Search

We used three purple soil (Hechuan, Jialing, and Cangxi) samples from the Jialing River basin as the research objects and added different proportions of an acid–base modified Alternanthera philoxeroides biochar (Cm) to the purple soil to study the effect of Cm on the adsorption of chlortetracycline (CTC) in the purple soil. The results indicated the following: (1) At 30 °C and pH = 6, the soil adsorption capacity increased with an increasing initial concentration of CTC. The maximum adsorption amount of CTC for each tested sample was in the range of 2054.63–3631.21 mg/kg, and the adsorption capacity in different Cm amended soils was ranked in the order of 10% Cm > 5% Cm > 2% Cm > CK. The adsorption capacity of CTC increased with an increase in the proportion of Cm. Furthermore, under the same addition ratio of Cm, Hechuan soil was found to have a better adsorption effect for CTC than Jialing and Cangxi soil. (2) The Langmuir model was the most suitable for fitting the adsorption behavior of CTC on different purple soils, and the fitting coefficients were all greater than 0.9, indicating that the adsorption of CTC on each soil sample occurred via monolayer adsorption. The thermodynamic experiment results showed that an increase in temperature was beneficial to the process of CTC adsorption, which was a spontaneous, endothermic, and entropy-adding process. (3) At pH = 6, the ionic strength ranged from 0.01 to 0.5 mol/L and the adsorption capacity of CTC of the soil samples decreased with an increase in ionic strength. In the range of pH 2–10, the adsorption capacity of CTC in all the soil samples decreased with an increase in pH. The inhibition capacity of CTC in the soil samples under acidic conditions was notably higher than that under alkaline conditions. [ABSTRACT FROM AUTHOR]

Copyright of Journal of South China Agricultural University is the property of Gai Kan Bian Wei Hui and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Alternanthera philoxeroides (Mart.) Griseb., commonly known as "Alligator weed" in English, and "Malancha" in Bengali, is a leafy vegetable from the family Amaranthaceae A. L. de Jussieu. This species is native to China, particularly to the provinces around the Yangtze River, other Far East and South-East Asian countries, and countries from other continents (e.g., South America). This plant also grows in certain areas in Australia, New Zealand, and the USA. While in Bangladesh the leaves of this plant are consumed as a vegetable, in China, this plant has been used widely as a traditional remedy for the treatment of various viral diseases (e.g., measles, influenza, and haemorrhagic fever). Flavonoids and saponins are the two largest groups of phytochemicals produced by this plant, and the antiviral property of this plant and its compounds has been studied extensively. This review article reviews all published literature on this plant and critically appraises its phytochemical profile linking to biomolecular interactions and therapeutic potential, particularly, against viral diseases. [ABSTRACT FROM AUTHOR]

Alternanthera philoxeroides (Mart.) Griseb. (Alternanthera philoxeroides) is an important herbage species, which could provide high-quality feed for livestock and poultry breeding. This paper is the first to report the A. philoxeroides’s chloroplast genomes, which were detected by de novo sequencing. The results showed that the length of A. philoxeroides’ chloroplast genome sequence was 152,255 bp, including a large single-copy (LSC) region (84,670 bp), a small single-copy (SSC) region (17,343 bp), and two inverted repeat (IR) regions (25,121 bp). Alternanthera philoxeroides’ chloroplast genome encoded 132 genes including 8 rRNA, 38 tRNA, and 86 protein-coding genes. After phylogenetic and cluster analysis, A. philoxeroides was closest to Amaranthaceae, and the relationship between Amaranthus and Achyranthes was closest.

Copyright of Journal of South China Agricultural University is the property of Gai Kan Bian Wei Hui and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To investigate the effect of invasive Alternanthera philoxeroides mats on native leaf litter decomposition, we allocated two native leaf species of contrasting recalcitrance (Neosinocalamus affinis and Ficus virens) in litterbags with four different mesh sizes (0.025, 0.042, 0.5, and 5 mm) and the bags were either incubated under floating A. philoxeroides mats (Vegetated site) or under floating plastic foam boards without A. philoxeroides mats (Unvegetated site) for 65 days in Jianhu Lake, China, in July 2020. The average decomposition rates increased with pore size of litterbags. The interaction intensity of the site effect in leaf mass loss was negative in 0.025 mesh and positive in other meshes, while no significance existed between two native species in the same mesh sizes and sites. The contribution of microbes to decomposition was more than 50% in both sites. The contribution in the vegetation site was as follows: microbes > microinvertebrates > meioinvertebrates > macroinvertebrates, compared with microbes > macroinvertebrates > meioinvertebrates > microinvertebrates in the unvegetated site. The results suggest that A. philoxeroides mats can promote the decomposition of native leaf litter, and that the roles of micro-, meio-, and macroinvertebrates in decomposition are important but underestimated. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Applied Entomology is the property of Chinese Journal of Applied Entomology, Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Xinyang Normal University Natural Science Edition is the property of Journal of Xinyang Normal University Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract Background Alternanthera philoxeroides (alligator weed) is a highly invasive alien plant that has continuously and successfully expanded from the tropical to the temperate regions of China via asexual reproduction. During this process, the continuous decrease in temperature has been a key limiting environmental factor. Results In this study, we provide a comprehensive analysis of the cold tolerance of alligator weed via transcriptomics. The transcriptomic differences between the southernmost population and the northernmost population of China were compared at different time points of cold treatments. GO enrichment and KEGG pathway analyses showed that the alligator weed transcriptional response to cold stress is associated with genes encoding protein kinases, transcription factors, plant-pathogen interactions, plant hormone signal transduction and metabolic processes. Although members of the same gene family were often expressed in both populations, the levels of gene expression between them varied. Further ChIP experiments indicated that histone epigenetic modification changes at the candidate transcription factor gene loci are accompanied by differences in gene expression in response to cold, without variation in the coding sequences of these genes in these two populations. These results suggest that histone changes may contribute to the cold-responsive gene expression divergence between these two populations to provide the most beneficial response to chilling stimuli. Conclusion We demonstrated that the major alterations in gene expression levels belonging to the main cold-resistance response processes may be responsible for the divergence in the cold resistance of these two populations. During this process, histone modifications in cold-responsive genes have the potential to drive the major alterations in cold adaption necessary for the northward expansion of alligator weed.

The effects of invasive species on the local community (e.g., structure and stability) are highly environmentally dependent. Invasions of amphibious species usually take place in both xeric and humid environments, yet they are relatively poorly understood. In this study, we analyzed the communities that were dominated by Alternanthera philoxeroides using ecological niche and interspecific association. A total of 66 species and 67 species were recorded in the xeric environment and humid environment, respectively. In both environments, species in family Gramineae, such as Echinochloa crusgalli and Cynodon dactylon, exhibited a higher level of importance values and greater ecological niche widths. The interspecific association and stability of the dominant species were weak and the dominant species were relatively independent of each other. In the xeric environment, A. philoxeroides was more compatible with E. crusgalli and C. dactylon in terms of ecological niche requirements and habitat suitability. In humid habitats, A. philoxeroides had a greater correlation with E. crusgalli, C. dactylon, and Persicaria lapathifolia, suggesting a higher possibility of concomitant occurrence. Overall, we suggested that during the revegetation after A. philoxeroides invasion, E. crusgalli and C. dactylon can be the alternative plants. Meanwhile, alternative control measures for A. philoxeroides invasion in agricultural fields should give more consideration to the use of plants with economic or ecological value.

Soil microbes play an important role in plant invasion, and parasitic plants regulate the growth of invasive plants. However, the mechanisms by which parasitic plants regulate the effects of soil microbes on invasive plants have not been investigated. Here, we used the invasive plant Alternanthera philoxeroides and the holoparasitic plant Cuscuta grovonii to test whether and how C. grovonii parasitism shifts the effect of native soil microbes on the growth of A. philoxeroides. In a factorial setup, A. philoxeroides was grown in pots with the presence versus absence of parasitism and the presence versus absence of native soil microbes. The findings showed that native soil microbes increased the biomass and clonal growth of A. philoxeroides only in the absence of a parasite, whereas parasitism decreased the biomass and clonal growth of A. philoxeroides only in the presence of soil microbes. In addition, the presence of soil microbes increased the deleterious effects of the parasite on A. philoxeroides. These results indicate that parasitism can shift the effects of native soil microbes on the growth of the invasive plant A. philoxeroides. Our results enrich the understanding of the mechanisms underlying the success of plant invasion.

Agasicles hygrophila Selman and Vogt is used in the biological control of the invasive weed Alternanthera philoxeroides (Mart.) Griseb. However, with the northward establishment of A. philoxeroides in China, the weak adaptivity of A. hygrophila to cold weather has resulted in the ineffective control of A. philoxeroides in northern China. Cold acclimation can significantly enhance insect cold tolerance, enabling them to cope with more frequent climate fluctuations. To improve the biological control efficacy of A. hygrophila in cold climates, we compared the effects of rapid cold hardening and acclimation on A. hygrophila under laboratory conditions. On initially transferring adults from 26 to −10 °C for 2 h, mortality reached 80%. However, when pre-exposed to 0 °C for 2 h and then transferred to −10 °C for 2 h, adult mortality was reduced to 36.67%. These findings indicate that cold acclimation can enhance the cold tolerance of A. hygrophila under laboratory conditions. However, the beneficial cold acclimation effects waned after more than 15 min of recovery at 26 °C. Exposure to 15 °C for 24 h or gradual cooling from 0 to −10 °C at 1 °C·min−1 also induced cold acclimation, indicating that long-term cold and fluctuating cold acclimation are also potentially effective strategies for enhancing low-temperature tolerance.

Aim: An increasing number of exotic plants and their biological control agents are being introduced into new regions. Therefore, it is necessary to study their interactions and to manage the future directions of plant invasions under different scenarios of temperature rise. Location: China. Method: We investigated the distribution patterns of the two most prevalent invasive aquatic plants in the world, Alternanthera philoxeroides and Eichhornia crassipes, at a large scale and studied the interactions of both invasive plants with their respective biological control agents, Agasicles hygrophila and Neochetina eichhorniae, in response to different scenarios of temperature rise. Results: Both plants performed better in warmer climates in common garden experiments. However, large populations of A. philoxeroides occurred only in the temperate zone because this species experienced competitive exclusion from E. crassipes and suppression due to A. hygrophila herbivory in tropical and subtropical areas. Moreover, in both subtropical zones, where the two plants and A. hygrophila co‐occur, and the temperate zone, where only A. philoxeroides occurs at present, A. hygrophila herbivory and the competition from E. crassipes hindered the performance of A. philoxeroides. Moreover, in the extreme high‐temperature environment, A. philoxeroides performance improved, while E. crassipes performance worsened. In addition, the combination of N. eichhorniae herbivory and competition from A. philoxeroides also reduced the performance of E. crassipes, but E. crassipes still dominated when in competition with A. philoxeroides. Main conclusions: Our results indicate that climate warming and the introduction of herbivores do not alter the interspecific relationship between E. crassipes and A. philoxeroides. Moreover, our study suggests that under climate warming, E. crassipes will replace A. philoxeroides as the dominant species in some communities in warm temperate zones, though extremely high‐temperature events will slow this replacement process. [ABSTRACT FROM AUTHOR]

Pharmaceutical and personal care products (PPCPs) are a representative class of emerging contaminants. This study aimed to investigate the PPCP removal performance and application safety of a biochar fabricated using the invasive plant Alternanthera philoxeroides (APBC). According to scanning electron microscopy and pore size analyses, APBC exhibited a porous structure with a specific surface area of 857.5 m2/g. A Fourier transform infrared spectroscopy analysis indicated the presence of surface functional groups, including phosphorus-containing groups, C=O, C=C, and –OH. The adsorption experiment showed that the maximum removal efficiency of ibuprofen was 97% at an initial concentration of 10 mg/L and APBC dosage of 0.8 g/L. The adsorption kinetics were fitted by the pseudo-second-order model with the highest correlation coefficient (R2 = 0.9999). The adsorption isotherms were well described by the Freundlich model (R2 = 0.9896), which indicates a dominant multilayer adsorption. The maximum adsorption capacity of APBC was 172 mg/g. A toxicity evaluation, based on Chlorella pyrenoidosa and human epidermal BEAS-2B cells, was carried out using a spectrum analysis, thiazolyl blue tetrazolium bromide assay, and flow cytometry. The results of the above showed the low cytotoxicity of APBC and demonstrated its low toxicity in potential environmental applications. [ABSTRACT FROM AUTHOR]

Long-term pre-release evaluations of how invasive plants respond to herbivory in introduced ranges can help identify the most effective biological control agents. However, most evaluations have been conducted within only one generation of introduced invasive species. This study tested effects across seven generations of simulated herbivory (i.e., defoliation) and habitat types on the invasive weed Alternanthera philoxeroides. We found total biomass of A. philoxeroides was decreased by defoliation during the first three generations when grown in a simulated aquatic habitat, but was decreased by defoliation only in the first generation when grown in a simulated terrestrial habitat. Defoliation significantly decreased stem diameter and collenchyma thickness and increased cortex thickness and total phenol production in A. philoxeroides grown in a simulated terrestrial or aquatic habitat during the first generation, but showed little effect during the following six successive generations. The associations between stem anatomical structural parameters and biomass significantly differed between non-defoliation and defoliation treatments in the simulated aquatic habitat, but not in the simulated terrestrial habitat. Our results suggest simulated herbivory exerted successful biological control on A. philoxeroides during the first generation in a simulated terrestrial habitat and the first three generations in a simulated aquatic habitat, but failed to restrain the vegetative offspring of A. philoxeroides. This failure of long-term biological control on A. philoxeroides might be caused by changes in the stem anatomical structure and compensatory growth. Our study highlights the need for long-term pre-release evaluation when testing the efficiency of biological control agents. [ABSTRACT FROM AUTHOR]

The majority of problematic invasive plants exhibit clonal growth, and the clonal traits are widely recognized as critical determinants contributing to their invasiveness. Division of labor represents a crucial advantage associated with clonal growth; therefore, it is reasonable to anticipate that this particular trait may confer a growth advantage upon invasive clonal species in comparison to native ones. To test this hypothesis, we conducted a comparative experiment in the greenhouse involving the highly invasive plant Alternanthera philoxeroides , its native congener A. sessilis , and its native co-occurring Jussiaea repens. We grew clonal fragments of these three stoloniferous plants under negative spatial covariance of light and soil nutrients while either preventing or allowing division of labor through severing or keeping intact their stolon connections. The results showed that stolon connection significantly increased the root mass to shoot mass ratio of basal ramets under low light and high soil nutrient conditions, but greatly decreased it in the apical ramets under high light and low soil nutrient conditions, suggesting induced division of labor in all studied plants. Moreover, the invasive plant A. philoxeroides demonstrated a greater capacity for division of labor than its co-genus and co-occurring native partners, which conferred it with greater growth performance at the whole clonal fragment level. Given that the commonly observed competitive superiority of invasive clonal plants over co-occurring native species due to their high intrinsic growth rates, these findings suggest that the division of labor may confer a competitive advantage upon some invasive clonal plants, thereby facilitating their successful invasion in heterogeneous habitats characterized by a strong negative correlation between light availability and soil nutrient levels. • Division of labor is a critical clonal trait that affects the success of plant invasion. • Invasive plants may benefit from division of labor more than natives. • The division of labor was induced in all studied plants in heterogeneous habitats. • Greater specialization led to more biomass increase in an invasive plant compared to natives. • Division of labor may give invasive plants a competitive edge, aiding their invasion. [ABSTRACT FROM AUTHOR]

[Display omitted] • Innovatively utilizing DES synthesized from choline chloride and lactic acid for biomass pretreatment and co-pyrolysis. • Highest removal rate of lignin from biomass achieved after pretreatment reaches 82.37%. • ZSM-5 catalytic pyrolysis increases hydrocarbons by 23.23%, reaching 54.53%. • Significant reduction in acids and carbonyls content observed after pretreatment. The primary objective of this study is to explore the application of a deep eutectic solvent, synthesized from lactic acid and choline chloride, in combination with a pre-treatment involving ZSM-5 catalytic fast pyrolysis, aimed at upgrading the quality of bio-oil. Characterization results demonstrate a reduction in lignin content post-treatment, alongside a significant decrease in carboxyls and carbonyls, leading to an increase in the C/O ratio and noticeable enhancement in crystallinity. During catalytic fast pyrolysis experiments, the pre-treatment facilitates the production of oil fractions, achieving yields of 54.53% for total hydrocarbons and 39.99% for aromatics hydrocarbons under optimized conditions. These findings validate the positive influence of the deep eutectic solvent pre-treatment combined with ZSM-5 catalytic fast pyrolysis on the efficient production of bio-oil and high-value chemical derivatives.. [ABSTRACT FROM AUTHOR]

Natural disturbances and human activities frequently fragment aquatic plants. Vegetative fragments of invasive clonal plants have a high capacity for colonization and regrowth, which results in rapid spreading of these plants. A case study was conducted to explore the effects of the water level and light on the colonization and regrowth of a clonal invasive plant – Alternanthera philoxeroides. In the study, the growth of 10-cm-long fragments of A. philoxeroides was followed in three water levels (0, 2, and 10 cm) and two light conditions (10% and 80% of natural light). Results showed that total biomass of A. philoxeroides under all treatments except 10% of natural light and 10 cm of water level was higher than the initial biomass, which suggested that fragments of A. philoxeroides can regrow under most conditions. However, treatments of high water levels and low light inhibited regrowth, clonal expansion, and vegetative propagation of clonal fragments by reducing their total biomass, number of nodes and storage root biomass. Creating habitats of high water levels and low light, for example, by planting native emergent aquatic plants, can hamper the spread of this clonal invader. Our study contributes a new perspective to controlling the spread of invasive clonal plants by creating habitats that inhibit the colonization of invasive plant propagules. • High water level and low light inhibited regrowth of clonal fragments of Alternanthera philoxeroides. • High water level and low light inhibited clonal expansion of clonal fragments of A. philoxeroides. • High water level and low light inhibited vegetative propagation of clonal fragments of A. philoxeroides. • It may be feasible to change environmental factors to prevent invasion of alien clonal plants in the uninvaded habitats. [ABSTRACT FROM AUTHOR]

Plants release a variety of volatiles and herbivore-induced plant volatiles (HIPVs) after being damaged by herbivorous insects, which play multiple roles in the interactions with other plants and insects. Agasicles hygrophila Selman and Vogt (Coleoptera: Chrysomelidae) is a monophagous natural enemy and an effective biocontrol agent for Alternanthera philoxeroides (Mart.) Griseb. Here, we reported differences among the volatiles of A. philoxeroides by solid phase microextraction (SPME) using a gas chromatography-mass spectrometer (GC-MS). We compared the volatile emission of: (1) clean plants (CK); (2) A. philoxeroides plants with mechanical damage treatment (MD); and (3) A. philoxeroides plants infested with A. hygrophila 1st, 2nd, and 3rd larvae and female and male adults. A total of 97 volatiles were recorded, of which 5 occurred consistently in all treatments, while 61 volatiles were only observed in A. philoxeroides infested by A. hygrophila, such as trans-nerolidol, (E)-β-farnesene, and (3E,7E)-4,8,12-trimethyltrideca-1,3,7,11-tetraene (E, E-TMTT), etc. Among the 97 volatile compounds, 37 compounds belong to alkenes, 29 compounds belong to alkanes, and there were 8 esters, 8 alcohols and 6 ketones. Orthogonal partial least squares-discrimination analysis (OPLS-DA) showed that the different treatments were separated from each other, especially insect feeding from CK and MD treatments, and 19 volatiles contributed most to the separation among the treatments, with variable importance for the projection (VIP) values > 1. Our findings indicated that the alligatorweed plants could be induced to release volatiles by different stages of A. hygrophila, and the volatile compounds released differ quantitatively and qualitatively. The results from this study laid an important foundation for using volatile organic compounds (VOCs) and HIPVs of alligatorweed to improve the control effect of A. hygrophila on A. philoxeroides.

Like any other biological tissue, plant tissue also exhibits optical properties like refraction, transmission, absorption, coloration, scattering and so on. Several studies have been conducted using different parts of plants such as leaves, seedlings, roots, stems and so on, and their optical properties have been analyzed to study plant physiology, influence of environmental cues on plant metabolism, light propagation through plant parts and the like. Thus, it is essential to study in detail the optical properties of several plant parts to determine their structural relationship. In this backdrop, an experimental study was conducted to observe and analyze the optical properties of node and inter-nodal tissue cross-sections of the plant Alternanthera philoxeroides under a polarizing microscope constructed and standardized in the laboratory. The observed optical properties of the microscopic tissue sections have been then studied to determine a significant structural relationship between nodal and inter-nodal tissue arrangement patterns as a whole. Tissue sections that have undergone a sort of biological perturbation like loss of water (dried in air for 15 min) have also been studied to study the change in the pattern of tissue optical property when compared with that of normal plant-tissue cross-sections under a polarizing microscope. This type of biological perturbation was chosen for the study because water plays an important role in maintenance of the normal physiological processes in plants and most other forms of life. [ABSTRACT FROM AUTHOR]

Summary: Re‐establishment of heritable latitudinal clines in growth‐related traits has been recognised as evidence for adaptive evolution in invasive plants. However, less information is known about latitudinal clines in defence and joint clinal evolution of growth and defence in invasive plants.We planted 14 native Argentinean populations and 14 introduced Chinese populations of Alternanthera philoxeroides in replicate common gardens in China. We investigated the latitudinal clines of traits related to growth and defence, and plasticity of these traits in relation to experiment site and soil nitrogen.We found that chemical defence decreased with latitude in introduced populations but increased with latitude in native populations. For growth rate, latitudinal clines were positive in introduced populations but nonexistent in native populations. There were also parallel positive latitudinal clines in total/shoot biomass and specific leaf area. Experiment site affected the occurrence or magnitude of latitudinal clines in growth rate, branch intensity and triterpenoid saponins concentration. Introduced populations were more plastic to experiment site and soil nitrogen than native populations.We provide evidence for rapid evolution of clines in growth and defence in an invasive plant. Altered herbivory gradients and trade‐off between growth and defence may explain nonparallel clines between the native and introduced ranges. [ABSTRACT FROM AUTHOR]

Alternanthera philoxeroides (Mart.) Griseb., commonly known as “Alligator weed” in English, and “Malancha” in Bengali, is a leafy vegetable from the family Amaranthaceae A. L. de Jussieu. This species is native to China, particularly to the provinces around the Yangtze River, other Far East and South-East Asian countries, and countries from other continents (e.g., South America). This plant also grows in certain areas in Australia, New Zealand, and the USA. While in Bangladesh the leaves of this plant are consumed as a vegetable, in China, this plant has been used widely as a traditional remedy for the treatment of various viral diseases (e.g., measles, influenza, and haemorrhagic fever). Flavonoids and saponins are the two largest groups of phytochemicals produced by this plant, and the antiviral property of this plant and its compounds has been studied extensively. This review article reviews all published literature on this plant and critically appraises its phytochemical profile linking to biomolecular interactions and therapeutic potential, particularly, against viral diseases.

Alligator weed(Alternanthera philoxeroides)adapts to both aquatic and terrestrial habitats due to its phenotypic plasticity, high growth rate and asexual reproduction. The anatomical structure, histochemical characteristics, and apoptotic permeability of adventitious roots and stems of A. philoxeroides growing at aquatic and terrestrial habitats were studied using light and fluorescence microscope. The results were as follows:(1)The aquatic adventitious roots had a large schizogenous aerenchyma in cortex, casparian bands, suberin lamellae and lignin on the endodermis, heavily lignified in cortex and hypodermis and without secondary growth.(2)The terrestrial adventitious roots had secondary growth, with intercellular aerenchyma in cortex, casparian bands, suberin lamellae and lignin on the endodermis, slightly lignified in cortex and hypodermis; Additionally, the terrestrial adventitious roots had supernumerary cambia which produce secondary vascular bundles, parenchyma and adventitious buds; The old perennial adventitious roots possessed dilated parenchyma, and periderm had casparian bands, suberin lamellae and lignin.(3)The stolons in both aquatic and terrestrial habitats had pith, pith cavity, endodermis, collenchyma, and secondary growth, with schizo-lysigeny aerenchyma in cortex, and cuticle with suberin lamellae and lignin. The periderm possessed suberin lamellae, and lignin in the terrestrial stolons.(4)The apoplastic barriers were found in roots and stems of A. philoxeroides, which had a complex structure, and berberine can not penetrate these apoplastic barriers. The above anatomical characteristics identify the adaptation of A. philoxeroides to both aquatic and terrestrial habitats. [ABSTRACT FROM AUTHOR]

Wetlands have been considered as a vital reservoir of global carbon and are vulnerable to plant invasion. However, the influence mechanism of plant invasion on soil organic carbon (SOC) in wetlands remains unclear. In this study, we investigated SOC, soil physicochemical properties, and soil microbes in the invaded and non-invaded sites in Xinxue River and Xinxue River Constructed Wetland to research the effects of Alternanthera philoxeroides invasion on SOC and explore the related mechanisms. The invasion of A. philoxeroides increased SOC content and density in both the river and the constructed wetland. SOC in the two types of wetlands was positively correlated with moisture content and negatively correlated with bulk density, dissolved oxygen, water temperature, soil temperature, and pH. The invasion decreased the dissolved oxygen in the river and the soil temperature in the constructed wetland which might be the explanation for the increase of SOC in the two types of wetlands. In the river, the decrease of dissolved oxygen caused by plant invasion could alter the microbial community and limit the decomposition of SOC by microbes, which was confirmed by the increase of microbial α diversity indices and the correlations between soil microbial community in the river and dissolved oxygen showed by RDA analysis. The invasion of A. philoxeroides significantly shifted the soil microbial community in the constructed wetland. Redundancy analysis showed that the variation of soil microbial community structure in the constructed wetland could be mainly explained by soil pH and soil temperature. The decrease of soil temperature in the constructed wetland might inhibit microbial activities and result in the accumulation of SOC. In addition, the indicator species reflecting soil microbial community shifted by plant invasion were highly correlated with SOC, suggesting that the variation of indicator species between invaded sites and non-invaded sites might be another reason for the difference in SOC. The study indicates that A. philoxeroides invasion might increase the carbon storage in rivers and constructed wetlands with different mechanisms.

Thermal adaptation plays a fundamental role in the expansion and distribution of insects, and heat shock proteins (Hsps) play important roles in the temperature adaptation of various organisms. To determine the roles of Hsp genes (Hsp70, Hsp21, and sHsp21) on the high temperature tolerance of Agasicles hygrophila, we obtained complete cDNA (complementary DNA) sequences for Hsp70, Hsp21, and sHsp21 by rapid amplification of cDNA ends (RACE), analyzed their expression profiles under different high temperature treatments by quantitative reverse transcription polymerase chain reaction (RT-qPCR), and performed functional verification by RNA interference (RNAi). The open reading frames of Hsp70, Hsp21, and sHsp21 were 1940, 543, and 567 bp, encoding 650, 180, and 188 amino acids, respectively. Their molecular weights (MWs) were 71.757, 20.879, and 21.510 kDa, and the isoelectric points were 5.63, 6.45, and 6.24, respectively. Phylogenetic tree analysis showed that the Hsp70, Hsp21, and sHsp21 genes of A. hygrophila were relatively conserved in evolution. The Hsp70 and Hsp21 genes in A. hygrophila were homologous to those in Leptinotarsa decemlineata (87 and 79% similarity, respectively), and the sHsp21 gene in A. hygrophila was homologous to that in Lissorhoptrus oryzophilus (74% similarity). The amino acid polypeptide chain had highly conserved sequences of DLGGGTFD, VLVGGSTR, and GPTIEEVD. The sequence of EEVD was the characteristic motif of cytoplasmic Hsp70, and the highly conserved sequences of MALFR and MSLLP were characteristic sequences of Hsp2 and sHsp21, respectively. Relative quantitative real time PCR showed that the three Hsps could be induced by 4-h treatment at high temperatures. Significant upregulation of these Hsps was observed when the temperature was further increased. The RNAi results showed that the injection of the three Hsps’ dsRNA could suppress the expression at the gene level significantly. Compared with the control group, high temperature heat shock reduced the fecundity of A. hygrophila significantly, and the fecundity decreased with the increase in temperature. Our results suggest that Hsp70, Hsp21, and sHsp21 might play key roles in high temperature adaptation of A. hygrophila and help improve our understanding of their mechanism of thermotolerance.

Resource sharing between the connected ramets of clonal plants through physiological integration can increase the tolerance of plants to environmental stress. However, the role of physiological integration in the translocation of heavy-metal pollutants between different habitats receives little attention, especially in the aquatic-terrestrial ecotones. An amphibious clonal plant Alternanthera philoxeroides was used to simulate plant expansion from unpolluted soil to a chromium (Cr)-polluted water environment. Basal older ramets growing in unpolluted soil were connected or disconnected with apical younger ramets of the same fragments in polluted environments at different Cr concentrations. Harvested basal ramets were also used for decomposition tests for the loss of residual mass and release of Cr to soil. With increasing Cr concentration there was reduction in biomass of the apical ramets, especially those separated from the basal parts. Cr was detected in the basal ramets with connection to apical parts. The decomposition of plant litter from the basal ramets connected with polluted apical parts might release retained Cr to unpolluted soil. The amount and chemical forms of Cr in the plant litter changed over time. It is concluded that Cr could be transferred from polluted aquatic to unpolluted terrestrial habitats through amphibious clonal plants.

Background: Alternanthera philoxeroides (alligator weed) is a highly invasive alien plant that has continuously and successfully expanded from the tropical to the temperate regions of China via asexual reproduction. During this process, the continuous decrease in temperature has been a key limiting environmental factor. Results: In this study, we provide a comprehensive analysis of the cold tolerance of alligator weed via transcriptomics. The transcriptomic differences between the southernmost population and the northernmost population of China were compared at different time points of cold treatments. GO enrichment and KEGG pathway analyses showed that the alligator weed transcriptional response to cold stress is associated with genes encoding protein kinases, transcription factors, plant-pathogen interactions, plant hormone signal transduction and metabolic processes. Although members of the same gene family were often expressed in both populations, the levels of gene expression between them varied. Further ChIP experiments indicated that histone epigenetic modification changes at the candidate transcription factor gene loci are accompanied by differences in gene expression in response to cold, without variation in the coding sequences of these genes in these two populations. These results suggest that histone changes may contribute to the cold-responsive gene expression divergence between these two populations to provide the most beneficial response to chilling stimuli. Conclusion: We demonstrated that the major alterations in gene expression levels belonging to the main cold-resistance response processes may be responsible for the divergence in the cold resistance of these two populations. During this process, histone modifications in cold-responsive genes have the potential to drive the major alterations in cold adaption necessary for the northward expansion of alligator weed. [ABSTRACT FROM AUTHOR]

【Objective】 The present paper aimed to explore the effects of heterogeneous habitats on the nutrient element content and their stoichiometric characteristics of invasive weed Alternanthera philoxeroides in Guangxi and Henan Province, providing reference for the biological invasions control and agricultural safe productions. 【Method】We collected samples in plots where A. philoxeroides continuously invaded more than 100 m2 in Laibin city, Guilin city of Guangxi Province and Xinyang city of Henan Province, measured the total carbon, nitrogen, phosphorus and potassium, as well as calculated their stoichiometric ratios. Meanwhile, we recorded the longitude, latitude, elevation, annual mean temperature and annual mean precipitation, using the methods of regression analysis and redundancy analysis(RDA) to explore the ecological effects of environmental factors. 【Result】(i) The average content of total C(380.319 mg·g-1) of A. philoxeroides in study area was relatively lower, while the contents of N(33.825 mg·g-1) and P(1.802 mg·g-1) were all higher than that of terrestrial plants in China. N:P>16 indicated the growth of this invasive plant was mainly restricted by P. Spatial variability of K content of A. philoxeroides(6.424 mg·g-1) was low.(ii) The increases in temperature and elevation significantly increased the total P and P:K but decreased N:P. The increases in longitude and latitude significantly decreased the total P and P:K but increased N:P. The trend of P:K mainly depended on the content of P. Habitat fluctuation resulted in the weakened absorptions of N, P while A. philoxeroides assimilated the C.(iii) Higher stoichiometric stability of C:K and N:K of A. philoxeroides were helpful to maintain the invasion advantage in changeable environment. 【Conclusion】The stoichiometric characteristics of A. philoxeroides were significantly influenced by heterogeneous habitats at large spatial scales, thus, we should make appropriate bio-control measures according to these characteristics of different habitats, for effectively formulating the invasion spread of this noxious weed. [ABSTRACT FROM AUTHOR]

[Objective] The present paper aimed to evaluate the potential of white clover (Trifolium repens L.) as forage grass and ecological engineering plant on paddy field ridges in southern China. [Method] The clover was planted on the ridge of paddy fields in Ilengnan, Ilunan province and Jiangyou, Sichuan province in the spring of 2015. Cabover-ground parts, mainly leaves and petioles, were harvested monthly from July of 2016 to June of 2017. Dry matter was weighted after desiccation in a stove at 105 °C for 15 minutes and 70 °C for 24 hours. Dry samples harvested in the same season were mixed after storing at -20 °C . The contents of crude protein, nitrogen, phosphorus and potassium of such mixed samples were then determined by the standard procedures. The antagonism experiment with Alternant her a philoxeroides was conducted by face-to-face cultivation in concreted circles located in a plastic greenhouse from July of 2017 to March of 2018. [Result] At the experiment site in Sichuan, the highest dry matter weight of the white clove was obtained at the first harvest and the dropped until January of 2017 and increase gradually till the end of the experiment. It dropped also in Ilunan after the first harvest but started to increase since August and reached the highest point in April of 2017. The contents of crude protein, nitrogen and phosphorus were the highest in the first quarter at both sites. The content of potassium was the highest in the third quarter at Jiangvou but in the second quarter at Ilengnan. In the antagonism experiment, the growth of A. philoxeroides under each treatment was obviously better than that of clover in the summer, but white clover grew significantly better than A. philoxeroides under each irrigation regime and dominated the community in terms of occupying area, fresh weight and dry weight. [Conclusion] White clover on paddy didges has shown strong regeneration ability both in Sichuan and Hunan and could be used as high-quality forage and green manure crop. It could strongly inhibit the growth of A. philoxeroides at low temperature and soil humidity. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Soil resource heterogeneity can affect plant growth and competitive ability. However, little is known about how soil resource heterogeneity affects competitive interactions between invasive and native plants. We conducted an experiment with an invasive clonal plant Alternanthera philoxeroides and a coexisting native one Alternanthera sessilis. The experiment was a randomized design with three factors, i.e. two species (A. philoxeroides and A. sessilis), two interspecific competition treatments (with and without) and five soil treatments (three homogeneous treatments and two small-scale heterogeneous treatments consisting of two patches of 10 cm × 15 cm and with different initial planting positions). Irrespective of competition, increasing soil resource availability increased the growth of A. philoxeroides. Increasing soil resource availability also increased the growth of A. sessilis without competition, but had no impact with competition. Irrespective of competition, soil resource heterogeneity increased biomass and ramet production of A. philoxeroides, and such effects were independent of initial planting position. For A. sessilis, however, soil resource heterogeneity only increased ramet production when the initial plant was grown in the low-resource patch without competition. Our results suggest that both high soil resource availability and small-scale soil resource heterogeneity can increase the relative competitive ability of the invasive plant A. philoxeroides when grown with its native congener A. sessilis. These findings may partly explain the invasion success of this clonal species in area with high soil resource availability and heterogeneity caused by e.g. nitrogen deposition, fertilization and disturbance. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Xinyang Normal University Natural Science Edition is the property of Journal of Xinyang Normal University Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Alternanthera philoxeroides (Mart.) Griseb is a plant species which has become one of the most damaging weeds in ecosystems. We examined potential effects of the invasive plant A. philoxeroides on soil animal community by considering four levels of plant invasion (including non-invaded, slightly invaded, moderately invaded and heavily invaded ecosystems) in Nanfeihe, Hefei, China. The following conclusions: A total of 2406 individuals of soil animals, belonging to 25 families, 13 orders and 7 classes, and Acarina and Collembola accounted for 64.52% of the total amount of soil animals captured, thus comprising the dominant species; Individual number of soil animals varied with different rate of invasion; the diversity and evenness indices of the soil fauna showed a pattern of noninvaded < heavily invaded < moderately invaded < slightly invaded, however, there were no significant differences between the moderately and slightly invaded plots. The vertical distribution of the species number and individual number of soil fauna had obvious surface segregation with the increased soil depth; The degree of invasion affects the soil physicochemical properties, and the total potassium content is significantly correlated with the number of soil fauna groups. [ABSTRACT FROM AUTHOR]

Copyright of Acta Prataculturae Sinica is the property of Acta Prataculturae Sinica Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Thermal adaptation plays a fundamental role in the expansion and distribution of insects, and heat shock proteins (Hsps) play important roles in the temperature adaptation of various organisms. To determine the roles of Hsp genes (Hsp70 , Hsp21 , and sHsp21) on the high temperature tolerance of Agasicles hygrophila , we obtained complete cDNA (complementary DNA) sequences for Hsp70 , Hsp21 , and sHsp21 by rapid amplification of cDNA ends (RACE), analyzed their expression profiles under different high temperature treatments by quantitative reverse transcription polymerase chain reaction (RT-qPCR), and performed functional verification by RNA interference (RNAi). The open reading frames of Hsp70 , Hsp21 , and sHsp21 were 1940, 543, and 567 bp, encoding 650, 180, and 188 amino acids, respectively. Their molecular weights (MWs) were 71.757, 20.879, and 21.510 kDa, and the isoelectric points were 5.63, 6.45, and 6.24, respectively. Phylogenetic tree analysis showed that the Hsp70 , Hsp21 , and sHsp21 genes of A. hygrophila were relatively conserved in evolution. The Hsp70 and Hsp21 genes in A. hygrophila were homologous to those in Leptinotarsa decemlineata (87 and 79% similarity, respectively), and the sHsp21 gene in A. hygrophila was homologous to that in Lissorhoptrus oryzophilus (74% similarity). The amino acid polypeptide chain had highly conserved sequences of DLGGGTFD, VLVGGSTR, and GPTIEEVD. The sequence of EEVD was the characteristic motif of cytoplasmic Hsp70 , and the highly conserved sequences of MALFR and MSLLP were characteristic sequences of Hsp2 and sHsp21 , respectively. Relative quantitative real time PCR showed that the three Hsps could be induced by 4-h treatment at high temperatures. Significant upregulation of these Hsps was observed when the temperature was further increased. The RNAi results showed that the injection of the three Hsps ' dsRNA could suppress the expression at the gene level significantly. Compared with the control group, high temperature heat shock reduced the fecundity of A. hygrophila significantly, and the fecundity decreased with the increase in temperature. Our results suggest that Hsp70 , Hsp21 , and sHsp21 might play key roles in high temperature adaptation of A. hygrophila and help improve our understanding of their mechanism of thermotolerance. [ABSTRACT FROM AUTHOR]

Abstract Background In recent years, two of the crinivirus, Tomato chlorosis virus (ToCV) and Cucurbit chlorotic yellows virus (CCYV) have gained increasing attention due to their rapid spread and devastating impacts on vegetable production worldwide. Both of these viruses are transmitted by the sweet potato whitefly, Bemisia tabaci (Gennadius), in a semi-persistent manner. Up to now, there is still lack of report in Hainan, the south of China. Methods We used observational and experimental methods to explore the prevalence and incidence dynamic of CCYV and ToCV transmitted by whiteflies in Hainan of China. Results In 2016, the chlorosis symptom was observed in the tomato and cucumber plants with a large number of B. tabaci on the infected leaves in Hainan, China, with the incidence rate of 69.8% and 62.6% on tomato and cucumber, respectively. Based on molecular identification, Q biotype was determined with a viruliferous rate of 65.0% and 55.0% on the tomato and cucumber plants, respectively. The weed, Alternanthera philoxeroides near the tomato and cucumber was co-infected by the two viruses. Furthermore, incidence dynamic of ToCV and CCYV showed a close relationship with the weed, Alternanthera philoxeroides, which is widely distributed in Hainan. Conclusion Our results firstly reveal that the weed, A. philoxeroides is infected by both ToCV and CCYV. Besides, whiteflies showed a high viruliferous rate of ToCV and CCYV. Hainan is an extremely important vegetable production and seed breeding center in China. If the whitefly can carry these two viruses concurrently, co-infection in their mutual host plants can lead to devastating losses in the near future.

Alternanthera philoxeroides (Mart.) Griseb. (Alternanthera philoxeroides) is an important herbage species, which could provide high-quality feed for livestock and poultry breeding. This paper is the first to report the A. philoxeroides's chloroplast genomes, which were detected by de novo sequencing. The results showed that the length of A. philoxeroides' chloroplast genome sequence was 152,255 bp, including a large single-copy (LSC) region (84,670 bp), a small single-copy (SSC) region (17,343 bp), and two inverted repeat (IR) regions (25,121 bp). Alternanthera philoxeroides' chloroplast genome encoded 132 genes including 8 rRNA, 38 tRNA, and 86 protein-coding genes. After phylogenetic and cluster analysis, A. philoxeroides was closest to Amaranthaceae, and the relationship between Amaranthus and Achyranthes was closest. [ABSTRACT FROM AUTHOR]

Epigenetic variation may play an important role in how plants cope with novel environments. While significant epigenetic differences among plants from contrasting habitats have often been observed in the field, the stability of these differences remains little understood. Here, we combined field monitoring with a multi-generation common garden approach to study the dynamics of DNA methylation variation in invasive Chinese populations of the clonal alligator weed (Alternanthera philoxeroides). Using AFLP and MSAP markers, we found little variation in DNA sequence but substantial epigenetic population differentiation. In the field, these differences remained stable across multiple years, whereas in a common environment they were maintained at first but then progressively eroded. However, some epigenetic differentiation remained even after 10 asexual generations. Our data indicate that epigenetic variation in alligator weed most likely results from a combination of environmental induction and spontaneous epimutation, and that much of it is neither rapidly reversible (phenotypic plasticity) nor long-term stable, but instead displays an intermediate level of stability. Such transient epigenetic stability could be a beneficial mechanism in novel and heterogeneous environments, particularly in a genetically impoverished invader.

Alternanthera philoxeroides recently expanded its range northwards in China. It is unknown if the range expansion has a genetic and/or epigenetic basis, or merely an environmental basis due to a warming climate. To test these possibilities, we used an RNAseq approach with a common greenhouse design to examine gene expression in individuals from the northern edge and central portion of alligator weed range from China to determine if there were differences in their responses to cold temperatures. We hypothesized that if the recent range expansion was primarily environmental, we would observe few differences or only differences unrelated to low-temperature adaptations. We assembled over 75,000 genes of which over 65,000 had long open reading frames with similarity to sequences from arabidopsis. Differences in expression between northern and southern populations that were both exposed to low temperatures showed similar expression among genes in the C-REPEAT/DRE BINDING FACTOR (CBF) regulon. However, gene set and sub-network enrichment analysis indicated differences in the response of photosynthetic processes and oxidative stress responses were different between the two populations and we relate these differences to cold adaptation. The transcriptome differences in response to cold between the individuals from the two populations is consistent with adaptations potentiating or resulting from selection after expansion into colder environments and may indicate that genetic changes have accompanied the recent northward expansion of A. philoxeroides in China. However, we cannot rule out the possibility of epigenetic changes may have a role in this expansion.

The crude ethanol extract of the whole plant of Alternanthera philoxeroides (Mart.) Griseb was investigated for its potential as antidementia, induced by estrogen deprivation, based on in vitro antioxidant activity, β-amyloid aggregation inhibition and cholinesterase inhibitory activity, as well as in vivo Morris water maze task (MWMT), novel object recognition task (NORT), and Y-maze task. To better understand the effect of the extract, oxidative stress-induced brain membrane damage through lipid peroxidation in the whole brain was also investigated. Additionally, expressions of neuroinflammatory cytokines (IL-1β, IL-6 and TNF-α) and estrogen receptor-mediated facilitation genes such as PI3K and AKT mRNA in the hippocampus and frontal cortex were also evaluated. These effects were confirmed by the determination of its serum metabolites by NMR metabolomic analysis. Both the crude extract of A. philoxeroides and its flavone constituents were found to inhibit β-amyloid (Aβ) aggregation.

Environments experienced by parent ramets of clonal plants can potentially influence fitness of clonal offspring ramets. Such clonal parental effects may result from heritable epigenetic changes, such as DNA methylation, which can be removed by application of DNA de‐methylation agents such as 5‐azacytidine.To test whether parental shading effects occur via clonal generation and whether DNA methylation plays a role in such effects, parent plants of the clonal herb Alternanthera philoxeroides were first subjected to two levels of light intensity (high versus low) crossed with two levels of DNA de‐methylation (no or with de‐methylation by application of 5‐azacytidine), and then clonal offspring taken from each of these four types of parent plant were subjected to the same two light levels.Parental shading effects transmitted via clonal generation decreased growth and modified morphology of clonal offspring. Offspring responses were also influenced by DNA methylation level of parent plants. For clonal offspring growing under low light, parental shading effects on growth and morphology were always negative, irrespective of the parental de‐methylation treatment. For clonal offspring growing under high light, parental shading effects on offspring growth and morphology were negative when the parents were not treated with 5‐azacytidine, but neutral when they were treated with 5‐azacytidine.Overall, parental shading effects on clonal offspring performance of A. philoxeroides were found, and DNA methylation is likely to be involved in such effects. However, parental shading effects contributed little to the tolerance of clonal offspring to shading. [ABSTRACT FROM AUTHOR]

Parasitic plants represent a peculiar and highly specialized group and are important members of terrestrial ecosystems. Although much is known about how parasitic plants influence growth, reproduction, physiology, and metabolism of host plants, their possible role as modulators of microbial community properties remains largely unexplored. Using next-generation sequencing of the bacterial 16S rRNA gene and fungal rRNA internal transcribed spacer, we analyzed the effects of parasitism on both composition and diversity of soil microbial communities in the rhizosphere of an invasive species Alternanthera philoxeroides parasitized by Cuscuta australis , and feedback effects of parasitism-altered soil microbes on the growth of the host (A. philoxeroides) and on the co-existing native Trifolium repens. Cuscuta australis parasitism increased alpha-diversity and changed the composition of both bacterial and fungal community in the rhizospheric soil of A. philoxeroides. Alternanthera philoxeroides produced significantly less plant biomass when grown in soils inoculated with microbial communities of A. philoxeroides parasitized by C. australis compared to non-parasitized soils and control soils, whereas T. repens produced significantly more biomass grown in soils inoculated with microbial communities of A. philoxeroides parasitized by C. australis. Inoculation with soil microbial communities of A. philoxeroides not parasitized by C. australis increased the competitiveness of A. philoxeroides to neighboring T. repens , whereas, inoculation with soil microbial communities of A. philoxeroides parasitized by C. australis reduced the competitiveness of A. philoxeroides. These results suggest that plant parasitism-induced changes in soil microbiome can negatively affect host plant growth, and positively affect the growth of the native neighbor plants, via shift of the competitive hierarchy between the host and co-existing native plants. • Parasitism changed diversity and structure of rhizospheric soil microbes. • Host plant grew worse on parasitized rhizospheric soil. • Competitive ability of host plant was weakened on parasitized rhizospheric soil. [ABSTRACT FROM AUTHOR]

Background and Aims The strengths of biotic interactions such as herbivory are expected to decrease with increasing latitude for native species. To what extent this applies to invasive species and what the consequences of this variation are for competition among native and invasive species remain unexplored. Here, herbivore impacts on the invasive plant Alternanthera philoxeroides and its competition with the native congener A. sessilis were estimated across latitudes in China. Methods An common garden experiment spanning ten latitudinal degrees was conducted to test how herbivore impacts on A. philoxeroides and A. sessilis , and competition between them change with latitude. In addition, a field survey was conducted from 21°N to 36.8°N to test whether A. philoxeroides invasiveness changes with latitude in nature as a result of variations in herbivory. Key Results In the experiment, A. sessilis cover was significantly higher than A. philoxeroides cover when they competed in the absence of herbivores, but otherwise their cover was comparable at low latitude. However, A. philoxeroides cover was always higher on average than A. sessilis cover at middle latitude. At high latitude, only A. sessilis emerged in the second year. Herbivore abundance decreased with latitude and A. philoxeroides emerged earlier than A. sessilis at middle latitude. In the field survey, the ratio of A. philoxeroides to A. sessilis cover was hump shaped with latitude. Conclusion These results indicate that herbivory may promote A. philoxeroides invasion only at low latitude by altering the outcome of competition in favour of the invader and point to the importance of other factors, such as earlier emergence, in A. philoxeroides invasion at higher latitudes. These results suggest that the key factors promoting plant invasions might change with latitude, highlighting the importance of teasing apart the roles of multiple factors in plant invasions within a biogeographic framework. [ABSTRACT FROM AUTHOR]

Highlights from the article: Herbivory in the apical part severely reduced leaf growth (leaf mass, Ramets and two apical ramets with a stem apex (the horizontal arrow), were planted under high-N supply (left panel) and low-N supply (right Total mass Leaf mass Stem mass Root mass Number of nodes Number of leaves Leaf area Root to shoot ratio Total mass Leaf mass Stem mass Root mass Number of nodes Number of leaves Leaf area Root to shoot ratio Leaf C Stem C Root C Leaf N Stem N Root N.