such as the growth hormone (GH) and insulin-like growth factor (IGF) signaling system, the human placental lactogen, and insulin play an integral role in early growth. Genetic factors affecting the GH-IGF system and insulin secretion and actions, and epigenetic mechanisms including DNA methylation have been further implicated as contributory factors. These hormonal systems, on a background of genetic susceptibility, together with other factors including maternal nutrition, placental and environmental factors, regulate not only early growth but also development. These interactions may impact on later health consequences in adult life. Accumulating data in the last few decades on developmental programming and later life metabolic disorders has provided a novel perspective on the possible pathogenesis of metabolic dysregulation. Despite postulations put forward to elucidate the mechanism underlying the association between early growth and later life metabolic disorders, it remains unclear what the dominant factor(s) would be, how any underlying mechanisms interact, or whether these mechanisms are truly causal.

  5. Expert System Control of Plant Growth in an Enclosed Space

    NASA Technical Reports Server (NTRS)

    May, George; Lanoue, Mark; Bathel, Matthew; Ryan, Robert E.

    2008-01-01

    The Expert System is an enclosed, controlled environment for growing plants, which incorporates a computerized, knowledge-based software program that is designed to capture the knowledge, experience, and problem-solving skills of one or more human experts in a particular discipline. The Expert System is trained to analyze crop/plant status, to monitor the condition of the plants and the environment, and to adjust operational parameters to optimize the plant-growth process. This system is intended to provide a way to remotely control plant growth with little or no human intervention. More specifically, the term control implies an autonomous method for detecting plant states such as health (biomass) or stress and then for recommending and implementing cultivation and/or remediation to optimize plant growth and to minimize consumption of energy and nutrients. Because of difficulties associated with delivering energy and nutrients remotely, a key feature of this Expert System is its ability to minimize this effort and to achieve optimum growth while taking into account the diverse range of environmental considerations that exist in an enclosed environment. The plant-growth environment for the Expert System could be made from a variety of structures, including a greenhouse, an underground cavern, or another enclosed chamber. Imaging equipment positioned within or around the chamber provides spatially distributed crop/plant-growth information. Sensors mounted in the chamber provide data and information pertaining to environmental conditions that could affect plant development. Lamps in the growth environment structure supply illumination, and other additional equipment in the chamber supplies essential nutrients and chemicals.

  6. Functional approach to high-throughput plant growth analysis

    PubMed Central

    2013-01-01

    Method Taking advantage of the current rapid development in imaging systems and computer vision algorithms, we present HPGA, a high-throughput phenotyping platform for plant growth modeling and functional analysis, which produces better understanding of energy distribution in regards of the balance between growth and defense. HPGA has two components, PAE (Plant Area Estimation) and GMA (Growth Modeling and Analysis). In PAE, by taking the complex leaf overlap problem into consideration, the area of every plant is measured from top-view images in four steps. Given the abundant measurements obtained with PAE, in the second module GMA, a nonlinear growth model is applied to generate growth curves, followed by functional data analysis. Results Experimental results on model plant Arabidopsis thaliana show that, compared to an existing approach, HPGA reduces the error rate of measuring plant area by half. The application of HPGA on the cfq mutant plants under fluctuating light reveals the correlation between low photosynthetic rates and small plant area (compared to wild type), which raises a hypothesis that knocking out cfq changes the sensitivity of the energy distribution under fluctuating light conditions to repress leaf growth. Availability HPGA is available at http://www.msu.edu/~jinchen/HPGA. PMID:24565437

  7. Interplay between cell growth and cell cycle in plants.

    PubMed

    Sablowski, Robert; Carnier Dornelas, Marcelo

    2014-06-01

    The growth of organs and whole plants depends on both cell growth and cell-cycle progression, but the interaction between both processes is poorly understood. In plants, the balance between growth and cell-cycle progression requires coordinated regulation of four different processes: macromolecular synthesis (cytoplasmic growth), turgor-driven cell-wall extension, mitotic cycle, and endocycle. Potential feedbacks between these processes include a cell-size checkpoint operating before DNA synthesis and a link between DNA contents and maximum cell size. In addition, key intercellular signals and growth regulatory genes appear to target at the same time cell-cycle and cell-growth functions. For example, auxin, gibberellin, and brassinosteroid all have parallel links to cell-cycle progression (through S-phase Cyclin D-CDK and the anaphase-promoting complex) and cell-wall functions (through cell-wall extensibility or microtubule dynamics). Another intercellular signal mediated by microtubule dynamics is the mechanical stress caused by growth of interconnected cells. Superimposed on developmental controls, sugar signalling through the TOR pathway has recently emerged as a central control point linking cytoplasmic growth, cell-cycle and cell-wall functions. Recent progress in quantitative imaging and computational modelling will facilitate analysis of the multiple interconnections between plant cell growth and cell cycle and ultimately will be required for the predictive manipulation of plant growth.

  8. Early Successional Microhabitats Allow the Persistence of Endangered Plants in Coastal Sand Dunes

    PubMed Central

    2015-01-01

    Many species are adapted to disturbance and occur within dynamic, mosaic landscapes that contain early and late successional microhabitats. Human modification of disturbance regimes alters the availability of microhabitats and may affect the viability of species in these ecosystems. Because restoring historical disturbance regimes is typically expensive and requires action at large spatial scales, such restoration projects must be justified by linking the persistence of species with successional microhabitats. Coastal sand dune ecosystems worldwide are characterized by their endemic biodiversity and frequent disturbance. Dune-stabilizing invasive plants alter successional dynamics and may threaten species in these ecosystems. We examined the distribution and population dynamics of two federally endangered plant species, the annual Layia carnosa and the perennial Lupinus tidestromii, within a dune ecosystem in northern California, USA. We parameterized a matrix population model for L. tidestromii and examined the magnitude by which the successional stage of the habitat (early or late) influenced population dynamics. Both species had higher frequencies and L. tidestromii had higher frequency of seedlings in early successional habitats. Lupinus tidestromii plants in early successional microhabitats had higher projected rates of population growth than those associated with stabilized, late successional habitats, due primarily to higher rates of recruitment in early successional microhabitats. These results support the idea that restoration of disturbance is critical in historically dynamic landscapes. Our results suggest that large-scale restorations are necessary to allow persistence of the endemic plant species that characterize these ecosystems. PMID:25835390

  9. Early successional microhabitats allow the persistence of endangered plants in coastal sand dunes.

    PubMed

    Pardini, Eleanor A; Vickstrom, Kyle E; Knight, Tiffany M

    2015-01-01

    Many species are adapted to disturbance and occur within dynamic, mosaic landscapes that contain early and late successional microhabitats. Human modification of disturbance regimes alters the availability of microhabitats and may affect the viability of species in these ecosystems. Because restoring historical disturbance regimes is typically expensive and requires action at large spatial scales, such restoration projects must be justified by linking the persistence of species with successional microhabitats. Coastal sand dune ecosystems worldwide are characterized by their endemic biodiversity and frequent disturbance. Dune-stabilizing invasive plants alter successional dynamics and may threaten species in these ecosystems. We examined the distribution and population dynamics of two federally endangered plant species, the annual Layia carnosa and the perennial Lupinus tidestromii, within a dune ecosystem in northern California, USA. We parameterized a matrix population model for L. tidestromii and examined the magnitude by which the successional stage of the habitat (early or late) influenced population dynamics. Both species had higher frequencies and L. tidestromii had higher frequency of seedlings in early successional habitats. Lupinus tidestromii plants in early successional microhabitats had higher projected rates of population growth than those associated with stabilized, late successional habitats, due primarily to higher rates of recruitment in early successional microhabitats. These results support the idea that restoration of disturbance is critical in historically dynamic landscapes. Our results suggest that large-scale restorations are necessary to allow persistence of the endemic plant species that characterize these ecosystems.

  10. Life history biology of early land plants: Deciphering the gametophyte phase

    PubMed Central

    Taylor, Thomas N.; Kerp, Hans; Hass, Hagen

    2005-01-01

    The ca. 400-million-year-old Rhynie chert biota represents a benchmark for studies of early terrestrial ecosystems. The exquisite preservation of the organisms documents an ancient biodiversity that also includes various levels of biological interaction. Absent from the picture until recently has been detailed information about the development of the gametophyte phase and the alternation of generations of the macroplants in this ecosystem. Here, we trace the development of the gametophyte phase of Aglaophyton, an early land plant with an unusual complement of structural and morphological characters. Mature gametophytes consist of a fleshy protocorm attached to the substrate by basal rhizoids; arising from the upper surface are one to several upright gametangiophores bearing multiple gametangia. Stomata are present on the upper surface of the protocorm and gametangiophore, and endomycorrhizal fungi extend throughout the gametophyte. Gametophytes are unisexual, producing either antheridiophores or archegoniophores. There is no evidence that gametophytes later become hermaphroditic. The sexual dimorphism of the Rhynie chert gametophytes is inconsistent with theoretical ideas about the haploid phase of early land plants. The gametophyte phase of early land plants can now be considered within an ecological and evolutionary framework that, in turn, can be used to develop hypotheses about some aspects of the population dynamics and growth of these early land plants. PMID:15809414

  11. Chemical Growth Regulators for Guayule Plants

    NASA Technical Reports Server (NTRS)

    Dastoor, M. N.; Schubert, W. W.; Petersen, G. R.

    1982-01-01

    Test Tubes containing Guayule - tissue cultures were used in experiments to test effects of chemical-growth regulators. The shoots grew in response to addition of 2-(3,4-dichlorophenoxy)-triethylamine (triethylamine (TEA) derivative) to agar medium. Preliminary results indicate that a class of compounds that promotes growth in soil may also promote growth in a culture medium. Further experiments are needed to define the effect of the TEA derivative.

  12. A plant growth form dataset for the New World.

    PubMed

    Engemann, K; Sandel, B; Boyle, B; Enquist, B J; Jørgensen, P M; Kattge, J; McGill, B J; Morueta-Holme, N; Peet, R K; Spencer, N J; Violle, C; Wiser, S K; Svenning, J-C

    2016-11-01

    This dataset provides growth form classifications for 67,413 vascular plant species from North, Central, and South America. The data used to determine growth form were compiled from five major integrated sources and two original publications: the Botanical Information and Ecology Network (BIEN), the Plant Trait Database (TRY), the SALVIAS database, the USDA PLANTS database, Missouri Botanical Garden's Tropicos database, Wright (2010), and Boyle (1996). We defined nine plant growth forms based on woodiness (woody or non-woody), shoot structure (self-supporting or not self-supporting), and root traits (rooted in soil, not rooted in soil, parasitic or aquatic): Epiphyte, Liana, Vine, Herb, Shrub, Tree, Parasite, or Aquatic. Species with multiple growth form classifications were assigned the growth form classification agreed upon by the majority (>2/3) of sources. Species with ambiguous or otherwise not interpretable growth form assignments were excluded from the final dataset but are made available with the original data. Comparisons with independent estimates of species richness for the Western hemisphere suggest that our final dataset includes the majority of New World vascular plant species. Coverage is likely more complete for temperate than for tropical species. In addition, aquatic species are likely under-represented. Nonetheless, this dataset represents the largest compilation of plant growth forms published to date, and should contribute to new insights across a broad range of research in systematics, ecology, biogeography, conservation, and global change science.

  13. The microbiome of medicinal plants: diversity and importance for plant growth, quality and health.

    PubMed

    Köberl, Martina; Schmidt, Ruth; Ramadan, Elshahat M; Bauer, Rudolf; Berg, Gabriele

    2013-12-20

    Past medicinal plant research primarily focused on bioactive phytochemicals, however, the focus is currently shifting due to the recognition that a significant number of phytotherapeutic compounds are actually produced by associated microbes or through interaction with their host. Medicinal plants provide an enormous bioresource of potential use in modern medicine and agriculture, yet their microbiome is largely unknown. The objective of this review is (i) to introduce novel insights into the plant microbiome with a focus on medicinal plants, (ii) to provide details about plant- and microbe-derived ingredients of medicinal plants, and (iii) to discuss possibilities for plant growth promotion and plant protection for commercial cultivation of medicinal plants. In addition, we also present a case study performed both to analyse the microbiome of three medicinal plants (Matricaria chamomilla L., Calendula officinalis L., and Solanum distichum Schumach. and Thonn.) cultivated on organically managed Egyptian desert farm and to develop biological control strategies. The soil microbiome of the desert ecosystem was comprised of a high abundance of Gram-positive bacteria of prime importance for pathogen suppression under arid soil conditions. For all three plants, we observed a clearly plant-specific selection of the microbes as well as highly specific diazotrophic communities that overall identify plant species as important drivers in structural and functional diversity. Lastly, native Bacillus spec. div. strains were able to promote plant growth and elevate the plants' flavonoid production. These results underline the numerous links between the plant-associated microbiome and the plant metabolome.

  14. Arctic plant diversity in the Early Eocene greenhouse

    PubMed Central

    Harrington, Guy J.; Eberle, Jaelyn; Le-Page, Ben A.; Dawson, Mary; Hutchison, J. Howard

    2012-01-01

    For the majority of the Early Caenozoic, a remarkable expanse of humid, mesothermal to temperate forests spread across Northern Polar regions that now contain specialized plant and animal communities adapted to life in extreme environments. Little is known on the taxonomic diversity of Arctic floras during greenhouse periods of the Caenozoic. We show for the first time that plant richness in the globally warm Early Eocene (approx. 55–52 Myr) in the Canadian High Arctic (76° N) is comparable with that approximately 3500 km further south at mid-latitudes in the US western interior (44–47° N). Arctic Eocene pollen floras are most comparable in richness with today's forests in the southeastern United States, some 5000 km further south of the Arctic. Nearly half of the Eocene, Arctic plant taxa are endemic and the richness of pollen floras implies significant patchiness to the vegetation type and clear regional richness of angiosperms. The reduced latitudinal diversity gradient in Early Eocene North American plant species demonstrates that extreme photoperiod in the Arctic did not limit taxonomic diversity of plants. PMID:22072610

  15. Arctic plant diversity in the Early Eocene greenhouse.

    PubMed

    Harrington, Guy J; Eberle, Jaelyn; Le-Page, Ben A; Dawson, Mary; Hutchison, J Howard

    2012-04-22

    For the majority of the Early Caenozoic, a remarkable expanse of humid, mesothermal to temperate forests spread across Northern Polar regions that now contain specialized plant and animal communities adapted to life in extreme environments. Little is known on the taxonomic diversity of Arctic floras during greenhouse periods of the Caenozoic. We show for the first time that plant richness in the globally warm Early Eocene (approx. 55-52 Myr) in the Canadian High Arctic (76° N) is comparable with that approximately 3500 km further south at mid-latitudes in the US western interior (44-47° N). Arctic Eocene pollen floras are most comparable in richness with today's forests in the southeastern United States, some 5000 km further south of the Arctic. Nearly half of the Eocene, Arctic plant taxa are endemic and the richness of pollen floras implies significant patchiness to the vegetation type and clear regional richness of angiosperms. The reduced latitudinal diversity gradient in Early Eocene North American plant species demonstrates that extreme photoperiod in the Arctic did not limit taxonomic diversity of plants.

  16. Plant growth-promoting rhizobacteria and root system functioning

    PubMed Central

    Vacheron, Jordan; Desbrosses, Guilhem; Bouffaud, Marie-Lara; Touraine, Bruno; Moënne-Loccoz, Yvan; Muller, Daniel; Legendre, Laurent; Wisniewski-Dyé, Florence; Prigent-Combaret, Claire

    2013-01-01

    The rhizosphere supports the development and activity of a huge and diversified microbial community, including microorganisms capable to promote plant growth. Among the latter, plant growth-promoting rhizobacteria (PGPR) colonize roots of monocots and dicots, and enhance plant growth by direct and indirect mechanisms. Modification of root system architecture by PGPR implicates the production of phytohormones and other signals that lead, mostly, to enhanced lateral root branching and development of root hairs. PGPR also modify root functioning, improve plant nutrition and influence the physiology of the whole plant. Recent results provided first clues as to how PGPR signals could trigger these plant responses. Whether local and/or systemic, the plant molecular pathways involved remain often unknown. From an ecological point of view, it emerged that PGPR form coherent functional groups, whose rhizosphere ecology is influenced by a myriad of abiotic and biotic factors in natural and agricultural soils, and these factors can in turn modulate PGPR effects on roots. In this paper, we address novel knowledge and gaps on PGPR modes of action and signals, and highlight recent progress on the links between plant morphological and physiological effects induced by PGPR. We also show the importance of taking into account the size, diversity, and gene expression patterns of PGPR assemblages in the rhizosphere to better understand their impact on plant growth and functioning. Integrating mechanistic and ecological knowledge on PGPR populations in soil will be a prerequisite to develop novel management strategies for sustainable agriculture. PMID:24062756

  17. Plant growth-promoting rhizobacteria and root system functioning.

    PubMed

    Vacheron, Jordan; Desbrosses, Guilhem; Bouffaud, Marie-Lara; Touraine, Bruno; Moënne-Loccoz, Yvan; Muller, Daniel; Legendre, Laurent; Wisniewski-Dyé, Florence; Prigent-Combaret, Claire

    2013-09-17

    The rhizosphere supports the development and activity of a huge and diversified microbial community, including microorganisms capable to promote plant growth. Among the latter, plant growth-promoting rhizobacteria (PGPR) colonize roots of monocots and dicots, and enhance plant growth by direct and indirect mechanisms. Modification of root system architecture by PGPR implicates the production of phytohormones and other signals that lead, mostly, to enhanced lateral root branching and development of root hairs. PGPR also modify root functioning, improve plant nutrition and influence the physiology of the whole plant. Recent results provided first clues as to how PGPR signals could trigger these plant responses. Whether local and/or systemic, the plant molecular pathways involved remain often unknown. From an ecological point of view, it emerged that PGPR form coherent functional groups, whose rhizosphere ecology is influenced by a myriad of abiotic and biotic factors in natural and agricultural soils, and these factors can in turn modulate PGPR effects on roots. In this paper, we address novel knowledge and gaps on PGPR modes of action and signals, and highlight recent progress on the links between plant morphological and physiological effects induced by PGPR. We also show the importance of taking into account the size, diversity, and gene expression patterns of PGPR assemblages in the rhizosphere to better understand their impact on plant growth and functioning. Integrating mechanistic and ecological knowledge on PGPR populations in soil will be a prerequisite to develop novel management strategies for sustainable agriculture.

  18. Mathematical models to characterize early epidemic growth: A review

    NASA Astrophysics Data System (ADS)

    Chowell, Gerardo; Sattenspiel, Lisa; Bansal, Shweta; Viboud, Cécile

    2016-09-01

    There is a long tradition of using mathematical models to generate insights into the transmission dynamics of infectious diseases and assess the potential impact of different intervention strategies. The increasing use of mathematical models for epidemic forecasting has highlighted the importance of designing reliable models that capture the baseline transmission characteristics of specific pathogens and social contexts. More refined models are needed however, in particular to account for variation in the early growth dynamics of real epidemics and to gain a better understanding of the mechanisms at play. Here, we review recent progress on modeling and characterizing early epidemic growth patterns from infectious disease outbreak data, and survey the types of mathematical formulations that are most useful for capturing a diversity of early epidemic growth profiles, ranging from sub-exponential to exponential growth dynamics. Specifically, we review mathematical models that incorporate spatial details or realistic population mixing structures, including meta-population models, individual-based network models, and simple SIR-type models that incorporate the effects of reactive behavior changes or inhomogeneous mixing. In this process, we also analyze simulation data stemming from detailed large-scale agent-based models previously designed and calibrated to study how realistic social networks and disease transmission characteristics shape early epidemic growth patterns, general transmission dynamics, and control of international disease emergencies such as the 2009 A/H1N1 influenza pandemic and the 2014-2015 Ebola epidemic in West Africa.

  19. Experiments with Corn To Demonstrate Plant Growth and Development.

    ERIC Educational Resources Information Center

    Haldeman, Janice H.; Gray, Margarit S.

    2000-01-01

    Explores using corn seeds to demonstrate plant growth and development. This experiment allows students to formulate hypotheses, observe and record information, and practice mathematics. Presents background information, materials, procedures, and observations. (SAH)

  20. Quassinoids from Eurycoma longifolia as plant growth inhibitors.

    PubMed

    Jiwajinda, S; Santisopasri, V; Murakami, A; Hirai, N; Ohigashi, H

    2001-11-01

    Seven quassinoids including a new 12-epi-11-dehydroklaineanone were isolated from the leaves of Eurycoma longifolia (Simaroubaceae) as plant growth inhibitors or related compounds. The strongest activity was found in 14,15beta-dihydroxyklaineanone.

  1. An engineering analysis of a closed cycle plant growth module

    NASA Technical Reports Server (NTRS)

    Stickford, G. H., Jr.; Jakob, F. E.; Landstrom, D. K.

    1986-01-01

    The SOLGEM model is a numerical engineering model which solves the flow and energy balance equations for the air flowing through a growing environment, assuming quasi-steady state conditions within the system. SOLGEM provides a dynamic simulation of the controlled environment system in that the temperature and flow conditions of the growing environment are estimated on an hourly basis in response to the weather data and the plant growth parameters. The flow energy balance considers the incident solar flux; incoming air temperature, humidity, and flow rate; heat exchange with the roof and floor; and heat and moisture exchange with the plants. A plant transpiration subroutine was developed based plant growth research facility, intended for the study of bioregenerative life support theories. The results of a performance analysis of the plant growth module are given. The estimated energy requirements of the module components and the total energy are given.

  2. Plant Growth Models Using Artificial Neural Networks

    NASA Technical Reports Server (NTRS)

    Bubenheim, David

    1997-01-01

    In this paper, we descrive our motivation and approach to devloping models and the neural network architecture. Initial use of the artificial neural network for modeling the single plant process of transpiration is presented.

  3. Early History of Arthropod and Vascular Plant Associations

    NASA Astrophysics Data System (ADS)

    Labandeira, Conrad C.

    Although research on modern plant-arthropod associations is one of the cornerstones of biodiversity studies, very little of that interest has percolated down to the fossil record. Much of this neglect is attributable to dismissal of Paleozoic plant-arthropod interactions as being dominated by detritivory, with substantive herbivory not emerging until the Mesozoic. Recent examination of associations from some of the earliest terrestrial communities indicates that herbivory probably extends to the Early Devonian, in the form of spore feeding and piercing-and-sucking. External feeding on pinnule margins and the intimate and intricate association of galling are documented from the Middle and Late Pennsylvanian, respectively. During the Early Permian, the range of external foliage feeding extended to hole feeding and skeletonization and was characterized by the preferential targeting of certain seed plants. At the close of the Paleozoic, surface fluid feeding was established, but there is inconclusive evidence for mutualistic relationships between insect pollinivores and seed plants. These data are gleaned from the largely separate trace-fossil records of gut contents, coprolites, and plant damage and the body-fossil records of plant reproductive and vegetative structures, insect mouthparts, and ovipositors. While these discoveries accentuate the potential for identifying particular associations, the greatest theoretical demand is to establish the spectrum and level of intensity for the emergence of insect herbivory in a range of environments during the Pennsylvanian and Permian.

  4. Germination and Early Growth of Sunflowers in Weak ELF Electromagnetic Fields

    DTIC Science & Technology

    1975-05-01

    fields on the frequency of germination of sunflower seeds ( Helianthus annuus ) and on early growth of seedlings and older plants were performed in 1971...brought about by an, other micro-environmental factors. L1) D C AR 16 1976 L m) D D I OVA 1473 _________ NC.1 IXE UNCIASSIFIED ___se.. curity...brought about by any other micro- environmental factors. I • .1 L 2. INTRODUCTION Experiments seeking to determine the effects of weak elec- tromagnetic

  5. Plant Growth and Morphogenesis under Different Gravity Conditions: Relevance to Plant Life in Space

    PubMed Central

    Hoson, Takayuki

    2014-01-01

    The growth and morphogenesis of plants are entirely dependent on the gravitational acceleration of earth. Under microgravity conditions in space, these processes are greatly modified. Recent space experiments, in combination with ground-based studies, have shown that elongation growth is stimulated and lateral expansion suppressed in various shoot organs and roots under microgravity conditions. Plant organs also show automorphogenesis in space, which consists of altered growth direction and spontaneous curvature in the dorsiventral (back and front) directions. Changes in cell wall properties are responsible for these modifications of growth and morphogenesis under microgravity conditions. Plants live in space with interesting new sizes and forms. PMID:25370193

  6. Magnetic field effects on plant growth, development, and evolution

    PubMed Central

    Maffei, Massimo E.

    2014-01-01

    The geomagnetic field (GMF) is a natural component of our environment. Plants, which are known to sense different wavelengths of light, respond to gravity, react to touch and electrical signaling, cannot escape the effect of GMF. While phototropism, gravitropism, and tigmotropism have been thoroughly studied, the impact of GMF on plant growth and development is not well-understood. This review describes the effects of altering magnetic field (MF) conditions on plants by considering plant responses to MF values either lower or higher than those of the GMF. The possible role of GMF on plant evolution and the nature of the magnetoreceptor is also discussed. PMID:25237317

  7. The microbiome of medicinal plants: diversity and importance for plant growth, quality and health

    PubMed Central

    Köberl, Martina; Schmidt, Ruth; Ramadan, Elshahat M.; Bauer, Rudolf; Berg, Gabriele

    2013-01-01

    Past medicinal plant research primarily focused on bioactive phytochemicals, however, the focus is currently shifting due to the recognition that a significant number of phytotherapeutic compounds are actually produced by associated microbes or through interaction with their host. Medicinal plants provide an enormous bioresource of potential use in modern medicine and agriculture, yet their microbiome is largely unknown. The objective of this review is (i) to introduce novel insights into the plant microbiome with a focus on medicinal plants, (ii) to provide details about plant- and microbe-derived ingredients of medicinal plants, and (iii) to discuss possibilities for plant growth promotion and plant protection for commercial cultivation of medicinal plants. In addition, we also present a case study performed both to analyse the microbiome of three medicinal plants (Matricaria chamomilla L., Calendula officinalis L., and Solanum distichum Schumach. and Thonn.) cultivated on organically managed Egyptian desert farm and to develop biological control strategies. The soil microbiome of the desert ecosystem was comprised of a high abundance of Gram-positive bacteria of prime importance for pathogen suppression under arid soil conditions. For all three plants, we observed a clearly plant-specific selection of the microbes as well as highly specific diazotrophic communities that overall identify plant species as important drivers in structural and functional diversity. Lastly, native Bacillus spec. div. strains were able to promote plant growth and elevate the plants’ flavonoid production. These results underline the numerous links between the plant-associated microbiome and the plant metabolome. PMID:24391634

  8. All about Plant Structure & Growth. Plant Life for Children[TM]. Schlessinger Science Library. [Videotape].

    ERIC Educational Resources Information Center

    2000

    How does a tiny seed sprout and grow into a towering tree? Join the kids from M.A.P.L.E as they learn about some of the incredible transformations that a plant goes through during its lifetime. In All About Plant Structure & Growth, uncover the secrets of roots, stems and leaves - structures that are vital to a plant's role as an energy…

  9. Plant growth regulation of Bt-cotton through Bacillus species.

    PubMed

    Pindi, Pavan Kumar; Sultana, Tasleem; Vootla, Praveen Kumar

    2014-06-01

    Deccan plateau in India periodically experiences droughts due to irregular rain fall and the soil in many parts of the region is considered to be poor for farming. Plant growth promoting rhizobacteria are originally defined as root-colonizing bacteria, i.e., Bacillus that cause either plant growth promotion or biological control of plant diseases. The study aims at the isolation of novel Bacillus species and to assess the biotechnological potential of the novel species as a biofertilizer, with respect to their plant growth promoting properties as efficient phosphate-solubilizing bacteria. Seven different strains of Bacillus were isolated from cotton rhizosphere soil near boys' hostel of Palamuru University which belongs to Deccan plateau. Among seven isolated strains, Bacillus strain-7 has shown maximum support for good growth of eight cotton cultivars. This bacterial species is named Bacillus sp. PU-7 based on the phenotypic and phylogenetic analysis. Among eight cotton cultivars, Mahyco has shown high levels of IAA, proteins, chlorophyll, sugars and low level of proline. Efficacy of novel Bacillus sp. PU-7 with Mahyco cultivar has been checked experimentally at field level in four different cotton grown agricultural soils. The strains supported plant growth in almost all the cases, especially in the deep black soil, with a clear evidence of maximum plant growth by increased levels of phytohormone production and biochemical analysis, followed by shallow black soil. Hence, it is inferred that the novel isolate can be used as bioinoculant in the cotton fields.

  10. Plant growth promotion by Bacillus megaterium involves cytokinin signaling

    PubMed Central

    Ortíz-Castro, Randy; Valencia-Cantero, Eduardo

    2008-01-01

    Accumulating evidence indicates that plant growth promoting rhizobacteria (PGPR) influence plant growth and development by the production of phytohormones such as auxins, gibberellins, and cytokinins. Little is known on the genetic basis and signal transduction components that mediate the beneficial effects of PGPRs in plants. We recently reported the identification of a Bacillus megaterium strain that promoted growth of A. thaliana and P. vulgaris seedlings. In this addendum, the role of cytokinin signaling in mediating the plant responses to bacterial inoculation was investigated using A. thaliana mutants lacking one, two or three of the putative cytokinin receptors CRE1, AHK2 and AHK3, and RPN12 a gene involved in cytokinin signaling. We show that plant growth promotion by B. megaterium is reduced in AHK2-2 single and double mutant combinations and in RPN12. Furthermore, the triple cytokinin-receptor CRE1-12/AHK2-2/AHK3-3 knockout was insensitive to inoculation in terms of growth promotion and root developmental responses. Our results indicate that cytokinin receptors play a complimentary role in plant growth promotion by B. megaterium. PMID:19704649

  11. Mammalian Herbivores Alter the Population Growth and Spatial Establishment of an Early-Establishing Grassland Species.

    PubMed

    Sullivan, Lauren L; Danielson, Brent J; Harpole, W Stanley

    2016-01-01

    Plant-herbivore interactions influence the establishment context of plant species, as herbivores alter the community context in which individual species establish, and the spatial relationship between individuals and their source population as plants invade. This relationship can be described using an establishment kernel, which takes into account movement through seed dispersal, and subsequent establishment of adults. Mammalian herbivores are hypothesized to influence plant population growth and establishment through a combination of consumption of seeds and seedlings, and movement of seeds. While the movement abilities of plants are well known, we have very few empirical mechanistic tests of how biotic factors like mammalian herbivores influence this spread potential. As herbivores of all sizes are abundant on the landscape, we asked the question, how do mammalian herbivores influence the population growth, spatial establishment, and the community establishment context of an early-recruiting native prairie legume, Chamaecrista fasciculata? We planted C. fasciculata in source populations within a four-acre tallgrass prairie restoration in plots with and without herbivores, and monitored its establishment with respect to distance from the source populations. We found that herbivores decreased population growth, and decreased the mean and range establishment distance. Additionally, C. fasciculata established more often without herbivores, and when surrounded by weedy, annual species. Our results provide insight into how the interactions between plants and herbivores can alter the spatial dynamics of developing plant communities, which is vital for colonization and range spread with fragmentation and climate change. Mammalian herbivores have the potential to both slow rates of establishment, but also determine the types of plant communities that surround invading species. Therefore, it is essential to consider the herbivore community when attempting to restore

  12. Mammalian Herbivores Alter the Population Growth and Spatial Establishment of an Early-Establishing Grassland Species

    PubMed Central

    Sullivan, Lauren L.; Danielson, Brent J.; Harpole, W. Stanley

    2016-01-01

    Plant-herbivore interactions influence the establishment context of plant species, as herbivores alter the community context in which individual species establish, and the spatial relationship between individuals and their source population as plants invade. This relationship can be described using an establishment kernel, which takes into account movement through seed dispersal, and subsequent establishment of adults. Mammalian herbivores are hypothesized to influence plant population growth and establishment through a combination of consumption of seeds and seedlings, and movement of seeds. While the movement abilities of plants are well known, we have very few empirical mechanistic tests of how biotic factors like mammalian herbivores influence this spread potential. As herbivores of all sizes are abundant on the landscape, we asked the question, how do mammalian herbivores influence the population growth, spatial establishment, and the community establishment context of an early-recruiting native prairie legume, Chamaecrista fasciculata? We planted C. fasciculata in source populations within a four-acre tallgrass prairie restoration in plots with and without herbivores, and monitored its establishment with respect to distance from the source populations. We found that herbivores decreased population growth, and decreased the mean and range establishment distance. Additionally, C. fasciculata established more often without herbivores, and when surrounded by weedy, annual species. Our results provide insight into how the interactions between plants and herbivores can alter the spatial dynamics of developing plant communities, which is vital for colonization and range spread with fragmentation and climate change. Mammalian herbivores have the potential to both slow rates of establishment, but also determine the types of plant communities that surround invading species. Therefore, it is essential to consider the herbivore community when attempting to restore

  13. Multiscale Models in the Biomechanics of Plant Growth

    PubMed Central

    Fozard, John A.

    2015-01-01

    Plant growth occurs through the coordinated expansion of tightly adherent cells, driven by regulated softening of cell walls. It is an intrinsically multiscale process, with the integrated properties of multiple cell walls shaping the whole tissue. Multiscale models encode physical relationships to bring new understanding to plant physiology and development. PMID:25729061

  14. Plant growth with new fluorescent lamps : II. Growth and reproduction of mature bean plants and dwarf marigold plants.

    PubMed

    Thomas, A S; Dunn, S

    1966-06-01

    Bean and marigold plants were grown to maturity under several kinds of fluorescent lamps to evaluate the effects of spectral differences on development and reproduction. Six kinds of lamps were tested including five lamps that were used in closely related experiments on tomato seedling growth (THOMAS and DUNN, 1967). Evaluation was by fresh- and dry-weight yields of immature and mature pods, and of vegetative tops of plants for bean; and by flowering and fresh-and dry-weight yields for marigold.Bean plants grown under two experimental lamps, Com I and IR III produced significantly higher fresh- and dry-weight yields of both mature and total pods than under Warm-white lamps. This effect could be attributed largely to the considerable energy emitted by the experimental lamps in the red and far-red, as compared to a larger emission in the green and blue for the Warm-white lamps. The differences in the yields for immature pods and vegetative portions of the mature tops were not significant.In a comparison of the effects of three experimental lamps with those of three commercial lamps on growth response of bean plants, the yields were in general higher for the experimental lamps, except for immature pods. The yields of vegetative tops were significantly greater for the 78/22 lamp over the yields for all other lamps. The larger proportion of red and far-red light emitted by the experimental lamps is again the probable cause of the higher yields with these lamps.Two sets of experiments on growth and flowering of marigold under various experimental and commercial lamps were largely inconclusive although there was some indication of beneficial effects by the experimental lamps.In general, the results with bean agree with those for tomato (THOMAS and DUNN, 1967), in that best growth was obtained with a lamp high in red light emission, a moderate amount in the far-red, and very little in the blue part of the spectrum.

  15. IMPLICATIONS OF CHILD GROWTH AND DEVELOPMENT FOR SCHOOL PLANT DESIGN.

    ERIC Educational Resources Information Center

    CHERRY, RALPH W.

    IT IS THE BELIEF OF SOME THAT SCHOOL PLANTS ARE FOR CHILDREN. TO SERVE AS A STUDY GUIDE FOR IMPLEMENTATION OF THIS BELIEF, THIS PAPER PRESENTS PRINCIPLES, NEEDS OF CHILDREN, AND A LIST OF SUGGESTED READING. BASIC PRINCIPLES DISCUSSED ARE--(1) DEVELOPMENT IS A PRODUCT OF TWO FACTORS--LEARNING AND GROWTH, (2) HUMAN GROWTH AND DEVELOPMENT FOLLOW AN…

  16. Growth, nitrogen uptake and flow in maize plants affected by root growth restriction.

    PubMed

    Xu, Liangzheng; Niu, Junfang; Li, Chunjian; Zhang, Fusuo

    2009-07-01

    The objective of the present study was to investigate the influence of a reduced maize root-system size on root growth and nitrogen (N) uptake and flow within plants. Restriction of shoot-borne root growth caused a strong decrease in the absorption of root: shoot dry weight ratio and a reduction in shoot growth. On the other hand, compensatory growth and an increased N uptake rate in the remaining roots were observed. Despite the limited long-distance transport pathway in the mesocotyl with restriction of shoot-borne root growth, N cycling within these plants was higher than those in control plants, implying that xylem and phloem flow velocities via the mesocotyl were considerably higher than in plants with an intact root system. The removal of the seminal roots in addition to restricting shoot-borne root development did not affect whole plant growth and N uptake, except for the stronger compensatory growth of the primary roots. Our results suggest that an adequate N supply to maize plant is maintained by compensatory growth of the remaining roots, increased N uptake rate and flow velocities within the xylem and phloem via the mesocotyl, and reduction in the shoot growth rate.

  17. Hydraulics of Asteroxylon mackei, an early Devonian vascular plant, and the early evolution of water transport tissue in terrestrial plants.

    PubMed

    Wilson, J P; Fischer, W W

    2011-03-01

    The core of plant physiology is a set of functional solutions to a tradeoff between CO(2) acquisition and water loss. To provide an important evolutionary perspective on how the earliest land plants met this tradeoff, we constructed a mathematical model (constrained geometrically with measurements of fossils) of the hydraulic resistance of Asteroxylon, an Early Devonian plant. The model results illuminate the water transport physiology of one of the earliest vascular plants. Results show that Asteroxylon's vascular system contains cells with low hydraulic resistances; these resistances are low because cells were covered by scalariform pits, elliptical structures that permit individual cells to have large areas for water to pass from one cell to another. Asteroxylon could move a large amount of water quickly given its large pit areas; however, this would have left these plants particularly vulnerable to damage from excessive evapotranspiration. These results highlight a repeated pattern in plant evolution, wherein the evolution of highly conductive vascular tissue precedes the appearance of adaptations to increase water transport safety. Quantitative insight into the vascular transport of Asteroxylon also allows us to reflect on the quality of CO(2) proxy estimates based on early land plant fossils. Because Asteroxylon's vascular tissue lacked any safety features to prevent permanent damage, it probably used stomatal abundance and behavior to prevent desiccation. If correct, low stomatal frequencies in Asteroxylon reflect the need to limit evapotranspiration, rather than adaptation to high CO(2) concentrations in the atmosphere. More broadly, methods to reveal and understand water transport in extinct plants have a clear use in testing and bolstering fossil plant-based paleoclimate proxies.

  18. Effects of glycoalkaloids from Solanum plants on cucumber root growth.

    PubMed

    Sun, Fang; Li, Shengyu; He, Dajun; Cao, Gang; Ni, Xiuzhen; Tai, Guihua; Zhou, Yifa; Wang, Deli

    2010-09-01

    The phytotoxic effect of four glycoalkaloids and two 6-O-sulfated glycoalkaloid derivatives were evaluated by testing their inhibition of cucumber root growth. The bioassays were performed using both compounds singly and in equimolar mixtures, respectively. Cucumber root growth was reduced by chaconine (C), solanine (S), solamargine (SM) and solasonine (SS) with IC(50) values of 260 (C), 380 (S), 530 (SM), and 610 microM (SS). The inhibitory effect was concentration-dependent. 6-O-sulfated chaconine and 6-O-sulfated solamargine had no inhibitory effects, which indicated that the carbohydrate moieties play an important role in inhibiting cucumber root growth. The equimolar mixtures of paired glycoalkaloids, both chaconine/solanine and solamargine/solasonine, produced synergistic effects on inhibition of cucumber root growth. By contrast, mixtures of unpaired glycoalkaloids from different plants had no obviously synergistic effects. The growth inhibited plant roots lacked hairs, which implied that inhibition was perhaps at the level of root hair growth.

  19. Factors affecting plant growth in membrane nutrient delivery

    NASA Technical Reports Server (NTRS)

    Dreschel, T. W.; Wheeler, R. M.; Sager, J. C.; Knott, W. M.

    1990-01-01

    The development of the tubular membrane plant growth unit for the delivery of water and nutrients to roots in microgravity has recently focused on measuring the effects of changes in physical variables controlling solution availability to the plants. Significant effects of membrane pore size and the negative pressure used to contain the solution were demonstrated. Generally, wheat grew better in units with a larger pore size but equal negative pressure and in units with the same pore size but less negative pressure. Lettuce also exhibited better plant growth at less negative pressure.

  20. Material and methods to increase plant growth and yield

    DOEpatents

    Kirst, Matias

    2015-09-15

    The present invention relates to materials and methods for modulating growth rates, yield, and/or resistance to drought conditions in plants. In one embodiment, a method of the invention comprises increasing expression of an hc1 gene (or a homolog thereof that provides for substantially the same activity), or increasing expression or activity of the protein encoded by an hc1 gene thereof, in a plant, wherein expression of the hc1 gene or expression or activity of the protein encoded by an hc1 gene results in increased growth rate, yield, and/or drought resistance in the plant.

  1. Detection of early plant stress responses in hyperspectral images

    NASA Astrophysics Data System (ADS)

    Behmann, Jan; Steinrücken, Jörg; Plümer, Lutz

    2014-07-01

    Early stress detection in crop plants is highly relevant, but hard to achieve. We hypothesize that close range hyperspectral imaging is able to uncover stress related processes non-destructively in the early stages which are invisible to the human eye. We propose an approach which combines unsupervised and supervised methods in order to identify several stages of progressive stress development from series of hyperspectral images. Stress of an entire plant is detected by stress response levels at pixel scale. The focus is on drought stress in barley (Hordeum vulgare). Unsupervised learning is used to separate hyperspectral signatures into clusters related to different stages of stress response and progressive senescence. Whereas all such signatures may be found in both, well watered and drought stressed plants, their respective distributions differ. Ordinal classification with Support Vector Machines (SVM) is used to quantify and visualize the distribution of progressive stages of senescence and to separate well watered from drought stressed plants. For each senescence stage a distinctive set of most relevant Vegetation Indices (VIs) is identified. The method has been applied on two experiments involving potted barley plants under well watered and drought stress conditions in a greenhouse. Drought stress is detected up to ten days earlier than using NDVI. Furthermore, it is shown that some VIs have overall relevance, while others are specific to particular senescence stages. The transferability of the method to the field is illustrated by an experiment on maize (Zea mays).

  2. Stomatal Blue Light Response Is Present in Early Vascular Plants.

    PubMed

    Doi, Michio; Kitagawa, Yuki; Shimazaki, Ken-ichiro

    2015-10-01

    Light is a major environmental factor required for stomatal opening. Blue light (BL) induces stomatal opening in higher plants as a signal under the photosynthetic active radiation. The stomatal BL response is not present in the fern species of Polypodiopsida. The acquisition of a stomatal BL response might provide competitive advantages in both the uptake of CO2 and prevention of water loss with the ability to rapidly open and close stomata. We surveyed the stomatal opening in response to strong red light (RL) and weak BL under the RL with gas exchange technique in a diverse selection of plant species from euphyllophytes, including spermatophytes and monilophytes, to lycophytes. We showed the presence of RL-induced stomatal opening in most of these species and found that the BL responses operated in all euphyllophytes except Polypodiopsida. We also confirmed that the stomatal opening in lycophytes, the early vascular plants, is driven by plasma membrane proton-translocating adenosine triphosphatase and K(+) accumulation in guard cells, which is the same mechanism operating in stomata of angiosperms. These results suggest that the early vascular plants respond to both RL and BL and actively regulate stomatal aperture. We also found three plant species that absolutely require BL for both stomatal opening and photosynthetic CO2 fixation, including a gymnosperm, C. revoluta, and the ferns Equisetum hyemale and Psilotum nudum.

  3. Characteristics of coal mine overburden important to plant growth

    SciTech Connect

    McFee, W.W.; Byrnes, W.R.; Stockton, J.G.

    1981-09-01

    This investigation was conducted to determine physical and chemical properties of mineland overburden, to evaluate plant growth in these materials, and to identify properties of overburden materials before mining that may serve as predictors of potential plant growth. Eighteen overburden materials from five surface coal mines in the Illinois coal basin of southwestern Indiana were sampled and analyzed for 20 physical and chemical properties. Twelve were unconsolidated materials, including A and B horizons, lacustrine sediments, and glacial tills, and six were rock strata that break and weather easily. Growth potential for overburden materials, with and without sewage sludge and fertilizer amendments, was evaluated in greenhouse pot culture using alfalfa, wheat, and white pine. Oats yield, and survival and growth of Virginia pine and yellow-poplar were evaluated for 10 materials in outdoor containers. Regression analysis of plant growth against chemical and physical properties of the overburden materials did not reveal properties that could be consistently used in a formula approach to predicting plant growth potential of the materials. Electrical conductivity of the material extract and water storage capacity was most frequently significantly related to growth. High plant tissue levels of B, Fe, Mn, and Al suggested toxicity problems on some materials. The general ranking of overburden materials evaluated for plant growth potential was lacustrine sediment greater than or equal to A horizons > B horizons = glacial tills greater than or equal to brown shale > sandstone > gray shale > black fissile shales; however, physical properties unfavorable to extraction and replacement of lacustrine material may limit its use under field conditions. Addition of sewage sludge resulted in vastly improved growth of wheat, and to a lesser extent alfalfa, on most materials in the greenhouse.

  4. Early onset of vegetation growth vs. rapid green-up: impacts on juvenile mountain ungulates.

    PubMed

    Pettorelli, Nathalie; Pelletier, Fanie; Von Hardenberg, Achaz; Festa-Bianchet, Marco; Côté, Steeve D

    2007-02-01

    Seasonal patterns of climate and vegetation growth are expected to be altered by global warming. In alpine environments, the reproduction of birds and mammals is tightly linked to seasonality; therefore such alterations may have strong repercussions on recruitment. We used the normalized difference vegetation index (NDVI), a satellite-based measurement that correlates strongly with aboveground net primary productivity, to explore how annual variations in the timing of vegetation onset and in the rate of change in primary production during green-up affected juvenile growth and survival of bighorn sheep (Ovis canadensis), Alpine ibex (Capra ibex), and mountain goats (Oreamnos americanus) in four different populations in two continents. We indexed timing of onset of vegetation growth by the integrated NDVI (INDVI) in May. The rate of change in primary production during green-up (early May to early July) was estimated as (1) the maximal slope between any two successive bimonthly NDVI values during this period and (2) the slope in NDVI between early May and early July. The maximal slope in NDVI was negatively correlated with lamb growth and survival in both populations of bighorn sheep, growth of mountain goat kids, and survival of Alpine ibex kids, but not with survival of mountain goat kids. There was no effect of INDVI in May and of the slope in NDVI between early May and early July on juvenile growth and survival for any species. Although rapid changes in NDVI during the green-up period could translate into higher plant productivity, they may also lead to a shorter period of availability of high-quality forage over a large spatial scale, decreasing the opportunity for mountain ungulates to exploit high-quality forage. Our results suggest that attempts to forecast how warmer winters and springs will affect animal population dynamics and life histories in alpine environments should consider factors influencing the rate of changes in primary production during green

  5. Bioassay of Plant Growth Regulator Activity on Aquatic Plants

    DTIC Science & Technology

    1990-07-01

    weed submersed aquatic plants, hydrilla (Hydrilla verticillata Royle) and Eurasian watermilfoil (11yriophyllum splcatum L .). The gibberellin synthesis...Programs, Mr. J. L . Decell, Manager. The HQUSACE Technical Monitor for the APCRP was Mr. James W. Wolcott. The principal investigator for this work was...supervision of Dr. John Harrison, Chief, EL, and Mr. Donald L . Robey, Chief, ERSD, and under the direct supervision of Dr. Thomas L . Hart, Chief

  6. The early growth of the first black holes

    DOE PAGES

    Johnson, Jarrett L.; Haardt, Francesco

    2016-03-04

    With detections of quasars powered by increasingly massive black holes at increasingly early times in cosmic history over the past decade, there has been correspondingly rapid progress made on the theory of early black hole formation and growth. Here, we review the emerging picture of how the first massive black holes formed from the primordial gas and then grew to supermassive scales. We discuss the initial conditions for the formation of the progenitors of these seed black holes, the factors dictating the initial masses with which they form, and their initial stages of growth via accretion, which may occur atmore » super-Eddington rates. Lastly, we briefly discuss how these results connect to large-scale simulations of the growth of supermassive black holes in the first billion years after the Big Bang.« less

  7. The early growth of the first black holes

    SciTech Connect

    Johnson, Jarrett L.; Haardt, Francesco

    2016-03-04

    With detections of quasars powered by increasingly massive black holes at increasingly early times in cosmic history over the past decade, there has been correspondingly rapid progress made on the theory of early black hole formation and growth. Here, we review the emerging picture of how the first massive black holes formed from the primordial gas and then grew to supermassive scales. We discuss the initial conditions for the formation of the progenitors of these seed black holes, the factors dictating the initial masses with which they form, and their initial stages of growth via accretion, which may occur at super-Eddington rates. Lastly, we briefly discuss how these results connect to large-scale simulations of the growth of supermassive black holes in the first billion years after the Big Bang.

  8. The Early Growth of the First Black Holes

    NASA Astrophysics Data System (ADS)

    Johnson, Jarrett L.; Haardt, Francesco

    2016-03-01

    With detections of quasars powered by increasingly massive black holes at increasingly early times in cosmic history over the past decade, there has been correspondingly rapid progress made on the theory of early black hole formation and growth. Here, we review the emerging picture of how the first massive black holes formed from the primordial gas and then grew to supermassive scales. We discuss the initial conditions for the formation of the progenitors of these seed black holes, the factors dictating the initial masses with which they form, and their initial stages of growth via accretion, which may occur at super-Eddington rates. Finally, we briefly discuss how these results connect to large-scale simulations of the growth of supermassive black holes in the first billion years after the Big Bang.

  9. The role of microbial signals in plant growth and development

    PubMed Central

    Ortíz-Castro, Randy; Contreras-Cornejo, Hexon Angel; Macías-Rodríguez, Lourdes

    2009-01-01

    Plant growth and development involves a tight coordination of the spatial and temporal organization of cell division, cell expansion and cell differentiation. Orchestration of these events requires the exchange of signaling molecules between the root and shoot, which can be affected by both biotic and abiotic factors. The interactions that occur between plants and their associated microorganisms have long been of interest, as knowledge of these processes could lead to the development of novel agricultural applications. Plants produce a wide range of organic compounds including sugars, organic acids and vitamins, which can be used as nutrients or signals by microbial populations. On the other hand, microorganisms release phytohormones, small molecules or volatile compounds, which may act directly or indirectly to activate plant immunity or regulate plant growth and morphogenesis. In this review, we focus on recent developments in the identification of signals from free-living bacteria and fungi that interact with plants in a beneficial way. Evidence has accumulated indicating that classic plant signals such as auxins and cytokinins can be produced by microorganisms to efficiently colonize the root and modulate root system architecture. Other classes of signals, including N-acyl-L-homoserine lactones, which are used by bacteria for cell-to-cell communication, can be perceived by plants to modulate gene expression, metabolism and growth. Finally, we discuss the role played by volatile organic compounds released by certain plant growth-promoting rhizobacteria in plant immunity and developmental processes. The picture that emerges is one in which plants and microbes communicate themselves through transkingdom signaling systems involving classic and novel signals. PMID:19820333

  10. The role of microbial signals in plant growth and development.

    PubMed

    Ortíz-Castro, Randy; Contreras-Cornejo, Hexon Angel; Macías-Rodríguez, Lourdes; López-Bucio, José

    2009-08-01

    Plant growth and development involves a tight coordination of the spatial and temporal organization of cell division, cell expansion and cell differentiation. Orchestration of these events requires the exchange of signaling molecules between the root and shoot, which can be affected by both biotic and abiotic factors. The interactions that occur between plants and their associated microorganisms have long been of interest, as knowledge of these processes could lead to the development of novel agricultural applications. Plants produce a wide range of organic compounds including sugars, organic acids and vitamins, which can be used as nutrients or signals by microbial populations. On the other hand, microorganisms release phytohormones, small molecules or volatile compounds, which may act directly or indirectly to activate plant immunity or regulate plant growth and morphogenesis. In this review, we focus on recent developments in the identification of signals from free-living bacteria and fungi that interact with plants in a beneficial way. Evidence has accumulated indicating that classic plant signals such as auxins and cytokinins can be produced by microorganisms to efficiently colonize the root and modulate root system architecture. Other classes of signals, including N-acyl-L-homoserine lactones, which are used by bacteria for cell-to-cell communication, can be perceived by plants to modulate gene expression, metabolism and growth. Finally, we discuss the role played by volatile organic compounds released by certain plant growth-promoting rhizobacteria in plant immunity and developmental processes. The picture that emerges is one in which plants and microbes communicate themselves through transkingdom signaling systems involving classic and novel signals.

  11. Plant reproduction: GABA gradient, guidance and growth.

    PubMed

    Ma, Hong

    2003-10-28

    How a pollen tube manages to navigate through the female tissues during plant reproduction has been a mystery. A new analysis of an Arabidopsis mutant has provided the strongest evidence yet that a GABA gradient may be a critical signal for correct targeting of the pollen tube.

  12. Plant Growth-Promoting Bacteria for Phytostabilization of Mine Tailings

    SciTech Connect

    Grandlic, C.J.; Mendez, M.O.; Chorover, J.; Machado, B.; Maier, R.M.

    2009-05-19

    Eolian dispersion of mine tailings in arid and semiarid environments is an emerging global issue for which economical remediation alternatives are needed. Phytostabilization, the revegetation of these sites with native plants, is one such alternative. Revegetation often requires the addition of bulky amendments such as compost which greatly increases cost. We report the use of plant growth-promoting bacteria (PGPB) to enhance the revegetation of mine tailings and minimize the need for compost amendment. Twenty promising PGPB isolates were used as seed inoculants in a series of greenhouse studies to examine revegetation of an extremely acidic, high metal content tailings sample previously shown to require 15% compost amendment for normal plant growth. Several isolates significantly enhanced growth of two native species, quailbush and buffalo grass, in tailings. In this study, PGPB/compost outcomes were plant specific; for quailbush, PGPB were most effective in combination with 10% compost addition while for buffalo grass, PGPB enhanced growth in the complete absence of compost. Results indicate that selected PGPB can improve plant establishment and reduce the need for compost amendment. Further, PGPB activities necessary for aiding plant growth in mine tailings likely include tolerance to acidic pH and metals.

  13. Design and Construction of an Inexpensive Homemade Plant Growth Chamber

    PubMed Central

    Katagiri, Fumiaki; Canelon-Suarez, Dario; Griffin, Kelsey; Petersen, John; Meyer, Rachel K.; Siegle, Megan; Mase, Keisuke

    2015-01-01

    Plant growth chambers produce controlled environments, which are crucial in making reproducible observations in experimental plant biology research. Commercial plant growth chambers can provide precise controls of environmental parameters, such as temperature, humidity, and light cycle, and the capability via complex programming to regulate these environmental parameters. But they are expensive. The high cost of maintaining a controlled growth environment is often a limiting factor when determining experiment size and feasibility. To overcome the limitation of commercial growth chambers, we designed and constructed an inexpensive plant growth chamber with consumer products for a material cost of $2,300. For a comparable growth space, a commercial plant growth chamber could cost $40,000 or more. Our plant growth chamber had outside dimensions of 1.5 m (W) x 1.8 m (D) x 2 m (H), providing a total growth area of 4.5 m2 with 40-cm high clearance. The dimensions of the growth area and height can be flexibly changed. Fluorescent lights with large reflectors provided a relatively spatially uniform photosynthetically active radiation intensity of 140–250 μmoles/m2/sec. A portable air conditioner provided an ample cooling capacity, and a cooling water mister acted as a powerful humidifier. Temperature, relative humidity, and light cycle inside the chamber were controlled via a z-wave home automation system, which allowed the environmental parameters to be monitored and programmed through the internet. In our setting, the temperature was tightly controlled: 22.2°C±0.8°C. The one-hour average relative humidity was maintained at 75%±7% with short spikes up to ±15%. Using the interaction between Arabidopsis and one of its bacterial pathogens as a test experimental system, we demonstrate that experimental results produced in our chamber were highly comparable to those obtained in a commercial growth chamber. In summary, our design of an inexpensive plant growth chamber

  14. Design and construction of an inexpensive homemade plant growth chamber.

    PubMed

    Katagiri, Fumiaki; Canelon-Suarez, Dario; Griffin, Kelsey; Petersen, John; Meyer, Rachel K; Siegle, Megan; Mase, Keisuke

    2015-01-01

    Plant growth chambers produce controlled environments, which are crucial in making reproducible observations in experimental plant biology research. Commercial plant growth chambers can provide precise controls of environmental parameters, such as temperature, humidity, and light cycle, and the capability via complex programming to regulate these environmental parameters. But they are expensive. The high cost of maintaining a controlled growth environment is often a limiting factor when determining experiment size and feasibility. To overcome the limitation of commercial growth chambers, we designed and constructed an inexpensive plant growth chamber with consumer products for a material cost of $2,300. For a comparable growth space, a commercial plant growth chamber could cost $40,000 or more. Our plant growth chamber had outside dimensions of 1.5 m (W) x 1.8 m (D) x 2 m (H), providing a total growth area of 4.5 m2 with 40-cm high clearance. The dimensions of the growth area and height can be flexibly changed. Fluorescent lights with large reflectors provided a relatively spatially uniform photosynthetically active radiation intensity of 140-250 μmoles/m2/sec. A portable air conditioner provided an ample cooling capacity, and a cooling water mister acted as a powerful humidifier. Temperature, relative humidity, and light cycle inside the chamber were controlled via a z-wave home automation system, which allowed the environmental parameters to be monitored and programmed through the internet. In our setting, the temperature was tightly controlled: 22.2°C±0.8°C. The one-hour average relative humidity was maintained at 75%±7% with short spikes up to ±15%. Using the interaction between Arabidopsis and one of its bacterial pathogens as a test experimental system, we demonstrate that experimental results produced in our chamber were highly comparable to those obtained in a commercial growth chamber. In summary, our design of an inexpensive plant growth chamber

  15. Manufactured soils for plant growth at a lunar base

    NASA Technical Reports Server (NTRS)

    Ming, Douglas W.

    1989-01-01

    Advantages and disadvantages of synthetic soils are discussed. It is pointed out that synthetic soils may provide the proper physical and chemical properties necessary to maximize plant growth, such as a toxic-free composition and cation exchange capacities. The importance of nutrient retention, aeration, moisture retention, and mechanical support as qualities for synthetic soils are stressed. Zeoponics, or the cultivation of plants in zeolite substrates that both contain essential plant-growth cations on their exchange sites and have minor amounts of mineral phases and/or anion-exchange resins that supply essential plant growth ions, is discussed. It is suggested that synthetic zeolites at lunar bases could provide adsorption media for separation of various gases, act as catalysts and as molecular sieves, and serve as cation exchangers in sewage-effluent treatment, radioactive-waste disposal, and pollution control. A flow chart of a potential zeoponics system illustrates this process.

  16. Plant growth promotion induced by phosphate solubilizing endophytic Pseudomonas isolates

    PubMed Central

    Oteino, Nicholas; Lally, Richard D.; Kiwanuka, Samuel; Lloyd, Andrew; Ryan, David; Germaine, Kieran J.; Dowling, David N.

    2015-01-01

    The use of plant growth promoting bacterial inoculants as live microbial biofertilizers provides a promising alternative to chemical fertilizers and pesticides. Inorganic phosphate solubilization is one of the major mechanisms of plant growth promotion by plant associated bacteria. This involves bacteria releasing organic acids into the soil which solubilize the phosphate complexes converting them into ortho-phosphate which is available for plant up-take and utilization. The study presented here describes the ability of endophytic bacteria to produce gluconic acid (GA), solubilize insoluble phosphate, and stimulate the growth of Pisum sativum L. plants. This study also describes the genetic systems within three of these endophyte strains thought to be responsible for their effective phosphate solubilizing abilities. The results showed that many of the endophytic strains produced GA (14–169 mM) and have moderate to high phosphate solubilization capacities (~400–1300 mg L−1). When inoculated into P. sativum L. plants grown in soil under soluble phosphate limiting conditions, the endophytes that produced medium-high levels of GA displayed beneficial plant growth promotion effects. PMID:26257721

  17. GABA signalling modulates plant growth by directly regulating the activity of plant-specific anion transporters.

    PubMed

    Ramesh, Sunita A; Tyerman, Stephen D; Xu, Bo; Bose, Jayakumar; Kaur, Satwinder; Conn, Vanessa; Domingos, Patricia; Ullah, Sana; Wege, Stefanie; Shabala, Sergey; Feijó, José A; Ryan, Peter R; Gilliham, Matthew; Gillham, Matthew

    2015-07-29

    The non-protein amino acid, gamma-aminobutyric acid (GABA) rapidly accumulates in plant tissues in response to biotic and abiotic stress, and regulates plant growth. Until now it was not known whether GABA exerts its effects in plants through the regulation of carbon metabolism or via an unidentified signalling pathway. Here, we demonstrate that anion flux through plant aluminium-activated malate transporter (ALMT) proteins is activated by anions and negatively regulated by GABA. Site-directed mutagenesis of selected amino acids within ALMT proteins abolishes GABA efficacy but does not alter other transport properties. GABA modulation of ALMT activity results in altered root growth and altered root tolerance to alkaline pH, acid pH and aluminium ions. We propose that GABA exerts its multiple physiological effects in plants via ALMT, including the regulation of pollen tube and root growth, and that GABA can finally be considered a legitimate signalling molecule in both the plant and animal kingdoms.

  18. Hyperspectral remote sensing techniques for early detection of plant diseases

    NASA Astrophysics Data System (ADS)

    Krezhova, Dora; Maneva, Svetla; Zdravev, Tomas

    Hyperspectral remote sensing is an emerging, multidisciplinary field with diverse applications in Earth observation. Nowadays spectral remote sensing techniques allow presymptomatic monitoring of changes in the physiological state of plants with high spectral resolution. Hyperspectral leaf reflectance and chlorophyll fluorescence proved to be highly suitable for identification of growth anomalies of cultural plants that result from the environmental changes and different stress factors. Hyperspectral technologies can find place in many scientific areas, as well as for monitoring of plants status and functioning to help in making timely management decisions. This research aimed to detect a presence of viral infection in young pepper plants (Capsicum annuum L.) caused by Cucumber Mosaic Virus (CMV) by using hyperspectral reflectance and fluorescence data and to assess the effect of some growth regulators on the development of the disease. In Bulgaria CMV is one of the widest spread pathogens, causing the biggest economical losses in crop vegetable production. Leaf spectral reflectance and fluorescence data were collected by a portable fibre-optics spectrometer in the spectral ranges 450÷850 nm and 600-900 nm. Greenhouse experiment with pepper plants of two cultivars, Sivria (sensitive to CMV) and Ostrion (resistant to CMV) were used. The plants were divided into six groups. The first group consisted of healthy (control) plants. At growth stage 4-6 expanded leaf, the second group was inoculated with CMV. The other four groups were treated with growth regulators: Spermine, MEIA (beta-monomethyl ester of itaconic acid), ВТН (benzo(1,2,3)thiadiazole-7-carbothioic acid-S-methyl ester) and Phytoxin. On the next day, the pepper plants of these four groups were inoculated with CMV. The viral concentrations in the plants were determined by the serological method DAS-ELISA. Statistical, first derivative and cluster analysis were applied and several vegetation indices were

  19. Release characteristics of encapsulated formulations incorporating plant growth factors.

    PubMed

    Wybraniec, Slawomir; Schwartz, Liliana; Wiesman, Zeev; Markus, Arie; Wolf, David

    2002-05-01

    The release characteristics of encapsulated formulations containing a combination of plant growth factors (PGF)--plant hormones (IBA, paclobutrazol), nutrients (fertilizers, microelements), and fungicide (prochloraz)--were studied. The formulations were prepared by encapsulating the active ingredients in a polyethylene matrix and, in some cases, subsequently coating the product with polyurethane. Dissolution experiments were carried out with both coated and non-coated formulations to determine the sustained release patterns of the active ingredients. The PGF controlled-release systems obtained have been shown to promote development of root systems, vegetative growth, and reproductive development in cuttings, potted plants, or garden plants of various plant species. These beneficial effects are attributable to the lasting and balanced PGF availability provided by these systems.

  20. [Plant growth with limited water]. Performance report

    SciTech Connect

    Not Available

    1992-10-01

    When water is in short supply, soybean stem growth is inhibited by a physical limitation followed in a few hours by metabolic changes that reduce the extensibility of the cell walls. The extensibility then becomes the main limitation. With time, there is a modest recovery in extensibility along with an accumulation of a 28kD protein in the walls of the growth-affected cells. A 3lkD protein that was 80% similar in amino acid sequence also was present but did not accumulate in the walls of the stem cells. In the stem, growth was inhibited and the mRNA for the 28kD protein increased in response to water deprivation but the mRNA for the 3 1 kD protein did not. The roots continued to grow and the mRNA for the 28kD protein did not accumulate but the mRNA for the 3lkD protein did. Thus, there was a tissuespecific response of gene expression that correlated with the contrasting growth response to low water potential in the same seedlings. Further work using immunogold labeling, fluorescence labeling, and western blotting gave evidence that the 28kD protein is located in the cell wall as well as several compartments in the cytoplasm. Preliminary experiments indicate that the 28kD protein is a phosphatase.

  1. Microsensor Technologies for Plant Growth System Monitoring

    NASA Technical Reports Server (NTRS)

    Kim, Chang-Soo

    2004-01-01

    This document covered the following: a) demonstration of feasibility of microsensor for tube and particulate growth systems; b) Dissolved oxygen; c)Wetness; d) Flexible microfluidic substrate with microfluidic channels and microsensor arrays; e)Dynamic root zone control/monitoring in microgravity; f)Rapid prototyping of phytoremediation; and g) A new tool for root physiology and pathology.

  2. Early rapid growth, early birth: Accelerated fetal growth and spontaneous late preterm birth

    PubMed Central

    Kusanovic, Juan Pedro; Erez, Offer; Espinoza, Jimmy; Gotsch, Francesca; Goncalves, Luis; Hassan, Sonia; Gomez, Ricardo; Nien, Jyh Kae; Frongillo, Edward A.; Romero, Roberto

    2011-01-01

    The past two decades in the United States have seen a 24 % rise in spontaneous late preterm delivery (34 to 36 weeks) of unknown etiology. This study tested the hypothesis that fetal growth was identical prior to spontaneous preterm (n=221, median gestational age at birth 35.6 weeks) and term (n=3706) birth among pregnancies followed longitudinally in Santiago, Chile. The hypothesis was not supported: Preterm-delivered fetuses were significantly larger than their term-delivered peers by mid-second trimester in estimated fetal weight, head, limb and abdominal dimensions, and they followed different growth trajectories. Piecewise regression assessed time-specific differences in growth rates at 4-week intervals from 16 weeks. Estimated fetal weight and abdominal circumference growth rates faltered at 20 weeks among the preterm-delivered, only to match and/or exceed their term-delivered peers at 24–28 weeks. After an abrupt decline at 28 weeks attenuating growth rates in all dimensions, fetuses delivered preterm did so at greater population-specific sex and age-adjusted weight than their peers from uncomplicated pregnancies (p<0.01). Growth rates predicted birth timing: one standard score of estimated fetal weight increased the odds ratio for preterm birth from 2.8 prior to 23 weeks, to 3.6 (95% confidence interval, 1.82–7.11, p<0.05) between 23 and 27 weeks. After 27 weeks, increasing size was protective (OR: 0.56, 95% confidence interval, 0.38–0.82, p=0.003). These data document, for the first time, a distinctive fetal growth pattern across gestation preceding spontaneous late preterm birth, identify the importance of mid-gestation for alterations in fetal growth, and add perspective on human fetal biological variability. PMID:18988282

  3. Root foraging influences plant growth responses to earthworm foraging.

    PubMed

    Cameron, Erin K; Cahill, James F; Bayne, Erin M

    2014-01-01

    Interactions among the foraging behaviours of co-occurring animal species can impact population and community dynamics; the consequences of interactions between plant and animal foraging behaviours have received less attention. In North American forests, invasions by European earthworms have led to substantial changes in plant community composition. Changes in leaf litter have been identified as a critical indirect mechanism driving earthworm impacts on plants. However, there has been limited examination of the direct effects of earthworm burrowing on plant growth. Here we show a novel second pathway exists, whereby earthworms (Lumbricus terrestris L.) impact plant root foraging. In a mini-rhizotron experiment, roots occurred more frequently in burrows and soil cracks than in the soil matrix. The roots of Achillea millefolium L. preferentially occupied earthworm burrows, where nutrient availability was presumably higher than in cracks due to earthworm excreta. In contrast, the roots of Campanula rotundifolia L. were less likely to occur in burrows. This shift in root behaviour was associated with a 30% decline in the overall biomass of C. rotundifolia when earthworms were present. Our results indicate earthworm impacts on plant foraging can occur indirectly via physical and chemical changes to the soil and directly via root consumption or abrasion and thus may be one factor influencing plant growth and community change following earthworm invasion. More generally, this work demonstrates the potential for interactions to occur between the foraging behaviours of plants and soil animals and emphasizes the importance of integrating behavioural understanding in foraging studies involving plants.

  4. Analysing growth and development of plants jointly using developmental growth stages

    PubMed Central

    Dambreville, Anaëlle; Lauri, Pierre-Éric; Normand, Frédéric; Guédon, Yann

    2015-01-01

    Background and Aims Plant growth, the increase of organ dimensions over time, and development, the change in plant structure, are often studied as two separate processes. However, there is structural and functional evidence that these two processes are strongly related. The aim of this study was to investigate the co-ordination between growth and development using mango trees, which have well-defined developmental stages. Methods Developmental stages, determined in an expert way, and organ sizes, determined from objective measurements, were collected during the vegetative growth and flowering phases of two cultivars of mango, Mangifera indica. For a given cultivar and growth unit type (either vegetative or flowering), a multistage model based on absolute growth rate sequences deduced from the measurements was first built, and then growth stages deduced from the model were compared with developmental stages. Key Results Strong matches were obtained between growth stages and developmental stages, leading to a consistent definition of integrative developmental growth stages. The growth stages highlighted growth asynchronisms between two topologically connected organs, namely the vegetative axis and its leaves. Conclusions Integrative developmental growth stages emphasize that developmental stages are closely related to organ growth rates. The results are discussed in terms of the possible physiological processes underlying these stages, including plant hydraulics, biomechanics and carbohydrate partitioning. PMID:25452250

  5. Effect of planting date and spacing on growth and yield of fennel (Foeniculum vulgare Mill.) under irrigated conditions.

    PubMed

    Al-Dalain, Saddam Aref; Abdel-Ghani, Adel H; Al-Dala'een, Jawad A; Thalaen, Haditha A

    2012-12-01

    Fennel (Foeniculum vulgare Mill.) plant is a medicinal aromatic herb and belongs to Apiaceae family. It has a rich nutritional value and has many medicinal usages. Very limited information is available in the literature about fennel cultivation and production practices. Therefore, this study was carried out to evaluate the effect of planting date and plant spacing and their interactive effects on yield, yield components and growth of Fennel under irrigation. Three planting dates (Oct. 1st, Nov. 1st and Dec. 1st) and four plant spacings (10, 20, 30 and 40 cm with constant row width, 60 cm) were used. Fruit yield was significantly (p<0.05) influenced by plant spacing and planting date and their interaction. Early planting significantly increased the fruit yield combined with higher number of branches per plant, number of umbrella per plant, number of fruit per plant and plant height. The percentage of increases in Oct. 1st were 34.4 and 32.2% in fruit and biological yield respectively compared with Dec. 1st. Harvest index and thousand fruit weight was not significantly affected by planting date. Increase plant spacing to 30 cm led to more than 15% increase in fruit and biological yield. The early planting date with 30 cm plant spacing resulted in higher fruit (4136 kg ha(-1)) and biological yield (10,114 kg ha(-1)).

  6. Effects of plant density on plant growth before and after recurrent selection in maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Breeding for higher grain yield in Maize (Zea mays L.) has produced varieties that are adapted to grow at higher population densities. While the effects of density on final grain yield and plant phenotypes are well known, how density affects the early development of the plant has been less studied....

  7. Catch-up growth occurs after diarrhea in early childhood.

    PubMed

    Richard, Stephanie A; Black, Robert E; Gilman, Robert H; Guerrant, Richard L; Kang, Gagandeep; Lanata, Claudio F; Mølbak, Kåre; Rasmussen, Zeba A; Sack, R Bradley; Valentiner-Branth, Palle; Checkley, William

    2014-06-01

    Diarrhea and linear growth faltering continue to burden low-income countries and are among the most important contributors to poor health during early childhood. Diarrhea is thought to adversely affect linear growth, but catch-up growth can occur if no additional insults are experienced. We sought to characterize catch-up growth in relation to diarrhea burden in a multisite dataset of 1007 children. Using longitudinal anthropometry and diarrheal surveillance data from 7 cohort studies in 4 countries, we examined the relation between diarrhea prevalence and growth in 3- to 6-mo periods using linear mixed-effect models. Growth during each period was calculated as a function of age using linear splines. We incorporated the longitudinal prevalence of diarrhea in both current and previous periods into the model. Diarrhea during the current period was associated with slower linear and ponderal growth. Faster (catch-up) growth in length was observed in children with no diarrhea in age groups immediately after an age group in which diarrhea was experienced [age group >6-12 mo: 0.03 mm/mo for each percentage diarrhea prevalence in the previous period (95% CI: 0.007, 0.06) relative to 11.3 mm/mo mean growth rate; age group >12-18 mo: 0.04 mm/mo (95% CI: 0.02, 0.06) relative to 8.9 mm/mo mean growth rate; age group >18-24 mo: 0.04 mm/mo (95% CI: 0.003, 0.09) relative to 7.9 mm/mo mean growth rate]. The associations were stronger in boys than in girls when separate models were run. Similar results were observed when weight was the outcome variable. When diarrheal episodes are followed by diarrhea-free periods in the first 2 y of life, catch-up growth is observed that may allow children to regain their original trajectories. The finding of a greater effect of diarrhea on linear growth in boys than in girls was unexpected and requires additional study. Diarrhea burdens are high throughout the first 2 y of life in these study sites, therefore reducing the likelihood of catch

  8. Harzianolide, a novel plant growth regulator and systemic resistance elicitor from Trichoderma harzianum.

    PubMed

    Cai, Feng; Yu, Guanghui; Wang, Ping; Wei, Zhong; Fu, Lin; Shen, Qirong; Chen, Wei

    2013-12-01

    A detailed understanding of the effect of natural products on plant growth and protection will underpin new product development for plant production. The isolation and characterization of a known secondary metabolite named harzianolide from Trichoderma harzianum strain SQR-T037 were described, and the bioactivity of the purified compound as well as the crude metabolite extract in plant growth promotion and systemic resistance induction was investigated in this study. The results showed that harzianolide significantly promoted tomato seedling growth by up to 2.5-fold (dry weight) at a concentration of 0.1 ppm compared with the control. The result of root scan suggested that Trichoderma secondary metabolites may influence the early stages of plant growth through better root development for the enhancement of root length and tips. Both of the purified harzianolide and crude metabolite extract increased the activity of some defense-related enzymes to response to oxidative stress. Examination of six defense-related gene expression by real-time reverse transcription-PCR analysis revealed that harzianolide induces the expression of genes involved in the salicylic acid (PR1 and GLU) and jasmonate/ethylene (JERF3) signaling pathways while crude metabolite extract inhibited some gene expression (CHI-II and PGIP) related to basal defense in tomato plants. Further experiment showed that a subsequent challenge of harzianolide-pretreated plants with the pathogen Sclerotinia sclerotiorum resulted in higher systemic resistance by the reduction of lesion size. These results indicate that secondary metabolites of Trichoderma spp., like harzianolide, may play a novel role in both plant growth regulation and plant defense responses.

  9. Gravity related features of plant growth behavior studied with rotating machines.

    PubMed

    Brown, A H

    1996-04-01

    Research in plant physiology consists mostly of studies on plant growth because almost everything a plant does is done by growing. Most aspects of plant growth are strongly influenced by the earth's gravity vector. Research on those phenomena address scientific questions specifically about how plants use gravity to guide their growth processes.

  10. Gravity related features of plant growth behavior studied with rotating machines

    NASA Technical Reports Server (NTRS)

    Brown, A. H.

    1996-01-01

    Research in plant physiology consists mostly of studies on plant growth because almost everything a plant does is done by growing. Most aspects of plant growth are strongly influenced by the earth's gravity vector. Research on those phenomena address scientific questions specifically about how plants use gravity to guide their growth processes.

  11. Symbiotic regulation of plant growth, development and reproduction

    USGS Publications Warehouse

    Rodriguez, R.J.; Freeman, D. Carl; McArthur, E.D.; Kim, Y.-O.; Redman, R.S.

    2009-01-01

    The growth and development of rice (Oryzae sativa) seedlings was shown to be regulated epigenetically by a fungal endophyte. In contrast to un-inoculated (nonsymbiotic) plants, endophyte colonized (symbiotic) plants preferentially allocated resources into root growth until root hairs were well established. During that time symbiotic roots expanded at five times the rate observed in nonsymbiotic plants. Endophytes also influenced sexual reproduction of mature big sagebrush (Artemisia tridentata) plants. Two spatially distinct big sagebrush subspecies and their hybrids were symbiotic with unique fungal endophytes, despite being separated by only 380 m distance and 60 m elevation. A double reciprocal transplant experiment of parental and hybrid plants, and soils across the hybrid zone showed that fungal endophytes interact with the soils and different plant genotypes to confer enhanced plant reproduction in soil native to the endophyte and reduced reproduction in soil alien to the endophyte. Moreover, the most prevalent endophyte of the hybrid zone reduced the fitness of both parental subspecies. Because these endophytes are passed to the next generation of plants on seed coats, this interaction provides a selective advantage, habitat specificity, and the means of restricting gene flow, thereby making the hybrid zone stable, narrow and potentially leading to speciation. ?? 2009 Landes Bioscience.

  12. Fibroblast growth factor signaling during early vertebrate development.

    PubMed

    Böttcher, Ralph T; Niehrs, Christof

    2005-02-01

    Fibroblast growth factors (FGFs) have been implicated in diverse cellular processes including apoptosis, cell survival, chemotaxis, cell adhesion, migration, differentiation, and proliferation. This review presents our current understanding on the roles of FGF signaling, the pathways employed, and its regulation. We focus on FGF signaling during early embryonic processes in vertebrates, such as induction and patterning of the three germ layers as well as its function in the control of morphogenetic movements.

  13. Non-destructive Phenotyping of Lettuce Plants in Early Stages of Development with Optical Sensors.

    PubMed

    Simko, Ivan; Hayes, Ryan J; Furbank, Robert T

    2016-01-01

    Rapid development of plants is important for the production of 'baby-leaf' lettuce that is harvested when plants reach the four- to eight-leaf stage of growth. However, environmental factors, such as high or low temperature, or elevated concentrations of salt, inhibit lettuce growth. Therefore, non-destructive evaluations of plants can provide valuable information to breeders and growers. The objective of the present study was to test the feasibility of using non-destructive phenotyping with optical sensors for the evaluations of lettuce plants in early stages of development. We performed the series of experiments to determine if hyperspectral imaging and chlorophyll fluorescence imaging can determine phenotypic changes manifested on lettuce plants subjected to the extreme temperature and salinity stress treatments. Our results indicate that top view optical sensors alone can accurately determine plant size to approximately 7 g fresh weight. Hyperspectral imaging analysis was able to detect changes in the total chlorophyll (RCC) and anthocyanin (RAC) content, while chlorophyll fluorescence imaging revealed photoinhibition and reduction of plant growth caused by the extreme growing temperatures (3 and 39°C) and salinity (100 mM NaCl). Though no significant correlation was found between Fv/Fm and decrease in plant growth due to stress when comparisons were made across multiple accessions, our results indicate that lettuce plants have a high adaptability to both low (3°C) and high (39°C) temperatures, with no permanent damage to photosynthetic apparatus and fast recovery of plants after moving them to the optimal (21°C) temperature. We have also detected a strong relationship between visual rating of the green- and red-leaf color intensity and RCC and RAC, respectively. Differences in RAC among accessions suggest that the selection for intense red color may be easier to perform at somewhat lower than the optimal temperature. This study serves as a proof of concept

  14. Non-destructive Phenotyping of Lettuce Plants in Early Stages of Development with Optical Sensors

    PubMed Central

    Simko, Ivan; Hayes, Ryan J.; Furbank, Robert T.

    2016-01-01

    Rapid development of plants is important for the production of ‘baby-leaf’ lettuce that is harvested when plants reach the four- to eight-leaf stage of growth. However, environmental factors, such as high or low temperature, or elevated concentrations of salt, inhibit lettuce growth. Therefore, non-destructive evaluations of plants can provide valuable information to breeders and growers. The objective of the present study was to test the feasibility of using non-destructive phenotyping with optical sensors for the evaluations of lettuce plants in early stages of development. We performed the series of experiments to determine if hyperspectral imaging and chlorophyll fluorescence imaging can determine phenotypic changes manifested on lettuce plants subjected to the extreme temperature and salinity stress treatments. Our results indicate that top view optical sensors alone can accurately determine plant size to approximately 7 g fresh weight. Hyperspectral imaging analysis was able to detect changes in the total chlorophyll (RCC) and anthocyanin (RAC) content, while chlorophyll fluorescence imaging revealed photoinhibition and reduction of plant growth caused by the extreme growing temperatures (3 and 39°C) and salinity (100 mM NaCl). Though no significant correlation was found between Fv/Fm and decrease in plant growth due to stress when comparisons were made across multiple accessions, our results indicate that lettuce plants have a high adaptability to both low (3°C) and high (39°C) temperatures, with no permanent damage to photosynthetic apparatus and fast recovery of plants after moving them to the optimal (21°C) temperature. We have also detected a strong relationship between visual rating of the green- and red-leaf color intensity and RCC and RAC, respectively. Differences in RAC among accessions suggest that the selection for intense red color may be easier to perform at somewhat lower than the optimal temperature. This study serves as a proof of

  15. Diel growth patterns of young soybean (Glycine max) leaflets are synchronous throughout different positions on a plant.

    PubMed

    Friedli, Michael; Walter, Achim

    2015-03-01

    Leaf growth is controlled by various internal and external factors. Leaves of dicotyledonous plants show pronounced diel (24 h) growth patterns that are controlled by the circadian clock. To date, it is still uncertain whether diel leaf growth patterns remain constant throughout the development of a plant. In this study, we followed growth from the primary leaves to leaflets of the seventh trifoliate leaf of soybean (Glycine max) on the same plants with a recently developed imaging-based method under controlled conditions and at a high temporal resolution. We found that all leaflets displayed a consistent diel growth pattern with maximum growth towards the end of the night. In some leaves, growth maxima occurred somewhat later - at dawn - as long as the leaves were still in a very early developmental stage. Yet, overall, diel growth patterns of leaves from different positions within the canopy were highly synchronous. Therefore, the diel growth pattern of any leaf at a given point in time is representative for the overall diel growth pattern of the plant leaf canopy and a deviation from the normal diel growth pattern can indicate that the plant is currently facing stress.

  16. Ventilation Homogeneity Improves with Growth Early in Life

    PubMed Central

    Chakr, Valentina C.; Llapur, Conrado J.; Sarria, Edgar E.; Mattiello, Rita; Kisling, Jeffrey; Tiller, Christina; Kimmel, Risa; Poindexter, Brenda; Tepper, Robert S.

    2011-01-01

    Some studies have suggested that lung clearance index (LCI) is age-independent among healthy subjects early in life, which implies that ventilation distribution does not vary with growth. However, other studies of older children and adolescents suggest that ventilation becomes more homogenous with somatic growth. We describe a new technique to obtain multiple breath washout (MBWO) in sedated infants and toddlers using slow augmented inflation breaths that yields an assessment of LCI and the slope of phase III, which is another index of ventilation inhomogeneity. We evaluated whether ventilation becomes more homogenous with increasing age early in life, and whether infants with chronic lung disease of infancy (CLDI) have increased ventilation inhomogeneity relative to full term controls. Fullterm controls (N = 28) and CLDI (N = 22) subjects between 3 and 28 months corrected-age were evaluated. LCI decreased with increasing age; however, there was no significant difference between the two groups (9.3 vs. 9.5; p = 0.56). Phase III slopes adjusted for expired volume (SND) increased with increasing breath number during the washout and decreased with increasing age. There was no significant difference in SND between fullterm and CLDI subjects (211 vs. 218; P = 0.77). Our findings indicate that ventilation becomes more homogenous with lung growth and maturation early in life; however, there is no evidence that ventilation inhomogeneity is a significant component of the pulmonary pathophysiology of CLDI. PMID:21901860

  17. Time interval between cover crop termination and planting influences corn seedling disease, plant growth, and yield

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Experiments were established in controlled and field environment to evaluate the effect of time intervals between cereal rye cover crop termination and corn planting on corn seedling disease, corn growth, and grain yield in 2014 and 2015. Rye termination dates ranged from 25 days before planting (DB...

  18. Contrasting Responses of Arctic Tussock Tundra to Early Season Snow Melt: Growth Acceleration Versus Frost Damage

    NASA Astrophysics Data System (ADS)

    Oberbauer, S. F.; Starr, G.; Pop, E. W.; Ahlquist, L. E.; Parker, I. C.

    2003-12-01

    Climate warming scenarios for the Arctic include early snow melt marking the beginning of the growing season. From the perspective of the vegetation, early snow melt may have advantageous or disadvantageous effects. With warm weather following snow melt, bud break and flowering will occur early providing a longer period for growth and photosynthesis. However, if very cold weather follows snowmelt, plants will be exposed directly to freezing conditions that plants under the snow would not. Such exposed plants may suffer freeze damage and delayed bud break. We have been experimentally manipulating snow cover at Toolik Lake, Alaska, since 1995. In 9 years of early snow removal treatments, in only two years has the second scenario occurred, in 2001 and 2002. Here we document the effects of very cold conditions following snow removal on green biomass as assessed by NDVI of treatment plots relative to controls. In 2001 evergreens shrubs were killed, bud break was delayed, and NDVI was lower on treatment plots relative to controls. In contrast, in a year with warm spring temperatures following snow melt, 1999, NDVI on treatment plots was significantly greater than that of controls. Cold conditions following snow melt may lead to death of shrubs and delayed budbreak, effects that will carry over throughout the growing season and ultimately, affect community composition and ecosystem function.

  19. Use of lunar regolith as a substrate for plant growth

    NASA Astrophysics Data System (ADS)

    Ming, D. W.; Henninger, D. L.

    1994-11-01

    Regenerative Life Support Systems (RLSS) will be required to regenerate air, water, and wastes, and to produce food for human consumption during long-duration missions to the Moon and Mars. It may be possible to supplement some of the materials needed for a lunar RLSS from resources on the Moon. Natural materials at the lunar surface may be used for a variety of lunar RLSS needs, including (i) soils or solid-support substrates for plant growth, (ii) sources for extraction of essential, plant-growth nutrients, (iii) substrates for microbial populations in the degradation of wastes, (iv) sources of O2 and H2, which may be used to manufacture water, (v) feed stock materials for the synthesis of useful minerals (e.g., molecular sieves), and (vi) shielding materials surrounding the outpost structure to protect humans, plants, and microorganism from harmful radiation. Use of indigenous lunar regolith as a terrestrial-like soil for plant growth could offer a solid support substrate, buffering capacity, nutrient source/storage/retention capabilities, and should be relatively easy to maintain. The lunar regolith could, with a suitable microbial population, play a role in waste renovation; much like terrestrial waste application directly on soils. Issues associated with potentially toxic elements, pH, nutrient availability, air and fluid movement parameters, and cation exchange capacity of lunar regolith need to be addressed before lunar materials can be used effectively as soils for plant growth.

  20. Use of lunar regolith as a substrate for plant growth

    NASA Technical Reports Server (NTRS)

    Ming, D. W.; Henninger, D. L.

    1994-01-01

    Regenerative Life Support Systems (RLSS) will be required to regenerate air, water, and wastes, and to produce food for human consumption during long-duration missions to the Moon and Mars. It may be possible to supplement some of the materials needed for a lunar RLSS from resources on the Moon. Natural materials at the lunar surface may be used for a variety of lunar RLSS needs, including (1) soils or solid-support substrates for plant growth, (2) sources for extraction of essential, plant-growth nutrients, (3) substrates for microbial populations in the degradation of wastes, (4) sources of O2 and H2, which may be used to manufacture water, (5) feed stock materials for the synthesis of useful minerals (e.g., molecular sieves), and (6) shielding materials surrounding the outpost structure to protect humans, plants, and microorganisms from harmful radiation. Use of indigenous lunar regolith as a terrestrial-like soil for plant growth could offer a solid support substrate, buffering capacity, nutrient source/storage/retention capabilities, and should be relatively easy to maintain. The lunar regolith could, with a suitable microbial population, play a role in waste renovation; much like terrestrial waste application directly on soils. Issues associated with potentially toxic elements, pH, nutrient availability, air and fluid movement parameters, and cation exchange capacity of lunar regolith need to be addressed before lunar materials can be used effectively as soils for plant growth.

  1. Plant Growth-Promoting Bacteria: Mechanisms and Applications

    PubMed Central

    Glick, Bernard R.

    2012-01-01

    The worldwide increases in both environmental damage and human population pressure have the unfortunate consequence that global food production may soon become insufficient to feed all of the world's people. It is therefore essential that agricultural productivity be significantly increased within the next few decades. To this end, agricultural practice is moving toward a more sustainable and environmentally friendly approach. This includes both the increasing use of transgenic plants and plant growth-promoting bacteria as a part of mainstream agricultural practice. Here, a number of the mechanisms utilized by plant growth-promoting bacteria are discussed and considered. It is envisioned that in the not too distant future, plant growth-promoting bacteria (PGPB) will begin to replace the use of chemicals in agriculture, horticulture, silviculture, and environmental cleanup strategies. While there may not be one simple strategy that can effectively promote the growth of all plants under all conditions, some of the strategies that are discussed already show great promise. PMID:24278762

  2. Designing Extraterrestrial Plant Growth Habitats With Low Pressure Atmospheres

    NASA Technical Reports Server (NTRS)

    Corey, Kenneth A.

    2001-01-01

    In-situ resource utilization, provision of human life support requirements by bioregenerative methods, and engineering constraints for construction and deployment of plant growth structures on the surface of Mars all suggest the need for plant growth studies at hypobaric pressures. Past work demonstrated that plants will likely tolerate and grow at pressures at or below 10 kPa. Based upon this premise, concepts are developed for the design of reduced pressure atmospheres in lightweight, inflatable structures for plant growth systems on Mars with the goals of maximizing design simplicity and the use of local resources. A modular pod design is proposed as it could be integrated with large-scale production systems. Atmospheric modification of pod clusters would be based upon a pulse and scrub system using mass flow methods for atmospheric transport. A specific modification and control scenario is developed for a lettuce pod to illustrate the dynamics of carbon dioxide and oxygen exchange within a pod. Considerations of minimal atmospheric crop requirements will aid in the development of engineering designs and strategies for extraterrestrial plant growth structures that employ rarefied atmospheres.

  3. Designing Extraterrestrial Plant Growth Habitats with Low Pressure Atmospheres

    NASA Technical Reports Server (NTRS)

    Corey, Kenneth A.

    2002-01-01

    In-situ resource utilization, provision of human life support requirements by bioregenerative methods, and engineering constraints for construction and deployment of plant growth structures on the surface of Mars all suggest the need for plant growth studies at hypobaric pressures. Past work demonstrated that plants will likely tolerate and grow at pressures at or below 10 kPa. Based upon this premise, concepts are developed for the design of reduced pressure atmospheres in lightweight, inflatable structures for plant growth systems on Mars with the goals of maximizing design simplicity and the use of local resources. A modular pod design is proposed as it could be integrated with large-scale production systems. Atmospheric modification of pod clusters would be based upon a pulse and scrub system using mass flow methods for atmospheric transport. A specific modification and control scenario is developed for a lettuce pod to illustrate the dynamics of carbon dioxide and oxygen exchange within a pod. Considerations of minimal atmospheric crop requirements will aid in the development of engineering designs and strategies for extraterrestrial plant growth structures that employ rarefied atmospheres.

  4. Use of lunar regolith as a substrate for plant growth.

    PubMed

    Ming, D W; Henninger, D L

    1994-01-01

    Regenerative Life Support Systems (RLSS) will be required to regenerate air, water, and wastes, and to produce food for human consumption during long-duration missions to the Moon and Mars. It may be possible to supplement some of the materials needed for a lunar RLSS from resources on the Moon. Natural materials at the lunar surface may be used for a variety of lunar RLSS needs, including (i) soils or solid-support substrates for plant growth, (ii) sources for extraction of essential, plant-growth nutrients, (iii) substrates for microbial populations in the degradation of wastes, (iv) sources of O2 and H2, which may be used to manufacture water, (v) feed stock materials for the synthesis of useful minerals (e.g., molecular sieves), and (vi) shielding materials surrounding the outpost structure to protect humans, plants, and microorganisms from harmful radiation. Use of indigenous lunar regolith as a terrestrial-like soil for plant growth could offer a solid support substrate, buffering capacity, nutrient source/storage/retention capabilities, and should be relatively easy to maintain. The lunar regolith could, with a suitable microbial population, play a role in waste renovation; much like terrestrial waste application directly on soils. Issues associated with potentially toxic elements, pH, nutrient availability, air and fluid movement parameters, and cation exchange capacity of lunar regolith need to be addressed before lunar materials can be used effectively as soils for plant growth.

  5. Plant growth-promoting rhizobacteria (PGPR): emergence in agriculture.

    PubMed

    Bhattacharyya, P N; Jha, D K

    2012-04-01

    Plant growth-promoting rhizobacteria (PGPR) are the rhizosphere bacteria that can enhance plant growth by a wide variety of mechanisms like phosphate solubilization, siderophore production, biological nitrogen fixation, rhizosphere engineering, production of 1-Aminocyclopropane-1-carboxylate deaminase (ACC), quorum sensing (QS) signal interference and inhibition of biofilm formation, phytohormone production, exhibiting antifungal activity, production of volatile organic compounds (VOCs), induction of systemic resistance, promoting beneficial plant-microbe symbioses, interference with pathogen toxin production etc. The potentiality of PGPR in agriculture is steadily increased as it offers an attractive way to replace the use of chemical fertilizers, pesticides and other supplements. Growth promoting substances are likely to be produced in large quantities by these rhizosphere microorganisms that influence indirectly on the overall morphology of the plants. Recent progress in our understanding on the diversity of PGPR in the rhizosphere along with their colonization ability and mechanism of action should facilitate their application as a reliable component in the management of sustainable agricultural system. The progress to date in using the rhizosphere bacteria in a variety of applications related to agricultural improvement along with their mechanism of action with special reference to plant growth-promoting traits are summarized and discussed in this review.

  6. The Mars Plant Growth Experiment and Implications for Planetary Protection

    NASA Astrophysics Data System (ADS)

    Smith, Heather

    Plants are the ultimate and necessary solution for O2 production at a human base on Mars. Currently it is unknown if seeds can germinate on the Martian surface. The Mars Plant growth experiment (MPX) is a proposal for the first step in the development of a plant- based O2 production system by demonstrating plant germination and growth on the Martian surface. There is currently no planetary protection policy in place that covers plants on the Martian surface. We describe a planetary protection plan in compliance with NASA and COSPAR policy for a closed plant growth chamber on a Mars rover. We divide the plant growth chamber into two categories for planetary protection, the Outside: the outside of the chamber exposed to the Martian environment, and the Inside: the inside of the chamber which is sealed off from Mars atmosphere and contains the plant seeds and ancillary components for seed growth. We will treat outside surfaces of the chamber as other outside surfaces on the rover, wiped with a mixture of isopropyl alcohol and water as per Category IVb planetary protection requirements. All internal components of the MPX except the seeds and camera (including the water system, the plant growth stage and interior surface walls) will be sterilized by autoclave and subjected to sterilizing dry heat at a temperature of 125°C at an absolute humidity corresponding to a relative humidity of less than 25 percent referenced to the standard conditions of 0°C and 760 torr pressure. The seeds and internal compartments of the MPX in contact with the growth media will be assembled and tested to be free of viable microbes. MPX, once assembled, cannot survive Dry Heat Microbial Reduction. The camera with the radiation and CO2 sensors will be sealed in their own container and vented through HEPA filters. The seeds will be vernalized (microbe free) as per current Space Station methods described by Paul et al. 2001. Documentation of the lack of viable microbes on representative seeds

  7. Use of Hydrogen Peroxide to Disinfect Hydroponic Plant Growth Systems

    NASA Technical Reports Server (NTRS)

    Barta, Daniel J.; Henderson, Keith

    2000-01-01

    Hydrogen peroxide was studied as an alternative to conventional bleach and rinsing methods to disinfect hydroponic plant growth systems. A concentration of 0.5% hydrogen peroxide was found to be effective. Residual hydrogen peroxide can be removed from the system by repeated rinsing or by flowing the solution through a platinum on aluminum catalyst. Microbial populations were reduced to near zero immediately after treatment but returned to pre-disinfection levels 2 days after treatment. Treating nutrient solution with hydrogen peroxide and planting directly into trays being watered with the nutrient solution without replenishment, was found to be detrimental to lettuce germination and growth.

  8. Influence of Atmospheric Pressure Torch Plasma Irradiation on Plant Growth

    NASA Astrophysics Data System (ADS)

    Akiyoshi, Yusuke; Hayashi, Nobuya; Kitazaki, Satoshi; Koga, Kazunori; Shiratani, Masaharu

    2011-10-01

    Growth stimulation characteristics of plants seeds are investigated by an atmospheric discharge irradiation into plasma seeds. Atmospheric pressure plasma torch is consisted of alumina ceramics tube and the steel mesh electrodes wind inside and outside of the tube. When AC high voltage (8 kHz) is applied to the electrode gap, the barrier discharge plasma is produced inside the alumina ceramics tube. The barrier discharge plasma is blown outside with the gas flow in ceramics tube. Radish sprouts seeds locate at 1 cm from the torch edge. The growth stimulation was observed in the length of a stem and a root after the plasma irradiation. The stem length increases approximately 2.8 times at the cultivation time of 24 h. And the growth stimulation effect is found to be maintained for 40 h, after sowing seeds. The mechanism of the growth stimulation would be the redox reaction inside plant cells induced by oxygen radicals.

  9. Early growth and chronic disease: a public health overview.

    PubMed

    Law, Catherine

    2005-07-01

    Infant and childhood growth result from and reflect a range of influences in pre- and postnatal life. These include nutrition, burden of infection and the psycho-social environment. Nutrition in young children is dependent on individual level factors such as fetal experience, infant feeding and weaning practices, and on societal factors such as education of women and economic conditions. The relationship of early postnatal growth to adult disease may be indicative or causal, and may reveal both biological and sociological processes. Although non-insulin-dependent diabetes mellitus (NIDDM) and obesity are risk factors for ischaemic heart disease, the relationships of these three conditions to infant growth differ. Poor infant growth has been associated with higher levels of NIDDM and ischaemic heart disease, but lower levels of adult obesity. Most research has been of populations living in developed countries at different stages of nutritional transition. However, differences in context are not simply limited to the stage of the nutritional transition. They also need to consider the nature of that transition and its social correlates, which may result in the clustering of aetiological influences such as increased body mass and poverty. The size of effect of the relationship of infant growth to adult disease is important not only to determine its relative aetiological importance but also for its potential for public health policy. Such policy also needs to consider the relationships of infant growth to a range of outcomes, both health and human capital, which are not the subject of this workshop.

  10. Providing controlled environments for plant growth in space.

    PubMed

    Bula, R J; Ignatius, R W

    1996-12-01

    Providing a controlled environment for growth of plants in a space environment involves development of unique technologies for the various subsystems of the plant growing facility. These subsystems must be capable of providing the desired environmental control within the operational constraints of currently available space vehicles, primarily the US Space Shuttle or the Russian Space Station, MIR. These constraints include available electrical power, limited total payload mass, and limited volume of the payload. In addition, the space hardware must meet safety requirements for a man-rated space vehicle. The ASTROCULTURE (TM) space-based plant growth unit provides control of temperature, humidity, and carbon dioxide concentration of the plant chamber air. A light emitting diode (LED) unit provides red and blue photons with a total intensity adjustable from 0 to 500 micromoles m-2 s-1. Ethylene released by the plant material is removed with a non-consumable ethylene removable unit. A porous tube and rooting matrix subsystem is used to supply water and nutrients to the plants. The ASTROCULTURE(TM) flight unit is sized to be accommodated in a single middeck locker of the US Space Shuttle, the SPACEHAB module, and with slight modification in the SPACELAB module. The environmental control capabilities of the subsystems used in the ASTROCULTURE(TM) flight unit have been validated in a microgravity environment during five US Space Shuttle missions, including two with plants. The unique environmental control technologies developed for the space-based plant growth facility can be used to enhance the environmental control capabilities of terrestrial controlled environment plant chambers.

  11. Magnetic fluids effect upon growth processes in plants

    NASA Astrophysics Data System (ADS)

    Sala, F.

    1999-07-01

    The metabolic processes of plants growth and development take place according to some organic rules which are specific to their genetic potential. These processes may exhibit modifications of intensity, rhythm, sense, under the influence of the environmental conditions of agricultural systems, through certain factors and bioregulators artificially introduced by man. The results of some investigations regarding effects of biocompatible magnetic fluids (LMW 100 G) on the vegetal organism's (growth, development, fructifying, the level and quality of the yield precocity) are presented.

  12. High-Throughput Phenotyping and QTL Mapping Reveals the Genetic Architecture of Maize Plant Growth.

    PubMed

    Zhang, Xuehai; Huang, Chenglong; Wu, Di; Qiao, Feng; Li, Wenqiang; Duan, Lingfeng; Wang, Ke; Xiao, Yingjie; Chen, Guoxing; Liu, Qian; Xiong, Lizhong; Yang, Wanneng; Yan, Jianbing

    2017-03-01

    With increasing demand for novel traits in crop breeding, the plant research community faces the challenge of quantitatively analyzing the structure and function of large numbers of plants. A clear goal of high-throughput phenotyping is to bridge the gap between genomics and phenomics. In this study, we quantified 106 traits from a maize (Zea mays) recombinant inbred line population (n = 167) across 16 developmental stages using the automatic phenotyping platform. Quantitative trait locus (QTL) mapping with a high-density genetic linkage map, including 2,496 recombinant bins, was used to uncover the genetic basis of these complex agronomic traits, and 988 QTLs have been identified for all investigated traits, including three QTL hotspots. Biomass accumulation and final yield were predicted using a combination of dissected traits in the early growth stage. These results reveal the dynamic genetic architecture of maize plant growth and enhance ideotype-based maize breeding and prediction.

  13. Transgenic tomato plants alter quorum sensing in plant growth-promoting rhizobacteria.

    PubMed

    Barriuso, Jorge; Ramos Solano, Beatriz; Fray, Rupert G; Cámara, Miguel; Hartmann, Anton; Gutiérrez Mañero, F Javier

    2008-06-01

    Two Gram-negative, plant growth-promoting rhizobacteria (PGPRs), denominated as M12 and M14, were classified by 16S rDNA sequencing as Burkholderia graminis species. Both strains were shown to produce a variety of N-acyl-homoserine lactone (AHL) quorum sensing (QS) signalling molecules. The involvement of these molecules in plant growth promotion and the induction of protection against salt stress was examined. AHL production was evaluated in vitro by thin-layer chromatography using AHL biosensors, and the identity of the AHLs produced was determined by liquid chromatography-tandem mass spectrometry. The in situ production of AHLs by M12 and M14 in the rhizosphere of Arabidopsis thaliana plants was detected by co-inoculation with green fluorescent protein-based biosensor strains and confocal laser scanning microscopy. To determine whether plant growth promotion and protection against salt stress were mediated by QS, these PGPRs were assayed on wild-type tomato plants, as well as their corresponding transgenics expressing YenI (short-chain AHL producers) and LasI (long-chain AHL producers). In wild-type tomato plants, only M12 promoted plant growth, and this effect disappeared in both transgenic lines. In contrast, M14 did not promote growth in wild-type tomatoes, but did so in the LasI transgenic line. Resistance to salt stress was induced by M14 in wild-type tomato, but this effect disappeared in both transgenic lines. The strain M12, however, did not induce salt resistance in wild-type tomato, but did so in LasI tomato plants. These results reveal that AHL QS signalling molecules mediate the ability of both PGPR strains M12 and M14 to promote plant growth and to induce protection against salt stress.

  14. Alum sludge land application and its effect on plant growth

    SciTech Connect

    Lucas, J.B. ); Dillaha, T.A.; Reneau, R.B.; Novak, J.T.; Knocke, W.R. )

    1994-11-01

    These investigators conducted three greenhouse experiments to determine the impact of alum sludge from the Harwood's Mill water treatment plant, newport News, Va., on the growth and chemical composition of fescue grass. Fescue yields decreased with increased sludge addition, a trend that was attributed to reductions in plant-available phosphorus (P) at higher loadings. Supplemental P fertilization corrected this deficiency. Lime addition did not affect yield. The presence of manganese and copper in the sludge increased metal uptake by the plants but did not affect yield.

  15. Effects of spring post-planting flooding on early soybean production systems in Mississippi

    Technology Transfer Automated Retrieval System (TEKTRAN)

    April planting of early-maturing soybean to avoid late-summer drought and to allow early harvest has become a common management practice in Mississippi. However, most of the early-planted soybeans on Sharkey clay soils in Mississippi are often exposed to waterlogged conditions during the early sprin...

  16. Early competition shapes maize whole-plant development in mixed stands

    PubMed Central

    Evers, Jochem B.

    2014-01-01

    Mixed cropping is practised widely in developing countries and is gaining increasing interest for sustainable agriculture in developed countries. Plants in intercrops grow differently from plants in single crops, due to interspecific plant interactions, but adaptive plant morphological responses to competition in mixed stands have not been studied in detail. Here the maize (Zea mays) response to mixed cultivation with wheat (Triticum aestivum) is described. Evidence is provided that early responses of maize to the modified light environment in mixed stands propagate throughout maize development, resulting in different phenotypes compared with pure stands. Photosynthetically active radiation (PAR), red:far-red ratio (R:FR), leaf development, and final organ sizes of maize grown in three cultivation systems were compared: pure maize, an intercrop with a small distance (25cm) between maize and wheat plants, and an intercop with a large distance (44cm) between the maize and the wheat. Compared with maize in pure stands, maize in the mixed stands had lower leaf and collar appearance rates, increased blade and sheath lengths at low ranks and smaller sizes at high ranks, increased blade elongation duration, and decreased R:FR and PAR at the plant base during early development. Effects were strongest in the treatment with a short distance between wheat and maize strips. The data suggest a feedback between leaf initiation and leaf emergence at the plant level and coordination between blade and sheath growth at the phytomer level. A conceptual model, based on coordination rules, is proposed to explain the development of the maize plant in pure and mixed stands. PMID:24307719

  17. Early competition shapes maize whole-plant development in mixed stands.

    PubMed

    Zhu, Junqi; Vos, Jan; van der Werf, Wopke; van der Putten, Peter E L; Evers, Jochem B

    2014-02-01

    Mixed cropping is practised widely in developing countries and is gaining increasing interest for sustainable agriculture in developed countries. Plants in intercrops grow differently from plants in single crops, due to interspecific plant interactions, but adaptive plant morphological responses to competition in mixed stands have not been studied in detail. Here the maize (Zea mays) response to mixed cultivation with wheat (Triticum aestivum) is described. Evidence is provided that early responses of maize to the modified light environment in mixed stands propagate throughout maize development, resulting in different phenotypes compared with pure stands. Photosynthetically active radiation (PAR), red:far-red ratio (R:FR), leaf development, and final organ sizes of maize grown in three cultivation systems were compared: pure maize, an intercrop with a small distance (25cm) between maize and wheat plants, and an intercop with a large distance (44cm) between the maize and the wheat. Compared with maize in pure stands, maize in the mixed stands had lower leaf and collar appearance rates, increased blade and sheath lengths at low ranks and smaller sizes at high ranks, increased blade elongation duration, and decreased R:FR and PAR at the plant base during early development. Effects were strongest in the treatment with a short distance between wheat and maize strips. The data suggest a feedback between leaf initiation and leaf emergence at the plant level and coordination between blade and sheath growth at the phytomer level. A conceptual model, based on coordination rules, is proposed to explain the development of the maize plant in pure and mixed stands.

  18. Growth Chambers on the International Space Station for Large Plants

    NASA Technical Reports Server (NTRS)

    Massa, G. D.; Wheeler, R. M.; Morrow, R. C.; Levine, H. G.

    2016-01-01

    The International Space Station (ISS) now has platforms for conducting research on horticultural plant species under LED lighting, and those capabilities continue to expand. The 'Veggie' vegetable production system was deployed to the ISS as an applied research platform for food production in space. Veggie is capable of growing a wide array of horticultural crops. It was designed for low power usage, low launch mass and stowage volume, and minimal crew time requirements. The Veggie flight hardware consists of a light cap containing red (630 nm), blue, (455 nm) and green (530 nm) LEDs. Interfacing with the light cap is an extendable bellows/baseplate for enclosing the plant canopy. A second large plant growth chamber, the Advanced Plant Habitat (APH), is will fly to the ISS in 2017. APH will be a fully controllable environment for high-quality plant physiological research. APH will control light (quality, level, and timing), temperature, CO2, relative humidity, and irrigation, while scrubbing any cabin or plant-derived ethylene and other volatile organic compounds. Additional capabilities include sensing of leaf temperature and root zone moisture, root zone temperature, and oxygen concentration. The light cap will have red (630 nm), blue (450 nm), green (525 nm), far red (730 nm) and broad spectrum white LEDs (4100K). There will be several internal cameras (visible and IR) to monitor and record plant growth and operations. Veggie and APH are available for research proposals.

  19. Growth Chambers on the International Space Station for Large Plants

    NASA Technical Reports Server (NTRS)

    Massa, Gioia D.; Wheeler, Raymond M.; Morrow, Robert C.; Levine, Howard G.

    2016-01-01

    The International Space Station (ISS) now has platforms for conducting research on horticultural plant species under LED (Light Emitting Diodes) lighting, and those capabilities continue to expand. The Veggie vegetable production system was deployed to the ISS as an applied research platform for food production in space. Veggie is capable of growing a wide array of horticultural crops. It was designed for low power usage, low launch mass and stowage volume, and minimal crew time requirements. The Veggie flight hardware consists of a light cap containing red (630 nanometers), blue, (455 nanometers) and green (530 nanometers) LEDs. Interfacing with the light cap is an extendable bellowsbaseplate for enclosing the plant canopy. A second large plant growth chamber, the Advanced Plant Habitat (APH), is will fly to the ISS in 2017. APH will be a fully controllable environment for high-quality plant physiological research. APH will control light (quality, level, and timing), temperature, CO2, relative humidity, and irrigation, while scrubbing any cabin or plant-derived ethylene and other volatile organic compounds. Additional capabilities include sensing of leaf temperature and root zone moisture, root zone temperature, and oxygen concentration. The light cap will have red (630 nm), blue (450 nm), green (525 nm), far red (730 nm) and broad spectrum white LEDs (4100K). There will be several internal cameras (visible and IR) to monitor and record plant growth and operations. Veggie and APH are available for research proposals.

  20. Effects of Engineered Nanomaterials on Plants Growth: An Overview

    PubMed Central

    Bagheri, Samira; Muhd Julkapli, Nurhidayatullaili; Juraimi, Abdul Shukor; Hashemi, Farahnaz Sadat Golestan

    2014-01-01

    Rapid development and wide applications of nanotechnology brought about a significant increment on the number of engineered nanomaterials (ENs) inevitably entering our living system. Plants comprise of a very important living component of the terrestrial ecosystem. Studies on the influence of engineered nanomaterials (carbon and metal/metal oxides based) on plant growth indicated that in the excess content, engineered nanomaterials influences seed germination. It assessed the shoot-to-root ratio and the growth of the seedlings. From the toxicological studies to date, certain types of engineered nanomaterials can be toxic once they are not bound to a substrate or if they are freely circulating in living systems. It is assumed that the different types of engineered nanomaterials affect the different routes, behavior, and the capability of the plants. Furthermore, different, or even opposing conclusions, have been drawn from most studies on the interactions between engineered nanomaterials with plants. Therefore, this paper comprehensively reviews the studies on the different types of engineered nanomaterials and their interactions with different plant species, including the phytotoxicity, uptakes, and translocation of engineered nanomaterials by the plant at the whole plant and cellular level. PMID:25202734

  1. Effects of engineered nanomaterials on plants growth: an overview.

    PubMed

    Aslani, Farzad; Bagheri, Samira; Muhd Julkapli, Nurhidayatullaili; Juraimi, Abdul Shukor; Hashemi, Farahnaz Sadat Golestan; Baghdadi, Ali

    2014-01-01

    Rapid development and wide applications of nanotechnology brought about a significant increment on the number of engineered nanomaterials (ENs) inevitably entering our living system. Plants comprise of a very important living component of the terrestrial ecosystem. Studies on the influence of engineered nanomaterials (carbon and metal/metal oxides based) on plant growth indicated that in the excess content, engineered nanomaterials influences seed germination. It assessed the shoot-to-root ratio and the growth of the seedlings. From the toxicological studies to date, certain types of engineered nanomaterials can be toxic once they are not bound to a substrate or if they are freely circulating in living systems. It is assumed that the different types of engineered nanomaterials affect the different routes, behavior, and the capability of the plants. Furthermore, different, or even opposing conclusions, have been drawn from most studies on the interactions between engineered nanomaterials with plants. Therefore, this paper comprehensively reviews the studies on the different types of engineered nanomaterials and their interactions with different plant species, including the phytotoxicity, uptakes, and translocation of engineered nanomaterials by the plant at the whole plant and cellular level.

  2. The transcriptional regulator BZR1 mediates trade-off between plant innate immunity and growth

    PubMed Central

    Lozano-Durán, Rosa; Macho, Alberto P; Boutrot, Freddy; Segonzac, Cécile; Somssich, Imre E; Zipfel, Cyril

    2013-01-01

    The molecular mechanisms underlying the trade-off between plant innate immunity and steroid-mediated growth are controversial. Here, we report that activation of the transcription factor BZR1 is required and sufficient for suppression of immune signaling by brassinosteroids (BR). BZR1 induces the expression of several WRKY transcription factors that negatively control early immune responses. In addition, BZR1 associates with WRKY40 to mediate the antagonism between BR and immune signaling. We reveal that BZR1-mediated inhibition of immunity is particularly relevant when plant fast growth is required, such as during etiolation. Thus, BZR1 acts as an important regulator mediating the trade-off between growth and immunity upon integration of environmental cues. DOI: http://dx.doi.org/10.7554/eLife.00983.001 PMID:24381244

  3. The transcriptional regulator BZR1 mediates trade-off between plant innate immunity and growth.

    PubMed

    Lozano-Durán, Rosa; Macho, Alberto P; Boutrot, Freddy; Segonzac, Cécile; Somssich, Imre E; Zipfel, Cyril

    2013-12-31

    The molecular mechanisms underlying the trade-off between plant innate immunity and steroid-mediated growth are controversial. Here, we report that activation of the transcription factor BZR1 is required and sufficient for suppression of immune signaling by brassinosteroids (BR). BZR1 induces the expression of several WRKY transcription factors that negatively control early immune responses. In addition, BZR1 associates with WRKY40 to mediate the antagonism between BR and immune signaling. We reveal that BZR1-mediated inhibition of immunity is particularly relevant when plant fast growth is required, such as during etiolation. Thus, BZR1 acts as an important regulator mediating the trade-off between growth and immunity upon integration of environmental cues. DOI: http://dx.doi.org/10.7554/eLife.00983.001.

  4. The state of gravity sensors and peculiarities of plant growth during different gravitational loads

    NASA Astrophysics Data System (ADS)

    Merkys, A. J.; Laurinavichius, R. S.; Rupainene, O. J.; Savichene, E. K.; Jaroshius, A. V.; Shvegzhdene, D. V.; Bendoraityte, D. P.

    In the primary roots of lettuce shoots grown under altered gravitational conditions - 180° inversion on the centrifuged clinostat, horizontal clinostat and in dynamic weightlessness - localization of the cellular organelles, cell morphology and peculiarities of growth have been studied. Significant changes took place in the localization of amyloplasts on the horizontal clinostat. The changes of amyloplast position in the cap cells on the horizontal clinostat and under weightlessness are similar. A change of the normal shoot position (180° inversion and horizontal clinostat) causes an inhibition of growth. Weightlessness increases the length of axial organs and cells in the zone of elongation, but decreases the mitotic index in comparison to the centrifuged control. The analysis of the formation of generative organs has been carried out for Arabidopsis plants grown on board the orbital station Salyut-6. The ability of plants to undergo vegetative growth and to pass through early phases of generative development under weightlessness was confirmed.

  5. Mixed planting with a leguminous plant outperforms bacteria in promoting growth of a metal remediating plant through histidine synthesis.

    PubMed

    Adediran, Gbotemi A; Ngwenya, Bryne T; Mosselmans, J Frederick W; Heal, Kate V; Harvie, Barbra A

    2016-01-01

    The effectiveness of plant growth promoting bacteria (PGPB) in improving metal phytoremediation is still limited by stunted plant growth under high soil metal concentrations. Meanwhile, mixed planting with leguminous plants is known to improve yield in nutrient deficient soils but the use of a metal tolerant legume to enhance metal tolerance of a phytoremediator has not been explored. We compared the use of Pseudomonas brassicacearum, Rhizobium leguminosarum, and the metal tolerant leguminous plant Vicia sativa to promote the growth of Brassica juncea in soil contaminated with 400 mg Zn kg(-1), and used synchrotron based microfocus X-ray absorption spectroscopy to probe Zn speciation in plant roots. B. juncea grew better when planted with V. sativa than when inoculated with PGPB. By combining PGPB with mixed planting, B. juncea recovered full growth while also achieving soil remediation efficiency of >75%, the maximum ever demonstrated for B. juncea. μXANES analysis of V. sativa suggested possible root exudation of the Zn chelates histidine and cysteine were responsible for reducing Zn toxicity. We propose the exploration of a legume-assisted-phytoremediation system as a more effective alternative to PGPB for Zn bioremediation.

  6. MHD channel performance for potential early commercial MHD power plants

    NASA Technical Reports Server (NTRS)

    Swallom, D. W.

    1981-01-01

    The commercial viability of full and part load early commercial MHD power plants is examined. The load conditions comprise a mass flow of 472 kg/sec in the channel, Rosebud coal, 34% by volume oxygen in the oxidizer preheated to 922 K, and a one percent by mass seeding with K. The full load condition is discussed in terms of a combined cycle plant with optimized electrical output by the MHD channel. Various electrical load parameters, pressure ratios, and magnetic field profiles are considered for a baseload MHD generator, with a finding that a decelerating flow rate yields slightly higher electrical output than a constant flow rate. Nominal and part load conditions are explored, with a reduced gas mass flow rate and an enriched oxygen content. An enthalpy extraction of 24.6% and an isentropic efficiency of 74.2% is predicted for nominal operation of a 526 MWe MHD generator, with higher efficiencies for part load operation.

  7. Root and bacterial secretions regulate the interaction between plants and PGPR leading to distinct plant growth promotion effects

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant growth-promoting rhizobacteria (PGPR) have garnered interest in agriculture due to their ability to influence the growth and production of host plants. ATP-binding cassette (ABC) transporters play important roles in plant-microbe interactions by modulating plant root exudation. The present stu...

  8. Near-criticality underlies the behavior of early tumor growth

    NASA Astrophysics Data System (ADS)

    Remy, Guillaume; Cluzel, Philippe

    2016-04-01

    The controlling factors that underlie the growth of tumors have often been hard to identify because of the presence in this system of a large number of intracellular biochemical parameters. Here, we propose a simplifying framework to identify the key physical parameters that govern the early growth of tumors. We model growth by means of branching processes where cells of different types can divide and differentiate. First, using this process that has only one controlling parameter, we study a one cell type model and compute the probability for tumor survival and the time of tumor extinction. Second, we show that when cell death and cell division are perfectly balanced, stochastic effects dominate the growth dynamics and the system exhibits a near-critical behavior that resembles a second-order phase transition. We show, in this near-critical regime, that the time interval before tumor extinction is power-law distributed. Finally, we apply this branching formalism to infer, from experimental growth data, the number of different cell types present in the observed tumor.

  9. Short-Chain Chitin Oligomers: Promoters of Plant Growth.

    PubMed

    Winkler, Alexander J; Dominguez-Nuñez, Jose Alfonso; Aranaz, Inmaculada; Poza-Carrión, César; Ramonell, Katrina; Somerville, Shauna; Berrocal-Lobo, Marta

    2017-02-15

    Chitin is the second most abundant biopolymer in nature after cellulose, and it forms an integral part of insect exoskeletons, crustacean shells, krill and the cell walls of fungal spores, where it is present as a high-molecular-weight molecule. In this study, we showed that a chitin oligosaccharide of lower molecular weight (tetramer) induced genes in Arabidopsis that are principally related to vegetative growth, development and carbon and nitrogen metabolism. Based on plant responses to this chitin tetramer, a low-molecular-weight chitin mix (CHL) enriched to 92% with dimers (2mer), trimers (3mer) and tetramers (4mer) was produced for potential use in biotechnological processes. Compared with untreated plants, CHL-treated plants had increased in vitro fresh weight (10%), radicle length (25%) and total carbon and nitrogen content (6% and 8%, respectively). Our data show that low-molecular-weight forms of chitin might play a role in nature as bio-stimulators of plant growth, and they are also a known direct source of carbon and nitrogen for soil biomass. The biochemical properties of the CHL mix might make it useful as a non-contaminating bio-stimulant of plant growth and a soil restorer for greenhouses and fields.

  10. Short-Chain Chitin Oligomers: Promoters of Plant Growth

    PubMed Central

    Winkler, Alexander J.; Dominguez-Nuñez, Jose Alfonso; Aranaz, Inmaculada; Poza-Carrión, César; Ramonell, Katrina; Somerville, Shauna; Berrocal-Lobo, Marta

    2017-01-01

    Chitin is the second most abundant biopolymer in nature after cellulose, and it forms an integral part of insect exoskeletons, crustacean shells, krill and the cell walls of fungal spores, where it is present as a high-molecular-weight molecule. In this study, we showed that a chitin oligosaccharide of lower molecular weight (tetramer) induced genes in Arabidopsis that are principally related to vegetative growth, development and carbon and nitrogen metabolism. Based on plant responses to this chitin tetramer, a low-molecular-weight chitin mix (CHL) enriched to 92% with dimers (2mer), trimers (3mer) and tetramers (4mer) was produced for potential use in biotechnological processes. Compared with untreated plants, CHL-treated plants had increased in vitro fresh weight (10%), radicle length (25%) and total carbon and nitrogen content (6% and 8%, respectively). Our data show that low-molecular-weight forms of chitin might play a role in nature as bio-stimulators of plant growth, and they are also a known direct source of carbon and nitrogen for soil biomass. The biochemical properties of the CHL mix might make it useful as a non-contaminating bio-stimulant of plant growth and a soil restorer for greenhouses and fields. PMID:28212295

  11. Early detection of invasive plants: principles and practices

    USGS Publications Warehouse

    Welch, Bradley A.; Geissler, Paul H.; Latham, Penelope

    2014-01-01

    Invasive plants infest an estimated 2.6 million acres of the 83 million acres managed by the National Park Service (NPS) in the United States. The consequences of these invasions present a significant challenge for the NPS to manage the agency’s natural resources “unimpaired for the enjoyment of future generations.” More NPS lands are infested daily despite diligent efforts to curtail the problem. Impacts from invasive species have been realized in most parks, resulting in an expressed need to control existing infestations and restore affected ecosystems. There is a growing urgency in the NPS and other resource management organizations to be proactive. The NPS I&M Program, in collaboration with the U.S. Geological Survey (USGS) Status and Trends Program, compiled this document to provide guidance and insight to parks and other natural areas engaged in developing early-detection monitoring protocols for invasive plants. While several rapid response frameworks exist, there is no consistent or comprehensive guidance informing the active detection of nonnative plants early in the invasion process. Early-detection was selected as a primary focus for invasive-species monitoring because, along with rapid response, it is a key strategy for successful management of invasive species. Eradication efforts are most successful on small infestations (that is less than 1 hectare) and become less successful as infestation size increases, to the point that eradication is unlikely for large (that is greater than 1,000 hectares) populations of invasive plants. This document provides guidance for natural resource managers wishing to detect invasive plants early through an active, directed monitoring program. It has a Quick-Start Guide to direct readers to specific chapters and text relevant to their needs. Decision trees and flow charts assist the reader in deciding what methods to choose and when to use them. This document is written in a modular format to accommodate use of

  12. Herbivory: effects on plant abundance, distribution and population growth

    PubMed Central

    Maron, John L; Crone, Elizabeth

    2006-01-01

    Plants are attacked by many different consumers. A critical question is how often, and under what conditions, common reductions in growth, fecundity or even survival that occur due to herbivory translate to meaningful impacts on abundance, distribution or dynamics of plant populations. Here, we review population-level studies of the effects of consumers on plant dynamics and evaluate: (i) whether particular consumers have predictably more or less influence on plant abundance, (ii) whether particular plant life-history types are predictably more vulnerable to herbivory at the population level, (iii) whether the strength of plant–consumer interactions shifts predictably across environmental gradients and (iv) the role of consumers in influencing plant distributional limits. Existing studies demonstrate numerous examples of consumers limiting local plant abundance and distribution. We found larger effects of consumers on grassland than woodland forbs, stronger effects of herbivory in areas with high versus low disturbance, but no systematic or unambiguous differences in the impact of consumers based on plant life-history or herbivore feeding mode. However, our ability to evaluate these and other patterns is limited by the small (but growing) number of studies in this area. As an impetus for further study, we review strengths and challenges of population-level studies, such as interpreting net impacts of consumers in the presence of density dependence and seed bank dynamics. PMID:17002942

  13. Phosphorus mobilizing consortium Mammoth P™ enhances plant growth

    PubMed Central

    Bell, Colin; Mancini, Lauren M.; Lee, Melanie N.; Conant, Richard T.; Wallenstein, Matthew D.

    2016-01-01

    Phosphorus (P) is a critical nutrient used to maximize plant growth and yield. Current agriculture management practices commonly experience low plant P use efficiency due to natural chemical sorption and transformations when P fertilizer is applied to soils. A perplexing challenge facing agriculture production is finding sustainable solutions to deliver P more efficiently to plants. Using prescribed applications of specific soil microbial assemblages to mobilize soil bound—P to improve crop nutrient uptake and productivity has rarely been employed. We investigated whether inoculation of soils with a bacterial consortium developed to mobilize soil P, named Mammoth PTM, could increase plant productivity. In turf, herbs, and fruits, the combination of conventional inorganic fertilizer combined with Mammoth PTM increased productivity up to twofold compared to the fertilizer treatments without the Mammoth PTM inoculant. Jalapeño plants were found to bloom more rapidly when treated with either Mammoth P. In wheat trials, we found that Mammoth PTM by itself was able to deliver yields equivalent to those achieved with conventional inorganic fertilizer applications and improved productivity more than another biostimulant product. Results from this study indicate the substantial potential of Mammoth PTM to enhance plant growth and crop productivity. PMID:27326379

  14. Phosphorus mobilizing consortium Mammoth P(™) enhances plant growth.

    PubMed

    Baas, Peter; Bell, Colin; Mancini, Lauren M; Lee, Melanie N; Conant, Richard T; Wallenstein, Matthew D

    2016-01-01

    Phosphorus (P) is a critical nutrient used to maximize plant growth and yield. Current agriculture management practices commonly experience low plant P use efficiency due to natural chemical sorption and transformations when P fertilizer is applied to soils. A perplexing challenge facing agriculture production is finding sustainable solutions to deliver P more efficiently to plants. Using prescribed applications of specific soil microbial assemblages to mobilize soil bound-P to improve crop nutrient uptake and productivity has rarely been employed. We investigated whether inoculation of soils with a bacterial consortium developed to mobilize soil P, named Mammoth P(TM), could increase plant productivity. In turf, herbs, and fruits, the combination of conventional inorganic fertilizer combined with Mammoth P(TM) increased productivity up to twofold compared to the fertilizer treatments without the Mammoth P(TM) inoculant. Jalapeño plants were found to bloom more rapidly when treated with either Mammoth P. In wheat trials, we found that Mammoth P(TM) by itself was able to deliver yields equivalent to those achieved with conventional inorganic fertilizer applications and improved productivity more than another biostimulant product. Results from this study indicate the substantial potential of Mammoth P(TM) to enhance plant growth and crop productivity.

  15. Characterization of Minnesota lunar simulant for plant growth

    NASA Technical Reports Server (NTRS)

    Oglesby, James P.; Lindsay, Willard L.; Sadeh, Willy Z.

    1993-01-01

    Processing of lunar regolith into a plant growth medium is crucial in the development of a regenerative life support system for a lunar base. Plants, which are the core of such a system, produce food and oxygen for humans and, at the same time, consume carbon dioxide. Because of the scarcity of lunar regolith, simulants must be used to infer its properties and to develop procedures for weathering and chemical analyses. The Minnesota Lunar Simulant (MLS) has been identified to date as the best available simulant for lunar regolith. Results of the dissolution studies reveal that appropriately fertilized MLS can be a suitable medium for plant growth. The techniques used in conducting these studies can be extended to investigate the suitability of actual lunar regolith as a plant growth medium. Dissolution experiments were conducted using the MLS to determine its nutritional and toxicity characteristics for plant growth and to develop weathering and chemical analysis techniques. Two weathering regimes, one with water and one with dilute organic acids simulating the root rhizosphere microenvironment, were investigated. Elemental concentrations were measured using inductively-coupled-plasma (ICP) emission spectrometry and ion chromatography (IC). The geochemical speciation model, MINTEQA2, was used to determine the major solution species and the minerals controlling them. Acidification was found to be a useful method for increasing cation concentrations to meaningful levels. Initial results indicate that MLS weathers to give neutral to slightly basic solutions which contain acceptable amounts of the essential elements required for plant nutrition (i.e., potassium, calcium, magnesium, sulfur, zinc, sodium, silicon, manganese, copper, chlorine, boron, molybdenum, and cobalt). Elements that need to be supplemented include carbon, nitrogen, and perhaps phosphorus and iron. Trace metals in solution were present at nontoxic levels.

  16. Plant growth promoting bacteria from Crocus sativus rhizosphere.

    PubMed

    Ambardar, Sheetal; Vakhlu, Jyoti

    2013-12-01

    Present study deals with the isolation of rhizobacteria and selection of plant growth promoting bacteria from Crocus sativus (Saffron) rhizosphere during its flowering period (October-November). Bacterial load was compared between rhizosphere and bulk soil by counting CFU/gm of roots and soil respectively, and was found to be ~40 times more in rhizosphere. In total 100 bacterial isolates were selected randomly from rhizosphere and bulk soil (50 each) and screened for in-vitro and in vivo plant growth promoting properties. The randomly isolated bacteria were identified by microscopy, biochemical tests and sequence homology of V1-V3 region of 16S rRNA gene. Polyphasic identification categorized Saffron rhizobacteria and bulk soil bacteria into sixteen different bacterial species with Bacillus aryabhattai (WRF5-rhizosphere; WBF3, WBF4A and WBF4B-bulk soil) common to both rhizosphere as well as bulk soil. Pseudomonas sp. in rhizosphere and Bacillus and Brevibacterium sp. in the bulk soil were the predominant genera respectively. The isolated rhizobacteria were screened for plant growth promotion activity like phosphate solubilization, siderophore and indole acetic acid production. 50 % produced siderophore and 33 % were able to solubilize phosphate whereas all the rhizobacterial isolates produced indole acetic acid. The six potential PGPR showing in vitro activities were used in pot trial to check their efficacy in vivo. These bacteria consortia demonstrated in vivo PGP activity and can be used as PGPR in Saffron as biofertilizers.This is the first report on the isolation of rhizobacteria from the Saffron rhizosphere, screening for plant growth promoting bacteria and their effect on the growth of Saffron plant.

  17. Computational Morphodynamics: A modeling framework to understand plant growth

    PubMed Central

    Chickarmane, Vijay; Roeder, Adrienne H.K.; Tarr, Paul T.; Cunha, Alexandre; Tobin, Cory; Meyerowitz, Elliot M.

    2014-01-01

    Computational morphodynamics utilizes computer modeling to understand the development of living organisms over space and time. Results from biological experiments are used to construct accurate and predictive models of growth. These models are then used to make novel predictions providing further insight into the processes in question, which can be tested experimentally to either confirm or rule out the validity of the computational models. This review highlights two fundamental issues: (1.) models should span and integrate single cell behavior with tissue development and (2.) the necessity to understand the feedback between mechanics of growth and chemical or molecular signaling. We review different approaches to model plant growth and discuss a variety of model types that can be implemented, with the aim of demonstrating how this methodology can be used, to explore the morphodynamics of plant development. PMID:20192756

  18. Peat soil composition as indicator of plants growth environment

    NASA Astrophysics Data System (ADS)

    Noormets, M.; Tonutare, T.; Kauer, K.; Szajdak, L.; Kolli, R.

    2009-04-01

    Exhausted milled peat areas have been left behind as a result of decades-lasting intensive peat production in Estonia and Europe. According to different data there in Estonia is 10 000 - 15 000 ha of exhausted milled peat areas that should be vegetated. Restoration using Sphagnum species is most advantageous, as it creates ecological conditions closest to the natural succession towards a natural bog area. It is also thought that the large scale translocation of vegetation from intact bogs, as used in some Canadian restoration trials, is not applicable in most of European sites due to limited availability of suitable donor areas. Another possibility to reduce the CO2 emission in these areas is their use for cultivation of species that requires minimum agrotechnical measures exploitation. It is found by experiments that it is possible to establish on Vaccinium species for revegetation of exhausted milled peat areas. Several physiological activity of the plant is regulated by the number of phytohormones. These substances in low quantities move within the plant from a site of production to a site of action. Phytohormone, indole-3-acetic acid (IAA) is formed in soils from tryptophane by enzymatic conversion. This compound seems to play an important function in nature as result to its influence in regulation of plant growth and development. A principal feature of IAA is its ability to affect growth, development and health of plants. This compound activates root morphology and metabolic changes in the host plant. The physiological impact of this substance is involved in cell elongation, apical dominance, root initiation, parthenocarpy, abscission, callus formation and the respiration. The investigation areas are located in the county of Tartu (58˚ 22' N, 26˚ 43' E), in the southern part of Estonia. The soil of the experimental fields belongs according to the WRB soil classification, to the soils subgroups of Fibri-Dystric Histosols. The investigation areas were

  19. 15. international conference on plant growth substances: Program -- Abstracts

    SciTech Connect

    1995-12-31

    Since the 14th Conference in Amsterdam in 1991, progress in plant hormone research and developmental plant biology has been truly astonishing. The five ``classical`` plant hormones, auxin, gibberellin, cytokinin, ethylene, and abscisic acid, have been joined by a number of new signal molecules, e.g., systemin, jasmonic acid, salicylic acid, whose biosynthesis and functions are being understood in ever greater detail. Molecular genetics has opened new vistas in an understanding of transduction pathways that regulate developmental processes in response to hormonal and environmental signals. The program of the 15th Conference includes accounts of this progress and brings together scientists whose work focuses on physiological, biochemical, and chemical aspects of plant growth regulation. This volume contains the abstracts of papers presented at this conference.

  20. The Growth of Early Galaxies and Reionization of Hydrogen

    NASA Astrophysics Data System (ADS)

    Chary, Ranga Ram

    2012-07-01

    The reionization of the intergalactic medium about a billion years after the Big Bang was an important event which occurred due to the release of ionizing photons from the growth of stellar mass and black holes in the early Universe. By leveraging the benefits of field galaxy surveys, I will present some recent breakthroughs in our understanding of how the earliest galaxies in the Universe evolved. I will present evidence that unlike in the local Universe where galaxy growth occurs through intermittent cannibalism, star-formation in the distant Universe is a more continuous if violent process with an overabundance of massive stars. Implications for the reionization history of the Universe will also be discussed.

  1. Differential growth responses of Brachypodium distachyon genotypes to inoculation with plant growth promoting rhizobacteria.

    PubMed

    do Amaral, Fernanda P; Pankievicz, Vânia C S; Arisi, Ana Carolina M; de Souza, Emanuel M; Pedrosa, Fabio; Stacey, Gary

    2016-04-01

    Plant growth promoting rhizobacteria (PGPR) can associate and enhance the growth of important crop grasses. However, in most cases, the molecular mechanisms responsible for growth promotion are not known. Such research could benefit by the adoption of a grass model species that showed a positive response to bacterial inoculation and was amenable to genetic and molecular research methods. In this work we inoculated different genotypes of the model grass Brachypodium distachyon with two, well-characterized PGPR bacteria, Azospirillum brasilense and Herbaspirillum seropedicae, and evaluated the growth response. Plants were grown in soil under no nitrogen or with low nitrogen (i.e., 0.5 mM KNO3). A variety of growth parameters (e.g., shoot height, root length, number of lateral roots, fresh and dry weight) were measured 35 days after inoculation. The data indicate that plant genotype plays a very important role in determining the plant response to PGPR inoculation. A positive growth response was observed with only four genotypes grown under no nitrogen and three genotypes tested under low nitrogen. However, in contrast, relatively good root colonization was seen with most genotypes, as measured by drop plate counting and direct, microscopic examination of roots. In particular, the endophytic bacteria H. seropedicae showed strong epiphytic and endophytic colonization of roots.

  2. Improvements in plant growth rate using underwater discharge

    NASA Astrophysics Data System (ADS)

    Takaki, K.; Takahata, J.; Watanabe, S.; Satta, N.; Yamada, O.; Fujio, T.; Sasaki, Y.

    2013-03-01

    The drainage water from plant pots was irradiated by plasma and then recycled to irrigate plants for improving the growth rate by supplying nutrients to plants and inactivating the bacteria in the bed-soil. Brassica rapa var. perviridis (Chinese cabbage; Brassica campestris) plants were cultivated in pots filled with artificial soil, which included the use of chicken droppings as a fertiliser. The water was recycled once per day from a drainage water pool and added to the bed-soil in the pots. A magnetic compression type pulsed power generator was used to produce underwater discharge with repetition rate of 250 pps. The plasma irradiation times were set as 10 and 20 minutes per day over 28 days of cultivation. The experimental results showed that the growth rate increased significantly with plasma irradiation into the drainage water. The growth rate increased with the plasma irradiation time. The nitrogen concentration of the leaves increased as a result of plasma irradiation based on chlorophyll content analysis. The bacteria in the drainage water were inactivated by the plasma irradiation.

  3. miRNA-based heavy metal homeostasis and plant growth.

    PubMed

    Noman, Ali; Aqeel, Muhammad

    2017-02-22

    Plants have been naturally gifted with mechanisms to adjust under very high or low nutrient concentrations. Heavy metal toxicity is considered as a major growth and yield-limiting factor for plants. This stress includes essential as well as non-essential metals. MicroRNAs (miRNAs) are known for mediating post-transcriptional regulation by cleaving transcripts or translational inhibition. It is commonly agreed that an extensive understanding of plant miRNAs will significantly help in the induction of tolerance against environmental stresses. With the introduction of the latest technology like next generation sequencing (NGS), a growing figure of miRNAs has been productively recognized in several plants for their diverse roles. These miRNAs are well-known modulators of plant responses to heavy metal (HM) stress. Data regarding metal-responsive miRNAs point out the vital role of plant miRNAs in supplementing metal detoxification by means of transcription factors (TF) or gene regulation. Acting as systemic signals, miRNAs also synchronize different physiological processes for plant responses to metal toxicities. In contrast to practicing techniques, using miRNA is a greatly helpful, pragmatic, and feasible approach. The earlier findings point towards miRNAs as a prospective target to engineer heavy metal tolerance in plants. Therefore, there is a need to augment our knowledge about the orchestrated functions of miRNAs during HM stress. We reviewed the deterministic significance of plant miRNAs in heavy metal tolerance and their role in mediating plant responses to HM toxicities. This review also summarized the topical developments by identification and validation of different metal stress-responsive miRNAs.

  4. Use of reflectance spectroscopy for early detection of calcium deficiency in plants

    NASA Astrophysics Data System (ADS)

    Li, Bingqing; Wah, Liew Oi; Asundi, Anand K.

    2005-04-01

    This article investigates calcium deficiency symptoms of the plants grown under hydroponics conditions. Leaf reflectance data were collected from plants, and then transformed to L*, a*, b* values, which provide color information of the leaves. After comparing the color information of deficient plants to control plants, a set of deficiency criterion was established for early detection of calcium deficiency in the plants. Calcium deficiency could be detected as early as two days from the onset of stress in mature plants when optical data were collected from terminal young leaves. Young plants subjected to calcium stress for 9 days could not be distinguished from nutrient sufficient plants.

  5. Quantitative trait loci for early plant vigour of maize grown in chilly environments.

    PubMed

    Presterl, Thomas; Ouzunova, Milena; Schmidt, Walter; Möller, Evelyn M; Röber, Frank K; Knaak, Carsten; Ernst, Karin; Westhoff, Peter; Geiger, Hartwig H

    2007-04-01

    Maize (Zea mays L.) is particularly sensitive to chilling in the early growth stages. The objective of this study was to determine quantitative trait loci (QTL) for early plant vigour of maize grown under cool and moderately warm conditions in Central Europe. A population of 720 doubled haploid (DH) lines was derived from a cross between two dent inbred lines contrasting in early vigour and were genotyped with 188 SSR markers. The DH lines per se and their testcrosses with a flint line were evaluated in field experiments across 11 environments in 2001 and 2002. Plants were harvested after six to eight leaves had been fully developed to assess fresh matter yield as a criterion of early vigour. Seven QTL were detected for line performance and ten QTL for testcross performance, explaining 64 and 49% of the genetic variance. Six out of seven QTL detected in the lines per se were also significant in their testcrosses. Significant QTL x environment interaction was observed, but no relationship existed between the size of the QTL effects and the mean temperature in the individual environment. The correlation between fresh matter yield and days to silking was non-significant, indicating that differences in early plant vigour were not simply caused by maturity differences. For three additional chilling-related traits, leaf chlorosis, leaf purpling, and frost damage seven, six, and five QTL were detected, respectively. Three QTL for leaf chlorosis, two for leaf purpling, and two for frost damage co-localized with QTL for fresh matter yield. Results are considered as a reliable basis for further genetic, molecular, and physiological investigations.

  6. Dynamic trajectories of growth and nitrogen capture by competing plants.

    PubMed

    Trinder, Clare; Brooker, Rob; Davidson, Hazel; Robinson, David

    2012-03-01

    Although dynamic, plant competition is usually estimated as biomass differences at a single, arbitrary time; resource capture is rarely measured. This restricted approach perpetuates uncertainty. To address this problem, we characterized the competitive dynamics of Dactylis glomerata and Plantago lanceolata as continuous trajectories of biomass production and nitrogen (N) capture. Plants were grown together or in isolation. Biomass and N content were measured at 17 harvests up to 76 d after sowing. Data were fitted to logistic models to derive instantaneous growth and N capture rates. Plantago lanceolata was initially more competitive in terms of cumulative growth and N capture, but D. glomerata was eventually superior. Neighbours reduced maximum biomass, but influenced both maximum N capture and its rate constant. Timings of maximal instantaneous growth and N capture rates were similar between species when they were isolated, but separated by 16 d when they were competing, corresponding to a temporal convergence in maximum growth and N capture rates in each species. Plants processed N and produced biomass differently when they competed. Biomass and N capture trajectories demonstrated that competitive outcomes depend crucially on when and how 'competition' is measured. This potentially compromises the interpretation of conventional competition experiments.

  7. Plant Growth/Plant Phototropism - Skylab Student Experiment ED-61/62

    NASA Technical Reports Server (NTRS)

    1973-01-01

    This chart describes the Skylab student experiment ED-61, Plant Growth, and experiment ED-62, Plant Phototropism. Two similar proposals were submitted by Joel G. Wordekemper of West Point, Nebraska, and Donald W. Schlack of Downey, California. Wordekemper's experiment (ED-61) was to see how the lack of gravity would affect the growth of roots and stems of plants. Schlack's experiment (ED-62) was to study the effect of light on a seed developing in zero gravity. The growth container of the rice seeds for their experiment consisted of eight compartments arranged in two parallel rows of four. Each had two windowed surfaces to allow periodic photography of the developing seedlings. In March 1972, NASA and the National Science Teachers Association selected 25 experiment proposals for flight on Skylab. Science advisors from the Marshall Space Flight Center aided and assisted the students in developing the proposals for flight on Skylab.

  8. Simulation model for plant growth in controlled environment systems

    NASA Technical Reports Server (NTRS)

    Raper, C. D., Jr.; Wann, M.

    1986-01-01

    The role of the mathematical model is to relate the individual processes to environmental conditions and the behavior of the whole plant. Using the controlled-environment facilities of the phytotron at North Carolina State University for experimentation at the whole-plant level and methods for handling complex models, researchers developed a plant growth model to describe the relationships between hierarchial levels of the crop production system. The fundamental processes that are considered are: (1) interception of photosynthetically active radiation by leaves, (2) absorption of photosynthetically active radiation, (3) photosynthetic transformation of absorbed radiation into chemical energy of carbon bonding in solube carbohydrates in the leaves, (4) translocation between carbohydrate pools in leaves, stems, and roots, (5) flow of energy from carbohydrate pools for respiration, (6) flow from carbohydrate pools for growth, and (7) aging of tissues. These processes are described at the level of organ structure and of elementary function processes. The driving variables of incident photosynthetically active radiation and ambient temperature as inputs pertain to characterization at the whole-plant level. The output of the model is accumulated dry matter partitioned among leaves, stems, and roots; thus, the elementary processes clearly operate under the constraints of the plant structure which is itself the output of the model.

  9. Response of tomato (Lycopersicon esculentum Mill.) to salinity in the early growth stages for agricultural cultivation in saline environments.

    PubMed

    Akinci, Sermin; Yilmaz, Kadir; Akinci, Irfan Ersin

    2004-07-01

    Salinity is a serious environmental problem. Growing of plants like tomato can be solution for coping with soil salinity. For this purpose, response of tomato to salinity has been tested in the early growth stages. Characteristics of germination (percentage and period; length and fresh-dry weight of radicle and hypcotyl) and seedling (length and fresh-dry weight of root, shoot and whole plant; leaf number and area based on Relative Growth Rate); Na+ and K+ content of leaf; K+/Na+ rate of leaf has been studied at the 0, 50, 100 and 150 mM NaCl levels. Thus, it determined that tomato can be indicator for agricultural cultivation at the salinity environments at the early growth stages.

  10. The effect of ultradian and orbital cycles on plant growth

    NASA Technical Reports Server (NTRS)

    Berry, W.; Hoshizaki, T.; Ulrich, A.

    1986-01-01

    In a series of experiments using sugar beets, researchers investigated the effects of varying cycles lengths on growth (0.37 hr to 48 hr). Each cycle was equally divided into a light and dark period so that each treatment regardless of cycle length received the same amount of light over the 17 weeks of the experiment. Two growth parameters were used to evaluate the effects of cycle length, total fresh weight and sucrose content of the storage root. Both parameters showed very similar responses in that under long cycles (12 hr or greater) growth was normal, whereas plants growing under shorter cycle periods were progressively inhibited. Minimum growth occurred at a cycle period of 0.75 hr. The yield at the 0.75 hr cycle, where was at a minimum, for total fresh weight was only 51 percent compared to the 24 hr cycle. The yield of sucrose was even more reduced at 41 percent of the 24 hr cycle.

  11. Copper oxychloride fungicide and its effect on growth and oxidative stress of potato plants.

    PubMed

    Ferreira, Leonardo Cesar; Scavroni, Joseane; da Silva, João Renato Vaz; Cataneo, Ana Catarina; Martins, Dagoberto; Boaro, Carmen Sílvia Fernandes

    2014-06-01

    Excess copper in plants causes physiological alterations that lead to crop productivity losses. However, cupric fungicides have been utilized in the control of Alternaria solani and Phytophthora infestans fungi, which cause early blight and late blight in potato, respectively. Thus, this study aimed to investigate the effect of different copper oxychloride levels on potato plants through some biochemical and physiological parameters. The fungicide was applied at the recommended level (2.50gL(-1)), at a reduced level (1.25gL(-1)), and at 5.00gL(-1), to simulate spraying in the field twice during the same period with the recommended level. The results revealed that superoxide dismutase (SOD, EC 1.15.1.1) protected plants against oxidative stress at the beginning of the cycle since lipoperoxide levels were low in that period. In addition, increased SOD activity positively correlated with increased usable leaf area for photosynthesis (leaf area ratio, LAR), photosynthetic effectiveness (net assimilation rate, NAR), and growth relative to pre-existing dry matter (relative growth rate, RGR). Concomitantly, there was a negative correlation between lipoperoxide levels and LAR and RGR. Plants randomly sprayed twice in the same period with the level recommended for potato crop protection in the field do not present damage regarding their development. However, additional studies are needed in order to reduce the use of copper fungicides in the control of early and late blight in potato crop production, then decreasing the release of copper in the environment.

  12. A Novel Pyrimidin-Like Plant Activator Stimulates Plant Disease Resistance and Promotes Growth

    PubMed Central

    Sun, Tie-Jun; Lu, Yun; Narusaka, Mari; Shi, Chao; Yang, Yu-Bing; Wu, Jian-Xin; Zeng, Hong-Yun; Narusaka, Yoshihiro; Yao, Nan

    2015-01-01

    Plant activators are chemicals that induce plant defense responses to a broad spectrum of pathogens. Here, we identified a new potential plant activator, 5-(cyclopropylmethyl)-6-methyl-2-(2-pyridyl)pyrimidin-4-ol, named PPA (pyrimidin-type plant activator). Compared with benzothiadiazole S-methyl ester (BTH), a functional analog of salicylic acid (SA), PPA was fully soluble in water and increased fresh weight of rice (Oryza sativa) and Arabidopsis plants at low concentrations. In addition, PPA also promoted lateral root development. Microarray data and real-time PCR revealed that PPA-treated leaves not challenged with pathogen showed up-regulation of genes related to reactive oxygen species (ROS), defenses and SA. During bacterial infection, Arabidopsis plants pretreated with PPA showed dramatically decreased disease symptoms and an earlier and stronger ROS burst, compared with plants pretreated with BTH. Microscopy revealed that H2O2 accumulated in the cytosol, plasma membrane and cell wall around intracellular bacteria, and also on the bacterial cell wall, indicating that H2O2 was directly involved in killing bacteria. The increase in ROS-related gene expression also supported this observation. Our results indicate that PPA enhances plant defenses against pathogen invasion through the plant redox system, and as a water-soluble compound that can promote plant growth, has broad potential applications in agriculture. PMID:25849038

  13. Automated Diagnosis Of Conditions In A Plant-Growth Chamber

    NASA Technical Reports Server (NTRS)

    Clinger, Barry R.; Damiano, Alfred L.

    1995-01-01

    Biomass Production Chamber Operations Assistant software and hardware constitute expert system that diagnoses mechanical failures in controlled-environment hydroponic plant-growth chamber and recommends corrective actions to be taken by technicians. Subjects of continuing research directed toward development of highly automated closed life-support systems aboard spacecraft to process animal (including human) and plant wastes into food and oxygen. Uses Microsoft Windows interface to give technicians intuitive, efficient access to critical data. In diagnostic mode, system prompts technician for information. When expert system has enough information, it generates recovery plan.

  14. Coumarin-related compounds as plant growth inhibitors from two rutaceous plants in Thailand.

    PubMed

    Jiwajinda, S; Santisopasri, V; Ohigashi, H

    2000-02-01

    Chemical investigation of naturally occurring plant growth inhibitors from Rutaceous plants in Thailand led us to identify five 7-methoxycoumarins and one 5,7-dimethoxycoumarin from Murraya paniculata, and six furanocoumarins from Citrus aurantifolia. Of these compounds, murranganon senecioate (1) is a new natural compound found in M. paniculata. Minumicrolin (6) was found to be highly active against the 2nd leaf sheath elongation of rice seedlings.

  15. Poor early growth and high salt intake in Indian infants.

    PubMed

    Genovesi, Simonetta; Antolini, Laura; Orlando, Antonina; Brahmochary, Sujit; De Servi, Alessandra; Capelli, Silvia; Giussani, Marco; Nava, Elisa; Agostoni, Carlo; Gallieni, Maurizio

    2016-11-06

    The influence of feeding patterns on the growth of infants and how salt is included in the diet are unknown in the area of West Bengal, India. A cross-sectional study was carried on 517 infants (median age 6.5 months). Negative Z-scores were observed for all anthropometric parameters. About 72.7% of infants aged 0-6 months received exclusive breastfeeding. In the 6-12-month-old group (n = 235), 91.5% had salt added to foods. In a regression model adjusted for age, a low salt diet resulted a significant factor in increasing weight-for-length and BMI for age z-scores, with increments equal to 0.637 SD (p = 0.037) and 0.650 SD (p = 0.036), respectively. In West Bengal infants showing poor growth, breastfeeding was associated with better anthropometric indexes, but early in life salt is added to their diet. Early life low weight coupled with high salt intake may be a risk factor for arterial hypertension in Indian children.

  16. Inhibitory effects of essential oils of medicinal plants from growth of plant pathogenic fungi.

    PubMed

    Panjehkeh, N; Jahani Hossein-Abadi, Z

    2011-01-01

    Plant cells produce a vast amount of secondary metabolites. Production of some compounds is restricted to a single species. Some compounds are nearly always found only in certain specific plant organs and during a specific developmental period of the plant. Some secondary metabolites of plants serve as defensive compounds against invading microorganisms. Nowadays, it is attempted to substitute the biological and natural agents with chemically synthesized fungicides. In the present research, the antifungal activities of essential oils of seven medicinal plants on mycelial growth of three soilborne plant pathogenic fungi were investigated. The plants consisted of Zataria multiflora, Thymus carmanicus, Mentha pieperata, Satureja hortensis, Lavandual officinolis, Cuminum cyminum and Azadirachta indica. The first five plants are from the family Labiatae. Examined fungi, Fusarium oxysporum f.sp. lycopersici, Fusarium solani and Rhizoctonia solani are the causal agents of tomato root rot. Essential oils of Z. multiflora, T. carmanicus, M. pieperata, S. hortensis and C. cyminum were extracted by hydro-distillation method. Essential oils of L. officinalis and A. indica were extracted by vapor-distillation method. A completely randomized design with five replicates was used to examine the inhibitory impact of each concentration (300, 600 and 900 ppm) of each essential oil. Poisoned food assay using potato dextrose agar (PDA) medium was employed. Results showed that essential oils of A. indica, Z. multiflora, T. carmanicus and S. hortensis in 900 ppm at 12 days post-inoculation, when the control fungi completely covered the plates, prevented about 90% from mycelial growth of each of the fungi. While, the essential oils of M. pieperata, C. cyminum and L. officinalis in the same concentration and time prevented 54.86, 52.77 and 48.84%, respectively, from F. solani growth. These substances did not prevent from F. oxysporum f.sp. lycopersici and R. solani growth. Minimum

  17. Reduced Wind Speed Improves Plant Growth in a Desert City

    PubMed Central

    Bang, Christofer; Sabo, John L.; Faeth, Stanley H.

    2010-01-01

    Background The often dramatic effects of urbanization on community and ecosystem properties, such as primary productivity, abundances, and diversity are now well-established. In most cities local primary productivity increases and this extra energy flows upwards to alter diversity and relative abundances in higher trophic levels. The abiotic mechanisms thought to be responsible for increases in urban productivity are altered temperatures and light regimes, and increased nutrient and water inputs. However, another abiotic factor, wind speed, is also influenced by urbanization and well known for altering primary productivity in agricultural systems. Wind effects on primary productivity have heretofore not been studied in the context of urbanization. Methodology/Principal Findings We designed a field experiment to test if increased plant growth often observed in cities is explained by the sheltering effects of built structures. Wind speed was reduced by protecting Encelia farinosa (brittlebush) plants in urban, desert remnant and outlying desert localities via windbreaks while controlling for water availability and nutrient content. In all three habitats, we compared E. farinosa growth when protected by experimental windbreaks and in the open. E. farinosa plants protected against ambient wind in the desert and remnant areas grew faster in terms of biomass and height than exposed plants. As predicted, sheltered plants did not differ from unprotected plants in urban areas where wind speed is already reduced. Conclusion/Significance Our results indicate that reductions in wind speed due to built structures in cities contribute to increased plant productivity and thus also to changes in abundances and diversity of higher trophic levels. Our study emphasizes the need to incorporate wind speed in future urban ecological studies, as well as in planning for green space and sustainable cities. PMID:20548790

  18. Plant Growth Biophysics: the Basis for Growth Asymmetry Induced by Gravity

    NASA Technical Reports Server (NTRS)

    Cosgrove, D.

    1985-01-01

    The identification and quantification of the physical properties altered by gravity when plant stems grow upward was studied. Growth of the stem in vertical and horizontal positions was recorded by time lapse photography. A computer program that uses a cubic spline fitting algorithm was used to calculate the growth rate and curvature of the stem as a function of time. Plant stems were tested to ascertain whether cell osmotic pressure was altered by gravity. A technique for measuring the yielding properties of the cell wall was developed.

  19. Signalling of abscisic acid to regulate plant growth.

    PubMed Central

    Himmelbach, A; Iten, M; Grill, E

    1998-01-01

    Abscisic acid (ABA) mediated growth control is a fundamental response of plants to adverse environmental cues. The linkage between ABA perception and growth control is currently being unravelled by using different experimental approaches such as mutant analysis and microinjection experiments. So far, two protein phosphatases, ABI1 and ABI2, cADPR, pH, and Ca2+ have been identified as main components of the ABA signalling pathway. Here, the ABA signal transduction pathway is compared to signalling cascades from yeast and mammalian cells. A model for a bifurcated ABA signal transduction pathway exerting a positive and negative control mechanism is proposed. PMID:9800207

  20. Telomere dynamics in wild brown trout: effects of compensatory growth and early growth investment.

    PubMed

    Näslund, Joacim; Pauliny, Angela; Blomqvist, Donald; Johnsson, Jörgen I

    2015-04-01

    After a period of food deprivation, animals often respond with a period of faster than normal growth. Such responses have been suggested to result in decreased chromosomal maintenance, which in turn may affect the future fitness of an individual. Here, we present a field experiment in which a food deprivation period of 24 days was enforced on fish from a natural population of juvenile brown trout (Salmo trutta) at the start of the high-growth season in spring. The growth of the food-deprived fish and a non-deprived control group was then monitored in the wild during 1 year. Fin tissue samples were taken at the start of the experiment and 1 year after food deprivation to monitor the telomere dynamics, using reduced telomere length as an indicator of maintenance cost. The food-deprived fish showed partial compensatory growth in both mass and length relative to the control group. However, we found no treatment effects on telomere dynamics, suggesting that growth-compensating brown trout juveniles are able to maintain their telomeres during their second year in the stream. However, body size at the start of the experiment, reflecting growth rate during their first year of life, was negatively correlated with change in telomere length over the following year. This result raises the possibility that rapid growth early in life induces delayed costs in cellular maintenance.

  1. Restoring directional growth sense to plants in space

    NASA Astrophysics Data System (ADS)

    Gorgolewski, S.

    Introduction of new plant classification: electrotropic (Et) and non-electrotropic (nEt) plants gives us a criterion which plants need electric field to grow "normally" in space. The electric field: E is measured in V/m (volt per meter). Do not confuse "electrotropism" understood by some as the response to current flow transversely through the plant's root. This effect was previously described in biological textbooks. I suggest to call it as (Ct) (here C stands for current and t for tropism). In the laboratory we have in the plant growth chamber two transparent to light (wire mesh) conducting sheets separated by m(meters) and V volts potential difference. It has been shown in laboratory that Et is a very important factor in electrotropic plant development. Space experiments with plants grown in orbit from seed to seed have been fully successful only (in my very best knowledge) with nEt plants. The most common nEt plants are grasses (more than 50% of all plants). The nEt plants in space use phototropism as their sensor of direction. In space (and most greenhouses) we have to provide the electric field at least for the Et plants. It has been shown that the electric field is also beneficial to nEt plants which also acquire the sense of direction imposed by stronger than the normal 130V/m E field (vector). The stronger horizontal E field of 1.6kV/m (slightly more than 12 times stronger than 130V/m) does not influence the rate of growth of maize (which is nEt) in 130V/m vertical field or even in the Faraday cage 0V/m. Yet when the maize gets its leaves, they all lean in the horizontal field (1.6kV/m) towards the anode. The direction of the E vector is defined by the E field lines running from the positive to the negative charges. Because the electric forces are a factor of 1038 times stronger than the gravitational forces, it is not important for the E field whether it acts on ions in the gravity or in weightlessness. We have to recall that on the Earth and in space Et

  2. Increasing plant growth by modulating omega-amidase expression in plants

    DOEpatents

    Unkefer, Pat J.; Anderson, Penelope S.; Knight, Thomas J.

    2015-06-30

    The present disclosure relates to compositions and methods for increasing the leaf-to-root ratio of the signal metabolite 2-oxoglutaramate and related proline molecules in plants by modulating levels of .omega.-amidase to increase nitrogen use efficiency, resulting in enhanced growth, faster growth rates, greater seed and fruit/pod yields, earlier and more productive flowering, increased tolerance to high salt conditions, and increased biomass yields.

  3. Plant growth promotion traits of phosphobacteria isolated from Puna, Argentina.

    PubMed

    Viruel, Emilce; Lucca, María E; Siñeriz, Faustino

    2011-07-01

    The ability of soil microorganisms to solubilize phosphate is an important trait of plant growth-promoting bacteria leading to increased yields and smaller use of fertilizers. This study presents the isolation and characterization of phosphobacteria from Puna, northwestern Argentina and the ability to produce phosphate solubilization, alkaline phosphatase, siderophores, and indole acetic acid. The P-solubilizing activity was coincidental with a decrease in pH values of the tricalcium phosphate medium for all strains after 72 h of incubation. All the isolates showed the capacity to produce siderophores and indoles. Identification by 16S rDNA sequencing and phylogenetic analysis revealed that these strains belong to the genera Pantoea, Serratia, Enterobacter, and Pseudomonas. These isolates appear attractive for exploring their plant growth-promoting activity and potential field application.

  4. Plant development in space: Observations on root formation and growth

    NASA Technical Reports Server (NTRS)

    Levine, H. G.; Kann, R. P.; Krikorian, Abraham D.

    1990-01-01

    Root growth in space is discussed and observations on root production from plants flown as part of the Chromex project that were defined as to their origin, stage of development and physiological status, are presented. Roots were generated from fully differentiated, aseptically maintained individuals of Haplopappus gracilis (Compositae) under spaceflight conditions. Results are compared for tissue culture generated plantlets and comparably sized seedling clone individuals, both of which had their roots trimmed on Earth before they were loaded into NASA's plant growth unit and subjected to a 5 day shuttle flight (STS-29). Asepsis was maintained throughout the experiment. Overall root production was 40 to 50 percent greater under spaceflight conditions than during ground control tests. However, root formation slowed down towards the end of the flight. This decrease in new roots did not occur in the ground controls that sought to simulate flight except for microgravity.

  5. Impact of accelerated plant growth on seed variety development

    NASA Astrophysics Data System (ADS)

    Christophersen, Eric

    1998-01-01

    The commercial lives of agricultural seed products have steadily declined in recent years. The introduction of genetically engineered crop seeds in 1966 has accentuated that trend. Widespread grower demand for genetically engineered seed requires competitive response by industry followers in order to avert market share losses to the industry leaders. Limitations on plant transformation technology, regulatory requirements and patent impediments require companies to rapidly convert transformed lines into elite commercial products. Massive multigenerational backcrossing efforts are required to distribute genetically engineered traits into a broad product mix. Significant incidents of expression failures, or ``gene silencing,'' have occurred unexpectedly, requiring product substitution strategies. First-to-market strategies, competitive response, broad germplasm conversion and rescue of product failures all share the element of urgency. Technologies which reliably accelerate product development rates can expect favorable reception by commercial seed developers. A growth chamber which dramatically accelerates the rate of plant growth is described.

  6. (Metabolic mechanisms of plant growth at low water potentials)

    SciTech Connect

    Not Available

    1990-01-01

    The work supported by DOE showed that water-limitation inhibits plant growth first by imposing a physical limitation that is followed in a few h by metabolic changes leading to reduced wall extensibility in the enlarging cells. After the wall extensibility decreased, a 28kD protein accumulated particularly in the walls of the growth-affected cells. Antibodies were used to identify cDNA for the protein. The base sequence of the cDNA was typical of an enzyme rather than known structural components of walls. The sequence was identical to one published by another laboratory at the same time and encoding a protein that accumulates in vacuoles of depodded soybean plants.

  7. Assessing early growth and adiposity: report from an EarlyNutrition Academy workshop.

    PubMed

    Ward, Leigh C; Poston, Lucilla; Godfrey, Keith M; Koletzko, Berthold

    2013-01-01

    This report provides a summary of a workshop organised by the European Commission-funded EarlyNutrition Project and the EarlyNutrition Academy. Accurate and reliable methods to assess body composition are needed in research on prenatal and early post-natal influences of nutrition on later health because common surrogate measures of maternal and offspring adiposity (body fat content), such as body mass index (BMI), have relatively poor predictive power for the risk of later disease. The key goals of the workshop were to discuss approaches to assess growth and body composition from pregnancy to adolescence, to summarise conclusions and to prepare a framework for research in the EarlyNutrition Project. The participants concluded that there is a pressing need to harmonise the methodologies for assessing body composition, recognising that each has advantages and limitations. Essential core measurements across studies assessing early growth and body composition were identified, including weight, length, BMI, waist and mid-upper arm circumference, subscapular and triceps skinfold thicknesses, and bioelectrical impedance analysis. In research settings with access to more sophisticated technologies, additional methods could include dual-energy X-ray absorptiometry, peripheral quantitative computed tomography, ultrasound assessment of regional body fat, magnetic resonance imaging (MRI), air displacement plethysmography (ADP), and deuterium dilution. These provide richer data to answer research questions in greater depth but also increase costs. Where overall whole-body composition is the primary outcome measure, ADP or tracer dilution should be used whenever possible. Where regional distribution of body fat is of greater interest, an imaging technique such as MRI is preferred.

  8. A general theory of early growth?. Comment on: "Mathematical models to characterize early epidemic growth: A review" by Gerardo Chowell et al.

    NASA Astrophysics Data System (ADS)

    House, Thomas

    2016-09-01

    Chowell et al. [1] consider the early growth behaviour of various epidemic models that range from phenomenological approaches driven by data to mechanistic descriptions of complex interactions between individuals. This is particularly timely given the recent Ebola epidemic, although non-exponential early growth may be more common (but less immediately evident) than we realise.

  9. Growth and photosynthetic responses of wheat plants grown in space.

    PubMed

    Tripathy, B C; Brown, C S; Levine, H G; Krikorian, A D

    1996-03-01

    Growth and photosynthesis of wheat (Triticum aestivum L. cv Super Dwarf) plants grown onboard the space shuttle Discovery for 10 d were examined. Compared to ground control plants, the shoot fresh weight of space-grown seedlings decreased by 25%. Postflight measurements of the O2 evolution/photosynthetic photon flux density response curves of leaf samples revealed that the CO2-saturated photosynthetic rate at saturating light intensities in space-grown plants declined 25% relative to the rate in ground control plants. The relative quantum yield of CO2-saturated photosynthetic O2 evolution measured at limiting light intensities was not significantly affected. In space-grown plants, the light compensation point of the leaves increased by 33%, which likely was due to an increase (27%) in leaf dark-respiration rates. Related experiments with thylakoids isolated from space-grown plants showed that the light-saturated photosynthetic electron transport rate from H2O through photosystems II and I was reduced by 28%. These results demonstrate that photosynthetic functions are affected by the microgravity environment.

  10. Growth and photosynthetic responses of wheat plants grown in space

    NASA Technical Reports Server (NTRS)

    Tripathy, B. C.; Brown, C. S.; Levine, H. G.; Krikorian, A. D.

    1996-01-01

    Growth and photosynthesis of wheat (Triticum aestivum L. cv Super Dwarf) plants grown onboard the space shuttle Discovery for 10 d were examined. Compared to ground control plants, the shoot fresh weight of space-grown seedlings decreased by 25%. Postflight measurements of the O2 evolution/photosynthetic photon flux density response curves of leaf samples revealed that the CO2-saturated photosynthetic rate at saturating light intensities in space-grown plants declined 25% relative to the rate in ground control plants. The relative quantum yield of CO2-saturated photosynthetic O2 evolution measured at limiting light intensities was not significantly affected. In space-grown plants, the light compensation point of the leaves increased by 33%, which likely was due to an increase (27%) in leaf dark-respiration rates. Related experiments with thylakoids isolated from space-grown plants showed that the light-saturated photosynthetic electron transport rate from H2O through photosystems II and I was reduced by 28%. These results demonstrate that photosynthetic functions are affected by the microgravity environment.

  11. Growth and photosynthetic responses of wheat plants grown in space.

    PubMed Central

    Tripathy, B C; Brown, C S; Levine, H G; Krikorian, A D

    1996-01-01

    Growth and photosynthesis of wheat (Triticum aestivum L. cv Super Dwarf) plants grown onboard the space shuttle Discovery for 10 d were examined. Compared to ground control plants, the shoot fresh weight of space-grown seedlings decreased by 25%. Postflight measurements of the O2 evolution/photosynthetic photon flux density response curves of leaf samples revealed that the CO2-saturated photosynthetic rate at saturating light intensities in space-grown plants declined 25% relative to the rate in ground control plants. The relative quantum yield of CO2-saturated photosynthetic O2 evolution measured at limiting light intensities was not significantly affected. In space-grown plants, the light compensation point of the leaves increased by 33%, which likely was due to an increase (27%) in leaf dark-respiration rates. Related experiments with thylakoids isolated from space-grown plants showed that the light-saturated photosynthetic electron transport rate from H2O through photosystems II and I was reduced by 28%. These results demonstrate that photosynthetic functions are affected by the microgravity environment. PMID:8819868

  12. Solidification and convective instability during early sea ice growth

    NASA Astrophysics Data System (ADS)

    Hitchen, Joseph; Wells, Andrew

    2016-04-01

    Growing sea ice rejects large amounts of cold, salty water into the underlying ocean which contributes to the formation of Antarctic Bottom Water, North Atlantic Deep Water, and maintaining the cold halocline in the Arctic ocean. This cold, salty water is formed by the partial solidification of sea water to form porous sea ice, which is an example of a mushy layer. Convection within the porous ice interior drives the drainage of dense brine into the underlying ocean. We consider how realistic surface cooling and variations in physical properties affect the time-dependent development of early sea ice growth, and the impact on solidification and convective instability within the ice. Whilst many previous studies of mushy layers have focussed on growth at a steady rate, we here model geophysically-motivated settings where the growth rate evolves with time. We quantify how the onset of convection in sea ice depends on the initial salinity of the sea water and the rate of heat loss to the overlying atmosphere, and show that slower cooling rates can promote the formation of larger convection cells within the ice.

  13. Effects of Red Light Night Break Treatment on Growth and Flowering of Tomato Plants.

    PubMed

    Cao, Kai; Cui, Lirong; Ye, Lin; Zhou, Xiaoting; Bao, Encai; Zhao, Hailiang; Zou, Zhirong

    2016-01-01

    Compact and healthy young plants increase crop production and improve vegetable quality. Adverse climatic conditions and shading can cause young plants to become elongated and spindly. We investigated the effects of night break (NB) treatments on tomato plants using red light (RL) with an intensity of 20 μmol·m(2)·s(-1). Tomato plants were subjected to NB treatments with different frequencies ranging from every 1, 2, 3, and 4 h, and plant growth, flowering, and yield were monitored. The results showed that with the increase of RL NB frequency, plant height decreased, stem diameter increased, and flower initiation delayed, the content of indole-3-acetic acid (IAA) and gibberellin 3 (GA3) in the leaf and stem declined. When the RL NB frequency was every 1 h, the heights of tomato plant decreased by 32.73% compared with the control, the diameter of tomato plants increased by 27.09% compared with the control, the number of leaves produced before flowering increased to 11, compared with 8 in the control, the contents of IAA and GA3 in the leaf decreased by 33.3 and 41.29% respectively compared with the control, the contents of IAA and GA3 in the stem decreased by 56.04 and 57.14% respectively compared with the control. After RL NB treatments, tomato plants were transplanted into a solar greenhouse to evaluate tomato yield. When tomato plants pre-treated with RL NB, per tomato fresh weight of the first spica increased with the increase of RL NB frequencies. These results indicate that more compact and healthier tomato plants could be gotten by RL NB treatments and improve tomato early yield.

  14. Effects of Red Light Night Break Treatment on Growth and Flowering of Tomato Plants

    PubMed Central

    Cao, Kai; Cui, Lirong; Ye, Lin; Zhou, Xiaoting; Bao, Encai; Zhao, Hailiang; Zou, Zhirong

    2016-01-01

    Compact and healthy young plants increase crop production and improve vegetable quality. Adverse climatic conditions and shading can cause young plants to become elongated and spindly. We investigated the effects of night break (NB) treatments on tomato plants using red light (RL) with an intensity of 20 μmol·m2·s−1. Tomato plants were subjected to NB treatments with different frequencies ranging from every 1, 2, 3, and 4 h, and plant growth, flowering, and yield were monitored. The results showed that with the increase of RL NB frequency, plant height decreased, stem diameter increased, and flower initiation delayed, the content of indole-3-acetic acid (IAA) and gibberellin 3 (GA3) in the leaf and stem declined. When the RL NB frequency was every 1 h, the heights of tomato plant decreased by 32.73% compared with the control, the diameter of tomato plants increased by 27.09% compared with the control, the number of leaves produced before flowering increased to 11, compared with 8 in the control, the contents of IAA and GA3 in the leaf decreased by 33.3 and 41.29% respectively compared with the control, the contents of IAA and GA3 in the stem decreased by 56.04 and 57.14% respectively compared with the control. After RL NB treatments, tomato plants were transplanted into a solar greenhouse to evaluate tomato yield. When tomato plants pre-treated with RL NB, per tomato fresh weight of the first spica increased with the increase of RL NB frequencies. These results indicate that more compact and healthier tomato plants could be gotten by RL NB treatments and improve tomato early yield. PMID:27148344

  15. Aromatic fluorine compounds. VIII. Plant growth regulators and intermediates

    USGS Publications Warehouse

    Finger, G.C.; Gortatowski, M.J.; Shiley, R.H.; White, R.H.

    1959-01-01

    The preparation and properties of 41 fluorophenoxyacetic acids, 4 fluorophenoxypropionic acids, 2 fluorobenzoic acids, several indole derivatives, and a number of miscellaneous compounds are described. Data are given for many intermediates such as new fluorinated phenols, anisoles, anilines and nitrobenzenes. Most of the subject compounds are related to a number of well-known herbicides or plant growth regulators such as 2,4-D, 2,4,5-T and others.

  16. Technology for subsystems of space-based plant growth facilities

    NASA Technical Reports Server (NTRS)

    Bula, R. J.; Morrow, R. C.; Tibbitts, T. W.; Corey, R. B.

    1990-01-01

    Technologies for different subsystems of space-based plant growth facilities are being developed at the Wisconsin Center for Space Automation and Robotics, a NASA Center for the Commercial Development of Space. The technologies include concepts for water and nutrient delivery, for nutrient composition control, and for irradiation. Effort is being concentrated on these subsystems because available technologies cannot be effectively utilized for space applications.

  17. Water stress amelioration and plant growth promotion in wheat plants by osmotic stress tolerant bacteria.

    PubMed

    Chakraborty, U; Chakraborty, B N; Chakraborty, A P; Dey, P L

    2013-05-01

    Soil microorganisms with potential for alleviation of abiotic stresses in combination with plant growth promotion would be extremely useful tools in sustainable agriculture. To this end, the present study was initiated where forty-five salt tolerant bacterial isolates with ability to grow in high salt medium were obtained from the rhizosphere of Triticum aestivum and Imperata cylindrica. These bacteria were tested for plant-growth-promoting rhizobacteria traits in vitro such as phosphate solubilization, siderophore, ACC deaminase and IAA production. Of the forty-five isolates, W10 from wheat rhizosphere and IP8 from blady grass rhizosphere, which tested positive in all the tests were identified by morpholological, biochemical and 16SrDNA sequencing as Bacillus safensis and Ochrobactrum pseudogregnonense respectively and selected for in vivo studies. Both the bacteria could promote growth in six varieties of wheat tested in terms of increase in root and shoot biomass, height of plants, yield, as well as increase in chlorophyll content. Besides, the wheat plants could withstand water stress more efficiently in presence of the bacteria as indicated by delay in appearance of wilting symptoms increases in relative water content of treated water stressed plants in comparison to untreated stressed ones, and elevated antioxidant responses. Enhanced antioxidant responses were evident as elevated activities of enzymes such as catalase, peroxidase, ascorbate peroxidase, superoxide dismutase and glutathione reductase as well as increased accumulation of antioxidants such as carotenoids and ascorbate. Results clearly indicate that the ability of wheat plants to withstand water stress is enhanced by application of these bacteria which also function as plant growth promoting rhizobacteria.

  18. Review and analysis of over 40 years of space plant growth systems

    NASA Astrophysics Data System (ADS)

    Zabel, P.; Bamsey, M.; Schubert, D.; Tajmar, M.

    2016-08-01

    The cultivation of higher plants occupies an essential role within bio-regenerative life support systems. It contributes to all major functional aspects by closing the different loops in a habitat like food production, CO2 reduction, O2 production, waste recycling and water management. Fresh crops are also expected to have a positive impact on crew psychological health. Plant material was first launched into orbit on unmanned vehicles as early as the 1960s. Since then, more than a dozen different plant cultivation experiments have been flown on crewed vehicles beginning with the launch of Oasis 1, in 1971. Continuous subsystem improvements and increasing knowledge of plant response to the spaceflight environment has led to the design of Veggie and the Advanced Plant Habitat, the latest in the series of plant growth systems. The paper reviews the different designs and technological solutions implemented in higher plant flight experiments. Using these analyses a comprehensive comparison is compiled to illustrate the development trends of controlled environment agriculture technologies in bio-regenerative life support systems, enabling future human long-duration missions into the solar system.

  19. A hydroponic method for plant growth in microgravity

    NASA Technical Reports Server (NTRS)

    Wright, B. D.

    1985-01-01

    A hydroponic apparatus under development for long-term microgravity plant growth is described. The capillary effect root environment system (CERES) is designed to keep separate the nutrient and air flows, although both must be simultaneously available to the roots. Water at a pressure slightly under air pressure is allowed to seep into a plastic depression covered by a plastic screen and a porous membrane. A root in the air on the membrane outer surface draws the moisture through it. The laboratory model has a wire-based 1.241 mm mesh polyethylene screen and a filter membrane with 0.45 micron pores, small enough to prohibit root hair penetration. The design eliminates the need to seal-off the plant environment. Problems still needing attention include scaling up of the CERES size, controlling biofouling of the membrane, and extending the applications to plants without fibrous root systems.

  20. Enzyme-Less Growth in Chara and Terrestrial Plants

    PubMed Central

    Boyer, John S.

    2016-01-01

    Enzyme-less chemistry appears to control the growth rate of the green alga Chara corallina. The chemistry occurs in the wall where a calcium pectate cycle determines both the rate of wall enlargement and the rate of pectate deposition into the wall. The process is the first to indicate that a wall polymer can control how a plant cell enlarges after exocytosis releases the polymer to the wall. This raises the question of whether other species use a similar mechanism. Chara is one of the closest relatives of the progenitors of terrestrial plants and during the course of evolution, new wall features evolved while pectate remained one of the most conserved components. In addition, charophytes contain auxin which affects Chara in ways resembling its action in terrestrial plants. Therefore, this review considers whether more recently acquired wall features require different mechanisms to explain cell expansion. PMID:27446106

  1. Host plant secondary metabolite profiling shows a complex, strain-dependent response of maize to plant growth-promoting rhizobacteria of the genus Azospirillum.

    PubMed

    Walker, Vincent; Bertrand, Cédric; Bellvert, Floriant; Moënne-Loccoz, Yvan; Bally, René; Comte, Gilles

    2011-01-01

    Most Azospirillum plant growth-promoting rhizobacteria (PGPR) benefit plant growth through source effects related to free nitrogen fixation and/or phytohormone production, but little is known about their potential effects on plant physiology. These effects were assessed by comparing the early impacts of three Azospirillum inoculant strains on secondary metabolite profiles of two different maize (Zea mays) cultivars. After 10d of growth in nonsterile soil, maize methanolic extracts were analyzed by reverse-phase high-performance liquid chromatography (RP-HPLC) and secondary metabolites identified by liquid chromatography/mass spectrometry (LC/MS) and nuclear magnetic resonance (NMR). Seed inoculation resulted in increased shoot biomass (and also root biomass with one strain) of hybrid PR37Y15 but had no stimulatory effect on hybrid DK315. In parallel, Azospirillum inoculation led to major qualitative and quantitative modifications of the contents of secondary metabolites, especially benzoxazinoids, in the maize plants. These modifications depended on the PGPR strain×plant cultivar combination. Thus, Azospirillum inoculation resulted in early, strain-dependent modifications in the biosynthetic pathways of benzoxazine derivatives in maize in compatible interactions. This is the first study documenting a PGPR effect on plant secondary metabolite profiles, and suggests the establishment of complex interactions between Azospirillum PGPR and maize.

  2. Mitogen-activated protein kinase cascades in signaling plant growth and development.

    PubMed

    Xu, Juan; Zhang, Shuqun

    2015-01-01

    Mitogen-activated protein kinase (MAPK) cascades are ubiquitous signaling modules in eukaryotes. Early research of plant MAPKs has been focused on their functions in immunity and stress responses. Recent studies reveal that they also play essential roles in plant growth and development downstream of receptor-like protein kinases (RLKs). With only a limited number of MAPK components, multiple functional pathways initiated from different receptors often share the same MAPK components or even a complete MAPK cascade. In this review, we discuss how MAPK cascades function as molecular switches in response to spatiotemporal-specific ligand-receptor interactions and the availability of downstream substrates. In addition, we discuss other possible mechanisms governing the functional specificity of plant MAPK cascades, a question central to our understanding of MAPK functions.

  3. Key Gaps for Enabling Plant Growth in Future Missions

    NASA Technical Reports Server (NTRS)

    Anderson, Molly; Motil, Brian; Barta, Dan; Fritsche, Ralph; Massa, Gioia; Quincy, Charlie; Romeyn, Matthew; Wheeler, Ray; Hanford, Anthony

    2017-01-01

    Growing plants to provide food or psychological benefits to crewmembers is a common vision for the future of human spaceflight, often represented in media and in serious concept studies. The complexity of controlled environment agriculture, and plant growth in microgravity have and continue to be the subject of dedicated scientific research. However, actually implementing these systems in a way that will be cost effective, efficient, and sustainable for future space missions is a complex, multi-disciplinary problem. Key questions exist in many areas: human medical research in nutrition and psychology, horticulture, plant physiology and microbiology, multi-phase microgravity fluid physics, hardware design and technology development, and system design, operations and mission planning. This paper describes key knowledge gaps identified by a multi-disciplinary working group within the National Aeronautics and Space Administration (NASA). It also begins to identify solutions to the simpler questions identified by the group based on work initiated in 2017. Growing plants to provide food or psychological benefits to crewmembers is a common vision for the future of human spaceflight, often represented in media and in serious concept studies. The complexity of controlled environment agriculture, and plant growth in microgravity have and continue to be the subject of dedicated scientific research. However, actually implementing these systems in a way that will be cost effective, efficient, and sustainable for future space missions is a complex, multi-disciplinary problem. Key questions exist in many areas: human medical research in nutrition and psychology, horticulture, plant physiology and microbiology, multi-phase microgravity fluid physics, hardware design and technology development, and system design, operations and mission planning. This paper describes key knowledge gaps identified by a multi-disciplinary working group within the National Aeronautics and Space

  4. Early rhizosphere microbiome composition is related to the growth and Zn uptake of willows introduced to a former landfill.

    PubMed

    Bell, Terrence H; Cloutier-Hurteau, Benoît; Al-Otaibi, Fahad; Turmel, Marie-Claude; Yergeau, Etienne; Courchesne, François; St-Arnaud, Marc

    2015-08-01

    Although plants introduced for site restoration are pre-selected for specific traits (e.g. trace element bioaccumulation, rapid growth in poor soils), the in situ success of these plants likely depends on the recruitment of appropriate rhizosphere microorganisms from their new environment. We introduced three willow (Salix spp.) cultivars to a contaminated landfill, and performed soil chemical analyses, plant measurements, and Ion Torrent sequencing of rhizospheric fungal and bacterial communities at 4 and 16 months post-planting. The abundance of certain dominant fungi was linked to willow accumulation of Zn, the most abundant trace element at the site. Interestingly, total Zn accumulation was better explained by fungal community structure 4 months post-planting than 16 months post-planting, suggesting that initial microbial recruitment may be critical. In addition, when the putative ectomycorrhizal fungi Sphaerosporella brunnea and Inocybe sp. dominated the rhizosphere 4 months post-planting, Zn accumulation efficiency was negatively correlated with fungal diversity. Although field studies such as this rely on correlation, these results suggest that the soil microbiome may have the greatest impact on plant function during the early stages of growth, and that plant-fungus specificity may be essential.

  5. [Effects of water level on the rhizomatic germination and growth of typical wetland plants in Sanjiang Plain].

    PubMed

    Wang, Li; Hu, Jin-ming; Song, Chang-chun; Yang, Tao

    2007-11-01

    With simulation test, this paper studied the effects of water level on the rhizomati germination and growth of Calamagrostis angustifolia and Carex lasiocarpa, the two typical wetland plants in Sanjiang Plain. The results showed that these two plants had different responses to water level. The population density, mean height, and maximum height of C. angustifolia reached the peak at 0 cm water level; while the mean and maximum height of C. lasiocarpa increased, but its population density decreased with increasing water level. At the early stage of germination, definite duration without inundation promoted the rhizomatic germination of these two plants, while continuous inundation constrained it. During growth period, excess inundation limited the growth of C. angustifolia, but C. lasiocarpa grew better under deeper water. Drought constrained the growth of C. angustifolia and C. lasiocarpa, and possibly, changed their life history.

  6. Evaluating and optimizing horticultural regimes in space plant growth facilities

    NASA Technical Reports Server (NTRS)

    Berkovich, Y. A.; Chetirkin, P. V.; Wheeler, R. M.; Sager, J. C.

    2004-01-01

    In designing innovative space plant growth facilities (SPGF) for long duration space flight, various limitations must be addressed including onboard resources: volume, energy consumption, heat transfer and crew labor expenditure. The required accuracy in evaluating on board resources by using the equivalent mass methodology and applying it to the design of such facilities is not precise. This is due to the uncertainty of the structure and not completely understanding the properties of all associated hardware, including the technology in these systems. We present a simple criteria of optimization for horticultural regimes in SPGF: Qmax = max [M x (EBI)2/(V x E x T], where M is the crop harvest in terms of total dry biomass in the plant growth system; EBI is the edible biomass index (harvest index), V is volume occupied by the crop; E is the crop light energy supply during growth; T is the crop growth duration. The criterion reflects directly on the consumption of onboard resources for crop production. c2004 COSPAR. Published by Elsevier Ltd. All rights reserved.

  7. Evolution of plant growth and defense in a continental introduction.

    PubMed

    Agrawal, Anurag A; Hastings, Amy P; Bradburd, Gideon S; Woods, Ellen C; Züst, Tobias; Harvey, Jeffrey A; Bukovinszky, Tibor

    2015-07-01

    Substantial research has addressed adaptation of nonnative biota to novel environments, yet surprisingly little work has integrated population genetic structure and the mechanisms underlying phenotypic differentiation in ecologically important traits. We report on studies of the common milkweed Asclepias syriaca, which was introduced from North America to Europe over the past 400 years and which lacks most of its specialized herbivores in the introduced range. Using 10 populations from each continent grown in a common environment, we identified several growth and defense traits that have diverged, despite low neutral genetic differentiation between continents. We next developed a Bayesian modeling approach to account for relationships between molecular and phenotypic differences, confirming that continental trait differentiation was greater than expected from neutral genetic differentiation. We found evidence that growth-related traits adaptively diverged within and between continents. Inducible defenses triggered by monarch butterfly herbivory were substantially reduced in European populations, and this reduction in inducibility was concordant with altered phytohormonal dynamics, reduced plant growth, and a trade-off with constitutive investment. Freedom from the community of native and specialized herbivores may have favored constitutive over induced defense. Our replicated analysis of plant growth and defense, including phenotypically plastic traits, suggests adaptive evolution following a continental introduction.

  8. Ligand Receptor-Mediated Regulation of Growth in Plants.

    PubMed

    Haruta, Miyoshi; Sussman, Michael R

    2017-01-01

    Growth and development of multicellular organisms are coordinately regulated by various signaling pathways involving the communication of inter- and intracellular components. To form the appropriate body patterns, cellular growth and development are modulated by either stimulating or inhibiting these pathways. Hormones and second messengers help to mediate the initiation and/or interaction of the various signaling pathways in all complex multicellular eukaryotes. In plants, hormones include small organic molecules, as well as larger peptides and small proteins, which, as in animals, act as ligands and interact with receptor proteins to trigger rapid biochemical changes and induce the intracellular transcriptional and long-term physiological responses. During the past two decades, the availability of genetic and genomic resources in the model plant species, Arabidopsis thaliana, has greatly helped in the discovery of plant hormone receptors and the components of signal transduction pathways and mechanisms used by these immobile but highly complex organisms. Recently, it has been shown that two of the most important plant hormones, auxin and abscisic acid (ABA), act through signaling pathways that have not yet been recognized in animals. For example, auxins stimulate cell elongation by bringing negatively acting transcriptional repressor proteins to the proteasome to be degraded, thus unleashing the gene expression program required for increasing cell size. The "dormancy" inducing hormone, ABA, binds to soluble receptor proteins and inhibits a specific class of protein phosphatases (PP2C), which activates phosphorylation signaling leading to transcriptional changes needed for the desiccation of the seeds prior to entering dormancy. While these two hormone receptors have no known animal counterparts, there are also many similarities between animal and plant signaling pathways. For example, in plants, the largest single gene family in the genome is the protein kinase

  9. The TIP GROWTH DEFECTIVE1 S-acyl transferase regulates plant cell growth in Arabidopsis.

    PubMed

    Hemsley, Piers A; Kemp, Alison C; Grierson, Claire S

    2005-09-01

    TIP GROWTH DEFECTIVE1 (TIP1) of Arabidopsis thaliana affects cell growth throughout the plant and has a particularly strong effect on root hair growth. We have identified TIP1 by map-based cloning and complementation of the mutant phenotype. TIP1 encodes an ankyrin repeat protein with a DHHC Cys-rich domain that is expressed in roots, leaves, inflorescence stems, and floral tissue. Two homologues of TIP1 in yeast (Saccharomyces cerevisiae) and human (Homo sapiens) have been shown to have S-acyl transferase (also known as palmitoyl transferase) activity. S-acylation is a reversible hydrophobic protein modification that offers swift, flexible control of protein hydrophobicity and affects protein association with membranes, signal transduction, and vesicle trafficking within cells. We show that TIP1 binds the acyl group palmitate, that it can rescue the morphological, temperature sensitivity, and yeast casein kinase2 localization defects of the yeast S-acyl transferase mutant akr1Delta, and that inhibition of acylation in wild-type Arabidopsis roots reproduces the Tip1- mutant phenotype. Our results demonstrate that S-acylation is essential for normal plant cell growth and identify a plant S-acyl transferase, an essential research tool if we are to understand how this important, reversible lipid modification operates in plant cells.

  10. Simulating unstressed crop development and growth using the Unified Plant Growth Model (UPGM)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since development of the EPIC model in 1989, many versions of the plant growth component have been incorporated into other erosion and crop management models and subsequently modified to meet model objectives (e.g., WEPS, WEPP, SWAT, ALMANAC, GPFARM). This has resulted in different versions of the ...

  11. Plant hydraulic traits govern forest water use and growth

    NASA Astrophysics Data System (ADS)

    Matheny, Ashley; Bohrer, Gil; Fiorella, Rich; Mirfenderesgi, Golnazalsadat

    2016-04-01

    Biophysical controls at the leaf, stem, and root levels govern plant water acquisition and use. Suites of sometimes co-varying traits afford plants the ability to manage water stress at each of these three levels. We studied the contrasting hydraulic strategies of red oaks (Q. rubra) and red maples (A. rubrum) in northern Michigan, USA. These two species differ in stomatal regulation strategy and xylem architecture, and are thought to root at different depths. Water use was monitored through sap flux, stem water storage, and leaf water potential measurements. Depth of water acquisition was determined on the basis of stable oxygen and hydrogen isotopes from xylem water samples taken from both species. Fifteen years of bole growth records were used to compare the influence of the trees' opposing hydraulic strategies on carbon acquisition and growth. During non-limiting soil moisture conditions, transpiration from red maples typically exceeded that of red oak. However, during a 20% soil dry down, transpiration from red maples decreased by more than 80%, while transpiration from red oaks only fell by 31%. Stem water storage in red maple also declined sharply, while storage in red oaks remained nearly constant. The more consistent isotopic compositions of xylem water samples indicated that oaks can draw upon a steady, deep supply of water which red maples cannot access. Additionally, red maple bole growth correlated strongly with mean annual soil moisture, while red oak bole growth did not. These results indicate that the deeper rooting strategy of red oaks allowed the species to continue transpiration and carbon uptake during periods of intense soil water limitation, when the shallow-rooted red maples ceased transpiration. The ability to root deeply could provide an additional buffer against drought-induced mortality, which may permit some anisohydric species, like red oak, to survive hydrologic conditions that would be expected to favor survival of more isohydric

  12. 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

  13. 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.

  14. Minimising toxicity of cadmium in plants--role of plant growth regulators.

    PubMed

    Asgher, Mohd; Khan, M Iqbal R; Anjum, Naser A; Khan, Nafees A

    2015-03-01

    A range of man-made activities promote the enrichment of world-wide agricultural soils with a myriad of chemical pollutants including cadmium (Cd). Owing to its significant toxic consequences in plants, Cd has been one of extensively studied metals. However, sustainable strategies for minimising Cd impacts in plants have been little explored. Plant growth regulators (PGRs) are known for their role in the regulation of numerous developmental processes. Among major PGRs, plant hormones (such as auxins, gibberellins, cytokinins, abscisic acid, jasmonic acid, ethylene and salicylic acid), nitric oxide (a gaseous signalling molecule), brassinosteroids (steroidal phytohormones) and polyamines (group of phytohormone-like aliphatic amine natural compounds with aliphatic nitrogen structure) have gained attention by agronomist and physiologist as a sustainable media to induce tolerance in abiotic-stressed plants. Considering recent literature, this paper: (a) overviews Cd status in soil and its toxicity in plants, (b) introduces major PGRs and overviews their signalling in Cd-exposed plants, (c) appraises mechanisms potentially involved in PGR-mediated enhanced plant tolerance to Cd and (d) highlights key aspects so far unexplored in the subject area.

  15. Plant growth modeling at the JSC variable pressure growth chamber - An application of experimental design

    NASA Technical Reports Server (NTRS)

    Miller, Adam M.; Edeen, Marybeth; Sirko, Robert J.

    1992-01-01

    This paper describes the approach and results of an effort to characterize plant growth under various environmental conditions at the Johnson Space Center variable pressure growth chamber. Using a field of applied mathematics and statistics known as design of experiments (DOE), we developed a test plan for varying environmental parameters during a lettuce growth experiment. The test plan was developed using a Box-Behnken approach to DOE. As a result of the experimental runs, we have developed empirical models of both the transpiration process and carbon dioxide assimilation for Waldman's Green lettuce over specified ranges of environmental parameters including carbon dioxide concentration, light intensity, dew-point temperature, and air velocity. This model also predicts transpiration and carbon dioxide assimilation for different ages of the plant canopy.

  16. Embryological Features of Tofieldia glutinosa and Their Bearing on the Early Diversification of Monocotyledonous Plants

    PubMed Central

    Holloway, Samuel J.; Friedman, William E.

    2008-01-01

    Background and Aims Although much is known about the vegetative traits associated with early monocot evolution, less is known about the reproductive features of early monocotyledonous lineages. A study was made of the embryology of Tofieldia glutinosa, a member of an early divergent monocot clade (Tofieldiaceae), and aspects of its development were compared with the development of other early divergent monocots in order to gain insight into defining reproductive features of early monocots. Methods Field-collected developing gynoecial tissues of Tofieldia glutinosa were prepared for histological examination. Over 600 ovules were sectioned and studied using brightfield, differential interference contrast, and fluorescence microscopy. High-resolution digital imaging was used to document important stages of megasporogenesis, megagametogenesis and early endosperm development. Key Results Development of the female gametophyte in T. glutinosa is of a modified Polygonum-type. At maturity the female gametophyte is seven-celled and 11-nucleate with a standard three-celled egg apparatus, a binucleate central cell (where ultimately, the two polar nuclei will fuse into a diploid secondary nucleus) and three binucleate antipodal cells. The antipodal nuclei persist past fertilization, and the process of double fertilization appears to yield a diploid zygote and triploid primary endosperm cell, as is characteristic of plants with Polygonum-type female gametophytes. Endosperm development is helobial, and free-nuclear growth initially proceeds at equal rates in both the micropylar and chalazal endosperm chambers. Conclusions The analysis suggests that the shared common ancestor of monocots possessed persistent and proliferating antipodals similar to those found in T. glutinosa and other early-divergent monocots (e.g. Acorus and members of the Araceae). Helobial endosperm among monocots evolved once in the common ancestor of all monocots excluding Acorus. Thus, the analysis further

  17. HSPRO controls early Nicotiana attenuata seedling growth during interaction with the fungus Piriformospora indica.

    PubMed

    Schuck, Stefan; Camehl, Iris; Gilardoni, Paola A; Oelmueller, Ralf; Baldwin, Ian T; Bonaventure, Gustavo

    2012-10-01

    In a previous study aimed at identifying regulators of Nicotiana attenuata responses against chewing insects, a 26-nucleotide tag matching the HSPRO (ORTHOLOG OF SUGAR BEET Hs1(pro)(-)(1)) gene was found to be strongly induced after simulated herbivory (Gilardoni et al., 2010). Here we characterized the function of HSPRO during biotic interactions in transgenic N. attenuata plants silenced in its expression (ir-hspro). In wild-type plants, HSPRO expression was not only induced during simulated herbivory but also when leaves were inoculated with Pseudomonas syringae pv tomato DC3000 and roots with the growth-promoting fungus Piriformospora indica. Reduced HSPRO expression did not affect the regulation of direct defenses against Manduca sexta herbivory or P. syringae pv tomato DC3000 infection rates. However, reduced HSPRO expression positively influenced early seedling growth during interaction with P. indica; fungus-colonized ir-hspro seedlings increased their fresh biomass by 30% compared with the wild type. Grafting experiments demonstrated that reduced HSPRO expression in roots was sufficient to induce differential growth promotion in both roots and shoots. This effect was accompanied by changes in the expression of 417 genes in colonized roots, most of which were metabolic genes. The lack of major differences in the metabolic profiles of ir-hspro and wild-type colonized roots (as analyzed by liquid chromatography time-of-flight mass spectrometry) suggested that accelerated metabolic rates were involved. We conclude that HSPRO participates in a whole-plant change in growth physiology when seedlings interact with P. indica.

  18. Evaluating and optimizing horticultural regimes in space plant growth facilities

    NASA Astrophysics Data System (ADS)

    Berkovich, Y.; Chetirkin, R.; Wheeler, R.; Sager, J.

    In designing innovative Space Plant Growth Facilities (SPGF) for long duration space f ightl various limitations must be addressed including onboard resources: volume, energy consumption, heat transfer and crew labor expenditure. The required accuracy in evaluating onboard resources by using the equivalent mass methodology and applying it to the design of such facilities is not precise. This is due to the uncertainty of the structure and not completely understanding of the properties of all associated hardware, including the technology in these systems. We present a simple criteria of optimization for horticultural regimes in SPGF: Qmax = max [M · (EBI) 2 / (V · E · T) ], where M is the crop harvest in terms of total dry biomass in the plant growth system; EBI is the edible biomass index (harvest index), V is a volume occupied by the crop; E is the crop light energy supply during growth; T is the crop growth duration. The criterion reflects directly on the consumption of onboard resources for crop production. We analyzed the efficiency of plant crops and the environmental parameters by examining the criteria for 15 salad and 12 wheat crops from the data in the ALS database at Kennedy Space Center. Some following conclusion have been established: 1. The technology involved in growing salad crops on a cylindrical type surface provides a more meaningful Q-criterion; 2. Wheat crops were less efficient than leafy greens (salad crops) when examining resource utilization; 3. By increasing light intensity of the crop the efficiency of the resource utilization could decrease. Using the existing databases and Q-criteria we have found that the criteria can be used in optimizing design and horticultural regimes in the SPGF.

  19. High nutrient-use efficiency during early seedling growth in diverse Grevillea species (Proteaceae)

    PubMed Central

    He, Tianhua; Fowler, William M.; Causley, Casey L.

    2015-01-01

    Several hypotheses have been proposed to explain the rich floristic diversity in regions characterised by nutrient-impoverished soils; however, none of these hypotheses have been able to explain the rapid diversification over a relatively short evolutionary time period of Grevillea, an Australian plant genus with 452 recognised species/subspecies and only 11 million years of evolutionary history. Here, we hypothesise that the apparent evolutionary success of Grevillea might have been triggered by the highly efficient use of key nutrients. The nutrient content in the seeds and nutrient-use efficiency during early seedling growth of 12 species of Grevillea were compared with those of 24 species of Hakea, a closely related genus. Compared with Hakea, the Grevillea species achieved similar growth rates (root and shoot length) during the early stages of seedling growth but contained only approximately half of the seed nutrient content. We conclude that the high nutrient-use efficiency observed in Grevillea might have provided a selective advantage in nutrient-poor ecosystems during evolution and that this property likely contributed to the evolutionary success in Grevillea. PMID:26607493

  20. Preferential Promotion of Lycopersicon esculentum (Tomato) Growth by Plant Growth Promoting Bacteria Associated with Tomato.

    PubMed

    Vaikuntapu, Papa Rao; Dutta, Swarnalee; Samudrala, Ram Babu; Rao, Vukanti R V N; Kalam, Sadaf; Podile, Appa Rao

    2014-12-01

    A total of 74 morphologically distinct bacterial colonies were selected during isolation of bacteria from different parts of tomato plant (rhizoplane, phylloplane and rhizosphere) as well as nearby bulk soil. The isolates were screened for plant growth promoting (PGP) traits such as production of indole acetic acid, siderophore, chitinase and hydrogen cyanide as well as phosphate solubilization. Seven isolates viz., NR4, NR6, RP3, PP1, RS4, RP6 and NR1 that exhibited multiple PGP traits were identified, based on morphological, biochemical and 16S rRNA gene sequence analysis, as species that belonged to four genera Aeromonas, Pseudomonas, Bacillus and Enterobacter. All the seven isolates were positive for 1-aminocyclopropane-1-carboxylate deaminase. Isolate NR6 was antagonistic to Fusarium solani and Fusarium moniliforme, and both PP1 and RP6 isolates were antagonistic to F. moniliforme. Except RP6, all isolates adhered significantly to glass surface suggestive of biofilm formation. Seed bacterization of tomato, groundnut, sorghum and chickpea with the seven bacterial isolates resulted in varied growth response in laboratory assay on half strength Murashige and Skoog medium. Most of the tomato isolates positively influenced tomato growth. The growth response was either neutral or negative with groundnut, sorghum and chickpea. Overall, the results suggested that bacteria with PGP traits do not positively influence the growth of all plants, and certain PGP bacteria may exhibit host-specificity. Among the isolates that positively influenced growth of tomato (NR1, RP3, PP1, RS4 and RP6) only RS4 was isolated from tomato rhizosphere. Therefore, the best PGP bacteria can also be isolated from zones other than rhizosphere or rhizoplane of a plant.

  1. Developmental programming: variations in early growth and adult disease.

    PubMed

    Gallo, Linda A; Tran, Melanie; Moritz, Karen M; Wlodek, Mary E

    2013-11-01

    Suboptimal conditions in utero are associated with the development of adult-onset diseases in offspring. Uteroplacental insufficiency in rats is a well-established animal model used to mimic and study the effects of developmental insults relevant to countries of abundant nutrient supply. However, wide-ranging outcomes for the offspring are apparent between the different investigators that use this model and also between cohorts generated in our laboratory. We aimed to explore the reasons for variability in rat models of uteroplacental insufficiency between different investigators and also between our own animal cohorts. We suggest differences in growth and disease development reflect uniqueness in susceptibility and highlight the complexity of interactions between genetic potential and environmental exposures. The impact of adverse exposures in utero has been described as having far-reaching effects that extend well beyond the first, directly exposed generation. However, the resulting phenotypes are not consistent between generations. This suggests that programmed effects are established de novo in each generation and challenges the prediction of disease. Characterization of growth and disease in the numerous rat models has led to our understanding of the impact of early life experiences on adult health. In order to drive the development of preventative and/or treatment strategies, future studies should focus on identifying the initial cause(s) of uteroplacental insufficiency, including genetic origins and the influence of poor diets.

  2. Physiological and morphological changes during early and later stages of fruit growth in Capsicum annuum.

    PubMed

    Tiwari, Aparna; Vivian-Smith, Adam; Ljung, Karin; Offringa, Remko; Heuvelink, Ep

    2013-03-01

    Fruit-set involves a series of physiological and morphological changes that are well described for tomato and Arabidopsis, but largely unknown for sweet pepper (Capsicum annuum). The aim of this paper is to investigate whether mechanisms of fruit-set observed in Arabidopsis and tomato are also applicable to C. annuum. To do this, we accurately timed the physiological and morphological changes in a post-pollinated and un-pollinated ovary. A vascular connection between ovule and replum was observed in fertilized ovaries that undergo fruit development, and this connection was absent in unfertilized ovaries that abort. This indicates that vascular connection between ovule and replum is an early indicator for successful fruit development after pollination and fertilization. Evaluation of histological changes in the carpel of a fertilized and unfertilized ovary indicated that increase in cell number and cell diameter both contribute to early fruit growth. Cell division contributes more during early fruit growth while cell expansion contributes more at later stages of fruit growth in C. annuum. The simultaneous occurrence of a peak in auxin concentration and a strong increase in cell diameter in the carpel of seeded fruits suggest that indole-3-acetic acid stimulates a major increase in cell diameter at later stages of fruit growth. The series of physiological and morphological events observed during fruit-set in C. annuum are similar to what has been reported for tomato and Arabidopsis. This indicates that tomato and Arabidopsis are suitable model plants to understand details of fruit-set mechanisms in C. annuum.

  3. Light and Plants. A Series of Experiments Demonstrating Light Effects on Seed Germination, Plant Growth, and Plant Development.

    ERIC Educational Resources Information Center

    Downs, R. J.; And Others

    A brief summary of the effects of light on plant germination, growth and development, including photoperiodism and pigment formation, introduces 18 experiments and demonstrations which illustrate aspects of these effects. Detailed procedures for each exercise are given, the expected results outlined, and possible sources of difficulty discussed.…

  4. Phylogenomic Analyses Indicate that Early Fungi Evolved Digesting Cell Walls of Algal Ancestors of Land Plants.

    PubMed

    Chang, Ying; Wang, Sishuo; Sekimoto, Satoshi; Aerts, Andrea L; Choi, Cindy; Clum, Alicia; LaButti, Kurt M; Lindquist, Erika A; Yee Ngan, Chew; Ohm, Robin A; Salamov, Asaf A; Grigoriev, Igor V; Spatafora, Joseph W; Berbee, Mary L

    2015-05-14

    As decomposers, fungi are key players in recycling plant material in global carbon cycles. We hypothesized that genomes of early diverging fungi may have inherited pectinases from an ancestral species that had been able to extract nutrients from pectin-containing land plants and their algal allies (Streptophytes). We aimed to infer, based on pectinase gene expansions and on the organismal phylogeny, the geological timing of the plant-fungus association. We analyzed 40 fungal genomes, three of which, including Gonapodya prolifera, were sequenced for this study. In the organismal phylogeny from 136 housekeeping loci, Rozella diverged first from all other fungi. Gonapodya prolifera was included among the flagellated, predominantly aquatic fungal species in Chytridiomycota. Sister to Chytridiomycota were the predominantly terrestrial fungi including zygomycota I and zygomycota II, along with the ascomycetes and basidiomycetes that comprise Dikarya. The Gonapodya genome has 27 genes representing five of the seven classes of pectin-specific enzymes known from fungi. Most of these share a common ancestry with pectinases from Dikarya. Indicating functional and sequence similarity, Gonapodya, like many Dikarya, can use pectin as a carbon source for growth in pure culture. Shared pectinases of Dikarya and Gonapodya provide evidence that even ancient aquatic fungi had adapted to extract nutrients from the plants in the green lineage. This implies that 750 million years, the estimated maximum age of origin of the pectin-containing streptophytes represents a maximum age for the divergence of Chytridiomycota from the lineage including Dikarya.

  5. Bacillus megaterium strain XTBG34 promotes plant growth by producing 2-pentylfuran.

    PubMed

    Zou, Changsong; Li, Zhifang; Yu, Diqiu

    2010-08-01

    Several chemical changes in soil are associated with plant growth-promoting rhizobacteria. An endosporeforming bacterium, strain XTBG34, was isolated from a Xishuangbanna Tropical Botanical Garden soil sample and identified as Bacillus megaterium. The strain's volatiles had remarkable plant growth promotion activity in Arabidopsis thaliana plants; after 15 days treatment, the fresh weight of plants inoculated with XTBG34 was almost 2-fold compared with those inoculated with DH5alpha. Head space volatile compounds produced by XTBG34, trapped with headspace solid phase microextraction and identified by gas chromatography-mass spectrometry, included aldehydes, alkanes, ketones and aroma components. Of the 11 compounds assayed for plant growth promotion activity in divided Petri plates, only 2-pentylfuran increased plant growth. We have therefore identified a new plant growth promotion volatile of B. megaterium XTBG34, which deserves further study in the mechanisms of interaction between plant growth-promoting rhizobacteria and plants.

  6. Nutrition, acid-base status and growth in early childhood.

    PubMed

    Kalhoff, H; Manz, F

    2001-10-01

    Optimal growth is only possible in a well-balanced "inner milieu". Premature infants are especially vulnerable for disturbances of acid-base metabolism with a predisposition to metabolic acidosis due to a transient disproportion between age-related low renal capacity for net acid excretion (NAE) and an unphysiologically high actual renal NAE on nutrition with standard formulas. During a 50 month period, 452 low birth-weight infants were screened for spontaneous development of incipient late metabolic acidosis (ILMA), an early stage during the development of retention acidosis, characterized by maximum renal acid stimulation (MRAS, urine-pH < 5.4) on two consecutive days but still compensated systemic acid-base status. Compared with controls, patients with ILMA showed higher serum creatinine values, an increased urinary excretion of sodium, aldosterone and nitrogen, but only slightly lower blood pH (7.38 vs 7.41) and base excess (-2.8 vs. 0.2 mmol/l) with respiratory compensation (PCO2 35 vs 37 mm Hg). Patients with altogether 149 episodes of ILMA were subsequently randomly allocated to either treatment with NaHCO3 2 mmol/kg/d for 7 days or no special therapy in protocol I, or NaHCO3 vs NaCl each 2 mmol/kg/d for 7 days in protocol II. Patients of protocol I with persistent MRAS for 7 days showed lowest weight gain and a tendency for a further increase in urinary aldosterone and nitrogen excretion. NaCl supplementation (protocol II) seemed to promote weight gain without affecting either impaired mineralization or suboptimal nitrogen retention. Patients with alkali therapy under both protocols showed normal weight gain and normalization of hormonal stimulation, mineralization (protocol II) and nitrogen assimilation. Modification of the mineral content of a standard preterm formula decreased renal NAE to the low level seen on alimentation with human milk and reduced the incidence of ILMA in preterm and small-for-gestational-age infants to 1%. The data show that ILMA is

  7. Contributions of green light to plant growth and development.

    PubMed

    Wang, Yihai; Folta, Kevin M

    2013-01-01

    Light passing through or reflected from adjacent foliage provides a developing plant with information that is used to guide specific genetic and physiological processes. Changes in gene expression underlie adaptation to, or avoidance of, the light-compromised environment. These changes have been well described and are mostly attributed to a decrease in the red light to far-red light ratio and/or a reduction in blue light fluence rate. In most cases, these changes rely on the integration of red/far-red/blue light signals, leading to changes in phytohormone levels. Studies over the last decade have described distinct responses to green light and/or a shift of the blue-green, or red-green ratio. Responses to green light are typically low-light responses, suggesting that they may contribute to the adaptation to growth under foliage or within close proximity to other plants. This review summarizes the growth responses in artificially manipulated light environments with an emphasis on the roles of green wavebands. The information may be extended to understanding the influence of green light in shade avoidance responses as well as other plant developmental and physiological processes.

  8. Achieving and documenting closure in plant growth facilities

    NASA Technical Reports Server (NTRS)

    Knott, W. M.; Sager, John C.; Wheeler, Ray

    1992-01-01

    As NASA proceeds with its effort to develop a Controlled Ecological Life Support System (CELSS) that will provide life support to crews during long duration space missions, it must address the question of facility and system closure. The concept of closure as it pertains to CELSS and engineering specifications, construction problems and monitoring procedures used in the development and operation of a closed plant growth facility for the CELSS program are described. A plant growth facility is one of several modules required for a CELSS. A prototype of this module at Kennedy Space Center is the large (7m tall x 3.5m diameter) Biomass Production Chamber (BPC), the central facility of the CELSS Breadboard Project. The BPC is atmospherically sealed to a leak rate of approximately 5 percent of its total volume per 24 hours. This paper will discuss the requirements for atmospheric closure in the facility, present CO2 and trace gas data from initial tests of the BPC with and without plants, and describe how the chamber was sealed atmospherically. Implications that research conducted in this type of facility will have for the CELSS program are discussed.

  9. Theoretical search for the growth-temperature relationship in plants.

    PubMed

    Lewicka, S; Pietruszka, M

    2006-06-01

    In this article we deal with the definition of a new phenomenological model with physical bases for the response of short-term cell expansion growth to temperature. Although the interest on both the biomechanical bases of elongation growth and on temperature responses has a long lasting development in plant biology and biophysics, yet the question of the mode of actions of temperature is a very relevant and still open one. The purpose of our paper was not to deal with all the complexity of the possible effects of temperature on a growing cell but to concentrate on two more focused questions: i) whether it is possible to specify an optimal temperature for growth responses all along development by defining some phenomenological equations for temperature response, ii) can we learn something from that on the temperature dependence of the cell wall expansion process using a minimal analytical modelling? To answer both questions we introduce (by extending Lockhart approach) the notion of temperature by simple thermodynamical reasoning. Assuming incompressibility of water (by the constant molar density n/V ) we also accounted for the role of osmosis and consequently - the role of water uptake in growing cell. This approach allowed us (by comparing theoretical solutions and experimental results) not only to determine the specific (resonance) temperature (or corresponding absorption energy kBT*) of the optimal growth but also draw conclusions about the cell wall extensibility dependence on temperature and its evolution in time. A straightforward application of our method to determine optimum growth temperature for different plant species in a greenhouse practice (as its simple implication) can also be recommended.

  10. Effect of crop development on biogenic emissions from plant populations grown in closed plant growth chambers

    NASA Technical Reports Server (NTRS)

    Batten, J. H.; Stutte, G. W.; Wheeler, R. M.

    1995-01-01

    The Biomass Production Chamber at John F. Kennedy Space Center is a closed plant growth chamber facility that can be used to monitor the level of biogenic emissions from large populations of plants throughout their entire growth cycle. The head space atmosphere of a 26-day-old lettuce (Lactuca sativa cv. Waldmann's Green) stand was repeatedly sampled and emissions identified and quantified using GC-mass spectrometry. Concentrations of dimethyl sulphide, carbon disulphide, alpha-pinene, furan and 2-methylfuran were not significantly different throughout the day; whereas, isoprene showed significant differences in concentration between samples collected in light and dark periods. Volatile organic compounds from the atmosphere of wheat (Triticum aestivum cv. Yecora Rojo) were analysed and quantified from planting to maturity. Volatile plant-derived compounds included 1-butanol, 2-ethyl-1-hexanol, nonanal, benzaldehyde, tetramethylurea, tetramethylthiourea, 2-methylfuran and 3-methylfuran. Concentrations of volatiles were determined during seedling establishment, vegetative growth, anthesis, grain fill and senescence and found to vary depending on the developmental stage. Atmospheric concentrations of benzaldehyde and nonanal were highest during anthesis, 2-methylfuran and 3-methylfuran concentrations were greatest during grain fill, and the concentration of the tetramethylurea peaked during senescence.

  11. Experimental determination of magnesium isotope fractionation during higher plant growth

    NASA Astrophysics Data System (ADS)

    Bolou-Bi, Emile B.; Poszwa, Anne; Leyval, Corinne; Vigier, Nathalie

    2010-05-01

    Two higher plant species (rye grass and clover) were cultivated under laboratory conditions on two substrates (solution, phlogopite) in order to constrain the corresponding Mg isotope fractionations during plant growth and Mg uptake. We show that bulk plants are systematically enriched in heavy isotopes relative to their nutrient source. The Δ 26Mg plant-source range from 0.72‰ to 0.26‰ for rye grass and from 1.05‰ to 0.41‰ for clover. Plants grown on phlogopite display Mg isotope signatures (relative to the Mg source) ˜0.3‰ lower than hydroponic plants. For a given substrate, rye grass display lower δ 26Mg (by ˜0.3‰) relative to clover. Magnesium desorbed from rye grass roots display a δ 26Mg greater than the nutrient solution. Adsorption experiments on dead and living rye grass roots also indicate a significant enrichment in heavy isotopes of the Mg adsorbed on the root surface. Our results indicate that the key processes responsible for heavy isotope enrichment in plants are located at the root level. Both species also exhibit an enrichment in light isotopes from roots to shoots (Δ 26Mg leaf-root = -0.65‰ and -0.34‰ for rye grass and clover grown on phlogopite respectively, and Δ 26Mg leaf-root of -0.06‰ and -0.22‰ for the same species grown hydroponically). This heavy isotope depletion in leaves can be explained by biological processes that affect leaves and roots differently: (1) organo-Mg complex (including chlorophyll) formation, and (2) Mg transport within plant. For both species, a positive correlation between δ 26Mg and K/Mg was observed among the various organs. This correlation is consistent with the link between K and Mg internal cycles, as well as with formation of organo-magnesium compounds associated with enrichment in heavy isotopes. Considering our results together with the published range for δ 26Mg of natural plants and rivers, we estimate that a significant change in continental vegetation would induce a change of

  12. Nickel detoxification and plant growth promotion by multi metal resistant plant growth promoting Rhizobium species RL9.

    PubMed

    Wani, Parvaze Ahmad; Khan, Mohammad Saghir

    2013-07-01

    Pollution of the biosphere by heavy metals is a global threat that has accelerated dramatically since the beginning of industrial revolution. The aim of the study is to check the resistance of RL9 towards the metals and to observe the effect of Rhizobium species on growth, pigment content, protein and nickel uptake by lentil in the presence and absence of nickel. The multi metal tolerant and plant growth promoting Rhizobium strain RL9 was isolated from the nodules of lentil. The strain not only tolerated nickel but was also tolerant o cadmium, chromium, nickel, lead, zinc and copper. The strain tolerated nickel 500 μg/mL, cadmium 300 μg/mL, chromium 400 μg/mL, lead 1,400 μg/mL, zinc 1,000 μg/mL and copper 300 μg/mL, produced good amount of indole acetic acid and was also positive for siderophore, hydrogen cyanide and ammonia. The strain RL9 was further assessed with increasing concentrations of nickel when lentil was used as a test crop. The strain RL9 significantly increased growth, nodulation, chlorophyll, leghaemoglobin, nitrogen content, seed protein and seed yield compared to plants grown in the absence of bioinoculant but amended with nickel The strain RL9 decreased uptake of nickel in lentil compared to plants grown in the absence of bio-inoculant. Due to these intrinsic abilities strain RL9 could be utilized for growth promotion as well as for the remediation of nickel in nickel contaminated soil.

  13. Plant Growth and Development in the ASTROCULTURE(trademark) Space-Based Growth Unit-Ground Based Experiments

    NASA Technical Reports Server (NTRS)

    Bula, R. J.

    1997-01-01

    The ASTROCULTURE(trademark) plant growth unit flown as part on the STS-63 mission in February 1995, represented the first time plants were flown in microgravity in a enclosed controlled environment plant growth facility. In addition to control of the major environmental parameters, nutrients were provided to the plants with the ZEOPONICS system developed by NASA Johnson Space Center scientists. Two plant species were included in this space experiment, dwarf wheat (Triticum aestivum) and a unique mustard called "Wisconsin Fast Plants" (Brassica rapa). Extensive post-flight analyses have been performed on the plant material and it has been concluded that plant growth and development was normal during the period the plants were in the microgravity environment of space. However, adequate plant growth and development control data were not available for direct comparisons of plant responses to the microgravity environment with those of plants grown at 1 g. Such data would allow for a more complete interpretation of the extent that microgravity affects plant growth and development.

  14. Weijia Zhou Inspects the Advanced Astroculture plant growth unit

    NASA Technical Reports Server (NTRS)

    2003-01-01

    Dr. Weijia Zhou, director of the Wisconsin Center for Space Automation and Robotics at the University of Wisconsin-Madison, inspects the Advanced Astroculture(tm) plant growth unit before its first flight last spring. Coating technology is used inside the miniature plant greenhouse to remove ethylene, a chemical produced by plant leaves that can cause plants to mature too quickly. This same coating technology is used in a new anthrax-killing device. The Space Station experiment is managed by the Space Product Development Program at NASA's Marshall Space Flight Center in Huntsville, Ala. DuPont is partnering with NASA and the Wisconsin Center for Space Automation and Robotics (WCSAR) at the University of Wisconsin-Madison to grow soybeans aboard the Space Station to find out if they have improved oil, protein, carbohydrates or secondary metabolites that could benefit farmers and consumers. Principal Investigators: Dr. Tom Corbin, Pioneer Hi-Bred International Inc., a Dupont Company, with headquarters in Des Moines, Iowa, and Dr. Weijia Zhou, Wisconsin Center for Space Automation and Robotics (WCSAR), University of Wisconsin-Madison.

  15. DNA from soil mirrors plant taxonomic and growth form diversity.

    PubMed

    Yoccoz, N G; Bråthen, K A; Gielly, L; Haile, J; Edwards, M E; Goslar, T; Von Stedingk, H; Brysting, A K; Coissac, E; Pompanon, F; Sønstebø, J H; Miquel, C; Valentini, A; De Bello, F; Chave, J; Thuiller, W; Wincker, P; Cruaud, C; Gavory, F; Rasmussen, M; Gilbert, M T P; Orlando, L; Brochmann, C; Willerslev, E; Taberlet, P

    2012-08-01

    Ecosystems across the globe are threatened by climate change and human activities. New rapid survey approaches for monitoring biodiversity would greatly advance assessment and understanding of these threats. Taking advantage of next-generation DNA sequencing, we tested an approach we call metabarcoding: high-throughput and simultaneous taxa identification based on a very short (usually <100 base pairs) but informative DNA fragment. Short DNA fragments allow the use of degraded DNA from environmental samples. All analyses included amplification using plant-specific versatile primers, sequencing and estimation of taxonomic diversity. We tested in three steps whether degraded DNA from dead material in soil has the potential of efficiently assessing biodiversity in different biomes. First, soil DNA from eight boreal plant communities located in two different vegetation types (meadow and heath) was amplified. Plant diversity detected from boreal soil was highly consistent with plant taxonomic and growth form diversity estimated from conventional above-ground surveys. Second, we assessed DNA persistence using samples from formerly cultivated soils in temperate environments. We found that the number of crop DNA sequences retrieved strongly varied with years since last cultivation, and crop sequences were absent from nearby, uncultivated plots. Third, we assessed the universal applicability of DNA metabarcoding using soil samples from tropical environments: a large proportion of species and families from the study site were efficiently recovered. The results open unprecedented opportunities for large-scale DNA-based biodiversity studies across a range of taxonomic groups using standardized metabarcoding approaches.

  16. Results from conceptual design study of potential early commercial MHD/steam power plants

    NASA Technical Reports Server (NTRS)

    Hals, F.; Kessler, R.; Swallom, D.; Westra, L.; Zar, J.; Morgan, W.; Bozzuto, C.

    1981-01-01

    This paper presents conceptual design information for a potential early MHD power plant developed in the second phase of a joint study of such plants. Conceptual designs of plant components and equipment with performance, operational characteristics and costs are reported on. Plant economics and overall performance including full and part load operation are reviewed. Environmental aspects and the methods incorporated in plant design for emission control of sulfur and nitrogen oxides are reviewed. Results from reliability/availability analysis conducted are also included.

  17. Plant Growth on a Gravel Soil: Greenhouse Studies

    DTIC Science & Technology

    1981-03-01

    P and K, respectively. monium nitrate (34.0.0); P, superphosphate (0-20.0); Although little information exists oi nutrient limi- and K, muriate of...Reubens and common KB, K.31 and T.5 tall fes. excess acidity generated by repeated fertilizer appli- cue, FL I HF, Yorktown II PR, AR, and sheep...fescue. cations. The amount of lime will depend on the acid . Plant yields were recorded after 76 days of growth ifying effect of the fertilizer (Pesek et

  18. Hierarchical Helical Order in the Twisted Growth of Plant Organs

    NASA Astrophysics Data System (ADS)

    Wada, Hirofumi

    2012-09-01

    The molecular and cellular basis of left-right asymmetry in plant morphogenesis is a fundamental issue in biology. A rapidly elongating root or hypocotyl of twisting mutants of Arabidopsis thaliana exhibits a helical growth with a handedness opposite to that of the underlying cortical microtubule arrays in epidermal cells. However, how such a hierarchical helical order emerges is currently unknown. We propose a model for investigating macroscopic chiral asymmetry in Arabidopsis mutants. Our elastic model suggests that the helical pattern observed is a direct consequence of the simultaneous presence of anisotropic growth and tilting of cortical microtubule arrays. We predict that the root helical pitch angle is a function of the microtubule helical angle and elastic moduli of the tissues. The proposed model is versatile and is potentially important for other biological systems ranging from protein fibrous structures to tree trunks.

  19. Effects of perchlorate on growth of four wetland plants and its accumulation in plant tissues.

    PubMed

    He, Hongzhi; Gao, Haishuo; Chen, Guikui; Li, Huashou; Lin, Hai; Shu, Zhenzhen

    2013-10-01

    Perchlorate contamination in water is of concern because of uncertainties about toxicity and health effects, impact on ecosystems, and possible indirect exposure pathways to humans. Therefore, it is very important to investigate the ecotoxicology of perchlorate and to screen plant species for phytoremediation. Effects of perchlorate (20, 200, and 500 mg/L) on the growth of four wetland plants (Eichhornia crassipes, Acorus calamus L., Thalia dealbata, and Canna indica) as well as its accumulation in different plant tissues were investigated through water culture experiments. Twenty milligrams per liter of perchlorate had no significant effects on height, root length, aboveground part weight, root weight, and oxidizing power of roots of four plants, except A. calamus, and increasing concentrations of perchlorate showed that out of the four wetland plants, only A. calamus had a significant (p<0.05) dose-dependent decrease in these parameters. When treated with 500 mg/L perchlorate, these parameters and chlorophyll content in the leaf of plants showed significant decline contrasted to control groups, except the root length of E. crassipes and C. indica. The order of inhibition rates of perchlorate on root length, aboveground part weight and root weight, and oxidizing power of roots was: A. calamus > C. indica > T. dealbata > E. crassipes and on chlorophyll content in the leaf it was: A. calamus > T. dealbata > C. indica > E. crassipes. The higher the concentration of perchlorate used, the higher the amount of perchlorate accumulation in plants. Perchlorate accumulation in aboveground tissues was much higher than that in underground tissues and leaf was the main tissue for perchlorate accumulation. The order of perchlorate accumulation content and the bioconcentration factor in leaf of four plants was: E. crassipes > C. indica > T. dealbata > A. calamus. Therefore, E. crassipes might be an ideal plant with high tolerance ability and accumulation ability for constructing

  20. Plant growth-promoting rhizobacteria affect the growth and nutrient uptake of Fraxinus americana container seedlings.

    PubMed

    Liu, Fangchun; Xing, Shangjun; Ma, Hailin; Du, Zhenyu; Ma, Bingyao

    2013-05-01

    Plant growth-promoting rhizobacteria (PGPR) are important catalysts that regulate the functional properties of agricultural systems. However, there is little information on the effect of PGPR inoculation on the growth and nutrient accumulation of forest container seedlings. This study determined the effects of a growth medium inoculated with PGPR on the nutrient uptake, nutrient accumulation, and growth of Fraxinus americana container seedlings. PGPR inoculation with fertilizer increased the dry matter accumulation of the F. americana aerial parts with delayed seedling emergence time. Under fertilized conditions, the accumulation time of phosphorous (P) and potassium (K) in the F. americana aerial parts was 13 days longer due to PGPR inoculation. PGPR increased the maximum daily P and K accumulations in fertilized seedlings by 9.31 and 10.44 %, respectively, but had little impact on unfertilized ones. Regardless of fertilizer application, the root exudates, namely sugars, amino acids, and organic acids significantly increased because of PGPR inoculation. PGPR inoculation with fertilizer increased the root, shoot, and leaf yields by 19.65, 22.94, and 19.44 %, respectively, as well as the P and K contents by 8.33 and 10.60 %, respectively. Consequently, the N, P, and K uptakes increased by 19.85, 31.97, and 33.95 %, respectively. Hence, PGPR inoculation with fertilizer can be used as a bioenhancer for plant growth and nutrient uptake in forest container seedling nurseries.

  1. Effects of fertilization, tillage, and phorate on thrips and TSWV incidence in early planted peanuts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thrips feeding is usually more prevalent in early planted peanuts (Arachis hypogaea L.), which often directly results in higher incidence of tomato spotted wilt virus (TSWV). Several management tools are available to reduce thrips feeding and/or the threat of TSWV in early planted peanuts, includin...

  2. Dynamic quantification of canopy structure to characterize early plant vigour in wheat genotypes

    PubMed Central

    Duan, T.; Chapman, S.C.; Holland, E.; Rebetzke, G.J.; Guo, Y.; Zheng, B.

    2016-01-01

    Early vigour is an important physiological trait to improve establishment, water-use efficiency, and grain yield for wheat. Phenotyping large numbers of lines is challenging due to the fast growth and development of wheat seedlings. Here we developed a new photo-based workflow to monitor dynamically the growth and development of the wheat canopy of two wheat lines with a contrasting early vigour trait. Multiview images were taken using a ‘vegetation stress’ camera at 2 d intervals from emergence to the sixth leaf stage. Point clouds were extracted using the Multi-View Stereo and Structure From Motion (MVS-SFM) algorithm, and segmented into individual organs using the Octree method, with leaf midribs fitted using local polynomial function. Finally, phenotypic parameters were calculated from the reconstructed point cloud including: tiller and leaf number, plant height, Haun index, phyllochron, leaf length, angle, and leaf elongation rate. There was good agreement between the observed and estimated leaf length (RMSE=8.6mm, R 2=0.98, n=322) across both lines. Significant contrasts of phenotyping parameters were observed between the two lines and were consistent with manual observations. The early vigour line had fewer tillers (2.4±0.6) and larger leaves (308.0±38.4mm and 17.1±2.7mm for leaf length and width, respectively). While the phyllochron of both lines was quite similar, the non-vigorous line had a greater Haun index (more leaves on the main stem) on any date, as the vigorous line had slower development of its first two leaves. The workflow presented in this study provides an efficient method to phenotype individual plants using a low-cost camera (an RGB camera is also suitable) and could be applied in phenotyping for applications in both simulation modelling and breeding. The rapidity and accuracy of this novel method can characterize the results of specific selection criteria (e.g. width of leaf three, number of tillers, rate of leaf appearance) that

  3. Understanding and engineering beneficial plant-microbe interactions: plant growth promotion in energy crops.

    PubMed

    Farrar, Kerrie; Bryant, David; Cope-Selby, Naomi

    2014-12-01

    Plant production systems globally must be optimized to produce stable high yields from limited land under changing and variable climates. Demands for food, animal feed, and feedstocks for bioenergy and biorefining applications, are increasing with population growth, urbanization and affluence. Low-input, sustainable, alternatives to petrochemical-derived fertilizers and pesticides are required to reduce input costs and maintain or increase yields, with potential biological solutions having an important role to play. In contrast to crops that have been bred for food, many bioenergy crops are largely undomesticated, and so there is an opportunity to harness beneficial plant-microbe relationships which may have been inadvertently lost through intensive crop breeding. Plant-microbe interactions span a wide range of relationships in which one or both of the organisms may have a beneficial, neutral or negative effect on the other partner. A relatively small number of beneficial plant-microbe interactions are well understood and already exploited; however, others remain understudied and represent an untapped reservoir for optimizing plant production. There may be near-term applications for bacterial strains as microbial biopesticides and biofertilizers to increase biomass yield from energy crops grown on land unsuitable for food production. Longer term aims involve the design of synthetic genetic circuits within and between the host and microbes to optimize plant production. A highly exciting prospect is that endosymbionts comprise a unique resource of reduced complexity microbial genomes with adaptive traits of great interest for a wide variety of applications.

  4. Early diet, insulin-like growth factor-1, growth and later obesity.

    PubMed

    Michaelsen, Kim F; Larnkjaer, Anni; Molgaard, Christian

    2013-01-01

    There is increasing evidence that factors in early life are important for the risk of developing overweight and obesity later in childhood. Among the postnatal factors, breastfeeding and complementary feeding are especially interesting because the pattern of these two factors can be changed. Breastfeeding has been shown to reduce the risk of later obesity, although the effect is not substantial. Complementary feeding also seems to play a role. There is some evidence that a high protein intake is associated with a higher risk of obesity later in childhood, whereas a high fat intake during the complementary feeding period does not seem to be a risk factor for later obesity. Thus, the dietary pattern during this period is different from the pattern seen in older children and adults where a high fat intake is associated with a higher risk of obesity and a high protein intake in some studies seems to protect against obesity. A few studies have also suggested that early introduction of complementary foods (before age 4 months) is associated with an increased risk of later obesity. A high weight gain during early life, especially the first 6 months, is associated with a higher risk of developing obesity. However, some studies suggest that weight gain during the 6- to 12-month age period, when complementary feeding is introduced, is not associated with later obesity. Insulin-like growth factor-1 (IGF-1) values and body composition both play a role in the complex pattern between early diet and later obesity, but our present knowledge about how these factors are influenced by diet during infancy is limited. Future studies should include longitudinal data on IGF-1 and body composition during infancy to improve our understanding of how diet in early life can play a role in prevention of later obesity.

  5. Overview: early history of crop growth and photosynthesis modeling.

    PubMed

    El-Sharkawy, Mabrouk A

    2011-02-01

    As in industrial and engineering systems, there is a need to quantitatively study and analyze the many constituents of complex natural biological systems as well as agro-ecosystems via research-based mechanistic modeling. This objective is normally addressed by developing mathematically built descriptions of multilevel biological processes to provide biologists a means to integrate quantitatively experimental research findings that might lead to a better understanding of the whole systems and their interactions with surrounding environments. Aided with the power of computational capacities associated with computer technology then available, pioneering cropping systems simulations took place in the second half of the 20th century by several research groups across continents. This overview summarizes that initial pioneering effort made to simulate plant growth and photosynthesis of crop canopies, focusing on the discovery of gaps that exist in the current scientific knowledge. Examples are given for those gaps where experimental research was needed to improve the validity and application of the constructed models, so that their benefit to mankind was enhanced. Such research necessitates close collaboration among experimentalists and model builders while adopting a multidisciplinary/inter-institutional approach.

  6. MAPK-dependent JA and SA signalling in Nicotiana attenuata affects plant growth and fitness during competition with conspecifics

    PubMed Central

    2012-01-01

    Background Induced defense responses to herbivores are generally believed to have evolved as cost-saving strategies that defer the fitness costs of defense metabolism until these defenses are needed. The fitness costs of jasmonate (JA)-mediated defenses have been well documented. Those of the early signaling units mediating induced resistance to herbivores have yet to be examined. Early signaling components that mediate herbivore-induced defense responses in Nicotiana attenuata, have been well characterized and here we examine their growth and fitness costs during competition with conspecifics. Two mitogen-activated protein kinases (MAPKs), salicylic acid (SA)-induced protein kinase (SIPK) and wound-induced protein kinase (WIPK) are rapidly activated after perception of herbivory and both kinases regulate herbivory-induced JA levels and JA-mediated defense metabolite accumulations. Since JA-induced defenses result in resource-based trade-offs that compromise plant productivity, we evaluated if silencing SIPK (irSIPK) and WIPK (irWIPK) benefits the growth and fitness of plants competiting with wild type (WT) plants, as has been shown for plants silenced in JA-signaling by the reduction of Lipoxygenase 3 (LOX3) levels. Results As expected, irWIPK and LOX3-silenced plants out-performed their competing WT plants. Surprisingly, irSIPK plants, which have the largest reductions in JA signaling, did not. Phytohormone profiling of leaves revealed that irSIPK plants accumulated higher levels of SA compared to WT. To test the hypothesis that these high levels of SA, and their presumed associated fitness costs of pathogen associated defenses in irSIPK plants had nullified the JA-deficiency-mediated growth benefits in these plants, we genetically reduced SA levels in irSIPK plants. Reducing SA levels partially recovered the biomass and fitness deficits of irSIPK plants. We also evaluated whether the increased fitness of plants with reduced SA or JA levels resulted from

  7. Plant tests for determining the suitability of grape marc composts as components of plant growth media.

    PubMed

    Paradelo, Remigio; Moldes, Ana Belén; González, Desiree; Barral, María Teresa

    2012-10-01

    Five grape marc composts prepared by different procedures (composting and vermicompost at several scales) were tested as potential components of plant growth media. The five composts had high organic matter content (>90%), low electric conductivity (<1 dS m(-1)) and a pH between 7 and 8. Different chemical and biochemical analyses performed indicated the higher stability of those composts submitted to a longer composting process or to a vermicomposting process (lower water soluble organic matter, respiration and dehydrogenase activity). In order to determine the suitability of the composts as substrate components, plant growth tests were performed by blending the composts with peat or commercial substrate at two compost rates (25% and 50%). The mixtures were sown with barley (Hordeum vulgare L.) and grown under controlled conditions in an incubation chamber. No prejudicial effects derived from the use of composted grape marc were observed, whatever the procedure of composting used. The results showed that four out of the five composts would be suitable for use in plant growth substrates elaboration, as they did not reduce productivity with respect to the control substrates.

  8. The early growth and development study: a prospective adoption design.

    PubMed

    Leve, Leslie D; Neiderhiser, Jenae M; Ge, Xiaojia; Scaramella, Laura V; Conger, Rand D; Reid, John B; Shaw, Daniel S; Reiss, David

    2007-02-01

    The Early Growth and Development Study is a prospective adoption study of birth parents, adoptive parents, and adopted children (N=359 triads) that was initiated in 2003. The primary study aims are to examine how family processes mediate or moderate the expression of genetic influences in order to aid in the identification of specific family processes that could serve as malleable targets for intervention. Participants in the study are recruited through adoption agencies located throughout the United States, following the birth of a child. Assessments occur at 6-month intervals until the child reaches 3 years of age. Data collection includes the following primary constructs: infant and toddler temperament, social behavior, and health; birth and adoptive parent personality characteristics, psychopathology, competence, stress, and substance use; adoptive parenting and marital relations; and prenatal exposure to drugs and maternal stress. Preliminary analyses suggest the representativeness of the sample and minimal confounding effects of current trends in adoption practices, including openness and selective placement. Future plans are described.

  9. The Breadboard Project - A functioning CELSS plant growth system

    NASA Technical Reports Server (NTRS)

    Knott, W. M.

    1992-01-01

    The primary objective of the Breadboard Project for the next 3-4 years is to develop, integrate and operate a Controlled Ecological Life Support System (CELSS) at a one-person scale. The focus of this project over the past two years has been the development of the plant growth facility, the first module of the CELSS. The other major modules, food preparation, biomass processing, and resource recovery, have been researched at the laboratory scale during the past two years and facilities are currently under construction to scale-up these modules to an operational state. This paper will outline the design requirements for the Biomass Production Chamber (BPC), the plant growth facility for the project, and the control and monitoring subsystems which operate the chamber and will present results from both engineering and biological tests of the facility. Three production evaluations of wheat, conducted in the BPC during the past year, will be described and the data generated from these tests discussed.

  10. Implementation of Autonomous Control Technology for Plant Growth Chambers

    NASA Technical Reports Server (NTRS)

    Costello, Thomas A.; Sager, John C.; Krumins, Valdis; Wheeler, Raymond M.

    2002-01-01

    The Kennedy Space Center has significant infrastructure for research using controlled environment plant growth chambers. Such research supports development of bioregenerative life support technology for long-term space missions. Most of the existing chambers in Hangar L and Little L will be moved to the new Space Experiment Research and Processing Laboratory (SERPL) in the summer of 2003. The impending move has created an opportunity to update the control system technologies to allow for greater flexibility, less labor for set-up and maintenance, better diagnostics, better reliability and easier data retrieval. Part of these improvements can be realized using hardware which communicates through an ethernet connection to a central computer for supervisory control but can be operated independently of the computer during routine run-time. Both the hardware and software functionality of an envisioned system were tested on a prototype plant growth chamber (CEC-4) in Hangar L. Based upon these tests, recommendations for hardware and software selection and system design for implementation in SERPL are included.

  11. Helical growth trajectories in plant roots interacting with stiff barriers

    NASA Astrophysics Data System (ADS)

    Gerbode, Sharon; Noar, Roslyn; Harrison, Maria

    2009-03-01

    Plant roots successfully navigate heterogeneous soil environments with varying nutrient and water concentrations, as well as a variety of stiff obstacles. While it is thought that the ability of roots to penetrate into a stiff lower soil layer is important for soil erosion, little is known about how a root actually responds to a rigid interface. We have developed a laser sheet imaging technique for recording the 3D growth dynamics of plant roots interacting with stiff barriers. We find that a root encountering an angled interface does not grow in a straight line along the surface, but instead follows a helical trajectory. These experiments build on the pioneering studies of roots grown on a tilted 2D surface, which reported ``root waving,'' a similar curved pattern thought to be caused by the root's sensitivity to both gravity and the rigid surface on which it is grown. Our measurements extend these results to the more physiologically relevant case of 3D growth, where the spiral trajectory can be altered by tuning the relative strengths of the gravity and touch stimuli, providing some intuition for the physical mechanism driving it.

  12. Sulphur limitation and early sulphur deficiency responses in poplar: significance of gene expression, metabolites, and plant hormones.

    PubMed

    Honsel, Anne; Kojima, Mikiko; Haas, Richard; Frank, Wolfgang; Sakakibara, Hitoshi; Herschbach, Cornelia; Rennenberg, Heinz

    2012-03-01

    The influence of sulphur (S) depletion on the expression of genes related to S metabolism, and on metabolite and plant hormone contents was analysed in young and mature leaves, fine roots, xylem sap, and phloem exudates of poplar (Populus tremula×Populus alba) with special focus on early consequences. S depletion was applied by a gradual decrease of sulphate availability. The observed changes were correlated with sulphate contents. Based on the decrease in sulphate contents, two phases of S depletion could be distinguished that were denominated as 'S limitation' and 'early S deficiency'. S limitation was characterized by improved sulphate uptake (enhanced root-specific sulphate transporter PtaSULTR1;2 expression) and reduction capacities (enhanced adenosine 5'-phosphosulphate (APS) reductase expression) and by enhanced remobilization of sulphate from the vacuole (enhanced putative vacuolar sulphate transporter PtaSULTR4;2 expression). During early S deficiency, whole plant distribution of S was impacted, as indicated by increasing expression of the phloem-localized sulphate transporter PtaSULTR1;1 and by decreasing glutathione contents in fine roots, young leaves, mature leaves, and phloem exudates. Furthermore, at 'early S deficiency', expression of microRNA395 (miR395), which targets transcripts of PtaATPS3/4 (ATP sulphurylase) for cleavage, increased. Changes in plant hormone contents were observed at 'early S deficiency' only. Thus, S depletion affects S and plant hormone metabolism of poplar during 'S limitation' and 'early S deficiency' in a time series of events. Despite these consequences, the impact of S depletion on growth of poplar plants appears to be less severe than in Brassicaceae such as Arabidopsis thaliana or Brassica sp.

  13. Seed biopriming with plant growth promoting rhizobacteria: a review.

    PubMed

    Mahmood, Ahmad; Turgay, Oğuz Can; Farooq, Muhammad; Hayat, Rifat

    2016-08-01

    Beneficial microbes are applied to the soil and plant tissues directly or through seed inoculation, whereas soil application is preferred when there is risk of inhibitors or antagonistic microbes on the plant tissues. Insufficient survival of the microorganisms, hindrance in application of fungicides to the seeds and exposure to heat and sunlight in subsequent seed storage in conventional inoculation methods force to explore appropriate and efficient bacterial application method. Seed priming, where seeds are hydrated to activate metabolism without actual germination followed by drying, increases the germination, stand establishment and stress tolerance in different crops. Seed priming with living bacterial inoculum is termed as biopriming that involves the application of plant growth promoting rhizobacteria. It increases speed and uniformity of germination; also ensures rapid, uniform and high establishment of crops; and hence improves harvest quality and yield. Seed biopriming allows the bacteria to enter/adhere the seeds and also acclimatization of bacteria in the prevalent conditions. This review focuses on methods used for biopriming, and also the role in improving crop productivity and stress tolerance along with prospects of this technology. The comparison of methods being followed is also reviewed proposing biopriming as a promising technique for application of beneficial microbes to the seeds.

  14. Mechanical Stress Regulation of Plant Growth and Development

    NASA Technical Reports Server (NTRS)

    Mitchell, C. A.

    1985-01-01

    Growth dynamics analysis was used to determine to what extent the seismic stress induced reduction in photosynthetic productivity in shaken soybeans was due to less photosynthetic surface, and to what extent to lower efficiency of assimulation. Seismic stress reduces shoot transpiration rate 17% and 15% during the first and second 45 minute periods following a given treatment. Shaken plants also had a 36% greater leaf water potential 30 minutes after treatment. Continuous measurement of whole plant photosynthetic rate shows that a decline in CO2 fixation began within seconds after the onset of shaking treatment and continued to decline to 16% less than that of controls 20 minutes after shaking, after which gradual recovery of photosynthesis begins. Photosynthetic assimilation recovered completely before the next treatment 5 hours later. The transitory decrease in photosynthetic rate was due entirely to a two fold increase in stomatal resistance to CO2 by the abaxial leaf surface. Mesophyll resistance was not significantly affected by periodic seismic treatment. Temporary stomatal aperture reduction and decreased CO2 fixation are responsible for the lower dry weight of seismic stressed plants growing in a controlled environment.

  15. Three redundant brassinosteroid early response genes encode putative bHLH transcription factors required for normal growth.

    PubMed Central

    Friedrichsen, Danielle M; Nemhauser, Jennifer; Muramitsu, Takamichi; Maloof, Julin N; Alonso, José; Ecker, Joseph R; Furuya, Masaki; Chory, Joanne

    2002-01-01

    Brassinosteroids (BRs) are a class of polyhydroxylated steroids that are important regulators of plant growth and development. We have identified three closely related basic helix-loop-helix (bHLH) transcription factors, BEE1, BEE2, and BEE3, as products of early response genes required for full BR response. Comparison of the phenotypes of plants that overexpress BEE1 with bee1 bee2 bee3 triple-knockout mutant plants suggests that BEE1, BEE2, and BEE3 are functionally redundant positive regulators of BR signaling. Expression of BEE1, BEE2, and BEE3 is also regulated by other hormones, notably abscisic acid (ABA), a known antagonist of BR signaling. Reduced ABA response in plants overexpressing BEE1 suggests that BEE proteins may function as signaling intermediates in multiple pathways. PMID:12454087

  16. Trade-off between early emergence and herbivore susceptibility mediates exotic success in an experimental California plant community.

    PubMed

    Waterton, Joseph; Cleland, Elsa E

    2016-12-01

    Ecological trade-offs are fundamental to theory in community ecology; critical for understanding species coexistence in diverse plant communities, as well as the evolution of diverse life-history strategies. Invasions by exotic species can provide insights into the importance of trade-offs in community assembly, because the ecological strategies of invading species often differ from those present in the native species pool. Exotic annual species have invaded many Mediterranean-climate areas around the globe, and often germinate and emerge earlier in the growing season than native species. Early-season growth can enable exotic annual species to preempt space and resources, competitively suppressing later-emerging native species; however, early-emerging individuals may also be more apparent to herbivores. This suggests a potential trade-off between seasonal phenology and susceptibility to herbivory. To evaluate this hypothesis, we monitored the emergence and growth of 12 focal species (six each native and exotic) in monoculture and polyculture, while experimentally excluding generalist herbivores both early and later in the growing season. Consistent with past studies, the exotic species emerged earlier than native species. Regardless of species origin, earlier-emerging species achieved greater biomass by the end of the experiment, but were more negatively impacted by herbivory, particularly in the early part of the growing season. This greater impact of early-season herbivory on early-active species led to a reduction in the competitive advantage of exotic species growing in polyculture, and improved the performance of later-emerging natives. Such a trade-off between early growth and susceptibility to herbivores could be an important force in community assembly in seasonal herbaceous-dominated ecosystems. These results also show how herbivore exclusion favors early-active exotic species in this system, with important implications for management in many areas invaded

  17. Effect of metal tolerant plant growth promoting bacteria on growth and metal accumulation in Zea mays plants grown in fly ash amended soil.

    PubMed

    Kumar, Kalpna V; Patra, D D

    2013-01-01

    The present study was undertaken to examine the effect of the application of fly ash (FA) into Garden soil (GS), with and without inoculation of plant growth promoting bacteria (PGPB), on the growth and metal uptake by Zea mays plants. Three FA tolerant PGPB strains, Pseudomonas sp. PS5, PS14, and Bacillus sp. BC29 were isolated from FA contaminated soils and assessed for their plant growth promoting features on the Z. mays plants. All three strains were also examined for their ability to solubilize phosphate and to produce Indole Acetic Acid (IAA), siderophores, and hydrogencynide acid (HCN) production. Although inoculation of all strains significantly enhanced the growth of plants at both the concentration of FA but maximum growth was observed in plants inoculated with BC29 and PS14 at low level (25%) of FA concentration. The experimental results explored the plant growth promoting features of selected strains which not only enhanced growth and biomass of plants but also protected them from toxicity of FA.

  18. Trickle water and feeding system in plant culture and light-dark cycle effects on plant growth.

    PubMed

    Takano, T; Inada, K; Takanashi, J

    1987-01-01

    Rockwool, as an inert medium covered or bagged with polyethylene film, can be effectively used for plant culture in space station. The most important machine is the pump adjusting the dripping rate in the feeding system. Hydro-aeroponics may be adaptable to a space laboratory. The shortening of the light-dark cycles inhibits plant growth and induces an abnormal morphogenesis. A photoperiod of 12-hr-dark may be needed for plant growth.

  19. Trickle water and feeding system in plant culture and light-dark cycle effects on plant growth

    NASA Astrophysics Data System (ADS)

    Takano, T.; Inada, K.; Takanashi, J.

    Rockwool, as an inert medium covered or bagged with polyethylene film, can be effectively used for plant culture in space station. The most important machine is the pump adjusting the dripping rate in the feeding system. Hydro-aeroponics may be adaptable to a space laboratory. The shortening of the light-dark cycles inhibits plant growth and induces an abnormal morphogenesis. A photoperiod of 12-hr-dark may be needed for plant growth.

  20. Trickle water and feeding system in plant culture and light-dark cycle effects on plant growth

    NASA Technical Reports Server (NTRS)

    Takano, T.; Inada, K.; Takanashi, J.

    1987-01-01

    Rockwool, as an inert medium covered or bagged with polyethylene film, can be effectively used for plant culture in space stations. The most important machine is the pump adjusting the dripping rate in the feeding system. Hydro-aeroponics may be adaptable to a space laboratory. The shortening of the light-dark cycles inhibits plant growth and induces an abnormal morphogenesis. A photoperiod of 12 hr dark may be needed for plant growth.

  1. Mechanism of Growth Enhancement of Plants Induced by Active Species in Plasmas

    NASA Astrophysics Data System (ADS)

    Watanabe, Satoshi; Ono, Reoto; Hayashi, Nobuya

    2015-09-01

    Plant growth enhances when seeds are irradiated by plasma. However the mechanism of the growth enhancement by plasma has not been clarified. In this study, growth enhancement of plants using various active species and variation of plant cells are investigated. RF plasma is generated under conditions where pressure is 60 Pa and input electrical power is 60 W. Irradiation period varies from 0 (control) to 75 min. Air plasma shows maximum growth of plants with irradiation period of 60 min on the other hand, oxygen plasma shows the maximum growth with irradiation period of 15 min. From change of gaseous species and pressure dependence, growth enhancing factor is expected to be active oxygen species produced in plasma. According to gene expression analysis of Arabidopsis, there are two speculated mechanism of plant growth enhancement. The first is acceleration of cell cycle by gene expressions of photosynthesis and glycolytic pathway, and the second is increase of cell size via plant hormone production.

  2. Parametric study of potential early commercial MHD power plants. Task 3: Parameter variation of plant size

    NASA Technical Reports Server (NTRS)

    Hals, F. A.

    1981-01-01

    Plants with a nominal output of 200 and 500 MWe and conforming to the same design configuration as the Task II plant were investigated. This information is intended to permit an assessment of the competitiveness of first generation MHD/steam plants with conventional steam plants over the range of 200 to 1000 MWe. The results show that net plant efficiency of the MHD plant is significantly higher than a conventional steam plant of corresponding size. The cost of electricity is also less for the MHD plant over the entire plant size range. As expected, the cost differential is higher for the larger plant and decreases with plant size. Even at the 200 MWe capacity, however, the differential in COE between the MHD plant and the conventional plant is sufficient attractive to warrant serious consideration. Escalating fuel costs will enhance the competitive position of MHD plants because they can utilize the fuel more efficiently than conventional steam plants.

  3. Physiological, structural and molecular traits activated in strawberry plants after inoculation with the plant growth-promoting bacterium Azospirillum brasilense REC3.

    PubMed

    Guerrero-Molina, M F; Lovaisa, N C; Salazar, S M; Martínez-Zamora, M G; Díaz-Ricci, J C; Pedraza, R O

    2015-05-01

    The plant growth-promoting strain REC3 of Azospirillum brasilense, isolated from strawberry roots, prompts growth promotion and systemic protection against anthracnose disease in this crop. Hence, we hypothesised that A. brasilense REC3 can induce different physiological, structural and molecular responses in strawberry plants. Therefore, the aim of this work was to study these traits activated in Azospirillum-colonised strawberry plants, which have not been assessed until now. Healthy, in vitro micropropagated plants were root-inoculated with REC3 under hydroponic conditions; root and leaf tissues were sampled at different times, and oxidative burst, phenolic compound content, malondialdehyde (MDA) concentration, callose deposition, cell wall fortification and gene expression were evaluated. Azospirillum inoculation enhanced levels of soluble phenolic compounds after 12 h post-inoculation (hpi), while amounts of cell wall bound phenolics were similar in inoculated and control plants. Other early responses activated by REC3 (at 24 hpi) were a decline of lipid peroxidation and up-regulation of strawberry genes involved in defence (FaPR1), bacterial recognition (FaFLS2) and H₂O₂ depuration (FaCAT and FaAPXc). The last may explain the apparent absence of oxidative burst in leaves after bacterial inoculation. Also, REC3 inoculation induced delayed structural responses such as callose deposition and cell wall fortification (at 72 hpi). Results showed that A. brasilense REC3 is capable of exerting beneficial effects on strawberry plants, reinforcing their physiological and cellular characteristics, which in turns contribute to improve plant performance.

  4. Increased plant growth and copper uptake of host and non-host plants by metal-resistant and plant growth-promoting endophytic bacteria.

    PubMed

    Sun, Leni; Wang, Xiaohan; Li, Ya

    2016-01-01

    The effects of inoculation with two metal-resistant and plant growth-promoting endophytic bacteria (Burkholderia sp. GL12 and Bacillus megaterium JL35) were evaluated on the plant growth and Cu uptake in their host Elsholtzia splendens and non-host Brassica napus plants grown in natural Cu-contaminated soil. The two strains showed a high level of ACC deaminase activities. In pot experiments, inoculation with strain GL12 significantly increased root and above-ground tissue dry weights of both plants, consequently increasing the total Cu uptake of E. splendens and Brassica napus by 132% and 48.2% respectively. Inoculation with strain JL35 was found to significantly increase not only the biomass of B. napus, consequently increasing the total Cu uptake of B. napus by 31.3%, but Cu concentration of E. splendens for above-ground tissues by 318% and roots by 69.7%, consequently increasing the total Cu uptake of E. splendens by 223%. The two strains could colonize the rhizosphere soils and root interiors of both plants. Notably, strain JL35 could colonize the shoot tissues and significantly increase the translocation factors and bioaccumulation factors of E. splendens. These results suggested that Burkholderia sp. GL12 and B. megaterium JL35 were valuable bacterial resource which had the potential in improving the efficiency of Cu phytoextraction by E. splendens and B. napus in a natural Cu-contaminated soil.

  5. Dredged Illinois River Sediments: Plant Growth and Metal Uptake

    USGS Publications Warehouse

    Darmody, R.G.; Marlin, J.C.; Talbott, J.; Green, R.A.; Brewer, E.F.; Stohr, C.

    2004-01-01

    Sedimentation of the Illinois River in central Illinois has greatly diminished the utility and ecological value of the Peoria Lakes reach of the river. Consequently, a large dredging project has been proposed to improve its wildlife habitat and recreation potential, but disposal of the dredged sediment presents a challenge. Land placement is an attractive option. Previous work in Illinois has demonstrated that sediments are potentially capable of supporting agronomic crops due to their high natural fertility and water holding capacity. However, Illinois River sediments have elevated levels of heavy metals, which may be important if they are used as garden or agricultural soil. A greenhouse experiment was conducted to determine if these sediments could serve as a plant growth medium. A secondary objective was to determine if plants grown on sediments accumulated significant heavy metal concentrations. Our results indicated that lettuce (Lactuca sativa L.), barley (Hordeum vulgare L.), radish (Raphanus sativus L.), tomato (Lycopersicon lycopersicum L.), and snap bean (Phaseolus vulagaris L. var. humillis) grown in sediment and a reference topsoil did not show significant or consistent differences in germination or yields. In addition, there was not a consistent statistically significant difference in metal content among tomatoes grown in sediments, topsoil, or grown locally in gardens. In the other plants grown on sediments, while Cd and Cu in all cases and As in lettuce and snap bean were elevated, levels were below those considered excessive. Results indicate that properly managed, these relatively uncontaminated calcareous sediments can make productive soils and that metal uptake of plants grown in these sediments is generally not a concern.

  6. Selenium promotes sulfur accumulation and plant growth in wheat (Triticum aestivum)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Selenium (Se) is an essential micronutrient for animals and humans and a target for biofortification in crops. Sulfur (S) is a crucial nutrient for plant growth. To gain better understanding of Se and S nutrition and interaction in plants, the effects of Se dosages and forms on plant growth as well ...

  7. Bacillus spp. from rainforest soil promote plant growth under limited nitrogen conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aims: The aim of this study was to evaluate effects of PGPR (Plant Growth Promoting Rhizobacteria) isolated from rainforest on different plants under limited nitrogen conditions. Methods and Results: Bacterial isolates from a Peruvian rainforest soil were screened for plant growth promoting effects...

  8. Genome Sequence of the Banana Plant Growth-Promoting Rhizobacterium Pseudomonas fluorescens PS006

    PubMed Central

    Gamez, Rocío M.; Rodríguez, Fernando; Ramírez, Sandra; Gómez, Yolanda; Agarwala, Richa; Landsman, David

    2016-01-01

    Pseudomonas fluorescens is a well-known plant growth-promoting rhizobacterium (PGPR). We report here the first whole-genome sequence of PGPR P. fluorescens evaluated in Colombian banana plants. The genome sequences contains genes involved in plant growth and defense, including bacteriocins, 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase, and genes that provide resistance to toxic compounds. PMID:27151797

  9. [The effect of soil inoculation with microbial pesticide destructors on plant growth and development].

    PubMed

    Lisina, T O; Garan'kina, N G; Kruglov, Iu V

    2001-01-01

    Soil inoculation with liquid cultures of Bacillus megaterium 501 and Exophiala nigrum A-29 capable of degrading several organophosphorus pesticides accelerated growth and development of experimental plants, formation of their generative organs, and improved their productivity. This was particularly observed under stress plant growth conditions on phytotoxic peach substrates. The microorganisms inoculated can probably degrade phytotoxins present in soils, thereby favoring the plant development.

  10. Biochar Treatment Resulted in a Combined Effect on Soybean Growth Promotion and a Shift in Plant Growth Promoting Rhizobacteria

    PubMed Central

    Egamberdieva, Dilfuza; Wirth, Stephan; Behrendt, Undine; Abd_Allah, Elsayed F.; Berg, Gabriele

    2016-01-01

    The application of biochar to soil is considered to have the potential for long-term soil carbon sequestration, as well as for improving plant growth and suppressing soil pathogens. In our study we evaluated the effect of biochar on the plant growth of soybeans, as well as on the community composition of root-associated bacteria with plant growth promoting traits. Two types of biochar, namely, maize biochar (MBC), wood biochar (WBC), and hydrochar (HTC) were used for pot experiments to monitor plant growth. Soybean plants grown in soil amended with HTC char (2%) showed the best performance and were collected for isolation and further characterization of root-associated bacteria for multiple plant growth promoting traits. Only HTC char amendment resulted in a statistically significant increase in the root and shoot dry weight of soybeans. Interestingly, rhizosphere isolates from HTC char amended soil showed higher diversity than the rhizosphere isolates from the control soil. In addition, a higher proportion of isolates from HTC char amended soil compared with control soil was found to express plant growth promoting properties and showed antagonistic activity against one or more phytopathogenic fungi. Our study provided evidence that improved plant growth by biochar incorporation into soil results from the combination of a direct effect that is dependent on the type of char and a microbiome shift in root-associated beneficial bacteria. PMID:26941730

  11. Biochar Treatment Resulted in a Combined Effect on Soybean Growth Promotion and a Shift in Plant Growth Promoting Rhizobacteria.

    PubMed

    Egamberdieva, Dilfuza; Wirth, Stephan; Behrendt, Undine; Abd Allah, Elsayed F; Berg, Gabriele

    2016-01-01

    The application of biochar to soil is considered to have the potential for long-term soil carbon sequestration, as well as for improving plant growth and suppressing soil pathogens. In our study we evaluated the effect of biochar on the plant growth of soybeans, as well as on the community composition of root-associated bacteria with plant growth promoting traits. Two types of biochar, namely, maize biochar (MBC), wood biochar (WBC), and hydrochar (HTC) were used for pot experiments to monitor plant growth. Soybean plants grown in soil amended with HTC char (2%) showed the best performance and were collected for isolation and further characterization of root-associated bacteria for multiple plant growth promoting traits. Only HTC char amendment resulted in a statistically significant increase in the root and shoot dry weight of soybeans. Interestingly, rhizosphere isolates from HTC char amended soil showed higher diversity than the rhizosphere isolates from the control soil. In addition, a higher proportion of isolates from HTC char amended soil compared with control soil was found to express plant growth promoting properties and showed antagonistic activity against one or more phytopathogenic fungi. Our study provided evidence that improved plant growth by biochar incorporation into soil results from the combination of a direct effect that is dependent on the type of char and a microbiome shift in root-associated beneficial bacteria.

  12. [Coupling Effects of Decomposed Potamogeton crispus and Growing Ceratophyllum demersum on Water Quality and Plant Growth].

    PubMed

    Ma, Yue; Wang, Guo-xiang; Cao, Xun; Wang, Xiao-yun; Ma, Jie

    2015-07-01

    In order to study the coupling effects of decomposed Potamogeton crispus (P. crispus) and growing Ceratophyllum demersum (C. demersum) on water quality and the effects of different decomposed biomass on plant growth, the simulating experiments for seasonal changes of submerged macrophytes were conducted. The results indicated that the nutrient concentrations in water remained at a relatively low level with different decomposed biomass and they remained stable after 29 days of the experiment. The concentrations of total dissolved nitrogen (DTN), total nitrogen (TN), total phosphorous (TP), total dissolved phosphorous (DTP), organic carbon (TOC) and chlorophyll-a (Chl-a) were lower than 0. 514, 0. 559, 0. 080, 0. 014, 13. 94 and 26. 546 mg . L-1, respectively. The obvious improving effects on water quality were observed under coupling condition of decomposition and growth, especially when the treatment of decomposed P. crispus was 20 g, and the removal efficiency of TN, DTN, TP, DTP, TOC and Chl-a reached 89. 67% , 52. 51%, 94. 99%, 55. 59% and 98. 55%, respectively. Compared with the physiology of C. demersum in the early stage, the contents of total chlorophyll, soluble protein and malondialdehyde all increased under different decomposed biomass conditions, which suggested that the nutrient released from decomposed P. crispus promoted the growth of C. demersum. The coupling effects between P. crispus decomposition and C. demersum growth showed better improving effect on water quality and growth of C. demersum with treatment of 20 g decomposed P. crispus.

  13. Plant-microbe interactions promoting plant growth and health: perspectives for controlled use of microorganisms in agriculture.

    PubMed

    Berg, Gabriele

    2009-08-01

    Plant-associated microorganisms fulfill important functions for plant growth and health. Direct plant growth promotion by microbes is based on improved nutrient acquisition and hormonal stimulation. Diverse mechanisms are involved in the suppression of plant pathogens, which is often indirectly connected with plant growth. Whereas members of the bacterial genera Azospirillum and Rhizobium are well-studied examples for plant growth promotion, Bacillus, Pseudomonas, Serratia, Stenotrophomonas, and Streptomyces and the fungal genera Ampelomyces, Coniothyrium, and Trichoderma are model organisms to demonstrate influence on plant health. Based on these beneficial plant-microbe interactions, it is possible to develop microbial inoculants for use in agricultural biotechnology. Dependent on their mode of action and effects, these products can be used as biofertilizers, plant strengtheners, phytostimulators, and biopesticides. There is a strong growing market for microbial inoculants worldwide with an annual growth rate of approximately 10%. The use of genomic technologies leads to products with more predictable and consistent effects. The future success of the biological control industry will benefit from interdisciplinary research, e.g., on mass production, formulation, interactions, and signaling with the environment, as well as on innovative business management, product marketing, and education. Altogether, the use of microorganisms and the exploitation of beneficial plant-microbe interactions offer promising and environmentally friendly strategies for conventional and organic agriculture worldwide.

  14. Genome sequence of the plant growth-promoting rhizobacterium Bacillus sp. strain JS.

    PubMed

    Song, Ju Yeon; Kim, Hyun A; Kim, Ji-Seoung; Kim, Seon-Young; Jeong, Haeyoung; Kang, Sung Gyun; Kim, Byung Kwon; Kwon, Soon-Kyeong; Lee, Choong Hoon; Yu, Dong Su; Kim, Beom Seok; Kim, Sun-Hyung; Kwon, Suk Yoon; Kim, Jihyun F

    2012-07-01

    Volatile and nonvolatile compounds emitted from the plant growth-promoting rhizobacterium Bacillus sp. strain JS enhance the growth of tobacco and lettuce. Here, we report the high-quality genome sequence of this bacterium. Its 4.1-Mb genome reveals a number of genes whose products are possibly involved in promotion of plant growth or antibiosis.

  15. Growth under elevated atmospheric CO(2) concentration accelerates leaf senescence in sunflower (Helianthus annuus L.) plants.

    PubMed

    de la Mata, Lourdes; Cabello, Purificación; de la Haba, Purificación; Agüera, Eloísa

    2012-09-15

    Some morphogenetic and metabolic processes were sensitive to a high atmospheric CO(2) concentration during sunflower primary leaf ontogeny. Young leaves of sunflower plants growing under elevated CO(2) concentration exhibited increased growth, as reflected by the high specific leaf mass referred to as dry weight in young leaves (16 days). The content of photosynthetic pigments decreased with leaf development, especially in plants grown under elevated CO(2) concentrations, suggesting that high CO(2) accelerates chlorophyll degradation, and also possibly leaf senescence. Elevated CO(2) concentration increased the oxidative stress in sunflower plants by increasing H(2)O(2) levels and decreasing activity of antioxidant enzymes such as catalase and ascorbate peroxidase. The loss of plant defenses probably increases the concentration of reactive oxygen species in the chloroplast, decreasing the photosynthetic pigment content as a result. Elevated CO(2) concentration was found to boost photosynthetic CO(2) fixation, especially in young leaves. High CO(2) also increased the starch and soluble sugar contents (glucose and fructose) and the C/N ratio during sunflower primary leaf development. At the beginning of senescence, we observed a strong increase in the hexoses to sucrose ratio that was especially marked at high CO(2) concentration. These results indicate that elevated CO(2) concentration could promote leaf senescence in sunflower plants by affecting the soluble sugar levels, the C/N ratio and the oxidative status during leaf ontogeny. It is likely that systemic signals produced in plants grown with elevated CO(2), lead to early senescence and a higher oxidation state of the cells of these plant leaves.

  16. Influence of plant maturity, shoot reproduction and sex on vegetative growth in the dioecious plant Urtica dioica

    PubMed Central

    Oñate, Marta; Munné-Bosch, Sergi

    2009-01-01

    Background and Aims Stinging nettle (Urtica dioica) is a herbaceous, dioecious perennial that is widely distributed around the world, reproduces both sexually and asexually, and is characterized by rapid growth. This work was aimed at evaluating the effects of plant maturity, shoot reproduction and sex on the growth of leaves and shoots. Methods Growth rates of apical shoots, together with foliar levels of phytohormones (cytokinins, auxins, absicisic acid, jasmonic acid and salicylic acid) and other indicators of leaf physiology (water contents, photosynthetic pigments, α-tocopherol and Fv/Fm ratios) were measured in juvenile and mature plants, with a distinction made between reproductive and non-reproductive shoots in both males and females. Vegetative growth rates were not only evaluated in field-grown plants, but also in cuttings obtained from these plants. All measurements were performed during an active vegetative growth phase in autumn, a few months after mature plants reproduced during spring and summer. Key Results Vegetative growth rates in mature plants were drastically reduced compared with juvenile ones (48 % and 78 % for number of leaves and leaf biomass produced per day, respectively), which was associated with a loss of photosynthetic pigments (up to 24 % and 48 % for chlorophylls and carotenoids, respectively) and increases of α-tocopherol (up to 2·7-fold), while endogenous levels of phytohormones did not differ between mature and juvenile plants. Reductions in vegetative growth were particularly evident in reproductive shoots of mature plants, and occurred similarly in both males and females. Conclusions It is concluded that (a) plant maturity reduces vegetative growth in U. dioica, (b) effects of plant maturity are evident both in reproductive and non-reproductive shoots, but particularly in the former, and (c) these changes occur similarly in both male and female plants. PMID:19633309

  17. Phytohormone profiles induced by trichoderma isolates correspond with their biocontrol and plant growth-promoting activity on melon plants.

    PubMed

    Martínez-Medina, Ainhoa; Del Mar Alguacil, Maria; Pascual, Jose A; Van Wees, Saskia C M

    2014-07-01

    The application of Trichoderma strains with biocontrol and plant growth-promoting capacities to plant substrates can help reduce the input of chemical pesticides and fertilizers in agriculture. Some Trichoderma isolates can directly affect plant pathogens, but they also are known to influence the phytohormonal network of their host plant, thus leading to an improvement of plant growth and stress tolerance. In this study, we tested whether alterations in the phytohormone signature induced by different Trichoderma isolates correspond with their ability for biocontrol and growth promotion. Four Trichoderma isolates were collected from agricultural soils and were identified as the species Trichoderma harzianum (two isolates), Trichoderma ghanense, and Trichoderma hamatum. Their antagonistic activity against the plant pathogen Fusarium oxysporum f. sp. melonis was tested in vitro, and their plant growth-promoting and biocontrol activity against Fusarium wilt on melon plants was examined in vivo, and compared to that of the commercial strain T. harzianum T-22. Several growth- and defense-related phytohormones were analyzed in the shoots of plants that were root-colonized by the different Trichoderma isolates. An increase in auxin and a decrease in cytokinins and abscisic acid content were induced by the isolates that promoted the plant growth. Principal component analysis (PCA) was used to evaluate the relationship between the plant phenotypic and hormonal variables. PCA pointed to a strong association of auxin induction with plant growth stimulation by Trichoderma. Furthermore, the disease-protectant ability of the Trichoderma strains against F. oxysporum infection seems to be more related to their induced alterations in the content of the hormones abscisic acid, ethylene, and the cytokinin trans-zeatin riboside than to the in vitro antagonism activity against F. oxysporum.

  18. A method of variable spacing for controlled plant growth systems in spaceflight and terrestrial agriculture applications

    NASA Technical Reports Server (NTRS)

    Knox, J.

    1986-01-01

    A higher plant growth system for Controlled Ecological Life Support System (CELSS) applications is described. The system permits independent movement of individual plants during growth. Enclosed within variable geometry growth chambers, the system allocates only the volume required by the growing plants. This variable spacing system maintains isolation between root and shoot environments, providing individual control for optimal growth. The advantages of the system for hydroponic and aeroponic growth chambers are discussed. Two applications are presented: (1) the growth of soybeans in a space station common module, and (2) in a terrestrial city greenhouse.

  19. Belowground rhizomes in paleosols: The hidden half of an Early Devonian vascular plant

    NASA Astrophysics Data System (ADS)

    Xue, Jinzhuang; Deng, Zhenzhen; Huang, Pu; Huang, Kangjun; Benton, Michael J.; Cui, Ying; Wang, Deming; Liu, Jianbo; Shen, Bing; Basinger, James F.; Hao, Shougang

    2016-08-01

    The colonization of terrestrial environments by rooted vascular plants had far-reaching impacts on the Earth system. However, the belowground structures of early vascular plants are rarely documented, and thus the plant-soil interactions in early terrestrial ecosystems are poorly understood. Here we report the earliest rooted paleosols (fossil soils) in Asia from Early Devonian deposits of Yunnan, China. Plant traces are extensive within the soil and occur as complex network-like structures, which are interpreted as representing long-lived, belowground rhizomes of the basal lycopsid Drepanophycus. The rhizomes produced large clones and helped the plant survive frequent sediment burial in well-drained soils within a seasonal wet-dry climate zone. Rhizome networks contributed to the accumulation and pedogenesis of floodplain sediments and increased the soil stabilizing effects of early plants. Predating the appearance of trees with deep roots in the Middle Devonian, plant rhizomes have long functioned in the belowground soil ecosystem. This study presents strong, direct evidence for plant-soil interactions at an early stage of vascular plant radiation. Soil stabilization by complex rhizome systems was apparently widespread, and contributed to landscape modification at an earlier time than had been appreciated.

  20. Belowground rhizomes in paleosols: The hidden half of an Early Devonian vascular plant.

    PubMed

    Xue, Jinzhuang; Deng, Zhenzhen; Huang, Pu; Huang, Kangjun; Benton, Michael J; Cui, Ying; Wang, Deming; Liu, Jianbo; Shen, Bing; Basinger, James F; Hao, Shougang

    2016-08-23

    The colonization of terrestrial environments by rooted vascular plants had far-reaching impacts on the Earth system. However, the belowground structures of early vascular plants are rarely documented, and thus the plant-soil interactions in early terrestrial ecosystems are poorly understood. Here we report the earliest rooted paleosols (fossil soils) in Asia from Early Devonian deposits of Yunnan, China. Plant traces are extensive within the soil and occur as complex network-like structures, which are interpreted as representing long-lived, belowground rhizomes of the basal lycopsid Drepanophycus The rhizomes produced large clones and helped the plant survive frequent sediment burial in well-drained soils within a seasonal wet-dry climate zone. Rhizome networks contributed to the accumulation and pedogenesis of floodplain sediments and increased the soil stabilizing effects of early plants. Predating the appearance of trees with deep roots in the Middle Devonian, plant rhizomes have long functioned in the belowground soil ecosystem. This study presents strong, direct evidence for plant-soil interactions at an early stage of vascular plant radiation. Soil stabilization by complex rhizome systems was apparently widespread, and contributed to landscape modification at an earlier time than had been appreciated.

  1. Advances in the application of plant growth-promoting rhizobacteria in phytoremediation of heavy metals.

    PubMed

    Tak, Hamid Iqbal; Ahmad, Faheem; Babalola, Olubukola Oluranti

    2013-01-01

    . Although not yet widely applied, utilizing a plant-microbe partnership is now being recognized as an important tool to enhance successful phytoremediaton of metal-contaminated sites. Hence, soil microbes are essential to soil health and sustainability. The key to their usefulness is their close association with, and positive influence on, plant growth and function. To capitalize on the early success of this technique and to improve it, additional research is needed on successful colonization and survival of inoculums under field conditions, because there are vital for the success of this approach. In addition, the effects of the interaction of PGPR and plant root-mediated process on the metal mobilization in soil are required, to better elucidate the mechanism that underlines bacterial-assisted phytoremediation is important. Finally, applying PGPR-associated phytoremediation under field conditions is important, because, to date, only locally contaminated sites have been treated with this technique, by using microbes cultured in the laboratory.

  2. Characterization of the bioactive metabolites from a plant growth-promoting rhizobacteria and their exploitation as antimicrobial and plant growth-promoting agents.

    PubMed

    George, Emrin; Kumar, S Nishanth; Jacob, Jubi; Bommasani, Bhaskara; Lankalapalli, Ravi S; Morang, P; Kumar, B S Dileep

    2015-05-01

    A plant growth-promoting bacterial strain, PM 105, isolated from a tea plantation soil from the North Eastern region of India was identified as Pseudomonas aeruginosa through classical and 16S ribosomal DNA (rDNA) gene sequencing. Further studies with this strain confirmed broad spectrum antifungal activity against ten human and plant pathogenic fungal pathogens viz. Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, Aspergillus tubingensis, Candida albicans, Colletotrichum gloeosporioides, Fusarium oxysporum, Pencillium expansum, Rhizoctonia solani, Trichophyton rubrum besides growth-promoting property in cowpea (Vigna unguiculata) and pigeon pea (Cajanus cajan). However, no antibacterial property was exhibited by this strain against the four test bacterial pathogens tested in agar overlay method. The crude bioactive metabolites produced by this strain were isolated with three different solvents that exhibited significant antimicrobial and plant growth-promoting activity. Chloroform extract recorded significant antimicrobial and plant growth-promoting activity. Three major compounds viz. 1-hydroxyphenazine, pyocyanin, and phenazine-1-carboxamide were purified and characterized from crude extracts of this strain by various spectral data. The purified compounds recorded prominent antimicrobial activity but failed to establish the plant growth promotion activity in test crop plants under gnotobiotic conditions. Pyocyanin recorded significant antimicrobial activity, and best activity was recorded against T. rubrum (29 mm), followed by P. expansum (28 mm). These results suggest the use of PM 105 as plant growth-promoting agent in crop plants after successful field trials.

  3. Melatonin enhances plant growth and abiotic stress tolerance in soybean plants.

    PubMed

    Wei, Wei; Li, Qing-Tian; Chu, Ya-Nan; Reiter, Russel J; Yu, Xiao-Min; Zhu, Dan-Hua; Zhang, Wan-Ke; Ma, Biao; Lin, Qing; Zhang, Jin-Song; Chen, Shou-Yi

    2015-02-01

    Melatonin is a well-known agent that plays multiple roles in animals. Its possible function in plants is less clear. In the present study, we tested the effect of melatonin (N-acetyl-5-methoxytryptamine) on soybean growth and development. Coating seeds with melatonin significantly promoted soybean growth as judged from leaf size and plant height. This enhancement was also observed in soybean production and their fatty acid content. Melatonin increased pod number and seed number, but not 100-seed weight. Melatonin also improved soybean tolerance to salt and drought stresses. Transcriptome analysis revealed that salt stress inhibited expressions of genes related to binding, oxidoreductase activity/process, and secondary metabolic processes. Melatonin up-regulated expressions of the genes inhibited by salt stress, and hence alleviated the inhibitory effects of salt stress on gene expressions. Further detailed analysis of the affected pathways documents that melatonin probably achieved its promotional roles in soybean through enhancement of genes involved in cell division, photosynthesis, carbohydrate metabolism, fatty acid biosynthesis, and ascorbate metabolism. Our results demonstrate that melatonin has significant potential for improvement of soybean growth and seed production. Further study should uncover more about the molecular mechanisms of melatonin's function in soybeans and other crops.

  4. The effects of solar radiation on plant growth

    SciTech Connect

    Agard, J.

    1995-09-01

    This phase of this continuing project was completed in April, 1994, using Dahlgren No. 855 hybrid sunflower seeds and Park Seeds No. 0950 non-hybrid sunflower seeds in both the control groups and the tests groups. The control groups (1, 2, 3, 4, 5, and 6) were grown under normal, un-radiated, conditions. The tests groups (1a, 2a, 3a, 4a, 5a, and 6a) were grown onboard the Space Shuttle Discovery on the STS-60 flight in February 1994. All data from this experiment (both control and test groups) will be taken and recorded in a data log and compared against each other to determine the radiation effects of solar radiation on plant germination and growth.

  5. The effects of solar radiation on plant growth

    NASA Technical Reports Server (NTRS)

    Agard, Joslyn

    1995-01-01

    This phase of this continuing project was completed in April, 1994, using Dahlgren #855 hybrid sunflower seeds and Park Seeds #0950 non-hybrid sunflower seeds in both the control groups and the tests groups. The control groups (1, 2, 3, 4, 5, and 6) were grown under normal, un-radiated, conditions. The tests groups (1a, 2a, 3a, 4a, 5a, and 6a) were grown onboard the Space Shuttle Discovery on the STS-60 flight in February 1994. All data from this experiment (both control and test groups) will be taken and recorded in a data log and compared against each other to determine the radiation effects of solar radiation on plant germination and growth.

  6. A soil irrigation method for experimental plant growth

    NASA Astrophysics Data System (ADS)

    Pop, M. N.; Soran, M. L.

    2015-12-01

    An irrigation method developed in order to ensure periodic wetting of several batches of soil, for experimental plant growth, is proposed. An experimental irrigation installation, intended to perform real-time soil moisturizing, by adding known quantities (preset for a certain batch of soil) of aqueous solutions has been built and tested. The prototype installation comprises six miniature pumps for water dosage, each meant to moisturize a batch of soil. Each pump is actuated from the mains power supply, with zero-crossing synchronization. The administrated quantity of aqueous solution is a multiple of the minimum volume, 0.2±0.01 ml of fluid. Due to its structure, the system allows the administration of different aqueous solutions for each batch of soil. Due to its modular construction the experimental installation can be expanded in order to ensure water disposal over an increased number of soil batches and the method may be suited also for micro irrigation systems.

  7. Perspective of plant growth promoting rhizobacteria (PGPR) containing ACC deaminase in stress agriculture.

    PubMed

    Saleem, Muhammad; Arshad, Muhammad; Hussain, Sarfraz; Bhatti, Ahmad Saeed

    2007-10-01

    Ethylene is a gaseous plant growth hormone produced endogenously by almost all plants. It is also produced in soil through a variety of biotic and abiotic mechanisms, and plays a key role in inducing multifarious physiological changes in plants at molecular level. Apart from being a plant growth regulator, ethylene has also been established as a stress hormone. Under stress conditions like those generated by salinity, drought, waterlogging, heavy metals and pathogenicity, the endogenous production of ethylene is accelerated substantially which adversely affects the root growth and consequently the growth of the plant as a whole. Certain plant growth promoting rhizobacteria (PGPR) contain a vital enzyme, 1-aminocyclopropane-1-carboxylate (ACC) deaminase, which regulates ethylene production by metabolizing ACC (an immediate precursor of ethylene biosynthesis in higher plants) into alpha-ketobutyrate and ammonia. Inoculation with PGPR containing ACC deaminase activity could be helpful in sustaining plant growth and development under stress conditions by reducing stress-induced ethylene production. Lately, efforts have been made to introduce ACC deaminase genes into plants to regulate ethylene level in the plants for optimum growth, particularly under stressed conditions. In this review, the primary focus is on giving account of all aspects of PGPR containing ACC deaminase regarding alleviation of impact of both biotic and abiotic stresses onto plants and of recent trends in terms of introduction of ACC deaminase genes into plant and microbial species.

  8. Nitrogen-fixing bacteria with multiple plant growth-promoting activities enhance growth of tomato and red pepper.

    PubMed

    Islam, Md Rashedul; Sultana, Tahera; Joe, M Melvin; Yim, Woojong; Cho, Jang-Cheon; Sa, Tongmin

    2013-12-01

    As a suitable alternative to chemical fertilizers, the application of plant growth-promoting rhizobacteria has been increasing in recent years due to their potential to be used as biofertilizers. In the present work, 13 nitrogen-fixing bacterial strains belonging to 11 different genera were tested for their PGP attributes. All of the strains were positive for 1-aminocyclopropane-1-carboxylate deaminase (ACCD), indole-3-acetic acid (IAA), salicylic acid, and ammonia production while negative for cellulase, pectinase, and hydrocyanic acid production. The strains Pseudomonas sp. RFNB3 and Serratia sp. RFNB14 were the most effective in solubilizing both tri-calcium phosphate and zinc oxide. In addition, all strains except Pseudomonas sp. RFNB3 were able to oxidize sulfur, and six strains were positive for siderophore synthesis. Each strain tested in this study possesses at least four PGP properties in addition to nitrogen fixation. Nine strains were selected based on their multiple PGP potential, particularly ACCD and IAA production, and evaluated for their effects on early growth of tomato and red pepper under gnotobiotic conditions. Bacterial inoculation considerably influenced root and shoot length, seedling vigor, and dry biomass of the two crop plants. Three strains that demonstrated substantial effects on plant performance were further selected for greenhouse trials with red pepper, and among them Pseudomonas sp. RFNB3 resulted in significantly higher plant height (26%) and dry biomass (28%) compared to control. The highest rate of nitrogen fixation, as determined by acetylene reduction assay, occurred in Novosphingobium sp. RFNB21 inoculated red pepper root (49.6 nM of ethylene/h/g of dry root) and rhizosphere soil (41.3 nM of ethylene/h/g of dry soil). Inoculation with nitrogen-fixing bacteria significantly increased chlorophyll content, and the uptake of different macro- and micro-nutrient contents enhancing also in red pepper shoots, in comparison with

  9. A unique plant ESCRT component, FREE1, regulates multivesicular body protein sorting and plant growth.

    PubMed

    Gao, Caiji; Luo, Ming; Zhao, Qiong; Yang, Renzhi; Cui, Yong; Zeng, Yonglun; Xia, Jun; Jiang, Liwen

    2014-11-03

    Tight control of membrane protein homeostasis by selective degradation is crucial for proper cell signaling and multicellular organismal development. Membrane proteins destined for degradation, such as misfolded proteins or activated receptors, are usually ubiquitinated and sorted into the intraluminal vesicles (ILVs) of prevacuolar compartments/multivesicular bodies (PVCs/MVBs), which then fuse with vacuoles/lysosomes to deliver their contents to the lumen for degradation by luminal proteases. The formation of ILVs and the sorting of ubiquitinated membrane cargoes into them are facilitated by the endosomal sorting complex required for transport (ESCRT) machinery. Plants possess most evolutionarily conserved members of the ESCRT machinery but apparently lack orthologs of ESCRT-0 subunits and the ESCRT-I component Mvb12. Here, we identified a unique plant ESCRT component called FYVE domain protein required for endosomal sorting 1 (FREE1). FREE1 binds to phosphatidylinositol-3-phosphate (PI3P) and ubiquitin and specifically interacts with Vps23 via PTAP-like tetrapeptide motifs to be incorporated into the ESCRT-I complex. Arabidopsis free1 mutant is seedling lethal and defective in the formation of ILVs in MVBs. Consequently, endocytosed plasma membrane (PM) proteins destined for degradation, such as the auxin efflux carrier PIN2, cannot reach the lumen of the vacuole and mislocalize to the tonoplast. Collectively, our findings provide the first functional characterization of a plant FYVE domain protein, which is essential for plant growth via its role as a unique evolutionary ESCRT component for MVB biogenesis and vacuolar sorting of membrane proteins.

  10. Rhizobacteria of Populus euphratica Promoting Plant Growth Against Heavy Metals.

    PubMed

    Zhu, Donglin; Ouyang, Liming; Xu, Zhaohui; Zhang, Lili

    2015-01-01

    The heavy metal-resistant bacteria from rhizospheric soils of wild Populus euphratica forest growing in arid and saline area of northwestern China were investigated by cultivation-dependent methods. After screening on medium sparked with zinc, copper, nickel and lead, 146 bacteria strains with different morphology were isolated and most of them were found to be resistant to at least two kinds of heavy metals. Significant increase in fresh weight and leaf surface area of Arabidopsis thaliana seedlings under metal stress were noticed after inoculated with strains especially those having multiple-resistance to heavy metals such as Phyllobacterium sp. strain C65. Investigation on relationship between auxin production and exogenous zinc concentration revealed that Phyllobacterium sp. strain C65 produced auxin, and production decreased as the concentration of zinc in medium increased. For wheat seedlings treated with zinc of 2 mM, zinc contents in roots of inoculated plants decreased by 27% (P < 0.05) compared to the uninoculated control. Meanwhile, zinc accumulation in the above-ground tissues increased by 22% (P < 0.05). The translocation of zinc from root to above-ground tissues induced by Phyllobacterium sp. strain C65 helped host plants extract zinc from contaminated environments more efficiently thus alleviated the growth inhibition caused by heavy metals.

  11. PRODUCTION OF PLANT GROWTH PROMOTING SUBSTANCES IN BACTERIAL ISOLATES FROM THE SEAGRASS RHIZOSPHERE

    EPA Science Inventory

    Plants and rhizosphere bacteria have evolved chemical signals that enable their mutual growth. These relationships have been well investigated with agriculturally important plants, but not in seagrasses, which are important to the stability of estuaries. Seagrasses are rooted in ...

  12. The effect of lichen-dominated biological soil crusts on growth and physiological characteristics of three plant species in a temperate desert of northwest China.

    PubMed

    Zhuang, W W; Serpe, M; Zhang, Y M

    2015-11-01

    Biocrusts (biological soil crusts) cover open spaces between vascular plants in most arid and semi-arid areas. Information on effects of biocrusts on seedling growth is controversial, and there is little information on their effects on plant growth and physiology. We examined impacts of biocrusts on growth and physiological characteristics of three habitat-typical plants, Erodium oxyrhynchum, Alyssum linifolium and Hyalea pulchella, growing in the Gurbantunggut Desert, northwest China. The influence of biocrusts on plant biomass, leaf area, leaf relative water content, photosynthesis, maximum quantum efficiency of PSII (F(v)/F(m)), chlorophyll, osmotic solutes (soluble sugars, protein, proline) and antioxidant enzymes (superoxide dismutase, catalase, peroxidase) was investigated on sites with or without biocrust cover. Biomass, leaf area, leaf water content, photosynthesis, F(v)/F(m) and chlorophyll content in crusted soils were higher than in uncrusted soils during early growth and lower later in the growth period. Soluble sugars, proline and antioxidant enzyme activity were always higher in crusted than in uncrusted soils, while soluble protein content was always lower. These findings indicate that biocrusts have different effects on these three ephemeral species during growth in this desert, primarily via effects on soil moisture, and possibly on soil nutrients. The influence of biocrusts changes during plant development: in early plant growth, biocrusts had either positive or no effect on growth and physiological parameters. However, biocrusts tended to negatively influence plants during later growth. Our results provide insights to explain why previous studies have found different effects of biocrusts on vascular plant growth.

  13. Plant hormone cross-talk: the pivot of root growth.

    PubMed

    Pacifici, Elena; Polverari, Laura; Sabatini, Sabrina

    2015-02-01

    Root indeterminate growth and its outstanding ability to produce new tissues continuously make this organ a highly dynamic structure able to respond promptly to external environmental stimuli. Developmental processes therefore need to be finely tuned, and hormonal cross-talk plays a pivotal role in the regulation of root growth. In contrast to what happens in animals, plant development is a post-embryonic process. A pool of stem cells, placed in a niche at the apex of the meristem, is a source of self-renewing cells that provides cells for tissue formation. During the first days post-germination, the meristem reaches its final size as a result of a balance between cell division and cell differentiation. A complex network of interactions between hormonal pathways co-ordinates such developmental inputs. In recent years, by means of molecular and computational approaches, many efforts have been made aiming to define the molecular components of these networks. In this review, we focus our attention on the molecular mechanisms at the basis of hormone cross-talk during root meristem size determination.

  14. Computational insight into the chemical space of plant growth regulators.

    PubMed

    Bushkov, Nikolay A; Veselov, Mark S; Chuprov-Netochin, Roman N; Marusich, Elena I; Majouga, Alexander G; Volynchuk, Polina B; Shumilina, Daria V; Leonov, Sergey V; Ivanenkov, Yan A

    2016-02-01

    An enormous technological progress has resulted in an explosive growth in the amount of biological and chemical data that is typically multivariate and tangled in structure. Therefore, several computational approaches have mainly focused on dimensionality reduction and convenient representation of high-dimensional datasets to elucidate the relationships between the observed activity (or effect) and calculated parameters commonly expressed in terms of molecular descriptors. We have collected the experimental data available in patent and scientific publications as well as specific databases for various agrochemicals. The resulting dataset was then thoroughly analyzed using Kohonen-based self-organizing technique. The overall aim of the presented study is to investigate whether the developed in silico model can be applied to predict the agrochemical activity of small molecule compounds and, at the same time, to offer further insights into the distinctive features of different agrochemical categories. The preliminary external validation with several plant growth regulators demonstrated a relatively high prediction power (67%) of the constructed model. This study is, actually, the first example of a large-scale modeling in the field of agrochemistry.

  15. Bioprospecting glacial ice for plant growth promoting bacteria.

    PubMed

    Balcazar, Wilvis; Rondón, Johnma; Rengifo, Marcos; Ball, María M; Melfo, Alejandra; Gómez, Wileidy; Yarzábal, Luis Andrés

    2015-08-01

    Glaciers harbor a wide diversity of microorganisms, metabolically versatile, highly tolerant to multiple environmental stresses and potentially useful for biotechnological purposes. Among these, we hypothesized the presence of bacteria able to exhibit well-known plant growth promoting traits (PGP). These kinds of bacteria have been employed for the development of commercial biofertilizers; unfortunately, these biotechnological products have proven ineffective in colder climates, like the ones prevailing in mountainous ecosystems. In the present work, we prospected glacial ice collected from two small tropical glaciers, located above 4.900 m in the Venezuelan Andes, for cold-active PGP bacteria. The initial screening strategy allowed us to detect the best inorganic-P solubilizers at low temperatures, from a sub-sample of 50 bacterial isolates. Solubilization of tricalcium phosphate, aluminum- and iron-phosphate, occurred in liquid cultures at low temperatures and was dependent on medium acidification by gluconic acid production, when bacteria were supplied with an appropriate source of carbon. Besides, the isolates were psychrophilic and in some cases exhibited a broad range of growth-temperatures, from 4 °C to 30 °C. Additional PGP abilities, including phytohormone- and HCN production, siderophore excretion and inhibition of phytopathogens, were confirmed in vitro. Nucleotidic sequence analysis of 16S rRNA genes allowed us to place the isolates within the Pseudomonas genus. Our results support the possible use of these strains to develop cold-active biofertilizers to be used in mountainous agriculture.

  16. Contrasting Strategies of Alfalfa Stem Elongation in Response to Fall Dormancy in Early Growth Stage: The Tradeoff between Internode Length and Internode Number

    PubMed Central

    Wang, Zongli; Sun, Qizhong

    2015-01-01

    Fall dormancy (FD) in alfalfa (Medicago sativa L.) can be described using 11 FD ratings, is widely used as an important indicator of stress resistance, productive performance and spring growth. However, the contrasting growth strategies in internode length and internode number in alfalfa cultivars with different FD rating are poorly understood. Here, a growth chamber study was conducted to investigate the effect of FD on plant height, aboveground biomass, internode length, and internode number in alfalfa individuals in the early growth stages. In order to simulate the alfalfa growth environment in the early stage, 11 alfalfa cultivars with FD ratings from one to 11 were chosen and seeded at the greenhouse, and then were transplanted into an artificial growth chamber. The experimental design was a randomized complete block in a split-plot arrangement with three replicates. Plant height, above-ground biomass, internode length, and internode number were measured in early growth stage in all individuals. Our findings showed that plant height and the aboveground biomass of alfalfa did not significantly differ among 11 different FD rated cultivars. Also, internode length and internode number positively affected plant height and the aboveground biomass of alfalfa individuals and the average internode length significantly increased with increasing FD rating. However, internode number tended to sharply decline when the FD rating increased. Moreover, there were no correlations, slightly negative correlations, and strongly negative correlations between internode length and internode number in alfalfa individuals among the three scales, including within-FD ratings, within-FD categories and inter-FD ratings, respectively. Therefore, our results highlighted that contrasting growth strategies in stem elongation were adopted by alfalfa with different FD ratings in the early growth stage. Alfalfa cultivars with a high FD rating have longer internodes, whereas more dormant alfalfa

  17. Microflora inside closed modules with plant growth facility

    NASA Astrophysics Data System (ADS)

    Zyablova, Natalya V.; Berkovich, Yuliy A.; Shanturin, Nikolai; Deshevaya, Elena; Smolyanina, Svetlana O.

    Currently, plant growth facility (PGF) is included in the LSS in many scenarios of Martian expedition. A number of investigators assume growing of crops can accelerate microflora re-production in closed ecological system. To estimate experimentally the change of density of microbiological community in the isolated module, Chinese cabbage Brassica hinensis L., cv. Vesnyanka, has been grown in the closed climatic chambers in volume 0.07 m3, 3 m3 and 250 m3 under continuous illumination in the range of values of temperature and relative humidity of air 23 -270 and 30 -60%, respectively. There were no differences in growth and develop-ment of plants grown during 30 days on the test-beds in the laboratory room (control) and in the closed chamber by 0.07 m3 volume (test). The microbiological analysis of root zone has revealed the presence of exclusively saprophytic species -the typical representatives of the soil microbiota. Then the plants were growing during 45 days in the prototype of the conveyor space PGF "Phytocycle LED" placed inside the chamber of 3 m3 volume. Every 3 days 50 -60 cm3 of liquid imitator of air condensate (IAC) from inhabited module had been injected to the chamber to simulate air pollution. The content of colony-forming units of the micromycetes in the air of the chamber, on the inner surfaces of the climate chamber, internal and external surfaces of the PGF and the leaves did not exceed the permissible values. When the PGF has been installed during 14 days inside the inhabited module with volume of 250 m3, the representatives of saprophytic and conditioned-pathogenic species of micromycetes (Trichethe-cium rozeum, Trichoderma sp., Fuzarrium sp., Mucor sp., Penicillium sp.) have been found out exclusively on the open surfaces of artificial soil and water-saturated porous passage. The obtained data shows that PGF inside closed modules can assure microbiological safety when all wet surfaces are isolated from the gas environment.

  18. High-Throughput Phenotyping and QTL Mapping Reveals the Genetic Architecture of Maize Plant Growth1[OPEN

    PubMed Central

    Huang, Chenglong; Wu, Di; Qiao, Feng; Li, Wenqiang; Duan, Lingfeng; Wang, Ke; Xiao, Yingjie; Chen, Guoxing; Liu, Qian; Yang, Wanneng

    2017-01-01

    With increasing demand for novel traits in crop breeding, the plant research community faces the challenge of quantitatively analyzing the structure and function of large numbers of plants. A clear goal of high-throughput phenotyping is to bridge the gap between genomics and phenomics. In this study, we quantified 106 traits from a maize (Zea mays) recombinant inbred line population (n = 167) across 16 developmental stages using the automatic phenotyping platform. Quantitative trait locus (QTL) mapping with a high-density genetic linkage map, including 2,496 recombinant bins, was used to uncover the genetic basis of these complex agronomic traits, and 988 QTLs have been identified for all investigated traits, including three QTL hotspots. Biomass accumulation and final yield were predicted using a combination of dissected traits in the early growth stage. These results reveal the dynamic genetic architecture of maize plant growth and enhance ideotype-based maize breeding and prediction. PMID:28153923

  19. Biological management of Sclerotinia sclerotiorum in pea using plant growth promoting microbial consortium.

    PubMed

    Jain, Akansha; Singh, Akanksha; Singh, Surendra; Singh, Harikesh Bahadur

    2015-08-01

    The beneficial plant-microbe interactions play crucial roles in protection against large number of plant pathogens causing disease. The present study aims to investigate the growth promoting traits induced by beneficial microbes namely Pseudomonas aeruginosa PJHU15, Trichoderma harzianum TNHU27, and Bacillus subtilis BHHU100 treated singly and in combinations under greenhouse and field conditions to control Sclerotinia sclerotiorum. Plants treated with three microbe consortium enhanced plant growth maximally both in the presence and absence of the pathogen. Increase in plant length, total biomass, number of leaves, nodules and secondary roots, total chlorophyll and carotenoid content, and yield were recorded in plants treated with microbial consortia. Also, a decrease in plant mortality was observed in plants treated with microbial consortia in comparison to untreated control plants challenged with S. sclerotiorum. Furthermore, the decrease in disease of all the treatments can be associated with differential improvement of growth induced in pea.

  20. Early East Antarctic Ice Sheet growth recorded in the landscape of the Gamburtsev Subglacial Mountains

    NASA Astrophysics Data System (ADS)

    Rose, Kathryn C.; Ferraccioli, Fausto; Jamieson, Stewart S. R.; Bell, Robin E.; Corr, Hugh; Creyts, Timothy T.; Braaten, David; Jordan, Tom A.; Fretwell, Peter T.; Damaske, Detlef

    2013-08-01

    The Gamburtsev Subglacial Mountains are regarded as a key nucleation site for the Antarctic Ice Sheet and they retain a unique long-term record of pre-glacial and early glacial landscape evolution. Here, we use a range of morphometric analyses to constrain the nature of early glaciation and subsequent ice sheet evolution in the interior of East Antarctica, using a new digital elevation model of the Gamburtsev Subglacial Mountains, derived from an extensive airborne radar survey. We find that an inherited fluvial landscape confirms the existence of the Gamburtsev Subglacial Mountains prior to the onset of glaciation at the Eocene-Oligocene climate boundary (ca. 34 Ma). Features characteristic of glaciation, at a range of scales, are evident across the mountains. High elevation alpine valley heads, akin to cirques, identified throughout the mountains, are interpreted as evidence for early phases of glaciation in East Antarctica. The equilibrium line altitudes associated with these features, combined with information from fossil plant assemblages, suggest that they formed at, or prior to, 34 Ma. It cannot be ruled out that they may have been eroded by ephemeral ice between the Late Cretaceous and the Eocene (100-34 Ma). Hanging valleys, overdeepenings, truncated spurs and steep-sided, linear valley networks are indicative of a more widespread alpine glaciation in this region. These features represent ice growth at, or before, 33.7 Ma and provide a minimum estimate for the scale of the East Antarctic Ice Sheet between ca. 34 and 14 Ma, when dynamic fluctuations in ice extent are recorded at the coast of Antarctica. The implications are that the early East Antarctic Ice Sheet grew rapidly and developed a cold-based core that preserved the alpine landscape. The patterns of landscape evolution identified provide the earliest evidence for the development of the East Antarctic Ice Sheet and can be used to test coupled ice-climate evolution models.

  1. [Advances in studies on growth metabolism and response mechanisms of medicinal plants under drought stress].

    PubMed

    Si, Can; Zhang, Jun-Yi; Xu, Hu-Chao

    2014-07-01

    Drought stress exerts a considerable effect on growth, physiology and secondary metabolisms of the medicinal plants. It could inhabit the growth of the medicinal plants but promote secretion of secondary metabolites. Other researches indicated that the medicinal plants could depend on the ABA signaling pathway and secreting osmotic substances to resist the drought stress and reduce the damage by it. The article concludes the changes in growth, physiology, secondary metabolisms and response mechanisms of medicinal plants to drought stress that provides a theoretical basis for exploring the relationship between medicinal plants and drought stress.

  2. Plant vascular development: from early specification to differentiation.

    PubMed

    De Rybel, Bert; Mähönen, Ari Pekka; Helariutta, Yrjö; Weijers, Dolf

    2016-01-01

    Vascular tissues in plants are crucial to provide physical support and to transport water, sugars and hormones and other small signalling molecules throughout the plant. Recent genetic and molecular studies have identified interconnections among some of the major signalling networks that regulate plant vascular development. Using Arabidopsis thaliana as a model system, these studies enable the description of vascular development from the earliest tissue specification events during embryogenesis to the differentiation of phloem and xylem tissues. Moreover, we propose a model for how oriented cell divisions give rise to a three-dimensional vascular bundle within the root meristem.

  3. Synchrony between growth and reproductive patterns in human females: Early investment in growth among Pumé foragers.

    PubMed

    Kramer, Karen L; Greaves, Russell D

    2010-02-01

    Life history is an important framework for understanding many aspects of ontogeny and reproduction relative to fitness outcomes. Because growth is a key influence on the timing of reproductive maturity and age at first birth is a critical demographic variable predicting lifetime fertility, it raises questions about the synchrony of growth and reproductive strategies. Among the Pumé, a group of South American foragers, young women give birth to their first child on average at age 15.5. Previous research showed that this early age at first birth maximizes surviving fertility under conditions of high infant mortality. In this study we evaluate Pumé growth data to test the expectation that if early reproduction is advantageous, then girls should have a developmental trajectory that best prepares them for young childbearing. Analyses show that comparatively Pumé girls invest in skeletal growth early, enter puberty having achieved a greater proportion of adult body size and grow at low velocities during adolescence. For early reproducers growing up in a food-limited environment, a precocious investment in growth is advantageous because juveniles have no chance of pregnancy and it occurs before the onset of the competing metabolic demands of final reproductive maturation and childbearing. Documenting growth patterns under preindustrial energetic and demographic conditions expands the range of developmental variation not otherwise captured by normative growth standards and contributes to research on human phenotypic plasticity in diverse environments.

  4. Plant Growth Experiments in Zeoponic Substrates: Applications for Advanced Life Support Systems

    NASA Technical Reports Server (NTRS)

    Ming, Douglas W.; Gruener, J. E.; Henderson, K. E.; Steinberg, S. L.; Barta, D. J.; Galindo, C.; Henninger, D. L.

    2001-01-01

    A zeoponic plant-growth system is defined as the cultivation of plants in artificial soils, which have zeolites as a major component (Allen and Ming, 1995). Zeolites are crystalline, hydrated aluminosilicate minerals that have the ability to exchange constituent cations without major change of the mineral structure. Recently, zeoponic systems developed at the National Aeronautics and Space Administration (NASA) slowly release some (Allen et at., 1995) or all of the essential plant-growth nutrients (Ming et at., 1995). These systems have NH4- and K-exchanged clinoptilolite (a natural zeolite) and either natural or synthetic apatite (a calcium phosphate mineral). For the natural apatite system, Ca and P were made available to the plant by the dissolution of apatite. Potassium and NH4-N were made available by ion-exchange reactions involving Ca(2+) from apatite dissolution and K(+) and NH4(+) on zeolitic exchange sites. In addition to NH4-N, K, Ca, and P, the synthetic apatite system also supplied Mg, S, and other micronutrients during dissolution (Figure 1). The overall objective of this research task is to develop zeoponic substrates wherein all plant growth nutrients are supplied by the plant growth medium for several growth seasons with only the addition of water. The substrate is being developed for plant growth in Advanced Life Support (ALS) testbeds (i.e., BioPLEX) and microgravity plant growth experiments. Zeoponic substrates have been used for plant growth experiments on two Space Shuttle flight experiments (STS-60; STS-63; Morrow et aI., 1995). These substrates may be ideally suited for plant growth experiments on the International Space Station and applications in ALS testbeds. However, there are several issues that need to be resolved before zeoponics will be the choice substrate for plant growth experiments in space. The objective of this paper is to provide an overview on recent research directed toward the refinement of zeoponic plant growth substrates.

  5. A whole-plant perspective reveals unexpected impacts of above- and belowground herbivores on plant growth and defense.

    PubMed

    Mundim, Fabiane M; Alborn, Hans T; Vieira-Neto, Ernane H M; Bruna, Emilio M

    2017-01-01

    Trade-offs between plant growth and defense are central to theoretical frameworks used to study the ecology and evolution of plant defense against herbivores. However, these frameworks, as well as the experiments designed to test them, rarely include belowground herbivores. We experimentally challenged seedlings of the tropical shrub Solanum lycocarpum (Solanaceae) with either aboveground foliar herbivores (Spodoptera caterpillars) or belowground root herbivores (the nematode Meloidogyne incognita) and measured the resulting changes in plant growth rates, biomass allocation, and the concentration of defensive terpenoids in roots and leaves. We found that plants that suffered aboveground herbivory responded with aboveground growth but belowground defense. Similarly, belowground herbivory resulted in root growth but elevated defenses of leaves. These results underscore the importance of belowground plant-herbivore interactions, and suggest that, in contrast to theoretical predictions, plants can simultaneously invest in both growth and defense. Finally, they emphasize the need for a "whole-plant" perspective in theoretical and empirical evaluations of plant-herbivore interactions.

  6. Small solar thermal electric power plants with early commercial potential

    NASA Technical Reports Server (NTRS)

    Jones, H. E.; Bisantz, D. J.; Clayton, R. N.; Heiges, H. H.; Ku, A. C.

    1979-01-01

    Cost-effective small solar thermal electric power plants (1- to 10-MW nominal size) offer an attractive way of helping the world meet its future energy needs. The paper describes the characteristics of a conceptual near-term plant (about 1 MW) and a potential 1990 commercial version. The basic system concept is one in which steam is generated using two-axis tracking, parabolic dish, and point-focusing collectors. The steam is transported through low-loss piping to a central steam turbine generator unit where it is converted to electricity. The plants have no energy storage and their output power level varies with the solar insolation level. This system concept, which is firmly based on state-of-the-art technology, is projected to offer one of the fastest paths for U.S. commercialization of solar thermal electric power plants through moderate technology advances and mass production.

  7. Effect of plant growth-promoting bacteria on the growth and fructan production of Agave americana L.

    PubMed

    De La Torre-Ruiz, Neyser; Ruiz-Valdiviezo, Víctor Manuel; Rincón-Molina, Clara Ivette; Rodríguez-Mendiola, Martha; Arias-Castro, Carlos; Gutiérrez-Miceli, Federico Antonio; Palomeque-Dominguez, Héctor; Rincón-Rosales, Reiner

    2016-01-01

    The effect of plant growth-promoting bacteria inoculation on plant growth and the sugar content in Agave americana was assessed. The bacterial strains ACO-34A, ACO-40, and ACO-140, isolated from the A. americana rhizosphere, were selected for this study to evaluate their phenotypic and genotypic characteristics. The three bacterial strains were evaluated via plant inoculation assays, and Azospirillum brasilense Cd served as a control strain. Phylogenetic analysis based on the 16S rRNA gene showed that strains ACO-34A, ACO-40 and ACO-140 were Rhizobium daejeonense, Acinetobacter calcoaceticus and Pseudomonas mosselii, respectively. All of the strains were able to synthesize indole-3-acetic acid (IAA), solubilize phosphate, and had nitrogenase activity. Inoculation using the plant growth-promoting bacteria strains had a significant effect (p<0.05) on plant growth and the sugar content of A. americana, showing that these native plant growth-promoting bacteria are a practical, simple, and efficient alternative to promote the growth of agave plants with proper biological characteristics for agroindustrial and biotechnological use and to increase the sugar content in this agave species.

  8. Regulation of early human growth: impact on long-term health.

    PubMed

    Koletzko, Berthold; Chourdakis, Michael; Grote, Veit; Hellmuth, Christian; Prell, Christine; Rzehak, Peter; Uhl, Olaf; Weber, Martina

    2014-01-01

    Growth and development are central characteristics of childhood. Deviations from normal growth can indicate serious health challenges. The adverse impact of early growth faltering and malnutrition on later health has long been known. In contrast, the impact of rapid early weight and body fat gain on programming of later disease risk have only recently received increased attention. Numerous observational studies related diet in early childhood and rapid early growth to the risk of later obesity and associated disorders. Causality was confirmed in a large, double-blind randomised trial testing the 'Early Protein Hypothesis'. In this trial we found that attenuation of protein supply in infancy normalized early growth and markedly reduced obesity prevalence in early school age. These results indicate the need to describe and analyse growth patterns and their regulation through diet in more detail and to characterize the underlying metabolic and epigenetic mechanisms, given the potential major relevance for public health and policy. Better understanding of growth patterns and their regulation could have major benefits for the promotion of public health, consumer-orientated nutrition recommendations, and the development of improved food products for specific target populations.

  9. The effect of plant growth-promoting rhizobacteria on the growth, physiology, and Cd uptake of Arundo donax L.

    PubMed

    Sarathambal, Chinnathambi; Khankhane, Premraj Jagoji; Gharde, Yogita; Kumar, Bhumesh; Varun, Mayank; Arun, Sellappan

    2017-04-03

    In this study, plant growth-promoting potential isolates from rhizosphere of 10 weed species grown in heavy metal-contaminated areas were identified and their effect on growth, antioxidant enzymes, and cadmium (Cd) uptake in Arundo donax L. was explored. Plant growth-promoting traits of isolates were also analyzed. These isolates were found to produce siderophores and enzymes such as 1-aminocyclopropane-1-carboxylate (ACC) deaminase, and aid in solubilization of mineral nutrients and modulate plant growth and development. Based on the presence of multiple plant growth-promoting traits, isolates were selected for molecular characterization and inoculation studies. Altogether, 58 isolates were obtained and 20% of them were able to tolerate Cd up to 400 ppm. The sequence analysis of the 16S rRNA genes indicates that the isolates belong to the phylum Firmicutes. Bacillus sp. along with mycorrhizae inoculation significantly improves the growth, the activity of antioxidants enzymes, and the Cd uptake in A. donax than Bacillus alone. Highly significant correlations were observed between Cd uptake, enzymatic activities, and plant growth characteristics at 1% level of significance. The synergistic interaction effect between these organisms helps to alleviate Cd effects on soil. Heavy metal-tolerant isolate along with arbuscular mycorrhizae (AM) could be used to improve the phytoremedial potential of plants.

  10. Understanding Plant Community Responses to Combinations of Biotic and Abiotic Factors in Different Phases of the Plant Growth Cycle

    PubMed Central

    Wood, Kevin A.; Stillman, Richard A.; Clarke, Ralph T.; Daunt, Francis; O’Hare, Matthew T.

    2012-01-01

    Understanding plant community responses to combinations of biotic and abiotic factors is critical for predicting ecosystem response to environmental change. However, studies of plant community regulation have seldom considered how responses to such factors vary with the different phases of the plant growth cycle. To address this deficit we studied an aquatic plant community in an ecosystem subject to gradients in mute swan (Cygnus olor) herbivory, riparian shading, water temperature and distance downstream of the river source. We quantified abundance, species richness, evenness, flowering and dominance in relation to biotic and abiotic factors during the growth-, peak-, and recession-phases of the plant growth cycle. We show that the relative importance of biotic and abiotic factors varied between plant community properties and between different phases of the plant growth cycle. Herbivory became more important during the later phases of peak abundance and recession due to an influx of swans from adjacent pasture fields. Shading by riparian vegetation also had a greater depressing effect on biomass in later seasons, probably due to increased leaf abundance reducing light intensity reaching the aquatic plants. The effect of temperature on community diversity varied between upstream and downstream sites by altering the relative competitiveness of species at these sites. These results highlight the importance of seasonal patterns in the regulation of plant community structure and function by multiple factors. PMID:23166777

  11. Understanding plant community responses to combinations of biotic and abiotic factors in different phases of the plant growth cycle.

    PubMed

    Wood, Kevin A; Stillman, Richard A; Clarke, Ralph T; Daunt, Francis; O'Hare, Matthew T

    2012-01-01

    Understanding plant community responses to combinations of biotic and abiotic factors is critical for predicting ecosystem response to environmental change. However, studies of plant community regulation have seldom considered how responses to such factors vary with the different phases of the plant growth cycle. To address this deficit we studied an aquatic plant community in an ecosystem subject to gradients in mute swan (Cygnus olor) herbivory, riparian shading, water temperature and distance downstream of the river source. We quantified abundance, species richness, evenness, flowering and dominance in relation to biotic and abiotic factors during the growth-, peak-, and recession-phases of the plant growth cycle. We show that the relative importance of biotic and abiotic factors varied between plant community properties and between different phases of the plant growth cycle. Herbivory became more important during the later phases of peak abundance and recession due to an influx of swans from adjacent pasture fields. Shading by riparian vegetation also had a greater depressing effect on biomass in later seasons, probably due to increased leaf abundance reducing light intensity reaching the aquatic plants. The effect of temperature on community diversity varied between upstream and downstream sites by altering the relative competitiveness of species at these sites. These results highlight the importance of seasonal patterns in the regulation of plant community structure and function by multiple factors.

  12. [Plant growth promoting microorganisms as alternative to chemical protection from pathogens (review)].

    PubMed

    Maksimov, I V; Abizgil'dina, R R; Pusenkova, L I

    2011-01-01

    The review analyses data on physiological and biochemical influence of rhizospheric and endophytic microorganisms promoting plant growth (PGPR-plant growth promoting rhizobacteria) on induced resistance of plants and the possibility of its use in plant cultivation to protect crops from pathogens and phytophages. Resistance of plants provided by PGPR due to their endosymbiotic interrelationships is directly achieved because they produce peptide antibiotics and hydrolases ofchitin and glucan and also because plants form their own system of induced resistance, followed by changes in the balance of defensive proteins, phytohormones, and pro-/antioxidant status.

  13. Different Growth Promoting Effects of Endophytic Bacteria on Invasive and Native Clonal Plants

    PubMed Central

    Dai, Zhi-Cong; Fu, Wei; Wan, Ling-Yun; Cai, Hong-Hong; Wang, Ning; Qi, Shan-Shan; Du, Dao-Lin

    2016-01-01

    The role of the interactions between endophytes and alien plants has been unclear yet in plant invasion. We used a completely germ-free culture system to quantify the plant growth-promoting (PGP) effects of endophytic bacteria Bacillus sp. on aseptic seedlings of Wedelia trilobata and of its native clonal congener W. chinensis. The endophytic bacteria did not affect the growth of W. chinensis, but they significantly promoted the growth of W. trilobata. With the PGP effects of endophytic bacteria, relative change ratios of the clonal traits and the ramets’ growth traits of W. trilobata were significantly greater than those of W. chinensis. Our results indicate that the growth-promoting effects of endophytes may differ between invasive and native clonal plants, and the endophytes of invasive plant may be host-specific to facilitate plant invasion. PMID:27252722

  14. Predictors of Longitudinal Growth in Inhibitory Control in Early Childhood

    ERIC Educational Resources Information Center

    Moilanen, Kristin L.; Shaw, Daniel S.; Dishion, Thomas J.; Gardner, Frances; Wilson, Melvin

    2010-01-01

    In the current study, we examined latent growth in 731 young children's inhibitory control from the ages of two to four years, and whether demographic characteristics or parenting behaviors were related to initial levels and growth in inhibitory control. As part of an ongoing longitudinal evaluation of the family check-up, children's inhibitory…

  15. Plant Growth Promotion by Volatile Organic Compounds Produced by Bacillus subtilis SYST2

    PubMed Central

    Tahir, Hafiz A. S.; Gu, Qin; Wu, Huijun; Raza, Waseem; Hanif, Alwina; Wu, Liming; Colman, Massawe V.; Gao, Xuewen

    2017-01-01

    Bacterial volatiles play a significant role in promoting plant growth by regulating the synthesis or metabolism of phytohormones. In vitro and growth chamber experiments were conducted to investigate the effect of volatile organic compounds (VOCs) produced by the plant growth promoting rhizobacterium Bacillus subtilis strain SYST2 on hormone regulation and growth promotion in tomato plants. We observed a significant increase in plant biomass under both experimental conditions; we observed an increase in photosynthesis and in the endogenous contents of gibberellin, auxin, and cytokinin, while a decrease in ethylene levels was noted. VOCs emitted by SYST2 were identified through gas chromatography-mass spectrometry analysis. Of 11 VOCs tested in glass jars containing plants in test tubes, only two, albuterol and 1,3-propanediole, were found to promote plant growth. Furthermore, tomato plants showed differential expression of genes involved in auxin (SlIAA1. SlIAA3), gibberellin (GA20ox-1), cytokinin (SlCKX1), expansin (Exp2, Exp9. Exp 18), and ethylene (ACO1) biosynthesis or metabolism in roots and leaves in response to B. subtilis SYST2 VOCs. Our findings suggest that SYST2-derived VOCs promote plant growth by triggering growth hormone activity, and provide new insights into the mechanism of plant growth promotion by bacterial VOCs. PMID:28223976

  16. Beneficial role of plant growth promoting bacteria and arbuscular mycorrhizal fungi on plant responses to heavy metal stress.

    PubMed

    Gamalero, Elisa; Lingua, Guido; Berta, Graziella; Glick, Bernard R

    2009-05-01

    Heavy metal pollution is a major worldwide environmental concern that has recently motivated researchers to develop a variety of novel approaches towards its cleanup. As an alternative to traditional physical and chemical methods of environmental cleanup, scientists have developed phytoremediation approaches that include the use of plants to remove or render harmless a range of compounds. Both plant growth promoting bacteria (PGPB) and arbuscular mycorrhizal fungi (AMF) can be used to facilitate the process of phytoremediation and the growth of plants in metal-contaminated soils. This review focuses on the recent literature dealing with the effects of plant growth-promoting bacteria and AM fungi on the response of plants to heavy metal stress and points the way to strategies that may facilitate the practical realization of this technology.

  17. Belowground rhizomes in paleosols: The hidden half of an Early Devonian vascular plant

    PubMed Central

    Xue, Jinzhuang; Deng, Zhenzhen; Huang, Pu; Huang, Kangjun; Benton, Michael J.; Cui, Ying; Wang, Deming; Liu, Jianbo; Shen, Bing; Basinger, James F.; Hao, Shougang

    2016-01-01

    The colonization of terrestrial environments by rooted vascular plants had far-reaching impacts on the Earth system. However, the belowground structures of early vascular plants are rarely documented, and thus the plant−soil interactions in early terrestrial ecosystems are poorly understood. Here we report the earliest rooted paleosols (fossil soils) in Asia from Early Devonian deposits of Yunnan, China. Plant traces are extensive within the soil and occur as complex network-like structures, which are interpreted as representing long-lived, belowground rhizomes of the basal lycopsid Drepanophycus. The rhizomes produced large clones and helped the plant survive frequent sediment burial in well-drained soils within a seasonal wet−dry climate zone. Rhizome networks contributed to the accumulation and pedogenesis of floodplain sediments and increased the soil stabilizing effects of early plants. Predating the appearance of trees with deep roots in the Middle Devonian, plant rhizomes have long functioned in the belowground soil ecosystem. This study presents strong, direct evidence for plant−soil interactions at an early stage of vascular plant radiation. Soil stabilization by complex rhizome systems was apparently widespread, and contributed to landscape modification at an earlier time than had been appreciated. PMID:27503883

  18. An assessment of the contribution of NRC (Nuclear Regulatory Commission) regulatory growth to nuclear plant cost growth using engineering scope changes

    SciTech Connect

    Cohen, S.

    1987-03-01

    The purpose of this study is to determine the contribution of NRC regulations to the growth in nuclear power plant capital costs using the case study method. The two plants selected for the case studies are Florida Power and Light Company's (FP and L) St. Lucie Unit 1 (SL1) and St. Lucie Unit 2 (SL2). SL1 was constructed in the early 1970s and was granted an operating license in 1976. SL2 was constructed in the late 1970s and early 1980s, and was granted an operating license in 1983. The information bases were the amendments to the contracts between FP and L and its architect-engineer/constructor, i.e., the ''scope changes''. These were examined and analyzed for causation, i.e., NRC-initiated or utility-initiated, and all of the costs associated with scope changes of each type were aggregated to determine the contribution of each. Although the scope changes accounted for only a small fraction of the total cost growth for either plant, they were still used to determine the relative contribution of regulatory growth to cost growth. Unexpectedly, a significantly higher percentage of out-of-scope work (approximately 84%) was attributable to NRC regulatory requirements for SL1 than SL2 (approximately 47%). These results were unexpected because SL2 was constructed during a period in which regulation was considered to be particularly unstable. However, a more detailed analysis of causation indicates that a shift occurred from an ad-hoc mode of regulation in the early 1970s to a more prescriptive process in the late 1970s. Thus the number of formal NRC requirements may not be a valid measure of regulatory stability.

  19. Plant growth-promoting rhizobacteria strain Bacillus amyloliquefaciens NJN-6-enriched bio-organic fertilizer suppressed Fusarium wilt and promoted the growth of banana plants.

    PubMed

    Yuan, Jun; Ruan, Yunze; Wang, Beibei; Zhang, Jian; Waseem, Raza; Huang, Qiwei; Shen, Qirong

    2013-04-24

    Bacillus amyloliquefaciens strain NJN-6 is an important plant growth-promoting rhizobacteria (PGPR) which can produce secondary metabolites antagonistic to several soil-borne pathogens. In this study, the ability of a bio-organic fertilizer (BIO) containing NJN-6 strain to promote the growth and suppress Fusarium wilt of banana plants was evaluated in a pot experiment. The results showed that the application of BIO significantly decreased the incidence of Fusarium wilt and promoted the growth of banana plants compared to that for the organic fertilizer (OF). To determine the beneficial mechanism of the strain, the colonization of NJN-6 strain on banana roots was evaluated using scanning electron microscopy (SEM). The plant growth-promoting hormones indole-3-acetic acid (IAA) and gibberellin A3 (GA3), along with antifungal lipopeptides iturin A, were detected when the NJN-6 strain was incubated in both Landy medium with additional l-tryptophan and in root exudates of banana plants. In addition, some antifungal volatile organic compounds and iturin A were also detected in BIO. In summary, strain NJN-6 could colonize the roots of banana plants after the application of BIO and produced active compounds which were beneficial for the growth of banana plants.

  20. Plant growth promoting bacteria from cow dung based biodynamic preparations.

    PubMed

    Radha, T K; Rao, D L N

    2014-12-01

    Indigenous formulations based on cow dung fermentation are commonly used in organic farming. Three biodynamic preparations viz., Panchagavya (PG), BD500 and 'Cow pat pit' (CPP) showed high counts of lactobacilli (10(9) ml(-1)) and yeasts (10(4) ml(-1)). Actinomycetes were present only in CPP (10(4) ml(-1)) and absent in the other two. Seven bacterial isolates from these ferments were identified by a polyphasic approach: Bacillus safensis (PG1), Bacillus cereus (PG2, PG4 PG5), Bacillus subtilis (BD2) Lysinibacillus xylanilyticus (BD3) and Bacillus licheniformis (CPP1). This is the first report of L. xylanilyticus and B. licheniformis in biodynamic preparations. Only three carbon sources-dextrose, sucrose and trehalose out of 21 tested were utilized by all the bacteria. None could utilize arabinose, dulcitol, galactose, inositol, inulin, melibiose, raffinose, rhamnose and sorbitol. All the strains produced indole acetic acid (1.8-3.7 μg ml(-1) culture filtrate) and ammonia. None could fix nitrogen; but all except B. safensis and B. licheniformis could solubilize phosphorous from insoluble tri-calcium phosphate. All the strains except L. xylaniliticus exhibited antagonism to the plant pathogen Rhizoctonia bataticola whereas none could inhibit Sclerotium rolfsi. In green house experiment in soil microcosms, bacterial inoculation significantly promoted growth of maize; plant dry weight increased by ~21 % due to inoculation with B. cereus (PG2). Results provide a basis for understanding the beneficial effects of biodynamic preparations and industrial deployment of the strains.

  1. A stoichiometric model of early plant primary succession.

    PubMed

    Marleau, Justin N; Jin, Yu; Bishop, John G; Fagan, William F; Lewis, Mark A

    2011-02-01

    The relative importance of plant facilitation and competition during primary succession depends on the development of ecosystem nutrient pools, yet the interaction of these processes remains poorly understood. To explore how these mechanisms interact to drive successional dynamics, we devised a stoichiometric ecosystem-level model that considers the role of nitrogen and phosphorus limitation in plant primary succession. We applied this model to the primary plant community on Mount St. Helens, Washington State, to check the validity of the proposed mechanisms. Our results show that the plant community is colimited by nitrogen and phosphorus, and they confirm previous suggestions that the presence of a nitrogen-fixing legume, Lupinus lepidus, can enhance community biomass. In addition, the observed nutrient supply rates may promote alternative successional trajectories that depend on the initial plant abundances, which may explain the observed heterogeneity in community development. The model further indicates the importance of mineralization rates and other ecosystem parameters to successional rates. We conclude that a model framework based on ecological stoichiometry allows integration of key biotic processes that interact nonlinearly with biogeochemical aspects of succession. Extension of this approach will improve the understanding of the process of primary succession and its application to ecosystem rehabilitation.

  2. Soybean Photosynthetic Rate and Carbon Fixation at Early and Late Planting Dates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Early planting (late April to early May) is recommended for increasing soybean yield but a full understanding of the physiological response is lacking. This study was conducted to determine whether carbon dioxide exchange rate (CER) could explain this yield difference. A study with five (2007) and s...

  3. Early detection of plant disease using infrared thermal imaging

    NASA Astrophysics Data System (ADS)

    Xu, Huirong; Zhu, Shengpan; Ying, Yibin; Jiang, Huanyu

    2006-10-01

    By using imaging techniques, plant physiological parameters can be assessed without contact with the plant and in a non-destructive way. During plant-pathogen infection, the physiological state of the infected tissue is altered, such as changes in photosynthesis, transpiration, stomatal conductance, accumulation of Salicylic acid (SA) and even cell death. In this study, the different temperature distribution between the leaves infected by tobacco mosaic virus strain-TMV-U1 and the noninfected leaves was visualized by digital infrared thermal imaging with the microscopic observations of the different structure within different species tomatoes. Results show a presymptomatic decrease in leaf temperature about 0.5-1.3 °C lower than the healthy leaves. The temperature difference allowed the discrimination between the infected and healthy leaves before the appearance of visible necrosis on leaves.

  4. The origin and early evolution of tracheids in vascular plants: integration of palaeobotanical and neobotanical data.

    PubMed Central

    Friedman, W E; Cook, M E

    2000-01-01

    Although there is clear evidence for the establishment of terrestrial plant life by the end of the Ordovician, the fossil record indicates that land plants remained extremely small and structurally simple until the Late Silurian. Among the events associated with this first major radiation of land plants is the evolution of tracheids, complex water-conducting cells defined by the presence of lignified secondary cell wall thickenings. Recent palaeobotanical analyses indicate that Early Devonian tracheids appear to possess secondary cell wall thickenings composed of two distinct layers: a degradation-prone layer adjacent to the primary cell wall and a degradation-resistant (possibly lignified) layer next to the cell lumen. In order to understand better the early evolution of tracheids, developmental and comparative studies of key basal (and potentially plesiomorphic) extant vascular plants have been initiated. Ultrastructural analysis and enzyme degradation studies of wall structure (to approximate diagenetic alterations of fossil tracheid structure) have been conducted on basal members of each of the two major clades of extant vascular plants: Huperzia (Lycophytina) and Equisetum (Euphyllophytina. This research demonstrates that secondary cell walls of extant basal vascular plants include a degradation-prone layer ('template layer') and a degradation-resistant layer ('resistant layer'). This pattern of secondary cell wall formation in the water-conducting cells of extant vascular plants matches the pattern of wall thickenings in the tracheids of early fossil vascular plants and provides a key evolutionary link between tracheids of living vascular plants and those of their earliest fossil ancestors. Further studies of tracheid development and structure among basal extant vascular plants will lead to a more precise reconstruction of the early evolution of water-conducting tissues in land plants, and will add to the current limited knowledge of spatial, temporal and

  5. Predicting longitudinal growth curves of height and weight using ecological factors for children with and without early growth deficiency.

    PubMed

    Black, M M; Krishnakumar, A

    1999-02-01

    Growth curve models were used to examine the effect of genetic and ecological factors on changes in height and weight of 225 children from low income, urban families who were assessed up to eight times in the first 6 y of life. Children with early growth deficiency [failure to thrive (FTT)] (n = 127) and a community sample of children without growth deficiency (n = 98) were examined to evaluate how genetic, child and family characteristics influenced growth. Children of taller and heavier parents, who were recruited at younger ages and did not have a history of growth deficiency, had accelerated growth from recruitment through age 6 y. In addition, increases in height were associated with better health, less difficult temperament, nurturant mothers and female gender; increases in weight were associated with better health. Children with a history of growth deficiency demonstrated slower rates of growth than children in the community group without a history of growth deficiency. In the community group, changes in children's height and weight were related to maternal perceptions of health and temperament and maternal nurturance during feeding, whereas in the FTT group, maternal perceptions and behavior were not in synchrony with children's growth. These findings suggest that, in addition to genetic factors, growth is dependent on a nurturant and sensitive caregiving system. Interventions to promote growth should consider child and family characteristics, including maternal perceptions of children's health and temperament and maternal mealtime behavior.

  6. Effects of Plant Growth Hormones on Mucor indicus Growth and Chitosan and Ethanol Production

    PubMed Central

    Safaei, Zahra; Karimi, Keikhosro; Golkar, Poorandokht; Zamani, Akram

    2015-01-01

    The objective of this study was to investigate the effects of indole-3-acetic acid (IAA) and kinetin (KIN) on Mucor indicus growth, cell wall composition, and ethanol production. A semi-synthetic medium, supplemented with 0–5 mg/L hormones, was used for the cultivations (at 32 °C for 48 h). By addition of 1 mg/L of each hormone, the biomass and ethanol yields were increased and decreased, respectively. At higher levels, however, an inverse trend was observed. The glucosamine fraction of the cell wall, as a representative for chitosan, followed similar but sharper changes, compared to the biomass. The highest level was 221% higher than that obtained without hormones. The sum of glucosamine and N-acetyl glucosamine (chitin and chitosan) was noticeably enhanced in the presence of the hormones. Increase of chitosan was accompanied by a decrease in the phosphate content, with the lowest phosphate (0.01 g/g cell wall) being obtained when the chitosan was at the maximum (0.45 g/g cell wall). In conclusion, IAA and KIN significantly enhanced the M. indicus growth and chitosan production, while at the same time decreasing the ethanol yield to some extent. This study shows that plant growth hormones have a high potential for the improvement of fungal chitosan production by M. indicus. PMID:26204839

  7. A whole-plant perspective reveals unexpected impacts of above- and belowground herbivores on plant growth and defense

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tradeoffs between plant growth and defense are central to theoretical frameworks used to study the ecology and evolution of plant defense against herbivores. However, these frameworks, as well as the experiments designed to test them, rarely include the remarkable diversity of belowground herbivores...

  8. Early growth, dominance acquisition and lifetime reproductive success in male and female cooperative meerkats.

    PubMed

    English, Sinead; Huchard, Elise; Nielsen, Johanna F; Clutton-Brock, Tim H

    2013-11-01

    In polygynous species, variance in reproductive success is higher in males than females. There is consequently stronger selection for competitive traits in males and early growth can have a greater influence on later fitness in males than in females. As yet, little is known about sex differences in the effect of early growth on subsequent breeding success in species where variance in reproductive success is higher in females than males, and competitive traits are under stronger selection in females. Greater variance in reproductive success has been documented in several singular cooperative breeders. Here, we investigated consequences of early growth for later reproductive success in wild meerkats. We found that, despite the absence of dimorphism, females who exhibited faster growth until nutritional independence were more likely to become dominant, whereas early growth did not affect dominance acquisition in males. Among those individuals who attained dominance, there was no further influence of early growth on dominance tenure or lifetime reproductive success in males or females. These findings suggest that early growth effects on competitive abilities and fitness may reflect the intensity of intrasexual competition even in sexually monomorphic species.

  9. Early growth, dominance acquisition and lifetime reproductive success in male and female cooperative meerkats

    PubMed Central

    English, Sinead; Huchard, Elise; Nielsen, Johanna F; Clutton-Brock, Tim H

    2013-01-01

    In polygynous species, variance in reproductive success is higher in males than females. There is consequently stronger selection for competitive traits in males and early growth can have a greater influence on later fitness in males than in females. As yet, little is known about sex differences in the effect of early growth on subsequent breeding success in species where variance in reproductive success is higher in females than males, and competitive traits are under stronger selection in females. Greater variance in reproductive success has been documented in several singular cooperative breeders. Here, we investigated consequences of early growth for later reproductive success in wild meerkats. We found that, despite the absence of dimorphism, females who exhibited faster growth until nutritional independence were more likely to become dominant, whereas early growth did not affect dominance acquisition in males. Among those individuals who attained dominance, there was no further influence of early growth on dominance tenure or lifetime reproductive success in males or females. These findings suggest that early growth effects on competitive abilities and fitness may reflect the intensity of intrasexual competition even in sexually monomorphic species. PMID:24340181

  10. Effects of plant growth-promoting bacteria isolated from copper tailings on plants in sterilized and non-sterilized tailings.

    PubMed

    Liu, Weiqiu; Yang, Chao; Shi, Si; Shu, Wensheng

    2014-02-01

    Ten strains of Cu-tolerant bacteria with potential plant growth-promoting ability were isolated by selecting strains with the ability to use 1-aminocyclopropane-1-carboxylate as a sole nitrogen source (designated ACC-B) or fix nitrogen (designated FLN-B) originating from the rhizosphere of plants growing on copper tailings. All 10 strains proved to have intrinsic ability to produce indole acetic acid and siderophores, and most of them could mobilize insoluble phosphate. In addition, a greenhouse study showed that ACC-B, FLN-B and a mixture of both had similar, potent ability to stimulate growth of Pennisetum purpureum, Medicago sativa and Oenothera erythrosepala plants grown on sterilized tailings. For instance, above-ground biomass of P. purpureum was 278-357% greater after 60d growth on sterilized tailings in their presence. They could also significantly promote the growth of the plants grown on non-sterilized tailings, though the growth-promoting effects were much weaker. So, strategies for using of the plant growth-promoting bacteria in the practice of phytoremediation deserve further studies to get higher growth-promoting efficiency.

  11. Exploration of plant growth and development using the European Modular Cultivation System facility on the International Space Station.

    PubMed

    Kittang, A-I; Iversen, T-H; Fossum, K R; Mazars, C; Carnero-Diaz, E; Boucheron-Dubuisson, E; Le Disquet, I; Legué, V; Herranz, R; Pereda-Loth, V; Medina, F J

    2014-05-01

    Space experiments provide a unique opportunity to advance our knowledge of how plants respond to the space environment, and specifically to the absence of gravity. The European Modular Cultivation System (EMCS) has been designed as a dedicated facility to improve and standardise plant growth in the International Space Station (ISS). The EMCS is equipped with two centrifuges to perform experiments in microgravity and with variable gravity levels up to 2.0 g. Seven experiments have been performed since the EMCS was operational on the ISS. The objectives of these experiments aimed to elucidate phototropic responses (experiments TROPI-1 and -2), root gravitropic sensing (GRAVI-1), circumnutation (MULTIGEN-1), cell wall dynamics and gravity resistance (Cell wall/Resist wall), proteomic identification of signalling players (GENARA-A) and mechanism of InsP3 signalling (Plant signalling). The role of light in cell proliferation and plant development in the absence of gravity is being analysed in an on-going experiment (Seedling growth). Based on the lessons learned from the acquired experience, three preselected ISS experiments have been merged and implemented as a single project (Plant development) to study early phases of seedling development. A Topical Team initiated by European Space Agency (ESA), involving experienced scientists on Arabidopsis space research experiments, aims at establishing a coordinated, long-term scientific strategy to understand the role of gravity in Arabidopsis growth and development using already existing or planned new hardware.

  12. Phenolic-rich leaf carbon fractions differentially influence microbial respiration and plant growth.

    PubMed

    Meier, Courtney L; Bowman, William D

    2008-11-01

    Phenolics can reduce soil nutrient availability, either indirectly by stimulating microbial nitrogen (N) immobilization or directly by enhancing physical protection within soil. Phenolic-rich plants may therefore negatively affect neighboring plant growth by restricting the N supply. We used a slow-growing, phenolic-rich alpine forb, Acomastylis rossii, to test the hypothesis that phenolic-rich carbon (C) fractions stimulate microbial population growth and reduce plant growth. We generated low-molecular-weight (LMW) fractions, tannin fractions, and total soluble C fractions from A. rossii and measured their effects on soil respiration and growth of Deschampsia caespitosa, a fast-growing, co-dominant grass. Fraction effects fell into two distinct categories: (1) fractions did not increase soil respiration and killed D. caespitosa plants, or (2) fractions stimulated soil respiration and reduced plant growth and plant N concentration while simultaneously inhibiting root growth. The LMW phenolic-rich fractions increased soil respiration and reduced plant growth more than tannins. These results suggest that phenolic compounds can inhibit root growth directly as well as indirectly affect growth by reducing pools of plant available N by stimulating soil microbes. Both mechanisms illustrate how below-ground phenolic effects may influence the growth of neighboring plants. We also examined patterns of foliar phenolic concentrations among populations of A. rossii across a natural productivity gradient (productivity was used as a proxy for competition intensity). Concentrations of some LMW phenolics increased significantly in more productive sites where A. rossii is a competitive equal with the faster growing D. caespitosa. Taken together, our results contribute important information to the growing body of evidence indicating that the quality of C moving from plants to soils can have significant effects on neighboring plant performance, potentially associated with phytoxic

  13. Fusarium Oxysporum Volatiles Enhance Plant Growth Via Affecting Auxin Transport and Signaling.

    PubMed

    Bitas, Vasileios; McCartney, Nathaniel; Li, Ningxiao; Demers, Jill; Kim, Jung-Eun; Kim, Hye-Seon; Brown, Kathleen M; Kang, Seogchan

    2015-01-01

    Volatile organic compounds (VOCs) have well-documented roles in plant-plant communication and directing animal behavior. In this study, we examine the less understood roles of VOCs in plant-fungal relationships. Phylogenetically and ecologically diverse strains of Fusarium oxysporum, a fungal species complex that often resides in the rhizosphere of assorted plants, produce volatile compounds that augment shoot and root growth of Arabidopsis thaliana and tobacco. Growth responses of A. thaliana hormone signaling mutants and expression patterns of a GUS reporter gene under the auxin-responsive DR5 promoter supported the involvement of auxin signaling in F. oxysporum volatile-mediated growth enhancement. In addition, 1-naphthylthalamic acid, an inhibitor of auxin efflux, negated F. oxysporum volatile-mediated growth enhancement in both plants. Comparison of the profiles of volatile compounds produced by F. oxysporum strains that differentially affected plant growth suggests that the relative compositions of both growth inhibitory and stimulatory compounds may determine the degree of plant growth enhancement. Volatile-mediated signaling between fungi and plants may represent a potentially conserved, yet mostly overlooked, mechanism underpinning plant-fungus interactions and fungal niche adaption.

  14. Fusarium Oxysporum Volatiles Enhance Plant Growth Via Affecting Auxin Transport and Signaling

    PubMed Central

    Bitas, Vasileios; McCartney, Nathaniel; Li, Ningxiao; Demers, Jill; Kim, Jung-Eun; Kim, Hye-Seon; Brown, Kathleen M.; Kang, Seogchan

    2015-01-01

    Volatile organic compounds (VOCs) have well-documented roles in plant-plant communication and directing animal behavior. In this study, we examine the less understood roles of VOCs in plant-fungal relationships. Phylogenetically and ecologically diverse strains of Fusarium oxysporum, a fungal species complex that often resides in the rhizosphere of assorted plants, produce volatile compounds that augment shoot and root growth of Arabidopsis thaliana and tobacco. Growth responses of A. thaliana hormone signaling mutants and expression patterns of a GUS reporter gene under the auxin-responsive DR5 promoter supported the involvement of auxin signaling in F. oxysporum volatile-mediated growth enhancement. In addition, 1-naphthylthalamic acid, an inhibitor of auxin efflux, negated F. oxysporum volatile-mediated growth enhancement in both plants. Comparison of the profiles of volatile compounds produced by F. oxysporum strains that differentially affected plant growth suggests that the relative compositions of both growth inhibitory and stimulatory compounds may determine the degree of plant growth enhancement. Volatile-mediated signaling between fungi and plants may represent a potentially conserved, yet mostly overlooked, mechanism underpinning plant-fungus interactions and fungal niche adaption. PMID:26617587

  15. Dechlorination of chloroacetanilide herbicides by plant growth regulator sodium bisulfite.

    PubMed

    Bian, Haitao; Chen, Jingwen; Cai, Xiyun; Liu, Ping; Wang, Ying; Huang, Liping; Qiao, Xianliang; Hao, Ce

    2009-08-01

    Chloroacetanilide herbicides are frequently detected in groundwater and surface waters, and pose high risks to aquatic biota. In this study, sodium bisulfite (NaHSO(3)), a plant growth regulator used in China, was used to remove three chloroacetanilide herbicides including alachlor, acetochlor and S-metolachlor. These herbicides were rapidly dechlorinated by NaHSO(3) in neutral conditions. The dechlorination was accelerated with increasing pH, temperature and NaHSO(3) concentrations. Kinetic analysis and mass spectrum identification revealed that the reaction followed S(N)2 nucleophilic substitution, in which the chlorine was replaced by the reactive specie sulfite. Alachlor and its isomer acetochlor had similar reaction rates, whereas they were more readily transformed than S-metolachlor that had larger steric hindrance and weaker electrophilicity. The transformation products were chloroacetanilide ethane sulfonic acids (ESAs), which were also encountered as major metabolites of these herbicides in natural environment via common metabolic pathways and were less toxic to green algae compared to the parent herbicides. These results indicate that NaHSO(3) can accelerate transformation of chloroacetanilide herbicides to the less toxic transformation products by nucleophilic substitution and dechlorination in aquatic environment. NaHSO(3) can be potentially used for the removal of chloroacetanilide herbicides from wastewater effluent, spill sites and accidental discharge.

  16. Plant growth responses of apple and pear trees to doses of glyphosate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Glyphosate is commonly used for intra-row weed management in perennial plantations, where unintended crop exposure to this herbicide can cause growth reduction. The objective of this research was to analyze the initial plant growth behavior of young apple and pear plants exposed to glyphosate. Glyph...

  17. Bio-control and plant growth promotion potential of Salicaceae endophytes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Microbial endophytes are important for growth benefits in a variety of plant species. Microbial communities of the poplar (Populus sp.) and willow (Salix sp.) endosphere have been demonstrated to be important for plant growth promotion, protection from abiotic stresses, and degradation of toxic subs...

  18. Genome Sequence of the Plant Growth-Promoting Bacterium Enterobacter cloacae GS1

    PubMed Central

    Shankar, Manoharan; Ponraj, Paramasivan; Ilakiam, Devaraj; Rajendhran, Jeyaprakash

    2012-01-01

    Here, we present the genome sequence of Enterobacter cloacae GS1. This strain proficiently colonizes rice roots and promotes plant growth by improving plant nutrition. Analyses of the E. cloacae GS1 genome will throw light on the genetic factors involved in root colonization, growth promotion, and ecological success of this rhizobacterium. PMID:22843603

  19. Complete Genome of the Plant Growth-Promoting Rhizobacterium Pseudomonas putida BIRD-1

    SciTech Connect

    Matilla, M.A.; van der Lelie, D.; Pizarro-Tobias, P.; Roca, A.; Fernandez, M.; Duque, E.; Molina, L.; Wu, X.; Gomez, M. J.; Segura, A.; Ramos, J.-L.

    2011-03-01

    We report the complete sequence of the 5.7-Mbp genome of Pseudomonas putida BIRD-1, a metabolically versatile plant growth-promoting rhizobacterium that is highly tolerant to desiccation and capable of solubilizing inorganic phosphate and iron and of synthesizing phytohormones that stimulate seed germination and plant growth.

  20. Preschool Children's Explanations of Plant Growth and Rain Formation: A Comparative Analysis

    ERIC Educational Resources Information Center

    Christidou, Vasilia; Hatzinikita, Vassilia

    2006-01-01

    This paper explores the different types and characteristics of preschool children's explanations of plant growth and rain formation. The children's explanations were categorized as naturalistic, non-naturalistic, or synthetic, i.e., explanations containing both naturalistic and non-naturalistic parts. In regards to plant growth the children…

  1. Genome Sequence of Enterobacter radicincitans DSM16656T, a Plant Growth-Promoting Endophyte

    PubMed Central

    Witzel, Katja; Gwinn-Giglio, Michelle; Nadendla, Suvarna; Shefchek, Kent

    2012-01-01

    Enterobacter radicincitans sp. nov. DSM16656T represents a new species of the genus Enterobacter which is a biological nitrogen-fixing endophytic bacterium with growth-promoting effects on a variety of crop and model plant species. The presence of genes for nitrogen fixation, phosphorous mobilization, and phytohormone production reflects this microbe's potential plant growth-promoting activity. PMID:22965092

  2. Genome sequence of Enterobacter radicincitans DSM16656(T), a plant growth-promoting endophyte.

    PubMed

    Witzel, Katja; Gwinn-Giglio, Michelle; Nadendla, Suvarna; Shefchek, Kent; Ruppel, Silke

    2012-10-01

    Enterobacter radicincitans sp. nov. DSM16656(T) represents a new species of the genus Enterobacter which is a biological nitrogen-fixing endophytic bacterium with growth-promoting effects on a variety of crop and model plant species. The presence of genes for nitrogen fixation, phosphorous mobilization, and phytohormone production reflects this microbe's potential plant growth-promoting activity.

  3. Draft Genome Sequence of Ochrobactrum intermedium Strain SA148, a Plant Growth-Promoting Desert Rhizobacterium

    PubMed Central

    Lafi, Feras F.; Alam, Intikhab; Geurts, Rene; Bisseling, Ton; Bajic, Vladimir B.

    2017-01-01

    ABSTRACT Ochrobactrum intermedium strain SA148 is a plant growth-promoting bacterium isolated from sandy soil in the Jizan area of Saudi Arabia. Here, we report the 4.9-Mb draft genome sequence of this strain, highlighting different pathways characteristic of plant growth promotion activity and environmental adaptation of SA148. PMID:28254977

  4. Germination and early plant development of ten plant species exposed to titanium dioxide and cerium oxide nanoparticles

    EPA Science Inventory

    Ten agronomic plant species were exposed to different concentrations of nano titanium dioxide (nTiO2) or nano cerium oxide (nCeO2) (0, 250, 500 and 1000 mg/L) to examine potential effects on germination and early seedling development. We modified a standard test protocol develop...

  5. Controlled ecological life support systems: Development of a plant growth module

    NASA Technical Reports Server (NTRS)

    Averner, Mel M.; Macelroy, Robert D.; Smernoff, David T.

    1987-01-01

    An effort was made to begin defining the scientific and technical requirements for the design and construction of a ground-based plant growth facility. In particular, science design criteria for the Plant Growth Module (PGM) of the Controlled Ecological Life Support System (CELSS) were determined in the following areas: (1) irradiation parameters and associated equipment affecting plant growth; (2) air flow; (3) planting, culture, and harvest techniques; (4) carbon dioxide; (5) temperature and relative humidity; (6) oxygen; (7) construction materials and access; (8) volatile compounds; (9) bacteria, sterilization, and filtration; (10) nutrient application systems; (11) nutrient monitoring; and (12) nutrient pH and conductivity.

  6. Constraining the role of early land plants in Palaeozoic weathering and global cooling.

    PubMed

    Quirk, Joe; Leake, Jonathan R; Johnson, David A; Taylor, Lyla L; Saccone, Loredana; Beerling, David J

    2015-08-22

    How the colonization of terrestrial environments by early land plants over 400 Ma influenced rock weathering, the biogeochemical cycling of carbon and phosphorus, and climate in the Palaeozoic is uncertain. Here we show experimentally that mineral weathering by liverworts—an extant lineage of early land plants—partnering arbuscular mycorrhizal (AM) fungi, like those in 410 Ma-old early land plant fossils, amplified calcium weathering from basalt grains threefold to sevenfold, relative to plant-free controls. Phosphate weathering by mycorrhizal liverworts was amplified 9-13-fold over plant-free controls, compared with fivefold to sevenfold amplification by liverworts lacking fungal symbionts. Etching and trenching of phyllosilicate minerals increased with AM fungal network size and atmospheric CO2 concentration. Integration of grain-scale weathering rates over the depths of liverwort rhizoids and mycelia (0.1 m), or tree roots and mycelia (0.75 m), indicate early land plants with shallow anchorage systems were probably at least 10-fold less effective at enhancing the total weathering flux than later-evolving trees. This work challenges the suggestion that early land plants significantly enhanced total weathering and land-to-ocean fluxes of calcium and phosphorus, which have been proposed as a trigger for transient dramatic atmospheric CO2 sequestration and glaciations in the Ordovician.

  7. Constraining the role of early land plants in Palaeozoic weathering and global cooling

    PubMed Central

    Quirk, Joe; Leake, Jonathan R.; Johnson, David A.; Taylor, Lyla L.; Saccone, Loredana; Beerling, David J.

    2015-01-01

    How the colonization of terrestrial environments by early land plants over 400 Ma influenced rock weathering, the biogeochemical cycling of carbon and phosphorus, and climate in the Palaeozoic is uncertain. Here we show experimentally that mineral weathering by liverworts—an extant lineage of early land plants—partnering arbuscular mycorrhizal (AM) fungi, like those in 410 Ma-old early land plant fossils, amplified calcium weathering from basalt grains threefold to sevenfold, relative to plant-free controls. Phosphate weathering by mycorrhizal liverworts was amplified 9–13-fold over plant-free controls, compared with fivefold to sevenfold amplification by liverworts lacking fungal symbionts. Etching and trenching of phyllosilicate minerals increased with AM fungal network size and atmospheric CO2 concentration. Integration of grain-scale weathering rates over the depths of liverwort rhizoids and mycelia (0.1 m), or tree roots and mycelia (0.75 m), indicate early land plants with shallow anchorage systems were probably at least 10-fold less effective at enhancing the total weathering flux than later-evolving trees. This work challenges the suggestion that early land plants significantly enhanced total weathering and land-to-ocean fluxes of calcium and phosphorus, which have been proposed as a trigger for transient dramatic atmospheric CO2 sequestration and glaciations in the Ordovician. PMID:26246550

  8. Essential role for Max in early embryonic growth and development

    PubMed Central

    Shen-Li, Hong; O'Hagan, Rónán C.; Hou, Harry; Horner, James W.; Lee, Han-Woong; DePinho, Ronald A.

    2000-01-01

    Loss of Max function in the mouse resulted in generalized developmental arrest of both embryonic and extraembryonic tissues at early postimplantation (∼E5.5–6.5), coincident with loss or dilution of maternal Max stores in the expanding embryo in vivo and in blastocyst outgrowths in vitro. Developmentally arrested embryos were reduced in size and exhibited widespread cytological degeneration and feeble BrdU incorporation. Max and, by extension, the Myc superfamily, serve essential roles in early mammalian development and a maternal reservoir of Max exists in sufficient amount to sustain Myc superfamily function through preimplantation stages of development. PMID:10640271

  9. Sildenafil citrate therapy for severe early-onset intrauterine growth restriction.

    PubMed

    von Dadelszen, P; Dwinnell, S; Magee, L A; Carleton, B C; Gruslin, A; Lee, B; Lim, K I; Liston, R M; Miller, S P; Rurak, D; Sherlock, R L; Skoll, M A; Wareing, M M; Baker, P N

    2011-04-01

    Sildenafil citrate therapy for severe early-onset intrauterine growth restriction. BJOG 2011;118:624-628. Currently, there is no effective therapy for severe early-onset intrauterine growth restriction (IUGR). Sildenafil citrate vasodilates the myometrial arteries isolated from women with IUGR-complicated pregnancies. Women were offered Sildenafil (25 mg three times daily until delivery) if their pregnancy was complicated by early-onset IUGR [abdominal circumference (AC)< 5th percentile] and either the gestational age was <25(+0) weeks or an estimate of the fetal weight was <600 g (excluding known fetal anomaly/syndrome and/or planned termination). Sildenafil treatment was associated with increased fetal AC growth [odds ratio, 12.9; 95% confidence interval (CI), 1.3, 126; compared with institutional Sildenafil-naive early-onset IUGR controls]. Randomised controlled trial data are required to determine whether Sildenafil improves perinatal outcomes for early-onset IUGR-complicated pregnancies.

  10. Effects of microgravity on growth hormone concentration and distribution in plants

    NASA Technical Reports Server (NTRS)

    Schulze, Aga; Jensen, Philip; Desrosiers, Mark; Bandurski, Robert S.

    1989-01-01

    On earth, gravity affects the distribution of the plant growth hormone, indole-3-acetic acid (IAA), in a manner such that the plant grows into a normal vertical orientation (shoots up, roots down). How the plant controls the amount and distribution of IAA is only partially understood and is currently under investigation in this laboratory. The question to be answered in the flight experiment concerns the effect of gravity on the concentration, turn over, and distribution of the growth hormone. The answer to this question will aid in understanding the mechanism by which plants control the amount and distribution of growth hormone. Such knowledge of a plant's hormonal metabolism may aid in the growth of plants in space and will lead to agronomic advances.

  11. Development of a Configurable Growth Chamber with a Computer Vision System to Study Circadian Rhythm in Plants

    PubMed Central

    Navarro, Pedro J.; Fernández, Carlos; Weiss, Julia; Egea-Cortines, Marcos

    2012-01-01

    Plant development is the result of an endogenous morphogenetic program that integrates environmental signals. The so-called circadian clock is a set of genes that integrates environmental inputs into an internal pacing system that gates growth and other outputs. Study of circadian growth responses requires high sampling rates to detect changes in growth and avoid aliasing. We have developed a flexible configurable growth chamber comprising a computer vision system that allows sampling rates ranging between one image per 30 s to hours/days. The vision system has a controlled illumination system, which allows the user to set up different configurations. The illumination system used emits a combination of wavelengths ensuring the optimal growth of species under analysis. In order to obtain high contrast of captured images, the capture system is composed of two CCD cameras, for day and night periods. Depending on the sample type, a flexible image processing software calculates different parameters based on geometric calculations. As a proof of concept we tested the system in three different plant tissues, growth of petunia- and snapdragon (Antirrhinum majus) flowers and of cladodes from the cactus Opuntia ficus-indica. We found that petunia flowers grow at a steady pace and display a strong growth increase in the early morning, whereas Opuntia cladode growth turned out not to follow a circadian growth pattern under the growth conditions imposed. Furthermore we were able to identify a decoupling of increase in area and length indicating that two independent growth processes are responsible for the final size and shape of the cladode. PMID:23202214

  12. Development of a configurable growth chamber with a computer vision system to study circadian rhythm in plants.

    PubMed

    Navarro, Pedro J; Fernández, Carlos; Weiss, Julia; Egea-Cortines, Marcos

    2012-11-09

    Plant development is the result of an endogenous morphogenetic program that integrates environmental signals. The so-called circadian clock is a set of genes that integrates environmental inputs into an internal pacing system that gates growth and other outputs. Study of circadian growth responses requires high sampling rates to detect changes in growth and avoid aliasing. We have developed a flexible configurable growth chamber comprising a computer vision system that allows sampling rates ranging between one image per 30 s to hours/days. The vision system has a controlled illumination system, which allows the user to set up different configurations. The illumination system used emits a combination of wavelengths ensuring the optimal growth of species under analysis. In order to obtain high contrast of captured images, the capture system is composed of two CCD cameras, for day and night periods. Depending on the sample type, a flexible image processing software calculates different parameters based on geometric calculations. As a proof of concept we tested the system in three different plant tissues, growth of petunia- and snapdragon (Antirrhinum majus) flowers and of cladodes from the cactus Opuntia ficus-indica. We found that petunia flowers grow at a steady pace and display a strong growth increase in the early morning, whereas Opuntia cladode growth turned out not to follow a circadian growth pattern under the growth conditions imposed. Furthermore we were able to identify a decoupling of increase in area and length indicating that two independent growth processes are responsible for the final size and shape of the cladode.

  13. Gestational weight gain and offspring longitudinal growth in early life

    PubMed Central

    Diesel, Jill C.; Eckhardt, Cara L.; Day, Nancy L.; Brooks, Maria M.; Arslanian, Silva A.; Bodnar, Lisa M.

    2015-01-01

    Background Excessive gestational weight gain (GWG) increases the risk of childhood obesity, but little is known about its association with infant growth patterns. Aim To examine the GWG-infant growth association. Methods Pregnant women (n=743) self-reported GWG at delivery, which we classified as inadequate, adequate, or excessive based on current guidelines. Offspring weight-for-age z-scores (WAZ), length-for-age z-scores (LAZ (with height-for-age (HAZ) in place of length at 36 months)), and body mass index z-scores (BMIZ) were calculated at birth, 8, 18, and 36 months using the 2006 WHO growth standards. Linear mixed models estimated the change in z-scores from birth to 36 months by GWG. Results The mean (SD) WAZ was −0.22 (1.20) at birth. Overall, WAZ and BMIZ increased from birth to approximately 24 months and decreased from 24 to 36 months, while LAZ/HAZ decreased from birth through 36 months. Excessive GWG was associated with higher offspring WAZ and BMIZ at birth, 8, and 36 months, and higher HAZ at 36 months, compared with adequate GWG. Compared with the same referent, inadequate GWG was associated with smaller WAZ and BMIZ at birth and 8 months. Conclusion Excessive GWG may predispose infants to obesogenic growth patterns while inadequate GWG may not have a lasting impact on infant growth. PMID:26279171

  14. Early child growth: how do nutrition and infection interact?

    PubMed

    Dewey, Kathryn G; Mayers, Daniel R

    2011-10-01

    It is well known that the relationship between child nutrition and infection is bidirectional, i.e. frequent illness can impair nutritional status and poor nutrition can increase the risk of infection. What is less clear is whether infection reduces the effectiveness of nutrition interventions or, vice versa, whether malnutrition lessens the impact of infection control strategies. The objective of this paper is to review the evidence regarding this interaction between nutrition and infection with respect to child growth in low-income populations. Even when there are no obvious symptoms, physiological conditions associated with infections can impair growth by suppressing appetite, impairing absorption of nutrients, increasing nutrient losses and diverting nutrients away from growth. However, there is little direct evidence that nutrition interventions are less effective when infection is common; more research is needed on this question. On the other hand, evidence from four intervention trials suggests that the adverse effects of certain infections (e.g. diarrhoea) on growth can be reduced or eliminated by improving nutrition. Interventions that combine improved nutrition with prevention and control of infections are likely to be most effective for enhancing child growth and development.

  15. Regulatory functions of SnRK1 in stress-responsive gene expression and in plant growth and development.

    PubMed

    Cho, Young-Hee; Hong, Jung-Woo; Kim, Eun-Chul; Yoo, Sang-Dong

    2012-04-01

    Sucrose-nonfermentation1-related protein kinase1 (SnRK1) is an evolutionarily conserved energy sensor protein that regulates gene expression in response to energy depletion in plants. Efforts to elucidate the functions and mechanisms of this protein kinase are hampered, however, by inherent growth defects of snrk1-null mutant plants. To overcome these limitations and study SnRK1 functions in vivo, we applied a method combining transient expression in leaf mesophyll protoplasts and stable expression in transgenic plants. We found that both rice (Oryza sativa) and Arabidopsis (Arabidopsis thaliana) SnRK1 activities critically influence stress-inducible gene expression and the induction of stress tolerance. Genetic, molecular, and chromatin immunoprecipitation analyses further revealed that the nuclear SnRK1 modulated target gene transcription in a submergence-dependent manner. From early seedling development through late senescence, SnRK1 activities appeared to modulate developmental processes in the plants. Our findings offer insight into the regulatory functions of plant SnRK1 in stress-responsive gene regulation and in plant growth and development throughout the life cycle.

  16. Early subtropical forest growth is driven by community mean trait values and functional diversity rather than the abiotic environment

    PubMed Central

    Kröber, Wenzel; Li, Ying; Härdtle, Werner; Ma, Keping; Schmid, Bernhard; Schmidt, Karsten; Scholten, Thomas; Seidler, Gunnar; von Oheimb, Goddert; Welk, Erik; Wirth, Christian; Bruelheide, Helge

    2015-01-01

    While functional diversity (FD) has been shown to be positively related to a number of ecosystem functions including biomass production, it may have a much less pronounced effect than that of environmental factors or species-specific properties. Leaf and wood traits can be considered particularly relevant to tree growth, as they reflect a trade-off between resources invested into growth and persistence. Our study focussed on the degree to which early forest growth was driven by FD, the environment (11 variables characterizing abiotic habitat conditions), and community-weighted mean (CWM) values of species traits in the context of a large-scale tree diversity experiment (BEF-China). Growth rates of trees with respect to crown diameter were aggregated across 231 plots (hosting between one and 23 tree species) and related to environmental variables, FD, and CWM, the latter two of which were based on 41 plant functional traits. The effects of each of the three predictor groups were analyzed separately by mixed model optimization and jointly by variance partitioning. Numerous single traits predicted plot-level tree growth, both in the models based on CWMs and FD, but none of the environmental variables was able to predict tree growth. In the best models, environment and FD explained only 4 and 31% of variation in crown growth rates, respectively, while CWM trait values explained 42%. In total, the best models accounted for 51% of crown growth. The marginal role of the selected environmental variables was unexpected, given the high topographic heterogeneity and large size of the experiment, as was the significant impact of FD, demonstrating that positive diversity effects already occur during the early stages in tree plantations. PMID:26380685

  17. Modulation of plant growth and metabolism in cadmium-enriched environments.

    PubMed

    Qadir, Shaista; Jamshieed, Sumiya; Rasool, Saiema; Ashraf, Muhammad; Akram, Nudrat Aisha; Ahmad, Parvaiz

    2014-01-01

    Cadmium (Cd) is a water soluble metal pollutant that is not essential to plant growth.It has attracted attention from soil scientists and plant nutritionists in recent years because of its toxicity and mobility in the soil-plant continuum. Even low levels of Cd (0.1-1 J.!M) cause adverse effects on plant growth and metabolism. Cadmium is known to trigger the synthesis of reactive oxygen species, hinder utilization, uptake and transport of essential nutrients and water, and modify photosynthetic machinery,thereby resulting in plant tissue death. Although the effects of Cd are dose- as well as plant species-dependent, some plants show Cd tolerance through a wide range of cellular responses. Such tolerance results from synthesis of osmolytes,generation of enzymatic and non-enzymatic antioxidants and metal-detoxifying peptides, changes in gene expression, and metal ion homeostasis and compartmentalization of ligand-metal complexes. Cd toxicity in plants produces effects on chlorophyllbio synthesis, reduces photosynthesis, and upsets plant water relations and hormonal and/or nutritional balances. All of these effects on plants and on plant metabolism ultimately reduce growth and productivity.In this review, we describe the extent to which Cd affects underlying metabolic processes in plants and how such altered processes affect plant growth. We review the sources of Cd contamination, its uptake, transportation and bioavailability and accumulation in plants, and its antagonistic and synergistic effects with other metals and compounds. We further address the effects of Cd on plant genetics and metabolism,and how plants respond to mitigate the adverse effects of Cd exposure, as well as strategies(e.g., plant breeding) that can reduce the impact of Cd contamination on plants.

  18. Frequent Daytime Naps Predict Vocabulary Growth in Early Childhood

    ERIC Educational Resources Information Center

    Horváth, Klára; Plunkett, Kim

    2016-01-01

    Background: The facilitating role of sleep for language learning is well-attested in adults and to a lesser extent in infants and toddlers. However, the longitudinal relationship between sleep patterns and early vocabulary development is not well understood. Methods: This study investigates how measures of sleep are related to the development of…

  19. Evaluation of Irrigation Methods for Highbush Blueberry. I. Growth and Water Requirements of Young Plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A study was conducted in a new field of northern highbush blueberry (Vaccinium corymbosum L. 'Elliott') to determine the effects of different irrigation methods on growth and water requirements of uncropped plants during the first 2 years after planting. The plants were grown on mulched, raised beds...

  20. Draft genome sequence of the plant growth-promoting bacterium Bacillus siamensis KCTC 13613T.

    PubMed

    Jeong, Haeyoung; Jeong, Da-Eun; Kim, Sun Hong; Song, Geun Cheol; Park, Soo-Young; Ryu, Choong-Min; Park, Seung-Hwan; Choi, Soo-Keun

    2012-08-01

    Bacillus siamensis KCTC 13613(T), a novel halophilic Bacillus species isolated from a salted Thai food, produced antimicrobial compounds against plant pathogens and promoted plant growth by volatile emission. We determined the 3.8-Mb genome sequence of B. siamensis KCTC 13613(T) to reveal the plant-beneficial effect at the genomic level.

  1. Specifications for and preliminary design of a plant growth chamber for orbital experimental experiments

    NASA Technical Reports Server (NTRS)

    Sweet, H. C.; Simmonds, R. C.

    1976-01-01

    It was proposed that plant experiments be performed on board the space shuttle. To permit the proper execution of most tests, the craft must contain a plant growth chamber which is adequately designed to control those environmental factors which can induce changes in a plant's physiology and morphology. The various needs of, and environmental factors affecting, plants are identified. The permissilbe design, construction and performance limits for a plant-growth chamber are set, and tentative designs were prepared for units which are compatible with both the botanical requirements and the constraints imposed by the space shuttle.

  2. Visualization of early stress responses in plant leaves

    NASA Astrophysics Data System (ADS)

    Chaerle, Laury; vandeVen, Martin J.; Valcke, Roland L.; Van Der Straeten, Dominique

    2002-03-01

    Plant leaves possess microscopic valves, called stomata, that enable control of transpirational water loss. In case of water shortage, stomata close, resulting in decreased transpirational cooling. The ensuing temperature increase is readily visualized by thermography. Salicylic acid, a central compound in the defense of plants against pathogens, also closes stomata in several species. In previous work, thermography permitted to monitor an increase in temperature after infection of resistant tobacco by tobacco mosaic virus, before visual symptoms appeared. Furthermore, cell death was visualized with high contrast in both tobacco and Arabidopsis. In addition to transpiration, photosynthetic assimilation is a key physiological parameter. If the amount of light absorbed by chlorophyll exceeds the capacity of the photosynthetic chain, the surplus is dissipated as light of longer wavelength. This phenomenon is known as chlorophyll fluorescence. If a plant leaf is affected by stress, photosynthesis is impaired resulting in a bigger share of non-utilized light energy emitted as fluorescence. The potential of an automated imaging setup combining thermal and fluorescence imaging was shown by monitoring spontaneous cell death in tobacco. This represents a first step to multispectral characterization of a wide range of emerging stresses, which likely affect one or both key physiological parameters.

  3. Early genome duplications in conifers and other seed plants.

    PubMed

    Li, Zheng; Baniaga, Anthony E; Sessa, Emily B; Scascitelli, Moira; Graham, Sean W; Rieseberg, Loren H; Barker, Michael S

    2015-11-01

    Polyploidy is a common mode of speciation and evolution in angiosperms (flowering plants). In contrast, there is little evidence to date that whole genome duplication (WGD) has played a significant role in the evolution of their putative extant sister lineage, the gymnosperms. Recent analyses of the spruce genome, the first published conifer genome, failed to detect evidence of WGDs in gene age distributions and attributed many aspects of conifer biology to a lack of WGDs. We present evidence for three ancient genome duplications during the evolution of gymnosperms, based on phylogenomic analyses of transcriptomes from 24 gymnosperms and 3 outgroups. We use a new algorithm to place these WGD events in phylogenetic context: two in the ancestry of major conifer clades (Pinaceae and cupressophyte conifers) and one in Welwitschia (Gnetales). We also confirm that a WGD hypothesized to be restricted to seed plants is indeed not shared with ferns and relatives (monilophytes), a result that was unclear in earlier studies. Contrary to previous genomic research that reported an absence of polyploidy in the ancestry of contemporary gymnosperms, our analyses indicate that polyploidy has contributed to the evolution of conifers and other gymnosperms. As in the flowering plants, the evolution of the large genome sizes of gymnosperms involved both polyploidy and repetitive element activity.

  4. Early genome duplications in conifers and other seed plants

    PubMed Central

    Li, Zheng; Baniaga, Anthony E.; Sessa, Emily B.; Scascitelli, Moira; Graham, Sean W.; Rieseberg, Loren H.; Barker, Michael S.

    2015-01-01

    Polyploidy is a common mode of speciation and evolution in angiosperms (flowering plants). In contrast, there is little evidence to date that whole genome duplication (WGD) has played a significant role in the evolution of their putative extant sister lineage, the gymnosperms. Recent analyses of the spruce genome, the first published conifer genome, failed to detect evidence of WGDs in gene age distributions and attributed many aspects of conifer biology to a lack of WGDs. We present evidence for three ancient genome duplications during the evolution of gymnosperms, based on phylogenomic analyses of transcriptomes from 24 gymnosperms and 3 outgroups. We use a new algorithm to place these WGD events in phylogenetic context: two in the ancestry of major conifer clades (Pinaceae and cupressophyte conifers) and one in Welwitschia (Gnetales). We also confirm that a WGD hypothesized to be restricted to seed plants is indeed not shared with ferns and relatives (monilophytes), a result that was unclear in earlier studies. Contrary to previous genomic research that reported an absence of polyploidy in the ancestry of contemporary gymnosperms, our analyses indicate that polyploidy has contributed to the evolution of conifers and other gymnosperms. As in the flowering plants, the evolution of the large genome sizes of gymnosperms involved both polyploidy and repetitive element activity. PMID:26702445

  5. Early Diagenesis of Plant Pigments in Hudson River Sediments

    NASA Astrophysics Data System (ADS)

    Bianchi, Thomas S.; Dibb, Jack E.; Findlay, Stuart

    1993-06-01

    Plant pigment concentrations were measured using high performance liquid chromatography in Hudson River sediments. Sedimentation rates and mixing characteristics were determined from depth profiles of the naturally occurring radionuclides 7Be, 210Pb. Previous estimates of the mean-lives (1/λ) of plant pigments (chlorophylls a and b, fucoxanthin) from laboratory experiments, indicate a range of c. 20-40 days. However, in the field, we observed that these pigments decreased less rapidly with depth and penetrated deeper than 7Be (mean-life 77 days) in Hudson sediments 95% of the time. Assuming similar mixing processes for particles carrying 7Be and pigments, this indicates that pigment decay rates in the field are slower than the 0·013 day -1 decay rate of 7Be, hence, more than 2-fold slower than the derived laboratory rates. We believe that high inputs of vascular plant detritus in the Hudson may increase the complexation of humic substances with pigments resulting in slower decay rates. While most pigments showed an exponential decrease with sediment depth, lutein concentrations generally increased with depth. This pattern of decay resistance is in agreement with laboratory experiments which show that lutein is the most decay resistant among dominant pigments. These data along with other studies demonstrate that the carotenoids lacking the 5,6-epoxide group (i.e., lutein) are more decay resistant than pigments that contain it (i.e., fucoxanthin).

  6. Involvement of hexokinase1 in plant growth promotion as mediated by Burkholderia phytofirmans.

    PubMed

    Park, Jae Min; Lazarovits, George

    2014-06-01

    Potato plantlets inoculated with strain PsJN of the bacterium Burkholderia phytofirmans exhibit consistent and significant increases in plant growth under in vitro conditions, when compared with uninoculated plants. The greatest influence on the degree and type of growth enhancement that develops has been shown to be mediated by the sugar concentration in the agar media. Bacterial growth promotion has been suggested in other studies to be regulated by the sugar sensor enzyme hexokinase1, the role of which is activation of glucose phosphorylation. In this present study, we examined the co-relationship between root and stem development in potato plants treated with PsJN and the activity of hexokinase1. Plants grown in the presence of 1.5% and 3% sucrose showed increased levels of hexokinase1 activity only in the roots of inoculated plants, suggesting that the increased enzyme levels may be associated with root growth. Analysis for mRNA using reverse transcriptase did not reveal any significant differences in transcription levels of the gene between inoculated and uninoculated plants. When PsJN-inoculated plants were grown in 1.5% and 3% concentrations of glucose and fructose, stem height and mass, leaf number, root mass, and overall biomass increased. No growth promotion occurred when PsJN-inoculated plants were grown in 3% maltose. Subsequently, a hexokinase1 activity assay showed that PsJN-induced growth of potato plants was found to only occur when plants were grown in the presence of sugars that are recognized by the plant hexokinase1. The results suggest that PsJN may enhance sugar uptake in plants by direct or indirect stimulation of hexokinase1 activity in roots and this results in enhanced overall plant growth.

  7. Comparative analysis of the conceptual design studies of potential early commercial MHD power plants (CSPEC)

    NASA Technical Reports Server (NTRS)

    Sovie, R. J.; Winter, J. M.; Juhasz, A. J.; Berg, R. D.

    1982-01-01

    A conceptual design study of the MHD/steam plant that incorporates the use of oxygen enriched air preheated in a metallic heat exchanger as the combustor oxidant showed that this plant is the most attractive for early commercial applications. The variation of performance and cost was investigated as a function of plant size. The contractors' results for the overall efficiencies are in reasonable agreement considering the slight differences in their plant designs. NASA LeRC is reviewing cost and performance results for consistency with those of previous studies, including studies of conventional steam plants. LeRC in house efforts show that there are still many tradeoffs to be considered for these oxygen enriched plants and considerable variations can be made in channel length and level of oxygen enrichment with little change in overall plant efficiency.