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The increasing heavy metal presence in the environment affects plant growth and physiology, seed production and crop quality. Moreover, it could indirectly influence people's health and the quality of the environment. Chelidonium majus L. is an object of study in order to investigate its sensitivity to the toxic effects of heavy metals because of its growth in populated areas and common occurrence. The results of this study revealed that the heavy metal influence on seed germination and seedling growth depended on the type and concentration of the heavy metals and the type of the substrate they supplemented. The studied heavy metals (Cd, Cu, Pb, Zn) did not inhibit the germination of the seeds on filter paper but retarded root and hypocotyl growth on this substrate, except Pb2+, which did not. On agar substrate the metals inhibited both the germination (excl. Pb2+) and seedling growth regardless of concentrations applied. [ABSTRACT FROM AUTHOR]

Abstract: We studied the effects of long-term exposure (nine years) of birch (Betula papyrifera) trees to elevated CO2 and/or O3 on reproduction and seedling development at the Aspen FACE (Free-Air Carbon Dioxide Enrichment) site in Rhinelander, WI. We found that elevated CO2 increased both the number of trees that flowered and the quantity of flowers (260% increase in male flower production), increased seed weight, germination rate, and seedling vigor. Elevated O3 also increased flowering but decreased seed weight and germination rate. In the combination treatment (elevated CO2 +O3) seed weight is decreased (20% reduction) while germination rate was unaffected. The evidence from this study indicates that elevated CO2 may have a largely positive impact on forest tree reproduction and regeneration while elevated O3 will likely have a negative impact. [Copyright &y& Elsevier]

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Antibiotic resistance (AR) is becoming a worldwide threat due to the increasing occurrence of antibiotic-resistant pathogenic bacterial strains. There is a general consensus about the potential implications of the use of antibiotics in livestock on the onset of antibiotic resistant bacteria (ARB), mainly through meat consumption. However, the ever-increasing use of reclaimed wastewater (RWW) in agriculture may also contribute significantly to the non-accounted exposure to antibiotics, ARB, and antibiotic resistance genes (ARGs). This position paper aims at evaluating the current knowledge concerning the occurrence of antibiotics, ARBs, and ARGs in edible parts of different common crops irrigated with RWW. We will discuss which regulations on the use of RWW may contribute to the minimization of the prevalence of these contaminants in crops, and provide recommendations on how to minimize the impact of these practices. [ABSTRACT FROM AUTHOR]

The article discusses studies which investigated the transpiring power of plants as indicated by the method of standardized hygrometric paper. It explains the idea of a standard evaporating surface, the power of which to give off water to the hygrometric cobalt chloride paper was compared directly with the similar power possessed by the leaf surface in question. The use of saturated blotting paper as standard evaporating surface to avoid some of the difficulties arising from the use of the free water surface is also described.

The article presents abstracts of certain research papers published related to plant diseases. In the research paper "Efficacy of PRO-MIX ® With Biofungicide Against Root Disease Caused by Pythium spp," the authors C. Martinez, G. Roy, and A. Bourassa, developed in the past few years peat-based growing media mended with a biocontrol agent, "Bacillus subtilis" MBI600. This strain was selected as the one showing the most efficient biofungicidal activity after screening. Additional research was conducted to evaluate more extensively the biofungicidal activity against Pythium spp., the causal agent of damping-off and root rot. The research paper "Evaluation of Alternative Control Strategies Against the Apple Replant Disease," evaluates the impact of different soil amendment combinations of canola seedmeal, soil fungicides, fumigation, a commercial mycorrhizal inoculant, and of four rotation crops on tree growth and to evaluate the contribution of nematodes to the disease complex under local conditions.

Wood “cell-wall deformation” is a comprehensive term describing any physical dislocation in the wall caused by mechanical forces. The development and effect of fibre dislocations on wood fibres, and their ultimate impact on the mechanical properties of paper remain rather obscure and controversial. Dislocations are difficult to quantify through a lack of defined measurable features, and research is aggravated by the inherent difficulties of applying statistical tools. A direct approach for studying the effect of dislocations on the mechanical properties of paper was used in this study. Dislocations in fibre cell walls were introduced by exposing whole wood fibres in mature and juvenile wood samples to compression stress. Sapwood samples of Norway spruce ( Picea abies Karst.) were loaded by compression to their ultimate strength using an Alwetron-50 universal testing machine. Failure of samples conditioned to a moisture content of 9–15% always occurred in an oblique (relative to the fibre axis) plane and all fibres in the plane were deformed. When samples were loaded in a wet condition (i.e., moisture content close to the fibre saturation point), failure occurred at one end of the samples, resulting in highly disorganised fibres. Pulp and paper from the compressed fibres were produced and the mechanical properties of the paper were tested. Results of the mechanical tests were compared statistically to results derived from paper made from matched non-compressed control samples. Morphological features of fibres and dislocations after compression failure were characterised using microscopy (scanning electron microscopy, polarised light) on the whole wood and macerated fibres before and after paper testing. The above experimental approach showed that paper made from control samples had significantly better mechanical properties than paper made from samples loaded by compression under dry or wet conditions. At a tensile index of 90 N m/g, the tear index was measured as 23.6 mN m 2 /g for controls, while the corresponding values for compressed wet wood samples was 12.6 and 16.3 mN m 2 /g for samples at 9–15% moisture content. Paper made from juvenile wood also showed lower mechanical properties compared to controls. The results prove the negative effect of dislocations on the mechanical properties of paper in the worst case scenario and are of practical importance. [ABSTRACT FROM AUTHOR]

The blue light using FAD (BLUF)-EAL protein YcgF is a known blue-light sensor of Escherichia coli, but its direct regulatory output and physiological function have remained unknown. Here, we demonstrate that unlike other EAL domain proteins, YcgF does not degrade the signaling molecule c-di-GMP, but directly binds to and releases the MerR-like repressor YcgE from its operator DNA upon blue-light irradiation. As a consequence, a distinct regulon of eight small proteins (of 71-126 amino acids) is strongly induced. These include YmgA and YmgB, which, via the RcsC/RcsD/RcsB two-component phosphorelay system, activate production of the biofilm matrix substance colanic acid as well as acid resistance genes and the biofilm-associated bdm gene and down-regulate adhesive curli fimbriae. Thus, small proteins under YcgF/YcgE control seem to act as "connectors" that provide additional signal input into a two-component signaling pathway. Moreover, we found ycgF and ycgE expression to be strongly activated at low temperature, and we elucidate how blue light, cold, and starvation signals are integrated in the expression and activity of the YcgF/YcgE/small protein signaling pathway. In conclusion, this pathway may modulate biofilm formation via the two-component network when E. coli has to survive in an extrahost aquatic environment. [ABSTRACT FROM AUTHOR]

Currently, the major thrust of plant physiology research is to identify and understand the regulation of genes that might be relevant in plant development and growth. The dominance of a genocentric view of plant behaviour has, unfortunately, resulted in the development of major disconnects in the classical view of plant physiology as a partnership between fundamental and practical research contributing to improved plant production. One disconnect is that much of the genocentric research appears to be organized and executed without regard to the practical needs of enhancing plant performance under applied conditions. Although practical benefits from genocentric research are often claimed, basic assumptions guiding much research and the experimental protocols used are commonly not relevant for real-world plant production. A second disconnect is a failure fully to appreciate the lessons learned in 40 years of classical plant physiology research concerning the role of physiological processes in altering whole plant performance. Regulation of plant systems has proved to be complex and redundant. Alteration of a single physiological process is compensated or dampened so that commonly very little change in plant growth and yield results from modification of a single physiological process. Based on a few successful projects employing classical plant physiology to achieve crop yield increase, key characteristics for research projects that truly seek to increase plant performance in production systems are identified. Basically, the partnership between the fundamental and practical research long espoused for plant physiology needs to be re-established in an intimate and meaningful way. [ABSTRACT FROM PUBLISHER]

In order to elucidate the allelopathic effect of leaf litter leachates under laboratory conditions, a modified ‘sandwich method’, which places leaves between two layers of agar, was used. Fifty mg of leaves was used per 10 cm2 cell. Agar concentrations at 0.5–1.0% were the best for gel support in determining radicle and hypocotyl elongation of lettuce. The optimum incubation time for bioassay was three days after imbibition onset. Among 20 typical tree species in Asia, Cymbopogon citratus and Derris scandens showed the strongest inhibitory activity determined by the sandwich method, followed by Piper betle, Tamarindus indica, and Gliricidia sepium. This bioassay seems to be a reliable method for screening allelopathic activity from leaf litter leachates. [ABSTRACT FROM AUTHOR]

In this communication, the results of seed germination inhibitory activity of pulp and paper mill effluent of Faizabad has been evaluated on the basis of experiments conducted under standard laboratory conditions during the year 2005-2006 in the Botany Department of K. S. Saket PG) College, Ayodhya, Faizabad (U.P.), India. [ABSTRACT FROM AUTHOR]

This document discusses the use of omics analysis, such as genomics, transcriptomics, proteomics, and metabolomics, in plant research to uncover the physiological mechanisms of plant development, stress responses, and key trait formation. The document includes ten papers that cover topics such as hormone effects on cutting rooting in woody plants, gene expression in sandalwood and maize, volatile aroma formation in pears, and the transcriptional regulation of miRNAs in plants. The research papers highlight the importance of combining omics and physiological analyses to enhance plant conservation and utilization. Two review papers provide an overview of phosphate-binding loop guanosine triphosphatases (P-loop GTPases) and the transcriptional regulation of miRNAs in plants. The authors emphasize the need for further research using innovative omics techniques to expand our knowledge of plant physiology. [Extracted from the article]

Abstract: Although foliar reflectance in the visible wavelengths is largely understood, species-specific relations between leaf spectral properties, pigment content and carbon exchange, and interdependence of these fundamental drivers that ultimately produce large-scale signals complicate understanding of and upscaling in remote sensing applications. We recorded seasonal patterns in foliar reflectance in relation to leaf photosynthetic, biochemical, structural and optical properties in two co-occurring tree species, red oak (Quercus rubra) and paper birch (Betula papyrifera). Over the course of a growing season, we monitored the timing of phenological events, i.e. bud break, near-complete leaf expansion and leaf fall, on mature trees. On a monthly basis, maximum rate of carboxylation (V cmax) and maximum rate of electron transport (J max) were estimated from leaf-level gas exchange measurements in the upper crown for three individuals per species. Thereafter, visible and near infrared spectral properties, nitrogen content and specific leaf area were determined for sampled sunlit leaves. These data were compared with color indices extracted from digital images of sampled leaves throughout the growing season. Studied leaf traits significantly varied between the two species and throughout the growing season. Paper birch was characterized by relatively early bud break and rapid leaf expansion. Hence, interactions between species and day of year could be partly contributed to contrasting spring phenology of paper birch and red oak. Spectral vegetation indices, Chlorophyll Normalized Difference Index (Chl NDI), Photochemical Reflectance Index (PRI) and in particular Red Edge Position (λRE), gave a good indication of leaf physiology over the course of the growing season, more specifically of photosynthesis and leaf nitrogen on an area basis (N area). On the other hand, color indices performed rather poorly at tracking key leaf functional traits in this study. Overall, dark green leaves characterized by low Intensity (I, derived from HSI color space) displayed highest photosynthetic activity and highest values of spectral vegetation indices. [Copyright &y& Elsevier]

This paper discusses the mechanisms by which fungi manipulate plant physiology and suppress plant defense responses by producing effectors that can target various host proteins. Effector-triggered immunity and effector-triggered susceptibility are pivotal elements in the complex molecular dialogue underlying plant–pathogen interactions. Pathogen-produced effector molecules possess the ability to mimic pathogen-associated molecular patterns or hinder the binding of pattern recognition receptors. Effectors can directly target nucleotide-binding domain, leucine-rich repeat receptors, or manipulate downstream signaling components to suppress plant defense. Interactions between these effectors and receptor-like kinases in host plants are critical in this process. Biotrophic fungi adeptly exploit the signaling networks of key plant hormones, including salicylic acid, jasmonic acid, abscisic acid, and ethylene, to establish a compatible interaction with their plant hosts. Overall, the paper highlights the importance of understanding the complex interplay between plant defense mechanisms and fungal effectors to develop effective strategies for plant disease management. [ABSTRACT FROM AUTHOR]

White birch (Betula papyrifera) is a dominant tree species of the Boreal Forest. Recent studies have shown that it is fairly resistant to heavy metal contamination, specifically to nickel. Knowledge of regulation of genes associated with metal resistance in higher plants is very sketchy. Availability and annotation of the dwarf birch (B. nana) enables the use of high throughout sequencing approaches to understanding responses to environmental challenges in other Betula species such as B. papyrifera. The main objectives of this study are to 1) develop and characterize the B. papyrifera transcriptome, 2) assess gene expression dynamics of B. papyrifera in response to nickel stress, and 3) describe gene function based on ontology. Nickel resistant and susceptible genotypes were selected and used for transcriptome analysis. A total of 208,058 trinity genes were identified and were assembled to 275,545 total trinity transcripts. The transcripts were mapped to protein sequences and based on best match; we annotated the B. papyrifera genes and assigned gene ontology. In total, 215,700 transcripts were annotated and were compared to the published B. nana genome. Overall, a genomic match for 61% transcripts with the reference genome was found. Expression profiles were generated and 62,587 genes were found to be significantly differentially expressed among the nickel resistant, susceptible, and untreated libraries. The main nickel resistance mechanism in B. papyrifera is a downregulation of genes associated with translation (in ribosome), binding, and transporter activities. Five candidate genes associated to nickel resistance were identified. They include Glutathione S–transferase, thioredoxin family protein, putative transmembrane protein and two Nramp transporters. These genes could be useful for genetic engineering of birch trees. [ABSTRACT FROM AUTHOR]

Evidence indicating the natural occurrence of the auxin substance, phenylacetic acid (PAA), in a range of crop plants has been obtained from paper chromatography followed by bioassay and from HPLC and GLC analysis of acidic ether extracts from vegetative shoots of these plants. Confirmatory evidence for the presence of PAA in tobacco shoots has been obtained from GC-MS analysis. Quantitative estimation of the relative amounts of the two auxins, IAA and PAA, in the different shoot extracts was achieved by paper chromatography followed by gas chromatography. The amount of PAA in all six plants was found to be several times greater than that of IAA and calculation of average internal concentrations revealed that PAA is present in vegetative shoots at physiologically active concentrations. Present knowledge of the growth-regulating activity of this new natural auxin is discussed. [ABSTRACT FROM AUTHOR]

This article focuses on determining foliar characteristics and the transpiring power of plant leaves. It stresses that transpiring power represents the summed total of all the conditions inside the leaf that either accelerate or retard transpiration. This paper aimed to measure the transpiring power of leaves at different hours of the day by means of standardized cobalt chloride paper and to compare the values obtained with those derived from porometer readings. This article also discusses the hygrometric paper method.

Simple Summary: The use of sound wave technology on different plant species has revealed that variations in the Hz, sound pressure intensity, treatment time, and type of setup of the sound source significantly impact the plant performance. For example, a study conducted on cotton plants treated by Plant Acoustic Frequency Technology (PAFT) highlighted improvements across various growth parameters. In particular, the treated samples showed increases in the height, leaf area, and number of boll-bearing branches, as well as other plant anatomical parts. In other cases, such as in transgenic rice plants, GUS expression was upregulated or downregulated concerning the Hz employed. This paper presents a complete, rationalized and updated review of the literature on the effects of sound waves on the physiology and growth parameters of sound-treated plants. The application of sound wave technology to different plant species has revealed that variations in the Hz, sound pressure intensity, treatment duration, and type of setup of the sound source significantly impact the plant performance. A study conducted on cotton plants treated with Plant Acoustic Frequency Technology (PAFT) highlighted improvements across various growth metrics. In particular, the treated samples showed increases in the height, size of the fourth expanded leaf from the final one, count of branches carrying bolls, quantity of bolls, and weight of individual bolls. Another study showed how the impact of a 4 kHz sound stimulus positively promoted plant drought tolerance. In other cases, such as in transgenic rice plants, GUS expression was upregulated at 250 Hz but downregulated at 50 Hz. In the same way, sound frequencies have been found to enhance the osmotic potential, with the highest observed in samples treated with frequencies of 0.5 and 0.8 kHz compared to the control. Furthermore, a sound treatment with a frequency of 0.4 kHz and a sound pressure level (SPL) of 106 dB significantly increased the paddy rice germination index, as evidenced by an increase in the stem height and relative fresh weight. This paper presents a complete, rationalized and updated review of the literature on the effects of sound waves on the physiology and growth parameters of sound-treated plants. [ABSTRACT FROM AUTHOR]

Citrus are the most produced fruits worldwide. It is expected that these crops will be severely affected by climate change. However, the literature lacks works that attempt to understand the influence of climate change on citrus. For this reason, a bibliometric analysis was conducted on climate change and citrus to investigate its development and current trends in this research domain. The main trends, keywords, and their relations were identified. The period from 1992 to 2022 was analyzed, resulting in 178 documents in the Scopus database. The most significant publishers' countries were also the largest citrus producers in the world besides being G7 members. Three main research areas were identified: modeling, socio-political issues, and plant physiology. A tendency to change interest from modeling and risk analysis to physiology and stress studies was observed. Additionally, some of the most cited papers observed the positive impacts of climate change on certain citrus crops. Despite the multidisciplinary publications, two main gaps were identified: (i) the lack of investigations with combined stresses (abiotic and biotic) instead of isolated studies, and (ii) the lack of studies of predictive models for citrus production in different conditions and climate change scenarios. Finally, there was a tendency toward studying water use and irrigation alternatives due to water scarcity and management solutions to improve the production system's resilience, considering the potential impacts of climate change. [ABSTRACT FROM AUTHOR]

This paper presents the results obtained from the analysis of physiological and biochemical parameters in the radish, species Raphanus sativus L., variety Rond Ecarlate, which was grown in three different systems (in the field, in the solarium and in the climate chamber). Several parameters necessary for the evaluation of biomass, physiological processes and nutritional values were determined. Regarding the biometric parameters, it was noticed that in the field cultivation the plants formed 11-12 leaves, in the solarium average 12-13 leaves, and in the climatic chamber the analyzed plants formed 7-9 leaves, on an average. The total biomass of the plant was recorded with the following average values: in the field 70.05 grams, in the solarium 92.3 grams and in the climate chamber 32.9 grams. Regarding the circumference of the tuberous hypocotyl axis, the values are higher in plants grown in solarium (16.9 cm), with the smallest dimensions being recorded in plants grown in the climate chamber (7.2 cm). The highest average pulp firmness value was observed in plants grown in the solarium (0.27 kg force), and the lowest values were seen in plants grown in the climate chamber (0.14 kg force). Regarding the amount of water lost through perspiration by the leaves of radish plants, the highest average values were recorded at plants grown in the solarium, and the lowest at plants grown in the climatic chamber. The average soluble dry matter content was higher (over 4%) in plants grown in the climate chamber compared to other harvesting systems. The analysis of the average carbohydrate content shows that the total soluble carbohydrates were present only in the hypocotyl axis and glucose was found both in the hypocotyl axis of the studied plants and in the leaves. Vitamin C was present in variable amounts, both in the hypocotyl axis and in the leaves. The average amino acid content (expressed in amino nitrogen) was between 0.003% and 0.006%. The anthocyanin was present with highest values (54.5 mg) in field-grown plants, and catalase activity was present both in the hypocotyl axis and in the leaves and roots. Air humidity and temperature had a high influence on the development of plant biomass, on the content of dry matter and on the loss of water through transpiration. The biometric, physiological and biochemical parameters varied depending on the cultivation system. [ABSTRACT FROM AUTHOR]

We describe an implementation of the Ecosystem Demography (ED) concept in the Community Land Model. The structure of CLM(ED) and the physiological and structural modifications applied to the CLM are presented. A major motivation of this development is to allow the prediction of biome boundaries directly from plant physiological traits via their competitive interactions. Here we investigate the performance of the model for an example biome boundary in Eastern North America. We explore the sensitivity of the predicted biome boundaries and ecosystem properties to the variation of leaf properties determined by the parameter space defined by the GLOPNET global leaf trait database. Further, we investigate the impact of four sequential alterations to the structural assumptions in the model governing the relative carbon economy of deciduous and evergreen plants. The default assumption is that the costs and benefits of deciduous vs. evergreen leaf strategies, in terms of carbon assimilation and expenditure, can reproduce the geographical structure of biome boundaries and ecosystem functioning. We find some support for this assumption, but only under particular combinations of model traits and structural assumptions. Many questions remain regarding the preferred methods for deployment of plant trait information in land surface models. In some cases, plant traits might best be closely linked with each other, but we also find support for direct linkages to environmental conditions. We advocate for intensified study of the costs and benefits of plant life history strategies in different environments, and for the increased use of parametric and structural ensembles in the development and analysis of complex vegetation models. [ABSTRACT FROM AUTHOR]

The combination of autoradiography and a filter paper 'sandwich' technique using wheat plants labelled with [SUP14]C has shown that roots of wheat exude two types of compounds, viz. (a) non-diffusible material released from the apices of both primary and lateral roots and (b) diffusible material released along the whole length of the roots. The high amount of non-diffusible material compared with diffusible material suggests that the former may be more significant than previously anticipated in relation to root functions and microorganisms in the rhizosphere. [ABSTRACT FROM AUTHOR]

Oil sands mining in northeastern Alberta, Canada, generates tailings containing sand, silt, clay, water, and residual bitumen with hydrocarbons. The impact of tailings on revegetation is a major environmental concern and poses a significant land reclamation challenge. Oil sands companies have recently developed technologies that use thickeners in combination with carbon dioxide to produce non‐segregating tailings (NST), to accelerate the consolidation of tailings while sequestering greenhouse gases. Effects of these tailings on plant re‐establishment have yet to be determined. We investigated the impact of NST on biomass and physiology of 20 boreal woody plant species grown in environmentally controlled growth rooms. The seedlings were grown for 8 weeks in NST capped with boreal forest topsoil or peat‐mineral soil mix or petroleum coke in 50‐cm‐long polyvinyl chloride pipes. We found that the biomass of balsam fir, beaked hazelnut, blueberry, green alder, Labrador tea, lowbush cranberry, paper birch, and raspberry was severely reduced by NST, while the effects on balsam poplar, Bebb's willow, chokecherry, dogwood, saskatoon, and white spruce were relatively weak. This was also the case for jack pine, which showed poor survival in NST. The negative impact of NST on plants can be largely explained by elevated sodium and decreased foliar nutrient concentrations. The impact of NST capping with petroleum coke on plant growth was non‐significant. Differences among species in their survival and biomass responses to NST appeared to be partly a reflection of their natural habitats. Findings from this study can help guide revegetation oil sands reclamation strategies. [ABSTRACT FROM AUTHOR]