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1

The use of a halophytic plant species and organic amendments for the remediation of a trace elements-contaminated soil under semi-arid conditions.  

PubMed

The halophytic shrub Atriplex halimus L. was used in a field phytoremediation experiment in a semi-arid area highly contaminated by trace elements (As, Cd, Cu, Mn, Pb and Zn) within the Sierra Minera of La Unión-Cartagena (SE Spain). The effects of compost and pig slurry on soil conditions and plant growth were determined. The amendments (particularly compost) only slightly affected trace element concentrations in soil pore water or their availability to the plants, increased soil nutrient and organic matter levels and favoured the development of a sustainable soil microbial biomass (effects that were enhanced by the presence of A. halimus) as well as, especially for slurry, increasing A. halimus biomass and ground cover. With regard to the minimisation of trace elements concentrations in the above-ground plant parts, the effectiveness of both amendments was greatest 12-16 months after their incorporation. The findings demonstrate the potential of A. halimus, particularly in combination with an organic amendment, for the challenging task of the phytostabilisation of contaminated soils in (semi-)arid areas and suggest the need for an ecotoxicological evaluation of the remediated soils. However, the ability of A. halimus to accumulate Zn and Cd in the shoot may limit its use to moderately-contaminated sites. PMID:22595543

Clemente, Rafael; Walker, David J; Pardo, Tania; Martínez-Fernández, Domingo; Bernal, M Pilar

2012-07-15

2

Modeling Halophytic Plants in APEX for Sustainable Water and Agriculture  

NASA Astrophysics Data System (ADS)

A major problem for irrigated agricultural production is soil salinization, which can occur naturally or can be human-induced. Human-induced, or secondary salinization, is particularly a problem in arid and semi-arid regions, especially in irrigated areas. Irrigated land has more than twice the production of rainfed land, and accounts for about one third of the world's food, but nearly 20% of irrigated lands are salt-affected. Many farmers worldwide currently seasonally leach their land to reduce the soil salt content. These practices, however, create further problems such as a raised groundwater table, and salt, fertilizer, and pesticide pollution of nearby lakes and groundwater. In Uzbekistan, a combination of these management practices and a propensity to cultivate 'thirsty' crops such as cotton has also contributed to the Aral Sea shrinking nearly 90% by volume since the 1950s. Most common agricultural crops are glycophytes that have reduced yields when subjected to salt-stress. Some plants, however, are known as halophytic or 'salt-loving' plants and are capable of completing their life-cycle in higher saline soil or water environments. Halophytes may be useful for human consumption, livestock fodder, or biofuel, and may also be able to reduce or maintain salt levels in soil and water. To assess the potential for these halophytes to assist with salinity management, we are developing a model that is capable of tracking salinity under different management practices in agricultural environments. This model is interdisciplinary as it combines fields such as plant ecology, hydrology, and soil science. The US Department of Agriculture (USDA) model, Agricultural Policy/Environmental Extender (APEX), is being augmented with a salinity module that tracks salinity as separate ions across the soil-plant-water interface. The halophytes Atriplex nitens, Climacoptera lanata, and Salicornia europaea are being parameterized and added into the APEX model database. Field sites in the Central Kyzylkum and Khorezm regions of Uzbekistan are being characterized in the model, where halophytes are being grown and plant, soil, and water data are being collected for model verification. This presentation will discuss the plant and site parameterizations as well as preliminary progress on developing and applying the APEX salinity module for modeling the salt cycle through soil, water, and halophytes under different management practices.

DeRuyter, T.; Saito, L.; Nowak, B.; Rossi, C.; Toderich, K.

2013-12-01

3

Flooding tolerance in halophytes.  

PubMed

Flooding is a common environmental variable with salinity. Submerged organs can suffer from O(2) deprivation and the resulting energy deficits can compromise ion transport processes essential for salinity tolerance. Tolerance of soil waterlogging in halophytes, as in glycophytes, is often associated with the production of adventitious roots containing aerenchyma, and the resultant internal O(2) supply. For some species, shallow rooting in aerobic upper soil layers appears to be the key to survival on frequently flooded soils, although little is known of the anoxia tolerance in halophytes. Halophytic species that inhabit waterlogged substrates are able to regulate their shoot ion concentrations in spite of the hypoxic (or anoxic) medium in which they are rooted, this being in stark contrast with most other plants which suffer when salinity and waterlogging occur in combination. Very few studies have addressed the consequences of submergence of the shoots by saline water; these have, however, demonstrated tolerance of temporary submergence in some halophytes. PMID:18482227

Colmer, Timothy D; Flowers, Timothy J

2008-01-01

4

Impact of Compost on Metals Phytostabilization Potential of two Halophytes Species.  

PubMed

ABSTRACT Phytostabilization of heavy metals in contaminated soils should be subject to two conditions, the first is the choice plant must be able to stabilize heavy metals in soil, the second is the plant material which produced from the phytostabilization process must be safe and useful to avoid overload on environmental system. A field experiment was conducted out to evaluate the phytostabilization potential of two halophyte species (Atriplex lentiformis and Atriplex undulata). Compost at rates of 0, 15 and 30 ton ha(-1) was used to examine its role in plant growth and heavy metals uptake. The high rate of compost (30 ton ha(-1)) decreased zinc (Zn) concentrations in the leaves of A. lentiformis and A. undulata by 15.8 and 13.0%, while lead (Pb) in the leaves decreased by 37.6 and 35.2% respectively. Despite the extremely high total heavy metals concentrations in the studied soil, plants of Atriplex were able grow and maintain shoots metals content below the toxic level and the produced plant materials had a high nutritive value compared to the conventional forage crops. Phosphorus (P) and chloride (Cl) in the roots of Atriplex plants play important function in heavy metals phytostabilization mechanism by the two halophyte plants. PMID:25191928

Eissa, Mamdouh A

2014-09-01

5

Radical scavenging, antioxidant and antimicrobial activities of halophytic species Laetitia Meot-Durosa*  

E-print Network

Radical scavenging, antioxidant and antimicrobial activities of halophytic species Laetitia Meot-11Jan2011 #12;scavenging activity (Ksouri et al., 2006), but no antimicrobial properties have been investigations on in vitro antibacterial, radical scavenging and antioxidant activities of the extracts

Paris-Sud XI, Université de

6

Identification and cloning of the Cu/Zn superoxide dismutase gene from halophyte plant Aeluropus littoralis.  

PubMed

Reactive oxygen species (ROS) derived from molecular oxygen under biotic and abiotic stress such as salinity which have deleterious effects on cell metabolism. The toxic effect of ROS counteract by enzymatic as well as non-enzymatic antioxidant system. Superoxide dismutase (SOD) has a potential role for elimination of ROS. Halophytes respond to salt stress at different levels and can be a model for increasing salt tolerance in crop plants. Thus salt tolerance gene isolation and cloning of gene as well as subsequent transformation are first step for sensitive crop improvement. Aeluropus littoralis is a halophyte plant from poaceae family can be as a beneficial plant with high potential for creal breeding. There was no report on isolation of SOD gene from A. littoralis and little genomic study of this plant carried out. In this study a novel gene from A. littoralis isolated. This gene amplified by reverse transcription-PCR and cloned in E. coli pTZ57R/T cloning vector. The AlSOD gene sequence contained 456 bp and the deduced transcripts encoding 152 amino acids shared a high homology with those putative CuZnSOD of higher plants like Zea mays and Oryza sativa. PMID:22567863

Modarresi, M; Nematzadeh, G A; Moradian, F; Alavi, S M

2012-01-01

7

ELECTROSTATIC CHANGES IN ROOT PLASMA MEMBRANE OF GLYCOPHYTIC AND HALOPHYTIC SPECIES OF TOMATO  

Technology Transfer Automated Retrieval System (TEKTRAN)

We investigated the effect of salt stress on the electrostatic properties of plasma membrane vesicles from the glycophytic tomato, Lycopersicon esculentum (Mill, cfs Heinz 1350 and VF 36) and the halophytic, wild species, L. cheesmanii (Hook, C.H. Mull, ecotype 1401) grown under control and saline c...

8

Halophyte plant diversity, coastal habitat types and their conservation status in Cyprus  

Microsoft Academic Search

\\u000a This chapter focuses on the identification, description and determination of the conservation status of the halophytic plant\\u000a diversity and the coastal habitat types of Cyprus. The chapter presents the results of a study that was undertaken during\\u000a 2006–2008 in the coastal zone of Cyprus, which revealed that a total of 457 plant taxa with distinct features are distributed\\u000a along a

M. Öztürk; S. Gucel; A. Guvensen; C. Kadis; C. Kounnamas

9

Influence of halophytic hosts on their parasites-the case of Plicosepalus acaciae.  

PubMed

Halophytes develop various morphological and physiological traits that enable them to grow successfully on saline substrates. Parasitic plants on halophytic hosts may also encounter salt stress. We investigated the mistletoe Plicosepalus acaciae (syn: Loranthus acacia; Loranthaceae), which occurs on 5 halophytic and at least 10 non-halophytic hosts in the Southern Arava Valley (Israel). Plicosepalus acaciae is a common parasite north of Eilat to the Dead Sea area and in the Jordan Valley. Morphological and physiological responses of P. acaciae to salinity were investigated by comparison of plants on halophytic with those on non-halophytic hosts. Ion patterns of different host-parasite associations were determined as was the development of leaf succulence at different growth stages. The leaf water content of P. acaciae increased and leaves developed succulence when growing on halophytic hosts, especially on Tamarix species, where leaf water content was three times higher than that on non-halophytic hosts and the leaf volume increased four to five times. The reason for increased succulence was a higher ion concentration of, and osmotic adjustment with, Na(+) and Cl(-). Plicosepalus acaciae showed a high morphological and ecophysiological plasticity, enabling it to cope with salt stress, and can be classified as a facultative eu-halophyte, which increases its halo-succulence according to the host. Host-parasite associations are a model system for the investigation of halophytes under different salt stress conditions. PMID:25515726

Veste, Maik; Todt, Henning; Breckle, Siegmar-W

2014-01-01

10

Use of halophytic plants for recycling NaCl in human liquid waste in a bioregenerative life support system  

NASA Astrophysics Data System (ADS)

The purpose of this work was to develop technology for recycling NaCl containing in human liquid waste as intrasystem matter in a bioregenerative life support system (BLSS). The circulation of Na + and Cl - excreted in urine is achieved by inclusion of halophytes, i.e. plants that naturally inhabit salt-rich soils and accumulate NaCl in their organs. A model of Na + and Cl - recycling in a BLSS was designed, based on the NaCl turnover in the human-urine-nutrient solution-halophytic plant-human cycle. The study consisted of (i) selecting a halophyte suitable for inclusion in a BLSS, and (ii) determining growth conditions supporting maximal Na + and Cl - accumulation in the shoots of the halophyte growing in a nutrient solution simulating mineralized urine. For the selected halophytic plant, Salicornia europaea, growth rate under optimal conditions, biomass production and quantities of Na + and Cl - absorbed were determined. Characteristics of a plant production conveyor consisting of S.europaea at various ages, and allowing continuity of Na + and Cl - turnover, were estimated. It was shown that closure of the NaCl cycle in a BLSS can be attained if the daily ration of fresh Salicornia biomass for a BLSS inhabitant is approximately 360 g.

Balnokin, Yurii; Nikolai, Myasoedov; Larisa, Popova; Alexander, Tikhomirov; Sofya, Ushakova; Christophe, Lasseur; Jean-Bernard, Gros

2010-09-01

11

Differential Activity of Plasma and Vacuolar Membrane Transporters Contributes to Genotypic Differences in Salinity Tolerance in a Halophyte Species, Chenopodium quinoa.  

PubMed

Halophytes species can be used as a highly convenient model system to reveal key ionic and molecular mechanisms that confer salinity tolerance in plants. Earlier, we reported that quinoa (Chenopodium quinoa Willd.), a facultative C3 halophyte species, can efficiently control the activity of slow (SV) and fast (FV) tonoplast channels to match specific growth conditions by ensuring that most of accumulated Na+ is safely locked in the vacuole (Bonales-Alatorre et al. (2013) Plant Physiology). This work extends these finding by comparing the properties of tonoplast FV and SV channels in two quinoa genotypes contrasting in their salinity tolerance. The work is complemented by studies of the kinetics of net ion fluxes across the plasma membrane of quinoa leaf mesophyll tissue. Our results suggest that multiple mechanisms contribute towards genotypic differences in salinity tolerance in quinoa. These include: (i) a higher rate of Na+ exclusion from leaf mesophyll; (ii) maintenance of low cytosolic Na+ levels; (iii) better K+ retention in the leaf mesophyll; (iv) a high rate of H+ pumping, which increases the ability of mesophyll cells to restore their membrane potential; and (v) the ability to reduce the activity of SV and FV channels under saline conditions. These mechanisms appear to be highly orchestrated, thus enabling the remarkable overall salinity tolerance of quinoa species. PMID:23629664

Bonales-Alatorre, Edgar; Pottosin, Igor; Shabala, Lana; Chen, Zhong-Hua; Zeng, Fanrong; Jacobsen, Sven-Erik; Shabala, Sergey

2013-01-01

12

Differential Activity of Plasma and Vacuolar Membrane Transporters Contributes to Genotypic Differences in Salinity Tolerance in a Halophyte Species, Chenopodium quinoa  

PubMed Central

Halophytes species can be used as a highly convenient model system to reveal key ionic and molecular mechanisms that confer salinity tolerance in plants. Earlier, we reported that quinoa (Chenopodium quinoa Willd.), a facultative C3 halophyte species, can efficiently control the activity of slow (SV) and fast (FV) tonoplast channels to match specific growth conditions by ensuring that most of accumulated Na+ is safely locked in the vacuole (Bonales-Alatorre et al. (2013) Plant Physiology). This work extends these finding by comparing the properties of tonoplast FV and SV channels in two quinoa genotypes contrasting in their salinity tolerance. The work is complemented by studies of the kinetics of net ion fluxes across the plasma membrane of quinoa leaf mesophyll tissue. Our results suggest that multiple mechanisms contribute towards genotypic differences in salinity tolerance in quinoa. These include: (i) a higher rate of Na+ exclusion from leaf mesophyll; (ii) maintenance of low cytosolic Na+ levels; (iii) better K+ retention in the leaf mesophyll; (iv) a high rate of H+ pumping, which increases the ability of mesophyll cells to restore their membrane potential; and (v) the ability to reduce the activity of SV and FV channels under saline conditions. These mechanisms appear to be highly orchestrated, thus enabling the remarkable overall salinity tolerance of quinoa species. PMID:23629664

Bonales-Alatorre, Edgar; Pottosin, Igor; Shabala, Lana; Chen, Zhong-Hua; Zeng, Fanrong; Jacobsen, Sven-Erik; Shabala, Sergey

2013-01-01

13

A review on Cressa cretica Linn.: A halophytic plant  

PubMed Central

Herbal medicine is used by up to 80% of the population in developing countries. Cressa cretica L. is a popular holophytic plant and is used in folklore medicine for ailments including diabetes, ulcers, asthma, anthelmintic, stomachic, tonic and aphrodisiac purposes, enriches the blood, and is useful in constipation, leprosy, and urinary discharges. The plant is traditionally used in Bahrain as expectorant and antibilious agent. Scientific evidence suggests its versatile biological functions such as its antibacterial, antifungal, antitussive, anticancer with some other plants, anti-inflammatory, and improving testicular function in rats. In this article, a comprehensive account of the morphology, phytochemical constituents, ethnobotany, and biological activities are included in view of the recent findings of importance on the plant, C. cretica. PMID:22228956

Priyashree, S.; Jha, S.; Pattanayak, S. P.

2010-01-01

14

NaCl alleviates polyethylene glycol-induced water stress in the halophyte species Atriplex halimus L  

Microsoft Academic Search

Atriplex halimus L. is a C4 xero-halophyte species well adapted to salt and drought conditions. To collect information on the physiological impact of low salt levels on their water-stress resistance, seedlings were exposed for 6 d to nutrient solution containing either 0% or 15% polyethylene glycol 10 000 (PEG), in the presence or in the absence of 50 mM NaCl.

Juan-Pablo Martinez; Jean-Marie Kinet; Mohammed Bajji; Stanley Lutts

2005-01-01

15

Effects of plant growth regulators and l -glutamic acid on shoot organogenesis in the halophyte Leymus chinensis (Trin.)  

Microsoft Academic Search

The halophyte Leymus chinensis (Trin.) is a perennial rhizome grass (tribe Gramineae) that is widely distributed in China, Mongolia and Siberia, where it\\u000a is produced as a forage product. In this report, we establish a highly reproducible plant regeneration system through somatic\\u000a embryogenesis. Two explants, mature seeds and leaf base segments were used; these parts displayed different responses to combinations

Yan-Lin Sun; Soon-Kwan Hong

2010-01-01

16

Effect of sodium chloride on the response of the halophyte species Sesuvium portulacastrum grown in mannitol-induced water stress  

Microsoft Academic Search

Sesuvium portulacastrum is a halophytic species well adapted to salinity and drought. In order to evaluate the physiological impact of salt on water\\u000a deficit-induced stress response, we cultivated seedlings for 12 days, in the presence or absence of 100 mmol l?1 NaCl, on a nutrient solution containing either 0 mmol l?1 or 25 mmol l?1 mannitol. Mannitol-induced water stress reduced growth, increased the root\\/shoot ratio, and led

Inès Slama; Tahar Ghnaya; Dorsaf Messedi; Kamel Hessini; Nahla Labidi; Arnould Savoure; Chedly Abdelly

2007-01-01

17

Adaptive Mechanisms of Halophytes in Desert Regions  

Microsoft Academic Search

Plants growing in desert regions have to face a number of environmental adversaries such as high temperature, soil salinity\\u000a and water stress due to low precipitation. Halophytes are among the successful plants that grow in desert saline regions.\\u000a Halophytes use many different strategies to survive under these conditions. Some halophytes seeds can germinate in the presence\\u000a of high salinity. Seeds

D. J. Weber

18

Potential use of halophytes to remediate saline soils.  

PubMed

Salinity is one of the rising problems causing tremendous yield losses in many regions of the world especially in arid and semiarid regions. To maximize crop productivity, these areas should be brought under utilization where there are options for removing salinity or using the salt-tolerant crops. Use of salt-tolerant crops does not remove the salt and hence halophytes that have capacity to accumulate and exclude the salt can be an effective way. Methods for salt removal include agronomic practices or phytoremediation. The first is cost- and labor-intensive and needs some developmental strategies for implication; on the contrary, the phytoremediation by halophyte is more suitable as it can be executed very easily without those problems. Several halophyte species including grasses, shrubs, and trees can remove the salt from different kinds of salt-affected problematic soils through salt excluding, excreting, or accumulating by their morphological, anatomical, physiological adaptation in their organelle level and cellular level. Exploiting halophytes for reducing salinity can be good sources for meeting the basic needs of people in salt-affected areas as well. This review focuses on the special adaptive features of halophytic plants under saline condition and the possible ways to utilize these plants to remediate salinity. PMID:25110683

Hasanuzzaman, Mirza; Nahar, Kamrun; Alam, Md Mahabub; Bhowmik, Prasanta C; Hossain, Md Amzad; Rahman, Motior M; Prasad, Majeti Narasimha Vara; Ozturk, Munir; Fujita, Masayuki

2014-01-01

19

Halophytic plants as a component of a bioregenerative life support system for recycling of NaCl contained in human liquid waste.  

NASA Astrophysics Data System (ADS)

Currently, the closure of matter turnover is one of the urgent problems of bioregenerative life support system (BLSS) designing. The important aspect of the problem is involving of substances contained in liquid and solid exometabolites of humans inhabiting BLSS into intrasystem matter turnover. Recycling of Na+ and Cl- contained in human liquid exometabolites, i.e. urine is acknowledged to be among the main tasks of the matter turnover in BLSS. The ions excreted with urine may be returned to human organism with food. A way to allow this is including edible halophytic plants into the phototrophic compartment of BLSS. Halophytes are defined as plants which can grow on saline soils and produce high biomass under these conditions. Some halophytes can take up high quantities of Na+ and Cl- and accumulate the ions in the shoots or extrude them to leaf surface by means of salt glands. To allow Na+ and Cl- recycling through halophyte utilization, the following principal steps should be accomplished: (i) mineralization of the exometabolites by physicochemical methods; (ii) oxidation of ammonia formed during the exometabolite mineralization to nitrate by nitrifying bacteria, (iii) growing the halophyte on the nutrient solution prepared on the basis of the mineralized exometabolites, (iv) introducing the halophyte green biomass into human food. The present work is devoted to the following problems: (i) selection of a salt-accumulating/extruding halophytic plant suitable for Na+ and Cl- recycling in BLSS and (ii) parameter evaluation of a plant conveyor containing the halophytic plants at various ages. Halophytic plants selected for BLSS should meet the following criteria: (i) ability to grow under 24-hour-illumination, (ii) high productivity, (iii) ability to accumulate Na+ and Cl- in high quantities in shoots or to excrete salts to leaf surface, (iv) edibility, and (v) high nutritive value of the biomass. Relying on these criteria, salt-accumulating halophyte Salicornia europaea was selected from seven halophytic plant candidates, preliminary chosen from observations in their natural habitats, from our previous investigations and literature data. Characterization of the plant performance was obtained in the experiments on plants grown in water culture in a cultivation chamber under controlled conditions. A model nutrient solution simulating mineralized urine was used for halophyte growing. Under the experimental conditions, S.europaea exhibited high productivity and accumulated Na+ and Cl- in the shoots in high quantities. It has been shown that above-ground organs of S.europaea exhibit high nutritive value, the proteins are enriched with the essential amino acids and displayed high abundance of leucine, aspartic and glutamic acids. The results demonstrate that it is feasible to put into practice permanent Na+ and Cl- recycling in BLSS by a various-aged S.europaea conveyor. Relying on data on distribution of Na+ and Cl- between the plant and growth medium, parameters of the conveyor for permanent ion turnover in the system humans - exometabolites - nutrient solution - S.europaea - humans have been evaluated.

Balnokin, Yurii; Balnokin, Yurii; Myasoedov, Nikolay; Popova, Larissa; Tikhomirov, Alexander A.; Ushakova, Sofya; Tikhomirova, Natalia; Lasseur, Christophe; Gros, Jean-Bernard

20

On the halophytic nature of mangroves  

USGS Publications Warehouse

Scientists have discussed the halophytic nature of intertidal plants for decades, and have generally suggested that inherent differentiation of an obligate halophyte from a facultative halophyte relates strongly to whether the plant can survive in fresh water, and not much else. In this mini-review, we provide additional insight to support the pervasive notion that mangroves as a group are truly facultative halophytes, and thus add discourse to the alternate view that mangroves have an obligate salinity requirement. Indeed, growth and physiological optima are realized at moderate salinity concentrations in mangroves, but we maintain the notion that current evidence suggests that survival is not dependent upon a physiological requirement for salt.

Krauss, Ken W.; Ball, Marilyn C.

2013-01-01

21

RESTORING ASSEMBLAGES OF SALT MARSH HALOPHYTES IN THE PRESENCE OF A RAPIDLY COLONIZING DOMINANT SPECIES  

E-print Network

or stress (Tilman and Down- ing 1994), stronger resistance to invasion (Hector et al. 2001), and for plant, USA 90095-1772 3 Present address: Texas A & M University at Galveston Department of Marine Biology Drive Tiburon, California, USA 94920-1205 Abstract: Establishing species-rich plant communities

Boyer, Katharyn

22

Influence of biological, environmental and technical factors on phenolic content and antioxidant activities of Tunisian halophytes.  

PubMed

Halophyte ability to withstand salt-triggered oxidative stress is governed by multiple biochemical mechanisms that facilitate retention and/or acquisition of water, protect chloroplast functioning, and maintain ion homeostasis. Most essential traits include the synthesis of osmolytes, specific proteins, and antioxidant molecules. This might explain the utilization of some halophytes as traditional medicinal and dietary plants. The present study aimed at assessing the phenolic content and antioxidant activities of some Tunisian halophytes (Cakile maritima, Limoniastrum monopetalum, Mesembryanthemum crystallinum, M. edule, Salsola kali, and Tamarix gallica), depending on biological (species, organ and developmental stage), environmental, and technical (extraction solvent) factors. The total polyphenol contents and antioxidant activities (DPPH and superoxide radicals scavenging activities, and iron chelating and reducing powers) were strongly affected by the above-cited factors. Such variability might be of great importance in terms of valorising these halophytes as a source of naturally secondary metabolites, and the methods for phenolic and antioxidant production. PMID:18940702

Ksouri, Riadh; Megdiche, Wided; Falleh, Hanen; Trabelsi, Nejla; Boulaaba, Mondher; Smaoui, Abderrazak; Abdelly, Chedly

2008-11-01

23

Maritime Halophyte Species from Southern Portugal as Sources of Bioactive Molecules  

PubMed Central

Extracts of five halophytes from southern Portugal (Arthrocnemum macrostachyum, Mesembryanthemum edule, Juncus acutus, Plantago coronopus and Halimione portulacoides), were studied for antioxidant, anti-inflammatory and in vitro antitumor properties. The most active extracts towards the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical were the methanol extracts of M. edule (IC50 = 0.1 mg/mL) and J. acutus (IC50 = 0.4 mg/mL), and the ether extracts of J. acutus (IC50 = 0.2 mg/mL) and A. macrostachyum (IC50 = 0.3 mg/mL). The highest radical scavenging activity (RSA) against the 2,2?-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical was obtained in the ether extract of J. acutus (IC50 = 0.4 mg/mL) and H. portulacoides (IC50 = 0.9 mg/mL). The maximum total phenolic content (TPC) was found in the methanol extract of M. edule (147 mg gallic acid equivalents (GAE)/g) and in the ether extract of J. acutus (94 mg GAE/g). Significant decreases in nitric oxide (NO) production were observed after incubation of macrophages with lipopolysaccharide (LPS) and the chloroform extract of H. portulacoides (IC50 = 109 µg/mL) and the hexane extract of P. coronopus (IC50 = 98.0 µg/mL). High in vitro cytotoxic activity and selectivity was obtained with the ether extract of J. acutus. Juncunol was identified as the active compound and for the first time was shown to display selective in vitro cytotoxicity towards various human cancer cells. PMID:24727393

Rodrigues, Maria João; Gangadhar, Katkam N.; Vizetto-Duarte, Catarina; Wubshet, Sileshi G.; Nyberg, Nils T.; Barreira, Luísa; Varela, João; Custódio, Luísa

2014-01-01

24

Maritime halophyte species from southern Portugal as sources of bioactive molecules.  

PubMed

Extracts of five halophytes from southern Portugal (Arthrocnemum macrostachyum, Mesembryanthemum edule, Juncus acutus, Plantago coronopus and Halimione portulacoides), were studied for antioxidant, anti-inflammatory and in vitro antitumor properties. The most active extracts towards the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical were the methanol extracts of M. edule (IC?? = 0.1 mg/mL) and J. acutus (IC?? = 0.4 mg/mL), and the ether extracts of J. acutus (IC?? = 0.2 mg/mL) and A. macrostachyum (IC?? = 0.3 mg/mL). The highest radical scavenging activity (RSA) against the 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical was obtained in the ether extract of J. acutus (IC?? = 0.4 mg/mL) and H. portulacoides (IC?? = 0.9 mg/mL). The maximum total phenolic content (TPC) was found in the methanol extract of M. edule (147 mg gallic acid equivalents (GAE)/g) and in the ether extract of J. acutus (94 mg GAE/g). Significant decreases in nitric oxide (NO) production were observed after incubation of macrophages with lipopolysaccharide (LPS) and the chloroform extract of H. portulacoides (IC?? = 109 µg/mL) and the hexane extract of P. coronopus (IC?? = 98.0 µg/mL). High in vitro cytotoxic activity and selectivity was obtained with the ether extract of J. acutus. Juncunol was identified as the active compound and for the first time was shown to display selective in vitro cytotoxicity towards various human cancer cells. PMID:24727393

Rodrigues, Maria João; Gangadhar, Katkam N; Vizetto-Duarte, Catarina; Wubshet, Sileshi G; Nyberg, Nils T; Barreira, Luísa; Varela, João; Custódio, Luísa

2014-04-01

25

[Response characteristics of the field-measured spectrum for the four gerneral types of halophyte and species recognition in the northern slope area of Tianshan Mountain in Xinjiang].  

PubMed

Based on the field-measured Vis-NIR reflectance of four common types of halophyte (Achnatherum splendens(Trin.) Nevski, Sophora alopecuroides L., Camphorosma monspeliaca L. subsp. lessingii(L.)Aellen, Alhagi sparsifolia shap) within given spots in the Northern Slope Area of Tianshan Mountain in Xinjiang, the spectral response characteristics and species recognition of these types of halophyte were analyzed. The results showed that (Alhagi sparsifolia shap) had higher chlorophyll and carotenoid by CARI and SIPI index. (Sophora alopecuroides L. was at a vigorously growing state and had a higher NDVI compared with the other three types of halophyte because of its greater canopy density. But its CARI and SIPI values were lower due to the influence of its flowers. (Sophora alopecuroides L.) and (Camphorosma monspeliaca L. subsp. lessingii(L.)) had stable REPs and BEPs, but REPs and BEPs of (Achnatherum splendens(Trin.)Nevski, Aellen, Alhagi sparsifolia shap) whose spectra red shift and spectra blue shift occurred concurrently obviously changed. There was little difference in spectral curves among the four types of halophyte, so the spectrum mixing phenomenon was severe. (Camphorosma monspeliaca L. subsp. lessingii (L.)Aellen) and (Alhagi sparsifolia shap) could not be separated exactly in a usual R/NIR feature space in remote sensing. Using the stepwise discriminant analysis, five indices were selected to establish the discriminant model, and the model accuracy was discussed using the validated sample group. The total accuracy of the discriminant model was above 92% and (Achnatherum splendens(Trin.)Nevski) and (Camphorosma monspeliaca L. subsp. lessingii(L.)Aellen) could be respectively recognized 100% correctly. PMID:22295790

Zhang, Fang; Xiong, Hei-gang; Nurbay, Abdusalih; Luan, Fu-ming

2011-12-01

26

The roots of the halophyte Salicornia brachiata are a source of new halotolerant diazotrophic bacteria with plant growth-promoting potential  

Microsoft Academic Search

Soil salinity is the major cause limiting plant productivity worldwide. Nitrogen-fixing bacteria were enriched and characterised\\u000a from roots of Salicornia brachiata, an extreme halophyte which has substantial economic value as a bioresource of diverse and valuable products. Nitrogen-free\\u000a semisolid NFb medium with malate as carbon source and up to 4% NaCl were used for enrichment and isolation of diazotrophic\\u000a bacteria.

Bhavanath Jha; Iti Gontia; Anton Hartmann

27

Biosynthesis and accumulation of osmoprotective compounds by halophytic plants of the genus Limonium  

SciTech Connect

Analyses of quaternary ammonium compounds in leaf and root tissues of halophytic Limonium spp. using fast atom bombardment mass spectrometry revealed that only 3 out of 21 spp. accumulated glycine betaine, the common angiosperm osmolyte. The 18 other spp. accumulated {beta}-alanine betaine instead. However, all the Limonium spp. studied accumulated choline-O-sulfate and their leaf disks metabolized ({sup 14}C) choline to choline-O-sulfate. Only the glycine betaine accumulators oxidized ({sup 14}C) choline to glycine betaine and only {beta}-alanine betaine accumulators converted {beta}-({sup 14}C)alanine to {beta}-alanine betaine. When {beta}-alanine betaine and glycine betaine accumulators were salinized with NaCl, the levels of their respective betaines and of choline sulfate were closely correlated with solute potential. Glycine betaine accumulators had less choline-O-sulfate than {beta}-alanine betaine accumulators and increasing the SO{sub 4}{sup 2}/Cl ratio in the medium increased choline-O-sulfate and caused a matching decrease in glycine betaine. Thus, it appears that {beta}-alanine betaine has replaced glycine betaine in most members of this genus, eliminating a possible competition between glycine betaine and choline-O-sulfate for choline.

Hanson, A.D.; Rathinasabapathi, B. (Michigan State Univ. Plant Research Lab., East Lansing (United States)); Gage, D.A. (Michigan State Univ., East Lansing (United States))

1991-05-01

28

ROS homeostasis in halophytes in the context of salinity stress tolerance.  

PubMed

Halophytes are defined as plants that are adapted to live in soils containing high concentrations of salt and benefiting from it, and thus represent an ideal model to understand complex physiological and genetic mechanisms of salinity stress tolerance. It is also known that oxidative stress signalling and reactive oxygen species (ROS) detoxification are both essential components of salinity stress tolerance mechanisms. This paper comprehensively reviews the differences in ROS homeostasis between halophytes and glycophytes in an attempt to answer the questions of whether stress-induced ROS production is similar between halophytes and glycophytes; is the superior salinity tolerance in halophytes attributed to higher antioxidant activity; and is there something special about the specific 'pool' of enzymatic and non-enzymatic antioxidants in halophytes. We argue that truly salt-tolerant species possessing efficient mechanisms for Na(+) exclusion from the cytosol may not require a high level of antioxidant activity, as they simply do not allow excessive ROS production in the first instance. We also suggest that H2O2 'signatures' may operate in plant signalling networks, in addition to well-known cytosolic calcium 'signatures'. According to the suggested concept, the intrinsically higher superoxide dismutase (SOD) levels in halophytes are required for rapid induction of the H2O2 'signature', and to trigger a cascade of adaptive responses (both genetic and physiological), while the role of other enzymatic antioxidants may be in decreasing the basal levels of H2O2, once the signalling has been processed. Finally, we emphasize the importance of non-enzymatic antioxidants as the only effective means to prevent detrimental effects of hydroxyl radicals on cellular structures. PMID:24368505

Bose, Jayakumar; Rodrigo-Moreno, Ana; Shabala, Sergey

2014-03-01

29

Changes in cellular distribution regulate SKD1 ATPase activity in response to a sudden increase in environmental salinity in halophyte ice plant  

PubMed Central

Halophyte Mesembryanthemum crystallinum L. (ice plant) rapidly responds to sudden increases in salinity in its environment by activating specific salt-tolerant mechanisms. One major strategy is to regulate a series of ion transporters and proton pumps to maintain cellular Na+/K+ homeostasis. Plant SKD1 (suppressor of K+ transport growth defect 1) proteins accumulate in cells actively engaged in the secretory processes, and play a critical role in intracellular protein trafficking. Ice plant SKD1 redistributes from the cytosol to the plasma membrane hours after salt stressed. In combination with present knowledge of this protein, we suggest that stress facilitates SKD1 movement to the plasma membrane where ADP/ATP exchange occurs, and functions in the regulation of membrane components such as ion transporters to avoid ion toxicity. PMID:24390077

Jou, Yingtzy; Chiang, Chih-Pin; Yen, Hungchen Emilie

2013-01-01

30

The role of proline accumulation in halophytes  

Microsoft Academic Search

It is shown that in the majority of higher plant halophytes examined proline is the major component of the amino acid pool in plants collected from the field. In Triglochin maritima L. free proline can represent 10–20% of the shoot dry weight. Under non-saline conditions proline levels are low and increase as the salinity is raised. Comparisons of inland and

G. R. Stewart; J. A. Lee

1974-01-01

31

Halophytes Energy Feedstocks: Back to Our Roots  

NASA Technical Reports Server (NTRS)

Of the Earth s landmass, approx.43% is arid or semi-arid, and 97% of the Earth s water is seawater. Halophytes are salt-tolerant plants (micro and macro) that can prosper in seawater or brackish waters and are common feedstocks for fuel and food (fuel-food feedstocks) in depressed countries. Two types, broadly classed as coastal and desert, can be found in marshes, coastal planes, inland lakes, and deserts. Major arid or semi-arid halophyte agriculture problems include pumping and draining the required high volumes of irrigation water from sea or ocean sources. Also, not all arid or semi-arid lands are suitable for crops. Benefits of halophyte agriculture include freeing up arable land and freshwater resources, cleansing the environment, decontaminating soils, desalinating brackish waters, and carbon sequestration. Sea and ocean halophyte agriculture problems include storms, transport, and diffuse harvesting. Benefits include available nutrients, ample water, and Sun. Careful attention to details and use of saline agriculture fuel feedstocks are required to prevent anthropogenic disasters. It is shown that the potential for fuel-food feedstock halophyte production is high; based on test plot data, it could supply 421.4 Quad, or 94% of the 2004 world energy consumption and sequester carbon, with major impact on the Triangle of Conflicts.

Hendricks, Robert C.; Bushnell, Dennis M.

2007-01-01

32

Increased content of very-long-chain fatty acids in the lipids of halophyte vegetative organs  

Microsoft Academic Search

Qualitative and quantitative compositions of esterified fatty acids (FAs) in the total lipids from the leaves, shoots, and\\u000a roots of halophile plants, such as suaeda (Suaeda altissima), samphire (Salicornia europaea), and wormwood (Artemisia lerchiana), collected in their natural environments were estimated by GLC techniques. It was shown that the vegetative organs of these\\u000a halophytes contained 24 FA species, and 16

T. V. Ivanova; N. A. Myasoedov; V. P. Pchelkin; V. D. Tsydendambaev; A. G. Vereshchagin

2009-01-01

33

Plants & Animals Invasive Species  

E-print Network

See Also: Plants & Animals Invasive Species Insects (and Butterflies) Evolutionary Biology Earth) for S. invicta; and Garret Suen and Cameron Currie (University of Wisconsin-Madison) for A. cephalotes, guaranteed results! SwissFrenchSchool.ch AFM Tips by NanoAndMore AFM Tips For Any Application. Fast Delivery

Alvarez, Nadir

34

Habitat specificity of a threatened and endemic, cliff-dwelling halophyte  

PubMed Central

Coastal areas and other saline environments are major contributors to regional and global biodiversity patterns. In these environments, rapidly changing gradients require highly specialized plants like halophytes. In European coastal cliff-tops, rocky and sandy seashores, and saltmarshes, typical halophytes from the genus Limonium are commonly found. Among them, the aneuploid tetraploid (2n = 4x = 35, 36, 37) Limonium multiflorum, endemic to the west coast of Portugal, is an interesting case study for investigating the ecology and conservation of a halophyte agamospermic species. Although it is listed in the IUCN red list of threatened species, information on its population size or rarity, as well as its ecology, in some respects is still unknown. Field surveys in the largest known population were performed (Raso cape, Portugal) in order to determine habitat requirements and conservation status. A total of 88 quadrats were monitored, 43 of which contained at least one L. multiflorum individual. For each sampled quadrat, four abiotic and four biotic variables as well as two spatially derived variables were recorded. Principal component analysis and cluster analysis showed narrow habitat specificity for this species which appeared to be intolerant to competition with invasive alien plants. We conclude that in situ conservation in a local ‘hotspot’ of this rare and vulnerable species emerges as a priority in order to ensure that biodiversity is not lost. PMID:24942513

Caperta, Ana D.; Espírito-Santo, M. Dalila; Silva, Vasco; Ferreira, Ana; Paes, Ana P.; Róis, Ana S.; Costa, José C.; Arsénio, Pedro

2014-01-01

35

Habitat specificity of a threatened and endemic, cliff-dwelling halophyte.  

PubMed

Coastal areas and other saline environments are major contributors to regional and global biodiversity patterns. In these environments, rapidly changing gradients require highly specialized plants like halophytes. In European coastal cliff-tops, rocky and sandy seashores, and saltmarshes, typical halophytes from the genus Limonium are commonly found. Among them, the aneuploid tetraploid (2n = 4x = 35, 36, 37) Limonium multiflorum, endemic to the west coast of Portugal, is an interesting case study for investigating the ecology and conservation of a halophyte agamospermic species. Although it is listed in the IUCN red list of threatened species, information on its population size or rarity, as well as its ecology, in some respects is still unknown. Field surveys in the largest known population were performed (Raso cape, Portugal) in order to determine habitat requirements and conservation status. A total of 88 quadrats were monitored, 43 of which contained at least one L. multiflorum individual. For each sampled quadrat, four abiotic and four biotic variables as well as two spatially derived variables were recorded. Principal component analysis and cluster analysis showed narrow habitat specificity for this species which appeared to be intolerant to competition with invasive alien plants. We conclude that in situ conservation in a local 'hotspot' of this rare and vulnerable species emerges as a priority in order to ensure that biodiversity is not lost. PMID:24942513

Caperta, Ana D; Espírito-Santo, M Dalila; Silva, Vasco; Ferreira, Ana; Paes, Ana P; Róis, Ana S; Costa, José C; Arsénio, Pedro

2014-01-01

36

Genetically Altered Plant Species  

NASA Technical Reports Server (NTRS)

Researchers in Robert Ferl's lab at the University of Florida in Gainesville, genetically altered this Arabdopsis Thaliana (a brassica species) plant to learn how extreme environments, such as the low atmospheric pressure on Mars, affect plant genes. They inserted green fluorescent protein (GFP) near the on/off switches for anoxia and drought genes. When those genes were turned on after exposure to reduced atmospheric pressure, GFP was turned on as well, causing cells expressing those genes to glow green under a blue light. The natural fluorescence of chlorophyll accounts for the red glow.

2003-01-01

37

On the distribution and evaluation of Na, Mg and Cl in leaves of selected halophytes  

NASA Astrophysics Data System (ADS)

Diverse physiological, biochemical and morphological adaptations enable plants to survive in extreme saline environments where osmotic and ionic stresses limit growth and development. Halophytes are salt-tolerant plants that can withstand extraordinarily high levels of Na and Cl in their leaves. The tissue and cellular distribution patterns of salt ions can be linked to the underlying mechanisms of salt tolerance. Application of fast, reliable, multi-elemental and quantitative techniques such as micro-proton-induced X-ray emission (micro-PIXE) will significantly contribute to and accelerate studies of plant salt tolerance, especially as micro-PIXE also provides spatially resolved quantitative data for light elements, such as Na and Mg. The spatial concentration distributions of Na, Mg, Cl, K, P and S in leaves of four halophytes (Bassia indica, Atriplex prostrata, Spartina maritima and Limonium angustifolium) were determined using micro-PIXE, to study the salt-tolerance strategies of the selected halophytes. Different distribution patterns of the studied elements were seen in the leaves; however, in all four of these plant species, Na was excluded from photosynthetically active chlorophyl tissues. With the exception of L. angustifolium, Cl, P and S contents (representing chloride, phosphate and sulphate ionic forms, respectively) did not ensure charge balance in the leaves, which suggests other anionic compounds, such as nitrate and organic anions, have crucial roles in maintaining electroneutrality in these halophytes. By increasing soil salinisation worldwide, the possibility to reliably complement spatial distributions of Na, Mg, Cl, K, P and S with plant structural morphology will contribute significantly to our understanding of plant tolerance mechanisms at the tissue and cell levels. In addition, these kinds of studies are of particular value for designing crop plants with high salt tolerance and for the development of phytoremediation technologies.

Pongrac, Paula; Vogel-Mikuš, Katarina; Regvar, Marjana; Kaligari?, Mitja; Vavpeti?, Primož; Kelemen, Mitja; Grlj, Nataša; Shelef, Oren; Golan-Goldhirsh, Avi; Rachmilevitch, Shimon; Pelicon, Primož

2013-07-01

38

Conveyor Cultivation of the Halophytic Plant Salicornia europaea for the Recycling of NaCl from Human Liquid Waste in a Biological Life Support System.  

NASA Astrophysics Data System (ADS)

One problem in designing bioregenerative life support systems (BLSS) is developing technolo-gies to include human liquid and solid waste in intrasystem recycling. A specific task is recycling of NaCl excreted in urine by humans. We showed recently that this could be achieved through inclusion of the salt accumulating halophyte Salicornia europaea in the autotrophic compart-ment of the BLSS (Balnokin et al., ASR, 2010, in press). A model of NaCl circulation in BLSS with inclusion of S. europaea was based on the NaCl turnover in the human -urine -nutrient solution -S. europaea -human cycle. Mineralized urine was used as a basis for preparation of a nutrient solution for the halophyte cultivation. The shoots of the halophyte cultivated in the mineralized urine and containing NaCl could to be used by the BLSS inhabitants in their diets. In this report we describe cultivation of S. europaea which allows turnover of NaCl and produces daily shoot biomass containing Na+ and Cl- in quantities approximately equal to those excreted in daily human urine. The plants were grown in water culture in a climatic chamber under controlled conditions. A solution simulating mineralized urine (SSMU) was used as a basis for preparation of a nutri-ent solution for S. europaea cultivation. For continuous biomass production, seedlings of S. europaea, germinated preliminary in moist sand, were being transferred to the nutrient solu-tion at regular intervals (every two days). Duration of the conveyor operation was 112 days. During the first 56 days, the seedlings were being planted in SSMU diluted by a factor of 1.5 (2/3 SSMU). The same solution was introduced into the growth vessels as volumes of growth medium decreased due to plant transpiration. Starting from the 56th day as conveyor operation was initiated, the plants were being harvested every two days; the solutions from the discharged vessels were mixed with the fresh SSMU and the mixture was introduced into all other growth vessels of the conveyor. Thus, during the first 56-d period, the plants grew only in the fresh nutrient solution, whereas during the second 56-d period, the worked out nutrient solutions were being returned into the cycle having been added to the growth vessels along with the fresh SSMU. Growth characteristics, water and ionic relations of S. europaea plants, balance of nutrients between organs and growth media for the first and second 56-d periods of the conveyor operation are presented. There was no significant difference in the rates of shoot biomass production during the first and the second periods. The plants were producing shoot biomass with the rates close to those observed under optimal conditions. However, substantial increase in root biomass production (by 50% on the dry mass basis) was observed in the second period as compared with the first one. Decrease in organ water contents on the dry mass basis (by 13% and 30% for shoots and roots, respectively) and transpiration rates (by 25%) occurred also in the second period as compared with the first one. Measurements of Na+ , Cl- and nutrient contents in the growth media and plant organs and calculation of their balances showed that the plants did not suffer from a deficiency of nutrients during the 112 days of the conveyor operation while accumulating required NaCl amounts. Observed root proliferation and deterioration of water relations in the second 56-d period of the conveyor operation may be caused by toxic plant metabolites exuded by roots into the growth medium.

Balnokin, Yurii; Myasoedov, Nikolay; Popova, Larissa; Tikhomirov, Alexander A.; Ushakova, Sofya; Tikhomirova, Natalia; Lasseur, Christophe; Gros, Jean-Bernard

39

Manipulating the antioxidant capacity of halophytes to increase their cultural and economic value through saline cultivation.  

PubMed

Halophytes, salt-tolerant plants, are a source of valuable secondary metabolites with potential economic value. The steady-state pools of many stress-related metabolites are already enhanced in halophytes when compared with glycophytes, but growth under conditions away from the optimum can induce stress and consequently result in changes to secondary metabolites such as antioxidants. However, direct evidence for increasing the concentration of valuable secondary metabolites as a consequence of altering the salinity of the growing environment still remains equivocal. To address this, we analysed a range of metabolites with antioxidant capacity (including total phenols, flavonoids, ascorbate, reduced/oxidized glutathione and reactive oxygen species scavenging enzymes) in seedlings and plants from different families (Amaranthaceae, Brassicaceae, Plantaginaceae and Rhizophoraceae) and habitats grown under different salt concentrations. We show that it is possible to manipulate the antioxidant capacity of plants and seedlings by altering the saline growing environment, the length of time under saline cultivation and the developmental stage. Among the species studied, the halophytes Tripolium pannonicum, Plantago coronopus, Lepidium latifolium and Salicornia europaea demonstrated the most potential as functional foods or nutraceuticals. PMID:25125698

Boestfleisch, Christian; Wagenseil, Niko B; Buhmann, Anne K; Seal, Charlotte E; Wade, Ellie Merrett; Muscolo, Adele; Papenbrock, Jutta

2014-01-01

40

Manipulating the antioxidant capacity of halophytes to increase their cultural and economic value through saline cultivation  

PubMed Central

Halophytes, salt-tolerant plants, are a source of valuable secondary metabolites with potential economic value. The steady-state pools of many stress-related metabolites are already enhanced in halophytes when compared with glycophytes, but growth under conditions away from the optimum can induce stress and consequently result in changes to secondary metabolites such as antioxidants. However, direct evidence for increasing the concentration of valuable secondary metabolites as a consequence of altering the salinity of the growing environment still remains equivocal. To address this, we analysed a range of metabolites with antioxidant capacity (including total phenols, flavonoids, ascorbate, reduced/oxidized glutathione and reactive oxygen species scavenging enzymes) in seedlings and plants from different families (Amaranthaceae, Brassicaceae, Plantaginaceae and Rhizophoraceae) and habitats grown under different salt concentrations. We show that it is possible to manipulate the antioxidant capacity of plants and seedlings by altering the saline growing environment, the length of time under saline cultivation and the developmental stage. Among the species studied, the halophytes Tripolium pannonicum, Plantago coronopus, Lepidium latifolium and Salicornia europaea demonstrated the most potential as functional foods or nutraceuticals. PMID:25125698

Boestfleisch, Christian; Wagenseil, Niko B.; Buhmann, Anne K.; Seal, Charlotte E.; Wade, Ellie Merrett; Muscolo, Adele; Papenbrock, Jutta

2014-01-01

41

Plant responses to heterogeneous salinity: growth of the halophyte Atriplex nummularia is determined by the root-weighted mean salinity of the root zone.  

PubMed

Soil salinity is generally spatially heterogeneous, but our understanding of halophyte physiology under such conditions is limited. The growth and physiology of the dicotyledonous halophyte Atriplex nummularia was evaluated in split-root experiments to test whether growth is determined by: (i) the lowest; (ii) the highest; or (iii) the mean salinity of the root zone. In two experiments, plants were grown with uniform salinities or horizontally heterogeneous salinities (10-450 mM NaCl in the low-salt side and 670 mM in the high-salt side, or 10 mM NaCl in the low-salt side and 500-1500 mM in the high-salt side). The combined data showed that growth and gas exchange parameters responded most closely to the root-weighted mean salinity rather than to the lowest, mean, or highest salinity in the root zone. In contrast, midday shoot water potentials were determined by the lowest salinity in the root zone, consistent with most water being taken from the least negative water potential source. With uniform salinity, maximum shoot growth was at 120-230 mM NaCl; ~90% of maximum growth occurred at 10 mM and 450 mM NaCl. Exposure of part of the roots to 1500 mM NaCl resulted in an enhanced (+40%) root growth on the low-salt side, which lowered root-weighted mean salinity and enabled the maintenance of shoot growth. Atriplex nummularia grew even with extreme salinity in part of the roots, as long as the root-weighted mean salinity of the root zone was within the 10-450 mM range. PMID:23125356

Bazihizina, Nadia; Barrett-Lennard, Edward G; Colmer, Timothy D

2012-11-01

42

Germination of Dimorphic Seeds of the Desert Annual Halophyte Suaeda aralocaspica (Chenopodiaceae), a C4 Plant without Kranz Anatomy  

PubMed Central

Background and Aims Suaeda aralocaspica is a C4 summer annual halophyte without Kranz anatomy that is restricted to the deserts of central Asia. It produces two distinct types of seeds that differ in colour, shape and size. The primary aims of the present study were to compare the dormancy and germination characteristics of dimorphic seeds of S. aralocaspica and to develop a conceptual model of their dynamics. Methods Temperatures simulating those in the natural habitat of S. aralocaspica were used to test for primary dormancy and germination behaviour of fresh brown and black seeds. The effects of cold stratification, gibberellic acid, seed coat scarification, seed coat removal and dry storage on dormancy breaking were tested in black seeds. Germination percentage and recovery responses of brown seeds, non-treated black seeds and 8-week cold-stratified black seeds to salt stress were tested. Key Results Brown seeds were non-dormant, whereas black seeds had non-deep Type 2 physiological dormancy (PD). Germination percentage and rate of germination of brown seeds and of variously pretreated black seeds were significantly higher than those of non-pretreated black seeds. Exposure of seeds to various salinities had significant effects on germination, germination recovery and induction into secondary dormancy. A conceptual model is presented that ties these results together and puts them into an ecological context. Conclusions The two seed morphs of S. aralocaspica exhibit distinct differences in dormancy and germination characteristics. Suaeda aralocaspica is the first cold desert halophyte for which non-deep Type 2 PD has been documented. PMID:18772148

Wang, Lei; Huang, Zhenying; Baskin, Carol C.; Baskin, Jerry M.; Dong, Ming

2008-01-01

43

Medicinal halophytes: potent source of health promoting biomolecules with medical, nutraceutical and food applications.  

PubMed

Salt-tolerant plants grow in a wide variety of saline habitats, from coastal regions, salt marshes and mudflats to inland deserts, salt flats and steppes. Halophytes living in these extreme environments have to deal with frequent changes in salinity level. This can be done by developing adaptive responses including the synthesis of several bioactive molecules. Consequently, several salt marsh plants have traditionally been used for medical, nutritional, and even artisanal purposes. Currently, an increasing interest is granted to these species because of their high content in bioactive compounds (primary and secondary metabolites) such as polyunsaturated fatty acids, carotenoids, vitamins, sterols, essential oils (terpenes), polysaccharides, glycosides, and phenolic compounds. These bioactive substances display potent antioxidant, antimicrobial, anti-inflammatory, and anti-tumoral activities, and therefore represent key-compounds in preventing various diseases (e.g. cancer, chronic inflammation, atherosclerosis and cardiovascular disorder) and ageing processes. The ongoing research will lead to the utilisation of halophytes as a new source of healthy products as functional foods, nutraceuticals or active principles in several industries. This contribution focuses on the ethnopharmacological uses of halophytes in traditional medicine and reviews recent investigations on their biological activities and nutraceuticals. The work is distributed according to the different families of nutraceuticals (lipids, vitamins, proteins, glycosides, phenolic compounds, etc.) discussing the analytical techniques employed for their determination. Information about the claimed health promoting effects of the different families of nutraceuticals is also provided together with data on their application. PMID:22129270

Ksouri, Riadh; Ksouri, Wided Megdiche; Jallali, Inès; Debez, Ahmed; Magné, Christian; Hiroko, Isoda; Abdelly, Chedly

2012-12-01

44

Z .Aquaculture 175 1999 255268 Halophytes for the treatment of saline aquaculture  

E-print Network

Z .Aquaculture 175 1999 255­268 Halophytes for the treatment of saline aquaculture effluent J. Jed the feasibility of using salt-tolerant plants halophytes as biofilters to remove nutrients from saline aquaculture fraction, using aquaculture effluent generated from an intensive tilapia culture system. The effluent

Smith, Steven E.

45

Assessment of the potential of halophytes as energy crops for the electric utility industry. Final report  

Microsoft Academic Search

This technical report assesses and estimates the potential of selected halophytes as future renewable energy resources, especially by US electric utilities, and familiarizes nonspecialists with research and development problems that must be resolved before these energy sources can become dependable supplies of energy. A literature search related to both indigenous and exotic species of halophytes has been done and appropriate

Goodin

1984-01-01

46

Comparative study of rhizobacterial community structure of plant species in oil-contaminated soil.  

PubMed

In this study, the identity and distribution of plants and the structure of their associated rhizobacterial communities were examined in an oil-contaminated site. The number of plant species that formed a community or were scattered was 24. The species living in soil highly contaminated with total petroleum hydrocarbon (TPH) (9,000-4,5000 mg/g-soil) were Cynodon dactylon, Persicaria lapathifolia, and Calystegia soldanella (a halophytic species). Among the 24 plant species, the following have been known to be effective for oil removal: C. dactylon, Digitaria sanguinalis, and Cyperus orthostachyus. Denaturing gradient gel electrophoresis (DGGE) profile analysis showed that the following pairs of plant species had highly similar (above 70%) rhizobacterial community structures: Artemisia princeps and Hemistepta lyrata; C. dactylon and P. lapathifolia; Carex kobomugi and Cardamine flexuosa; and Equisetum arvense and D. sanguinalis. The major groups of rhizobacteria were Betaproteobacteria, Gamma-proteobacteria, Chloroflexi, Actinobacteria, and unknown. Based on DGGE analysis, P. lapathifolia, found for the first time in this study growing in the presence of high TPH, may be a good species for phytoremediation of oil-contaminated soils and in particular, C. soldanella may be useful for soils with high TPH and salt concentrations. Overall, this study suggests that the plant roots, regardless of plant species, may have a similar influence on the bacterial community structure in oil-contaminated soil. PMID:20890100

Lee, Eun-Hee; Cho, Kyong-Suk; Kim, Jaisoo

2010-09-01

47

Membrane-forming lipids of wild halophytes growing under the conditions of Prieltonie of South Russia.  

PubMed

The composition of membrane-forming lipids has been examined for 10 wild halophyte species growing in southern Russian on alkaline soil. The plants belong to seven taxa of family rank: by their life form, which are semi-shrubs, herbaceous annuals, and perennial plants; their salt tolerance, which are classified as the euhalophytes, crynohalophytes, and glycohalophytes; and by their sensitivity to water, classifications of mesoxerophytes and xeromesophytes. Parallels have been found between the lipid composition and the ecological status of the plants. It has also been revealed that the similarity in the glyco- and phospholipid composition of different plant groups relates to the water factor and the type of salt accumulation, respectively. The fatty acid compositions of the examined plants is determined at the species level. PMID:24890389

Rozentsvet, Olga A; Nesterov, Victor N; Bogdanova, Elena S

2014-09-01

48

Investigations of adaptation mechanisms of different halophytes types in different soil salinity conditions (Southern Central Siberia, Russia)  

Microsoft Academic Search

High salt concentration in the soil is one of the limiting factors affecting plant growth and development. However, there are plants that are physiologically adapted to high salts concen-trations -halophytes. Studies of halophytes reveals mechanisms of adaptation to this factor. Investigations were conducted in the steppe zone of Southern Central Siberia (Russia, Khaka-sia), nearest coastal zone of the Lake Kurinka.

Natalia Slyusar; Nickolay Pechurkin

2010-01-01

49

The role of proline accumulation in halophytes.  

PubMed

It is shown that in the majority of higher plant halophytes examined proline is the major component of the amino acid pool in plants collected from the field. In Triglochin maritima L. free proline can represent 10-20% of the shoot dry weight. Under non-saline conditions proline levels are low and increase as the salinity is raised. Comparisons of inland and coastal populations of Ameria maritima Willd. suggest that the capacity to accumulate proline is correlated with salt tolerance. It is suggested that proline functions as a source of solute for intracellular osmotic adjustments under saline conditions. PMID:24442703

Stewart, G R; Lee, J A

1974-01-01

50

Role of model plant species.  

PubMed

The use of model or reference species has played a major role in furthering detailed understanding of mechanisms and processes in the plant kingdom over the past 25 years. Species which have been adopted as models for dicotyledons and monocotyledons include arabidopsis and rice and more recently brachy-podium,Such models are diploids, have few and small chromosomes, well developed genetics, rapid life cycles, are easily transformed and have extensive sets of technical resources and databases curated by international resource centres. The study of crop genomics today is deeply rooted in earlier studies on model species. Genomes of model species share reasonable genetic synteny with key crop plants which facilitates the discovery of genes and association of genes with phenotypes. While some mechanisms and processes are conserved across the plant kingdom and so can be revealed by studies on any model species,others have diverged during evolution and so are revealed by studying only a closely related model species.Examples of processes that are conserved across the plant kingdom and others that have diverged and therefore need to be understood by studying a more closely related model species are described. PMID:19347660

Flavell, Richard

2009-01-01

51

Seaweeds and halophytes to remove carbon from the atmosphere  

SciTech Connect

The utility industry and other interested parties have investigated strategies to mitigate the buildup of atmospheric CO{sub 2}. One option that has been considered is the planting of trees on a massive scale to absorb carbon through photosynthesis. A dilemma of using tree plantations, however, is that they might occupy land that will be needed for food production or other needs for an expected doubling of human population in the tropical regions. We evaluated seaweeds and salt-tolerant terrestrial plants (halophytes) to be grown on the coastal shelves and salt deserts of the world as possible alternatives to tree plantations. An estimated 1.3 {times} 10{sup 6} km{sup 2} of continental shelf and 1.3 {times} 10{sup 6} km{sup 2} of salt desert may be usable for seaweed and halophyte plantations. The production rates of managed seaweed and halophyte plantings are similar to managed tree plantations. Seaweeds and halophytes could conceivably absorb 10--20% of annual fossil fuel carbon emissions through biomass production, similar to estimates made for tree plantations. Present costs of halophyte biomass production are similar to costs of tree biomass production, whereas seaweed biomass is much more expensive to produce using existing technologies. Storage of seaweed carbon might be accomplished by allowing it to enter the sediment detritus chain whereas halophyte carbon might be sequestered in the soil, or used as biomass fuel. As has been concluded for reforestation, these saline biomass crops could at best help delay rather than solve the carbon dioxide build-up problem. 1 fig., 13 tabs.

Glenn, E.P.; Kent, K.J.; Thompson, T.L.; Frye, R.J. (Arizona Univ., Tucson, AZ (USA). Environmental Research Lab.)

1991-02-01

52

Evidence for bioaccumulation of PAHs within internal shoot tissues by a halophytic plant artificially exposed to petroleum-polluted sediments.  

PubMed

Polycyclic aromatic hydrocarbons (PAHs) are widespread environmental pollutants of natural and anthropic origins. Despite their poor water solubility, they can be taken up and bioaccumulated by plants. This study was aimed at determining whether the PAHs present in sediments artificially polluted by heavy fuel oil are transferred to shoots of a coastal and edible plant, Salicornia fragilis Ball et Tutin. Bioaccumulation was quantified after a one-week exposure to sediments polluted with 0.2%, 2% and 20% fuel oil (w/w) and over a six-week monitoring at 0.2%. Quantification by GC-MS of PAH amounts in plants and sediments evidenced a bioaccumulation in the shoots by a soil-to-plant transfer through the root system. This bioaccumulation depended on the duration of exposure and on the substratum contamination. PAHs distributions in plants and sediments looked alike with a predominance of low- and medium-weight hydrocarbons. Moreover, high-weight PAHs were also detected in the upper part of plants. PMID:16527326

Meudec, A; Dussauze, J; Deslandes, E; Poupart, N

2006-10-01

53

Responses of halophytes to high salinities and low water potentials.  

PubMed

The effects of nonsaline polyethylene glycol (PEG)-6000 and saline seawater solutions of comparable osmotic potential on the concentrations of organic solutes and inorganic ions in the tissues of halophytes (Plantago maritima L., Triglochin maritima L., Limonium vulgare Mill., Halimione portulacoides (L.) Aell) have been investigated. Studies were made to determine whether high salinities induce specific ion effects that are absent in plants grown in nonsaline solutions of comparable osmotic potential. Over-all, the responses of each species to the two different treatments (seawater or PEG) are similar; the accumulation of organic solutes (compatible osmotica) in tissues is primarily correlated with a decrease in the osmotic potential of culture solutions. Depending on the species, sorbitol, proline, reducing sugars, quaternary ammonium compounds, and alpha-amino nitrogen accumulate in tissues as the water potential of the tissues falls. Within a species there are differences in the concentrations of inorganic ions and organic solutes between roots and shoots of plants grown at high salinities or at high concentrations of PEG. PMID:16661119

Jefferies, R L; Rudmik, T; Dillon, E M

1979-12-01

54

Effectiveness of the aquatic halophyte Sarcocornia perennis spp. perennis as a biotool for ecological restoration of metal-contaminated salt marshes  

Technology Transfer Automated Retrieval System (TEKTRAN)

Ecological restoration and creation of salt marshes is needed to compensate for their degradation and loss, but little is known about halophytes as plant biotools in restoration projects. Restoration plantings of halophytes have been established following eradication of invasive populations of the e...

55

Growth responses and ion accumulation in the halophytic legume Prosopis strombulifera are determined by Na2 SO4 and NaCl.  

PubMed

Halophytes are potential gene sources for genetic manipulation of economically important crop species. This study addresses the physiological responses of a widespread halophyte, Prosopis strombulifera (Lam.) Benth to salinity. We hypothesised that increasing concentrations of the two major salts present in soils of central Argentina (Na2 SO4 , NaCl, or their iso-osmotic mixture) would produce distinct physiological responses. We used hydroponically grown P. strombulifera to test this hypothesis, analysing growth parameters, water relations, photosynthetic pigments, cations and anions. These plants showed a halophytic response to NaCl, but strong general inhibition of growth in response to iso-osmotic solutions containing Na2 SO4 . The explanation for the adaptive success of P. strombulifera in high NaCl conditions seems to be related to a delicate balance between Na(+) accumulation (and its use for osmotic adjustment) and efficient compartmentalisation in vacuoles, the ability of the whole plant to ensure sufficient K(+) supply by maintaining high K(+) /Na(+) discrimination, and maintenance of normal Ca(2+) levels in leaves. The three salt treatments had different effects on the accumulation of ions. Findings in bi-saline-treated plants were of particular interest, where most of the physiological parameters studied showed partial alleviation of SO4 (2-) -induced toxicity by Cl(-) . Thus, discussions on physiological responses to salinity could be further expanded in a way that more closely mimics natural salt environments. PMID:23869994

Reginato, M; Sosa, L; Llanes, A; Hampp, E; Vettorazzi, N; Reinoso, H; Luna, V

2013-07-22

56

High apoplastic solute concentrations in leaves alter water relations of the halophytic shrub, Sarcobatus vermiculatus  

Microsoft Academic Search

Predawn plant water potential (Ww) is used to estimate soil moisture available to plants because plants are expected to equilibrate with the root-zone Ww. Although this equilibrium assumption provides the basis for interpreting many physiological and ecological param- eters, much work suggests predawn plant Ww is often more negative than root-zone soil Ww. For many halophytes even when soils are

J. J. James; N. N. Alder; K. H. Muhling; A. E. Lauchli; K. A. Shackel; L. A. Donovan; J. H. Richards

2006-01-01

57

Response to salinity in the homoploid hybrid species Helianthus paradoxus and its progenitors H. annuus and H. petiolaris  

Microsoft Academic Search

Summary •T o contribute to the understanding of ecological differentiation in speciation, we compared salinity responses of the halophytic diploid hybrid species Helianthus paradoxus and its glycophytic progenitors Helianthus annuus and Helianthus petiolaris . • Plants of three populations of each species were subjected to a control (nonsaline) and three salinity treatments, including one simulating the ion composition in the

Sophie Karrenberg; Cecile Edelist; Christian Lexer; Loren Rieseberg

2006-01-01

58

Genome structures and halophyte-specific gene expression of the extremophile Thellungiella parvula in comparison with Thellungiella salsuginea (Thellungiella halophila) and Arabidopsis.  

PubMed

The genome of Thellungiella parvula, a halophytic relative of Arabidopsis (Arabidopsis thaliana), is being assembled using Roche-454 sequencing. Analyses of a 10-Mb scaffold revealed synteny with Arabidopsis, with recombination and inversion and an uneven distribution of repeat sequences. T. parvula genome structure and DNA sequences were compared with orthologous regions from Arabidopsis and publicly available bacterial artificial chromosome sequences from Thellungiella salsuginea (previously Thellungiella halophila). The three-way comparison of sequences, from one abiotic stress-sensitive species and two tolerant species, revealed extensive sequence conservation and microcolinearity, but grouping Thellungiella species separately from Arabidopsis. However, the T. parvula segments are distinguished from their T. salsuginea counterparts by a pronounced paucity of repeat sequences, resulting in a 30% shorter DNA segment with essentially the same gene content in T. parvula. Among the genes is SALT OVERLY SENSITIVE1 (SOS1), a sodium/proton antiporter, which represents an essential component of plant salinity stress tolerance. Although the SOS1 coding region is highly conserved among all three species, the promoter regions show conservation only between the two Thellungiella species. Comparative transcript analyses revealed higher levels of basal as well as salt-induced SOS1 expression in both Thellungiella species as compared with Arabidopsis. The Thellungiella species and other halophytes share conserved pyrimidine-rich 5' untranslated region proximal regions of SOS1 that are missing in Arabidopsis. Completion of the genome structure of T. parvula is expected to highlight distinctive genetic elements underlying the extremophile lifestyle of this species. PMID:20833729

Oh, Dong-Ha; Dassanayake, Maheshi; Haas, Jeffrey S; Kropornika, Anna; Wright, Chris; d'Urzo, Matilde Paino; Hong, Hyewon; Ali, Shahjahan; Hernandez, Alvaro; Lambert, Georgina M; Inan, Gunsu; Galbraith, David W; Bressan, Ray A; Yun, Dae-Jin; Zhu, Jian-Kang; Cheeseman, John M; Bohnert, Hans J

2010-11-01

59

The Invasive Plant Species Education Guide  

ERIC Educational Resources Information Center

To help high school students gain a solid understanding of invasive plant species, university faculty and students from the University of Wisconsin-Stout (UW-Stout) and a local high school teacher worked together to develop the Invasive Plant Species (IPS) Education Guide. The IPS Education Guide includes nine lessons that give students an…

Mason, Kevin; James, Krista; Carlson, Kitrina; D'Angelo, Jean

2010-01-01

60

Endangered Species (Plants). LC Science Tracer Bullet.  

ERIC Educational Resources Information Center

This guide is intended for those who wish to study the literature dealing with various aspects of endangered plant species. This document includes the following sections, some of which are bibliographies: (1) "Introductions to the Topic"; (2) "Subject Headings" (for endangered species of plants used by the Library of Congress); (3) "General…

Niskern, Diana, Comp.

61

A computerized plant species recognition system  

Microsoft Academic Search

In this paper, a computerized plant species recognition system (CPSRS) is presented. CPSRS is a Web-based application, which provides a familiar and efficient way to search and identify plant species in the field. It is built on the Java Web infrastructure to support platform-independent application. The Java applets and servlets are adopted to balance the computing burden in both client

Yanhua Ye; Chun Chen; Chun-Tak Li; Hong Fu; Zheru Chi

2004-01-01

62

The Invasive Plant Species Education Guide  

NSDL National Science Digital Library

To help high school students gain a solid understanding of invasive plant species, university faculty and students from the University of Wisconsin-Stout (UW-Stout) and a local high school teacher worked together to develop the Invasive Plant Species (IPS

Jean D'Angelo

2010-04-01

63

Salt tolerance is related to a specific antioxidant response in the halophyte cordgrass, Spartina densiflora  

NASA Astrophysics Data System (ADS)

Halophytes usually have a robust antioxidative defense system to alleviate oxidative damage during salt stress. Spartina densiflora is a colonizing halophyte cordgrass, native of South America, which has become a common species in salt marshes of northern hemisphere, where it is ousting indigenous species. This study addressed salinity stress in S. densiflora; the occurrence of oxidative stress and the possible involvement of the antioxidative system in its high salt tolerance were studied. Plants were evaluated at in situ conditions, in the laboratory during a 28 day-acclimation period (AP) in clean substrate irrigated with a control salt content of 4 g L-1 (68 mM) and during a subsequent 28 day-treatment period (TP) exposed to different NaCl concentrations: control (68 mM), 428 mM or 680 mM. In the in situ setting, the high leave Na+ content was accompanied by high levels of hydroperoxides and reduced levels of total chlorophyll and carotenes, which correlated with enhanced activation of antioxidant defense biomarkers as total ascorbic acid (AA) content and guaiacol peroxidase (POD: EC 1.11.1.7)), catalase (CAT: EC 1.11.1.6) and ascorbate peroxidase (APX: EC 1.11.1.11) activities. Throughout the AP, leave Na+ and oxidative stress markers decreased concomitantly and reached stable low levels. During the TP, dose and time-dependent accumulation of Na+ in high NaCl-treated plants was concurrent with a decrease in content of total chlorophyll and carotenes and with an increase in the levels of total AA and CAT and APX activities. In conclusion, as hypothesized, high salinity induces conditions of oxidative stress in S. densiflora, so that its salt tolerance appears to be related to the implementation of a specific antioxidant response. This may account for Spartina densiflora's successful adaptation to habitats with fluctuating salinity and favour its phytoremediation potential.

Canalejo, Antonio; Martínez-Domínguez, David; Córdoba, Francisco; Torronteras, Rafael

2014-06-01

64

Why Some Plant Species Are Rare  

PubMed Central

Biodiversity, including plant species diversity, is threatened worldwide as a result of anthropogenic pressures such as an increase of pollutants and climate change. Rare species in particular are on the verge of becoming extinct. It is still unclear as to why some plant species are rare and others are not. Are they rare due to: intrinsic reasons, dispersal capacity, the effects of management or abiotic circumstances? Habitat preference of rare plant species may play an important role in determining why some species are rare. Based on an extensive data set of soil parameters we investigated if rarity is due to a narrow habitat preference for abiotic soil parameters. For 23 different abiotic soil parameters, of which the most influential were groundwater-table, soil-pH and nutrient-contents, we estimated species responses for common and rare species. Based on the responses per species we calculated the range of occurrence, the range between the 5 and 95 percentile of the response curve giving the habitat preference. Subsequently, we calculated the average response range for common and rare species. In addition, we designed a new graphic in order to provide a better means for presentation of the results. The habitat preferences of rare species for abiotic soil conditions are significantly narrower than for common species. Twenty of the twenty-three abiotic parameters showed on average significantly narrower habitat preferences for rare species than for common species; none of the abiotic parameters showed on average a narrower habitat preference for common species. The results have major implications for the conservation of rare plant species; accordingly management and nature development should be focussed on the maintenance and creation of a broad range of environmental conditions, so that the requirements of rare species are met. The conservation of (abiotic) gradients within ecosystems is particularly important for preserving rare species. PMID:25054424

Wamelink, G. W. Weiger; Goedhart, Paul W.; Frissel, Josep Y.

2014-01-01

65

Why some plant species are rare.  

PubMed

Biodiversity, including plant species diversity, is threatened worldwide as a result of anthropogenic pressures such as an increase of pollutants and climate change. Rare species in particular are on the verge of becoming extinct. It is still unclear as to why some plant species are rare and others are not. Are they rare due to: intrinsic reasons, dispersal capacity, the effects of management or abiotic circumstances? Habitat preference of rare plant species may play an important role in determining why some species are rare. Based on an extensive data set of soil parameters we investigated if rarity is due to a narrow habitat preference for abiotic soil parameters. For 23 different abiotic soil parameters, of which the most influential were groundwater-table, soil-pH and nutrient-contents, we estimated species responses for common and rare species. Based on the responses per species we calculated the range of occurrence, the range between the 5 and 95 percentile of the response curve giving the habitat preference. Subsequently, we calculated the average response range for common and rare species. In addition, we designed a new graphic in order to provide a better means for presentation of the results. The habitat preferences of rare species for abiotic soil conditions are significantly narrower than for common species. Twenty of the twenty-three abiotic parameters showed on average significantly narrower habitat preferences for rare species than for common species; none of the abiotic parameters showed on average a narrower habitat preference for common species. The results have major implications for the conservation of rare plant species; accordingly management and nature development should be focussed on the maintenance and creation of a broad range of environmental conditions, so that the requirements of rare species are met. The conservation of (abiotic) gradients within ecosystems is particularly important for preserving rare species. PMID:25054424

Wamelink, G W Weiger; Goedhart, Paul W; Frissel, Josep Y

2014-01-01

66

Two Cladonia Lichen Species Among Blueberry Plants  

USGS Multimedia Gallery

Two Cladonia lichen species, C. stellaris and C. rangiferina are pictured here among some blueberry plants in Newfoundland.  Lichens -- which are often mistaken for moss -- are unusual plant-like organisms that are actually symbioses of fungi, algae and bacteria living together. They usually li...

67

Comparative chlorine requirements of different plant species  

Microsoft Academic Search

Summary Recognition of chlorine as a plant micronutrient has been extended to include ten species. Acute chlorine deficiencies or decreased yields were produced with lettuce, tomato, cabbage, carrot, sugar beet, barley, alfalfa, buckwheat, corn, and beans. Squash plants showed neither loss in yield nor other deficiency symptoms when cultured at the same time and under the same conditions as the

C. M. Johnson; P. R. Stout; T. C. Broyer; A. B. Carlton

1957-01-01

68

SENSITVE PLANT SPECIES AND NOXIOUS WEED ASSESSMENT  

E-print Network

This report summarizes vegetation survey results for the proposed Boulder Bay Resort in Crystal Bay, Lake Tahoe, Nevada. The proposed project is located on private land, including the existing Tahoe Biltmore and the old Tahoe Mariner site. The survey addressed special interest, proposed, endangered, threatened, and sensitive plant species as well as noxious and invasive species.

unknown authors

2009-01-01

69

ALLELOPATHIC PLANTS. XVI. ARTEMISIA SPECIES  

Technology Transfer Automated Retrieval System (TEKTRAN)

The allelopathic effects of Artemisia annua, A. californica, A. princeps var. orientalis, A. tridentata, and A. vulgaris are reviewed. Naturally produced allelopathic compounds that reach target species via natural methods of dissemination (air, soil, and rain) are emphasized. Possible modes of ac...

70

Two new flavonoid glycosides from the halophyte Limonium franchetii.  

PubMed

Two new flavonoid glycosides, named quercetin-3-O-(2?-O-tigloyl)-?-L-rhamnopyranoside (1) and quercetin-3-O-(3?-O-tigloyl)-?-L-rhamnopyranoside (2), together with 10 known flavonoids (3-12), were isolated from the whole plant of the halophyte Limonium franchetii. Their structures were elucidated on the basis of extensive spectroscopic analysis including 2D NMR and HR-EI-MS. In addition, primary bioassays showed that compound 1 had moderate cytotoxic activity against rat C6 glioma cell lines. PMID:24597719

Kong, Na-Na; Fang, Sheng-Tao; Wang, Jian-Hua; Wang, Zhen-Hua; Xia, Chuan-Hai

2014-01-01

71

Responses of Halophytes to High Salinities and Low Water Potentials 1  

PubMed Central

The effects of nonsaline polyethylene glycol (PEG)-6000 and saline seawater solutions of comparable osmotic potential on the concentrations of organic solutes and inorganic ions in the tissues of halophytes (Plantago maritima L., Triglochin maritima L., Limonium vulgare Mill., Halimione portulacoides (L.) Aell) have been investigated. Studies were made to determine whether high salinities induce specific ion effects that are absent in plants grown in nonsaline solutions of comparable osmotic potential. Over-all, the responses of each species to the two different treatments (seawater or PEG) are similar; the accumulation of organic solutes (compatible osmotica) in tissues is primarily correlated with a decrease in the osmotic potential of culture solutions. Depending on the species, sorbitol, proline, reducing sugars, quaternary ammonium compounds, and ?-amino nitrogen accumulate in tissues as the water potential of the tissues falls. Within a species there are differences in the concentrations of inorganic ions and organic solutes between roots and shoots of plants grown at high salinities or at high concentrations of PEG. PMID:16661119

Jefferies, Robert L.; Rudmik, Tony; Dillon, Eva M.

1979-01-01

72

Ensemble habitat mapping of invasive plant species.  

PubMed

Ensemble species distribution models combine the strengths of several species environmental matching models, while minimizing the weakness of any one model. Ensemble models may be particularly useful in risk analysis of recently arrived, harmful invasive species because species may not yet have spread to all suitable habitats, leaving species-environment relationships difficult to determine. We tested five individual models (logistic regression, boosted regression trees, random forest, multivariate adaptive regression splines (MARS), and maximum entropy model or Maxent) and ensemble modeling for selected nonnative plant species in Yellowstone and Grand Teton National Parks, Wyoming; Sequoia and Kings Canyon National Parks, California, and areas of interior Alaska. The models are based on field data provided by the park staffs, combined with topographic, climatic, and vegetation predictors derived from satellite data. For the four invasive plant species tested, ensemble models were the only models that ranked in the top three models for both field validation and test data. Ensemble models may be more robust than individual species-environment matching models for risk analysis. PMID:20136746

Stohlgren, Thomas J; Ma, Peter; Kumar, Sunil; Rocca, Monique; Morisette, Jeffrey T; Jarnevich, Catherine S; Benson, Nate

2010-02-01

73

Ensemble habitat mapping of invasive plant species  

USGS Publications Warehouse

Ensemble species distribution models combine the strengths of several species environmental matching models, while minimizing the weakness of any one model. Ensemble models may be particularly useful in risk analysis of recently arrived, harmful invasive species because species may not yet have spread to all suitable habitats, leaving species-environment relationships difficult to determine. We tested five individual models (logistic regression, boosted regression trees, random forest, multivariate adaptive regression splines (MARS), and maximum entropy model or Maxent) and ensemble modeling for selected nonnative plant species in Yellowstone and Grand Teton National Parks, Wyoming; Sequoia and Kings Canyon National Parks, California, and areas of interior Alaska. The models are based on field data provided by the park staffs, combined with topographic, climatic, and vegetation predictors derived from satellite data. For the four invasive plant species tested, ensemble models were the only models that ranked in the top three models for both field validation and test data. Ensemble models may be more robust than individual species-environment matching models for risk analysis. ?? 2010 Society for Risk Analysis.

Stohlgren, T.J.; Ma, P.; Kumar, S.; Rocca, M.; Morisette, J.T.; Jarnevich, C.S.; Benson, N.

2010-01-01

74

Evidence for electrotropism in some plant species.  

PubMed

The ever-present global Atmospheric Electrical Field (AEF) is used by many plant species. There are many natural habitats with electrotropic plants and habitats with no AEF. The plants growing there are not electrotropic, like the plants growing under the canopies of the trees or the Arecibo radio telescope. Examples are given of different plants which belong to one or the other class, and the criteria how to distinguish them. In addition to natural habitat observations, laboratory experiments were run in search of the sensitivity of electrotropic effect to different electric field intensities. During a few years, it was established that in very strong fields (of the order of 1 MV/m) all plants respond immediately to the field. This type of reaction is due to the Coulomb forces, but electrotropism depends on electric field interaction with ions. The "reference field" (130 V/m) was always used with stronger fields in the several kV/m range which enhance plant growth rate and size similar to plant growth hormones. Surprising effects were also observed with reversed and horizontal field polarity. In conclusion electrotropic plants deprived of the electrical field do not develop as expected, as can be seen in Biosphere 2. This is an instructive example of what happens when we forget to provide the plants with this vital natural environmental factor. Electrical fields of different intensity, directions and configurations are cheap and easy to generate. PMID:11803965

Gorgolewski, S; Rozej, B

2001-01-01

75

Invasive Plant Species and the Ornamental Horticulture Industry  

E-print Network

Chapter 9 Invasive Plant Species and the Ornamental Horticulture Industry Alex X. Niemiera the various fundamental biological factors of plant invasion, as well as the environmental impacts to mitigate its role in dispersing invasive, nonnative plant species. Keywords Ornamental horticulture

Von Holle, Betsy

76

Plant species descriptions show signs of disease.  

PubMed

It is well known that diseases can greatly influence the morphology of plants, but often the incidence of disease is either too rare or the symptoms too obvious for the 'abnormalities' to cause confusion in systematics. However, we have recently come across several misinterpretations of disease-induced traits that may have been perpetuated into modern species inventories. Anther-smut disease (caused by the fungus Microbotryum violaceum) is common in many members of the Caryophyllaceae and related plant families. This disease causes anthers of infected plants to be filled with dark-violet fungal spores rather than pollen. Otherwise, their vegetative morphology is within the normal range of healthy plants. Here, we present the results of a herbarium survey showing that a number of type specimens (on which the species name and original description are based) in the genus Silene from Asia are diseased with anther smut. The primary visible disease symptom, namely the dark-violet anthers, is incorporated into the original species descriptions and some of these descriptions have persisted unchanged into modern floras. This raises the question of whether diseased type specimens have erroneously been given unique species names. PMID:14667368

Hood, Michael E; Antonovics, Janis

2003-11-01

77

Plant species descriptions show signs of disease.  

PubMed Central

It is well known that diseases can greatly influence the morphology of plants, but often the incidence of disease is either too rare or the symptoms too obvious for the 'abnormalities' to cause confusion in systematics. However, we have recently come across several misinterpretations of disease-induced traits that may have been perpetuated into modern species inventories. Anther-smut disease (caused by the fungus Microbotryum violaceum) is common in many members of the Caryophyllaceae and related plant families. This disease causes anthers of infected plants to be filled with dark-violet fungal spores rather than pollen. Otherwise, their vegetative morphology is within the normal range of healthy plants. Here, we present the results of a herbarium survey showing that a number of type specimens (on which the species name and original description are based) in the genus Silene from Asia are diseased with anther smut. The primary visible disease symptom, namely the dark-violet anthers, is incorporated into the original species descriptions and some of these descriptions have persisted unchanged into modern floras. This raises the question of whether diseased type specimens have erroneously been given unique species names. PMID:14667368

Hood, Michael E; Antonovics, Janis

2003-01-01

78

Species-specific positive effects in an annual plant community  

Microsoft Academic Search

Plant facilitation studies commonly test the nurse-plant hypothesis wherein an adult shrub species enhances the establishment of associated herbaceous species under its canopy. Using field and glasshouse experiments, this hypothesis is extended by testing the following four predictions: (1) nurse-plant effects can occur between species with similar life- forms and phenologies (2) positive effects are species specific, (3) the outcome

Christopher J. Lortie; Roy Turkington

2008-01-01

79

[Invasion and its effects of xerarch halophytes in reclaimed tidal wetlands].  

PubMed

With the reclaimed tidal wetland of Chongming Dongtan in Shanghai as a case, and based on the landscape pattern analysis of colored infrared aerial photographs and field survey, this paper studied the invasion of xerarch halophytes and its effects on the original reed community in the wetland after artificial drainage. The results showed that in the test reclaimed tidal wetland area, the xerarch halophyte community with Tripolium vulgare as edificator was spreading from northeast to southwest at a high speed of 143 m per year, with the original reed patch reduced and broken sharply, causing a 22.7 times increase in patch density index and a 1.3 times increase in shape index. After the growth seasons in 2006 and 2007, the biomass of T. vulgare in the plant community reached as high as 2783.8 g x m(-2), occupying 98% of the total, and the importance value reached 88%. At the mean time, the biomass and importance value of original reed decreased 98% and 83%, respectively. The invasion process of xerarch halophytes was meaningfully correlated with the moisture content and salinity in 0-20 cm soil layer. To effectively control the rapid invasion of xerarch halophytes, the mechanisms of their invasion and the strategies of rational and dynamic drainage management should be deeply studied. PMID:19449562

Gong, Jin-nan; Wang, Kai-yun; Zhang, Chao; Ma, Yong-liang

2009-01-01

80

Screening of 18 species for digestate phytodepuration.  

PubMed

This experiment assesses the aptitude of 18 species in treating the digestate liquid fraction (DLF) in a floating wetland treatment system. The pilot system was created in NE Italy in 2010 and consists of a surface-flow system with 180 floating elements (Tech-IA®) vegetated with ten halophytes and eight other wetland species. The species were transplanted in July 2011 in basins filled with different proportions of DLF/water (DLF/w); periodic increasing of the DLF/w ratio was imposed after transplanting, reaching the worst conditions for plants in summer 2012 (highest EC value 7.3 mS cm/L and NH4-N content 225 mg/L). It emerged that only Cynodon dactylon, Typha latifolia, Elytrigia atherica, Halimione portulacoides, Salicornia fruticosa, Artemisia caerulescens, Spartina maritima and Puccinellia palustris were able to survive under the system conditions. Halophytes showed higher dry matter production than other plants. The best root development (up to 40-cm depth) was recorded for Calamagrostis epigejos, Phragmites australis, T. latifolia and Juncus maritimus. The highest nitrogen (10-15 g/m(2)) and phosphorus (1-4 g/m(2)) uptakes were obtained with P. palustris, Iris pseudacorus and Aster tripolium. In conclusion, two halophytes, P. palustris and E. atherica, present the highest potential to be used to treat DLF in floating wetlands. PMID:25005162

Pavan, Francesca; Breschigliaro, Simone; Borin, Maurizio

2015-02-01

81

RESPONSE OF WETLAND PLANT SPECIES TO HYDROLOGIC CONDITIONS  

EPA Science Inventory

Understanding hydrologic requirements of native and introduced species is critical to sustaining native plant communities in wetlands of disturbed landscapes. We examined plant assemblages and 31 species from emergent wetlands in an urbanizing area of the Pacific Northwest, USA,...

82

RESPONSE OF WETLAND PLANT SPECIES TO HYDROLOGIC CONDITIONS  

EPA Science Inventory

Understanding hydrologic requirements of native and introduced species is critical to sustaining native plant communities in wetlands of disturbed landscapes. We examined plant assemblages and 31 species from emergent wetlands in an urbanizing area of the Pacific Northwest, USA, ...

83

American Journal of Plant Sciences, 2011, 2, 808-815 doi:10.4236/ajps.2011.26095 Published Online December 2011 (http://www.SciRP.org/journal/ajps)  

E-print Network

of Tamarix ramosissima to Extreme NaCl Concentrations Jacob M. Carter1,2* , Jesse B. Nippert1,3 1 Division of an introduced halophytic species, Tamarix ramosissima (Ledeb.). The physiological responses of Tamarix measured several whole plant and leaf-level physiological responses of Tamarix ramosissima cuttings grown

Nippert, Jesse

84

Interactions Among Grassland Plant Species, Microbial Communities, and Soil Processes  

Microsoft Academic Search

Plant-microbial interactions are thought to be an important determinant of ecosystem processes, yet we do not know whether impacts of plant species on soil microbial community composition translate to impacts on function. We established field plots in a California annual grassland of five plant monocultures for two years to determine the effects of different plant species on the composition of

V. Eviner; M. Waldrop; E. Schwartz; J. Pett-Ridge; M. Firestone

2002-01-01

85

Salt stimulation of growth and photosynthesis in an extreme halophyte, Arthrocnemum macrostachyum.  

PubMed

Halophytes that are capable of tolerating a wide range of salinity may grow best at intermediate salinities, but the physiological mechanisms underlying positive growth responses to salinity are not clear. This work investigated the growth of Arthrocnemum macrostachyum (Moric) C. Koch (a halophytic C3 shrub) over a wide range of salinities, and the extent to which its responses can be explained by photosynthetic physiology. Growth, gas exchange and chlorophyll fluorescence characteristics of plants were examined in a glasshouse experiment; tissue concentrations of photosynthetic pigments, ash, sodium, potassium, calcium and nitrogen were also determined. Plants showed marked stimulation of growth by salt, with a broad optimum of 171-510 mm NaCl for relative growth rate (RGR). Stimulation of RGR appeared to depend mainly on an increase in specific shoot area, whereas reduced RGR at high salinity (1030 mm) could be attributed to a combination of lower unit shoot (leaf) rate and lower shoot mass fraction. The non-saline treatment plants had the greatest fraction of non-photosynthetic, atrophied surface area. However, net photosynthesis (A) was also stimulated by NaCl, with an optimum of c. 510 mm NaCl. The responses of A to salinity could be accounted for largely by limitation by stomatal conductance (Gs) and intercellular CO(2) concentration (Ci). Even the most hypersaline treatment apparently had no effect on photosystem II (PSII) function, and this resistance could be an important strategy for this halophyte in saline soils. In contrast, Fv/Fm indicated that absence of salt represents an environmental stress for A. macrostachyum and this could be a contributory factor to salt stimulation of A. Notwithstanding the importance of the ability to develop and maintain assimilatory surface area under saline conditions, stimulatory effects on A also appear to be part of a suite of halophytic adaptations in this plant. PMID:20653890

Redondo-Gómez, S; Mateos-Naranjo, E; Figueroa, M E; Davy, A J

2010-01-01

86

Biophysical and biochemical constraints imposed by salt stress: learning from halophytes  

PubMed Central

Soil salinization is one of the most important factors impacting plant productivity. About 3.6 billion of the world’s 5.2 billion ha of agricultural dry land, have already suffered erosion, degradation, and salinization. Halophytes are typically considered as plants able to complete their life cycle in environments where the salt concentration is above 200 mM NaCl. Salinity adjustment is a complex phenomenon but essential mechanism to overcome salt stress, with both biophysical and biochemical implications. At this level, halophytes evolved in several directions, adopting different strategies. Otherwise, the lack of adaptation to a salt environment would negatively affect their electron transduction pathways and the entire energetic metabolism, the foundation of every plant photosynthesis and biomass production. The maintenance of ionic homeostasis is in the basis of all cellular counteractive measures, in particular in terms of redox potential and energy transduction. In the present work the biophysical mechanisms underlying energy capture and transduction in halophytes are discussed alongside with their relation with biochemical counteractive mechanisms, integrating data from photosynthetic light harvesting complexes, electron transport chains to the quinone pools, carbon fixation, and energy dissipation metabolism. PMID:25566311

Duarte, Bernardo; Sleimi, Noomene; Caçador, Isabel

2014-01-01

87

Southern Wetland Flora: Field Office Guide to Plant Species  

NSDL National Science Digital Library

The US Department of Agriculture's (USDA) Soil Conservation Service branch in Fort Worth, Texas produced the Southern Wetland Flora: Field Office Guide to Plant Species. The guide contains black and white illustrations, full species descriptions (with color photographs, illustrations, and small distribution maps), illustrated glossaries, an alphabetical species list (provides common and scientific names for 300 species of vascular plants), and a key to generalized plant groups. The guide may be browsed online or downloaded in .zip format.

88

Northeast Wetland Flora: Field Office Guide to Plant Species  

NSDL National Science Digital Library

The USDA Natural Resource Conservation Service's Northeast National Technical Center in Chester, Pennsylvania produced Northeast Wetland Flora: Field Office Guide to Plant Species. The guide contains black and white illustrations, full species descriptions (with color photographs, illustrations, and small distribution maps), illustrated glossaries, an alphabetical species list (provides common and scientific names for 300 species of vascular plants), and a key to generalized plant groups. The guide may be browsed online or downloaded in .zip format.

89

Reduced Tonoplast Fast-Activating and Slow-Activating Channel Activity Is Essential for Conferring Salinity Tolerance in a Facultative Halophyte, Quinoa1[C][W][OA  

PubMed Central

Halophyte species implement a “salt-including” strategy, sequestering significant amounts of Na+ to cell vacuoles. This requires a reduction of passive Na+ leak from the vacuole. In this work, we used quinoa (Chenopodium quinoa) to investigate the ability of halophytes to regulate Na+-permeable slow-activating (SV) and fast-activating (FV) tonoplast channels, linking it with Na+ accumulation in mesophyll cells and salt bladders as well as leaf photosynthetic efficiency under salt stress. Our data indicate that young leaves rely on Na+ exclusion to salt bladders, whereas old ones, possessing far fewer salt bladders, depend almost exclusively on Na+ sequestration to mesophyll vacuoles. Moreover, although old leaves accumulate more Na+, this does not compromise their leaf photochemistry. FV and SV channels are slightly more permeable for K+ than for Na+, and vacuoles in young leaves express less FV current and with a density unchanged in plants subjected to high (400 mm NaCl) salinity. In old leaves, with an intrinsically lower density of the FV current, FV channel density decreases about 2-fold in plants grown under high salinity. In contrast, intrinsic activity of SV channels in vacuoles from young leaves is unchanged under salt stress. In vacuoles of old leaves, however, it is 2- and 7-fold lower in older compared with young leaves in control- and salt-grown plants, respectively. We conclude that the negative control of SV and FV tonoplast channel activity in old leaves reduces Na+ leak, thus enabling efficient sequestration of Na+ to their vacuoles. This enables optimal photosynthetic performance, conferring salinity tolerance in quinoa species. PMID:23624857

Bonales-Alatorre, Edgar; Shabala, Sergey; Chen, Zhong-Hua; Pottosin, Igor

2013-01-01

90

Physiological responses of a halophytic shrub to salt stress by Na2SO4 and NaCl: oxidative damage and the role of polyphenols in antioxidant protection.  

PubMed

Salt stress conditions lead to increased production of reactive oxygen species (ROS) in plant cells. Halophytes have the ability to reduce these toxic ROS by means of a powerful antioxidant system that includes enzymatic and non-enzymatic components. In this research, we used the halophytic shrub Prosopis strombulifera to investigate whether the ability of this species to grow under increasing salt concentrations and mixtures was related to the synthesis of polyphenolic compounds and to the maintenance of leaf pigment contents for an adequate photosynthetic activity. Seedlings of P. strombulifera were grown hydroponically in Hoagland's solution, gradually adding Na2SO4 and NaCl separately or in mixtures until reaching final osmotic potentials of -1, -1.9 and -2.6 MPa. Control plants were allowed to develop in Hoagland's solution without salt. Oxidative damage in tissues was determined by H2O2 and malondialdehyde content. Leaf pigment analysis was performed by high-performance liquid chromatography with ultraviolet, and total phenols, total flavonoids, total flavan-3-ols, condensed tannins, tartaric acid esters and flavonols were spectrophotometrically assayed. Treatment with Na2SO4 increased H2O2 production and lipid peroxidation in tissues and induced a sharp increase in flavonoid compounds (mainly flavan-3-ols) and consequently in the antioxidant activity. Also, Na2SO4 treatment induced an increased carotenoid/chlorophyll ratio, which may represent a strategy to protect photosystems against photooxidation. NaCl treatment, however, did not affect H2O2 content, lipid peroxidation, pigments or polyphenols synthesis. The significant accumulation of flavonoids in tissues under Na2SO4 treatment and their powerful antioxidant activity indicates a role for these compounds in counteracting the oxidative damage induced by severe salt stress, particularly, ionic stress. We demonstrate that ionic interactions between different salts in salinized soils modify the biochemical and morpho-physiological responses of P. strombulifera plants to salinity. PMID:25063834

Reginato, Mariana A; Castagna, Antonella; Furlán, Ana; Castro, Stella; Ranieri, Annamaria; Luna, Virginia

2014-01-01

91

Physiological responses of a halophytic shrub to salt stress by Na2SO4 and NaCl: oxidative damage and the role of polyphenols in antioxidant protection  

PubMed Central

Salt stress conditions lead to increased production of reactive oxygen species (ROS) in plant cells. Halophytes have the ability to reduce these toxic ROS by means of a powerful antioxidant system that includes enzymatic and non-enzymatic components. In this research, we used the halophytic shrub Prosopis strombulifera to investigate whether the ability of this species to grow under increasing salt concentrations and mixtures was related to the synthesis of polyphenolic compounds and to the maintenance of leaf pigment contents for an adequate photosynthetic activity. Seedlings of P. strombulifera were grown hydroponically in Hoagland's solution, gradually adding Na2SO4 and NaCl separately or in mixtures until reaching final osmotic potentials of ?1, ?1.9 and ?2.6 MPa. Control plants were allowed to develop in Hoagland's solution without salt. Oxidative damage in tissues was determined by H2O2 and malondialdehyde content. Leaf pigment analysis was performed by high-performance liquid chromatography with ultraviolet, and total phenols, total flavonoids, total flavan-3-ols, condensed tannins, tartaric acid esters and flavonols were spectrophotometrically assayed. Treatment with Na2SO4 increased H2O2 production and lipid peroxidation in tissues and induced a sharp increase in flavonoid compounds (mainly flavan-3-ols) and consequently in the antioxidant activity. Also, Na2SO4 treatment induced an increased carotenoid/chlorophyll ratio, which may represent a strategy to protect photosystems against photooxidation. NaCl treatment, however, did not affect H2O2 content, lipid peroxidation, pigments or polyphenols synthesis. The significant accumulation of flavonoids in tissues under Na2SO4 treatment and their powerful antioxidant activity indicates a role for these compounds in counteracting the oxidative damage induced by severe salt stress, particularly, ionic stress. We demonstrate that ionic interactions between different salts in salinized soils modify the biochemical and morpho-physiological responses of P. strombulifera plants to salinity. PMID:25063834

Reginato, Mariana A.; Castagna, Antonella; Furlán, Ana; Castro, Stella; Ranieri, Annamaria; Luna, Virginia

2014-01-01

92

Reduced tonoplast fast-activating and slow-activating channel activity is essential for conferring salinity tolerance in a facultative halophyte, quinoa.  

PubMed

Halophyte species implement a "salt-including" strategy, sequestering significant amounts of Na(+) to cell vacuoles. This requires a reduction of passive Na(+) leak from the vacuole. In this work, we used quinoa (Chenopodium quinoa) to investigate the ability of halophytes to regulate Na(+)-permeable slow-activating (SV) and fast-activating (FV) tonoplast channels, linking it with Na(+) accumulation in mesophyll cells and salt bladders as well as leaf photosynthetic efficiency under salt stress. Our data indicate that young leaves rely on Na(+) exclusion to salt bladders, whereas old ones, possessing far fewer salt bladders, depend almost exclusively on Na(+) sequestration to mesophyll vacuoles. Moreover, although old leaves accumulate more Na(+), this does not compromise their leaf photochemistry. FV and SV channels are slightly more permeable for K(+) than for Na(+), and vacuoles in young leaves express less FV current and with a density unchanged in plants subjected to high (400 mm NaCl) salinity. In old leaves, with an intrinsically lower density of the FV current, FV channel density decreases about 2-fold in plants grown under high salinity. In contrast, intrinsic activity of SV channels in vacuoles from young leaves is unchanged under salt stress. In vacuoles of old leaves, however, it is 2- and 7-fold lower in older compared with young leaves in control- and salt-grown plants, respectively. We conclude that the negative control of SV and FV tonoplast channel activity in old leaves reduces Na(+) leak, thus enabling efficient sequestration of Na(+) to their vacuoles. This enables optimal photosynthetic performance, conferring salinity tolerance in quinoa species. PMID:23624857

Bonales-Alatorre, Edgar; Shabala, Sergey; Chen, Zhong-Hua; Pottosin, Igor

2013-06-01

93

Effects of salinity on flowering, morphology, biomass accumulation and leaf metabolites in an edible halophyte  

PubMed Central

The fresh water shortage in agriculture is an increasing problem worldwide, therefore the possibility of cultivating crops under saline conditions is of high importance. Crithmum maritimum, a halophytic plant naturally found on the rocky coastlines of the Atlantic Ocean and the Mediterranean Sea, has a long history of human consumption and was recently suggested as a cash crop for biosaline agriculture. In the present study, we compared the responses of different genotypes originating from France, Portugal and Israel to moderate saline irrigation (up to 100 mM NaCl). The genotypes varied greatly in the onset of flowering, their leaf appearance, growth habits and leaf metabolite content. Both Atlantic genotypes (from France and Portugal) flowered earlier than those from the Mediterranean, but the number of inflorescences decreased with salinity. Irrigation with 50 and 100 mM NaCl led to a reduction in biomass production in both the Israeli and the Portuguese genotypes, while the French genotype was found to produce maximum leaf yield at 50 mM NaCl. With increasing salinity, salt was accumulated by the plants, as indicated by increasing electrical conductivities of the leaf extracts. Concomitantly, antioxidant compounds (such as ascorbic acid), total polyphenols and ureides responded to salinity in a genotype-dependent manner; either they increased, decreased or were unaffected. Notably, the total fatty acid concentration increased with salinity in both Mediterranean genotypes, reaching 2.7 and 2.4 % total fatty acids (on a dry weight basis) at 100 mM NaCl. Moreover, the proportion assigned to omega-3 fatty acids in these genotypes was higher than in their Atlantic counterparts at the highest salinity tested. Our results highlight the variations existing among C. maritimum genotypes from different origins regarding salt-induced changes in plant growth, flowering behaviour and leaf metabolites with nutritional value. Thus, genotypic characteristics should be taken into account when evaluating a wild plant species for future crop cultivation. PMID:25178274

Ventura, Yvonne; Myrzabayeva, Malika; Alikulov, Zerekbay; Omarov, Rustem; Khozin-Goldberg, Inna; Sagi, Moshe

2014-01-01

94

Contributed Papers Predicting Plant Extinction Based on Species-Area  

E-print Network

Contributed Papers Predicting Plant Extinction Based on Species-Area Curves in Prairie Fragments fragmentation, island biogeography theory, plant, species-area curves Predicci´on de la Extinci´on de Plantas, Soil and Water Research Laboratory, USDA­ARS, Temple, TX 76502, U.S.A. Abstract: Species-area

Wilsey, Brian J.

95

Plant species diversity in Amazonian forests M. R. Silman  

E-print Network

#12;#12;10 Plant species diversity in Amazonian forests M. R. Silman 10.1 INTRODUCTION Looking diverse on the planet, estimated to harbor 30,000 species of vascular plants, with 5,000±10,000 species of Neotropical forests as spectacularly diverse, how diversity is distributed across the landscape is less well

Silman, Miles R.

96

Dioxin uptake by Indian plant species.  

PubMed

Dioxins like various gaseous pollutants and aerosols can be scavenged by appropriate vegetative greenbelts. Based on their stomatal properties and the models for contaminant uptake, uptake of dioxin (2,3,7,8-TCDD) by three important Indian plant species, viz. Eugenia jambolana (Jamun), Azadirachta indica (Neem) and Ficus religiosa (Peepal), has been estimated. 2,3,7,8-TCDD is a contaminant with severe harmful ecological ramifications. Computations show that Ficus religiosa has highest uptake capacity. The present exercise has its utility in designing appropriate green-belts for mitigating adverse environmental and human health impacts due to dioxins. This can be an effective management option for mitigating the damages caused by dioxins. PMID:17874332

Pandey, J S; Kumar, R; Wate, S R

2008-08-01

97

New pasture plants intensify invasive species risk.  

PubMed

Agricultural intensification is critical to meet global food demand, but intensification threatens native species and degrades ecosystems. Sustainable intensification (SI) is heralded as a new approach for enabling growth in agriculture while minimizing environmental impacts. However, the SI literature has overlooked a major environmental risk. Using data from eight countries on six continents, we show that few governments regulate conventionally bred pasture taxa to limit threats to natural areas, even though most agribusinesses promote taxa with substantial weed risk. New pasture taxa (including species, subspecies, varieties, cultivars, and plant-endophyte combinations) are bred with characteristics typical of invasive species and environmental weeds. By introducing novel genetic and endophyte variation, pasture taxa are imbued with additional capacity for invasion and environmental impact. New strategies to prevent future problems are urgently needed. We highlight opportunities for researchers, agribusiness, and consumers to reduce environmental risks associated with new pasture taxa. We also emphasize four main approaches that governments could consider as they build new policies to limit weed risks, including (i) national lists of taxa that are prohibited based on environmental risk; (ii) a weed risk assessment for all new taxa; (iii) a program to rapidly detect and control new taxa that invade natural areas; and (iv) the polluter-pays principle, so that if a taxon becomes an environmental weed, industry pays for its management. There is mounting pressure to increase livestock production. With foresight and planning, growth in agriculture can be achieved sustainably provided that the scope of SI expands to encompass environmental weed risks. PMID:25368175

Driscoll, Don A; Catford, Jane A; Barney, Jacob N; Hulme, Philip E; Inderjit; Martin, Tara G; Pauchard, Aníbal; Pyšek, Petr; Richardson, David M; Riley, Sophie; Visser, Vernon

2014-11-18

98

Plant Species Recovery on a Compacted Skid Road  

PubMed Central

This study was executed to determine the plant species of herbaceous cover in a skid road subjected to soil compaction due to timber skidding in a beech (Fagus orientalis Lipsky.) stand. Our previous studies have shown that ground based timber skidding destroys the soils extremely, and degradations on ecosystem because of the timber skidding limit recovery and growth of plant cover on skid roads. However, some plant species show healthy habitat, recovery and they can survive after the extreme degradation in study area. We evaluated composition of these plant species and their cover-abundance scales in 100 m x 3 m transect. 15 plant species were determined belongs to 12 plant families and Liliaceae was the highest representative plant family. Smilax aspera L., Epimedium pubigerum (DC.) Moren et Decaisne, Carex distachya Desf. var. distachya Desf., Pteridium aquilinum (L.) Kuhn., Trachystemon orientalis (L.) G. Don, Hedera helix L. have the highest cover-abundance scale overall of determined species on compacted skid road.

Demir, Murat; Makineci, Ender; Gungor, Beyza Sat

2008-01-01

99

Phytophthora species, new threats to the plant health in Korea.  

PubMed

Given the lack of a resistant genetic pool in host plants, the introduction of exotic invasive pathogens can result in epidemics that affect a specific ecosystem and economy. Plant quarantine, which is designed to protect endemic plant resources, is a highly invaluable safeguard that should keep biosecurity with increasing international trade and global transportation. A total of 34 species of plant pathogens including Phytophthora infestans were documented as introduced from other countries into Korea from 1900 to 2010. The genus Phytophthora, classified in oomycetes, includes more than 120 species that are mostly recognized worldwide as highly invasive plant pathogens. After 2000, over 50 new species of Phytophthora were identified internationally as plant pathogens occurring in crops and forest trees. In Korea, Phytophthora is also one of the most serious plant pathogens. To date, 22 species (about one-fifth of known species) of the genus have been identified and reported as plant pathogens in the country. The likelihood of new exotic Phytophthora species being introduced into Korea continues to increase, thus necessitating intensive plant quarantine inspections. As new potential threats to plant health in Korea, six Phytophthora species, namely, P. alni, P. inundata, P. kernoviae, P. pinifolia, P. quercina, and P. ramorum, are discussed in this review with focus on history, disease, biology, management, and plant quarantine issues. PMID:25506298

Hyun, Ik-Hwa; Choi, Woobong

2014-12-01

100

Overexpression of the halophyte Kalidium foliatum H?-pyrophosphatase gene confers salt and drought tolerance in Arabidopsis thaliana.  

PubMed

According to sequences of H(+)-pyrophosphatase genes from GenBank, a new H(+)-pyrophosphatase gene (KfVP1) from the halophyte Kalidium foliatum, a very salt-tolerant shrub that is highly succulent, was obtained by using reverse transcription PCR and rapid amplification of cDNA ends methods. The obtained KfVP1 cDNA contained a 2295 bp ORF and a 242 bp 3'-untranslated region. It encoded 764 amino acids with a calculated molecular mass of 79.78 kDa. The deduced amino acid sequence showed high identity to those of H(+)-PPase of some Chenopodiaceae plant species. Semi-quantitative PCR results revealed that transcription of KfVP1 in K. foliatum was induced by NaCl, ABA and PEG stress. Transgenic lines of A. thaliana with 35S::KfVP1 were generated. Three transgenic lines grew more vigorous than the wild type (ecotype Col-0) under salt and drought stress. Moreover, the transgenic plants accumulated more Na(+) in the leaves compared to wild type plants. These results demonstrated that KfVP1 from K. foliatum may be a functional tonoplast H(+)-pyrophosphatase in contributing to salt and drought tolerance. PMID:22539184

Yao, Manhong; Zeng, Youling; Liu, Lin; Huang, Yunlan; Zhao, Enfeng; Zhang, Fuchun

2012-08-01

101

Learning from halophytes: physiological basis and strategies to improve abiotic stress tolerance in crops  

PubMed Central

Background Global annual losses in agricultural production from salt-affected land are in excess of US$12 billion and rising. At the same time, a significant amount of arable land is becoming lost to urban sprawl, forcing agricultural production into marginal areas. Consequently, there is a need for a major breakthrough in crop breeding for salinity tolerance. Given the limited range of genetic diversity in this trait within traditional crops, stress tolerance genes and mechanisms must be identified in extremophiles and then introduced into traditional crops. Scope and Conclusions This review argues that learning from halophytes may be a promising way of achieving this goal. The paper is focused around two central questions: what are the key physiological mechanisms conferring salinity tolerance in halophytes that can be introduced into non-halophyte crop species to improve their performance under saline conditions and what specific genes need to be targeted to achieve this goal? The specific traits that are discussed and advocated include: manipulation of trichome shape, size and density to enable their use for external Na+ sequestration; increasing the efficiency of internal Na+ sequestration in vacuoles by the orchestrated regulation of tonoplast NHX exchangers and slow and fast vacuolar channels, combined with greater cytosolic K+ retention; controlling stomata aperture and optimizing water use efficiency by reducing stomatal density; and efficient control of xylem ion loading, enabling rapid shoot osmotic adjustment while preventing prolonged Na+ transport to the shoot. PMID:24085482

Shabala, Sergey

2013-01-01

102

Soil organisms shape the competition between grassland plant species.  

PubMed

Decomposers and arbuscular mycorrhizal fungi (AMF) both determine plant nutrition; however, little is known about their interactive effects on plant communities. We set up a greenhouse experiment to study effects of plant competition (one- and two-species treatments), Collembola (Heteromurus nitidus and Protaphorura armata), and AMF (Glomus intraradices) on the performance (above- and belowground productivity and nutrient uptake) of three grassland plant species (Lolium perenne, Trifolium pratense, and Plantago lanceolata) belonging to three dominant plant functional groups (grasses, legumes, and herbs). Generally, L. perenne benefited from being released from intraspecific competition in the presence of T. pratense and P. lanceolata. However, the presence of AMF increased the competitive strength of P. lanceolata and T. pratense against L. perenne and also modified the effects of Collembola on plant productivity. The colonization of roots by AMF was reduced in treatments with two plant species suggesting that plant infection by AMF was modified by interspecific plant interactions. Collembola did not affect total colonization of roots by AMF, but increased the number of mycorrhizal vesicles in P. lanceolata. AMF and Collembola both enhanced the amount of N and P in plant shoot tissue, but impacts of Collembola were less pronounced in the presence of AMF. Overall, the results suggest that, by differentially affecting the nutrient acquisition and performance of plant species, AMF and Collembola interactively modify plant competition and shape the composition of grassland plant communities. The results suggest that mechanisms shaping plant community composition can only be understood when complex belowground interactions are considered. PMID:22678109

Sabais, Alexander C W; Eisenhauer, Nico; König, Stephan; Renker, Carsten; Buscot, François; Scheu, Stefan

2012-12-01

103

Mechanisms of plant species impacts on ecosystem nitrogen cycling  

Microsoft Academic Search

Plant species are hypothesized to impact ecosystem nitrogen cycling in two distinctly different ways. First, differences in nitrogen use efficiency can lead to positive feedbacks on the rate of nitrogen cycling. Alternatively, plant species can also control the inputs and losses of nitrogen from ecosystems. Our current understanding of litter decomposition shows that most nitrogen present within litter is not

J. M. H. Knops; K. L. Bradley; D. A. Wedin

2002-01-01

104

Microbial immobilization drives nitrogen cycling differences among plant species  

E-print Network

1840 Microbial immobilization drives nitrogen cycling differences among plant species Ramesh cycling. We examined four potential mechanisms of plant species effects on nitrogen (N) cycling. We found. of Nebraska, 348 Manter Hall, Lincoln, NE 68588, USA. In many terrestrial ecosystems nitrogen (N) limits

Minnesota, University of

105

Final Report Parris Island Depot Invasive Plant Species  

E-print Network

Final Report Parris Island Depot Invasive Plant Species Control Monitoring December 2010 Submitted-native invasive species are difficult to eradicate and must be managed for control. Parris Island Marine Recruit Depot has contracted Invasive Plant Control Inc. for herbicide treatments since 2001 for the control

Bolding, M. Chad

106

Global response patterns of terrestrial plant species to nitrogen addition  

Microsoft Academic Search

Summary • Better understanding of the responses of terrestrial plant species under global nitrogen (N) enrichment is critical for projection of changes in structure, functioning, and service of terrestrial ecosystems.  Here, a meta-analysis of data from 304 studies was carried out to reveal the general response patterns of terrestrial plant species to the addition of N.  Across 456

Jianyang Xia; Shiqiang Wan

2008-01-01

107

USING REMOTE SENSING TO DETECT AND MAP INVASIVE PLANT SPECIES  

Technology Transfer Automated Retrieval System (TEKTRAN)

Invasive exotic plant species present a serious problem to natural resource managers in the United States. This paper presents an overview on the application of aerial photography and airborne videography for detecting invasive plant species in terrestrial and aquatic environments in the United Sta...

108

Plant species richness, endemism, and genetic resources in Namibia  

Microsoft Academic Search

Namibia is a floristically diverse, arid to mesic country, with several highly distinct taxa. Including naturalized plants, there are about 4334 vascular plant species and infraspecific taxa within the country's borders, a substantial increase from the existing major reference work. Dominant families are the Poaceae (422species), Fabaceae (377), Asteraceae (385) and Mesembryanthemaceae (177). Freshwater algae and most other groups of

Gillian L. Maggs; Patricia Craven; Herta H. Kolberg

1998-01-01

109

Plant species richness, endemism, and genetic resources in Namibia  

Microsoft Academic Search

Namibia is a floristically diverse, arid to mesic country, with several highly distinct taxa. Including naturalized plants, there are about 4334 vascular plant species and infraspecific taxa within the country's borders, a substantial increase from the existing major reference work. Dominant families are the Poaceae (422 species), Fabaceae (377), Asteraceae (385) and Mesembryanthemaceae (177). Freshwater algae and most other groups

GILLIAN L. MAGGS; PATRICIA CRAVEN; HERTA H. KOLBERG

1998-01-01

110

Phylogeographic patterns of highland and lowland plant species in Japan  

Microsoft Academic Search

As a result of ecological and historical factors, plant species occurring in mountainous regions often exhibit complex phylogeographical\\u000a structure. The aim of this review is to identify the main phylogeographic patterns of plant species in the Japanese Archipelago,\\u000a based on 63 previous studies; in particular, the intention is to examine the effects of mountains on these patterns. We classified\\u000a species

Takafumi Ohsawa; Yuji Ide

2011-01-01

111

FORUM REVIEW ARTICLE Reactive Oxygen Species in Plant Pathogenesis  

E-print Network

species (ROS) play multiple roles in interactions between plants and microbes, both as host defense as programmed cell death responses are central to plant defenses against invading pathogens. Contact of ROS, in- cluding hydrogen peroxide (H2O2), which diffuses into cells and activates plant defenses (6

Daub, Margaret

112

Gas chromatographic-mass spectrometric method for polycyclic aromatic hydrocarbon analysis in plant biota.  

PubMed

Using gas chromatography-mass spectrometry, a new method was developed for the identification and the quantification of polycyclic aromatic hydrocarbons (PAHs) in plants. This method was particularly optimised for PAH analyses in marine plants such as the halophytic species, Salicornia fragilis Ball et Tutin. The saponification of samples and their clean up by Florisil solid-phase extraction succeeded in eliminating pigments and natural compounds, which may interfere with GC-MS analysis. Moreover, a good recovery of the PAHs studied was obtained with percentages ranging from 88 to 116%. Application to the determination of PAH in a wide range of coastal halophytic plants is presented and validated the efficiency, the accuracy and the reproducibility of this method. PMID:16442550

Meudec, A; Dussauze, J; Jourdin, M; Deslandes, E; Poupart, N

2006-03-10

113

Halophytes of Pakistan: characteristics, distribution and potential economic usages  

Microsoft Academic Search

Fresh water resources are becoming increasingly limited and agricultural irrigation systems will steadily increase in salinity\\u000a in the near future. The time has come to develop sustainable biological production systems that can use low quality saline\\u000a water for irrigation of halophytic crops in saline lands. A large number of halophytes could be used as cash crop (forage,\\u000a fodder, fuel, medicine,

M. Ajmal Khan; M. Qaiser

114

Biological Assessment for Threatened and Endangered Plant Species  

E-print Network

Current management direction for threatened and endangered species as contained in the Endangered Species Act of 1973 includes: "... all Federal departments and agencies shall seek to conserve endangered species and threatened species and shall utilize their authorities in furtherance of the purposes of this Act." U.S. Department of Interior (1997) listed threatened and endangered plant species by state. Those listed for Utah were considered in this BA. Within Utah, distribution of these species and those proposed for listing and their habitat have been determined by extensive botanical survey and herbarium search. Survey for plants has been intensive in the past few decades in the Intermountain Region including Utah, the Uintah Basin, the Uinta Mountains, and specifically the Ashley National Forest. Many thousands of plant collections housed at the major and minor herbaria of Utah and at other institutions including New York Botanical Garden are the basis for geographic limits, elevational ranges, geological formation and other habitat

Travel Management; Ashley National Forest

115

Exotic plants increase and native plants decrease with loss of foundation species in sagebrush steppe  

Microsoft Academic Search

Dominant plant species, or foundation species, are recognized to have a disproportionate control over resources in ecosystems,\\u000a but few studies have evaluated their relationship to exotic invasions. Loss of foundation species could increase resource\\u000a availability to the benefit of exotic plants, and could thereby facilitate invasion. The success of exotic plant invasions\\u000a in sagebrush steppe was hypothesized to benefit from

Janet S. Prevéy; Matthew J. Germino; Nancy J. Huntly; Richard S. Inouye

2010-01-01

116

Plant Species Diversity and Pasture Management  

Technology Transfer Automated Retrieval System (TEKTRAN)

Farmers face many challenges in pasture management, such as evolving agri-environmental schemes to protect natural resources, and need new management techniques to remain sustainable. Ecological research indicates that increased plant biodiversity benefits ecosystem functions such as primary product...

117

Effects of Salinity on the Response of the Wetland Halophyte Kosteletzkya virginica (L.) Presl. to Copper Toxicity  

Microsoft Academic Search

Kosteletzkya virginica (L.) Presl. is a perennial wetland halophyte which could be exposed to heavy metals in polluted salt marsh environments.\\u000a In order to investigate the interaction between salinity (50 mM NaCl) and heavy metal, young plants were exposed in hydroponic\\u000a culture to 10 ?M Cu in the presence or absence of 50 mM NaCl. Copper strongly inhibited the leaf emergence and lateral

Rui-Ming Han; Isabelle Lefèvre; Cheng-Jiang Ruan; Natacha Beukelaers; Pei Qin; Stanley Lutts

118

TREE PLANTING SITE EVALUATION FORM "SITE DICTATES SPECIES"  

E-print Network

TREE PLANTING SITE EVALUATION FORM "SITE DICTATES SPECIES" ABOVE GROUND Utilities: Electric ordinances.) Stop signs: Yes______ No______ Business signs: Yes______ No______ Vehicle sight problems: Yes ___________________________ NA______ Utilities: Location and distance from Water meter

119

Human population, grasshopper and plant species richness in European countries  

NASA Astrophysics Data System (ADS)

Surprisingly, several studies over large scales have reported a positive spatial correlation of people and biodiversity. This pattern has important implications for conservation and has been documented for well studied taxa such as plants, amphibians, reptiles, birds and mammals. However, it is unknown whether the pattern applies also to invertebrates other than butterflies and more work is needed to establish whether the species-people relationship is explained by both variables correlating with other environmental factors. We studied whether grasshopper species richness (Orthoptera, suborder Caelifera) is related to human population size in European countries. As expected, the number of Caelifera species increases significantly with increasing human population size. But this is not the case when controlling for country area, latitude and number of plant species. Variations in Caelifera species richness are primarily associated with variations in plant species richness. Caelifera species richness also increases with decreasing mean annual precipitation, Gross Domestic Product per capita (used as an indicator for economic development) and net fertility rate of the human population. Our analysis confirms the hypothesis that the broad-scale human population-biodiversity correlations can be explained by concurrent variations in factors other than human population size such as plant species richness, environmental productivity, or habitat heterogeneity. Nonetheless, more populated countries in Europe still have more Caelifera species than less populated countries and this poses a particular challenge for conservation.

Steck, Claude E.; Pautasso, Marco

2008-11-01

120

ROS generation and proline metabolism in calli of halophyte Nitraria tangutorum Bobr. to sodium nitroprusside treatment.  

PubMed

Nitric oxide (NO) is a stress factor or a signal molecule involved in various plant physiological and developmental processes. In the present study, the generation of reactive oxygen species and the metabolism of proline due to different sodium nitroprusside (SNP, an NO donor) concentrations were investigated in callus from halophyte Nitraria tangutorum Bobr. Treatment with SNP led to significant increases of hydrogen peroxide (H2O2) content and cell viability but notable reductions in hydrogen radical level and lipid peroxidation degree, and superoxide onion (O2 (-)) content also enhanced in 100 ?M SNP-treated calli. Using a chemical inhibitor for plasma membrane (PM) NADPH oxidase diphenylene iodonium (DPI), we found low O2 (-) generation in untreated and 25 ?M SNP-treated calli, whereas in those treated with 100 ?M SNP O2 (-) level exhibited a very little alteration, comparable to the absence of DPI. These suggest a high activity of PM NADPH oxidase in untreated calli. H2O2 scavenging enzymes (catalase, peroxidase [POD] and ascorbate peroxidase) and H2O2 forming enzymes (superoxide dismutase [SOD], cell wall-POD and diamine oxidase [DAO]) stimulated significantly in calli treated with different SNP concentrations while glutathione reductase activity decreased. In addition, a reduction in proline content was observed in SNP-treated calli. Moreover, different SNP concentrations stimulated proline dehydrogenase (PDH) and ornithine ?-aminotransferase but inhibited r-glutamyl kinase (GK). In conclusion, our results suggest that the increasing H2O2 generation was associated with the stimulation of SOD, cell wall-POD and DAO, and that the reduction of proline content might be the consequence of increased PDH activity and decreased GK activity in N. tangutorum Bobr. calli under SNP treatment. PMID:23838886

Yang, Fan; Ding, Fan; Duan, Xiaohui; Zhang, Jing; Li, Xiaoning; Yang, Yingli

2014-01-01

121

Martelella endophytica sp. nov., an antifungal bacterium associated with a halophyte.  

PubMed

A Gram-staining-negative, non-spore-forming endophytic bacterium, designated strain YC6887(T), was isolated from a root sample of a halophyte, Rosa rugosa, collected from a tidal flat area of Namhae Island, located at the southern end of Korea. Strain YC6887(T) was found to exhibit inhibitory activity against oomycete plant pathogens. The cells were non-motile and aerobic rods. The strain was able to grow at 4-40 °C (optimum 28-30 °C) and at pH 5.0-9.0 (optimum pH 7.0-8.5). Strain YC6887(T) was able to grow at NaCl concentrations of 0-9 % (w/v) with optimum growth at 4-5 % (w/v) NaCl, but NaCl is not essential for growth. Comparison of 16S rRNA gene sequences showed that the strain was a member of the genus Martelella, a member of order Rhizobiales, exhibiting highest similarity with Martelella mediterranea (98.6 %). The DNA-DNA relatedness between strain YC6887(T) and M. mediterranea MACL11(T) was 19.8 ± 6.8. Chemotaxonomically, strain YC6887(T) contained C19 : 0 cyclo ?8c (28.0 %) and C18 : 1?7c (17.9 %) as predominant fatty acids, confirming the affiliation of strain YC6887(T) with the genus Martelella. The major respiratory quinone was Q-10 and the DNA G+C content was 62.1 mol%. On the basis of phylogenetic analysis, physiological and biochemical characterization and DNA-DNA hybridization data, strain YC6887(T) should be classified as representing a novel species of the genus Martelella, for which the name Martelella endophytica sp. nov. is proposed. The type strain is YC6887(T) ( = KCCM 43011(T) = NBRC 109149(T)). PMID:23355694

Bibi, Fehmida; Chung, Eu Jin; Khan, Ajmal; Jeon, Che Ok; Chung, Young Ryun

2013-08-01

122

Regeneration and transformation in adult plants of Campanula species  

Microsoft Academic Search

Adult plants are known for recalcitrance when it comes to adventitious organ formation and regeneration. Methods used for\\u000a regeneration in explants from seedlings of Campanula carpatica failed to work for explants from adult plants of the same species. The present investigation generated efficient regeneration\\u000a methods for mature specimens of four species of Campanula, C. carpatica, C. haylodgensis, C. portenschlagiana and

Sridevy Sriskandarajah; Heiko Mibus; Margrethe Serek

2008-01-01

123

Induced responses in three alkaloid-containing plant species  

Microsoft Academic Search

In this paper we test three plant species for the inducibility of their alkaloid production. The plants were heavily damaged by cutting off 50% of their leaf surface using a pair of scissors. The cut-off leaf tips were used as controls for possible diurnal fluctuations. After 3, 6, 12, 24 and 48 h, respectively, the leaf bases of the damaged

Nicole M. van Dam; Ed van der Meijden; Robert Verpoorte

1993-01-01

124

Computer-aided plant species identification (CAPSI) based on leaf  

E-print Network

Computer-aided plant species identification (CAPSI) based on leaf shape matching technique Ji identification (CAPSI) approach is proposed, which is based on plant leaf images using a shape matching technique. Firstly, a DouglasÁ Peucker approximation algorithm is adopted to the original leaf shapes and a new shape

Hefei Institute of Intelligent Machines

125

Transmission specificities of plant viruses with the newly identified species of the Bemisia tabaci species complex.  

PubMed

Bemisia tabaci has had a colorful nomenclatural past and is now recognized as a species complex. This new species framework has added many new areas of research including adding new insight into the virus transmission specificity of the species in the B. tabaci species complex. There is a wide disparity in what is known about the transmission of plant viruses by different members of the B. tabaci species complex. In this paper, we have synthesized the transmission specificities of the plant viruses transmitted by species belonging to the complex. There are five genera of plant viruses with members that are transmitted by species of the B. tabaci species complex. The transmission of viruses belonging to two of these, Begomovirus and Crinivirus, are well studied and much is known in regards to the relationship between species and transmission and etiology. This is in contrast to viruses of the genera, Torradovirus and Carlavirus, for which very little is known inregards to their transmission. This is the first attempt to integrate viral data within the new B. tabaci species complex framework. It is clear that matching historical transmission data with the current species framework is difficult due to the lack of awareness of the underlying genetic diversity within B. tabaci. We encourage all researchers to determine which species of B. tabaci they are using to facilitate association of phenotypic traits with particular members of the complex. PMID:24464790

Polston, Jane E; De Barro, Paul; Boykin, Laura M

2014-10-01

126

When Are Native Species Inappropriate for Conservation Plantings  

EPA Science Inventory

Conservation agencies and organizations are generally reluctant to encourage the use of invasive plant species in conservation programs. Harsh lessons learned in the past have resulted in tougher screening protocols for non-indigenous species introductions and removal of many no...

127

Plant species differences in particulate matter accumulation on leaf surfaces.  

PubMed

Particulate matter (PM) accumulation on leaves of 22 trees and 25 shrubs was examined in test fields in Norway and Poland. Leaf PM in different particle size fractions (PM(10), PM(2.5), PM(0.2)) differed among the species, by 10- to 15-folds at both test sites. Pinus mugo and Pinus sylvestris, Taxus media and Taxus baccata, Stephanandra incisa and Betula pendula were efficient species in capturing PM. Less efficient species were Acer platanoides, Prunus avium and Tilia cordata. Differences among species within the same genus were also observed. Important traits for PM accumulation were leaf properties such as hair and wax cover. The ranking presented in terms of capturing PM can be used to select species for air pollution removal in urban areas. Efficient plant species and planting designs that can shield vulnerable areas in urban settings from polluting traffic etc. can be used to decrease human exposure to anthropogenic pollutants. PMID:22554531

Sæbø, A; Popek, R; Nawrot, B; Hanslin, H M; Gawronska, H; Gawronski, S W

2012-06-15

128

Species-area relationships in Mediterranean-climate plant communities  

Microsoft Academic Search

Aim To determine the best-fit model of species-area relationships for Mediterranean- type plant communities and evaluate how community structure affects these species-area models. Location Data were collected from California shrublands and woodlands and com- pared with literature reports for other Mediterranean-climate regions. Methods The number of species was recorded from 1, 100 and 1000 m2 nested plots. Best fit to

Jon E. Keeley; C. J. Fotheringham

2003-01-01

129

Biodiversity of Asterina species on Neotropical host plants: new species and records from Panama.  

PubMed

Two new species of the genus Asterina are described from living leaves collected in provinces Chiriquí and Bocas del Toro in western Panama. Asterina alloplecti on Alloplectus ichtyoderma (Gesneriaceae) differs from other Asterina on Gesneriaceae by its stalked appressoria and host relationship. Asterina compsoneurae on Compsoneura sprucei (Myristicaceae) can be distinguished from other members of Asterina on Myristicaceae by its larger ascomata, larger, prominently spinose ascospores and host relationship. New records for Panama are Asterina corallopoda from a new host plant species (Solanum trizygum, Solanaceae), A. diplopoda, A. ekmanii from a new host plant species (Gonzalagunia rudis, Rubiaceae), A. siphocampyli from a new host plant genus and species (Burmeistera vulgaris, Campanulaceae) and A. styracina from a new host-plant species (Styrax argenteus, Styracaceae). This study increases the number of species of Asterina known for Panama from 12 to 19 and the number of Asterinaceae from 14 to 21. Asterina corallopoda, A. diplopoda, A. ekmanii, A. siphocampyli and A. styracina are illustrated for the first time. A phylogeny inferred from the analysis of LSU rDNA sequences of species of Asterina is presented. The diversity and host-plant patterns of known Neotropical species of Asterina are discussed. PMID:21659457

Hofmann, T A; Piepenbring, M

2011-01-01

130

Predicting species' maximum dispersal distances from simple plant traits.  

PubMed

Many studies have shown plant species' dispersal distances to be strongly related to life-history traits, but how well different traits can predict dispersal distances is not yet known. We used cross-validation techniques and a global data set (576 plant species) to measure the predictive power of simple plant traits to estimate species' maximum dispersal distances. Including dispersal syndrome (wind, animal, ant, ballistic, and no special syndrome), growth form (tree, shrub, herb), seed mass, seed release height, and terminal velocity in different combinations as explanatory variables we constructed models to explain variation in measured maximum dispersal distances and evaluated their power to predict maximum dispersal distances. Predictions are more accurate, but also limited to a particular set of species, if data on more specific traits, such as terminal velocity, are available. The best model (R2 = 0.60) included dispersal syndrome, growth form, and terminal velocity as fixed effects. Reasonable predictions of maximum dispersal distance (R2 = 0.53) are also possible when using only the simplest and most commonly measured traits; dispersal syndrome and growth form together with species taxonomy data. We provide a function (dispeRsal) to be run in the software package R. This enables researchers to estimate maximum dispersal distances with confidence intervals for plant species using measured traits as predictors. Easily obtainable trait data, such as dispersal syndrome (inferred from seed morphology) and growth form, enable predictions to be made for a large number of species. PMID:24669743

Tamme, Riin; Götzenberger, Lars; Zobel, Martin; Bullock, James M; Hooftman, Danny A P; Kaasik, Ants; Pärtel, Meelis

2014-02-01

131

Towards a working list of all known plant species.  

PubMed Central

A complete listing of the world's known plant species has long been considered desirable but has remained an elusive target for generations of botanists. The adoption of the Global Strategy for Plant Conservation has reinforced the urgent need for a global plant checklist to support, facilitate and monitor the conservation and sustainable use of plant diversity worldwide. The increasing availability of large databases of biological information over the Internet has demonstrated that many of the obstacles to the collation and dissemination of vast, shared datasets can be overcome. We examine the challenges that still remain to be addressed if the botanical community is to achieve its ambitious objective of delivering a working list of all known plant species by 2010. PMID:15253353

Lughadha, Eimear Nic

2004-01-01

132

No universal scale-dependent impacts of invasive species on native plant species richness.  

PubMed

A growing number of studies seeking generalizations about the impact of plant invasions compare heavily invaded sites to uninvaded sites. But does this approach warrant any generalizations? Using two large datasets from forests, grasslands and desert ecosystems across the conterminous United States, we show that (i) a continuum of invasion impacts exists in many biomes and (ii) many possible species-area relationships may emerge reflecting a wide range of patterns of co-occurrence of native and alien plant species. Our results contradict a smaller recent study by Powell et al. 2013 (Science 339, 316-318. (doi:10.1126/science.1226817)), who compared heavily invaded and uninvaded sites in three biomes and concluded that plant communities invaded by non-native plant species generally have lower local richness (intercepts of log species richness-log area regression lines) but steeper species accumulation with increasing area (slopes of the regression lines) than do uninvaded communities. We conclude that the impacts of plant invasions on plant species richness are not universal. PMID:24478201

Stohlgren, Thomas J; Rejmánek, Marcel

2014-01-01

133

Suppressor of K+ transport growth defect 1 (SKD1) interacts with RING-type ubiquitin ligase and sucrose non-fermenting 1-related protein kinase (SnRK1) in the halophyte ice plant  

PubMed Central

SKD1 (suppressor of K+ transport growth defect 1) is an AAA-type ATPase that functions as a molecular motor. It was previously shown that SKD1 accumulates in epidermal bladder cells of the halophyte Mesembryanthemum crystallinum. SKD1 knock-down Arabidopsis mutants showed an imbalanced Na+/K+ ratio under salt stress. Two enzymes involved in protein post-translational modifications that physically interacted with McSKD1 were identified. McCPN1 (copine 1), a RING-type ubiquitin ligase, has an N-terminal myristoylation site that links to the plasma membrane, a central copine domain that interacts with McSKD1, and a C-terminal RING domain that catalyses protein ubiquitination. In vitro ubiquitination assay demonstrated that McCPN1 was capable of mediating ubiquitination of McSKD1. McSnRK1 (sucrose non-fermenting 1-related protein kinase) is a Ser/Thr protein kinase that contains an N-terminal STKc catalytic domain to phosphorylate McSKD1, and C-terminal UBA and KA1 domains to interact with McSKD1. The transcript and protein levels of McSnRK1 increased as NaCl concentrations increased. The formation of an SKD1–SnRK1–CPN1 ternary complex was demonstrated by yeast three-hybrid and bimolecular fluorescence complementation. It was found that McSKD1 preferentially interacts with McSnRK1 in the cytosol, and salt induced the re-distribution of McSKD1 and McSnRK1 towards the plasma membrane via the microtubule cytoskeleton and subsequently interacted with RING-type E3 McCPN1. The potential effects of ubiquitination and phosphorylation on McSKD1, such as changes in the ATPase activity and cellular localization, and how they relate to the functions of SKD1 in the maintenance of Na+/K+ homeostasis under salt stress, are discussed. PMID:23580756

Chiang, Chih-Pin; Li, Chang-Hua; Chen, Yu-Chan; Yen, Hungchen Emilie

2013-01-01

134

Floristic summary of plant species in the air pollution literature  

USGS Publications Warehouse

A floristic summary and analysis was performed on a list of the plant species that have been studied for the effects of gaseous and chemical air pollutants on vegetation in order to compare the species with the flora of North America north of Mexico. The scientific names of 2081 vascular plant species were extracted from almost 4000 journal articles stored in two large literature databases on the effects of air pollutants on plants. Three quarters of the plant species studied occur in North America, but this was only 7% of the total North American flora. Sixteen percent and 56% of all North American genera and families have been studied. The most studied genus is Pinus with 70% of the North American species studied, and the most studied family is the grass family, with 12% of the species studied. Although Pinus is ranked 86th in the North American flora, the grass family is ranked third, indicating that representation at the family level is better than at the genus level. All of the top ten families in North America are represented in the top 20 families in the air pollution effects literature, but only one genus (Lupinus) in the top ten genera in North America is represented in the top thirteen genera in the air pollution literature.

Bennett, J.P.

1996-01-01

135

Machine vision detection parameters for plant species identification  

NASA Astrophysics Data System (ADS)

Machine vision based on classical image processing techniques has the potential to be a useful tool for plant detection and identification. Plant identification is needed for weed detection, herbicide application or other efficient chemical spot spraying operations. The key to successful detection and identification of plants as species types is the segmentation of plants form background pixel regions. In particular, it would be beneficial to segment individual leaves form tops of canopies as well. The segmentation process yields an edge or binary image which contains shape feature information. Results indicate that red-green-blue formats might provide the best segmentation criteria, based on models of human color perception. The binary image can be also used as a template to investigate textural features of the plant pixel region, using gray image co-occurrence matrices. Texture features considers leaf venation, colors, or additional canopy structure that might be used to identify various type of grasses or broadleaf plants.

Meyer, George E.; Hindman, Timothy W.; Laksmi, Koppolu

1999-01-01

136

High apoplastic solute concentrations in leaves alter water relations of the halophytic shrub, Sarcobatus vermiculatus.  

PubMed

Predawn plant water potential (Psi(w)) is used to estimate soil moisture available to plants because plants are expected to equilibrate with the root-zone Psi(w). Although this equilibrium assumption provides the basis for interpreting many physiological and ecological parameters, much work suggests predawn plant Psi(w) is often more negative than root-zone soil Psi(w). For many halophytes even when soils are well-watered and night-time shoot and root water loss eliminated, predawn disequilibrium (PDD) between leaf and soil Psi(w) can exceed 0.5 MPa. A model halophyte, Sarcobatus vermiculatus, was used to test the predictions that low predawn solute potential (Psi(s)) in the leaf apoplast is a major mechanism driving PDD and that low Psi(s) is due to high Na+ and K+ concentrations in the leaf apoplast. Measurements of leaf cell turgor (Psi(p)) and solute potential (Psi(s)) of plants grown under a range of soil salinities demonstrated that predawn symplast Psi(w) was 1.7 to 2.1 MPa more negative than predawn xylem Psi(w), indicating a significant negative apoplastic Psi(s). Measurements on isolated apoplastic fluid indicated that Na+ concentrations in the leaf apoplast ranged from 80 to 230 mM, depending on salinity, while apoplastic K+ remained around 50 mM. The water relations measurements suggest that without a low apoplastic Psi(s), predawn Psi(p) may reach pressures that could cause cell damage. It is proposed that low predawn apoplastic Psi(s) may be an efficient way to regulate Psi(p) in plants that accumulate high concentrations of osmotica or when plants are subject to fluctuating patterns of soil water availability. PMID:16317037

James, J J; Alder, N N; Mühling, K H; Läuchli, A E; Shackel, K A; Donovan, L A; Richards, J H

2006-01-01

137

Differential nitrogen and phosphorus retention by five wetland plant species  

Microsoft Academic Search

Riparian wetlands have a demonstrated ability to filter and control nitrogen (N) and phosphorus (P) movement into streams\\u000a and other bodies of water; few studies, however, have examined the roles that individual plant species serve in sequestering\\u000a N and P pollutants. We evaluated the potential for growth and consequent N and P accumulation by five species of wetland perennials.\\u000a We

Jenny T. Kao; John E. Titus; Wei-Xing Zhu

2003-01-01

138

Stakeholders' perceptions of the impacts of invasive exotic plant species in the Mediterranean region  

E-print Network

Stakeholders' perceptions of the impacts of invasive exotic plant species in the Mediterranean, exotic plants, invasive species, landscape, Likert analysis, Mediterra- nean, stakeholder perception Abstract Invasive species pose an increasing environmental problem across the globe, but to date socio

Boudouresque, Charles F.

139

45 CFR 670.25 - Designation of specially protected species of native mammals, birds, and plants.  

Code of Federal Regulations, 2012 CFR

...Designation of specially protected species of native mammals, birds, and plants...Designation of specially protected species of native mammals, birds, and plants. The following species has been designated as...

2012-10-01

140

45 CFR 670.25 - Designation of specially protected species of native mammals, birds, and plants.  

Code of Federal Regulations, 2011 CFR

...Designation of specially protected species of native mammals, birds, and plants...Designation of specially protected species of native mammals, birds, and plants. The following species has been designated as...

2011-10-01

141

45 CFR 670.25 - Designation of specially protected species of native mammals, birds, and plants.  

Code of Federal Regulations, 2013 CFR

...Designation of specially protected species of native mammals, birds, and plants...Designation of specially protected species of native mammals, birds, and plants. The following species has been designated as...

2013-10-01

142

45 CFR 670.25 - Designation of specially protected species of native mammals, birds, and plants.  

Code of Federal Regulations, 2014 CFR

...Designation of specially protected species of native mammals, birds, and plants...Designation of specially protected species of native mammals, birds, and plants. The following species has been designated as...

2014-10-01

143

45 CFR 670.25 - Designation of specially protected species of native mammals, birds, and plants.  

Code of Federal Regulations, 2010 CFR

...Designation of specially protected species of native mammals, birds, and plants...Designation of specially protected species of native mammals, birds, and plants. The following species has been designated as...

2010-10-01

144

Metal species involved in long distance metal transport in plants  

PubMed Central

The mechanisms plants use to transport metals from roots to shoots are not completely understood. It has long been proposed that organic molecules participate in metal translocation within the plant. However, until recently the identity of the complexes involved in the long-distance transport of metals could only be inferred by using indirect methods, such as analyzing separately the concentrations of metals and putative ligands and then using in silico chemical speciation software to predict metal species. Molecular biology approaches also have provided a breadth of information about putative metal ligands and metal complexes occurring in plant fluids. The new advances in analytical techniques based on mass spectrometry and the increased use of synchrotron X-ray spectroscopy have allowed for the identification of some metal-ligand species in plant fluids such as the xylem and phloem saps. Also, some proteins present in plant fluids can bind metals and a few studies have explored this possibility. This study reviews the analytical challenges researchers have to face to understand long-distance metal transport in plants as well as the recent advances in the identification of the ligand and metal-ligand complexes in plant fluids. PMID:24723928

Álvarez-Fernández, Ana; Díaz-Benito, Pablo; Abadía, Anunciación; López-Millán, Ana-Flor; Abadía, Javier

2014-01-01

145

Spatial connectedness of plant species: potential links for apparent competition via plant diseases  

E-print Network

. Bouteloua curtipendula was uncommon but occurred in all environments, while Buchloe dactyloides and Bouteloua gracilis were uncommon and only occurred in upland sites. Co-occurrence of plant species

Garrett, Karen A.

146

Ecological Effects of Roads on the Plant Diversity of Coastal Wetland in the Yellow River Delta  

PubMed Central

The 26 sample sites in 7 study plots adjacent to asphalt road and earth road in coastal wetland in the Yellow River Delta were selected to quantify plant diversity using quadrat sampling method in plant bloom phase of July and August 2012. The indice of ?T and Jaccard's coefficient were applied to evaluate the species diversity. The results showed that the plant diversities and alien plants were high in the range of 0–20?m to the road verge. There were more exotics and halophytes in plots of asphalt roadside than that of earth roadside. However, proportion of halophytes in habitats of asphalt roadsides was lower than that of earth roadside. By comparing ?-diversity, there were more common species in the asphalt roadsides than that in the earth roadsides. The similarity of plant communities in studied plots of asphalt roadsides and earth roadsides increased with increasing the distance to road verge. The effect range of roads for plant diversity in study region was about 20?m to road verge. Our results indicate that the construction and maintenance of roads in wetland could increase the plant species diversities of communities and risk of alien species invasion. PMID:25147872

Li, Yunzhao; Du, Siyao; Han, Guangxuan; Qu, Fanzhu; Wang, Guangmei; Fu, Yuqin; Zhan, Chao

2014-01-01

147

Ecological effects of roads on the plant diversity of coastal wetland in the Yellow River Delta.  

PubMed

The 26 sample sites in 7 study plots adjacent to asphalt road and earth road in coastal wetland in the Yellow River Delta were selected to quantify plant diversity using quadrat sampling method in plant bloom phase of July and August 2012. The indice of ? T and Jaccard's coefficient were applied to evaluate the species diversity. The results showed that the plant diversities and alien plants were high in the range of 0-20 m to the road verge. There were more exotics and halophytes in plots of asphalt roadside than that of earth roadside. However, proportion of halophytes in habitats of asphalt roadsides was lower than that of earth roadside. By comparing ?-diversity, there were more common species in the asphalt roadsides than that in the earth roadsides. The similarity of plant communities in studied plots of asphalt roadsides and earth roadsides increased with increasing the distance to road verge. The effect range of roads for plant diversity in study region was about 20 m to road verge. Our results indicate that the construction and maintenance of roads in wetland could increase the plant species diversities of communities and risk of alien species invasion. PMID:25147872

Li, Yunzhao; Yu, Junbao; Ning, Kai; Du, Siyao; Han, Guangxuan; Qu, Fanzhu; Wang, Guangmei; Fu, Yuqin; Zhan, Chao

2014-01-01

148

Evolution of SINE S1 retroposons in Cruciferae plant species.  

PubMed

The S1 element is a plant short interspersed element (SINE) that was first described and studied in Brassica napus. In this work, we investigated the distribution and the molecular phylogeny of the S1 element within the Cruciferae (= Brassicaceae). S1 elements were found to be widely distributed within the Cruciferae, especially in species of the tribe Brassiceae. The molecular phylogeny of S1 elements in eight Cruciferae species (Brassica oleracea, Brassica rapa, Brassica napus, Brassica nigra, Sinapis, arvensis, Sinapis pubescens, Coincya monensis, and Vella spinosa) was inferred using 14-36 elements per species. Significant neighbor-joining and maximum-parsimony phylogenetic clusters, supported by high bootstrap P values and/or represented in 100% of the most-parsimonious trees, were observed for each species. Most of these clusters probably correspond to recent species-specific bursts of S1 amplification. Since these species diverged recently, S1 amplification in Cruciferae plants is proposed to be a highly dynamic process that could contribute to genome rearrangements and eventually lead to reproductive isolation. S1 sequence analysis also revealed putative gene conversion events that occurred between different S1 elements of a given species. These events suggest that gene conversion is a minor but significant component of the molecular drive governing S1 concerted evolution. PMID:9287426

Lenoir, A; Cournoyer, B; Warwick, S; Picard, G; Deragon, J M

1997-09-01

149

Do plant species of different resource qualities form dissimilar energy channels below-ground?  

Microsoft Academic Search

This study aimed at examining whether plant species of varying resource quality give rise to a fungal- or bacterial-based energy channel in the plants’ rhizosphere, when planted in soil, in which the plant species naturally occur. In an 18-month large-scale laboratory mesocosm experiment, two plant species (Holcus lanatus and Lotus corniculatus) producing labile litter and two plant species (Picea abies

Christina Witt; Heikki Setälä

2010-01-01

150

ORGANIC PESTICIDE MODIFICATION OF SPECIES INTERACTIONS USING ANNUAL PLANT COMMUNITIES  

EPA Science Inventory

A method is proposed and tested for assessing multispecies responses to three pesticides (atrazine, 2,4,D and malathion). Pesticides were applied at two concentrations, mon model plant communities grown in raised beds using soil containing a natural weed bank. over by species was...

151

Image processing methods for identifying species of plants  

Microsoft Academic Search

More selective methods for applying agricultural herbicides on fields can result in substantial cost savings. Three image processing methods were tested for their ability to identify four different images of plant species. First two images were different and the other two were similar. The images are preprocessed by segmentation and spatial filtering using the Color Chromaticity Chart. The test results

Shulin Dave; Ken Runtz

1995-01-01

152

The importance of education in managing invasive plant species  

Technology Transfer Automated Retrieval System (TEKTRAN)

Invasive plant species can establish in diverse environments and with the increase in human mobility, they are no longer restricted to isolated pockets in remote parts of the world. Cheat grass (Bromus tectorum L.) in rangelands, purple loosestrife (Lythrum salicaria L.) in wet lands and Canada this...

153

Effect of Burning on Germination of Tallgrass Prairie Plant Species  

Microsoft Academic Search

Seeds from 10 prairie plant species of burned and unburned portions of three tallgrass prairies were collected and tested for germinability. Germination of big bluestem (Andropogon gerardii Vitman) consistently averaged higher with burning. Indiangrass (Sorghastrum nutans L.) and sideoats grama [Bouteloua curtipendula (Michx.) Torr.] averaged 5% higher with burning on two of the three sites, although for indiangrass average germination

Sherry R. Rohn; Thomas B. Bragg

1989-01-01

154

ASSESSMENT OF WIND DISPERSAL POTENTIAL IN PLANT SPECIES  

Microsoft Academic Search

Conventional plant dispersal classification systems use simple binary as- signment schemes classifying each species as either being dispersed by means of a certain dispersal vector or not. However, because the dispersal potential ranges continually, this dichotomy appears to be rather artificial, and the existing systems may not be very useful for addressing ecological questions. To quantify gradual differences in the

Oliver Tackenberg; Peter Poschlod; Susanne Bonn

2003-01-01

155

AIRBORNE HYPERSPECTRAL IDENTIFICATION OF INVASIVE AND OPPORTUNISTIC WETLANDS PLANT SPECIES  

EPA Science Inventory

Coastal wetlands are among the most fragmented and disturbed ecosystems and the Great Lakes are no exception. One possible result is the observed increase in the presence and dominance of invasive and other opportunistic plant species, such as the common reed (Phragmites australi...

156

Halophyte die-off in response to anthropogenic impacts on tidal flats  

NASA Astrophysics Data System (ADS)

This study analyzed an abrupt change in halophyte populations, especially the annual plant Suaeda japonica. The boundaries and distributions of S. japonica and Phragmites australis were determined based on the decision tree classifier of TerraSAR-X, SAVI of Landsat ETM+, and density slicing of aerial photography. A large patch of S. japonica in the eastern parts of Donggum-do, South Korea, disappeared in 2007, while populations have been stable in the western parts of the island. To understand the reason behind the sudden die-off, mean sea level was analyzed based on gaged tidal data. Sedimentation rate was measured using Vernier caliper and RTK leveling data. Sedimentation rate between 2006 and 2007 was above the threshold at which S. japonica can germinate. After the loss of an 11-ha S. japonica patch from the eastern part of Donggum-do, sedimentation was accelerated because of a decrease in tidal current caused by a series of land reclamation projects. The increased monthly exposure duration due to continuous sediment accretion altered the type of salt marsh. Our results imply that accumulated effects from a series of coastal construction projects around Ganghwa-do can change not only tide and current hydrodynamics, but also sedimentation and erosion rates, which can cause large halophyte patches to disappear.

Lee, Yoon-Kyung; Park, Wook; Choi, Jong-Kuk; Ryu, Joo-Hyung; Won, Joong-Sun

2014-12-01

157

Genetic diversity of a relict plant species, Ligularia sibirica (L.) Cass. (Asteraceae)  

Microsoft Academic Search

Rare plant species can be divided into naturally, ‘old rare’ species and anthropogenically, ‘new rare’ species. Many recent studies explored genetic diversity of ‘new rare’ species. Less is, however, known about genetic diversity of ‘old rare’ species. We examined isozyme genetic variability of 20 populations of an ‘old rare’ plant species, Ligularia sibirica (Asteraceae) in the Czech and Slovak Republic.

Anna Šmídová; Zuzana Münzbergová; Ivana Pla?ková

2011-01-01

158

Accumulation of K+ and Cs+ in Tropical Plant Species  

NASA Astrophysics Data System (ADS)

Concentrations of K+ and 137Cs+ in tissues of the Citrus aurantifolia were measured both by gamma spectrometry and neutron activation analysis, aiming to understand the behavior of monovalent inorganic cations in plants as well as its capability to store these elements. In contrast to K+, Cs+ ions are not essential elements to plants, what might explain the difference in bioavailability. However, our results have shown that 137Cs+ is positively correlated to 40K+ concentration within tropical plant species, suggesting that these elements might be assimilated in a similar way, and that they pass through the biological cycle together. A simple mathematical model was also proposed to describe the temporal evolution of 40K activity concentration in such tropical woody fruit species. This model exhibited close agreement with the 40K experimental results in the fruit ripening processes of lemon trees.

Velasco, H.; Anjos, R. M.; Zamboni, C. B.; Macario, K. D.; Rizzotto, M.; Cid, A. S.; Medeiros, I. M. A.; Fernández, J.; Rubio, L.; Audicio, P.; Lacerda, T.

2010-08-01

159

Horizontal transfer of chloroplast genomes between plant species  

PubMed Central

The genomes of DNA-containing cell organelles (mitochondria, chloroplasts) can be laterally transmitted between organisms, a process known as organelle capture. Organelle capture often occurs in the absence of detectable nuclear introgression, and the capture mechanism is unknown. Here, we have considered horizontal genome transfer across natural grafts as a mechanism underlying chloroplast capture in plants. By grafting sexually incompatible species, we show that complete chloroplast genomes can travel across the graft junction from one species into another. We demonstrate that, consistent with reported phylogenetic evidence, replacement of the resident plastid genome by the alien genome occurs in the absence of intergenomic recombination. Our results provide a plausible mechanism for organelle capture in plants and suggest natural grafting as a path for horizontal gene and genome transfer between sexually incompatible species. PMID:22308367

Stegemann, Sandra; Keuthe, Mandy; Greiner, Stephan; Bock, Ralph

2012-01-01

160

Plant species richness and ecosystem multifunctionality in global drylands  

USGS Publications Warehouse

Experiments suggest that biodiversity enhances the ability of ecosystems to maintain multiple functions, such as carbon storage, productivity, and the buildup of nutrient pools (multifunctionality). However, the relationship between biodiversity and multifunctionality has never been assessed globally in natural ecosystems. We report here on a global empirical study relating plant species richness and abiotic factors to multifunctionality in drylands, which collectively cover 41% of Earth's land surface and support over 38% of the human population. Multifunctionality was positively and significantly related to species richness. The best-fitting models accounted for over 55% of the variation in multifunctionality and always included species richness as a predictor variable. Our results suggest that the preservation of plant biodiversity is crucial to buffer negative effects of climate change and desertification in drylands.

Maestre, Fernando T.; Quero, Jose L.; Gotelli, Nicholas J.; Escudero, Adrian; Ochoa, Victoria; Delgado-Baquerizo, Manuel; Garcia-Gomez, Miguel; Bowker, Matthew A.; Soliveres, Santiago; Escolar, Cristina; Garcia-Palacios, Pablo; Berdugo, Miguel; Valencia, Enrique; Gozalo, Beatriz; Gallardo, Antonio; Aguilera, Lorgio; Arredondo, Tulio; Blones, Julio; Boeken, Bertrand; Bran, Donaldo; Conceicao, Abel A.; Cabrera, Omar; Chaieb, Mohamed; Derak, Mchich; Eldridge, David J.; Espinosa, Carlos I.; Florentino, Adriana; Gaitan, Juan; Gatica, M. Gabriel; Ghiloufi, Wahida; Gomez-Gonzalez, Susana; Gutie, Julio R.; Hernandez, Rosa M.; Huang, Xuewen; Huber-Sannwald, Elisabeth; Jankju, Mohammad; Miriti, Maria; Monerris, Jorge; Mau, Rebecca L.; Morici, Ernesto; Naseri, Kamal; Ospina, Abelardo; Polo, Vicente; Prina, Anibal; Pucheta, Eduardo; Ramirez-Collantes, David A.; Romao, Roberto; Tighe, Matthew; Torres-Diaz, Cristian; Val, James; Veiga, Jose P.; Wang, Deli; Zaady, Eli

2012-01-01

161

Deficit irrigation of a landscape halophyte for reuse of saline waste water in a desert city  

USGS Publications Warehouse

Saline waste waters from industrial and water treatment processes are an under-utilized resource in desert urban environments. Management practices to safely use these water sources are still in development. We used a deeprooted native halophyte, Atriplex lentiformis (quailbush), to absorb mildly saline effluent (1800 mg l-1 total dissolved solids, mainly sodium sulfate) from a water treatment plant in the desert community of Twentynine Palms, California. We developed a deficit irrigation strategy to avoid discharging water past the root zone to the aquifer. The plants were irrigated at about one-third the rate of reference evapotranspiration (ETo) calculated from meteorological data over five years and soil moisture levels were monitored to a soil depth of 4.7 m at monthly intervals with a neutron hydroprobe. The deficit irrigation schedule maintained the soil below field capacity throughout the study. Water was presented on a more or less constant schedule, so that the application rates were less than ETo in summer and equal to or slightly greater than ETo in winter, but the plants were able to consume water stored in the profile in winter to support summer ET. Sodium salts gradually increased in the soil profile over the study but sulfate levels remained low, due to formation of gypsum in the calcic soil. The high salt tolerance, deep roots, and drought tolerance of desert halophytes such as A. lentiformis lend these plants to use as deficit-irrigated landscape plants for disposal of effluents in urban setting when protection of the aquifer is important. ?? 2008 Elsevier B.V.

Glenn, E.P.; Mckeon, C.; Gerhart, V.; Nagler, P.L.; Jordan, F.; Artiola, J.

2009-01-01

162

Sagina maritima Don (Caryophyllaceae) and other halophytes in London  

Microsoft Academic Search

Sagina maritima has been recorded at three sites by the River Thames near central London, much further from the open sea than elsewhere in Britain. Other halophytes occur nearby. Hydrological data and other records suggest that saline water carrying seeds or other propagules penetrated far upstream during periods of unusually low freshwater river flow. These are the first records of

J. A. EDGINGTON

163

Differences in proton pumping and Na/H exchange at the leaf cell tonoplast between a halophyte and a glycophyte.  

PubMed

The tonoplast Na(+)/H(+) antiporter and tonoplast H(+) pumps are essential components of salt tolerance in plants. The objective of this study was to investigate the transport activity of the tonoplast Na(+)/H(+) antiporter and the tonoplast V-H(+)-ATPase and V-H(+)-PPase in a highly tolerant salt-accumulating halophyte, Salicornia dolichostachya, and to compare these transport activities with activities in the related glycophyte Spinacia oleracea. Vacuolar membrane vesicles were isolated by density gradient centrifugation, and the proton transport and hydrolytic activity of both H(+) pumps were studied. Furthermore, the Na(+)/H(+)-exchange capacity of the vesicles was investigated by 9-amino-6-chloro-2-methoxyacridine fluorescence. Salt treatment induced V-H(+)-ATPase and V-H(+)-PPase activity in vesicles derived from S. oleracea, whereas V-H(+)-ATPase and V-H(+)-PPase activity in S. dolichostachya was not affected by salt treatment. Na(+)/H(+)-exchange capacity followed the same pattern, i.e. induced in response to salt treatment (0 and 200 mM NaCl) in S. oleracea and not influenced by salt treatment (10 and 200 mM NaCl) in S. dolichostachya. Our results suggest that S. dolichostachya already generates a high tonoplast H(+) gradient at low external salinities, which is likely to contribute to the high cellular salt accumulation of this species at low external salinities. At high external salinities, S. dolichostachya showed improved growth compared with S. oleracea, but V-H(+)-ATPase, V-H(+)-PPase and Na(+)/H(+)-exchange activities were comparable between the species, which might imply that S. dolichostachya more efficiently retains Na(+) in the vacuole. PMID:24887002

Katschnig, Diana; Jaarsma, Rinse; Almeida, Pedro; Rozema, Jelte; Schat, Henk

2014-01-01

164

Mercury uptake and accumulation by four species of aquatic plants.  

PubMed

The effectiveness of four aquatic plants including water hyacinth (Eichornia crassipes), water lettuce (Pistia stratiotes), zebra rush (Scirpus tabernaemontani) and taro (Colocasia esculenta) were evaluated for their capabilities in removing mercury from water. The plants were exposed to concentrations of 0 mg/L, 0.5 mg/L or 2 mg/L of mercury for 30 days. Assays were conducted using both Microtox (water) and cold vapor Atomic Absorption Spectroscopy (AAS) (roots and water). The Microtox results indicated that the mercury induced acute toxicity had been removed from the water. AAS confirmed an increase of mercury within the plant root tissue and a corresponding decrease of mercury in the water. All species of plants appeared to reduce mercury concentrations in the water via root uptake and accumulation. Water lettuce and water hyacinth appeared to be the most effective, followed by taro and zebra rush, respectively. PMID:16781033

Skinner, Kathleen; Wright, Nicole; Porter-Goff, Emily

2007-01-01

165

Effects of thermoperiod on recovery of seed germination of halophytes from saline conditions.  

PubMed

Recovery of seed germination from NaCl salinity of desert shrubs (Haloxylon recurvum and Suaeda fruticosa, and the herbs Zygophyllum simplex and Triglochin maritima was studied under various thermoperiods. The percentage of ungerminated seeds that recovered when they were transferred to distilled water varied significantly with variation in species and thermoperiods. Zygophyllum simplex had little recovery from all NaCl concentrations in all thermoperiods. Haloxylon recurvum, S. fruticosa, and T. maritima showed substantial recovery. Percentage recovery was highest in S. fruticosa, followed by T. maritima, and H. recurvum. Thermoperiodic effects varied with the species investigated. There was little thermoperodic effect on the percentage recovery of S. fruticosa, except in the higher salinity treatment at higher thermoperiods. Variation in thermoperiod appears to play an important role in recovery of germination of halophytes from salt stress when seeds are transferred to distilled water. PMID:21712207

Khan, M; Ungar, I

1997-02-01

166

Plant species richness increases phosphatase activities in an experimental grassland  

NASA Astrophysics Data System (ADS)

Plant species richness has been shown to increase aboveground nutrient uptake requiring the mobilization of soil nutrient pools. For phosphorus (P) the underlying mechanisms for increased P release in soil under highly diverse grassland mixtures remain obscure because aboveground P storage and concentrations of inorganic and organic P in soil solution and differently reactive soil P pools are unrelated (Oelmann et al. 2011). The need of plants and soil microorganisms for P can increase the exudation of enzymes hydrolyzing organically bound P (phosphatases) which might represent an important release mechanism of inorganic P in a competitive environment such as highly diverse grassland mixtures. Our objectives were to test the effects of i) plant functional groups (legumes, grasses, non-leguminous tall and small herbs), and of (ii) plant species richness on microbial P (Pmic) and phosphatase activities in soil. In autumn 2013, we measured Pmic and alkaline phosphomonoesterase and phosphodiesterase activities in soil of 80 grassland mixtures comprising different community compositions and species richness (1, 2, 4, 8, 16, 60) in the Jena Experiment. In general, Pmic and enzyme activities were correlated (r = 0.59 and 0.46 for phosphomonoesterase and phosphodiesterase activities, respectively; p

Hacker, Nina; Wilcke, Wolfgang; Oelmann, Yvonne

2014-05-01

167

Species differences in whole plant carbon balance following winter dormancy in Alaskan tundra plants  

SciTech Connect

We froze ramets of seven vascular plant species and a mixed community of mosses common to upland tussock tundra for several months, then measured whole-plant photosynthesis and respiration in a growth chamber under simulated spring conditions, to examine whole plant carbon metabolism following winter dormancy. In addition, respiration and photosynthesis of aboveground stems and leaves were measured in the field in a spatial gradient away from a melting snowbank, at comparable developmental stages. Species differences in early respiration were not pronounced, but large differences were seen once development of leaves began. Root development in deciduous shrubs delayed their attainment of a positive whole plant carbon balance compared to that seen in aboveground stems and leaves alone, and partially compensated for differences in photosynthetic rates between shrubs and other species. Temporal patterns of carbon metabolism during spring growth may affect competitive balance in tussock tundra and vegetation response to global change.

Bret-Harte, M.S.; Chapin, F.S. III [Univ. of California, Berkeley, CA (United States)

1995-09-01

168

Effects of plant species richness on invasion dynamics, disease outbreaks, insect abundances and  

E-print Network

Effects of plant species richness on invasion dynamics, disease outbreaks, insect abundances vulnerability to invasions by plant species, enhance the spread of plant fungal diseases, and alter the richness studies have shown that biodiversity loss of basal species, such as autotrophs or plants, affects

Crews, Stephen

169

Variation in grazing tolerance among three tallgrass prairie plant species.  

PubMed

Three tallgrass prairie plant species, two common perennial forbs (Artemisia ludoviciana and Aster ericoides [Asteraceae]) and a dominant C(4) perennial grass (Sorghastrum nutans) were studied under field and greenhouse conditions to evaluate interspecific variation in grazing tolerance (compensatory growth capacity). Adaptation to ungulate grazing was also assessed by comparing defoliation responses of plants from populations with a 25-yr history of no grazing or moderate ungulate grazing. Under field conditions, all three species showed significant reductions in shoot relative growth rates (RGR), biomass, and reproduction with defoliation. In the two forbs, clipping resulted in negative shoot RGR and reductions in both number and length of shoot branches per ramet. Sorghastrum nutans maintained positive RGR under defoliation due to a compensatory increase in leaf production. Defoliation reduced rhizome production in A. ericoides and S. nutans, but not in A. ludoviciana. Clipping significantly reduced sexual reproductive allocation in all three species, although S. nutans showed a smaller reduction than the forbs. All three species showed similar responses to defoliation in burned and unburned sites. Under greenhouse conditions, a similar clipping regimen resulted in smaller reductions in growth and reproduction than those observed in the field. For all three species, the grazing tolerance indices calculated under natural field conditions were significantly lower than those estimated from greenhouse-grown plants, and the interspecific patterns of grazing tolerance were different. Aster ericoides exhibited the highest overall defoliation tolerance under greenhouse conditions, followed by S. nutans. Artemisia ludoviciana, the only study species that is typically not grazed by ungulates in the field, showed the lowest grazing tolerance. In the field experiment S. nutans showed the highest grazing tolerance and the two forbs had similar low tolerance indices. These patterns indicate that, despite high compensatory growth potential, limited resource availability and competition in the field significantly reduce the degree of compensation and alter interspecific differences in grazing tolerance among prairie plants. In all three species, defoliation suppressed sexual reproduction more than growth or vegetative reproduction. Significant interactions between plant responses to defoliation and site of origin (historically grazed or ungrazed sites) for some response variables (root/shoot ratios, rhizome bud initiation, and reproductive allocation) indicated some degree of population differentiation and genetic adaptation in response to a relatively short history of ungulate grazing pressure. The results of this study indicate that patterns of grazing tolerance in tallgrass prairie are both genetically based and also environmentally dependent. PMID:21665591

Damhoureyeh, Said A; Hartnett, David C

2002-10-01

170

Methylated arsenic species in plants originate from soil microorganisms.  

PubMed

• Inorganic arsenic (iAs) is a ubiquitous human carcinogen, and rice (Oryza sativa) is the main contributor to iAs in the diet. Methylated pentavalent As species are less toxic and are routinely found in plants; however, it is currently unknown whether plants are able to methylate As. • Rice, tomato (Solanum lycopersicum) and red clover (Trifolium pratense) were exposed to iAs, monomethylarsonic acid (MMA(V)), or dimethylarsinic acid (DMA(V)), under axenic conditions. Rice seedlings were also grown in two soils under nonsterile flooded conditions, and rice plants exposed to arsenite or DMA(V) were grown to maturity in nonsterile hydroponic culture. Arsenic speciation in samples was determined by HPLC-ICP-MS. • Methylated arsenicals were not found in the three plant species exposed to iAs under axenic conditions. Axenically grown rice was able to take up MMA(V) or DMA(V), and reduce MMA(V) to MMA(III) but not convert it to DMA(V). Methylated As was detected in the shoots of soil-grown rice, and in rice grain from nonsterile hydroponic culture. GeoChip analysis of microbial genes in a Bangladeshi paddy soil showed the presence of the microbial As methyltransferase gene arsM. • Our results suggest that plants are unable to methylate iAs, and instead take up methylated As produced by microorganisms. PMID:22098145

Lomax, Charlotte; Liu, Wen-Ju; Wu, Liyou; Xue, Kai; Xiong, Jinbo; Zhou, Jizhong; McGrath, Steve P; Meharg, Andrew A; Miller, Anthony J; Zhao, Fang-Jie

2012-02-01

171

Plant functional traits and the multidimensional nature of species coexistence.  

PubMed

Understanding the processes maintaining species diversity is a central problem in ecology, with implications for the conservation and management of ecosystems. Although biologists often assume that trait differences between competitors promote diversity, empirical evidence connecting functional traits to the niche differences that stabilize species coexistence is rare. Obtaining such evidence is critical because traits also underlie the average fitness differences driving competitive exclusion, and this complicates efforts to infer community dynamics from phenotypic patterns. We coupled field-parameterized mathematical models of competition between 102 pairs of annual plants with detailed sampling of leaf, seed, root, and whole-plant functional traits to relate phenotypic differences to stabilizing niche and average fitness differences. Single functional traits were often well correlated with average fitness differences between species, indicating that competitive dominance was associated with late phenology, deep rooting, and several other traits. In contrast, single functional traits were poorly correlated with the stabilizing niche differences that promote coexistence. Niche differences could only be described by combinations of traits, corresponding to differentiation between species in multiple ecological dimensions. In addition, several traits were associated with both fitness differences and stabilizing niche differences. These complex relationships between phenotypic differences and the dynamics of competing species argue against the simple use of single functional traits to infer community assembly processes but lay the groundwork for a theoretically justified trait-based community ecology. PMID:25561561

Kraft, Nathan J B; Godoy, Oscar; Levine, Jonathan M

2015-01-20

172

Cupriavidus plantarum sp. nov., a plant-associated species.  

PubMed

During a survey of plant-associated bacteria in northeast Mexico, a group of 13 bacteria was isolated from agave, maize and sorghum plants rhizosphere. This group of strains was related to Cupriavidus respiraculi (99.4 %), but a polyphasic investigation based on DNA-DNA hybridization analysis, other genotypic studies and phenotypic features showed that this group of strains actually belongs to a new Cupriavidus species. Consequently, taking all the results together, the description of Cupriavidus plantarum sp. nov. is proposed. PMID:25098225

Estrada-de Los Santos, Paulina; Solano-Rodríguez, Roosivelt; Matsumura-Paz, Lucía Tomiko; Vásquez-Murrieta, María Soledad; Martínez-Aguilar, Lourdes

2014-11-01

173

Antimicrobial potential of some plant extracts against Candida species.  

PubMed

The increase in the resistance to antimicrobial drugs in use has attracted the attention of the scientific community, and medicinal plants have been extensively studied as alternative agents for the prevention of infections. The Candida genus yeast can become an opportunistic pathogen causing disease in immunosuppressive hosts. The purpose of this study was to evaluate dichloromethane and methanol extracts from Mentha piperita, Rosmarinus officinalis, Arrabidaea chica, Tabebuia avellanedae, Punica granatum and Syzygium cumini against Candida species through the analysis of Minimum Inhibitory Concentration (MIC). Results presented activity of these extracts against Candida species, especially the methanol extract. PMID:21180915

Höfling, J F; Anibal, P C; Obando-Pereda, G A; Peixoto, I A T; Furletti, V F; Foglio, M A; Gonçalves, R B

2010-11-01

174

Corridors Increase Plant Species Richness at Large Scales  

SciTech Connect

Habitat fragmentation is one of the largest threats to biodiversity. Landscape corridors, which are hypothesized to reduce the negative consequences of fragmentation, have become common features of ecological management plans worldwide. Despite their popularity, there is little evidence documenting the effectiveness of corridors in preserving biodiversity at large scales. Using a large-scale replicated experiment, we showed that habitat patches connected by corridors retain more native plant species than do isolated patches, that this difference increases over time, and that corridors do not promote invasion by exotic species. Our results support the use of corridors in biodiversity conservation.

Damschen, Ellen I.; Haddad, Nick M.; Orrock,John L.; Tewksbury, Joshua J.; Levey, Douglas J.

2006-09-01

175

Hybrid Viability and Fertility in Co-occuring Plant Species  

NASA Astrophysics Data System (ADS)

Similar species of plants can co-exist due to reproductive barriers that keep them from hybridizing. In the case of Lasthenia gracilis and L. californica, certain reproductive barriers allow them to co-exist at Jasper Ridge without hybridization. The two species are locally adapted to different regions of the same hillside, and have slight differences in flowering time but hybrids can be created at low rate in the green house. We tested the viability and fertility of green house produced hybrids to quantify post-zygotic reproductive isolation at Jasper Ridge. We planted 10 hybrid seeds and 10 control seeds from 11 different families. We measured the percent germination, survival to flowering and pollen fertility of the seeds. We expect lower germination, lower survival to flowering, and lower pollen viability of hybrid seeds as compared to control seeds.

Hernandez, E.; Garcia, C.; Yost, J.

2012-12-01

176

Behavioral Response of Nothanguina phyllobia to Selected Plant Species.  

PubMed

The silver-leaf nightshade nenmtode, Nothanguina phyllobia, is a promising biological control agent for its only reported host, Solanum elaeagnifolium Cav. When infective larvae of N. phyllobia and stem tissue of 39 econmnically important plant species were suspended in 0.5% water agar, nematodes aggregated about S. elaeagnifolium, Solanum carolinense L., Solanum melongena L., Solanum tuberosum L., and Prunus caroliniana (Mill.) Ait. Nematodes responded to Solanum spp. via positive chemotaxis and/or klinokinesis, but aggregated near tissue of P. caroliniana as a result of orthokinetic effects. Nematodes aggregated away from tissue of Hibiscus esculentus L., Triticum aestivum L., Santolina sp., Rosa sp., and Kochia scoparia (L.) Schrad. in the absence of orthokinetic effects. Experiments that excluded light and maintained relative humidity at 100% showed N. phyllobia to ascend the stems of 35 plant species to a height of > 9 cm within 12 h. Differences in stem ascension were not attributable to stem surface characteristics. PMID:19305532

Robinson, A F; Orr, C C; Abernathy, J R

1979-01-01

177

Behavioral Response of Nothanguina phyllobia to Selected Plant Species  

PubMed Central

The silver-leaf nightshade nenmtode, Nothanguina phyllobia, is a promising biological control agent for its only reported host, Solanum elaeagnifolium Cav. When infective larvae of N. phyllobia and stem tissue of 39 econmnically important plant species were suspended in 0.5% water agar, nematodes aggregated about S. elaeagnifolium, Solanum carolinense L., Solanum melongena L., Solanum tuberosum L., and Prunus caroliniana (Mill.) Ait. Nematodes responded to Solanum spp. via positive chemotaxis and/or klinokinesis, but aggregated near tissue of P. caroliniana as a result of orthokinetic effects. Nematodes aggregated away from tissue of Hibiscus esculentus L., Triticum aestivum L., Santolina sp., Rosa sp., and Kochia scoparia (L.) Schrad. in the absence of orthokinetic effects. Experiments that excluded light and maintained relative humidity at 100% showed N. phyllobia to ascend the stems of 35 plant species to a height of > 9 cm within 12 h. Differences in stem ascension were not attributable to stem surface characteristics. PMID:19305532

Robinson, A. F.; Orr, C. C.; Abernathy, J. R.

1979-01-01

178

Pollinators visit related plant species across 29 plant–pollinator networks  

PubMed Central

Understanding the evolution of specialization in host plant use by pollinators is often complicated by variability in the ecological context of specialization. Flowering communities offer their pollinators varying numbers and proportions of floral resources, and the uniformity observed in these floral resources is, to some degree, due to shared ancestry. Here, we find that pollinators visit related plant species more so than expected by chance throughout 29 plant–pollinator networks of varying sizes, with “clade specialization” increasing with community size. As predicted, less versatile pollinators showed more clade specialization overall. We then asked whether this clade specialization varied with the ratio of pollinator species to plant species such that pollinators were changing their behavior when there was increased competition (and presumably a forced narrowing of the realized niche) by examining pollinators that were present in at least three of the networks. Surprisingly, we found little evidence that variation in clade specialization is caused by pollinator species changing their behavior in different community contexts, suggesting that clade specialization is observed when pollinators are either restricted in their floral choices due to morphological constraints or innate preferences. The resulting pollinator sharing between closely related plant species could result in selection for greater pollinator specialization. PMID:25360269

Vamosi, Jana C; Moray, Clea M; Garcha, Navdeep K; Chamberlain, Scott A; Mooers, Arne Ø

2014-01-01

179

Nuclear DNA content of some important plant species  

Microsoft Academic Search

Nuclear DNA contents of more than 100 important plant species were measured by flow cytometry of isolated nuclei stained with\\u000a propidium iodide.Arabidopsis exhibits developmentally regulated multiploidy and has a 2C nuclear DNA content of 0.30 pg (145 Mbp\\/1C), twice the value\\u000a usually cited. The 2C value for rice is only about three times that ofArabidopsis. Tomato has a 2C value

K. Arumuganathan; E. D. Earle

1991-01-01

180

Does phosphorus limitation promote species-rich plant communities?  

Microsoft Academic Search

It is known that the number of limiting nutrients may affect the species richness of plant communities, but it is unclear\\u000a whether the type of nutrient limitation is also important. I place the results from a study in Patagonia (elsewhere in this\\u000a issue) in the context of the number and types of nutrients that are limiting. I present four mechanisms

Harry Olde Venterink

181

Arsenic species: effects on and accumulation by tomato plants.  

PubMed

The uptake of arsenic (As) species by Lycopersicum esculentum, growing under soilless culture conditions, was studied. A 4 x 3 x 2 factorial experiment was conducted with four As species (arsenite, arsenate, methylarsonate, and dimethylarsinate), three As concentrations (1, 2, and 5 mg L(-)(1)) and two tomato cultivars (Marmande and Muchamiel). The phytoavailability and phytotoxicity were primarily determined by the As species. The concentrations of As in plant increased significantly with increasing As concentration in solution. Both MA and DMA showed a higher upward translocation than arsenite and arsenate, and treatments with MA and DMA clearly reduced plant growth and fruit yield. The As concentration in tomatoes treated with arsenite or arsenate were within the range considered normal in food crops; however, the As concentration in tomatoes treated with MA and DMA were close to or even above the maximum limit. When tomato plants are exposed to high concentrations of As in nutrient solutions, they may uptake As to concentrations unacceptable for human food. PMID:10552445

Burló, F; Guijarro, I; Carbonell-Barrachina, A A; Valero, D; Martínez-Sánchez, F

1999-03-01

182

Biodegradation of 2,4-dinitrotoluene by different plant species.  

PubMed

Over the past century, rapid growth of population, mining and industrialization significantly contributed to extensive soil, air and water contamination. The 2,4-dinitrotoluene (2,4-DNT), used mostly as explosive, belongs to the hazardous xenobiotics. Soils and waters contaminated with 2,4-DNT may be cleaned by phytoremediation using suitable plant species. The ability of crop plants (hemp, flax, sunflower and mustard) to germinate and grow on soils contaminated with 2,4-DNT was compared. Stimulation of their growth was found at 0.252 mg/g 2,4-DNT. The lethal concentration for the growth for these species was around 1 mg/g. In hydropony, the above mentioned species were able to survive 200 mg/l 2,4-DNT, the concentration close to maximal solubility of 2,4-DNT in water. Metabolism of 2,4-DNT was tested using suspension culture of soapwort and reed. The degradation products 2-aminonitrotoluene and 4-aminonitrotoluene were found both in the medium and in the acetone extract of plant cells. The test showed that the toxicity of these metabolites was higher than the toxicity of the parent compound, but 2,4-diaminotoluene, the product of next reduction step, was less toxic in the concentration range tested (0-200 mg/l). PMID:25463853

Podlipná, Radka; Pospíšilová, Blanka; Van?k, Tomáš

2015-02-01

183

Fuel breaks affect nonnative species abundance in Californian plant communities.  

PubMed

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. PMID:16711041

Merriam, Kyle E; Keeley, Jon E; Beyers, Jan L

2006-04-01

184

Reactive oxygen species signaling in plants under abiotic stress.  

PubMed

Abiotic stresses like heavy metals, drought, salt, low temperature, etc. are the major factors that limit crop productivity and yield. These stresses are associated with production of certain deleterious chemical entities called reactive oxygen species (ROS), which include hydrogen peroxide (H?O?), superoxide radical (O?(-)), hydroxyl radical (OH(-)), etc. ROS are capable of inducing cellular damage by degradation of proteins, inactivation of enzymes, alterations in the gene and interfere in various pathways of metabolic importance. Our understanding on ROS in response to abiotic stress is revolutionized with the advancements in plant molecular biology, where the basic understanding on chemical behavior of ROS is better understood. Understanding the molecular mechanisms involved in ROS generation and its potential role during abiotic stress is important to identify means by which plant growth and metabolism can be regulated under acute stress conditions. ROS mediated oxidative stress, which is the key to understand stress related toxicity have been widely studied in many plants and the results in those studies clearly revealed that oxidative stress is the main symptom of toxicity. Plants have their own antioxidant defense mechanisms to encounter ROS that is of enzymic and non-enzymic nature . Coordinated activities of these antioxidants regulate ROS detoxification and reduces oxidative load in plants. Though ROS are always regarded to impart negative impact on plants, some reports consider them to be important in regulating key cellular functions; however, such reports in plant are limited. Molecular approaches to understand ROS metabolism and signaling have opened new avenues to comprehend its critical role in abiotic stress. ROS also acts as secondary messenger that signals key cellular functions like cell proliferation, apoptosis and necrosis. In higher eukaryotes, ROS signaling is not fully understood. In this review we summarize our understanding on ROS and its signaling behavior in plants under abiotic stress. PMID:23425848

Choudhury, Shuvasish; Panda, Piyalee; Sahoo, Lingaraj; Panda, Sanjib Kumar

2013-04-01

185

Effects of ‘Target’ Plant Species Body Size on Neighbourhood Species Richness and Composition in Old-Field Vegetation  

PubMed Central

Competition is generally regarded as an important force in organizing the structure of vegetation, and evidence from several experimental studies of species mixtures suggests that larger mature plant size elicits a competitive advantage. However, these findings are at odds with the fact that large and small plant species generally coexist, and relatively smaller species are more common in virtually all plant communities. Here, we use replicates of ten relatively large old-field plant species to explore the competitive impact of target individual size on their surrounding neighbourhoods compared to nearby neighbourhoods of the same size that are not centred by a large target individual. While target individuals of the largest of our test species, Centaurea jacea L., had a strong impact on neighbouring species, in general, target species size was a weak predictor of the number of other resident species growing within its immediate neighbourhood, as well as the number of resident species that were reproductive. Thus, the presence of a large competitor did not restrict the ability of neighbouring species to reproduce. Lastly, target species size did not have any impact on the species size structure of neighbouring species; i.e. they did not restrict smaller, supposedly poorer competitors, from growing and reproducing close by. Taken together, these results provide no support for a size-advantage in competition restricting local species richness or the ability of small species to coexist and successfully reproduce in the immediate neighbourhood of a large species. PMID:24349177

Schamp, Brandon S.; Aarssen, Lonnie W.; Wight, Stephanie

2013-01-01

186

Alleviatory effects of calcium on the toxicity of sodium, potassium and magnesium chlorides to seed germination in three non-halophytes  

Microsoft Academic Search

Saline soils contain numerous salts with varying impact on seed germination. Seeds of three non-halophytic species found in Chinese sandy deserts (Artemisia ordosica, Aristida adscensionis and Bassia dasyphylla) were incubated in salt solutions (NaCl, KCl or MgCl2, each with or without CaCl2) at 20°C in the dark. The effects of each salt on the percentage of seeds from which visibly

Kazuo Tobe; Liping Zhang; Kenji Omasa

2003-01-01

187

Invasive Plant Species: Inventory, Mapping, and Monitoring - A National Strategy  

USGS Publications Warehouse

America is under siege by invasive species of plants and animals, and by diseases. The current environmental, economic, and health-related costs of invasive species could exceed $138 billion per year-more than all other natural disasters combined. Notorious examples include West Nile virus, Dutch elm disease, chestnut blight, and purple loose- strife in the Northeast; kudzu, Brazilian peppertree, water hyacinth, nutria, and fire ants in the Southeast; zebra mussels, leafy spurge, and Asian long-horn beetles in the Midwest; salt cedar, Russian olive, and Africanized bees in the Southwest; yellow star thistle, European wild oats, oak wilt disease, Asian clams, and white pine blister rust in California; cheatgrass, various knapweeds, and thistles in the Great Basin; whirling disease of salmonids in the Northwest; hundreds of invasive species from microbes to mammals in Hawaii; and the brown tree snake in Guam. Thousands of species from other countries are introduced intentionally or accidentally into the United States each year. Based on past experience, 10-15 percent can be expected to establish free-living populations and about 1 percent can be expected to cause significant impacts to ecosystems, native species, economic productivity, and (or) human health.

Ludke, J. Larry; D'Erchia, Frank; Coffelt, Jan; Hanson, Leanne

2002-01-01

188

Treatment of Domestic Wastewater by Three Plant Species in Constructed Wetlands  

Microsoft Academic Search

Three common Appalachian plant species (Juncus effusus L., Scirpus validus L., and Typha latifolia L.) were planted into small-scale constructed wetlands receivingprimary treated wastewater. The experimental design includedtwo wetland gravel depths (45 and 60 cm) and five plantingtreatments (each species in monoculture, an equal mixture of the three species, and controls without vegetation), with two replicates per depth × planting

Jerry Coleman; Keith Hench; Keith Garbutt; Alan Sexstone; Gary Bissonnette; Jeff Skousen

2001-01-01

189

Ozone sensitivity of wild field layer plant species of northern Europe. A review  

Microsoft Academic Search

The increasing tropospheric ozone (O3) concentration constitutes a potential threat to nature. Plants are known to react to O3, but knowledge of the sensitivity and type of responses of different species and plant communities is widely lacking. This review focuses on the ecological effects of O3 on northern wild field layer plant species. Most of the 65 species examined thus

Ulla Timonen; Satu Huttunen; Sirkku Manninen

2004-01-01

190

Effects of Invasive, Non-Indigenous Plant Species on Ecosystem Processes: Lessons from Florida  

Microsoft Academic Search

Individual plant species that modify ecosystem properties have traditionally been thought to be uncommon in natural systems. I hypothesize that many invasive non- indigenous species do alter these properties at several scales. The non-indigenous plant species in Florida considered the most invasive by the Florida Exotic Pest Plant Council are examined for this capability through review of the available literature.

Doria R. Gordon

1998-01-01

191

Genetic control of invasive plants species using selfish genetic elements  

PubMed Central

Invasive plants cause substantial environmental damage and economic loss. Here, we explore the possibility that a selfish genetic element found in plants called cytoplasmic male sterility (CMS) could be exploited for weed control. CMS is caused by mutations in the mitochondrial genome that sterilize male reproductive organs. We developed an analytical model and a spatial simulation to assess the use of CMS alleles to manage weed populations. Specifically, we examined how fertility, selfing, pollen limitation and dispersal influenced extinction rate and time until extinction in populations where CMS arises. We found that the introduction of a CMS allele can cause rapid population extinction, but only under a restricted set of conditions. Both models suggest that the CMS strategy will be appropriate for species where pollen limitation is negligible, inbreeding depression is high and the fertility advantage of females over hermaphrodites is substantial. In general, spatial structure did not have a strong influence on the simulation outcome, although low pollen dispersal and intermediate levels of seed dispersal tended to reduce population extinction rates. Given these results, the introduction of CMS alleles into a population of invasive plants probably represents an effective control method for only a select number of species.

Hodgins, Kathryn A; Rieseberg, Loren; Otto, Sarah P

2009-01-01

192

Species-area relationships in Mediterranean-climate plant communities  

USGS Publications Warehouse

Aim: To determine the best-fit model of species-area relationships for Mediterranean-type plant communities and evaluate how community structure affects these species-area models. Location: Data were collected from California shrublands and woodlands and compared with literature reports for other Mediterranean-climate regions. Methods: The number of species was recorded from 1, 100 and 1000 m2 nested plots. Best fit to the power model or exponential model was determined by comparing adjusted r2 values from the least squares regression, pattern of residuals, homoscedasticity across scales, and semi-log slopes at 1-100 m2 and 100-1000 m2. Dominance-diversity curves were tested for fit to the lognormal model, MacArthur's broken stick model, and the geometric and harmonic series. Results: Early successional Western Australia and California shrublands represented the extremes and provide an interesting contrast as the exponential model was the best fit for the former, and the power model for the latter, despite similar total species richness. We hypothesize that structural differences in these communities account for the different species-area curves and are tied to patterns of dominance, equitability and life form distribution. Dominance-diversity relationships for Western Australian heathlands exhibited a close fit to MacArthur's broken stick model, indicating more equitable distribution of species. In contrast, Californian shrublands, both postfire and mature stands, were best fit by the geometric model indicating strong dominance and many minor subordinate species. These regions differ in life form distribution, with annuals being a major component of diversity in early successional Californian shrublands although they are largely lacking in mature stands. Both young and old Australian heathlands are dominated by perennials, and annuals are largely absent. Inherent in all of these ecosystems is cyclical disequilibrium caused by periodic fires. The potential for community reassembly is greater in Californian shrublands where only a quarter of the flora resprout, whereas three quarters resprout in Australian heathlands. Other Californian vegetation types sampled include coniferous forests, oak savannas and desert scrub, and demonstrate that different community structures may lead to a similar species-area relationship. Dominance-diversity relationships for coniferous forests closely follow a geometric model whereas associated oak savannas show a close fit to the lognormal model. However, for both communities, species-area curves fit a power model. The primary driver appears to be the presence of annuals. Desert scrub communities illustrate dramatic changes in both species diversity and dominance-diversity relationships in high and low rainfall years, because of the disappearance of annuals in drought years. Main conclusions: Species-area curves for immature shrublands in California and the majority of Mediterranean plant communities fit a power function model. Exceptions that fit the exponential model are not because of sampling error or scaling effects, rather structural differences in these communities provide plausible explanations. The exponential species-area model may arise in more than one way. In the highly diverse Australian heathlands it results from a rapid increase in species richness at small scales. In mature California shrublands it results from very depauperate richness at the community scale. In both instances the exponential model is tied to a preponderance of perennials and paucity of annuals. For communities fit by a power model, coefficients z and log c exhibit a number of significant correlations with other diversity parameters, suggesting that they have some predictive value in ecological communities.

Keeley, J.E.; Fotheringham, C.J.

2003-01-01

193

Plant-associated bacterial populations on native and invasive plant species: comparisons between 2 freshwater environments.  

PubMed

Plant-microbial interactions have been well studied because of the ecological importance of such relationships in aquatic systems. However, general knowledge regarding the composition of these biofilm communities is still evolving, partly as a result of several confounding factors that are attributable to plant host properties and to hydrodynamic conditions in aquatic environments. In this study, the occurrences of various bacterial phylogenetic taxa on 2 native plants, i.e., mayapple (Podophyllum peltatum L.) and cow parsnip (Heracleum maximum Bartram), and on an invasive species, i.e., garlic mustard (Alliaria petiolata (M. Bieb.) Cavara & Grande), were quantitatively examined using nucleic acid staining and fluorescence in situ hybridization. The plants were incubated in triplicates for about a week within the Kalamazoo River and Pierce Cedar Creek as well as in microcosms. The bacterial groups targeted for enumeration are known to globally occur in relatively high abundance and are also ubiquitously distributed in freshwater environments. Fluorescence in situ hybridization analyses of the bacterioplankton assemblages revealed that the majority of bacterial cells that hybridized with the different probes were similar between the 2 sites. In contrast, the plant-associated populations while similar on the 3 plants incubated in Kalamazoo River, their representations were highest on the 2 native plants relative to the invasive species in Pierce Cedar Creek. Overall, our results further suggested that epiphytic bacterial assemblages are probably under the influences of and probably subsequently respond to multiple variables and conditions in aquatic milieus. PMID:22625420

Olapade, Ola A; Pung, Kayleigh

2012-06-01

194

Reprints Available from the Halophyte Biotechnology Center  

E-print Network

, and J.L. Gallagher. 2005. Tissue culture and plant regeneration of the salt marsh monocots Juncus roemerianus and Juncus gerardii. In Vitro Cellular and Developmental Biology ­ Plant 41:274-280. Wu, J., D

Firestone, Jeremy

195

Plant species richness, elevated CO2, and atmospheric nitrogen deposition alter soil microbial community  

E-print Network

), global change, grassland ecosystem, microbial biomass, phospholipid fatty acid (PLFA), plant diversityPlant species richness, elevated CO2, and atmospheric nitrogen deposition alter soil microbial soil microbial community composition and function in a field experiment in which plant communities

Minnesota, University of

196

Some essential nutrient elements in forest plants as related to species, plant part, season and location  

Microsoft Academic Search

Natural vegetation common to the forested areas of Nova Scotia was sampled and analyzed for the nutrient elements calcium, phosphorus, cobalt, molybdenum, manganese, zinc and copper. Results showed considerable variation within and between species. Variations due to plant part, season and location of sampling also occurred but to a lesser degree. With the possible exception of molybdenum and copper, the

W. M. Langille; K. S. Maclean

1976-01-01

197

Spatial aggregation facilitates coexistence and diversity of wild plant species in field margins  

Microsoft Academic Search

European agri-environment schemes encourage farmers to establish sown field margin strips to protect and enhance wild plant diversity. However, plant diversity in such wild plant sowings based on seed mixtures is often low due to the high competitiveness of few, common species. Here we analysed whether intraspecific aggregation could enhance the performance of less competitive species, and how plant performance

Birte Eleen Wassmuth; Peter Stoll; Teja Tscharntke; Carsten Thies

2009-01-01

198

Metabolomics Unravel Contrasting Effects of Biodiversity on the Performance of Individual Plant Species  

Microsoft Academic Search

In spite of evidence for positive diversity-productivity relationships increasing plant diversity has highly variable effects on the performance of individual plant species, but the mechanisms behind these differential responses are far from being understood. To gain deeper insights into the physiological responses of individual plant species to increasing plant diversity we performed systematic untargeted metabolite profiling on a number of

Christian Scherling; Christiane Roscher; Patrick Giavalisco; Ernst-Detlef Schulze; Wolfram Weckwerth; Jerome Chave

2010-01-01

199

Biodiversity, exotic plant species, and herbivory: The good, the bad, and the ungulate  

Microsoft Academic Search

Invasion of natural ecosystems by exotic plant species is a major threat to biodiversity. Disturbance to native plant communities, whether natural or management induced, is a primary factor contributing to successful invasion by exotic plant species. Herbivory by both wild and domestic ungulates exerts considerable impact on structure and composition of native plant communities. Intensive herbivory by ungulates can enhance

Marty Vavra; Catherine G. Parks; Michael J. Wisdom

2007-01-01

200

Antimicrobial potentials of some plant species of the Bignoniaceae family.  

PubMed

The methanol extracts of the leaves and stem bark of four Bignoniaceae plants Jacaranda mimosifolia D. Dol., Tecoma stans Linn., Tabebuia rosea (Bertol) D.C., and Crescentia cujete Linn. were studied for their antimicrobial activity using a wide range of Gram-positive and Gram-negative bacteria and fungi. Extracts of both the leaves and stem bark of majority of plant species studied showed variable but remarkable broad spectrum antimicrobial activity. However, methanol extracts of Tecoma stans leaves was found to be effective against only Candida albicans at the concentrations employed. It was observed that the extracts of stem bark generally showed better antimicrobial activity than those of the leaves and some organisms were selectively more sensitive to the extracts than others. Preliminary phytochemical screening of these plants revealed the presence of tannins, flavonoids, alkaloids, quinones and traces of saponins. The antimicrobial activity observed are discussed in relation to the chemical constituents reportedly isolated from these plants and their traditional uses. PMID:7604753

Binutu, O A; Lajubutu, B A

1994-09-01

201

Reactive oxygen species generation and signaling in plants  

PubMed Central

The introduction of molecular oxygen into the atmosphere was accompanied by the generation of reactive oxygen species (ROS) as side products of many biochemical reactions. ROS are permanently generated in plastids, peroxisomes, mitochiondria, the cytosol and the apoplast. Imbalance between ROS generation and safe detoxification generates oxidative stress and the accumulating ROS are harmful for the plants. On the other hand, specific ROS function as signaling molecules and activate signal transduction processes in response to various stresses. Here, we summarize the generation of ROS in the different cellular compartments and the signaling processes which are induced by ROS. PMID:23072988

Tripathy, Baishnab Charan; Oelmüller, Ralf

2012-01-01

202

Preliminary experimentation in mechanically planting large seeded tree species  

SciTech Connect

Present methods of reforestation are very limiting to the mining industry in its attempts to reclaim large areas to commercially important tree species. A possible solution to some of the limitations would be the use of a mechanical planter that can plant and fertilize tree seed on steep mine slopes. This paper is a report on the preliminary work being done in the development of such a planter. A commercially available planter is being modified for this purpose and initial success is encouraging further development.

Richards, T.W.; Graves, D.H.

1980-12-01

203

Nutrient relations of the halophytic shrub, Sarcobatus vermiculatus, along a soil salinity gradient  

Microsoft Academic Search

Recent water level declines of a saline and alkaline lake (Mono Lake, California, USA) have exposed large areas of former lake bottom substrates that have been sparsely colonized by the halophytic shrub, Sarcobatus vermiculatus. To increase understanding of the interaction of salt and nutrient relations in halophytes we investigated spatial and seasonal patterns of leaf elemental composition and growth for

Lisa A. Donovan; James H. Richards; E. Joy Schaber

1997-01-01

204

Cross-species translocation of mRNA from host plants into the parasitic plant dodder.  

PubMed

An intriguing new paradigm in plant biology is that systemically mobile mRNAs play a role in coordinating development. In this process, specific mRNAs are loaded into the phloem transport stream for translocation to distant tissues, where they may impact on developmental processes. However, despite its potential significance for plant growth regulation, mRNA trafficking remains poorly understood and challenging to study. Here, we show that phloem-mobile mRNAs can also traffic between widely divergent species from a host to the plant parasite lespedeza dodder (Cuscuta pentagona Engelm.). Reverse transcription-polymerase chain reaction and microarray analysis were used to detect specific tomato (Lycopersicon esculentum Mill.) transcripts in dodder grown on tomato that were not present in control dodder grown on other host species. Foreign transcripts included LeGAI, which has previously been shown to be translocated in the phloem, as well as nine other transcripts not reported to be mobile. Dodders are parasitic plants that obtain resources by drawing from the phloem of a host plant and have joint plasmodesmata with host cortical cells. Although viruses are known to move between dodder and its hosts, translocation of endogenous plant mRNA has not been reported. These results point to a potentially new level of interspecies communication, and raise questions about the ability of parasites to recognize, use, and respond to transcripts acquired from their hosts. PMID:17189329

Roney, Jeannine K; Khatibi, Piyum A; Westwood, James H

2007-02-01

205

Spatial variation of plant communities and shoot Cu concentrations of plant species at a timber treatment site  

Microsoft Academic Search

Plant species, spatial variability in plant diversity and vegetation cover were recorded at a French timber treatment site\\u000a with Cu-contaminated soils (65–2600 mg\\/kg). Shoot biomass, shoot Cu concentration and accumulation were determined for each\\u000a plant species found on 168 quadrats with increasing total Cu in soil and soil solution. A total of 91 species occurred on\\u000a the site including four considered

Clémence M. Bes; Michel Mench; Maurice Aulen; Hélène Gaste; Julie Taberly

2010-01-01

206

Duck productivity in restored species-rich native and species-poor non-native plantings.  

PubMed

Conservation efforts to increase duck production have led the United States Fish and Wildlife Service to restore grasslands with multi-species (3-5) mixtures of introduced cool season vegetation often termed dense nesting cover (DNC). The effectiveness of DNC to increase duck production has been variable, and maintenance of the cover type is expensive. In an effort to decrease the financial and ecological costs (increased carbon emissions from plowing and reseeding) of maintaining DNC and provide a long-term, resilient cover that will support a diversity of grassland fauna, restoration of multi-species (16-32) plantings of native plants has been explored. We investigated the vegetation characteristics, nesting density and nest survival between the 2 aforementioned cover types in the Prairie Pothole Region of North Dakota, USA from 2010-2011 to see if restored-native plantings provide similar benefits to nesting hens as DNC. We searched 14 fields (7 DNC, 271 ha; and 7 restored native, 230 ha) locating 3384 nests (1215 in restored-native vegetation and 2169 in DNC) in 2010-2011. Nest survival was similar between cover types in 2010, while DNC had greater survival than native plantings in 2011. Densities of nests adjusted for detection probability were not different between cover types in either year. We found no structural difference in vegetation between cover types in 2010; however, a difference was detected during the late sampling period in 2011 with DNC having deeper litter and taller vegetation. Our results indicate restored-native plantings are able to support similar nesting density as DNC; however, nest survival is more stable between years in DNC. It appears the annual variation in security between cover types goes undetected by hens as hens selected cover types at similar levels both years. PMID:23840898

Haffele, Ryan D; Eichholz, Michael W; Dixon, Cami S

2013-01-01

207

Phytoaccumulation of trace elements by wetland plants: 3. Uptake and accumulation of ten trace elements by twelve plant species  

Microsoft Academic Search

Interest is increasing in using wetland plants in constructed wetlands to remove toxic elements from polluted wastewater. To identify those wetland plants that hyperaccumulate trace elements, 12 plant species were tested for their efficiency to bioconcentrate 10 potentially toxic trace elements including As, b, Cd, Cr, Cu, Pb, Mn, Hg, Ni, and Se. Individual plants were grown under carefully controlled

Jin-Hong Qian; Adel Zayed; Yong-Liang Zhu; Mei Yu; Norman Terry

1999-01-01

208

The predominance of inorganic arsenic species in plants from Yellowknife, Northwest Territories, Canada  

SciTech Connect

Elevated levels of arsenic in Yellowknife, NWT, Canada, from historic and recent gold mine operations, are of increasing concern to Yellowknife residents. The study of arsenic in Yellowknife plants is a part of ongoing bioavailability and food chain research. A variety of plants from Yellowknife were analyzed for total arsenic and water soluble arsenic species. The plants included vascular plants and bryophytes (mosses). Total amounts of arsenic were greatest in mosses and varied greatly within specimens of the same plant species from different locations. Mostly inorganic arsenic species were extracted from plants using methanol/water (1:1). This result is very important from a toxicological point of view, since inorganic species are relatively toxic arsenic species. Small amounts of methylated arsenic species, as well as arsenosugars, were present in some plants. On average, greater than 50% of arsenic in these plants was not extracted; the chemical and toxicological characteristics of this fraction remain a topic for further study.

Koch, I.; Wang, L.; Ollson, C.A.; Cullen, W.R.; Reimer, K.J.

2000-01-01

209

Imperfect replacement of native species by non-native species as pollinators of endemic Hawaiian plants.  

PubMed

Native plant species that have lost their mutualist partners may require non-native pollinators or seed dispersers to maintain reproduction. When natives are highly specialized, however, it appears doubtful that introduced generalists will partner effectively with them. We used visitation observations and pollination treatments (experimental manipulations of pollen transfer) to examine relationships between the introduced, generalist Japanese White-eye (Zosterops japonicus) and 3 endemic Hawaiian plant species (Clermontia parviflora, C. montis-loa, and C. hawaiiensis). These plants are characterized by curved, tubular flowers, apparently adapted for pollination by curve-billed Hawaiian honeycreepers. Z. japonicus were responsible for over 80% of visits to flowers of the small-flowered C. parviflora and the midsize-flowered C. montis-loa. Z. japonicus-visited flowers set significantly more seed than did bagged flowers. Z. japonicus also demonstrated the potential to act as an occasional Clermontia seed disperser, although ground-based frugivory by non-native mammals likely dominates seed dispersal. The large-flowered C. hawaiiensis received no visitation by any birds during observations. Unmanipulated and bagged C. hawaiiensis flowers set similar numbers of seeds. Direct examination of Z. japonicus and Clermontia morphologies suggests a mismatch between Z. japonicus bill morphology and C. hawaiiensis flower morphology. In combination, our results suggest that Z. japonicus has established an effective pollination relationship with C. parviflora and C. montis-loa and that the large flowers of C. hawaiiensis preclude effective visitation by Z. japonicus. PMID:24372761

Aslan, Clare E; Zavaleta, Erika S; Tershy, Bernie; Croll, Don; Robichaux, Robert H

2014-04-01

210

Status of endangered and threatened plant species on Nevada Test Site: a survey. Part 2. Threatened species  

Microsoft Academic Search

This is the second of a two-part study of plant species on the Nevada Test Site (NTS) that are listed as possibly threatened or endangered by the U.S. Fish and Wildlife Service (FWS). This study was undertaken as a response by DOE to comply with the Endangered Species Act of 1973 (the Act). Part 1 treated species listed under terms

W. A. Rhoads; S. A. Cochrane; M. P. Williams

1978-01-01

211

Novel chemistry of invasive plants: exotic species have more unique metabolomic profiles than native congeners  

PubMed Central

It is often assumed that exotic plants can become invasive when they possess novel secondary chemistry compared with native plants in the introduced range. Using untargeted metabolomic fingerprinting, we compared a broad range of metabolites of six successful exotic plant species and their native congeners of the family Asteraceae. Our results showed that plant chemistry is highly species-specific and diverse among both exotic and native species. Nonetheless, the exotic species had on average a higher total number of metabolites and more species-unique metabolites compared with their native congeners. Herbivory led to an overall increase in metabolites in all plant species. Generalist herbivore performance was lower on most of the exotic species compared with the native species. We conclude that high chemical diversity and large phytochemical uniqueness of the exotic species could be indicative of biological invasion potential. PMID:25077026

Macel, Mirka; de Vos, Ric C H; Jansen, Jeroen J; van der Putten, Wim H; van Dam, Nicole M

2014-01-01

212

Niche pre-emption increases with species richness in experimental plant communities  

Microsoft Academic Search

In plant communities, invasion resistance may increase with diversity because empty niche space decreases simultaneously. However, it is not clear if this only applies to exotic species or also to native species arriving at a site with few other native species during community assembly. We tested the latter by transplanting four native species into experimental grassland communities varying in species

PETER N. MWANGI; MARTIN SCHMITZ; CHRISTOPH SCHERBER; CHRISTIANE ROSCHER; JENS SCHUMACHER; MICHAEL SCHERER-LORENZEN; WOLFGANG W. WEISSER; BERNHARD SCHMID

2007-01-01

213

The Reduction of Amphibian Species Richness in the Presence of Non-Native Plants  

Microsoft Academic Search

Wetlands are critical habitat for many species, making their protection a priority for biodiversity conservation. However, these ecosystems are being degraded at substantial rates. One factor that can be particularly detrimental is the presence of non­ native plant species. Exotic species have been known to out compete native species, alter trophic interactions between native species and transform habitat structure. To

Kaitlyn Schott

2012-01-01

214

The evolution of cultivated plant species: classical plant breeding versus genetic engineering  

Microsoft Academic Search

Agriculture is the most intensive form of environmental exploitation performed by mankind. It involves replacing the natural\\u000a ecosystem with an artificial plant community comprising one or more crop species, and weeds can invade the cleared land. Initially,\\u000a the adoption of agriculture did not necessarily imply an improvement in standard of living (there is, in fact, evidence to\\u000a the contrary), but

Hakan Ulukan

2009-01-01

215

Species-driven changes in nitrogen cycling can provide a mechanism for plant invasions  

E-print Network

Species-driven changes in nitrogen cycling can provide a mechanism for plant invasions Ramesh than competing established spe- cies. In many terrestrial ecosystems nitrogen limits plant growth, and is a key factor determining productivity and the outcome of competition among species. Plant nitrogen use

Minnesota, University of

216

Uptake of organic nitrogen by eight dominant plant species in Kobresia meadows  

Microsoft Academic Search

15N-labelled glycine experiments were carried out in both a Kobresia pygmaea meadow and a Kobresia humilis meadow to investigate whether alpine plants can take up organic nitrogen directly from the soil and whether different plant species differ in this respect. Eight plant species were selected in the two meadows, five in the Kobresia humilis meadow and four in the Kobresia

Xingliang Xu; Hua Ouyang; Guangmin Cao; Zhiyong Pei; Caiping Zhou

2004-01-01

217

Abstract Only recently has the importance of positive interactions among plant species in structuring natural  

E-print Network

- gen-fixing plants have been shown to enhance growth of other plants, enhance rates of colonizationAbstract Only recently has the importance of positive interactions among plant species between a woody nitrogen-fixing shrub (Myrica pensylvanica) and two herbaceous sand dune species (Solidago

Shumway, Scott W.

218

Ecophysiological differences among juvenile and reproductive plants of several woody species  

Microsoft Academic Search

Photosynthetic and water relations characteristics of small juvenile and large reproductive plants were investigated during one growing season for four woody species native to Red Butte Canyon, Utah, USA: Acer negundo, Artemisia tridentata, Chrysothamnus nauseosus, and Salix exigua. For all species, juvenile plants differed from reproductive plants in at least one of the following characters: water potential, stomatal conductance, photosynthetic

Lisa A. Donovan; James R. Ehleringer

1991-01-01

219

Species-specific Effects of Vascular Plants on Carbon Turnover and Methane Emissions from Wetlands  

Microsoft Academic Search

Species composition affects the carbon turnover and the formation and emission of the greenhouse gas methane (CH4) in wetlands. Here we investigate the individual effects of vascular plant species on the carbon cycling in a wetland ecosystem. We used a novel combination of laboratory methods and controlled environment facilities and studied three different vascular plant species (Eriophorum vaginatum, Carex rostrata

Lena Ström; Mikhail Mastepanov; Torben R. Christensen

2005-01-01

220

Flowers, Nectar and Insect Visits: Evaluating British Plant Species for Pollinator-friendly Gardens  

Microsoft Academic Search

Twenty-four plant species native or naturalized in Britain were grown in the Cambridge University Botanic Garden, UK and evaluated as potential resources for nectar-foraging bees, butterflies and hoverflies. In ten plant species a series of measurements were made, at regular intervals from dawn to dusk, of nectar secretion rate and standing crop, and in all species insect visits were monitored

LIVIO COMBA; SARAH A CORBET; LYNN HUNT; BEN WARREN

1999-01-01

221

Riparian zones as havens for exotic plant species in the central grasslands  

Microsoft Academic Search

In the Central Grasslands of the United States, we hypothesized that riparian zones high in soil fertility would contain more exotic plant species than upland areas of low soil fertility. Our alternate hypothesis was that riparian zones high in native plant species richness and cover would monopolize available resources and resist invasion by exotic species. We gathered nested-scale vegetation data

Thomas J. Stohlgren; Kelly A. Bull; Yuka Otsuki; Cynthia A. Villa; Michelle Lee

1998-01-01

222

Productivity Is a Poor Predictor of Plant Species Richness.  

SciTech Connect

For more than 30 years, the relationship between net primary productivity and species richness has generated intense debate in ecology about the processes regulating local diversity. The original view, which is still widely accepted, holds that the relationship is hump-shaped, with richness first rising and then declining with increasing productivity. Although recent meta-analyses questioned the generality of hump-shaped patterns, these syntheses have been criticized for failing to account for methodological differences among studies. We addressed such concerns by conducting standardized sampling in 48 herbaceous-dominated plant communities on five continents. We found no clear relationship between productivity and fine-scale (meters-2) richness within sites, within regions, or across the globe. Ecologists should focus on fresh, mechanistic approaches to understanding the multivariate links between productivity and richness.

Peter B. Adler; et al.

2011-09-22

223

Productivity is a poor predictor of plant species richness  

USGS Publications Warehouse

For more than 30 years, the relationship between net primary productivity and species richness has generated intense debate in ecology about the processes regulating local diversity. The original view, which is still widely accepted, holds that the relationship is hump-shaped, with richness first rising and then declining with increasing productivity. Although recent meta-analyses questioned the generality of hump-shaped patterns, these syntheses have been criticized for failing to account for methodological differences among studies. We addressed such concerns by conducting standardized sampling in 48 herbaceous-dominated plant communities on five continents. We found no clear relationship between productivity and fine-scale (meters-2) richness within sites, within regions, or across the globe. Ecologists should focus on fresh, mechanistic approaches to understanding the multivariate links between productivity an

Adler, Peter B.; Seabloom, Eric W.; Borer, Elizabeth T.; Hillebrand, Helmut; Hautier, Yann; Hector, Andy; Harpole, W. Stanley; O'Halloran, Lydia R.; Grace, James B.; Anderson, T. Michael; Bakker, Jonathan D.; Biederman, Lori A.; Brown, Cynthia S.; Buckley, Yvonne M.; Calabrese, Laura B.; Chu, Cheng-Jin; Cleland, Elsa E.; Collins, Scott L.; Cottingham, Kathryn L.; Crawley, Michael J.; Damschen, Ellen I.; Davies, Kendi F.; DeCrappeo, Nicole M.; Fay, Philip A.; Firn, Jennifer; Frater, Paul; Gasarch, Eve I.; Gruner, Daneil S.; Hagenah, Nicole; Lambers, Janneke Hille Ris; Humphries, Hope; Jin, Virginia L.; Kay, Adam D.; Kirkman, Kevin P.; Klein, Julia A.; Knops, Johannes M.H.; La Pierre, Kimberly J.; Lambrinos, John G.; Li, Wei; MacDougall, Andrew S.; McCulley, Rebecca L.; Melbourne, Brett A.; Mitchell, Charles E.; Moore, Joslin L.; Morgan, John W.; Mortensen, Brent; Orrock, John L.; Prober, Suzanne M.; Pyke, David A.; Risch, Anita C.; Schuetz, Martin; Smith, Melinda D.; Stevens, Carly J.; Sullivan, Lauren L.; Wang, Gang; Wragg, Peter D.; Wright, Justin P.; Yang, Louie H.

2011-01-01

224

Species-driven changes in nitrogen cycling can provide a mechanism for plant invasions  

PubMed Central

Traits that permit successful invasions have often seemed idiosyncratic, and the key biological traits identified vary widely among species. This fundamentally limits our ability to determine the invasion potential of a species. However, ultimately, successful invaders must have positive growth rates that longer term result in higher biomass accumulation than competing established species. In many terrestrial ecosystems nitrogen limits plant growth, and is a key factor determining productivity and the outcome of competition among species. Plant nitrogen use may provide a powerful framework to evaluate the invasive potential of a species in nitrogen-limiting ecosystems. Six mechanisms influence plant nitrogen use or acquisition: photosynthetic tissue allocation, photosynthetic nitrogen use efficiency, nitrogen fixation, nitrogen-leaching losses, gross nitrogen mineralization, and plant nitrogen residence time. Here we show that among these alternatives, the key mechanism allowing invasion for Pinus strobus into nitrogen limited grasslands was its higher nitrogen residence time. This higher nitrogen residence time created a positive feedback that redistributed nitrogen from the soil into the plant. This positive feedback allowed P. strobus to accumulate twice as much nitrogen in its tissues and four times as much nitrogen to photosynthetic tissues, as compared with other plant species. In turn, this larger leaf nitrogen pool increased total plant carbon gain of P. strobus two- to sevenfold as compared with other plant species. Thus our data illustrate that plant species can change internal ecosystem nitrogen cycling feedbacks and this mechanism can allow them to gain a competitive advantage over other plant species. PMID:19592506

Laungani, Ramesh; Knops, Johannes M. H.

2009-01-01

225

Plant Trait-Species Abundance Relationships Vary with Environmental Properties in Subtropical Forests in Eastern China  

PubMed Central

Understanding how plant trait-species abundance relationships change with a range of single and multivariate environmental properties is crucial for explaining species abundance and rarity. In this study, the abundance of 94 woody plant species was examined and related to 15 plant leaf and wood traits at both local and landscape scales involving 31 plots in subtropical forests in eastern China. Further, plant trait-species abundance relationships were related to a range of single and multivariate (PCA axes) environmental properties such as air humidity, soil moisture content, soil temperature, soil pH, and soil organic matter, nitrogen (N) and phosphorus (P) contents. At the landscape scale, plant maximum height, and twig and stem wood densities were positively correlated, whereas mean leaf area (MLA), leaf N concentration (LN), and total leaf area per twig size (TLA) were negatively correlated with species abundance. At the plot scale, plant maximum height, leaf and twig dry matter contents, twig and stem wood densities were positively correlated, but MLA, specific leaf area, LN, leaf P concentration and TLA were negatively correlated with species abundance. Plant trait-species abundance relationships shifted over the range of seven single environmental properties and along multivariate environmental axes in a similar way. In conclusion, strong relationships between plant traits and species abundance existed among and within communities. Significant shifts in plant trait-species abundance relationships in a range of environmental properties suggest strong environmental filtering processes that influence species abundance and rarity in the studied subtropical forests. PMID:23560114

Yan, En-Rong; Yang, Xiao-Dong; Chang, Scott X.; Wang, Xi-Hua

2013-01-01

226

Changes in Semi-Arid Plant Species Associations along a Livestock Grazing Gradient  

PubMed Central

In semi-arid ecosystems, vegetation is heterogeneously distributed, with plant species often associating in patches. These associations between species are not constant, but depend on the particular response of each species to environmental factors. Here, we investigated how plant species associations change in response to livestock grazing in a semi-arid ecosystem, Cabo de Gata-Níjar Natural Park in South East Spain. We established linear point-intercept transects at four sites with different grazing intensity, and recorded all species at each point. We investigated plant associations by comparing the number of times that each pair of species occurred at the same spatial point (co-occurrences), with the expected number of times based on species abundances. We also assessed associations for each shrub and grass species by considering all their pairs of associations and for the whole plant community by considering all pairs of associations on each site. At all sites, the plant community had a negative pattern of association, with fewer co-occurrences than expected. Negative association in the plant community increased at maximum grazing intensity. Most species associated as expected, particularly grass species, and positive associations were most important at intermediate grazing intensities. No species changed its type of association along the grazing gradient. We conclude that in the present plant community, grazing-resistant species compete among themselves and segregate in space. Some shrub species act as refuges for grazing-sensitive species that benefit from being spatially associated with shrub species, particularly at intermediate grazing intensities where positive associations were highest. At high grazing intensity, these shrubs can no longer persist and positive associations decrease due to the disappearance of refuges. Spatial associations between plant species and their response to grazing help identify the factors that organize plant communities, and may contribute to improving management of semi-arid ecosystems. PMID:22792367

Saiz, Hugo; Alados, Concepción L.

2012-01-01

227

Effects of plant type, size of geographical range and taxonomic isolation on number of insect species associated with British plants  

Microsoft Academic Search

IN this communication we analyse the insects associated with higher plants other than trees, which have already received attention1-5. We are concerned with two basic problems. First, we ask how various types of higher plants differ in the numbers of species of insects which they support; we do this by comparing standard species-area curves1,3,6,7 for five different sorts of plants.

J. H. Lawton

1977-01-01

228

Divergent composition but similar function of soil food webs of individual plants: plant species and community effects.  

PubMed

Soils are extremely rich in biodiversity, and soil organisms play pivotal roles in supporting terrestrial life, but the role that individual plants and plant communities play in influencing the diversity and functioning of soil food webs remains highly debated. Plants, as primary producers and providers of resources to the soil food web, are of vital importance for the composition, structure, and functioning of soil communities. However, whether natural soil food webs that are completely open to immigration and emigration differ underneath individual plants remains unknown. In a biodiversity restoration experiment we first compared the soil nematode communities of 228 individual plants belonging to eight herbaceous species. We included grass, leguminous, and non-leguminous species. Each individual plant grew intermingled with other species, but all plant species had a different nematode community. Moreover, nematode communities were more similar when plant individuals were growing in the same as compared to different plant communities, and these effects were most apparent for the groups of bacterivorous, carnivorous, and omnivorous nematodes. Subsequently, we analyzed the composition, structure, and functioning of the complete soil food webs of 58 individual plants, belonging to two of the plant species, Lotus corniculatus (Fabaceae) and Plantago lanceolata (Plantaginaceae). We isolated and identified more than 150 taxa/groups of soil organisms. The soil community composition and structure of the entire food webs were influenced both by the species identity of the plant individual and the surrounding plant community. Unexpectedly, plant identity had the strongest effects on decomposing soil organisms, widely believed to be generalist feeders. In contrast, quantitative food web modeling showed that the composition of the plant community influenced nitrogen mineralization under individual plants, but that plant species identity did not affect nitrogen or carbon mineralization or food web stability. Hence, the composition and structure of entire soil food webs vary at the scale of individual plants and are strongly influenced by the species identity of the plant. However, the ecosystem functions these food webs provide are determined by the identity of the entire plant community. PMID:21058562

Bezemer, T M; Fountain, M T; Barea, J M; Christensen, S; Dekker, S C; Duyts, H; van Hal, R; Harvey, J A; Hedlund, K; Maraun, M; Mikola, J; Mladenov, A G; Robin, C; de Ruiter, P C; Scheu, S; Setälä, H; Smilauer, P; van der Putten, W H

2010-10-01

229

Plant species distributions along environmental gradients: do belowground interactions with fungi matter?  

PubMed Central

The distribution of plants along environmental gradients is constrained by abiotic and biotic factors. Cumulative evidence attests of the impact of biotic factors on plant distributions, but only few studies discuss the role of belowground communities. Soil fungi, in particular, are thought to play an important role in how plant species assemble locally into communities. We first review existing evidence, and then test the effect of the number of soil fungal operational taxonomic units (OTUs) on plant species distributions using a recently collected dataset of plant and metagenomic information on soil fungi in the Western Swiss Alps. Using species distribution models (SDMs), we investigated whether the distribution of individual plant species is correlated to the number of OTUs of two important soil fungal classes known to interact with plants: the Glomeromycetes, that are obligatory symbionts of plants, and the Agaricomycetes, that may be facultative plant symbionts, pathogens, or wood decayers. We show that including the fungal richness information in the models of plant species distributions improves predictive accuracy. Number of fungal OTUs is especially correlated to the distribution of high elevation plant species. We suggest that high elevation soil show greater variation in fungal assemblages that may in turn impact plant turnover among communities. We finally discuss how to move beyond correlative analyses, through the design of field experiments manipulating plant and fungal communities along environmental gradients. PMID:24339830

Pellissier, Loïc; Pinto-Figueroa, Eric; Niculita-Hirzel, Hélène; Moora, Mari; Villard, Lucas; Goudet, Jérome; Guex, Nicolas; Pagni, Marco; Xenarios, Ioannis; Sanders, Ian; Guisan, Antoine

2013-01-01

230

Increased plant carbon translocation linked to overyielding in grassland species mixtures.  

PubMed

Plant species richness and productivity often show a positive relationship, but the underlying mechanisms are not fully understood, especially at the plant species level. We examined how growing plants in species mixture influences intraspecific rates of short-term carbon (C-) translocation, and determined whether such short-term responses are reflected in biomass yields. We grew monocultures and mixtures of six common C3 grassland plant species in outdoor mesocosms, applied a (13)C-CO(2) pulse in situ to trace assimilated C through plants, into the soil, and back to the atmosphere, and quantified species-specific biomass. Pulse derived (13)C enrichment was highest in the legumes Lotus corniculatus and Trifolium repens, and relocation (i.e. transport from the leaves to other plant parts) of the recently assimilated (13)C was most rapid in T. repens grown in 6-species mixtures. The grass Anthoxanthum odoratum also showed high levels of (13)C enrichment in 6-species mixtures, while (13)C enrichment was low in Lolium perenne, Plantago lanceolata and Achillea millefolium. Rates of C loss through respiration were highest in monocultures of T. repens and relatively low in species mixtures, while the proportion of (13)C in the respired CO(2) was similar in monocultures and mixtures. The grass A. odoratum and legume T. repens were most promoted in 6-species mixtures, and together with L. corniculatus, caused the net biomass increase in 6-species mixtures. These plant species also had highest rates of (13)C-label translocation, and for A. odoratum and T. repens this effect was greatest in plant individuals grown in species mixtures. Our study reveals that short-term plant C translocation can be accelerated in plant individuals of legume and C3 grass species when grown in mixtures, and that this is strongly positively related to overyielding. These results demonstrate a mechanistic coupling between changes in intraspecific plant carbon physiology and increased community level productivity in grassland systems. PMID:23049893

De Deyn, Gerlinde B; Quirk, Helen; Oakley, Simon; Ostle, Nick J; Bardgett, Richard D

2012-01-01

231

Increased Plant Carbon Translocation Linked to Overyielding in Grassland Species Mixtures  

PubMed Central

Plant species richness and productivity often show a positive relationship, but the underlying mechanisms are not fully understood, especially at the plant species level. We examined how growing plants in species mixture influences intraspecific rates of short-term carbon (C-) translocation, and determined whether such short-term responses are reflected in biomass yields. We grew monocultures and mixtures of six common C3 grassland plant species in outdoor mesocosms, applied a 13C-CO2 pulse in situ to trace assimilated C through plants, into the soil, and back to the atmosphere, and quantified species-specific biomass. Pulse derived 13C enrichment was highest in the legumes Lotus corniculatus and Trifolium repens, and relocation (i.e. transport from the leaves to other plant parts) of the recently assimilated 13C was most rapid in T. repens grown in 6-species mixtures. The grass Anthoxanthum odoratum also showed high levels of 13C enrichment in 6-species mixtures, while 13C enrichment was low in Lolium perenne, Plantago lanceolata and Achillea millefolium. Rates of C loss through respiration were highest in monocultures of T. repens and relatively low in species mixtures, while the proportion of 13C in the respired CO2 was similar in monocultures and mixtures. The grass A. odoratum and legume T. repens were most promoted in 6-species mixtures, and together with L. corniculatus, caused the net biomass increase in 6-species mixtures. These plant species also had highest rates of 13C-label translocation, and for A. odoratum and T. repens this effect was greatest in plant individuals grown in species mixtures. Our study reveals that short-term plant C translocation can be accelerated in plant individuals of legume and C3 grass species when grown in mixtures, and that this is strongly positively related to overyielding. These results demonstrate a mechanistic coupling between changes in intraspecific plant carbon physiology and increased community level productivity in grassland systems. PMID:23049893

De Deyn, Gerlinde B.; Quirk, Helen; Oakley, Simon; Ostle, Nick J.; Bardgett, Richard D.

2012-01-01

232

Cytoprotective and antioxidant effects of the edible halophyte Sarcocornia perennis L. (swampfire) against lead-induced toxicity in renal cells.  

PubMed

Lead (Pb) exposure is considered as a risk factor responsible for renal impairment in humans. On the other hand, the halophyte Sarcocornia perennis is a fresh vegetable crop suitable for leafy vegetable production. This study was designed to evaluate the in vitro protective activity of S. perennis against lead-induced damages in HEK293 kidney cells. Morphological and biochemical indicators were used to assess cytotoxicity and oxidative damages caused by Pb treatment on the cells. Our results showed that lead induced (1) a decrease in cell viability (MTT), (2) cell distortion and cohesion loss, (3) superoxide anion production and lipid peroxidation. Conversely, addition of S. perennis extract to the lead-containing medium alleviated every above syndrome. Thus, cell survival was increased and the production of reactive oxygen species caused by Pb treatment was inhibited. Taken together, our study revealed that S. perennis has potent cytoprotective effect against Pb-induced toxicity in HEK 293 cell. Such action would proceed through the decrease in ROS levels and resulting oxidative stress, which suggests a potential interest of this halophyte in the treatment of oxidative-stress related diseases. PMID:23755863

Gargouri, Manel; Magné, Christian; Dauvergne, Xavier; Ksouri, Riadh; El Feki, Abdelfattah; Metges, Marie-Agnès Giroux; Talarmin, Hélène

2013-09-01

233

Plant species richness in the Cape Verde Islands—eco-geographical determinants  

Microsoft Academic Search

Plant species richness in the Cape Verde archipelago is examined relative to island eco-geographical factors. Species-area\\u000a and species-area-habitat relationships are analysed using the classical species-area model and the recently proposed species-choros\\u000a model. The number of floristic zones (used to estimate the choros parameter) provides an adequate estimate of the potential\\u000a habitat diversity, and the species-choros model achieved a better fit

Maria Cristina Duarte; Francisco Rego; Maria Manuel Romeiras; Ilídio Moreira

2008-01-01

234

Microbial assimilation of new photosynthate is altered by plant species richness and nitrogen deposition  

E-print Network

an increase in plant production, total PLFA decreased under N deposition. Moreover, N deposition also greater plant detritus production in species- rich plant communities and larger and more active soil diversity can negatively influence aboveground ecosystem processes, as evidenced by lower plant production

Minnesota, University of

235

Performance of dryland and wetland plant species on extensive green roofs  

PubMed Central

Background and Aims Green roofs are constructed ecosystems where plants perform valuable services, ameliorating the urban environment through roof temperature reductions and stormwater interception. Plant species differ in functional characteristics that alter ecosystem properties. Plant performance research on extensive green roofs has so far indicated that species adapted to dry conditions perform optimally. However, in moist, humid climates, species typical of wetter soils might have advantages over dryland species. In this study, survival, growth and the performance of thermal and stormwater capture functions of three pairs of dryland and wetland plant species were quantified using an extensive modular green roof system. Methods Seedlings of all six species were germinated in a greenhouse and planted into green roof modules with 6 cm of growing medium. There were 34 treatments consisting of each species in monoculture and all combinations of wet- and dryland species in a randomized block design. Performance measures were survival, vegetation cover and roof surface temperature recorded for each module over two growing seasons, water loss (an estimate of evapotranspiration) in 2007, and albedo and water capture in 2008. Key Results Over two seasons, dryland plants performed better than wetland plants, and increasing the number of dryland species in mixtures tended to improve functioning, although there was no clear effect of species or habitat group diversity. All species had survival rates >75 % after the first winter; however, dryland species had much greater cover, an important indicator of green roof performance. Sibbaldiopsis tridentata was the top performing species in monoculture, and was included in the best treatments. Conclusions Although dryland species outperformed wetland species, planting extensive green roofs with both groups decreased performance only slightly, while increasing diversity and possibly habitat value. This study provides further evidence that plant composition and diversity can influence green roof functions. PMID:21292676

MacIvor, J. Scott; Ranalli, Melissa A.; Lundholm, Jeremy T.

2011-01-01

236

Reciprocal Effects of Litter from Exotic and Congeneric Native Plant Species via Soil Nutrients  

PubMed Central

Invasive exotic plant species are often expected to benefit exclusively from legacy effects of their litter inputs on soil processes and nutrient availability. However, there are relatively few experimental tests determining how litter of exotic plants affects their own growth conditions compared to congeneric native plant species. Here, we test how the legacy of litter from three exotic plant species affects their own performance in comparison to their congeneric natives that co-occur in the invaded habitat. We also analyzed litter effects on soil processes. In all three comparisons, soil with litter from exotic plant species had the highest respiration rates. In two out of the three exotic-native species comparisons, soil with litter from exotic plant species had higher inorganic nitrogen concentrations than their native congener, which was likely due to higher initial litter quality of the exotics. When litter from an exotic plant species had a positive effect on itself, it also had a positive effect on its native congener. We conclude that exotic plant species develop a legacy effect in soil from the invaded range through their litter inputs. This litter legacy effect results in altered soil processes that can promote both the exotic plant species and their native congener. PMID:22359604

Meisner, Annelein; de Boer, Wietse; Cornelissen, Johannes H. C.; van der Putten, Wim H.

2012-01-01

237

Arbuscular mycorrhizal fungi species-specifically affect induced plant responses to a spider mite  

Microsoft Academic Search

It is widely recognized that arbuscular mycorrhizal fungi (AMF) improve plant growth and nutrient conditions, but their effects\\u000a can vary from negative to positive depending on AMF species. Since the performance of herbivorous arthropods varies with plant\\u000a quality, different AMF species should differently affect the density of herbivorous arthropods on plants and the herbivore-induced\\u000a plant responses. We examined the indirect

Takaaki Nishida; Noboru Katayama; Naoyuki Izumi; Takayuki Ohgushi

2010-01-01

238

Vascular plant and vertebrate species richness in national parks of the eastern United States  

USGS Publications Warehouse

Given the estimates that species diversity is diminishing at 50-100 times the normal rate, it is critical that we be able to evaluate changes in species richness in order to make informed decisions for conserving species diversity. In this study, we examined the potential of vascular plant species richness to be used as a surrogate for vertebrate species richness in the classes of amphibians, reptiles, birds, and mammals. Vascular plants, as primary producers, represent the biotic starting point for ecological community structure and are the logical place to start for understanding vertebrate species associations. We used data collected by the United States (US) National Park Service (NPS) on species presence within parks in the eastern US to estimate simple linear regressions between plant species richness and vertebrate richness. Because environmental factors may also influence species diversity, we performed simple linear regressions of species richness versus natural logarithm of park area, park latitude, mean annual precipitation, mean annual temperature, and human population density surrounding the parks. We then combined plant species richness and environmental variables in multiple regressions to determine the variables that remained as significant predictors of vertebrate species richness. As expected, we detected significant relationships between plant species richness and amphibian, bird, and mammal species richness. In some cases, plant species richness was predicted by park area alone. Species richness of mammals was only related to plant species richness. Reptile species richness, on the other hand, was related to plant species richness, park latitude and annual precipitation, while amphibian species richness was related to park latitude, park area, and plant species richness. Thus, plant species richness predicted species richness of different vertebrate groups to varying degrees and should not be used exclusively as a surrogate for vertebrate species richness. Plant species richness should be included with other variables such as area and climate when considering strategies to manage and conserve species in US National Parks. It is not always appropriate to draw conclusions about analyses of taxonomic surrogates from one area to another. Two patterns evident from the linear regressions were the increase in species richness with the increase of park area and with increase of vascular plant species richness. To test whether there were differences in these patterns among networks, we used analysis of covariance (ANCOVA). Differences among networks were detected only in bird species richness versus plant species richness and for all taxa except mammals for vertebrate species richness versus park area. Some of these results may be due to small sample size among networks, and therefore, low statistical power. Other factors that could have contributed to these results were differences in average park area and habitat heterogeneity among networks, latitudinal gradients, low variation in mean annual precipitation, and different use of vegetation by migratory species. Based on these results we recommend that management of biodiversity be approached from local and site specific criteria rather than applying management directives derived from other regions of the US. It is also recommended that analyses similar to those presented here be conducted for all national parks, once data become available for all networks in the US, to gain a better understanding of how vascular plant species richness, area, and vertebrate species richness are related in the US.

Hatfield, Jeffrey S.; Myrick, Kaci E.; Huston, Michael A.; Weckerly, Floyd W.; Green, M. Clay

2013-01-01

239

Interactions between alien plant species traits and habitat characteristics in agricultural landscapes in Finland  

Microsoft Academic Search

The survival and success of alien plant species is determined by species traits (i.e., invasiveness) and the characteristics\\u000a of the habitats in the region of introduction (i.e., invasibility). However, little is known about species traits as related\\u000a to habitat characteristics. We assessed the characteristics of successful invaders and the interaction of environmental factors\\u000a and life-history traits for alien plant species.

Miia Jauni; Terho Hyvönen

240

Differential herbivory tolerance of dominant and subordinate plant species along gradients of nutrient availability and competition  

Microsoft Academic Search

We tested whether differences in the herbivory tolerance of plant species is related to their abundance in grassland communities\\u000a and how herbivory and nutrient availability affect competitive balances among plant species through changes in their tolerance.\\u000a The experimental approach involved a simulated grazing treatment (clipping) of two competitive grass species (Arrhenatherum elatius and Holcus lanatus) and two subordinate forb species

Pejman Tahmasebi Kohyani; B. Bossuyt; D. Bonte; M. Hoffmann

2009-01-01

241

Differential herbivory tolerance of dominant and subordinate plant species along gradients of nutrient availability and competition  

Microsoft Academic Search

We tested whether differences in the herbivory tolerance of plant species is related to their abundance in grassland communities\\u000a and how herbivory and nutrient availability affect competitive balances among plant species through changes in their tolerance.\\u000a The experimental approach involved a simulated grazing treatment (clipping) of two competitive grass species (Arrhenatherum elatius and Holcus lanatus) and two subordinate forb species

Pejman Tahmasebi Kohyani; B. Bossuyt; D. Bonte; M. Hoffmann

242

Species Richness and Patterns of Invasion in Plants, Birds, and Fishes in the United States  

Microsoft Academic Search

We quantified broad-scale patterns of species richness and species density (mean # species\\/km2) for native and non-indigenous plants, birds, and fishes in the continental USA and Hawaii. We hypothesized that the species\\u000a density of native and non-indigenous taxa would generally decrease in northern latitudes and higher elevations following declines\\u000a in potential evapotranspiration, mean temperature, and precipitation. County data on plants

Thomas J. Stohlgren; David Barnett; Curtis Flather; Pam Fuller; Bruce Peterjohn; John Kartesz; Lawrence L. Master

2006-01-01

243

Invasive plant species as potential bioenergy producers and carbon contributors.  

SciTech Connect

Current cellulosic bioenergy sources in the United States are being investigated in an effort to reduce dependence on foreign oil and the associated risks to national security and climate change (Koh and Ghazoul 2008; Demirbas 2007; Berndes et al. 2003). Multiple sources of renewable plant-based material have been identified and include agricultural and forestry residues, municipal solid waste, industrial waste, and specifically grown bioenergy crops (Demirbas et al. 2009; Gronowska et al. 2009). These sources are most commonly converted to energy through direct burning, conversion to gas, or conversion to ethanol. Annual crops, such as corn (Zea Mays L.) and sorghum grain, can be converted to ethanol through fermentation, while soybean and canola are transformed into fatty acid methyl esters (biodiesel) by reaction with an alcohol (Demirbas 2007). Perennial grasses are one of the more viable sources for bioenergy due to their continuous growth habit, noncrop status, and multiple use products (Lewandowski el al. 2003). In addition, a few perennial grass species have very high water and nutrient use efficiencies producing large quantities of biomass on an annual basis (Dohleman et al. 2009; Grantz and Vu 2009).

Young, S.; Gopalakrishnan, G.; Keshwani, D. (Energy Systems); (Univ. of Nebraska)

2011-03-01

244

'Halophyte filters': the potential of constructed wetlands for application in saline aquaculture.  

PubMed

World consumption of seafood continues to rise, but the seas and oceans are already over-exploited. Land-based (saline) aquaculture may offer a sustainable way to meet the growing demand for fish and shellfish. A major problem of aquaculture is nutrient waste, as most of the nutrients added through feed are released into the environment in dissolved form. Wetlands are nature's water purifiers. Constructed wetlands are commonly used to treat contaminated freshwater effluent. Experience with saline systems is more limited. This paper explores the potential of constructed saline wetlands for treating the nutrient-rich discharge from land-based saline aquaculture systems. The primary function of constructed wetlands is water purification, but other ancillary benefits can also be incorporated into treatment wetland designs. Marsh vegetation enhances landscape beauty and plant diversity, and wetlands may offer habitat for fauna and recreational areas. Various approaches can be taken in utilizing plants (halophytes, macro-algae, micro-algae) in the treatment of saline aquaculture effluent. Their strengths and weaknesses are reviewed here, and a conceptual framework is presented that takes into account economic and ecological benefits as well as spatial constraints. Use of the framework is demonstrated for assessing various saline aquaculture systems in the southwestern delta region of the Netherlands. PMID:23488001

De Lange, H J; Paulissen, M P C P; Slim, P A

2013-01-01

245

Effects of invasive plant species on pollinator service and reproduction in native plants at Acadia National Park  

USGS Publications Warehouse

Invasive plant species can have profound negative effects on natural communities by competively excluding native species. Berberis thunbergii (Japanese barberry), Frangula alnus (glossy or alder buckthorn) and Lythrum salicaria (purple loosestrife) are invasive species known to reduce native plant diversity and are thus of great concern to Acadia National Park. Pollinators visit them for nectar and pollen. The effects of invasive plant species on pollinator behavior were investigated by comparing pollinator visitation to co-flowering native and invasive species with visitation to native species growing alone. The effect of invasives on pollination of native plants was studied by comparing fruit set in patches of the native species growing near invasives with patches far from invasive species in Acadia National Park. The coflowering pairs were as follows: in the spring native Vaccinium angustifolium (lowbush blueberry) was paired with B. thunbergii; in early summer native Viburnum nudum (wild raisin) was paired with F. alnus ; in late summer native Spiraea alba (meadowsweet) was paired with L. salicaria. We investigated whether these invasives competed with native plants for pollinators in Acadia and thus negatively affected native plant reproduction. Our objectives were to determine: 1) the influence, if any, of each invasive on pollinator visitation to a co-flowering native species, 2) factors that might affect visitation, 3) invasive pollen transfer to native plants, and 4) whether invasives influence native plant reproduction (fruit set). Our findings indicate that at times the number of flower visitors to natives was lower or the species composition of visitors different when invasives were present, that invasives sometimes attracted more pollinators, that generally the invasives were more rewarding as far as nectar and pollen availability for pollinators, and that generally native plant fruit set and seed set was not significantly lowered in the presence of the invasive. In fact, in one year fruit set of S. alba was significantly greater in the presence of L. salicaria. The number of invasive pollen grains on native stigmas was extremely low; on average less than one grain per stigma. These fruit set and pollen deposition findings indicate that native plant reproduction was not adversely affected in the short term by these invasive species and that therefore competition between the native and invasive species for pollinators did not occur. Native bee populations monitored in 2004-2005 at sites with and without B. thunbergii and/or F. alnus indicated a greater abundance of native bees at sites with these invasives present. Native bees collected from the native and invasive plants were compared with historical records to assess whether invasive plants favor different bee species than those that formerly predominated on Mount Desert Island. This does not appear to be the case. Several species of bumble bees (Bombus spp.) as well as nine solitary bee species were found that were not documented by the Procter surveys of 1917-1940. Collecting of native bees was limited to the study plants, which may, in part, explain why some bee species documented in the Procter Surveys were not found in the present research. A field guide for identification of native bumble bees has been produced to help Park Natural Resource personnel monitor the status of native bee populations in Acadia. Other educational materials were also developed, aimed at educating Park visitors by exposing them to: 1) the role of native plants and their bee pollinators in terrestrial ecosystems; 2) the effects of invasive plants on native plant-pollinator mutualisms; 3) the need for conserving native bees and other pollinators; and 4) conservation strategies for protecting and enhancing native plant-pollinator mutualisms in the Park. Based on the present findings, Acadia Park Resource Management personnel should continue to closely

Stubbs, C.J.; Drummond, F.; Ginsberg, H.

2007-01-01

246

Strategies of heavy metal uptake by three plant species growing near a metal smelter  

Microsoft Academic Search

Some higher plant species have developed heavy metal tolerance strategies which enable them to survive and reproduce in highly metal-contaminated soils. We have investigated such heavy metal uptake and accumulation strategies of two absolute metallophyte species (Armeria maritima ssp. halleri and Cardaminopsis halleri) and one pseudometallophyte (Agrostis tenuis) growing near a former metal smelter. Samples of plant parts and soil

H Dahmani-Muller; F van Oort; B Gélie; M Balabane

2000-01-01

247

Predicting the Growth Interactions between Plants in Mixed Species Stands using a Simple Mechanistic Model  

Microsoft Academic Search

The Conductance model is a simple mechanistic model used to predict the growth of species in monoculture or mixtures from parameter values derived from plants grown in isolation. In contrast to many mechanistic models that require extensive parameterization, the Conductance model is able to capture the growth of a broad range of species using a few simplified assumptions regarding plant

S. E. Park; L. R. Benjamin; D. P. Aikman; A. R. Watkinson

2001-01-01

248

Plant Species Fed on by Lemur catta in Gallery Forests of the Southern Domain of Madagascar  

Microsoft Academic Search

In this paper, we provide an overview of the feeding trends of Lemur catta, the ringtailed lemur, including a checklist of all plant species and plant items known to be ingested by this prosimian species in three different forests of southwestern and southern Madagascar. Ringtailed lemurs have been mainly studied in gallery forests including riverine forest, closed canopy forest, and

Bruno Simmen; MICHELLE L. SAUTHER; Takayo Soma; Hantanirina Rasamimanana; Robert Sussman; Alison Jolly; Laurent Tarnaud; Annette Hladik

249

Distribution of three endangered medicinal plant species and their colonization with arbuscular mycorrhizal fungi  

Microsoft Academic Search

A field study of 12 districts of arid zones of Rajasthan was undertaken to evaluate the occurrence of three selected endangered medicinal plant species (Leptadenia reticulata, Mitragyna parvifolia, Withania coagulans), and arbuscular mycorrhizal fungal (AMF) associations with them. Five genera were identified in the rhizosphere of these selected plant species. A high diversity of AMF was observed which varied between

J. Panwar; J. C. Tarafdar

2006-01-01

250

Identification of microRNAs and their targets in switchgrass, a model biofuel plant species  

Microsoft Academic Search

In recent years, several plant species such as switchgrass, Miscanthus and Brachypodium have been recognized as potential model plant species for cellulosic bioenergy production. Of these, switchgrass has attracted much attention in the United States and worldwide because it can grow well on marginal lands and tolerate frequent drought spells. However, little is known about the basic biology of the

Jessica Matts; Guru Jagadeeswaran; Bruce A. Roe; Ramanjulu Sunkar

2010-01-01

251

Combining Leaf Salient Points and Leaf Contour Descriptions for Plant Species Recognition  

E-print Network

Combining Leaf Salient Points and Leaf Contour Descriptions for Plant Species Recognition Sofiene for plant species recognition, based on the leaf observation. We consider two sources of information: the leaf margin and the leaf salient points. For the leaf shape description, we investigate the shape

Verroust-Blondet, Anne

252

Hydrocarbon and rubber-producing crops: evaluation of 100 US plant species  

Microsoft Academic Search

Agricultural production of rubber and other hydrocarbons in the United States may be compatible with increased food and fiber production if entire plants are harvested and processed for fiber, protein, and carbohydrate as well. Procedures and criteria have been established for the preliminary evaluation of plant species as potential multi-use hydrocarbon-producing crops. Previously, 106 species representing 44 families and 81

R. T. Buchanan; I. M. Cull; F. H. Otey; C. R. Russell

1978-01-01

253

Risk assessment: Simultaneously prioritizing the control of invasive plant species and the conservation of rare plant species  

Microsoft Academic Search

Although the consequences of the homogenization of Earth’s flora and fauna are not well understood, experts agree that biological invasions pose hazards to rare species. As a result, there is a need for a systematic approach to assess risks from invasive species. The Relative Risk Model can be adapted to assess combinations of rare species, invasive species, and regions. It

Thaddeus K. Miller; Craig R. Allen; Wayne G. Landis; James W. Merchant

2010-01-01

254

Assaying Ornithine and Arginine Decarboxylases in Some Plant Species 1  

PubMed Central

A release of 14CO2 not related to ornithine decarboxylase activity was found in crude leaf extracts from Lycopersicon esculentum, Avena sativa, and especially from the pyrrolizidine alkaloid-bearing Heliotropium angiospermum when incubated with [1-14C]- or [U-14C]ornithine. The total 14CO2 produced was about 5- to 100-fold higher than that due to ornithine decarboxylase activities calculated from labeled putrescine (Put) found by thin-layer electrophoresis in the incubation mixtures. Partial purification with (NH4)2SO4 did not eliminate completely the interfering decarboxylation. When incubated with labeled arginine, a very significant 14CO2 release not related to arginine decarboxylase activity was observed only in extracts from H. angiospermum leaves, especially in Tris·HCl buffer. Under the assay conditions, these extracts exhibited oxidative degradation of added Put and agmatine (Agm) and also revealed a high arginase activity. Amino-guanidine at 0.1 to 0.2 millimolar prevented Put degradation and greatly decreased oxidative degradation of Agm; ornithine at 15 to 20 millimolar significantly inhibited arginase activity. A verification of the reliability of the standard 14CO2-based method by assessing labeled Put and/or Agm—formed in the presence of added aminoguanidine and/or ornithine when needed—is recommended especially when crude or semicrude plant extracts are assayed. When based on Put and/or Agm formed at 1.0 to 2.5 millimolar of substrate, the activities of ornithine decarboxylase and arginine decarboxylase in the youngest leaves of the tested species ranged between 1.1 and 3.6 and 1 and 1600 nanomoles per hour per gram fresh weight, respectively. The enzyme activities are discussed in relation to the biosynthesis of pyrrolizidine alkaloids. PMID:16664441

Birecka, Helena; Bitonti, Alan J.; McCann, Peter P.

1985-01-01

255

Investigating Effects of Invasive Species on Plant Community Structure  

ERIC Educational Resources Information Center

In this article, the author presents a field study project that explores factors influencing forest community structure and lifts the veil off of "plant blindness." This ecological study consists of three laboratories: (1) preliminary field trip to the study site; (2) plant survey; and (3) analyzing plant community structure with descriptive…

Franklin, Wilfred

2008-01-01

256

Compensation and Plasticity in an Invasive Plant Species  

Microsoft Academic Search

Plant plasticity under varying resources is one character that contributes to competitiveness and invasibility. The plasticity of plant modules of the invasive Japanese stilt grass (Microstegium vimineum) was examined under different light and nutrient levels using a balanced field and greenhouse study. Ample light and nutrients resulted in the greatest biomass accumulation in all plant modules. However, M. vimineum showed

Kevin Claridge; Scott B. Franklin

2002-01-01

257

The ability of several high arctic plant species to utilize nitrate nitrogen under field conditions  

Microsoft Academic Search

The ability to utilize NOinf3sup-in seven high arctic plant species from Truelove Lowland, Devon Island, Canada was investigated, using an in vivo assay of maximum potential nitrate reductase (NR) activity and applications of 15N. Plant species were selected on the basis of being characteristic of nutrient-poor and nutrient-rich habitats. In all species leaves were the dominant site of NR activity.

Owen K. Atkin; Rafael Villar; W. Raymond Cummins

1993-01-01

258

Patterns of invasive plant species distribution in the Upper Volga basin  

Microsoft Academic Search

The patterns of invasive plant species distribution in the Upper Volga basin territory (including five administrative oblasts—Ivanovo,\\u000a Kostroma, Vladimir, Yaroslavl, and Tver) are considered. The present flora of this district comprises 770 alien species, among\\u000a which 135 are successfully naturalized in natural and seminatural communities and 32 (4.2%) are invasive plants. Only 24 invasive\\u000a species (3.1%) are widespread in all

E. A. Borisova

2011-01-01

259

Assessing Vulnerability to Invasion by Nonnative Plant Species at Multiple Spatial Scales  

Microsoft Academic Search

Basic information on where nonnative plant species have successfully invaded is lacking. We assessed the vulnerability of\\u000a 22 vegetation types (25 sets of four plots in nine study areas) to nonnative plant invasions in the north–central United States.\\u000a In general, habitats with high native species richness were more heavily invaded than species-poor habitats, low-elevation\\u000a areas were more invaded than high-elevation

THOMAS J. STOHLGREN; GENEVA W. CHONG; LISA D. SCHELL; KELLY A. RIMAR; YUKA OTSUKI; MICHELLE LEE; MOHAMMED A. KALKHAN; CYNTHIA A. VILLA

2002-01-01

260

Patterns of plant invasions: a case example in native species hotspots and rare habitats  

Microsoft Academic Search

Land managers require landscape-scale information on where exotic plant species have successfully established, to better guide research, control, and restoration efforts. We evaluated the vulnerability of various habitats to invasion by exotic plant species in a 100,000 ha area in the southeast corner of Grand Staircase-Escalante National Monument, Utah. For the 97 0.1-ha plots in 11 vegetation types, exotic species

Thomas J. Stohlgren; Yuka Otsuki; Cynthia A. Villa; Michelle Lee; Jayne Belnap

2001-01-01

261

The effect of AMF suppression on plant species composition in a nutrient-poor dry grassland.  

PubMed

Arbuscular mycorrhizal fungi (AMF) are expected to be one of the key drivers determining the diversity of natural plant communities, especially in nutrient-poor and dry habitats. Several previous studies have explored the importance of AMF for the composition of plant communities in various types of habitats. Surprisingly, studies of the role of AMF in nutrient-poor dry grassland communities dominated by less mycotrophic plant species are still relatively rare. We present the results of a 3-year study in which a plant community in a species-rich dry grassland was subjected to the fungicide carbendazim to suppress AMF colonization. We tested the effect of the fungicide on the following parameters: the plant species composition; the number of plant species; the cover of the rare, highly mycorrhiza-dependent species Aster amellus; the cover of the dominant, less mycorrhiza-dependent species Brachypodium pinnatum; and the cover of graminoids and perennial forbs. In addition, we examined the mycorrhizal inoculation potential of the soil. We found that the suppression of AMF with fungicide resulted in substantial changes in plant species composition and significant decrease in species richness, the cover of A. amellus and the cover of perennial forbs. In contrast the species increasing their cover after fungicide application were graminoids--the C3 grasses B. pinnatum and Bromus erectus and the sedge Carex flacca. These species appear to be less mycorrhiza dependent. Moreover, due to their clonal growth and efficient nutrient usage, they are, most likely, better competitors than perennial forbs under fungicide application. Our results thus suggest that AMF are an essential part of the soil communities supporting a high diversity of plant species in species-rich dry grasslands in nutrient-poor habitats. The AMF are especially important for the maintenance of the populations of perennial forbs, many of which are rare and endangered in the area. PMID:24265829

Dostálek, Tomáš; Pánková, Hana; Münzbergová, Zuzana; Rydlová, Jana

2013-01-01

262

Alien Roadside Species More Easily Invade Alpine than Lowland Plant Communities in a Subarctic Mountain Ecosystem  

PubMed Central

Effects of roads on plant communities are not well known in cold-climate mountain ecosystems, where road building and development are expected to increase in future decades. Knowledge of the sensitivity of mountain plant communities to disturbance by roads is however important for future conservation purposes. We investigate the effects of roads on species richness and composition, including the plant strategies that are most affected, along three elevational gradients in a subarctic mountain ecosystem. We also examine whether mountain roads promote the introduction and invasion of alien plant species from the lowlands to the alpine zone. Observations of plant community composition were made together with abiotic, biotic and anthropogenic factors in 60 T-shaped transects. Alpine plant communities reacted differently to road disturbances than their lowland counterparts. On high elevations, the roadside species composition was more similar to that of the local natural communities. Less competitive and ruderal species were present at high compared with lower elevation roadsides. While the effects of roads thus seem to be mitigated in the alpine environment for plant species in general, mountain plant communities are more invasible than lowland communities. More precisely, relatively more alien species present in the roadside were found to invade into the surrounding natural community at high compared to low elevations. We conclude that effects of roads and introduction of alien species in lowlands cannot simply be extrapolated to the alpine and subarctic environment. PMID:24586947

Lembrechts, Jonas J.; Milbau, Ann; Nijs, Ivan

2014-01-01

263

Links between plant litter chemistry, species diversity, and below-ground ecosystem function  

PubMed Central

Decomposition is a critical source of plant nutrients, and drives the largest flux of terrestrial C to the atmosphere. Decomposing soil organic matter typically contains litter from multiple plant species, yet we lack a mechanistic understanding of how species diversity influences decomposition processes. Here, we show that soil C and N cycling during decomposition are controlled by the composition and diversity of chemical compounds within plant litter mixtures, rather than by simple metrics of plant species diversity. We amended native soils with litter mixtures containing up to 4 alpine plant species, and we used 9 litter chemical traits to evaluate the chemical composition (i.e., the identity and quantity of compounds) and chemical diversity of the litter mixtures. The chemical composition of the litter mixtures was the strongest predictor of soil respiration, net N mineralization, and microbial biomass N. Soil respiration and net N mineralization rates were also significantly correlated with the chemical diversity of the litter mixtures. In contrast, soil C and N cycling rates were poorly correlated with plant species richness, and there was no relationship between species richness and the chemical diversity of the litter mixtures. These results indicate that the composition and diversity of chemical compounds in litter are potentially important functional traits affecting decomposition, and simple metrics like plant species richness may fail to capture variation in these traits. Litter chemical traits therefore provide a mechanistic link between organisms, species diversity, and key components of below-ground ecosystem function. PMID:19064910

Meier, Courtney L.; Bowman, William D.

2008-01-01

264

Dynamics of host plant use and species diversity in Polygonia butterflies (Nymphalidae)  

Microsoft Academic Search

The ability of insects to utilize different host plants has been suggested to be a dynamic and transient phase. During or after this phase, species can shift to novel host plants or respecialize on ancestral ones. Expanding the range of host plants might also be a factor leading to higher levels of net speciation rates. In this paper, we have

E. WEINGARTNER; N. WAHLBERG; S. NYLIN

2005-01-01

265

Plastic responses to light intensity and planting density in three Lamium species  

Microsoft Academic Search

In this survey plastic responses to light intensity and planting density were examined in three Lamium species (L. purpureum, L. album and L. maculatum). Low light intensity enhanced plant height, length and width of leaves, but reduced number of shoots and leaves, as well\\u000a as root and shoot weights. Higher density resulted in smaller plants and leaves, but had significant

N. Bariši?; B. Stojkovi?; A. Tarasjev

2006-01-01

266

Carbon cycling traits of plant species are linked with mycorrhizal strategy  

Microsoft Academic Search

Ecosystem carbon cycling depends strongly on the productivity of plant species and the decomposition rates of the litter they produce. We tested the hypothesis that classifying plant functional types according to mycorrhizal association explains important interspecific variation in plant carbon cycling traits, particularly in those traits that feature in a hypothesized feedback between vegetation productivity and litter turnover. We compared

J. H. C. Cornelissen; R. Aerts; B. Cerabolini; M. J. A. Werger; M. G. A. van der Heijden

2001-01-01

267

Site and species-specific differences in endophyte occurrence in two herbaceous plants  

Microsoft Academic Search

Summary 1 Endophyte fungi exist within the living tissues of all plants, but compared with grasses and trees, remarkably little is known about their ecology in herbaceous species. These fungi produce an array of metabolites in culture and there is some evidence that they can increase the resistance of plants to herbivorous insects. 2 As herbaceous plant endophytes are thought

ALAN C. GANGE; SOMA DEY; AMANDA F. CURRIE; BRIAN C. SUTTON

2007-01-01

268

Moose as a vector for non-indigenous plant species in Alaska  

Technology Transfer Automated Retrieval System (TEKTRAN)

White sweetclover and narrowleaf hawksbeard are non-indigenous invasive plant species in Alaska that are rapidly spreading, including into areas that are otherwise free of non-indigenous plants. There has been concern that native moose could be dispersing viable seed from these plants after ingestio...

269

BEYOND THE ECOLOGICAL: BIOLOGICAL INVASIONS ALTER NATURAL SELECTION ON A NATIVE PLANT SPECIES  

Microsoft Academic Search

Biological invasions can have strong ecological effects on native communities by altering ecosystem functions, species interactions, and community composition. Even though these ecological effects frequently impact the population dynamics and fitness of native species, the evolutionary consequences of biological invasions have received relatively little attention. Here, I show that invasions impose novel selective pressures on a native plant species. By

Jennifer A. Lau

2008-01-01

270

Colonization and persistence ability explain the extent to which plant species fill their potential range  

Microsoft Academic Search

Aim How species traits and environmental conditions affect biogeographical dynamics is poorly understood. Here we test whether estimates of a species' evolu- tionary age, colonization and persistence ability can explain its current 'range filling' (the ratio between realized and potential range size). Location Fynbos biome (Cape Floristic Region, South Africa). Methods For 37 species of woody plants (Proteaceae), we estimate

Frank M. Schurr; Guy F. Midgley; Anthony G. Rebelo; Gail Reeves; Peter Poschlod; Steven I. Higgins

2007-01-01

271

Local Species Richness of Leaf-Chewing Insects Feeding on Woody Plants from One Hectare  

E-print Network

species-accumulation curves, to combine these two data sets and estimate the number ofspecies ofleaf-chewing herbivoresfeeding on woodyplantsfrom the 1-ha area. We recorded 58,483feeding individualsfrom 940 species ofleafLocal Species Richness of Leaf-Chewing Insects Feeding on Woody Plants from One Hectare

Mathis, Wayne N.

272

The Main Environmental Driving Forces of the Invasive Plant Species in the Romanian Protected Areas  

Microsoft Academic Search

The invasive flora of Romania currently includes more than 400 species (13.87% of the Romanian flora) and according to the third National Report of Biological Diversity Convention, six of them are tree species. Within the protected areas, some of the most representative invasive plant species (IPS) are: Amorpha fruticosa in Balta Mica a Brailei National Park, Ailanthus altissima in Muntii

Monica Dumitrascu; Ines Grigorescu; Mihaela Nastase; Carmen Dragota; Gheorghe Kucsicsa

2010-01-01

273

Resource-based niches provide a basis for plant species diversity and dominance in arctic tundra  

Microsoft Academic Search

Ecologists have long been intrigued by the ways co-occurring species divide limiting resources. Such resource partitioning, or niche differentiation, may promote species diversity by reducing competition. Although resource partitioning is an important determinant of species diversity and composition in animal communities, its importance in structuring plant communities has been difficult to resolve. This is due mainly to difficulties in studying

Robert B. McKane; Loretta C. Johnson; Gaius R. Shaver; Knute J. Nadelhoffer; Edward B. Rastetter; Brian Fry; Anne E. Giblin; Knut Kielland; Bonnie L. Kwiatkowski; James A. Laundre; Georgia Murray

2002-01-01

274

Seedling herbivory and the influence of plant species richness in seedling neighbourhoods  

Microsoft Academic Search

The aim of this experiment was to determine how increasing species richness within artificially created grassland gaps affected the overall magnitude of seedling losses to, and the selectivity of, seedling herbivores. Using chemical exclusion methods, the influence of molluscs the principal invertebrate herbivores in temperate grasslands, was assessed at three levels of plant species diversity (3, 6, and 12 species

M. E. Hanley

2004-01-01

275

Race to Displace: A Game to Model the Effects of Invasive Species on Plant Communities  

ERIC Educational Resources Information Center

Invasive species are a substantial threat to biodiversity. Educating students about invasive species introduces fundamental concepts in biology, ecology, and environmental science. In the Race to Displace game, students assume the characteristics of select native or introduced plants and experience first hand the influences of species interactions…

Hopwood, Jennifer L.; Flowers, Susan K.; Seidler, Katie J.; Hopwood, Erica L.

2013-01-01

276

Hurricane Activity and the Large-Scale Pattern of Spread of an Invasive Plant Species  

E-print Network

Hurricane Activity and the Large-Scale Pattern of Spread of an Invasive Plant Species Ganesh P of invasive species. However, the effects of large-scale disturbances, such as hurricanes and tropical storms, on the broad geographic patterns of invasive species growth and spread have not been investigated. We used

Cronin, James T.

277

Effect of Carpobrotus spp. on the pollination success of native plant species of the Balearic Islands  

Microsoft Academic Search

Invasive plant species are often considered as potential competitors of native species due to their usually greater capacity for colonization and expansion, but we still have scarce information on whether invasives can also compete for pollination services with natives. In the present study, we hypothesized that the showy flowers of the highly invasive Carpobrotu spp. can compete with native species

Eva Moragues; Anna Traveset

2005-01-01

278

Effect of Carpobrotus spp. on the pollination success of native plant species of the Balearic Islands  

E-print Network

Effect of Carpobrotus spp. on the pollination success of native plant species of the Balearic of native species due to their usually greater capacity for col- onization and expansion, but we still have with native species (Cistus monspeliensis, Cistus salviifolius, Anthyllis cytisoides and Lotus cytisoides

Traveset, Anna

279

ORIGINAL ARTICLE1 2 The demography of native and non-native plant species  

E-print Network

REVISED PROOF ORIGINAL ARTICLE1 2 The demography of native and non-native plant species 3. In 2009, 14 monitoring plots were established for populations of a non- 15 native species (Linaria dalmatica) and a closely related 16 native species (Castilleja miniata) on an elevation gradient 17

Maxwell, Bruce D.

280

publication 450-237 Many of the tree species commonly planted in Virginia  

E-print Network

. This native species is beautiful in flower (May). It prefers deep, moist, fertile, acid soils, but tolerates, pendulous flowers in May. This species, native to the cen- tral and southern states, tolerates drypublication 450-237 Many of the tree species commonly planted in Virginia landscapes suffer from

Liskiewicz, Maciej

281

Classification and identification of metal-accumulating plant species by cluster analysis.  

PubMed

Identification and classification of metal-accumulating plant species is essential for phytoextraction. Cluster analysis is used for classifying individuals based on measured characteristics. In this study, classification of plant species for metal accumulation was conducted using cluster analysis based on a practical survey. Forty plant samples belonging to 21 species were collected from an ancient silver-mining site. Five groups such as hyperaccumulator, potential hyperaccumulator, accumulator, potential accumulator, and normal accumulating plant were graded. For Cd accumulation, the ancient silver-mining ecotype of Sedum alfredii was treated as a Cd hyperaccumulator, and the others were normal Cd-accumulating plants. For Zn accumulation, S. alfredii was considered as a potential Zn hyperaccumulator, Conyza canadensis and Artemisia lavandulaefolia were Zn accumulators, and the others were normal Zn-accumulating plants. For Pb accumulation, S. alfredii and Elatostema lineolatum were potential Pb hyperaccumulators, Rubus hunanensis, Ajuga decumbens, and Erigeron annuus were Pb accumulators, C. canadensis and A. lavandulaefolia were potential Pb accumulators, and the others were normal Pb-accumulating plants. Plant species with the potential for phytoextraction were identified such as S. alfredii for Cd and Zn, C. canadensis and A. lavandulaefolia for Zn and Pb, and E. lineolatum, R. hunanensis, A. decumbens, and E. annuus for Pb. Cluster analysis is effective in the classification of plant species for metal accumulation and identification of potential species for phytoextraction. PMID:24888623

Yang, Wenhao; Li, He; Zhang, Taoxiang; Sen, Lin; Ni, Wuzhong

2014-09-01

282

The effects of plant diversity and insect herbivory on performance of individual plant species in experimental grassland  

Microsoft Academic Search

1 There is increasing evidence that components of biodiversity affect processes at the ecosystem level; yet, the effects of biodiversity on the performance of individual organisms or particular trophic interactions are largely unexplored. 2 We transplanted 10 individuals of Rumex acetosa into 82 experimental grassland plots differing in plant species and functional group richness. Half of the plants received an

CHRISTOPH SCHERBER; ALEXANDRU MILCU; STEPHAN PARTSCH; STEFAN SCHEU; WOLFGANG W. WEISSER

2006-01-01

283

Polyaromatic Hydrocarbons in Rhizosphere Soil of Different Plants: Effect of Soil Properties, Plant Species, and Intensity of Anthropogenic Pressure  

Microsoft Academic Search

The objective of the present study was to determine the content of polycyclic aromatic hydrocarbons (PAH) in the rhizospheres of some selected plant species (Cucumis dativus, Daucus carota, Allium cepa, Cueurbita, Petroselinum sativum, Cucurbitaceae, Phaseolus vulgaris, Beta vulgaris, Apium graveolens, Allium porrum, Vicia faba). Various anthropogenic influences on the PAH content in the rhizospheres of the three species selected were

Patryk Oleszczuk; Stanis?aw Baran

2007-01-01

284

Past and present effectiveness of protected areas for conservation of naturally and anthropogenically rare plant species.  

PubMed

The Global Strategy of Plant Conservation states that at least 60% of threatened plant species should be within protected areas. This goal has been met in some regions with long traditions of plant protection. We used gap analysis to explore how particular groups of species of conservation interest, representing different types of natural or anthropogenic rarity, have been covered by protected areas on a national scale in Estonia during the last 100 years. Species-accumulation curves indicated that plant species that are naturally rare (restricted global or local distribution, always small populations, or very rare habitat requirements) needed almost twice as many protected areas to reach the 60% target as plant species that are rare owing to lack of suitable management (species depending on grassland management, moderate forest disturbances, extensive traditional agriculture, or species potentially threatened by collecting). Temporal analysis of the establishment of protected areas suggested that grouping plant species according to the predominant cause of rarity accurately reflected the history of conservation decision making. Species found in very rare habitats have previously received special conservation attention; species dependent on traditional extensive agriculture have been largely ignored until recently. Legislative initiative and new nature-protection schemes (e.g., Natura 2000, network of protected areas in the European Union) have had a positive influence on all species groups. Consequently, the species groups needing similar action for their conservation are sensitive indicators of the effectiveness of protected-area networks. Different species groups, however, may not be uniformly conserved within protected areas, and all species groups should fulfill the target of 60% coverage within protected areas. PMID:19128324

Vellak, Ain; Tuvi, Eva-Liis; Reier, Ülle; Kalamees, Rein; Roosaluste, Elle; Zobel, Martin; Pärtel, Meelis

2009-06-01

285

Regional climate model downscaling may improve the prediction of alien plant species distributions  

NASA Astrophysics Data System (ADS)

Distributions of invasive species are commonly predicted with species distribution models that build upon the statistical relationships between observed species presence data and climate data. We used field observations, climate station data, and Maximum Entropy species distribution models for 13 invasive plant species in the United States, and then compared the models with inputs from a General Circulation Model (hereafter GCM-based models) and a downscaled Regional Climate Model (hereafter, RCM-based models).We also compared species distributions based on either GCM-based or RCM-based models for the present (1990-1999) to the future (2046-2055). RCM-based species distribution models replicated observed distributions remarkably better than GCM-based models for all invasive species under the current climate. This was shown for the presence locations of the species, and by using four common statistical metrics to compare modeled distributions. For two widespread invasive taxa ( Bromus tectorum or cheatgrass, and Tamarix spp. or tamarisk), GCM-based models failed miserably to reproduce observed species distributions. In contrast, RCM-based species distribution models closely matched observations. Future species distributions may be significantly affected by using GCM-based inputs. Because invasive plants species often show high resilience and low rates of local extinction, RCM-based species distribution models may perform better than GCM-based species distribution models for planning containment programs for invasive species.

Liu, Shuyan; Liang, Xin-Zhong; Gao, Wei; Stohlgren, Thomas J.

2014-12-01

286

Arbuscular mycorrhizal fungi reduce the differences in competitiveness between dominant and subordinate plant species.  

PubMed

In grassland communities, plants can be classified as dominants or subordinates according to their relative abundances, but the factors controlling such distributions remain unclear. Here, we test whether the presence of the arbuscular mycorrhizal (AM) fungus Glomus intraradices affects the competitiveness of two dominant (Taraxacum officinale and Agrostis capillaris) and two subordinate species (Prunella vulgaris and Achillea millefolium). Plants were grown in pots in the presence or absence of the fungus, in monoculture and in mixtures of both species groups with two and four species. In the absence of G. intraradices, dominants were clearly more competitive than subordinates. In inoculated pots, the fungus acted towards the parasitic end of the mutualism-parasitism continuum and had an overall negative effect on the growth of the plant species. However, the negative effects of the AM fungus were more pronounced on dominant species reducing the differences in competitiveness between dominant and subordinate species. The effects of G. intraradices varied with species composition highlighting the importance of plant community to mediate the effects of AM fungi. Dominant species were negatively affected from the AM fungus in mixtures, while subordinates grew identically with and without the fungus. Therefore, our findings predict that the plant dominance hierarchy may flatten out when dominant species are more reduced than subordinate species in an unfavourable AM fungal relationship (parasitism). PMID:23064770

Mariotte, Pierre; Meugnier, Claire; Johnson, David; Thébault, Aurélie; Spiegelberger, Thomas; Buttler, Alexandre

2013-05-01

287

Molecular Cloning and Bioinformatics Analysis of a New Plasma Membrane Na+/H+ Antiporter Gene from the Halophyte Kosteletzkya virginica  

PubMed Central

A new plasma membrane Na+/H+ antiporter gene (named as KvSOS1) was cloned from the halophyte Kosteletzkya virginica by reverse-transcription-polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE) technology, which is a homologue of SOS1 (salt overly sensitive 1). The full-length cDNA is 3850?bp and contains an open reading frame (ORF) encoding a protein of 1147 amino acids with a molecular weight of 127.56?kDa and a theoretical pI of 6.18. Bioinformatics analysis indicated that the deduced protein appears to be a transmembrane protein with 12 transmembrane domains at the N-terminal region and a long hydrophilic tail in cytoplasm at its C-terminal region and shares 72–82% identity at the peptide level with other plant plasma membrane Na+/H+ antiporters. PMID:25093196

Wang, Hongyan; Tang, Xiaoli; Shao, Chuyang; Shao, Hongbo; Wang, Honglei

2014-01-01

288

Understanding local and regional plant diversity: species pools, species saturation, and the multi-scalar effects of plant productivity  

E-print Network

-scalar effects of plant productivity Joel M. Gramling A dissertation submitted to the faculty of the University saturation, and the multi-scalar effects of plant productivity (Under the direction of Robert K. Peet. The generality of the productivity-diversity relationship is assessed across ecologically-distinct plant

Peet, Robert K.

289

Cattle grazing increases plant species richness of most species trait groups in mesic semi-natural grasslands  

Microsoft Academic Search

The effects of cattle grazing on plant species trait groups were studied by comparing three kinds of mesic seminatural grasslands in southern Finland: old (continuously cattle grazed), new (cattle grazing restarted 3–8 years ago) and abandoned pastures (grazing terminated > 10 years ago). Two spatial scales were studied: 1 m2 and grassland patch (0.25–0.8 ha). Species richness was higher among

Juha Pykälä

2005-01-01

290

A proposed classification of invasive alien plant species in South Africa: towards prioritizing species and areas for management action  

Microsoft Academic Search

Many invasive alien plant species in South Africa are already well-established and cause substantial damage, while scores of others are at the early stages of invasion (only recently introduced and\\/or entering a phase of rapid population growth). Management programmes must target well-established invaders, but must also give appropriate attention to emerging problems. Protocols for objectively prioritizing species in the two

J. L. Nel; D. M. Richardson; M. Rouget; T. N. Mgidi; N. Mdzeke; D. C. Le Maitre; B. W. van Wilgen; L. Schonegevel; L. Henderson; S. Neser

291

Postglacial migration supplements climate in determining plant species ranges in Europe  

PubMed Central

The influence of dispersal limitation on species ranges remains controversial. Considering the dramatic impacts of the last glaciation in Europe, species might not have tracked climate changes through time and, as a consequence, their present-day ranges might be in disequilibrium with current climate. For 1016 European plant species, we assessed the relative importance of current climate and limited postglacial migration in determining species ranges using regression modelling and explanatory variables representing climate, and a novel species-specific hind-casting-based measure of accessibility to postglacial colonization. Climate was important for all species, while postglacial colonization also constrained the ranges of more than 50 per cent of the species. On average, climate explained five times more variation in species ranges than accessibility, but accessibility was the strongest determinant for one-sixth of the species. Accessibility was particularly important for species with limited long-distance dispersal ability, with southern glacial ranges, seed plants compared with ferns, and small-range species in southern Europe. In addition, accessibility explained one-third of the variation in species' disequilibrium with climate as measured by the realized/potential range size ratio computed with niche modelling. In conclusion, we show that although climate is the dominant broad-scale determinant of European plant species ranges, constrained dispersal plays an important supplementary role. PMID:21543356

Normand, Signe; Ricklefs, Robert E.; Skov, Flemming; Bladt, Jesper; Tackenberg, Oliver; Svenning, Jens-Christian

2011-01-01

292

Comparing salt tolerance of beet cultivars and their halophytic ancestor: consequences of domestication and breeding programs.  

PubMed

Salt tolerance of higher plants is determined by a complex set of traits, the timing and rate of evolution of which is largely unknown. We compared the salt tolerance of cultivars of sugar beet and their ancestor, sea beet, in hydroponic studies and evaluated whether traditional domestication and more recent breeding have changed salt tolerance of the cultivars relative to their ancestor. Our comparison of salt tolerance of crop cultivars is based on values of the relative growth rate (RGR) of the entire plant at various salinity levels. We found considerable salt tolerance of the sea beet and slightly, but significantly, reduced salt tolerance of the sugar beet cultivars. This indicates that traditional domestication by selection for morphological traits such as leaf size, beet shape and size, enhanced productivity, sugar content and palatability slightly affected salt tolerance of sugar beet cultivars. Salt tolerance among four sugar beet cultivars, three of which have been claimed to be salt tolerant, did not differ. We analysed the components of RGR to understand the mechanism of salt tolerance at the whole-plant level. The growth rate reduction at higher salinity was linked with reduced leaf area at the whole plant level (LAR) and at the individual leaf level (SLA). The Leaf Weight Fraction was not affected by increased salinity. On the other hand, succulence and leaf thickness and the net assimilation per unit of leaf area (ULR) increased in response to salt treatment, thus partially counteracting reduced capture of light by lower leaf area. This compensatory mechanism may form part of the salt tolerance mechanism of sea beet and the four studied sugar beet cultivars. Together, our results indicate that domestication of halophytic ancestor sea beet slightly reduced salt tolerance and that breeding for improved salt tolerance of sugar beet cultivars has not been effective. PMID:25492122

Rozema, Jelte; Cornelisse, Danny; Zhang, Yuancheng; Li, Hongxiu; Bruning, Bas; Katschnig, Diana; Broekman, Rob; Ji, Bin; van Bodegom, Peter

2014-12-01

293

Plant translational genomics: from model species to crops  

Microsoft Academic Search

Plant genomic research now faces the ultimate challenge to develop applications in crop plants which implies the translation\\u000a of gene functions from a model to a crop which is the field of ‘Plant translational genomics’. In this paper we discuss the\\u000a perspectives of the candidate gene approach (CGA) as a tool for translational genomics in the ‘whole genome’ era. Factors

Elma M. J. Salentijn; Andy Pereira; Gerco C. Angenent; C. Gerard van der Linden; Frans Krens; Marinus J. M. Smulders; Ben Vosman

2007-01-01

294

Actinotalea suaedae sp. nov., isolated from the halophyte Suaeda physophora in Xinjiang, Northwest China.  

PubMed

A Gram-stain-positive, aerobic, non-motile, coryneform bacterium, designated strain EGI 60002(T), was isolated from the halophyte Suaeda physophora. Cells were coryneform shaped and polymorphic. Phylogenetic analysis based on 16S rRNA gene sequences showed that the new isolate was closely related to Actinotalea ferrariae CF5-4(T) (95.8 % gene sequence similarity). The peptidoglycan type of strain EGI 60002(T) was A4?, containing L-Orn-D-Ser-D-Asp. The cell-wall sugars were mannose, ribose, rhamnose and glucose. The major fatty acids (>5 %) of strain EGI 60002(T) were iso-C14:0, iso-C15:0, anteiso-C15:1 A and anteiso-C15:0. The predominant respiratory quinone was MK-10(H4). The major polar lipids were diphosphatidylglycerol (DPG), one unidentified phosphoglycolipid (PGL) and one unidentified phospholipid (PL1). The genomic DNA G+C content was 72.3 mol%. On the basis of morphological, physiological, chemotaxonomic data, and phylogenetic analysis, strain EGI 60002(T) should be classified as a novel species within the genus Actinotalea, for which the name Actinotalea suaedae sp. nov. is proposed. The type strain is EGI 60002T (=JCM 19624(T) = KACC 17839(T) = KCTC 29256(T)). PMID:25307231

Zhao, Shuai; Li, Li; Li, Shan-Hui; Wang, Hong-Fei; Hozzein, Wael N; Zhang, Yong-Guang; Wadaan, Mohammed A M; Li, Wen-Jun; Tian, Chang-Yan

2014-10-12

295

Accumulation and tolerance characteristics of cadmium in a halophytic Cd-hyperaccumulator, Arthrocnemum macrostachyum.  

PubMed

The potential of the extreme halophyte Arthrocnemum macrostachyum was examined to determine its tolerance and ability to accumulate cadmium for phytoremediation purposes. A glasshouse experiment was designed to investigate the effect of cadmium from 0 to 1.35 mmol l(-1) on the growth and the photosynthetic apparatus of A. macrostachyum by measuring chlorophyll fluorescence parameters, gas exchange and photosynthetic pigment concentrations. We also determined ash, cadmium, calcium, copper, iron, manganese, magnesium, phosphorous, sodium, and zinc concentrations, and C/N ratio. A. macrostachyum demonstrated hypertolerance to cadmium stress; it did not show phytotoxicity at shoot concentration as high as 70 mg kg(-1). The bioaccumulator factors exceeded the critical value (1.0) for all Cd treatments, and the transport factors indicated that this species has higher ability to transfer Cd from roots to shoots at lower Cd concentrations. At 1.35 mmol l(-1) Cd A. macrostachyum showed 25% biomass reduction after a month of treatment. Long-term effects of cadmium on the growth were mainly determined by variations in net photosynthetic rate (P(N)). Reductions in P(N) could be accounted by higher dark respiration and lower pigment concentrations. Finally, A. macrostachyum has the basic characteristics of a Cd-hyperaccumulator and may be useful for restoring Cd-contaminated sites. PMID:20832167

Redondo-Gómez, Susana; Mateos-Naranjo, Enrique; Andrades-Moreno, Luis

2010-12-15

296

Host plant species effects on arbuscular mycorrhizal fungal communities in tallgrass prairie  

Microsoft Academic Search

Symbiotic associations between plants and arbuscular mycorrhizal (AM) fungi are ubiquitous in many herbaceous plant communities\\u000a and can have large effects on these communities and ecosystem processes. The extent of species-specificity between these plant\\u000a and fungal symbionts in nature is poorly known, yet reciprocal effects of the composition of plant and soil microbe communities\\u000a is an important assumption of recent

Ahn-Heum Eom; David C. Hartnett; G. W. T. Wilson

2000-01-01

297

Species-Specific Responses to Community Density in an Unproductive Perennial Plant Community  

PubMed Central

Most studies of density dependent regulation in plants consider a single target species, but regulation may also occur at the level of the entire community. Knowing whether a community is at carrying capacity is essential for understanding its behaviour because low density plant communities may behave quite differently than their high density counterparts. Also, because the intensity of density dependence may differ considerably between species and physical environments, generalizations about its effects on community structure requires comparisons under a range of conditions. We tested if: (1) density dependent regulation occurs at the level of an entire plant community as well as within individual species; (2) the intensity (effect of increasing community density on mean plant mass) and importance (the effect of increasing density, relative to other factors, on mean plant mass) of competition increases, decreases or remains unchanged with increasing fertilization; (3) there are species-specific responses to changes in community density and productivity. In 63 1 m2 plots, we manipulated the abundance of the nine most common species by transplanting or removing them to create a series of Initial Community Densities above and below the average natural field density, such that the relative proportion of species was consistent for all densities. Plots were randomly assigned to one of three fertilizer levels. At the community level, negative density dependence of mean plant size was observed for each of the 4 years of the study and both the intensity and importance of competition increased each year. At the species level, most species' mean plant mass were negatively density dependent. Fertilizer had a significant effect only in the final year when it had a negative effect on mean plant mass. Our data demonstrate a yield-density response at the entire community-level using perennial plant species in a multi-year experiment. PMID:25050710

Treberg, Michael A.; Turkington, Roy

2014-01-01

298

Invasive clonal plant species have a greater root-foraging plasticity than non-invasive ones.  

PubMed

Clonality is frequently positively correlated with plant invasiveness, but which aspects of clonality make some clonal species more invasive than others is not known. Due to their spreading growth form, clonal plants are likely to experience spatial heterogeneity in nutrient availability. Plasticity in allocation of biomass to clonal growth organs and roots may allow these plants to forage for high-nutrient patches. We investigated whether this foraging response is stronger in species that have become invasive than in species that have not. We used six confamilial pairs of native European clonal plant species differing in invasion success in the USA. We grew all species in large pots under homogeneous or heterogeneous nutrient conditions in a greenhouse, and compared their nutrient-foraging response and performance. Neither invasive nor non-invasive species showed significant foraging responses to heterogeneity in clonal growth organ biomass or in aboveground biomass of clonal offspring. Invasive species had, however, a greater positive foraging response in terms of root and belowground biomass than non-invasive species. Invasive species also produced more total biomass. Our results suggest that the ability for strong root foraging is among the characteristics promoting invasiveness in clonal plants. PMID:24352844

Keser, Lidewij H; Dawson, Wayne; Song, Yao-Bin; Yu, Fei-Hai; Fischer, Markus; Dong, Ming; van Kleunen, Mark

2014-03-01

299

Individual-Based Ant-Plant Networks: Diurnal-Nocturnal Structure and Species-Area Relationship  

PubMed Central

Despite the importance and increasing knowledge of ecological networks, sampling effort and intrapopulation variation has been widely overlooked. Using continuous daily sampling of ants visiting three plant species in the Brazilian Neotropical savanna, we evaluated for the first time the topological structure over 24 h and species-area relationships (based on the number of extrafloral nectaries available) in individual-based ant-plant networks. We observed that diurnal and nocturnal ant-plant networks exhibited the same pattern of interactions: a nested and non-modular pattern and an average level of network specialization. Despite the high similarity in the ants’ composition between the two collection periods, ant species found in the central core of highly interacting species totally changed between diurnal and nocturnal sampling for all plant species. In other words, this “night-turnover” suggests that the ecological dynamics of these ant-plant interactions can be temporally partitioned (day and night) at a small spatial scale. Thus, it is possible that in some cases processes shaping mutualistic networks formed by protective ants and plants may be underestimated by diurnal sampling alone. Moreover, we did not observe any effect of the number of extrafloral nectaries on ant richness and their foraging on such plants in any of the studied ant-plant networks. We hypothesize that competitively superior ants could monopolize individual plants and allow the coexistence of only a few other ant species, however, other alternative hypotheses are also discussed. Thus, sampling period and species-area relationship produces basic information that increases our confidence in how individual-based ant-plant networks are structured, and the need to consider nocturnal records in ant-plant network sampling design so as to decrease inappropriate inferences. PMID:24918750

Dáttilo, Wesley; Fagundes, Roberth; Gurka, Carlos A. Q.; Silva, Mara S. A.; Vieira, Marisa C. L.; Izzo, Thiago J.; Díaz-Castelazo, Cecília; Del-Claro, Kleber; Rico-Gray, Victor

2014-01-01

300

Comparative pharmacognostic evaluation of some species of the genera Suaeda and Salsola leaf (Chenopodiaceae).  

PubMed

The genera Suaeda and Salsola are halophytic plants belong to the family Chenopodiaceae. Species of these genera have been extensively used in traditional medicines against many diseases due to their various bioactive compounds such as carotenoids, vitamins, sterol, phenolic compounds etc. The present research was carried out to establish detailed pharmacognosy of Suaeda fruticosa, Suaeda monoica, Salsola imbricata and Salsola tragus, which included macroscopy, microscopy, physico-chemical parameters and qualitative phytochemical screening of leaf samples extracted with methanol and chloroform. It was observed that macroscopic and microscopic characteristics were diagnostic features and can be used for distinction and identification of these closely related plant species. Phytochemically, these plant species are rich in constituents like anthraquinones, alkaloids, carbohydrates, cardiac glycosides, flavonoids, saponins, phenolic compounds and terpenoids. Physico-chemical parameters revealed that in all investigated plant species; methanol extractive values were higher than that of chloroform. Moreover, total ash values were found to be higher than other acid insoluble and water-soluble ash values, while a considerable amount of moisture was present in the species of both genera. On the basis of pharmacognosy, species of Suaeda were found to be more promising than Salsola. Present investigation will contribute towards establishment of pharmacognostic profile of these medicinally effective plants species. PMID:25176385

Munir, Uzma; Perveen, Anjum; Qamarunnisa, Syeda

2014-09-01

301

Polar Desert Adaptations of a High Arctic Plant Species  

Microsoft Academic Search

Plants of Saxifraga oppositifolia (Saxifragaceae) possess metabolic adaptations that allow them to grow successfully in polar desert microenvironments. Net photosynthesis (net carbon uptake) continues to be positive during drought until the leaf water stress declines to the range of -21 to -29 bars, which is considerably below the nonstress range of 0 to -10 bars. The plants can survive leaf

J. A. Teeri

1973-01-01

302

Selected aquatic plants as indicator species for heavy metal pollution  

Microsoft Academic Search

Heavy metal pollution of the aquatic environment is often responsible for depletion of fishery resources and sudden fish?kills. Some aquatic plants do selectively accumulate specific metals and can serve as biological monitors. Two vascular plants, Potamogeton and Equisetum and a blue algae Oscillatoria have proved useful for monitoring metal pollution.

S. Ray; W. White

1976-01-01

303

Aminomethylphosphonic acid accumulation in plant species treated with glyphosate  

Technology Transfer Automated Retrieval System (TEKTRAN)

Aminomethylphosphonic acid (AMPA) is the most frequently detected metabolite of glyphosate in plants. Greenhouse studies were conducted to determine the glyphosate I50 values (rate required to cause a 50% reduction in plant growth) and to quantify AMPA and shikimate concentrations in selected legum...

304

Active Oxygen Species in Plant Defense against Pathogens  

Microsoft Academic Search

Plant disease resistance to pathogens such as fungi, bac- teria, and viruses often depends on whether the plant is able to recognize the pathogen early in the infection process. The recognition event leads to a rapid tissue necrosis at the site of infection, which is called the HR. The HR deprives the pathogen of nutrients and\\/or releases toxic molecules, thereby

Mona C. Mehdy

1993-01-01

305

Differential effects of abiotic factors and host plant traits on diversity and community composition of root-colonizing arbuscular mycorrhizal fungi in a salt-stressed ecosystem.  

PubMed

Arbuscular mycorrhizal fungi (AMF) were investigated in roots of 18 host plant species in a salinized south coastal plain of Laizhou Bay, China. From 18 clone libraries of 18S rRNA genes, all of the 22 AMF phylotypes were identified into Glomus, of which 18 and 4 were classified in group A and B in the phylogenetic tree, respectively. The phylotypes related to morphologically defined Glomus species occurred generally in soil with higher salinity. AMF phylotype richness, Shannon index, and evenness were not significantly different between root samples from halophytes vs. non-halophytes, invades vs. natives, or annuals vs. perennials. However, AMF diversity estimates frequently differed along the saline gradient or among locations, but not among pH gradients. Moreover, UniFrac tests showed that both plant traits (salt tolerance, life style or origin) and abiotic factors (salinity, pH, or location) significantly affected the community composition of AMF colonizers. Redundancy and variation partitioning analyses revealed that soil salinity and pH, which respectively explained 6.9 and 4.2 % of the variation, were the most influential abiotic variables in shaping the AMF community structure. The presented data indicate that salt tolerance, life style, and origin traits of host species may not significantly affect the AMF diversity in roots, but do influence the community composition in this salinized ecosystem. The findings also highlight the importance of soil salinity and pH in driving the distribution of AMF in plant and soil systems. PMID:23900649

Guo, Xiaohong; Gong, Jun

2014-02-01

306

TESTING LIFE HISTORY CORRELATES OF INVASIVENESS USING CONGENERIC PLANT SPECIES  

Microsoft Academic Search

We used three congeneric annual thistles, which vary in their ability to invade California (USA) annual grasslands, to test whether invasiveness is related to differences in life history traits. We hypothesized that populations of these summer-flowering Centaurea species must pass through a demographic gauntlet of survival and reproduction in order to persist and that the most invasive species (C. solstitialis)

John D. Gerlach; Kevin J. Rice

2003-01-01

307

Development and characterization of microsatellite markers in Sarracenia L. (pitcher plant) species  

PubMed Central

Sarracenia species (pitcher plants) are carnivorous plants which obtain a portion of their nutrients from insects captured in the pitchers. Sarracenia species naturally hybridize with each other, and hybrid swarms have been identified. A number of the taxa within the genus are considered endangered. In order to facilitate evolutionary, ecological and conservation genetic analyses within the genus, we developed 25 microsatellite loci which show variability either within species or between species. Three S. purpurea populations were examined with 10 primer sets which showed within population variability. PMID:21170168

Rogers, Willie L.; Cruse-Sanders, Jennifer M.; Determann, Ron; Malmberg, Russell L.

2010-01-01

308

Pollinator Behavior Mediates Negative Interactions between Two Congeneric Invasive Plant Species.  

PubMed

Simultaneously flowering plant species may indirectly interact with each other by influencing the quantity of pollinator visitation and/or the quality of pollen that is transferred. These effects on pollination may depend on how pollinators respond to floral resources at multiple levels. In this study, we demonstrate pollinator-mediated negative interactions between two invasive plants, Carduus acanthoides and Carduus nutans. Using constructed arrays of the two species, alone and in mixture, we quantified pollinator visitation at the patch and individual plant levels and measured seed production. We found that co-occurrence of our species led to a shift in pollinator services at both levels. Greater interference occurred when arrays were small and spacings between neighboring plants were large. A spatially explicit movement model suggests that pollinator foraging behavior, which mediates the interactions between plants, was driven by floral display size rather than species identity per se. Pollinator behavior significantly reduced the proportion of seed set for both species relative to that in single-species arrays. Overall, the dependence of pollinator behavior on patch size, spacing between plants, and patch composition can lead to pollinator-mediated plant interactions that range from facilitative to competitive. PMID:21117967

Yang, Suann; Ferrari, Matthew J; Shea, Katriona

2011-01-01

309

Assessment of bioaccumulation of heavy metals by different plant species grown on fly ash dump.  

PubMed

A field experiment was conducted on a 10-hectare area on fly ash dump at Khaperkheda Thermal Power Plant, Nagpur, India, where different ecologically and economically important plant species were planted using bioremediation technology. The technology involves the use of organic amendment and selection of suitable plant species along with site-specific nitrogen-fixing strains of biofertilizers. The study was conducted to find out the metal accumulation potential of different plant species. The total heavy metal contents in fly ash were determined and their relative abundance was found in the order of Fe>Mn>Zn>Cu>Ni>Cr>Pb>Cd. Fly ash samples had acidic pH, low electrical conductivity, low level of organic carbon and trace amounts of N and P. Plantation of divergent species was done on fly ash dump using the bioremediation technique. After 3 years of plantation, luxuriant growth of these species was found covering almost the entire fly ash dump. The results of the metal analysis of these species indicated that iron accumulated to the greatest extent in vegetation followed by Mn, Ni, Zn, Cu, Cr and Pb. Cassia siamea was found to accumulate all metals at higher concentrations compared to other species. The experimental study revealed that C. siamea could be used as a hyper-accumulator plant for bioremediation of fly ash dump. PMID:19171381

Jambhulkar, Hemlata P; Juwarkar, Asha A

2009-05-01

310

Quantitative resistance traits and suitability of woody plant species for a polyphagous scarab, Popillia japonica Newman.  

PubMed

The Japanese beetle, Popillia japonica Newman, has an unusually broad host range among deciduous woody plants, yet it feeds only sparingly, or not at all, on certain species in the field. We evaluated beetles' preference, survival over time and fecundity on eight woody plant species historically rated as susceptible or resistant and, after verifying those ratings, tested whether resistance is correlated with so-called quantitative defense traits including leaf toughness, low nutrient content (water, nitrogen, and sugars), and relatively high amounts of tannins or saponins, traditionally associated with such plants. We further tested whether species unsuitable for Japanese beetles are also rejected by fall webworms, Hyphantria cunea (Drury) (Lepidoptera: Arctiidae), the expected outcome if the aforementioned traits serve as broad-based defenses against generalists. Choice tests supported historical resistance ratings for the selected species: tuliptree, lilac, dogwood, and Bradford callery pear were rejected by Japanese beetles, whereas sassafras, cherry plum, Virginia creeper, and littleleaf linden were readily eaten. Rejected species also were unsuitable for survival over time, or egg-laying, indicating beetles' inability to overcome the resistance factors through habituation, compensatory feeding, or detoxification. None of the aforementioned leaf traits was consistently higher or lower in the resistant or susceptible plants, and plant species rejected by Japanese beetles often were not rejected by fall webworms. Specialized secondary chemistry, not quantitative defenses, likely determines the Japanese beetle's dietary range among deciduous woody plant species it may encounter. PMID:19161699

Keathley, Craig P; Potter, Daniel A

2008-12-01

311

From Spring to Fall: Life Cycle Responses of Plant Species and Communities to Climate Change  

NASA Astrophysics Data System (ADS)

The shifting life cycles of plants in response to environmental changes are well-documented. However, our understanding of the reasons for the shifts remains insufficient for prediction. Complex data sets that include season-long responses of plant species and communities to climate, including extreme climate years and experimental manipulations, are needed to address the gaps in our understanding. Using near-surface sensing technologies and observations of individual species' and plant community responses, we identified season-long shifts of plant life cycles to observed and experimental climate variation. Changes to plant life cycles often included shifts in the timing of spring and fall events for individual species and plant communities, leading to a longer growing season. Community patterns were more predictable than species' responses, although non-native species' responses led to less predictable community patterns. Seasonal patterns of snow cover and water availability influenced the effect of temperature on species' and community life cycles. Multi-factor climate change experiments and data during extreme climate years are essential to determine thresholds by which snow cover and soil water content influence species and community responses to climate warming.

Steltzer, H.; Chong, G.; Weintraub, M. N.

2013-12-01

312

Species richness and selenium accumulation of plants in soils with elevated concentration of selenium and salinity  

SciTech Connect

Field studies were conducted in soils with elevated concentrations of Se and salinity at Kesterson, California. Biomass distribution, species richness, and selenium accumulation of plants were examined for two sites where 15 cm of surface soil was removed and replaced with fill dirt in the fall of 1989, and two sites were native soil cover. The Se concentrations in the top 15 cm of fill dirt ranged from undetectable to 36 ng g-1. For the native soil sites, Se levels ranged from 75 to 550 ng g-1. Soil Se concentrations below 15 cm ranged from 300 to 700 ng g-1 and were comparable between the fill dirt and the native soil sites. At least 20 different plant species were brought into the two fill dirt sites with the top soil. Avena fatua L., Bassia hyssopifolia Kuntze Rev. Gen. Pl., Centaurea solstitialis L., Erysimum officianale L., Franseria acanthicarpa Cav. Icon., and Melilotus indica (L.) All. contributed over 60% of the total biomass. Only 5 species were found in the native soil sites, and salt grass (Distichlis spicata L.) was the predominant species and accounted for over 80% of the total biomass. Between 1989 and 1990, two years after the surface soil replacement, the two fill dirt sites had a 70% reduction in species richness. Plant tissue selenium concentrations were found to be quite variable between plant species and between sites of sampling. At the fill dirt sites, the plant species with deep root systems accumulated greater amounts of selenium than the shallow-rooted species. The soil selenium concentration of the field soil had no negative effect on pollen fertility, seed set, and seed germination for the plant species examined. However, seedling growth was impaired by the soil selenium concentrations. This suggests that a selection pressure of soil Se concentration may have been imposed on plant species such as M. indica in an early stage of its life cycle.

Huang, Z.Z.; Wu, L. (Department of Environmental Horticulture, University of California, Davis (United States))

1991-12-01

313

Germination characteristics of six plant species growing on the Hanford Site. [Disturbed land revegetation feasibility studies  

SciTech Connect

Six plant species (Siberian and thickspike wheatgrass, cheatgrass, sand dropseed, Indian ricegrass, and Russian thistle) found on the Hanford Site were studied as part of an investigation into the revegetation of disturbed areas. Germination response to three environmental parameters (soil moisture, soil temperature, and planting depth) were measured. Results indicated that when a polyethylene glycol solution was used to control the osmotic potential of the imbibition media, no significant decrease in germination rate occurred down to -3.0 bars. However, below -7.0 bars all species experienced a decrease in germination. When germinated in soil, all species except Russian thistle exhibited a significant decrease in germination rate at -0.3 bars. Russian thistle was the only species tested that exhibited germination at a soil temperature of 1/sup 0/C. All species gave optimum germination at temperatures between 10 and 15/sup 0/C. Thickspike wheatgrass was the only species tested which was able to germinate and emerge from a planting depth of greater than 2 inches. If supplemental moisture is provided, a shallow planting would be advisable for those species tested. If not overcome by pretreatment prior to planting, seed dormancy may be a significant factor which will reduce the germination potential of some species tested.

Cox, G.R.; Kirkham, R.R.; Cline, J.F.

1980-03-01

314

Dormancy cycling and persistence of seeds in soil of a cold desert halophyte shrub  

PubMed Central

Background and Aims Formation of seed banks and dormancy cycling are well known in annual species, but not in woody species. In this study it was hypothesized that the long-lived halophytic cold desert shrub Kalidium gracile has a seed bank and dormancy cycling, which help restrict germination to a favourable time for seedling survival. Methods Fresh seeds were buried in November 2009 and exhumed and tested for germination monthly from May 2010 to December 2011 over a range of temperatures and salinities. Germination recovery and viability were determined after exposure to salinity and water stress. Seedling emergence and dynamics of the soil seed bank were investigated in the field. Key Results Seeds of K. gracile had a soil seed bank of 7030 seeds m?2 at the beginning of the growing season. About 72 % of the seeds were depleted from the soil seed bank during a growing season, and only 1·4 % of them gave rise to seedlings that germinated early enough to reach a stage of growth at which they could survive to overwinter. About 28 % of the seeds became part of a persistent soil seed bank. Buried seeds exhibited an annual non-dormancy/conditional dormancy (ND/CD) cycle, and germination varied in sensitivity to salinity during the cycle. Dormancy cycling is coordinated with seasonal environmental conditions in such a way that the seeds germinate in summer, when there is sufficient precipitation for seedling establishment. Conclusions Kalidium gracile has three life history traits that help ensure persistence at a site: a polycarpic perennial life cycle, a persistent seed bank and dormancy cycling. The annual ND/CD cycle in seeds of K. gracile contributes to seedling establishment of this species in the unpredictable desert environment and to maintenance of a persistent soil seed bank. This is the first report of a seed dormancy cycle in a cold desert shrub. PMID:24249808

Cao, Dechang; Baskin, Carol C.; Baskin, Jerry M.; Yang, Fan; Huang, Zhenying

2014-01-01

315

Mapping invasive plant species in aquatic and terrestrial ecosystems helps to understand the causes of their progres-  

E-print Network

Abstract Mapping invasive plant species in aquatic and terrestrial ecosystems helps to understand. Introduction The invasion of aquatic and terrestrial ecosystems by non- indigenous plant and animal species of Optimal Dates for the Discrimination of Invasive Wetland Plant Species Using Derivative Spectral Analysis

Tsai, Fuan "Alfonso"

316

The influence of disturbance and habitat on the presence of non-native plant species along transport corridors  

Microsoft Academic Search

The impact from transportation corridors on surrounding habitat often reaches far beyond the edge of the corridor. The altered disturbance regime in plant communities along corridor edges and vehicle traffic facilitate the spread and establishment of invasive non-native plant species. We compared the frequency of non-native plant species along highways and railways and the ability of these species to invade

Malin J. Hansen; Anthony P. Clevenger

2005-01-01

317

Disturbance, spatial turnover, and species coexistence in grassland plant communities  

E-print Network

Humans have dramatically altered natural disturbance regimes. We thus need to understand how these alterations affect plant communities and whether natural disturbance regimes can be restored. I explored the effect of ...

Questad, Erin

2008-08-18

318

Polar desert adaptations of a high arctic plant species.  

PubMed

Plants of Saxifraga oppositifolia (Saxifragaceae) possess metabolic adaptations that allow them to grow successfully in polar desert microenvironments. Net photosynthesis (net carbon uptake) continues to be positive during drought until the leaf water stress declines to the range of -21 to -29 bars, which is considerably below the nonstress range of 0 to -10 bars. The plants can survive leaf water stresses of at least -44 bars in the field and leaf water stresses of -55 bars in a growth chamber. PMID:17739145

Teeri, J A

1973-02-01

319

Comparative analysis of polyphenol oxidase from plant and fungal species  

Microsoft Academic Search

Polyphenol oxidase from plants and fungi is a metalloenzyme containing a type-3 copper center and is homologous to oxygen-carrying hemocyanin of molluscs. Molluscan hemocyanin consists of two domains, an N-terminal domain containing the copper center and a smaller C-terminal domain, connected by an alpha-helical linker. It is presumed that the same is true of polyphenol oxidase from plants and fungi

Carrie M. Marusek; Nicole M. Trobaugh; William H. Flurkey; Jennifer K. Inlow

2006-01-01

320

Growth responses to ozone in plant species from wetlands  

Microsoft Academic Search

Ten wet grassland species were fumigated with four concentrations of ozone (charcoal-filtered air, non-filtered air and non-filtered air plus 25 or 50 nl l?1 ozone) in open-top chambers during one growing season to investigate the long-term effect of this air pollutant on various growth variables. Only Eupatorium cannabinum showed ozone-related foliar injury, while five species reacted with significantly ozone-enhanced senescence.

J. H. Franzaring; A. E. G. Tonneijck; A. W. N. Kooijman; Th. A. Dueck

2000-01-01

321

The new flora of northeastern USA: quantifying introduced plant species occupancy in forest ecosystems.  

PubMed

Introduced plant species have significant negative impacts in many ecosystems and are found in many forests around the world. Some factors linked to the distribution of introduced species include fragmentation and disturbance, native species richness, and climatic and physical conditions of the landscape. However, there are few data sources that enable the assessment of introduced species occupancy in native plant communities over broad regions. Vegetation data from 1,302 forest inventory plots across 24 states in northeastern and mid-western USA were used to examine and compare the distribution of introduced species in relation to forest fragmentation across ecological provinces and forest types, and to examine correlations between native and introduced species richness. There were 305 introduced species recorded, and 66 % of all forested plots had at least one introduced species. Forest edge plots had higher constancy and occupancy of introduced species than intact forest plots, but the differences varied significantly among ecological provinces and, to a lesser degree, forest types. Weak but significant positive correlations between native and introduced species richness were observed most often in intact forests. Rosa multiflora was the most common introduced species recorded across the region, but Hieracium aurantiacum and Epipactus helleborine were dominant in some ecological provinces. Identifying regions and forest types with high and low constancies and occupation by introduced species can help target forest stands where management actions will be the most effective. Identifying seemingly benign introduced species that are more prevalent than realized will help focus attention on newly emerging invasives. PMID:22961328

Schulz, Bethany K; Gray, Andrew N

2013-05-01

322

Are trade-offs among species' ecological interactions scale dependent? A test using pitcher-plant inquiline species.  

PubMed

Trade-offs among species' ecological interactions is a pervasive explanation for species coexistence. The traits associated with trade-offs are typically measured to mechanistically explain species coexistence at a single spatial scale. However, species potentially interact at multiple scales and this may be reflected in the traits among coexisting species. I quantified species' ecological traits associated with the trade-offs expected at both local (competitive ability and predator tolerance) and regional (competitive ability and colonization rate) community scales. The most common species (four protozoa and a rotifer) from the middle trophic level of a pitcher plant (Sarracenia purpurea) inquiline community were used to link species traits to previously observed patterns of species diversity and abundance. Traits associated with trade-offs (competitive ability, predator tolerance, and colonization rate) and other ecological traits (size, growth rate, and carrying capacity) were measured for each of the focal species. Traits were correlated with one another with a negative relationship indicative of a trade-off. Protozoan and rotifer species exhibited a negative relationship between competitive ability and predator tolerance, indicative of coexistence at the local community scale. There was no relationship between competitive ability and colonization rate. Size, growth rate, and carrying capacity were correlated with each other and the trade-off traits: Size was related to both competitive ability and predator tolerance, but growth rate and carrying capacity were correlated with predator tolerance. When partial correlations were conducted controlling for size, growth rate and carrying capacity, the trade-offs largely disappeared. These results imply that body size is the trait that provides the basis for ecological interactions and trade-offs. Altogether, this study showed that the examination of species' traits in the context of coexistence at different scales can contribute to our understanding of the mechanisms underlying community structure. PMID:22844526

Kneitel, Jamie M

2012-01-01

323

Are Trade-Offs Among Species’ Ecological Interactions Scale Dependent? A Test Using Pitcher-Plant Inquiline Species  

PubMed Central

Trade-offs among species’ ecological interactions is a pervasive explanation for species coexistence. The traits associated with trade-offs are typically measured to mechanistically explain species coexistence at a single spatial scale. However, species potentially interact at multiple scales and this may be reflected in the traits among coexisting species. I quantified species’ ecological traits associated with the trade-offs expected at both local (competitive ability and predator tolerance) and regional (competitive ability and colonization rate) community scales. The most common species (four protozoa and a rotifer) from the middle trophic level of a pitcher plant (Sarracenia purpurea) inquiline community were used to link species traits to previously observed patterns of species diversity and abundance. Traits associated with trade-offs (competitive ability, predator tolerance, and colonization rate) and other ecological traits (size, growth rate, and carrying capacity) were measured for each of the focal species. Traits were correlated with one another with a negative relationship indicative of a trade-off. Protozoan and rotifer species exhibited a negative relationship between competitive ability and predator tolerance, indicative of coexistence at the local community scale. There was no relationship between competitive ability and colonization rate. Size, growth rate, and carrying capacity were correlated with each other and the trade-off traits: Size was related to both competitive ability and predator tolerance, but growth rate and carrying capacity were correlated with predator tolerance. When partial correlations were conducted controlling for size, growth rate and carrying capacity, the trade-offs largely disappeared. These results imply that body size is the trait that provides the basis for ecological interactions and trade-offs. Altogether, this study showed that the examination of species’ traits in the context of coexistence at different scales can contribute to our understanding of the mechanisms underlying community structure. PMID:22844526

Kneitel, Jamie M.

2012-01-01

324

Cello-oligosaccharides released from host plants induce pathogenicity in scab-causing Streptomyces species  

Technology Transfer Automated Retrieval System (TEKTRAN)

Thaxtomin, a phytotoxic dipeptide that inhibits cellulose synthesis in expanding plant cells, is a pathogenicity determinant in scab-causing Streptomyces species. Cellobiose and cellotriose, the smallest subunits of cellulose, stimulated thaxtomin production in a defined medium, while other oligosa...

325

Mapping plant species ranges in the Hawaiian Islands: developing a methodology and associated GIS layers  

USGS Publications Warehouse

This report documents a methodology for projecting the geographic ranges of plant species in the Hawaiian Islands. The methodology consists primarily of the creation of several geographic information system (GIS) data layers depicting attributes related to the geographic ranges of plant species. The most important spatial-data layer generated here is an objectively defined classification of climate as it pertains to the distribution of plant species. By examining previous zonal-vegetation classifications in light of spatially detailed climate data, broad zones of climate relevant to contemporary concepts of vegetation in the Hawaiian Islands can be explicitly defined. Other spatial-data layers presented here include the following: substrate age, as large areas of the island of Hawai'i, in particular, are covered by very young lava flows inimical to the growth of many plant species; biogeographic regions of the larger islands that are composites of multiple volcanoes, as many of their species are restricted to a given topographically isolated mountain or a specified group of them; and human impact, which can reduce the range of many species relative to where they formerly were found. Other factors influencing the geographic ranges of species that are discussed here but not developed further, owing to limitations in rendering them spatially, include topography, soils, and disturbance. A method is described for analyzing these layers in a GIS, in conjunction with a database of species distributions, to project the ranges of plant species, which include both the potential range prior to human disturbance and the projected present range. Examples of range maps for several species are given as case studies that demonstrate different spatial characteristics of range. Several potential applications of species-range maps are discussed, including facilitating field surveys, informing restoration efforts, studying range size and rarity, studying biodiversity, managing invasive species, and planning of conservation efforts.

Price, Jonathan P.; Jacobi, James D.; Gon, Samuel M., III; Matsuwaki, Dwight; Mehrhoff, Loyal; Wagner, Warren; Lucas, Matthew; Rowe, Barbara

2012-01-01

326

Laser-induced fluorescence of green plants. I - A technique for the remote detection of plant stress and species differentiation  

NASA Technical Reports Server (NTRS)

The laser-induced fluorescence (LIF) of green plants was evaluated as a means of remotely detecting plant stress and determining plant type. Corn and soybeans were used as representatives of monocots and dicots, respectively, in these studies. The fluorescence spectra of several plant pigments was excited with a nitrogen laser emitting at 337 nm. Intact leaves from corn and soybeans also fluoresced using the nitrogen laser. The two plant species exhibited fluorescence spectra which had three maxima in common at 440, 690, and 740 nm. However, the relative intensities of these maxima were distinctly different for the two species. Soybeans had an additional slight maxima at 525 nm. Potassium deficiency in corn caused an increase in fluorescence at 690 and 740 nm. Simulated water stress in soybeans resulted in increased fluorescence at 440, 525, 690, and 740 nm. The inhibition of photosynthesis in soybeans by 3-(3-4-dichlorophenyl)-1-1-dimethyl urea (DCMU) gave incresed fluorescence primarily at 690 and 740 nm. Chlorosis as occurring in senescent soybean leaves caused a decrease in fluorescence at 690 and 740 nm. These studies indicate that LIF measurements of plants offer the potential for remotely detecting certain types of stress condition and also for differentiating plant species.

Chappelle, E. W.; Wood, F. M., Jr.; Mcmurtrey, J. E., III; Newcomb, W. W.

1984-01-01

327

Variation in habitat suitability does not always relate to variation in species' plant functional traits  

PubMed Central

Habitat suitability models, which relate species occurrences to environmental variables, are assumed to predict suitable conditions for a given species. If these models are reliable, they should relate to change in plant growth and function. In this paper, we ask the question whether habitat suitability models are able to predict variation in plant functional traits, often assumed to be a good surrogate for a species' overall health and vigour. Using a thorough sampling design, we show a tight link between variation in plant functional traits and habitat suitability for some species, but not for others. Our contrasting results pave the way towards a better understanding of how species cope with varying habitat conditions and demonstrate that habitat suitability models can provide meaningful descriptions of the functional niche in some cases, but not in others. PMID:19793738

Thuiller, Wilfried; Albert, Cécile H.; Dubuis, Anne; Randin, Christophe; Guisan, Antoine

2010-01-01

328

Arsenic species in soil solution and plant uptake of arsenic under flooded conditions  

E-print Network

ARSENIC SPECIES IN SOIL SOLUTION AND PLANT UPTAKE OF ARSENIC UNDER FLOODED CONDITIONS A Thesis by BLAKE MORGAN ONKEN Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE May 1988 Major Subject: Soil Science ARSENIC SPECIES IN SOIL SOLUTION AND PLANT UPTAKE OF ARSENIC UNDER FLOODED CONDITIONS A Thesis by BLAKE MORGAN ONKEN Approved as to style and content by: Lloyd R. Hossner (Chair of Committee...

Onken, Blake Morgan

2012-06-07

329

Mycorrhizal status of plant species in the Chaco Serrano Woodland from central Argentina  

Microsoft Academic Search

We examined the mycorrhizal type of 128 plant species in two patches of native vegetation of the Chaco Serrano Woodland, central\\u000a Argentina, the largest dry forest area in South America. Of the 128 plant species investigated (belonging to 111 genera in\\u000a 53 families), 114 were colonized by arbuscular mycorrhizal fungi (AM), orchid mycorrhizal associations were present in the\\u000a five terrestrial

Sebastian Fracchia; Adriana Aranda; Analia Gopar; Vanesa Silvani; Laura Fernandez; Alicia Godeas

2009-01-01

330

Responses of wild plant species to polycyclic aromatic hydrocarbons in soil.  

PubMed

Responses of plants to polycyclic aromatic hydrocarbons (PAHs) contamination were determined with fifty-five Korean wild plants. Responsiveness of species was evaluated based on germination and shoot weight and shoot length of plants grown in soil spiked with four PAHs (pyrene, fluorene, phenanthrene and fluoranthene). Seeds of test plants were germinated with mixtures of PAHs of 0, 10, 30, 100, 300 mg kg(-1) spiked in soil. Seed germination of test plants changed when subjected to PAHs. As compared to control germination percentages ranged from 0 (completely inhibited) to 242.9% (highly promoted) of control at 300 mg kg(-1) of PAHs. In germination responses, Fabaceae plants were much less affected (105% of control) compared to species belonging to Caryophyllaceae (18.7% of control), which showed highly susceptible responses. Results demonstrated that seed germination was affected by species-specific responses to PAHs. In seedling growth experiments on Bromus tectorum and Veronica persica, species classified as highly susceptible in germination experiments, a low No Observed Effect Concentration (NOEC) of 10 mg kg(-1) was observed. On the other hand, NOEC was 100 mg kg(-1) in Bromus japonicus and Cerastium holosteoides var. hallaisanense, which were also classified as highly susceptible by the germination experiment. However, most species classified as susceptible showed high NOEC of greater than 10 mg kg(-1). EC(50) values of test species ranged from 2.87 x 10(2) (Humulus japonicus) to 8.05 x 10(81) mg kg(-1) (Bidens bipinnata) based on shoot length. The wide range of EC(50) for shoot weight suggests that shoot weight is more appropriate as an endpoint for PAHs toxicity than shoot length for determining the susceptibility of plant species to PAHs. It was confirmed that dose-response of plants to PAHs spiked soil can be used to estimate critical concentration of PAHs inhibiting early establishment of plants in contaminated fields. PMID:19724837

Hong, S H; Kang, B H; Kang, M H; Chung, J W; Jun, W J; Chung, J I; Kim, M C; Shim, S I

2009-09-01

331

A population genomic analysis of species boundaries: neutral processes, adaptive divergence and introgression between two hybridizing plant species.  

PubMed

Little is known about the nature of species boundaries between closely related plant species and about the extent of introgression as a consequence of hybridization upon secondary contact. To address these topics we analyzed genome-wide differentiation between two closely related Silene species, Silene latifolia and S. dioica, and assessed the strength of introgression in sympatry. More than 300 AFLP markers were genotyped in three allopatric and three sympatric populations of each species. Outlier analyses were performed separately for sympatric and allopatric populations. Both positive and negative outlier loci were found, indicating that divergent and balancing selection, respectively, have shaped patterns of divergence between the two species. Sympatric populations of the two species were found to be less differentiated genetically than allopatric populations, indicating that hybridization has led to gene introgression. We conclude that differentiation between S. latifolia and S. dioica has been shaped by a combination of introgression and selection. These results challenge the view that species differentiation is a genome-wide phenomenon, and instead support the idea that genomes can be porous and that species differentiation has a genic basis. PMID:18321255

Minder, A M; Widmer, A

2008-03-01

332

Subtropical reservoir shorelines have reduced plant species and functional richness compared with adjacent riparian wetlands  

NASA Astrophysics Data System (ADS)

Dam construction has large negative effects on biodiversity in river and riparian ecosystems worldwide. This study aimed to determine whether reservoir shorelines had lower plant species diversity and functional diversity than unregulated or lightly regulated riparian wetlands and to examine the responses of plant diversity and functional traits to reservoir shoreline environmental gradients. We surveyed 146, 44, and 67 plots on reservoir shorelines and in mainstem and tributary riparian wetlands, respectively, in a subtropical river-reservoir system. Species richness, functional richness, evenness, and divergence were calculated to reflect the species and functional diversity of plant communities. Environmental factors including elevation above water level, slope, landform type, substrate, disturbance, and cover were measured. The results showed that both species and functional richness were significantly lower on reservoir shorelines than in riparian wetlands. The relative species number of clonal plants and relative cover of annual plants were both negatively related to slope and elevation. Structural equation modeling and other statistical analyses indicated that most environmental factors had significant effects on species and functional richness on reservoir shorelines but had no significant effect on functional evenness and divergence. Our findings suggest that reservoir shoreline wetlands formed by damming rivers and inundating pre-existing riparian wetlands can be a biodiversity coldspot in regulated rivers at the plot level. Topographic factors are important in determining the plant diversity and vegetation establishment on reservoir shorelines in the Yangtze River basin.

Liu, Wenzhi; Liu, Guihua; Liu, Hui; Song, Yu; Zhang, Quanfa

2013-12-01

333

Evidence of qualitative differences between soil-occupancy effects of invasive vs. native grassland plant species  

USGS Publications Warehouse

Diversified grasslands that contain native plant species are being recognized as important elements of agricultural landscapes and for production of biofuel feedstocks as well as a variety of other ecosystem services. Unfortunately, establishment of such grasslands is often difficult, unpredictable, and highly vulnerable to interference and invasion by weeds. Evidence suggests that soil-microbial "legacies" of invasive perennial species can inhibit growth of native grassland species. However, previous assessments of legacy effects of soil occupancy by invasive species that invade grasslands have focused on single invasive species and on responses to invasive soil occupancy in only a few species. In this study, we tested the hypothesis that legacy effects of invasive species differ qualitatively from those of native grassland species. In a glasshouse, three invasive and three native grassland perennials and a native perennial mixture were grown separately through three cycles of growth and soil conditioning in soils with and without arbuscular mycorrhizal fungi (AMF), after which we assessed seedling growth in these soils. Native species differed categorically from invasives in their response to soil conditioning by native or invasive species, but these differences depended on the presence of AMF. When AMF were present, native species largely had facilitative effects on invasive species, relative to effects of invasives on other invasives. Invasive species did not facilitate native growth; neutral effects were predominant, but strong soil-mediated inhibitory effects on certain native species occurred. Our results support the hypothesis that successful plant invaders create biological legacies in soil that inhibit native growth, but suggest also this mechanism of invasion will have nuanced effects on community dynamics, as some natives may be unaffected by such legacies. Such native species may be valuable as nurse plants that provide cost-effective restoration of soil conditions needed for efficient establishment of diversified grasslands. ?? Weed Science Society of America.

Jordan, N.R.; Larson, D.L.; Huerd, S.C.

2011-01-01

334

Evidence of qualitative differences between soil-occupancy effects of invasive vs. native grassland plant species  

USGS Publications Warehouse

Diversified grasslands that contain native plant species are being recognized as important elements of agricultural landscapes and for production of biofuel feedstocks as well as a variety of other ecosystem services. Unfortunately, establishment of such grasslands is often difficult, unpredictable, and highly vulnerable to interference and invasion by weeds. Evidence suggests that soil-microbial "legacies" of invasive perennial species can inhibit growth of native grassland species. However, previous assessments of legacy effects of soil occupancy by invasive species that invade grasslands have focused on single invasive species and on responses to invasive soil occupancy in only a few species. In this study, we tested the hypothesis that legacy effects of invasive species differ qualitatively from those of native grassland species. In a glasshouse, three invasive and three native grassland perennials and a native perennial mixture were grown separately through three cycles of growth and soil conditioning in soils with and without arbuscular mycorrhizal fungi (AMF), after which we assessed seedling growth in these soils. Native species differed categorically from invasives in their response to soil conditioning by native or invasive species, but these differences depended on the presence of AMF. When AMF were present, native species largely had facilitative effects on invasive species, relative to effects of invasives on other invasives. Invasive species did not facilitate native growth; neutral effects were predominant, but strong soil-mediated inhibitory effects on certain native species occurred. Our results support the hypothesis that successful plant invaders create biological legacies in soil that inhibit native growth, but suggest also this mechanism of invasion will have nuanced effects on community dynamics, as some natives may be unaffected by such legacies. Such native species may be valuable as nurse plants that provide cost-effective restoration of soil conditions needed for efficient establishment of diversified grasslands.

Jordan, Nicholas R.; Larson, Diane L.; Huerd, Sheri C.

2011-01-01

335

Application of RAPD for molecular characterization of plant species of medicinal value from an arid environment.  

PubMed

The use of highly discriminatory methods for the identification and characterization of genotypes is essential for plant protection and appropriate use. We utilized the RAPD method for the genetic fingerprinting of 11 plant species of desert origin (seven with known medicinal value). Andrachne telephioides, Zilla spinosa, Caylusea hexagyna, Achillea fragrantissima, Lycium shawii, Moricandia sinaica, Rumex vesicarius, Bassia eriophora, Zygophyllum propinquum subsp migahidii, Withania somnifera, and Sonchus oleraceus were collected from various areas of Saudi Arabia. The five primers used were able to amplify the DNA from all the plant species. The amplified products of the RAPD profiles ranged from 307 to 1772 bp. A total of 164 bands were observed for 11 plant species, using five primers. The number of well-defined and major bands for a single plant species for a single primer ranged from 1 to 10. The highest pair-wise similarities (0.32) were observed between A. fragrantissima and L. shawii, when five primers were combined. The lowest similarities (0) were observed between A. telephioides and Z. spinosa; Z. spinosa and B. eriophora; B. eriophora and Z. propinquum. In conclusion, the RAPD method successfully discriminates among all the plant species, therefore providing an easy and rapid tool for identification, conservation and sustainable use of these plants. PMID:21064026

Arif, I A; Bakir, M A; Khan, H A; Al Farhan, A H; Al Homaidan, A A; Bahkali, A H; Al Sadoon, M; Shobrak, M

2010-01-01

336

Screening of radical scavenging activity and polyphenol content of Bulgarian plant species  

PubMed Central

Background: Discovery of new plant species with antioxidant properties is a priority of many research teams. Most of the species included in this study are unstudied for antioxidant properties, but they are taxonomically related to reference plants with well-documented antioxidant activity. Materials and Methods: Free radical scavenging activity of plant extracts was evaluated using a 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. An aluminum chloride colorimetric method was used for flavonoid determination. The amount of phenolic compounds in the extracts was estimated by using the Folin–Ciocalteu reagent. Results: As a result of screening, it was found that the significant antioxidant properties possess several unstudied until now plant species (Veronica bellidioides L., V. kellereri Deg. et Urm, V. vindobonensis (M. Fisher) M. Fisher, V. beccabunga L., V. rhodopaea L., V. austriaca (Velen.) Degen., Clinopodium vulgare L., Stachysrecta L., Clematis vitalba L., and Xeranthemum annum L.). The antioxidant potential of the new species is comparable to that of reference medicinal plants. Conclusions: The existing data presented here provide new information for antioxidant potential of plant species that have not been traditionally used as medicinal plants. PMID:22224049

Nikolova, Milena

2011-01-01

337

Phylloepiphytic interaction between bacteria and different plant species in a tropical agricultural system.  

PubMed

Plant surfaces are a favourable niche for bacterial establishment, and hypothetically, plant species differ in their capacity to harbour epiphytic bacterial communities. This study was conducted to evaluate and describe the structural relationship of a bacterial community at the phyllosphere level with different plant species in a tropical ecosystem. Leaf blades of 47 plant species distributed in 27 botanical families were collected on a typical small Brazilian farm and prepared for observation under light and scanning electron microscopy. Naturally occurring bacteria were the most abundant settlers of the phylloplane, followed by fungal spore or hyphae. All plant species studied were colonized by phylloepiphytic bacteria, which were observed as solitary cells, microcolonies, and biofilms. However, independent of the family, the plant species differed in the pattern of phyllosphere colonization, as reflected in bacteria frequency and presence or absence of anatomical features that would favour the association. The phylloepiphytic bacteria were preferentially established on the following sites: epidermal cell wall junctions, glandular and nonglandular trichomes, veins, stomata, and epidermal cell wall surface. Profuse bacteria and fungi colonization was observed, at a level that was at least comparable with temperate regions. Interestingly, fungi seemed to alter the bacteria colonization pattern, most probably by microenvironmental modifications. The trichome type and density as well as the presence of epicuticular wax on the leaf blade surface seemed to be the most determinant anatomical features for the pattern of phyllosphere colonization. The presence of trichomes has a favourable, and epicuticular wax an unfavourable influence on the plant-bacteria interaction. PMID:18997848

Baldotto, Lílian Estrela Borges; Olivares, Fábio Lopes

2008-11-01

338

Flowering phenology of invasive alien plant species compared with native species in three Mediterranean-type ecosystems  

PubMed Central

Background and Aims Flowering phenology is a potentially important component of success of alien species, since elevated fecundity may enhance invasiveness. The flowering patterns of invasive alien plant species and related natives were studied in three regions with Mediterranean-type climate: California, Spain and South Africa's Cape region. Methods A total of 227 invasive–native pairs were compared for seven character types across the regions, with each pair selected on the basis that they shared the same habitat type within a region, had a common growth form and pollination type, and belonged to the same family or genus. Key Results Invasive alien plant species have different patterns of flowering phenology from native species in the three regions. Whether the alien species flower earlier, later or at the same time as natives depends on the climatic regime in the native range of the aliens and the proportion of species in the invasive floras originating from different regions. Species invading at least two of the regions displayed the same flowering pattern, showing that flowering phenology is a conservative trait. Invasive species with native ranges in temperate climates flower earlier than natives, those from Mediterranean-type climates at the same time, and species from tropical climates flower later. In California, where the proportion of invaders from the Mediterranean Basin is high, the flowering pattern did not differ between invasive and native species, whereas in Spain the high proportion of tropical species results in a later flowering than natives, and in the Cape region early flowering than natives was the result of a high proportion of temperate invaders. Conclusions Observed patterns are due to the human-induced sympatry of species with different evolutionary histories whose flowering phenology evolved under different climatic regimes. The severity of the main abiotic filters imposed by the invaded regions (e.g. summer drought) has not been strong enough (yet) to shift the flowering pattern of invasive species to correspond with that of native relatives. It does, however, determine the length of the flowering season and the type of habitat invaded by summer-flowering aliens. Results suggest different implications for impacts at evolutionary time scales among the three regions. PMID:19033284

Godoy, Oscar; Richardson, David M.; Valladares, Fernando; Castro-Díez, Pilar

2009-01-01

339

Photosynthetic and respiratory activity in germfree higher plant species  

NASA Technical Reports Server (NTRS)

Equipment developed for the study of gas exchange in germfree plants is described. The equipment includes a gas exchange chamber to house the plant under study, a gas feed assembly to introduce and remove gas from the chamber, and a clinostat to rotate the apparatus. Fluorescent and incandescent lights are used to illuminate the chamber and a sealed plastic barrier is used to isolate the potting soil from the chamber atmosphere. The gas outflow from the chamber can be diverted to an infrared CO2 analyzer. The performance of the system was evaluated.

1976-01-01

340

Shifts in species richness, herbivore specialization, and plant resistance along elevation gradients  

PubMed Central

Environmental gradients have been postulated to generate patterns of diversity and diet specialization, in which more stable environments, such as tropical regions, should promote higher diversity and specialization. Using field sampling and phylogenetic analyses of butterfly fauna over an entire alpine region, we show that butterfly specialization (measured as the mean phylogenetic distance between utilized host plants) decreases at higher elevations, alongside a decreasing gradient of plant diversity. Consistent with current hypotheses on the relationship between biodiversity and the strength of species interactions, we experimentally show that a higher level of generalization at high elevations is associated with lower levels of plant resistance: across 16 pairs of plant species, low-elevation plants were more resistant vis-à-vis their congeneric alpine relatives. Thus, the links between diversity, herbivore diet specialization, and plant resistance along an elevation gradient suggest a causal relationship analogous to that hypothesized along latitudinal gradients. PMID:22957184

Pellissier, Loïc; Fiedler, Konrad; Ndribe, Charlotte; Dubuis, Anne; Pradervand, Jean-Nicolas; Guisan, Antoine; Rasmann, Sergio

2012-01-01

341

Using habitat suitability models to target invasive plant species surveys.  

PubMed

Managers need new tools for detecting the movement and spread of nonnative, invasive species. Habitat suitability models are a popular tool for mapping the potential distribution of current invaders, but the ability of these models to prioritize monitoring efforts has not been tested in the field. We tested the utility of an iterative sampling design (i.e., models based on field observations used to guide subsequent field data collection to improve the model), hypothesizing that model performance would increase when new data were gathered from targeted sampling using criteria based on the initial model results. We also tested the ability of habitat suitability models to predict the spread of invasive species, hypothesizing that models would accurately predict occurrences in the field, and that the use of targeted sampling would detect more species with less sampling effort than a nontargeted approach. We tested these hypotheses on two species at the state scale (Centaurea stoebe and Pastinaca sativa) in Wisconsin (USA), and one genus at the regional scale (Tamarix) in the western United States. These initial data were merged with environmental data at 30-m2 resolution for Wisconsin and 1-km2 resolution for the western United States to produce our first iteration models. We stratified these initial models to target field sampling and compared our models and success at detecting our species of interest to other surveys being conducted during the same field season (i.e., nontargeted sampling). Although more data did not always improve our models based on correct classification rate (CCR), sensitivity, specificity, kappa, or area under the curve (AUC), our models generated from targeted sampling data always performed better than models generated from nontargeted data. For Wisconsin species, the model described actual locations in the field fairly well (kappa = 0.51, 0.19, P < 0.01), and targeted sampling did detect more species than nontargeted sampling with less sampling effort (chi2 = 47.42, P < 0.01). From these findings, we conclude that habitat suitability models can be highly useful tools for guiding invasive species monitoring, and we support the use of an iterative sampling design for guiding such efforts. PMID:23495636

Crall, Alycia W; Jarnevich, Catherine S; Panke, Brendon; Young, Nick; Renz, Mark; Morisette, Jeffrey

2013-01-01

342

Surface flavonoid aglycones in newly studied plant species.  

PubMed

Several newly studied species of the Scrophulariaceae, Lamiaceae, and Ranunculaceae spread in Bulgaria have been analyzed for their surface flavonoid profiles. Except Pulsatilla montana (Hope) Rchb. (Ranunculaceae) all taxa now studied accumulated mainly apigenin, luteolin, and it's derivatives. This is the first report for the presence on external flavonoid aglycones in genus Pulsatilla. Quercetin-3'-methyl ether is a new citation for P. montana. The presence on surface flavonoid aglycones in species Veronica bellidioides L., V. persica Poir., Odontites verna (Bell.) Dum., Laminiastrum galeobdolon Heist ex Fabr., Glechoma herbaceae L., Ajuga genevensis L., and A. reptans L. are reported for the first time too. PMID:16286319

Nikolova, M; Asenov, A

2006-01-01

343

Zinc Accumulation in Plant Species Indigenous to a Portuguese Polluted Site: Relation with Soil Contamination  

Microsoft Academic Search

The levels of zinc accumulated by roots, stems, and leaves of two plant species, Rubus ulmifoliusand Phragmites australis, indigenous to the banks of a stream in a Portuguese contaminated site were inves- tigated in field conditions. R. ulmifolius, a plant for which studies on phytoremediation potential are scarce, dominated on the right side of the stream, while P. australis proliferated

Ana P. G. C. Marques; Antonio O. S. S. Rangel; Paula M. L. Castro

2007-01-01

344

Genome Wide Analyses Reveal Little Evidence for Adaptive Evolution in Many Plant Species  

E-print Network

Genome Wide Analyses Reveal Little Evidence for Adaptive Evolution in Many Plant Species Toni I, and bacteria have undergone extensive adaptive evolution,hominids show littleor no evidence. To study the matter further, we have investigatedwhether plants show evidence of adaptive evolution using

Eyre-Walker, Adam

345

EFFECT OF PLANT SPECIES DIVERSITY ON INTAKE AND PRODUCTIVITY OF LIVESTOCK  

Technology Transfer Automated Retrieval System (TEKTRAN)

Grassland ecology is concerned primarily with those factors influencing the composition of plant species under grazing conditions, particularly how they relate to sustaining productive plant communities. With the recent trend of livestock operations opting for less capital-intensive production syst...

346

Plant species effects and carbon and nitrogen cycling in a sagebrush–crested wheatgrass soil  

Microsoft Academic Search

Shifts in plant community structure in shrub and grass-dominated ecosystems are occurring over large land areas in the western US. It is not clear what effect this vegetative change will have on rates of carbon and nitrogen cycling, and thus long-term ecosystem productivity. To study the effect of different plant species on the decomposability of soil organic substrates and rates

Jian Chen; John M. Stark

2000-01-01

347

Accumulation of Cd, Pb and Zn by 19 wetland plant species in constructed wetland.  

PubMed

Uptake and distribution of Cd, Pb and Zn by 19 wetland plant species were investigated with experiments in small-scale plot constructed wetlands, into which artificial wastewater dosed with Cd, Pb and Zn at concentrations of 0.5, 2.0 and 5.0mgl(-1) was irrigated. The results showed that the removal efficiency of Cd, Pb and Zn from the wastewater were more than 90%. Generally, there were tens differences among the 19 plant species in the concentrations and quantity accumulations of the heavy metals in aboveground part, underground part and whole plants. The distribution ratios into aboveground parts for the metals absorbed by plants varied also largely from about 30% to about 90%. All the plants accumulated, in one harvest, 19.85% of Cd, 22.55% of Pb and 23.75% of Zn that were added into the wastewater. Four plant species, e.g. Alternanthera philoxeroides, Zizania latifolia, Echinochloa crus-galli and Polygonum hydropiper, accumulated high amounts of Cd, Pb and Zn. Monochoria vaginalis was capable for accumulating Cd and Pb, Isachne globosa for Cd and Zn, and Digitaria sanguinalis and Fimbristylis miliacea for Zn. The results indicated that the plants, in constructed wetland for the treatment of wastewater polluted by heavy metals, can play important roles for removal of heavy metals through phytoextraction. Selection of plant species for use in constructed wetland will influence considerably removal efficiency and the function duration of the wetland. PMID:17353090

Liu, Jianguo; Dong, Yuan; Xu, Hai; Wang, Deke; Xu, Jiakuan

2007-08-25

348

VARIATION IN GRAZING TOLERANCE AMONG THREE TALLGRASS PRAIRIE PLANT SPECIES1  

Microsoft Academic Search

Three tallgrass prairie plant species, two common perennial forbs (Artemisia ludoviciana and Aster ericoides (Asteraceae)) and a dominant C4 perennial grass (Sorghastrum nutans) were studied under field and greenhouse conditions to evaluate interspecific variation in grazing tolerance (compensatory growth capacity). Adaptation to ungulate grazing was also assessed by comparing defoliation responses of plants from populations with a 25-yr history of

SAID A. DAMHOUREYEH; DAVID C. HARTNETT

349

Computer-Aided Plant Species Identification (CAPSI) Based on Leaf Shape Matching Technique  

Microsoft Academic Search

In this paper, an efficient computer-aided plant species identification (CAPSI) approach is proposed, which is based on plant leaf images using a shape matching technique. Firstly, a Douglas Peucker approximation algorithm is adopted to the original leaf shapes and a new shape representation is used to form the sequence of invariant attributes. Then a modified dynamic programming (MDP) algorithm for

Ji-Xiang Du; De-Shuang Huang; Xiao-Feng Wang; Xiao Gu

2006-01-01

350

The Potential of Irankoh Indigenous Plant Species for the Phytoremediation of Cadmium and Lead Contaminated Land  

Microsoft Academic Search

A field survey of higher terrestrial plants growing on a metalliferous site of the Iranian arid mountain in Isfahan was conducted to identify species accumulating exceptionally large concentrations of Cd and Pb in shoots and roots. Plant samples were collected from Irankoh areas near the Bama Pb and Zn mine. Sampling was carried out in Spring 2004 and analyzed for

Ali Akbar Safari Sinegani; Farzad Shanbeh Dastjerdi

2008-01-01

351

The potential of Thai indigenous plant species for the phytoremediation of arsenic contaminated land  

Microsoft Academic Search

To assess the potential of the native plant species for phytoremediation, plant and soil samples were collected from two areas in Thailand that have histories of arsenic pollution from mine tailings. The areas were the Ron Phibun District (Nakorn Si Thammarat province) and Bannang Sata District (Yala province), and samples were taken in 1998 and 1999 and analysed for total

P Visoottiviseth; K Francesconi; W Sridokchan

2002-01-01

352

Observation and Confirmation of Foliar Ozone Symptoms of Native Plant Species of Switzerland and Southern Spain  

Microsoft Academic Search

Tropospheric ozone is considered as the major pollutant of concern to the health and productivity of forests in the eastern United States and has more recently become of increasing concern within the forests of southern Europe. Recent observations have clearly demonstrated foliar injury symptoms to be occurring on many tree and native plant species within remote forested areas. Several plant

J. M. Skelly; J. L. Innes; J. E. Savage; K. R. Snyder; D. Vanderheyden; J. Zhang; M. J. Sanz

1999-01-01

353

Occurrence of methylated arsenic species in parts of plants growing in polluted soils  

Microsoft Academic Search

Arsenic compounds were determined in extracts of branches, leaves and roots from plants growing in a mining contaminated area. The selected species were Dryopteris filix-max, Quercus pubescens, Dipsacus fullonum, Alnus glutinosa, Buxus sempervirens and Brachythecium cf. reflexum. Total arsenic content in the subsamples was analysed by ICPMS after acidic digestion. In general, concentrations in the plant parts followed the gradient

Maria Jose Ruiz-Chancho; Jose Fermín López-Sánchez; Roser Rubio

2011-01-01

354

Developing a plant-based vole repellent: screening of ten candidate species  

Microsoft Academic Search

Voles are a major pest in orchards and coniferous plantations. Currently, vole control relies primarily on the use of rodenticides and herbicides. Our goal was to identify a plant species that could be used to develop a non-lethal and effective repellent. No-choice feeding trials with prairie voles (Microtus ochrogaster, Wagner) were used to assess the relative ability of 10 plant

Paul D. Curtis; Elizabeth D. Rowland; George L. Good

2002-01-01

355

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 ...

356

Effects of acid precipitation on reproduction in alpine plant species. [Erythronium grandiflorum; Aquilegia caerulea  

Microsoft Academic Search

A series of experiments were designed to determine the impact of acid rain on plant reproductive processes, a critical component of a species life history. Research was carried out in herbaceous alpine communities at the USDA (United States Department of Agriculture) Forest Service Glacier Lakes Ecosystem Experiments Site in the Snowy Mts. of Wyoming. A range of species were surveyed

M. A. McKenna; M. Hille-Salgueiro; R. C. Musselman

1990-01-01

357

Slow response of plant species richness to habitat loss and fragmentation  

Microsoft Academic Search

We examined the response of vascular plant species richness to long-term habitat loss and fragmentation of Estonian calcareous grasslands (alvars). The current number of habitat specialist species in 35 alvars was not explained by their current areas and connectivities but it was explained by their areas and connectivities 70 years ago (R2 ¼ 0.27). We estimated the magnitude of extinction

Aveliina Helm; Ilkka Hanski; Meelis Partel

2006-01-01

358

Variation among plant species in pollutant removal from stormwater in biofiltration systems  

Microsoft Academic Search

Biofiltration systems use vegetation to improve efficiency of pollutant removal from stormwater, but little is known of how plants vary in their capacity to improve biofilter effectiveness. We used a pot trial of 20 Australian species to investigate how species vary in the removal of pollutants from semisynthetic stormwater passing through a soil filter medium. Effluent levels of total suspended

Jennifer Read; Tricia Wevill; Tim Fletcher; Ana Deletic

2008-01-01

359

USFS Region 2 Plant Species Assessments: Errata and New Information September 7, 2006. One page.  

E-print Network

1 USFS Region 2 Plant Species Assessments: Errata and New Information September 7, 2006. One page. Botrychium lineare, 5/25/2004 Added new documents: · Botrychium Lineare Population Status in Colorado: Clarifications and Suggested Species Assessment Update and Erratum. Written by Steve J. Popovich, April 12, 2004

360

Before, During and After: The Need for Long-term Monitoring in Invasive Plant Species Management  

Microsoft Academic Search

The invasion of non-indigenous plants is considered one of the primary threats to rare and endangered species as well as to the integrity and function of North American ecosystems. However, many of the suspected negative ecosystem impacts are based on anecdotal evidence. For example, there is almost unanimous agreement among natural resource managers of the detrimental ecological impacts of species

Bernd Blossey

1999-01-01

361

Before, during and after: the need for long-term monitoring in invasive plant species management  

Microsoft Academic Search

The invasion of non-indigenous plants is considered one of the primary threats to rare and endangered species as well as to the integrity and function of North American ecosystems. However, many of the suspected negative ecosystem impacts are based on anecdotal evidence. For example, there is almost unanimous agreement among natural resource managers of the detrimental ecological impacts of species

Bernd Blossey

1999-01-01

362

Characteristics of heavy metal uptake by plant species with potential for phytoremediation and phytomining  

Microsoft Academic Search

Genetically transformed hairy root cultures were established for a range of plant species and applied in studies of growth and accumulation of heavy metals. Experiments were conducted using liquid nutrient medium containing elevated concentrations of Ni, Cd or Cu. Hairy roots of three hyperaccumulator species were tested for Ni uptake, of these, Alyssum bertolonii accumulated the highest Ni contents in

T. V. Nedelkoska; P. M. Doran

2000-01-01

363

Distribution of plant species at a biome transition zone in New Mexico  

Microsoft Academic Search

Question: Is there a difference in plant species and life form composition between two major patch types at a biome transi- tion zone? Are subordinate species associated with different patch types at the shortgrass steppe - Chihuahuan desert grass- land transition zone? Is this association related to differences in soil texture between patch types and the geographic range of associated

György Kröel-Dulay; Péter Ódor; Debra P. C. Peters; Tamara Hochstrasser

2004-01-01

364

Assessing the risk of Glyphosate to native plants and weedy Brassicaceae species of North Dakota  

EPA Science Inventory

This study was conducted to determine the ecological risk to native plants and weedy Brassicaceae species which may be growing in areas affected by off target movement of glyphosate applied to glyphosate-resistant canola (Brassica napus). Ten native grass and forb species were ...

365

Effects of sediment type and water level on biomass production of wetland plant species  

Microsoft Academic Search

We investigated how water level and different sediment types affect the growth of wetland plant species. Twelve different species were grown in drained and waterlogged sediments, which represented types normally encountered in wetlands: a mineral sediment from exposed sites, a sediment from a sheltered site rich in labile organic matter and an organic sediment with decomposing litter of Phragmites australis

John P. M. Lenssen; Frank B. J. Menting; Wim H. van der Putten; Cornelis W. P. M. Blom

1999-01-01

366

The effect of flooding on the recruitment of reed marsh and tall forb plant species  

Microsoft Academic Search

Recruitment of plant species in wetlands dominated by Phragmites australis often results in a zonation of two vegetation types. A development of reed marshes takes place in the shallow flooded parts where the dominant P. australis becomes accompanied by interstitial marsh species. The vegetation on higher elevations becomes dominated by tall forbs. We investigated whether this zonation is related to

J. P. M. Lenssen; G. E. ten Dolle; C. W. P. M. Blom

1998-01-01

367

Students' Perception of Plant and Animal Species: A Case Study from Rural Argentina  

ERIC Educational Resources Information Center

Exotic species seriously affect local biodiversity in Argentina. This article investigates how students in San Juan province perceive native and exotic species. With the help of a written questionnaire, 865 students (9-17 years old) were asked to name the plant and animal they liked most, disliked most, and perceived as most useful, and to name…

Nates, Juliana; Campos, Claudia; Lindemann-Matthies, Petra

2010-01-01

368

Prediction of plant species distributions across six Peter B. Pearman,1  

E-print Network

LETTER Prediction of plant species distributions across six millennia Peter B. Pearman,1 The usefulness of species distribution models (SDMs) in predicting impacts of climate change on biodiversity alternative way to evaluate the predictive ability of SDMs across time is to compare their predictions

Zimmermann, Niklaus E.

369

Biotic Interactions Overrule Plant Responses to Climate, Depending on the Species' Biogeography  

PubMed Central

This study presents an experimental approach to assess the relative importance of climatic and biotic factors as determinants of species' geographical distributions. We asked to what extent responses of grassland plant species to biotic interactions vary with climate, and to what degree this variation depends on the species' biogeography. Using a gradient from oceanic to continental climate represented by nine common garden transplant sites in Germany, we experimentally tested whether congeneric grassland species of different geographic distribution (oceanic vs. continental plant range type) responded differently to combinations of climate, competition and mollusc herbivory. We found the relative importance of biotic interactions and climate to vary between the different components of plant performance. While survival and plant height increased with precipitation, temperature had no effect on plant performance. Additionally, species with continental plant range type increased their growth in more benign climatic conditions, while those with oceanic range type were largely unable to take a similar advantage of better climatic conditions. Competition generally caused strong reductions of aboveground biomass and growth. In contrast, herbivory had minor effects on survival and growth. Against expectation, these negative effects of competition and herbivory were not mitigated under more stressful continental climate conditions. In conclusion we suggest variation in relative importance of climate and biotic interactions on broader scales, mediated via species-specific sensitivities and factor-specific response patterns. Our results have important implications for species distribution models, as they emphasize the large-scale impact of biotic interactions on plant distribution patterns and the necessity to take plant range types into account. PMID:25356912

Welk, Astrid; Welk, Erik; Bruelheide, Helge

2014-01-01

370

Phytotoxicity of biosolids and screening of selected plant species with potential for mercury phytoextraction  

Microsoft Academic Search

Mercury contaminated stockpiles of biosolids (3.5–8.4mgkg?1 Hg) from Melbourne Water's Western Treatment Plant (MW-WTP) were investigated to evaluate the possibility for their phytoremediation. Nine plant species (Atriplex codonocarpa, Atriplex semibaccata, Austrodanthonia caespitosa, Brassica juncea, Brassica napus, Gypsophila paniculata, Sorghum bicolor, Themeda triandra and Trifolium subterraneum) were screened for phytoextraction potential in Hg-contaminated biosolids from MW-WTP. In addition, the same plant

Cristina Lomonte; Augustine I. Doronila; David Gregory; Alan J. M. Baker; Spas D. Kolev

2010-01-01

371

Effect of medium acidity on growth and rooting of different plant species growing in vitro  

Microsoft Academic Search

Micropropagated Choisya, Daphne, Delphinium, Hemerocallis, Hosta, Iris and Photinia were found to adjust the pH of Murashige and Skoog's plant tissue culture medium (initial pH 5.6 or 3.5) to different values depending on the species. When plant growth and rooting rates were determined after plants had been grown on media initially adjusted or buffered to values between 2.6 and 5.7

C. Leifert; Samantha Pryce; P. J. Lumsden; W. M. Waites

1992-01-01

372

Roles of the reactive oxygen species-generating peroxidase reactions in plant defense and growth induction  

Microsoft Academic Search

Extracellularly secreted plant peroxidases (POXs) are considered to catalyze the generation of reactive oxygen species (ROS) coupled to oxidation of plant hormone indole-3-acetic acid (IAA) and defense-related compounds salicylic acid (SA), aromatic monoamines (AMAs) and chitooligosaccharides (COSs). This review article consists of two parts, which describe H2O2-dependent and H2O2-independent mechanisms for ROS generation, respectively. Recent studies have shown that plant

T. Kawano

2003-01-01

373

Metabolomics: creating new potentials for unraveling the mechanisms in response to salt and drought stress and for the biotechnological improvement of xero-halophytes.  

PubMed

Breeders have long been interested in understanding the biological function and mechanism of xero-halophytes and their ability for growth in drought-stricken and salinized environments. However, the mechanisms in response to stress have been difficult to unravel because their defenses require regulatory changes to the activation of multiple genes and pathways. Metabolomics is becoming a key tool in comprehensively understanding the cellular response to abiotic stress and represents an important addition to the tools currently employed in genomics-assisted selection for plant improvement. In this review, we highlight the applications of plant metabolomics in characterizing metabolic responses to salt and drought stress, and identifying metabolic quantitative trait loci (QTLs). We also discuss the potential of metabolomics as a tool to unravel stress response mechanisms, and as a viable option for the biotechnological improvement of xero-halophytes when no other genetic information such as linkage maps and QTLs are available, by combining with germplasm-regression-combined marker-trait association identification. PMID:21058928

Ruan, Cheng-Jiang; Teixeira da Silva, Jaime A

2011-06-01

374

Plant species identification using Elliptic Fourier leaf shape analysis  

Microsoft Academic Search

Elliptic Fourier (EF) and discriminant analyses were used to identify young soybean (Glycine max (L.) merrill), sunflower (Helianthus pumilus), redroot pigweed (Amaranthus retroflexus) and velvetleaf (Abutilon theophrasti Medicus) plants, based on leaf shape. Chain encoded, Elliptic Fourier harmonic functions were generated based on leaf boundary. A complexity index of the leaf shape was computed using the variation between consecutive EF

João Camargo Neto; George E. Meyer; David D. Jones; Ashok K. Samal

2006-01-01

375

PENICILLIUM SPECIES ENDOPHYTIC IN COFFEE PLANTS AND OCHRATOXIN A PRODUCTION.  

Technology Transfer Automated Retrieval System (TEKTRAN)

Tissues from Coffea arabica, C. liberica, C. dewevrei and C. congensis collected in Hawaii, Colombia and at a local plant nursery in Maryland were sampled for the presence of fungal endophytes. Surface sterilized tissues including roots, leaves, stems, and various part of the berry were plated on y...

376

Phytoaccumulation of Lead by Selected Wetland Plant Species  

Microsoft Academic Search

Several anthropogenic activities lead to the production of substantial amounts of aqueous effluents that contain various toxic trace and heavy metals and which pose potential threats to the wild habitat of wetlands. As a part of the remediation of heavy metals, it is necessary to identify some aquatic hyperaccumulator plants. To this end, a greenhouse study was conducted to investigate

Tapan Adhikari; Ajay Kumar; M. V. Singh; A. Subba Rao

2010-01-01

377

Specific plant induced biofilm formation in Methylobacterium species  

PubMed Central

Two endophytic strains of Methylobacterium spp. were used to evaluate biofilm formation on sugarcane roots and on inert wooden sticks. Results show that biofilm formation is variable and that plant surface and possibly root exudates have a role in Methylobacterium spp. host recognition, biofilm formation and successful colonization as endophytes. PMID:24031703

Rossetto, Priscilla B.; Dourado, Manuella N.; Quecine, Maria C.; Andreote, Fernando D.; Araújo, Welington L.; Azevedo, João L.; Pizzirani-Kleiner, Aline A.

2011-01-01

378

Plant community and target species affect responses to restoration strategies  

Technology Transfer Automated Retrieval System (TEKTRAN)

Increases in Kentucky bluegrass and smooth brome on northern Great Plains rangelands have the potential to negatively impact ecosystem function, lower plant diversity and alter seasonal forage distribution, but control strategies are lacking in the region. A project was initiated on a heavily invad...

379

The influence of plant species on the plant/air partitioning coefficients of PCBs and chlorinated benzenes  

SciTech Connect

The plant/air partitioning coefficients (K{sub PA}) of pentachlorobenzene, hexachlorobenzene and 16 PCB congeners were determined in five different grass and herb species common to Central Europe (Lolium multiflorum, Trifolium repens, Plantago lanceolata, Crepis biennis, Achillea millefolium). The measurements were conducted between 5 C and 35 C using a solid phase fugacity meter. Octanol/air partition coefficients (K{sub OA}) were also measured over a similar temperature range. In all cases an excellent linear relationship between log K{sub PA} and log K{sub OA} was observed (r{sup 2} between 0.80 and 0.99). However, while the slope of this relationship was 1 for Lolium multiflorum (ryegrass), in agreement with previous work, the slopes of the log K{sub PA} vs. log K{sub OA} plot were less than 1 for the other 4 species, lying as low as 0.49 for Achillea millefolium (yarrow). Large differences in the enthalpy of phase change (plant/air) were also observed between the different species, but these differences were not related to the differences in the partition coefficients. These observations demonstrate that the contaminant storage properties of plants are variable, and that the lipophilic compartment in some plants is considerably more polar than octanol. This places constraints on the applicability of current models of plant uptake, almost all of which assume that the lipophilic compartment behaves like octanol, and reinforces the need for more research into the contaminant storage properties of plants.

Koemp, P.; McLachlan, M.S. [Univ. of Bayreuth (Germany)

1995-12-31

380

Surface flavonoid aglycones in newly studied plant species  

Microsoft Academic Search

Several newly studied species of the Scrophulariaceae, Lamiaceae, and Ranunculaceae spread in Bulgaria have been analyzed for their surface flavonoid profiles. Except Pulsatilla montana (Hope) Rchb. (Ranunculaceae) all taxa now studied accumulated mainly apigenin, luteolin, and it's derivatives. This is the first report for the presence on external flavonoid aglycones in genus Pulsatilla. Quercetin-3?-methyl ether is a new citation for

M. Nikolova; A. Asenov

2006-01-01

381

Growth responses to ozone in plant species from wetlands.  

PubMed

Ten wet grassland species were fumigated with four concentrations of ozone (charcoal-filtered air, non-filtered air and non-filtered air plus 25 or 50 nl l(-1) ozone) in open-top chambers during one growing season to investigate the long-term effect of this air pollutant on various growth variables. Only Eupatorium cannabinum showed ozone-related foliar injury, while five species reacted with significantly ozone-enhanced senescence. Premature senescence was paralleled by a significant ozone-induced reduction of green leaf area in Achillea ptarmica, E. cannabinum and Plantago lanceolata. At the intermediate harvest performed after 28 days shoot weights were significantly decreased by ozone in A. ptarmica and increased in Molinia caerulea. At the final harvest performed at the end of the growing season two other species, Cirsium dissectum and E. cannabinum had a significantly reduced shoot weight due to ozone. Root biomass was determined only at the intermediate harvest. The root:shoot ratio (RSR) was significantly reduced in C. dissectum, while it increased in M. caerulea. Seven of the species developed flowers during the experiment. While no significant ozone effects on flowering date and flower numbers were detected, flower weights were significantly reduced in E. cannabinum and P. lanceolata. PMID:10927127

Franzaring; Tonneijck; Kooijman; Dueck

2000-08-01

382

Effect of ploughing on plant species abundance and diversity in the northwestern coastal desert of Egypt  

Microsoft Academic Search

This study focuses on the effect of ploughing on plant abundance,vegetation cover, species richness, and taxonomic diversity during the growingseasons (winter and spring) of 1992 and 2000 in the habitat of inland plateau(natural habitat), 21 km south of Mersa-Matrouh (Egypt).Ninety-five species belonging to 27 families were recorded. High percentages oflife-forms and a large number of species were recorded in ploughed

Sania K. Hammouda; Selim Z. Heneidy

2003-01-01

383

Interactions between non-native plant species and the floristic composition of common habitats  

Microsoft Academic Search

Summary 1 We investigated the role of non-native species (neophytes) in common British plant communities using botanical data from two stratified random surveys carried out in 1990 and 1998. 2 We found that from 16 851 plots surveyed in 1998 there were 123 non-native species found mostly in arable, tall grass\\/herb and fertile grassland habitats. Invasive non-native species, e.g. Fallopia

L. C. MASKELL; L. G. FIRBANK; Ken Thompson; J. M. BULLOCK; S. M. SMART

2006-01-01

384

Alien plant species favoured over congeneric natives under experimental climate warming in temperate Belgian climate  

Microsoft Academic Search

Climate warming and biological invasions by alien species are two key factors threatening the world’s biodiversity. To date,\\u000a their impact has largely been studied independently, and knowledge on whether climate warming will promote invasions relies\\u000a strongly on bioclimatic models. We therefore set up a study to experimentally compare responses to warming in native and alien\\u000a plant species. Ten congeneric species pairs were

M. Verlinden; I. Nijs

2010-01-01

385

Temporal differentiation in maximum biomass and nutrient accumulation rates in two coexisting annual plant species  

Microsoft Academic Search

The temporal patterns of growth and nutrient accumulation into above-ground biomass of two annual coexisting plant species were studied in a semi-arid unfertile grassland. The hypothesis that temporal differences in growth and in nutrient accumulation into above-ground biomass facilitate species coexistence was also tested. Of the annual species identified, only the growth data of Vulpia myuros (L.) C.C. Gmel. and

A. P. Mamolos

2006-01-01

386

Using habitat suitability models to target invasive plant species surveys  

USGS Publications Warehouse

Managers need new tools for detecting the movement and spread of nonnative, invasive species. Habitat suitability models are a popular tool for mapping the potential distribution of current invaders, but the ability of these models to prioritize monitoring efforts has not been tested in the field. We tested the utility of an iterative sampling design (i.e., models based on field observations used to guide subsequent field data collection to improve the model), hypothesizing that model performance would increase when new data were gathered from targeted sampling using criteria based on the initial model results. We also tested the ability of habitat suitability models to predict the spread of invasive species, hypothesizing that models would accurately predict occurrences in the field, and that the use of targeted sampling would detect more species with less sampling effort than a nontargeted approach. We tested these hypotheses on two species at the state scale (Centaurea stoebe and Pastinaca sativa) in Wisconsin (USA), and one genus at the regional scale (Tamarix) in the western United States. These initial data were merged with environmental data at 30-m2 resolution for Wisconsin and 1-km2 resolution for the western United States to produce our first iteration models. We stratified these initial models to target field sampling and compared our models and success at detecting our species of interest to other surveys being conducted during the same field season (i.e., nontargeted sampling). Although more data did not always improve our models based on correct classification rate (CCR), sensitivity, specificity, kappa, or area under the curve (AUC), our models generated from targeted sampling data always performed better than models generated from nontargeted data. For Wisconsin species, the model described actual locations in the field fairly well (kappa = 0.51, 0.19, P 2) = 47.42, P < 0.01). From these findings, we conclude that habitat suitability models can be highly useful tools for guiding invasive species monitoring, and we support the use of an iterative sampling design for guiding such efforts.

Crall, Alycia W.; Jarnevich, Catherine S.; Panke, Brendon; Young, Nick; Renz, Mark; Morisette, Jeffrey

2013-01-01

387

Predicting rarity and decline in animals, plants, and mushrooms based on species attributes and indicator groups  

PubMed Central

In decisions on nature conservation measures, we depend largely on knowledge of the relationship between threats and environmental factors for a very limited number of species groups, with relevant environmental factors often being deduced from the relationship between threat and species traits. But can relationships between traits and levels of threats be identified across species from completely different taxonomic groups; and how accurately do well-known taxonomic groups indicate levels of threat in other species groups? To answer these questions, we first made a list of 152 species attributes of morphological and demographic traits and habitat requirements. Based on these attributes we then grew random forests of decision trees for 1183 species in the 18 different taxonomic groups for which we had Red Lists available in the Netherlands, using these to classify animals, plants, and mushrooms according to their rarity and decline. Finally, we grew random forests for four species groups often used as indicator groups to study how well the relationship between attribute and decline within these groups reflected that relationship within the larger taxonomic group to which these groups belong. Correct classification of rarity based on all attributes was as high as 88% in animals, 85% in plants, and 94% in mushrooms and correct classification of decline was 78% in animals, 69% in plants, and 70% in mushrooms. Vertebrates indicated decline in all animals well, as did birds for all vertebrates and vascular plants for all plants. However, butterflies poorly indicated decline in all insects. Random forests are a useful tool to relate rarity and decline to species attributes thereby making it possible to generalize rarity and decline to a wider set of species groups. Random forests can be used to estimate the level of threat to complete faunas and floras of countries or regions. In regions like the Netherlands, conservation policy based on attributes known to be relevant for the decline to birds, vertebrates or plants will probably also impact all aboveground terrestrial and freshwater macrofauna or macrophytes. PMID:24223278

Musters, C J M; Kalkman, Vincent; van Strien, Arco

2013-01-01

388

Assessment of potential indigenous plant species for the phytoremediation of arsenic-contaminated areas of Bangladesh.  

PubMed

Soil and water contaminated with arsenic (As) pose a major environmental and human health problem in Bangladesh. Phytoremediation, a plant-based technology, may provide an economically viable solution for remediating the As-polluted sites. The use of indigenous plants with a high tolerance and accumulation capacity for As may be a very convenient approach for phytoremediation. To assess the potential of native plant species for phytoremediation, plant and soil samples were collected from four As-contaminated (groundwater) districts in Bangladesh. The main criteria used for selecting plants for phytoremediation were high bioconcentration factors (BCFs) and translocation factors (TFs) of As. From the results of a screening of 49 plant species belonging to 29 families, only one species of fern (Dryopteris filix-mas), three herbs (Blumea lacera, Mikania cordata, and Ageratum conyzoides), and two shrubs (Clerodendrum trichotomum and Ricinus communis) were found to be suitable for phytoremediation. Arsenic bioconcentration and translocation factors > 1 suggest that these plants are As-tolerant accumulators with potential use in phytoextraction. Three floating plants (Eichhornia crassipes, Spirodela polyrhiza, and Azolla pinnata) and a common wetland weed (Monochoria vaginalis) also showed high BCF and TF values; therefore, these plants may be promising candidates for cleaningup As-contaminated surface water and wetland areas. The BCF of Oryza sativa, obtained from As-contaminated districts was > 1, which highlights possible food-chain transfer issues for As-contaminated areas in Bangladesh. PMID:18709925

Mahmud, Rezwanul; Inoue, Naoto; Kasajima, Shin-Ya; Shaheen, Riffat

2008-01-01

389

Profiling mRNAs of two Cuscuta species reveals possible candidate transcripts shared by parasitic plants.  

PubMed

Dodders are among the most important parasitic plants that cause serious yield losses in crop plants. In this report, we sought to unveil the genetic basis of dodder parasitism by profiling the trancriptomes of Cuscuta pentagona and C. suaveolens, two of the most common dodder species using a next-generation RNA sequencing platform. De novo assembly of the sequence reads resulted in more than 46,000 isotigs and contigs (collectively referred to as expressed sequence tags or ESTs) for each species, with more than half of them predicted to encode proteins that share significant sequence similarities with known proteins of non-parasitic plants. Comparing our datasets with transcriptomes of 12 other fully sequenced plant species confirmed a close evolutionary relationship between dodder and tomato. Using a rigorous set of filtering parameters, we were able to identify seven pairs of ESTs that appear to be shared exclusively by parasitic plants, thus providing targets for tailored management approaches. In addition, we also discovered ESTs with sequences similarities to known plant viruses, including cryptic viruses, in the dodder sequence assemblies. Together this study represents the first comprehensive transcriptome profiling of parasitic plants in the Cuscuta genus, and is expected to contribute to our understanding of the molecular mechanisms of parasitic plant-host plant interactions. PMID:24312295

Jiang, Linjian; Wijeratne, Asela J; Wijeratne, Saranga; Fraga, Martina; Meulia, Tea; Doohan, Doug; Li, Zhaohu; Qu, Feng

2013-01-01

390

Profiling mRNAs of Two Cuscuta Species Reveals Possible Candidate Transcripts Shared by Parasitic Plants  

PubMed Central

Dodders are among the most important parasitic plants that cause serious yield losses in crop plants. In this report, we sought to unveil the genetic basis of dodder parasitism by profiling the trancriptomes of Cuscuta pentagona and C. suaveolens, two of the most common dodder species using a next-generation RNA sequencing platform. De novo assembly of the sequence reads resulted in more than 46,000 isotigs and contigs (collectively referred to as expressed sequence tags or ESTs) for each species, with more than half of them predicted to encode proteins that share significant sequence similarities with known proteins of non-parasitic plants. Comparing our datasets with transcriptomes of 12 other fully sequenced plant species confirmed a close evolutionary relationship between dodder and tomato. Using a rigorous set of filtering parameters, we were able to identify seven pairs of ESTs that appear to be shared exclusively by parasitic plants, thus providing targets for tailored management approaches. In addition, we also discovered ESTs with sequences similarities to known plant viruses, including cryptic viruses, in the dodder sequence assemblies. Together this study represents the first comprehensive transcriptome profiling of parasitic plants in the Cuscuta genus, and is expected to contribute to our understanding of the molecular mechanisms of parasitic plant-host plant interactions. PMID:24312295

Wijeratne, Saranga; Fraga, Martina; Meulia, Tea; Doohan, Doug; Li, Zhaohu; Qu, Feng

2013-01-01

391

Fourteen microsatellite loci for the Chinese medicinal plant Epimedium sagittatum and cross-species application in other medicinal species.  

PubMed

Epimedium sagittatum is a well-known medicinal plant as well as potential ground cover and ornamental plant. A total of 14 polymorphic microsatellite markers were developed for use in taxonomy, phylogenetics and conservation genetics. Markers were presented between two and eight alleles per locus. The observed heterozygosity (H(O) ) and expected heterozygosity (H(E) ) ranged from 0.03 to 0.81 and from 0.05 to 0.81, respectively. Cross-amplification among other four medicinal species revealed promising results in three to six polymorphic loci. These microsatellite loci contributed to the limited number of useful markers currently available for E. sagittatum. PMID:21585857

Xu, Yanqin; Li, Zuozhou; Wang, Ying

2008-05-01

392

Dominant species, rather than diversity, regulates temporal stability of plant communities.  

PubMed

A growing body of empirical evidence suggests that the temporal stability of communities typically increases with diversity. The counterview to this is that dominant species, rather than diversity itself, might regulate temporal stability. However, empirical studies that have explicitly examined the relative importance of diversity and dominant species in maintaining community stability have yielded few clear-cut patterns. Here, using a long-term data set, we examined the relative importance of changes in diversity components and dominance hierarchy following the removal of a dominant C4 grass, Bouteloua gracilis, in stabilizing plant communities. We also examined the relationships between the variables of diversity and dominance hierarchy and the statistical components of temporal stability. We found a significant negative relationship between temporal stability and species richness, number of rare species, and relative abundance of rare species, whereas a significant positive relationship existed between temporal stability and relative abundance of the dominant species. Variances and covariances summed over all species significantly increased with increasing species richness, whereas they significantly decreased with increasing relative abundance of dominant species. We showed that temporal stability in a shortgrass steppe plant community was controlled by dominant species rather than by diversity itself. The generality of diversity-stability relationships might be restricted by the dynamics of dominant species, especially when they have characteristics that contribute to stability in highly stochastic systems. A clear implication is that dominance hierarchies and their changes might be among the most important ecological components to consider in managing communities to maintain ecosystem functioning. PMID:21279386

Sasaki, Takehiro; Lauenroth, William K

2011-07-01

393

Plant species richness drives the density and diversity of Collembola in temperate grassland  

NASA Astrophysics Data System (ADS)

Declining biodiversity is one of the most important aspects of anthropogenic global change phenomena, but the implications of plant species loss for soil decomposers are little understood. We used the experimental grassland community of the Jena Experiment to assess the response of density and diversity of Collembola to varying plant species richness, plant functional group richness and plant functional group identity. We sampled the experimental plots in spring and autumn four years after establishment of the experimental plant communities. Collembola density and diversity significantly increased with plant species and plant functional group richness highlighting the importance of the singular hypothesis for soil invertebrates. Generally, grasses and legumes beneficially affected Collembola density and diversity, whereas effects of small herbs usually were detrimental. These impacts were largely consistent in spring and autumn. By contrast, in the presence of small herbs the density of hemiedaphic Collembola and the diversity of Isotomidae increased in spring whereas they decreased in autumn. Beneficial impacts of plant diversity as well as those of grasses and legumes were likely due to increased root and microbial biomass, and elevated quantity and quality of plant residues serving as food resources for Collembola. By contrast, beneficial impacts of small herbs in spring probably reflect differences in microclimatic conditions, and detrimental effects in autumn likely were due to low quantity and quality of resources. The results point to an intimate relationship between plants and the diversity of belowground biota, even at small spatial scales, contrasting the findings of previous studies. The pronounced response of soil animals in the present study was presumably due to the fact that plant communities had established over several years. As decomposer invertebrates significantly impact plant performance, changes in soil biota density and diversity are likely to have major feedbacks on plant community productivity and composition.

Sabais, Alexander C. W.; Scheu, Stefan; Eisenhauer, Nico

2011-05-01

394

Modelling plant species distribution in alpine grasslands using airborne imaging spectroscopy.  

PubMed

Remote sensing using airborne imaging spectroscopy (AIS) is known to retrieve fundamental optical properties of ecosystems. However, the value of these properties for predicting plant species distribution remains unclear. Here, we assess whether such data can add value to topographic variables for predicting plant distributions in French and Swiss alpine grasslands. We fitted statistical models with high spectral and spatial resolution reflectance data and tested four optical indices sensitive to leaf chlorophyll content, leaf water content and leaf area index. We found moderate added-value of AIS data for predicting alpine plant species distribution. Contrary to expectations, differences between species distribution models (SDMs) were not linked to their local abundance or phylogenetic/functional similarity. Moreover, spectral signatures of species were found to be partly site-specific. We discuss current limits of AIS-based SDMs, highlighting issues of scale and informational content of AIS data. PMID:25079495

Pottier, Julien; Malenovský, Zbyn?k; Psomas, Achilleas; Homolová, Lucie; Schaepman, Michael E; Choler, Philippe; Thuiller, Wilfried; Guisan, Antoine; Zimmermann, Niklaus E

2014-07-01

395

Phytoaccumulation of trace elements by wetland plants: 3. Uptake and accumulation of ten trace elements by twelve plant species  

SciTech Connect

Interest is increasing in using wetland plants in constructed wetlands to remove toxic elements from polluted wastewater. To identify those wetland plants that hyperaccumulate trace elements, 12 plant species were tested for their efficiency to bioconcentrate 10 potentially toxic trace elements including As, b, Cd, Cr, Cu, Pb, Mn, Hg, Ni, and Se. Individual plants were grown under carefully controlled conditions and supplied with 1 mg L{sup {minus}1} of each trace element individually for 10 d. Except B, all elements accumulated to much higher concentrations in roots than in shoots. Highest shoot tissue concentrations (mg kg{sup {minus}1} DW) of the various trace elements were attained by the following species: umbrella plant (Cyperus alternifolius L.) for Mn (198) and Cr (44); water zinnia (Wedelia trilobata Hitchc.) for Cd (148) and Ni (80); smartweed (Polygonum hydropiperoides Michx.) for Cu (95) and Pb (64); water lettuce (Pistia stratiotes L.) for Hg (92), As (34), and Se (39); and mare's tail (hippuris vulgaris L.) for B (1132). Whereas, the following species attained the highest root tissue concentrations (mg kg{sup {minus}1} DW); stripped rush (Baumia rubiginosa) for Mn (1683); parrot's feather (Myriophyllum brasiliense Camb.) for Cd (1426) and Ni (1077); water lettuce for Cu (1038), Hg (1217), and As (177); smartweed for Cr (2980) and Pb (1882); mare's tail for B (1277); and monkey flower (Mimulus guttatus Fisch.) for Se (384). From a phytoremediation perspective, smartweed was probably the best plant species for trace element removal from wastewater due to its faster growth and higher plant density.

Qian, J.H.; Zayed, A.; Zhu, Y.L.; Yu, M.; Terry, N.

1999-10-01

396

Sulfate uptake by salinity?tolerant plant species  

Microsoft Academic Search

High soluble?sulfate (SO4) concentrations affect water quality, soil chemistry, plant sulfur (S) levels, and possibly ruminant?animal health. The objective of this greenhouse pot study was to determine the potential for accumulating high levels of S by tansy mustard (Descurainia pinnata (Walt.) Britton), kochia (Kochia scoparia L. Schrad.), yellow sweet clover (Melilotus officinalis L.), slender wheatgrass (Elymus trachycaulus (Link) Gould ex

H. F. Mayland; C. W. Robbins

1994-01-01

397

Tropical Plant–Herbivore Networks: Reconstructing Species Interactions Using DNA Barcodes  

PubMed Central

Plants and their associated insect herbivores, represent more than 50% of all known species on earth. The first step in understanding the mechanisms generating and maintaining this important component of biodiversity is to identify plant-herbivore associations. In this study we determined insect-host plant associations for an entire guild of insect herbivores using plant DNA extracted from insect gut contents. Over two years, in a tropical rain forest in Costa Rica (La Selva Biological Station), we recorded the full diet breadth of rolled-leaf beetles, a group of herbivores that feed on plants in the order Zingiberales. Field observations were used to determine the accuracy of diet identifications using a three-locus DNA barcode (rbcL, trnH-psbA and ITS2). Using extraction techniques for ancient DNA, we obtained high-quality sequences for two of these loci from gut contents (rbcL and ITS2). Sequences were then compared to a comprehensive DNA barcode library of the Zingiberales. The rbcL locus identified host plants to family (success/sequence?=?58.8%) and genus (success/sequence?=?47%). For all Zingiberales except Heliconiaceae, ITS2 successfully identified host plants to genus (success/sequence?=?67.1%) and species (success/sequence?=?61.6%). Kindt’s sampling estimates suggest that by collecting ca. four individuals representing each plant-herbivore interaction, 99% of all host associations included in this study can be identified to genus. For plants that amplified ITS2, 99% of the hosts can be identified to species after collecting at least four individuals representing each interaction. Our study demonstrates that host plant identifications at the species-level using DNA barcodes are feasible, cost-effective, and reliable, and that reconstructing plant-herbivore networks with these methods will become the standard for a detailed understanding of these interactions. PMID:23308128

García-Robledo, Carlos; Erickson, David L.; Staines, Charles L.; Erwin, Terry L.; Kress, W. John

2013-01-01

398

An evaluation of the contaminant impacts on plants serving as habitat for an endangered species  

SciTech Connect

As part of an ecological risk assessment at a Superfund site in Monterey County, California, potential impacts on an endangered species, the Smith`s blue butterfly (Euphilotes enoptes smithi) were evaluated. This species of butterfly lives along beach dunes historically used as small arms trainfire ranges. Historical land use resulted in the accumulation of spent bullets and varying concentrations of metals in site soil. Two species of buckwheat occurring at the site (Erigonium parvifolium and E. latifolium) that serve as the sole habitat for the butterfly were evaluated. It was assumed that if there were no impacts to the habitat, there would be no impacts to the endangered species itself. Surface soil and collocated plants were sampled and chemically analyzed in order to correlate soil concentrations with plant tissue concentrations. Surface soil and collocated plants were also sampled at reference sites to determine background concentrations. Tissue concentrations were compared to benchmark concentrations to evaluate potential impacts. In addition, soil samples and seeds from buckwheat growing at the site were collected and used to conduct root elongation assays in the laboratory. The objective of the assays was to assess effects of metals associated with the spent bullets in soil on plant growth. Within the plants, higher concentrations of all metals except zinc were found in the roots; zinc was equally distributed throughout the plants. No chemical-related impacts to the plants were identified.

DeShields, B.R.; Stelljes, M.E.; Hawkins, E.T.; Alsop, W.R. [Harding Lawson Associates, Novato, CA (United States); Collins, W. [Dept. of the Army, Fort Ord, CA (United States)

1995-12-31

399

Engineered Rhizosphere: the Trophic Bias Generated by Opine-Producing Plants Is Independent of the Opine Type, the Soil Origin, and the Plant Species  

PubMed Central

In a previous study, we demonstrated that transgenic Lotus plants producing opines (which are small amino acid and sugar conjugates) specifically favor growth of opine-degrading rhizobacteria. The opine-induced bias was repeated and demonstrated with another soil type and another plant species (Solanum nigrum). This phenomenon is therefore independent of both soil type and plant species. PMID:11976135

Mansouri, Hounayda; Petit, Annik; Oger, Phil; Dessaux, Yves

2002-01-01

400

Temporal-Spatial Dynamics in Orthoptera in Relation to Nutrient Availability and Plant Species Richness  

PubMed Central

Nutrient availability in ecosystems has increased dramatically over the last century. Excess reactive nitrogen deposition is known to negatively impact plant communities, e.g. by changing species composition, biomass and vegetation structure. In contrast, little is known on how such impacts propagate to higher trophic levels. To evaluate how nitrogen deposition affects plants and herbivore communities through time, we used extensive databases of spatially explicit historical records of Dutch plant species and Orthoptera (grasshoppers and crickets), a group of animals that are particularly susceptible to changes in the C:N ratio of their resources. We use robust methods that deal with the unstandardized nature of historical databases to test whether nitrogen deposition levels and plant richness changes influence the patterns of richness change of Orthoptera, taking into account Orthoptera species functional traits. Our findings show that effects indeed also propagate to higher trophic levels. Differences in functional traits affected the temporal-spatial dynamics of assemblages of Orthoptera. While nitrogen deposition affected plant diversity, contrary to our expectations, we could not find a strong significant effect of food related traits. However we found that species with low habitat specificity, limited dispersal capacity and egg deposition in the soil were more negativly affected by nitrogen deposition levels. Despite the lack of significant effect of plant richness or food related traits on Orthoptera, the negative effects of nitrogen detected within certain trait groups (e.g. groups with limited disperse ability) could be related to subtle changes in plant abundance and plant quality. Our results, however, suggest that the changes in soil conditions (where many Orthoptera species lay their eggs) or other habitat changes driven by nitrogen have a stronger influence than food related traits. To fully evaluate the negative effects of nitrogen deposition on higher trophic levels it is essential to take into account species life-history traits. PMID:23951232

Hendriks, Rob J. J.; Carvalheiro, Luisa G.; Kleukers, Roy M. J. C.; Biesmeijer, Jacobus C.

2013-01-01

401

Obsolete pesticides and application of colonizing plant species for remediation of contaminated soil in Kazakhstan.  

PubMed

In Kazakhstan, there is a problem of finding ways to clean local sites contaminated with pesticides. In particular, such sites are the deserted and destroyed storehouses where these pesticides were stored; existing storehouses do not fulfill sanitary standards. Phytoremediation is one potential method for reducing risk from these pesticides. Genetic heterogeneity of populations of wild and weedy species growing on pesticide-contaminated soil provides a source of plant species tolerant to these conditions. These plant species may be useful for phytoremediation applications. In 2008-2009 and 2011, we surveyed substances stored in 80 former pesticide storehouses in Kazakhstan (Almaty oblast) to demonstrate an inventory process needed to understand the obsolete pesticide problem throughout the country, and observed a total of 354.7 t of obsolete pesticides. At the sites, we have found organochlorine pesticides residues in soil including metabolites of dichlorodiphenyltrichloroethane and isomers of hexachlorocyclohexane. Twenty-four of the storehouse sites showed pesticides concentrations in soil higher than maximum allowable concentration which is equal to 100 ?g kg(-1) in Kazakhstan. Seventeen pesticide-tolerant wild plant species were selected from colonizing plants that grew into/near the former storehouse's pesticides. The results have shown that colonizing plant annual and biannual species growing on soils polluted by pesticides possess ability to accumulate organochlorine pesticide residues and reduce pesticide concentrations in soil. Organochlorine pesticides taken up by the plants are distributed unevenly in different plant tissues. The main organ of organochlorine pesticide accumulation is the root system. The accumulation rate of organochlorine pesticides was found to be a specific characteristic of plant species and dependent on the degree of soil contamination. This information can be used for technology development of phytoremediation of pesticide-contaminated soils. PMID:22890508

Nurzhanova, Asil; Kalugin, Sergey; Zhambakin, Kabl

2013-04-01

402

Effect of fertiliser application and abandonment on plant species composition of Festuca rubra grassland  

NASA Astrophysics Data System (ADS)

Little is known about the effects of nitrogen (N), phosphorus (P) and potassium (K) application on soil chemical properties and plant species composition of mountain Festuca rubra grasslands. In this study, we aimed to determine whether fertiliser application affects plant species composition and soil properties during periods of management, and whether residual after-effects of fertiliser application can be detected eight years after its use is abandoned. The experiment with unfertilised control, PK treatment and treatments with low and higher level of NPK application under three (intensive management from 1993 to 1997) and two cut management (moderate management from 1997 to 1999) was established in the Jizera Mts. (Czech Republic) on F. rubra meadow and then the experiment was eight years abandoned. Immediately after the introduction of intensive management, a decrease in species richness and diversification of plant species composition occurred. Plant communities which had diversified in different fertiliser treatments persisted under moderately intensive management. The cover of Alopecurus pratensis increased to >50% while the cover of Agrostis capillaris decreased to <5% in NPK treatments during the period of intensive management. Trifolium repens became the dominant species in the PK treatment. Within eight years, under no management, the differences in plant species composition disappeared, species richness decreased and F. rubra, followed by Hypericum maculatum, became dominant in all treatments. The differences in biomass P concentration and plant available P and K concentrations in the soil were still detectable eight years after the last fertiliser application. As shown in this study, moderate application of NPK and consequent abandonment need not generate irreversible changes in species composition of mountain grassland.

Pavl?, Vilém; Gaisler, Jan; Pavl?, Lenka; Hejcman, Michal; Ludvíková, Vendula

2012-11-01

403

Ecological implications of reduced pollen deposition in alpine plants: a case study using a dominant cushion plant species  

PubMed Central

The reproductive assurance hypothesis states that self-incompatible female plants must produce twice the number of seeds relative to their self-compatible hermaphroditic counterparts to persist in gynodioecious populations. This is a viable life-history strategy, provided that pollination rates are sufficiently high. However, reduced pollination rates in alpine plants are likely due to climate induced plant-pollinator mismatches and general declines in pollinators. Using a gynodioecious population of the dominant plant Silene acaulis (Caryophyllaceae), we tested the reproductive assurance hypothesis and also the stress gradient hypothesis with a series of pollinator exclusion trials and extensive measurements of subsequent reproductive output (gender ratio, plant size, percent fruit-set, fruit weight, seeds per fruit, total seeds, seed weight, and seed germination). The reproductive assurance hypothesis was supported with female plants being more sensitive to and less likely to be viable under reductions in pollination rates. These findings are the first to show that the stress gradient hypothesis is also supported under a gradient of pollen supply instead of environmental limitations. Beneficiary abundance was negatively correlated to percent fruit-set under current pollen supply, but became positive under reduced pollen supply suggesting that there are important plant-plant-pollinator interactions related to reproduction in these alpine plant species. PMID:25075305

Reid, Anya; Hooper, Robyn; Molenda, Olivia; Lortie, Christopher J.

2014-01-01

404

Phylogenetic diversity of plants alters the effect of species richness on invertebrate herbivory  

PubMed Central

Long-standing ecological theory proposes that diverse communities of plants should experience a decrease in herbivory. Yet previous empirical examinations of this hypothesis have revealed that plant species richness increases herbivory in just as many systems as it decreases it. In this study, I ask whether more insight into the role of plant diversity in promoting or suppressing herbivory can be gained by incorporating information about the evolutionary history of species in a community. In an old field system in southern Ontario, I surveyed communities of plants and measured levels of leaf damage on 27 species in 38 plots. I calculated a measure of phylogenetic diversity (PSE) that encapsulates information about the amount of evolutionary history represented in each of the plots and looked for a relationship between levels of herbivory and both species richness and phylogenetic diversity using a generalized linear mixed model (GLMM) that could account for variation in herbivory levels between species. I found that species richness was positively associated with herbivore damage at the plot-level, in keeping with the results from several other recent studies on this question. On the other hand, phylogenetic diversity was associated with decreased herbivory. Importantly, there was also an interaction between species richness and phylogenetic diversity, such that plots with the highest levels of herbivory were plots which had many species but only if those species tended to be closely related to one another. I propose that these results are the consequence of interactions with herbivores whose diets are phylogenetically specialized (for which I introduce the term cladophage), and how phylogenetic diversity may alter their realized host ranges. These results suggest that incorporating a phylogenetic perspective can add valuable additional insight into the role of plant diversity in explaining or predicting levels of herbivory at a whole-community scale. PMID:23825795

2013-01-01

405

Plant species dominance shifts across erosion edge-meadow transects in the Swiss Alps.  

PubMed

While exerting no obvious function under "average" environmental conditions, the presence of certain plant specialists becomes crucial in the event of a complete failure of a community due to severe disturbance such as landslides. Plants capable of growing at erosion edges may act as potential edge-engineers by coping with unstable ground and stabilizing the soil with their roots. We hypothesized that life conditions at erosion edges select for a particular set of specialists or species with specific traits, the identification of which was the aim of the study. Across 17 small-scale transects (0.40 × 1.60 m) from intact meadows to landslide edges (Ursern Valley, Swiss Alps, c. 1,600 m a.s.l.), we quantified plant species abundance by the point intercept method and characterized growth conditions based on Landolt's indicator values, leaf ?(13)C, and volumetric soil moisture in the uppermost soil layers. We observed a clear change of plant species composition and relative abundance from the meadow to the edge, presumably induced by the 25 % lower soil moisture and microclimatic exposure. Species richness at the edge was two-thirds of that in the meadow, but was positively correlated with species richness of the adjacent meadow. Species with "edge-preference" had either (1) rolled or festucoid leaves like Festuca spp., Avenella flexuosa and Nardus stricta, or (2) small, scleromorphic leaves like Vaccinium vitis-idaea, Calluna vulgaris and Thymus ssp. Graminoids with rolled/festucoid leaves were found to be the most dominant edge-specialists. The grass Festuca valesiaca s.l. emerged as the most dominant plant species at the edge, having an 11-times higher cover at the edge than in the meadow. In this montane grassland, a single species contributes to the stabilization of erosion edges and may be regarded as a potential keystone species for slope stability and regeneration after landslides even its role has not so far been established. PMID:23337968

Huck, Corinne; Körner, Christian; Hiltbrunner, Erika

2013-03-01

406

Plant DNA Barcodes Can Accurately Estimate Species Richness in Poorly Known Floras  

PubMed Central

Background Widespread uptake of DNA barcoding technology for vascular plants has been slow due to the relatively poor resolution of species discrimination (?70%) and low sequencing and amplification success of one of the two official barcoding loci, matK. Studies to date have mostly focused on finding a solution to these intrinsic limitations of the markers, rather than posing questions that can maximize the utility of DNA barcodes for plants with the current technology. Methodology/Principal Findings Here we test the ability of plant DNA barcodes using the two official barcoding loci, rbcLa and matK, plus an alternative barcoding locus, trnH-psbA, to estimate the species diversity of trees in a tropical rainforest plot. Species discrimination accuracy was similar to findings from previous studies but species richness estimation accuracy proved higher, up to 89%. All combinations which included the trnH-psbA locus performed better at both species discrimination and richness estimation than matK, which showed little enhanced species discriminatory power when concatenated with rbcLa. The utility of the trnH-psbA locus is limited however, by the occurrence of intraspecific variation observed in some angiosperm families to occur as an inversion that obscures the monophyly of species. Conclusions/Significance We demonstrate for the first time, using a case study, the potential of plant DNA barcodes for the rapid estimation of species richness in taxonomically poorly known areas or cryptic populations revealing a powerful new tool for rapid biodiversity assessment. The combination of the rbcLa and trnH-psbA loci performed better for this purpose than any two-locus combination that included matK. We show that although DNA barcodes fail to discriminate all species of plants, new perspectives and methods on biodiversity value and quantification may overshadow some of these shortcomings by applying barcode data in new ways. PMID:22096501

Costion, Craig; Ford, Andrew; Cross, Hugh; Crayn, Darren; Harrington, Mark; Lowe, Andrew

2011-01-01

407

Bacterial Communities of Two Parthenogenetic Aphid Species Cocolonizing Two Host Plants across the Hawaiian Islands ?  

PubMed Central

Aphids (Hemiptera: Aphididae) have been the focus of several studies with respect to their interactions with inherited symbionts, but bacterial communities of most aphid species are still poorly characterized. In this research, we used bar-coded pyrosequencing to characterize bacterial communities in aphids. Specifically, we examined the diversity of bacteria in two obligately parthenogenetic aphid species (the melon aphid, Aphis gossypii, and the cardamom aphid, Pentalonia caladii) cocolonizing two plant species (taro, Colocasia esculenta, and ginger, Alpinia purpurata) across four Hawaiian Islands (Hawaii, Kauai, Maui, and Oahu). Results from this study revealed that heritable symbionts dominated the bacterial communities for both aphid species. The bacterial communities differed significantly between the two species, and A. gossypii harbored a more diverse bacterial community than P. caladii. The bacterial communities also differed across aphid populations sampled from the different islands; however, communities did not differ between aphids collected from the two host plants. PMID:21965398

Jones, Ryan T.; Bressan, Alberto; Greenwell, April M.; Fierer, Noah

2011-01-01

408

Bacterial communities of two parthenogenetic aphid species cocolonizing two host plants across the Hawaiian Islands.  

PubMed

Aphids (Hemiptera: Aphididae) have been the focus of several studies with respect to their interactions with inherited symbionts, but bacterial communities of most aphid species are still poorly characterized. In this research, we used bar-coded pyrosequencing to characterize bacterial communities in aphids. Specifically, we examined the diversity of bacteria in two obligately parthenogenetic aphid species (the melon aphid, Aphis gossypii, and the cardamom aphid, Pentalonia caladii) cocolonizing two plant species (taro, Colocasia esculenta, and ginger, Alpinia purpurata) across four Hawaiian Islands (Hawaii, Kauai, Maui, and Oahu). Results from this study revealed that heritable symbionts dominated the bacterial communities for both aphid species. The bacterial communities differed significantly between the two species, and A. gossypii harbored a more diverse bacterial community than P. caladii. The bacterial communities also differed across aphid populations sampled from the different islands; however, communities did not differ between aphids collected from the two host plants. PMID:21965398

Jones, Ryan T; Bressan, Alberto; Greenwell, April M; Fierer, Noah

2011-12-01

409

Species-specific effects of elevated ozone on wetland plants and decomposition processes.  

PubMed

Seven species from two contrasting wetlands, an upland bog and a lowland rich fen in North Wales, UK, were exposed to elevated ozone (150 ppb for 5 days and 20 ppb for 2 days per week) or low ozone (20 ppb) for four weeks in solardomes. The rich fen species were: Molinia caerulea, Juncus subnodulosus, Potentilla erecta and Hydrocotyle vulgaris and the bog species were: Carex echinata, Potentilla erecta and Festuca rubra. Senescence significantly increased under elevated ozone in all seven species but only Molinia caerulea showed a reduction in biomass under elevated ozone. Decomposition rates of plants exposed to elevated ozone, as measured by carbon dioxide efflux from dried plant material inoculated with peat slurry, increased for Potentilla erecta with higher hydrolytic enzyme activities. In contrast, a decrease in enzyme activities and a non-significant decrease in carbon dioxide efflux occurred in the grasses, sedge and rush species. PMID:20185216

Williamson, Jennifer; Mills, Gina; Freeman, Chris

2010-05-01

410

The region effect on mesoscale plant species richness between eastern Asia and eastern North America  

E-print Network

129 /136. The greater number of plant species in temperate eastern Asia compared to eastern North America has been ascribed to both local environment and regional characteristics, but the relative contributions of each have not been resolved. In this analysis, we related species richness of flowering plants in mesoscale floras (B/10 4 km 2) dominated by temperate forest vegetation to area, elevation, latitude, and several climate variables. When analyses were conducted separately within each region, area and, in eastern Asia, elevation, were the primary determinants of species richness. It appears that the number of species in mesic temperate floras within these regions is largely unrelated to the relatively narrow range of local climate factors associated with these floras. Analysis of covariance of the logarithm of species richness with the logarithm of area (b /0.148) and climate measurements as independent variables revealed a region effect, with species richness in eastern Asia exceeding that in eastern North America by 0.294 log10 units, or a factor of 2.0. Similar regional differences in species richness were apparent in floras compiled from larger areas. Understanding differences in plant species richness between regions requires consideration of regional influences, whose effects should be tested in comparative analyses based on floristic surveys of ecologically characterized small areas.

Robert E. Ricklefs; Hong Qian; Peter S. White

411

Are Plant Species Able to Keep Pace with the Rapidly Changing Climate?  

PubMed Central

Future climate change is predicted to advance faster than the postglacial warming. Migration may therefore become a key driver for future development of biodiversity and ecosystem functioning. For 140 European plant species we computed past range shifts since the last glacial maximum and future range shifts for a variety of Intergovernmental Panel on Climate Change (IPCC) scenarios and global circulation models (GCMs). Range shift rates were estimated by means of species distribution modelling (SDM). With process-based seed dispersal models we estimated species-specific migration rates for 27 dispersal modes addressing dispersal by wind (anemochory) for different wind conditions, as well as dispersal by mammals (dispersal on animal's coat – epizoochory and dispersal by animals after feeding and digestion – endozoochory) considering different animal species. Our process-based modelled migration rates generally exceeded the postglacial range shift rates indicating that the process-based models we used are capable of predicting migration rates that are in accordance with realized past migration. For most of the considered species, the modelled migration rates were considerably lower than the expected future climate change induced range shift rates. This implies that most plant species will not entirely be able to follow future climate-change-induced range shifts due to dispersal limitation. Animals with large day- and home-ranges are highly important for achieving high migration rates for many plant species, whereas anemochory is relevant for only few species. PMID:23894290

Cunze, Sarah; Heydel, Felix; Tackenberg, Oliver

2013-01-01

412

Planting six tree species on soda-saline-alkali soil  

Microsoft Academic Search

Populus simonigra, Salix matsudana, Ulmus pumila, Populus nigra, Acer negundo, Fraxinus mandshurica. Tamarix chinensis, Hippophae\\u000a rhammoldes, Syriga onlata were planted on the soda-saline-alkali. The soil had pH 8.5–9.6, salinity 0.1%–0.3%, sodiumionized\\u000a ratio 16%–51% and normality ratio of saline base Na+\\/(Ca+++Mg++)>4. Populus simonigra grows very well on the all kinds of soda-saline-alkali soils except on the alkali sport with the worst

Zhang Yujiang; Liu Peng; Yang Dewei; Ma Chenghui; Liu Gang

1998-01-01

413

Phytophthora multivora sp. nov., a new species recovered from declining Eucalyptus, Banksia, Agonis and other plant species in Western Australia.  

PubMed

A new Phytophthora species, isolated from rhizosphere soil of declining or dead trees of Eucalyptus gomphocephala, E. marginata, Agonis flexuosa, and another 13 plant species, and from fine roots of E. marginata and collar lesions of Banksia attenuata in Western Australia, is described as Phytophthora multivora sp. nov. It is homothallic and produces semipapillate sporangia, smooth-walled oogonia containing thick-walled oospores, and paragynous antheridia. Although morphologically similar to P. citricola, phylogenetic analyses of the ITS and cox1 gene regions demonstrate that P. multivora is unique. Phytophthora multivora is pathogenic to bark and cambium of E. gomphocephala and E. marginata and is believed to be involved in the decline syndrome of both eucalypt species within the tuart woodland in south-west Western Australia. PMID:20198133

Scott, P M; Burgess, T I; Barber, P A; Shearer, B L; Stukely, M J C; Hardy, G E St J; Jung, T

2009-06-01

414

Actual and potential use of population viability analyses in recovery of plant species listed under the US endangered species act.  

PubMed

Use of population viability analyses (PVAs) in endangered species recovery planning has been met with both support and criticism. Previous reviews promote use of PVA for setting scientifically based, measurable, and objective recovery criteria and recommend improvements to increase the framework's utility. However, others have questioned the value of PVA models for setting recovery criteria and assert that PVAs are more appropriate for understanding relative trade-offs between alternative management actions. We reviewed 258 final recovery plans for 642 plants listed under the U.S. Endangered Species Act to determine the number of plans that used or recommended PVA in recovery planning. We also reviewed 223 publications that describe plant PVAs to assess how these models were designed and whether those designs reflected previous recommendations for improvement of PVAs. Twenty-four percent of listed species had recovery plans that used or recommended PVA. In publications, the typical model was a matrix population model parameterized with ?5 years of demographic data that did not consider stochasticity, genetics, density dependence, seed banks, vegetative reproduction, dormancy, threats, or management strategies. Population growth rates for different populations of the same species or for the same population at different points in time were often statistically different or varied by >10%. Therefore, PVAs parameterized with underlying vital rates that vary to this degree may not accurately predict recovery objectives across a species' entire distribution or over longer time scales. We assert that PVA, although an important tool as part of an adaptive-management program, can help to determine quantitative recovery criteria only if more long-term data sets that capture spatiotemporal variability in vital rates become available. Lacking this, there is a strong need for viable and comprehensive methods for determining quantitative, science-based recovery criteria for endangered species with minimal data availability. Uso Actual y Potencial del Análisis de Viabilidad Poblacional para la Recuperación de Especies de Plantas Enlistadas en el Acta de Especies En Peligro de E.U.A. PMID:24033732

Zeigler, Sara L; Che-Castaldo, Judy P; Neel, Maile C

2013-12-01

415

Beyond the ecological: biological invasions alter natural selection on a native plant species.  

PubMed

Biological invasions can have strong ecological effects on native communities by altering ecosystem functions, species interactions, and community composition. Even though these ecological effects frequently impact the population dynamics and fitness of native species, the evolutionary consequences of biological invasions have received relatively little attention. Here, I show that invasions impose novel selective pressures on a native plant species. By experimentally manipulating community composition, I found that the exotic plant Medicago polymorpha and the exotic herbivore Hypera brunneipennis alter the strength and, in some instances, the direction of natural selection on the competitive ability and anti-herbivore defenses of the native plant Lotus wrangelianus. Furthermore, the community composition of exotics influenced which traits were favored. For example, high densities of the exotic herbivore Hypera selected for increased resistance to herbivores in the native Lotus; however, when Medicago also was present, selection on this defense was eliminated. In contrast, selection on tolerance, another plant defense trait, was highest when both Hypera and Medicago were present at high densities. Thus, multiple exotic species may interact to influence the evolutionary trajectories of native plant populations, and patterns of selection may change as additional exotic species invade the community. PMID:18481527

Lau, Jennifer A

2008-04-01

416

Mycorrhizal associations in woody plant species at the Mt. Usu volcano, Japan.  

PubMed

We investigated the association between ectomycorrhizal (ECM) and arbuscular mycorrhizal (AM) fungi and pioneer woody plant species in areas devastated by the eruption of Mt. Usu, Japan, in 2000. We observed eight woody plant species at the research site, most of which were associated with ECM and/or AM fungi. In particular, dominant woody plant species Populus maximowiczii, Salix hultenii var. angustifolia and Salix sachalinensis were consistently associated with ECM fungi and erratically associated with AM fungi. We found one to six morphotypes in the roots of each ECM host and, on average, two in the roots of each seedling, indicating low ECM fungal diversity. ECM colonization ranged from 17 to 42% of root tips. Using morphotyping and molecular analyses, 15 ECM fungi were identified. ECM fungi differed greatly between hosts. However, Laccaria amethystea, Hebeloma mesophaeum, Thelephora terrestris and other Thelephoraceae had high relative colonization, constituting the majority of the ECM colonization in the roots of each plant species. These ECM fungi may be important for the establishment of pioneer woody plant species and further revegetation at Mt. Usu volcano. PMID:17216274

Obase, Keisuke; Tamai, Yutaka; Yajima, Takashi; Miyamoto, Toshizumi

2007-05-01

417

Phytotoxicity of biosolids and screening of selected plant species with potential for mercury phytoextraction.  

PubMed

Mercury contaminated stockpiles of biosolids (3.5-8.4 mg kg(-1) Hg) from Melbourne Water's Western Treatment Plant (MW-WTP) were investigated to evaluate the possibility for their phytoremediation. Nine plant species (Atriplex codonocarpa, Atriplex semibaccata, Austrodanthonia caespitosa, Brassica juncea, Brassica napus, Gypsophila paniculata, Sorghum bicolor, Themeda triandra and Trifolium subterraneum) were screened for phytoextraction potential in Hg-contaminated biosolids from MW-WTP. In addition, the same plant species were germinated and grown in two other substrates (i.e. potting mix and potting mix spiked with mercury(II)). Growth measurements and the mercury uptake for all three substrates were compared. Some plant species grown in potting mix spiked with mercury(II) grew more vigorously than in the other two substrates and showed higher levels of sulphur in their tissues. These results suggested that the mercury stress activated defence mechanisms and it was hypothesised that this was the likely reason for the enhanced production of sulphur compounds in the plant species studied which stimulated their growth. Some species did not grow in biosolids because of the combined effect of high mercury toxicity and high salt content. Atriplex conodocarpa and Australodanthonia caespitose proved to be the most suitable candidates for mercury phytoextraction because of their ability to translocate mercury from roots to the above-ground tissues. PMID:19775810

Lomonte, Cristina; Doronila, Augustine I; Gregory, David; Baker, Alan J M; Kolev, Spas D

2010-01-15

418

Cross-Species Translocation of mRNA from Host Plants into the Parasitic Plant Dodder1[OA  

PubMed Central

An intriguing new paradigm in plant biology is that systemically mobile mRNAs play a role in coordinating development. In this process, specific mRNAs are loaded into the phloem transport stream for translocation to distant tissues, where they may impact on developmental processes. However, despite its potential significance for plant growth regulation, mRNA trafficking remains poorly understood and challenging to study. Here, we show that phloem-mobile mRNAs can also traffic between widely divergent species from a host to the plant parasite lespedeza dodder (Cuscuta pentagona Engelm.). Reverse transcription-polymerase chain reaction and microarray analysis were used to detect specific tomato (Lycopersicon esculentum Mill.) transcripts in dodder grown on tomato that were not present in control dodder grown on other host species. Foreign transcripts included LeGAI, which has previously been shown to be translocated in the phloem, as well as nine other transcripts not reported to be mobile. Dodders are parasitic plants that obtain resources by drawing from the phloem of a host plant and have joint plasmodesmata with host cortical cells. Although viruses are known to move between dodder and its hosts, translocation of endogenous plant mRNA has not been reported. These results point to a potentially new level of interspecies communication, and raise questions about the ability of parasites to recognize, use, and respond to transcripts acquired from their hosts. PMID:17189329

Roney, Jeannine K.; Khatibi, Piyum A.; Westwood, James H.

2007-01-01

419

Field observations of oviposition by a specialist herbivore on plant parts and plant species unsuitable as larval food.  

PubMed

Where a female places her eggs can have a major impact on the fitness of her offspring, especially for insects in which the winged adults are far more mobile than the neonates. Larvae of Heliothis subflexa (Guenee) (Lepidoptera: Noctuidae), a specialist moth phylogenetically nested within a generalist clade, feed only on fruit of some Physalis species. Field observations of the oviposition behavior of H. subflexa revealed that 1) females laid most of their eggs on leaves of the Physalis plant, despite the larvae's frugivorous diet, and 2) females laid nearly 20% of the eggs on nonhost plant species. Most eggs oviposited on nonhosts were placed close to the host plant-88% were within 15 cm of the Physalis plant. However, in a study of neonate movement, we found that a distance of 2 cm from the hatch site to the host plant significantly decreased the ability of neonates to establish on the host plant. The estimated fitness cost, quantified as reduced neonate survival, for females ovipositing on nonhosts is 8-17%. Many ecological and evolutionary factors could result in oviposition on less suitable host parts and on nonhosts. One possibility is that specialization on Physalis has recently evolved in H. subflexa, and females have not fully optimized their oviposition behavior. However, the fitness cost of oviposition on nonhosts may be balanced by fitness benefits of such behavior, such as faster decision-making and reduced predation. PMID:22217764

Benda, Nicole D; Brownie, Cavell; Schal, Coby; Gould, Fred

2011-12-01

420

Amazonian Dark Earth and Plant Species from the Amazon Region Contribute to Shape Rhizosphere Bacterial Communities.  

PubMed

Amazonian Dark Earths (ADE) or Terra Preta de Índio formed in the past by pre-Columbian populations are highly sustained fertile soils supported by microbial communities that differ from those extant in adjacent soils. These soils are found in the Amazon region and are considered as a model soil when compared to the surrounding and background soils. The aim of this study was to assess the effects of ADE and its surrounding soil on the rhizosphere bacterial communities of two leguminous plant species that frequently occur in the Amazon region in forest sites (Mimosa debilis) and open areas (Senna alata). Bacterial community structure was evaluated using terminal restriction fragment length polymorphism (T-RFLP) and bacterial community composition by V4 16S rRNA gene region pyrosequencing. T-RFLP analysis showed effect of soil types and plant species on rhizosphere bacterial community structure. Differential abundance of bacterial phyla, such as Acidobacteria, Actinobacteria, Verrucomicrobia, and Firmicutes, revealed that soil type contributes to shape the bacterial communities. Furthermore, bacterial phyla such as Firmicutes and Nitrospira were mostly influenced by plant species. Plant roots influenced several soil chemical properties, especially when plants were grown in ADE. These results showed that differences observed in rhizosphere bacterial community structure and composition can be influenced by plant species and soil fertility due to variation in soil attributes. PMID:25103911

Barbosa Lima, Amanda; Cannavan, Fabiana Souza; Navarrete, Acacio Aparecido; Teixeira, Wenceslau Geraldes; Kuramae, Eiko Eurya; Tsai, Siu Mui

2014-08-01

421

Species Differentiation of Chinese Mollitrichosiphum (Aphididae: Greenideinae) Driven by Geographical Isolation and Host Plant Acquirement  

PubMed Central

The impact of both the uplift of the Qinghai-Tibetan Plateau (QTP) and the separation of the Taiwan and Hainan Islands on the evolution of the fauna and flora in adjacent regions has been a topic of considerable interest. Mollitrichosiphum is a polyphagous insect group with a wide range of host plants (14 families) and distributions restricted to Southeast Asia. Based on the mitochondrial Cytochrome C Oxidase Subunit I (COI) and Cytochrome b (Cytb) genes, the nuclear elongation factor-1? (EF-1?) gene, and the detailed distribution and host plant data, we investigated the species differentiation modes of the Chinese Mollitrichosiphum species. Phylogenetic analyses supported the monophyly of Mollitrichosiphum. The divergence time of Mollitrichosiphum tenuicorpus (c. 11.0 mya (million years ago)), Mollitrichosiphum nandii and Mollitrichosiphum montanum (c. 10.6 mya) was within the time frame of the uplift of the QTP. Additionally, basal species mainly fed on Fagaceae, while species that fed on multiple plants diverged considerably later. Ancestral state reconstruction suggests that Fagaceae may be the first acquired host, and the acquisition of new hosts and the expansion of host range may have promoted species differentiation within this genus. Overall, it can be concluded that geographical isolation and the expansion of the host plant range may be the main factors driving species differentiation of Mollitrichosiphum. PMID:22949873

Zhang, Ruiling; Huang, Xiaolei; Jiang, Liyun; Lei, Fumin; Qiao, Gexia

2012-01-01

422

Metabolomics unravel contrasting effects of biodiversity on the performance of individual plant species.  

PubMed

In spite of evidence for positive diversity-productivity relationships increasing plant diversity has highly variable effects on the performance of individual plant species, but the mechanisms behind these differential responses are far from being understood. To gain deeper insights into the physiological responses of individual plant species to increasing plant diversity we performed systematic untargeted metabolite profiling on a number of herbs derived from a grassland biodiversity experiment (Jena Experiment). The Jena Experiment comprises plots of varying species number (1, 2, 4, 8, 16 and 60) and number and composition of functional groups (1 to 4; grasses, legumes, tall herbs, small herbs). In this study the metabolomes of two tall-growing herbs (legume: Medicago x varia; non-legume: Knautia arvensis) and three small-growing herbs (legume: Lotus corniculatus; non-legumes: Bellis perennis, Leontodon autumnalis) in plant communities of increasing diversity were analyzed. For metabolite profiling we combined gas chromatography coupled to time-of-flight mass spectrometry (GC-TOF-MS) and UPLC coupled to FT-ICR-MS (LC-FT-MS) analyses from the same sample. This resulted in several thousands of detected m/z-features. ANOVA and multivariate statistical analysis revealed 139 significantly changed metabolites (30 by GC-TOF-MS and 109 by LC-FT-MS). The small-statured plants L. autumnalis, B. perennis and L. corniculatus showed metabolic response signatures to increasing plant diversity and species richness in contrast to tall-statured plants. Key-metabolites indicated C- and N-limitation for the non-leguminous small-statured species B. perennis and L. autumnalis, while the metabolic signature of the small-statured legume L. corniculatus indicated facilitation by other legumes. Thus, metabolomic analysis provided evidence for negative effects of resource competition on the investigated small-statured herbs that might mechanistically explain their decreasing performance with increasing plant diversity. In contrast, taller species often becoming dominant in mixed plant communities did not show modified metabolite profiles in response to altered resource availability with increasing plant diversity. Taken together, our study demonstrates that metabolite profiling is a strong diagnostic tool to assess individual metabolic phenotypes in response to plant diversity and ecophysiological adjustment. PMID:20830202

Scherling, Christian; Roscher, Christiane; Giavalisco, Patrick; Schulze, Ernst-Detlef; Weckwerth, Wolfram

2010-01-01

423

Metabolomics Unravel Contrasting Effects of Biodiversity on the Performance of Individual Plant Species  

PubMed Central

In spite of evidence for positive diversity-productivity relationships increasing plant diversity has highly variable effects on the performance of individual plant species, but the mechanisms behind these differential responses are far from being understood. To gain deeper insights into the physiological responses of individual plant species to increasing plant diversity we performed systematic untargeted metabolite profiling on a number of herbs derived from a grassland biodiversity experiment (Jena Experiment). The Jena Experiment comprises plots of varying species number (1, 2, 4, 8, 16 and 60) and number and composition of functional groups (1 to 4; grasses, legumes, tall herbs, small herbs). In this study the metabolomes of two tall-growing herbs (legume: Medicago x varia; non-legume: Knautia arvensis) and three small-growing herbs (legume: Lotus corniculatus; non-legumes: Bellis perennis, Leontodon autumnalis) in plant communities of increasing diversity were analyzed. For metabolite profiling we combined gas chromatography coupled to time-of-flight mass spectrometry (GC-TOF-MS) and UPLC coupled to FT-ICR-MS (LC-FT-MS) analyses from the same sample. This resulted in several thousands of detected m/z-features. ANOVA and multivariate statistical analysis revealed 139 significantly changed metabolites (30 by GC-TOF-MS and 109 by LC-FT-MS). The small-statured plants L. autumnalis, B. perennis and L. corniculatus showed metabolic response signatures to increasing plant diversity and species richness in contrast to tall-statured plants. Key-metabolites indicated C- and