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Plant Leaves (plant + leaf)
Selected AbstractsBiochemical universality of living matter and its metabolic implicationsFUNCTIONAL ECOLOGY, Issue 4 2005A. M. MAKARIEVA Summary 1Recent discussions of metabolic scaling laws focus on the model of West, Brown & Enquist (WBE). The core assumptions of the WBE model are the size-invariance of terminal units at which energy is consumed by living matter and the size-invariance of the rate of energy supply to these units. Both assumptions are direct consequences of the biochemical universality of living matter. However, the second assumption contradicts the central prediction of the WBE model that mass-specific metabolic rate q should decrease with body mass with a scaling exponent µ = ,1/4, thus making the model logically inconsistent. 2Examination of evidence interpreted by WBE and colleagues in favour of a universal µ = ,1/4 across 15 and more orders of magnitude range in body mass reveals that this value resulted from methodological errors in data assortment and analysis. 3Instead, the available evidence is shown to be consistent with the existence of a size-independent mean value of mass-specific metabolic rate common to most taxa. Plotted together, q -values of non-growing unicells, insects and mammals in the basal state yield µ , 0. Estimated field metabolic rates of bacteria and vertebrates are also size-independent. 4Standard mass-specific metabolic rates of most unicells, insects and mammals studied are confined between 1 and 10 W kg,1. Plant leaves respire at similar rates. This suggests the existence of a metabolic optimum for living matter. With growing body size and diminishing surface-to-volume ratio organisms have to change their physiology and perfect their distribution networks to keep their q in the vicinity of the optimum. [source] Colonisation of pitcher plant leaves at several spatial scalesECOLOGICAL ENTOMOLOGY, Issue 4 2003M. Kurtis Trzcinski Abstract., 1.,The effect of meso-scale (zone within bog and local plant density) and fine-scale (leaf length and resource availability) factors on the colonisation of pitcher plant leaves by arthropods was examined in an eastern Canadian bog. 2.,In spring, the abundances of three arthropods, the mosquito Wyeomyia smithii, the midge Metriocnemus knabi, and the mite Sarraceniopus gibsoni, were determined for plots with low, moderate, and high densities of pitcher plants. All overwintering inhabitants were then removed from the plots. Newly opening leaves were colonised from outside the plots, and arthropod abundances were assessed again in autumn. 3.,Pitcher plant fauna varied in their response to the meso-scale factors. In autumn (soon after colonisation), midges were more abundant in areas with high densities of pitcher plants. The relationship between mosquito abundance and plant density, and the variation in abundance among zones within the bog in the spring, were probably due to overwintering mortality. 4.,All taxa responded to the fine-scale factors, leaf length, and capture rate, in the autumn, but the strength of the responses frequently depended on a meso-scale factor (plant density), in which responses were usually strongest where plants were sparse. Thus, the interaction between meso- and fine-scale processes needs to be considered when interpreting patterns of species abundance within arthropod assemblages in pitcher plant leaves. [source] Uptake of inorganic chemicals from soil by plant leaves: Regressions of field data,ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 11 2001Rebecca A. Efroymson Abstract The estimation of chemical concentrations in wildlife foods, such as plant foliage, is often performed for risk assessments at contaminated sites. Regression models and uptake factors for use in estimating the uptake of inorganic elements from soil by above-ground plant tissues were derived in this study. These included models for arsenic, cadmium, copper, lead, mercury, nickel, selenium, and zinc. Models were developed using published data from soil contaminated in the field and were validated using measured concentrations from two contaminated sites. Single-variable regression models of log-transformed concentrations in plants versus log-transformed concentrations in soil are generally recommended over simple uptake factors for use in estimating plant uptake of inorganic contaminants in ecological risk assessments. Multiple regression models with soil concentration and pH as the variables are also recommended for estimating the uptake of four chemicals (cadmium, mercury, selenium, and zinc) by plants. Models for use in screening risk assessments, i.e., the upper 95% prediction limits on the regressions, are recommended to provide conservative estimates of uptake of inorganic chemicals by plants. [source] Effect of light and predator abundance on the habitat choice of plant-attached zooplanktonFRESHWATER BIOLOGY, Issue 3 2007LEENA NURMINEN Summary 1. The diurnal variations in the habitat choice of the periodically plant-attached cladoceran Sida crystallina together with light environment and predator abundance were studied. 2. The density of S. crystallina attached to floating leaves of Nuphar lutea increased between 18:00 and 20:00 hours, when light intensity underneath the leaves was temporarily increased, and decreased again when light intensity declined. A proportion of S. crystallina remained in the swimming mode underneath the leaves even during daylight, indicating that the water column sheltered by the leaves is safer than the open water. 3. In the water adjacent to the leaves, the density of S. crystallina increased steeply in the dark. The increase was not accompanied by a decrease in S. crystallina attached to plant leaves, indicating that the nocturnal increment in the open water density of S. crystallina was due to migration from daytime refuges other than floating leaves. 4. Sida crystallina was most intensively consumed by perch (Perca fluviatilis). Predation threat by fish had weaker effects on the density of S. crystallina attached to plant leaves than on cladocerans in the adjacent water. Cladocerans underneath floating plant leaves, whether attached or not, are probably less vulnerable to fish predation than those outside the leaf cover. 5. The results suggested that light intensity is the proximate factor regulating the attachment of zooplankton to the lower surfaces of floating macrophyte leaves. Light intensity has a positive effect on the density of S. crystallina attached to the floating leaves and a negative effect on density in the water. Predation threat by fish has a strong effect on the migration of zooplankters into the open water habitat. [source] Spatial variation in population growth rate and community structure affects local and regional dynamicsJOURNAL OF ANIMAL ECOLOGY, Issue 6 2008M. Kurtis Trzcinski Summary 1Theory predicting that populations with high maximum rates of increase (rmax) will be less stable, and that metapopulations with high average rmax will be less synchronous, was tested using a small protist, Bodo, that inhabits pitcher plant leaves (Sarracenia purpurea L.). The effects of predators and resources on these relationships were also determined. 2Abundance data collected for a total of 60 populations of Bodo, over a period of 3 months, at six sites in three bogs in eastern Canada, were used to test these predictions. Mosquitoes were manipulated in half the leaves partway through the season to increase the range of predation rates. 3Dynamics differed greatly among leaves and sites, but most populations exhibited one or more episodes of rapid increase followed by a population crash. Estimates of rmax obtained using a linear mixed-effects model, ranged from 1·5 to 2·7 per day. Resource levels (captured insect) and midge abundances affected rmax. 4Higher rmax was associated with greater temporal variability and lower synchrony as predicted. However, in contrast to expectations, populations with higher rmax also had lower mean abundance and were more suppressed by predators. 5This study demonstrates that the link between rmax and temporal variability is key to understanding the dynamics of populations that spend little time near equilibrium, and to predicting and interpreting the effects of community structure on the dynamics of such populations. [source] In-vitro and in-vivo antioxidant activity of different extracts of the leaves of Clerodendron colebrookianum Walp in the ratJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 12 2003D. Rajlakshmi ABSTRACT The in-vitro antioxidant activities of different concentrations of the water, alcoholic, petroleum ether and ethyl acetate extracts of the dried leaves of Clerodendron colebrookianum Walp, and in-vivo antioxidant activity of the water extract was studied in experimental rat models. The results obtained from in-vitro lipid peroxidation induced by FeSO4 -ascorbate in rat liver homogenate showed a significant inhibition of lipid peroxidation by different extracts of C. colebrookianum leaf. Water extracts at concentrations (w/v) of 1:30, 1:50, 1:200 and 1:1000 showed the strongest inhibitory activity over the other organic extracts, suggesting maximum antioxidant effect. Chronic feeding of the water extract to Wistar albino rats (both sexes, 150,200g) in 1 or 2g kg,1/day doses for 14 days significantly increased the ferric reducing ability of plasma by 19% and 40% on the seventh day, and by 45% and 57% on the fourteenth day of treatment, respectively. Thiobarbituric acid reactive substances (TBARS), as a marker of lipid peroxidation, and some cellular antioxidants (superoxide dismutase, catalase and reduced glutathione) were estimated in heart, liver and kidney. There was a significant reduction in hepatic and renal TBARS with both the doses, without any change in myocardial TBARS. There was no change in the level of antioxidants in heart, liver and kidney, except for the hepatic superoxide dismutase. The findings of this study showed that the leaf extract of C. colebrookianum increased the antioxidant capacity of blood and had an inhibitory effect on the basal level of lipid peroxidation of liver and kidney. This lends scientific support to the therapeutic use of the plant leaves, as claimed by the tribal medicine of North-East India. [source] Impact of organic and inorganic fertilizers on yield, taste, and nutritional quality of tomatoesJOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, Issue 4 2006Anuschka Heeb Abstract In a greenhouse experiment, tomato plants were grown in sand culture to test whether different fertilization regimes (mineral or organic fertilizers) at low (500 mg N plant,1 week,1) and high (750 mg N plant,1 week,1) nitrogen levels affected yield, nutritional quality, and taste of the fruits. In the mineral-fertilizer treatments, nitrate- or ammonium-dominated nutrient solutions were used. Organic fertilizer was supplied as fresh cut grass-clover mulch (a total of 2.4,kg and 3.6,kg were given per plant at low and high N level, respectively) without (orgN) and with additional sulfur fertilization (orgN+S). Yields of red tomatoes from the organically fertilized plants were significantly lower (1.3,1.8,kg plant,1) than yields from plants that received mineral fertilizer (2.2,2.8,kg plant,1). At the final harvest, yields of green tomatoes in the organic treatment with extra sulfur were similar (1.1,1.2,kg plant,1) to the NO -dominated treatments at both nutrient levels and the NH -dominated treatment at high nutrient level. Organic fertilizers released nutrients more slowly than mineral fertilizers, resulting in decreased S and P concentrations in the leaves, which limited growth and yield in the orgN treatments. Analysis of tomato fruits and plants as well as taste-test results gave no conclusive answer on the relationship between sugar or acid contents in the fruits, macronutrient content of plant leaves and fruits, and perceived taste. Sugar contents were higher in the fruits given mineral fertilizer, whereas acid contents were higher in the fruits given organic fertilizer. Preference in taste was given to the tomatoes from plants fertilized with the nitrate-dominated nutrient solution and to those given organic fertilizer with extra sulfur. Thus, a reduction in growth, which was expected to lead to a higher concentration of compounds like sugars and acids, did not result in better taste. Overall, it can be concluded that an appropriate nutrient supply is crucial to reach high yields and good taste. [source] The tetraspanin BcPls1 is required for appressorium-mediated penetration of Botrytis cinerea into host plant leavesMOLECULAR MICROBIOLOGY, Issue 3 2004M. Gourgues Summary Animal tetraspanins are membrane proteins controlling cell adhesion, morphology and motility. In fungi, the tetraspanin MgPls1 controls an appressorial function required for the penetration of Magnaporthe grisea into host plants. An orthologue of MgPLS1, BcPLS1, was identified in the necrotrophic fungal plant pathogen Botrytis cinerea. We constructed a Bcpls1::bar null mutant by targeted gene replacement. Bcpls1::bar is not pathogenic on intact plant tissues of bean, tomato or rose, but it infects wounded plant tissues. Both wild type and Bcpls1::bar differentiate appressoria on plant and artificial surfaces, a process involving an arrest of polarized growth, apex swelling and its cell wall reinforcement. Although wild-type appressoria allowed the penetration of the fungus into the host plant within 6,12 h, no successful penetration events were observed with Bcpls1::bar, suggesting that its appressoria are not functional. An eGFP transcriptional fusion showed that BcPLS1 was specifically expressed in conidia, germ tubes and appressoria during host penetration. Our results indicate that BcPLS1 is required for the penetration of B. cinerea into intact host plants. The defect in pathogenicity of Bcpls1::bar also demonstrates that functional B. cinerea appressoria are required for a successful penetration process. As Bcpls1::bar and Mgpls1,::hph penetration defects are similar, fungal tetraspanins are likely to be required for an essential appressorial function widespread among fungi. [source] Leaf respiratory CO2 is 13C-enriched relative to leaf organic components in five species of C3 plantsNEW PHYTOLOGIST, Issue 3 2004Cheng-yuan Xu Summary ,,Here, we compared the carbon isotope ratios of leaf respiratory CO2 (,13CR) and leaf organic components (soluble sugar, water soluble fraction, starch, protein and bulk organic matter) in five C3 plants grown in a glasshouse and inside Biosphere 2. One species, Populus deltoides, was grown under three different CO2 concentrations. ,,The Keeling plot approach was applied to the leaf scale to measure leaf ,13CR and these results were compared with the ,13C of leaf organic components. ,,In all cases, leaf respiratory CO2 was more 13C-enriched than leaf organic components. The amount of 13C enrichment displayed a significant species-specific pattern, but the effect of CO2 treatment was not significant on P. deltoides. ,,In C3 plant leaves, 13C-enriched respiratory CO2 appears widespread. Among currently hypothesized mechanisms contributing to this phenomenon, non-statistical carbon isotope distribution within the sugar substrates seems most likely. However, caution should be taken when attempting to predict the ,13C of leaf respiratory CO2 at the ecosystem scale by upscaling the relationship between leaf ,13CR and ,13C of leaf organic components. [source] Drought stress effects on photosystem I content and photosystem II thermotolerance analyzed using Chl a fluorescence kinetics in barley varieties differing in their drought tolerancePHYSIOLOGIA PLANTARUM, Issue 2 2009Abdallah Oukarroum Drought stress has multiple effects on the photosynthetic system. Here, we show that a decrease of the relative contribution of the I-P phase, ,VIP = ,VI = (FM,FI)/(FM, Fo), to the fluorescence transient OJIP is observed in 10 drought-stressed barley and 9 chickpea varieties. The extent of the I-P loss in the barley varieties depended on their drought tolerance. The relative loss of the I-P phase seems to be related to a loss of photosystem (PS) I reaction centers as determined by 820-nm transmission measurements. In the second part of this study, the interaction of drought and heat stress in two barley varieties (the drought tolerant variety A¨t Baha and the drought sensitive variety Lannaceur) was studied using a new approach. Heat stress was induced by exposing the plant leaves to temperatures of 25,45°C and the inactivation of the O2 -evolving complex (OEC) was followed measuring chlorophyll a (Chl a) fluorescence using a protocol consisting of two 5-ms pulses spaced 2.3 ms apart. In active reaction centers, the dark interval is long enough to allow the OEC to recover from the first pulse; whereas in heat-inactivated reaction centers it is not. In the latter category of reaction centers, no further fluorescence rise is induced by the second pulse. Lannaceur, under well-watered conditions, was more heat tolerant than Aït Baha. However, this difference was lost following drought stress. Drought stress considerably increased the thermostability of PS II of both varieties. [source] Jasmonic acid is involved in the water-stress-induced betaine accumulation in pear leavesPLANT CELL & ENVIRONMENT, Issue 4 2004X.-P. GAO ABSTRACT Jasmonic acid (JA) is known to be involved in the response of plants to environmental stresses such as drought, and betaine (glycinebetaine) is an osmopretectant accumulated in plants under environmental stresses including drought. However, it remains currently unclear whether JA is involved in the water-stress-induced betaine accumulation in plant leaves. The present experiment, performed with the whole pear plant (Pyrus bretschneideri Redh. cv. Suli), revealed that the exogenously applied JA induced a significant increase of the betaine level in the pear leaves when the plants were not yet stressed by drought, and when the plants were subjected to water stress, the ,JA plus drought' treatment induced a significant higher betaine level than did the drought treatment alone. Meanwhile, the ,JA plus drought' treatment induced higher levels of betaine aldehyde dehydrogenase (BADH, E C 1.2.1.8) and activities in the leaves than did the drought treatment alone. These results obtained in the whole plant experiments were supported by the results of detached leaf experiments. In detached leaves JA induced significant increases in betaine levels, BADH activities and BADH protein amounts in a time- and concentration-dependent manner. These data demonstrate that JA is involved in the drought-induced betaine accumulation in pear leaves. [source] The effect of gravity on surface temperatures of plant leavesPLANT CELL & ENVIRONMENT, Issue 4 2003Y. KITAYA ABSTRACT A fundamental study was conducted to develop a facility having an adequate air circulation system for growing healthy plants over a long-term under microgravity conditions in space. To clarify the effects of gravity on heat exchange between plant leaves and the ambient air, surface temperatures of sweet potato and barley leaves and replica leaves made of wet paper and copper were evaluated at gravity levels of 0.01, 1.0, 1.5 and 2.0 g for 20 s each during parabolic aeroplane flights. Thermal images were captured using infrared thermography at an air temperature of 26 °C, a relative humidity of 18% and an irradiance of 260 W m,2. Mean leaf temperatures increased by 0.9,1.0 °C with decreasing gravity levels from 1.0 to 0.01 g and decreased by 0.5 °C with increasing gravity levels from 1.0 to 2.0 g. The increase in leaf temperatures was at most 1.9 °C for sweet potato leaves over 20 s as gravity decreased from 1.0 to 0.01 g. The boundary layer conductance to sensible heat exchange decreased by 5% when the gravity decreased from 1.0 to 0.01 g at the air velocity of 0.2 m s,1. The decrease in the boundary layer conductance with decrease in the gravity levels was more significant in a lower air velocity. Heat exchange between leaves and the ambient air was more retarded at lower gravity levels because of less sensible and latent heat transfers with less heat convection. [source] Proteomic analysis of tobacco mosaic virus-infected tomato (Lycopersicon esculentum M.) fruits and detection of viral coat proteinPROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue S1 2006Juan Casado-Vela Abstract Tobacco mosaic virus (TMV) is a widespread plant virus from the genus Tobamovirus that affects tobacco and tomato plants causing a pathology characterised by cell breakage and disorganisation in plant leaves and fruits. In this study we undertook a proteomic approach to investigate the molecular and biochemical mechanisms potentially involved in tomato fruit defence against the viral infection. The comparison of 2-D gels from control and TMV-infected but asymptomatic tomato fruits revealed changes in several proteins. The differential expression of peptidases, endoglucanase, chitinase and proteins participating in the ascorbate-glutathione cycle in infected fruits suggests that pathogenesis-related proteins and antioxidant enzymes may play a role in the protection against TMV infection. TMV coat protein appeared as a prominent spot in 2-D gels from TMV-infected asymptomatic fruits. A Triton X-114 phase-partitioning step of tomato protein extracts favoured the solubilisation of TMV coat protein and the enrichment of two aminopeptidases not present in control fruits. PMF and MS/MS data of the 2-D gel-isolated TMV coat protein is proposed as a powerful analysis method for the simultaneous tobamovirus detection, species determination and strain differentiation in virus-infected fruit commodities. [source] Uptake of perchlorate by vegetation growing at field sites in arid and subhumid climatesREMEDIATION, Issue 4 2007Dawit D. Yifru Previous greenhouse and field studies show that terrestrial and aquatic vegetation, including trees, grasses, and agricultural produce grown on perchlorate-contaminated soil or with perchlorate-contaminated irrigation water, accumulate perchlorate mainly in their leaf tissue. The phytoaccumulated perchlorate poses potential ecological risk by either contaminating the food chain of humans and animals or recycling in the ecosystem as leaf litter fall that accumulates on topsoil. In this study, the uptake and phytoaccumulation of perchlorate in terrestrial and aquatic vegetation growing at two perchlorate-contaminated sites (the Longhorn Army Ammunition Plant [LHAAP] in Karnack, Texas, and the Las Vegas Wash [LVW], Nevada) was monitored during multiple growing seasons. The LHAAP site is located in a subhumid climate, while the LVW site is located in an arid climate. All vegetation species collected from both sites contained quantifiable levels of perchlorate. The detected concentrations varied with the type of plant species, amount of perchlorate concentration in soil, and season and stage of plant maturity. The highest perchlorate concentrations were measured in willows (Salix nigra), crabgrass (Digitaria spp.), and Bermuda grass (Cynodon dactylon) at the LHAAP, while salt cedar (Tamarix ramosissima) at the LVW phytoaccumulated the highest mass of perchlorate. The concentrations of perchlorate measured in plant leaves growing over contaminated soils at multiple LHAAP locations did not reveal the strong seasonal variability observed at the LVW site. The slow rate of phytodegradation of the perchlorate fraction taken up by plants during the growing season explained the detection of higher perchlorate concentrations in leaves collected later in the growing season (fall) and in senesced leaves compared to younger, live leaves. This proves that senesced plant leaves potentially recycle perchlorate back into the soil on which plant litter collects. To minimize the potential recycling of perchlorate during phytoremediation, it is recommended that senesced leaves be collected and composted or phytoremediation be designed to enhance rapid rhizodegradation (rhizoremediation). © 2007 Wiley Periodicals, Inc. [source] Nitric oxide modulates ozone-induced cell death, hormone biosynthesis and gene expression in Arabidopsis thalianaTHE PLANT JOURNAL, Issue 1 2009Reetta Ahlfors Summary Nitric oxide (NO) is involved together with reactive oxygen species (ROS) in the activation of various stress responses in plants. We have used ozone (O3) as a tool to elicit ROS-activated stress responses, and to activate cell death in plant leaves. Here, we have investigated the roles and interactions of ROS and NO in the induction and regulation of O3 -induced cell death. Treatment with O3 induced a rapid accumulation of NO, which started from guard cells, spread to adjacent epidermal cells and eventually moved to mesophyll cells. During the later time points, NO production coincided with the formation of hypersensitive response (HR)-like lesions. The NO donor sodium nitroprusside (SNP) and O3 individually induced a large set of defence-related genes; however, in a combined treatment SNP attenuated the O3 induction of salicylic acid (SA) biosynthesis and other defence-related genes. Consistent with this, SNP treatment also decreased O3 -induced SA accumulation. The O3 -sensitive mutant rcd1 was found to be an NO overproducer; in contrast, Atnoa1/rif1 (Arabidopsis nitric oxide associated 1/resistant to inhibition by FSM1), a mutant with decreased production of NO, was also O3 sensitive. This, together with experiments combining O3 and the NO donor SNP suggested that NO can modify signalling, hormone biosynthesis and gene expression in plants during O3 exposure, and that a functional NO production is needed for a proper O3 response. In summary, NO is an important signalling molecule in the response to O3. [source] Species richness and abundance of defoliating Lepidoptera associated with Eucalyptus grandis in Brazil and their response to plant ageAUSTRAL ECOLOGY, Issue 6 2001J. C. Zanuncio Abstract The present paper documents patterns of species richness and abundance in Lepidoptera associated with a Eucalyptus grandis plantation, and how these patterns relate to plant age. The large number of species collected (1385), the lack of dominant species and the absence of pest outbreaks during the survey may be related to the high level of plant diversity of the native forest reserves in the area. There was no clear pattern of seasonal variation in species richness, but there were seasonal fluctuations in abundance, with minor defoliator species prevailing in October at the start of the rainy season. Species richness and abundance of Lepidoptera were positively correlated, with both variables decreasing in older plantations. However, the greatest numbers of major outbreak species and minor eucalypt defoliators were observed in plants after the mid-point (6 years old) of their cutting cycle (7,10 years). This may be because of a larger amount of better-quality plant leaves after this mid-point or the reduction in silvicultural management interventions at this period of the Eucalyptus cutting cycle. The abundance of the main outbreak species observed in the survey, Stenalcidia grosica Schaus (Geometridae), was negatively correlated with plant age. Nonetheless, the effect was weak (r = , 0.21, P = 0.03) and we were not able to find further significant correlations between plant age and abundance of the other most frequent and constant species that were collected. [source] High-Level Transient Production of a Heterologous Protein in Plants by Optimizing Induction of a Chemically Inducible Viral Amplicon Expression SystemBIOTECHNOLOGY PROGRESS, Issue 6 2007Michael A. Plesha We have demonstrated that the method of chemical induction using a chemically inducible viral amplicon expression system can be optimized to increase expression of a heterologous protein in plants. A cucumber mosaic virus inducible viral amplicon (CMViva) expression system was used to transiently produce a recombinant human blood protein, ,-1-antitrypsin (AAT), by co-infiltrating intact and detached Nicotiana benthamiana leaves with two Agrobacterium tumefaciens strains, one containing the CMViva expression cassette carrying the AAT gene and the other containing a binary vector carrying the gene silencing suppressor p19. Infiltrated plants were induced by either topical applications or pressure injections and inducer was applied at either a single or multiple time points. Applying induction solution every 2 days via topical application resulted in increasing maximum levels of biologically functional rAAT from 0.71% to 1.3% of the total soluble protein (TSP) in detached plant leaves, a 1.8-fold improvement. Multiple applications of induction solution via pressure injection into intact leaves resulted in maximum levels of biologically functional rAAT being elevated 3-fold up to 2.4% of TSP compared to 0.8% of TSP when using the conventional method of a single topical application, and expression levels remained high 6 days post-induction. Overall production of rAAT in intact leaves was found to have a maximum level of 5.8% of TSP or 390 mg rAAT per kg leaf tissue when applying multiple injections of chemical induction solution. [source] Plant-Arthropod Associations from the Lower Miocene of the Most Basin in Northern Bohemia (Czech Republic): A Preliminary ReportACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 4 2010Jakub PROKOP Abstract: Terrestrial plants and insects currently account for the majority of the Earth's biodiversity, and approximately half of insect species are herbivores. Thus, insects and plants share ancient associations that date back more than 400 Myr. However, investigations of their past interactions are at the preliminary stages in Western Europe. Herein, we present the first results of our study of various feeding damage based on a dataset of nearly 3500 examined plant specimens from the Lower Miocene of the Lagerstätte Bílina Mine in the Most Basin, Czech Republic. This site provides a unique view of the Neogene freshwater ecosystems. It has long been studied by scientists working in different branches of sedimentology, paleobotany, and paleozoology. The fossils are preserved in three characteristic horizons overlaying the coal seam (Clayey Superseam Horizon, Delta Sandy Horizon, and Lake Clayey Horizon), reflecting paleoenvironmental changes in a short time period of development. The trace fossils are classified as functional feeding groups or "guilds", without searching for a direct cause or a recent analog host relation. Approximately 23% of specimens of dicotyledonous plant leaves were found to be damaged and associated with some leaf "morphotypes". Deciduous plant-host taxa, and those with a chartaceous texture typical of riparian habitats, were frequently damaged, such as Populus, recorded with two species Populus zaddachii and Populus populina (57.9% and 31% herbivory levels, respectively), followed by Acer, Alnus, and Carya, averaging almost 30% of damaged leaves/leaflets. There has been evidence of 60 damage types (DT) representing all functional feeding groups recorded at the Bílina Mine, including 12 types of leaf mines and 16 gall-type DT. In total, Lower Miocene of the Lagerstätte Bílina Mine exhibits a high level of external foliage feeding types (23.7%), and a low level of more specialized DT, such as galls (4.3%) and leaf mines (<1%). A broader comparison based on DT of the main sedimentary environments shows significance supporting different biomes by frequency of damage levels and DT diversities. [source] | ||||||||||||||||||||||||||||