Science.gov

Sample records for adversely affect plant

  1. FACTORS ADVERSELY AFFECTING AMPHIBIAN POPULATIONS IN THE US

    EPA Science Inventory

    Factors known or suspected to be adversely affecting native amphibian populations in the US were identified using information from species accounts written in a standardized format by multiple authors in a forthcoming book. Specific adverse factors were identified for 53 (58%) of...

  2. Parents' Psychiatric Issues May Adversely Affect Some Children

    MedlinePlus

    ... Adversely Affect Some Children History of antisocial disorder, suicide attempt or marijuana abuse showed the most effect, ... illness may be at higher risk for attempting suicide and/or engaging in violent behavior, a new ...

  3. Adversity before Conception Will Affect Adult Progeny in Rats

    ERIC Educational Resources Information Center

    Shachar-Dadon, Alice; Schulkin, Jay; Leshem, Micah

    2009-01-01

    The authors investigated whether adversity in a female, before she conceives, will influence the affective and social behavior of her progeny. Virgin female rats were either undisturbed (controls) or exposed to varied, unpredictable, stressors for 7 days (preconceptual stress [PCS]) and then either mated immediately after the end of the stress…

  4. The synthetic progestin megestrol acetate adversely affects zebrafish reproduction.

    PubMed

    Han, Jian; Wang, Qiangwei; Wang, Xianfeng; Li, Yonggang; Wen, Sheng; Liu, Shan; Ying, Guangguo; Guo, Yongyong; Zhou, Bingsheng

    2014-05-01

    Synthetic progestins contaminate the aquatic ecosystem, and may cause adverse health effects on aquatic organisms. Megestrol acetate (MTA) is present in the aquatic environment, but its possible effects on fish reproduction are unknown. In the present study, we investigated the endocrine disruption and impact of MTA on fish reproduction. After a pre-exposure period of 14 days, reproductively mature zebrafish (Danio rerio) (F0) were exposed to MTA at environmental concentrations (33, 100, 333, and 666 ng/L) for 21 days. Egg production was decreased in F0 fish exposed to MTA, with a significant decrease at 666 ng/L. The exposure significantly decreased the circulating concentrations of estradiol (E2) and testosterone (T) in female fish or 11-keto testosterone (11-KT) in male fish. MTA exposure significantly downregulated the transcription of certain genes along the hypothalamic-pituitary-gonadal (HPG) axis. MTA did not affect early embryonic development or hatching success in the F1 generation. The present study showed that MTA is a potent endocrine disruptor in fish, and short-term exposure to MTA could significantly affect reproduction in fish and negatively impact the fish population. PMID:24647012

  5. The synthetic progestin megestrol acetate adversely affects zebrafish reproduction.

    PubMed

    Han, Jian; Wang, Qiangwei; Wang, Xianfeng; Li, Yonggang; Wen, Sheng; Liu, Shan; Ying, Guangguo; Guo, Yongyong; Zhou, Bingsheng

    2014-05-01

    Synthetic progestins contaminate the aquatic ecosystem, and may cause adverse health effects on aquatic organisms. Megestrol acetate (MTA) is present in the aquatic environment, but its possible effects on fish reproduction are unknown. In the present study, we investigated the endocrine disruption and impact of MTA on fish reproduction. After a pre-exposure period of 14 days, reproductively mature zebrafish (Danio rerio) (F0) were exposed to MTA at environmental concentrations (33, 100, 333, and 666 ng/L) for 21 days. Egg production was decreased in F0 fish exposed to MTA, with a significant decrease at 666 ng/L. The exposure significantly decreased the circulating concentrations of estradiol (E2) and testosterone (T) in female fish or 11-keto testosterone (11-KT) in male fish. MTA exposure significantly downregulated the transcription of certain genes along the hypothalamic-pituitary-gonadal (HPG) axis. MTA did not affect early embryonic development or hatching success in the F1 generation. The present study showed that MTA is a potent endocrine disruptor in fish, and short-term exposure to MTA could significantly affect reproduction in fish and negatively impact the fish population.

  6. Factors affecting the development of adverse drug reactions (Review article)

    PubMed Central

    Alomar, Muaed Jamal

    2013-01-01

    Objectives To discuss the effect of certain factors on the occurrence of Adverse Drug Reactions (ADRs). Data Sources A systematic review of the literature in the period between 1991 and 2012 was made based on PubMed, the Cochrane database of systematic reviews, EMBASE and IDIS. Key words used were: medication error, adverse drug reaction, iatrogenic disease factors, ambulatory care, primary health care, side effects and treatment hazards. Summary Many factors play a crucial role in the occurrence of ADRs, some of these are patient related, drug related or socially related factors. Age for instance has a very critical impact on the occurrence of ADRs, both very young and very old patients are more vulnerable to these reactions than other age groups. Alcohol intake also has a crucial impact on ADRs. Other factors are gender, race, pregnancy, breast feeding, kidney problems, liver function, drug dose and frequency and many other factors. The effect of these factors on ADRs is well documented in the medical literature. Taking these factors into consideration during medical evaluation enables medical practitioners to choose the best drug regimen. Conclusion Many factors affect the occurrence of ADRs. Some of these factors can be changed like smoking or alcohol intake others cannot be changed like age, presence of other diseases or genetic factors. Understanding the different effects of these factors on ADRs enables healthcare professionals to choose the most appropriate medication for that particular patient. It also helps the healthcare professionals to give the best advice to patients. Pharmacogenomics is the most recent science which emphasizes the genetic predisposition of ADRs. This innovative science provides a new perspective in dealing with the decision making process of drug selection. PMID:24648818

  7. Shrub clearing adversely affects the abundance of Ixodes ricinus ticks.

    PubMed

    Tack, Wesley; Madder, Maxime; Baeten, Lander; Vanhellemont, Margot; Verheyen, Kris

    2013-07-01

    In order to get a better understanding of the importance of vertical forest structure as a component of Ixodes ricinus tick habitat, an experiment was set up in a coniferous forest on sandy soils in northern Belgium. Ticks were sampled in six control and six treatment plots on various sampling occasions in 2008-2010. In the course of the study period, a moderate thinning was carried out in all plots and shrub clearing was performed in the treatment plots. Thinning had no effect on tick abundance, while shrub clearing had an adverse affect on the abundance of all three life stages (larva, nymph, adult) up to 2 years post-clearing. Our findings are especially relevant in the light of the ongoing efforts to improve vertical forest structure in Belgium and many other parts of Europe, which might create suitable habitats for ticks and change the epidemiology of tick-borne diseases. Also, our results indicate that shrub clearing could be applied as a tick control measure in recreational areas where there is a high degree of human-tick contact.

  8. Does Ramadan Fasting Adversely Affect Cognitive Function in Young Females?

    PubMed Central

    Ghayour Najafabadi, Mahboubeh; Rahbar Nikoukar, Laya; Memari, Amir; Ekhtiari, Hamed; Beygi, Sara

    2015-01-01

    We examined the effects of Ramadan fasting on cognitive function in 17 female athletes. Data were obtained from participants of two fasting (n = 9) and nonfasting (n = 8) groups at three periods of the study (before Ramadan, at the third week in Ramadan, and after Ramadan). Digit span test (DST) and Stroop color test were employed to assess short-term memory and inhibition/cognitive flexibility at each time point. There were no significant changes for DST and Stroop task 1 in both groups, whereas Stroop task 2 and task 3 showed significant improvements in Ramadan condition (p < 0.05). Interference indices did not change significantly across the study except in post-Ramadan period of fasting group (p < 0.05). Group × week interaction was significant only for error numbers (p < 0.05). Athletes in nonfasting showed a significant decrease in number of errors in Ramadan compared to baseline (p < 0.05). The results suggest that Ramadan fasting may not adversely affect cognitive function in female athletes. PMID:26697263

  9. Why Does Military Combat Experience Adversely Affect Marital Relations?

    ERIC Educational Resources Information Center

    Gimbel, Cynthia; Booth, Alan

    1994-01-01

    Describes investigation of ways in which combat decreases marital quality and stability. Results support three models: (1) factors propelling men into combat also make them poor marriage material; (2) combat causes problems that increase marital adversity; and (3) combat intensifies premilitary stress and antisocial behavior which then negatively…

  10. 47 CFR 73.4157 - Network signals which adversely affect affiliate broadcast service.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 4 2011-10-01 2011-10-01 false Network signals which adversely affect affiliate broadcast service. 73.4157 Section 73.4157 Telecommunication FEDERAL COMMUNICATIONS COMMISSION....4157 Network signals which adversely affect affiliate broadcast service. See Public Notice, FCC...

  11. 47 CFR 73.4157 - Network signals which adversely affect affiliate broadcast service.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Network signals which adversely affect affiliate broadcast service. 73.4157 Section 73.4157 Telecommunication FEDERAL COMMUNICATIONS COMMISSION....4157 Network signals which adversely affect affiliate broadcast service. See Public Notice, FCC...

  12. [Adaptation mechanisms of alpine plants photosynthetic apparatus against adverse stress: a review].

    PubMed

    Wang, Yu-Ping; Gao, Hui-Hui; Liu, Yue-Shan; Mu, Ping; Yu, Xiao-Jun; An, Li-Zhe; Zhang, Feng

    2013-07-01

    Photosynthesis is one of the vital physiological processes easily affected by environmental changes. As a plant group growing in specific low temperature and strong irradiance environment, the photosynthetic apparatus of alpine plants have developed special morphologically and physiologically mechanisms in adapting to this extreme adverse environment. However, due to the high heterogeneity of habitats, there exist great differences in the photo-protection and adaptation mechanisms among different alpine plants. This paper reviewed the recent researches about the morphology and ultramicro-anatomical structure of the chloroplasts in photosynthetic apparatus of alpine plants and the photo-protection and adaptation mechanisms of the plants, and proposed the further research directions on the physiological adaptation of the photosynthesis of alpine plants.

  13. Root-Zone Glyphosate Exposure Adversely Affects Two Ditch Species

    PubMed Central

    Saunders, Lyndsay E.; Koontz, Melissa B.; Pezeshki, Reza

    2013-01-01

    Glyphosate, one of the most applied herbicides globally, has been extensively studied for its effects on non-target organisms. In the field, following precipitation, glyphosate runs off into agricultural ditches where it infiltrates into the soil and thus may encounter the roots of vegetation. These edge-of-field ditches share many characteristics with wetlands, including the ability to reduce loads of anthropogenic chemicals through uptake, transformation, and retention. Different species within the ditches may have a differential sensitivity to exposure of the root zone to glyphosate, contributing to patterns of abundance of ruderal species. The present laboratory experiment investigated whether two species commonly found in agricultural ditches in southcentral United States were affected by root zone glyphosate in a dose-dependent manner, with the objective of identifying a sublethal concentration threshold. The root zone of individuals of Polygonum hydropiperoides and Panicum hemitomon were exposed to four concentrations of glyphosate. Leaf chlorophyll content was measured, and the ratio of aboveground biomass to belowground biomass and survival were quantified. The findings from this study showed that root zone glyphosate exposure negatively affected both species including dose-dependent reductions in chlorophyll content. P. hydropiperdoides showed the greatest negative response, with decreased belowground biomass allocation and total mortality at the highest concentrations tested. PMID:24833234

  14. Urban sprawl and you: how sprawl adversely affects worker health.

    PubMed

    Pohanka, Mary; Fitzgerald, Sheila

    2004-06-01

    Urban sprawl, once thought of as just an environmental issue, is currently gaining momentum as an emerging public health issue worthy of research and political attention. Characteristics seen in sprawling communities include increasing traffic volumes; inadequate public transportation; pedestrian unfriendly streets; and the division of businesses, shops, and homes. These characteristics can affect health in many ways. Greater air pollution contributes to higher asthma and other lung disorder rates. An increased dependence on the automobile encourages a more sedentary lifestyle and can potentially contribute to obesity. The increased danger and stress of long commutes can lead to more accidents, anxiety, and social isolation. Occupational health nurses can become involved by promoting physical activity in the workplace, creating programs for injury prevention and stress management, becoming involved in political smart growth measures, and educating and encouraging colleagues to become active in addressing this issue.

  15. ABSENCE OF SCLEROSTIN ADVERSELY AFFECTS B CELL SURVIVAL

    PubMed Central

    Cain, Corey J.; Rueda, Randell; McLelland, Bryce; Collette, Nicole M.; Loots, Gabriela G.; Manilay, Jennifer O.

    2012-01-01

    Increased osteoblast activity in sclerostin-knockout (Sost−/−) mice results in generalized hyperostosis and bones with small bone marrow cavities due to hyperactive mineralizing osteoblast populations. Hematopoietic cell fate decisions are dependent on their local microenvironment, which contains osteoblast and stromal cell populations that support both hematopoietic stem cell quiescence and facilitate B cell development. In this study, we investigated whether high bone mass environments affect B cell development via the utilization of Sost−/− mice, a model of sclerosteosis. We found the bone marrow of Sost−/− mice to be specifically depleted of B cells, due to elevated apoptosis at all B cell developmental stages. In contrast, B cell function in the spleen was normal. Sost expression analysis confirmed that Sost is primarily expressed in osteocytes and is not expressed in any hematopoietic lineage, which indicated that the B cell defects in Sost−/− mice are non-cell autonomous and this was confirmed by transplantation of wildtype (WT) bone marrow into lethally irradiated Sost−/− recipients. WT→Sost−/− chimeras displayed a reduction in B cells, whereas reciprocal Sost−/−→WT chimeras did not, supporting the idea that the Sost−/− bone environment cannot fully support normal B cell development. Expression of the pre-B cell growth stimulating factor, Cxcl12, was significantly lower in bone marrow stromal cells of Sost−/− mice while the Wnt target genes Lef-1 and Ccnd1 remained unchanged in B cells. Taken together, these results demonstrate a novel role for Sost in the regulation of bone marrow environments that support B cells. PMID:22434688

  16. 40 CFR 230.75 - Actions affecting plant and animal populations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... populations. 230.75 Section 230.75 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN... Actions To Minimize Adverse Effects § 230.75 Actions affecting plant and animal populations. Minimization of adverse effects on populations of plants and animals can be achieved by: (a) Avoiding changes...

  17. 40 CFR 230.75 - Actions affecting plant and animal populations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... populations. 230.75 Section 230.75 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN... Actions To Minimize Adverse Effects § 230.75 Actions affecting plant and animal populations. Minimization of adverse effects on populations of plants and animals can be achieved by: (a) Avoiding changes...

  18. 40 CFR 230.75 - Actions affecting plant and animal populations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... populations. 230.75 Section 230.75 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN... Actions To Minimize Adverse Effects § 230.75 Actions affecting plant and animal populations. Minimization of adverse effects on populations of plants and animals can be achieved by: (a) Avoiding changes...

  19. 40 CFR 230.75 - Actions affecting plant and animal populations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... populations. 230.75 Section 230.75 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN... Actions To Minimize Adverse Effects § 230.75 Actions affecting plant and animal populations. Minimization of adverse effects on populations of plants and animals can be achieved by: (a) Avoiding changes...

  20. 40 CFR 230.75 - Actions affecting plant and animal populations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... populations. 230.75 Section 230.75 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) OCEAN... Actions To Minimize Adverse Effects § 230.75 Actions affecting plant and animal populations. Minimization of adverse effects on populations of plants and animals can be achieved by: (a) Avoiding changes...

  1. Trichoderma secondary metabolites that affect plant metabolism.

    PubMed

    Vinale, Francesco; Sivasithamparam, Krishnapillai; Ghisalberti, Emilio L; Ruocco, Michelina; Wood, Sheridan; Lorito, Matteo

    2012-11-01

    Recently, there have been many exciting new developments relating to the use of Trichoderma spp. as agents for biocontrol of pathogens and as plant growth promoters. Several mechanisms have been proposed to explain the positive effects of these microorganisms on the plant host. One factor that contributes to their beneficial biological activities is related to the wide variety of metabolites that they produce. These metabolites have been found not only to directly inhibit the growth and pathogenic activities of the parasites, but also to increase disease resistance by triggering the system of defence in the plant host. In addition, these metabolites are also capable of enhancing plant growth, which enables the plant to counteract the disease with compensatory vegetative growth by the augmented production of root and shoot systems. This review takes into account the Trichoderma secondary metabolites that affect plant metabolism and that may play an important role in the complex interactions of this biocontrol agent with the plant and pathogens.

  2. Genetic polymorphisms affect efficacy and adverse drug reactions of DMARDs in rheumatoid arthritis.

    PubMed

    Zhang, Ling Ling; Yang, Sen; Wei, Wei; Zhang, Xue Jun

    2014-11-01

    Disease-modifying antirheumatic drugs (DMARDs) and biological agents are critical in preventing the severe complications of rheumatoid arthritis (RA). However, the outcome of treatment with these drugs in RA patients is quite variable and unpredictable. Drug-metabolizing enzymes (dihydrofolate reductase, cytochrome P450 enzymes, N-acetyltransferases, etc.), drug transporters (ATP-binding cassette transporters), and drug targets (tumor necrosis factor-α receptors) are coded for by variant alleles. These gene polymorphisms may influence the pharmacokinetics, pharmacodynamics, and side effects of medicines. The cause for differences in efficacy and adverse drug reactions may be genetic variation in drug metabolism among individuals. Polymorphisms in drug transporter genes may change the distribution and excretion of medicines, and the sensitivity of the targets to drugs is strongly influenced by genetic variations. In this article, we review the genetic polymorphisms that affect the efficacy of DMARDs or the occurrence of adverse drug reactions associated with DMARDs in RA.

  3. Factors Affecting Ice Nucleation in Plant Tissues

    PubMed Central

    Ashworth, Edward N.; Davis, Glen A.; Anderson, Jeffrey A.

    1985-01-01

    Factors affecting the ice nucleation temperature of plants and plant tissues were examined. The mass of a sample had a marked effect on ice nucleation temperature. Small tissue samples supercooled to −10°C and were not accurate predictors of the nucleation temperature of intact plants in either laboratory or field experiments. This effect was not unique to plant tissues and was observed in autoclaved and control soil samples. Ice nucleation temperatures of bean, corn, cotton, and soybean seedlings were influenced by the length of subzero exposure, presence of ice nucleation active bacteria, and leaf surface wetness. The number of factors influencing ice nucleation temperature suggested that predicting the freezing behavior of plants in the field will be complex. PMID:16664524

  4. Family Adversity and Autonomic Reactivity Association With Immune Changes in HIV-Affected School Children

    PubMed Central

    Thomas, Melanie; Wara, Diane; Saxton, Katherine; Truskier, Mary; Chesney, Margaret; Boyce, W. Thomas

    2013-01-01

    Objective To explore whether primary school entry is associated with changes in immune system parameters in HIV-affected children. HIV-affected children are vulnerable to psychosocial stressors, regardless of their own HIV serological status. Methods Data from 38 HIV+ and 29 HIV− children born to seropositive women were obtained before and after school entry. Measures included family adversity questionnaires, autonomic nervous system (ANS) reactivity (based on mean arterial responses to challenge tasks), and enumerative and functional changes in peripheral blood immune parameters. Results In comparison to children who were HIV−, children who were HIV+ at baseline had fewer CD4+ T lymphocytes (M = 916 vs. 1206 cells/mm3 × 103; F = 7.8, p = .007), more CD8+ cells (M = 1046 vs. 720 cells/mm3 ×103; F = 7.98, p = .006), and diminished NK cell cytotoxicity (M =−.29 vs. .41; F = 8.87, p = .004). School entry was associated with changes in immune parameters, but HIV status was not associated with the magnitude of changes. Changes in immune parameters following school entry were associated with family stress and pre school entry ANS reactivity. Highly ANS reactive children had either the greatest increase in CD8+ cells following school entry or the greatest decrease, depending upon reported levels of family adversity (B = 215.35; t = 3.74, p < .001). Changes in functional immune assays were significantly associated with the interactions between HIV status and ANS reactivity. Conclusions These results suggest that autonomic reactivity is associated with increased immunological sensitivity to adverse or challenging social contexts among children affected by HIV. PMID:23766380

  5. Developing robust crop plants for sustaining growth and yield under adverse climatic changes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Agricultural production and quality are expected to suffer from adverse changes in climatic conditions, including global warming, and this will affect worldwide human and animal food security. Global warming has been shown to negatively impact crop yield and therefore will affect sustainability of a...

  6. 42 CFR 137.435 - Will an appeal adversely affect the Indian Tribe's rights in other compact, funding negotiations...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... rights in other compact, funding negotiations, or construction project agreement? 137.435 Section 137.435... another compact, funding agreement, or construction project agreement. ... appeal adversely affect the Indian Tribe's rights in other compact, funding negotiations, or...

  7. 42 CFR 137.435 - Will an appeal adversely affect the Indian Tribe's rights in other compact, funding negotiations...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... rights in other compact, funding negotiations, or construction project agreement? 137.435 Section 137.435... another compact, funding agreement, or construction project agreement. ... appeal adversely affect the Indian Tribe's rights in other compact, funding negotiations, or...

  8. 42 CFR 137.435 - Will an appeal adversely affect the Indian Tribe's rights in other compact, funding negotiations...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... rights in other compact, funding negotiations, or construction project agreement? 137.435 Section 137.435... another compact, funding agreement, or construction project agreement. ... appeal adversely affect the Indian Tribe's rights in other compact, funding negotiations, or...

  9. 42 CFR 137.435 - Will an appeal adversely affect the Indian Tribe's rights in other compact, funding negotiations...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... rights in other compact, funding negotiations, or construction project agreement? 137.435 Section 137.435... another compact, funding agreement, or construction project agreement. ... appeal adversely affect the Indian Tribe's rights in other compact, funding negotiations, or...

  10. 42 CFR 137.435 - Will an appeal adversely affect the Indian Tribe's rights in other compact, funding negotiations...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... rights in other compact, funding negotiations, or construction project agreement? 137.435 Section 137.435... another compact, funding agreement, or construction project agreement. ... appeal adversely affect the Indian Tribe's rights in other compact, funding negotiations, or...

  11. Dietary restriction does not adversely affect bone geometry and mechanics in rapidly growing male wistar rats.

    PubMed

    Lambert, Jennifer; Lamothe, Jeremy M; Zernicke, Ronald F; Auer, Roland N; Reimer, Raylene A

    2005-02-01

    The present study assessed the effects of dietary restriction on tibial and vertebral mechanical and geometrical properties in 2-mo-old male Wistar rats. Two-month-old male Wistar rats were randomized to the ad libitum (n=8) or the 35% diet-restricted (DR) feeding group (n=9) for 5 mo. Tibiae and L6 vertebrae were dissected out for microcomputed tomography (microCT) scanning and subsequently fractured in biomechanical testing to determine geometrical and mechanical properties. The DR group had significantly lower mean tibial length, mass, area, and cross-sectional moment of inertia, as well as vertebral energy to maximal load. After adjustment for body mass, however, DR tibial mean maximal load and stiffness, and DR vertebral area, height, volume, and maximal load were significantly greater, relative to ad libitum means. No significant differences were found between the DR and ad libitum mineral ash fractions. Because the material properties of the tibiae between the two groups were not significantly different, presumably the material integrity of the bones was not adversely affected as a consequence of DR. The similar material characteristics were consistent with mineral ash fractions that were not different between the two groups. Vertebral maximal load and stiffness were not significant between the DR and ad libitum animals. Importantly, we show that a level of dietary restriction (35%) that is less severe than many studies (40%), and without micronutrient compensation does not adversely affect tibial and vertebral mechanical properties in young growing male rats when normalized for body mass. PMID:15585686

  12. Plant-associated bacteria degrade defense chemicals and reduce their adverse effects on an insect defoliator.

    PubMed

    Mason, Charles J; Couture, John J; Raffa, Kenneth F

    2014-07-01

    Phytophagous insects must contend with numerous secondary defense compounds that can adversely affect their growth and development. The gypsy moth (Lymantria dispar) is a polyphagous herbivore that encounters an extensive range of hosts and chemicals. We used this folivore and a primary component of aspen chemical defenses, namely, phenolic glycosides, to investigate if bacteria detoxify phytochemicals and benefit larvae. We conducted insect bioassays using bacteria enriched from environmental samples, analyses of the microbial community in the midguts of bioassay larvae, and in vitro phenolic glycoside metabolism assays. Inoculation with bacteria enhanced larval growth in the presence, but not absence, of phenolic glycosides in the artificial diet. This effect of bacteria on growth was observed only in larvae administered bacteria from aspen foliage. The resulting midgut community composition varied among the bacterial treatments. When phenolic glycosides were included in diet, the composition of midguts in larvae fed aspen bacteria was significantly altered. Phenolic glycosides increased population responses by bacteria that we found able to metabolize these compounds in liquid growth cultures. Several aspects of these results suggest that vectoring or pairwise symbiosis models are inadequate for understanding microbial mediation of plant-herbivore interactions in some systems. First, bacteria that most benefitted larvae were initially foliar residents, suggesting that toxin-degrading abilities of phyllosphere inhabitants indirectly benefit herbivores upon ingestion. Second, assays with single bacteria did not confer the benefits to larvae obtained with consortia, suggesting multi- and inter-microbial interactions are also involved. Our results show that bacteria mediate insect interactions with plant defenses but that these interactions are community specific and highly complex. PMID:24798201

  13. Factors Affecting the Timing of Signal Detection of Adverse Drug Reactions.

    PubMed

    Hashiguchi, Masayuki; Imai, Shungo; Uehara, Keiko; Maruyama, Junya; Shimizu, Mikiko; Mochizuki, Mayumi

    2015-01-01

    We investigated factors affecting the timing of signal detection by comparing variations in reporting time of known and unknown ADRs after initial drug release in the USA. Data on adverse event reactions (AERs) submitted to U.S. FDA was used. Six ADRs associated with 6 drugs (rosuvastatin, aripiprazole, teriparatide, telithromycin, exenatide, varenicline) were investigated: Changes in the proportional reporting ratio, reporting odds ratio, and information component as indexes of signal detection were followed every 3 months after each drugs release, and the time for detection of signals was investigated. The time for the detection of signal to be detected after drug release in the USA was 2-10 months for known ADRs and 19-44 months for unknown ones. The median lag time for known and unknown ADRs was 99.0-122.5 days and 185.5-306.0 days, respectively. When the FDA released advisory information on rare but potentially serious health risks of an unknown ADR, the time lag to report from the onset of ADRs to the FDA was shorter. This study suggested that one factor affecting signal detection time is whether an ADR was known or unknown at release. PMID:26641634

  14. Sexually Dimorphic Responses to Early Adversity: Implications for Affective Problems and Autism Spectrum Disorder

    PubMed Central

    Davis, Elysia Poggi; Pfaff, Donald

    2014-01-01

    During gestation, development proceeds at a pace that is unmatched by any other stage of the lifecycle. For these reason the human fetus is particularly susceptible not only to organizing influences, but also to pathogenic disorganizing influences. Growing evidence suggests that exposure to prenatal adversity leads to neurological changes that underlie lifetime risks for mental illness. Beginning early in gestation, males and females show differential developmental trajectories and responses to stress. It is likely that sex-dependent organization of neural circuits during the fetal period influences differential vulnerability to mental health problems. We consider in this review evidence that sexually dimorphic responses to early life stress are linked to two developmental disorders: affective problems (greater female prevalence) and autism spectrum disorder (greater male prevalence). Recent prospective studies illustrating the neurodevelopmental consequences of fetal exposure to stress and stress hormones for males and females are considered here. Plausible biological mechanisms including the role of the sexually differentiated placenta are discussed. We consider in this review evidence that sexually dimorphic responses to early life stress are linked to two sets of developmental disorders: affective problems (greater female prevalence) and autism spectrum disorders (greater male prevalence). PMID:25038479

  15. 30 CFR 285.816 - What must I do if environmental or other conditions adversely affect a cable, pipeline, or facility?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... conditions adversely affect a cable, pipeline, or facility? 285.816 Section 285.816 Mineral Resources BUREAU... other conditions adversely affect a cable, pipeline, or facility? If environmental or other conditions adversely affect a cable, pipeline, or facility so as to endanger the safety or the environment, you...

  16. 42 CFR 137.445 - Will an immediate reassumption appeal adversely affect the Self-Governance Tribe's rights in...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... affect the Self-Governance Tribe's rights in other self-governance negotiations? 137.445 Section 137.445..., DEPARTMENT OF HEALTH AND HUMAN SERVICES TRIBAL SELF-GOVERNANCE Appeals Appeals of An Immediate Reassumption of A Self-Governance Program § 137.445 Will an immediate reassumption appeal adversely affect...

  17. 42 CFR 137.445 - Will an immediate reassumption appeal adversely affect the Self-Governance Tribe's rights in...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... affect the Self-Governance Tribe's rights in other self-governance negotiations? 137.445 Section 137.445..., DEPARTMENT OF HEALTH AND HUMAN SERVICES TRIBAL SELF-GOVERNANCE Appeals Appeals of An Immediate Reassumption of A Self-Governance Program § 137.445 Will an immediate reassumption appeal adversely affect...

  18. 42 CFR 137.445 - Will an immediate reassumption appeal adversely affect the Self-Governance Tribe's rights in...

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... affect the Self-Governance Tribe's rights in other self-governance negotiations? 137.445 Section 137.445..., DEPARTMENT OF HEALTH AND HUMAN SERVICES TRIBAL SELF-GOVERNANCE Appeals Appeals of An Immediate Reassumption of A Self-Governance Program § 137.445 Will an immediate reassumption appeal adversely affect...

  19. 42 CFR 137.445 - Will an immediate reassumption appeal adversely affect the Self-Governance Tribe's rights in...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... affect the Self-Governance Tribe's rights in other self-governance negotiations? 137.445 Section 137.445..., DEPARTMENT OF HEALTH AND HUMAN SERVICES TRIBAL SELF-GOVERNANCE Appeals Appeals of An Immediate Reassumption of A Self-Governance Program § 137.445 Will an immediate reassumption appeal adversely affect...

  20. 42 CFR 137.445 - Will an immediate reassumption appeal adversely affect the Self-Governance Tribe's rights in...

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... affect the Self-Governance Tribe's rights in other self-governance negotiations? 137.445 Section 137.445..., DEPARTMENT OF HEALTH AND HUMAN SERVICES TRIBAL SELF-GOVERNANCE Appeals Appeals of An Immediate Reassumption of A Self-Governance Program § 137.445 Will an immediate reassumption appeal adversely affect...

  1. Early Life in a Barren Environment Adversely Affects Spatial Cognition in Laying Hens (Gallus gallus domesticus).

    PubMed

    Tahamtani, Fernanda M; Nordgreen, Janicke; Nordquist, Rebecca E; Janczak, Andrew M

    2015-01-01

    Spatial cognition in vertebrates is adversely affected by a lack of environmental complexity during early life. However, to our knowledge, no previous studies have tested the effect of early exposure to varying degrees of environmental complexity on specific components of spatial cognition in chickens. There are two main rearing systems for laying hens in the EU: aviaries and cages. These two systems differ from one another in environmental complexity. The aim of the present study was to test the hypothesis that rearing in a barren cage environment relative to a complex aviary environment causes long-lasting deficits in the ability to perform spatial tasks. For this purpose, 24 white Dekalb laying hens, half of which had been reared in an aviary system and the other half in a conventional cage system, were tested in a holeboard task. Birds from both treatment groups learnt the task; however, the cage-reared hens required more time to locate rewards and had poorer levels of working memory. The latter finding supports the hypothesis that rearing in a barren environment causes long-term impairment of short-term memory in chickens. PMID:26664932

  2. Exposing physicians to reduced residency work hours did not adversely affect patient outcomes after residency.

    PubMed

    Jena, Anupam B; Schoemaker, Lena; Bhattacharya, Jay

    2014-10-01

    In 2003, work hours for physicians-in-training (residents) were capped by regulation at eighty hours per week, leading to the hotly debated but unexplored issue of whether physicians today are less well trained as a result of these work-hour reforms. Using a unique database of nearly all hospitalizations in Florida during 2000-09 that were linked to detailed information on the medical training history of the physician of record for each hospitalization, we studied whether hospital mortality and patients' length-of-stay varied according to the number of years a physician was exposed to the 2003 duty-hour regulations during his or her residency. We examined this database of practicing Florida physicians, using a difference-in-differences analysis that compared trends in outcomes of junior physicians (those with one-year post-residency experience) pre- and post-2003 to a control group of senior physicians (those with ten or more years of post-residency experience) who were not exposed to these reforms during their residency. We found that the duty-hour reforms did not adversely affect hospital mortality and length-of-stay of patients cared for by new attending physicians who were partly or fully exposed to reduced duty hours during their own residency. However, assessment of the impact of the duty-hour reforms on other clinical outcomes is needed.

  3. Early Life in a Barren Environment Adversely Affects Spatial Cognition in Laying Hens (Gallus gallus domesticus)

    PubMed Central

    Tahamtani, Fernanda M.; Nordgreen, Janicke; Nordquist, Rebecca E.; Janczak, Andrew M.

    2015-01-01

    Spatial cognition in vertebrates is adversely affected by a lack of environmental complexity during early life. However, to our knowledge, no previous studies have tested the effect of early exposure to varying degrees of environmental complexity on specific components of spatial cognition in chickens. There are two main rearing systems for laying hens in the EU: aviaries and cages. These two systems differ from one another in environmental complexity. The aim of the present study was to test the hypothesis that rearing in a barren cage environment relative to a complex aviary environment causes long-lasting deficits in the ability to perform spatial tasks. For this purpose, 24 white Dekalb laying hens, half of which had been reared in an aviary system and the other half in a conventional cage system, were tested in a holeboard task. Birds from both treatment groups learnt the task; however, the cage-reared hens required more time to locate rewards and had poorer levels of working memory. The latter finding supports the hypothesis that rearing in a barren environment causes long-term impairment of short-term memory in chickens. PMID:26664932

  4. Neonicotinoid clothianidin adversely affects insect immunity and promotes replication of a viral pathogen in honey bees.

    PubMed

    Di Prisco, Gennaro; Cavaliere, Valeria; Annoscia, Desiderato; Varricchio, Paola; Caprio, Emilio; Nazzi, Francesco; Gargiulo, Giuseppe; Pennacchio, Francesco

    2013-11-12

    Large-scale losses of honey bee colonies represent a poorly understood problem of global importance. Both biotic and abiotic factors are involved in this phenomenon that is often associated with high loads of parasites and pathogens. A stronger impact of pathogens in honey bees exposed to neonicotinoid insecticides has been reported, but the causal link between insecticide exposure and the possible immune alteration of honey bees remains elusive. Here, we demonstrate that the neonicotinoid insecticide clothianidin negatively modulates NF-κB immune signaling in insects and adversely affects honey bee antiviral defenses controlled by this transcription factor. We have identified in insects a negative modulator of NF-κB activation, which is a leucine-rich repeat protein. Exposure to clothianidin, by enhancing the transcription of the gene encoding this inhibitor, reduces immune defenses and promotes the replication of the deformed wing virus in honey bees bearing covert infections. This honey bee immunosuppression is similarly induced by a different neonicotinoid, imidacloprid, but not by the organophosphate chlorpyriphos, which does not affect NF-κB signaling. The occurrence at sublethal doses of this insecticide-induced viral proliferation suggests that the studied neonicotinoids might have a negative effect at the field level. Our experiments uncover a further level of regulation of the immune response in insects and set the stage for studies on neural modulation of immunity in animals. Furthermore, this study has implications for the conservation of bees, as it will contribute to the definition of more appropriate guidelines for testing chronic or sublethal effects of pesticides used in agriculture.

  5. Neonicotinoid clothianidin adversely affects insect immunity and promotes replication of a viral pathogen in honey bees.

    PubMed

    Di Prisco, Gennaro; Cavaliere, Valeria; Annoscia, Desiderato; Varricchio, Paola; Caprio, Emilio; Nazzi, Francesco; Gargiulo, Giuseppe; Pennacchio, Francesco

    2013-11-12

    Large-scale losses of honey bee colonies represent a poorly understood problem of global importance. Both biotic and abiotic factors are involved in this phenomenon that is often associated with high loads of parasites and pathogens. A stronger impact of pathogens in honey bees exposed to neonicotinoid insecticides has been reported, but the causal link between insecticide exposure and the possible immune alteration of honey bees remains elusive. Here, we demonstrate that the neonicotinoid insecticide clothianidin negatively modulates NF-κB immune signaling in insects and adversely affects honey bee antiviral defenses controlled by this transcription factor. We have identified in insects a negative modulator of NF-κB activation, which is a leucine-rich repeat protein. Exposure to clothianidin, by enhancing the transcription of the gene encoding this inhibitor, reduces immune defenses and promotes the replication of the deformed wing virus in honey bees bearing covert infections. This honey bee immunosuppression is similarly induced by a different neonicotinoid, imidacloprid, but not by the organophosphate chlorpyriphos, which does not affect NF-κB signaling. The occurrence at sublethal doses of this insecticide-induced viral proliferation suggests that the studied neonicotinoids might have a negative effect at the field level. Our experiments uncover a further level of regulation of the immune response in insects and set the stage for studies on neural modulation of immunity in animals. Furthermore, this study has implications for the conservation of bees, as it will contribute to the definition of more appropriate guidelines for testing chronic or sublethal effects of pesticides used in agriculture. PMID:24145453

  6. Neonicotinoid clothianidin adversely affects insect immunity and promotes replication of a viral pathogen in honey bees

    PubMed Central

    Di Prisco, Gennaro; Cavaliere, Valeria; Annoscia, Desiderato; Varricchio, Paola; Caprio, Emilio; Nazzi, Francesco; Gargiulo, Giuseppe; Pennacchio, Francesco

    2013-01-01

    Large-scale losses of honey bee colonies represent a poorly understood problem of global importance. Both biotic and abiotic factors are involved in this phenomenon that is often associated with high loads of parasites and pathogens. A stronger impact of pathogens in honey bees exposed to neonicotinoid insecticides has been reported, but the causal link between insecticide exposure and the possible immune alteration of honey bees remains elusive. Here, we demonstrate that the neonicotinoid insecticide clothianidin negatively modulates NF-κB immune signaling in insects and adversely affects honey bee antiviral defenses controlled by this transcription factor. We have identified in insects a negative modulator of NF-κB activation, which is a leucine-rich repeat protein. Exposure to clothianidin, by enhancing the transcription of the gene encoding this inhibitor, reduces immune defenses and promotes the replication of the deformed wing virus in honey bees bearing covert infections. This honey bee immunosuppression is similarly induced by a different neonicotinoid, imidacloprid, but not by the organophosphate chlorpyriphos, which does not affect NF-κB signaling. The occurrence at sublethal doses of this insecticide-induced viral proliferation suggests that the studied neonicotinoids might have a negative effect at the field level. Our experiments uncover a further level of regulation of the immune response in insects and set the stage for studies on neural modulation of immunity in animals. Furthermore, this study has implications for the conservation of bees, as it will contribute to the definition of more appropriate guidelines for testing chronic or sublethal effects of pesticides used in agriculture. PMID:24145453

  7. Associations Between Residential Proximity to Power Plants and Adverse Birth Outcomes

    PubMed Central

    Ha, Sandie; Hu, Hui; Roth, Jeffrey; Kan, Haidong; Xu, Xiaohui

    2015-01-01

    Few studies have assessed the associations between residential proximity to power plants and adverse birth outcomes including preterm delivery (PTD), very preterm delivery (VPTD), and term low birth weight (LBW). We geocoded 423,719 singleton Florida births born from 2004 to 2005 and all active power plants and determined residential proximity to the nearest power plant for each birth. Prenatal exposure to particulate matter less than 2.5 µm in diameter for women living near different types of power plants was also determined by using National Environmental Public Health Tracking Network data. Logistic regression models were used to test the hypothesized associations. Women who lived closer to coal and solid waste power plants were exposed to higher levels of particulate matter less than 2.5 µm in diameter compared with other types. We observed a 1.8% (95% confidence interval (CI): 1.3, 2.3) increased odds for PTD, 2.2% (95% CI: 1.0, 3.4) for VPTD, and 1.1% (95% CI: 0.2, 2.0) for term LBW for each 5 km closer to any power plant. When stratifying by different fuel type, we found that only solid waste had an association with term LBW, whereas oil, gas, and solid waste all had an association with PTD and VPTD. Results were consistent when exposure was categorized by number of power plants. Our study found evidence of increasing odds of adverse birth outcomes among infants born to pregnant women living closer to power plants. More research is warranted to better understand the causal relationship. PMID:26121989

  8. Probabilities of adverse weather affecting transport in Europe: climatology and scenarios up to the 2050s

    NASA Astrophysics Data System (ADS)

    Vajda, A.; Tuomenvirta, H.; Jokinen, P.; Luomaranta, A.; Makkonen, L.; Tikanmäki, M.; Groenemeijer, P.; Saarikivi, P.; Michaelides, S.; Papadakis, M.; Tymvios, F.; Athanasatos, S.

    2012-04-01

    This paper provides the first comprehensive climatology of the adverse and extreme weather events affecting the European transport system by estimating the frequency (or probability) of phenomena for the present climate (1971-2000) and an overview of the projected changes in some of these extremes in the future climate until the 2050s. The research was carried out within the framework of the EWENT Project that addresses the European Union (EU) policies and strategies related to climate change, with a particular focus on extreme weather impacts on the EU transportation system. This project is funded by the Seventh Framework Programme (Transports, call ID FPT7-TPT-2008-RTD-1). The analyzed phenomena are wind, snow, blizzards, heavy precipitation, cold spells and heat waves. In addition, reduced visibility conditions determined by fog and dust events, small-scale phenomena affecting the transport system, such as thunderstorms, lightning, large hail and tornadoes and events damaging infrastructure of the transport system, have been considered. Frequency and probability analysis of past and present ex¬tremes were performed using observational and atmospheric reanalysis data. Future changes in the probability of severe events were assessed based on six regional climate model simulations produced in the FP6 ENSEMBLES project (http://www.ensembles-eu.org/). To facilitate the assessment of impacts and consequences of extreme phenomena on a continental level, the WP2 Deliverable introduces a regionalization of the European extreme phenomena, defining the climate zones with similarities in extreme phenomena. The projected changes as well as large natural variability in weather extremes on the transportation network will have impacts of both signs. The decline of extreme cold and snowfall over most of the continent implies a positive impact on road, rail, inland water and air transportation, e.g., by reducing snow removal. However, even with a general decreasing trend in

  9. 41 CFR 102-78.40 - What responsibilities do Federal agencies have when an undertaking adversely affects a historic...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Federal agencies have when an undertaking adversely affects a historic or cultural property? 102-78.40... or cultural property? Federal agencies must not perform an undertaking that could alter, destroy, or modify an historic or cultural property until they have consulted with the SHPO and the Advisory...

  10. 41 CFR 102-78.40 - What responsibilities do Federal agencies have when an undertaking adversely affects a historic...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... guidance on the protection of historic and cultural properties in 36 CFR part 800. ... Federal agencies have when an undertaking adversely affects a historic or cultural property? 102-78.40... (Continued) FEDERAL MANAGEMENT REGULATION REAL PROPERTY 78-HISTORIC PRESERVATION Historic Preservation §...

  11. 50 CFR 402.45 - Alternative consultation on FIFRA actions that are not likely to adversely affect listed species...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... OF COMMERCE); ENDANGERED SPECIES COMMITTEE REGULATIONS SUBCHAPTER A INTERAGENCY COOPERATION-ENDANGERED SPECIES ACT OF 1973, AS AMENDED Counterpart Regulations Governing Actions by the U.S... that are not likely to adversely affect listed species or critical habitat. 402.45 Section...

  12. 50 CFR 402.45 - Alternative consultation on FIFRA actions that are not likely to adversely affect listed species...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... OF COMMERCE); ENDANGERED SPECIES COMMITTEE REGULATIONS SUBCHAPTER A INTERAGENCY COOPERATION-ENDANGERED SPECIES ACT OF 1973, AS AMENDED Counterpart Regulations Governing Actions by the U.S... that are not likely to adversely affect listed species or critical habitat. 402.45 Section...

  13. 50 CFR 402.45 - Alternative consultation on FIFRA actions that are not likely to adversely affect listed species...

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... OF COMMERCE); ENDANGERED SPECIES COMMITTEE REGULATIONS SUBCHAPTER A INTERAGENCY COOPERATION-ENDANGERED SPECIES ACT OF 1973, AS AMENDED Counterpart Regulations Governing Actions by the U.S... that are not likely to adversely affect listed species or critical habitat. 402.45 Section...

  14. Exposure to serotonin adversely affects oligodendrocyte development and myelination in vitro.

    PubMed

    Fan, Lir-Wan; Bhatt, Abhay; Tien, Lu-Tai; Zheng, Baoying; Simpson, Kimberly L; Lin, Rick C S; Cai, Zhengwei; Kumar, Praveen; Pang, Yi

    2015-05-01

    patterns of contactin-associated protein (Caspr) clustering were observed at the sites of Node of Ranvier, suggesting that 5-HT exposure may affect other axon-derived factors for myelination. In summary, this is the first study to demonstrate that manipulation of serotonin levels affects OL development and myelination, which may contribute to altered neural connectivity noted in SSRIs-treated animals. The current in vitro study demonstrated that exposure to high level of serotonin (5-HT) led to aberrant oligodendrocyte (OL) development, cell injury, and myelination deficit. We propose that elevated extracellular serotonin levels in the fetal brain, such as upon the use of selective serotonin reuptake inhibitors (SSRIs) during pregnancy, may adversely affect OL development and/or myelination, thus contributing to altered neural connectivity seen in Autism Spectrum Disorders. OPC = oligodendrocyte progenitor cell.

  15. Correlation of adverse effects of cisplatin administration in patients affected by solid tumours: A retrospective evaluation

    PubMed Central

    ASTOLFI, LAURA; GHISELLI, SARA; GUARAN, VALERIA; CHICCA, MILVIA; SIMONI, EDI; OLIVETTO, ELENA; LELLI, GIORGIO; MARTINI, ALESSANDRO

    2013-01-01

    Cisplatin is the most common antineoplastic drug used for the therapy of solid tumours. To date, researchers have focused on the dosage to be administered for each specific tumour, mainly considering the local adverse effects. The aim of this study was to correlate the severity of the adverse effects with: i) the dosage of cisplatin; ii) the specific site of the tumour; iii) the association with other drugs; and iv) the symptoms. We analysed data from 123 patients with 11 different tumour classes undergoing therapy from 2007 to 2008 at St. Anna Hospital (Ferrara, Italy), using the Spearman non-parametric correlation index. Even though significant correlations were found among the variables, the overall results showed that the main factor influencing the severity of the adverse effects was the dosage of cisplatin administered. PMID:23404427

  16. Ethanol inducible expression of a mesophilic cellulase avoids adverse effects on plant development

    PubMed Central

    2013-01-01

    Background Plant-produced biomass-degrading enzymes are promising tools for the processing of lignocellulose to fermentable sugars. A major limitation of in planta production is that high-level expression of such enzymes could potentially affect the structure and integrity of the plant cell wall and negatively influence plant growth and development. Results Here, we evaluate the impact on tobacco plant development of constitutive versus alcohol-inducible expression of the endoglucanase TrCel5A from the mesophilic fungus Trichoderma reesei. Using this system, we are able to demonstrate that constitutive expression of the enzyme, controlled by the doubled Cauliflower Mosaic Virus promoter, leads to lower cellulose content of the plant combined with severe effects on plant growth. However, using an alcohol-inducible expression of the endoglucanase in the plant leaves, we achieved similar enzymatic expression levels with no changes in the crystalline cellulose content. Conclusion We were able to produce significant amounts of cellulase in the plant leaves without detrimental effects to plant development. These results demonstrate the potential feasibility of an inducible expression system for producing biomass degrading enzymes in plants. PMID:23587418

  17. Severe Affective and Behavioural Dysregulation Is Associated with Significant Psychosocial Adversity and Impairment

    ERIC Educational Resources Information Center

    Jucksch, Viola; Salbach-Andrae, Harriet; Lenz, Klaus; Goth, Kirstin; Dopfner, Manfred; Poustka, Fritz; Freitag, Christine M.; Lehmkuhl, Gerd; Lehmkuhl, Ulrike; Holtmann, Martin

    2011-01-01

    Background: Recently, a highly heritable behavioral phenotype of simultaneous deviance on the Anxious/Depressed, Attention Problems, and Aggressive Behavior syndrome scales has been identified on the Child Behavior Checklist (CBCL-Dysregulation Profile, CBCL-DP). This study aims to investigate psychosocial adversity and impairment of the CBCL-DP.…

  18. 30 CFR 585.816 - What must I do if environmental or other conditions adversely affect a cable, pipeline, or facility?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... conditions adversely affect a cable, pipeline, or facility? 585.816 Section 585.816 Mineral Resources BUREAU... affect a cable, pipeline, or facility? If environmental or other conditions adversely affect a cable, pipeline, or facility so as to endanger the safety or the environment, you must: (a) Submit a plan...

  19. 30 CFR 585.816 - What must I do if environmental or other conditions adversely affect a cable, pipeline, or facility?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... conditions adversely affect a cable, pipeline, or facility? 585.816 Section 585.816 Mineral Resources BUREAU... affect a cable, pipeline, or facility? If environmental or other conditions adversely affect a cable, pipeline, or facility so as to endanger the safety or the environment, you must: (a) Submit a plan...

  20. 30 CFR 585.816 - What must I do if environmental or other conditions adversely affect a cable, pipeline, or facility?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... conditions adversely affect a cable, pipeline, or facility? 585.816 Section 585.816 Mineral Resources BUREAU... affect a cable, pipeline, or facility? If environmental or other conditions adversely affect a cable, pipeline, or facility so as to endanger the safety or the environment, you must: (a) Submit a plan...

  1. Between-Population Outbreeding Affects Plant Defence

    PubMed Central

    Leimu, Roosa; Fischer, Markus

    2010-01-01

    Between-population crosses may replenish genetic variation of populations, but may also result in outbreeding depression. Apart from direct effects on plant fitness, these outbreeding effects can also alter plant-herbivore interactions by influencing plant tolerance and resistance to herbivory. We investigated effects of experimental within- and between-population outbreeding on herbivore resistance, tolerance and plant fitness using plants from 13 to 19 Lychnis flos-cuculi populations. We found no evidence for outbreeding depression in resistance reflected by the amount of leaf area consumed. However, herbivore performance was greater when fed on plants from between-population compared to within-population crosses. This can reflect outbreeding depression in resistance and/or outbreeding effects on plant quality for the herbivores. The effects of type of cross on the relationship between herbivore damage and plant fitness varied among populations. This demonstrates how between-population outbreeding effects on tolerance range from outbreeding depression to outbreeding benefits among plant populations. Finally, herbivore damage strengthened the observed outbreeding effects on plant fitness in several populations. These results raise novel considerations on the impact of outbreeding on the joint evolution of resistance and tolerance, and on the evolution of multiple defence strategies. PMID:20838662

  2. Kin recognition affects plant communication and defence.

    PubMed

    Karban, Richard; Shiojiri, Kaori; Ishizaki, Satomi; Wetzel, William C; Evans, Richard Y

    2013-04-01

    The ability of many animals to recognize kin has allowed them to evolve diverse cooperative behaviours; such ability is less well studied for plants. Many plants, including Artemisia tridentata, have been found to respond to volatile cues emitted by experimentally wounded neighbours to increase levels of resistance to herbivory. We report that this communication was more effective among A. tridentata plants that were more closely related based on microsatellite markers. Plants in the field that received cues from experimentally clipped close relatives experienced less leaf herbivory over the growing season than those that received cues from clipped neighbours that were more distantly related. These results indicate that plants can respond differently to cues from kin, making it less likely that emitters will aid strangers and making it more likely that receivers will respond to cues from relatives. More effective defence adds to a growing list of favourable consequences of kin recognition for plants.

  3. Methods of affecting nitrogen assimilation in plants

    DOEpatents

    Coruzzi, Gloria; Gutierrez, Rodrigo A.; Nero, Damion C.

    2016-10-11

    Provided herein are compositions and methods for producing transgenic plants. In specific embodiments, transgenic plants comprise a construct comprising a polynucleotide encoding CCA1, GLK1 or bZIP1, operably linked to a plant-specific promote, wherein the CCA1, GLK1 or bZIP1 is ectopically overexpressed in the transgenic plants, and wherein the promoter is optionally a constitutive or inducible promoter. In other embodiments, transgenic plants in which express a lower level of CCA1, GLK1 or bZIP1 are provided. Also provided herein are commercial products (e.g., pulp, paper, paper products, or lumber) derived from the transgenic plants (e.g., transgenic trees) produced using the methods provided herein.

  4. Plant Hormones: How They Affect Root Formation.

    ERIC Educational Resources Information Center

    Reinhard, Diana Hereda

    This science study aid, produced by the U.S. Department of Agriculture, includes a series of plant rooting activities for secondary science classes. The material in the pamphlet is written for students and includes background information on plant hormones, a vocabulary list, and five learning activities. Objectives, needed materials, and…

  5. Adverse Effects of Plant Food Supplements and Plants Consumed as Food: Results from the Poisons Centres-Based PlantLIBRA Study.

    PubMed

    Lüde, Saskia; Vecchio, Sarah; Sinno-Tellier, Sandra; Dopter, Aymeric; Mustonen, Harriet; Vucinic, Slavica; Jonsson, Birgitta; Müller, Dieter; Veras Gimenez Fruchtengarten, Ligia; Hruby, Karl; De Souza Nascimento, Elizabeth; Di Lorenzo, Chiara; Restani, Patrizia; Kupferschmidt, Hugo; Ceschi, Alessandro

    2016-06-01

    Plant food supplements (PFS) are products of increasing popularity and wide-spread distribution. Nevertheless, information about their risks is limited. To fill this gap, a poisons centres-based study was performed as part of the EU project PlantLIBRA. Multicentre retrospective review of data from selected European and Brazilian poisons centres, involving human cases of adverse effects due to plants consumed as food or as ingredients of food supplements recorded between 2006 and 2010. Ten poisons centres provided a total of 75 cases. In 57 cases (76%) a PFS was involved; in 18 (24%) a plant was ingested as food. The 10 most frequently reported plants were Valeriana officinalis, Camellia sinensis, Paullinia cupana, Melissa officinalis, Passiflora incarnata, Mentha piperita, Glycyrrhiza glabra, Ilex paraguariensis, Panax ginseng, and Citrus aurantium. The most frequently observed clinical effects were neurotoxicity and gastro-intestinal symptoms. Most cases showed a benign clinical course; however, five cases were severe. PFS-related adverse effects seem to be relatively infrequent issues for poisons centres. Most cases showed mild symptoms. Nevertheless, the occurrence of some severe adverse effects and the increasing popularity of PFS require continuous active surveillance, and further research is warranted. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26948409

  6. Osmolyte cooperation affects turgor dynamics in plants.

    PubMed

    Argiolas, Alfredo; Puleo, Gian Luigi; Sinibaldi, Edoardo; Mazzolai, Barbara

    2016-01-01

    Scientists have identified turgor-based actuation as a fundamental mechanism in plant movements. Plant cell turgor is generated by water influx due to the osmolyte concentration gradient through the cell wall and the plasma membrane behaving as an osmotic barrier. Previous studies have focused on turgor modulation with respect to potassium chloride (KCl) concentration changes, although KCl is not efficiently retained in the cell, and many other compounds, including L-glutamine (L-Gln) and D-glucose (D-Glc), are present in the cytosol. In fact, the contributions of other osmolytes to turgor dynamics remain to be elucidated. Here, we show the association of osmolytes and their consequent cooperative effects on the time-dependent turgor profile generated in a model cytosol consisting of KCl, D-Glc and L-Gln at experimentally measured plant motor/generic cell concentrations and at modified concentrations. We demonstrate the influence and association of the osmolytes using osmometry and NMR measurements. We also show, using a plant cell-inspired device we previously developed, that osmolyte complexes, rather than single osmolytes, permit to obtain higher turgor required by plant movements. We provide quantitative cues for deeper investigations of osmolyte transport for plant movement, and reveal the possibility of developing osmotic actuators exploiting a dynamically varying concentration of osmolytes. PMID:27445173

  7. Osmolyte cooperation affects turgor dynamics in plants

    PubMed Central

    Argiolas, Alfredo; Puleo, Gian Luigi; Sinibaldi, Edoardo; Mazzolai, Barbara

    2016-01-01

    Scientists have identified turgor-based actuation as a fundamental mechanism in plant movements. Plant cell turgor is generated by water influx due to the osmolyte concentration gradient through the cell wall and the plasma membrane behaving as an osmotic barrier. Previous studies have focused on turgor modulation with respect to potassium chloride (KCl) concentration changes, although KCl is not efficiently retained in the cell, and many other compounds, including L-glutamine (L-Gln) and D-glucose (D-Glc), are present in the cytosol. In fact, the contributions of other osmolytes to turgor dynamics remain to be elucidated. Here, we show the association of osmolytes and their consequent cooperative effects on the time-dependent turgor profile generated in a model cytosol consisting of KCl, D-Glc and L-Gln at experimentally measured plant motor/generic cell concentrations and at modified concentrations. We demonstrate the influence and association of the osmolytes using osmometry and NMR measurements. We also show, using a plant cell-inspired device we previously developed, that osmolyte complexes, rather than single osmolytes, permit to obtain higher turgor required by plant movements. We provide quantitative cues for deeper investigations of osmolyte transport for plant movement, and reveal the possibility of developing osmotic actuators exploiting a dynamically varying concentration of osmolytes. PMID:27445173

  8. Osmolyte cooperation affects turgor dynamics in plants

    NASA Astrophysics Data System (ADS)

    Argiolas, Alfredo; Puleo, Gian Luigi; Sinibaldi, Edoardo; Mazzolai, Barbara

    2016-07-01

    Scientists have identified turgor-based actuation as a fundamental mechanism in plant movements. Plant cell turgor is generated by water influx due to the osmolyte concentration gradient through the cell wall and the plasma membrane behaving as an osmotic barrier. Previous studies have focused on turgor modulation with respect to potassium chloride (KCl) concentration changes, although KCl is not efficiently retained in the cell, and many other compounds, including L-glutamine (L-Gln) and D-glucose (D-Glc), are present in the cytosol. In fact, the contributions of other osmolytes to turgor dynamics remain to be elucidated. Here, we show the association of osmolytes and their consequent cooperative effects on the time-dependent turgor profile generated in a model cytosol consisting of KCl, D-Glc and L-Gln at experimentally measured plant motor/generic cell concentrations and at modified concentrations. We demonstrate the influence and association of the osmolytes using osmometry and NMR measurements. We also show, using a plant cell-inspired device we previously developed, that osmolyte complexes, rather than single osmolytes, permit to obtain higher turgor required by plant movements. We provide quantitative cues for deeper investigations of osmolyte transport for plant movement, and reveal the possibility of developing osmotic actuators exploiting a dynamically varying concentration of osmolytes.

  9. Does Maternal Prenatal Stress Adversely Affect the Child's Learning and Memory at Age Six?

    ERIC Educational Resources Information Center

    Gutteling, Barbara M.; de Weerth, Carolina; Zandbelt, Noortje; Mulder, Eduard J. H.; Visser, Gerard H. A.; Buitelaar, Jan K.

    2006-01-01

    Prenatal maternal stress has been shown to affect postnatal development in animals and humans. In animals, the morphology and function of the offspring's hippocampus is negatively affected by prenatal maternal stress. The present study prospectively investigated the influence of prenatal maternal stress on learning and memory of 112 children (50…

  10. 30 CFR 285.816 - What must I do if environmental or other conditions adversely affect a cable, pipeline, or facility?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 2 2010-07-01 2010-07-01 false What must I do if environmental or other conditions adversely affect a cable, pipeline, or facility? 285.816 Section 285.816 Mineral Resources..., pipeline, or facility? If environmental or other conditions adversely affect a cable, pipeline, or...

  11. Adverse effects of plant food supplements and botanical preparations: a systematic review with critical evaluation of causality

    PubMed Central

    Di Lorenzo, Chiara; Ceschi, Alessandro; Kupferschmidt, Hugo; Lüde, Saskia; De Souza Nascimento, Elizabeth; Dos Santos, Ariana; Colombo, Francesca; Frigerio, Gianfranco; Nørby, Karin; Plumb, Jenny; Finglas, Paul; Restani, Patrizia

    2015-01-01

    AIMS The objective of this review was to collect available data on the following: (i) adverse effects observed in humans from the intake of plant food supplements or botanical preparations; (ii) the misidentification of poisonous plants; and (iii) interactions between plant food supplements/botanicals and conventional drugs or nutrients. METHODS PubMed/MEDLINE and Embase were searched from database inception to June 2014, using the terms ‘adverse effect/s’, ‘poisoning/s’, ‘plant food supplement/s’, ‘misidentification/s’ and ‘interaction/s’ in combination with the relevant plant name. All papers were critically evaluated according to the World Health Organization Guidelines for causality assessment. RESULTS Data were obtained for 66 plants that are common ingredients of plant food supplements; of the 492 papers selected, 402 (81.7%) dealt with adverse effects directly associated with the botanical and 89 (18.1%) concerned interactions with conventional drugs. Only one case was associated with misidentification. Adverse effects were reported for 39 of the 66 botanical substances searched. Of the total references, 86.6% were associated with 14 plants, including Glycine max/soybean (19.3%), Glycyrrhiza glabra/liquorice (12.2%), Camellia sinensis/green tea ( 8.7%) and Ginkgo biloba/gingko (8.5%). CONCLUSIONS Considering the length of time examined and the number of plants included in the review, it is remarkable that: (i) the adverse effects due to botanical ingredients were relatively infrequent, if assessed for causality; and (ii) the number of severe clinical reactions was very limited, but some fatal cases have been described. Data presented in this review were assessed for quality in order to make the results maximally useful for clinicians in identifying or excluding deleterious effects of botanicals. PMID:25251944

  12. Can aircraft noise less than or equal 115 to dBA adversely affect reproductive outcome in USAF women?

    NASA Astrophysics Data System (ADS)

    Brubaker, P. A.

    1985-06-01

    It has been suggested, mainly through animal studies, that exposure to high noise levels may be associated with lower birth weight, reduced gestational length and other adverse reproductive outcomes. Few studies have been done on humans to show this association. The Air Force employs pregnant women in areas where there is a high potential for exposure to high noise levels. This study proposes a method to determine if there is an association between high frequency noise levels or = 115 dBA and adverse reproductive outcomes through a review of records and self-administered questionnaires in a case-comparison design. Prevelance rates will be calculated and a multiple logistic regression analysis computed for the independent variables that can affect reproduction.

  13. Proanthocyanidin as a cytogenetic protective agent against adverse effects of plant growth regulators supplementation in rats.

    PubMed

    Hassan, Hanaa A; El-Kholy, Wafaa M; Nour, Samar E

    2014-08-01

    The aim of the present study was to investigate the protective role of grape seed extract (containing proanthocyandin) against the adverse effects of plant growth regulators (GA3 (gibberellic acid) and IAA (indoleacetic acid)). The present data showed that the administration of either GA3 and IAA caused undesirable changes in both hepatic and testicular structure. This was evidenced by a disturbed hepatic strands, pyknotic nuclei, central vein with collapsed endothelium, dilatation in bile sinusoids, congested blood vessel, binucleatd hepatocytes, lymphocytic infiltration, vacuolation, giant hepatic cells, increased Kupffer cells and karyoryxis. Additionally, it was shown that degenerative changes in the testis, spermatogenic arrest, moderate tubular necrosis, Leydig cell degeneration and reduction in the number and size of the seminiferous tubules with some spermatogonia detached from the basement membrane. Concerning flow cytometric study of the liver a significant decrease in G0/1 % and a significant increase in S phase %, G2/M  %, P(53) % and apoptosis % (sub G1) were detected. However, in testis the data recorded a significant decrease in the percentage of mature sperm (percentage of haploid cells) and a significant increase in the percentage of spermatide, diploid cells, P(53) and of apoptotic cells. On the other hand, a distinct recovery of the mentioned hepatic and testicular histopathological and cytogenetic disorders was observed when proanthocyanidin was supplemented to rats administered either of the plant growth hormones (GA3 and IAA).

  14. Elevated depressive affect is associated with adverse cardiovascular outcomes among African Americans with chronic kidney disease

    PubMed Central

    Fischer, Michael J.; Kimmel, Paul L.; Greene, Tom; Gassman, Jennifer J.; Wang, Xuelei; Brooks, Deborah H.; Charleston, Jeanne; Dowie, Donna; Thornley-Brown, Denyse; Cooper, Lisa A.; Bruce, Marino A.; Kusek, John W.; Norris, Keith C.; Lash, James P.

    2011-01-01

    This study was designed to examine the impact of elevated depressive affect on health outcomes among participants with hypertensive chronic kidney disease in the African-American Study of Kidney Disease and Hypertension (AASK) Cohort Study. Elevated depressive affect was defined by Beck Depression Inventory II (BDI-II) thresholds of 11 or more, above 14, and by 5-Unit increments in the score. Cox regression analyses were used to relate cardiovascular death/hospitalization, doubling of serum creatinine/end-stage renal disease, overall hospitalization, and all-cause death to depressive affect evaluated at baseline, the most recent annual visit (time-varying), or average from baseline to the most recent visit (cumulative). Among 628 participants at baseline, 42% had BDI-II scores of 11 or more and 26% had a score above 14. During a 5-year follow-up, the cumulative incidence of cardiovascular death/hospitalization was significantly greater for participants with baseline BDI-II scores of 11 or more compared with those with scores <11. The baseline, time-varying, and cumulative elevated depressive affect were each associated with a significant higher risk of cardiovascular death/hospitalization, especially with a time-varying BDI-II score over 14 (adjusted HR 1.63) but not with the other outcomes. Thus, elevated depressive affect is associated with unfavorable cardiovascular outcomes in African Americans with hypertensive chronic kidney disease. PMID:21633409

  15. Adverse childhood experiences associate to reduced glutamate levels in the hippocampus of patients affected by mood disorders.

    PubMed

    Poletti, Sara; Locatelli, Clara; Falini, Andrea; Colombo, Cristina; Benedetti, Francesco

    2016-11-01

    Adverse childhood experiences (ACE) can possibly permanently alter the stress response system, affect the glutamatergic system and influence hippocampal volume in mood disorders. The aim of the study is to investigate the association between glutamate levels in the hippocampus, measured through single proton magnetic resonance spectroscopy (1H-MRS), and ACE in patients affected by mood disorders and healthy controls. Higher levels of early stress associate to reduced levels of Glx/Cr in the hippocampus in depressed patients but not in healthy controls. Exposure to stress during early life could lead to a hypofunctionality of the glutamatergic system in the hippocampus of depressed patients. Abnormalities of glutamatergic signaling could then possibly underpin the structural and functional abnormalities observed in patients affected by mood disorders.

  16. Coralline algal physiology is more adversely affected by elevated temperature than reduced pH.

    PubMed

    Vásquez-Elizondo, Román Manuel; Enríquez, Susana

    2016-01-01

    In this study we analyzed the physiological responses of coralline algae to ocean acidification (OA) and global warming, by exposing algal thalli of three species with contrasting photobiology and growth-form to reduced pH and elevated temperature. The analysis aimed to discern between direct and combined effects, while elucidating the role of light and photosynthesis inhibition in this response. We demonstrate the high sensitivity of coralline algae to photodamage under elevated temperature and its severe consequences on thallus photosynthesis and calcification rates. Moderate levels of light-stress, however, were maintained under reduced pH, resulting in no impact on algal photosynthesis, although moderate adverse effects on calcification rates were still observed. Accordingly, our results support the conclusion that global warming is a stronger threat to algal performance than OA, in particular in highly illuminated habitats such as coral reefs. We provide in this study a quantitative physiological model for the estimation of the impact of thermal-stress on coralline carbonate production, useful to foresee the impact of global warming on coralline contribution to reef carbon budgets, reef cementation, coral recruitment and the maintenance of reef biodiversity. This model, however, cannot yet account for the moderate physiological impact of low pH on coralline calcification. PMID:26740396

  17. Coralline algal physiology is more adversely affected by elevated temperature than reduced pH.

    PubMed

    Vásquez-Elizondo, Román Manuel; Enríquez, Susana

    2016-01-07

    In this study we analyzed the physiological responses of coralline algae to ocean acidification (OA) and global warming, by exposing algal thalli of three species with contrasting photobiology and growth-form to reduced pH and elevated temperature. The analysis aimed to discern between direct and combined effects, while elucidating the role of light and photosynthesis inhibition in this response. We demonstrate the high sensitivity of coralline algae to photodamage under elevated temperature and its severe consequences on thallus photosynthesis and calcification rates. Moderate levels of light-stress, however, were maintained under reduced pH, resulting in no impact on algal photosynthesis, although moderate adverse effects on calcification rates were still observed. Accordingly, our results support the conclusion that global warming is a stronger threat to algal performance than OA, in particular in highly illuminated habitats such as coral reefs. We provide in this study a quantitative physiological model for the estimation of the impact of thermal-stress on coralline carbonate production, useful to foresee the impact of global warming on coralline contribution to reef carbon budgets, reef cementation, coral recruitment and the maintenance of reef biodiversity. This model, however, cannot yet account for the moderate physiological impact of low pH on coralline calcification.

  18. Coral and mollusc resistance to ocean acidification adversely affected by warming

    NASA Astrophysics Data System (ADS)

    Rodolfo-Metalpa, R.; Houlbrèque, F.; Tambutté, É.; Boisson, F.; Baggini, C.; Patti, F. P.; Jeffree, R.; Fine, M.; Foggo, A.; Gattuso, J.-P.; Hall-Spencer, J. M.

    2011-09-01

    Increasing atmospheric carbon dioxide (CO2) concentrations are expectedto decrease surface ocean pH by 0.3-0.5 units by 2100 (refs , ), lowering the carbonate ion concentration of surfacewaters. This rapid acidification is predicted to dramatically decrease calcification in many marine organisms. Reduced skeletal growth under increased CO2 levels has already been shown for corals, molluscs and many other marine organisms. The impact of acidification on the ability of individual species to calcify has remained elusive, however, as measuring net calcification fails to disentangle the relative contributions of gross calcification and dissolution rates on growth. Here, we show that corals and molluscs transplanted along gradients of carbonate saturation state at Mediterranean CO2 vents are able to calcify and grow at even faster than normal rates when exposed to the high CO2 levels projected for the next 300 years. Calcifiers remain at risk, however, owing to the dissolution of exposed shells and skeletons that occurs as pH levels fall. Our results show that tissues and external organic layers play a major role in protecting shells and skeletons from corrosive sea water, limiting dissolution and allowing organisms to calcify. Our combined field and laboratory results demonstrate that the adverse effects of global warming are exacerbated when high temperatures coincide with acidification.

  19. Coralline algal physiology is more adversely affected by elevated temperature than reduced pH

    PubMed Central

    Vásquez-Elizondo, Román Manuel; Enríquez, Susana

    2016-01-01

    In this study we analyzed the physiological responses of coralline algae to ocean acidification (OA) and global warming, by exposing algal thalli of three species with contrasting photobiology and growth-form to reduced pH and elevated temperature. The analysis aimed to discern between direct and combined effects, while elucidating the role of light and photosynthesis inhibition in this response. We demonstrate the high sensitivity of coralline algae to photodamage under elevated temperature and its severe consequences on thallus photosynthesis and calcification rates. Moderate levels of light-stress, however, were maintained under reduced pH, resulting in no impact on algal photosynthesis, although moderate adverse effects on calcification rates were still observed. Accordingly, our results support the conclusion that global warming is a stronger threat to algal performance than OA, in particular in highly illuminated habitats such as coral reefs. We provide in this study a quantitative physiological model for the estimation of the impact of thermal-stress on coralline carbonate production, useful to foresee the impact of global warming on coralline contribution to reef carbon budgets, reef cementation, coral recruitment and the maintenance of reef biodiversity. This model, however, cannot yet account for the moderate physiological impact of low pH on coralline calcification. PMID:26740396

  20. Weight Reduction in Athletes May Adversely Affect the Phagocytic Function of Monocytes.

    ERIC Educational Resources Information Center

    Kono, Ichiro; And Others

    1988-01-01

    Study of the monocyte phagocytic function in nine competitive athletes before and after a two-week weight reduction (through calorie restriction) program revealed that their pre-program phagocytic activity was higher than in sedentary controls but decreased significantly after the program. This suggests calorie restriction may affect the human…

  1. [Examination of factors affecting efficacy and adverse effect, for the retrospective study of vancomycin hydrochloride (VCM)].

    PubMed

    Tanaka, M; Orii, T; Kobayashi, H; Hirono, S

    2001-08-01

    Vancomycin hydrochloride (VCM) is widely used for treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections. However, this drug can cause sever adverse reactions, such as red neck syndrome, nephrotoxicity and ototoxicity. Thus, therapeutic drug monitoring (TDM) was bringing into effect for well effectiveness and to prevent side effects. In Kanto Medical Center NTT EC, TDM of VCM has been brought into effect since 1994. The date were accumulated from 200 patients. In this study, the retrospective research was carried out based on 117 cases selected from the above accumulated data, and then several factors such as VCM inducing side effect, a therapeutic effect, and the forecast of pharmacokinetic parameter using laboratory data were examined. Consequently, the high blood concentration trough level, the high value after 1 to 2 hours infusion, and the extension of t1/2 were brought forward as a nephrotoxicity causing factor, and more over each laboratory data (BUN, Cr, GOT, GPT, gamma-GTP, T-BiL, ALP, LDH) was high before infusion of VCM in patients with renal dysfunction. High value T-Bil and lower value TP were brought forward in patients with hepatic dysfunction, and high eosinophils and high blood concentration were brought forward after 1 or 2 hours infusion. In relation to side effects, it was found that the outbreak rate of side effects is high in patients with a complication of hypertension or diabetes. The administration term was considered as a factor which influences the therapeutic effects. The unchanged effect was 10.9 +/- 7.9 days, the improved effect was 14.6 +/- 9.3 days, the remarkably improved effect was 17.7 +/- 14.1 days. As the administration term gets longer, the improvement rate was recognized to be an upward tendency. The difference in significant effects was recognized between unchanged and remarkably unchanged (p < 0.05) effects. As the forecast of pharmacokinetic parameter using the laboratory data, VCMt1/2 showed a

  2. Depressing Antidepressant: Fluoxetine Affects Serotonin Neurons Causing Adverse Reproductive Responses in Daphnia magna.

    PubMed

    Campos, Bruno; Rivetti, Claudia; Kress, Timm; Barata, Carlos; Dircksen, Heinrich

    2016-06-01

    Selective serotonin reuptake inhibitors (SSRIs) are widely used antidepressants. As endocrine disruptive contaminants in the environment, SSRIs affect reproduction in aquatic organisms. In the water flea Daphnia magna, SSRIs increase offspring production in a food ration-dependent manner. At limiting food conditions, females exposed to SSRIs produce more but smaller offspring, which is a maladaptive life-history strategy. We asked whether increased serotonin levels in newly identified serotonin-neurons in the Daphnia brain mediate these effects. We provide strong evidence that exogenous SSRI fluoxetine selectively increases serotonin-immunoreactivity in identified brain neurons under limiting food conditions thereby leading to maladaptive offspring production. Fluoxetine increases serotonin-immunoreactivity at low food conditions to similar maximal levels as observed under high food conditions and concomitantly enhances offspring production. Sublethal amounts of the neurotoxin 5,7-dihydroxytryptamine known to specifically ablate serotonin-neurons markedly decrease serotonin-immunoreactivity and offspring production, strongly supporting the effect to be serotonin-specific by reversing the reproductive phenotype attained under fluoxetine. Thus, SSRIs impair serotonin-regulation of reproductive investment in a planktonic key organism causing inappropriately increased reproduction with potentially severe ecological impact. PMID:27128505

  3. Combining S-cone and luminance signals adversely affects discrimination of objects within backgrounds

    PubMed Central

    Jennings, Ben J.; Tsattalios, Konstantinos; Chakravarthi, Ramakrishna; Martinovic, Jasna

    2016-01-01

    The visual system processes objects embedded in complex scenes that vary in both luminance and colour. In such scenes, colour contributes to the segmentation of objects from backgrounds, but does it also affect perceptual organisation of object contours which are already defined by luminance signals, or are these processes unaffected by colour’s presence? We investigated if luminance and chromatic signals comparably sustain processing of objects embedded in backgrounds, by varying contrast along the luminance dimension and along the two cone-opponent colour directions. In the first experiment thresholds for object/non-object discrimination of Gaborised shapes were obtained in the presence and absence of background clutter. Contrast of the component Gabors was modulated along single colour/luminance dimensions or co-modulated along multiple dimensions simultaneously. Background clutter elevated discrimination thresholds only for combined S-(L + M) and L + M signals. The second experiment replicated and extended this finding by demonstrating that the effect was dependent on the presence of relatively high S-(L + M) contrast. These results indicate that S-(L + M) signals impair spatial vision when combined with luminance. Since S-(L + M) signals are characterised by relatively large receptive fields, this is likely to be due to an increase in the size of the integration field over which contour-defining information is summed. PMID:26856308

  4. Secreted biofilm factors adversely affect cellular wound healing responses in vitro.

    PubMed

    Jeffery Marano, Robert; Jane Wallace, Hilary; Wijeratne, Dulharie; William Fear, Mark; San Wong, Hui; O'Handley, Ryan

    2015-08-17

    Although most chronic wounds possess an underlying pathology, infectious agents also contribute. In many instances, pathogens exist as biofilms forming clusters surrounded by a secreted extracellular substance. We hypothesized that compounds secreted by biofilm bacteria may inhibit normal wound healing events including cell proliferation and migration. Conditioned media from two common bacterial species associated with chronic skin wounds and chronic tympanic membrane perforations, Staphylococcus aureus and Pseudomonas aeruginosa, were evaluated for their capacity to affect keratinocyte proliferation and migration. Additionally, proteomic analysis was performed to identify proteins within the biofilm conditioned media that may contribute to these observed effects. Biofilm conditioned media from both species inhibited proliferation in human tympanic membrane derived keratinocytes, whereas only biofilm conditioned media from S. aureus inhibited migration. Human epidermal keratinocytes were found to be more sensitive to the effects of the conditioned media resulting in high levels of cell death. Heat treatment and microfiltration suggested that S. aureus activity was due to a protein, while P. aeruginosa activity was more likely due to a small molecule. Proteomic analysis identified several proteins with putative links to delayed wound healing. These include alpha hemolysin, alcohol dehydrogenase, fructose-bisphosphate aldolase, lactate dehydrogenase and epidermal cell differentiation inhibitor.

  5. Secreted biofilm factors adversely affect cellular wound healing responses in vitro.

    PubMed

    Jeffery Marano, Robert; Jane Wallace, Hilary; Wijeratne, Dulharie; William Fear, Mark; San Wong, Hui; O'Handley, Ryan

    2015-01-01

    Although most chronic wounds possess an underlying pathology, infectious agents also contribute. In many instances, pathogens exist as biofilms forming clusters surrounded by a secreted extracellular substance. We hypothesized that compounds secreted by biofilm bacteria may inhibit normal wound healing events including cell proliferation and migration. Conditioned media from two common bacterial species associated with chronic skin wounds and chronic tympanic membrane perforations, Staphylococcus aureus and Pseudomonas aeruginosa, were evaluated for their capacity to affect keratinocyte proliferation and migration. Additionally, proteomic analysis was performed to identify proteins within the biofilm conditioned media that may contribute to these observed effects. Biofilm conditioned media from both species inhibited proliferation in human tympanic membrane derived keratinocytes, whereas only biofilm conditioned media from S. aureus inhibited migration. Human epidermal keratinocytes were found to be more sensitive to the effects of the conditioned media resulting in high levels of cell death. Heat treatment and microfiltration suggested that S. aureus activity was due to a protein, while P. aeruginosa activity was more likely due to a small molecule. Proteomic analysis identified several proteins with putative links to delayed wound healing. These include alpha hemolysin, alcohol dehydrogenase, fructose-bisphosphate aldolase, lactate dehydrogenase and epidermal cell differentiation inhibitor. PMID:26278131

  6. Nutritional characteristics of the leaves of native plants growing in adverse soils of humid tropical lowlands.

    PubMed

    Osaki, Mitsuru; Watanabe, Toshihiro; Ishizawa, Tetsuya; Nilnond, Chairatna; Nuyim, Tanit; Shinano, Takuro; Urayama, Masaru; Tuah, Sehat Jaya

    2003-01-01

    Acid sulfate, peat, sandy podzolic, and saline soils are widely distributed in the lowlands of Thailand and Malaysia. The nutrient concentrations in the leaves of plants grown in these type of soils were studied with the aim of developing a nutritional strategy for adapting to such problem soils. In sago and oil palms that were well-adapted to peat soil, the N, P, and K concentrations were the same in the mature leaves, while the Ca, Mg, Na, and Fe concentrations were higher in the mature leaves of the oil palm than of the sago palm. Melastoma malabathricum and Melaleuca cajuputi plants that were well-adapted to low pH soils, peat. and acid sulfate soils were also studied. It was observed that a high amount of Al accumulated in the M. marabathricum leaves, while Al did not accumulate in M. cajuputi leaves. M. cajuputi plants accumulated large amounts of Na in their leaves or stems regardless of the exchangeable Na concentration in the soil, while M. malabathricum that was growing in saline-affected soils excluded Na. Positive relationships between macronutrients were recognized between P and N, between K and N, and between P and K. Al showed antagonistic relationships with P, K, Ca, Mg, Fe, Zn, Cu, and Na. Na also showed antagonistic relationships with P, K, Zn, Mn, Cu, and Al. Fe showed weak antagonistic relationships with Zn, Mn, Cu, and Al.

  7. Nutrient supplementation may adversely affect maternal oral health--a randomised controlled trial in rural Malawi.

    PubMed

    Harjunmaa, Ulla; Järnstedt, Jorma; Dewey, Kathryn G; Ashorn, Ulla; Maleta, Kenneth; Vosti, Stephen A; Ashorn, Per

    2016-01-01

    Nutritional supplementation during pregnancy is increasingly recommended especially in low-resource settings, but its oral health impacts have not been studied. Our aim was to examine whether supplementation with multiple micronutrients (MMN) or small-quantity lipid-based nutrient supplements affects dental caries development or periodontal health in a rural Malawian population. The study was embedded in a controlled iLiNS-DYAD trial that enrolled 1391 pregnant women <20 gestation weeks. Women were provided with one daily iron-folic acid capsule (IFA), one capsule with 18 micronutrients (MMN) or one sachet of lipid-based nutrient supplements (LNS) containing protein, carbohydrates, essential fatty acids and 21 micronutrients. Oral examination of 1024 participants was conducted and panoramic X-ray taken within 6 weeks after delivery. The supplement groups were similar at baseline in average socio-economic, nutritional and health status. At the end of the intervention, the prevalence of caries was 56.7%, 69.1% and 63.3% (P = 0.004), and periodontitis 34.9%, 29.8% and 31.2% (P = 0.338) in the IFA, MMN and LNS groups, respectively. Compared with the IFA group, women in the MMN group had 0.60 (0.18-1.02) and in the LNS group 0.59 (0.17-1.01) higher mean number of caries lesions. In the absence of baseline oral health data, firm conclusions on causality cannot be drawn. However, although not confirmatory, the findings are consistent with a possibility that provision of MMN or LNS may have increased the caries incidence in this target population. Because of the potential public health impacts, further research on the association between gestational nutrient interventions and oral health in low-income settings is needed.

  8. Adverse Effects of Plant Food Supplements Self-Reported by Consumers in the PlantLIBRA Survey Involving Six European Countries

    PubMed Central

    Restani, Patrizia; Di Lorenzo, Chiara; Garcia-Alvarez, Alicia; Badea, Mihaela; Ceschi, Alessandro; Egan, Bernadette; Dima, Lorena; Lüde, Saskia; Maggi, Franco M.; Marculescu, Angela; Milà-Villarroel, Raimon; Raats, Monique M.; Ribas-Barba, Lourdes; Uusitalo, Liisa; Serra-Majem, Lluís

    2016-01-01

    Background The use of food supplements containing botanicals is increasing in European markets. Although intended to maintain the health status, several cases of adverse effects to Plant Food Supplements (PFS) have been described. Objectives To describe the self-reported adverse effects collected during the European PlantLIBRA PFS Consumer Survey 2011–2012, with a critical evaluation of the plausibility of the symptomatology reported using data from the literature and from the PlantLIBRA Poisons Centers' survey. Subjects/Setting From the total sample of 2359 consumers involved in the consumers' survey, 82 subjects reported adverse effects due to a total of 87 PFS. Results Cases were self-reported, therefore causality was not classified on the basis of clinical evidence, but by using the frequency/strength of adverse effects described in scientific papers: 52 out of 87 cases were defined as possible (59.8%) and 4 as probable (4.6%). Considering the most frequently cited botanicals, eight cases were due to Valeriana officinalis (garden valerian); seven to Camellia sinensis (tea); six to Ginkgo biloba (Maidenhair tree) and Paullinia cupana (guarana). Most adverse events related to the gastrointestinal tract, nervous and cardiovascular systems. Conclusions Comparing the data from this study with those published in scientific papers and obtained by the PlantLIBRA Poisons Centers' survey, some important conclusions can be drawn: severe adverse effects to PFS are quite rare, although mild or moderate adverse symptoms can be present. Data reported in this paper can help health professionals (and in particular family doctors) to become aware of possible new problems associated with the increasing use of food supplements containing botanicals. PMID:26928206

  9. The cultivation of Bt corn producing Cry1Ac toxins does not adversely affect non-target arthropods.

    PubMed

    Guo, Yanyan; Feng, Yanjie; Ge, Yang; Tetreau, Guillaume; Chen, Xiaowen; Dong, Xuehui; Shi, Wangpeng

    2014-01-01

    Transgenic corn producing Cry1Ac toxins from Bacillus thuringiensis (Bt) provides effective control of Asian corn borer, Ostrinia furnacalis (Guenée), and thus reduces insecticide applications. However, whether Bt corn exerts undesirable effects on non-target arthropods (NTAs) is still controversial. We conducted a 2-yr study in Shangzhuang Agricultural Experiment Station to assess the potential impact of Bt corn on field population density, biodiversity, community composition and structure of NTAs. On each sampling date, the total abundance, Shannon's diversity index, Pielou's evenness index and Simpson's diversity index were not significantly affected by Bt corn as compared to non-Bt corn. The "sampling dates" had a significant effect on these indices, but no clear tendencies related to "Bt corn" or "sampling dates X corn variety" interaction were recorded. Principal response curve analysis of variance indicated that Bt corn did not alter the distribution of NTAs communities. Bray-Curtis dissimilarity and distance analysis showed that Cry1Ac toxin exposure did not increase community dissimilarities between Bt and non-Bt corn plots and that the evolution of non-target arthropod community was similar on the two corn varieties. The cultivation of Bt corn failed to show any detrimental evidence on the density of non-target herbivores, predators and parasitoids. The composition of herbivores, predators and parasitoids was identical in Bt and non-Bt corn plots. Taken together, results from the present work support that Bt corn producing Cry1Ac toxins does not adversely affect NTAs.

  10. The cultivation of Bt corn producing Cry1Ac toxins does not adversely affect non-target arthropods.

    PubMed

    Guo, Yanyan; Feng, Yanjie; Ge, Yang; Tetreau, Guillaume; Chen, Xiaowen; Dong, Xuehui; Shi, Wangpeng

    2014-01-01

    Transgenic corn producing Cry1Ac toxins from Bacillus thuringiensis (Bt) provides effective control of Asian corn borer, Ostrinia furnacalis (Guenée), and thus reduces insecticide applications. However, whether Bt corn exerts undesirable effects on non-target arthropods (NTAs) is still controversial. We conducted a 2-yr study in Shangzhuang Agricultural Experiment Station to assess the potential impact of Bt corn on field population density, biodiversity, community composition and structure of NTAs. On each sampling date, the total abundance, Shannon's diversity index, Pielou's evenness index and Simpson's diversity index were not significantly affected by Bt corn as compared to non-Bt corn. The "sampling dates" had a significant effect on these indices, but no clear tendencies related to "Bt corn" or "sampling dates X corn variety" interaction were recorded. Principal response curve analysis of variance indicated that Bt corn did not alter the distribution of NTAs communities. Bray-Curtis dissimilarity and distance analysis showed that Cry1Ac toxin exposure did not increase community dissimilarities between Bt and non-Bt corn plots and that the evolution of non-target arthropod community was similar on the two corn varieties. The cultivation of Bt corn failed to show any detrimental evidence on the density of non-target herbivores, predators and parasitoids. The composition of herbivores, predators and parasitoids was identical in Bt and non-Bt corn plots. Taken together, results from the present work support that Bt corn producing Cry1Ac toxins does not adversely affect NTAs. PMID:25437213

  11. The Cultivation of Bt Corn Producing Cry1Ac Toxins Does Not Adversely Affect Non-Target Arthropods

    PubMed Central

    Guo, Yanyan; Feng, Yanjie; Ge, Yang; Tetreau, Guillaume; Chen, Xiaowen; Dong, Xuehui; Shi, Wangpeng

    2014-01-01

    Transgenic corn producing Cry1Ac toxins from Bacillus thuringiensis (Bt) provides effective control of Asian corn borer, Ostrinia furnacalis (Guenée), and thus reduces insecticide applications. However, whether Bt corn exerts undesirable effects on non-target arthropods (NTAs) is still controversial. We conducted a 2-yr study in Shangzhuang Agricultural Experiment Station to assess the potential impact of Bt corn on field population density, biodiversity, community composition and structure of NTAs. On each sampling date, the total abundance, Shannon's diversity index, Pielou's evenness index and Simpson's diversity index were not significantly affected by Bt corn as compared to non-Bt corn. The “sampling dates” had a significant effect on these indices, but no clear tendencies related to “Bt corn” or “sampling dates X corn variety” interaction were recorded. Principal response curve analysis of variance indicated that Bt corn did not alter the distribution of NTAs communities. Bray-Curtis dissimilarity and distance analysis showed that Cry1Ac toxin exposure did not increase community dissimilarities between Bt and non-Bt corn plots and that the evolution of non-target arthropod community was similar on the two corn varieties. The cultivation of Bt corn failed to show any detrimental evidence on the density of non-target herbivores, predators and parasitoids. The composition of herbivores, predators and parasitoids was identical in Bt and non-Bt corn plots. Taken together, results from the present work support that Bt corn producing Cry1Ac toxins does not adversely affect NTAs. PMID:25437213

  12. Making phytoremediation work better: maximizing a plant's growth potential in the midst of adversity.

    PubMed

    Glick, Bernard R; Stearns, Jennifer C

    2011-01-01

    While a number of different plants can either breakdown a variety of organic contaminants or hyperaccumulate metals from the environment, even the most efficient of those plants is typically inhibited by the presence of the toxicant(s). The plant stress that is induced by the presence of various environmental toxicants typically limits a plant's growth and ultimately its ability to phytoremediate the toxicant(s). Here, it is argued that the simple strategy of adding plant growth-promoting bacteria (preferably endophytes) that reduce plant ethylene levels by ACC deaminase activity and have the ability to synthesize the phytohoromone IAA, and are used to phytoremediate various toxicants can significantly (and often dramatically) increase both plant growth and phytoremediation activity in the presence of those toxicants. PMID:22046748

  13. Corridors affect plants, animals, and their interactions in fragmented landscapes.

    SciTech Connect

    Tewksbury, Joshua, J.; Levey, Douglas, J.; Haddad, Nick, M.; Sargent, Sarah; Orrock, John, L.; Weldon, Aimee; Danielson, Brent, J.; Brinkerhoff, Jory; Damschen, Ellen, I.; Townsend, Patricia

    2002-10-01

    Tewksbury, J.J., D.J. Levey, N.M. Haddad, S. Sargent, J.L. Orrock, A. Weldon, B.J. Danielson, J. Brinkerhoff, E.I. Damschen, and P. Townsend. 2002. Corridors affect plants, animals, and their interactions in fragmented landscapes. PNAS 99(20):12923-12926. Among the most popular strategies for maintaining populations of both plants and animals in fragmented landscapes is to connect isolated patches with thin strips of habitat, called corridors. Corridors are thought to increase the exchange of individuals between habitat patches, promoting genetic exchange and reducing population fluctuations. Empirical studies addressing the effects of corridors have either been small in scale or have ignored confounding effects of increased habitat area created by the presence of a corridor. These methodological difficulties, coupled with a paucity of studies examining the effects of corridors on plants and plant-animal interactions, have sparked debate over the purported value of corridors in conservation planning. We report results of a large-scale experiment that directly address this debate. We demonstrate that corridors not only increase the exchange of animals between patches, but also facilitate two key plant-animal interactions: pollination and seed dispersal. Our results show that the beneficial effects of corridors extend beyond the area they add, and suggest that increased plant and animal movement through corridors will have positive impacts on plant populations and community interactions in fragmented landscapes.

  14. [The assessment of no adverse effect doses for plant populations chronically exposed to radionuclides of uranium and thorium decay series].

    PubMed

    Evseeva, T I; Maĭstrenko, T A; Belykh, E S; Geras'kin, S A

    2010-01-01

    Dose rates cause no adverse effects on natural populations of Pinus sylvestris L. and Vicia cracca L. inhabiting territories contaminated by uranium mill tailings and radium production wastes (Vodny settlement, Komi Republic) were determined. A significant increase in embryonic lethal mutation frequency in V. cracca legumes and decrease in seedlings survival rate as compared with control values were registered at dose rate equal to 1.67 mGy/day, that is 280 times higher than the one calculated for the reference site. The adverse effects in P. sylvestris expressed in increased frequency of chromosome aberrations in meristematic root tips and decreased reproductive capacity of seeds were determined at absorbed dose rate equal to 0.083 mGy/day. Data obtained show that the decrease in plant reproductive capacity in case of chronic exposure of radionuclides of uranium and thorium decay series can observe at lower weighted absorbed dose rates than in case of environmental contamination by artificial radionuclides.

  15. ADP1 affects plant architecture by regulating local auxin biosynthesis.

    PubMed

    Li, Ruixi; Li, Jieru; Li, Shibai; Qin, Genji; Novák, Ondřej; Pěnčík, Aleš; Ljung, Karin; Aoyama, Takashi; Liu, Jingjing; Murphy, Angus; Gu, Hongya; Tsuge, Tomohiko; Qu, Li-Jia

    2014-01-01

    Plant architecture is one of the key factors that affect plant survival and productivity. Plant body structure is established through the iterative initiation and outgrowth of lateral organs, which are derived from the shoot apical meristem and root apical meristem, after embryogenesis. Here we report that ADP1, a putative MATE (multidrug and toxic compound extrusion) transporter, plays an essential role in regulating lateral organ outgrowth, and thus in maintaining normal architecture of Arabidopsis. Elevated expression levels of ADP1 resulted in accelerated plant growth rate, and increased the numbers of axillary branches and flowers. Our molecular and genetic evidence demonstrated that the phenotypes of plants over-expressing ADP1 were caused by reduction of local auxin levels in the meristematic regions. We further discovered that this reduction was probably due to decreased levels of auxin biosynthesis in the local meristematic regions based on the measured reduction in IAA levels and the gene expression data. Simultaneous inactivation of ADP1 and its three closest homologs led to growth retardation, relative reduction of lateral organ number and slightly elevated auxin level. Our results indicated that ADP1-mediated regulation of the local auxin level in meristematic regions is an essential determinant for plant architecture maintenance by restraining the outgrowth of lateral organs. PMID:24391508

  16. Plant ecology. Anthropogenic environmental changes affect ecosystem stability via biodiversity.

    PubMed

    Hautier, Yann; Tilman, David; Isbell, Forest; Seabloom, Eric W; Borer, Elizabeth T; Reich, Peter B

    2015-04-17

    Human-driven environmental changes may simultaneously affect the biodiversity, productivity, and stability of Earth's ecosystems, but there is no consensus on the causal relationships linking these variables. Data from 12 multiyear experiments that manipulate important anthropogenic drivers, including plant diversity, nitrogen, carbon dioxide, fire, herbivory, and water, show that each driver influences ecosystem productivity. However, the stability of ecosystem productivity is only changed by those drivers that alter biodiversity, with a given decrease in plant species numbers leading to a quantitatively similar decrease in ecosystem stability regardless of which driver caused the biodiversity loss. These results suggest that changes in biodiversity caused by drivers of environmental change may be a major factor determining how global environmental changes affect ecosystem stability.

  17. Extreme Air Pollution Conditions Adversely Affect Blood Pressure and Insulin Resistance: The Air Pollution and Cardiometabolic Disease Study.

    PubMed

    Brook, Robert D; Sun, Zhichao; Brook, Jeffrey R; Zhao, Xiaoyi; Ruan, Yanping; Yan, Jianhua; Mukherjee, Bhramar; Rao, Xiaoquan; Duan, Fengkui; Sun, Lixian; Liang, Ruijuan; Lian, Hui; Zhang, Shuyang; Fang, Quan; Gu, Dongfeng; Sun, Qinghua; Fan, Zhongjie; Rajagopalan, Sanjay

    2016-01-01

    Mounting evidence supports that fine particulate matter adversely affects cardiometabolic diseases particularly in susceptible individuals; however, health effects induced by the extreme concentrations within megacities in Asia are not well described. We enrolled 65 nonsmoking adults with metabolic syndrome and insulin resistance in the Beijing metropolitan area into a panel study of 4 repeated visits across 4 seasons since 2012. Daily ambient fine particulate matter and personal black carbon levels ranged from 9.0 to 552.5 µg/m(3) and 0.2 to 24.5 µg/m(3), respectively, with extreme levels observed during January 2013. Cumulative fine particulate matter exposure windows across the prior 1 to 7 days were significantly associated with systolic blood pressure elevations ranging from 2.0 (95% confidence interval, 0.3-3.7) to 2.7 (0.6-4.8) mm Hg per SD increase (67.2 µg/m(3)), whereas cumulative black carbon exposure during the previous 2 to 5 days were significantly associated with ranges in elevations in diastolic blood pressure from 1.3 (0.0-2.5) to 1.7 (0.3-3.2) mm Hg per SD increase (3.6 µg/m(3)). Both black carbon and fine particulate matter were significantly associated with worsening insulin resistance (0.18 [0.01-0.36] and 0.22 [0.04-0.39] unit increase per SD increase of personal-level black carbon and 0.18 [0.02-0.34] and 0.22 [0.08-0.36] unit increase per SD increase of ambient fine particulate matter on lag days 4 and 5). These results provide important global public health warnings that air pollution may pose a risk to cardiometabolic health even at the extremely high concentrations faced by billions of people in the developing world today. PMID:26573709

  18. Increased Fracture Collapse after Intertrochanteric Fractures Treated by the Dynamic Hip Screw Adversely Affects Walking Ability but Not Survival

    PubMed Central

    Fang, Christian; Gudushauri, Paata; Wong, Tak-Man; Lau, Tak-Wing; Pun, Terence; Leung, Frankie

    2016-01-01

    In osteoporotic hip fractures, fracture collapse is deliberately allowed by commonly used implants to improve dynamic contact and healing. The muscle lever arm is, however, compromised by shortening. We evaluated a cohort of 361 patients with AO/OTA 31.A1 or 31.A2 intertrochanteric fracture treated by the dynamic hip screw (DHS) who had a minimal follow-up of 3 months and an average follow-up of 14.6 months and long term survival data. The amount of fracture collapse and shortening due to sliding of the DHS was determined at the latest follow-up and graded as minimal (<1 cm), moderate (1-2 cm), or severe (>2 cm). With increased severity of collapse, more patients were unable to maintain their premorbid walking function (minimal collapse = 34.2%, moderate = 33.3%, severe = 62.8%, and p = 0.028). Based on ordinal regression of risk factors, increased fracture collapse was significantly and independently related to increasing age (p = 0.037), female sex (p = 0.024), A2 fracture class (p = 0.010), increased operative duration (p = 0.011), poor reduction quality (p = 0.000), and suboptimal tip-apex distance of >25 mm (p = 0.050). Patients who had better outcome in terms of walking function were independently predicted by younger age (p = 0.036), higher MMSE marks (p = 0.000), higher MBI marks (p = 0.010), better premorbid walking status (p = 0.000), less fracture collapse (p = 0.011), and optimal lag screw position in centre-centre or centre-inferior position (p = 0.020). According to Kaplan-Meier analysis, fracture collapse had no association with mortality from 2.4 to 7.6 years after surgery. In conclusion, increased fracture collapse after fixation of geriatric intertrochanteric fractures adversely affected walking but not survival. PMID:26955637

  19. Extreme Air Pollution Conditions Adversely Affect Blood Pressure and Insulin Resistance: The Air Pollution and Cardiometabolic Disease Study.

    PubMed

    Brook, Robert D; Sun, Zhichao; Brook, Jeffrey R; Zhao, Xiaoyi; Ruan, Yanping; Yan, Jianhua; Mukherjee, Bhramar; Rao, Xiaoquan; Duan, Fengkui; Sun, Lixian; Liang, Ruijuan; Lian, Hui; Zhang, Shuyang; Fang, Quan; Gu, Dongfeng; Sun, Qinghua; Fan, Zhongjie; Rajagopalan, Sanjay

    2016-01-01

    Mounting evidence supports that fine particulate matter adversely affects cardiometabolic diseases particularly in susceptible individuals; however, health effects induced by the extreme concentrations within megacities in Asia are not well described. We enrolled 65 nonsmoking adults with metabolic syndrome and insulin resistance in the Beijing metropolitan area into a panel study of 4 repeated visits across 4 seasons since 2012. Daily ambient fine particulate matter and personal black carbon levels ranged from 9.0 to 552.5 µg/m(3) and 0.2 to 24.5 µg/m(3), respectively, with extreme levels observed during January 2013. Cumulative fine particulate matter exposure windows across the prior 1 to 7 days were significantly associated with systolic blood pressure elevations ranging from 2.0 (95% confidence interval, 0.3-3.7) to 2.7 (0.6-4.8) mm Hg per SD increase (67.2 µg/m(3)), whereas cumulative black carbon exposure during the previous 2 to 5 days were significantly associated with ranges in elevations in diastolic blood pressure from 1.3 (0.0-2.5) to 1.7 (0.3-3.2) mm Hg per SD increase (3.6 µg/m(3)). Both black carbon and fine particulate matter were significantly associated with worsening insulin resistance (0.18 [0.01-0.36] and 0.22 [0.04-0.39] unit increase per SD increase of personal-level black carbon and 0.18 [0.02-0.34] and 0.22 [0.08-0.36] unit increase per SD increase of ambient fine particulate matter on lag days 4 and 5). These results provide important global public health warnings that air pollution may pose a risk to cardiometabolic health even at the extremely high concentrations faced by billions of people in the developing world today.

  20. Endocrine disrupters and human health: could oestrogenic chemicals in body care cosmetics adversely affect breast cancer incidence in women?

    PubMed

    Harvey, Philip W; Darbre, Philippa

    2004-01-01

    In the decade that has elapsed since the suggestion that exposure of the foetal/developing male to environmental oestrogens could be the cause of subsequent reproductive and developmental effects in men, there has been little definitive research to provide conclusions to the hypothesis. Issues of exposure and low potency of environmental oestrogens may have reduced concerns. However, the hypothesis that chemicals applied in body care cosmetics (including moisturizers, creams, sprays or lotions applied to axilla or chest or breast areas) may be affecting breast cancer incidence in women presents a different case scenario, not least in the consideration of the exposure issues. The specific cosmetic type is not relevant but the chemical ingredients in the formulations and the application to the skin is important. The most common group of body care cosmetic formulation excipients, namely p-hydroxybenzoic acid esters or parabens, have been shown recently to be oestrogenic in vitro and in vivo and now have been detected in human breast tumour tissue, indicating absorption (route and causal associations have yet to be confirmed). The hypothesis for a link between oestrogenic ingredients in underarm and body care cosmetics and breast cancer is forwarded and reviewed here in terms of: data on exposure to body care cosmetics and parabens, including dermal absorption; paraben oestrogenicity; the role of oestrogen in breast cancer; detection of parabens in breast tumours; recent epidemiology studies of underarm cosmetics use and breast cancer; the toxicology database; the current regulatory status of parabens and regulatory toxicology data uncertainties. Notwithstanding the major public health issue of the causes of the rising incidence of breast cancer in women, this call for further research may provide the first evidence that environmental factors may be adversely affecting human health by endocrine disruption, because exposure to oestrogenic chemicals through application

  1. Assessment of wastewater treatment plant effluent on fish reproduction utilizing the adverse outcome pathway conceptual framework

    EPA Science Inventory

    Wastewater treatment plant (WWTP) effluents are a known contributor of chemical mixture inputs into the environment. Whole effluent testing guidelines were developed to screen these complex mixtures for acute toxicity. However, efficient and cost-effective approaches for screenin...

  2. Foliar application of brassinosteroids alleviates adverse effects of zinc toxicity in radish (Raphanus sativus L.) plants.

    PubMed

    Ramakrishna, Bellamkonda; Rao, S Seeta Ram

    2015-03-01

    Growth chamber experiments were conducted to investigate the comparative effect of 24-epibrassinolide (EBL) and 28-homobrassinolide (HBL) at 0.5, 1.0, or 2.0 μM concentrations by foliar application on radish plants growing under Zn(2+) stress. In radish plants exposed to excess Zn(2+), growth was substantially reduced in terms of shoot and root length, fresh and dry weight. However, foliar application of brassinosteroids (BRs) was able to alleviate Zn(2+)-induced stress and significantly improve the above growth traits. Zinc stress decreased chlorophyll a, b, and carotenoids levels in radish plants. However, follow-up treatment with BRs increased the photosynthetic pigments in stressed and stress-free plants. The treatment of BRs led to reduced levels of H2O2, lipid peroxidation and, electrolyte leakage (ELP) and improved the leaf relative water content (RWC) in stressed plants. Increased levels of carbonyls indicating enhanced protein oxidation under Zn(2+) stress was effectively countered by supplementation of BRs. Under Zn(2+) stress, the activities of catalase (CAT), ascorbate peroxidase (APX), and superoxidase dismutase (SOD) were increased but peroxidase (POD) and glutathione reductase (GR) decreased. Foliar spraying of BRs enhanced all these enzymatic activities in radish plants under Zn(2+) stress. The BRs application greatly enhanced contents of ascorbate (ASA), glutathione (GSH), and proline under Zn(2+) stress. The decrease in the activity of nitrate reductase (NR) caused by Zn(2+) stress was restored to the level of control by application of BRs. These results point out that BRs application elevated levels of antioxidative enzymes as well as antioxidants could have conferred resistance to radish plants against Zn(2+) stress resulting in improved plant growth, relative water content and photosynthetic attributes. Of the two BRs, EBL was most effective in amelioration of Zn(2+) stress.

  3. Do social disadvantage and early family adversity affect the diurnal cortisol rhythm in infants? The Generation R Study.

    PubMed

    Saridjan, Nathalie S; Huizink, Anja C; Koetsier, Jitske A; Jaddoe, Vincent W; Mackenbach, Johan P; Hofman, Albert; Kirschbaum, Clemens; Verhulst, Frank C; Tiemeier, Henning

    2010-02-01

    Dysregulation of diurnal cortisol secretion patterns may explain the link between adversities early in life and later mental health problems. However, few studies have investigated the influence of social disadvantage and family adversity on the hypothalamic-pituitary-adrenal (HPA) axis early in life. In 366 infants aged 12-20 months from the Generation R Study, a population-based cohort from fetal life onwards, parents collected saliva samples from their infant at 5 moments over the course of 1 day. The area under the curve (AUC), the cortisol awakening response (CAR) and the diurnal cortisol slope were calculated as different composite measures of the diurnal cortisol rhythm. Information about social disadvantage and early adversity was collected using prenatal and postnatal questionnaires. We found that older infants showed lower AUC levels; moreover, infants with a positive CAR were significantly older. Both the AUC and the CAR were related to indicators of social disadvantage and early adversity. Infants of low income families, in comparison to high income families, showed higher AUC levels and a positive CAR. Infants of mothers who smoked during pregnancy were also significantly more likely to show a positive CAR. Furthermore, infants of mothers experiencing parenting stress showed higher AUC levels. The results of our study show that effects of social disadvantage and early adversity on the diurnal cortisol rhythm are already observable in infants. This may reflect the influence of early negative life events on early maturation of the HPA axis. PMID:20006614

  4. Benefits of adversity?! How life history affects the behavioral profile of mice varying in serotonin transporter genotype

    PubMed Central

    Bodden, Carina; Richter, S. Helene; Schreiber, Rebecca S.; Kloke, Vanessa; Gerß, Joachim; Palme, Rupert; Lesch, Klaus-Peter; Lewejohann, Lars; Kaiser, Sylvia; Sachser, Norbert

    2015-01-01

    Behavioral profiles are influenced by both positive and negative experiences as well as the genetic disposition. Traditionally, accumulating adversity over lifetime is considered to predict increased anxiety-like behavior (“allostatic load”). The alternative “mismatch hypothesis” suggests increased levels of anxiety if the early environment differs from the later-life environment. Thus, there is a need for a whole-life history approach to gain a deeper understanding of how behavioral profiles are shaped. The aim of this study was to elucidate the effects of life history on the behavioral profile of mice varying in serotonin transporter (5-HTT) genotype, an established mouse model of increased anxiety-like behavior. For this purpose, mice grew up under either adverse or beneficial conditions during early phases of life. In adulthood, they were further subdivided so as to face a situation that either matched or mismatched the condition experienced so far, resulting in four different life histories. Subsequently, mice were tested for their anxiety-like and exploratory behavior. The main results were: (1) Life history profoundly modulated the behavioral profile. Surprisingly, mice that experienced early beneficial and later escapable adverse conditions showed less anxiety-like and more exploratory behavior compared to mice of other life histories. (2) Genotype significantly influenced the behavioral profile, with homozygous 5-HTT knockout mice displaying highest levels of anxiety-like and lowest levels of exploratory behavior. Our findings concerning life history indicate that the absence of adversity does not necessarily cause lower levels of anxiety than accumulating adversity. Rather, some adversity may be beneficial, particularly when following positive events. Altogether, we conclude that for an understanding of behavioral profiles, it is not sufficient to look at experiences during single phases of life, but the whole life history has to be considered

  5. Ozone affects gas exchange, growth and reproductive development in Brassica campestris (Wisconsin fast plants).

    PubMed

    Black, V J; Stewart, C A; Roberts, J A; Black, C R

    2007-01-01

    Exposure to ozone (O(3)) may affect vegetative and reproductive development, although the consequences for yield depend on the effectiveness of the compensatory processes induced. This study examined the impact on reproductive development of exposing Brassica campestris (Wisconsin Fast Plants) to ozone during vegetative growth. Plants were exposed to 70 ppb ozone for 2 d during late vegetative growth or 10 d spanning most of the vegetative phase. Effects on gas exchange, vegetative growth, reproductive development and seed yield were determined. Impacts on gas exchange and foliar injury were related to pre-exposure stomatal conductance. Exposure for 2 d had no effect on growth or reproductive characteristics, whereas 10-d exposure reduced vegetative growth and reproductive site number on the terminal raceme. Mature seed number and weight per pod and per plant were unaffected because seed abortion was reduced. The observation that mature seed yield per plant was unaffected by exposure during the vegetative phase, despite adverse effects on physiological, vegetative and reproductive processes, shows that indeterminate species such as B. campestris possess sufficient compensatory flexibility to avoid reductions in seed production. PMID:17803646

  6. Ozone affects gas exchange, growth and reproductive development in Brassica campestris (Wisconsin fast plants).

    PubMed

    Black, V J; Stewart, C A; Roberts, J A; Black, C R

    2007-01-01

    Exposure to ozone (O(3)) may affect vegetative and reproductive development, although the consequences for yield depend on the effectiveness of the compensatory processes induced. This study examined the impact on reproductive development of exposing Brassica campestris (Wisconsin Fast Plants) to ozone during vegetative growth. Plants were exposed to 70 ppb ozone for 2 d during late vegetative growth or 10 d spanning most of the vegetative phase. Effects on gas exchange, vegetative growth, reproductive development and seed yield were determined. Impacts on gas exchange and foliar injury were related to pre-exposure stomatal conductance. Exposure for 2 d had no effect on growth or reproductive characteristics, whereas 10-d exposure reduced vegetative growth and reproductive site number on the terminal raceme. Mature seed number and weight per pod and per plant were unaffected because seed abortion was reduced. The observation that mature seed yield per plant was unaffected by exposure during the vegetative phase, despite adverse effects on physiological, vegetative and reproductive processes, shows that indeterminate species such as B. campestris possess sufficient compensatory flexibility to avoid reductions in seed production.

  7. Soil microbes and plant invasions—how soil-borne pathogens regulate plant populations and affect plant invasions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Exotic plant invaders are a major global threat to biodiversity and ecosystem function. Here I present multiple lines of evidence suggesting that soil microbial communities affect the population growth rates of Prunus serotina in its native range and affect its invasiveness abroad. Research often ...

  8. The potentiality of Trichoderma harzianum in alleviation the adverse effects of salinity in faba bean plants.

    PubMed

    Abd El-Baki, G K; Mostafa, Doaa

    2014-12-01

    The interaction between sodium chloride and Trichoderma harzianum (T24) on growth parameters, ion contents, MDA content, proline, soluble proteins as well as SDS page protein profile were studied in Vicia faba Giza 429. A sharp reduction was found in fresh and dry mass of shoots and roots with increasing salinity. Trichoderma treatments promoted the growth criteria as compared with corresponding salinized plants. The water content and leaf area exhibited a marked decrease with increasing salinity. Trichoderma treatments induced a progressive increase in both parameters. Both proline and MDA contents were increased progressively as the salinity rose in the soil. Trichoderma treatments considerably retarded the accumulation of both parameters in shoots and roots. Both Na+ and K+ concentration increased in both organs by enhancing salinity levels. The treatment with Trichoderma harzianum enhanced the accumulation of both ions. Exposure of plants to different concentrations of salinity, or others treated with Trichoderma harzianum produced marked changes in their protein pattern. Three types of alterations were observed: the synthesis of certain proteins declined significantly, specific synthesis of certain other proteins were markedly observed and synthesis of a set specific protein was induced de novo in plant treated with Trichoderma harzianum.

  9. Endozoochorous dispersal of aquatic plants: does seed gut passage affect plant performance?

    PubMed

    Figuerola, Jordi; Santamaría, Luis; Green, Andy J; Luque, Isabel; Alvarez, Raquel; Charalambidou, Iris

    2005-04-01

    The ingestion of seeds by vertebrates can affect the germinability and/or germination rate of seeds. It is, however, unclear if an earlier germination as a result of ingestion affects later plant performance. For sago pondweed, Potamogeton pectinatus, the effects of seed ingestion by ducks on both germinability and germination rate have been previously reported from laboratory experiments. We performed an experiment to determine the effects of seed ingestion by ducks on germination, seedling survival, plant growth and asexual multiplication. Both at the start and end of the winter, seeds were fed to three captive shovelers (Anas clypeata) and planted outdoors in water-filled containers. Plant biomass and its allocation to vegetative parts (shoot and roots), tubers, and seeds were determined in autumn. More duck-ingested seeds than control (uningested) seeds germinated in early winter, but this difference disappeared for seeds planted in late winter, when the treatments were first stratified for 3 mo. None of the variables for measuring seedling survival and plant performance varied between treatments. Under our experimental conditions (no herbivory or competition), ingestion by ducks in early winter resulted in increased performance for seeds surviving gut passage due to enhanced seed germinability, without other costs or benefits for the seedlings.

  10. Identified Natural Hazards May Cause Adverse Impact on Sustainability of Desalination Plants in Red Sea

    NASA Astrophysics Data System (ADS)

    Aburizaiza, O. S.; Zaigham, N. A.; Nayyar, Z. A.; Mahar, G. A.; Siddique, A.; Eusufi, S. N.

    2011-12-01

    The Red Sea and its surrounding countries have harsh arid climatic conditions where fast growth of the socio-economic activities and rapid change of lifestyle have caused tremendous stress on water to the level of acute crisis. To meet the water demands, the Red Sea countries have adopted seawater desalination giving priority against their land-based resources. Saudi Arabia is the largest desalinated-water producers in the Red Sea and has practically no adequate backup plan in case of sudden unforeseen emergency. Out of about 3.64 million m3/day, Saudi Arabia is alone being desalinated about 3.29 m3/day seawater from Red Sea and more projects are in progress. Present integrated research study has identified some of natural and anthropogenic hazards, which may be major threats to the quality of the seawater as well as to the desalination plants themselves. Results of present study reveal that the submarine complex morphologic features may cause the isolation of Red Sea from any of the open sea, the increase in the seismicity trends, the active volcanism causing unique longitudinal as well as transverse deformations of the axial trough particularly in the southern part of the Red Sea, the consistently generating enormous hot-brine tectonic-factory all along the deeper parts of the Red Sea rifting trough and other related issues. Considering the identified odd conditions, the total dependence on seawater desalination may not be worthwhile for sustainable water management strategy and consequent socio-economic developments in future. It is recommended that the priority should also be given mainly in three main disciplines to meet the future water challenges - one, developing reliable backup water management; second, alternate options for the supplementary resources of water; and third, the development and immediate implementation of the water-use conservation strategy plan.

  11. CT and MR imaging findings of systemic complications occurring during pregnancy and puerperal period, adversely affected by natural changes

    PubMed Central

    Himoto, Yuki; Kido, Aki; Moribata, Yusaku; Yamaoka, Toshihide; Okumura, Ryosuke; Togashi, Kaori

    2015-01-01

    Dynamic physiological and anatomical changes for delivery may adversely induce various specific non-obstetric complications during pregnancy and puerperal period. These complications can be fatal to both the mother and the fetus, thus a precise and early diagnosis ensued by an early treatment is essential. Along with ultrasonography, computed tomography (CT) and magnetic resonance imaging (MRI) have assumed an increasing role in the diagnosis. This article aims to discuss the pathophysiology of these complications, the indications for CT and MRI, and the imaging findings. PMID:26937442

  12. Factors affecting the development of adverse drug reactions to β-blockers in hospitalized cardiac patient population

    PubMed Central

    Mugoša, Snežana; Djordjević, Nataša; Djukanović, Nina; Protić, Dragana; Bukumirić, Zoran; Radosavljević, Ivan; Bošković, Aneta; Todorović, Zoran

    2016-01-01

    The aim of the present study was to undertake a study on the prevalence of cytochrome P450 2D6 (CYP2D6) poor metabolizer alleles (*3, *4, *5, and *6) on a Montenegrin population and its impact on developing adverse drug reactions (ADRs) of β-blockers in a hospitalized cardiac patient population. A prospective study was conducted in the Cardiology Center of the Clinical Center of Montenegro and included 138 patients who had received any β-blocker in their therapy. ADRs were collected using a specially designed questionnaire, based on the symptom list and any signs that could point to eventual ADRs. Data from patients’ medical charts, laboratory tests, and other available parameters were observed and combined with the data from the questionnaire. ADRs to β-blockers were observed in 15 (10.9%) patients. There was a statistically significant difference in the frequency of ADRs in relation to genetically determined enzymatic activity (P<0.001), with ADRs’ occurrence significantly correlating with slower CYP2D6 metabolism. Our study showed that the adverse reactions to β-blockers could be predicted by the length of hospitalization, CYP2D6 poor metabolizer phenotype, and the concomitant use of other CYP2D6-metabolizing drugs. Therefore, in hospitalized patients with polypharmacy CYP2D6 genotyping might be useful in detecting those at risk of ADRs. PMID:27536078

  13. Impaired Glucose Tolerance or Newly Diagnosed Diabetes Mellitus Diagnosed during Admission Adversely Affects Prognosis after Myocardial Infarction: An Observational Study

    PubMed Central

    George, Anish; Bhatia, Raghav T.; Buchanan, Gill L.; Whiteside, Anne; Moisey, Robert S.; Beer, Stephen F.; Chattopadhyay, Sudipta; Sathyapalan, Thozhukat; John, Joseph

    2015-01-01

    Objective To investigate the prognostic effect of newly diagnosed diabetes mellitus (NDM) and impaired glucose tolerance (IGT) post myocardial infarction (MI). Research Design and Methods Retrospective cohort study of 768 patients without preexisting diabetes mellitus post-MI at one centre in Yorkshire between November 2005 and October 2008. Patients were categorised as normal glucose tolerance (NGT n = 337), IGT (n = 279) and NDM (n = 152) on pre- discharge oral glucose tolerance test (OGTT). Primary end-point was the first occurrence of major adverse cardiovascular events (MACE) including cardiovascular death, non-fatal MI, severe heart failure (HF) or non-haemorrhagic stroke. Secondary end-points were all cause mortality and individual components of MACE. Results Prevalence of NGT, impaired fasting glucose (IFG), IGT and NDM changed from 90%, 6%, 0% and 4% on fasting plasma glucose (FPG) to 43%, 1%, 36% and 20% respectively after OGTT. 102 deaths from all causes (79 as first events of which 46 were cardiovascular), 95 non fatal MI, 18 HF and 9 non haemorrhagic strokes occurred during 47.2 ± 9.4 months follow up. Event free survival was lower in IGT and NDM groups. IGT (HR 1.54, 95% CI: 1.06–2.24, p = 0.024) and NDM (HR 2.15, 95% CI: 1.42–3.24, p = 0.003) independently predicted MACE free survival. IGT and NDM also independently predicted incidence of MACE. NDM but not IGT increased the risk of secondary end-points. Conclusion Presence of IGT and NDM in patients presenting post-MI, identified using OGTT, is associated with increased incidence of MACE and is associated with adverse outcomes despite adequate secondary prevention. PMID:26571120

  14. A Computational Study on the Effects of Dynamic Roughness Application to Separated Transitional Flows Affected by Adverse Pressure Gradient

    NASA Astrophysics Data System (ADS)

    Campitelli, Gennaro

    The study of transitional flows is considered crucial for many practical engineering applications. In fact, a comprehensive understanding of the laminar-turbulent transition phenomenon often helps to improve the overall performance of apparatuses such as airfoils, wind turbines, hulls and turbomachinery blades. In addition to understanding and prediction of transitional flows, active research continues in the area of boundary layer control, which includes control of phenomena such as flow separation and transition. For instance, optimum geometrical shaping may be followed by the adoption on the wall-surface of riblets to adjust pressure gradient and reduce drag. Further "flow control" may also be acquired by introducing active devices able to modify the flow field in order to accomplish a desired aerodynamic task. Such flow manipulation is often achieved by using time-dependent forcing mechanisms which promote natural instabilities amplifying the control effectiveness. Localized energy inputs such as Lorentz-force actuator, piezoelectric flaps and synthetic jets all produce a consistent boundary layer mixing enhancement with lift increase and drag abatement. The current numerical study attempts to demonstrate the efficacy of dynamic roughness (DR) on altering separated-reattached transitional flows under adverse pressure gradient. It has already been proven how DR, acting on the boundary sublayer perturbation, is able to suppress (partially or completely) the typical leading edge separation for an airfoil at different angles of attack. This makes DR particularly suitable for separated flow control applications where the shear layer reattaches presenting the characteristic laminar separation bubble. A numerical sensitivity study has been conducted with an efficient orthogonal design taking into account four different control parameters on three levels (actuation frequency, humps height, rows displacement, synchronization) to provide an optimum DR setup which limits

  15. The type B brevetoxin (PbTx-3) adversely affects development, cardiovascular function, and survival in Medaka (Oryzias latipes) embryos.

    PubMed Central

    Colman, Jamie R; Ramsdell, John S

    2003-01-01

    Brevetoxins are produced by the red tide dinoflagellate Karenia brevis. The toxins are lipophilic polyether toxins that elicit a myriad of effects depending on the route of exposure and the target organism. Brevetoxins are therefore broadly toxic to marine and estuarine animals. By mimicking the maternal route of exposure to the oocytes in finfish, we characterized the adverse effects of the type B brevetoxin brevetoxin-3 (PbTx-3) on embryonic fish development and survival. The Japanese rice fish, medaka (Oryzias latipes), was used as the experimental model in which individual eggs were exposed via microinjection to various known concentrations of PbTx-3 dissolved in an oil vehicle. Embryos injected with doses exceeding 1.0 ng/egg displayed tachycardia, hyperkinetic twitches in the form of sustained convulsions, spinal curvature, clumping of the erythrocytes, and decreased hatching success. Furthermore, fish dosed with toxin were often unable to hatch in the classic tail-first fashion and emerged head first, which resulted in partial hatches and death. We determined that the LD(50) (dose that is lethal to 50% of the fish) for an injected dose of PbTx-3 is 4.0 ng/egg. The results of this study complement previous studies of the developmental toxicity of the type A brevetoxin brevetoxin-1 (PbTx-1), by illustrating in vivo the differing affinities of the two congeners for cardiac sodium channels. Consequently, we observed differing cardiovascular responses in the embryos, wherein embryos exposed to PbTx-3 exhibited persistent tachycardia, whereas embryos exposed to PbTx-1 displayed bradycardia, the onset of which was delayed. PMID:14644667

  16. The skin tissue is adversely affected by TNF-alpha blockers in patients with chronic inflammatory arthritis: a 5-year prospective analysis

    PubMed Central

    Machado, Natalia P.; dos Reis Neto, Edgard Torres; Soares, Maria Roberta M. P.; Freitas, Daniele S.; Porro, Adriana; Ciconelli, Rozana M.; Pinheiro, Marcelo M.

    2013-01-01

    OBJECTIVE: We evaluated the incidence of and the main risk factors associated with cutaneous adverse events in patients with chronic inflammatory arthritis following anti-TNF-α therapy. METHODS: A total of 257 patients with active arthritis who were taking TNF-α blockers, including 158 patients with rheumatoid arthritis, 87 with ankylosing spondylitis and 12 with psoriatic arthritis, were enrolled in a 5-year prospective analysis. Patients with overlapping or other rheumatic diseases were excluded. Anthropometric, socioeconomic, demographic and clinical data were evaluated, including the Disease Activity Score-28, Bath Ankylosing Spondylitis Disease Activity Index and Psoriasis Area Severity Index. Skin conditions were evaluated by two dermatology experts, and in doubtful cases, skin lesion biopsies were performed. Associations between adverse cutaneous events and clinical, demographic and epidemiological variables were determined using the chi-square test, and logistic regression analyses were performed to identify risk factors. The significance level was set at p<0.05. RESULTS: After 60 months of follow-up, 71 adverse events (73.85/1000 patient-years) were observed, of which allergic and immune-mediated phenomena were the most frequent events, followed by infectious conditions involving bacterial (47.1%), parasitic (23.5%), fungal (20.6%) and viral (8.8%) agents. CONCLUSION: The skin is significantly affected by adverse reactions resulting from the use of TNF-α blockers, and the main risk factors for cutaneous events were advanced age, female sex, a diagnosis of rheumatoid arthritis, disease activity and the use of infliximab. PMID:24141833

  17. Laser photoacoustic trace detection of C2H4 revealing adverse environmental effects of atmospheric pollution on plant material

    NASA Astrophysics Data System (ADS)

    Harren, Frans J. M.; Petruzzelli, Luciana

    1993-03-01

    The photoacoustic detection method for trace gases in the atmosphere is well developed towards very low limits of detection, in the last years. Due to the combination of a sensitive photoacoustic cell placed intracavity in an infrared CO2 laser we were able to detect C2H4 at ultralow (< 1:1011) concentrations within 10 seconds, C2H4 in a plant hormone which seems to play an important role throughout all the life stages of a plant, including seed germination. In addition, various types of stress have been reported to promote ethylene production from different plant tissues. As part of our ongoing research on the role of ethylene in seed germination, we have compared our laser photoacoustic set-up to a gaschromatograph for measuring C2H4 produced by germinating Pisum sativum L. seeds within the first days of imbibition. C2H4 evolution by intact seeds shows a maximum at about 25 hours of germination. Thereafter, the rate of ethylene measured by gaschromatograph continues to decrease while that measured by the laser-driven photoacoustic system shows further increases. Most of the ethylene produced by seeds is found in isolated embryonic axes. The fumigation with ozone affects the growth of seedlings and their ethylene evolution.

  18. Affective imagery and acceptance of replacing nuclear power plants.

    PubMed

    Keller, Carmen; Visschers, Vivianne; Siegrist, Michael

    2012-03-01

    This study examined the relationship between the content of spontaneous associations with nuclear power plants and the acceptance of using new-generation nuclear power plants to replace old ones. The study also considered gender as a variable. A representative sample of the German- and French-speaking population of Switzerland (N= 1,221) was used. Log-linear models revealed significant two-way interactions between the association content and acceptance, association content and gender, and gender and acceptance. Correspondence analysis revealed that participants who were opposed to nuclear power plants mainly associated nuclear power plants with risk, negative feelings, accidents, radioactivity, waste disposal, military use, and negative consequences for health and environment; whereas participants favoring nuclear power plants mainly associated them with energy, appearance descriptions of nuclear power plants, and necessity. Thus, individuals opposing nuclear power plants had both more concrete and more diverse associations with them than people who were in favor of nuclear power plants. In addition, participants who were undecided often mentioned similar associations to those participants who were in favor. Males more often expressed associations with energy, waste disposal, and negative health effects. Females more often made associations with appearance descriptions, negative feelings, and negative environmental effects. The results further suggest that acceptance of replacing nuclear power plants was higher in the German-speaking part of the country, where all of the Swiss nuclear power plants are physically located. Practical implications for risk communication are discussed.

  19. Nutrient enrichment affects the mechanical resistance of aquatic plants

    PubMed Central

    Puijalon, Sara

    2012-01-01

    For many plant species, nutrient availability induces important anatomical responses, particularly the production of low-density tissues to the detriment of supporting tissues. Due to the contrasting biomechanical properties of plant tissues, these anatomical responses may induce important modifications in the biomechanical properties of plant organs. The aim of this study was to determine the effects of nutrient enrichment on the anatomical traits of two freshwater plant species and its consequences on plant biomechanical performance. Two plant species were grown under controlled conditions in low versus high nutrient levels. The anatomical and biomechanical traits of the plant stems were measured. Both species produced tissues with lower densities under nutrient-rich conditions, accompanied by modifications in the structure of the aerenchyma for one species. As expected, nutrient enrichment also led to important modifications in the biomechanical properties of the stem for both species. In particular, mechanical resistance (breaking force and strength) and stiffness of stems were significantly reduced under nutrient rich conditions. The production of weaker stem tissues as a result of nutrient enrichment may increase the risk of plants to mechanical failure, thus challenging plant maintenance in mechanically stressful or disturbed habitats. PMID:23028018

  20. Nutrient enrichment affects the mechanical resistance of aquatic plants.

    PubMed

    Lamberti-Raverot, Barbara; Puijalon, Sara

    2012-10-01

    For many plant species, nutrient availability induces important anatomical responses, particularly the production of low-density tissues to the detriment of supporting tissues. Due to the contrasting biomechanical properties of plant tissues, these anatomical responses may induce important modifications in the biomechanical properties of plant organs. The aim of this study was to determine the effects of nutrient enrichment on the anatomical traits of two freshwater plant species and its consequences on plant biomechanical performance. Two plant species were grown under controlled conditions in low versus high nutrient levels. The anatomical and biomechanical traits of the plant stems were measured. Both species produced tissues with lower densities under nutrient-rich conditions, accompanied by modifications in the structure of the aerenchyma for one species. As expected, nutrient enrichment also led to important modifications in the biomechanical properties of the stem for both species. In particular, mechanical resistance (breaking force and strength) and stiffness of stems were significantly reduced under nutrient rich conditions. The production of weaker stem tissues as a result of nutrient enrichment may increase the risk of plants to mechanical failure, thus challenging plant maintenance in mechanically stressful or disturbed habitats. PMID:23028018

  1. Do sedentary motives adversely affect physical activity? Adding cross-behavioural cognitions to the theory of planned behaviour.

    PubMed

    Rhodes, Ryan E; Blanchard, Chris M

    2008-01-01

    The purpose of this study was to explore whether sedentary behavior cognitions explain physical activity (PA) intention and behavior when integrated within the theory of planned behavior framework (TPB). A random community sample of 206 adults and a sample of 174 undergraduate students completed measures of the TPB pertaining to PA and four popular leisure-time behaviors (TV viewing, computer use, sedentary hobbies, and sedentary socializing) and an adapted Godin Leisure-Time Exercize Questionnaire (community sample = cross-sectional, undergraduate sample = 2-week prospective). Results using ordinary least squares regression provided evidence that TV viewing intention explains additional variance in PA behavior, and affective attitude (community sample) and perceived behavioral control (undergraduate sample) towards TV viewing explains additional variance in PA intention even after controlling for PA-related TPB constructs. These results underscore the potential value of adding sedentary control interventions in concert with PA promotion.

  2. 7-Rhamnosylated Flavonols Modulate Homeostasis of the Plant Hormone Auxin and Affect Plant Development.

    PubMed

    Kuhn, Benjamin M; Errafi, Sanae; Bucher, Rahel; Dobrev, Petre; Geisler, Markus; Bigler, Laurent; Zažímalová, Eva; Ringli, Christoph

    2016-03-01

    Flavonols are a group of secondary metabolites that affect diverse cellular processes. They are considered putative negative regulators of the transport of the phytohormone auxin, by which they influence auxin distribution and concomitantly take part in the control of plant organ development. Flavonols are accumulating in a large number of glycosidic forms. Whether these have distinct functions and diverse cellular targets is not well understood. The rol1-2 mutant of Arabidopsis thaliana is characterized by a modified flavonol glycosylation profile that is inducing changes in auxin transport and growth defects in shoot tissues. To determine whether specific flavonol glycosides are responsible for these phenotypes, a suppressor screen was performed on the rol1-2 mutant, resulting in the identification of an allelic series of UGT89C1, a gene encoding a flavonol 7-O-rhamnosyltransferase. A detailed analysis revealed that interfering with flavonol rhamnosylation increases the concentration of auxin precursors and auxin metabolites, whereas auxin transport is not affected. This finding provides an additional level of complexity to the possible ways by which flavonols influence auxin distribution and suggests that flavonol glycosides play an important role in regulating plant development.

  3. Diabetes in Pregnancy Adversely Affects the Expression of Glycogen Synthase Kinase-3β in the Hippocampus of Rat Neonates.

    PubMed

    Hami, Javad; Karimi, Razieh; Haghir, Hossein; Gholamin, Mehran; Sadr-Nabavi, Ariane

    2015-10-01

    Diabetes during pregnancy causes a wide range of neurodevelopmental and neurocognitive abnormalities in offspring. Glycogen synthase kinase-3 (GSK-3) is widely expressed during brain development and regulates multiple cellular processes, and its dysregulation is implicated in the pathogenesis of diverse neurodegenerative and psychological diseases. This study was designed to examine the effects of maternal diabetes on GSK-3β messenger RNA (mRNA) expression and phosphorylation in the developing rat hippocampus. Female rats were maintained diabetic from a week before pregnancy through parturition, and male offspring was killed immediately after birth. We found a significant bilateral upregulation of GSK-3β mRNA expression in the hippocampus of pups born to diabetic mothers at P0, compared to controls. Moreover, at the same time point, there was a marked bilateral increase in the phosphorylation level of GSK-3β in the diabetic group. Unlike phosphorylation levels, there was a significant upregulation in hippocampal GSK-3β mRNA expression in the insulin-treated group, when compared to controls. The present study revealed that diabetes during pregnancy strongly influences the regulation of GSK-3β in the right/left developing hippocampi. These dysregulations may be part of the cascade of events through which diabetes during pregnancy affects the newborn's hippocampal structure and function.

  4. Factors Affecting Location Decisions of Food Processing Plants

    NASA Astrophysics Data System (ADS)

    Turhan, Sule; Canan Ozbag, Basak; Cetin, Bahattin

    The main aim of this study is to examine the determinants of location choices for food processing plants using the results of 59 personal surveys. The 61.3% of the food processing plants that were interviewed are small scale plants, 9.1% are large scale plants and 29.6% are medium scale plants. Sixteen of the firms process vegetables, 12 process poultry, 12 process dairy and 9 process seafood products. Business climate factors are divided into six categories (market, infrastructure, raw material, labor, personal and environmental) and 17 specific location factors are considered. The survey responses are analyzed by types of raw materials processed and by plant size. 43.7, 55.3 and 42.2% of the respondents cited categories of Market, Raw Material and Infrastructure respectively as important, while 44.3, 50.7 and 74.4% of the respondents cited, labor, personal and environmental regulation categories of as not important. Thus survey findings indicate that plant location choices are mainly driven by market, raw material and infra structural factors. Environmental factors such as environmental regulations and permissions are relatively insignificant.

  5. 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.

  6. Exogenously treated mammalian sex hormones affect inorganic constituents of plants.

    PubMed

    Erdal, Serkan; Dumlupinar, Rahmi

    2011-10-01

    The present study was undertaken to reveal the changes in inorganic constituents of plants exposed to mammalian sex hormones (MSH). Chickpea leaves were sprayed with 10(-4), 10(-6), 10(-9), 10(-12), and 10(-15) M concentrations of progesterone, β-estradiol, and androsterone at 7th day after sowing. The plants were harvested at the end of 18 days after treatment of MSH solutions and the inorganic components determined using a wavelength-dispersive X-ray fluorescence spectroscopy technique. At all of the concentrations tested, MSH significantly increased the contents of K, S, Na, Ca, Mg, Zn, Fe, P, Cu, and Ni. Interestingly, only Mn and Cl contents decreased. The maximum changes in the inorganic composition were recorded at 10(-6) M for plants treated with progesterone and 10(-9) M for plants treated with β-estradiol and androsterone.

  7. Self-recognition affects plant communication and defense.

    PubMed

    Karban, Richard; Shiojiri, Kaori

    2009-06-01

    Animals have the ability to distinguish self from non-self, which has allowed them to evolve immune systems and, in some instances, to act preferentially towards individuals that are genetically identical or related. Self-recognition is less well known for plants, although recent work indicates that physically connected roots recognize self and reduce competitive interactions. Sagebrush uses volatile cues emitted by clipped branches of self or different neighbours to increase resistance to herbivory. Here, we show that plants that received volatile cues from genetically identical cuttings accumulated less natural damage than plants that received cues from non-self cuttings. Volatile communication is required to coordinate systemic processes such as induced resistance and plants respond more effectively to self than non-self cues. This self/non-self discrimination did not require physical contact and is a necessary first step towards possible kin recognition and kin selection.

  8. A novel family of small proteins that affect plant development

    SciTech Connect

    John Charles Walker

    2011-04-29

    The DVL genes represent a new group of plant proteins that influence plant growth and development. Overexpression of DVL1, and other members of the DVL family, causes striking phenotypic changes. The DVL proteins share sequence homology in their C-terminal half. Point mutations in the C-terminal domain show it is necessary and deletion studies demonstrate the C-terminal domain is sufficient to confer the overexpression phenotypes. The phenotypes observed, and the conservation of the protein sequence in the plant kingdom, does suggest the DVL proteins have a role in modulating plant growth and development. Our working hypothesis is the DVL proteins function as regulators of cellular signaling pathways that control growth and development.

  9. Plant toxins that affect nicotinic acetylcholine receptors: A review

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plants produce wide variety of chemical compounds termed secondary metabolites that are not involved in basic metabolism, photosynthesis or reproduction. These compounds are used as flavors, fragrances, insecticides, dyes, hallucinogens, nutritional supplements, poisons, and pharmaceutical agents. ...

  10. Rhizosphere microbiome assemblage is affected by plant development

    PubMed Central

    Chaparro, Jacqueline M; Badri, Dayakar V; Vivanco, Jorge M

    2014-01-01

    There is a concerted understanding of the ability of root exudates to influence the structure of rhizosphere microbial communities. However, our knowledge of the connection between plant development, root exudation and microbiome assemblage is limited. Here, we analyzed the structure of the rhizospheric bacterial community associated with Arabidopsis at four time points corresponding to distinct stages of plant development: seedling, vegetative, bolting and flowering. Overall, there were no significant differences in bacterial community structure, but we observed that the microbial community at the seedling stage was distinct from the other developmental time points. At a closer level, phylum such as Acidobacteria, Actinobacteria, Bacteroidetes, Cyanobacteria and specific genera within those phyla followed distinct patterns associated with plant development and root exudation. These results suggested that the plant can select a subset of microbes at different stages of development, presumably for specific functions. Accordingly, metatranscriptomics analysis of the rhizosphere microbiome revealed that 81 unique transcripts were significantly (P<0.05) expressed at different stages of plant development. For instance, genes involved in streptomycin synthesis were significantly induced at bolting and flowering stages, presumably for disease suppression. We surmise that plants secrete blends of compounds and specific phytochemicals in the root exudates that are differentially produced at distinct stages of development to help orchestrate rhizosphere microbiome assemblage. PMID:24196324

  11. Plant surface wax affects parasitoid's response to host footprints

    NASA Astrophysics Data System (ADS)

    Rostás, Michael; Ruf, Daniel; Zabka, Vanessa; Hildebrandt, Ulrich

    2008-10-01

    The plant surface is the substrate upon which herbivorous insects and natural enemies meet and thus represents the stage for interactions between the three trophic levels. Plant surfaces are covered by an epicuticular wax layer which is highly variable depending on species, cultivar or plant part. Differences in wax chemistry may modulate ecological interactions. We explored whether caterpillars of Spodoptera frugiperda, when walking over a plant surface, leave a chemical trail (kairomones) that can be detected by the parasitoid Cotesia marginiventris. Chemistry and micromorphology of cuticular waxes of two barley eceriferum wax mutants ( cer-za.126, cer-yp.949) and wild-type cv. Bonus (wt) were assessed. The plants were then used to investigate potential surface effects on the detectability of caterpillar kairomones. Here we provide evidence that C. marginiventris responds to chemical footprints of its host. Parasitoids were able to detect the kairomone on wild-type plants and on both cer mutants but the response to cer-yp.949 (reduced wax, high aldehyde fraction) was less pronounced. Experiments with caterpillar-treated wt and mutant leaves offered simultaneously, confirmed this observation: no difference in wasp response was found when wt was tested against cer-za.126 (reduced wax, wt-like chemical composition) but wt was significantly more attractive than cer-yp.949. This demonstrates for the first time that the wax layer can modulate the detectability of host kairomones.

  12. Fuel breaks affect nonnative species abundance in Californian plant communities

    USGS Publications Warehouse

    Merriam, K.E.; Keeley, J.E.; Beyers, J.L.

    2006-01-01

    We evaluated the abundance of nonnative plants on fuel breaks and in adjacent untreated areas to determine if fuel treatments promote the invasion of nonnative plant species. Understanding the relationship between fuel treatments and nonnative plants is becoming increasingly important as federal and state agencies are currently implementing large fuel treatment programs throughout the United States to reduce the threat of wildland fire. Our study included 24 fuel breaks located across the State of California. We found that nonnative plant abundance was over 200% higher on fuel breaks than in adjacent wildland areas. Relative nonnative cover was greater on fuel breaks constructed by bulldozers (28%) than on fuel breaks constructed by other methods (7%). Canopy cover, litter cover, and duff depth also were significantly lower on fuel breaks constructed by bulldozers, and these fuel breaks had significantly more exposed bare ground than other types of fuel breaks. There was a significant decline in relative nonnative cover with increasing distance from the fuel break, particularly in areas that had experienced more numerous fires during the past 50 years, and in areas that had been grazed. These data suggest that fuel breaks could provide establishment sites for nonnative plants, and that nonnatives may invade surrounding areas, especially after disturbances such as fire or grazing. Fuel break construction and maintenance methods that leave some overstory canopy and minimize exposure of bare ground may be less likely to promote nonnative plants. ?? 2006 by the Ecological Society of America.

  13. Regression analysis of technical parameters affecting nuclear power plant performances

    SciTech Connect

    Ghazy, R.; Ricotti, M. E.; Trueco, P.

    2012-07-01

    Since the 80's many studies have been conducted in order to explicate good and bad performances of commercial nuclear power plants (NPPs), but yet no defined correlation has been found out to be totally representative of plant operational experience. In early works, data availability and the number of operating power stations were both limited; therefore, results showed that specific technical characteristics of NPPs were supposed to be the main causal factors for successful plant operation. Although these aspects keep on assuming a significant role, later studies and observations showed that other factors concerning management and organization of the plant could instead be predominant comparing utilities operational and economic results. Utility quality, in a word, can be used to summarize all the managerial and operational aspects that seem to be effective in determining plant performance. In this paper operational data of a consistent sample of commercial nuclear power stations, out of the total 433 operating NPPs, are analyzed, mainly focusing on the last decade operational experience. The sample consists of PWR and BWR technology, operated by utilities located in different countries, including U.S. (Japan)) (France)) (Germany)) and Finland. Multivariate regression is performed using Unit Capability Factor (UCF) as the dependent variable; this factor reflects indeed the effectiveness of plant programs and practices in maximizing the available electrical generation and consequently provides an overall indication of how well plants are operated and maintained. Aspects that may not be real causal factors but which can have a consistent impact on the UCF, as technology design, supplier, size and age, are included in the analysis as independent variables. (authors)

  14. Composition of hydroponic medium affects thorium uptake by tobacco plants.

    PubMed

    Soudek, Petr; Kufner, Daniel; Petrová, Sárka; Mihaljevič, Martin; Vaněk, Tomáš

    2013-08-01

    The ability of thorium uptake as well as responses to heavy metal stress were tested in tobacco cultivar La Burley 21. Thorium was accumulated preferentially in the root system. The presence of citric, tartaric and oxalic acids in hydroponic medium increased thorium accumulation in all plant organs. On the other hand, the addition of diamines and polyamines, the important antioxidants in plants, resulted in decrease of thorium accumulation, especially in the root system. Negative correlation was found between putrescine concentration and thorium accumulation. Nevertheless, the most important factor influencing the accumulation of thorium was the absence of phosphate ions in a hydroponic medium that caused more than 10-fold increase of thorium uptake in all plant parts. Accumulation and distribution of thorium was followed in six cultivars and 14 selected transformants. Cultivar La Barley 21 represented an average between the tested genotypes, having a very good distribution ratio between roots, stems and leaves.

  15. Cadmium content of plants as affected by soil cadmium concentration

    SciTech Connect

    Lehoczky, E.; Szabados, I.; Marth, P.

    1996-12-31

    Pot experiments were conducted in greenhouse conditions to study the effects of increasing cadmium (Cd) levels on biomass production and Cd contents in corn, (Zea mays L.), garlic (Allium sativum L.), and spinach (Spinacia oleracea L.). Plants were grown in two soil types: Eutric cambisol soil and A gleyic luvisol soil. Spinach proved to be the most sensitive to Cd treatments as its biomass considerably decreased with the increasing Cd levels. Cadmium contents of the three crops increased with increasing levels of Cd applications. Statistical differences were observed in the Cd contents of crops depending on soil type. With the same Cd rates, Cd tissue concentration of test plants grown in the strongly acidic Gleyic luvisol soil were many times higher than that of plants grown in a neutral Eutric cambisol soil. 14 refs., 4 tabs.

  16. How neighbor canopy architecture affects target plant performance

    SciTech Connect

    Tremmel, D.C.; Bazzaz, F.A. )

    1993-10-01

    Plant competition occurs through the negative effects that individual plants have on resource availability to neighboring individuals. Therefore competition experiments need to examine how different species change resource availability to their neighbors, and how different species respond to these changes-allocationally, architecturally, and physiologically-through time. In a greenhouse study we used a model system of annuals to examine how canopies of species having differing morphologies differed in their architectures and light-interception abilities, and how different species performed when grown in these canopies. Abutilon theophrasti, Datura stramonium, and Polygonum pensylvanicum were grown as [open quotes]targets[close quotes]. Plants were grown in pots, with one target plant and four neighbor plants. Detailed measurements of neighbor canopy structure and target plant canopy architecture were made at five harvests. Species with different morphologies showed large differences in canopy structure, particularly when grass and forb species were compared. Setaria, a grass, had a more open canopy than the other species (all forbs), and was a consistently weak competitor. Overall, however, the relative effects of different neighbors on target biomass varied with target species. Target biomass was poorly correlated with neighbor biomass and leaf area, but was highly correlated with a measure of target light-interception ability that took into account both target leaf deployment and neighbor light interception. Despite clear differences among neighbor species in canopy structure and effect on light penetration, the results suggest no broad generalizations about the effects of different species as neighbors. Knowledge of morphological, physiological, and life history characteristics of both the target and neighbor species may be necessary to explain the results of their competition. 53 refs., 4 figs., 4 tabs.

  17. Plant extracts affect in vitro rumen microbial fermentation.

    PubMed

    Busquet, M; Calsamiglia, S; Ferret, A; Kamel, C

    2006-02-01

    Different doses of 12 plant extracts and 6 secondary plant metabolites were incubated for 24 h in diluted ruminal fluid with a 50:50 forage:concentrate diet. Treatments were: control (no additive), plant extracts (anise oil, cade oil, capsicum oil, cinnamon oil, clove bud oil, dill oil, fenugreek, garlic oil, ginger oil, oregano oil, tea tree oil, and yucca), and secondary plant metabolites (anethol, benzyl salicylate, carvacrol, carvone, cinnamaldehyde, and eugenol). Each treatment was supplied at 3, 30, 300, and 3,000 mg/L of culture fluid. At 3,000 mg/L, most treatments decreased total volatile fatty acid concentration, but cade oil, capsicum oil, dill oil, fenugreek, ginger oil, and yucca had no effect. Different doses of anethol, anise oil, carvone, and tea tree oil decreased the proportion of acetate and propionate, which suggests that these compounds may not be nutritionally beneficial to dairy cattle. Garlic oil (300 and 3,000 mg/L) and benzyl salicylate (300 and 3,000 mg/L) reduced acetate and increased propionate and butyrate proportions, suggesting that methane production was inhibited. At 3,000 mg/L, capsicum oil, carvacrol, carvone, cinnamaldehyde, cinnamon oil, clove bud oil, eugenol, fenugreek, and oregano oil resulted in a 30 to 50% reduction in ammonia N concentration. Careful selection and combination of these extracts may allow the manipulation of rumen microbial fermentation.

  18. Maximizing plant density affects broccoli yield and quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increased demand for fresh market bunch broccoli (Brassica oleracea L. var. italica) has led to increased production along the United States east coast. Maximizing broccoli yields is a primary concern for quickly expanding southeastern commercial markets. This broccoli plant density study was carr...

  19. Host plant affects morphometric variation of Diaphorina citri (Hemiptera: Liviidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Asian citrus psyllid (ACP), due to its potential to vector the pathogen causing citrus greening disease or huanglongbing, is one of the most serious citrus pests worldwide. While optimal plant cultivars for ACP oviposition and development have been determined, little is known of the influence of...

  20. Herbivory of an invasive slug is affected by earthworms and the composition of plant communities

    PubMed Central

    2013-01-01

    Background Biodiversity loss and species invasions are among the most important human-induced global changes. Moreover, these two processes are interlinked as ecosystem invasibility is considered to increase with decreasing biodiversity. In temperate grasslands, earthworms serve as important ecosystem engineers making up the majority of soil faunal biomass. Herbivore behaviour has been shown to be affected by earthworms, however it is unclear whether these effects differ with the composition of plant communities. To test this we conducted a mesocosm experiment where we added earthworms (Annelida: Lumbricidae) to planted grassland communities with different plant species composition (3 vs. 12 plant spp.). Plant communities had equal plant densities and ratios of the functional groups grasses, non-leguminous forbs and legumes. Later, Arion vulgaris slugs (formerly known as A. lusitanicus; Gastropoda: Arionidae) were added and allowed to freely choose among the available plant species. This slug species is listed among the 100 worst alien species in Europe. We hypothesized that (i) the food choice of slugs would be altered by earthworms’ specific effects on the growth and nutrient content of plant species, (ii) slug herbivory will be less affected by earthworms in plant communities containing more plant species than in those with fewer plant species because of a more readily utilization of plant resources making the impacts of earthworms less pronounced. Results Slug herbivory was significantly affected by both earthworms and plant species composition. Slugs damaged 60% less leaves when earthworms were present, regardless of the species composition of the plant communities. Percent leaf area consumed by slugs was 40% lower in communities containing 12 plant species; in communities containing only three species earthworms increased slug leaf area consumption. Grasses were generally avoided by slugs. Leaf length and number of tillers was increased in mesocosms

  1. Microbial composition in a deep saline aquifer in the North German Basin -microbiologically induced corrosion and mineral precipitation affecting geothermal plant operation and the effects of plant downtime

    NASA Astrophysics Data System (ADS)

    Lerm, Stephanie; Westphal, Anke; Miethling-Graff, Rona; Alawi, Mashal; Seibt, Andrea; Wolfgramm, Markus; Würdemann, Hilke

    2013-04-01

    The microbial composition in fluids of a deep saline geothermal used aquifer in the North German Basin was characterized over a period of five years. The genetic fingerprinting techniques PCR-SSCP and PCR-DGGE revealed distinct microbial communities in fluids produced from the cold and warm side of the aquifer. Direct cell counting and quantification of 16S rRNA genes and dissimilatory sulfite reductase (dsrA) genes by real-time PCR proved different population sizes in fluids, showing higher abundance of Bacteria and sulfate reducing bacteria (SRB) in cold fluids compared to warm fluids. Predominating SRB in the cold well probably accounted for corrosion damage to the submersible well pump, and iron sulfide precipitates in the near wellbore area and topside facility filters. This corresponded to a lower sulfate content in fluids produced from the cold well as well as higher content of hydrogen gas that was probably released from corrosion, and maybe favoured growth of hydrogenotrophic SRB. Plant downtime significantly influenced the microbial biocenosis in fluids. Samples taken after plant restart gave indications about the processes occurring downhole during those phases. High DNA concentrations in fluids at the beginning of the restart process with a decreasing trend over time indicated a higher abundance of microbes during plant downtime compared to regular plant operation. It is likely that a gradual drop in temperature as well as stagnant conditions favoured the growth of microbes and maturation of biofilms at the casing and in pores of the reservoir rock in the near wellbore area. Furthermore, it became obvious that the microorganisms were more associated to particles then free-living. This study reflects the high influence of microbial populations for geothermal plant operation, because microbiologically induced precipitative and corrosive processes adversely affect plant reliability. Those processes may favourably occur during plant downtime due to enhanced

  2. Plant natural variability may affect safety assessment data.

    PubMed

    Batista, Rita; Oliveira, Margarida

    2010-12-01

    Before market introduction, genetic engineered (GE) food products, like any other novel food product, are subjected to extensive assessment of their potential effects on human health. In recent years, a number of profiling technologies have been explored aiming to increase the probability of detecting any unpredictable unintended effect and, consequently improving the efficiency of GE food safety assessment. These techniques still present limitations associated with the interpretation of the observed differences with respect to their biological relevance and toxicological significance. In order to address this issue, in this study, we have performed 2D-gel electrophoresis of five different ears of five different MON810 maize plants and of other five of the non-transgenic near-isogenic line. We have also performed 2D-gel electrophoresis of the pool of the five protein extractions of MON810 and control lines. We have notice that, in this example, the exclusive use of data from 2D-electrophoresed pooled samples, to compare these two lines, would be insufficient for an adequate safety evaluation. We conclude that, when using "omics" technologies, it is extremely important to eliminate all potential differences due to factors not related to the ones under study, and to understand the role of natural plant-to-plant variability in the encountered differences.

  3. Volatile exchange between undamaged plants - a new mechanism affecting insect orientation in intercropping.

    PubMed

    Ninkovic, Velemir; Dahlin, Iris; Vucetic, Andja; Petrovic-Obradovic, Olivera; Glinwood, Robert; Webster, Ben

    2013-01-01

    Changes in plant volatile emission can be induced by exposure to volatiles from neighbouring insect-attacked plants. However, plants are also exposed to volatiles from unattacked neighbours, and the consequences of this have not been explored. We investigated whether volatile exchange between undamaged plants affects volatile emission and plant-insect interaction. Consistently greater quantities of two terpenoids were found in the headspace of potato previously exposed to volatiles from undamaged onion plants identified by mass spectrometry. Using live plants and synthetic blends mimicking exposed and unexposed potato, we tested the olfactory response of winged aphids, Myzus persicae. The altered potato volatile profile deterred aphids in laboratory experiments. Further, we show that growing potato together with onion in the field reduces the abundance of winged, host-seeking aphids. Our study broadens the ecological significance of the phenomenon; volatiles carry not only information on whether or not neighbouring plants are under attack, but also information on the emitter plants themselves. In this way responding plants could obtain information on whether the neighbouring plant is a competitive threat and can accordingly adjust their growth towards it. We interpret this as a response in the process of adaptation towards neighbouring plants. Furthermore, these physiological changes in the responding plants have significant ecological impact, as behaviour of aphids was affected. Since herbivore host plants are potentially under constant exposure to these volatiles, our study has major implications for the understanding of how mechanisms within plant communities affect insects. This knowledge could be used to improve plant protection and increase scientific understanding of communication between plants and its impact on other organisms.

  4. Volatile Exchange between Undamaged Plants - a New Mechanism Affecting Insect Orientation in Intercropping

    PubMed Central

    Ninkovic, Velemir; Dahlin, Iris; Vucetic, Andja; Petrovic-Obradovic, Olivera; Glinwood, Robert; Webster, Ben

    2013-01-01

    Changes in plant volatile emission can be induced by exposure to volatiles from neighbouring insect-attacked plants. However, plants are also exposed to volatiles from unattacked neighbours, and the consequences of this have not been explored. We investigated whether volatile exchange between undamaged plants affects volatile emission and plant-insect interaction. Consistently greater quantities of two terpenoids were found in the headspace of potato previously exposed to volatiles from undamaged onion plants identified by mass spectrometry. Using live plants and synthetic blends mimicking exposed and unexposed potato, we tested the olfactory response of winged aphids, Myzus persicae. The altered potato volatile profile deterred aphids in laboratory experiments. Further, we show that growing potato together with onion in the field reduces the abundance of winged, host-seeking aphids. Our study broadens the ecological significance of the phenomenon; volatiles carry not only information on whether or not neighbouring plants are under attack, but also information on the emitter plants themselves. In this way responding plants could obtain information on whether the neighbouring plant is a competitive threat and can accordingly adjust their growth towards it. We interpret this as a response in the process of adaptation towards neighbouring plants. Furthermore, these physiological changes in the responding plants have significant ecological impact, as behaviour of aphids was affected. Since herbivore host plants are potentially under constant exposure to these volatiles, our study has major implications for the understanding of how mechanisms within plant communities affect insects. This knowledge could be used to improve plant protection and increase scientific understanding of communication between plants and its impact on other organisms. PMID:23922710

  5. Surrogate species selection for assessing potential adverse environmental impacts of genetically engineered plants on non-target organisms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Most regulatory authorities require that developers of genetically engineered insect-resistant (GEIR) crops evaluate the potential for these crops to have adverse impacts on valued non-target organisms (NTOs), i.e., organisms not intended to be controlled by the trait. In many cases, impacts to NTOs...

  6. Absence of heat treatment of serum for culture medium supplementation does not adversely affect the outcome of in-vitro fertilization.

    PubMed

    Imoedemhe, D A; Sigue, A B; Pacpaco, E L; Olazo, A B; Luciano, E C

    1994-09-01

    This study was carried out to determine if not heat-treating serum prior to use for medium supplementation adversely affected in-vitro fertilization (IVF) of human oocytes. Morphologically mature human oocytes derived from 135 patients undergoing IVF treatment were studied. A total of 504 oocytes were incubated, inseminated and the resulting pronuclear oocytes cultured further in Earle's balanced salt solution (EBSS) supplemented with 10% non-heat-treated serum. Comparisons of fertilization rate and embryonic development were made between these and 687 control oocytes derived from the same patients but incubated, inseminated and resulting pronuclear oocytes cultured further in EBSS supplemented with 10% heat-treated serum. The fertilization rate of 74.4% (375/504) of oocytes handled in serum-supplemented medium that had not been heat-treated was significantly better than the rate of 67.7% (465/687) for controls (P < 0.0125). The proportion of pronucleate oocytes that cleaved was also significantly better in the non-heat-treated serum group: 270/300 (90%) versus 307/375 (81.8%) (P < 0.0025). There was no significant difference in the proportion of embryos with four or more cells at the time of embryo transfer. The results show that the absence of heat treatment of serum used to supplement culture medium has no adverse effect on the fertilization rate and short-term embryo development in vitro; hence we suggest that serum heat treatment is an unnecessary procedure and could be abandoned. PMID:7836531

  7. Habitats as complex odour environments: how does plant diversity affect herbivore and parasitoid orientation?

    PubMed

    Wäschke, Nicole; Hardge, Kristin; Hancock, Christine; Hilker, Monika; Obermaier, Elisabeth; Meiners, Torsten

    2014-01-01

    Plant diversity is known to affect success of host location by pest insects, but its effect on olfactory orientation of non-pest insect species has hardly been addressed. First, we tested in laboratory experiments the hypothesis that non-host plants, which increase odour complexity in habitats, affect the host location ability of herbivores and parasitoids. Furthermore, we recorded field data of plant diversity in addition to herbivore and parasitoid abundance at 77 grassland sites in three different regions in Germany in order to elucidate whether our laboratory results reflect the field situation. As a model system we used the herb Plantago lanceolata, the herbivorous weevil Mecinus pascuorum, and its larval parasitoid Mesopolobus incultus. The laboratory bioassays revealed that both the herbivorous weevil and its larval parasitoid can locate their host plant and host via olfactory cues even in the presence of non-host odour. In a newly established two-circle olfactometer, the weeviĺs capability to detect host plant odour was not affected by odours from non-host plants. However, addition of non-host plant odours to host plant odour enhanced the weeviĺs foraging activity. The parasitoid was attracted by a combination of host plant and host volatiles in both the absence and presence of non-host plant volatiles in a Y-tube olfactometer. In dual choice tests the parasitoid preferred the blend of host plant and host volatiles over its combination with non-host plant volatiles. In the field, no indication was found that high plant diversity disturbs host (plant) location by the weevil and its parasitoid. In contrast, plant diversity was positively correlated with weevil abundance, whereas parasitoid abundance was independent of plant diversity. Therefore, we conclude that weevils and parasitoids showed the sensory capacity to successfully cope with complex vegetation odours when searching for hosts. PMID:24416354

  8. Habitats as Complex Odour Environments: How Does Plant Diversity Affect Herbivore and Parasitoid Orientation?

    PubMed Central

    Wäschke, Nicole; Hardge, Kristin; Hancock, Christine; Hilker, Monika; Obermaier, Elisabeth; Meiners, Torsten

    2014-01-01

    Plant diversity is known to affect success of host location by pest insects, but its effect on olfactory orientation of non-pest insect species has hardly been addressed. First, we tested in laboratory experiments the hypothesis that non-host plants, which increase odour complexity in habitats, affect the host location ability of herbivores and parasitoids. Furthermore, we recorded field data of plant diversity in addition to herbivore and parasitoid abundance at 77 grassland sites in three different regions in Germany in order to elucidate whether our laboratory results reflect the field situation. As a model system we used the herb Plantago lanceolata, the herbivorous weevil Mecinus pascuorum, and its larval parasitoid Mesopolobus incultus. The laboratory bioassays revealed that both the herbivorous weevil and its larval parasitoid can locate their host plant and host via olfactory cues even in the presence of non-host odour. In a newly established two-circle olfactometer, the weeviĺs capability to detect host plant odour was not affected by odours from non-host plants. However, addition of non-host plant odours to host plant odour enhanced the weeviĺs foraging activity. The parasitoid was attracted by a combination of host plant and host volatiles in both the absence and presence of non-host plant volatiles in a Y-tube olfactometer. In dual choice tests the parasitoid preferred the blend of host plant and host volatiles over its combination with non-host plant volatiles. In the field, no indication was found that high plant diversity disturbs host (plant) location by the weevil and its parasitoid. In contrast, plant diversity was positively correlated with weevil abundance, whereas parasitoid abundance was independent of plant diversity. Therefore, we conclude that weevils and parasitoids showed the sensory capacity to successfully cope with complex vegetation odours when searching for hosts. PMID:24416354

  9. Spatial heterogeneity of plant-soil feedback affects root interactions and interspecific competition.

    PubMed

    Hendriks, Marloes; Ravenek, Janneke M; Smit-Tiekstra, Annemiek E; van der Paauw, Jan Willem; de Caluwe, Hannie; van der Putten, Wim H; de Kroon, Hans; Mommer, Liesje

    2015-08-01

    Plant-soil feedback is receiving increasing interest as a factor influencing plant competition and species coexistence in grasslands. However, we do not know how spatial distribution of plant-soil feedback affects plant below-ground interactions. We investigated the way in which spatial heterogeneity of soil biota affects competitive interactions in grassland plant species. We performed a pairwise competition experiment combined with heterogeneous distribution of soil biota using four grassland plant species and their soil biota. Patches were applied as quadrants of 'own' and 'foreign' soils from all plant species in all pairwise combinations. To evaluate interspecific root responses, species-specific root biomass was quantified using real-time PCR. All plant species suffered negative soil feedback, but strength was species-specific, reflected by a decrease in root growth in own compared with foreign soil. Reduction in root growth in own patches by the superior plant competitor provided opportunities for inferior competitors to increase root biomass in these patches. These patterns did not cascade into above-ground effects during our experiment. We show that root distributions can be determined by spatial heterogeneity of soil biota, affecting plant below-ground competitive interactions. Thus, spatial heterogeneity of soil biota may contribute to plant species coexistence in species-rich grasslands. PMID:25871977

  10. Spatial heterogeneity of plant-soil feedback affects root interactions and interspecific competition.

    PubMed

    Hendriks, Marloes; Ravenek, Janneke M; Smit-Tiekstra, Annemiek E; van der Paauw, Jan Willem; de Caluwe, Hannie; van der Putten, Wim H; de Kroon, Hans; Mommer, Liesje

    2015-08-01

    Plant-soil feedback is receiving increasing interest as a factor influencing plant competition and species coexistence in grasslands. However, we do not know how spatial distribution of plant-soil feedback affects plant below-ground interactions. We investigated the way in which spatial heterogeneity of soil biota affects competitive interactions in grassland plant species. We performed a pairwise competition experiment combined with heterogeneous distribution of soil biota using four grassland plant species and their soil biota. Patches were applied as quadrants of 'own' and 'foreign' soils from all plant species in all pairwise combinations. To evaluate interspecific root responses, species-specific root biomass was quantified using real-time PCR. All plant species suffered negative soil feedback, but strength was species-specific, reflected by a decrease in root growth in own compared with foreign soil. Reduction in root growth in own patches by the superior plant competitor provided opportunities for inferior competitors to increase root biomass in these patches. These patterns did not cascade into above-ground effects during our experiment. We show that root distributions can be determined by spatial heterogeneity of soil biota, affecting plant below-ground competitive interactions. Thus, spatial heterogeneity of soil biota may contribute to plant species coexistence in species-rich grasslands.

  11. Parasitoid-specific induction of plant responses to parasitized herbivores affects colonization by subsequent herbivores.

    PubMed

    Poelman, Erik H; Zheng, Si-Jun; Zhang, Zhao; Heemskerk, Nanda M; Cortesero, Anne-Marie; Dicke, Marcel

    2011-12-01

    Plants are exposed to a suite of herbivorous attackers that often arrive sequentially. Herbivory affects interactions between the host plants and subsequently attacking herbivores. Moreover, plants may respond to herbivory by emitting volatile organic compounds (VOCs) that attract carnivorous natural enemies of the herbivores. However, information borne by VOCs is ubiquitous and may attract carnivores, such as parasitoids, that differ in their effectiveness at releasing the plant from its herbivorous attackers. Furthermore, the development of parasitoids within their herbivorous hosts, attacking a given host plant, may influence the elicitation of defensive reactions in the host plant. This may, in turn, affect the behavior of subsequent herbivores attacking the host plant. Here, we show that the species identity of a parasitoid had a more significant effect on defense responses of Brassica oleracea plants than the species identity of the herbivorous hosts of the parasitoids. Consequently, B. oleracea plants that were damaged by caterpillars (Pieris spp.) parasitized by different parasitoid species varied in the degree to which diamondback moths (Plutella xylostella) selected the plants for oviposition. Attracting parasitoids in general benefitted the plants by reducing diamondback moth colonization. However, the species of parasitoid that parasitized the herbivore significantly affected the magnitude of this benefit by its species-specific effect on herbivore-plant interactions mediated by caterpillar regurgitant. Our findings show that information-mediated indirect defense may lead to unpredictable consequences for plants when considering trait-mediated effects of parasitized caterpillars on the host plant and their consequences because of community-wide responses to induced plants. PMID:22084113

  12. Parasitoid-specific induction of plant responses to parasitized herbivores affects colonization by subsequent herbivores.

    PubMed

    Poelman, Erik H; Zheng, Si-Jun; Zhang, Zhao; Heemskerk, Nanda M; Cortesero, Anne-Marie; Dicke, Marcel

    2011-12-01

    Plants are exposed to a suite of herbivorous attackers that often arrive sequentially. Herbivory affects interactions between the host plants and subsequently attacking herbivores. Moreover, plants may respond to herbivory by emitting volatile organic compounds (VOCs) that attract carnivorous natural enemies of the herbivores. However, information borne by VOCs is ubiquitous and may attract carnivores, such as parasitoids, that differ in their effectiveness at releasing the plant from its herbivorous attackers. Furthermore, the development of parasitoids within their herbivorous hosts, attacking a given host plant, may influence the elicitation of defensive reactions in the host plant. This may, in turn, affect the behavior of subsequent herbivores attacking the host plant. Here, we show that the species identity of a parasitoid had a more significant effect on defense responses of Brassica oleracea plants than the species identity of the herbivorous hosts of the parasitoids. Consequently, B. oleracea plants that were damaged by caterpillars (Pieris spp.) parasitized by different parasitoid species varied in the degree to which diamondback moths (Plutella xylostella) selected the plants for oviposition. Attracting parasitoids in general benefitted the plants by reducing diamondback moth colonization. However, the species of parasitoid that parasitized the herbivore significantly affected the magnitude of this benefit by its species-specific effect on herbivore-plant interactions mediated by caterpillar regurgitant. Our findings show that information-mediated indirect defense may lead to unpredictable consequences for plants when considering trait-mediated effects of parasitized caterpillars on the host plant and their consequences because of community-wide responses to induced plants.

  13. Fusion and metabolism of plant cells as affected by microgravity.

    PubMed

    Hampp, R; Hoffmann, E; Schönherr, K; Johann, P; De Filippis, L

    1997-01-01

    Plant cell protoplasts derived from leaf tissue of two different tobacco species (Nicotiana tabacum., N. rustica L.) were exposed to short-term (sounding rocket experiments) and long-term (spacelab) microgravity environments in order to study both (electro) cell fusion and cell metabolism during early and later stages of tissue regeneration. The period of exposure to microgravity varied from 10 min (sounding rocket) to 10 d (space shuttle). The process of electro fusion of protoplasts was improved under conditions of microgravity: the time needed to establish close membrane contact between protoplasts (alignment time) was reduced (5 as compared to 15 s under 1 g) and numbers of fusion products between protoplasts of different specific density were increased by a factor of about 10. In addition, viability of fusion products, as shown by the ability to form callus, increased from about 60% to more than 90%. Regenerated fusion products obtained from both sounding-rocket and spacelab experiments showed a wide range of intermediate properties between the two parental plants. This was verified by isozyme analysis and random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR). In order to address potential metabolic responses, more general markers such as the overall energy state (ATP/ADP ratio), the redox charge of the diphosphopyridine nucleotide system (NADH/NAD ratio), and the pool size of fructose-2,6-bisphosphate (Fru 2,6 bisp), a regulator of the balance between glycolysis and gluconeogenesis, were determined. Responses of these parameters were different with regard to short-term and long-term exposure. Shortly after transition to reduced gravitation (sounding rocket) ratios of ATP/ADP exhibited strong fluctuation while the pool size of NAD decreased (indicating an increased NADH/NAD ratio) and that of Fru 2,6 bisp increased. As similar changes can be observed under stress conditions, this response is probably indicative of a metabolic stress

  14. Allocation, stress tolerance and carbon transport in plants: how does phloem physiology affect plant ecology?

    PubMed

    Savage, Jessica A; Clearwater, Michael J; Haines, Dustin F; Klein, Tamir; Mencuccini, Maurizio; Sevanto, Sanna; Turgeon, Robert; Zhang, Cankui

    2016-04-01

    Despite the crucial role of carbon transport in whole plant physiology and its impact on plant-environment interactions and ecosystem function, relatively little research has tried to examine how phloem physiology impacts plant ecology. In this review, we highlight several areas of active research where inquiry into phloem physiology has increased our understanding of whole plant function and ecological processes. We consider how xylem-phloem interactions impact plant drought tolerance and reproduction, how phloem transport influences carbon allocation in trees and carbon cycling in ecosystems and how phloem function mediates plant relations with insects, pests, microbes and symbiotes. We argue that in spite of challenges that exist in studying phloem physiology, it is critical that we consider the role of this dynamic vascular system when examining the relationship between plants and their biotic and abiotic environment. PMID:26147312

  15. Allocation, stress tolerance and carbon transport in plants: how does phloem physiology affect plant ecology?

    PubMed

    Savage, Jessica A; Clearwater, Michael J; Haines, Dustin F; Klein, Tamir; Mencuccini, Maurizio; Sevanto, Sanna; Turgeon, Robert; Zhang, Cankui

    2016-04-01

    Despite the crucial role of carbon transport in whole plant physiology and its impact on plant-environment interactions and ecosystem function, relatively little research has tried to examine how phloem physiology impacts plant ecology. In this review, we highlight several areas of active research where inquiry into phloem physiology has increased our understanding of whole plant function and ecological processes. We consider how xylem-phloem interactions impact plant drought tolerance and reproduction, how phloem transport influences carbon allocation in trees and carbon cycling in ecosystems and how phloem function mediates plant relations with insects, pests, microbes and symbiotes. We argue that in spite of challenges that exist in studying phloem physiology, it is critical that we consider the role of this dynamic vascular system when examining the relationship between plants and their biotic and abiotic environment.

  16. Reassessment of selected factors affecting siting of Nuclear Power Plants

    SciTech Connect

    Davis, R.E.; Hanson, A.L.; Mubayi, V.; Nourbakhsh, H.P.

    1997-02-01

    Brookhaven National Laboratory has performed a series of probabilistic consequence assessment calculations for nuclear reactor siting. This study takes into account recent insights into severe accident source terms and examines consequences in a risk based format consistent with the quantitative health objectives (QHOs) of the NRC`s Safety Goal Policy. Simplified severe accident source terms developed in this study are based on the risk insights of NUREG-1150. The results of the study indicate that both the quantity of radioactivity released in a severe accident as well as the likelihood of a release are lower than those predicted in earlier studies. The accident risks using the simplified source terms are examined at a series of generic plant sites, that vary in population distribution, meteorological conditions, and exclusion area boundary distances. Sensitivity calculations are performed to evaluate the effects of emergency protective action assumptions on the risk of prompt fatality and latent cancers fatality, and population relocation. The study finds that based on the new source terms the prompt and latent fatality risks at all generic sites meet the QHOs of the NRC`s Safety Goal Policy by margins ranging from one to more than three orders of magnitude. 4 refs., 17 figs., 24 tabs.

  17. A Fungal Endosymbiont Affects Host Plant Recruitment Through Seed- and Litter-mediated Mechanisms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    1. Many grass species are associated with maternally transmitted fungal endophytes. Increasing evidence shows that endophytes enhance host plant success under varied conditions, yet studies have rarely considered alternative mechanisms whereby these mutualistic symbionts may affect regeneration from...

  18. Seed germination of medicinal plant, fennel (Foeniculum vulgare Mill), as affected by different priming techniques.

    PubMed

    Tahaei, Amirreza; Soleymani, Ali; Shams, Majid

    2016-09-01

    Reduced seed germination is among the most important factors adversely affecting crop stand and subsequent plant growth. Fennel (Foeniculum vulgare Mill) is an important medicinal plant with poor seed germination rate, occasionally. It is accordingly pertinent to find methods which can enhance fennel seed germination and remove the barriers of dormancy breaking. The present experiments studied the effects of two different priming (cold moist stratification and osmopriming) and 14 dormancy breaking techniques (hormonal, osmopriming, biopriming, chemical priming, and hydropriming) on the seed germination and seedling growth of two different fennel genotypes under growth chamber conditions. In the first and second experiment, the priming techniques including the time lengths of cold moist stratification (0, 15, 30, and 45 days) and the concentrations of polyethylene glycol 6000 (PEG6000, osmopriming at -0.99, -1.35, and -2.33 MPa) were used as the main plots. However, in both experiments, the dormancy breaking techniques and fennel genotypes were factorially combined and used as the subplots. Different seed- and seedling-related parameters including germination (%), plumule, radicle and seedling length, average germination time, rate and homogeneity of germination, and seed vigor index were determined. Both priming techniques were efficient on the enhancement of seed germination and seedling growth. Among the dormancy breaking techniques, Aminol Forte (biopriming), kadostim (biopriming), benzyl adenine + kinetin (biopriming), distilled water (hydropriming), gibberellin + kinetin (hormonal priming), and benzyl adenine + kinetin + gibberellin (biopriming) were the most effective ones. The related concentrations were equal to 100 mg/l, 10(-5) M, and 0.4 %. The fennel genotypes reacted significantly different under priming conditions. It is possible to enhance seed germination and seedling growth of fennel using priming and dormancy breaking

  19. Seed germination of medicinal plant, fennel (Foeniculum vulgare Mill), as affected by different priming techniques.

    PubMed

    Tahaei, Amirreza; Soleymani, Ali; Shams, Majid

    2016-09-01

    Reduced seed germination is among the most important factors adversely affecting crop stand and subsequent plant growth. Fennel (Foeniculum vulgare Mill) is an important medicinal plant with poor seed germination rate, occasionally. It is accordingly pertinent to find methods which can enhance fennel seed germination and remove the barriers of dormancy breaking. The present experiments studied the effects of two different priming (cold moist stratification and osmopriming) and 14 dormancy breaking techniques (hormonal, osmopriming, biopriming, chemical priming, and hydropriming) on the seed germination and seedling growth of two different fennel genotypes under growth chamber conditions. In the first and second experiment, the priming techniques including the time lengths of cold moist stratification (0, 15, 30, and 45 days) and the concentrations of polyethylene glycol 6000 (PEG6000, osmopriming at -0.99, -1.35, and -2.33 MPa) were used as the main plots. However, in both experiments, the dormancy breaking techniques and fennel genotypes were factorially combined and used as the subplots. Different seed- and seedling-related parameters including germination (%), plumule, radicle and seedling length, average germination time, rate and homogeneity of germination, and seed vigor index were determined. Both priming techniques were efficient on the enhancement of seed germination and seedling growth. Among the dormancy breaking techniques, Aminol Forte (biopriming), kadostim (biopriming), benzyl adenine + kinetin (biopriming), distilled water (hydropriming), gibberellin + kinetin (hormonal priming), and benzyl adenine + kinetin + gibberellin (biopriming) were the most effective ones. The related concentrations were equal to 100 mg/l, 10(-5) M, and 0.4 %. The fennel genotypes reacted significantly different under priming conditions. It is possible to enhance seed germination and seedling growth of fennel using priming and dormancy breaking

  20. Molecular and Functional Characterization of a Wheat B2 Protein Imparting Adverse Temperature Tolerance and Influencing Plant Growth.

    PubMed

    Singh, Akanksha; Khurana, Paramjit

    2016-01-01

    Genomic attempts were undertaken to elucidate the plant developmental responses to heat stress, and to characterize the roles of B2 protein in mediating those responses. A wheat expressed sequence tag for B2 protein was identified which was cloned and characterized to assess its functional relevance causing plant growth and development during stress adaptation. Here, we show that wheat B2 protein is highly expressed in root and shoot tissues as well as in developing seed tissues under high temperature stress conditions. Morphological studies of transgenic Arabidopsis overexpressing gene encoding wheat B2 protein and Δb2 mutant plants were studied at major developmental stages. The stunted growth phenotype of mutant plants, together with hypocotyl and root elongation analysis of transgenic plants showed that B2 protein exhibits a crucial role in plant growth and development. Additional physiological analyses highlights the role of B2 protein in increased tolerance to heat and cold stresses by maintaining high chlorophyll content, strong activity of photosystem II and less membrane damage of overexpression transgenics as compared with the wild-type. Furthermore, the constitutive overexpression of TaB2 in Arabidopsis resulted in ABA hypersensitivity. Taken together, these studies suggest a novel perspectives of B2 protein in plant development and in mediating the thermal stress tolerance.

  1. Molecular and Functional Characterization of a Wheat B2 Protein Imparting Adverse Temperature Tolerance and Influencing Plant Growth

    PubMed Central

    Singh, Akanksha; Khurana, Paramjit

    2016-01-01

    Genomic attempts were undertaken to elucidate the plant developmental responses to heat stress, and to characterize the roles of B2 protein in mediating those responses. A wheat expressed sequence tag for B2 protein was identified which was cloned and characterized to assess its functional relevance causing plant growth and development during stress adaptation. Here, we show that wheat B2 protein is highly expressed in root and shoot tissues as well as in developing seed tissues under high temperature stress conditions. Morphological studies of transgenic Arabidopsis overexpressing gene encoding wheat B2 protein and Δb2 mutant plants were studied at major developmental stages. The stunted growth phenotype of mutant plants, together with hypocotyl and root elongation analysis of transgenic plants showed that B2 protein exhibits a crucial role in plant growth and development. Additional physiological analyses highlights the role of B2 protein in increased tolerance to heat and cold stresses by maintaining high chlorophyll content, strong activity of photosystem II and less membrane damage of overexpression transgenics as compared with the wild-type. Furthermore, the constitutive overexpression of TaB2 in Arabidopsis resulted in ABA hypersensitivity. Taken together, these studies suggest a novel perspectives of B2 protein in plant development and in mediating the thermal stress tolerance. PMID:27242843

  2. Molecular and Functional Characterization of a Wheat B2 Protein Imparting Adverse Temperature Tolerance and Influencing Plant Growth.

    PubMed

    Singh, Akanksha; Khurana, Paramjit

    2016-01-01

    Genomic attempts were undertaken to elucidate the plant developmental responses to heat stress, and to characterize the roles of B2 protein in mediating those responses. A wheat expressed sequence tag for B2 protein was identified which was cloned and characterized to assess its functional relevance causing plant growth and development during stress adaptation. Here, we show that wheat B2 protein is highly expressed in root and shoot tissues as well as in developing seed tissues under high temperature stress conditions. Morphological studies of transgenic Arabidopsis overexpressing gene encoding wheat B2 protein and Δb2 mutant plants were studied at major developmental stages. The stunted growth phenotype of mutant plants, together with hypocotyl and root elongation analysis of transgenic plants showed that B2 protein exhibits a crucial role in plant growth and development. Additional physiological analyses highlights the role of B2 protein in increased tolerance to heat and cold stresses by maintaining high chlorophyll content, strong activity of photosystem II and less membrane damage of overexpression transgenics as compared with the wild-type. Furthermore, the constitutive overexpression of TaB2 in Arabidopsis resulted in ABA hypersensitivity. Taken together, these studies suggest a novel perspectives of B2 protein in plant development and in mediating the thermal stress tolerance. PMID:27242843

  3. Surrogate species selection for assessing potential adverse environmental impacts of genetically engineered insect-resistant plants on non-target organisms

    PubMed Central

    Carstens, Keri; Cayabyab, Bonifacio; De Schrijver, Adinda; Gadaleta, Patricia G; Hellmich, Richard L; Romeis, Jörg; Storer, Nicholas; Valicente, Fernando H; Wach, Michael

    2014-01-01

    Most regulatory authorities require that developers of genetically engineered insect-resistant (GEIR) crops evaluate the potential for these crops to have adverse impacts on valued non-target organisms (NTOs), i.e., organisms not intended to be controlled by the trait. In many cases, impacts to NTOs are assessed using surrogate species, and it is critical that the data derived from surrogates accurately predict any adverse impacts likely to be observed from the use of the crop in the agricultural context. The key is to select surrogate species that best represent the valued NTOs in the location where the crop is going to be introduced, but this selection process poses numerous challenges for the developers of GE crops who will perform the tests, as well as for the ecologists and regulators who will interpret the test results. These issues were the subject of a conference “Surrogate Species Selection for Assessing Potential Adverse Environmental Impacts of Genetically Engineered Plants on Non-Target Organisms” convened by the Center for Environmental Risk Assessment, ILSI Research Foundation. This report summarizes the proceedings of the conference, including the presentations, discussions and the points of consensus agreed to by the participants. PMID:24637519

  4. Surrogate species selection for assessing potential adverse environmental impacts of genetically engineered insect-resistant plants on non-target organisms.

    PubMed

    Carstens, Keri; Cayabyab, Bonifacio; De Schrijver, Adinda; Gadaleta, Patricia G; Hellmich, Richard L; Romeis, Jörg; Storer, Nicholas; Valicente, Fernando H; Wach, Michael

    2014-01-01

    Most regulatory authorities require that developers of genetically engineered insect-resistant (GEIR) crops evaluate the potential for these crops to have adverse impacts on valued non-target organisms (NTOs), i.e., organisms not intended to be controlled by the trait. In many cases, impacts to NTOs are assessed using surrogate species, and it is critical that the data derived from surrogates accurately predict any adverse impacts likely to be observed from the use of the crop in the agricultural context. The key is to select surrogate species that best represent the valued NTOs in the location where the crop is going to be introduced, but this selection process poses numerous challenges for the developers of GE crops who will perform the tests, as well as for the ecologists and regulators who will interpret the test results. These issues were the subject of a conference "Surrogate Species Selection for Assessing Potential Adverse Environmental Impacts of Genetically Engineered Plants on Non-Target Organisms" convened by the Center for Environmental Risk Assessment, ILSI Research Foundation. This report summarizes the proceedings of the conference, including the presentations, discussions and the points of consensus agreed to by the participants.

  5. Widespread seed limitation affects plant density but not population trajectory in the invasive plant Centaurea solstitialis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In some plant populations, the availability of seeds strongly regulates recruitment. However, a scarcity of germination microsites, granivory or density dependent mortality can reduce the number of plants that germinate or survive to flowering. The relative strength of these controls is unknown for ...

  6. Drought stress affects plant metabolites and herbivore preference but not host location by its parasitoids.

    PubMed

    Weldegergis, Berhane T; Zhu, Feng; Poelman, Erik H; Dicke, Marcel

    2015-03-01

    One of the main abiotic stresses that strongly affects plant survival and the primary cause of crop loss around the world is drought. Drought stress leads to sequential morphological, physiological, biochemical and molecular changes that can have severe effects on plant growth, development and productivity. As a consequence of these changes, the interaction between plants and insects can be altered. Using cultivated Brassica oleracea plants, the parasitoid Microplitis mediator and its herbivorous host Mamestra brassicae, we studied the effect of drought stress on (1) the emission of plant volatile organic compounds (VOCs), (2) plant hormone titres, (3) preference and performance of the herbivore, and (4) preference of the parasitoid. Higher levels of jasmonic acid (JA) and abscisic acid (ABA) were recorded in response to herbivory, but no significant differences were observed for salicylic acid (SA) and indole-3-acetic acid (IAA). Drought significantly impacted SA level and showed a significant interactive effect with herbivory for IAA levels. A total of 55 VOCs were recorded and the difference among the treatments was influenced largely by herbivory, where the emission rate of fatty acid-derived volatiles, nitriles and (E)-4,8-dimethylnona-1,3,7-triene [(E)-DMNT] was enhanced. Mamestra brassicae moths preferred to lay eggs on drought-stressed over control plants; their offspring performed similarly on plants of both treatments. VOCs due to drought did not affect the choice of M. mediator parasitoids. Overall, our study reveals an influence of drought on plant chemistry and insect-plant interactions. PMID:25370387

  7. Volatile interaction between undamaged plants affects tritrophic interactions through changed plant volatile emission.

    PubMed

    Vucetic, Andja; Dahlin, Iris; Petrovic-Obradovic, Olivera; Glinwood, Robert; Webster, Ben; Ninkovic, Velemir

    2014-01-01

    Volatile interactions between unattacked plants can lead to changes in their volatile emissions. Exposure of potato plants to onion plant volatiles results in increased emission of 2 terpenoids, (E)-nerolidol and TMTT. We investigated whether this is detectable by the ladybird Coccinella septempunctata. The odor of onion-exposed potato was significantly more attractive to ladybirds than that of unexposed potato. Further, a synthetic blend mimicking the volatile profile of onion-exposed potato was more attractive than a blend mimicking that of unexposed potato. When presented individually, TMTT was attractive to ladybirds whereas (E)-nerolidol was repellent. Volatile exchange between unattacked plants and consequent increased attractiveness for ladybirds may be a mechanism that contributes to the increased abundance of natural enemies in complex plant habitats. PMID:25763628

  8. Volatile interaction between undamaged plants affects tritrophic interactions through changed plant volatile emission.

    PubMed

    Vucetic, Andja; Dahlin, Iris; Petrovic-Obradovic, Olivera; Glinwood, Robert; Webster, Ben; Ninkovic, Velemir

    2014-01-01

    Volatile interactions between unattacked plants can lead to changes in their volatile emissions. Exposure of potato plants to onion plant volatiles results in increased emission of 2 terpenoids, (E)-nerolidol and TMTT. We investigated whether this is detectable by the ladybird Coccinella septempunctata. The odor of onion-exposed potato was significantly more attractive to ladybirds than that of unexposed potato. Further, a synthetic blend mimicking the volatile profile of onion-exposed potato was more attractive than a blend mimicking that of unexposed potato. When presented individually, TMTT was attractive to ladybirds whereas (E)-nerolidol was repellent. Volatile exchange between unattacked plants and consequent increased attractiveness for ladybirds may be a mechanism that contributes to the increased abundance of natural enemies in complex plant habitats.

  9. Volatile interaction between undamaged plants affects tritrophic interactions through changed plant volatile emission.

    PubMed

    Vucetic, Andja; Dahlin, Iris; Petrovic-Obradovic, Olivera; Glinwood, Robert; Webster, Ben; Ninkovic, Velemir

    2014-06-13

    Volatile interactions between unattacked plants can lead to changes in their volatile emissions. Exposure of potato plants to onion plant volatiles results in increased emission of 2 terpenoids, (E)-nerolidol and TMTT. We investigated whether this is detectable by the ladybird Coccinella septempunctata. The odor of onion-exposed potato was significantly more attractive to ladybirds than that of unexposed potato. Further, a synthetic blend mimicking the volatile profile of onion-exposed potato was more attractive than a blend mimicking that of unexposed potato. When presented individually, TMTT was attractive to ladybirds whereas (E)-nerolidol was repellent. Volatile exchange between unattacked plants and consequent increased attractiveness for ladybirds may be a mechanism that contributes to the increased abundance of natural enemies in complex plant habitats.

  10. Climate warming affects biological invasions by shifting interactions of plants and herbivores.

    PubMed

    Lu, Xinmin; Siemann, Evan; Shao, Xu; Wei, Hui; Ding, Jianqing

    2013-08-01

    Plants and herbivorous insects can each be dramatically affected by temperature. Climate warming may impact plant invasion success directly but also indirectly through changes in their natural enemies. To date, however, there are no tests of how climate warming shifts the interactions among invasive plants and their natural enemies to affect invasion success. Field surveys covering the full latitudinal range of invasive Alternanthera philoxeroides in China showed that a beetle introduced for biocontrol was rare or absent at higher latitudes. In contrast, plant cover and mass increased with latitude. In a 2-year field experiment near the northern limit of beetle distribution, we found the beetle sustained populations across years under elevated temperature, dramatically decreasing A. philoxeroides growth, but it failed to overwinter in ambient temperature. Together, these results suggest that warming will allow the natural enemy to expand its range, potentially benefiting biocontrol in regions that are currently too cold for the natural enemy. However, the invader may also expand its range further north in response to warming. In such cases where plants tolerate cold better than their natural enemies, the geographical gap between plant and herbivorous insect ranges may not disappear but will shift to higher latitudes, leading to a new zone of enemy release. Therefore, warming will not only affect plant invasions directly but also drive either enemy release or increase that will result in contrasting effects on invasive plants. The findings are also critical for future management of invasive species under climate change.

  11. Crop size, plant aggregation, and microhabitat type affect fruit removal by birds from individual melastome plants in the Upper Amazon.

    PubMed

    Blendinger, Pedro G; Loiselle, Bette A; Blake, John G

    2008-11-01

    We studied the efficiency (proportion of the crop removed) and quantitative effectiveness (number of fruits removed) of dispersal of Miconia fosteri and M. serrulata (Melastomataceae) seeds by birds in lowland tropical wet forest of Ecuador. Specifically, we examined variation in fruit removal in order to reveal the spatial scale at which crop size influences seed dispersal outcome of individual plants, and to evaluate how the effect of crop size on plant dispersal success may be affected by conspecific fruit abundance and by the spatial distribution of frugivore abundance. We established two 9-ha plots in undisturbed terra-firme understory, where six manakin species (Pipridae) disperse most seeds of these two plant species. Mean levels of fruit removal were low for both species, with high variability among plants. In general, plants with larger crop sizes experienced greater efficiency and effectiveness of fruit removal than plants with smaller crops. Fruit removal, however, was also influenced by microhabitat, such as local topography and local neighborhood. Fruit-rich and disperser-rich patches overlapped spatially for M. fosteri but not M. serrulata, nonetheless fruit removal of M. serrulata was still much greater in fruit-rich patches. Fruit removal from individual plants did not decrease in patches with many fruiting conspecifics and, in fact, removal effectiveness was enhanced for M. fosteri with small crop sizes when such plants were in patches with more conspecifics. These results suggest that benefits of attracting dispersers to a patch balanced or outweighed the costs of competition for dispersers. Spatial pattern of fruit removal, a measure of plant fitness, depended on a complex interaction among plant traits, spatial patterns of plant distribution, and disperser behavior. PMID:18810498

  12. Adverse influence on reproduction and potential fitness cost in survivors of orthene-treated tarnished plant bug, Lygus lineolaris

    Technology Transfer Automated Retrieval System (TEKTRAN)

    By using dose response to Orthene at 80 mg/L (LC50 of the laboratory susceptible colony), a relative resistant population (71% survival rate) of the tarnished plant bug, Lygus lineolaris, was located near Tillar, Arkansas. This population was used in this study to evaluate potential fitness cost in ...

  13. Following Darwin's trail: interactions affecting the evolution of plant mating systems.

    PubMed

    Kariyat, Rupesh R; Sinclair, Jordan P; Golenberg, Edward M

    2013-06-01

    • Since the time of Charles Darwin, the variation in floral characteristics and its effects on plant mating system evolution have fascinated scientists. Recent advances in the field of genetics, molecular biology, and ecology have been very effective in addressing questions regarding mechanisms and interactions underlying the evolution of plant mating systems using various model and nonmodel species. The depth of plant mating system research reflects the complexity and diversity seen in nature, ranging from self-compatible hermaphroditic flowers to separate sexed individuals. Further, the mechanisms involved in the evolution of plant mating systems are much more diverse and differ even among closely related species. Here, as a special section, we present a suite of original papers that range from theoretical modeling to multiyear field research that address different factors affecting plant mating systems, and their effects on shaping interactions between plants, insects, and their environment.

  14. Plant diversity and functional groups affect Si and Ca pools in aboveground biomass of grassland systems.

    PubMed

    Schaller, Jörg; Roscher, Christiane; Hillebrand, Helmut; Weigelt, Alexandra; Oelmann, Yvonne; Wilcke, Wolfgang; Ebeling, Anne; Weisser, Wolfgang W

    2016-09-01

    Plant diversity is an important driver of nitrogen and phosphorus stocks in aboveground plant biomass of grassland ecosystems, but plant diversity effects on other elements also important for plant growth are less understood. We tested whether plant species richness, functional group richness or the presence/absence of particular plant functional groups influences the Si and Ca concentrations (mmol g(-1)) and stocks (mmol m(-2)) in aboveground plant biomass in a large grassland biodiversity experiment (Jena Experiment). In the experiment including 60 temperate grassland species, plant diversity was manipulated as sown species richness (1, 2, 4, 8, 16) and richness and identity of plant functional groups (1-4; grasses, small herbs, tall herbs, legumes). We found positive species richness effects on Si as well as Ca stocks that were attributable to increased biomass production. The presence of particular functional groups was the most important factor explaining variation in aboveground Si and Ca stocks (mmol m(-2)). Grass presence increased the Si stocks by 140 % and legume presence increased the Ca stock by 230 %. Both the presence of specific plant functional groups and species diversity altered Si and Ca stocks, whereas Si and Ca concentration were affected mostly by the presence of specific plant functional groups. However, we found a negative effect of species diversity on Si and Ca accumulation, by calculating the deviation between mixtures and mixture biomass proportions, but in monoculture concentrations. These changes may in turn affect ecosystem processes such as plant litter decomposition and nutrient cycling in grasslands.

  15. Plant diversity and functional groups affect Si and Ca pools in aboveground biomass of grassland systems.

    PubMed

    Schaller, Jörg; Roscher, Christiane; Hillebrand, Helmut; Weigelt, Alexandra; Oelmann, Yvonne; Wilcke, Wolfgang; Ebeling, Anne; Weisser, Wolfgang W

    2016-09-01

    Plant diversity is an important driver of nitrogen and phosphorus stocks in aboveground plant biomass of grassland ecosystems, but plant diversity effects on other elements also important for plant growth are less understood. We tested whether plant species richness, functional group richness or the presence/absence of particular plant functional groups influences the Si and Ca concentrations (mmol g(-1)) and stocks (mmol m(-2)) in aboveground plant biomass in a large grassland biodiversity experiment (Jena Experiment). In the experiment including 60 temperate grassland species, plant diversity was manipulated as sown species richness (1, 2, 4, 8, 16) and richness and identity of plant functional groups (1-4; grasses, small herbs, tall herbs, legumes). We found positive species richness effects on Si as well as Ca stocks that were attributable to increased biomass production. The presence of particular functional groups was the most important factor explaining variation in aboveground Si and Ca stocks (mmol m(-2)). Grass presence increased the Si stocks by 140 % and legume presence increased the Ca stock by 230 %. Both the presence of specific plant functional groups and species diversity altered Si and Ca stocks, whereas Si and Ca concentration were affected mostly by the presence of specific plant functional groups. However, we found a negative effect of species diversity on Si and Ca accumulation, by calculating the deviation between mixtures and mixture biomass proportions, but in monoculture concentrations. These changes may in turn affect ecosystem processes such as plant litter decomposition and nutrient cycling in grasslands. PMID:27164912

  16. The Salicylic Acid-Mediated Release of Plant Volatiles Affects the Host Choice of Bemisia tabaci.

    PubMed

    Shi, Xiaobin; Chen, Gong; Tian, Lixia; Peng, Zhengke; Xie, Wen; Wu, Qingjun; Wang, Shaoli; Zhou, Xuguo; Zhang, Youjun

    2016-01-01

    The whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) causes serious crop losses worldwide by transmitting viruses. We have previously shown that salicylic acid (SA)-related plant defenses directly affect whiteflies. In this study, we applied exogenous SA to tomato plants in order to investigate the interaction between SA-induced plant volatiles and nonviruliferous B. tabaci B and Q or B- and Q-carrying tomato yellow leaf curl virus (TYLCV). The results showed that exogenous SA caused plants to repel nonviruliferous whiteflies, but the effect was reduced when the SA concentration was low and when the whiteflies were viruliferous. Exogenous SA increased the number and quantity of plant volatiles-especially the quantity of methyl salicylate and δ-limonene. In Y-tube olfactometer assays, methyl salicylate and δ-limonene repelled the whiteflies, but the repellency was reduced for viruliferous Q. We suggest that the release of plant volatiles as mediated by SA affects the interaction between whiteflies, plants, and viruses. Further studies are needed to determine why viruliferous Q is less sensitive than nonviruliferous Q to repellent plant volatiles. PMID:27376280

  17. The Salicylic Acid-Mediated Release of Plant Volatiles Affects the Host Choice of Bemisia tabaci

    PubMed Central

    Shi, Xiaobin; Chen, Gong; Tian, Lixia; Peng, Zhengke; Xie, Wen; Wu, Qingjun; Wang, Shaoli; Zhou, Xuguo; Zhang, Youjun

    2016-01-01

    The whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) causes serious crop losses worldwide by transmitting viruses. We have previously shown that salicylic acid (SA)-related plant defenses directly affect whiteflies. In this study, we applied exogenous SA to tomato plants in order to investigate the interaction between SA-induced plant volatiles and nonviruliferous B. tabaci B and Q or B- and Q-carrying tomato yellow leaf curl virus (TYLCV). The results showed that exogenous SA caused plants to repel nonviruliferous whiteflies, but the effect was reduced when the SA concentration was low and when the whiteflies were viruliferous. Exogenous SA increased the number and quantity of plant volatiles—especially the quantity of methyl salicylate and δ-limonene. In Y-tube olfactometer assays, methyl salicylate and δ-limonene repelled the whiteflies, but the repellency was reduced for viruliferous Q. We suggest that the release of plant volatiles as mediated by SA affects the interaction between whiteflies, plants, and viruses. Further studies are needed to determine why viruliferous Q is less sensitive than nonviruliferous Q to repellent plant volatiles. PMID:27376280

  18. Deviation from niche optima affects the nature of plant-plant interactions along a soil acidity gradient.

    PubMed

    He, Lei; Cheng, Lulu; Hu, Liangliang; Tang, Jianjun; Chen, Xin

    2016-01-01

    There is increasing recognition of the importance of niche optima in the shift of plant-plant interactions along environmental stress gradients. Here, we investigate whether deviation from niche optima would affect the outcome of plant-plant interactions along a soil acidity gradient (pH = 3.1, 4.1, 5.5 and 6.1) in a pot experiment. We used the acid-tolerant species Lespedeza formosa Koehne as the neighbouring plant and the acid-tolerant species Indigofera pseudotinctoria Mats. or acid-sensitive species Medicago sativa L. as the target plants. Biomass was used to determine the optimal pH and to calculate the relative interaction index (RII). We found that the relationships between RII and the deviation of soil pH from the target's optimal pH were linear for both target species. Both targets were increasingly promoted by the neighbour as pH values deviated from their optima; neighbours benefitted target plants by promoting soil symbiotic arbuscular mycorrhizal fungi, increasing soil organic matter or reducing soil exchangeable aluminium. Our results suggest that the shape of the curve describing the relationship between soil pH and facilitation/competition depends on the soil pH optima of the particular species. PMID:26740568

  19. Planting geometry and plant population affect dryland maize grain yield and harvest index

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water for dryland grain production in the Texas panhandle is limited. Agronomic practices such as reduction in plant population or change in sowing time may help increase maize (Zea mays L.) yield potential. Tiller formation under dryland conditions leads to more vegetative growth and reduced yield....

  20. Crop-noncrop spillover: arable fields affect trophic interactions on wild plants in surrounding habitats.

    PubMed

    Gladbach, David J; Holzschuh, Andrea; Scherber, Christoph; Thies, Carsten; Dormann, Carsten F; Tscharntke, Teja

    2011-06-01

    Ecosystem processes in agricultural landscapes are often triggered by resource availability in crop and noncrop habitats. We investigated how oilseed rape (OSR; Brassica napus, Brassicaceae) affects noncrop plants in managed systems and semi-natural habitat, using trophic interactions among wild mustard (Sinapis arvensis, Brassicaceae), rape pollen beetles (Meligethes aeneus, Nitidulidae) and their parasitoids (Tersilochus heterocerus, Ichneumonidae). We exposed wild mustard as phytometer plants in two cropland habitat types (wheat field, field margin) and three noncrop habitat types (fallow, grassland, wood margin) across eight landscapes along a gradient from simple to complex (quantified as % arable land). Both landscape and local factors affected the abundance of rape pollen beetles and parasitoids. Rape pollen beetle infestation and parasitism rates on these plants were lower in noncrop habitats and higher in wheat fields and field margins, whereas beetles and parasitoids responded differently to landscape scale parameters. We found the hypothesized spillover from OSR crop onto wild plants in surrounding habitats only for parasitoids, but not for pollen beetles. Parasitism rates were not related to landscape simplification, but benefited from increasing proportions of OSR. In contrast, rape pollen beetles benefited from simple landscape structures, presumably due to multi-annual population build-ups resulting from long-term OSR planting (as part of the crop rotation). In conclusion, we showed that spillover from cropland affects parasitism rates on related wild plants outside cropland, which has not been shown so far, but can be expected to be a widespread effect shaping noncrop food webs.

  1. A highly stable minimally processed plant-derived recombinant acetylcholinesterase for nerve agent detection in adverse conditions

    PubMed Central

    Rosenberg, Yvonne J.; Walker, Jeremy; Jiang, Xiaoming; Donahue, Scott; Robosky, Jason; Sack, Markus; Lees, Jonathan; Urban, Lori

    2015-01-01

    Although recent innovations in transient plant systems have enabled gram quantities of proteins in 1–2 weeks, very few have been translated into applications due to technical challenges and high downstream processing costs. Here we report high-level production, using a Nicotiana benthamiana/p19 system, of an engineered recombinant human acetylcholinesterase (rAChE) that is highly stable in a minimally processed leaf extract. Lyophylized clarified extracts withstand prolonged storage at 70 °C and, upon reconstitution, can be used in several devices to detect organophosphate (OP) nerve agents and pesticides on surfaces ranging from 0 °C to 50 °C. The recent use of sarin in Syria highlights the urgent need for nerve agent detection and countermeasures necessary for preparedness and emergency responses. Bypassing cumbersome and expensive downstream processes has enabled us to fully exploit the speed, low cost and scalability of transient production systems resulting in the first successful implementation of plant-produced rAChE into a commercial biotechnology product. PMID:26268538

  2. Ozone affects growth and development of Pieris brassicae on the wild host plant Brassica nigra.

    PubMed

    Khaling, Eliezer; Papazian, Stefano; Poelman, Erik H; Holopainen, Jarmo K; Albrectsen, Benedicte R; Blande, James D

    2015-04-01

    When plants are exposed to ozone they exhibit changes in both primary and secondary metabolism, which may affect their interactions with herbivorous insects. Here we investigated the performance and preferences of the specialist herbivore Pieris brassicae on the wild plant Brassica nigra under elevated ozone conditions. The direct and indirect effects of ozone on the plant-herbivore system were studied. In both cases ozone exposure had a negative effect on P. brassicae development. However, in dual-choice tests larvae preferentially consumed plant material previously fumigated with the highest concentration tested, showing a lack of correlation between larval preference and performance on ozone exposed plants. Metabolomic analysis of leaf material subjected to combinations of ozone and herbivore-feeding, and focussing on known defence metabolites, indicated that P. brassicae behaviour and performance were associated with ozone-induced alterations to glucosinolate and phenolic pools.

  3. Ozone affects growth and development of Pieris brassicae on the wild host plant Brassica nigra.

    PubMed

    Khaling, Eliezer; Papazian, Stefano; Poelman, Erik H; Holopainen, Jarmo K; Albrectsen, Benedicte R; Blande, James D

    2015-04-01

    When plants are exposed to ozone they exhibit changes in both primary and secondary metabolism, which may affect their interactions with herbivorous insects. Here we investigated the performance and preferences of the specialist herbivore Pieris brassicae on the wild plant Brassica nigra under elevated ozone conditions. The direct and indirect effects of ozone on the plant-herbivore system were studied. In both cases ozone exposure had a negative effect on P. brassicae development. However, in dual-choice tests larvae preferentially consumed plant material previously fumigated with the highest concentration tested, showing a lack of correlation between larval preference and performance on ozone exposed plants. Metabolomic analysis of leaf material subjected to combinations of ozone and herbivore-feeding, and focussing on known defence metabolites, indicated that P. brassicae behaviour and performance were associated with ozone-induced alterations to glucosinolate and phenolic pools. PMID:25645061

  4. 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. PMID:26617587

  5. Ontogenetic shifts in plant interactions vary with environmental severity and affect population structure.

    PubMed

    le Roux, Peter C; Shaw, Justine D; Chown, Steven L

    2013-10-01

    Environmental conditions and plant size may both alter the outcome of inter-specific plant-plant interactions, with seedlings generally facilitated more strongly than larger individuals in stressful habitats. However, the combined impact of plant size and environmental severity on interactions is poorly understood. Here, we tested explicitly for the first time the hypothesis that ontogenetic shifts in interactions are delayed under increasingly severe conditions by examining the interaction between a grass, Agrostis magellanica, and a cushion plant, Azorella selago, along two severity gradients. The impact of A. selago on A. magellanica abundance, but not reproductive effort, was related to A. magellanica size, with a trend for delayed shifts towards more negative interactions under greater environmental severity. Intermediate-sized individuals were most strongly facilitated, leading to differences in the size-class distribution of A. magellanica on the soil and on A. selago. The A. magellanica size-class distribution was more strongly affected by A. selago than by environmental severity, demonstrating that the plant-plant interaction impacts A. magellanica population structure more strongly than habitat conditions. As ontogenetic shifts in plant-plant interactions cannot be assumed to be constant across severity gradients and may impact species population structure, studies examining the outcome of interactions need to consider the potential for size- or age-related variation in competition and facilitation.

  6. Plant volatiles induced by herbivore egg deposition affect insects of different trophic levels.

    PubMed

    Fatouros, Nina E; Lucas-Barbosa, Dani; Weldegergis, Berhane T; Pashalidou, Foteini G; van Loon, Joop J A; Dicke, Marcel; Harvey, Jeffrey A; Gols, Rieta; Huigens, Martinus E

    2012-01-01

    Plants release volatiles induced by herbivore feeding that may affect the diversity and composition of plant-associated arthropod communities. However, the specificity and role of plant volatiles induced during the early phase of attack, i.e. egg deposition by herbivorous insects, and their consequences on insects of different trophic levels remain poorly explored. In olfactometer and wind tunnel set-ups, we investigated behavioural responses of a specialist cabbage butterfly (Pieris brassicae) and two of its parasitic wasps (Trichogramma brassicae and Cotesia glomerata) to volatiles of a wild crucifer (Brassica nigra) induced by oviposition of the specialist butterfly and an additional generalist moth (Mamestra brassicae). Gravid butterflies were repelled by volatiles from plants induced by cabbage white butterfly eggs, probably as a means of avoiding competition, whereas both parasitic wasp species were attracted. In contrast, volatiles from plants induced by eggs of the generalist moth did neither repel nor attract any of the tested community members. Analysis of the plant's volatile metabolomic profile by gas chromatography-mass spectrometry and the structure of the plant-egg interface by scanning electron microscopy confirmed that the plant responds differently to egg deposition by the two lepidopteran species. Our findings imply that prior to actual feeding damage, egg deposition can induce specific plant responses that significantly influence various members of higher trophic levels. PMID:22912893

  7. 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

  8. Reproductive allocation in plants as affected by elevated carbon dioxide and other environmental changes: a synthesis using meta-analysis and graphical vector analysis.

    PubMed

    Wang, Xianzhong; Taub, Daniel R; Jablonski, Leanne M

    2015-04-01

    Reproduction is an important life history trait that strongly affects dynamics of plant populations. Although it has been well documented that elevated carbon dioxide (CO2) in the atmosphere greatly enhances biomass production in plants, the overall effect of elevated CO2 on reproductive allocation (RA), i.e., the proportion of biomass allocated to reproductive structures, is little understood. We combined meta-analysis with graphical vector analysis to examine the overall effect of elevated CO2 on RA and how other environmental factors, such as low nutrients, drought and elevated atmospheric ozone (O3), interacted with elevated CO2 in affecting RA in herbaceous plants. Averaged across all species of different functional groups and environmental conditions, elevated CO2 had little effect on RA (-0.9%). RA in plants of different reproductive strategies and functional groups, however, differed in response to elevated CO2. For example, RA in iteroparous wild species decreased by 8%, while RA in iteroparous crops increased significantly (+14%) at elevated CO2. RA was unaffected by CO2 in plants grown with no stress or in low-nutrient soils. RA decreased at elevated CO2 and elevated O3, but increased in response to elevated CO2 in drought-stressed plants, suggesting that elevated CO2 could ameliorate the adverse effect of drought on crop production to some extent. Our results demonstrate that elevated CO2 and other global environmental changes have the potential to greatly alter plant community composition through differential effects on RA of different plant species and thus affect the dynamics of natural and agricultural ecosystems in the future. PMID:25537120

  9. Reproductive allocation in plants as affected by elevated carbon dioxide and other environmental changes: a synthesis using meta-analysis and graphical vector analysis.

    PubMed

    Wang, Xianzhong; Taub, Daniel R; Jablonski, Leanne M

    2015-04-01

    Reproduction is an important life history trait that strongly affects dynamics of plant populations. Although it has been well documented that elevated carbon dioxide (CO2) in the atmosphere greatly enhances biomass production in plants, the overall effect of elevated CO2 on reproductive allocation (RA), i.e., the proportion of biomass allocated to reproductive structures, is little understood. We combined meta-analysis with graphical vector analysis to examine the overall effect of elevated CO2 on RA and how other environmental factors, such as low nutrients, drought and elevated atmospheric ozone (O3), interacted with elevated CO2 in affecting RA in herbaceous plants. Averaged across all species of different functional groups and environmental conditions, elevated CO2 had little effect on RA (-0.9%). RA in plants of different reproductive strategies and functional groups, however, differed in response to elevated CO2. For example, RA in iteroparous wild species decreased by 8%, while RA in iteroparous crops increased significantly (+14%) at elevated CO2. RA was unaffected by CO2 in plants grown with no stress or in low-nutrient soils. RA decreased at elevated CO2 and elevated O3, but increased in response to elevated CO2 in drought-stressed plants, suggesting that elevated CO2 could ameliorate the adverse effect of drought on crop production to some extent. Our results demonstrate that elevated CO2 and other global environmental changes have the potential to greatly alter plant community composition through differential effects on RA of different plant species and thus affect the dynamics of natural and agricultural ecosystems in the future.

  10. Methyl esterification of pectin plays a role during plant-pathogen interactions and affects plant resistance to diseases.

    PubMed

    Lionetti, Vincenzo; Cervone, Felice; Bellincampi, Daniela

    2012-11-01

    The cell wall is a complex structure mainly composed by a cellulose-hemicellulose network embedded in a cohesive pectin matrix. Pectin is synthesized in a highly methyl esterified form and is de-esterified in muro by pectin methyl esterases (PMEs). The degree and pattern of methyl esterification affect the cell wall structure and properties with consequences on both the physiological processes of the plants and their resistance to pathogens. PME activity displays a crucial role in the outcome of the plant-pathogen interactions by making pectin more susceptible to the action of the enzymes produced by the pathogens. This review focuses on the impact of pectin methyl esterification in plant-pathogen interactions and on the dynamic role of its alteration during pathogenesis.

  11. Vaccenic acid and trans fatty acid isomers from partially hydrogenated oil both adversely affect LDL cholesterol: a double-blind, randomized controlled trial

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Evidence of the adverse effects of industrially-produced trans fatty acids (iTFA) on risk of cardiovascular disease is consistent and well documented in the scientific literature; however, the cardiovascular effects of naturally-occurring TFA synthesized in ruminant animals (rTFA), such as vaccenic ...

  12. Soil Particle Heterogeneity Affects the Growth of a Rhizomatous Wetland Plant

    PubMed Central

    Xue, Wei; Peng, Yi-Ke; Zhang, Ming-Xiang; Yu, Fei-Hai

    2013-01-01

    Soil is commonly composed of particles of different sizes, and soil particle size may greatly affect the growth of plants because it affects soil physical and chemical properties. However, no study has tested the effects of soil particle heterogeneity on the growth of clonal plants. We conducted a greenhouse experiment in which individual ramets of the wetland plant Bolboschoenus planiculmis were grown in three homogeneous soil treatments with uniformly sized quartz particles (small: 0.75 mm, medium: 1.5 mm, or large: 3 mm), one homogeneous treatment with an even mixture of large and medium particles, and two heterogeneous treatments consisting of 16 or 4 patches of large and medium particles. Biomass, ramet number, rhizome length and spacer length were significantly greater in the treatment with only medium particles than in the one with only large particles. Biomass, ramet number, rhizome length and tuber number in the patchy treatments were greater in patches of medium than of large particles; this difference was more pronounced when patches were small than when they were large. Soil particle size and soil particle heterogeneity can greatly affect the growth of clonal plants. Thus, studies to test the effects of soil heterogeneity on clonal plants should distinguish the effects of nutrient heterogeneity from those of particle heterogeneity. PMID:23936110

  13. Relative abundance of an invasive alien plant affects insect-flower interaction networks in Ireland

    NASA Astrophysics Data System (ADS)

    Stout, Jane C.; Casey, Leanne M.

    2014-02-01

    Invasive alien flowering plants may affect native plant pollinator interactions and have knock on impacts on populations of native plants and animals. The magnitude of these impacts, however, may be modified by the relative abundance of the invasive plant and the number of flowers it presents.We tested this by examining the structure of insect-flower interaction networks in six sites with increasing levels of invasion by Rhododendron ponticum in Ireland.Neither flower-visiting insect abundance, species richness nor diversity were related to R. ponticum flower abundance, but the composition of insect communities was. The total number of flowers in a site increased with the relative abundance of R. ponticum flowers but the number of co-flowering native plant species in these sites was low (<6), making interaction networks relatively small.As a result, changes in interaction network properties (connectance, interaction evenness and network level specialisation), which correlated with R. ponticum flower abundance, were a result of the small network size rather than due to changes in the resilience of networks.Overall, we conclude that the impacts of invasive alien plants on native plant-pollinator interactions are not only species specific, but site specific, according to the abundance of flowers produced by both the invasive and the native plants.

  14. Cotyledon damage affects seed number through final plant size in the annual grassland species Medicago lupulina

    PubMed Central

    Zhang, Shiting; Zhao, Chuan; Lamb, Eric G.

    2011-01-01

    Background and Aims The effects of cotyledon damage on seedling growth and survival are relatively well established, but little is known about the effects on aspects of plant fitness such as seed number and size. Here the direct and indirect mechanisms linking cotyledon damage and plant fitness in the annual species Medicago lupulina are examined. Methods Growth and reproductive traits, including mature plant size, time to first flowering, flower number, seed number and individual seed mass were monitored in M. lupulina plants when zero, one or two cotyledons were removed at 7 d old. Structural equation modelling (SEM) was used to examine the mechanisms linking cotyledon damage to seed number and seed mass. Key Results Cotyledon damage reduced seed number but not individual seed mass. The primary mechanism was a reduction in plant biomass with cotyledon damage that in turn reduced seed number primarily through a reduction in flower numbers. Although cotyledon damage delayed flower initiation, it had little effect on seed number. Individual seed mass was not affected by cotyledon removal, but there was a trade-off between seed number and seed mass. Conclusions It is shown how a network of indirect mechanisms link damage to cotyledons and fitness in M. lupulina. Cotyledon damage had strong direct effects on both plant size and flowering phenology, but an analysis of the causal relationships among plant traits and fitness components showed that a reduction in plant size associated with cotyledon damage was an important mechanism influencing fitness. PMID:21196450

  15. Plant Volatiles Induced by Herbivore Egg Deposition Affect Insects of Different Trophic Levels

    PubMed Central

    Fatouros, Nina E.; Lucas-Barbosa, Dani; Weldegergis, Berhane T.; Pashalidou, Foteini G.; van Loon, Joop J. A.; Dicke, Marcel; Harvey, Jeffrey A.; Gols, Rieta; Huigens, Martinus E.

    2012-01-01

    Plants release volatiles induced by herbivore feeding that may affect the diversity and composition of plant-associated arthropod communities. However, the specificity and role of plant volatiles induced during the early phase of attack, i.e. egg deposition by herbivorous insects, and their consequences on insects of different trophic levels remain poorly explored. In olfactometer and wind tunnel set-ups, we investigated behavioural responses of a specialist cabbage butterfly (Pieris brassicae) and two of its parasitic wasps (Trichogramma brassicae and Cotesia glomerata) to volatiles of a wild crucifer (Brassica nigra) induced by oviposition of the specialist butterfly and an additional generalist moth (Mamestra brassicae). Gravid butterflies were repelled by volatiles from plants induced by cabbage white butterfly eggs, probably as a means of avoiding competition, whereas both parasitic wasp species were attracted. In contrast, volatiles from plants induced by eggs of the generalist moth did neither repel nor attract any of the tested community members. Analysis of the plant’s volatile metabolomic profile by gas chromatography-mass spectrometry and the structure of the plant-egg interface by scanning electron microscopy confirmed that the plant responds differently to egg deposition by the two lepidopteran species. Our findings imply that prior to actual feeding damage, egg deposition can induce specific plant responses that significantly influence various members of higher trophic levels. PMID:22912893

  16. Exogenous abscisic acid significantly affects proteome in tea plant (Camellia sinensis) exposed to drought stress

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Tea [Camellia sinensis (L.) O. Kuntze] is an important economic crop, and drought is the most important abiotic stress affecting yield and quality. Abscisic acid (ABA) is an important phytohormone responsible for activating drought resistance. Increased understanding of ABA effects on tea plant unde...

  17. Salinity and Alkaline pH in Irrigation Water Affect Marigold Plants: II. Mineral Ion Relations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Scarcity of water of good quality for landscape irrigation is of outmost importance in arid and semiarid regions due to the competition with urban population. This is forcing the use of degraded waters with high levels of salinity and high pH, which may affect plant establishment and growth. The o...

  18. Poisonous plants affecting the central nervous system of horses in Brazil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Poisoning by Indigofera pascuori was recently reported in horses in the state of Roraima. It causes chronic signs of sleepiness, unsteady gait, severe ataxia, and progressive weight loss. Some animals are blind. Young horses are more affected than adults. After the end of plant consumption the anima...

  19. Inoculation of Transgenic Resistant Potato by Phytophthora infestans Affects Host Plant Choice of a Generalist Moth.

    PubMed

    Abreha, Kibrom B; Alexandersson, Erik; Vossen, Jack H; Anderson, Peter; Andreasson, Erik

    2015-01-01

    Pathogen attack and the plant's response to this attack affect herbivore oviposition preference and larval performance. Introduction of major resistance genes against Phytophthora infestans (Rpi-genes), the cause of the devastating late blight disease, from wild Solanum species into potato changes the plant-pathogen interaction dynamics completely, but little is known about the effects on non-target organisms. Thus, we examined the effect of P. infestans itself and introduction of an Rpi-gene into the crop on host plant preference of the generalist insect herbivore, Spodoptera littoralis (Lepidoptera: Noctuidae). In two choice bioassays, S. littoralis preferred to oviposit on P. infestans-inoculated plants of both the susceptible potato (cv. Desiree) and an isogenic resistant clone (A01-22: cv. Desiree transformed with Rpi-blb1), when compared to uninoculated plants of the same genotype. Both cv. Desiree and clone A01-22 were equally preferred for oviposition by S. littoralis when uninoculated plants were used, while cv. Desiree received more eggs compared to the resistant clone when both were inoculated with the pathogen. No significant difference in larval and pupal weight was found between S. littoralis larvae reared on leaves of the susceptible potato plants inoculated or uninoculated with P. infestans. Thus, the herbivore's host plant preference in this system was not directly associated with larval performance. The results indicate that the Rpi-blb1 based resistance in itself does not influence insect behavior, but that herbivore oviposition preference is affected by a change in the plant-microbe interaction. PMID:26053171

  20. Methane transport and emissions from soil as affected by water table and vascular plants

    PubMed Central

    2013-01-01

    Background The important greenhouse gas (GHG) methane is produced naturally in anaerobic wetland soils. By affecting the production, oxidation and transport of methane to the atmosphere, plants have a major influence upon the quantities emitted by wetlands. Different species and functional plant groups have been shown to affect these processes differently, but our knowledge about how these effects are influenced by abiotic factors such as water regime and temperature remains limited. Here we present a mesocosm experiment comparing eight plant species for their effects on internal transport and overall emissions of methane under contrasting hydrological conditions. To quantify how much methane was transported internally through plants (the chimney effect), we blocked diffusion from the soil surface with an agar seal. Results We found that graminoids caused higher methane emissions than forbs, although the emissions from mesocosms with different species were either lower than or comparable to those from control mesocosms with no plant (i.e. bare soil). Species with a relatively greater root volume and a larger biomass exhibited a larger chimney effect, though overall methane emissions were negatively related to plant biomass. Emissions were also reduced by lowering the water table. Conclusions We conclude that plant species (and functional groups) vary in the degree to which they transport methane to the atmosphere. However, a plant with a high capacity to transport methane does not necessarily emit more methane, as it may also cause more rhizosphere oxidation of methane. A shift in plant species composition from graminoids to forbs and/or from low to high productive species may lead to reduction of methane emissions. PMID:24010540

  1. Warming, CO2, and nitrogen deposition interactively affect a plant-pollinator mutualism.

    PubMed

    Hoover, Shelley E R; Ladley, Jenny J; Shchepetkina, Anastasia A; Tisch, Maggie; Gieseg, Steven P; Tylianakis, Jason M

    2012-03-01

    Environmental changes threaten plant-pollinator mutualisms and their critical ecosystem service. Drivers such as land use, invasions and climate change can affect pollinator diversity or species encounter rates. However, nitrogen deposition, climate warming and CO(2) enrichment could interact to disrupt this crucial mutualism by altering plant chemistry in ways that alter floral attractiveness or even nutritional rewards for pollinators. Using a pumpkin model system, we show that these drivers non-additively affect flower morphology, phenology, flower sex ratios and nectar chemistry (sugar and amino acids), thereby altering the attractiveness of nectar to bumble bee pollinators and reducing worker longevity. Alarmingly, bees were attracted to, and consumed more, nectar from a treatment that reduced their survival by 22%. Thus, three of the five major drivers of global environmental change have previously unknown interactive effects on plant-pollinator mutualisms that could not be predicted from studies of individual drivers in isolation.

  2. Color of illumination during growth affects LHCII chiral macroaggregates in pea plant leaves.

    PubMed

    Gussakovsky, Eugene E; Shahak, Yosepha; Schroeder, Dana F

    2007-02-01

    To determine whether the color of illumination under which plants are grown, affects the structure of photosynthetic antennae, pea plants were grown under either blue-enriched, red-enriched, or white light. Carotenoid content of isolated chloroplasts was found to be insensitive to the color of illumination during growth, while chlorophyll a/b ratio in chloroplasts isolated from young illuminated leaves showed susceptibility to color. Color of illumination affects the LHCII chiral macroaggregates in intact leaves and isolated chloroplasts, providing light-induced alteration of the handedness of the LHCII chiral macroaggregate, as measured with circular dichroism and circularly polarized luminescence. The susceptibility of handedness to current illumination (red light excitation of chlorophyll fluorescence) is dependent on the color under which the plants were grown, and was maximal for the red-enriched illumination. We propose the existence of a long-term (growth period) color memory, which influences the susceptibility of the handedness of LHCII chiral macroaggregates to current light.

  3. How Do Earthworms, Soil Texture and Plant Composition Affect Infiltration along an Experimental Plant Diversity Gradient in Grassland?

    PubMed Central

    Fischer, Christine; Roscher, Christiane; Jensen, Britta; Eisenhauer, Nico; Baade, Jussi; Attinger, Sabine; Scheu, Stefan; Weisser, Wolfgang W.; Schumacher, Jens; Hildebrandt, Anke

    2014-01-01

    Background Infiltration is a key process in determining the water balance, but so far effects of earthworms, soil texture, plant species diversity and their interaction on infiltration capacity have not been studied. Methodology/Principal Findings We measured infiltration capacity in subplots with ambient and reduced earthworm density nested in plots of different plant species (1, 4, and 16 species) and plant functional group richness and composition (1 to 4 groups; legumes, grasses, small herbs, tall herbs). In summer, earthworm presence significantly increased infiltration, whereas in fall effects of grasses and legumes on infiltration were due to plant-mediated changes in earthworm biomass. Effects of grasses and legumes on infiltration even reversed effects of texture. We propose two pathways: (i) direct, probably by modifying the pore spectrum and (ii) indirect, by enhancing or suppressing earthworm biomass, which in turn influenced infiltration capacity due to change in burrowing activity of earthworms. Conclusions/Significance Overall, the results suggest that spatial and temporal variations in soil hydraulic properties can be explained by biotic processes, especially the presence of certain plant functional groups affecting earthworm biomass, while soil texture had no significant effect. Therefore biotic parameters should be taken into account in hydrological applications. PMID:24918943

  4. Inoculation of Transgenic Resistant Potato by Phytophthora infestans Affects Host Plant Choice of a Generalist Moth

    PubMed Central

    Abreha, Kibrom B.; Alexandersson, Erik; Vossen, Jack H.; Anderson, Peter; Andreasson, Erik

    2015-01-01

    Pathogen attack and the plant’s response to this attack affect herbivore oviposition preference and larval performance. Introduction of major resistance genes against Phytophthora infestans (Rpi-genes), the cause of the devastating late blight disease, from wild Solanum species into potato changes the plant-pathogen interaction dynamics completely, but little is known about the effects on non-target organisms. Thus, we examined the effect of P. infestans itself and introduction of an Rpi-gene into the crop on host plant preference of the generalist insect herbivore, Spodoptera littoralis (Lepidoptera: Noctuidae). In two choice bioassays, S. littoralis preferred to oviposit on P. infestans-inoculated plants of both the susceptible potato (cv. Desiree) and an isogenic resistant clone (A01-22: cv. Desiree transformed with Rpi-blb1), when compared to uninoculated plants of the same genotype. Both cv. Desiree and clone A01-22 were equally preferred for oviposition by S. littoralis when uninoculated plants were used, while cv. Desiree received more eggs compared to the resistant clone when both were inoculated with the pathogen. No significant difference in larval and pupal weight was found between S. littoralis larvae reared on leaves of the susceptible potato plants inoculated or uninoculated with P. infestans. Thus, the herbivore’s host plant preference in this system was not directly associated with larval performance. The results indicate that the Rpi-blb1 based resistance in itself does not influence insect behavior, but that herbivore oviposition preference is affected by a change in the plant-microbe interaction. PMID:26053171

  5. 4-Methylthiobutyl isothiocyanate (Erucin) from rocket plant dichotomously affects the activity of human immunocompetent cells.

    PubMed

    Gründemann, Carsten; Garcia-Käufer, Manuel; Lamy, Evelyn; Hanschen, Franziska S; Huber, Roman

    2015-03-15

    Isothiocyanates (ITC) from the Brassicaceae plant family are regarded as promising for prevention and treatment of cancer. However, experimental settings consider their therapeutic action without taking into account the risk of unwanted effects on healthy tissues. In the present study we investigated the effects of Eruca sativa seed extract containing MTBITC (Erucin) and pure Erucin from rocket plant on healthy cells of the human immune system in vitro. Hereby, high doses of the plant extract as well as of Erucin inhibited cell viability of human lymphocytes via induction of apoptosis to comparable amounts. Non-toxic low concentrations of the plant extract and pure Erucin altered the expression of the interleukin (IL)-2 receptor but did not affect further T cell activation, proliferation and the release of the effector molecules interferon (IFN)-gamma and IL-2 of T-lymphocytes. However, the activity of NK-cells was significantly reduced by non-toxic concentrations of the plant extract and pure Erucin. These results indicate that the plant extract and pure Erucin interfere with the function of human T lymphocytes and decreases the activity of NK-cells in comparable concentrations. Long-term clinical studies with ITC-enriched plant extracts from Brassicaceae should take this into account.

  6. Secondary metabolites from nonhost plants affect the motility and viability of phytopathogenic Aphanomyces cochlioides zoospores.

    PubMed

    Islam, Md Tofazzal

    2008-01-01

    The motile zoospores of the damping-off pathogen Aphanomyces cochlioides aggregate on host plants (e.g., sugar beet, spinach) guided by the host-specific plant signal cochliophilin A before infection. To assess the potential role of secondary metabolites in nonhost resistance, acetone extracts of 200 nonhost traditional medicinal plants from Chinese and Bangladeshi origins were tested for the motility behaviour of A. cochlioides zoospores using a particle bioassay method. Nearly one third of the tested plant extracts exhibited diverse deleterious activities such as repellent, stimulant, motility halting and lysis against A. cochlioides zoospores. Among these active plants, an extract of the Chinese medicinal plant Dalbergia odorifera displayed potent repellent activity toward zoospores. Chromatographic separation of D. odorifera constituents revealed that the repellent activity was regulated by the cumulative effect of three motility-affecting isoflavonoids, viz. (+/-)-medicarpin (repellent at 150 microg/ml), (-)-claussequinone (stimulant at 100 microg/ml) and formononetin (stimulant and attractant at 50 microg/ml). A mixture (1:1:1, w/w/w) of these three compounds exhibited only repellent activity toward zoospores at a concentration lower than 50 microg/ml. These results suggest that nonhost plants might possess potential bioactive secondary metabolites to ward off zoosporic phytopathogens. PMID:18533468

  7. Quantification of Heavy Metals in Mining Affected Soil and Their Bioaccumulation in Native Plant Species.

    PubMed

    Nawab, Javed; Khan, Sardar; Shah, Mohammad Tahir; Khan, Kifayatullah; Huang, Qing; Ali, Roshan

    2015-01-01

    Several anthropogenic and natural sources are considered as the primary sources of toxic metals in the environment. The current study investigates the level of heavy metals contamination in the flora associated with serpentine soil along the Mafic and Ultramafic rocks northern-Pakistan. Soil and wild native plant species were collected from chromites mining affected areas and analyzed for heavy metals (Cr, Ni, Fe, Mn, Co, Cu and Zn) using atomic absorption spectrometer (AAS-PEA-700). The heavy metal concentrations were significantly (p < 0.01) higher in mine affected soil as compared to reference soil, however Cr and Ni exceeded maximum allowable limit (250 and 60 mg kg(-1), respectively) set by SEPA for soil. Inter-metal correlations between soil, roots and shoots showed that the sources of contamination of heavy metals were mainly associated with chromites mining. All the plant species accumulated significantly higher concentrations of heavy metals as compared to reference plant. The open dumping of mine wastes can create serious problems (food crops and drinking water contamination with heavy metals) for local community of the study area. The native wild plant species (Nepeta cataria, Impatiens bicolor royle, Tegetis minuta) growing on mining affected sites may be used for soil reclamation contaminated with heavy metals.

  8. Quantification of Heavy Metals in Mining Affected Soil and Their Bioaccumulation in Native Plant Species.

    PubMed

    Nawab, Javed; Khan, Sardar; Shah, Mohammad Tahir; Khan, Kifayatullah; Huang, Qing; Ali, Roshan

    2015-01-01

    Several anthropogenic and natural sources are considered as the primary sources of toxic metals in the environment. The current study investigates the level of heavy metals contamination in the flora associated with serpentine soil along the Mafic and Ultramafic rocks northern-Pakistan. Soil and wild native plant species were collected from chromites mining affected areas and analyzed for heavy metals (Cr, Ni, Fe, Mn, Co, Cu and Zn) using atomic absorption spectrometer (AAS-PEA-700). The heavy metal concentrations were significantly (p < 0.01) higher in mine affected soil as compared to reference soil, however Cr and Ni exceeded maximum allowable limit (250 and 60 mg kg(-1), respectively) set by SEPA for soil. Inter-metal correlations between soil, roots and shoots showed that the sources of contamination of heavy metals were mainly associated with chromites mining. All the plant species accumulated significantly higher concentrations of heavy metals as compared to reference plant. The open dumping of mine wastes can create serious problems (food crops and drinking water contamination with heavy metals) for local community of the study area. The native wild plant species (Nepeta cataria, Impatiens bicolor royle, Tegetis minuta) growing on mining affected sites may be used for soil reclamation contaminated with heavy metals. PMID:26079739

  9. Timing of cotyledon damage affects growth and flowering in mature plants.

    PubMed

    Hanley, M E; Fegan, E L

    2007-07-01

    Although the effects of herbivory on plant fitness are strongly linked to age, we understand little about how the timing of herbivory at the seedling stage affects growth and reproduction for plants that survive attack. In this study, we subjected six north-western European, dicotyledonous grassland species (Leontodon autumnalis, Leontodon hispidus, Plantago lanceolata, Plantago major, Trifolium pratense and Trifolium repens) to cotyledon removal at 7, 14 and 21 d old. We monitored subsequent growth and flowering (number of inflorescences recorded, and time taken for first flowers to open) over a 107 d period. Cotyledon removal reduced growth during establishment (35 d) for all species, and a further three exhibited reduced growth at maturity. Four species developed fewer inflorescences, or had delayed flowering after cotyledon removal. Although early damage (7 d old) had the greatest long-term effect on plant performance, responses varied according to the age at which the damage occurred and the species involved. Our results illustrate how growth and flowering into the mature phase is affected by cotyledon damage during different stages of seedling ontogeny, and we highlight the ways in which ontogenetic variation in seedling tolerance of tissue loss might impact upon plant fitness in mature plant communities. PMID:17547653

  10. Plant sterols: factors affecting their efficacy and safety as functional food ingredients

    PubMed Central

    Berger, Alvin; Jones, Peter JH; Abumweis, Suhad S

    2004-01-01

    Plant sterols are naturally occurring molecules that humanity has evolved with. Herein, we have critically evaluated recent literature pertaining to the myriad of factors affecting efficacy and safety of plant sterols in free and esterified forms. We conclude that properly solubilized 4-desmetyl plant sterols, in ester or free form, in reasonable doses (0.8–1.0 g of equivalents per day) and in various vehicles including natural sources, and as part of a healthy diet and lifestyle, are important dietary components for lowering low density lipoprotein (LDL) cholesterol and maintaining good heart health. In addition to their cholesterol lowering properties, plant sterols possess anti-cancer, anti-inflammatory, anti-atherogenicity, and anti-oxidation activities, and should thus be of clinical importance, even for those individuals without elevated LDL cholesterol. The carotenoid lowering effect of plant sterols should be corrected by increasing intake of food that is rich in carotenoids. In pregnant and lactating women and children, further study is needed to verify the dose required to decrease blood cholesterol without affecting fat-soluble vitamins and carotenoid status. PMID:15070410

  11. Interaction between parental environment and genotype affects plant and seed performance in Arabidopsis

    PubMed Central

    He, Hanzi; de Souza Vidigal, Deborah; Snoek, L. Basten; Schnabel, Sabine; Nijveen, Harm; Hilhorst, Henk; Bentsink, Leónie

    2014-01-01

    Seed performance after dispersal is highly dependent on parental environmental cues, especially during seed formation and maturation. Here we examine which environmental factors are the most dominant in this respect and whether their effects are dependent on the genotypes under investigation. We studied the influence of light intensity, photoperiod, temperature, nitrate, and phosphate during seed development on five plant attributes and thirteen seed attributes, using 12 Arabidopsis genotypes that have been reported to be affected in seed traits. As expected, the various environments during seed development resulted in changed plant and/or seed performances. Comparative analysis clearly indicated that, overall, temperature plays the most dominant role in both plant and seed performance, whereas light has a prominent impact on plant traits. In comparison to temperature and light, nitrate mildly affected some of the plant and seed traits while phosphate had even less influence on those traits. Moreover, clear genotype-by-environment interactions were identified. This was shown by the fact that individual genotypes responded differentially to the environmental conditions. Low temperature significantly increased seed dormancy and decreased seed longevity of NILDOG1 and cyp707a1-1, whereas low light intensity increased seed dormancy and decreased seed longevity of NILDOG3 and NILDOG6. This also indicates that different genetic and molecular pathways are involved in the plant and seed responses. By identifying environmental conditions that affect the dormancy vs longevity correlation in the same way as previously identified naturally occurring loci, we have identified selective forces that probably shaped evolution for these important seed traits. PMID:25240065

  12. Interaction between parental environment and genotype affects plant and seed performance in Arabidopsis.

    PubMed

    He, Hanzi; de Souza Vidigal, Deborah; Snoek, L Basten; Schnabel, Sabine; Nijveen, Harm; Hilhorst, Henk; Bentsink, Leónie

    2014-12-01

    Seed performance after dispersal is highly dependent on parental environmental cues, especially during seed formation and maturation. Here we examine which environmental factors are the most dominant in this respect and whether their effects are dependent on the genotypes under investigation. We studied the influence of light intensity, photoperiod, temperature, nitrate, and phosphate during seed development on five plant attributes and thirteen seed attributes, using 12 Arabidopsis genotypes that have been reported to be affected in seed traits. As expected, the various environments during seed development resulted in changed plant and/or seed performances. Comparative analysis clearly indicated that, overall, temperature plays the most dominant role in both plant and seed performance, whereas light has a prominent impact on plant traits. In comparison to temperature and light, nitrate mildly affected some of the plant and seed traits while phosphate had even less influence on those traits. Moreover, clear genotype-by-environment interactions were identified. This was shown by the fact that individual genotypes responded differentially to the environmental conditions. Low temperature significantly increased seed dormancy and decreased seed longevity of NILDOG1 and cyp707a1-1, whereas low light intensity increased seed dormancy and decreased seed longevity of NILDOG3 and NILDOG6. This also indicates that different genetic and molecular pathways are involved in the plant and seed responses. By identifying environmental conditions that affect the dormancy vs longevity correlation in the same way as previously identified naturally occurring loci, we have identified selective forces that probably shaped evolution for these important seed traits.

  13. Plant-bacteria bioremediation agents affect the response of plant bioindicators independent of 2-chlorobenzoic acid degradation

    SciTech Connect

    Siciliano, S.D.; Germida, J.J.

    1995-12-31

    Plants are known to degrade toxicants in soil and are potentially useful bioremediation agents. The authors developed plant-bacteria associations (e.g., Meadow brome [Bromus riparius] and Pseudomonas aeruginosa strain R75) that degrade 2-chlorobenzoic acid (2CBA) in soil, and assessed their success using Slender wheatgrass (Agropyron trachycaulum) germination as a bioindicator of 2CBA levels. Gas chromatography was used to chemically assess 2CBA levels. Specific plant-bacteria bioremediation treatments decreased soil 2CBA levels by 17 to 52%, but bioindicator response did not correspond to chemical analysis. Contaminated and uncontaminated soil was subjected to bioremediation treatments. After 42 days, uncontaminated soil was collected and amended to various 2CBA levels. This soil and the remediated soil were analyzed by the plant bioindicator and gas chromatography. Bioremediation treatments altered germination of Slender wheatgrass in both contaminated and noncontaminated soils to a similar extent. These treatments decreased the toxicity of 2CBA to Slender wheatgrass in both contaminated and noncontaminated soils to a similar extent. These treatments decreased the toxicity of 2CBA to Slender wheatgrass at low 2CBA levels, but increased the toxicity of 2CBA at high 2CBA levels. For example, germination in soil subjected to the Meadow brome and R75 treatment was increased by ca. 30% at 50 mg kg{sup {minus}1} 2CBA, but decreased by ca. 50% at 150 mg kg{sup {minus}1} 2CBA. The results indicate that specific plant-bacteria bioremediation treatments affect plant bioindicator response independent of 2CBA degradation, and may confound efforts to determine the toxicity of 2CBA in soil.

  14. Carbon storage potential by four macrophytes as affected by planting diversity in a created wetland.

    PubMed

    Means, Mary M; Ahn, Changwoo; Korol, Alicia R; Williams, Lisa D

    2016-01-01

    Wetland creation has become a commonplace method for mitigating the loss of natural wetlands. Often mitigation projects fail to restore ecosystem services of the impacted natural wetlands. One of the key ecosystem services of newly created wetlands is carbon accumulation/sequestration, but little is known about how planting diversity (PD) affects the ability of herbaceous wetland plants to store carbon in newly created wetlands. Most mitigation projects involve a planting regime, but PD, which may be critical in establishing biologically diverse and ecologically functioning wetlands, is seldom required. Using a set of 34 mesocosms (∼1 m(2) each), we investigated the effects of planting diversity on carbon storage potential of four native wetland plant species that are commonly planted in created mitigation wetlands in Virginia - Carex vulpinoidea, Eleocharis obtusa, Juncus effusus, and Mimulus ringens. The plants were grown under the four distinctive PD treatments [i.e., monoculture (PD 1) through four different species mixture (PD 4)]. Plant biomass was harvested after two growing seasons and analyzed for tissue carbon content. Competition values (CV) were calculated to understand how the PD treatment affected the competitive ability of plants relative to their biomass production and thus carbon storage potentials. Aboveground biomass ranged from 988 g/m(2) - 1515 g/m(2), being greatest in monocultures, but only when compared to the most diverse mixture (p = 0.021). However, carbon storage potential estimates per mesocosm ranged between 344 g C/m(2) in the most diverse mesocosms (PD 4) to 610 g C/m(2) in monoculture ones with no significant difference (p = 0.089). CV of E. obtusa and C. vulpinoidea showed a declining trend when grown in the most diverse mixtures but J. effusus and M. ringens displayed no difference across the PD gradient (p = 0.910). In monocultures, both M. ringens, and J. effusus appeared to store carbon as biomass more

  15. Carbon storage potential by four macrophytes as affected by planting diversity in a created wetland.

    PubMed

    Means, Mary M; Ahn, Changwoo; Korol, Alicia R; Williams, Lisa D

    2016-01-01

    Wetland creation has become a commonplace method for mitigating the loss of natural wetlands. Often mitigation projects fail to restore ecosystem services of the impacted natural wetlands. One of the key ecosystem services of newly created wetlands is carbon accumulation/sequestration, but little is known about how planting diversity (PD) affects the ability of herbaceous wetland plants to store carbon in newly created wetlands. Most mitigation projects involve a planting regime, but PD, which may be critical in establishing biologically diverse and ecologically functioning wetlands, is seldom required. Using a set of 34 mesocosms (∼1 m(2) each), we investigated the effects of planting diversity on carbon storage potential of four native wetland plant species that are commonly planted in created mitigation wetlands in Virginia - Carex vulpinoidea, Eleocharis obtusa, Juncus effusus, and Mimulus ringens. The plants were grown under the four distinctive PD treatments [i.e., monoculture (PD 1) through four different species mixture (PD 4)]. Plant biomass was harvested after two growing seasons and analyzed for tissue carbon content. Competition values (CV) were calculated to understand how the PD treatment affected the competitive ability of plants relative to their biomass production and thus carbon storage potentials. Aboveground biomass ranged from 988 g/m(2) - 1515 g/m(2), being greatest in monocultures, but only when compared to the most diverse mixture (p = 0.021). However, carbon storage potential estimates per mesocosm ranged between 344 g C/m(2) in the most diverse mesocosms (PD 4) to 610 g C/m(2) in monoculture ones with no significant difference (p = 0.089). CV of E. obtusa and C. vulpinoidea showed a declining trend when grown in the most diverse mixtures but J. effusus and M. ringens displayed no difference across the PD gradient (p = 0.910). In monocultures, both M. ringens, and J. effusus appeared to store carbon as biomass more

  16. Salicylic acid negatively affects the response to salt stress in pea plants.

    PubMed

    Barba-Espín, G; Clemente-Moreno, M J; Alvarez, S; García-Legaz, M F; Hernández, J A; Díaz-Vivancos, P

    2011-11-01

    We studied the effect of salicylic acid (SA) treatment on the response of pea plants to salinity. Sodium chloride (NaCl)-induced damage to leaves was increased by SA, which was correlated with a reduction in plant growth. The content of reduced ascorbate and glutathione in leaves of salt-treated plants increased in response to SA, although accumulation of the respective oxidised forms occurred. An increase in hydrogen peroxide also occurred in leaves of salt-exposed plants treated with SA. In the absence of NaCl, SA increased ascorbate peroxidase (APX; 100 μm) and glutathione-S transferase (GST; 50 μm) activities and increased catalase (CAT) activity in a concentration-dependent manner. Salinity decreased glutathione reductase (GR) activity, but increased GST and CAT activity. In salt-stressed plants, SA also produced changes in antioxidative enzymes: 100 μm SA decreased APX but increased GST. Finally, a concentration-dependent increase in superoxide dismutase (SOD) activity was induced by SA treatment in salt-stressed plants. Induction of PR-1b was observed in NaCl-stressed plants treated with SA. The treatment with SA, as well as the interaction between salinity and SA treatment, had a significant effect on PsMAPK3 expression. The expression of PsMAPK3 was not altered by 70 mm NaCl, but was statistically higher in the absence than in the presence of SA. Overall, the results show that SA treatment negatively affected the response of pea plants to NaCl, and this response correlated with an imbalance in antioxidant metabolism. The data also show that SA treatment could enhance the resistance of salt-stressed plants to possible opportunistic pathogen attack, as suggested by increased PR-1b gene expression.

  17. 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.

  18. Does a decade of elevated [CO2] affect a desert perennial plant community?

    PubMed

    Newingham, Beth A; Vanier, Cheryl H; Kelly, Lauren J; Charlet, Therese N; Smith, Stanley D

    2014-01-01

    Understanding the effects of elevated [CO2 ] on plant community structure is crucial to predicting ecosystem responses to global change. Early predictions suggested that productivity in deserts would increase via enhanced water-use efficiency under elevated [CO2], but the response of intact arid plant communities to elevated [CO2 ] is largely unknown. We measured changes in perennial plant community characteristics (cover, species richness and diversity) after 10 yr of elevated [CO2] exposure in an intact Mojave Desert community at the Nevada Desert Free-Air CO2 Enrichment (FACE) Facility. Contrary to expectations, total cover, species richness, and diversity were not affected by elevated [CO2]. Over the course of the experiment, elevated [CO2] had no effect on changes in cover of the evergreen C3 shrub, Larrea tridentata; alleviated decreases in cover of the C4 bunchgrass, Pleuraphis rigida; and slightly reduced the cover of C3 drought-deciduous shrubs. Thus, we generally found no effect of elevated [CO2] on plant communities in this arid ecosystem. Extended drought, slow plant growth rates, and highly episodic germination and recruitment of new individuals explain the lack of strong perennial plant community shifts after a decade of elevated [CO2]. PMID:24117700

  19. Dioecy, more than monoecy, affects plant spatial genetic structure: the case study of Ficus

    PubMed Central

    Nazareno, Alison G; Alzate-Marin, Ana L; Pereira, Rodrigo Augusto S

    2013-01-01

    In this analysis, we attempt to understand how monoecy and dioecy drive spatial genetic structure (SGS) in plant populations. For this purpose, plants of the genus Ficus were used as a comparative model due to their particular characteristics, including high species diversity, variation in life histories, and sexual systems. One of the main issues we assessed is whether dioecious fig tree populations are more spatially genetically structured than monoecious populations. Using the Sp statistic, which allows for quantitative comparisons among different studies, we compared the extent of SGS between monoecious and dioecious Ficus species. To broaden our conclusions we used published data on an additional 27 monoecious and dioecious plant species. Furthermore, genetic diversity analyses were performed for two monoecious Ficus species using 12 microsatellite markers in order to strengthen our conclusions about SGS. Our results show that dioecy, more than monoecy, significantly contributes to SGS in plant populations. On average, the estimate of Sp was six times higher for dioecious Ficus species than monoecious Ficus species and it was two times higher in dioecious than monoecious plant species. Considering these results, we emphasize that the long-distance pollen dispersal mechanism in monoecious Ficus species seems to be the dominant factor in determining weak spatial genetic structure, high levels of genetic diversity, and lack of inbreeding. Although Ficus constitute a model species to study SGS, a more general comparison encompassing a wider range of plants is required in order to better understand how sexual systems affect genetic structure. PMID:24223285

  20. Macronutrient content of plant-based food affects growth of a carnivorous arthropod.

    PubMed

    Wilder, Shawn M; Holway, David A; Suarez, Andrew V; Eubanks, Micky D

    2011-02-01

    Many arthropods engage in mutualisms in which they consume plant-based foods including nectar, extrafloral nectar, and honeydew. However, relatively little is known about the manner in which the specific macronutrients in these plant-based resources affect growth, especially for carnivorous arthropods. Using a combination of laboratory and field experiments, we tested (1) how plant-based foods, together with ad libitum insect prey, affect the growth of a carnivorous ant, Solenopsis invicta, and (2) which macronutrients in these resources (i.e., carbohydrates, amino acids, or both) contribute to higher colony growth. Access to honeydew increased the production of workers and brood in experimental colonies. This growth effect appeared to be due to carbohydrates alone as colonies provided with the carbohydrate component of artificial extrafloral nectar had greater worker and brood production compared to colonies deprived of carbohydrates. Surprisingly, amino acids only had a slight interactive effect on the proportion of a colony composed of brood and negatively affected worker survival. Diet choice in the laboratory and field matched performance in the laboratory with high recruitment to carbohydrate baits and only slight recruitment to amino acids. The strong, positive effects of carbohydrates on colony growth and the low cost of producing this macronutrient for plants and hemipterans may have aided the evolution of food-for-protection mutualisms and help explain why these interactions are so common in ants. In addition, greater access to plant-based resources in the introduced range of S. invicta may help to explain the high densities achieved by this species throughout the southeastern United States.

  1. Macronutrient content of plant-based food affects growth of a carnivorous arthropod.

    PubMed

    Wilder, Shawn M; Holway, David A; Suarez, Andrew V; Eubanks, Micky D

    2011-02-01

    Many arthropods engage in mutualisms in which they consume plant-based foods including nectar, extrafloral nectar, and honeydew. However, relatively little is known about the manner in which the specific macronutrients in these plant-based resources affect growth, especially for carnivorous arthropods. Using a combination of laboratory and field experiments, we tested (1) how plant-based foods, together with ad libitum insect prey, affect the growth of a carnivorous ant, Solenopsis invicta, and (2) which macronutrients in these resources (i.e., carbohydrates, amino acids, or both) contribute to higher colony growth. Access to honeydew increased the production of workers and brood in experimental colonies. This growth effect appeared to be due to carbohydrates alone as colonies provided with the carbohydrate component of artificial extrafloral nectar had greater worker and brood production compared to colonies deprived of carbohydrates. Surprisingly, amino acids only had a slight interactive effect on the proportion of a colony composed of brood and negatively affected worker survival. Diet choice in the laboratory and field matched performance in the laboratory with high recruitment to carbohydrate baits and only slight recruitment to amino acids. The strong, positive effects of carbohydrates on colony growth and the low cost of producing this macronutrient for plants and hemipterans may have aided the evolution of food-for-protection mutualisms and help explain why these interactions are so common in ants. In addition, greater access to plant-based resources in the introduced range of S. invicta may help to explain the high densities achieved by this species throughout the southeastern United States. PMID:21618912

  2. Plant traits affecting herbivory on tree recruits in highly diverse subtropical forests.

    PubMed

    Schuldt, Andreas; Bruelheide, Helge; Durka, Walter; Eichenberg, David; Fischer, Markus; Kröber, Wenzel; Härdtle, Werner; Ma, Keping; Michalski, Stefan G; Palm, Wolf-Ulrich; Schmid, Bernhard; Welk, Erik; Zhou, Hongzhang; Assmann, Thorsten

    2012-07-01

    Differences in herbivory among woody species can greatly affect the functioning of forest ecosystems, particularly in species-rich (sub)tropical regions. However, the relative importance of the different plant traits which determine herbivore damage remains unclear. Defence traits can have strong effects on herbivory, but rarely studied geographical range characteristics could complement these effects through evolutionary associations with herbivores. Herein, we use a large number of morphological, chemical, phylogenetic and biogeographical characteristics to analyse interspecific differences in herbivory on tree saplings in subtropical China. Unexpectedly, we found no significant effects of chemical defence traits. Rather, herbivory was related to the plants' leaf morphology, local abundance and climatic niche characteristics, which together explained 70% of the interspecific variation in herbivory in phylogenetic regression. Our study indicates that besides defence traits and apparency to herbivores, previously neglected measures of large-scale geographical host distribution are important factors influencing local herbivory patterns among plant species.

  3. Plant hybrid zones affect biodiversity: Tools for a genetic-based understanding of community structure

    SciTech Connect

    Whitham, T.G.; Martinsen, G.D.; Keim, P.; Floate, K.D.; Dungey, H.S. |; Potts, B.M.

    1999-03-01

    Plant hybrid zones are dynamic centers of ecological and evolutionary processes for plants and their associated communities. Studies in the wild and in gardens with synthetic crosses showed that hybrid eucalypts supports the greatest species richness and abundances of insect and fungal taxa. In an updated review of 152 case studies of taxa associated with diverse hybridizing systems, there were 43 (28%) cases of hybrids being more susceptible than their parent species, 7 (5%) resistant, 35 (23%) additive, 35 (23%) dominant, and 32 (21%) showed no response to hybridization. Thus, most taxa respond to hybrids in ways that result in equal or greater abundance, and hybrids tend to accumulate the taxa of their parent species. These studies suggest that genetic-based plant traits affect the distribution of many species and that the variation in hybrids can be used as tools to examine the genetic components of community structure and biodiversity.

  4. CO2, nitrogen, and diversity differentially affect seed production of prairie plants.

    PubMed

    HilleRisLambers, J; Harpole, W S; Schnitzer, S; Tilman, D; Reich, P B

    2009-07-01

    Plant species composition and diversity is often influenced by early life history stages; thus, global change could dramatically affect plant community structure by altering seed production. Unfortunately, plant reproductive responses to global change are rarely studied in field settings, making it difficult to assess this possibility. To address this issue, we quantified the effects of elevated CO2, nitrogen deposition, and declining diversity on inflorescence production and inflorescence mass of 11 perennial grassland species in central Minnesota, U.S.A. We analyzed these data to ask whether (1) global change differentially affects seed production of co-occurring species; (2) seed production responses to global change are similar for species within the same functional group (defined by ecophysiology and growth form); and (3) seed production responses to global change match productivity responses: We found that, on average, allocation to seed production decreased under elevated CO2, although individual species responses were rarely significant due to low power (CO2 treatment df = 2). The effects of nitrogen deposition on seed production were similar within functional groups: C4 grasses tended to increase while C3 grasses tended to decrease allocation to seed production. Responses to nitrogen deposition were negatively correlated to productivity responses, suggesting a trade-off. Allocation to seed production of some species responded to a diversity gradient, but responses were uncorrelated to productivity responses and not similar within functional groups. Presumably, species richness has complex effects on the biotic and abiotic variables that influence seed production. In total, our results suggest that seed production of co-occurring species will be altered by global change, which may affect plant communities in unpredictable ways. Although functional groups could be used to generalize seed production responses to nitrogen deposition in Minnesota prairies, we

  5. Plant age and genotype affect the bacterial community composition in the tuber rhizosphere of field-grown sweet potato plants.

    PubMed

    Marques, Joana M; da Silva, Thais F; Vollu, Renata E; Blank, Arie F; Ding, Guo-Chun; Seldin, Lucy; Smalla, Kornelia

    2014-05-01

    The hypothesis that sweet potato genotypes containing different starch yields in their tuberous roots can affect the bacterial communities present in the rhizosphere (soil adhering to tubers) was tested in this study. Tuberous roots of field-grown sweet potato of genotypes IPB-149 (commercial genotype), IPB-052, and IPB-137 were sampled three and six months after planting and analyzed by denaturing gradient gel electrophoresis (DGGE) and pyrosequencing analysis of 16S rRNA genes PCR-amplified from total community DNA. The statistical analysis of the DGGE fingerprints showed that both plant age and genotypes influenced the bacterial community structure in the tuber rhizosphere. Pyrosequencing analysis showed that the IPB-149 and IPB-052 (both with high starch content) displayed similar bacterial composition in the tuber rhizosphere, while IPB-137 with the lowest starch content was distinct. In comparison with bulk soil, higher 16S rRNA gene copy numbers (qPCR) and numerous genera with significantly increased abundance in the tuber rhizosphere of IPB-137 (Sphingobium, Pseudomonas, Acinetobacter, Stenotrophomonas, Chryseobacterium) indicated a stronger rhizosphere effect. The genus Bacillus was strongly enriched in the tuber rhizosphere samples of all sweet potato genotypes studied, while other genera showed a plant genotype-dependent abundance. This is the first report on the molecular identification of bacteria being associated with the tuber rhizosphere of different sweet potato genotypes.

  6. The pinyon rhizosphere, plant stress, and herbivory affect the abundance of microbial decomposers in soils.

    PubMed

    Kuske, C R; Ticknor, L O; Busch, J D; Gehring, C A; Whitham, T G

    2003-05-01

    In terrestrial ecosystems, changes in environmental conditions that affect plant performance cause a cascade of effects through many trophic levels. In a 2-year field study, seasonal abundance measurements were conducted for fast-growing bacterial heterotrophs, humate-degrading actinomycetes, fungal heterotrophs, and fluorescent pseudomonads that represent the decomposers in soil. Links between plant health and soil microbiota abundance in pinyon rhizospheres were documented across two soil types: a dry, nutrient-poor volcanic cinder field and a sandy-loam soil. On the stressful cinder fields, we identified relationships between soil decomposer abundance, pinyon age, and stress due to insect herbivory. Across seasonal variation, consistent differences in microbial decomposer abundance were identified between the cinders and sandy-loam soil. Abundance of bacterial heterotrophs and humate-degrading actinomycetes was affected by both soil nutritional status and the pinyon rhizosphere. In contrast, abundance of the fungal heterotrophs and fluorescent pseudomonads was affected primarily by the pinyon rhizosphere. On the cinder field, the three bacterial groups were more abundant on 150-year-old trees than on 60-year-old trees, whereas fungal heterotrophs were unaffected by tree age. Fungal heterotrophs and actinomycetes were more abundant on insect-resistant trees than on susceptible trees, but the opposite was true for the fluorescent pseudomonads. Although all four groups were present in all the environments, the four microbial groups were affected differently by the pinyon rhizosphere, by tree age, and by tree stress caused by the cinder soil and insect herbivory.

  7. Temperature, plants, and oxygen: how does season affect constructed wetland performance?

    PubMed

    Stein, Otto R; Hook, Paul B

    2005-01-01

    The influence of temperature and plant-mediated oxygen transfer continues to draw attention from researchers, practitioners and regulators interested in the use of constructed wetlands for wastewater treatment. Because the vast majority of research on constructed wetland performance has been conducted during periods of active plant growth, the true influence of temperature, season, and plant species selection on constructed wetlands performance has not yet been evaluated adequately. In this article, we briefly summarize changes in the understanding of these influences on wetland performance, and suggest that effects of temperature and oxygen transfer are not readily separable because both factors respond to seasonal cycles and because effects of one can offset the other. We further speculate that the net effect of seasonal variation in these factors is such that plant-mediated oxygen transfer affects water treatment most in winter. Results of controlled-environment experiments conducted at Montana State University support these perspectives. Different plant species' capacities to oxidize the root zone responded differently to seasonal cycles of growth and dormancy, and species' effects on wastewater treatment were most pronounced in winter.

  8. Temperature, plants, and oxygen: how does season affect constructed wetland performance?

    PubMed

    Stein, Otto R; Hook, Paul B

    2005-01-01

    The influence of temperature and plant-mediated oxygen transfer continues to draw attention from researchers, practitioners and regulators interested in the use of constructed wetlands for wastewater treatment. Because the vast majority of research on constructed wetland performance has been conducted during periods of active plant growth, the true influence of temperature, season, and plant species selection on constructed wetlands performance has not yet been evaluated adequately. In this article, we briefly summarize changes in the understanding of these influences on wetland performance, and suggest that effects of temperature and oxygen transfer are not readily separable because both factors respond to seasonal cycles and because effects of one can offset the other. We further speculate that the net effect of seasonal variation in these factors is such that plant-mediated oxygen transfer affects water treatment most in winter. Results of controlled-environment experiments conducted at Montana State University support these perspectives. Different plant species' capacities to oxidize the root zone responded differently to seasonal cycles of growth and dormancy, and species' effects on wastewater treatment were most pronounced in winter. PMID:15921285

  9. High d(+)-fructose diet adversely affects testicular weight gain in weaning rats─protection by moderate d(+)-glucose diet.

    PubMed

    Shibata, Katsumi; Fukuwatari, Tsutomu

    2013-01-01

    The use of high D(+)-fructose corn syrup has increased over the past several decades in the developed countries, while overweight and obesity rates and the related diseases have risen dramatically. However, we found that feeding a high D(+)-fructose diet (80% D(+)-fructose as part of the diet) to weaning rats for 21 days led to reduced food intake (50% less, P < 0.0001) and thus delayed the weight gains in the body (40% less, P < 0.0001) and testes (40% less, P < 0.0001) compared to the no D(+)-fructose diet. We also challenged a minimum requirement of dietary D(+)-glucose for preventing the adverse effects of D(+)-fructose, such as lower food intake and reduction of body weight and testicular weight; the minimum requirement of D(+)-glucose was ≈23% of the diet. This glucose amount may be the minimum requirement of exogenous glucose for reducing weight gain. PMID:23935370

  10. Can corn plants inoculated with arbuscular mycorrhiza fungi affect soil clay assemblage?

    NASA Astrophysics Data System (ADS)

    Adamo, P.; Cozzolino, V.; Di Meo, V.; Velde, B.

    2012-04-01

    Plants can extract K from exchangeable and non-exchangeable sites in the soil clay mineral structures. The latter, known as fixed K, is usually seen as an illite layer, i.e. an anhydrous K layer that forms a 1.0 nm structural layer unit as seen by X-ray diffraction. Nutrient availability can be enhanced in the root zone by arbuscular mycorrhiza fungi. In this study, the effects of non-inoculated and Glomus intraradices inoculated corn plant growth under different experimental conditions on soil K-bearing clay minerals were identified. The soil, a Vertic Xerofluvent, was planted in corn in a 2008-2010 randomized field experiment. Bulk and rhizosphere soil sampling was carried out from May to September 2010 from fertilized plots (N200P90K160 and N200P0K160) with and without plants. According to XRD analysis, three major K-bearing minerals were present in soil: smectite-rich mixed layer mineral, illite-rich mixed layer mineral and illite. Results at 40DAS indicate extraction of K from clay minerals by plant uptake, whereas at 130DAS much of the nutrient seems to be returned to the soil. There is an apparent difference between bulk and rhizophere clays. The XRD patterns are not unequivocally affected by Glomus inoculation. There are observable changes in clay mineralogy in fallow unfertilized compared with fertilized soil. In the studied soil, the illite rich mixed-layer minerals seem to be the source of K absorbed by plants, while illite acts as sink of K released from the plant-microorganisms system at the end of the growing season and as source for the following crop.

  11. CLIMATE CONDITIONS AFFECTING THE WITHIN-PLANT SPREAD OF BROAD MITES ON AZALEA.

    PubMed

    Mechant, E; Pauwels, E; Gobin, B

    2014-01-01

    The broad mite Polyphagotarsonemus latus (Banks) is considered a major pest in potted azalea, Flanders' flagship ornamental crop of Rhododendron simsii hybrids. In addition to severe economic damage, the broad mite is dreaded for its increasing resistance to acaricides. Due to restrictions in the use of broad spectrum acaricides, Belgian azalea growers are left with only three compounds, belonging to two mode of action groups and restricted in their number of applications, for broad mite control: abamectin, milbemectin and pyrethrin. Although P. latus can be controlled with predatory mites, the high cost of this system makes it (not yet) feasible for integration into standard azalea pest management systems. Hence, a maximum efficacy of treatments with available compounds is essential. Because abamectin, milbemectin and pyrethrin are contact acaricides with limited trans laminar flow, only broad mites located on shoot tips of azalea plants will be controlled after spraying. Consequently, the efficacy of chemical treatments is influenced by the location and spread of P. latus on the plant. Unfortunately, little is known on broad mites' within-plant spread or how it is affected by climatic conditions like temperature and relative humidity. Therefore, experiments were set up to verify whether climate conditions have an effect on the location and migration of broad mites on azalea. Broad mite infected azalea plants were placed in standard growth chambers under different temperature (T:2.5-25°C) and relative humidity (RH:55-80%) treatments. Within-plant spread was determined by counting mites on the shoot tips and inner leaves of azalea plants. Results indicate that temperature and relative humidity have no significant effect on the within-plant spread of P. latus. To formulate recommendations for optimal spray conditions to maximize the efficacy of broad mite control with acaricides, further experiments on the effect of light intensity and rain are scheduled.

  12. Glacial history affected phenotypic differentiation in the alpine plant, Campanula thyrsoides.

    PubMed

    Scheepens, J F; Frei, Eva S; Stöcklin, Jürg

    2013-01-01

    Numerous widespread Alpine plant species show molecular differentiation among populations from distinct regions. This has been explained as the result of genetic drift during glacial survival in isolated refugia along the border of the European Alps. Since genetic drift may affect molecular markers and phenotypic traits alike, we asked whether phenotypic differentiation mirrors molecular patterns among Alpine plant populations from different regions. Phenotypic traits can be under selection, so we additionally investigated whether part of the phenotypic differentiation can be explained by past selection and/or current adaptation. Using the monocarpic Campanula thyrsoides as our study species, a common garden experiment with plants from 21 populations from four phylogeographic groups located in regions across the Alps and the Jura Mountains was performed to test for differentiation in morphological and phenological traits. Past selection was investigated by comparing phenotypic differentiation among and within regions with molecular differentiation among and within regions. The common garden results indicated regional differentiation among populations for all investigated phenotypic traits, particularly in phenology. Delayed flowering in plants from the South-eastern Alps suggested adaptation to long sub-mediterranean summers and contrasted with earlier flowering of plants experiencing shorter growing seasons in regions with higher elevation to the West. Comparisons between molecular and phenotypic differentiation revealed diversifying selection among regions in height and biomass, which is consistent with adaptation to environmental conditions in glacial refugia. Within regions, past selection acted against strong diversification for most phenotypic traits, causing restricted postglacial adaptation. Evidence consistent with post-glacial adaptation was also given by negative correlation coefficients between several phenotypic traits and elevation of the population

  13. Plant Protein and Animal Proteins: Do They Differentially Affect Cardiovascular Disease Risk?12

    PubMed Central

    Richter, Chesney K; Skulas-Ray, Ann C; Champagne, Catherine M; Kris-Etherton, Penny M

    2015-01-01

    Proteins from plant-based compared with animal-based food sources may have different effects on cardiovascular disease (CVD) risk factors. Numerous epidemiologic and intervention studies have evaluated their respective health benefits; however, it is difficult to isolate the role of plant or animal protein on CVD risk. This review evaluates the current evidence from observational and intervention studies, focusing on the specific protein-providing foods and populations studied. Dietary protein is derived from many food sources, and each provides a different composite of nonprotein compounds that can also affect CVD risk factors. Increasing the consumption of protein-rich foods also typically results in lower intakes of other nutrients, which may simultaneously influence outcomes. Given these complexities, blanket statements about plant or animal protein may be too general, and greater consideration of the specific protein food sources and the background diet is required. The potential mechanisms responsible for any specific effects of plant and animal protein are similarly multifaceted and include the amino acid content of particular foods, contributions from other nonprotein compounds provided concomitantly by the whole food, and interactions with the gut microbiome. Evidence to date is inconclusive, and additional studies are needed to further advance our understanding of the complexity of plant protein vs. animal protein comparisons. Nonetheless, current evidence supports the idea that CVD risk can be reduced by a dietary pattern that provides more plant sources of protein compared with the typical American diet and also includes animal-based protein foods that are unprocessed and low in saturated fat. PMID:26567196

  14. Sitona lineatus (Coleoptera: Curculionidae) Larval Feeding on Pisum sativum L. Affects Soil and Plant Nitrogen.

    PubMed

    Cárcamo, Héctor A; Herle, Carolyn E; Lupwayi, Newton Z

    2015-01-01

    Adults of Sitona lineatus (pea leaf weevil, PLW) feed on foliage of several Fabaceae species but larvae prefer to feed on nodules of Pisum sativum L. and Vicia faba L. Indirectly, through their feeding on rhizobia, weevils can reduce soil and plant available nitrogen (N). However, initial soil N can reduce nodulation and damage by the weevil and reduce control requirements. Understanding these interactions is necessary to make integrated pest management recommendations for PLW. We conducted a greenhouse study to quantify nodulation, soil and plant N content, and nodule damage by weevil larvae in relation to soil N amendment with urea, thiamethoxam insecticide seed coating and crop stage. PLWs reduced the number of older tumescent (multilobed) nodules and thiamethoxam addition increased them regardless of other factors. Nitrogen amendment significantly increased soil available N (>99% nitrate) as expected and PLW presence was associated with significantly lower levels of soil N. PLW decreased plant N content at early flower and thiamethoxam increased it, particularly at late flower. The study illustrated the complexity of interactions that determine insect herbivory effects on plant and soil nutrition for invertebrates that feed on N-fixing root nodules. We conclude that effects of PLW on nodulation and subsequent effects on plant nitrogen are more pronounced during the early growth stages of the plant. This suggests the importance of timing of PLW infestation and may explain the lack of yield depression in relation to this pest observed in many field studies. Also, pea crops in soils with high levels of soil N are unlikely to be affected by this herbivore and should not require insecticide inputs. PMID:26106086

  15. Plant protein and animal proteins: do they differentially affect cardiovascular disease risk?

    PubMed

    Richter, Chesney K; Skulas-Ray, Ann C; Champagne, Catherine M; Kris-Etherton, Penny M

    2015-11-01

    Proteins from plant-based compared with animal-based food sources may have different effects on cardiovascular disease (CVD) risk factors. Numerous epidemiologic and intervention studies have evaluated their respective health benefits; however, it is difficult to isolate the role of plant or animal protein on CVD risk. This review evaluates the current evidence from observational and intervention studies, focusing on the specific protein-providing foods and populations studied. Dietary protein is derived from many food sources, and each provides a different composite of nonprotein compounds that can also affect CVD risk factors. Increasing the consumption of protein-rich foods also typically results in lower intakes of other nutrients, which may simultaneously influence outcomes. Given these complexities, blanket statements about plant or animal protein may be too general, and greater consideration of the specific protein food sources and the background diet is required. The potential mechanisms responsible for any specific effects of plant and animal protein are similarly multifaceted and include the amino acid content of particular foods, contributions from other nonprotein compounds provided concomitantly by the whole food, and interactions with the gut microbiome. Evidence to date is inconclusive, and additional studies are needed to further advance our understanding of the complexity of plant protein vs. animal protein comparisons. Nonetheless, current evidence supports the idea that CVD risk can be reduced by a dietary pattern that provides more plant sources of protein compared with the typical American diet and also includes animal-based protein foods that are unprocessed and low in saturated fat.

  16. Sitona lineatus (Coleoptera: Curculionidae) Larval Feeding on Pisum sativum L. Affects Soil and Plant Nitrogen

    PubMed Central

    Cárcamo, Héctor A.; Herle, Carolyn E.; Lupwayi, Newton Z.

    2015-01-01

    Adults of Sitona lineatus (pea leaf weevil, PLW) feed on foliage of several Fabaceae species but larvae prefer to feed on nodules of Pisum sativum L. and Vicia faba L. Indirectly, through their feeding on rhizobia, weevils can reduce soil and plant available nitrogen (N). However, initial soil N can reduce nodulation and damage by the weevil and reduce control requirements. Understanding these interactions is necessary to make integrated pest management recommendations for PLW. We conducted a greenhouse study to quantify nodulation, soil and plant N content, and nodule damage by weevil larvae in relation to soil N amendment with urea, thiamethoxam insecticide seed coating and crop stage. PLWs reduced the number of older tumescent (multilobed) nodules and thiamethoxam addition increased them regardless of other factors. Nitrogen amendment significantly increased soil available N (>99% nitrate) as expected and PLW presence was associated with significantly lower levels of soil N. PLW decreased plant N content at early flower and thiamethoxam increased it, particularly at late flower. The study illustrated the complexity of interactions that determine insect herbivory effects on plant and soil nutrition for invertebrates that feed on N-fixing root nodules. We conclude that effects of PLW on nodulation and subsequent effects on plant nitrogen are more pronounced during the early growth stages of the plant. This suggests the importance of timing of PLW infestation and may explain the lack of yield depression in relation to this pest observed in many field studies. Also, pea crops in soils with high levels of soil N are unlikely to be affected by this herbivore and should not require insecticide inputs. PMID:26106086

  17. Sitona lineatus (Coleoptera: Curculionidae) Larval Feeding on Pisum sativum L. Affects Soil and Plant Nitrogen.

    PubMed

    Cárcamo, Héctor A; Herle, Carolyn E; Lupwayi, Newton Z

    2015-01-01

    Adults of Sitona lineatus (pea leaf weevil, PLW) feed on foliage of several Fabaceae species but larvae prefer to feed on nodules of Pisum sativum L. and Vicia faba L. Indirectly, through their feeding on rhizobia, weevils can reduce soil and plant available nitrogen (N). However, initial soil N can reduce nodulation and damage by the weevil and reduce control requirements. Understanding these interactions is necessary to make integrated pest management recommendations for PLW. We conducted a greenhouse study to quantify nodulation, soil and plant N content, and nodule damage by weevil larvae in relation to soil N amendment with urea, thiamethoxam insecticide seed coating and crop stage. PLWs reduced the number of older tumescent (multilobed) nodules and thiamethoxam addition increased them regardless of other factors. Nitrogen amendment significantly increased soil available N (>99% nitrate) as expected and PLW presence was associated with significantly lower levels of soil N. PLW decreased plant N content at early flower and thiamethoxam increased it, particularly at late flower. The study illustrated the complexity of interactions that determine insect herbivory effects on plant and soil nutrition for invertebrates that feed on N-fixing root nodules. We conclude that effects of PLW on nodulation and subsequent effects on plant nitrogen are more pronounced during the early growth stages of the plant. This suggests the importance of timing of PLW infestation and may explain the lack of yield depression in relation to this pest observed in many field studies. Also, pea crops in soils with high levels of soil N are unlikely to be affected by this herbivore and should not require insecticide inputs.

  18. Migration, neighborhoods, and networks: approaches to understanding how urban environmental conditions affect syndemic adverse health outcomes among gay, bisexual and other men who have sex with men.

    PubMed

    Egan, James E; Frye, Victoria; Kurtz, Steven P; Latkin, Carl; Chen, Minxing; Tobin, Karin; Yang, Cui; Koblin, Beryl A

    2011-04-01

    Adopting socioecological, intersectionality, and lifecourse theoretical frameworks may enhance our understanding of the production of syndemic adverse health outcomes among gay, bisexual and other men who have sex with men (MSM). From this perspective, we present preliminary data from three related studies that suggest ways in which social contexts may influence the health of MSM. The first study, using cross-sectional data, looked at migration of MSM to the gay resort area of South Florida, and found that amount of time lived in the area was associated with risk behaviors and HIV infection. The second study, using qualitative interviews, observed complex interactions between neighborhood-level social environments and individual-level racial and sexual identity among MSM in New York City. The third study, using egocentric network analysis with a sample of African American MSM in Baltimore, found that sexual partners were more likely to be found through face-to-face means than the Internet. They also observed that those who co-resided with a sex partner had larger networks of people to depend on for social and financial support, but had the same size sexual networks as those who did not live with a partner. Overall, these findings suggest the need for further investigation into the role of macro-level social forces on the emotional, behavioral, and physical health of urban MSM.

  19. Migration, Neighborhoods, and Networks: Approaches to Understanding How Urban Environmental Conditions Affect Syndemic Adverse Health Outcomes Among Gay, Bisexual and Other Men Who Have Sex with Men

    PubMed Central

    Egan, James E.; Kurtz, Steven P.; Latkin, Carl; Chen, Minxing; Tobin, Karin; Yang, Cui; Koblin, Beryl A.

    2011-01-01

    Adopting socioecological, intersectionality, and lifecourse theoretical frameworks may enhance our understanding of the production of syndemic adverse health outcomes among gay, bisexual and other men who have sex with men (MSM). From this perspective, we present preliminary data from three related studies that suggest ways in which social contexts may influence the health of MSM. The first study, using cross-sectional data, looked at migration of MSM to the gay resort area of South Florida, and found that amount of time lived in the area was associated with risk behaviors and HIV infection. The second study, using qualitative interviews, observed complex interactions between neighborhood-level social environments and individual-level racial and sexual identity among MSM in New York City. The third study, using egocentric network analysis with a sample of African American MSM in Baltimore, found that sexual partners were more likely to be found through face-to-face means than the Internet. They also observed that those who co-resided with a sex partner had larger networks of people to depend on for social and financial support, but had the same size sexual networks as those who did not live with a partner. Overall, these findings suggest the need for further investigation into the role of macro-level social forces on the emotional, behavioral, and physical health of urban MSM. PMID:21369730

  20. Rock glacier outflows may adversely affect lakes: lessons from the past and present of two neighboring water bodies in a crystalline-rock watershed.

    PubMed

    Ilyashuk, Boris P; Ilyashuk, Elena A; Psenner, Roland; Tessadri, Richard; Koinig, Karin A

    2014-06-01

    Despite the fact that rock glaciers are one of the most common geomorphological expressions of mountain permafrost, the impacts of their solute fluxes on lakes still remain largely obscure. We examined water and sediment chemistry, and biota of two neighboring water bodies with and without a rock glacier in their catchments in the European Alps. Paleolimnological techniques were applied to track long-term temporal trends in the ecotoxicological state of the water bodies and to establish their baseline conditions. We show that the active rock glacier in the mineralized catchment of Lake Rasass (RAS) represents a potent source of acid rock drainage that results in enormous concentrations of metals in water, sediment, and biota of RAS. The incidence of morphological abnormalities in the RAS population of Pseudodiamesa nivosa, a chironomid midge, is as high as that recorded in chironomid populations inhabiting sites heavily contaminated by trace metals of anthropogenic origin. The incidence of morphological deformities in P. nivosa of ∼70% persisted in RAS during the last 2.5 millennia and was ∼40% in the early Holocene. The formation of RAS at the toe of the rock glacier most probably began at the onset of acidic drainage in the freshly deglaciated area. The present adverse conditions are not unprecedented in the lake's history and cannot be associated exclusively with enhanced thawing of the rock glacier in recent years.

  1. Migration, neighborhoods, and networks: approaches to understanding how urban environmental conditions affect syndemic adverse health outcomes among gay, bisexual and other men who have sex with men.

    PubMed

    Egan, James E; Frye, Victoria; Kurtz, Steven P; Latkin, Carl; Chen, Minxing; Tobin, Karin; Yang, Cui; Koblin, Beryl A

    2011-04-01

    Adopting socioecological, intersectionality, and lifecourse theoretical frameworks may enhance our understanding of the production of syndemic adverse health outcomes among gay, bisexual and other men who have sex with men (MSM). From this perspective, we present preliminary data from three related studies that suggest ways in which social contexts may influence the health of MSM. The first study, using cross-sectional data, looked at migration of MSM to the gay resort area of South Florida, and found that amount of time lived in the area was associated with risk behaviors and HIV infection. The second study, using qualitative interviews, observed complex interactions between neighborhood-level social environments and individual-level racial and sexual identity among MSM in New York City. The third study, using egocentric network analysis with a sample of African American MSM in Baltimore, found that sexual partners were more likely to be found through face-to-face means than the Internet. They also observed that those who co-resided with a sex partner had larger networks of people to depend on for social and financial support, but had the same size sexual networks as those who did not live with a partner. Overall, these findings suggest the need for further investigation into the role of macro-level social forces on the emotional, behavioral, and physical health of urban MSM. PMID:21369730

  2. Rock Glacier Outflows May Adversely Affect Lakes: Lessons from the Past and Present of Two Neighboring Water Bodies in a Crystalline-Rock Watershed

    PubMed Central

    2014-01-01

    Despite the fact that rock glaciers are one of the most common geomorphological expressions of mountain permafrost, the impacts of their solute fluxes on lakes still remain largely obscure. We examined water and sediment chemistry, and biota of two neighboring water bodies with and without a rock glacier in their catchments in the European Alps. Paleolimnological techniques were applied to track long-term temporal trends in the ecotoxicological state of the water bodies and to establish their baseline conditions. We show that the active rock glacier in the mineralized catchment of Lake Rasass (RAS) represents a potent source of acid rock drainage that results in enormous concentrations of metals in water, sediment, and biota of RAS. The incidence of morphological abnormalities in the RAS population of Pseudodiamesa nivosa, a chironomid midge, is as high as that recorded in chironomid populations inhabiting sites heavily contaminated by trace metals of anthropogenic origin. The incidence of morphological deformities in P. nivosa of ∼70% persisted in RAS during the last 2.5 millennia and was ∼40% in the early Holocene. The formation of RAS at the toe of the rock glacier most probably began at the onset of acidic drainage in the freshly deglaciated area. The present adverse conditions are not unprecedented in the lake’s history and cannot be associated exclusively with enhanced thawing of the rock glacier in recent years. PMID:24804777

  3. Synthetic progestins medroxyprogesterone acetate and dydrogesterone and their binary mixtures adversely affect reproduction and lead to histological and transcriptional alterations in zebrafish (Danio rerio).

    PubMed

    Zhao, Yanbin; Castiglioni, Sara; Fent, Karl

    2015-04-01

    Medroxyprogesterone acetate (MPA) and dydrogesterone (DDG) are synthetic progestins widely used in human and veterinary medicine. Although aquatic organisms are exposed to them through wastewater and animal farm runoff, very little is known about their effects in the environment. Here we provide a comprehensive analysis of the responses of zebrafish (Danio rerio) to MPA, DDG, and their binary mixtures at measured concentrations between 4.5 and 1663 ng/L. DDG and both mixtures impaired reproductive capacities (egg production) of breeding pairs and led to histological alterations of ovaries and testes and increased gonadosomatic index. Transcriptional analysis of up to 28 genes belonging to different pathways demonstrated alterations in steroid hormone receptors, steroidogenesis enzymes, and specifically, the circadian rhythm genes, in different organs of adult zebrafish and eleuthero-embryos. Alterations occurred even at environmentally relevant concentrations of 4.5-4.8 ng/L MPA, DDG and the mixture in eleuthero-embryos and at 43-89 ng/L in adult zebrafish. Additionally, the mixtures displayed additive effects in most but not all parameters in adults and eleuthero-embryos, suggesting concentration addition. Our data suggest that MPA and DDG and their mixtures induce multiple transcriptional responses at environmentally relevant concentrations and adverse effects on reproduction and gonad histology at higher levels.

  4. Population variation affects interactions between two California salt marsh plant species more than precipitation.

    PubMed

    Noto, Akana E; Shurin, Jonathan B

    2016-02-01

    Species that occur along broad environmental gradients often vary in phenotypic traits that make them better adapted to local conditions. Variation in species interactions across gradients could therefore be due to either phenotypic differences among populations or environmental conditions that shift the balance between competition and facilitation. To understand how the environment (precipitation) and variation among populations affect species interactions, we conducted a common garden experiment using two common salt marsh plant species, Salicornia pacifica and Jaumea carnosa, from six salt marshes along the California coast encompassing a large precipitation gradient. Plants were grown alone or with an individual of the opposite species from the same site and exposed to one of three precipitation regimes. J. carnosa was negatively affected in the presence of S. pacifica, while S. pacifica was facilitated by J. carnosa. The strength of these interactions varied by site of origin but not by precipitation treatment. These results suggest that phenotypic variation among populations can affect interaction strength more than environment, despite a threefold difference in precipitation. Geographic intraspecific variation may therefore play an important role in determining the strength of interactions in communities.

  5. Population variation affects interactions between two California salt marsh plant species more than precipitation.

    PubMed

    Noto, Akana E; Shurin, Jonathan B

    2016-02-01

    Species that occur along broad environmental gradients often vary in phenotypic traits that make them better adapted to local conditions. Variation in species interactions across gradients could therefore be due to either phenotypic differences among populations or environmental conditions that shift the balance between competition and facilitation. To understand how the environment (precipitation) and variation among populations affect species interactions, we conducted a common garden experiment using two common salt marsh plant species, Salicornia pacifica and Jaumea carnosa, from six salt marshes along the California coast encompassing a large precipitation gradient. Plants were grown alone or with an individual of the opposite species from the same site and exposed to one of three precipitation regimes. J. carnosa was negatively affected in the presence of S. pacifica, while S. pacifica was facilitated by J. carnosa. The strength of these interactions varied by site of origin but not by precipitation treatment. These results suggest that phenotypic variation among populations can affect interaction strength more than environment, despite a threefold difference in precipitation. Geographic intraspecific variation may therefore play an important role in determining the strength of interactions in communities. PMID:26481794

  6. Plant species richness and functional traits affect community stability after a flood event.

    PubMed

    Fischer, Felícia M; Wright, Alexandra J; Eisenhauer, Nico; Ebeling, Anne; Roscher, Christiane; Wagg, Cameron; Weigelt, Alexandra; Weisser, Wolfgang W; Pillar, Valério D

    2016-05-19

    Climate change is expected to increase the frequency and magnitude of extreme weather events. It is therefore of major importance to identify the community attributes that confer stability in ecological communities during such events. In June 2013, a flood event affected a plant diversity experiment in Central Europe (Jena, Germany). We assessed the effects of plant species richness, functional diversity, flooding intensity and community means of functional traits on different measures of stability (resistance, resilience and raw biomass changes from pre-flood conditions). Surprisingly, plant species richness reduced community resistance in response to the flood. This was mostly because more diverse communities grew more immediately following the flood. Raw biomass increased over the previous year; this resulted in decreased absolute value measures of resistance. There was no clear response pattern for resilience. We found that functional traits drove these changes in raw biomass: communities with a high proportion of late-season, short-statured plants with dense, shallow roots and small leaves grew more following the flood. Late-growing species probably avoided the flood, whereas greater root length density might have allowed species to better access soil resources brought from the flood, thus growing more in the aftermath. We conclude that resource inputs following mild floods may favour the importance of traits related to resource acquisition and be less associated with flooding tolerance.

  7. Different Degrees of Plant Invasion Significantly Affect the Richness of the Soil Fungal Community

    PubMed Central

    Si, Chuncan; Liu, Xueyan; Wang, Congyan; Wang, Lei; Dai, Zhicong; Qi, Shanshan; Du, Daolin

    2013-01-01

    Several studies have shown that soil microorganisms play a key role in the success of plant invasion. Thus, ecologists have become increasingly interested in understanding the ecological effects of biological invasion on soil microbial communities given continuing increase in the effects of invasive plants on native ecosystems. This paper aims to provide a relatively complete depiction of the characteristics of soil microbial communities under different degrees of plant invasion. Rhizospheric soils of the notorious invasive plant Wedelia trilobata with different degrees of invasion (uninvaded, low-degree, and high-degree using its coverage in the invaded ecosystems) were collected from five discrete areas in Hainan Province, P. R. China. Soil physicochemical properties and community structure of soil microorganisms were assessed. Low degrees of W. trilobata invasion significantly increased soil pH values whereas high degrees of invasion did not significantly affected soil pH values. Moreover, the degree of W. trilobata invasion exerted significant effects on soil Ca concentration but did not significantly change other indices of soil physicochemical properties. Low and high degrees of W. trilobata invasion increased the richness of the soil fungal community but did not pose obvious effects on the soil bacterial community. W. trilobata invasion also exerted obvious effects on the community structure of soil microorganisms that take part in soil nitrogen cycling. These changes in soil physicochemical properties and community structure of soil microbial communities mediated by different degrees of W. trilobata invasion may present significant functions in further facilitating the invasion process. PMID:24392015

  8. Plant species richness and functional traits affect community stability after a flood event.

    PubMed

    Fischer, Felícia M; Wright, Alexandra J; Eisenhauer, Nico; Ebeling, Anne; Roscher, Christiane; Wagg, Cameron; Weigelt, Alexandra; Weisser, Wolfgang W; Pillar, Valério D

    2016-05-19

    Climate change is expected to increase the frequency and magnitude of extreme weather events. It is therefore of major importance to identify the community attributes that confer stability in ecological communities during such events. In June 2013, a flood event affected a plant diversity experiment in Central Europe (Jena, Germany). We assessed the effects of plant species richness, functional diversity, flooding intensity and community means of functional traits on different measures of stability (resistance, resilience and raw biomass changes from pre-flood conditions). Surprisingly, plant species richness reduced community resistance in response to the flood. This was mostly because more diverse communities grew more immediately following the flood. Raw biomass increased over the previous year; this resulted in decreased absolute value measures of resistance. There was no clear response pattern for resilience. We found that functional traits drove these changes in raw biomass: communities with a high proportion of late-season, short-statured plants with dense, shallow roots and small leaves grew more following the flood. Late-growing species probably avoided the flood, whereas greater root length density might have allowed species to better access soil resources brought from the flood, thus growing more in the aftermath. We conclude that resource inputs following mild floods may favour the importance of traits related to resource acquisition and be less associated with flooding tolerance. PMID:27114578

  9. Common gas phase molecules from fungi affect seed germination and plant health in Arabidopsis thaliana

    PubMed Central

    2014-01-01

    Fungal volatile organic compounds (VOCs) play important ecophysiological roles in mediating inter-kingdom signaling with arthropods but less is known about their interactions with plants. In this study, Arabidopsis thaliana was used as a model in order to test the physiological effects of 23 common vapor-phase fungal VOCs that included alcohols, aldehydes, ketones, and other chemical classes. After exposure to a shared atmosphere with the 23 individual VOCs for 72 hrs, seeds were assayed for rate of germination and seedling formation; vegetative plants were assayed for fresh weight and chlorophyll concentration. All but five of the VOCs tested (1-decene, 2-n-heptylfuran, nonanal, geosmin and -limonene) had a significant effect in inhibiting either germination, seedling formation or both. Seedling formation was entirely inhibited by exposure to 1-octen-3-one, 2-ethylhexanal, 3-methylbutanal, and butanal. As assayed by a combination of fresh weight and chlorophyll concentration, 2-ethylhexanal had a negative impact on two-week-old vegetative plants. Three other compounds (1-octen-3-ol, 2-ethylhexanal, and 2-heptylfuran) decreased fresh weight alone. Most of the VOCs tested did not change the fresh weight or chlorophyll concentration of vegetative plants. In summary, when tested as single compounds, fungal VOCs affected A. thaliana in positive, negative or neutral ways. PMID:25045602

  10. A hyperparasite affects the population dynamics of a wild plant pathogen

    PubMed Central

    Tollenaere, C; Pernechele, B; Mäkinen, H S; Parratt, S R; Németh, M Z; Kovács, G M; Kiss, L; Tack, A J M; Laine, A-L

    2014-01-01

    Assessing the impact of natural enemies of plant and animal pathogens on their host's population dynamics is needed to determine the role of hyperparasites in affecting disease dynamics, and their potential for use in efficient control strategies of pathogens. Here, we focus on the long-term study describing metapopulation dynamics of an obligate pathogen, the powdery mildew (Podosphaera plantaginis) naturally infecting its wild host plant (Plantago lanceolata) in the fragmented landscape of the Åland archipelago (southwest Finland). Regionally, the pathogen persists through a balance of extinctions and colonizations, yet factors affecting extinction rates remain poorly understood. Mycoparasites of the genus Ampelomyces appear as good candidates for testing the role of a hyperparasite, i.e. a parasite of other parasites, in the regulation of their fungal hosts' population dynamics. For this purpose, we first designed a quantitative PCR assay for detection of Ampelomyces spp. in field-collected samples. This newly developed molecular test was then applied to a large-scale sampling within the Åland archipelago, revealing that Ampelomyces is a widespread hyperparasite in this system, with high variability in prevalence among populations. We found that the hyperparasite was more common on leaves where multiple powdery mildew strains coexist, a pattern that may be attributed to differential exposure. Moreover, the prevalence of Ampelomyces at the plant level negatively affected the overwinter survival of its fungal host. We conclude that this hyperparasite may likely impact on its host population dynamics and argue for increased focus on the role of hyperparasites in disease dynamics. PMID:25204419

  11. Spectral quality affects disease development of three pathogens on hydroponically grown plants.

    PubMed

    Schuerger, A C; Brown, C S

    1997-02-01

    Plants were grown under light-emitting diode (LED) arrays with various spectra to determine the effects of light quality on the development of diseases caused by tomato mosaic virus (ToMV) on pepper (Capsicum annuum L.), powdery mildew [Sphaerotheca fuliginea (Schlectend:Fr.) Pollaci] on cucumber (Cucumis sativus L.), and bacterial wilt (Pseudomonas solanacearum Smith) on tomato (Lycopersicon esculentum Mill.). One LED (660) array supplied 99% red light at 660 nm (25 nm bandwidth at half-peak height) and 1% far-red light between 700 to 800 nm. A second LED (660/735) array supplied 83% red light at 660 nm and 17% far-red light at 735 nm (25 nm bandwidth at half-peak height). A third LED (660/BF) array supplied 98% red light at 660 nm, 1% blue light (BF) between 350 to 550 nm, and 1% far-red light between 700 to 800 nm. Control plants were grown under broad-spectrum metal halide (MH) lamps. Plants were grown at a mean photon flux (300 to 800 nm) of 330 micromoles m-2 s-1 under a 12-h day/night photoperiod. Spectral quality affected each pathosystem differently. In the ToMV/pepper pathosystem, disease symptoms developed slower and were less severe in plants grown under light sources that contained blue and UV-A wavelengths (MH and 660/BF treatments) compared to plants grown under light sources that lacked blue and UV-A wavelengths (660 and 660/735 LED arrays). In contrast, the number of colonies per leaf was highest and the mean colony diameters of S. fuliginea on cucumber plants were largest on leaves grown under the MH lamp (highest amount of blue and UV-A light) and least on leaves grown under the 660 LED array (no blue or UV-A light). The addition of far-red irradiation to the primary light source in the 660/735 LED array increased the colony counts per leaf in the S. fuliginea/cucumber pathosystem compared to the red-only (660) LED array. In the P. solanacearum/tomato pathosystem, disease symptoms were less severe in plants grown under the 660 LED array, but the

  12. Spectral quality affects disease development of three pathogens on hydroponically grown plants

    NASA Technical Reports Server (NTRS)

    Schuerger, A. C.; Brown, C. S.; Sager, J. C. (Principal Investigator)

    1997-01-01

    Plants were grown under light-emitting diode (LED) arrays with various spectra to determine the effects of light quality on the development of diseases caused by tomato mosaic virus (ToMV) on pepper (Capsicum annuum L.), powdery mildew [Sphaerotheca fuliginea (Schlectend:Fr.) Pollaci] on cucumber (Cucumis sativus L.), and bacterial wilt (Pseudomonas solanacearum Smith) on tomato (Lycopersicon esculentum Mill.). One LED (660) array supplied 99% red light at 660 nm (25 nm bandwidth at half-peak height) and 1% far-red light between 700 to 800 nm. A second LED (660/735) array supplied 83% red light at 660 nm and 17% far-red light at 735 nm (25 nm bandwidth at half-peak height). A third LED (660/BF) array supplied 98% red light at 660 nm, 1% blue light (BF) between 350 to 550 nm, and 1% far-red light between 700 to 800 nm. Control plants were grown under broad-spectrum metal halide (MH) lamps. Plants were grown at a mean photon flux (300 to 800 nm) of 330 micromoles m-2 s-1 under a 12-h day/night photoperiod. Spectral quality affected each pathosystem differently. In the ToMV/pepper pathosystem, disease symptoms developed slower and were less severe in plants grown under light sources that contained blue and UV-A wavelengths (MH and 660/BF treatments) compared to plants grown under light sources that lacked blue and UV-A wavelengths (660 and 660/735 LED arrays). In contrast, the number of colonies per leaf was highest and the mean colony diameters of S. fuliginea on cucumber plants were largest on leaves grown under the MH lamp (highest amount of blue and UV-A light) and least on leaves grown under the 660 LED array (no blue or UV-A light). The addition of far-red irradiation to the primary light source in the 660/735 LED array increased the colony counts per leaf in the S. fuliginea/cucumber pathosystem compared to the red-only (660) LED array. In the P. solanacearum/tomato pathosystem, disease symptoms were less severe in plants grown under the 660 LED array, but the

  13. Spectral quality affects disease development of three pathogens on hydroponically grown plants.

    PubMed

    Schuerger, A C; Brown, C S

    1997-02-01

    Plants were grown under light-emitting diode (LED) arrays with various spectra to determine the effects of light quality on the development of diseases caused by tomato mosaic virus (ToMV) on pepper (Capsicum annuum L.), powdery mildew [Sphaerotheca fuliginea (Schlectend:Fr.) Pollaci] on cucumber (Cucumis sativus L.), and bacterial wilt (Pseudomonas solanacearum Smith) on tomato (Lycopersicon esculentum Mill.). One LED (660) array supplied 99% red light at 660 nm (25 nm bandwidth at half-peak height) and 1% far-red light between 700 to 800 nm. A second LED (660/735) array supplied 83% red light at 660 nm and 17% far-red light at 735 nm (25 nm bandwidth at half-peak height). A third LED (660/BF) array supplied 98% red light at 660 nm, 1% blue light (BF) between 350 to 550 nm, and 1% far-red light between 700 to 800 nm. Control plants were grown under broad-spectrum metal halide (MH) lamps. Plants were grown at a mean photon flux (300 to 800 nm) of 330 micromoles m-2 s-1 under a 12-h day/night photoperiod. Spectral quality affected each pathosystem differently. In the ToMV/pepper pathosystem, disease symptoms developed slower and were less severe in plants grown under light sources that contained blue and UV-A wavelengths (MH and 660/BF treatments) compared to plants grown under light sources that lacked blue and UV-A wavelengths (660 and 660/735 LED arrays). In contrast, the number of colonies per leaf was highest and the mean colony diameters of S. fuliginea on cucumber plants were largest on leaves grown under the MH lamp (highest amount of blue and UV-A light) and least on leaves grown under the 660 LED array (no blue or UV-A light). The addition of far-red irradiation to the primary light source in the 660/735 LED array increased the colony counts per leaf in the S. fuliginea/cucumber pathosystem compared to the red-only (660) LED array. In the P. solanacearum/tomato pathosystem, disease symptoms were less severe in plants grown under the 660 LED array, but the

  14. 2.45-GHz microwave irradiation adversely affects reproductive function in male mouse, Mus musculus by inducing oxidative and nitrosative stress.

    PubMed

    Shahin, S; Mishra, V; Singh, S P; Chaturvedi, C M

    2014-05-01

    Electromagnetic radiations are reported to produce long-term and short-term biological effects, which are of great concern to human health due to increasing use of devices emitting EMR especially microwave (MW) radiation in our daily life. In view of the unavoidable use of MW emitting devices (microwaves oven, mobile phones, Wi-Fi, etc.) and their harmful effects on biological system, it was thought worthwhile to investigate the long-term effects of low-level MW irradiation on the reproductive function of male Swiss strain mice and its mechanism of action. Twelve-week-old mice were exposed to non-thermal low-level 2.45-GHz MW radiation (CW for 2 h/day for 30 days, power density = 0.029812 mW/cm(2) and SAR = 0.018 W/Kg). Sperm count and sperm viability test were done as well as vital organs were processed to study different stress parameters. Plasma was used for testosterone and testis for 3β HSD assay. Immunohistochemistry of 3β HSD and nitric oxide synthase (i-NOS) was also performed in testis. We observed that MW irradiation induced a significant decrease in sperm count and sperm viability along with the decrease in seminiferous tubule diameter and degeneration of seminiferous tubules. Reduction in testicular 3β HSD activity and plasma testosterone levels was also noted in the exposed group of mice. Increased expression of testicular i-NOS was observed in the MW-irradiated group of mice. Further, these adverse reproductive effects suggest that chronic exposure to nonionizing MW radiation may lead to infertility via free radical species-mediated pathway. PMID:24490664

  15. 2.45-GHz microwave irradiation adversely affects reproductive function in male mouse, Mus musculus by inducing oxidative and nitrosative stress.

    PubMed

    Shahin, S; Mishra, V; Singh, S P; Chaturvedi, C M

    2014-05-01

    Electromagnetic radiations are reported to produce long-term and short-term biological effects, which are of great concern to human health due to increasing use of devices emitting EMR especially microwave (MW) radiation in our daily life. In view of the unavoidable use of MW emitting devices (microwaves oven, mobile phones, Wi-Fi, etc.) and their harmful effects on biological system, it was thought worthwhile to investigate the long-term effects of low-level MW irradiation on the reproductive function of male Swiss strain mice and its mechanism of action. Twelve-week-old mice were exposed to non-thermal low-level 2.45-GHz MW radiation (CW for 2 h/day for 30 days, power density = 0.029812 mW/cm(2) and SAR = 0.018 W/Kg). Sperm count and sperm viability test were done as well as vital organs were processed to study different stress parameters. Plasma was used for testosterone and testis for 3β HSD assay. Immunohistochemistry of 3β HSD and nitric oxide synthase (i-NOS) was also performed in testis. We observed that MW irradiation induced a significant decrease in sperm count and sperm viability along with the decrease in seminiferous tubule diameter and degeneration of seminiferous tubules. Reduction in testicular 3β HSD activity and plasma testosterone levels was also noted in the exposed group of mice. Increased expression of testicular i-NOS was observed in the MW-irradiated group of mice. Further, these adverse reproductive effects suggest that chronic exposure to nonionizing MW radiation may lead to infertility via free radical species-mediated pathway.

  16. Soil biota can change after exotic plant invasion: Does this affect ecosystem processes?

    USGS Publications Warehouse

    Belnap, J.; Phillips, S.L.; Sherrod, S.K.; Moldenke, A.

    2005-01-01

    Invasion of the exotic annual grass Bromus tectorum into stands of the native perennial grass Hilaria jamesii significantly reduced the abundance of soil biota, especially microarthropods and nematodes. Effects of invasion on active and total bacterial and fungal biomass were variable, although populations generally increased after 50+ years of invasion. The invasion of Bromus also resulted in a decrease in richness and a species shift in plants, microarthropods, fungi, and nematodes. However, despite the depauperate soil fauna at the invaded sites, no effects were seen on cellulose decomposition rates, nitrogen mineralization rates, or vascular plant growth. When Hilaria was planted into soils from not-invaded, recently invaded, and historically invaded sites (all currently or once dominated by Hilaria), germination and survivorship were not affected. In contrast, aboveground Hilaria biomass was significantly greater in recently invaded soils than in the other two soils. We attributed the Hilaria response to differences in soil nutrients present before the invasion, especially soil nitrogen, phosphorus, and potassium, as these nutrients were elevated in the soils that produced the greatest Hilaria biomass. Our data suggest that it is not soil biotic richness per se that determines soil process rates or plant productivity, but instead that either (1) the presence of a few critical soil food web taxa can keep ecosystem function high, (2) nutrient loss is very slow in this ecosystem, and/or (3) these processes are microbially driven. However, the presence of Bromus may reduce key soil nutrients over time and thus may eventually suppress native plant success. ?? 2005 by the Ecological Society of America.

  17. Bioaerosols from a Food Waste Composting Plant Affect Human Airway Epithelial Cell Remodeling Genes

    PubMed Central

    Chang, Ming-Wei; Lee, Chung-Ru; Hung, Hsueh-Fen; Teng, Kuo-Sheng; Huang, Hsin; Chuang, Chun-Yu

    2013-01-01

    The composting procedure in food waste plants generates airborne bioaerosols that have the potential to damage human airway epithelial cells. Persistent inflammation and repair responses induce airway remodeling and damage to the respiratory system. This study elucidated the expression changes of airway remodeling genes in human lung mucoepidermoid NCI-H292 cells exposed to bioaerosols from a composting plant. Different types of microorganisms were detectable in the composting plant, using the agar culture method. Real-time polymerase chain reaction was used to quantify the level of Aspergillus fumigatus and the profile of remodeling genes. The real-time PCR results indicated that the amount of A. fumigatus in the composting hall was less than 102 conidia. The endotoxins in the field bioaerosols were determined using a limulus amebocyte lysate test. The endotoxin levels depended on the type of particulate matter (PM), with coarse particles (2.5–10 μm) having higher endotoxin levels than did fine particles (0.5–2.5 μm). After exposure to the conditioned medium of field bioaerosol samples, NCI-H292 cells showed increased pro-inflammatory interleukin (IL)-6 release and activated epidermal growth factor receptor (EGFR), transforming growth factor (TGF)-β1 and cyclin-dependent kinase inhibitor 1 (p21WAF1/CIP1) gene expression, but not of matrix metallopeptidase (MMP)-9. Airborne endotoxin levels were higher inside the composting hall than they were in other areas, and they were associated with PM. This suggested that airborne bioaerosols in the composting plant contained endotoxins and microorganisms besides A. fumigatus that cause the inflammatory cytokine secretion and augment the expression of remodeling genes in NCI-H292 cells. It is thus necessary to monitor potentially hazardous materials from bioaerosols in food composting plants, which could affect the health of workers. PMID:24368426

  18. Dynamic Response of Large Wind Power Plant Affected by Diverse Conditions at Individual Turbines

    SciTech Connect

    Elizondo, Marcelo A.; Lu, Shuai; Lin, Guang; Wang, Shaobu

    2014-07-31

    Diverse operating conditions at individual wind turbine generators (WTG) within wind power plants (WPPs) can affect the WPP dynamic response to system faults. For example, individual WTGs can experience diverse terminal voltage and power output caused by different wind direction and speed, affecting the response of protection and control limiters. In this paper, we present a study to investigate the dynamic response of a detailed WPP model under diverse power outputs of its individual WTGs. Wake effect is considered as the reason for diverse power outputs. The diverse WTG power output is evaluated in a test system where a large 168-machine test WPP is connected to the IEEE-39-bus system. The power output from each WTG is derived from a wake effect model that uses realistic statistical data for incoming wind speed and direction. The results show that diverse WTG output due to wake effect can affect the WPP dynamic response activating specialized control in some turbines. In addition, transient stability is affected by exhibiting uncertainty in critical clearing time calculation.

  19. Factors Affecting Population Trends of Plant-Parasitic Nematodes on Rangeland Grasses

    PubMed Central

    Griffin, G. D.; Asay, K. H.; Horton, W. H.

    1996-01-01

    The effects of environmental conditions on population trends of plant-parasitic nematodes were studied in experimental plots of five wheatgrasses in the western Utah desert. In a 3-year (1984-86) field study, soil water and temperature affected the population trends of the ectoparasites, Tylenchorhynchus acutoides and Xiphinema americanum, and the migratory endoparasite, Pratylenchus neglectus, on Fairway crested wheatgrass, Agropyron cristatum; 'Hycrest' crested wheatgrass, A. cristatum X A. desertorura; 'Rosana' western wheatgrass, Pascopyrum smithii; 'Oahe' intermediate wheatgrass, Thinopyrum intermedium; and RS-1 hybrid (Elytrigia repens X Pseudoroegneria spicata). The largest soil populations of these nematode species were collected in 1984 under good plant-growth conditions. A reduction in nematode populations occurred in 1985 and 1986, possibly because of low soil-water conditions. There was a positive relationship between high soil water and maximum population densities of T. acutoides in the spring and fall of 1984, and between low soil water and minimum population densities of the nematode in 1985 and 1986. Pratylenchus neglectus populations were affected by soil water, although to a lesser degree than the ectoparasitic nematodes. Population densities of the three nematode species were significantly lower in the drier years of 1985 and 1986 than in 1984. Nematode populations were greater at the lower soil depths in the fall than in the spring or summer. PMID:19277352

  20. The odor of a plant metabolite affects life history traits in dietary restricted adult olive flies.

    PubMed

    Gerofotis, Christos D; Ioannou, Charalampos S; Nakas, Christos T; Papadopoulos, Nikos T

    2016-01-01

    Food quality shapes life history traits either directly or through response of individuals to additional environmental factors, such as chemical cues. Plant extracts used as food additives modulate key life history traits; however little is known regarding such effects for olfactory chemical cues. Exploiting an interesting experimental system that involves the olive fly (Bactrocera oleae) and the plant metabolite α-pinene we asked whether exposure of adults to this compound modulates adult longevity and female reproduction in similar manner in a stressful - dietary (protein) restricted (DR) and in a relaxed- full diet (FD) feeding environment. Accordingly, we exposed males and females to the aroma of α-pinene and measured lifespan and age-specific fecundity in the above two dietary contexts. Our results demonstrate that exposure to α-pinene increased longevity in males and fecundity in females only under dietary restricted conditions. In relaxed food conditions, females exposed to α-pinene shifted high egg-laying towards younger ages compared to non-exposed ones. This is the first report demonstrating that a plant compound affects key life history traits of adult olive flies through olfaction. These effects are sex-specific and more pronounced in dietary restricted adults. Possible underlying mechanisms and the ecological significance are discussed. PMID:27339862

  1. Host plant affects the sexual attractiveness of the female white-spotted longicorn beetle, Anoplophora malasiaca.

    PubMed

    Yasui, Hiroe; Fujiwara-Tsujii, Nao

    2016-01-01

    Anoplophora malasiaca (Coleoptera: Cerambycidae) is a serious pest that destroys various landscape and crop trees in Japan. We evaluated the precopulatory responses of three different A. malasiaca populations collected from mandarin orange, willow and blueberry trees. Most of the males accepted mates from within the same host plant population as well as females from the willow and blueberry populations. However, significant number of males from the blueberry and willow populations rejected females from the mandarin orange population immediately after touching them with their antennae. Because all three of the female populations produced contact sex pheromones on their elytra, the females of the mandarin orange population were predicted to possess extra chemicals that repelled the males of the other two populations. β-Elemene was identified as a key component that was only found in mandarin orange-fed females and induced a rejection response in willow-fed males. Our results represent the first example of a female-acquired repellent against conspecific males of different host plant populations, indicating that the host plant greatly affects the female's sexual attractiveness. PMID:27412452

  2. Does Plant Biomass Manipulation in Static Chambers Affect Nitrous Oxide Emissions from Soils?

    PubMed

    Collier, Sarah M; Dean, Andrew P; Oates, Lawrence G; Ruark, Matthew D; Jackson, Randall D

    2016-03-01

    One of the most widespread approaches for measurement of greenhouse gas emissions from soils involves the use of static chambers. This method is relatively inexpensive, is easily replicated, and is ideally suited to plot-based experimental systems. Among its limitations is the loss of detection sensitivity with increasing chamber height, which creates challenges for deployment in systems including tall vegetation. It is not always possible to avoid inclusion of plants within chambers or to extend chamber height to fully accommodate plant growth. Thus, in many systems, such as perennial forages and biomass crops, plants growing within static chambers must either be trimmed or folded during lid closure. Currently, data on how different types of biomass manipulation affect measured results is limited. Here, we compare the effects of cutting vs. folding of biomass on nitrous oxide measurements in switchgrass ( L.) and alfalfa ( L.) systems. We report only limited evidence of treatment effects during discrete sampling events and little basis for concern that effects may intensify over time as biomass manipulation is repeatedly imposed. However, nonsignificant treatment effects that were consistently present amounted to significant overall trends in three out of the four systems studied. Such minor disparities in flux could amount to considerable quantities over time, suggesting that caution should be exercised when comparing cumulative emission values from studies using different biomass manipulation strategies.

  3. Inhibitors of plant invertases do not affect the structurally related enzymes of fructan metabolism.

    PubMed

    Kusch, Ute; Harms, Karsten; Rausch, Thomas; Greiner, Steffen

    2009-01-01

    Plant fructan active enzymes (FAZYs), including the enzymes involved in inulin metabolism, namely sucrose:sucrose 1-fructosyltransferase (1-SST; EC 2.4.1.99), fructan:fructan 1-fructosyltransferase (1-FFT; EC 2.4.1.100) and fructan 1-exohydrolase (1-FEH; EC 3.2.1.153), are evolutionarily related to acid invertases (AIs), that is, plant cell wall invertase (CWI) and vacuolar invertase (VI). Acid invertases are post-translationally controlled by proteinaceous inhibitors. Whether FAZYs are subject to similar controls is not known. To probe their possible interactions with invertase inhibitors, we transiently expressed chicory (Cichorium intybus) FAZYs, as well as several previously characterized invertase inhibitors from nonfructan species, and the C. intybus cell wall/vacuolar inhibitor of fructosidase (CiC/VIF), a putative invertase inhibitor of a fructan-accumulating plant, in leaves of Nicotiana benthamiana. Leaf extracts containing recombinant, enzymatically active FAZYs were used to explore the interaction with invertase inhibitors. Neither heterologous inhibitors nor CiC/VIF affected FAZY activities. CiC/VIF was confirmed as an AI inhibitor with a stronger effect on CWI than on VI. Its expression in planta was developmentally regulated (high in taproots, and undetectable in leaves and flowers). In agreement with its target specificities, CiC/VIF was associated with the cell wall. It is concluded that subtle structural differences between AIs and FAZYs result in pronounced selectivity of inhibitor action.

  4. Burkholderia cenocepacia Lipopolysaccharide Modification and Flagellin Glycosylation Affect Virulence but Not Innate Immune Recognition in Plants

    PubMed Central

    Khodai-Kalaki, Maryam; Andrade, Angel; Fathy Mohamed, Yasmine

    2015-01-01

    ABSTRACT Burkholderia cenocepacia causes opportunistic infections in plants, insects, animals, and humans, suggesting that “virulence” depends on the host and its innate susceptibility to infection. We hypothesized that modifications in key bacterial molecules recognized by the innate immune system modulate host responses to B. cenocepacia. Indeed, modification of lipopolysaccharide (LPS) with 4-amino-4-deoxy-l-arabinose and flagellin glycosylation attenuates B. cenocepacia infection in Arabidopsis thaliana and Galleria mellonella insect larvae. However, B. cenocepacia LPS and flagellin triggered rapid bursts of nitric oxide and reactive oxygen species in A. thaliana leading to activation of the PR-1 defense gene. These responses were drastically reduced in plants with fls2 (flagellin FLS2 host receptor kinase), Atnoa1 (nitric oxide-associated protein 1), and dnd1-1 (reduced production of nitric oxide) null mutations. Together, our results indicate that LPS modification and flagellin glycosylation do not affect recognition by plant receptors but are required for bacteria to establish overt infection. PMID:26045541

  5. Host plant affects the sexual attractiveness of the female white-spotted longicorn beetle, Anoplophora malasiaca

    PubMed Central

    Yasui, Hiroe; Fujiwara-Tsujii, Nao

    2016-01-01

    Anoplophora malasiaca (Coleoptera: Cerambycidae) is a serious pest that destroys various landscape and crop trees in Japan. We evaluated the precopulatory responses of three different A. malasiaca populations collected from mandarin orange, willow and blueberry trees. Most of the males accepted mates from within the same host plant population as well as females from the willow and blueberry populations. However, significant number of males from the blueberry and willow populations rejected females from the mandarin orange population immediately after touching them with their antennae. Because all three of the female populations produced contact sex pheromones on their elytra, the females of the mandarin orange population were predicted to possess extra chemicals that repelled the males of the other two populations. β-Elemene was identified as a key component that was only found in mandarin orange-fed females and induced a rejection response in willow-fed males. Our results represent the first example of a female-acquired repellent against conspecific males of different host plant populations, indicating that the host plant greatly affects the female’s sexual attractiveness. PMID:27412452

  6. Does Plant Biomass Manipulation in Static Chambers Affect Nitrous Oxide Emissions from Soils?

    PubMed

    Collier, Sarah M; Dean, Andrew P; Oates, Lawrence G; Ruark, Matthew D; Jackson, Randall D

    2016-03-01

    One of the most widespread approaches for measurement of greenhouse gas emissions from soils involves the use of static chambers. This method is relatively inexpensive, is easily replicated, and is ideally suited to plot-based experimental systems. Among its limitations is the loss of detection sensitivity with increasing chamber height, which creates challenges for deployment in systems including tall vegetation. It is not always possible to avoid inclusion of plants within chambers or to extend chamber height to fully accommodate plant growth. Thus, in many systems, such as perennial forages and biomass crops, plants growing within static chambers must either be trimmed or folded during lid closure. Currently, data on how different types of biomass manipulation affect measured results is limited. Here, we compare the effects of cutting vs. folding of biomass on nitrous oxide measurements in switchgrass ( L.) and alfalfa ( L.) systems. We report only limited evidence of treatment effects during discrete sampling events and little basis for concern that effects may intensify over time as biomass manipulation is repeatedly imposed. However, nonsignificant treatment effects that were consistently present amounted to significant overall trends in three out of the four systems studied. Such minor disparities in flux could amount to considerable quantities over time, suggesting that caution should be exercised when comparing cumulative emission values from studies using different biomass manipulation strategies. PMID:27065424

  7. The odor of a plant metabolite affects life history traits in dietary restricted adult olive flies

    PubMed Central

    Gerofotis, Christos D.; Ioannou, Charalampos S.; Nakas, Christos T.; Papadopoulos, Nikos T.

    2016-01-01

    Food quality shapes life history traits either directly or through response of individuals to additional environmental factors, such as chemical cues. Plant extracts used as food additives modulate key life history traits; however little is known regarding such effects for olfactory chemical cues. Exploiting an interesting experimental system that involves the olive fly (Bactrocera oleae) and the plant metabolite α-pinene we asked whether exposure of adults to this compound modulates adult longevity and female reproduction in similar manner in a stressful – dietary (protein) restricted (DR) and in a relaxed- full diet (FD) feeding environment. Accordingly, we exposed males and females to the aroma of α-pinene and measured lifespan and age-specific fecundity in the above two dietary contexts. Our results demonstrate that exposure to α-pinene increased longevity in males and fecundity in females only under dietary restricted conditions. In relaxed food conditions, females exposed to α-pinene shifted high egg-laying towards younger ages compared to non-exposed ones. This is the first report demonstrating that a plant compound affects key life history traits of adult olive flies through olfaction. These effects are sex-specific and more pronounced in dietary restricted adults. Possible underlying mechanisms and the ecological significance are discussed. PMID:27339862

  8. Plant material as bioaccumulator of arsenic in soils affected by mining activities

    NASA Astrophysics Data System (ADS)

    Martínez-López, Salvadora; Martínez-Sánchez, Maria Jose; García-Lorenzo, Maria Luz; Pérez-Sirvent, Carmen

    2010-05-01

    fraction (oxidaizable medium extraction procedure). Arsenic concentration in leaves was positively correlated with the arsenic extracted by HCl, with the oxidizable-organic matter and sulfides fraction and with the arsenic extracted by Mehra-Jackson extraction. According to our results, As is accumulated in the leaves of the plants and is linked with iron oxides of these soils affected by mining activities.

  9. Host Plants Affect the Foraging Success of Two Parasitoids that Attack Light Brown Apple Moth Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae)

    PubMed Central

    Feng, Yi; Wratten, Steve; Sandhu, Harpinder; Keller, Michael

    2015-01-01

    The light brown apple moth, Epiphyas postvittana is a key pest of wine grapes in Australia. Two parasitoids, Dolichogenidea tasmanica and Therophilus unimaculatus, attack the larval stage of this pest. D. tasmanica is dominant in vineyards, whereas T. unimaculatus is mainly active in native vegetation. We sought to understand why they differ in their use of habitats. Plants are a major component of habitats of parasitoids, and herbivore-infested plants influence parasitoid foraging efficiency by their architecture and emission of volatile chemicals. We investigated how different plant species infested by E. postvittana could affect the foraging success of the two parasitoid species in both laboratory and field experiments. Four common host-plant species were selected for this study. In paired-choice experiments to determine the innate foraging preferences for plants, both parasitoid species showed differences in innate search preferences among plant species. The plant preference of D. tasmanica was altered by oviposition experience with hosts that were feeding on other plant species. In a behavioral assay, the two parasitoid species allocated their times engaged in various types of behavior differently when foraging on different plant species. For both parasitoids, parasitism on Hardenbergia violacea was the highest of the four plant species. Significantly more larvae dropped from Myoporum insulare when attacked than from the other three host-plant species, which indicates that parasitism is also affected by interactions between plants and host insects. In vineyards, parasitism by D. tasmanica was significantly lower on M. insulare than on the other three host-plant species, but the parasitism rates were similar among the other three plant species. Our results indicate that plants play a role in the habitat preferences of these two parasitoid species by influencing their foraging behavior, and are likely to contribute to their distributions among habitats. PMID

  10. Host Plants Affect the Foraging Success of Two Parasitoids that Attack Light Brown Apple Moth Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae).

    PubMed

    Feng, Yi; Wratten, Steve; Sandhu, Harpinder; Keller, Michael

    2015-01-01

    The light brown apple moth, Epiphyas postvittana is a key pest of wine grapes in Australia. Two parasitoids, Dolichogenidea tasmanica and Therophilus unimaculatus, attack the larval stage of this pest. D. tasmanica is dominant in vineyards, whereas T. unimaculatus is mainly active in native vegetation. We sought to understand why they differ in their use of habitats. Plants are a major component of habitats of parasitoids, and herbivore-infested plants influence parasitoid foraging efficiency by their architecture and emission of volatile chemicals. We investigated how different plant species infested by E. postvittana could affect the foraging success of the two parasitoid species in both laboratory and field experiments. Four common host-plant species were selected for this study. In paired-choice experiments to determine the innate foraging preferences for plants, both parasitoid species showed differences in innate search preferences among plant species. The plant preference of D. tasmanica was altered by oviposition experience with hosts that were feeding on other plant species. In a behavioral assay, the two parasitoid species allocated their times engaged in various types of behavior differently when foraging on different plant species. For both parasitoids, parasitism on Hardenbergia violacea was the highest of the four plant species. Significantly more larvae dropped from Myoporum insulare when attacked than from the other three host-plant species, which indicates that parasitism is also affected by interactions between plants and host insects. In vineyards, parasitism by D. tasmanica was significantly lower on M. insulare than on the other three host-plant species, but the parasitism rates were similar among the other three plant species. Our results indicate that plants play a role in the habitat preferences of these two parasitoid species by influencing their foraging behavior, and are likely to contribute to their distributions among habitats. PMID

  11. Offering a forage crop at pasture did not adversely affect voluntary cow traffic or milking visits in a pasture-based automatic milking system.

    PubMed

    Scott, V E; Kerrisk, K L; Garcia, S C

    2016-03-01

    Feed is a strong incentive for encouraging cows in automatic milking systems (AMS) to voluntarily move around the farm and achieve milkings distributed across the 24 h day. It has been reported that cows show preferences for some forages over others, and it is possible that offering preferred forages may increase cow traffic. A preliminary investigation was conducted to determine the effect of offering a forage crop for grazing on premilking voluntary waiting times in a pasture-based robotic rotary system. Cows were offered one of two treatments (SOYBEAN or GRASS) in a cross-over design. A restricted maximum likelihood procedure was used to model voluntary waiting times. Mean voluntary waiting time was 45.5±6.0 min, with no difference detected between treatments. High and mid-production cows spent 55 min/milking for low-production cows, whereas waiting time increased as queue length increased. Voluntary waiting time was 23% and 80% longer when cows were fetched from the paddock or had a period of forced waiting before volunteering for milking, respectively. The time it took cows to return to the dairy since last exiting was not affected by treatment, with a mean return time of 13.7±0.6 h. Although offering SOYBEAN did not encourage cows to traffic more readily through the premilking yard, the concept of incorporating forage crops in AMS still remains encouraging if the aim is to increase the volume or quantity of home-grown feed rather than improving cow traffic.

  12. Cigarette smoking adversely affects disease activity and disease-specific quality of life in patients with Crohn’s disease at a tertiary referral center

    PubMed Central

    Quezada, Sandra M; Langenberg, Patricia; Cross, Raymond K

    2016-01-01

    Purpose Smoking has a negative impact on disease activity in Crohn’s disease (CD). Smoking may also affect the quality of life, but this has not been evaluated using validated measures over time. We assessed the relationship between smoking and disease-specific quality of life over time in a tertiary referral inflammatory bowel disease cohort. Patients and methods Retrospective cohort study from July 2004 to July 2009 in patients with CD identified from the University of Maryland, Baltimore, Institutional Review Board-approved University of Maryland School of Medicine Inflammatory Bowel Disease Program database. Smoking status was classified as current, former, and never. Age was categorized as <40 years, 40–59 years, and ≥60 years. Index visit disease activity and quality of life was measured with the Harvey–Bradshaw index, and the Short Inflammatory Bowel Disease Questionnaire (SIBDQ). Repeated measures linear regression was used to assess the association between smoking and quality of life over time after adjustment for confounding variables. Results A total of 608 patients were included, of whom 42% were male; 80% were Caucasian; 22% were current smokers; 24% were former smokers; and 54% were never smokers. Over time, adjusted Harvey–Bradshaw index scores declined in all patients, but current smokers had consistently higher scores. After adjustment for sex, age, and disease duration, never smokers had higher mean SIBDQ scores at index visit compared to former and current smokers (P<0.0001); all increased over time but SIBDQ scores for never smokers remained consistently highest. Conclusion Smoking has a negative impact on disease activity and quality of life in patients with CD. Prospects of improved disease activity and quality of life should be proposed as an additional incentive to encourage smoking cessation in patients with CD. PMID:27703391

  13. Unpreferred plants affect patch choice and spatial distribution of European brown hares

    NASA Astrophysics Data System (ADS)

    Kuijper, D. P. J.; Bakker, J. P.

    2008-11-01

    Many herbivore species prefer to forage on patches of intermediate biomass. Plant quality and forage efficiency are predicted to decrease with increasing plant standing crop which explains the lower preference of the herbivore. However, often is ignored that on the long-term, plant species composition is predicted to change with increasing plant standing crop. The amount of low-quality, unpreferred food plants increases with increasing plant standing crop. In the present study the effects of unpreferred plants on patch choice and distribution of European brown hare in a salt-marsh system were studied. In one experiment, unpreferred plants were removed from plots. In the second experiment, plots were planted with different densities of an unpreferred artificial plant. Removal of unpreferred plants increased hare-grazing pressure more than fivefold compared to unmanipulated plots. Planting of unpreferred plants reduced hare-grazing pressure, with a significant reduction of grazing already occurring at low unpreferred plant density. Spatial distribution of hares within this salt-marsh system was related to spatial arrangement of unpreferred plants. Hare-grazing intensity decreased strongly with increasing abundance of unpreferred plants despite a high abundance of principal food plants. The results of this study indicate that plant species replacement is an important factor determining patch choice and spatial distribution of hares next to changing plant quality. Increasing abundance of unpreferred plant species can strengthen the decreasing patch quality with increasing standing crop and can decrease grazing intensity when preferred food plants are still abundantly present.

  14. Does vegetation complexity affect host plant chemistry, and thus multitrophic interactions, in a human-altered landscape?

    PubMed

    Wäschke, Nicole; Hancock, Christine; Hilker, Monika; Obermaier, Elisabeth; Meiners, Torsten

    2015-09-01

    Anthropogenic land use may shape vegetation composition and affect trophic interactions by altering concentrations of host plant metabolites. Here, we investigated the hypotheses that: (1) plant N and defensive secondary metabolite contents of the herb Plantago lanceolata are affected by land use intensity (LUI) and the surrounding vegetation composition (=plant species richness and P. lanceolata density), and that (2) changes in plant chemistry affect abundances of the herbivorous weevils Mecinus pascuorum and Mecinus labilis, as well as their larval parasitoid Mesopolobus incultus, in the field. We determined plant species richness, P. lanceolata density, and abundances of the herbivores and the parasitoid in 77 grassland plots differing in LUI index in three regions across Germany. We also measured the N and secondary metabolite [the iridoid glycosides (IGs) aucubin and catalpol] contents of P. lanceolata leaves. Mixed-model analysis revealed that: (1) concentrations of leaf IGs were positively correlated with plant species richness; leaf N content was positively correlated with the LUI index. Furthermore: (2) herbivore abundance was not related to IG concentrations, but correlated negatively with leaf N content. Parasitoid abundance correlated positively only with host abundance over the three regions. Structural equation models revealed a positive impact of IG concentrations on parasitoid abundance in one region. We conclude that changes in plant chemistry due to land use and/or vegetation composition may affect higher trophic levels and that the manifestation of these effects may depend on local biotic or abiotic features of the landscape. PMID:25986560

  15. Does vegetation complexity affect host plant chemistry, and thus multitrophic interactions, in a human-altered landscape?

    PubMed

    Wäschke, Nicole; Hancock, Christine; Hilker, Monika; Obermaier, Elisabeth; Meiners, Torsten

    2015-09-01

    Anthropogenic land use may shape vegetation composition and affect trophic interactions by altering concentrations of host plant metabolites. Here, we investigated the hypotheses that: (1) plant N and defensive secondary metabolite contents of the herb Plantago lanceolata are affected by land use intensity (LUI) and the surrounding vegetation composition (=plant species richness and P. lanceolata density), and that (2) changes in plant chemistry affect abundances of the herbivorous weevils Mecinus pascuorum and Mecinus labilis, as well as their larval parasitoid Mesopolobus incultus, in the field. We determined plant species richness, P. lanceolata density, and abundances of the herbivores and the parasitoid in 77 grassland plots differing in LUI index in three regions across Germany. We also measured the N and secondary metabolite [the iridoid glycosides (IGs) aucubin and catalpol] contents of P. lanceolata leaves. Mixed-model analysis revealed that: (1) concentrations of leaf IGs were positively correlated with plant species richness; leaf N content was positively correlated with the LUI index. Furthermore: (2) herbivore abundance was not related to IG concentrations, but correlated negatively with leaf N content. Parasitoid abundance correlated positively only with host abundance over the three regions. Structural equation models revealed a positive impact of IG concentrations on parasitoid abundance in one region. We conclude that changes in plant chemistry due to land use and/or vegetation composition may affect higher trophic levels and that the manifestation of these effects may depend on local biotic or abiotic features of the landscape.

  16. Does nitrate co-pollution affect biological responses of an aquatic plant to two common herbicides?

    PubMed

    Nuttens, A; Chatellier, S; Devin, S; Guignard, C; Lenouvel, A; Gross, E M

    2016-08-01

    Aquatic systems in agricultural landscapes are subjected to multiple stressors, among them pesticide and nitrate run-off, but effects of both together have rarely been studied. We investigated possible stress-specific and interaction effects using the new OECD test organism, Myriophyllum spicatum, a widespread aquatic plant. In a fully factorial design, we used two widely applied herbicides, isoproturon and mesosulfuron-methyl, in concentration-response curves at two nitrate levels (219.63 and 878.52mg N-NO3). We applied different endpoints reflecting plant performance such as growth, pigment content, content in phenolic compounds, and plant stoichiometry. Relative growth rates based on length (RGR-L) were affected strongly by both herbicides, while effects on relative growth rate based on dry weight (RGR-DW) were apparent for isoproturon but hardly visible for mesosulfuron-methyl due to an increase in dry matter content. The higher nitrate level further reduced growth rates, specifically with mesosulfuron-methyl. Effects were visible between 50 and 500μgL(-1) for isoproturon and 0.5-5μgL(-1) for mesosulfuron-methyl, with some differences between endpoints. The two herbicides had opposite effects on chlorophyll, carotenoid and nitrogen contents in plants, with values increasing with increasing concentrations of isoproturon and decreasing for mesosulfuron-methyl. Herbicides and nitrate level exhibited distinct effects on the content in phenolic compounds, with higher nitrate levels reducing total phenolic compounds in controls and with isoproturon, but not with mesosulfuron-methyl. Increasing concentrations of mesosulfuron-methyl lead to a decline of total phenolic compounds, while isoproturon had little effect. Contents of carbon, nitrogen and phosphorus changed depending on the stressor combination. We observed higher phosphorus levels in plants exposed to certain concentrations of herbicides, potentially indicating a metabolic response. The C:N molar ratio

  17. Does nitrate co-pollution affect biological responses of an aquatic plant to two common herbicides?

    PubMed

    Nuttens, A; Chatellier, S; Devin, S; Guignard, C; Lenouvel, A; Gross, E M

    2016-08-01

    Aquatic systems in agricultural landscapes are subjected to multiple stressors, among them pesticide and nitrate run-off, but effects of both together have rarely been studied. We investigated possible stress-specific and interaction effects using the new OECD test organism, Myriophyllum spicatum, a widespread aquatic plant. In a fully factorial design, we used two widely applied herbicides, isoproturon and mesosulfuron-methyl, in concentration-response curves at two nitrate levels (219.63 and 878.52mg N-NO3). We applied different endpoints reflecting plant performance such as growth, pigment content, content in phenolic compounds, and plant stoichiometry. Relative growth rates based on length (RGR-L) were affected strongly by both herbicides, while effects on relative growth rate based on dry weight (RGR-DW) were apparent for isoproturon but hardly visible for mesosulfuron-methyl due to an increase in dry matter content. The higher nitrate level further reduced growth rates, specifically with mesosulfuron-methyl. Effects were visible between 50 and 500μgL(-1) for isoproturon and 0.5-5μgL(-1) for mesosulfuron-methyl, with some differences between endpoints. The two herbicides had opposite effects on chlorophyll, carotenoid and nitrogen contents in plants, with values increasing with increasing concentrations of isoproturon and decreasing for mesosulfuron-methyl. Herbicides and nitrate level exhibited distinct effects on the content in phenolic compounds, with higher nitrate levels reducing total phenolic compounds in controls and with isoproturon, but not with mesosulfuron-methyl. Increasing concentrations of mesosulfuron-methyl lead to a decline of total phenolic compounds, while isoproturon had little effect. Contents of carbon, nitrogen and phosphorus changed depending on the stressor combination. We observed higher phosphorus levels in plants exposed to certain concentrations of herbicides, potentially indicating a metabolic response. The C:N molar ratio

  18. Ozone Differentially Affects Perception of Plant Volatiles in Western Honey Bees.

    PubMed

    Dötterl, Stefan; Vater, Marina; Rupp, Thomas; Held, Andreas

    2016-06-01

    Floral scents play a key role in mediating plant-pollinator interactions. Volatile organic compounds (VOCs) emitted by flowers are used by flower visitors as olfactory cues to locate flowers, both from a distance and at close range. More recently it has been demonstrated that reactive molecules such as ozone can modify or degrade VOCs, and this may impair the communication between plants and their pollinators. However, it is not known whether such reactive molecules also may affect the olfactory system of pollinators, and thus not only influence signal transmission but perception of the signal. In this study, we used electroantennographic measurements to determine the effect of increased levels of ozone on antennal responses in western honey bees (Apis mellifera L.). Linalool and 2-phenylethanol, both known to be involved in location of flowers by the bees, and (Z)-3-hexenyl acetate, a widespread green leaf volatile also detected by bees, were used. The results showed that ozone affected antennal responses to the different substances differently. Ozone decreased antennal responses to (Z)-3-hexenyl acetate, whereas responses to linalool and 2-phenylethanol were not influenced by ozone. Overall, the study does not provide evidence that pollination by honey bees is impaired by damage in the olfactory system of the bees caused by increased levels of ozone, at least when linalool and 2-phenylethanol are the attractive signals. However, the results also suggest that ozone can change the overall perception of an odor blend. This might have negative effects in pollination systems and other organismic interactions mediated by specific ratios of compounds. PMID:27344162

  19. Spatial environmental heterogeneity affects plant growth and thermal performance on a green roof.

    PubMed

    Buckland-Nicks, Michael; Heim, Amy; Lundholm, Jeremy

    2016-05-15

    Green roofs provide ecosystem services, including stormwater retention and reductions in heat transfer through the roof. Microclimates, as well as designed features of green roofs, such as substrate and vegetation, affect the magnitude of these services. Many green roofs are partially shaded by surrounding buildings, but the effects of this within-roof spatial environmental heterogeneity on thermal performance and other ecosystem services have not been examined. We quantified the effects of spatial heterogeneity in solar radiation, substrate depth and other variables affected by these drivers on vegetation and ecosystem services in an extensive green roof. Spatial heterogeneity in substrate depth and insolation were correlated with differential growth, survival and flowering in two focal plant species. These effects were likely driven by the resulting spatial heterogeneity in substrate temperature and moisture content. Thermal performance (indicated by heat flux and substrate temperature) was influenced by spatial heterogeneity in vegetation cover and substrate depth. Areas with less insolation were cooler in summer and had greater substrate moisture, leading to more favorable conditions for plant growth and survival. Spatial variation in substrate moisture (7%-26% volumetric moisture content) and temperature (21°C-36°C) during hot sunny conditions in summer could cause large differences in stormwater retention and heat flux within a single green roof. Shaded areas promote smaller heat fluxes through the roof, leading to energy savings, but lower evapotranspiration in these areas should reduce stormwater retention capacity. Spatial heterogeneity can thus result in trade-offs between different ecosystem services. The effects of these spatial heterogeneities are likely widespread in green roofs. Structures that provide shelter from sun and wind may be productively utilized to design higher functioning green roofs and increase biodiversity by providing habitat

  20. Spatial environmental heterogeneity affects plant growth and thermal performance on a green roof.

    PubMed

    Buckland-Nicks, Michael; Heim, Amy; Lundholm, Jeremy

    2016-05-15

    Green roofs provide ecosystem services, including stormwater retention and reductions in heat transfer through the roof. Microclimates, as well as designed features of green roofs, such as substrate and vegetation, affect the magnitude of these services. Many green roofs are partially shaded by surrounding buildings, but the effects of this within-roof spatial environmental heterogeneity on thermal performance and other ecosystem services have not been examined. We quantified the effects of spatial heterogeneity in solar radiation, substrate depth and other variables affected by these drivers on vegetation and ecosystem services in an extensive green roof. Spatial heterogeneity in substrate depth and insolation were correlated with differential growth, survival and flowering in two focal plant species. These effects were likely driven by the resulting spatial heterogeneity in substrate temperature and moisture content. Thermal performance (indicated by heat flux and substrate temperature) was influenced by spatial heterogeneity in vegetation cover and substrate depth. Areas with less insolation were cooler in summer and had greater substrate moisture, leading to more favorable conditions for plant growth and survival. Spatial variation in substrate moisture (7%-26% volumetric moisture content) and temperature (21°C-36°C) during hot sunny conditions in summer could cause large differences in stormwater retention and heat flux within a single green roof. Shaded areas promote smaller heat fluxes through the roof, leading to energy savings, but lower evapotranspiration in these areas should reduce stormwater retention capacity. Spatial heterogeneity can thus result in trade-offs between different ecosystem services. The effects of these spatial heterogeneities are likely widespread in green roofs. Structures that provide shelter from sun and wind may be productively utilized to design higher functioning green roofs and increase biodiversity by providing habitat

  1. Decreased summer drought affects plant productivity and soil carbon dynamics in a Mediterranean woodland

    NASA Astrophysics Data System (ADS)

    Cotrufo, M. F.; Alberti, G.; Inglima, I.; Marjanović, H.; Lecain, D.; Zaldei, A.; Peressotti, A.; Miglietta, F.

    2011-09-01

    Precipitation patterns are expected to change in the Mediterranean region within the next decades, with projected decreases in total rainfall and increases in extreme events. We manipulated precipitation patterns in a Mediterranean woodland, dominated by Arbutus unedo L., to study the effects of changing precipitation regimes on above-ground net primary production (ANPP) and soil C dynamics, specifically plant-derived C input to soil and soil respiration (SR). Experimental plots were exposed to either a 20 % reduction of throughfall or to water addition targeted at maintaining soil water content above a minimum of 10 % v/v. Treatments were compared to control plots which received ambient precipitation. Enhanced soil moisture during summer months highly stimulated annual stem primary production, litter fall, SR and net annual plant-derived C input to soil which on average increased by 130 %, 26 %, 58 % and 220 %, respectively, as compared to the control. In contrast, the 20 % reduction in throughfall (equivalent to 10 % reduction in precipitation) did not significantly change soil moisture at the site, and therefore did not significantly affect ANPP or SR. We conclude that minor changes (around 10 % reduction) in precipitation amount are not likely to significantly affect ANPP or soil C dynamics in Mediterranean woodlands. However, if summer rain increases, C cycling will significantly accelerate but soil C stocks are not likely to be changed in the short-term. More studies involving modelling of long-term C dynamics are needed to predict if the estimated increases in soil C input under wet conditions is going to be sustained and if labile C is being substituted to stable C, with a negative effect on long-term soil C stocks.

  2. Decreased summer drought affects plant productivity and soil carbon dynamics in Mediterranean woodland

    NASA Astrophysics Data System (ADS)

    Cotrufo, M. F.; Alberti, G.; Inglima, I.; Marjanović, H.; Lecain, D.; Zaldei, A.; Peressotti, A.; Miglietta, F.

    2011-06-01

    Precipitation patterns are expected to change in the Mediterranean region within the next decades, with projected decreases in total rainfall and increases in extreme events. We manipulated precipitation patterns in a Mediterranean woodland, dominated by Arbutus unedo L., to study the effects of changing precipitation regimes on above-ground net primary production (ANPP) and soil C dynamics, specifically plant-derived C input to soil and soil respiration (SR). Experimental plots were exposed to either a 20 % reduction of throughfall or to water addition targeted at maintaining soil water content above a minimum of 10 % v/v. Treatments were compared to control plots which received ambient precipitation. The throughfall manipulation experiment started in 2004 and we report data up to the 2009 growing season. Enhanced soil moisture during summer months highly stimulated annual stem primary production, litter fall, SR and net annual plant-derived C input to soil which on average increased by 130 %, 26 %, 50 % and 220 %, respectively, as compared to control. In contrast, the 20 % reduction in throughfall (equivalent to 10 % reduction of precipitation) did not significantly change soil moisture at the site, and therefore did not significantly affect ANPP or SR. We conclude that minor changes (around 10 % reduction) in precipitation amount are not likely to significantly affect ANPP or soil C dynamics in Mediterranean woodland. However, if summer rain increases, C cycling will significantly accelerate but soil C stocks are not likely to be changed in the short-term. More studies involving modelling of long term C dynamics are needed to predict if the estimated increases in soil C input under wet conditions is going to be sustained and if labile C is being substituted to stable C, with a negative effect on long term soil C stocks.

  3. Glycogen catabolism, but not its biosynthesis, affects virulence of Fusarium oxysporum on the plant host.

    PubMed

    Corral-Ramos, Cristina; Roncero, M Isabel G

    2015-04-01

    The role of glycogen metabolism was investigated in the fungal pathogen Fusarium oxysporum. Targeted inactivation was performed of genes responsible for glycogen biosynthesis: gnn1 encoding glycogenin, gls1 encoding glycogen synthase, and gbe1 encoding glycogen branching enzyme. Moreover genes involved in glycogen catabolism were deleted: gph1 encoding glycogen phosphorylase and gdb1 encoding glycogen de-branching enzyme. Glycogen reserves increased steadily during growth of the wild type strain in axenic cultures, to reach up to 1500μg glucose equivalents mg(-1) protein after 14 days. Glycogen accumulation was abolished in mutants lacking biosynthesis genes, whereas it increased by 20-40% or 80%, respectively, in the single and double mutants affected in catabolic genes. Transcript levels of glycogen metabolism genes during tomato plant infection peaked at four days post inoculation, similar to the results observed during axenic culture. Significant differences were observed between gdb mutants and the wild type strain for vegetative hyphal fusion ability. The single mutants defective in glycogen metabolism showed similar levels of virulence in the invertebrate animal model Galleria mellonella. Interestingly, the deletion of gdb1 reduced virulence on the plant host up to 40% compared to the wild type in single and in double mutant backgrounds, whereas the other mutants showed the virulence at the wild-type level.

  4. Parental age affects somatic mutation rates in the progeny of flowering plants.

    PubMed

    Singh, Amit Kumar; Bashir, Tufail; Sailer, Christian; Gurumoorthy, Viswanathan; Ramakrishnan, Anantha Maharasi; Dhanapal, Shanmuhapreya; Grossniklaus, Ueli; Baskar, Ramamurthy

    2015-05-01

    In humans, it is well known that the parental reproductive age has a strong influence on mutations transmitted to their progeny. Meiotic nondisjunction is known to increase in older mothers, and base substitutions tend to go up with paternal reproductive age. Hence, it is clear that the germinal mutation rates are a function of both maternal and paternal ages in humans. In contrast, it is unknown whether the parental reproductive age has an effect on somatic mutation rates in the progeny, because these are rare and difficult to detect. To address this question, we took advantage of the plant model system Arabidopsis (Arabidopsis thaliana), where mutation detector lines allow for an easy quantitation of somatic mutations, to test the effect of parental age on somatic mutation rates in the progeny. Although we found no significant effect of parental age on base substitutions, we found that frameshift mutations and transposition events increased in the progeny of older parents, an effect that is stronger through the maternal line. In contrast, intrachromosomal recombination events in the progeny decrease with the age of the parents in a parent-of-origin-dependent manner. Our results clearly show that parental reproductive age affects somatic mutation rates in the progeny and, thus, that some form of age-dependent information, which affects the frequency of double-strand breaks and possibly other processes involved in maintaining genome integrity, is transmitted through the gametes. PMID:25810093

  5. Plant maturity and nitrogen fertilization affected fructan metabolism in harvestable tissues of timothy (Phleum pratense L.).

    PubMed

    Ould-Ahmed, Marouf; Decau, Marie-Laure; Morvan-Bertrand, Annette; Prud'homme, Marie-Pascale; Lafrenière, Carole; Drouin, Pascal

    2014-10-15

    Timothy (Phleum pratense L.) is an important grass forage used for pasture, hay, and silage in regions with cool and humid growth seasons. One of the factors affecting the nutritive value of this grass is the concentration of non-structural carbohydrates (NSC), mainly represented by fructans. NSC concentration depends on multiple factors, making it hardly predictable. To provide a better understanding of NSC metabolism in timothy, the effects of maturity stage and nitrogen (N) fertilization level on biomass, NSC and N-compound concentrations were investigated in the tissues used for forage (leaf blades and stems surrounded by leaf sheaths) of hydroponically grown plants. Moreover, activities and relative expression level of enzymes involved in fructan metabolism were measured in the same tissues. Forage biomass was not altered by the fertilization level but was strongly modified by the stage of development. It increased from vegetative to heading stages while leaf-to-stem biomass ratio decreased. Total NSC concentration, which was not altered by N fertilization level, increased between heading and anthesis due to an accumulation of fructans in leaf blades. Fructan metabolizing enzyme activities (fructosyltransferase-FT and fructan exohydrolase-FEH) were not or only slightly altered by both maturity stage and N fertilization level. Conversely, the relative transcript levels of genes coding for enzymes involved in fructan metabolism were modified by N supply (PpFT1 and Pp6-FEH1) or maturity stage (PpFT2). The relative transcript level of PpFT1 was the highest in low N plants while that of Pp6-FEH1 was the highest in high N plants. Morevoer, transcript level of PpFT1 was negatively correlated with nitrate concentration while that of PpFT2 was positively correlated with sucrose concentration. This distinct regulation of the two genes coding for 6-sucrose:fructan fructosyltransferase (6-SFT) may allow a fine adequation of C allocation towards fructan synthesis in

  6. Adverse ocular reactions to drugs.

    PubMed Central

    Spiteri, M. A.; James, D. G.

    1983-01-01

    Drugs acting on various parts of the body may also affect the eye insidiously. Increased awareness of such drug toxicity by the prescribing doctor should encourage him to consider effects on the cornea, lens, retina, optic nerve and elsewhere when checking the patient's progress. The following review concerns adverse ocular effects of systemic drug administration. PMID:6356101

  7. Herbivory Differentially Affects Plant Fitness in Three Populations of the Perennial Herb Lythrum salicaria along a Latitudinal Gradient.

    PubMed

    Lehndal, Lina; Ågren, Jon

    2015-01-01

    Herbivory can negatively and selectively affect plant fitness by reducing growth, survival and reproductive output, thereby influencing plant population dynamics and evolution. Latitudinal variation in intensity of herbivory is common, but the extent to which it translates into corresponding variation in effects on plant performance is still poorly known. We tested the hypothesis that variation in the fitness-consequences of herbivory mirror differences in intensity of herbivory among three natural populations of the perennial herb Lythrum salicaria along a latitudinal gradient from southern to northernmost Sweden. We documented intensity of herbivory and examined its effect on survival, growth and reproductive output over two years by experimentally removing herbivores with insecticide. The intensity of herbivory and the effects of herbivory on plant fitness were strongest in the southern population, intermediate in the central population and weakest in the northern population. The mean proportion of the leaf area removed ranged from 11% in the southern to 3% in the northern population. Herbivore removal increased plant height 1.5-fold in the southern and 1.2-fold in the central population, the proportion plants flowering 4-fold in the southern and 2-fold in the central population, and seed production per flower 1.6-fold in the southern and 1.2-fold in the central population, but did not affect plant fitness in the northern population. Herbivore removal thus affected the relative fecundity of plants in the three populations: In the control, seed output per plant was 8.6 times higher in the northern population compared to the southern population, whereas after herbivore removal it was 2.5 times higher in the southern population. The results demonstrate that native herbivores may strongly affect the demographic structure of L. salicaria populations and thereby shape geographic patterns of seed production. They further suggest that the strength of herbivore

  8. Herbivory Differentially Affects Plant Fitness in Three Populations of the Perennial Herb Lythrum salicaria along a Latitudinal Gradient

    PubMed Central

    Lehndal, Lina; Ågren, Jon

    2015-01-01

    Herbivory can negatively and selectively affect plant fitness by reducing growth, survival and reproductive output, thereby influencing plant population dynamics and evolution. Latitudinal variation in intensity of herbivory is common, but the extent to which it translates into corresponding variation in effects on plant performance is still poorly known. We tested the hypothesis that variation in the fitness-consequences of herbivory mirror differences in intensity of herbivory among three natural populations of the perennial herb Lythrum salicaria along a latitudinal gradient from southern to northernmost Sweden. We documented intensity of herbivory and examined its effect on survival, growth and reproductive output over two years by experimentally removing herbivores with insecticide. The intensity of herbivory and the effects of herbivory on plant fitness were strongest in the southern population, intermediate in the central population and weakest in the northern population. The mean proportion of the leaf area removed ranged from 11% in the southern to 3% in the northern population. Herbivore removal increased plant height 1.5-fold in the southern and 1.2-fold in the central population, the proportion plants flowering 4-fold in the southern and 2-fold in the central population, and seed production per flower 1.6-fold in the southern and 1.2-fold in the central population, but did not affect plant fitness in the northern population. Herbivore removal thus affected the relative fecundity of plants in the three populations: In the control, seed output per plant was 8.6 times higher in the northern population compared to the southern population, whereas after herbivore removal it was 2.5 times higher in the southern population. The results demonstrate that native herbivores may strongly affect the demographic structure of L. salicaria populations and thereby shape geographic patterns of seed production. They further suggest that the strength of herbivore

  9. Alkaloid Quantities in Endophyte-Infected Tall Fescue are Affected by the Plant-Fungus Combination and Environment.

    PubMed

    Helander, M; Phillips, T; Faeth, S H; Bush, L P; McCulley, R; Saloniemi, I; Saikkonen, K

    2016-02-01

    Many grass species are symbiotic with systemic, vertically-transmitted, asymptomatic Epichloë endophytic fungi. These fungi often produce alkaloids that defend the host against herbivores. We studied how environmental variables affect alkaloids in endophyte-infected tall fescue (Schedonorus phoenix) from three Northern European wild origins and the widely planted US cultivar 'Kentucky-31' (KY31). The plants were grown in identical common garden experiments in Finland and Kentucky for two growing seasons. Plants were left as controls (C) or given water (W), nutrient (N) or water and nutrient (WN) treatments. For 8-10 replications of each plant origin and treatment combination in both experiments, we analyzed ergot alkaloids, lysergic acid, and lolines. In Finland, tall fescue plants produced 50 % more ergot alkaloids compared to plants of the same origin and treatments in Kentucky. Origin of the plants affected the ergot alkaloid concentration at both study sites: the wild origin plants produced 2-4 times more ergot alkaloids than KY31, but the ergot alkaloid concentration of KY31 plants was the same at both locations. Overall lysergic acid content was 60 % higher in plants grown in Kentucky than in those grown in Finland. Nutrient treatments (N, WN) significantly increased ergot alkaloid concentrations in plants from Finland but not in plants from Kentucky. These results suggest that the success of KY31 in US is not due to selection for high ergot alkaloid production but rather other traits associated with the endophyte. In addition, the environmental effects causing variation in alkaloid production of grass-endophyte combinations should be taken into account when using endophyte-infected grasses agriculturally. PMID:26815170

  10. Rhizosphere Microbial Community Composition Affects Cadmium and Zinc Uptake by the Metal-Hyperaccumulating Plant Arabidopsis halleri

    PubMed Central

    Muehe, E. Marie; Weigold, Pascal; Adaktylou, Irini J.; Planer-Friedrich, Britta; Kraemer, Ute; Kappler, Andreas

    2015-01-01

    The remediation of metal-contaminated soils by phytoextraction depends on plant growth and plant metal accessibility. Soil microorganisms can affect the accumulation of metals by plants either by directly or indirectly stimulating plant growth and activity or by (im)mobilizing and/or complexing metals. Understanding the intricate interplay of metal-accumulating plants with their rhizosphere microbiome is an important step toward the application and optimization of phytoremediation. We compared the effects of a “native” and a strongly disturbed (gamma-irradiated) soil microbial communities on cadmium and zinc accumulation by the plant Arabidopsis halleri in soil microcosm experiments. A. halleri accumulated 100% more cadmium and 15% more zinc when grown on the untreated than on the gamma-irradiated soil. Gamma irradiation affected neither plant growth nor the 1 M HCl-extractable metal content of the soil. However, it strongly altered the soil microbial community composition and overall cell numbers. Pyrosequencing of 16S rRNA gene amplicons of DNA extracted from rhizosphere samples of A. halleri identified microbial taxa (Lysobacter, Streptomyces, Agromyces, Nitrospira, “Candidatus Chloracidobacterium”) of higher relative sequence abundance in the rhizospheres of A. halleri plants grown on untreated than on gamma-irradiated soil, leading to hypotheses on their potential effect on plant metal uptake. However, further experimental evidence is required, and wherefore we discuss different mechanisms of interaction of A. halleri with its rhizosphere microbiome that might have directly or indirectly affected plant metal accumulation. Deciphering the complex interactions between A. halleri and individual microbial taxa will help to further develop soil metal phytoextraction as an efficient and sustainable remediation strategy. PMID:25595759

  11. Sirtuin Inhibition Adversely Affects Porcine Oocyte Meiosis

    PubMed Central

    Zhang, Liang; Ma, Rujun; Hu, Jin; Ding, Xiaolin; Xu, Yinxue

    2015-01-01

    Sirtuins have been implicated in diverse biological processes, including oxidative stress, energy metabolism, cell migration, and aging. Here, we employed Sirtuin inhibitors, nicotinamide (NAM) and Sirtinol, to investigate their effects on porcine oocyte maturation respectively. The rate of polar body extrusion in porcine oocytes decreased after treatment with NAM and Sirtinol, accompanied with the failure of cumulus cell expansion. We further found that NAM and Sirtinol significantly disrupted oocyte polarity, and inhibited the formation of actin cap and cortical granule-free domain (CGFD). Moreover, the abnormal spindles and misaligned chromosomes were readily detected during porcine oocyte maturation after treatment with NAM and Sirtinol. Together, these results suggest that Sirtuins are involved in cortical polarity and spindle organization in porcine oocytes. PMID:26176547

  12. Salt tolerant plants increase nitrogen removal from biofiltration systems affected by saline stormwater.

    PubMed

    Szota, Christopher; Farrell, Claire; Livesley, Stephen J; Fletcher, Tim D

    2015-10-15

    Biofiltration systems are used in urban areas to reduce the concentration and load of nutrient pollutants and heavy metals entering waterways through stormwater runoff. Biofilters can, however be exposed to salt water, through intrusion of seawater in coastal areas which could decrease their ability to intercept and retain pollutants. We measured the effect of adding saline stormwater on pollutant removal by six monocotyledonous species with different levels of salt-tolerance. Carex appressa, Carex bichenoviana, Ficinia nodosa, Gahnia filum, Juncus kraussii and Juncus usitatus were exposed to six concentrations of saline stormwater, equivalent to electrical conductivity readings of: 0.09, 2.3, 5.5, 10.4, 20.0 and 37.6 mS cm(-1). Salt-sensitive species: C. appressa, C. bichenoviana and J. usitatus did not survive ≥10.4 mS cm(-1), removing their ability to take up nitrogen (N). Salt-tolerant species, such as F. nodosa and J. kraussii, maintained N-removal even at the highest salt concentration. However, their levels of water stress and stomatal conductance suggest that N-removal would not be sustained at concentrations ≥10.4 mS cm(-1). Increasing salt concentration indirectly increased phosphorus (P) removal, by converting dissolved forms of P to particulate forms which were retained by filter media. Salt concentrations ≥10 mS cm(-1) also reduced removal efficiency of zinc, manganese and cadmium, but increased removal of iron and lead, regardless of plant species. Our results suggest that biofiltration systems exposed to saline stormwater ≤10 mS cm(-1) can only maintain N-removal when planted with salt-tolerant species, while P removal and immobilisation of heavy metals is less affected by species selection.

  13. Polycomb Protein OsFIE2 Affects Plant Height and Grain Yield in Rice

    PubMed Central

    Sheng, Zhonghua; Jiao, Guiai; Tang, Shaoqing; Luo, Ju; Hu, Peisong

    2016-01-01

    Polycomb group (PcG) proteins have been shown to affect growth and development in plants. To further elucidate their role in these processes in rice, we isolated and characterized a rice mutant which exhibits dwarfism, reduced seed setting rate, defective floral organ, and small grains. Map-based cloning revealed that abnormal phenotypes were attributed to a mutation of the Fertilization Independent Endosperm 2 (OsFIE2) protein, which belongs to the PcG protein family. So we named the mutant as osfie2-1. Histological analysis revealed that the number of longitudinal cells in the internodes decreased in osfie2-1, and that lateral cell layer of the internodes was markedly thinner than wild-type. In addition, compared to wild-type, the number of large and small vascular bundles decreased in osfie2-1, as well as cell number and cell size in spikelet hulls. OsFIE2 is expressed in most tissues and the coded protein localizes in both nucleus and cytoplasm. Yeast two-hybrid and bimolecular fluorescence complementation assays demonstrated that OsFIE2 interacts with OsiEZ1 which encodes an enhancer of zeste protein previously identified as a histone methylation enzyme. RNA sequencing-based transcriptome profiling and qRT-PCR analysis revealed that some homeotic genes and genes involved in endosperm starch synthesis, cell division/expansion and hormone synthesis and signaling are differentially expressed between osfie2-1 and wild-type. In addition, the contents of IAA, GA3, ABA, JA and SA in osfie2-1 are significantly different from those in wild-type. Taken together, these results indicate that OsFIE2 plays an important role in the regulation of plant height and grain yield in rice. PMID:27764161

  14. Above- and belowground linkages in Sphagnum peatland: climate warming affects plant-microbial interactions.

    PubMed

    Jassey, Vincent E J; Chiapusio, Geneviève; Binet, Philippe; Buttler, Alexandre; Laggoun-Défarge, Fatima; Delarue, Frédéric; Bernard, Nadine; Mitchell, Edward A D; Toussaint, Marie-Laure; Francez, André-Jean; Gilbert, Daniel

    2013-03-01

    Peatlands contain approximately one third of all soil organic carbon (SOC). Warming can alter above- and belowground linkages that regulate soil organic carbon dynamics and C-balance in peatlands. Here we examine the multiyear impact of in situ experimental warming on the microbial food web, vegetation, and their feedbacks with soil chemistry. We provide evidence of both positive and negative impacts of warming on specific microbial functional groups, leading to destabilization of the microbial food web. We observed a strong reduction (70%) in the biomass of top-predators (testate amoebae) in warmed plots. Such a loss caused a shortening of microbial food chains, which in turn stimulated microbial activity, leading to slight increases in levels of nutrients and labile C in water. We further show that warming altered the regulatory role of Sphagnum-polyphenols on microbial community structure with a potential inhibition of top predators. In addition, warming caused a decrease in Sphagnum cover and an increase in vascular plant cover. Using structural equation modelling, we show that changes in the microbial food web affected the relationships between plants, soil water chemistry, and microbial communities. These results suggest that warming will destabilize C and nutrient recycling of peatlands via changes in above- and belowground linkages, and therefore, the microbial food web associated with mosses will feedback positively to global warming by destabilizing the carbon cycle. This study confirms that microbial food webs thus constitute a key element in the functioning of peatland ecosystems. Their study can help understand how mosses, as ecosystem engineers, tightly regulate biogeochemical cycling and climate feedback in peatlands.

  15. Salt tolerant plants increase nitrogen removal from biofiltration systems affected by saline stormwater.

    PubMed

    Szota, Christopher; Farrell, Claire; Livesley, Stephen J; Fletcher, Tim D

    2015-10-15

    Biofiltration systems are used in urban areas to reduce the concentration and load of nutrient pollutants and heavy metals entering waterways through stormwater runoff. Biofilters can, however be exposed to salt water, through intrusion of seawater in coastal areas which could decrease their ability to intercept and retain pollutants. We measured the effect of adding saline stormwater on pollutant removal by six monocotyledonous species with different levels of salt-tolerance. Carex appressa, Carex bichenoviana, Ficinia nodosa, Gahnia filum, Juncus kraussii and Juncus usitatus were exposed to six concentrations of saline stormwater, equivalent to electrical conductivity readings of: 0.09, 2.3, 5.5, 10.4, 20.0 and 37.6 mS cm(-1). Salt-sensitive species: C. appressa, C. bichenoviana and J. usitatus did not survive ≥10.4 mS cm(-1), removing their ability to take up nitrogen (N). Salt-tolerant species, such as F. nodosa and J. kraussii, maintained N-removal even at the highest salt concentration. However, their levels of water stress and stomatal conductance suggest that N-removal would not be sustained at concentrations ≥10.4 mS cm(-1). Increasing salt concentration indirectly increased phosphorus (P) removal, by converting dissolved forms of P to particulate forms which were retained by filter media. Salt concentrations ≥10 mS cm(-1) also reduced removal efficiency of zinc, manganese and cadmium, but increased removal of iron and lead, regardless of plant species. Our results suggest that biofiltration systems exposed to saline stormwater ≤10 mS cm(-1) can only maintain N-removal when planted with salt-tolerant species, while P removal and immobilisation of heavy metals is less affected by species selection. PMID:26150068

  16. Allelic differences in a vacuolar invertase affect Arabidopsis growth at early plant development.

    PubMed

    Leskow, Carla Coluccio; Kamenetzky, Laura; Dominguez, Pia Guadalupe; Díaz Zirpolo, José Antonio; Obata, Toshihiro; Costa, Hernán; Martí, Marcelo; Taboga, Oscar; Keurentjes, Joost; Sulpice, Ronan; Ishihara, Hirofumi; Stitt, Mark; Fernie, Alisdair Robert; Carrari, Fernando

    2016-07-01

    Improving carbon fixation in order to enhance crop yield is a major goal in plant sciences. By quantitative trait locus (QTL) mapping, it has been demonstrated that a vacuolar invertase (vac-Inv) plays a key role in determining the radical length in Arabidopsis. In this model, variation in vac-Inv activity was detected in a near isogenic line (NIL) population derived from a cross between two divergent accessions: Landsberg erecta (Ler) and Cape Verde Island (CVI), with the CVI allele conferring both higher Inv activity and longer radicles. The aim of the current work is to understand the mechanism(s) underlying this QTL by analyzing structural and functional differences of vac-Inv from both accessions. Relative transcript abundance analyzed by quantitative real-time PCR (qRT-PCR) showed similar expression patterns in both accessions; however, DNA sequence analyses revealed several polymorphisms that lead to changes in the corresponding protein sequence. Moreover, activity assays revealed higher vac-Inv activity in genotypes carrying the CVI allele than in those carrying the Ler allele. Analyses of purified recombinant proteins showed a similar K m for both alleles and a slightly higher V max for that of Ler. Treatment of plant extracts with foaming to release possible interacting Inv inhibitory protein(s) led to a large increase in activity for the Ler allele, but no changes for genotypes carrying the CVI allele. qRT-PCR analyses of two vac-Inv inhibitors in seedlings from parental and NIL genotypes revealed different expression patterns. Taken together, these results demonstrate that the vac-Inv QTL affects root biomass accumulation and also carbon partitioning through a differential regulation of vac-Inv inhibitors at the mRNA level. PMID:27194734

  17. The Gastropod Menace: Slugs on Brassica Plants Affect Caterpillar Survival through Consumption and Interference with Parasitoid Attraction.

    PubMed

    Desurmont, Gaylord A; Zemanova, Miriam A; Turlings, Ted C J

    2016-03-01

    Terrestrial molluscs and insect herbivores play a major role as plant consumers in a number of ecosystems, but their direct and indirect interactions have hardly been explored. The omnivorous nature of slugs makes them potential disrupters of predator-prey relationships, as a direct threat to small insects and through indirect, plant-mediated effects. Here, we examined the effects of the presence of two species of slugs, Arion rufus (native) and A. vulgaris (invasive) on the survivorship of young Pieris brassicae caterpillars when feeding on Brassica rapa plants, and on plant attractiveness to the main natural enemy of P. brassicae, the parasitoid Cotesia glomerata. In two separate predation experiments, caterpillar mortality was significantly higher on plants co-infested with A. rufus or A. vulgaris. Moreover, caterpillar mortality correlated positively with slug mass and leaf consumption by A. vulgaris. At the third trophic level, plants infested with slugs and plants co-infested with slugs and caterpillars were far less attractive to parasitoids than plants damaged by caterpillars only, independently of slug species. Chemical analyses confirmed that volatile emissions, which provide foraging cues for parasitoids, were strongly reduced in co-infested plants. Our study shows that the presence of slugs has the potential to affect insect populations, directly via consumptive effects, and indirectly via changes in plant volatiles that result in a reduced attraction of natural enemies. The fitness cost for P. brassicae imposed by increased mortality in presence of slugs may be counterbalanced by the benefit of escaping its parasitoids.

  18. The Gastropod Menace: Slugs on Brassica Plants Affect Caterpillar Survival through Consumption and Interference with Parasitoid Attraction.

    PubMed

    Desurmont, Gaylord A; Zemanova, Miriam A; Turlings, Ted C J

    2016-03-01

    Terrestrial molluscs and insect herbivores play a major role as plant consumers in a number of ecosystems, but their direct and indirect interactions have hardly been explored. The omnivorous nature of slugs makes them potential disrupters of predator-prey relationships, as a direct threat to small insects and through indirect, plant-mediated effects. Here, we examined the effects of the presence of two species of slugs, Arion rufus (native) and A. vulgaris (invasive) on the survivorship of young Pieris brassicae caterpillars when feeding on Brassica rapa plants, and on plant attractiveness to the main natural enemy of P. brassicae, the parasitoid Cotesia glomerata. In two separate predation experiments, caterpillar mortality was significantly higher on plants co-infested with A. rufus or A. vulgaris. Moreover, caterpillar mortality correlated positively with slug mass and leaf consumption by A. vulgaris. At the third trophic level, plants infested with slugs and plants co-infested with slugs and caterpillars were far less attractive to parasitoids than plants damaged by caterpillars only, independently of slug species. Chemical analyses confirmed that volatile emissions, which provide foraging cues for parasitoids, were strongly reduced in co-infested plants. Our study shows that the presence of slugs has the potential to affect insect populations, directly via consumptive effects, and indirectly via changes in plant volatiles that result in a reduced attraction of natural enemies. The fitness cost for P. brassicae imposed by increased mortality in presence of slugs may be counterbalanced by the benefit of escaping its parasitoids. PMID:27002323

  19. Can plant phloem properties affect the link between ecosystem assimilation and respiration?

    NASA Astrophysics Data System (ADS)

    Mencuccini, M.; Hölttä, T.; Sevanto, S.; Nikinmaa, E.

    2012-04-01

    Phloem transport of carbohydrates in plants under field conditions is currently not well understood. This is largely the result of the lack of techniques suitable for measuring phloem physiological properties continuously under field conditions. This lack of knowledge is currently hampering our efforts to link ecosystem-level processes of carbon fixation, allocation and use, especially belowground. On theoretical grounds, the properties of the transport pathway from canopy to roots must be important in affecting the link between carbon assimilation and respiration, but it is unclear whether their effect is partially or entirely masked by processes occurring in other parts of the ecosystem. One can also predict the characteristic time scales over which these effects should occur and, as consequence, predict whether the transfer of turgor and osmotic signals from the site of carbon assimilation to the sites of carbon use are likely to control respiration. We will present two sources of evidence suggesting that the properties of the phloem transport system may affect processes that are dependent on the supply of carbon substrate, such as root or soil respiration. Firstly, we will summarize the results of a literature survey on soil and ecosystem respiration where the speed of transfer of photosynthetic sugars from the plant canopy to the soil surface was determined. Estimates of the transfer speed could be grouped according to whether the study employed isotopic or canopy soil flux-based techniques. These two groups provided very different estimates of transfer times likely because transport of sucrose molecules, and pressure-concentration waves, in phloem differed. Secondly, we will argue that simultaneous measurements of bark and xylem diameters provide a novel tool to determine the continuous variations of phloem turgor in vivo in the field. We will present a model that interprets these changes in xylem and live bark diameters and present data testing the model

  20. Aphids Pick Their Poison: Selective Sequestration of Plant Chemicals Affects Host Plant Use in a Specialist Herbivore.

    PubMed

    Goodey, Nicole A; Florance, Hannah V; Smirnoff, Nicholas; Hodgson, Dave J

    2015-10-01

    In some plant-insect interactions, specialist herbivores exploit the chemical defenses of their food plant to their own advantage. Brassica plants produce glucosinolates that are broken down into defensive toxins when tissue is damaged, but the specialist aphid, Brevicoryne brassicae, uses these chemicals against its own natural enemies by becoming a "walking mustard-oil bomb". Analysis of glucosinolate concentrations in plant tissue and associated aphid colonies reveals that not only do aphids sequester glucosinolates, but they do so selectively. Aphids specifically accumulate sinigrin to high concentrations while preferentially excreting a structurally similar glucosinolate, progoitrin. Surveys of aphid infestation in wild populations of Brassica oleracea show that this pattern of sequestration and excretion maps onto host plant use. The probability of aphid infestation decreases with increasing concentrations of progoitrin in plants. Brassica brassicae, therefore, appear to select among food plants according to plant secondary metabolite profiles, and selectively store only some compounds that are used against their own enemies. The results demonstrate chemical and behavioral mechanisms that help to explain evidence of geographic patterns and evolutionary dynamics in Brassica-aphid interactions. PMID:26411571

  1. Aphids Pick Their Poison: Selective Sequestration of Plant Chemicals Affects Host Plant Use in a Specialist Herbivore.

    PubMed

    Goodey, Nicole A; Florance, Hannah V; Smirnoff, Nicholas; Hodgson, Dave J

    2015-10-01

    In some plant-insect interactions, specialist herbivores exploit the chemical defenses of their food plant to their own advantage. Brassica plants produce glucosinolates that are broken down into defensive toxins when tissue is damaged, but the specialist aphid, Brevicoryne brassicae, uses these chemicals against its own natural enemies by becoming a "walking mustard-oil bomb". Analysis of glucosinolate concentrations in plant tissue and associated aphid colonies reveals that not only do aphids sequester glucosinolates, but they do so selectively. Aphids specifically accumulate sinigrin to high concentrations while preferentially excreting a structurally similar glucosinolate, progoitrin. Surveys of aphid infestation in wild populations of Brassica oleracea show that this pattern of sequestration and excretion maps onto host plant use. The probability of aphid infestation decreases with increasing concentrations of progoitrin in plants. Brassica brassicae, therefore, appear to select among food plants according to plant secondary metabolite profiles, and selectively store only some compounds that are used against their own enemies. The results demonstrate chemical and behavioral mechanisms that help to explain evidence of geographic patterns and evolutionary dynamics in Brassica-aphid interactions.

  2. [Variations of microbial biomass and hydrolase activities in purple soil under different cropping modes as affected by ginger planting].

    PubMed

    Wang, Xu-Xi; Wu, Fu-Zhong; Yang, Wan-Qin; Wang, Ao

    2012-02-01

    This paper studied the variations of soil microbial biomass C, N, and P contents and soil hydrolase activities under different cropping modes, i.e., corn + sweet potato intercropping (CS), soybean mono-cropping (SM), continuous cropping of ginger (CG), and rice-milk vetch rotation (RM) , after ginger planting in the purple soil area at the lower reaches of Minjiang River. Ginger planting decreased the soil microbial biomass C, N and P contents significantly. The decrement of the soil microbial biomass C and N contents after ginger planting was lesser under CS and RM than under SM and CG, but the soil microbial biomass P content was in adverse. Ginger planting also decreased the soil acid phosphatase activity significantly, and the decrement was the greatest under CS but the least under RM. The soil invertase activity decreased significantly under CG, and the soil urease activity had a significant decrease under SM, CG and RM. After ginger planting, the soil urease and intervase activities under CS were higher, as compared with those under the other cropping modes.

  3. Species-abundance--seed-size patterns within a plant community affected by grazing disturbance.

    PubMed

    Wu, Gao-lin; Shang, Zhan-huan; Zhu, Yuan-jun; Ding, Lu-ming; Wang, Dong

    2015-04-01

    Seed size has been advanced as a key factor that influences the dynamics of plant communities, but there are few empirical or theoretical predictions of how community dynamics progress based on seed size patterns. Information on the abundance of adults, seedlings, soil seed banks, seed rains, and the seed mass of 96 species was collected in alpine meadows of the Qinghai-Tibetan Plateau (China), which had different levels of grazing disturbance. The relationships between seed-mass-abundance patterns for adults, seedlings, the soil seed bank, and seed rain in the plant community were evaluated using regression models. Results showed that grazing levels affected the relationship between seed size and abundance properties of adult species, seedlings, and the soil seed bank, suggesting that there is a shift in seed-size--species-abundance relationships as a response to the grazing gradient. Grazing had no effect on the pattern of seed-size-seed-rain-abundance at four grazing levels. Grazing also had little effect on the pattern of seed-size--species-abundance and pattern of seed-size--soil-seed-bank-abundance in meadows with no grazing, light grazing, and moderate grazing), but there was a significant negative effect in meadows with heavy grazing. Grazing had little effect on the pattern of seed-size--seedling-abundance with no grazing, but had significant negative effects with light, moderate, and heavy grazing, and the |r| values increased with grazing levels. This indicated that increasing grazing pressure enhanced the advantage of smaller-seeded species in terms of the abundances of adult species, seedlings, and soil seed banks, whereas only the light grazing level promoted the seed rain abundance of larger-seeded species in the plant communities. This study suggests that grazing disturbances are favorable for increasing the species abundance for smaller-seeded species but not for the larger-seeded species in an alpine meadow community. Hence, there is a clear

  4. Genes of the most conserved WOX clade in plants affect root and flower development in Arabidopsis

    PubMed Central

    2008-01-01

    Background The Wuschel related homeobox (WOX) family proteins are key regulators implicated in the determination of cell fate in plants by preventing cell differentiation. A recent WOX phylogeny, based on WOX homeodomains, showed that all of the Physcomitrella patens and Selaginella moellendorffii WOX proteins clustered into a single orthologous group. We hypothesized that members of this group might preferentially share a significant part of their function in phylogenetically distant organisms. Hence, we first validated the limits of the WOX13 orthologous group (WOX13 OG) using the occurrence of other clade specific signatures and conserved intron insertion sites. Secondly, a functional analysis using expression data and mutants was undertaken. Results The WOX13 OG contained the most conserved plant WOX proteins including the only WOX detected in the highly proliferating basal unicellular and photosynthetic organism Ostreococcus tauri. A large expansion of the WOX family was observed after the separation of mosses from other land plants and before monocots and dicots have arisen. In Arabidopsis thaliana, AtWOX13 was dynamically expressed during primary and lateral root initiation and development, in gynoecium and during embryo development. AtWOX13 appeared to affect the floral transition. An intriguing clade, represented by the functional AtWOX14 gene inside the WOX13 OG, was only found in the Brassicaceae. Compared to AtWOX13, the gene expression profile of AtWOX14 was restricted to the early stages of lateral root formation and specific to developing anthers. A mutational insertion upstream of the AtWOX14 homeodomain sequence led to abnormal root development, a delay in the floral transition and premature anther differentiation. Conclusion Our data provide evidence in favor of the WOX13 OG as the clade containing the most conserved WOX genes and established a functional link to organ initiation and development in Arabidopsis, most likely by preventing premature

  5. Spatial gradient in nitrogen deposition affects plant species frequency in acidic grasslands.

    PubMed

    Pannek, A; Duprè, C; Gowing, D J G; Stevens, C J; Diekmann, M

    2015-01-01

    Anthropogenic eutrophication impacts ecosystems worldwide. Here, we use a vegetation dataset from semi-natural grasslands on acidic soils sampled along a gradient in north-western Europe to examine the response of species frequency to nitrogen (N) deposition, controlling for the effects of other environmental variables. A second dataset of acidic grasslands from Germany and the Netherlands containing plots from different time periods was analysed to examine whether the results of the spatial gradient approach coincided with temporal changes in the abundance of species. Out of 44 studied species, 16 were affected by N deposition, 12 of them negatively. Soil pH and phosphorus (P) influenced 24 and 14 species, respectively, predominantly positively. Fewer species were related to the soil contents of NO3(-) or NH4(+), with no significant differences between the number of positive and negative effects. Whereas the temporal change of species was unrelated to their responses to pH, species responding negatively to N deposition, soil P and NO3(-) showed a significant decline over time in both countries. Species that were negatively affected by high N deposition and/or high soil P also showed a negative temporal trend and could be characterised by short stature and slow growth. The results confirm the negative role of N deposition for many plant species in semi-natural acidic grasslands. The negative temporal trends of species sensitive to high N deposition and soil P values clearly show a need for maintaining low soil nutrient status and for restoring the formerly infertile conditions in nutrient-enriched grasslands. PMID:25407619

  6. Cytonuclear interactions affect adaptive traits of the annual plant Arabidopsis thaliana in the field

    PubMed Central

    Roux, Fabrice; Mary-Huard, Tristan; Barillot, Elise; Wenes, Estelle; Botran, Lucy; Durand, Stéphanie; Villoutreix, Romain; Martin-Magniette, Marie-Laure; Camilleri, Christine; Budar, Françoise

    2016-01-01

    Although the contribution of cytonuclear interactions to plant fitness variation is relatively well documented at the interspecific level, the prevalence of cytonuclear interactions at the intraspecific level remains poorly investigated. In this study, we set up a field experiment to explore the range of effects that cytonuclear interactions have on fitness-related traits in Arabidopsis thaliana. To do so, we created a unique series of 56 cytolines resulting from cytoplasmic substitutions among eight natural accessions reflecting within-species genetic diversity. An assessment of these cytolines and their parental lines scored for 28 adaptive whole-organism phenotypes showed that a large proportion of phenotypic traits (23 of 28) were affected by cytonuclear interactions. The effects of these interactions varied from slight but frequent across cytolines to strong in some specific parental pairs. Two parental pairs accounted for half of the significant pairwise interactions. In one parental pair, Ct-1/Sha, we observed symmetrical phenotypic responses between the two nuclear backgrounds when combined with specific cytoplasms, suggesting nuclear differentiation at loci involved in cytonuclear epistasis. In contrast, asymmetrical phenotypic responses were observed in another parental pair, Cvi-0/Sha. In the Cvi-0 nuclear background, fecundity and phenology-related traits were strongly affected by the Sha cytoplasm, leading to a modified reproductive strategy without penalizing total seed production. These results indicate that natural variation in cytoplasmic and nuclear genomes interact to shape integrative traits that contribute to adaptation, thereby suggesting that cytonuclear interactions can play a major role in the evolutionary dynamics of A. thaliana. PMID:26979961

  7. Severe dry winter affects plant phenology and carbon balance of a cork oak woodland understorey

    NASA Astrophysics Data System (ADS)

    Correia, A. C.; Costa-e-Silva, F.; Dubbert, M.; Piayda, A.; Pereira, J. S.

    2016-10-01

    Mediterranean climates are prone to a great variation in yearly precipitation. The effects on ecosystem will depend on the severity and timing of droughts. In this study we questioned how an extreme dry winter affects the carbon flux in the understorey of a cork oak woodland? What is the seasonal contribution of understorey vegetation to ecosystem productivity? We used closed-system portable chambers to measure CO2 exchange of the dominant shrub species (Cistus salviifolius, Cistus crispus and Ulex airensis), of the herbaceous layer and on bare soil in a cork oak woodland in central Portugal during the dry winter year of 2012. Shoot growth, leaf shedding, flower and fruit setting, above and belowground plant biomass were measured as well as seasonal leaf water potential. Eddy-covariance and micrometeorological data together with CO2 exchange measurements were used to access the understorey species contribution to ecosystem gross primary productivity (GPP). The herbaceous layer productivity was severely affected by the dry winter, with half of the yearly maximum aboveground biomass in comparison with the 6 years site average. The semi-deciduous and evergreen shrubs showed desynchronized phenophases and lagged carbon uptake maxima. Whereas shallow-root shrubs exhibited opportunistic characteristics in exploiting the understorey light and water resources, deep rooted shrubs showed better water status but considerably lower assimilation rates. The contribution of understorey vegetation to ecosystem GPP was lower during summer with 14% and maximum during late spring, concomitantly with the lowest tree productivity due to tree canopy renewal. The herbaceous vegetation contribution to ecosystem GPP never exceeded 6% during this dry year stressing its sensitivity to winter and spring precipitation. Although shrubs are more resilient to precipitation variability when compared with the herbaceous vegetation, the contribution of the understorey vegetation to ecosystem GPP can

  8. Spatial gradient in nitrogen deposition affects plant species frequency in acidic grasslands.

    PubMed

    Pannek, A; Duprè, C; Gowing, D J G; Stevens, C J; Diekmann, M

    2015-01-01

    Anthropogenic eutrophication impacts ecosystems worldwide. Here, we use a vegetation dataset from semi-natural grasslands on acidic soils sampled along a gradient in north-western Europe to examine the response of species frequency to nitrogen (N) deposition, controlling for the effects of other environmental variables. A second dataset of acidic grasslands from Germany and the Netherlands containing plots from different time periods was analysed to examine whether the results of the spatial gradient approach coincided with temporal changes in the abundance of species. Out of 44 studied species, 16 were affected by N deposition, 12 of them negatively. Soil pH and phosphorus (P) influenced 24 and 14 species, respectively, predominantly positively. Fewer species were related to the soil contents of NO3(-) or NH4(+), with no significant differences between the number of positive and negative effects. Whereas the temporal change of species was unrelated to their responses to pH, species responding negatively to N deposition, soil P and NO3(-) showed a significant decline over time in both countries. Species that were negatively affected by high N deposition and/or high soil P also showed a negative temporal trend and could be characterised by short stature and slow growth. The results confirm the negative role of N deposition for many plant species in semi-natural acidic grasslands. The negative temporal trends of species sensitive to high N deposition and soil P values clearly show a need for maintaining low soil nutrient status and for restoring the formerly infertile conditions in nutrient-enriched grasslands.

  9. Cytonuclear interactions affect adaptive traits of the annual plant Arabidopsis thaliana in the field.

    PubMed

    Roux, Fabrice; Mary-Huard, Tristan; Barillot, Elise; Wenes, Estelle; Botran, Lucy; Durand, Stéphanie; Villoutreix, Romain; Martin-Magniette, Marie-Laure; Camilleri, Christine; Budar, Françoise

    2016-03-29

    Although the contribution of cytonuclear interactions to plant fitness variation is relatively well documented at the interspecific level, the prevalence of cytonuclear interactions at the intraspecific level remains poorly investigated. In this study, we set up a field experiment to explore the range of effects that cytonuclear interactions have on fitness-related traits in Arabidopsis thaliana To do so, we created a unique series of 56 cytolines resulting from cytoplasmic substitutions among eight natural accessions reflecting within-species genetic diversity. An assessment of these cytolines and their parental lines scored for 28 adaptive whole-organism phenotypes showed that a large proportion of phenotypic traits (23 of 28) were affected by cytonuclear interactions. The effects of these interactions varied from slight but frequent across cytolines to strong in some specific parental pairs. Two parental pairs accounted for half of the significant pairwise interactions. In one parental pair, Ct-1/Sha, we observed symmetrical phenotypic responses between the two nuclear backgrounds when combined with specific cytoplasms, suggesting nuclear differentiation at loci involved in cytonuclear epistasis. In contrast, asymmetrical phenotypic responses were observed in another parental pair, Cvi-0/Sha. In the Cvi-0 nuclear background, fecundity and phenology-related traits were strongly affected by the Sha cytoplasm, leading to a modified reproductive strategy without penalizing total seed production. These results indicate that natural variation in cytoplasmic and nuclear genomes interact to shape integrative traits that contribute to adaptation, thereby suggesting that cytonuclear interactions can play a major role in the evolutionary dynamics ofA. thaliana. PMID:26979961

  10. Vaccine Adverse Events

    MedlinePlus

    ... Vaccines, Blood & Biologics Animal & Veterinary Cosmetics Tobacco Products Vaccines, Blood & Biologics Home Vaccines, Blood & Biologics Safety & Availability ( ... Center for Biologics Evaluation & Research Vaccine Adverse Events Vaccine Adverse Events Share Tweet Linkedin Pin it More ...

  11. Thermal effects on microbial composition and microbiologically induced corrosion and mineral precipitation affecting operation of a geothermal plant in a deep saline aquifer.

    PubMed

    Lerm, Stephanie; Westphal, Anke; Miethling-Graff, Rona; Alawi, Mashal; Seibt, Andrea; Wolfgramm, Markus; Würdemann, Hilke

    2013-03-01

    The microbial diversity of a deep saline aquifer used for geothermal heat storage in the North German Basin was investigated. Genetic fingerprinting analyses revealed distinct microbial communities in fluids produced from the cold and warm side of the aquifer. Direct cell counting and quantification of 16S rRNA genes and dissimilatory sulfite reductase (dsrA) genes by real-time PCR proved different population sizes in fluids, showing higher abundance of bacteria and sulfate reducing bacteria (SRB) in cold fluids compared with warm fluids. The operation-dependent temperature increase at the warm well probably enhanced organic matter availability, favoring the growth of fermentative bacteria and SRB in the topside facility after the reduction of fluid temperature. In the cold well, SRB predominated and probably accounted for corrosion damage to the submersible well pump and iron sulfide precipitates in the near wellbore area and topside facility filters. This corresponded to lower sulfate content in fluids produced from the cold well as well as higher content of hydrogen gas that was probably released from corrosion, and maybe favored growth of hydrogenotrophic SRB. This study reflects the high influence of microbial populations for geothermal plant operation, because microbiologically induced precipitative and corrosive processes adversely affect plant reliability.

  12. Thermal effects on microbial composition and microbiologically induced corrosion and mineral precipitation affecting operation of a geothermal plant in a deep saline aquifer.

    PubMed

    Lerm, Stephanie; Westphal, Anke; Miethling-Graff, Rona; Alawi, Mashal; Seibt, Andrea; Wolfgramm, Markus; Würdemann, Hilke

    2013-03-01

    The microbial diversity of a deep saline aquifer used for geothermal heat storage in the North German Basin was investigated. Genetic fingerprinting analyses revealed distinct microbial communities in fluids produced from the cold and warm side of the aquifer. Direct cell counting and quantification of 16S rRNA genes and dissimilatory sulfite reductase (dsrA) genes by real-time PCR proved different population sizes in fluids, showing higher abundance of bacteria and sulfate reducing bacteria (SRB) in cold fluids compared with warm fluids. The operation-dependent temperature increase at the warm well probably enhanced organic matter availability, favoring the growth of fermentative bacteria and SRB in the topside facility after the reduction of fluid temperature. In the cold well, SRB predominated and probably accounted for corrosion damage to the submersible well pump and iron sulfide precipitates in the near wellbore area and topside facility filters. This corresponded to lower sulfate content in fluids produced from the cold well as well as higher content of hydrogen gas that was probably released from corrosion, and maybe favored growth of hydrogenotrophic SRB. This study reflects the high influence of microbial populations for geothermal plant operation, because microbiologically induced precipitative and corrosive processes adversely affect plant reliability. PMID:23358731

  13. Do different substitution patterns or plant origin in hydroxyethyl starches affect blood coagulation in vitro?

    PubMed

    Matsota, Paraskevi; Politou, Marianna; Kalimeris, Konstantinos; Apostolaki, Stella; Merkouri, Efrosyni; Gialeraki, Argyri; Travlou, Anthi; Kostopanagiotou, Georgia

    2010-07-01

    The effect of hydroxyethyl starches (HES) on blood coagulation is affected by their molecular weight, their molar substitution and the C2/C6 ratio. The solutions of 6% HES 130/0.4 and 6% HES 130/0.42 have similar molecular weight and molar substitution but different C2/C6 ratio and plant origin. In the present study, the comparative effect of 6% HES 130/0.4 versus 6% HES 130/0.42 on blood coagulation was investigated in vitro. Thirty milliliter of blood was obtained from 10 healthy volunteers and was diluted by 10, 30 and 50% using either 6% HES 130/0.4 or HES 130/0.42, respectively. Blood coagulation was assessed using thrombelastography measurements (clotting time, clot formation time, maximal clot firmness and alpha-angle). The assessment of platelet function was performed with whole blood aggregometry after adding thrombin-receptor-activating protein. No differences were noted between respective dilutions of the two HES. Both colloids produced significant reductions below the reference values range in clotting time at 10, 30 and 50% dilutions. The 50% dilution of both colloids resulted in significant reduction of maximal clot firmness, alpha-angle and platelet aggregation. The present study showed that the corn-derived 6% HES 130/0.4 and the potato-derived 6% HES 130/0.42 have the same effect on blood coagulation in vitro.

  14. Isotopic Tracing of Thallium Contamination in Soils Affected by Emissions from Coal-Fired Power Plants.

    PubMed

    Vaněk, Aleš; Grösslová, Zuzana; Mihaljevič, Martin; Trubač, Jakub; Ettler, Vojtěch; Teper, Leslaw; Cabala, Jerzy; Rohovec, Jan; Zádorová, Tereza; Penížek, Vít; Pavlů, Lenka; Holubík, Ondřej; Němeček, Karel; Houška, Jakub; Drábek, Ondřej; Ash, Christopher

    2016-09-20

    Here, for the first time, we report the thallium (Tl) isotope record in moderately contaminated soils with contrasting land management (forest and meadow soils), which have been affected by emissions from coal-fired power plants. Our findings clearly demonstrate that Tl of anthropogenic (high-temperature) origin with light isotope composition was deposited onto the studied soils, where heavier Tl (ε(205)Tl ∼ -1) naturally occurs. The results show a positive linear relationship (R(2) = 0.71) between 1/Tl and the isotope record, as determined for all the soils and bedrocks, also indicative of binary Tl mixing between two dominant reservoirs. We also identified significant Tl isotope variations within the products from coal combustion and thermo-desorption experiments with local Tl-rich coal pyrite. Bottom ash exhibited the heaviest Tl isotope composition (ε(205)Tl ∼ 0), followed by fly ash (ε(205)Tl between -2.5 and -2.8) and volatile Tl fractions (ε(205)Tl between -6.2 and -10.3), suggesting partial Tl isotope fractionations. Despite the evident role of soil processes in the isotope redistributions, we demonstrate that Tl contamination can be traced in soils and propose that the isotope data represent a possible tool to aid our understanding of postdepositional Tl dynamics in surface environments for the future.

  15. Isotopic Tracing of Thallium Contamination in Soils Affected by Emissions from Coal-Fired Power Plants.

    PubMed

    Vaněk, Aleš; Grösslová, Zuzana; Mihaljevič, Martin; Trubač, Jakub; Ettler, Vojtěch; Teper, Leslaw; Cabala, Jerzy; Rohovec, Jan; Zádorová, Tereza; Penížek, Vít; Pavlů, Lenka; Holubík, Ondřej; Němeček, Karel; Houška, Jakub; Drábek, Ondřej; Ash, Christopher

    2016-09-20

    Here, for the first time, we report the thallium (Tl) isotope record in moderately contaminated soils with contrasting land management (forest and meadow soils), which have been affected by emissions from coal-fired power plants. Our findings clearly demonstrate that Tl of anthropogenic (high-temperature) origin with light isotope composition was deposited onto the studied soils, where heavier Tl (ε(205)Tl ∼ -1) naturally occurs. The results show a positive linear relationship (R(2) = 0.71) between 1/Tl and the isotope record, as determined for all the soils and bedrocks, also indicative of binary Tl mixing between two dominant reservoirs. We also identified significant Tl isotope variations within the products from coal combustion and thermo-desorption experiments with local Tl-rich coal pyrite. Bottom ash exhibited the heaviest Tl isotope composition (ε(205)Tl ∼ 0), followed by fly ash (ε(205)Tl between -2.5 and -2.8) and volatile Tl fractions (ε(205)Tl between -6.2 and -10.3), suggesting partial Tl isotope fractionations. Despite the evident role of soil processes in the isotope redistributions, we demonstrate that Tl contamination can be traced in soils and propose that the isotope data represent a possible tool to aid our understanding of postdepositional Tl dynamics in surface environments for the future. PMID:27536872

  16. Diversity of fungi associated with hair roots of ericaceous plants is affected by land use.

    PubMed

    Hazard, Christina; Gosling, Paul; Mitchell, Derek T; Doohan, Fiona M; Bending, Gary D

    2014-03-01

    Culture-independent molecular studies have provided new insights into the diversity of fungi associating with ericaceous plant roots. However, there is little understanding of the distribution of these fungi across landscapes, or the effects of environmental heterogeneity on ericoid mycorrhizal (ERM) fungal diversity and distribution. Terminal-restriction fragment length polymorphism and selective sequence analyses of the internal transcribed spacer regions of rDNA were used to infer fungal diversity of bait Vaccinium macrocarpon grown in soils from nine peatland sites in Ireland, representing three different land uses (bog, rough grazing and forest plantation) and the fungal communities of field-collected Calluna vulgaris for five of these nine sites. A diverse range of potential ERM fungi were found, and the sampling approach significantly affected the diversity of the fungal community. Despite significant site groupings of the fungal communities associated with V. macrocarpon and C. vulgaris, fungal communities were significantly dissimilar between sites with different land uses. Soil nitrogen content significantly explained 52% of the variation in the V. macrocarpon fungal communities. Evidence suggests that environmental heterogeneity has a role in shaping ERM fungal community composition at the landscape scale.

  17. Proteomic analysis reveals suppression of bark chitinases and proteinase inhibitors in citrus plants affected by the citrus sudden death disease.

    PubMed

    Cantú, M D; Mariano, A G; Palma, M S; Carrilho, E; Wulff, N A

    2008-10-01

    Citrus sudden death (CSD) is a disease of unknown etiology that greatly affects sweet oranges grafted on Rangpur lime rootstock, the most important rootstock in Brazilian citriculture. We performed a proteomic analysis to generate information related to this plant pathogen interaction. Protein profiles from healthy, CSD-affected and CSD-tolerant stem barks, were generated using two-dimensional gel electrophoresis. The protein spots were well distributed over a pI range of 3.26 to 9.97 and a molecular weight (MW) range from 7.1 to 120 kDa. The patterns of expressed proteins on 2-DE gels made it possible to distinguish healthy barks from CSD-affected barks. Protein spots with MW around 30 kDa and pI values ranging from 4.5 to 5.2 were down-regulated in the CSD-affected root-stock bark. This set of protein spots was identified as chitinases. Another set of proteins, ranging in pI from 6.1 to 9.6 with an MW of about 20 kDa, were also suppressed in CSD-affected rootstock bark; these were identified as miraculin-like proteins, potential trypsin inhibitors. Down-regulation of chitinases and proteinase inhibitors in CSD-affected plants is relevant since chitinases are well-known pathogenesis-related protein, and their activity against plant pathogens is largely accepted. PMID:18943454

  18. Acclimations to light quality on plant and leaf level affect the vulnerability of pepper (Capsicum annuum L.) to water deficit.

    PubMed

    Hoffmann, Anna M; Noga, Georg; Hunsche, Mauricio

    2015-03-01

    We investigated the influence of light quality on the vulnerability of pepper plants to water deficit. For this purpose plants were cultivated either under compact fluorescence lamps (CFL) or light-emitting diodes (LED) providing similar photon fluence rates (95 µmol m(-2) s(-1)) but distinct light quality. CFL emit a wide-band spectrum with dominant peaks in the green and red spectral region, whereas LEDs offer narrow band spectra with dominant peaks at blue (445 nm) and red (665 nm) regions. After one-week acclimation to light conditions plants were exposed to water deficit by withholding irrigation; this period was followed by a one-week regeneration period and a second water deficit cycle. In general, plants grown under CFL suffered more from water deficit than plants grown under LED modules, as indicated by the impairment of the photosynthetic efficiency of PSII, resulting in less biomass accumulation compared to respective control plants. As affected by water shortage, plants grown under CFL had a stronger decrease in the electron transport rate (ETR) and more pronounced increase in heat dissipation (NPQ). The higher amount of blue light suppressed plant growth and biomass formation, and consequently reduced the water demand of plants grown under LEDs. Moreover, pepper plants exposed to high blue light underwent adjustments at chloroplast level (e.g., higher Chl a/Chl b ratio), increasing the photosynthetic performance under the LED spectrum. Differently than expected, stomatal conductance was comparable for water-deficit and control plants in both light conditions during the stress and recovery phases, indicating only minor adjustments at the stomatal level. Our results highlight the potential of the target-use of light quality to induce structural and functional acclimations improving plant performance under stress situations.

  19. The B-3 ethylene response factor MtERF1-1 mediates resistance to a subset of root pathogens in Medicago truncatula without adversely affecting symbiosis with rhizobia.

    PubMed

    Anderson, Jonathan P; Lichtenzveig, Judith; Gleason, Cynthia; Oliver, Richard P; Singh, Karam B

    2010-10-01

    The fungal necrotrophic pathogen Rhizoctonia solani is a significant constraint to a range of crops as diverse as cereals, canola, and legumes. Despite wide-ranging germplasm screens in many of these crops, no strong genetic resistance has been identified, suggesting that alternative strategies to improve resistance are required. In this study, we characterize moderate resistance to R. solani anastomosis group 8 identified in Medicago truncatula. The activity of the ethylene- and jasmonate-responsive GCC box promoter element was associated with moderate resistance, as was the induction of the B-3 subgroup of ethylene response transcription factors (ERFs). Genes of the B-1 subgroup showed no significant response to R. solani infection. Overexpression of a B-3 ERF, MtERF1-1, in Medicago roots increased resistance to R. solani as well as an oomycete root pathogen, Phytophthora medicaginis, but not root knot nematode. These results indicate that targeting specific regulators of ethylene defense may enhance resistance to an important subset of root pathogens. We also demonstrate that overexpression of MtERF1-1 enhances disease resistance without apparent impact on nodulation in the A17 background, while overexpression in sickle reduced the hypernodulation phenotype. This suggests that under normal regulation of nodulation, enhanced resistance to root diseases can be uncoupled from symbiotic plant-microbe interactions in the same tissue and that ethylene/ERF regulation of nodule number is distinct from the defenses regulated by B-3 ERFs. Furthermore, unlike the stunted phenotype previously described for Arabidopsis (Arabidopsis thaliana) ubiquitously overexpressing B-3 ERFs, overexpression of MtERF1-1 in M. truncatula roots did not show adverse effects on plant development.

  20. How grazing and soil quality affect native and exotic plant diversity in Rocky Mountain grasslands

    USGS Publications Warehouse

    Stohlgren, T.J.; Schell, L.D.; Vanden, Heuvel B.

    1999-01-01

    (adjacent and distant 1000-m2 plots) in the same vegetation type overlapped just 48.6 ?? 3.6%, and the ungrazed plots and distant grazed plots overlapped 49.4 ?? 3.6%. Differences in vegetation and soils between grazed and ungrazed sites were minimal in most cases, but soil characteristics and elevation were strongly correlated with native and exotic plant diversity in the study region. For the 78 1000-m2 plots, 59.4% of the variance in total species richness was explained by percentage of silt (coefficient = 0.647, t = 5.107, P < 0.001), elevation (coefficient = 0.012, t = 5.084, P < 0.001), and total foliar cover (coefficient = 0.110, t = 2.104, P < 0.039). Only 12.8% of the variance in exotic species cover (log10cover) was explained by percentage of clay (coefficient = -0.011, t = -2.878, P < 0.005), native species richness (coefficient = -0.011, t = -2.156, P < 0.034), and log10N (coefficient = 2.827, t = 1.860, P < 0.067). Native species cover and exotic species richness and frequency were also significantly positively correlated with percentage of soil N at the 1000-m2 plot scale. Our research led to five broad generalizations about current levels of grazing in these Rocky Mountain grasslands: (1) grazing probably has little effect on native species richness at landscape scales; (2) grazing probably has little effect on the accelerated spread of most exotic plant species at landscape scales; (3) grazing affects local plant species and life-form composition and cover, but spatial variation is considerable; (4) soil characteristics, climate, and disturbances may have a greater effect on plant species diversity than do current levels of grazing; and (5) few plant species show consistent, directional responses to grazing or cessation of grazing.

  1. Corn Response as Affected by Planting Distance from the Center of Strip-Till Fertilized Rows

    PubMed Central

    Adee, Eric; Hansel, Fernando D.; Ruiz Diaz, Dorivar A.; Janssen, Keith

    2016-01-01

    Strip-till has been used at a large scale in east central Kansas as an alternative to earlier planting dates under a no-till system. To determine the effects of planting corn (Zea mays) under previously established strip-tilled fertilized rows, experiments were conducted on an Osage silty clay loam soil in 2006 and 2008 and on a Woodson silt loam soil in 2009, 2010, and 2011 using three different planting distances from the strip-tilled fertilized rows (0, 10, 20, and 38 cm) with a strip-till operation performed between 1 and 73 days before planting. The depth of the strip-till fertilizer application was 13–15 cm below the soil surface. Corn that was planted 10 cm from the fertilized row showed greater early season growth, higher plant population, and grain yield. Planting 20 and 38 cm from the center of the fertilized rows showed none of the benefits that are typically associated with strip-tillage system. Enough time should be allowed between the strip-till operation and planting to reach satisfactory soil conditions (e.g., moist and firm seedbed). Our results suggest that the best location for planting strip-tilled fertilized corn vary depending on soil and climatic conditions as well as the time between fertilizer application with the strip-till operation and planting. With fewer number of days, planting directly on the center of fertilized strip-till resulted in decreased plant population and lower grain yield. However, the greatest yield benefit across different planting conditions was attained when planting within 10 cm of the strip. PMID:27588024

  2. Corn Response as Affected by Planting Distance from the Center of Strip-Till Fertilized Rows.

    PubMed

    Adee, Eric; Hansel, Fernando D; Ruiz Diaz, Dorivar A; Janssen, Keith

    2016-01-01

    Strip-till has been used at a large scale in east central Kansas as an alternative to earlier planting dates under a no-till system. To determine the effects of planting corn (Zea mays) under previously established strip-tilled fertilized rows, experiments were conducted on an Osage silty clay loam soil in 2006 and 2008 and on a Woodson silt loam soil in 2009, 2010, and 2011 using three different planting distances from the strip-tilled fertilized rows (0, 10, 20, and 38 cm) with a strip-till operation performed between 1 and 73 days before planting. The depth of the strip-till fertilizer application was 13-15 cm below the soil surface. Corn that was planted 10 cm from the fertilized row showed greater early season growth, higher plant population, and grain yield. Planting 20 and 38 cm from the center of the fertilized rows showed none of the benefits that are typically associated with strip-tillage system. Enough time should be allowed between the strip-till operation and planting to reach satisfactory soil conditions (e.g., moist and firm seedbed). Our results suggest that the best location for planting strip-tilled fertilized corn vary depending on soil and climatic conditions as well as the time between fertilizer application with the strip-till operation and planting. With fewer number of days, planting directly on the center of fertilized strip-till resulted in decreased plant population and lower grain yield. However, the greatest yield benefit across different planting conditions was attained when planting within 10 cm of the strip.

  3. Corn Response as Affected by Planting Distance from the Center of Strip-Till Fertilized Rows.

    PubMed

    Adee, Eric; Hansel, Fernando D; Ruiz Diaz, Dorivar A; Janssen, Keith

    2016-01-01

    Strip-till has been used at a large scale in east central Kansas as an alternative to earlier planting dates under a no-till system. To determine the effects of planting corn (Zea mays) under previously established strip-tilled fertilized rows, experiments were conducted on an Osage silty clay loam soil in 2006 and 2008 and on a Woodson silt loam soil in 2009, 2010, and 2011 using three different planting distances from the strip-tilled fertilized rows (0, 10, 20, and 38 cm) with a strip-till operation performed between 1 and 73 days before planting. The depth of the strip-till fertilizer application was 13-15 cm below the soil surface. Corn that was planted 10 cm from the fertilized row showed greater early season growth, higher plant population, and grain yield. Planting 20 and 38 cm from the center of the fertilized rows showed none of the benefits that are typically associated with strip-tillage system. Enough time should be allowed between the strip-till operation and planting to reach satisfactory soil conditions (e.g., moist and firm seedbed). Our results suggest that the best location for planting strip-tilled fertilized corn vary depending on soil and climatic conditions as well as the time between fertilizer application with the strip-till operation and planting. With fewer number of days, planting directly on the center of fertilized strip-till resulted in decreased plant population and lower grain yield. However, the greatest yield benefit across different planting conditions was attained when planting within 10 cm of the strip. PMID:27588024

  4. Elevated atmospheric carbon dioxide concentration affects interactions between Spodoptera exigua (Lepidoptera: Noctuidae) larvae and two host plant species outdoors

    SciTech Connect

    Caulfield, F.; Bunce, J.A. )

    1994-08-01

    Beet armyworm, Spodoptera exigua (Huebner), larvae were placed on sugarbeet (Beta vulgaris L.) and pigweed (Amaranthus hybridus L.) plants in outdoor chambers in which the plants were growing at either the ambient ([approximately] 350 [mu]l liter[sup [minus]1]) or ambient plus 350 [mu]l liter[sup [minus]1] ([approximately] 700 [mu]l liter[sup [minus]1]) carbon dioxide concentration. A series of experiments was performed to determine if larvae reduced plant growth differently at the two carbon dioxide concentrations in either species and if the insect growth or survival differed with carbon dioxide concentration. Leaf nitrogen, water, starch, and soluble carbohydrate contents were measured to assess carbon dioxide concentration effects on leaf quality. Insect feeding significantly reduced plant growth in sugarbeet plants at 350 [mu]l liter[sup [minus]1] but not at 700 [mu]l liter[sup [minus]1] nor in pigweed at either carbon dioxide concentration. Larval survival was greater on sugarbeet plants at the elevated carbon dioxide concentration. Increased survival occurred only if the insects were at the elevated carbon dioxide concentration and consumed leaf material grown at the elevated concentration. Leaf quality was only marginally affected by growth at elevated carbon dioxide concentration in these experiments. The results indicate that in designing experiments to predict effects of elevated atmospheric carbon dioxide concentrations on plant-insect interactions, both plants and insects should be exposed to the experimental carbon dioxide concentrations, as well as to as realistic environmental conditions as possible.

  5. Jasmonic acid affects plant morphology and calcium-dependent protein kinase expression and activity in Solanum tuberosum.

    PubMed

    Ulloa, Rita M; Raíces, Marcela; MacIntosh, Gustavo C; Maldonado, Sara; Téllez-Iñón, María T

    2002-07-01

    The effect of jasmonic acid (JA) on plant growth and on calcium-dependent protein kinase (CDPK) activity and expression was studied in non-photoperiodic potato plants, Solanum tuberosum L. var. Spunta, grown in vitro. Stem cuttings were grown for 45 days (long treatment, LT) in MS medium with increasing concentrations of JA. For short treatments (ST) adult plants grown in MS were transferred for 1, 4 and 20 h to JA containing media. During the LT, low concentrations of JA promoted cell expansion and shoot elongation while higher concentrations caused growth inhibition. Under these conditions, treated plants showed root shortening and tuber formation was not induced. Morphological and histochemical studies using light microscopy and TEM analysis of leaves from treated plants revealed that JA also affected subcellular organelles of mesophyll cells. Peroxisomes increased in size and number, and an autophagic process was triggered in response to high concentrations of the hormone. CDPK activity, determined in crude extracts of treated plants (LT), was inhibited (up to 80%). Plant growth and CDPK inhibition were reverted upon transfer of the plants to hormone-free medium. Soluble CDPK activity decreased in response to JA short treatment. Concomitantly, a decline in the steady state levels of StCDPK2 mRNA, a potato CDPK isoform that is expressed in leaves, was observed. These data suggest that the phytohormone down-regulated the expression and activity of the kinase.

  6. The impact of global warming on floral traits that affect the selfing rate in a high-altitude plant

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Changes in the abiotic environment, as those expected under global warming, can influence plant mating systems through changes in floral traits that affect selfing. Herkogamy (spatial separation of male and female functions within a flower), dichogamy (temporal separation) and total flower number af...

  7. Plant Products Affect Growth and Digestive Efficiency of Cultured Florida Pompano (Trachinotus carolinus) Fed Compounded Diets

    PubMed Central

    Lech, Gregory P.; Reigh, Robert C.

    2012-01-01

    Costs of compounded diets containing fish meal as a primary protein source can be expected to rise as fish meal prices increase in response to static supply and growing demand. Alternatives to fish meal are needed to reduce production costs in many aquaculture enterprises. Some plant proteins are potential replacements for fish meal because of their amino acid composition, lower cost and wide availability. In this study, we measured utilization of soybean meal (SBM) and soy protein concentrate (SPC) by Florida pompano fed compounded diets, to determine the efficacy of these products as fish meal replacements. We also calculated apparent digestibility coefficients (ADCs) for canola meal (CM), corn gluten meal (CGM), and distillers dried grains with solubles (DDGS), following typical methods for digestibility trials. Juvenile Florida pompano were fed fish-meal-free diets containing graded levels of SBM and SPC, and weight gain was compared to a control diet that contained SBM, SPC, and fish meal. Fish fed diets that contained 25–30 percent SBM in combination with 43–39 percent SPC had weight gain equivalent to fish fed the control diet with fish meal, while weight gain of fish fed other soy combinations was significantly less than that of the control group. Apparent crude protein digestibility of CGM was significantly higher than that of DDGS but not significantly different from CM. Apparent energy digestibility of DDGS was significantly lower than CGM but significantly higher than CM. Findings suggested that composition of the reference diet used in a digestibility trial affects the values of calculated ADCs, in addition to the chemical and physical attributes of the test ingredient. PMID:22536344

  8. Plant products affect growth and digestive efficiency of cultured Florida pompano (Trachinotus carolinus) fed compounded diets.

    PubMed

    Lech, Gregory P; Reigh, Robert C

    2012-01-01

    Costs of compounded diets containing fish meal as a primary protein source can be expected to rise as fish meal prices increase in response to static supply and growing demand. Alternatives to fish meal are needed to reduce production costs in many aquaculture enterprises. Some plant proteins are potential replacements for fish meal because of their amino acid composition, lower cost and wide availability. In this study, we measured utilization of soybean meal (SBM) and soy protein concentrate (SPC) by Florida pompano fed compounded diets, to determine the efficacy of these products as fish meal replacements. We also calculated apparent digestibility coefficients (ADCs) for canola meal (CM), corn gluten meal (CGM), and distillers dried grains with solubles (DDGS), following typical methods for digestibility trials. Juvenile Florida pompano were fed fish-meal-free diets containing graded levels of SBM and SPC, and weight gain was compared to a control diet that contained SBM, SPC, and fish meal. Fish fed diets that contained 25-30 percent SBM in combination with 43-39 percent SPC had weight gain equivalent to fish fed the control diet with fish meal, while weight gain of fish fed other soy combinations was significantly less than that of the control group. Apparent crude protein digestibility of CGM was significantly higher than that of DDGS but not significantly different from CM. Apparent energy digestibility of DDGS was significantly lower than CGM but significantly higher than CM. Findings suggested that composition of the reference diet used in a digestibility trial affects the values of calculated ADCs, in addition to the chemical and physical attributes of the test ingredient.

  9. Plant diversity affects behavior of generalist root herbivores, reduces crop damage, and enhances crop yield.

    PubMed

    Staudacher, Karin; Schallhart, Nikolaus; Thalinger, Bettina; Wallinger, Corinna; Juen, Anita; Traugott, Michael

    2013-07-01

    Soil-dwelling pests inflict considerable economic damage in agriculture but are hard to control. A promising strategy to reduce pest pressure on crops is to increase the plant diversity in agroecosystems. This approach, however, demands a sound understanding of species' interactions, which is widely lacking for subterranean herbivore-plant systems. Here, we examine the effects of plant diversification on wireworms, the soil-dwelling larvae of click beetles that threaten crops worldwide. We conducted a field experiment employing plant diversification by adding either wheat or a mix of six associated plants (grasses, legumes, and forbs) between rows of maize to protect it from Agriotes wireworms. Wireworm feeding behavior, dispersal between crop and associated plants, as well as maize damage and yield were examined. The former was assessed combining molecular gut content and stable isotope analysis. The pests were strongly attracted by the associated plants in August, when the crop was most vulnerable, whereas in September, shortly before harvest, this effect occurred only in the plant mix. In maize monoculture, the larvae stayed in the principal crop throughout the season. Larval delta13C signatures revealed that maize feeding was reduced up to sevenfold in wireworms of the vegetationally diversified treatments compared to those of the maize monoculture. These findings were confirmed by molecular analysis, which additionally showed a dietary preference of wireworms for specific plants in the associated plant mix. Compared to the monoculture, maize damage was reduced by 38% and 55% in the wheat and plant mix treatment, which translated into a yield increase of 30% and 38%, respectively. The present findings demonstrate that increasing the plant diversity in agroecosystems provides an effective insurance against soil pests. The underlying mechanisms are the diversion of the pest from the principle crop and a changed feeding behavior. The deployment of diverse mixes of

  10. Carbon nanotubes are able to penetrate plant seed coat and dramatically affect seed germination and plant growth.

    PubMed

    Khodakovskaya, Mariya; Dervishi, Enkeleda; Mahmood, Meena; Xu, Yang; Li, Zhongrui; Watanabe, Fumiya; Biris, Alexandru S

    2009-10-27

    Carbon nanotubes (CNTs) were found to penetrate tomato seeds and affect their germination and growth rates. The germination was found to be dramatically higher for seeds that germinated on medium containing CNTs (10-40 mug/mL) compared to control. Analytical methods indicated that the CNTs are able to penetrate the thick seed coat and support water uptake inside seeds, a process which can affect seed germination and growth of tomato seedlings. PMID:19772305

  11. The presence of Bt-transgenic oilseed rape in wild mustard populations affects plant growth.

    PubMed

    Liu, Yongbo; Stewart, C Neal; Li, Junsheng; Huang, Hai; Zhang, Xitao

    2015-12-01

    The adventitious presence of transgenic plants in wild plant populations is of ecological and regulatory concern, but the consequences of adventitious presence are not well understood. Here, we introduced Bacillus thuringiensis Cry1Ac (Bt)-transgenic oilseed rape (Bt OSR, Brassica napus) with various frequencies into wild mustard (Brassica juncea) populations. We sought to better understand the adventitious presence of this transgenic insecticidal crop in a wild-relative plant population. We assessed the factors of competition, resource availability and diamondback moth (Plutella xylostella) infestation on plant population dynamics. As expected, Bt OSR performed better than wild mustard in mixed populations under herbivore attack in habitats with enough resources, whereas wild mustard had higher fitness when Bt OSR was rarer in habitats with limited resources. Results suggest that the presence of insect-resistant transgenic plants could decrease the growth of wild mustard and Bt OSR plants and their populations, especially under high herbivore pressure.

  12. The presence of Bt-transgenic oilseed rape in wild mustard populations affects plant growth.

    PubMed

    Liu, Yongbo; Stewart, C Neal; Li, Junsheng; Huang, Hai; Zhang, Xitao

    2015-12-01

    The adventitious presence of transgenic plants in wild plant populations is of ecological and regulatory concern, but the consequences of adventitious presence are not well understood. Here, we introduced Bacillus thuringiensis Cry1Ac (Bt)-transgenic oilseed rape (Bt OSR, Brassica napus) with various frequencies into wild mustard (Brassica juncea) populations. We sought to better understand the adventitious presence of this transgenic insecticidal crop in a wild-relative plant population. We assessed the factors of competition, resource availability and diamondback moth (Plutella xylostella) infestation on plant population dynamics. As expected, Bt OSR performed better than wild mustard in mixed populations under herbivore attack in habitats with enough resources, whereas wild mustard had higher fitness when Bt OSR was rarer in habitats with limited resources. Results suggest that the presence of insect-resistant transgenic plants could decrease the growth of wild mustard and Bt OSR plants and their populations, especially under high herbivore pressure. PMID:26338267

  13. Plant species loss affects life-history traits of aphids and their parasitoids.

    PubMed

    Petermann, Jana S; Müller, Christine B; Roscher, Christiane; Weigelt, Alexandra; Weisser, Wolfgang W; Schmid, Bernhard

    2010-08-06

    The consequences of plant species loss are rarely assessed in a multi-trophic context and especially effects on life-history traits of organisms at higher trophic levels have remained largely unstudied. We used a grassland biodiversity experiment and measured the effects of two components of plant diversity, plant species richness and the presence of nitrogen-fixing legumes, on several life-history traits of naturally colonizing aphids and their primary and secondary parasitoids in the field. We found that, irrespective of aphid species identity, the proportion of winged aphid morphs decreased with increasing plant species richness, which was correlated with decreasing host plant biomass. Similarly, emergence proportions of parasitoids decreased with increasing plant species richness. Both, emergence proportions and proportions of female parasitoids were lower in plots with legumes, where host plants had increased nitrogen concentrations. This effect of legume presence could indicate that aphids were better defended against parasitoids in high-nitrogen environments. Body mass of emerged individuals of the two most abundant primary parasitoid species was, however, higher in plots with legumes, suggesting that once parasitoids could overcome aphid defenses, they could profit from larger or more nutritious hosts. Our study demonstrates that cascading effects of plant species loss on higher trophic levels such as aphids, parasitoids and secondary parasitoids begin with changed life-history traits of these insects. Thus, life-history traits of organisms at higher trophic levels may be useful indicators of bottom-up effects of plant diversity on the biodiversity of consumers.

  14. B-cell depletion inhibits arthritis in a collagen-induced arthritis (CIA) model, but does not adversely affect humoral responses in a respiratory syncytial virus (RSV) vaccination model.

    PubMed

    Dunussi-Joannopoulos, Kyri; Hancock, Gerald E; Kunz, Arthur; Hegen, Martin; Zhou, Xiaochuan X; Sheppard, Barbara J; Lamothe, Jennifer; Li, Evelyn; Ma, Hak-Ling; Hamann, Philip R; Damle, Nitin K; Collins, Mary

    2005-10-01

    We report the development of a mouse B cell-depleting immunoconjugate (anti-CD22 monoclonal antibody [mAb] conjugated to calicheamicin) and its in vivo use to characterize the kinetics of CD22+ B-cell depletion and reconstitution in murine primary and secondary lymphoid tissues. The effect of B-cell depletion was further studied in a murine collagen-induced arthritis (CIA) model and a respiratory syncytial virus (RSV) vaccination model. Our results show that (1) the immunoconjugate has B-cell-specific in vitro and in vivo cytotoxicity; (2) B-cell reconstitution starts in the bone marrow and spleen around day 30 after depletion and is completed in all tissues tested by day 50; (3) B-cell depletion inhibits the development of clinical and histologic arthritis in the CIA model; (4) depletion of type II collagen antibody levels is not necessary for clinical and histologic prevention of CIA; and (5) B-cell depletion does not adversely affect memory antibody responses after challenge nor clearance of infectious virus from lungs in the RSV vaccination model. These results demonstrate for the first time that only B-cell reduction but not type II collagen antibody levels correlate with the prevention of arthritis and represent key insights into the role of CD22-targeted B-cell depletion in mouse autoimmunity and vaccination models.

  15. Conventional and organic soil fertility management practices affect corn plant nutrition and Ostrinia nubilalis (Lepidoptera: Crambidae) larval performance.

    PubMed

    Murrell, Ebony G; Cullen, Eileen M

    2014-10-01

    Few studies compare how different soil fertilization practices affect plant mineral content and insect performance in organic systems. This study examined: 1) The European corn borer, Ostrinia nubilalis (Hübner), larval response on corn (Zea mays L.) grown in field soils with different soil management histories; and 2) resilience of these plants to O. nubilalis herbivory. Treatments included: 1) standard organic--organically managed soil fertilized with dairy manure and 2 yr of alfalfa (Medicago sativa L.) in the rotation; 2) basic cation saturation ratio--organically managed soil fertilized with dairy manure and alfalfa nitrogen credits, plus addition of gypsum (CaSO4·2H2O) according to the soil balance hypothesis; and 3) conventional--conventionally managed soil fertilized with synthetic fertilizers. Corn plants were reared to maturity in a greenhouse, and then infested with 0-40 O. nubilalis larvae for 17 d. O. nubilalis exhibited negative competitive response to increasing larval densities. Mean development time was significantly faster for larvae consuming basic cation saturation ratio plants than those on standard organic plants, with intermediate development time on conventional plants. Neither total yield (number of kernels) nor proportion kernels damaged differed among soil fertility treatments. Soil nutrients differed significantly in S and in Ca:Mg and Ca:K ratios, but principal components analysis of plant tissue samples taken before O. nubilalis infestation showed that S, Fe, and Cu contributed most to differences in plant nutrient profiles among soil fertility treatments. Results demonstrate that different fertilization regimens can significantly affect insect performance within the context of organic systems, but the effects in this study were relatively minor compared with effects of intraspecific competition.

  16. Conventional and organic soil fertility management practices affect corn plant nutrition and Ostrinia nubilalis (Lepidoptera: Crambidae) larval performance.

    PubMed

    Murrell, Ebony G; Cullen, Eileen M

    2014-10-01

    Few studies compare how different soil fertilization practices affect plant mineral content and insect performance in organic systems. This study examined: 1) The European corn borer, Ostrinia nubilalis (Hübner), larval response on corn (Zea mays L.) grown in field soils with different soil management histories; and 2) resilience of these plants to O. nubilalis herbivory. Treatments included: 1) standard organic--organically managed soil fertilized with dairy manure and 2 yr of alfalfa (Medicago sativa L.) in the rotation; 2) basic cation saturation ratio--organically managed soil fertilized with dairy manure and alfalfa nitrogen credits, plus addition of gypsum (CaSO4·2H2O) according to the soil balance hypothesis; and 3) conventional--conventionally managed soil fertilized with synthetic fertilizers. Corn plants were reared to maturity in a greenhouse, and then infested with 0-40 O. nubilalis larvae for 17 d. O. nubilalis exhibited negative competitive response to increasing larval densities. Mean development time was significantly faster for larvae consuming basic cation saturation ratio plants than those on standard organic plants, with intermediate development time on conventional plants. Neither total yield (number of kernels) nor proportion kernels damaged differed among soil fertility treatments. Soil nutrients differed significantly in S and in Ca:Mg and Ca:K ratios, but principal components analysis of plant tissue samples taken before O. nubilalis infestation showed that S, Fe, and Cu contributed most to differences in plant nutrient profiles among soil fertility treatments. Results demonstrate that different fertilization regimens can significantly affect insect performance within the context of organic systems, but the effects in this study were relatively minor compared with effects of intraspecific competition. PMID:25203485

  17. Soil moisture variations affect short-term plant-microbial competition for ammonium, glycine, and glutamate.

    PubMed

    Månsson, Katarina F; Olsson, Magnus O; Falkengren-Grerup, Ursula; Bengtsson, Göran

    2014-04-01

    We tested whether the presence of plant roots would impair the uptake of ammonium ([Formula: see text]), glycine, and glutamate by microorganisms in a deciduous forest soil exposed to constant or variable moisture in a short-term (24-h) experiment. The uptake of (15)NH4 and dual labeled amino acids by the grass Festuca gigantea L. and soil microorganisms was determined in planted and unplanted soils maintained at 60% WHC (water holding capacity) or subject to drying and rewetting. The experiment used a design by which competition was tested in soils that were primed by plant roots to the same extent in the planted and unplanted treatments. Festuca gigantea had no effect on microbial N uptake in the constant moist soil, but its presence doubled the microbial [Formula: see text] uptake in the dried and rewetted soil compared with the constant moist. The drying and rewetting reduced by half or more the [Formula: see text] uptake by F. gigantea, despite more than 60% increase in the soil concentration of [Formula: see text]. At the same time, the amino acid and [Formula: see text]-N became equally valued in the plant uptake, suggesting that plants used amino acids to compensate for the lower [Formula: see text] acquisition. Our results demonstrate the flexibility in plant-microbial use of different N sources in response to soil moisture fluctuations and emphasize the importance of including transient soil conditions in experiments on resource competition between plants and soil microorganisms. Competition between plants and microorganisms for N is demonstrated by a combination of removal of one of the potential competitors, the plant, and subsequent observations of the uptake of N in the organisms in soils that differ only in the physical presence and absence of the plant during a short assay. Those conditions are necessary to unequivocally test for competition.

  18. Retention of OsNMD3 in the cytoplasm disturbs protein synthesis efficiency and affects plant development in rice

    PubMed Central

    Shi, Yanyun; Liu, Xiangling; Li, Rui; Gao, Yaping; Xu, Zuopeng; Zhang, Baocai; Zhou, Yihua

    2014-01-01

    The ribosome is the basic machinery for translation, and biogenesis of ribosomes involves many coordinated events. However, knowledge about ribosomal dynamics in higher plants is very limited. This study chose a highly conserved trans-factor, the 60S ribosomal subunit nuclear export adaptor NMD3, to characterize the mechanism of ribosome biogenesis in the monocot plant Oryza sativa (rice). O. sativa NMD3 (OsNMD3) shares all the common motifs and shuttles between the nucleus and cytoplasm via CRM1/XPO1. A dominant negative form of OsNMD3 with a truncated nuclear localization sequence (OsNMD3ΔNLS) was retained in the cytoplasm, consequently interfering with the release of OsNMD3 from pre-60S particles and disturbing the assembly of ribosome subunits. Analyses of the transactivation activity and cellulose biosynthesis level revealed low protein synthesis efficiency in the transgenic plants compared with the wild-type plants. Pharmaceutical treatments demonstrated structural alterations in ribosomes in the transgenic plants. Moreover, global expression profiles of the wild-type and transgenic plants were investigated using the Illumina RNA sequencing approach. These expression profiles suggested that overexpression of OsNMD3ΔNLS affected ribosome biogenesis and certain basic pathways, leading to pleiotropic abnormalities in plant growth. Taken together, these results strongly suggest that OsNMD3 is important for ribosome assembly and the maintenance of normal protein synthesis efficiency. PMID:24723395

  19. Overexpression of OsDof12 affects plant architecture in rice (Oryza sativa L.).

    PubMed

    Wu, Qi; Li, Dayong; Li, Dejun; Liu, Xue; Zhao, Xianfeng; Li, Xiaobing; Li, Shigui; Zhu, Lihuang

    2015-01-01

    Dof (DNA binding with one finger) proteins, a class of plant-specific transcription factors, are involved in plant growth and developmental processes and stress responses. However, their biological functions remain to be elucidated, especially in rice (Oryza sativa L.). Previously, we have reported that OsDof12 can promote rice flowering under long-day conditions. Here, we further investigated the other important agronomical traits of the transgenic plants overexpressing OsDof12 and found that overexpressing OsDof12 could lead to reduced plant height, erected leaf, shortened leaf blade, and smaller panicle resulted from decreased primary and secondary branches number. These results implied that OsDof12 is involved in rice plant architecture formation. Furthermore, we performed a series of Brassinosteroid (BR)-responsive tests and found that overexpression of OsDof12 could also result in BR hyposensitivity. Of note, in WT plants the expression of OsDof12 was found up-regulated by BR treatment while in OsDof12 overexpression plants two positive BR signaling regulators, OsBRI1 and OsBZR1, were significantly down-regulated, indicating that OsDof12 may act as a negative BR regulator in rice. Taken together, our results suggested that overexpression of OsDof12 could lead to altered plant architecture by suppressing BR signaling. Thus, OsDof12 might be used as a new potential genetic regulator for future rice molecular breeding.

  20. Are herbage yield and yield stability affected by plant species diversity in sown pasture mixtures?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A tenet of plant biodiversity theory in grasslands is that increased diversity contributes to the stability of ecosystems. In managed grasslands, such as pastures, greater stability of herbage production as a result of increased plant species diversity would be beneficial. In this study, I combined ...

  1. Decoupling factors affecting plant diversity and cover on extensive green roofs.

    PubMed

    MacIvor, J Scott; Margolis, Liat; Puncher, Curtis L; Carver Matthews, Benjamin J

    2013-11-30

    Supplemental irrigation systems are often specified on green roofs to ensure plant cover and growth, both important components of green roof performance and aesthetics. Properties of the growing media environment too can alter the assemblage of plant species able to thrive. In this study we determine how plant cover, above ground biomass and species diversity are influenced by irrigation and growing media. Grass and forb vegetative cover and biomass were significantly greater in organic based growing media but there was no effect of supplemental irrigation, with two warm season grasses dominating in those treatments receiving no supplemental irrigation. On the other hand, plant diversity declined without irrigation in organic media, and having no irrigation in inorganic growing media resulted in almost a complete loss of cover. Sedum biomass was less in inorganic growing media treatments and species dominance shifted when growing media organic content increased. Our results demonstrate that supplemental irrigation is required to maintain plant diversity on an extensive green roof, but not necessarily plant cover or biomass. These results provide evidence that planting extensive green roofs with a mix of plant species can ensure the survival of some species; maintaining cover and biomass when supplemental irrigation is turned off to conserve water, or during extreme drought.

  2. Salt tolerance and stress level affect plant biomass-density relationships and neighbor effects

    NASA Astrophysics Data System (ADS)

    Yu, Zhenxing; Chen, Wenwen; Zhang, Qian; Yang, Haishui; Tang, Jianjun; Weiner, Jacob; Chen, Xin

    2014-07-01

    It has been shown that plant biomass-density relationships are altered under extreme or stressed conditions. We do not know whether variation in biomass-density relationships is a direct result of stress tolerance or occurs via changes in plant-plant interactions. Here, we evaluated biomass-density relationships and neighbor effects in six plant species that differ in salt tolerance in a salt marsh, and conducted a literature review of biomass-density relationship under higher and lower stress levels. Our field study showed that both neighbor effects and the exponent of the biomass-density relationship (α) varied among plant species with different degrees of salt tolerance. There was a positive relationship between neighbor effects (measured as relative interaction index) and α-value among the tested species. The literature review showed that α and its variation increased under higher stress. Our results indicate that plant species with different salinity tolerance differ in the direction and strength of neighbor effects, resulting in variation in biomass-density relationships. Our results support the hypothesis that differences in biomass-density relationships among species are not due to differences in stress tolerance alone, they are mediated by changes in plant-plant interactions.

  3. Overexpression of an Arabidopsis heterogeneous nuclear ribonucleoprotein gene, AtRNP1, affects plant growth and reduces plant tolerance to drought and salt stresses.

    PubMed

    Wang, Zhenyu; Zhao, Xiuyang; Wang, Bing; Liu, Erlong; Chen, Ni; Zhang, Wei; Liu, Heng

    2016-04-01

    Heterogeneous nuclear ribonucleoproteins (hnRNPs) participate in diverse regulations of plant growth and environmental stress responses. In this work, an Arabidopsis hnRNP of unknown function, AtRNP1, was investigated. We found that AtRNP1 gene is highly expressed in rosette and cauline leaves, and slightly induced under drought, salt, osmotic and ABA stresses. AtRNP1 protein is localized to both the nucleus and cytoplasm. We performed homologous overexpression of AtRNP1 and found that the transgenic plants showed shortened root length and plant height, and accelerated flowering. In addition, the transgenic plants also showed reduced tolerance to drought, salt, osmotic and ABA stresses. Further studies revealed that under both normal and stress conditions, the proline contents in the transgenic plants are markedly decreased, associated with reduced expression levels of a proline synthase gene and several stress-responsive genes. These results suggested that the overexpression of AtRNP1 negatively affects plant growth and abiotic stress tolerance. PMID:26923071

  4. Pharmacogenomics of adverse drug reactions

    PubMed Central

    2013-01-01

    Considerable progress has been made in identifying genetic risk factors for idiosyncratic adverse drug reactions in the past 30 years. These reactions can affect various tissues and organs, including liver, skin, muscle and heart, in a drug-dependent manner. Using both candidate gene and genome-wide association studies, various genes that make contributions of varying extents to each of these forms of reactions have been identified. Many of the associations identified for reactions affecting the liver and skin involve human leukocyte antigen (HLA) genes and for reactions relating to the drugs abacavir and carbamazepine, HLA genotyping is now in routine use prior to drug prescription. Other HLA associations are not sufficiently specific for translation but are still of interest in relation to underlying mechanisms for the reactions. Progress on non-HLA genes affecting adverse drug reactions has been less, but some important associations, such as those of SLCO1B1 and statin myopathy, KCNE1 and drug-induced QT prolongation and NAT2 and isoniazid-induced liver injury, are considered. Future prospects for identification of additional genetic risk factors for the various adverse drug reactions are discussed. PMID:23360680

  5. Volatiles produced by soil-borne endophytic bacteria increase plant pathogen resistance and affect tritrophic interactions

    PubMed Central

    Ton, Jurriaan; Brandenburg, Anna; Karlen, Danielle; Zopfi, Jakob; Turlings, Ted C. J.

    2014-01-01

    Volatile organic compounds (VOCs) released by soil microorganisms influence plant growth and pathogen resistance. Yet, very little is known about their influence on herbivores and higher trophic levels. We studied the origin and role of a major bacterial VOC, 2,3-butanediol (2,3-BD), on plant growth, pathogen and herbivore resistance, and the attraction of natural enemies in maize. One of the major contributors to 2,3-BD in the headspace of soil-grown maize seedlings was identified as Enterobacter aerogenes, an endophytic bacterium that colonizes the plants. The production of 2,3-BD by E. aerogenes rendered maize plants more resistant against the Northern corn leaf blight fungus Setosphaeria turcica. On the contrary, E. aerogenes-inoculated plants were less resistant against the caterpillar Spodoptera littoralis. The effect of 2,3-BD on the attraction of the parasitoid Cotesia marginiventris was more variable: 2,3-BD application to the headspace of the plants had no effect on the parasitoids, but application to the soil increased parasitoid attraction. Furthermore, inoculation of seeds with E. aerogenes decreased plant attractiveness, whereas inoculation of soil with a total extract of soil microbes increased parasitoid attraction, suggesting that the effect of 2,3-BD on the parasitoid is indirect and depends on the composition of the microbial community. PMID:24127750

  6. Plant water relations as affected by heavy metal stress: A review

    SciTech Connect

    Barcelo, J.; Poschenrieder, C. )

    1990-01-01

    Metal toxicity causes multiple direct and indirect effects in plants which concern practically all physiological functions. In this review the effects of excess heavy metals and aluminum on those functions which will alter plant water relations are considered. After a brief comment on the metal effects in cell walls and plasma-lemma, and their consequences for cell expansion growth, the influences of high meal availability on the factors which regulate water entry and water exit in plants are considered. Emphasis is placed on the importance of distinguishing between low water availability in mine and serpentine soils and toxicity effects in plants which may impair the ability of a plant to regulate water uptake. Examples on water relations of both plants grown on metalliferous soil and hydroponics are presented, and the effects of metal toxicity on root growth, water transport and transpiration are considered. It is concluded that future research has to focus on the mechanisms of metal-induced inhibition of both root elongation and morphogenetic processes within roots. In order to understand the relation between metal tolerance and drought resistance better, further studies into metal tolerance mechanisms at the cell wall, membrane and vacuolar level, as well as into the mechanisms of drought resistance of plants adapted to metalliferous soils are required. 135 refs., 7 figs., 6 tabs.

  7. Drought induced changes of plant belowground carbon allocation affect soil microbial community function in a subalpine meadow

    NASA Astrophysics Data System (ADS)

    Fuchslueger, L.; Bahn, M.; Fritz, K.; Hasibeder, R.; Richter, A.

    2012-12-01

    There is growing evidence that climate extremes may affect ecosystem carbon dynamics more strongly than gradual changes in temperatures or precipitation. Climate projections suggest more frequent heat waves accompanied by extreme drought periods in many parts of Europe, including the Alps. Drought is considered to decrease plant C uptake and turnover, which may in turn decrease belowground C allocation and potentially has significant consequences for microbial community composition and functioning. However, information on effects of drought on C dynamics at the plant-soil interface in real ecosystems is still scarce. Our study aimed at understanding how summer drought affects soil microbial community composition and the uptake of recently assimilated plant C by different microbial groups in grassland. We hypothesized that under drought 1) the microbial community shifts, fungi being less affected than bacteria, 2) plants decrease belowground C allocation, which further reduces C transfer to soil microbes and 3) the combined effects of belowground C allocation, reduced soil C transport due to reduced soil moisture and shift in microbial communities cause an accumulation of extractable organic C in the soil. Our study was conducted as part of a rain-exclusion experiment in a subalpine meadow in the Austrian Central Alps. After eight weeks of rain exclusion we pulse labelled drought and control plots with 13CO2 and traced C in plant biomass, extractable organic C (EOC) and soil microbial communities using phospholipid fatty acids (PLFA). Drought induced a shift of the microbial community composition: gram-positive bacteria became more dominant, whereas gram-negative bacteria were not affected by drought. Also the relative abundance of fungal biomass was not affected by drought. While total microbial biomass (as estimated by total microbial PLFA content) increased during drought, less 13C was taken up. This reduction was pronounced for bacterial biomarkers. It reflects

  8. Plant Quantity Affects Development and Survival of a Gregarious Insect Herbivore and Its Endoparasitoid Wasp.

    PubMed

    Fei, Minghui; Gols, Rieta; Zhu, Feng; Harvey, Jeffrey A

    2016-01-01

    Virtually all studies of plant-herbivore-natural enemy interactions focus on plant quality as the major constraint on development and survival. However, for many gregarious feeding insect herbivores that feed on small or ephemeral plants, the quantity of resources is much more limiting, yet this area has received virtually no attention. Here, in both lab and semi-field experiments using tents containing variably sized clusters of food plants, we studied the effects of periodic food deprivation in a tri-trophic system where quantitative constraints are profoundly important on insect performance. The large cabbage white Pieris brassicae, is a specialist herbivore of relatively small wild brassicaceous plants that grow in variable densities, with black mustard (Brassica nigra) being one of the most important. Larvae of P. brassicae are in turn attacked by a specialist endoparasitoid wasp, Cotesia glomerata. Increasing the length of food deprivation of newly molted final instar caterpillars significantly decreased herbivore and parasitoid survival and biomass, but shortened their development time. Moreover, the ability of caterpillars to recover when provided with food again was correlated with the length of the food deprivation period. In outdoor tents with natural vegetation, we created conditions similar to those faced by P. brassicae in nature by manipulating plant density. Low densities of B. nigra lead to potential starvation of P. brassicae broods and their parasitoids, replicating nutritional conditions of the lab experiments. The ability of both unparasitized and parasitized caterpillars to find corner plants was similar but decreased with central plant density. Survival of both the herbivore and parasitoid increased with plant density and was higher for unparasitized than for parasitized caterpillars. Our results, in comparison with previous studies, reveal that quantitative constraints are far more important that qualitative constraints on the performance of

  9. Plant Quantity Affects Development and Survival of a Gregarious Insect Herbivore and Its Endoparasitoid Wasp.

    PubMed

    Fei, Minghui; Gols, Rieta; Zhu, Feng; Harvey, Jeffrey A

    2016-01-01

    Virtually all studies of plant-herbivore-natural enemy interactions focus on plant quality as the major constraint on development and survival. However, for many gregarious feeding insect herbivores that feed on small or ephemeral plants, the quantity of resources is much more limiting, yet this area has received virtually no attention. Here, in both lab and semi-field experiments using tents containing variably sized clusters of food plants, we studied the effects of periodic food deprivation in a tri-trophic system where quantitative constraints are profoundly important on insect performance. The large cabbage white Pieris brassicae, is a specialist herbivore of relatively small wild brassicaceous plants that grow in variable densities, with black mustard (Brassica nigra) being one of the most important. Larvae of P. brassicae are in turn attacked by a specialist endoparasitoid wasp, Cotesia glomerata. Increasing the length of food deprivation of newly molted final instar caterpillars significantly decreased herbivore and parasitoid survival and biomass, but shortened their development time. Moreover, the ability of caterpillars to recover when provided with food again was correlated with the length of the food deprivation period. In outdoor tents with natural vegetation, we created conditions similar to those faced by P. brassicae in nature by manipulating plant density. Low densities of B. nigra lead to potential starvation of P. brassicae broods and their parasitoids, replicating nutritional conditions of the lab experiments. The ability of both unparasitized and parasitized caterpillars to find corner plants was similar but decreased with central plant density. Survival of both the herbivore and parasitoid increased with plant density and was higher for unparasitized than for parasitized caterpillars. Our results, in comparison with previous studies, reveal that quantitative constraints are far more important that qualitative constraints on the performance of

  10. Plant Quantity Affects Development and Survival of a Gregarious Insect Herbivore and Its Endoparasitoid Wasp

    PubMed Central

    Fei, Minghui; Gols, Rieta; Zhu, Feng; Harvey, Jeffrey A.

    2016-01-01

    Virtually all studies of plant-herbivore-natural enemy interactions focus on plant quality as the major constraint on development and survival. However, for many gregarious feeding insect herbivores that feed on small or ephemeral plants, the quantity of resources is much more limiting, yet this area has received virtually no attention. Here, in both lab and semi-field experiments using tents containing variably sized clusters of food plants, we studied the effects of periodic food deprivation in a tri-trophic system where quantitative constraints are profoundly important on insect performance. The large cabbage white Pieris brassicae, is a specialist herbivore of relatively small wild brassicaceous plants that grow in variable densities, with black mustard (Brassica nigra) being one of the most important. Larvae of P. brassicae are in turn attacked by a specialist endoparasitoid wasp, Cotesia glomerata. Increasing the length of food deprivation of newly molted final instar caterpillars significantly decreased herbivore and parasitoid survival and biomass, but shortened their development time. Moreover, the ability of caterpillars to recover when provided with food again was correlated with the length of the food deprivation period. In outdoor tents with natural vegetation, we created conditions similar to those faced by P. brassicae in nature by manipulating plant density. Low densities of B. nigra lead to potential starvation of P. brassicae broods and their parasitoids, replicating nutritional conditions of the lab experiments. The ability of both unparasitized and parasitized caterpillars to find corner plants was similar but decreased with central plant density. Survival of both the herbivore and parasitoid increased with plant density and was higher for unparasitized than for parasitized caterpillars. Our results, in comparison with previous studies, reveal that quantitative constraints are far more important that qualitative constraints on the performance of

  11. Plant Trait Assembly Affects Superiority of Grazer's Foraging Strategies in Species-Rich Grasslands

    PubMed Central

    Mládek, Jan; Mládková, Pavla; Hejcmanová, Pavla; Dvorský, Miroslav; Pavlu, Vilém; De Bello, Francesco; Duchoslav, Martin; Hejcman, Michal; Pakeman, Robin J.

    2013-01-01

    Background Current plant – herbivore interaction models and experiments with mammalian herbivores grazing plant monocultures show the superiority of a maximizing forage quality strategy (MFQ) over a maximizing intake strategy (MI). However, there is a lack of evidence whether grazers comply with the model predictions under field conditions. Methodology/Findings We assessed diet selection of sheep (Ovis aries) using plant functional traits in productive mesic vs. low-productivity dry species-rich grasslands dominated by resource-exploitative vs. resource-conservative species respectively. Each grassland type was studied in two replicates for two years. We investigated the first grazing cycle in a set of 288 plots with a diameter of 30 cm, i.e. the size of sheep feeding station. In mesic grasslands, high plot defoliation was associated with community weighted means of leaf traits referring to high forage quality, i.e. low leaf dry matter content (LDMC) and high specific leaf area (SLA), with a high proportion of legumes and the most with high community weighted mean of forage indicator value. In contrast in dry grasslands, high community weighted mean of canopy height, an estimate of forage quantity, was the best predictor of plot defoliation. Similar differences in selection on forage quality vs. quantity were detected within plots. Sheep selected plants with higher forage indicator values than the plot specific community weighted mean of forage indicator value in mesic grasslands whereas taller plants were selected in dry grasslands. However, at this scale sheep avoided legumes and plants with higher SLA, preferred plants with higher LDMC while grazing plants with higher forage indicator values in mesic grasslands. Conclusions Our findings indicate that MFQ appears superior over MI only in habitats with a predominance of resource-exploitative species. Furthermore, plant functional traits (LDMC, SLA, nitrogen fixer) seem to be helpful correlates of forage quality

  12. Thermal tolerance affects mutualist attendance in an ant-plant protection mutualism

    PubMed Central

    Fitzpatrick, Ginny; Lanan, Michele C.; Bronstein, Judith L.

    2014-01-01

    Mutualism is an often-complex interaction among multiple species, each of which may respond differently to abiotic conditions. The effects of temperature on the formation, dissolution, and success of these and other species interactions remain poorly understood. We studied the thermal ecology of the mutualism between the cactus Ferocactus wislizeni and its ant defenders (Forelius pruinosus, Crematogaster opuntiae, Solenopsis aurea, and Solenopsis xyloni) in the Sonoran Desert, USA. The ants are attracted to extrafloral nectar produced by the plants and in exchange protect the plants from herbivores; there is a hierarchy of mutualist effectiveness based on aggression toward herbivores. We determined the relationship between temperature and ant activity on plants, the thermal tolerance of each ant species, and ant activity in relation to the thermal environment of plants. Temperature played a role in determining which species interact as mutualists. Three of the four ant species abandoned the plants during the hottest part of the day (up to 40°C), returning when surface temperature began to decrease in the afternoon. The least effective ant mutualist, F. pruinosus, had a significantly higher critical thermal maximum than the other three species, was active across the entire range of plant surface temperatures observed (13.8-57.0°C), and visited plants that reached the highest temperatures. F. pruinosus occupied some plants full-time and invaded plants occupied by more dominant species when those species were thermally excluded. Combining data on thermal tolerance and mutualist effectiveness provides a potentially powerful tool for predicting the effects of temperature on mutualisms and mutualistic species. PMID:25012597

  13. Plant Fe status affects the composition of siderophore-secreting microbes in the rhizosphere

    PubMed Central

    Jin, Chong Wei; Li, Gui Xin; Yu, Xue Hui; Zheng, Shao Jiang

    2010-01-01

    Background and Aims Soil microbes have been demonstrated to play an important role in favouring plant iron (Fe) uptake under Fe-limiting conditions. However, the mechanisms involved are still unclear. This present study reported the effects of plant Fe status on the composition of siderophore-secreting microbes in the rhizosphere, and their potential function in improving plant Fe nutrition. Methods An Fe-efficient plant, red clover (Trifolium pratense ‘Kenland’) was cultured in a calcareous soil to obtain rhizosphere soils with (Fe-sufficient) or without (Fe-stressed) foliar FeEDTA spraying. The siderophore-producing ability of rhizospheric microbes was measured. The bioavailability of the siderophore-solubilized Fe from iron oxides/hydroxides was tested in hydroponic culture. Key Results In rhizosphere soil, the number of microbes that secreted siderophores quickly was more in the Fe-stressed treatment than in the Fe-sufficient one, while the number of microbes that did not secret siderophores was the opposite. A significantly higher concentration of phenolics was detected in the rhizosphere soil of Fe-stressed plants. Moreover, after the soil was incubated with phenolic root exudates, the composition of the siderophore-secreting microbial community was similar with that of the rhizosphere of Fe-stressed plant. Additionally, the siderophores produced by a rhizospheric microbe isolated from the Fe-stressed treatment can well solubilize iron oxides/hydroxides, and the utilization of the siderophore-solubilized Fe by plant was even more efficient than EDTA-Fe. Conclusions Iron-deficiency stress of red clover would alter the composition of siderophore-secreting microbes in the rhizosphere, which is probably due to the phenolics secretion of the root, and may in turn help to improve the solubility of Fe in soils and plant Fe nutrition via elevated microbial siderophore secretion. PMID:20356952

  14. Habitat Heterogeneity Affects Plant and Arthropod Species Diversity and Turnover in Traditional Cornfields

    PubMed Central

    Martínez, Eliana; Rös, Matthias; Bonilla, María Argenis; Dirzo, Rodolfo

    2015-01-01

    The expansion of the agricultural frontier by the clearing of remnant forests has led to human-dominated landscape mosaics. Previous studies have evaluated the effect of these landscape mosaics on arthropod diversity at local spatial scales in temperate and tropical regions, but little is known about fragmentation effects in crop systems, such as the complex tropical traditional crop systems that maintain a high diversity of weeds and arthropods in low-Andean regions. To understand the factors that influence patterns of diversity in human-dominated landscapes, we investigate the effect of land use types on plant and arthropod diversity in traditionally managed cornfields, via surveys of plants and arthropods in twelve traditional cornfields in the Colombian Andes. We estimated alpha and beta diversity to analyze changes in diversity related to land uses within a radius of 100 m to 1 km around each cornfield. We observed that forests influenced alpha diversity of plants, but not of arthropods. Agricultural lands had a positive relationship with plants and herbivores, but a negative relationship with predators. Pastures positively influenced the diversity of plants and arthropods. In addition, forest cover seemed to influence changes in plant species composition and species turnover of herbivore communities among cornfields. The dominant plant species varied among fields, resulting in high differentiation of plant communities. Predator communities also exhibited high turnover among cornfields, but differences in composition arose mainly among rare species. The crop system evaluated in this study represents a widespread situation in the tropics, therefore, our results can be of broad significance. Our findings suggest that traditional agriculture may not homogenize biological communities, but instead could maintain the regional pool of species through high beta diversity. PMID:26197473

  15. Habitat Heterogeneity Affects Plant and Arthropod Species Diversity and Turnover in Traditional Cornfields.

    PubMed

    Martínez, Eliana; Rös, Matthias; Bonilla, María Argenis; Dirzo, Rodolfo

    2015-01-01

    The expansion of the agricultural frontier by the clearing of remnant forests has led to human-dominated landscape mosaics. Previous studies have evaluated the effect of these landscape mosaics on arthropod diversity at local spatial scales in temperate and tropical regions, but little is known about fragmentation effects in crop systems, such as the complex tropical traditional crop systems that maintain a high diversity of weeds and arthropods in low-Andean regions. To understand the factors that influence patterns of diversity in human-dominated landscapes, we investigate the effect of land use types on plant and arthropod diversity in traditionally managed cornfields, via surveys of plants and arthropods in twelve traditional cornfields in the Colombian Andes. We estimated alpha and beta diversity to analyze changes in diversity related to land uses within a radius of 100 m to 1 km around each cornfield. We observed that forests influenced alpha diversity of plants, but not of arthropods. Agricultural lands had a positive relationship with plants and herbivores, but a negative relationship with predators. Pastures positively influenced the diversity of plants and arthropods. In addition, forest cover seemed to influence changes in plant species composition and species turnover of herbivore communities among cornfields. The dominant plant species varied among fields, resulting in high differentiation of plant communities. Predator communities also exhibited high turnover among cornfields, but differences in composition arose mainly among rare species. The crop system evaluated in this study represents a widespread situation in the tropics, therefore, our results can be of broad significance. Our findings suggest that traditional agriculture may not homogenize biological communities, but instead could maintain the regional pool of species through high beta diversity.

  16. Response of barley plants to Fe deficiency and Cd contamination as affected by S starvation.

    PubMed

    Astolfi, S; Zuchi, S; Neumann, G; Cesco, S; Sanità di Toppi, L; Pinton, R

    2012-02-01

    Both Fe deficiency and Cd exposure induce rapid changes in the S nutritional requirement of plants. The aim of this work was to characterize the strategies adopted by plants to cope with both Fe deficiency (release of phytosiderophores) and Cd contamination [production of glutathione (GSH) and phytochelatins] when grown under conditions of limited S supply. Experiments were performed in hydroponics, using barley plants grown under S sufficiency (1.2 mM sulphate) and S deficiency (0 mM sulphate), with or without Fe(III)-EDTA at 0.08 mM for 11 d and subsequently exposed to 0.05 mM Cd for 24 h or 72 h. In S-sufficient plants, Fe deficiency enhanced both root and shoot Cd concentrations and increased GSH and phytochelatin levels. In S-deficient plants, Fe starvation caused a slight increase in Cd concentration, but this change was accompanied neither by an increase in GSH nor by an accumulation of phytochelatins. Release of phytosiderophores, only detectable in Fe-deficient plants, was strongly decreased by S deficiency and further reduced after Cd treatment. In roots Cd exposure increased the expression of the high affinity sulphate transporter gene (HvST1) regardless of the S supply, and the expression of the Fe deficiency-responsive genes, HvYS1 and HvIDS2, irrespective of Fe supply. In conclusion, adequate S availability is necessary to cope with Fe deficiency and Cd toxicity in barley plants. Moreover, it appears that in Fe-deficient plants grown in the presence of Cd with limited S supply, sulphur may be preferentially employed in the pathway for biosynthesis of phytosiderophores, rather than for phytochelatin production.

  17. Urbanicity, social adversity and psychosis

    PubMed Central

    Heinz, Andreas; Deserno, Lorenz; Reininghaus, Ulrich

    2013-01-01

    In recent years, there has been increasing interest in research on geographical variation in the incidence of schizophrenia and other psychoses. In this paper, we review the evidence on variation in incidence of schizophrenia and other psychoses in terms of place, as well as the individual- and area-level factors that account for this variation. We further review findings on potential mechanisms that link adverse urban environment and psychosis. There is evidence from earlier and more recent studies that urbanicity is associated with an increased incidence of schizophrenia and non-affective psychosis. In addition, considerable variation in incidence across neighbourhoods has been observed for these disorders. Findings suggest it is unlikely that social drift alone can fully account for geographical variation in incidence. Evidence further suggests that the impact of adverse social contexts – indexed by area-level exposures such as population density, social fragmentation and deprivation – on risk of psychosis is explained (confounding) or modified (interaction) by environmental exposures at the individual level (i.e., cannabis use, social adversity, exclusion and discrimination). On a neurobiological level, several studies suggest a close link between social adversity, isolation and stress on the one hand, and monoamine dysfunction on the other, which resembles findings in schizophrenia patients. However, studies directly assessing correlations between urban stress or discrimination and neurobiological alterations in schizophrenia are lacking to date. PMID:24096775

  18. Big plants — Do they affect neighbourhood species richness and composition in herbaceous vegetation?

    NASA Astrophysics Data System (ADS)

    Aarssen, Lonnie W.; Schamp, Brandon S.; Wight, Stephanie

    2014-02-01

    According to traditional theory, success in competition between plant species generally involves a 'size-advantage'. We predicted therefore that plants with larger body size should impose greater limits on the number of species — especially relatively small ones — that can reside within their immediate neighbourhoods. Species composition was compared within local neighbourhoods surrounding target plants of different sizes belonging to one of the largest herbaceous species found within old-field vegetation in eastern Ontario Canada — Centaurea jacea. Resident species density was generally greater within immediate 'inner' target neighbourhoods than within adjacent circular 'outer' neighbourhoods, and mean body size of resident neighbour species was unrelated to increases in target plant size. As target plant size increased, the proportion of resident neighbour species that were reproductive increased. Relatively big plants of C. jacea do not limit the number or the proportion of reproductive species that can coexist within their immediate neighbourhoods, nor do they cause local exclusion of relatively small species from these neighbourhoods. These results fail to support the 'size-advantage' hypothesis and are more consistent with the 'reproductive economy advantage' hypothesis: success under intense competition is promoted by capacity to recruit offspring that — despite severe suppression — are able to reach their minimum body size needed for reproduction, and hence produce grand-offspring for the next generation. The latter is facilitated by a relatively small minimum reproductive threshold size, which is generally negatively correlated with a relatively large maximum potential body size.

  19. Magnitude of nighttime transpiration does not affect plant growth or nutrition in well-watered Arabidopsis.

    PubMed

    Christman, Mairgareth A; Donovan, Lisa A; Richards, James H

    2009-07-01

    Significant water loss occurs throughout the night via partially open stomata in many C(3) and C(4) plant species. Although apparently wasteful in terms of water use, nighttime transpiration (E(night)) is hypothesized to benefit plants by enhancing nutrient supply. We tested the hypothesis that plants with greater E(night) would have improved plant nutrient status and greater fitness, estimated as pre-bolting biomass, for Arabidopsis thaliana. Two very different levels of E(night) were generated in plants by exposing them to high vs low nighttime leaf-to-air vapor pressure deficits (VPD(leaf)) in controlled environment chambers. An assessment of responses of nighttime leaf conductance (g(night)) to VPD(leaf) indicated that E(night) differed by at least 80% between the treatments. This large difference in E(night), imposed over the entire vegetative growth phase of Arabidopsis, had no effect on leaf nutrient content (N, Ca, K) or pre-bolting rosette biomass. The lack of response to differences in E(night) held true for both a high and a low nitrogen (N) treatment, even though the low N treatment decreased leaf N and biomass by 40-60%. The N treatment had no effect on g(night). Thus, higher E(night) did not provide a nutrient or growth benefit to Arabidopsis, even when the plants were N-limited.

  20. NIMA-related kinase NEK6 affects plant growth and stress response in Arabidopsis.

    PubMed

    Zhang, Bo; Chen, Hao-Wei; Mu, Rui-Ling; Zhang, Wang-Ke; Zhao, Ming-Yu; Wei, Wei; Wang, Fang; Yu, Hui; Lei, Gang; Zou, Hong-Feng; Ma, Biao; Chen, Shou-Yi; Zhang, Jin-Song

    2011-12-01

    The NIMA-related kinases (NEKs) are a family of serine/threonine kinases involved largely in cell cycle control in fungi, mammals and other eukaryotes. In Arabidopsis, NEK6 is involved in the regulation of epidermal cell morphogenesis. However, other roles of NEK6 in plants are less well understood. Here we report functions of NEK6 in plant growth, development and stress responses in Arabidopsis. NEK6 transcripts and proteins are induced by ethylene precursor ACC and salt stress. Expression of other NEK genes except NEK5 is also responsive to the two treatments. Overexpression and mutant analysis disclose that the NEK6 gene increases rosette growth, seed yield and lateral root formation. However, NEK6 appears to play a negative role in the control of seed size. The gene also promotes plant tolerance to salt stress and osmotic stress in its overexpressing plants. The NEK6 gene may achieve its function through suppression of ethylene biosynthesis and activation of CYCB1;1 and CYCA3;1 expression. Our present study reveals new functions of the NEK6 gene in plant growth and stress tolerance, and manipulation of NEK6 may improve important agronomic traits in crop plants. PMID:21801253

  1. Drying and Storage Methods Affect Cyfluthrin Concentrations in Exposed Plant Samples.

    PubMed

    Moore, M T; Kröger, R; Locke, M A

    2016-08-01

    Standard procedures do not exist for drying and storage of plant samples prior to chemical analyses. Since immediate analysis is not always possible, current research examined which plant drying and storage method yielded the highest cyfluthrin recovery rates compared to traditional mechanical freeze-drying methods. Fifteen mesocosms were planted with rice. Cyfluthrin (5 mg L(-1)) was amended into the water column of individual mesocosms. 48 h later, plant material in the water column was collected from each mesocosm. Control (mechanical freeze drying) recovery was significantly greater (p < 0.001) than all 14 combinations of drying and storage. Significant differences also existed between all 14 different combinations. Greatest cyfluthrin recoveries in non-control plants were from the freezer-greenhouse-freezer drying and storage method. Results offer evidence for the efficient plant drying and storage methods prior to cyfluthrin analysis. Future studies should perform comparable analyses on various pesticide classes to determine possible relationships. PMID:27225509

  2. Population-related variation in plant defense more strongly affects survival of an herbivore than its solitary parasitoid wasp.

    PubMed

    Harvey, Jeffrey A; Gols, Rieta

    2011-10-01

    The performance of natural enemies, such as parasitoid wasps, is affected by differences in the quality of the host's diet, frequently mediated by species or population-related differences in plant allelochemistry. Here, we compared survival, development time, and body mass in a generalist herbivore, the cabbage moth, Mamestra brassicae, and its solitary endoparasitoid, Microplitis mediator, when reared on two cultivated (CYR and STH) and three wild (KIM, OH, and WIN) populations of cabbage, Brassica oleracea. Plants either were undamaged or induced by feeding of larvae of the cabbage butterfly, Pieris rapae. Development and biomass of M. brassicae and Mi. mediator were similar on both cultivated and one wild cabbage population (KIM), intermediate on the OH population, and significantly lower on the WIN population. Moreover, development was prolonged and biomass was reduced on herbivore-induced plants. However, only the survival of parasitized hosts (and not that of healthy larvae) was affected by induction. Analysis of glucosinolates in leaves of the cabbages revealed higher levels in the wild populations than cultivars, with the highest concentrations in WIN plants. Multivariate statistics revealed a negative correlation between insect performance and total levels of glucosinolates (GS) and levels of 3-butenyl GS. However, GS chemistry could not explain the reduced performance on induced plants since only indole GS concentrations increased in response to herbivory, which did not affect insect performance based on multivariate statistics. This result suggests that, in addition to aliphatic GS, other non-GS chemicals are responsible for the decline in insect performance, and that these chemicals affect the parasitoid more strongly than the host. Remarkably, when developing on WIN plants, the survival of Mi. mediator to adult eclosion was much higher than in its host, M. brassicae. This may be due to the fact that hosts parasitized by Mi. mediator pass through fewer

  3. How do soil texture, plant community composition and earthworms affected the infiltration rate in a grassland plant diversity experiment depending on season?

    NASA Astrophysics Data System (ADS)

    Fischer, Christine; Britta, Merkel; Nico, Eisenhauer; Christiane, Roscher; Sabine, Attinger; Stefan, Scheu; Anke, Hildebrandt

    2013-04-01

    Background and aims: In this study we analyzed the influences of plant community characteristics, soil texture and earthworm presence on infiltration rates on a managed grassland plant diversity experiment assessing the role of biotic and abiotic factors on soil hydrology. Methods: We measured infiltration using a hood infiltrometer in subplots with ambient and reduced earthworm density (earthworm extraction) nested in plots of different plant species richness (1, 4, and 16), plant functional group number and composition (1 to 4; legumes, grasses, small herbs, tall herbs) in early summer (June) and autumn (September, October) 2011. Results: The presence of certain plant functional groups such as grasses and legumes influenced infiltration rates and this effect enhanced during the growing season. Infiltration was significantly higher in plots containing legumes than in plots without, and it was significantly lower in the presence of grasses than in their absence. In early summer, earthworm presence and biomass increased the infiltration rates, independently of plant species richness. In October, plant species richness only affected infiltration rates in reduced earthworm plots. At the end of the growing season earthworm populations were negatively influenced by grasses and positively by legumes. In September, infiltration rates were positive related to the proportion of finer grains. The correlation disappears when removing all plots containing legumes from the sample. For all measurements the infiltration rates decreases from early summer to autumn at the matric potentials at pressure zero and -0.02 m, but not for smaller macropores at matric potentials -0.04 and -0.06m. Conclusions: Considering infiltration rates as ecosystem function, this function will largely depend on the ecosystem composition and season, not on biodiversity per se. Our results indicate that biotic factors are of overriding influence for shaping infiltration rates mainly for larger macropores

  4. Arbuscular mycorrhizal fungal phylogenetic groups differ in affecting host plants along heavy metal levels.

    PubMed

    He, Lei; Yang, Haishui; Yu, Zhenxing; Tang, Jianjun; Xu, Ligen; Chen, Xin

    2014-10-01

    Arbuscular mycorrhizal fungi (AMF) are important components of soil microbial communities, and play important role in plant growth. However, the effects of AMF phylogenetic groups (Glomeraceae and non-Glomeraceae) on host plant under various heavy metal levels are not clear. Here we conducted a meta-analysis to compare symbiotic relationship between AMF phylogenetic groups (Glomeraceae and non-Glomeraceae) and host plant functional groups (herbs vs. trees, and non-legumes vs. legumes) at three heavy metal levels. In the meta-analysis, we calculate the effect size (ln(RR)) by taking the natural logarithm of the response ratio of inoculated to non-inoculated shoot biomass from each study. We found that the effect size of Glomeraceae increased, but the effect size of non-Glomeraceae decreased under high level of heavy metal compared to low level. According to the effect size, both Glomeraceae and non-Glomeraceae promoted host plant growth, but had different effects under various heavy metal levels. Glomeraceae provided more benefit to host plants than non-Glomeraceae did under heavy metal condition, while non-Glomeraceae provided more benefit to host plants than Glomeraceae did under no heavy metal. AMF phylogenetic groups also differed in promoting plant functional groups under various heavy metal levels. Interacting with Glomeraceae, herbs and legumes grew better than trees and non-legumes did under high heavy metal level, while trees and legumes grew better than herbs and non-legumes did under medium heavy metal level. Interacting with non-Glomeraceae, herbs and legumes grew better than trees and non-legumes did under no heavy metal. We suggested that the combination of legume with Glomeraceae could be a useful way in the remediation of heavy metal polluted environment. PMID:25288547

  5. Arbuscular mycorrhizal fungal phylogenetic groups differ in affecting host plants along heavy metal levels.

    PubMed

    He, Lei; Yang, Haishui; Yu, Zhenxing; Tang, Jianjun; Xu, Ligen; Chen, Xin

    2014-10-01

    Arbuscular mycorrhizal fungi (AMF) are important components of soil microbial communities, and play important role in plant growth. However, the effects of AMF phylogenetic groups (Glomeraceae and non-Glomeraceae) on host plant under various heavy metal levels are not clear. Here we conducted a meta-analysis to compare symbiotic relationship between AMF phylogenetic groups (Glomeraceae and non-Glomeraceae) and host plant functional groups (herbs vs. trees, and non-legumes vs. legumes) at three heavy metal levels. In the meta-analysis, we calculate the effect size (ln(RR)) by taking the natural logarithm of the response ratio of inoculated to non-inoculated shoot biomass from each study. We found that the effect size of Glomeraceae increased, but the effect size of non-Glomeraceae decreased under high level of heavy metal compared to low level. According to the effect size, both Glomeraceae and non-Glomeraceae promoted host plant growth, but had different effects under various heavy metal levels. Glomeraceae provided more benefit to host plants than non-Glomeraceae did under heavy metal condition, while non-Glomeraceae provided more benefit to host plants than Glomeraceae did under no heavy metal. AMF phylogenetic groups also differed in promoting plant functional groups under various heavy metal levels. Interacting with Glomeraceae, herbs and legumes grew better than trees and non-legumes did under high heavy metal level, while trees and legumes grew better than herbs and non-legumes did under medium heavy metal level. Interacting with non-Glomeraceae, herbs and legumes grew better than trees and non-legumes did under no heavy metal. We suggested that the combination of legume with Glomeraceae could be a useful way in the remediation of heavy metal polluted environment.

  6. Fungal infection reduces herbivore-induced plant volatiles of maize but does not affect naïve parasitoids.

    PubMed

    Rostás, Michael; Ton, Jurriaan; Mauch-Mani, Brigitte; Turlings, Ted C J

    2006-09-01

    Plants attacked by insects release volatile compounds that attract the herbivores' natural enemies. This so-called indirect defense is plastic and may be affected by an array of biotic and abiotic factors. We investigated the effect of fungal infection as a biotic stress agent on the emission of herbivore-induced volatiles and the possible consequences for the attraction of two parasitoid species. Maize seedlings that were simultaneously attacked by the fungus Setosphaeria turcica and larvae of Spodoptera littoralis emitted a blend of volatiles that was qualitatively similar to the blend emitted by maize that was damaged by only the herbivore, but there was a clear quantitative difference. When simultaneously challenged by fungus and herbivore, the maize plants emitted in total 47% less of the volatiles. Emissions of green leaf volatiles were unaffected. In a six-arm olfactometer, the parasitoids Cotesia marginiventris and Microplitis rufiventris responded equally well to odors of herbivore-damaged and fungus- and herbivore-damaged maize plants. Healthy and fungus-infected plants were not attractive. An additional experiment showed that the performance of S. littoralis caterpillars was not affected by the presence of the pathogen, nor was there an effect on larvae of M. rufiventris developing inside the caterpillars. Our results confirm previous indications that naïve wasps may respond primarily to the green leaf volatiles.

  7. Increased phloem transport of S-methylmethionine positively affects sulfur and nitrogen metabolism and seed development in pea plants.

    PubMed

    Tan, Qiumin; Zhang, Lizhi; Grant, Jan; Cooper, Pauline; Tegeder, Mechthild

    2010-12-01

    Seeds of grain legumes are important energy and food sources for humans and animals. However, the yield and quality of legume seeds are limited by the amount of sulfur (S) partitioned to the seeds. The amino acid S-methylmethionine (SMM), a methionine derivative, has been proposed to be an important long-distance transport form of reduced S, and we analyzed whether SMM phloem loading and source-sink translocation are important for the metabolism and growth of pea (Pisum sativum) plants. Transgenic plants were produced in which the expression of a yeast SMM transporter, S-Methylmethionine Permease1 (MMP1, YLL061W), was targeted to the phloem and seeds. Phloem exudate analysis showed that concentrations of SMM are elevated in MMP1 plants, suggesting increased phloem loading. Furthermore, expression studies of genes involved in S transport and metabolism in source organs, as well as xylem sap analyses, support that S uptake and assimilation are positively affected in MMP1 roots. Concomitantly, nitrogen (N) assimilation in root and leaf and xylem amino acid profiles were changed, resulting in increased phloem loading of amino acids. When investigating the effects of increased S and N phloem transport on seed metabolism, we found that protein levels were improved in MMP1 seeds. In addition, changes in SMM phloem loading affected plant growth and seed number, leading to an overall increase in seed S, N, and protein content in MMP1 plants. Together, these results suggest that phloem loading and source-sink partitioning of SMM are important for plant S and N metabolism and transport as well as seed set.

  8. Changes in the salinity tolerance of sweet pepper plants as affected by nitrogen form and high CO2 concentration.

    PubMed

    Piñero, María C; Pérez-Jiménez, Margarita; López-Marín, Josefa; Del Amor, Francisco M

    2016-08-01

    The assimilation and availability of nitrogen in its different forms can significantly affect the response of primary productivity under the current atmospheric alteration and soil degradation. An elevated CO2 concentration (e[CO2]) triggers changes in the efficiency and efficacy of photosynthetic processes, water use and product yield, the plant response to stress being altered with respect to ambient CO2 conditions (a[CO2]). Additionally, NH4(+) has been related to improved plant responses to stress, considering both energy efficiency in N-assimilation and the overcoming of the inhibition of photorespiration at e[CO2]. Therefore, the aim of this work was to determine the response of sweet pepper plants (Capsicum annuum L.) receiving an additional supply of NH4(+) (90/10 NO3(-)/NH4(+)) to salinity stress (60mM NaCl) under a[CO2] (400μmolmol(-1)) or e[CO2] (800μmolmol(-1)). Salt-stressed plants grown at e[CO2] showed DW accumulation similar to that of the non-stressed plants at a[CO2]. The supply of NH4(+) reduced growth at e[CO2] when salinity was imposed. Moreover, NH4(+) differentially affected the stomatal conductance and water use efficiency and the leaf Cl(-), K(+), and Na(+) concentrations, but the extent of the effects was influenced by the [CO2]. An antioxidant-related response was prompted by salinity, the total phenolics and proline concentrations being reduced by NH4(+) at e[CO2]. Our results show that the effect of NH4(+) on plant salinity tolerance should be globally re-evaluated as e[CO2] can significantly alter the response, when compared with previous studies at a[CO2].

  9. Changes in the salinity tolerance of sweet pepper plants as affected by nitrogen form and high CO2 concentration.

    PubMed

    Piñero, María C; Pérez-Jiménez, Margarita; López-Marín, Josefa; Del Amor, Francisco M

    2016-08-01

    The assimilation and availability of nitrogen in its different forms can significantly affect the response of primary productivity under the current atmospheric alteration and soil degradation. An elevated CO2 concentration (e[CO2]) triggers changes in the efficiency and efficacy of photosynthetic processes, water use and product yield, the plant response to stress being altered with respect to ambient CO2 conditions (a[CO2]). Additionally, NH4(+) has been related to improved plant responses to stress, considering both energy efficiency in N-assimilation and the overcoming of the inhibition of photorespiration at e[CO2]. Therefore, the aim of this work was to determine the response of sweet pepper plants (Capsicum annuum L.) receiving an additional supply of NH4(+) (90/10 NO3(-)/NH4(+)) to salinity stress (60mM NaCl) under a[CO2] (400μmolmol(-1)) or e[CO2] (800μmolmol(-1)). Salt-stressed plants grown at e[CO2] showed DW accumulation similar to that of the non-stressed plants at a[CO2]. The supply of NH4(+) reduced growth at e[CO2] when salinity was imposed. Moreover, NH4(+) differentially affected the stomatal conductance and water use efficiency and the leaf Cl(-), K(+), and Na(+) concentrations, but the extent of the effects was influenced by the [CO2]. An antioxidant-related response was prompted by salinity, the total phenolics and proline concentrations being reduced by NH4(+) at e[CO2]. Our results show that the effect of NH4(+) on plant salinity tolerance should be globally re-evaluated as e[CO2] can significantly alter the response, when compared with previous studies at a[CO2]. PMID:27317970

  10. Do postfire mulching treatments affect plant community recovery in California coastal sage scrub lands?

    PubMed

    McCullough, Sarah A; Endress, Bryan A

    2012-01-01

    In recent years, the use of postfire mulch treatments to stabilize slopes and reduce soil erosion in shrubland ecosystems has increased; however, the potential effects on plant recovery have not been examined. To evaluate the effects of mulching treatments on postfire plant recovery in southern California coastal sage scrub, we conducted a field experiment with three experimental treatments, consisting of two hydromulch products and an erosion control blanket, plus a control treatment. The area burned in 2007, and treatments were applied to six plot blocks before the 2008 growing season. Treatment effects on plant community recovery were analyzed with a mixed effects ANOVA analysis using a univariate repeated measures approach. Absolute plant cover increased from 13 to 90% by the end of the second growing season, and the mean relative cover of exotic species was 32%. The two hydromulch treatments had no effect on any plant community recovery response variable measured. For the erosion control blanket treatment, the amount of bare ground cover at the end of the second growing season was significantly lower (P = 0.01), and greater shrub height was observed (P < 0.01). We conclude that postfire mulch treatments did not provide either a major benefit or negative impact to coastal sage scrub recovery on the study area.

  11. Uptake of Pharmaceuticals Influences Plant Development and Affects Nutrient and Hormone Homeostases.

    PubMed

    Carter, Laura J; Williams, Mike; Böttcher, Christine; Kookana, Rai S

    2015-10-20

    The detection of a range of active pharmaceutical ingredients (APIs) in the soil environment has led to a number of publications demonstrating uptake by crops, however very few studies have explored the potential for impacts on plant development as a result of API uptake. This study investigated the effect of carbamazepine and verapamil (0.005-10 mg/kg) on a range of plant responses in zucchini (Cucurbita pepo). Uptake increased in a dose-dependent manner, with maximum leaf concentrations of 821.9 and 2.2 mg/kg for carbamazepine and verapamil, respectively. Increased carbamazepine uptake by zucchini resulted in a decrease in above (<60%) and below (<30%) ground biomass compared to the controls (p < 0.05). At soil concentrations >4 mg/kg the mature leaves suffered from burnt edges and white spots as well as a reduction in photosynthetic pigments but no such effects were seen for verapamil. For both APIs, further investigations revealed significant differences in the concentrations of selected plant hormones (auxins, cytokinins, abscisic acid and jasmonates), and in the nutrient composition of the leaves in comparison to the controls (p < 0.05). This is some of the first research to demonstrate that the exposure of plants to APIs is likely to cause impacts on plant development with unknown implications.

  12. Morphological Characteristics of Maize Canopy Development as Affected by Increased Plant Density.

    PubMed

    Song, Youhong; Rui, Yukui; Bedane, Guta; Li, Jincai

    2016-01-01

    Improving crop productivity through higher plant density requires a detailed understanding of organ development in response to increased interplant competition. The objective of this paper is thus to investigate the characteristics of organ development under increased interplant competition. A field experiment was conducted to investigate organ development across 4 maize plant densities i.e. 2, 6, 12 and 20 plants m-2 (referred to PD2, PD6, PD12 and PD20 respectively). In response to increased interplant competition, lengths of both laminae and sheaths increased in lower phytomers, but decreased in upper phytomers. Sheath extension appeared to be less sensitive to increased interplant competition than lamina extension. Extension of laminae and internodes responded to increased plant density as soon as onset of mild interplant competition, but did not respond any further to severe competition. Both lamina width and internode diameter were reduced due to a smaller growth rate in response to increased plant density. Overall, this study identified that organ expansion rate can be taken as the key morphological factor to determine the degree of interplant competition.

  13. Morphological Characteristics of Maize Canopy Development as Affected by Increased Plant Density

    PubMed Central

    Song, Youhong; Rui, Yukui; Bedane, Guta; Li, Jincai

    2016-01-01

    Improving crop productivity through higher plant density requires a detailed understanding of organ development in response to increased interplant competition. The objective of this paper is thus to investigate the characteristics of organ development under increased interplant competition. A field experiment was conducted to investigate organ development across 4 maize plant densities i.e. 2, 6, 12 and 20 plants m–2 (referred to PD2, PD6, PD12 and PD20 respectively). In response to increased interplant competition, lengths of both laminae and sheaths increased in lower phytomers, but decreased in upper phytomers. Sheath extension appeared to be less sensitive to increased interplant competition than lamina extension. Extension of laminae and internodes responded to increased plant density as soon as onset of mild interplant competition, but did not respond any further to severe competition. Both lamina width and internode diameter were reduced due to a smaller growth rate in response to increased plant density. Overall, this study identified that organ expansion rate can be taken as the key morphological factor to determine the degree of interplant competition. PMID:27129101

  14. Uptake of Pharmaceuticals Influences Plant Development and Affects Nutrient and Hormone Homeostases.

    PubMed

    Carter, Laura J; Williams, Mike; Böttcher, Christine; Kookana, Rai S

    2015-10-20

    The detection of a range of active pharmaceutical ingredients (APIs) in the soil environment has led to a number of publications demonstrating uptake by crops, however very few studies have explored the potential for impacts on plant development as a result of API uptake. This study investigated the effect of carbamazepine and verapamil (0.005-10 mg/kg) on a range of plant responses in zucchini (Cucurbita pepo). Uptake increased in a dose-dependent manner, with maximum leaf concentrations of 821.9 and 2.2 mg/kg for carbamazepine and verapamil, respectively. Increased carbamazepine uptake by zucchini resulted in a decrease in above (<60%) and below (<30%) ground biomass compared to the controls (p < 0.05). At soil concentrations >4 mg/kg the mature leaves suffered from burnt edges and white spots as well as a reduction in photosynthetic pigments but no such effects were seen for verapamil. For both APIs, further investigations revealed significant differences in the concentrations of selected plant hormones (auxins, cytokinins, abscisic acid and jasmonates), and in the nutrient composition of the leaves in comparison to the controls (p < 0.05). This is some of the first research to demonstrate that the exposure of plants to APIs is likely to cause impacts on plant development with unknown implications. PMID:26418514

  15. Modification of nitrate uptake pathway in plants affects the cadmium uptake by roots.

    PubMed

    Guan, Mei Yan; Fan, Shi Kai; Fang, Xian Zhi; Jin, Chong Wei

    2015-01-01

    NRT1.1 is a dual-affinity nitrate (NO3(-)) transporter involved in both high- and low-affinity NO3(-) uptake in Arabidopsis plants. In a recent study, we showed that, under cadmium (Cd) exposure, blocking the NRT1.1-mediated NO3(-) uptake reduces Cd entry into roots, thus lowing Cd levels in plants and improving plant growth. In addition, we also found that the Cd levels in edible parts of 11 Chinese cabbage (Brassica rapa L. ssp. pekinensis) cultivars correlated well with the NO3(-) uptake rates of their roots. These results suggested that the NO3(-) uptake of roots negatively regulate Cd uptake. Modification of NO3(-) uptake in crops by modulating NO3(-) uptake pathway might provide a biological engineering approach to reducing Cd accumulation in edible organs, thus improving food safety.

  16. How do increasing background concentrations of tropospheric ozone affect peatland plant growth and carbon gas exchange?

    NASA Astrophysics Data System (ADS)

    Williamson, Jennifer L.; Mills, Gina; Hayes, Felicity; Jones, Timothy; Freeman, Chris

    2016-02-01

    In this study we have demonstrated that plants originating from upland peat bogs are sensitive to increasing background concentrations of ozone. Peatland mesocosms from an upland peat bog in North Wales, UK were exposed to eight levels of elevated background ozone in solardomes for 4 months from May to August, with 24 h mean ozone concentrations ranging from 16 to 94 ppb and cumulative AOT024hr ranging from 45.98 ppm h to 259.63 ppm h. Our results show that plant senescence increased with increasing exposure to ozone, although there was no significant effect of increasing ozone on plant biomass. Assessments of carbon dioxide and methane fluxes from the mesocosms suggests that there was no change in carbon dioxide fluxes over the 4 month exposure period but that methane fluxes increased as cumulative ozone exposure increased to a maximum AOT 024hr of approximately 120 ppm h and then decreased as cumulative ozone exposure increased further.

  17. Volatile communication between plants that affects herbivory: a meta-analysis.

    PubMed

    Karban, Richard; Yang, Louie H; Edwards, Kyle F

    2014-01-01

    Volatile communication between plants causing enhanced defence has been controversial. Early studies were not replicated, and influential reviews questioned the validity of the phenomenon. We collected 48 well-replicated studies and found overall support for the hypothesis that resistance increased for individuals with damaged neighbours. Laboratory or greenhouse studies and those conducted on agricultural crops showed stronger induced resistance than field studies on undomesticated species, presumably because other variation had been reduced. A cumulative analysis revealed that early, non-replicated studies were more variable and showed less evidence for communication. Effects of habitat and plant growth form were undetectable. In most cases, the mechanisms of resistance and alternative hypotheses were not considered. There was no indication that some response variables were more likely to produce large effects. These results indicate that plants of diverse taxonomic affinities and ecological conditions become more resistant to herbivores when exposed to volatiles from damaged neighbours.

  18. Plant waxy bloom on peas affects infection of pea aphids by Pandora neoaphidis.

    PubMed

    Duetting, Patrick S; Ding, Hongjian; Neufeld, Jeffrey; Eigenbrode, Sanford D

    2003-11-01

    This study examined the effects of the surface wax bloom of pea plants, Pisum sativum, on infection of pea aphids, Acyrthosiphon pisum, by the fungal pathogen Pandora neoaphidis. In prior field surveys, a higher proportion of P. neoaphidis-killed pea aphids (cadavers) had been observed on a pea line with reduced wax bloom, as compared with a sister line with normal surface wax bloom. Laboratory bioassays were conducted in order to examine the mechanisms. After plants of each line infested with aphids were exposed to similar densities of conidia, the rate of accumulation of cadavers on the reduced wax line was significantly greater than on the normal wax bloom line; at the end of the experiment (13d), the proportion of aphid cadavers on the reduced wax line was approximately four times that on the normal wax bloom line. When plants were exposed to conidia first and then infested with aphids, the rate of accumulation of cadavers was slightly but significantly greater on the reduced wax line, and infection at the end of the experiment (16d) did not differ between the lines. When aphids were exposed first and then released onto the plants, no differences in the proportion of aphid cadavers were observed between the pea lines. Greater infection of pea aphid on reduced wax peas appears to depend upon plants being exposed to inoculum while aphids are settled in typical feeding positions on the plant. Additional experiments demonstrated increased adhesion and germination by P. neoaphidis conidia to leaf surfaces of the reduced wax line as compared with normal wax line, and this could help explain the higher infection rate by P. neoaphidis on the reduced wax line. In bioassays using surface waxes extracted from the two lines, there was no effect of wax source on germination of P. neoaphidis conidia.

  19. Agave salmiana Plant Communities in Central Mexico as Affected by Commercial Use

    NASA Astrophysics Data System (ADS)

    Martínez Salvador, Martin; Mata-González, Ricardo; Morales Nieto, Carlos; Valdez-Cepeda, Ricardo

    2012-01-01

    Agave salmiana is a native plant species harvested for the commercial production of mezcal ( Agave spirits) in the highlands of central Mexico. The objective of this study was to identify vegetation changes in natural communities where A. salmiana has been differentially harvested for commercial purposes. Three plant community categories were identified in the state of Zacatecas based on their history of A. salmiana utilization: short (less than 10 years of use), moderate (about 25 years), and long (60 or more years). Species cover, composition, and density were evaluated in field surveys by use category. A gradient of vegetation structure of the communities parallels the duration of A. salmiana use. A. salmiana density was greatest (3,125 plants ha-1) in the short-use areas and less (892 plants ha-1) in the moderate-use areas, associated with markedly greater density of shrubs (200%) and Opuntia spp. (50%) in moderate-use areas. The main shrubs were Larrea tridentata, Mimosa biuncifera, Jatropha dioica and Buddleia scordioides while the main Opuntia species were Opuntia leucotricha and Opuntia robusta. A. salmiana density was least (652 plants ha-1) in the long-use areas where shrubs were less abundant but Opuntia spp. density was 25% higher than in moderate-use areas. We suggest that shrubs may increase with moderate use creating an intermediate successional stage that facilitates the establishment of Opuntia spp. Long-term Agave use is generating new plant communities dominated by Opuntia spp. (nopaleras) as a replacement of the original communities dominated by A. salmiana (magueyeras).

  20. Agave salmiana plant communities in central Mexico as affected by commercial use.

    PubMed

    Martínez Salvador, Martin; Mata-González, Ricardo; Morales Nieto, Carlos; Valdez-Cepeda, Ricardo

    2012-01-01

    Agave salmiana is a native plant species harvested for the commercial production of mezcal (Agave spirits) in the highlands of central Mexico. The objective of this study was to identify vegetation changes in natural communities where A. salmiana has been differentially harvested for commercial purposes. Three plant community categories were identified in the state of Zacatecas based on their history of A. salmiana utilization: short (less than 10 years of use), moderate (about 25 years), and long (60 or more years). Species cover, composition, and density were evaluated in field surveys by use category. A gradient of vegetation structure of the communities parallels the duration of A. salmiana use. A. salmiana density was greatest (3,125 plants ha(-1)) in the short-use areas and less (892 plants ha(-1)) in the moderate-use areas, associated with markedly greater density of shrubs (200%) and Opuntia spp. (50%) in moderate-use areas. The main shrubs were Larrea tridentata, Mimosa biuncifera, Jatropha dioica and Buddleia scordioides while the main Opuntia species were Opuntia leucotricha and Opuntia robusta. A. salmiana density was least (652 plants ha(-1)) in the long-use areas where shrubs were less abundant but Opuntia spp. density was 25% higher than in moderate-use areas. We suggest that shrubs may increase with moderate use creating an intermediate successional stage that facilitates the establishment of Opuntia spp. Long-term Agave use is generating new plant communities dominated by Opuntia spp. (nopaleras) as a replacement of the original communities dominated by A. salmiana (magueyeras).

  1. Plant species diversity affects soil-atmosphere fluxes of methane and nitrous oxide.

    PubMed

    Niklaus, Pascal A; Le Roux, Xavier; Poly, Franck; Buchmann, Nina; Scherer-Lorenzen, Michael; Weigelt, Alexandra; Barnard, Romain L

    2016-07-01

    Plant diversity effects on ecosystem functioning can potentially interact with global climate by altering fluxes of the radiatively active trace gases nitrous oxide (N2O) and methane (CH4). We studied the effects of grassland species richness (1-16) in combination with application of fertilizer (nitrogen:phosphorus:potassium = 100:43.6:83 kg ha(-1) a(-1)) on N2O and CH4 fluxes in a long-term field experiment. Soil N2O emissions, measured over 2 years using static chambers, decreased with species richness unless fertilizer was added. N2O emissions increased with fertilization and the fraction of legumes in plant communities. Soil CH4 uptake, a process driven by methanotrophic bacteria, decreased with plant species numbers, irrespective of fertilization. Using structural equation models, we related trace gas fluxes to soil moisture, soil inorganic N concentrations, nitrifying and denitrifying enzyme activity, and the abundance of ammonia oxidizers, nitrite oxidizers, and denitrifiers (quantified by real-time PCR of gene fragments amplified from microbial DNA in soil). These analyses indicated that plant species richness increased soil moisture, which in turn increased N cycling-related activities. Enhanced N cycling increased N2O emission and soil CH4 uptake, with the latter possibly caused by removal of inhibitory ammonium by nitrification. The moisture-related indirect effects were surpassed by direct, moisture-independent effects opposite in direction. Microbial gene abundances responded positively to fertilizer but not to plant species richness. The response patterns we found were statistically robust and highlight the potential of plant biodiversity to interact with climatic change through mechanisms unrelated to carbon storage and associated carbon dioxide removal. PMID:27038993

  2. Study of Plant Cell Wall Polymers Affected by Metal Accumulation Using Stimulated Raman Scattering Microscopy

    SciTech Connect

    Ding, Shi-You

    2015-03-02

    This project aims to employ newly-developed chemical imaging techniques to measure, in real-time, the concentration, dynamics and spatial distribution of plant cell wall polymers during biomass growth with inoculation of transgenic symbiotic fungi, and to explore a new pathway of delivering detoxified metal to plant apoplast using transgenic symbiotic fungi, which will enhance metal accumulation from soil, and potentially these metals may in turn be used as catalysts to improve the efficiency of biomass conversion to biofuels. The proposed new pathway of biomass production will: 1) benefit metal and radionuclide contaminant mobility in subsurface environments, and 2) potentially improve biomass production and process for bioenergy

  3. Overexpression of the CC-type glutaredoxin, OsGRX6 affects hormone and nitrogen status in rice plants

    PubMed Central

    El-Kereamy, Ashraf; Bi, Yong-Mei; Mahmood, Kashif; Ranathunge, Kosala; Yaish, Mahmoud W.; Nambara, Eiji; Rothstein, Steven J.

    2015-01-01

    Glutaredoxins (GRXs) are small glutathione dependent oxidoreductases that belong to the Thioredoxin (TRX) superfamily and catalyze the reduction of disulfide bonds of their substrate proteins. Plant GRXs include three different groups based on the motif sequence, namely CPYC, CGFS, and CC-type proteins. The rice CC-type proteins, OsGRX6 was identified during the screening for genes whose expression changes depending on the level of available nitrate. Overexpression of OsGRX6 in rice displayed a semi-dwarf phenotype. The OsGRX6 overexpressors contain a higher nitrogen content than the wild type, indicating that OsGRX6 plays a role in homeostatic regulation of nitrogen use. Consistent with this, OsGRX6 overexpressors displayed delayed chlorophyll degradation and senescence compared to the wild type plants. To examine if the growth defect of these transgenic lines attribute to disturbed plant hormone actions, plant hormone levels were measured. The levels of two cytokinins (CKs), 2-isopentenyladenine and trans-zeatin, and gibberellin A1 (GA1) were increased in these lines. We also found that these transgenic lines were less sensitive to exogenously applied GA, suggesting that the increase in GA1 is a result of the feedback regulation. These data suggest that OsGRX6 affects hormone signaling and nitrogen status in rice plants. PMID:26579177

  4. Factors affecting xylene-contaminated air removal by the ornamental plant Zamioculcas zamiifolia.

    PubMed

    Sriprapat, Wararat; Boraphech, Phattara; Thiravetyan, Paitip

    2014-02-01

    Fifteen plant species-Alternanthera bettzickiana, Drimiopsis botryoides, Aloe vera, Chlorophytum comosum, Aglaonema commutatum, Cordyline fruticosa, Philodendron martianum, Sansevieria hyacinthoides, Aglaonema rotundum, Fittonia albivenis, Muehlenbeckia platyclada, Tradescantia spathacea, Guzmania lingulata, Zamioculcas zamiifolia, and Cyperus alternifolius-were evaluated for the removal efficiency of xylene from contaminated air. Among the test plants, Z. zamiifolia showed the highest xylene removal efficiency. Xylene was toxic to Z. zamiifolia with an LC50 of 3,464 ppm. Higher concentrations of xylene exhibited damage symptoms, including leaf tips turning yellow, holonecrosis, and hydrosis. TEM images showed that a low concentration of xylene vapors caused minor changes in the chloroplast, while a high concentration caused swollen chloroplasts and damage. The effect of photosynthetic types on xylene removal efficiency suggests that a mixture of Z. zamiifolia, S. hyacinthoides, and A. commutatum which represent facultative CAM, CAM, and C3 plants, is the most suitable system for xylene removal. Therefore, for maximum improvement in removing xylene volatile compounds under various conditions, multiple species are needed. The effect of a plant's total leaf area on xylene removal indicates that at lower concentrations of xylene, a small leaf area might be as efficient as a large leaf area.

  5. Plant Defense Inhibitors Affect the Structures of Midgut Cells in Drosophila melanogaster and Callosobruchus maculatus.

    PubMed

    Li-Byarlay, Hongmei; Pittendrigh, Barry R; Murdock, Larry L

    2016-01-01

    Plants produce proteins such as protease inhibitors and lectins as defenses against herbivorous insects and pathogens. However, no systematic studies have explored the structural responses in the midguts of insects when challenged with plant defensive proteins and lectins across different species. In this study, we fed two kinds of protease inhibitors and lectins to the fruit fly Drosophila melanogaster and alpha-amylase inhibitors and lectins to the cowpea bruchid Callosobruchus maculatus. We assessed the changes in midgut cell structures by comparing them with such structures in insects receiving normal diets or subjected to food deprivation. Using light and transmission electron microscopy in both species, we observed structural changes in the midgut peritrophic matrix as well as shortened microvilli on the surfaces of midgut epithelial cells in D. melanogaster. Dietary inhibitors and lectins caused similar lesions in the epithelial cells but not much change in the peritrophic matrix in both species. We also noted structural damages in the Drosophila midgut after six hours of starvation and changes were still present after 12 hours. Our study provided the first evidence of key structural changes of midguts using a comparative approach between a dipteran and a coleopteran. Our particular observation and discussion on plant-insect interaction and dietary stress are relevant for future mode of action studies of plant defensive protein in insect physiology. PMID:27594789

  6. Plant invasions differentially affected by diversity and dominant species in native- and exotic-dominated grasslands.

    PubMed

    Xu, Xia; Polley, H Wayne; Hofmockel, Kirsten; Daneshgar, Pedram P; Wilsey, Brian J

    2015-12-01

    Plant invasions are an increasingly serious global concern, especially as the climate changes. Here, we explored how plant invasions differed between native- and novel exotic-dominated grasslands with experimental addition of summer precipitation in Texas in 2009. Exotic species greened up earlier than natives by an average of 18 days. This was associated with a lower invasion rate early in the growing season compared to native communities. However, invasion rate did not differ significantly between native and exotic communities across all sampling times. The predictors of invasion rate differed between native and exotic communities, with invasion being negatively influenced by species richness in natives and by dominant species in exotics. Interestingly, plant invasions matched the bimodal pattern of precipitation in Temple, Texas, and did not respond to the pulse of precipitation during the summer. Our results suggest that we will need to take different approaches in understanding of invasion between native and exotic grasslands. Moreover, with anticipated increasing variability in precipitation under global climate change, plant invasions may be constrained in their response if the precipitation pulses fall outside the normal growing period of invaders.

  7. Plant invasions differentially affected by diversity and dominant species in native- and exotic-dominated grasslands.

    PubMed

    Xu, Xia; Polley, H Wayne; Hofmockel, Kirsten; Daneshgar, Pedram P; Wilsey, Brian J

    2015-12-01

    Plant invasions are an increasingly serious global concern, especially as the climate changes. Here, we explored how plant invasions differed between native- and novel exotic-dominated grasslands with experimental addition of summer precipitation in Texas in 2009. Exotic species greened up earlier than natives by an average of 18 days. This was associated with a lower invasion rate early in the growing season compared to native communities. However, invasion rate did not differ significantly between native and exotic communities across all sampling times. The predictors of invasion rate differed between native and exotic communities, with invasion being negatively influenced by species richness in natives and by dominant species in exotics. Interestingly, plant invasions matched the bimodal pattern of precipitation in Temple, Texas, and did not respond to the pulse of precipitation during the summer. Our results suggest that we will need to take different approaches in understanding of invasion between native and exotic grasslands. Moreover, with anticipated increasing variability in precipitation under global climate change, plant invasions may be constrained in their response if the precipitation pulses fall outside the normal growing period of invaders. PMID:27069615

  8. Drying and storage methods affect cyfluthrin concentrations in exposed plant samples

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Standard procedures exist for collection and chemical analyses of pyrethroid insecticides in environmental matrices. However, less detail is given for drying and potential storage methods of plant samples prior to analyses. Due to equipment and financial limitations, immediate sample analysis is n...

  9. Factors affecting xylene-contaminated air removal by the ornamental plant Zamioculcas zamiifolia.

    PubMed

    Sriprapat, Wararat; Boraphech, Phattara; Thiravetyan, Paitip

    2014-02-01

    Fifteen plant species-Alternanthera bettzickiana, Drimiopsis botryoides, Aloe vera, Chlorophytum comosum, Aglaonema commutatum, Cordyline fruticosa, Philodendron martianum, Sansevieria hyacinthoides, Aglaonema rotundum, Fittonia albivenis, Muehlenbeckia platyclada, Tradescantia spathacea, Guzmania lingulata, Zamioculcas zamiifolia, and Cyperus alternifolius-were evaluated for the removal efficiency of xylene from contaminated air. Among the test plants, Z. zamiifolia showed the highest xylene removal efficiency. Xylene was toxic to Z. zamiifolia with an LC50 of 3,464 ppm. Higher concentrations of xylene exhibited damage symptoms, including leaf tips turning yellow, holonecrosis, and hydrosis. TEM images showed that a low concentration of xylene vapors caused minor changes in the chloroplast, while a high concentration caused swollen chloroplasts and damage. The effect of photosynthetic types on xylene removal efficiency suggests that a mixture of Z. zamiifolia, S. hyacinthoides, and A. commutatum which represent facultative CAM, CAM, and C3 plants, is the most suitable system for xylene removal. Therefore, for maximum improvement in removing xylene volatile compounds under various conditions, multiple species are needed. The effect of a plant's total leaf area on xylene removal indicates that at lower concentrations of xylene, a small leaf area might be as efficient as a large leaf area. PMID:24091527

  10. Will global warming affect soil-to-plant transfer of radionuclides?

    PubMed

    Dowdall, M; Standring, W; Shaw, G; Strand, P

    2008-11-01

    Recent assessments of global climate/environmental change are reaching a consensus that global climate change is occurring but there is significant uncertainty over the likely magnitude of this change and its impacts. There is little doubt that all aspects of the natural environment will be impacted to some degree. Soil-to-plant transfer of radionuclides has long been a significant topic in radioecology, both for the protection of humans and the environment from the effects of ionising radiation. Even after five decades of research considerable uncertainty exists as to the interplay of key environmental processes in controlling soil-plant transfer. As many of these processes are, to a lesser or greater extent, climate-dependent, it can be argued that climate/environmental change will impact soil-to-plant transfer of radionuclides and subsequent transfers in specific environments. This discussion attempts to highlight the possible role of climatic and climate-dependent variables in soil-to-plant transfer processes within the overall predictions of climate/environmental change. The work is speculative, and intended to stimulate debate on a theme that radioecology has either ignored or avoided in recent years.

  11. Mercury Concentrations in Plant Tissues as Affected by FGDG Application to Soil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flue Gas Desulfurization Gypsum (FGDG) is produced by reducing sulfur dioxide emissions from themo-electric coal-fired power plants. The most common practice of FGDG production may trap some of the Mercury (Hg) present in the coal that normally would escape as vapor in the stack gases. Concern for t...

  12. Molecular analyses of nuclear-cytoplasmic interactions affecting plant growth and yield. Final technical report

    SciTech Connect

    Newton, K.J.

    1998-11-01

    Mitochondria have a central role in the production of cellular energy. The biogenesis and functioning of mitochondria depends on the expression of both mitochondrial and nuclear genes. One approach to investigating the role of nuclear-mitochondrial cooperation in plant growth and development is to identify combinations of nuclear and mitochondrial genomes that result in altered but sublethal phenotypes. Plants that have certain maize nuclear genotypes in combination with cytoplasmic genomes from more distantly-related teosintes can exhibit incompatible phenotypes, such as reduced plant growth and yield and cytoplasmic male sterility, as well as altered mitochondrial gene expression. The characterization of these nuclear-cytoplasmic interactions was the focus of this grant. The authors were investigating the effects of two maize nuclear genes, RcmI and Mct, on mitochondrial function and gene expression. Plants with the teosinte cytoplasms and homozygous for the recessive rcm allele are small (miniature) and-slow-growing and the kernels are reduced in size. The authors mapped this locus to molecular markers on chromosome 7 and attempted to clone this locus by transposon tagging. The effects of the nuclear-cytoplasmic interaction on mitochondrial function and mitochondrial protein profiles were also studied.

  13. Chlorophyllase 1, a Damage Control Enzyme, Affects the Balance between Defense Pathways in Plants

    PubMed Central

    Kariola, Tarja; Brader, Günter; Li, Jing; Palva, E. Tapio

    2005-01-01

    Accumulation of reactive oxygen species (ROS) is central to plant response to several pathogens. One of the sources of ROS is the chloroplast because of the photoactive nature of the chlorophylls. Chlorophyllase 1 (encoded by AtCLH1) of Arabidopsis thaliana is quickly induced after tissue damage (e.g., caused by the bacterial necrotroph Erwinia carotovora or the necrotrophic fungus Alternaria brassicicola). RNA interference silencing of AtCLH1 resulted in failure to degrade free chlorophyll after tissue damage and in resistance to E. carotovora. Both inoculation with E. carotovora and exposure to high light caused elevated accumulation of hydrogen peroxide in AtCLH1 silenced plants. This was accompanied by expression of marker genes for systemic acquired resistance and induction of antioxidant defenses. Interestingly, downregulation of AtCLH1 resulted in increased susceptibility to A. brassicicola, resistance to which requires jasmonate signaling. We propose that AtCLH1 is involved in plant damage control and can modulate the balance between different plant defense pathways. PMID:15598807

  14. Differential Response in Plant Taxa Morphology and Physiology During Increases in Late-Quaternary Atmospheric CO2 Concentrations Affect Plant-Climate Interactions.

    NASA Astrophysics Data System (ADS)

    van de Water, P. K.; Barnum, E.

    2004-12-01

    The effects of changing atmospheric CO2 on plant physiology mediate vegetation response to climate change. For example, growth chamber studies on short-lived plants show significant changes in plant morphology and physiological parameters such as changes in biomass and water-use efficiency (WUE; the amount of carbon assimilated to plant water-loss) as atmospheric CO2 concentrations increases from ˜200 p.p.m. to modern concentrations and beyond. Many modern studies show WUE increases linearly with rising atmospheric CO2 meaning that less water is expended for each unit of carbon assimilated. To test for the consistency of these findings with past, long-lived plants and in past communities growing under a similar range of atmospheric CO2 levels, macrofossils of select species were analyzed from packrat (Neotoma sp.) midden chronologies gathered throughout western North America. Measurement of and analysis for the stable isotope content of these macrofossils shows greater morphological and eco-physiological differences between species than expected from study results using growth chambers. For example, isotopic analysis shows long-standing associates, Pinus edulis and Juniperus spp. have significantly different WUE during the transition from the Pleistocene to the Holocene. The WUE in Pinus edulis matches changes in atmospheric CO2 whereas Juniperus spp. does not. Yet over the same period, changes observed in Pinus flexilis needles from trees growing in cooler habitats above the pinyon-juniper woodlands are more similar to Juniperus spp. changes compared against trends in the more closely related Pinus edulis. Morphology changes occurring during this period include increased biomass and reduced stomata. These results show taxonomic differences in the morphological and physiological adaptation to changing CO2 concentrations. These responses need further assessment especially in light of their direct affect on plant-climate interactions.

  15. The town Crepis and the country Crepis: How does fragmentation affect a plant-pollinator interaction?

    NASA Astrophysics Data System (ADS)

    Andrieu, Emilie; Dornier, Antoine; Rouifed, Soraya; Schatz, Bertrand; Cheptou, Pierre-Olivier

    2009-01-01

    In fragmented habitats, one cause of the decrease of plant diversity and abundance is the disruption of plant-animal interactions, and in particular plant-pollinator interactions. Since habitat fragmentation acts both on pollinator behaviour and plant reproduction, its consequences for the stability of such interactions are complex. An extreme case of habitat fragmentation occurs in urbanised areas where suitable habitat (in the present study small patches around ornamental trees) is embedded in a highly unsuitable environment (concrete matrix). Based on simple experiments, we ask whether pollinators can adapt their foraging behaviour in response to the amount of available resources (flowers) in the fragments and their isolation, as predicted by the optimal foraging theory. To do so we analysed the effect of fragmentation on the behaviour of pollinators visiting Crepis sancta (L.) Bornm. (Asteraceae), which forms large populations in the countryside and patchy populations in urban environments. More precisely we studied pollinator visitation rates, capitulum visit durations, capitulum search durations and capitulum size choice. Pollinators chose larger capitula in both types of populations and their foraging behaviour differed between the two population types in three ways: (1) pollinator visits were lower in urban fragmented populations, perhaps due to the lower accessibility of urban patches; (2) capitulum visit durations were longer in urban fragmented populations, a possible compensation of energy lost during flights among patches; and (3) capitulum search durations where longer in urban fragmented populations, which may represent an increase in capitulum prospecting effort. We discuss the possible impacts of such differences for plant population functioning in the two types of populations.

  16. Trichobaris weevils distinguish amongst toxic host plants by sensing volatiles that do not affect larval performance.

    PubMed

    Lee, Gisuk; Joo, Youngsung; Diezel, Celia; Lee, Eun Ju; Baldwin, Ian T; Kim, Sang-Gyu

    2016-07-01

    Herbivorous insects use plant metabolites to inform their host plant selection for oviposition. These host-selection behaviours are often consistent with the preference-performance hypothesis; females oviposit on hosts that maximize the performance of their offspring. However, the metabolites used for these oviposition choices and those responsible for differences in offspring performance remain unknown for ecologically relevant interactions. Here, we examined the host-selection behaviours of two sympatric weevils, the Datura (Trichobaris compacta) and tobacco (T. mucorea) weevils in field and glasshouse experiments with transgenic host plants specifically altered in different components of their secondary metabolism. Adult females of both species strongly preferred to feed on D. wrightii rather than on N. attenuata leaves, but T. mucorea preferred to oviposit on N. attenuata, while T. compacta oviposited only on D. wrightii. These oviposition behaviours increased offspring performance: T. compacta larvae only survived in D. wrightii stems and T. mucorea larvae survived better in N. attenuata than in D. wrightii stems. Choice assays with nicotine-free, JA-impaired, and sesquiterpene-over-produced isogenic N. attenuata plants revealed that although half of the T. compacta larvae survived in nicotine-free N. attenuata lines, nicotine did not influence the oviposition behaviours of both the nicotine-adapted and nicotine-sensitive species. JA-induced sesquiterpene volatiles are key compounds influencing T. mucorea females' oviposition choices, but these sesquiterpenes had no effect on larval performance. We conclude that adult females are able to choose the best host plant for their offspring and use chemicals different from those that influence larval performance to inform their oviposition decisions. PMID:27146082

  17. Atmospheric CO2 level affects plants' carbon use efficiency: insights from a 13C labeling experiment on sunflower stands

    NASA Astrophysics Data System (ADS)

    Gong, Xiaoying; Schäufele, Rudi; Schnyder, Hans

    2015-04-01

    The increase of atmospheric CO2 concentration has been shown to stimulate plant photosynthesis and (to a lesser extent) growth, thereby acting as a possible sink for the additional atmospheric CO2. However, this effect is dependent on the efficiency with which plants convert atmospheric carbon into biomass carbon, since a considerable proportion of assimilated carbon is returned to the atmosphere via plant respiration. As a core parameter for carbon cycling, carbon use efficiency of plants (CUE, the ratio of net primary production to gross primary production) quantifies the proportion of assimilated carbon that is incorporated into plant biomass. CUE has rarely been assessed based on measurements of complete carbon balance, due to methodological difficulties in measuring respiration rate of plants in light. Moreover, foliar respiration is known to be inhibited in light, thus foliar respiration rate is generally lower in light than in dark. However, this phenomenon, termed as inhibition of respiration in light (IRL), has rarely been assessed at the stand-scale and been incorporated into the calculation of CUE. Therefore, how CUE responses to atmospheric CO2 levels is still not clear. We studied CUE of sunflower stands grown at sub-ambient CO2 level (200 μmol mol-1) and elevated CO2 level (1000 μmol mol-1) using mesocosm-scale gas exchange facilities which enabled continuous measurements of 13CO2/12CO2 exchange. Appling steady-state 13C labeling, fluxes of respiration and photosynthesis in light were separated, and tracer kinetic in respiration was analyzed. This study provides the first data on CUE at a mesocosm-level including respiration in light in different CO2 environments. We found that CUE of sunflower was lower at an elevated CO2 level than at a sub-ambient CO2 level; and the ignorance of IRL lead to erroneous estimations of CUE. Variation in CUE at atmospheric CO2 levels was attributed to several mechanisms. In this study, CO2 enrichment i) affected the

  18. Salinity and light interactively affect neotropical mangrove seedlings at the leaf and whole plant levels.

    PubMed

    López-Hoffman, Laura; Anten, Niels P R; Martínez-Ramos, Miguel; Ackerly, David D

    2007-01-01

    We have studied the interactive effects of salinity and light on Avicennia germinans mangrove seedlings in greenhouse and field experiments. We hypothesized that net photosynthesis, growth, and survivorship rates should increase more with an increase in light availability for plants growing at low salinity than for those growing at high salinity. This hypothesis was supported by our results for net photosynthesis and growth. Net daily photosynthesis did increase more with increasing light for low-salinity plants than for high-salinity plants. Stomatal conductance, leaf-level transpiration, and internal CO(2) concentrations were lower at high than at low salinity. At high light, the ratio of leaf respiration to assimilation was 2.5 times greater at high than at low salinity. Stomatal limitations and increased respiratory costs may explain why, at high salinity, seedlings did not respond to increased light availability with increased net photosynthesis. Seedling mass and growth rates increased more with increasing light availability at low than at high salinity. Ratios of root mass to leaf mass were higher at high salinity, suggesting that either water or nutrient limitations may have limited seedling growth at high salinity in response to increasing light. The interactive effects of salinity and light on seedling size and growth rates observed in the greenhouse were robust in the field, despite the presence of other factors in the field--such as inundation, nutrient gradients, and herbivory. In the field, seedling survivorship was higher at low than at high salinity and increased with light availability. Interestingly, the positive effect of light on seedling survivorship was stronger at high salinity, indicating that growth and survivorship rates are decoupled. In general, this study demonstrates that environmental effects at the leaf-level also influence whole plant growth in mangroves.

  19. Plant compartment and biogeography affect microbiome composition in cultivated and native Agave species.

    PubMed

    Coleman-Derr, Devin; Desgarennes, Damaris; Fonseca-Garcia, Citlali; Gross, Stephen; Clingenpeel, Scott; Woyke, Tanja; North, Gretchen; Visel, Axel; Partida-Martinez, Laila P; Tringe, Susannah G

    2016-01-01

    Desert plants are hypothesized to survive the environmental stress inherent to these regions in part thanks to symbioses with microorganisms, and yet these microbial species, the communities they form, and the forces that influence them are poorly understood. Here we report the first comprehensive investigation of the microbial communities associated with species of Agave, which are native to semiarid and arid regions of Central and North America and are emerging as biofuel feedstocks. We examined prokaryotic and fungal communities in the rhizosphere, phyllosphere, leaf and root endosphere, as well as proximal and distal soil samples from cultivated and native agaves, through Illumina amplicon sequencing. Phylogenetic profiling revealed that the composition of prokaryotic communities was primarily determined by the plant compartment, whereas the composition of fungal communities was mainly influenced by the biogeography of the host species. Cultivated A. tequilana exhibited lower levels of prokaryotic diversity compared with native agaves, although no differences in microbial diversity were found in the endosphere. Agaves shared core prokaryotic and fungal taxa known to promote plant growth and confer tolerance to abiotic stress, which suggests common principles underpinning Agave-microbe interactions.

  20. Comparison of Soybean Transformation Efficiency and Plant Factors Affecting Transformation during the Agrobacterium Infection Process

    PubMed Central

    Jia, Yuying; Yao, Xingdong; Zhao, Mingzhe; Zhao, Qiang; Du, Yanli; Yu, Cuimei; Xie, Futi

    2015-01-01

    The susceptibility of soybean genotype to Agrobacterium infection is a key factor for the high level of genetic transformation efficiency. The objective of this study is to evaluate the plant factors related to transformation in cotyledonary nodes during the Agrobacterium infection process. This study selected three genotypes (Williams 82, Shennong 9 and Bert) with high transformation efficiency, which presented better susceptibility to Agrobacterium infection, and three low transformation efficiency genotypes (General, Liaodou 16 and Kottman), which showed a relatively weak susceptibility. Gibberellin (GA) levels and soybean GA20ox2 and CYP707A2 transcripts of high-efficiency genotypes increased and were higher than those of low-efficiency genotypes; however, the opposite performance was shown in abscisic acid (ABA). Higher zeatin riboside (ZR) content and DNA quantity, and relatively higher expression of soybean IPT5, CYCD3 and CYCA3 were obtained in high-efficiency genotypes. High-efficiency genotypes had low methyl jasmonate (MeJA) content, polyphenol oxidase (PPO) and peroxidase (POD) activity, and relatively lower expression of soybean OPR3, PPO1 and PRX71. GA and ZR were positive plant factors for Agrobacterium-mediated soybean transformation by facilitating germination and growth, and increasing the number of cells in DNA synthesis cycle, respectively; MeJA, PPO, POD and ABA were negative plant factors by inducing defence reactions and repressing germination and growth, respectively. PMID:26262617

  1. Storage behavior of mango as affected by post harvest application of plant extracts and storage conditions.

    PubMed

    Gupta, Nisha; Jain, S K

    2014-10-01

    The use of plant extracts could be a useful alternative to synthetic fungicides in the post harvest handling of fruits and vegetables. The aim of this study was to access the efficacy of extracts obtained from four plants (neem, Pongamia, custard apple leaf and marigold flowers) on the extension of shelf life of mango fruits cv. Dashehri under two storage conditions (Cool store and ambient condition). The fruits were treated with 2 concentrations of each plant extracts (10 % and 20 %) were placed in perforated linear low density poly ethylene bags and stored in storage conditions viz., cool storage and ambient condition, respectively. The treatment of neem leaf extract in combination with cool storage gave encouraging results. Up to the end of the storage study the treatment combination of 20 % neem leaf extract and cool store completely inhibited the pathogens, and no spoilage was observed. There was minimum physiological loss in weight (6.24 %), minimum girth reduction (0.62 %), maximum ascorbic acid content (29.96 mg/ 100 g of pulp), maximum acidity (0.19 %), minimum pH (5.28), maximum total soluble solids (20.96 %), maximum total sugars (12.50 %), reducing sugars (4.12 %) and non- reducing sugars (7.96 %) and best organoleptic score (7.93/10) in this interaction. The inhibitory effect of neem leaf extract was ascribed to the presence of active principle azadirachtin. PMID:25328189

  2. Plant Defense Inhibitors Affect the Structures of Midgut Cells in Drosophila melanogaster and Callosobruchus maculatus

    PubMed Central

    Li-Byarlay, Hongmei; Pittendrigh, Barry R.; Murdock, Larry L.

    2016-01-01

    Plants produce proteins such as protease inhibitors and lectins as defenses against herbivorous insects and pathogens. However, no systematic studies have explored the structural responses in the midguts of insects when challenged with plant defensive proteins and lectins across different species. In this study, we fed two kinds of protease inhibitors and lectins to the fruit fly Drosophila melanogaster and alpha-amylase inhibitors and lectins to the cowpea bruchid Callosobruchus maculatus. We assessed the changes in midgut cell structures by comparing them with such structures in insects receiving normal diets or subjected to food deprivation. Using light and transmission electron microscopy in both species, we observed structural changes in the midgut peritrophic matrix as well as shortened microvilli on the surfaces of midgut epithelial cells in D. melanogaster. Dietary inhibitors and lectins caused similar lesions in the epithelial cells but not much change in the peritrophic matrix in both species. We also noted structural damages in the Drosophila midgut after six hours of starvation and changes were still present after 12 hours. Our study provided the first evidence of key structural changes of midguts using a comparative approach between a dipteran and a coleopteran. Our particular observation and discussion on plant–insect interaction and dietary stress are relevant for future mode of action studies of plant defensive protein in insect physiology. PMID:27594789

  3. Spatial heterogeneity in light supply affects intraspecific competition of a stoloniferous clonal plant.

    PubMed

    Wang, Pu; Lei, Jing-Pin; Li, Mai-He; Yu, Fei-Hai

    2012-01-01

    Spatial heterogeneity in light supply is common in nature. Many studies have examined the effects of heterogeneous light supply on growth, morphology, physiology and biomass allocation of clonal plants, but few have tested those effects on intraspecific competition. In a greenhouse experiment, we grew one (no competition) or nine ramets (with intraspecific competition) of a stoloniferous clonal plant, Duchesnea indica, in three homogeneous light conditions (high, medium and low light intensity) and two heterogeneous ones differing in patch size (large and small patch treatments). The total light in the two heterogeneous treatments was the same as that in the homogeneous medium light treatment. Both decreasing light intensity and intraspecific competition significantly decreased the growth (biomass, number of ramets and total stolon length) of D. indica. As compared with the homogeneous medium light treatment, the large patch treatment significantly increased the growth of D. indica without intraspecific competition. However, the growth of D. indica with competition did not differ among the homogeneous medium light, the large and the small patch treatments. Consequently, light heterogeneity significantly increased intraspecific competition intensity, as measured by the decreased log response ratio. These results suggest that spatial heterogeneity in light supply can alter intraspecific interactions of clonal plants.

  4. Plant compartment and biogeography affect microbiome composition in cultivated and native Agave species.

    PubMed

    Coleman-Derr, Devin; Desgarennes, Damaris; Fonseca-Garcia, Citlali; Gross, Stephen; Clingenpeel, Scott; Woyke, Tanja; North, Gretchen; Visel, Axel; Partida-Martinez, Laila P; Tringe, Susannah G

    2016-01-01

    Desert plants are hypothesized to survive the environmental stress inherent to these regions in part thanks to symbioses with microorganisms, and yet these microbial species, the communities they form, and the forces that influence them are poorly understood. Here we report the first comprehensive investigation of the microbial communities associated with species of Agave, which are native to semiarid and arid regions of Central and North America and are emerging as biofuel feedstocks. We examined prokaryotic and fungal communities in the rhizosphere, phyllosphere, leaf and root endosphere, as well as proximal and distal soil samples from cultivated and native agaves, through Illumina amplicon sequencing. Phylogenetic profiling revealed that the composition of prokaryotic communities was primarily determined by the plant compartment, whereas the composition of fungal communities was mainly influenced by the biogeography of the host species. Cultivated A. tequilana exhibited lower levels of prokaryotic diversity compared with native agaves, although no differences in microbial diversity were found in the endosphere. Agaves shared core prokaryotic and fungal taxa known to promote plant growth and confer tolerance to abiotic stress, which suggests common principles underpinning Agave-microbe interactions. PMID:26467257

  5. Plant Defense Inhibitors Affect the Structures of Midgut Cells in Drosophila melanogaster and Callosobruchus maculatus

    PubMed Central

    Li-Byarlay, Hongmei; Pittendrigh, Barry R.; Murdock, Larry L.

    2016-01-01

    Plants produce proteins such as protease inhibitors and lectins as defenses against herbivorous insects and pathogens. However, no systematic studies have explored the structural responses in the midguts of insects when challenged with plant defensive proteins and lectins across different species. In this study, we fed two kinds of protease inhibitors and lectins to the fruit fly Drosophila melanogaster and alpha-amylase inhibitors and lectins to the cowpea bruchid Callosobruchus maculatus. We assessed the changes in midgut cell structures by comparing them with such structures in insects receiving normal diets or subjected to food deprivation. Using light and transmission electron microscopy in both species, we observed structural changes in the midgut peritrophic matrix as well as shortened microvilli on the surfaces of midgut epithelial cells in D. melanogaster. Dietary inhibitors and lectins caused similar lesions in the epithelial cells but not much change in the peritrophic matrix in both species. We also noted structural damages in the Drosophila midgut after six hours of starvation and changes were still present after 12 hours. Our study provided the first evidence of key structural changes of midguts using a comparative approach between a dipteran and a coleopteran. Our particular observation and discussion on plant–insect interaction and dietary stress are relevant for future mode of action studies of plant defensive protein in insect physiology.

  6. Comparison of Soybean Transformation Efficiency and Plant Factors Affecting Transformation during the Agrobacterium Infection Process.

    PubMed

    Jia, Yuying; Yao, Xingdong; Zhao, Mingzhe; Zhao, Qiang; Du, Yanli; Yu, Cuimei; Xie, Futi

    2015-08-07

    The susceptibility of soybean genotype to Agrobacterium infection is a key factor for the high level of genetic transformation efficiency. The objective of this study is to evaluate the plant factors related to transformation in cotyledonary nodes during the Agrobacterium infection process. This study selected three genotypes (Williams 82, Shennong 9 and Bert) with high transformation efficiency, which presented better susceptibility to Agrobacterium infection, and three low transformation efficiency genotypes (General, Liaodou 16 and Kottman), which showed a relatively weak susceptibility. Gibberellin (GA) levels and soybean GA20ox2 and CYP707A2 transcripts of high-efficiency genotypes increased and were higher than those of low-efficiency genotypes; however, the opposite performance was shown in abscisic acid (ABA). Higher zeatin riboside (ZR) content and DNA quantity, and relatively higher expression of soybean IPT5, CYCD3 and CYCA3 were obtained in high-efficiency genotypes. High-efficiency genotypes had low methyl jasmonate (MeJA) content, polyphenol oxidase (PPO) and peroxidase (POD) activity, and relatively lower expression of soybean OPR3, PPO1 and PRX71. GA and ZR were positive plant factors for Agrobacterium-mediated soybean transformation by facilitating germination and growth, and increasing the number of cells in DNA synthesis cycle, respectively; MeJA, PPO, POD and ABA were negative plant factors by inducing defence reactions and repressing germination and growth, respectively.

  7. Managing adverse effects of glaucoma medications

    PubMed Central

    Inoue, Kenji

    2014-01-01

    Glaucoma is a chronic, progressive disease in which retinal ganglion cells disappear and subsequent, gradual reductions in the visual field ensues. Glaucoma eye drops have hypotensive effects and like all other medications are associated with adverse effects. Adverse reactions may either result from the main agent or from preservatives used in the drug vehicle. The preservative benzalkonium chloride, is one such compound that causes frequent adverse reactions such as superficial punctate keratitis, corneal erosion, conjunctival allergy, and conjunctival injection. Adverse reactions related to main hypotensive agents have been divided into those affecting the eye and those affecting the entire body. In particular, β-blockers frequently cause systematic adverse reactions, including bradycardia, decrease in blood pressure, irregular pulse and asthma attacks. Prostaglandin analogs have distinctive local adverse reactions, including eyelash bristling/lengthening, eyelid pigmentation, iris pigmentation, and upper eyelid deepening. No systemic adverse reactions have been linked to prostaglandin analog eye drop usage. These adverse reactions may be minimized when they are detected early and prevented by reducing the number of different eye drops used (via fixed combination eye drops), reducing the number of times eye drops are administered, using benzalkonium chloride-free eye drops, using lower concentration eye drops, and providing proper drop instillation training. Additionally, a one-time topical medication can be given to patients to allow observation of any adverse reactions, thereafter the preparation of a topical medication with the fewest known adverse reactions can be prescribed. This does require precise patient monitoring and inquiries about patient symptoms following medication use. PMID:24872675

  8. Healthy and Adverse Effects of Plant-Derived Functional Metabolites: The Need of Revealing their Content and Bioactivity in a Complex Food Matrix

    PubMed Central

    Lavecchia, Teresa; Rea, Giuseppina; Antonacci, Amina; Giardi, Maria T.

    2012-01-01

    In recent years, both food quality and its effect on human health have become a fundamental issue all over the world. As a consequence of this new and increased awareness, American, European, and Asian policymakers have strongly encouraged the research programs on food quality and safety thematic. Attempts to improve human health and to satisfy people's desire for healthcare without intake of pharmaceuticals, has led the food industry to focus attention on functional or nutraceutical food. For a long time, compounds with nutraceutical activity have been produced chemically, but the new demands for a sustainable life have gradually led the food industry to move towards natural compounds, mainly those derived from plants. Many phytochemicals are known to promote good health, but, sometimes, undesirable effects are also reported. Furthermore, several products present on the market show few benefits and sometimes even the reverse – unhealthy effects; the evidence of efficacy is often unconvincing and epidemiological studies are necessary to prove the truth of their claims. Therefore, there is a need for reliable analytical control systems to measure the bioactivity, content, and quality of these additives in the complex food matrix. This review describes the most widespread nutraceutics and an analytical control of the same using recently developed biosensors which are promising candidates for routine control of functional foods. PMID:23072533

  9. Contamination of soil, medicinal, and fodder plants with lead and cadmium present in mine-affected areas, Northern Pakistan.

    PubMed

    Nawab, Javed; Khan, Sardar; Shah, Mohammad Tahir; Qamar, Zahir; Din, Islamud; Mahmood, Qaisar; Gul, Nayab; Huang, Qing

    2015-09-01

    This study aimed to investigate the lead (Pb) and cadmium (Cd) concentrations in the soil and plants (medicinal and fodder) grown in chromite mining-affected areas, Northern Pakistan. Soil and plant samples were collected and analyzed for Pb and Cd concentrations using atomic absorption spectrometer. Soil pollution load indices (PLIs) were greater than 2 for both Cd and Pb, indicating high level of contamination in the study area. Furthermore, Cd concentrations in the soil surrounding the mining sites exceeded the maximum allowable limit (MAL) (0.6 mg kg(-1)), while the concentrations of Pb were lower than the MAL (350 mg kg(-1)) set by State Environmental Protection Administration (SEPA) for agriculture soil. The concentrations of Cd and Pb were significantly higher (P < 0.001) in the soil of the mining-contaminated sites as compared to the reference site, which can be attributed to the dispersion of toxic heavy metals, present in the bed rocks and waste of the mines. The concentrations of Pb and Cd in majority of medicinal and fodder plant species grown in surrounding areas of mines were higher than their MALs set by World Health Organization/Food Agriculture Organization (WHO/FAO) for herbal (10 and 0.3 mg kg(-1), respectively) and edible (0.3 and 0.2 mg kg(-1), respectively) plants. The high concentrations of Cd and Pb may cause contamination of the food chain and health risk.

  10. A novel role for Arabidopsis CBL1 in affecting plant responses to glucose and gibberellin during germination and seedling development.

    PubMed

    Li, Zhi-Yong; Xu, Zhao-Shi; Chen, Yang; He, Guang-Yuan; Yang, Guang-Xiao; Chen, Ming; Li, Lian-Cheng; Ma, You-Zhi

    2013-01-01

    Glucose and phytohormones such as abscisic acid (ABA), ethylene, and gibberellin (GA) coordinately regulate germination and seedling development. However, there is still inadequate evidence to link their molecular roles in affecting plant responses. Calcium acts as a second messenger in a diverse range of signal transduction pathways. As calcium sensors unique to plants, calcineurin B-like (CBL) proteins are well known to modulate abiotic stress responses. In this study, it was found that CBL1 was induced by glucose in Arabidopsis. Loss-of-function mutant cbl1 exhibited hypersensitivity to glucose and paclobutrazol, a GA biosynthetic inhibitor. Several sugar-responsive and GA biosynthetic gene expressions were altered in the cbl1 mutant. CBL1 protein physically interacted with AKINβ1, the regulatory β subunit of the SnRK1 complex which has a central role in sugar signaling. Our results indicate a novel role for CBL1 in modulating responses to glucose and GA signals.

  11. Plant Species and Functional Group Combinations Affect Green Roof Ecosystem Functions

    PubMed Central

    Lundholm, Jeremy; MacIvor, J. Scott; MacDougall, Zachary; Ranalli, Melissa

    2010-01-01

    Background Green roofs perform ecosystem services such as summer roof temperature reduction and stormwater capture that directly contribute to lower building energy use and potential economic savings. These services are in turn related to ecosystem functions performed by the vegetation layer such as radiation reflection and transpiration, but little work has examined the role of plant species composition and diversity in improving these functions. Methodology/Principal Findings We used a replicated modular extensive (shallow growing- medium) green roof system planted with monocultures or mixtures containing one, three or five life-forms, to quantify two ecosystem services: summer roof cooling and water capture. We also measured the related ecosystem properties/processes of albedo, evapotranspiration, and the mean and temporal variability of aboveground biomass over four months. Mixtures containing three or five life-form groups, simultaneously optimized several green roof ecosystem functions, outperforming monocultures and single life-form groups, but there was much variation in performance depending on which life-forms were present in the three life-form mixtures. Some mixtures outperformed the best monocultures for water capture, evapotranspiration, and an index combining both water capture and temperature reductions. Combinations of tall forbs, grasses and succulents simultaneously optimized a range of ecosystem performance measures, thus the main benefit of including all three groups was not to maximize any single process but to perform a variety of functions well. Conclusions/Significance Ecosystem services from green roofs can be improved by planting certain life-form groups in combination, directly contributing to climate change mitigation and adaptation strategies. The strong performance by certain mixtures of life-forms, especially tall forbs, grasses and succulents, warrants further investigation into niche complementarity or facilitation as mechanisms

  12. Lignin, land plants, and fungi: Biological evolution affecting Phanerozoic oxygen balance

    SciTech Connect

    Robinson, J.M. )

    1990-07-01

    As dominance shifted from lycopsids and pteridophytes in the Paleozoic, to gymnosperms in the Mesozoic, to angiosperms in the Tertiary, plant architecture became more sparing in its use of lignin. Lignin-degrading organisms were rare or absent in the Paleozoic, but diverse and abundant in the Tertiary. Thus the terrigenous organic-carbon cycle has quickened over time, the fraction of terrestrial primary production preserved in coals and kerogens has declined, and terrestrial production has been able to increase over time without concomitant rises in atmospheric O{sub 2}.

  13. Initial Assessment of Sulfur-Iodine Process Safety Issues and How They May Affect Pilot Plant Design and Operation

    SciTech Connect

    Robert S. Cherry

    2006-09-01

    The sulfur-iodine process to make hydrogen by the thermochemical splitting of water is under active development as part of a U.S. Department of Energy program. An integrated lab scale system is currently being designed and built. The next planned stage of development is a pilot plant with a thermal input of about 500 kW, equivalent to about 30,000 standard liters per hour of hydrogen production. The sulfur-iodine process contains a variety of hazards, including temperatures up to 850 ºC and hazardous chemical species including SO2, H2SO4, HI, I2, and of course H2. The siting and design of a pilot plant must consider these and other hazards. This report presents an initial analysis of the hazards that might affect pilot plant design and should be considered in the initial planning. The general hazards that have been identified include reactivity, flammability, toxicity, pressure, electrical hazards, and industrial hazards such as lifting and rotating equipment. Personnel exposure to these hazards could occur during normal operations, which includes not only running the process at the design conditions but also initial inventory loading, heatup, startup, shutdown, and system flushing before equipment maintenance. Because of the complexity and severity of the process, these ancillary operations are expected to be performed frequently. In addition, personnel could be exposed to the hazards during various abnormal situations which could include unplanned phase changes of liquids or solids, leaks of process fluids or cooling water into other process streams, unintentional introducion of foreign species into the process, and unexpected side reactions. Design of a pilot plant will also be affected by various codes and regulations such as the International Building Code, the International Fire Code, various National Fire Protection Association Codes, and the Emergency Planning and Community Right-to-Know Act.

  14. Camphene, a Plant Derived Monoterpene, Exerts Its Hypolipidemic Action by Affecting SREBP-1 and MTP Expression

    PubMed Central

    Vallianou, Ioanna; Hadzopoulou-Cladaras, Margarita

    2016-01-01

    The control of hyperlipidemia plays a central role in cardiovascular disease. Previously, we have shown that camphene, a constituent of mastic gum oil, lowers cholesterol and triglycerides (TG) in the plasma of hyperlipidemic rats without affecting HMG-CoA reductase activity, suggesting that its hypocholesterolemic and hypotriglyceridemic effects are associated with a mechanism of action different than that of statins. In the present study, we examine the mechanism by which camphene exerts its hypolipidemic action. We evaluated the effect of camphene on the de novo synthesis of cholesterol and TG from [14C]-acetate in HepG2 cells, along with the statin mevinolin. Camphene inhibited the biosynthesis of cholesterol in a concentration-dependent manner, and a maximal inhibition of 39% was observed at 100 μM while mevinolin nearly abolished cholesterol biosynthesis. Moreover, treatment with camphene reduced TG by 34% and increased apolipoprotein AI expression. In contrast, mevinolin increased TG by 26% and had a modest effect on apolipoprotein AI expression. To evaluate the mode of action of camphene, we examined its effects on the expression of SREBP-1, which affects TG biosynthesis and SREBP-2, which mostly affects sterol synthesis. Interestingly, camphene increased the nuclear translocation of the mature form of SREBP-1 while mevinolin was found to increase the amount of the mature form of SREBP-2. The effect of camphene is most likely regulated through SREBP-1 by affecting MTP levels in response to a decrease in the intracellular cholesterol. We propose that camphene upregulates SREBP-1 expression and MTP inhibition is likely to be a probable mechanism whereby camphene exerts its hypolipidemic effect. PMID:26784701

  15. Nature's amazing biopolymer: basic mechanical and hydrological properties of soil affected by plant exudates

    NASA Astrophysics Data System (ADS)

    Naveed, Muhammad; Roose, Tiina; Raffan, Annette; George, Timothy; Bengough, Glyn; Brown, Lawrie; Keyes, Sam; Daly, Keith; Hallett, Paul

    2016-04-01

    Plant exudates are known to have a very large impact on soil physical properties through changes in mechanical and hydrological processes driven by long-chain polysaccharides and surface active compounds. Whilst these impacts are well known, the basic physical properties of these exudates have only been reported in a small number of studies. We present data for exudates obtained from barley roots and chia seeds, incorporating treatments examining biological decomposition of the exudates. When these exudates were added to a sandy loam soil, contact angle and drop penetration time increased exponentially with increasing exudate concentration. These wetting properties were strongly correlated with both exudate density and zero-shear viscosity, but not with exudate surface tension. Water holding capacity and water repellency of exudate mixed soil tremendously increased with exudate concentration, however they were significantly reduced on decomposition when measured after 14 days of incubation at 16C. Mechanical stability greatly increased with increasing exudate amendment to soils, which was assessed using a rheological amplitude sweep test near saturation, at -50 cm matric potential (field capacity) using indentation test, and at air-dry condition using the Brazilian test. This reflects that exudates not only attenuate plant water stress but also impart mechanical stability to the rhizosphere. These data are highly relevant to the understanding and modelling of rhizosphere development, which is the next phase of our research.

  16. Interactions between soil habitat and geographic range location affect plant fitness.

    PubMed

    Stanton-Geddes, John; Shaw, Ruth G; Tiffin, Peter

    2012-01-01

    Populations are often found on different habitats at different geographic locations. This habitat shift may be due to biased dispersal, physiological tolerances or biotic interactions. To explore how fitness of the native plant Chamaecrista fasciculata depends on habitat within, at and beyond its range edge, we planted seeds from five populations in two soil substrates at these geographic locations. We found that with reduced competition, lifetime fitness was always greater or equivalent in one habitat type, loam soils, though early-season survival was greater on sand soils. At the range edge, natural populations are typically found on sand soil habitats, which are also less competitive environments. Early-season survival and fitness differed among source populations, and when transplanted beyond the range edge, range edge populations had greater fitness than interior populations. Our results indicate that even when the optimal soil substrate for a species does not change with geographic range location, the realized niche of a species may be restricted to sub-optimal habitats at the range edge because of the combined effects of differences in abiotic and biotic effects (e.g. competitors) between substrates.

  17. Metal contaminated biochar and wood ash negatively affect plant growth and soil quality after land application.

    PubMed

    Jones, D L; Quilliam, R S

    2014-07-15

    Pyrolysis or combustion of waste wood can provide a renewable source of energy and produce byproducts which can be recycled back to land. To be sustainable requires that these byproducts pose minimal threat to the environment or human health. Frequently, reclaimed waste wood is contaminated by preservative-treated timber containing high levels of heavy metals. We investigated the effect of feedstock contamination from copper-preservative treated wood on the behaviour of pyrolysis-derived biochar and combustion-derived ash in plant-soil systems. Biochar and wood ash were applied to soil at typical agronomic rates. The presence of preservative treated timber in the feedstock increased available soil Cu; however, critical Cu guidance limits were only exceeded at high rates of feedstock contamination. Negative effects on plant growth and soil quality were only seen at high levels of biochar contamination (>50% derived from preservative-treated wood). Negative effects of wood ash contamination were apparent at lower levels of contamination (>10% derived from preservative treated wood). Complete removal of preservative treated timber from wood recycling facilities is notoriously difficult and low levels of contamination are commonplace. We conclude that low levels of contamination from Cu-treated wood should pose minimal environmental risk to biochar and ash destined for land application. PMID:24915641

  18. Hydrologic alteration affects aquatic plant assemblages in an arid-land river

    USGS Publications Warehouse

    Vinson, Mark; Hestmark, Bennett; Barkworth, Mary E.

    2014-01-01

    We evaluated the effects of long-term flow alteration on primary-producer assemblages. In 1962, Flaming Gorge Dam was constructed on the Green River. The Yampa River has remained an unregulated hydrologically variable river that joins the Green River 100 km downstream from Flaming Gorge Dam. In the 1960s before dam construction only sparse occurrences of two macroalgae, Cladophora and Chara, and no submerged vascular plants were recorded in the Green and Yampa rivers. In 2009–2010, aquatic plants were abundant and widespread in the Green River from the dam downstream to the confluence with the Yampa River. The assemblage consisted of six vascular species, Elodea canadensis, Myriophyllum sibiricum, Nasturtium officinale,Potamogeton crispus, Potamogeton pectinatus, and Ranunculus aquatilis, the macroalgae Chara and Cladophora, and the bryophyte, Amblystegium riparium. In the Green River downstream from the Yampa River, and in the Yampa River, only sparse patches of Chara and Cladophora growing in the splash zone on boulders were collected. We attribute the observed changes in the Green River to an increase in water transparency and a reduction in suspended and bed-load sediment and high flow disturbances. The lack of hydrophyte colonization downstream from the confluence with the Yampa River has implications for understanding tributary amelioration of dam effects and for designing more natural flow-regime schedules downstream from large dams.

  19. Interactions between Soil Habitat and Geographic Range Location Affect Plant Fitness

    PubMed Central

    Stanton-Geddes, John; Shaw, Ruth G.; Tiffin, Peter

    2012-01-01

    Populations are often found on different habitats at different geographic locations. This habitat shift may be due to biased dispersal, physiological tolerances or biotic interactions. To explore how fitness of the native plant Chamaecrista fasciculata depends on habitat within, at and beyond its range edge, we planted seeds from five populations in two soil substrates at these geographic locations. We found that with reduced competition, lifetime fitness was always greater or equivalent in one habitat type, loam soils, though early-season survival was greater on sand soils. At the range edge, natural populations are typically found on sand soil habitats, which are also less competitive environments. Early-season survival and fitness differed among source populations, and when transplanted beyond the range edge, range edge populations had greater fitness than interior populations. Our results indicate that even when the optimal soil substrate for a species does not change with geographic range location, the realized niche of a species may be restricted to sub-optimal habitats at the range edge because of the combined effects of differences in abiotic and biotic effects (e.g. competitors) between substrates. PMID:22615745

  20. Within plant distribution of Potato Virus Y in hairy nightshade (Solanum sarrachoides): an inoculum source affecting PVY aphid transmission.

    PubMed

    Cervantes, Felix A; Alvarez, Juan M

    2011-08-01

    Potato virus Y (PVY) is vectored by several potato-colonizing and non-colonizing aphid species in a non-persistent manner and has a wide host range. It occurs naturally in several plant families. Myzus persicae and Macrosiphum euphorbiae are the most efficient potato-colonizing aphid vectors of PVY. Rhopalosiphum padi, a cereal aphid that migrates in large numbers through potato fields during the middle of the growing season, does not colonize potato plants but can transmit PVY. Hairy nightshade, Solanum sarrachoides, a prevalent annual solanaceous weed in the Pacific Northwest (PNW) of the United States, is an alternative host for PVY and a preferred host for M. persicae and M. euphorbiae. Hence, hairy nightshade plants might play an important role as an inoculum source in the epidemiology of PVY. We looked at titre accumulation and distribution of PVY(O), PVY(N:O) and PVY(NTN) in S. sarrachoides and potato after aphid inoculation with M. persicae and studied the transmission of PVY(O) and PVY(NTN), by M. persicae, M. euphorbiae and R. padi from hairy nightshade to potato plants. Virus titre at different positions on the plant was similar in S. sarrachoides and potato plants with strains PVY(O) and PVY(N:O). Titres of PVY(NTN) were similar in S. sarrachoides and potato but differences in titre were observed at different positions within the plant depending on the plant phenology. Percentage transmission of PVY(NTN) by M. persicae and M. euphorbiae was twice as high (46 and 34%, respectively) from hairy nightshade to potato than from potato to potato (20 and 14%). Percentage transmission of PVY(O) by M. persicae and M. euphorbiae was not affected by the inoculum source. No effect of the inoculum source was observed in the transmission of either PVY strain by R. padi. These results show that hairy nightshade may be an equal or better virus reservoir than potato and thus, important in the epidemiology of PVY.

  1. Does insect netting affect the containment of airborne pollen from (GM-) plants in greenhouses?

    PubMed

    van Hengstum, Thomas; Hooftman, Danny A P; den Nijs, Hans C M; van Tienderen, Peter H

    2012-09-01

    Greenhouses are a well-accepted containment strategy to grow and study genetically modified plants (GM) before release into the environment. Various containment levels are requested by national regulations to minimize GM pollen escape. We tested the amount of pollen escaping from a standard greenhouse, which can be used for EU containment classes 1 and 2. More specifically, we investigated the hypothesis whether pollen escape could be minimized by insect-proof netting in front of the roof windows, since the turbulent airflow around the mesh wiring could avoid pollen from escaping. We studied the pollen flow out of greenhouses with and without insect netting of two non-transgenic crops, Ryegrass (Loliummultiflorum) and Corn (Zea Mays). Pollen flow was assessed with Rotorod(®) pollen samplers positioned inside and outside the greenhouse' roof windows. A significant proportion of airborne pollen inside the greenhouse leaves through roof windows. Moreover, the lighter pollen of Lolium escaped more readily than the heavier pollen of Maize. In contrast to our expectations, we did not identify any reduction in pollen flow with insect netting in front of open windows, even under induced airflow conditions. We conclude that insect netting, often present by default in greenhouses, is not effective in preventing pollen escape from greenhouses of wind-pollinated plants for containment classes 1 or 2. Further research would be needed to investigate whether other alternative strategies, including biotic ones, are more effective. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s10453-011-9237-8) contains supplementary material, which is available to authorized users. PMID:22798704

  2. Soil moisture and fungi affect seed survival in California grassland annual plants.

    PubMed

    Mordecai, Erin A

    2012-01-01

    Survival of seeds in the seed bank is important for the population dynamics of many plant species, yet the environmental factors that control seed survival at a landscape level remain poorly understood. These factors may include soil moisture, vegetation cover, soil type, and soil pathogens. Because many soil fungi respond to moisture and host species, fungi may mediate environmental drivers of seed survival. Here, I measure patterns of seed survival in California annual grassland plants across 15 species in three experiments. First, I surveyed seed survival for eight species at 18 grasslands and coastal sage scrub sites ranging across coastal and inland Santa Barbara County, California. Species differed in seed survival, and soil moisture and geographic location had the strongest influence on survival. Grasslands had higher survival than coastal sage scrub sites for some species. Second, I used a fungicide addition and exotic grass thatch removal experiment in the field to tease apart the relative impact of fungi, thatch, and their interaction in an invaded grassland. Seed survival was lower in the winter (wet season) than in the summer (dry season), but fungicide improved winter survival. Seed survival varied between species but did not depend on thatch. Third, I manipulated water and fungicide in the laboratory to directly examine the relationship between water, fungi, and survival. Seed survival declined from dry to single watered to continuously watered treatments. Fungicide slightly improved seed survival when seeds were watered once but not continually. Together, these experiments demonstrate an important role of soil moisture, potentially mediated by fungal pathogens, in driving seed survival.

  3. Plant Pathogenic Microbial Communication Affected by Elevated Temperature in Pectobacterium carotovorum subsp. carotovorum.

    PubMed

    Saha, N D; Chaudhary, A; Singh, S D; Singh, D; Walia, S; Das, T K

    2015-11-01

    Gram-negative plant pathogenic bacteria regulate specific gene expression in a population density-dependent manner by sensing level of Acyl-Homoserine Lactone (HSL) molecules which they produce and liberate to the environment, called Quorum Sensing (QS). The production of virulence factors (extracellular enzyme viz. cellulase, pectinase, etc.) in Pectobacterium carotovorum subsp. carotovorum (Pcc) is under strong regulation of QS. The QS signal molecule, N-(3-oxohexanoyl)-L-Homoserine Lactone (OHHL) was found as the central regulatory system for the virulence factor production in Pcc and is also under strict regulation of external environmental temperature. Under seven different incubation temperatures (24, 26, 28, 30, 33, 35, and 37 °C) in laboratory condition, highest amount of OHHL (804 violacein unit) and highest (79 %) Disease Severity Index (DSI) were measured at 33 °C. The OHHL production kinetics showed accumulation of highest concentration of OHHL at late log phase of the growth but diminution in the concentration occurred during stationary phase onwards to death phase. At higher temperature (35 and 37 °C) exposure, OHHL was not at detectable range. The effect of temperature on virulence factor production is the concomitant effect of HSL production and degradation which justifies less disease severity index in cross-inoculated tomato fruits incubated at 35 and 37 °C. The nondetection of the OHHL in the elevated temperature may because of degradation as these signal molecules are quite sensitive and prone to get degraded under different physical factors. This result provides the rationale behind the highest disease severity up to certain elevated temperature and leaves opportunities for investigation on mutation, co-evolution of superior plant pathogen with more stable HSL signals-mediated pathogenesis under global warming context. PMID:26271295

  4. Flower litters of alpine plants affect soil nitrogen and phosphorus rapidly in the eastern Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Wang, Jinniu; Xu, Bo; Wu, Yan; Gao, Jing; Shi, Fusun

    2016-10-01

    Litters of reproductive organs have rarely been studied despite their role in allocating nutrients for offspring reproduction. This study determines the mechanism through which flower litters efficiently increase the available soil nutrient pool. Field experiments were conducted to collect plant litters and calculate biomass production in an alpine meadow of the eastern Tibetan Plateau. C, N, P, lignin, cellulose content, and their relevant ratios of litters were analyzed to identify their decomposition features. A pot experiment was performed to determine the effects of litter addition on the soil nutrition pool by comparing the treated and control samples. The litter-bag method was used to verify decomposition rates. The flower litters of phanerophyte plants were comparable with non-flower litters. Biomass partitioning of other herbaceous species accounted for 10-40 % of the aboveground biomass. Flower litter possessed significantly higher N and P levels but less C / N, N / P, lignin / N, and lignin and cellulose concentrations than leaf litter. The litter-bag experiment confirmed that the flower litters of Rhododendron przewalskii and Meconopsis integrifolia decompose approximately 3 times faster than mixed litters within 50 days. Pot experiment findings indicated that flower litter addition significantly increased the available nutrient pool and soil microbial productivity. The time of litter fall significantly influenced soil available N and P, and soil microbial biomass. Flower litters fed the soil nutrition pool and influenced nutrition cycling in alpine ecosystems more efficiently because of their non-ignorable production, faster decomposition rate, and higher nutrient contents compared with non-flower litters. The underlying mechanism can enrich nutrients, which return to the soil, and non-structural carbohydrates, which feed and enhance the transitions of soil microorganisms.

  5. Factors That Affect Riverbank Filtrate Water Temperature in Daesan Plants, Changwon, Korea

    NASA Astrophysics Data System (ADS)

    Shin, J.; Lim, J.; Lee, K.; Jung, W.; Kim, H.

    2008-12-01

    City of Changwon, Korea, has been using some of riverbank filtrate water for the indoor air-conditioning of Daesan purification plants since 2006. In this method, the most important factor to determine efficiency of heating and cooling is the temperature of the filtrate water. Thus, it is required to predict the available range of groundwater temperature in the case of changing pumping rate, pumping location or in the case of long term operation. Numerical simulation of temperature profile of riverbank filtrate water in Daesan plants using HydroGeoSphere shows that the primary factor in determining filtrate water temperature is the pumping rate. Distance from the river to the wells is long enough to equalize subsurface water temperature through its penetration path and all of the well screen sections are located at the depth of 30 m below surface which is part of the local aquifer. This is why the horizontal distance from the river to each well and the installed screen depth are less important than the pumping rate to determine filtrate water temperature in this facility. It also shows that maintaining the facility operation with present pumping rate for the next 30 years will not cause any significant change of water temperature. However, following the new plan of the city to install additional 37 wells with 6 times higher pumping rate than the current rate might cause about 2? decrease in filtrate water temperature in 10 years after the extension. All of these results demonstrate that basic hydrological study such as aquifer heterogeneity or pumping capacity is prerequisite for calculating and predicting extracted water temperature in riverbank filtration system.

  6. Nanosecond electric pulses affect a plant-specific kinesin at the plasma membrane.

    PubMed

    Kühn, Sebastian; Liu, Qiong; Eing, Christian; Frey, Wolfgang; Nick, Peter

    2013-12-01

    Electric pulses with high field strength and durations in the nanosecond range (nsPEFs) are of considerable interest for biotechnological and medical applications. However, their actual cellular site of action is still under debate--due to their extremely short rise times, nsPEFs are thought to act mainly in the cell interior rather than at the plasma membrane. On the other hand, nsPEFs can induce membrane permeability. We have revisited this issue using plant cells as a model. By mapping the cellular responses to nsPEFs of different field strength and duration in the tobacco BY-2 cell line, we could define a treatment that does not impinge on short-term viability, such that the physiological responses to the treatment can be followed. We observe, for these conditions, a mild disintegration of the cytoskeleton, impaired membrane localization of the PIN1 auxin-efflux transporter and a delayed premitotic nuclear positioning followed by a transient mitotic arrest. To address the target site of nsPEFs, we made use of the plant-specific KCH kinesin, which can assume two different states with different localization (either near the nucleus or at the cell membrane) driving different cellular functions. We show that nsPEFs reduce cell expansion in nontransformed cells but promote expansion in a line overexpressing KCH. Since cell elongation and cell widening are linked to the KCH localized at the cell membrane, the inverted response in the KCH overexpressor provides evidence for a direct action of nsPEFs, also at the cell membrane. PMID:24062185

  7. Soil Moisture and Fungi Affect Seed Survival in California Grassland Annual Plants

    PubMed Central

    Mordecai, Erin A.

    2012-01-01

    Survival of seeds in the seed bank is important for the population dynamics of many plant species, yet the environmental factors that control seed survival at a landscape level remain poorly understood. These factors may include soil moisture, vegetation cover, soil type, and soil pathogens. Because many soil fungi respond to moisture and host species, fungi may mediate environmental drivers of seed survival. Here, I measure patterns of seed survival in California annual grassland plants across 15 species in three experiments. First, I surveyed seed survival for eight species at 18 grasslands and coastal sage scrub sites ranging across coastal and inland Santa Barbara County, California. Species differed in seed survival, and soil moisture and geographic location had the strongest influence on survival. Grasslands had higher survival than coastal sage scrub sites for some species. Second, I used a fungicide addition and exotic grass thatch removal experiment in the field to tease apart the relative impact of fungi, thatch, and their interaction in an invaded grassland. Seed survival was lower in the winter (wet season) than in the summer (dry season), but fungicide improved winter survival. Seed survival varied between species but did not depend on thatch. Third, I manipulated water and fungicide in the laboratory to directly examine the relationship between water, fungi, and survival. Seed survival declined from dry to single watered to continuously watered treatments. Fungicide slightly improved seed survival when seeds were watered once but not continually. Together, these experiments demonstrate an important role of soil moisture, potentially mediated by fungal pathogens, in driving seed survival. PMID:22720037

  8. Distribution of Pseudomonas Species in a Dairy Plant Affected by Occasional Blue Discoloration

    PubMed Central

    Lomonaco, Sara; Nucera, Daniele; Garoglio, Davide; Dalmasso, Alessandra; Civera, Tiziana

    2014-01-01

    During 2010 many cases of discoloration in mozzarella, popularly termed as blue mozzarella, have been reported to the attention of public opinion. Causes of the alteration were bacteria belonging to the genus Pseudomonas. The strong media impact of such cases has created confusion, not only among consumers, but also among experts. In order to help improving the knowledge on microbial ecology of this microorganism a study has been set up with the collaboration of a medium-sized dairy plant producing fresh mozzarella cheese, with occasional blue discoloration, conducting surveys and sampling in the pre-operational, operational and post-operational process phase, milk before and after pasteurization, water (n=12), environmental surfaces (n=22) and the air (n=27). A shelf life test was conducted on finished products stored at different temperatures (4-8°C). Among the isolates obtained from the microbiological analysis of the samples, 60 were subjected to biomolecular tests in order to confirm the belonging to Pseudomonas genus and to get an identification at species level by the amplification and sequencing of the gyrB gene. The results of microbiological tests demonstrated the presence of microorganisms belonging to the genus Pseudomonas along the entire production lane; molecular tests showed 7 different species among the 40 isolates identified. One particular species (Pseudomonas koreensis) was isolated from blue discolored mozzarella cheese and was indicated as the most relevant for the production plant, both for the distribution along the processing chain and for the consequences on the finished product. PMID:27800364

  9. Plant Pathogenic Microbial Communication Affected by Elevated Temperature in Pectobacterium carotovorum subsp. carotovorum.

    PubMed

    Saha, N D; Chaudhary, A; Singh, S D; Singh, D; Walia, S; Das, T K

    2015-11-01

    Gram-negative plant pathogenic bacteria regulate specific gene expression in a population density-dependent manner by sensing level of Acyl-Homoserine Lactone (HSL) molecules which they produce and liberate to the environment, called Quorum Sensing (QS). The production of virulence factors (extracellular enzyme viz. cellulase, pectinase, etc.) in Pectobacterium carotovorum subsp. carotovorum (Pcc) is under strong regulation of QS. The QS signal molecule, N-(3-oxohexanoyl)-L-Homoserine Lactone (OHHL) was found as the central regulatory system for the virulence factor production in Pcc and is also under strict regulation of external environmental temperature. Under seven different incubation temperatures (24, 26, 28, 30, 33, 35, and 37 °C) in laboratory condition, highest amount of OHHL (804 violacein unit) and highest (79 %) Disease Severity Index (DSI) were measured at 33 °C. The OHHL production kinetics showed accumulation of highest concentration of OHHL at late log phase of the growth but diminution in the concentration occurred during stationary phase onwards to death phase. At higher temperature (35 and 37 °C) exposure, OHHL was not at detectable range. The effect of temperature on virulence factor production is the concomitant effect of HSL production and degradation which justifies less disease severity index in cross-inoculated tomato fruits incubated at 35 and 37 °C. The nondetection of the OHHL in the elevated temperature may because of degradation as these signal molecules are quite sensitive and prone to get degraded under different physical factors. This result provides the rationale behind the highest disease severity up to certain elevated temperature and leaves opportunities for investigation on mutation, co-evolution of superior plant pathogen with more stable HSL signals-mediated pathogenesis under global warming context.

  10. Does insect netting affect the containment of airborne pollen from (GM-) plants in greenhouses?

    PubMed

    van Hengstum, Thomas; Hooftman, Danny A P; den Nijs, Hans C M; van Tienderen, Peter H

    2012-09-01

    Greenhouses are a well-accepted containment strategy to grow and study genetically modified plants (GM) before release into the environment. Various containment levels are requested by national regulations to minimize GM pollen escape. We tested the amount of pollen escaping from a standard greenhouse, which can be used for EU containment classes 1 and 2. More specifically, we investigated the hypothesis whether pollen escape could be minimized by insect-proof netting in front of the roof windows, since the turbulent airflow around the mesh wiring could avoid pollen from escaping. We studied the pollen flow out of greenhouses with and without insect netting of two non-transgenic crops, Ryegrass (Loliummultiflorum) and Corn (Zea Mays). Pollen flow was assessed with Rotorod(®) pollen samplers positioned inside and outside the greenhouse' roof windows. A significant proportion of airborne pollen inside the greenhouse leaves through roof windows. Moreover, the lighter pollen of Lolium escaped more readily than the heavier pollen of Maize. In contrast to our expectations, we did not identify any reduction in pollen flow with insect netting in front of open windows, even under induced airflow conditions. We conclude that insect netting, often present by default in greenhouses, is not effective in preventing pollen escape from greenhouses of wind-pollinated plants for containment classes 1 or 2. Further research would be needed to investigate whether other alternative strategies, including biotic ones, are more effective. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s10453-011-9237-8) contains supplementary material, which is available to authorized users.

  11. Accumulation of N-Acetylglucosamine Oligomers in the Plant Cell Wall Affects Plant Architecture in a Dose-Dependent and Conditional Manner1[W][OPEN

    PubMed Central

    Vanholme, Bartel; Vanholme, Ruben; Turumtay, Halbay; Goeminne, Geert; Cesarino, Igor; Goubet, Florence; Morreel, Kris; Rencoret, Jorge; Bulone, Vincent; Hooijmaijers, Cortwa; De Rycke, Riet; Gheysen, Godelieve; Ralph, John; De Block, Marc; Meulewaeter, Frank; Boerjan, Wout

    2014-01-01

    To study the effect of short N-acetylglucosamine (GlcNAc) oligosaccharides on the physiology of plants, N-ACETYLGLUCOSAMINYLTRANSFERASE (NodC) of Azorhizobium caulinodans was expressed in Arabidopsis (Arabidopsis thaliana). The corresponding enzyme catalyzes the polymerization of GlcNAc and, accordingly, β-1,4-GlcNAc oligomers accumulated in the plant. A phenotype characterized by difficulties in developing an inflorescence stem was visible when plants were grown for several weeks under short-day conditions before transfer to long-day conditions. In addition, a positive correlation between the oligomer concentration and the penetrance of the phenotype was demonstrated. Although NodC overexpression lines produced less cell wall compared with wild-type plants under nonpermissive conditions, no indications were found for changes in the amount of the major cell wall polymers. The effect on the cell wall was reflected at the transcriptome level. In addition to genes encoding cell wall-modifying enzymes, a whole set of genes encoding membrane-coupled receptor-like kinases were differentially expressed upon GlcNAc accumulation, many of which encoded proteins with an extracellular Domain of Unknown Function26. Although stress-related genes were also differentially expressed, the observed response differed from that of a classical chitin response. This is in line with the fact that the produced chitin oligomers were too small to activate the chitin receptor-mediated signal cascade. Based on our observations, we propose a model in which the oligosaccharides modify the architecture of the cell wall by acting as competitors in carbohydrate-carbohydrate or carbohydrate-protein interactions, thereby affecting noncovalent interactions in the cell wall or at the interface between the cell wall and the plasma membrane. PMID:24664205

  12. Accumulation of N-acetylglucosamine oligomers in the plant cell wall affects plant architecture in a dose-dependent and conditional manner.

    PubMed

    Vanholme, Bartel; Vanholme, Ruben; Turumtay, Halbay; Goeminne, Geert; Cesarino, Igor; Goubet, Florence; Morreel, Kris; Rencoret, Jorge; Bulone, Vincent; Hooijmaijers, Cortwa; De Rycke, Riet; Gheysen, Godelieve; Ralph, John; De Block, Marc; Meulewaeter, Frank; Boerjan, Wout

    2014-05-01

    To study the effect of short N-acetylglucosamine (GlcNAc) oligosaccharides on the physiology of plants, N-ACETYLGLUCOSAMINYLTRANSFERASE (NodC) of Azorhizobium caulinodans was expressed in Arabidopsis (Arabidopsis thaliana). The corresponding enzyme catalyzes the polymerization of GlcNAc and, accordingly, β-1,4-GlcNAc oligomers accumulated in the plant. A phenotype characterized by difficulties in developing an inflorescence stem was visible when plants were grown for several weeks under short-day conditions before transfer to long-day conditions. In addition, a positive correlation between the oligomer concentration and the penetrance of the phenotype was demonstrated. Although NodC overexpression lines produced less cell wall compared with wild-type plants under nonpermissive conditions, no indications were found for changes in the amount of the major cell wall polymers. The effect on the cell wall was reflected at the transcriptome level. In addition to genes encoding cell wall-modifying enzymes, a whole set of genes encoding membrane-coupled receptor-like kinases were differentially expressed upon GlcNAc accumulation, many of which encoded proteins with an extracellular Domain of Unknown Function26. Although stress-related genes were also differentially expressed, the observed response differed from that of a classical chitin response. This is in line with the fact that the produced chitin oligomers were too small to activate the chitin receptor-mediated signal cascade. Based on our observations, we propose a model in which the oligosaccharides modify the architecture of the cell wall by acting as competitors in carbohydrate-carbohydrate or carbohydrate-protein interactions, thereby affecting noncovalent interactions in the cell wall or at the interface between the cell wall and the plasma membrane.

  13. Adverse reactions to cosmetics.

    PubMed

    Gendler, E

    1987-06-01

    Adverse reactions to cosmetics can be irritant or allergic and are most often caused by fragrances or preservatives. Preservatives include formaldehyde, formaldehyde releasers, and parabens. Other agents that cause allergy are paraphenylenediamine in hair dyes and toluene sulfonamide formaldehyde resin in nail polishes.

  14. Scientists Trace Adversity's Toll

    ERIC Educational Resources Information Center

    Sparks, Sarah D.

    2012-01-01

    The stress of a spelling bee or a challenging science project can enhance a student's focus and promote learning. But the stress of a dysfunctional or unstable home life can poison a child's cognitive ability for a lifetime, according to new research. Those studies show that stress forms the link between childhood adversity and poor academic…

  15. Endogenous levels of polyamines in the organs of cucumber plant (Cucumis sativus) and factors affecting leaf polyamine contents.

    PubMed

    Fujihara, Shinsuke; Yoneyama, Tadakatsu

    2001-11-01

    Polyamine compositions of various organs from hydroponically cultivated cucumber plants (Cucumis sativus L. cv. Sharp-1) and factors affecting the leaf polyamine content were examined. Diamine putrescine was found most abundantly in the root, while a relatively large amount of spermine was detected in the reproductive organs such as the immature fruit and the calyx (+stamen). Spermidine was present at the highest level in rapidly growing tissues such as newly expanded leaf and fruit at an early developing stage, implying the possible involvement of spermidine in the growth and development of these young tissues. Polyamine content of cucumber leaves changed during the day. Especially, the putrescine content of upper leaves showed a striking decrease from the morning to the night. Alterations of leaf Ca or Mg content did not significantly affect leaf polyamine composition. On the other hand, abnormal cucumber leaves showed altered polyamine composition. Yellowing of the leaf intervein resulted in a striking decrease in spermidine content without a significant change in putrescine and spermine content. By contrast, the leaves infected with the phytopathogen, powdery mildew, showed decreased putrescine and increased spermine content in response to the degree of fungi infection. The possible usefulness of polyamines as a diagnostic marker of plant development and physiological disorder is discussed. PMID:12060288

  16. How meristem plasticity in response to soil nutrients and light affects plant growth in four Festuca grass species.

    PubMed

    Sugiyama, Shu-ichi; Gotoh, Minako

    2010-02-01

    Investigation of responses of meristems to environmental conditions is important for understanding the mechanisms and consequences of plant phenotypic plasticity. Here, we examined how meristem plasticity to light and soil nutrients affected leaf growth and relative growth rate (RGR) in fast- and slow-growing Festuca grass species. Activity in shoot apical meristems was measured by leaf appearance rate, and that in leaf meristems by the duration and rate of cell production, which was further divided into single cell cycle time and the number of dividing cells. Light and soil nutrients affected activity in shoot apical meristems similarly. The high nutrient supply increased the number of dividing cells, which was responsible for enhancement of cell production rate; shaded conditions extended the duration of cell production. As a result, leaf length increased under high nutrient and shaded conditions. The RGR was correlated positively with the total meristem size of the shoot under a low nutrient supply, implying inhibition of RGR by cell production under nutrient-limited conditions. Fast-growing species were more plastic for cell production rate and specific leaf area (SLA) but less plastic for RGR than slow-growing species. This study demonstrates that meristem plasticity plays key roles in characterizing environmental responses of plant species.

  17. Climate Shifts and Plant-Community Transformations Affect Nitrogen Cycling in Semi-Arid Rangelands

    NASA Astrophysics Data System (ADS)

    Huber, D. P.; Hardenbrook, S.; Lohse, K. A.; Germino, M. J.; Reinhardt, K.

    2011-12-01

    Semi-arid rangelands are being impacted by climate shifts and plant-community transformations. However, little is known about how these ecosystems will respond to long-term changes in amount and seasonality of precipitation, or how shifts in vegetation modulate the response of plant-soil processes. Semi-arid rangelands are typically characterized by resource islands (perennial shrubs) and contrasting "interplant" (IP) spaces or patch types which may increase the complexity of ecosystem response to climate change. We used an established long-term ecohydrologic experiment (Est. 1993) located in southeastern Idaho to evaluate ecosystem response to changing precipitation seasonality and magnitude. The experiment consists of 3 replicated blocks of 2 vegetation types (a diverse sagebrush steppe assemblage or monoculture of exotic crested wheatgrass, CWG) and 3 irrigation treatments. We hypothesized that increased precipitation will enhance storage of soil organic matter (SOM) due to greater detrital inputs. Rates of nitrogen (N) mineralization and decomposition were also expected to increase relative to ambient treatments. Additionally, we expected that change from native sagebrush to CWG would reduce N availability due to differences in detrital C:N ratios and biomass partitioning. Preliminary results show increased precipitation enhanced carbon pools in native vegetation plots, with SOM in ambient, fall/spring, and summer precipitation treatments of 2.27, 2.73, and 2.71% respectively, and average plot cover of 29, 48, and 40% respectively. Under shrubs, available N increased with increased precipitation (3.5, 4.6, and 5.6 μg-N g-1 soil) although N-cycling rates remained constant. Conversely, IP patches experienced a steady increase in both net N mineralization and nitrification between ambient, fall/spring, and summer precipitation treatments. The IP patches experienced lower absolute values but similar trends in SOM and available N. Crested wheatgrass plots showed

  18. From facilitation to competition: temperature-driven shift in dominant plant interactions affects population dynamics in seminatural grasslands.

    PubMed

    Olsen, Siri L; Töpper, Joachim P; Skarpaas, Olav; Vandvik, Vigdis; Klanderud, Kari

    2016-05-01

    Biotic interactions are often ignored in assessments of climate change impacts. However, climate-related changes in species interactions, often mediated through increased dominance of certain species or functional groups, may have important implications for how species respond to climate warming and altered precipitation patterns. We examined how a dominant plant functional group affected the population dynamics of four co-occurring forb species by experimentally removing graminoids in seminatural grasslands. Specifically, we explored how the interaction between dominants and subordinates varied with climate by replicating the removal experiment across a climate grid consisting of 12 field sites spanning broad-scale temperature and precipitation gradients in southern Norway. Biotic interactions affected population growth rates of all study species, and the net outcome of interactions between dominants and subordinates switched from facilitation to competition with increasing temperature along the temperature gradient. The impacts of competitive interactions on subordinates in the warmer sites could primarily be attributed to reduced plant survival. Whereas the response to dominant removal varied with temperature, there was no overall effect of precipitation on the balance between competition and facilitation. Our findings suggest that global warming may increase the relative importance of competitive interactions in seminatural grasslands across a wide range of precipitation levels, thereby favouring highly competitive dominant species over subordinate species. As a result, seminatural grasslands may become increasingly dependent on disturbance (i.e. traditional management such as grazing and mowing) to maintain viable populations of subordinate species and thereby biodiversity under future climates. Our study highlights the importance of population-level studies replicated under different climatic conditions for understanding the underlying mechanisms of climate

  19. The Ecohydrological Consequences of Woody Plant Encroachment: How Accessibility to Deep Soil Water Resources Affects Ecosystem Carbon and Water Exchange

    NASA Astrophysics Data System (ADS)

    Scott, R. L.; Huxman, T. E.; Barron-Gafford, G.; Jenerette, D.; Young, J. M.

    2013-12-01

    Woody plant encroachment into grassland systems, a process that has increased rapidly over the last century, has potentially broad ecohydrological consequences by affecting the way ecosystems use water and cycle carbon. This study examines the influence of precipitation- and groundwater-derived water availability by comparing eddy covariance measurements of water vapor and carbon dioxide fluxes over a riparian grassland, shrubland, and woodland, and an upland grassland site in southeastern Arizona USA. Compared to the upland grassland, the riparian sites exhibited greater net carbon uptake (NEP) and higher evapotranspiration (ET) across a longer portion of the year. Among the riparian sites, however, the grassland was less able to take advantage of the stable groundwater supply. Increasing woody plant density facilitated greater water and carbon exchange that became increasingly decoupled from incident precipitation (P). How groundwater accessibility affected NEP was more complex than ET. Respiration (Reco) costs were higher for the riparian grassland so, while it had a similar ET and gross carbon uptake (GEP) to the shrubland, its NEP was substantially less. Also, riparian grassland fluxes were much more variable due to flooding that occurred at the site, which could stimulate or inhibit NEP. Woodland NEP was largest but surprisingly similar to the less mature and dense shrubland even while having much greater GEP. Woodland NEP responded negatively to P, due to the stimulation of Reco likely due to greater amounts of aboveground and soil carbon. With many areas of the world experiencing woody plants encroachment, encroachment into areas where there are additional deep soil water sources, such as in riparian settings or in areas of deep soil moisture recharge, will likely increase carbon sequestration but at the expense of higher water use.

  20. Seasonal timing of first rain storms affects rare plant population dynamics

    USGS Publications Warehouse

    Levine, J.M.; McEachern, A.K.; Cowan, C.

    2011-01-01

    A major challenge in forecasting the ecological consequences of climate change is understanding the relative importance of changes to mean conditions vs. changes to discrete climatic events, such as storms, frosts, or droughts. Here we show that the first major storm of the growing season strongly influences the population dynamics of three rare and endangered annual plant species in a coastal California (USA) ecosystem. In a field experiment we used moisture barriers and water addition to manipulate the timing and temperature associated with first major rains of the season. The three focal species showed two- to fivefold variation in per capita population growth rates between the different storm treatments, comparable to variation found in a prior experiment imposing eightfold differences in season-long precipitation. Variation in germination was a major demographic driver of how two of three species responded to the first rains. For one of these species, the timing of the storm was the most critical determinant of its germination, while the other showed enhanced germination with colder storm temperatures. The role of temperature was further supported by laboratory trials showing enhanced germination in cooler treatments. Our work suggests that, because of species-specific cues for demographic transitions such as germination, changes to discrete climate events may be as, if not more, important than changes to season-long variables.

  1. Ectopic KNOX Expression Affects Plant Development by Altering Tissue Cell Polarity and Identity[OPEN

    PubMed Central

    Rebocho, Alexandra B.

    2016-01-01

    Plant development involves two polarity types: tissue cell (asymmetries within cells are coordinated across tissues) and regional (identities vary spatially across tissues) polarity. Both appear altered in the barley (Hordeum vulgare) Hooded mutant, in which ectopic expression of the KNOTTED1-like Homeobox (KNOX) gene, BKn3, causes inverted polarity of differentiated hairs and ectopic flowers, in addition to wing-shaped outgrowths. These lemma-specific effects allow the spatiotemporal analysis of events following ectopic BKn3 expression, determining the relationship between KNOXs, polarity, and shape. We show that tissue cell polarity, based on localization of the auxin transporter SISTER OF PINFORMED1 (SoPIN1), dynamically reorients as ectopic BKn3 expression increases. Concurrently, ectopic expression of the auxin importer LIKE AUX1 and boundary gene NO APICAL MERISTEM is activated. The polarity of hairs reflects SoPIN1 patterns, suggesting that tissue cell polarity underpins oriented cell differentiation. Wing cell files reveal an anisotropic growth pattern, and computational modeling shows how polarity guiding growth can account for this pattern and wing emergence. The inverted ectopic flower orientation does not correlate with SoPIN1, suggesting that this form of regional polarity is not controlled by tissue cell polarity. Overall, the results suggest that KNOXs trigger different morphogenetic effects through interplay between tissue cell polarity, identity, and growth. PMID:27553356

  2. Factors affecting the uptake of 14C-labeled organic chemicals by plants from soil

    SciTech Connect

    Topp, E.; Scheunert, I.; Attar, A.; Korte, F.

    1986-04-01

    The uptake of /sup 14/C from various /sup 14/C-labeled organic chemicals from different chemical classes by barley and cress seedlings from soil was studied for 7 days in a closed aerated laboratory apparatus. Uptake by roots and by leaves via the air was determined separately. Although comparative long-term outdoor studies showed that an equilibrium is not reached within a short time period, plant concentration factors after 7 days could be correlated to some physicochemical and structural substance properties. Barley root concentration factors due to root uptake, expressed as concentration in roots divided by concentration in soil, gave a fairly good negative correlation to adsorption coefficients based on soil organic carbon. Barley root concentration factors, expressed as concentration in roots divided by concentration in soil liquid, gave a positive correlation to the n-octanol/water partition coefficients. Uptake of chemicals by barley leaves via air was strongly positively correlated to volatilization of chemicals from soil. Both root and foliar uptake by barley could be correlated well to the molecular weight of 14 chemicals. Uptake of chemicals by cress differed from that by barley, and correlations to physicochemical substance properties mostly were poor.

  3. Plant essential oils affect the toxicities of carbaryl and permethrin against Aedes aegypti (Diptera: Culicidae).

    PubMed

    Tong, Fan; Bloomquist, Jeffrey R

    2013-07-01

    ABSTRACT Phytochemicals have been considered as alternatives for conventional pesticides because of their low mammalian toxicity and environmental safety. They usually display less potent insecticidal effects than synthetic compounds, but may express as yet unknown modes of action. In the current study, we evaluated 14 plant essential oils for their toxicities and synergistic effects with carbaryl and permethrin against fourth instars of Aedes aegypti (L.) as well as 5-7-d-old adults. Six essential oils showed significant synergistic effects with carbaryl at 10-50 mg/liter, but paradoxically all of them decreased the toxicity of permethrin against Ae. aegypti larvae. None showed toxicity or synergistic effects on Ae. aegypti adults, at doses up to 2,000 ng/ insect. The six essential oils displaying synergistic effects in Ae. aegypti larvae inhibited the in vitro activities of cytochrome P450 monooxygenases and carboxylesterases in the low milligram per liter range. The data indicated that cytochrome P450 monooxygenases and carboxylesterase were probably targets for these natural synergists. Thus, the mechanism of synergism was most likely inhibition of metabolism and not interacting target site effects. PMID:23926781

  4. Occurrence and transport of pharmaceuticals in a karst groundwater system affected by domestic wastewater treatment plants.

    PubMed

    Einsiedl, Florian; Radke, Michael; Maloszewski, Piotr

    2010-09-20

    The occurrence of two pharmaceuticals, ibuprofen and diclofenac, in a vulnerable karst groundwater system was investigated. The hydrogeology of the karst system was identified by collecting (3)H samples in groundwater over 27years and by performing tracer tests. The isotopes and tracer data were interpreted by mathematical modeling to estimate the mean transit time of water and to characterize the hydrogeological flow paths in the groundwater system. By this approach, a mean (3)H transit time of 4.6 years for the fissured-porous karst aquifer was determined, whereas the fast flowing water in the conduit system showed a mean transit time of days. Both pharmaceuticals which infiltrated along sinkholes and small streams into the karst system were detected in concentrations of up to approximately 1 microg/L in effluent water of the wastewater treatment plants. Diclofenac was present in most samples collected from four springs discharging the karst groundwater to the rivers Altmühl and Anlauter in concentrations between 3.6 and 15.4 ng/L. In contrast, ibuprofen was rarely detected in groundwater. The results of this study suggest that both pharmaceuticals move into the fractured system of the karst system and go into storage. Thus dilution processes are the dominant control on the concentrations of both pharmaceuticals in the fractured system, whereas biodegradation is likely less important.

  5. Whole Genome Duplication Affects Evolvability of Flowering Time in an Autotetraploid Plant

    PubMed Central

    Martin, Sara L.; Husband, Brian C.

    2012-01-01

    Whole genome duplications have occurred recurrently throughout the evolutionary history of eukaryotes. The resulting genetic and phenotypic changes can influence physiological and ecological responses to the environment; however, the impact of genome copy number on evolvability has rarely been examined experimentally. Here, we evaluate the effect of genome duplication on the ability to respond to selection for early flowering time in lines drawn from naturally occurring diploid and autotetraploid populations of the plant Chamerion angustifolium (fireweed). We contrast this with the result of four generations of selection on synthesized neoautotetraploids, whose genic variability is similar to diploids but genome copy number is similar to autotetraploids. In addition, we examine correlated responses to selection in all three groups. Diploid and both extant tetraploid and neoautotetraploid lines responded to selection with significant reductions in time to flowering. Evolvability, measured as realized heritability, was significantly lower in extant tetraploids ( = 0.31) than diploids ( = 0.40). Neotetraploids exhibited the highest evolutionary response ( = 0.55). The rapid shift in flowering time in neotetraploids was associated with an increase in phenotypic variability across generations, but not with change in genome size or phenotypic correlations among traits. Our results suggest that whole genome duplications, without hybridization, may initially alter evolutionary rate, and that the dynamic nature of neoautopolyploids may contribute to the prevalence of polyploidy throughout eukaryotes. PMID:23028620

  6. Whole genome duplication affects evolvability of flowering time in an autotetraploid plant.

    PubMed

    Martin, Sara L; Husband, Brian C

    2012-01-01

    Whole genome duplications have occurred recurrently throughout the evolutionary history of eukaryotes. The resulting genetic and phenotypic changes can influence physiological and ecological responses to the environment; however, the impact of genome copy number on evolvability has rarely been examined experimentally. Here, we evaluate the effect of genome duplication on the ability to respond to selection for early flowering time in lines drawn from naturally occurring diploid and autotetraploid populations of the plant Chamerion angustifolium (fireweed). We contrast this with the result of four generations of selection on synthesized neoautotetraploids, whose genic variability is similar to diploids but genome copy number is similar to autotetraploids. In addition, we examine correlated responses to selection in all three groups. Diploid and both extant tetraploid and neoautotetraploid lines responded to selection with significant reductions in time to flowering. Evolvability, measured as realized heritability, was significantly lower in extant tetraploids (^b(T) =  0.31) than diploids (^b(T) =  0.40). Neotetraploids exhibited the highest evolutionary response (^b(T)  =  0.55). The rapid shift in flowering time in neotetraploids was associated with an increase in phenotypic variability across generations, but not with change in genome size or phenotypic correlations among traits. Our results suggest that whole genome duplications, without hybridization, may initially alter evolutionary rate, and that the dynamic nature of neoautopolyploids may contribute to the prevalence of polyploidy throughout eukaryotes. PMID:23028620

  7. High root temperature affects the tolerance to high light intensity in Spathiphyllum plants.

    PubMed

    Soto, Adriana; Hernández, Laura; Quiles, María José

    2014-10-01

    Spathiphyllum wallisii plants were sensitive to temperature stress under high illumination, although the susceptibility of leaves to stress may be modified by root temperature. Leaves showed higher tolerance to high illumination, in both cold and heat conditions, when the roots were cooled, probably because the chloroplast were protected by excess excitation energy dissipation mechanisms such as cyclic electron transport. When the roots were cooled both the activity of electron donation by NADPH and ferredoxin to plastoquinone and the amount of PGR5 polypeptide, an essential component of cyclic electron flow around PSI, increased. However, when the stems were heated or cooled under high illumination, but the roots were heated, the quantum yield of PSII decreased considerably and neither the electron donation activity by NADPH and ferredoxin to plastoquinone nor the amount of PGR5 polypeptide increased. In such conditions, the cyclic electron flow cannot be enhanced by high light and PSII is damaged as a result of insufficient dissipation of excess light energy. Additionally, the damage to PSII induced the increase in both chlororespiratory enzymes, NDH complex and PTOX.

  8. Occurrence and transport of pharmaceuticals in a karst groundwater system affected by domestic wastewater treatment plants

    NASA Astrophysics Data System (ADS)

    Einsiedl, Florian; Radke, Michael; Maloszewski, Piotr

    2010-09-01

    The occurrence of two pharmaceuticals, ibuprofen and diclofenac, in a vulnerable karst groundwater system was investigated. The hydrogeology of the karst system was identified by collecting 3H samples in groundwater over 27 years and by performing tracer tests. The isotopes and tracer data were interpreted by mathematical modeling to estimate the mean transit time of water and to characterize the hydrogeological flow paths in the groundwater system. By this approach, a mean 3H transit time of 4.6 years for the fissured-porous karst aquifer was determined, whereas the fast flowing water in the conduit system showed a mean transit time of days. Both pharmaceuticals which infiltrated along sinkholes and small streams into the karst system were detected in concentrations of up to approximately 1 μg/L in effluent water of the wastewater treatment plants. Diclofenac was present in most samples collected from four springs discharging the karst groundwater to the rivers Altmühl and Anlauter in concentrations between 3.6 and 15.4 ng/L. In contrast, ibuprofen was rarely detected in groundwater. The results of this study suggest that both pharmaceuticals move into the fractured system of the karst system and go into storage. Thus dilution processes are the dominant control on the concentrations of both pharmaceuticals in the fractured system, whereas biodegradation is likely less important.

  9. Solubility, mobility and plant uptake of toxic elements in retorted oil shales as affected by recarbonation

    SciTech Connect

    Reddy, K.J.

    1986-01-01

    The primary objective of this study was to develop a method of lowering the alkalinity of retorted shales and of reducing the solubility of toxic elements. The solubility relationships and mineral transformations associated with recarbonation of retorted shales were evaluated by determining the solubilities of different elements and by using X-ray diffraction analysis. An accurate method of measuring carbonate activity in shale extracts was developed. This method consisted of acidifying shale extracts with concentrated HCI. The evolved CO/sub 2/(g) was trapped in NaOH and titrated to pH 8.5. A computer speciation model was developed to calculate the equilibrium activities of different ions and the CO/sub 2/(g) partial pressure. Recarbonation dissolved silicates, restored the carbonate deficit, and lowered pH to near 8.5 when equilibrium with CaCO/sub 3/ and CO/sub 2/(g) partial pressure of approximately 10/sup -4.65/ atm. was attained. Furthermore, recarbonation decreased the solubilities of F, Ba, Cr, Sr, and Mo and lowered their concentrations in shale leachates, showing that recarbonation of spent shales can retard the movement of toxic elements into the groundwater. Tall wheatgrass (Agropyron elongatum) seeds placed in Lurgi shale without soil cover failed to germinate. On recarbonated Lurgi shale, plants grew normally without soil cover and accumulated normal levels of As, Se, Ba, B, Cu, Cd, Sr, and Ti. The results suggest that recarbonated retorted shales can be revegetated directly without a soil cover

  10. Factors affecting population of filamentous bacteria in wastewater treatment plants with nutrients removal.

    PubMed

    Miłobędzka, Aleksandra; Witeska, Anna; Muszyński, Adam

    2016-01-01

    Filamentous population in activated sludge and key operational parameters of full-scale municipal wastewater treatment plants (WWTPs) with bulking problems representative for Poland were investigated with quantitative fluorescence in situ hybridization. Statistical analyses revealed few relationships between operational parameters and biovolume of filamentous bacteria. Sludge age was not only positively correlated with abundance of Chloroflexi (parametric correlation and principal component analysis (PCA)), but also differentiated Microthrix population (analysis of variance (ANOVA)). Phylum Chloroflexi and pH presented a negative relation during the study (PCA). ANOVA showed that pH of influent and sludge volume index (SVI) differentiated abundance of types 0803 and 1851 of Chloroflexi and candidate division TM7. SVI increased along with higher abundance of Microthrix (positive parametric and non-parametric correlations and positive relation in PCA). Biovolumes of morphotypes 0803 and 1851 of Chloroflexi were differentiated by organic matter in influent, also by nutrients in the case of Chloroflexi type 1851. Chemical and biological oxygen demands (COD and BOD5, respectively) were negatively correlated with Microthrix. COD also differentiated the abundance of Haliscomenobacter hydrossis. Results of the study can be used to prevent WWTPs from excessive proliferation of filamentous bacteria and operational problems caused by them--bulking and foaming of activated sludge. PMID:26901721

  11. Factors affecting population of filamentous bacteria in wastewater treatment plants with nutrients removal.

    PubMed

    Miłobędzka, Aleksandra; Witeska, Anna; Muszyński, Adam

    2016-01-01

    Filamentous population in activated sludge and key operational parameters of full-scale municipal wastewater treatment plants (WWTPs) with bulking problems representative for Poland were investigated with quantitative fluorescence in situ hybridization. Statistical analyses revealed few relationships between operational parameters and biovolume of filamentous bacteria. Sludge age was not only positively correlated with abundance of Chloroflexi (parametric correlation and principal component analysis (PCA)), but also differentiated Microthrix population (analysis of variance (ANOVA)). Phylum Chloroflexi and pH presented a negative relation during the study (PCA). ANOVA showed that pH of influent and sludge volume index (SVI) differentiated abundance of types 0803 and 1851 of Chloroflexi and candidate division TM7. SVI increased along with higher abundance of Microthrix (positive parametric and non-parametric correlations and positive relation in PCA). Biovolumes of morphotypes 0803 and 1851 of Chloroflexi were differentiated by organic matter in influent, also by nutrients in the case of Chloroflexi type 1851. Chemical and biological oxygen demands (COD and BOD5, respectively) were negatively correlated with Microthrix. COD also differentiated the abundance of Haliscomenobacter hydrossis. Results of the study can be used to prevent WWTPs from excessive proliferation of filamentous bacteria and operational problems caused by them--bulking and foaming of activated sludge.

  12. How does altered precipitation and annual grass invasion affect plant N uptake in a native semi-arid shrub community?

    NASA Astrophysics Data System (ADS)

    Mauritz, M.; Lipson, D.; Cleland, E. E.

    2012-12-01

    Climate change is expected to alter precipitation patterns, which will change the timing and amount of plant resources. Precipitation patterns determine water and nitrogen (N) availability, because water stimulates microbial N turnover and N transport. In order for plants to utilize water and N, they must coincide with the phenology and meet physiological requirements of the plant. As resource supply shifts, differences in species' ability to acquire resources will affect plant community composition. Semiarid ecosystems, such as shrublands in Southern California, are particularly sensitive to shifts in precipitation because they are severely water limited. This study takes advantage of the altered phenology and resource demands presented by invasive annual grasses in a native semiarid shrubland. The goal is to understand how altered precipitation patterns affect plant N uptake. Rainfall levels were manipulated to 50% and 150% of ambient levels. It is expected that higher rainfall levels promote annual grass invasion because grasses have higher water and N requirements and begin to grow earlier in the season than shrubs. A 15N tracer was added with the first rain event and plant samples were collected regularly to track the movement of N into the plants. Net soil N accumulation was determined using resin bags. Invasive grasses altered the timing and amount of N uptake but amount of rainfall had less effect on N distribution. 15N was detected sooner and at higher level in grasses than shrubs. 24hours after the first rain event 15N was detectable in grasses, 15N accumulated rapidly and peaked 2 months earlier than shrubs. Shrub 15N levels remained at pre-rain event levels for the first 2 months and began to increase at the beginning of spring, peak mid-spring and decline as the shrubs entered summer dormancy. One year later 15N levels in annual grass litter remained high, while 15N levels in shrubs returned to initial background levels as a result of resorption. 15N

  13. High expression of Lifeact in Arabidopsis thaliana reduces dynamic reorganization of actin filaments but does not affect plant development.

    PubMed

    van der Honing, Hannie S; van Bezouwen, Laura S; Emons, Anne Mie C; Ketelaar, Tijs

    2011-10-01

    Lifeact is a novel probe that labels actin filaments in a wide range of organisms. We compared the localization and reorganization of Lifeact:Venus-labeled actin filaments in Arabidopsis root hairs and root epidermal cells of lines that express different levels of Lifeact: Venus with that of actin filaments labeled with GFP:FABD2, a commonly used probe in plants. Unlike GFP:FABD2, Lifeact:Venus labeled the highly dynamic fine F-actin in the subapical region of tip-growing root hairs. Lifeact:Venus expression at varying levels was not observed to affect plant development. However, at expression levels comparable to those of GFP:FABD2 in a well-characterized marker line, Lifeact:Venus reduced reorganization rates of bundles of actin filaments in root epidermal cells. Reorganization rates of cytoplasmic strands, which reflect the reorganization of the actin cytoskeleton, were also reduced in these lines. Moreover, in the same line, Lifeact:Venus-decorated actin filaments were more resistant to depolymerization by latrunculin B than those in an equivalent GFP:FABD2-expressing line. In lines where Lifeact: Venus is expressed at lower levels, these effects are less prominent or even absent. We conclude that Lifeact: Venus reduces remodeling of the actin cytoskeleton in Arabidopsis in a concentration-dependent manner. Since this reduction occurs at expression levels that do not cause defects in plant development, selection of normally growing plants is not sufficient to determine optimal Lifeact expression levels. When correct expression levels of Lifeact have been determined, it is a valuable probe that labels dynamic populations of actin filaments such as fine F-actin, better than FABD2 does.

  14. Metabonomics classifies pathways affected by bioactive compounds. Artificial neural network classification of NMR spectra of plant extracts.

    PubMed

    Ott, Karl-Heinz; Araníbar, Nelly; Singh, Bijay; Stockton, Gerald W

    2003-03-01

    The biochemical mode-of-action (MOA) for herbicides and other bioactive compounds can be rapidly and simultaneously classified by automated pattern recognition of the metabonome that is embodied in the 1H NMR spectrum of a crude plant extract. The ca. 300 herbicides that are used in agriculture today affect less than 30 different biochemical pathways. In this report, 19 of the most interesting MOAs were automatically classified. Corn (Zea mays) plants were treated with various herbicides such as imazethapyr, glyphosate, sethoxydim, and diuron, which represent various biochemical modes-of-action such as inhibition of specific enzymes (acetohydroxy acid synthase [AHAS], protoporphyrin IX oxidase [PROTOX], 5-enolpyruvylshikimate-3-phosphate synthase [EPSPS], acetyl CoA carboxylase [ACC-ase], etc.), or protein complexes (photosystems I and II), or major biological process such as oxidative phosphorylation, auxin transport, microtubule growth, and mitosis. Crude isolates from the treated plants were subjected to 1H NMR spectroscopy, and the spectra were classified by artificial neural network analysis to discriminate the herbicide modes-of-action. We demonstrate the use and refinement of the method, and present cross-validated assignments for the metabolite NMR profiles of over 400 plant isolates. The MOA screen also recognizes when a new mode-of-action is present, which is considered extremely important for the herbicide discovery process, and can be used to study deviations in the metabolism of compounds from a chemical synthesis program. The combination of NMR metabolite profiling and neural network classification is expected to be similarly relevant to other metabonomic profiling applications, such as in drug discovery. PMID:12590124

  15. A locus in Drosophila sechellia affecting tolerance of a host plant toxin.

    PubMed

    Hungate, Eric A; Earley, Eric J; Boussy, Ian A; Turissini, David A; Ting, Chau-Ti; Moran, Jennifer R; Wu, Mao-Lien; Wu, Chung-I; Jones, Corbin D

    2013-11-01

    Many insects feed on only one or a few types of host. These host specialists often evolve a preference for chemical cues emanating from their host and develop mechanisms for circumventing their host's defenses. Adaptations like these are central to evolutionary biology, yet our understanding of their genetics remains incomplete. Drosophila sechellia, an emerging model for the genetics of host specialization, is an island endemic that has adapted to chemical toxins present in the fruit of its host plant, Morinda citrifolia. Its sibling species, D. simulans, and many other Drosophila species do not tolerate these toxins and avoid the fruit. Earlier work found a region with a strong effect on tolerance to the major toxin, octanoic acid, on chromosome arm 3R. Using a novel assay, we narrowed this region to a small span near the centromere containing 18 genes, including three odorant binding proteins. It has been hypothesized that the evolution of host specialization is facilitated by genetic linkage between alleles contributing to host preference and alleles contributing to host usage, such as tolerance to secondary compounds. We tested this hypothesis by measuring the effect of this tolerance locus on host preference behavior. Our data were inconsistent with the linkage hypothesis, as flies bearing this tolerance region showed no increase in preference for media containing M. citrifolia toxins, which D. sechellia prefers. Thus, in contrast to some models for host preference, preference and tolerance are not tightly linked at this locus nor is increased tolerance per se sufficient to change preference. Our data are consistent with the previously proposed model that the evolution of D. sechellia as a M. citrifolia specialist occurred through a stepwise loss of aversion and gain of tolerance to M. citrifolia's toxins.

  16. Gross vs. net income: How plant toughness affects performance of an insect herbivore.

    PubMed

    Clissold, Fiona J; Sanson, Gordon D; Read, Jenny; Simpson, Stephen J

    2009-12-01

    Leaf biomechanical properties are thought to impose a significant obstacle to herbivores and as such influence patterns of herbivory more than leaf chemistry. However, evidence for the role of structural traits in influencing herbivore food choice and performance has come from correlative studies, whereas the underlying mechanisms have been given little attention. By manipulating the biomechanical properties of a host grass species through a combination of lyophilization and milling, and providing water separately, we were able to compare behavioral, physiological, and developmental responses of the Australian plague locust, Chortoicetes terminifera, to the biomechanical properties of plant food (exemplified by toughness) independently of the food's macronutrient content and the insect's demand for water. Increasing leaf toughness was associated with reduced rates of locust growth and prolonged development, with potential ecological consequences. Poorer performance on the tougher foods was primarily a consequence of a reduced rate of nutrient supply, which occurred as a result of (1) smaller meals being eaten more slowly, (2) slowed gut passage rates, which limited how quickly the next meal could be taken, and (3) reduced efficiency of assimilation of nutrients from food in the gut. In addition, there were deleterious changes in the ratio of protein to carbohydrate assimilated from the gut. Prolonged development time was associated with increased total nutrient demands throughout the extended developmental period. Because these demands could not be met by increased consumption, there was a decreased efficiency of conversion of assimilated nutrients to growth. By disentangling the effects of biomechanical properties from macronutrient and water content we have shown that leaf biomechanical traits can influence chewing herbivores independently of leaf chemical traits.

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

    PubMed

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

    2012-02-15

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

  18. Changes of the soil environment affected by fly ash dumping site of the electric power plant

    NASA Astrophysics Data System (ADS)

    Weber, Jerzy; Gwizdz, Marta; Jamroz, Elzbieta; Debicka, Magdalena; Kocowicz, Andrzej

    2014-05-01

    In this study the effect of fly ash dumping site of the electric power plant on the surrounding soil environment was investigated. The fly ash dumping site collect wastes form brown coal combustion of Belchatow electric power station, central Poland. The dumping site is surrounding by forest, where pine trees overgrow Podzols derived from loose quartz sands. The soil profiles under study were located at a distance of 50, 100, 400 and 500 m from the dumping site, while control profiles were located 8 km away from the landfill. In all horizons of soil profiles the mpain hysico-chemical and chemical properties were determined. The humic substances were extracted from ectohumus horizons by Shnitzer's method, purified using XAD resin and freeze-dried. The fulvic acids were passed through a cation exchange column and freeze-dried. Optical density, elemental composition and atomic ratios were determined in the humic and fulvic acids. Organic carbon by KMnO4 oxidation was also determined in the organic soil horizons. The fly ash from the landfill characterized by high salinity and strong alkaline reaction (pH=10), which contributed significantly to the changes of the pH values in soils horizons. The alkalization of soils adjacent to the landfill was found, which manifested in increasing of pH values in the upper soil horizons. The impact of the landfill was also noted in the changes of the soil morphology of Podzols analysed. As a result of the alkalization, Bhs horizons have been converted into a Bs horizons. Leaching of low molecular humus fraction - typical for podzolization - has been minimized as a result of pH changes caused by the impact of the landfill, and originally occurring humic substances in the Bhs horizon (present in the control profiles) have been probably transported out of the soil profile and then into the groundwater.

  19. Model of the biotic cycle "plants germs - microorganisms" by affect heavy metal salts

    NASA Astrophysics Data System (ADS)

    Pisman, Tamara

    The growth of wheat germ roots exposed to heavy metal salts (ZnSO4) was studied experimentally and theoretically. During the experiment the plant seeds were preliminarily treated with an experimental microbial association. As a result, data were obtained about the decrease of the inhibiting effect of zinc on the growth of wheat germ roots where the seeds had been treated with the microbial association. To understand such effect, calculations were made to reveal the specific growth rate of a germ root depending on the inhibitor concentration with and without microorganism association treatment. It was shown that in case with the wheat germ roots the seeds of which had been treated with the microorganisms the inhibition constant (kI = 45 MPC (Maximum Permissible Concentration) was higher than in the case with the roots growing out of the seeds that hadn't been treated with the microorganisms (kI = 32 MPC). One of possible reasons for the decrease of growth inhibition of wheat germ roots by zinc salt is the protective function of microorganism's treatment of the seeds. To verify and confirm the experimental results, a mathematical model was created imitating the interaction between wheat germ roots and microbial association exposed to an inhibitor. Investigation of the model proved that the microbial association has a positive effect on the growth of wheat germ roots exposed to an inhibitor. The experimental and theoretical results agreed quantitatively. It was found out that the increase of the inhibitor concentration led to the effect of maximum relief of zinc inhibiting impact. The work is supported by grants Yenissei 07-04-96806.

  20. Plant Proteins Differently Affect Body Fat Reduction in High-fat Fed Rats.

    PubMed

    Kim, Joohee; Lee, Hyo Jung; Kim, Ji Yeon; Kim, Mi Kyung; Kwon, Oran

    2012-09-01

    This study examined the effects of corn gluten (CG), wheat gluten (WG), and soybean protein isolate (SPI), as well as their hydrolysates, on weight reduction in rats fed a high-fat diet. Eight-month-old male Sprague-Dawley rats (n=70) were fed a high-fat diet (40% of the calories were fat) for 4 weeks. Rats were then randomly divided into seven groups and were fed isocaloric diets with different protein sources for 8 weeks. The protein sources were casein (control group), intact CG (CG group), CG hydrolysate (CGH group), intact WG (WG group), WG hydrolysate (WGH group), intact SPI (SPI group), and SPI hydrolysate (SPIH group). Body weight gain, adipose tissue weights, lipid profiles in plasma and liver; and hepatic activities of carnitine palmitoyl transferase, fatty acid synthase (FAS), malic enzyme, and glucose-6-phosphate dehydrogenase were assessed. The CGH group showed significant weight reduction compared with the other groups. Epididymal fat pad and plasma triglycerides in the CGH group were the lowest and were significantly different than those in the control group. FAS activity in the CGH group was significantly lower than that in the other groups. In conclusion, the CGH diet of these experimental animals demonstrated a weight-reducing effect by lowering the adipose tissue weight and by affecting the activities of hepatic lipogenic enzymes.

  1. Factors affecting choice of plant species for revegetation on the Hanford Site

    SciTech Connect

    Fuchs, M.R.; Cox, G.R.

    1983-04-01

    This study was conducted to evaluate three sites with vegetative communities whose dominant perennial grass species were Siberian wheatgrass-thickspike wheatgrass (Agropyron sibiricum-Agropyron dasytachyum), Indian ricegrass (Oryzopsis hymenoides), and Sandberg's bluegrass (Poa sandbergii), respectively. The principal objectives of the study were to determine the following: whether soil conditions influenced the establishment of these stands; the extent of these perennial grass species as members of the vegetation community on the Hanford Site prior to human influences, e.g., animal grazing, fire, construction, and excavation; and whether these perennial grasses could be established on other sites to be stabilized. The information obtained from this study has resulted in the following conclusions and recommendations: The depth of the soil to coarse sediments, the soil texture, and the percentage of gravel in the soil appear to affect the vegetation community on a site. It is recommended that Siberian, thickspike, and crested wheatgrass (Agropyron cristatum) be utilized for revegetation purposes on deep fine-textured soils of low gravel content. It is recommended that for revegetation purposes on shallow, coarse-textured or high gravel content soils, Indian ricegrass, needle and thread grass (Stipa comata), Sandberg's bluegrass, and sand dropseed (Sporobolus cryptandrus) be utilized. Greater success in stabilization/revegetation programs will be achieved if deep, fine-textured soils are utilized.

  2. Do non-native plant species affect the shape of productivity-diversity relationships?

    USGS Publications Warehouse

    Drake, J.M.; Cleland, E.E.; Horner-Devine, M. C.; Fleishman, E.; Bowles, C.; Smith, M.D.; Carney, K.; Emery, S.; Gramling, J.; Vandermast, D.B.; Grace, J.B.

    2008-01-01

    The relationship between ecosystem processes and species richness is an active area of research and speculation. Both theoretical and experimental studies have been conducted in numerous ecosystems. One finding of these studies is that the shape of the relationship between productivity and species richness varies considerably among ecosystems and at different spatial scales, though little is known about the relative importance of physical and biological mechanisms causing this variation. Moreover, despite widespread concern about changes in species' global distributions, it remains unclear if and how such large-scale changes may affect this relationship. We present a new conceptual model of how invasive species might modulate relationships between primary production and species richness. We tested this model using long-term data on relationships between aboveground net primary production and species richness in six North American terrestrial ecosystems. We show that primary production and abundance of non-native species are both significant predictors of species richness, though we fail to detect effects of invasion extent on the shapes of the relationship between species richness and primary production.

  3. Increased nitrogen deposition did not affect the composition and turnover of plant and microbial biomarkers in forest soil density fractions

    NASA Astrophysics Data System (ADS)

    Griepentrog, Marco; Bodé, Samuel; Boeckx, Pascal; Hagedorn, Frank; Wiesenberg, Guido L. B.; Schmidt, Michael W. I.

    2013-04-01

    Increased atmospheric nitrogen (N) deposition and elevated CO2 concentrations affect many forests and their ecosystem functions, including organic matter cycling in soils, the largest carbon pool of terrestrial ecosystems. However, it is still not clear how, and what the underlying mechanisms are. Specific molecules of plant and microbial origin (biomarkers) might respond differently to N deposition, depending on their internal N content. Microbial cell-wall-constituents with high-N content like amino sugars are reliable biomarkers to distinguish between fungal- and bacterial-derived organic residues. Individual lipids are plant-specific biomarkers that lack N in their molecular structure. Here, we tested the effects of elevated CO2 and increased N deposition on the dynamics of plant and microbial biomarkers by studying their composition and turnover in forest soil density fractions. Furthermore, we tested the hypothesis that these biomarkers respond differently to increased N deposition, depending on their internal N content. We used soil samples from a 4-year elevated CO2 and N deposition experiment in model forest ecosystems (open-top chambers), that were fumigated with ambient and 13C-depleted CO2 and treated with two levels of 15N-labeled fertilizer. Bulk soil was separated into free light fraction, occluded light fraction and heavy fraction by density fractionation and ultrasonic dispersion. The heavy fraction was further particle-size fractionated with 20 μm as a cut-off. We determined carbon and N concentrations and their isotopic compositions (δ13C, δ15N) within bulk soil and density fractions. Therein, we extracted and quantified individual amino sugars and lipids and conducted compound-specific stable-isotope-analysis using GC- and LC-IRMS. Results show that amino sugars were mainly stabilized in association with soil minerals. Especially bacterial amino sugars were preferentially associated with soil minerals, exemplified by a consistent decrease

  4. Adverse reactions to cosmetics.

    PubMed

    Dogra, A; Minocha, Y C; Kaur, S

    2003-01-0