Plant Identity Research Articles

A roadmap to embryo identity in plants.

Although plant embryogenesis is usually studied in the context of seed development, there are many alternative roads to embryo initiation. These include somatic embryogenesis in tissue culture and microspore embryogenesis, both widely used in breeding and crop propagation, but also include other modes of ectopic embryo initiation. In the past decades several genes, mostly transcription factors, were identified that can induce embryogenesis in somatic cells. Because the genetic networks in which such regulators operate to promote embryogenesis are largely unknown, a key question is how their activity relates to zygotic and alternative embryo initiation. We describe here the many roads to plant embryo initiation and discuss a framework for defining the developmental roles and mechanisms of plant embryogenesis regulators.

Risk management tools and the case study Brassica napus: Evaluating possible effects of genetically modified plants on soil microbial diversity

The cultivation of GMPs in Europe raises many questions about the environmental risks, in particular about their ecological impact on non-target organisms and on soil properties. The aim of a multidisciplinary group engaged in a LIFE+project (MAN-GMP-ITA) was to validate and improve an existing environmental risk assessment (ERA) methodology on GMPs within the European legislative framework on GMOs. Given the impossibility of evaluating GMO impact directly, as GMPs are banned in Italy, GMPs have not been used at any stage of the project. The project thus specifically focused on the conditions for the implementation of ERA in different areas of Italy, with an emphasis on some sensitive and protected areas located in the North, Centre, and South of the country, in order to lay the necessary baseline for evaluating the possible effects of a GMP on soil communities. Our sub-group carried out soil analyses in order to obtain soil health and fertility indicators to be used as baselines in the ERA model. Using various methods of chemical, biochemical, functional and genetic analysis, our study assessed the changes in diversity and functionality of bacterial populations, and arbuscular mycorrhizal fungi. The results show that plant identity and growth, soil characteristics, and field site climatic parameters are key factors in contributing to variation in microbial community structure and diversity, thus validating our methodological approach. Our project has come to the conclusion that the uneven composition and biological–agronomical quality of soils need to be taken into consideration in a risk analysis within the framework of ERA for the release of genetically modified plants.

Catabolic profiles of microbial communities in relation to plant identity and diversity in free-floating plant treatment wetland mesocosms

The objective of this study was to investigate if the catabolic capabilities (the overall ability to utilize a wide range of carbon sources) and catabolic profiles (the overall pattern of carbon source usage based on the carbon source types and relative usage extent) of microbial communities in free-floating plant treatment wetlands differ based on the presence or combination of different plant species. Free Floating-plant treatment wetland mesocosms were established using four different plant species: Limnobium laevigatum (L), Salvinia molesta (S), Eichhornia crassipes (E), and Pistia stratiotes (P). Mesocosms were either arranged as a monoculture (one plant species), biculture (two different plant species; all possible pairings), or quadricultures (one of each plant species). Mesocosms were fed twice weekly with 20L of reconstituted wastewater using diluted fish farm sludge effluent. The microbial communities in each mesocosm were assessed after a 4 month operational period using the community level physiological profiling (CLPP) method. It was observed that monoculture wetland systems had different catabolic activities and catabolic richness’ (number of carbon sources utilized) with the following respective trends: (L)>(P)=(S)>(E) and (L)>(E)=(P)>(S). It was also found that the carbon source utilization patterns of the microbial communities from the monoculture mesocosms were distinctly different from each other, and that the polyculture communities were different from the respective monoculture counterparts. These findings further support the hypothesis that plant type and combination plays a critical role in the development of the microbial communities present in treatment wetlands. It was also found that increasing the number of plant species did not, on average, promote the development of microbial communities with a more active and diverse catabolic capability, but rather specific plant selection and plant/plant interactions were important. In comparison to the other plant species E. crassipes had the largest amount of root mass available for microbial community attachment. Observations suggested that this larger root mass translated into E. crassipes having a dominating effect on defining the carbon source utilization patterns of microbial communities from polyculture mesocosms. Although microbial communities from the monoculture mesocosms containing E. crassipes had the lowest activities (on a per unit volume basis), E. crassipes mesocosms generally had the best COD removal rates in either monoculture or polyculture systems, potentially because of the greater amount of root mass available.

A meta-analysis of arbuscular mycorrhizal effects on plants grown under salt stress.

Salt stress limits crop yield and sustainable agriculture in most arid and semiarid regions of the world. Arbuscular mycorrhizal fungi (AMF) are considered bio-ameliorators of soil salinity tolerance in plants. In evaluating AMF as significant predictors of mycorrhizal ecology, precise quantifiable changes in plant biomass and nutrient uptake under salt stress are crucial factors. Therefore, the objective of the present study was to analyze the magnitude of the effects of AMF inoculation on growth and nutrient uptake of plants under salt stress through meta-analyses. For this, data were compared in the context of mycorrhizal host plant species, plant family and functional group, herbaceous vs. woody plants, annual vs. perennial plants, and the level of salinity across 43 studies. Results indicate that, under saline conditions, AMF inoculation significantly increased total, shoot, and root biomass as well as phosphorous (P), nitrogen (N), and potassium (K) uptake. Activities of the antioxidant enzymes superoxide dismutase, catalase, peroxidase, and ascorbate peroxidase also increased significantly in mycorrhizal compared to nonmycorrhizal plants growing under salt stress. In addition, sodium (Na) uptake decreased significantly in mycorrhizal plants, while changes in proline accumulation were not significant. Across most subsets of the data analysis, identities of AMF (Glomus fasciculatum) and host plants (Acacia nilotica, herbs, woody and perennial) were found to be essential in understanding plant responses to salinity stress. For the analyzed dataset, it is concluded that under salt stress, mycorrhizal plants have extensive root traits and mycorrhizal morphological traits which help the uptake of more P and K, together with the enhanced production of antioxidant enzymes resulting in salt stress alleviation and increased plant biomass.

Do interactions with neighbours modify the above-ground productivity response to drought? A test with two grassland species

Natural systems are predicted to be exposed to more frequent and more intense drought events in the near future. Plant–plant interactions form an important part of the whole of mechanisms that govern the responses of plant species and communities to drought. The accuracy of predictions on ecosystem functioning would therefore be improved by determining when plant interactions need to be considered and how these interactions can drive species responses. In this study, we assessed the effect of neighbour plants on the drought response of a target plant. Two grassland species (Plantago lanceolata and Lolium perenne) were grown in the presence of either six conspecific or three conspecific and three heterospecific neighbours in sunlit growth chambers. They were subjected to drought by withholding water for 20 days. Regardless of the identity of the target plant, having P. lanceolata as a neighbour increased the susceptibility to negative drought effects on biomass production while L. perenne neighbours buffered the target's drought response. Our results therefore suggest that drought responses depended largely on the identity and the traits of the neighbours. Such findings demonstrate that current models to predict ecosystem functioning may be misleading by not sufficiently taking plant–plant interactions into account.

Arbuscular mycorrhizal communities associated with maples (Acer spp.) in a common garden are influenced by season and host plant

The arbuscular mycorrhizal (AM) fungi are ubiquitous biotrophic root endophytes that form a significant link in macronutrient cycles. The AM fungi occupy two niches simultaneously, the intraradical niche, from which they gain carbon, and the bulk soil. We predict that AM community structure will vary through time, depending upon season and plant identity. In this study, we compared the AM fungal community colonising eight species of Acer L. (maple) grown in an arboretum. DNA from root samples was analysed using terminal restriction fragment length polymorphism (TRFLP) of AM fungal sequences. Three time points were sampled during the growing season, and ordination analysis showed this was the most important factor discriminating the TRFLP profiles. Analysis of each month separately showed that the host species was a significant factor in all samplings, but that the response of each species through time was different. This study demonstrates the dynamic nature of AM communities, and the importance of sampling habitats throughout the season to generate a complete picture of the AM community.

Genetic identity of putative Linnaean plants: Successful DNA amplification of Linnaeus's crab apple Malus baccata

AbstractAdvancements in molecular techniques enable us to extract DNA from historic herbarium specimens and facilitate genetic comparisons between herbarium material and living plant collections. These recent advances offer an exciting opportunity for identifying extant Linnaean plants by genetic comparisons of Linnaeus's own herbarium specimens with potentially remnant plants from his cultivations. DNA from the lectotype of Malus baccata (L.) Borkh. in the Linnaean Herbarium was successfully extracted and amplified for five of twelve loci of microsatellites. Results of genetic comparisons with M. baccata trees from Linnaeus's Hammarby, Sweden, show that the trees at Hammarby are closely related to each other, but not to the lectotype, which is closer to material from Russia. This suggests that Linnaeus received M. baccata from more than one source. Although not close to the lectotype and not represented by a specimen in the Linnaean Herbarium, the extant M. baccata at Hammarby may still represent Linnaean plants, that were grown by Linnaeus himself, or the descendants to such plants. Future studies on the almost 50 living, potential Linnaean plants may reveal an invaluable biological, scientific and cultural heritage from the era that saw the rise of systematic biology.

Rhizosphere fungal assemblages and soil enzymatic activities in a 110-years alpine chronosequence

The abundance, distribution and functions of soil fungi in alpine ecosystems remain poorly understood. We aimed at linking the fungal community structure with soil enzymatic activities in the rhizospheres of several plants associating with mycorrhizal fungi (arbuscular, ecto- and ericoid) and growing along a soil developmental gradient on the forefield of an alpine glacier. Fungal communities in roots and in rhizosphere soils were assessed using a site-tailored set of quantitative PCR assays with fluorescent hydrolysis probes. Enzymatic activities of mycorrhizal roots and rhizosphere soils were assessed using fluorogenic substrates. In this study we addressed: i) whether and how the structure of fungal communities and enzymatic activities in rhizosphere soils change along the soil developmental gradient, ii) whether the type of mycorrhiza shows a clear relationship to the pattern of enzymatic activities in the rhizosphere, and iii) how the structure of fungal communities and enzymatic activities in rhizosphere soils is related to plant species abundances along the soil chronosequence. The results suggest that plant identity affected the structure of both ecto- and arbuscular mycorrhizal fungal communities in rhizosphere soil and roots, whereas the community of non-mycorrhizal fungi was rather dictated by the soil developmental stage. Both plant identity and associated mycorrhizal fungi affected the enzymatic activity in the rhizosphere soil. Species-specific elevations of rhizosphere enzyme activities were detected for Salix helvetica (chitinase and α-glucosidase), Rhododendron ferrugineum (α-glucosidase and sulfatase), and Agrostis gigantea (phosphatase and xylosidase). These results indicate different functional roles played by different types of mycorrhizal symbiosis in a young alpine ecosystem.

Vishalyakarani asEupatorium ayapana: Retro-botanizing, Embedded Traditions, and Multiple Historicities of Plants in Colonial Bengal, 1890–1940

This article critically examines the assumptions and processes involved in identifying historically distinctive plant identities by their Latin botanical names. By following late-colonial efforts to identify a medicinal herb mentioned in some versions of the Ramayana, this paper argues for a historicist analysis of the process of “retro-botanizing.” In so doing, it also distinguishes between two different forms of “tradition,” the “factualized” and “embedded.” Finally, it blurs the allegedly watertight distinction between historical and mythic pasts. Instead of trying to distinguish these pasts ontologically, I argue that it is more productive to see specific pasts in relation to the sorts of futures they produce, that is, their respective historicities.

New phytoconstituents from the aerial parts of Fumaria parviflora Lam.

Fumaria parviflora Lam. (Fumariaceae) is an annual herb found throughout the world. Traditionally it has great significance in various disorders. In folk medicine of Turkey it is used against hepato-biliary dysfunction and imported from Iran. In Charaka and Sushruta, it is recommended for treatment of fevers, blood disorders, chronic skin diseases, urinary diseases and cough. The compounds were isolated from methanolic extract of the plants by column chromatography using silica gel (60-120 mesh) as stationary phase and structure of the isolated compounds have been established on the basis of spectral data analysis and chemical reactions. Phytochemical investigation of its aerial parts led to the isolation of five new compounds characterized as (5αH,11αH)-8-oxo-homoiridolide (1), n-docosanyl-2-O-β-D-glucopyranosyl salicylate (2), 2-methyl-6-hydroxymethylenedodecan-10-oyl-12, 15-olide14-O-β-D-xylopyranoside (3), 4-oxo-stigmast-5-en-3β-ol-D-glucopyranoside (4) and salicylic acid-O-β-D-xylopyranoside (5) along with the known compounds α-D-glucopyranosyl hexadecanoate (6) and α-D-glucopyranosyl- (2 → 1ʹ)-α-D-glucopyranoside (7). The isolated compounds are useful as they will provide essential data and information for the further researchers and development of effective analytical marker for identity, purity and quality control of this traditional plant in future.

The Coca Plant and Bolivian Identity

The political battle rages between the U.S. government, the U.N. and the Bolivian President, Evo Morales, about his efforts to protect, legalize and preserve the symbol of the Andean indigenous identity: the coca plant. The human rights of indigenous populations are being violated by culturally insensitive governments in compliance with U.S. and U.N. law. The questions posed are: Is coca cocaine? What are the economic benefits of the production of coca and who benefits? What is the relationship between coca and Bolivian identity? What would be the impact in the global community if coca is eradicated permanently?

How generalist herbivores exploit belowground plant diversity in temperate grasslands

Belowground herbivores impact plant performance, thereby inducing changes in plant community composition, which potentially leads to cascading effects onto higher trophic levels and ecosystem processes and productivity. Among soil-living insects, external root-chewing generalist herbivores have the strongest impact on plants. However, the lack of knowledge on their feeding behaviour under field conditions considerably hampers achieving a comprehensive understanding of how they affect plant communities. Here, we address this gap of knowledge by investigating the feeding behaviour of Agriotes click beetle larvae, which are common generalist external root-chewers in temperate grassland soils. Utilizing diagnostic multiplex PCR to assess the larval diet, we examined the seasonal patterns in feeding activity, putative preferences for specific plant taxa, and whether species identity and larval instar affect food choices of the herbivores. Contrary to our hypothesis, most of the larvae were feeding-active throughout the entire vegetation period, indicating that the grassland plants are subjected to constant belowground feeding pressure. Feeding was selective, with members of Plantaginaceae and Asteraceae being preferred; Apiaceae were avoided. Poaceae, although assumed to be most preferred, had an intermediate position. The food preferences exhibited seasonal changes, indicating a fluctuation in plant traits important for wireworm feeding choice. Species- and instar-specific differences in dietary choice of the Agriotes larvae were small, suggesting that species and larval instars occupy the same trophic niche. According to the current findings, the food choice of these larvae is primarily driven by plant identity, exhibiting seasonal changes. This needs to be considered when analysing soil herbivore–plant interactions.

Comparison of epifaunal assemblages betweenCymodocea nodosaandCaulerpa proliferameadows in Gran Canaria (eastern Atlantic)

Epifaunal invertebrates are sensitive to changes in the identity of the dominant host plant, so assessing differences in the structure of epifaunal assemblages is particularly pertinent in areas where seagrasses have been replaced by alternative vegetation (e.g. green seaweeds). In this study, we aimed to compare the diversity, abundance and structure of epifaunal assemblages, particularly amphipods, between meadows dominated by the seagrassCymodocea nodosaand the green rhizophytic algaeCaulerpa proliferaon shallow soft bottoms of Gran Canaria Island, determining whether patterns were temporally consistent between two times. The epifaunal assemblage structure (abundance and composition) consistently differed between both plants, those assemblages associated withC. prolifera-dominated beds being more diverse and abundant relative toC. nodosameadows. Amphipods constituted ~70% of total crustaceans for the overall study, including 37 species belonging to 16 families. The amphipod abundance was ~3 times larger inC. prolifera-dominated beds than inC. nodosameadows. We detected species-specific affinities; for example,Microdeutopus stationis, Dexamine spinosa, Aora spinicornis, Ischyrocerus inexpectatusandApherusa bispinosawere more abundant inC. prolifera-dominated beds; while the caprellidMantacaprella macaronensisdominated inC. nodosameadows. However, some species, such asPseudoprotella phasmaandAmpithoe ramondi,were found in both habitats with varying abundances between times.

How distinct are arbuscular mycorrhizal fungal communities associating with grapevines?

Grapevines form associations with arbuscular mycorrhizal (AM) fungi. These root-dwelling fungi have the potential to contribute to crop vigor, productivity, pathogen protection, and nutrient content in grapes. In this study the arbuscular mycorrhizal fungal communities of grapevines and the surrounding interrow and native vegetation are compared. We found over 40 different taxa associating with both vines and interrow vegetation, but these communities differed based on host plant identity. These differences were apparent even after accounting for differences in soil chemical properties and differences in host plant diversity between vinerows and interrows, indicating that Vitis preferentially interacts with a subset of the viticultural fungal community. Since AM fungal communities play a major role in grapevine health, our results suggest that host identity and the diversity of AM fungal hosts in a vineyard can have strong effects on arbuscular mycorrhizal fungi community structure. In this paper, we used high throughput sequencing of the large subunit rDNA to analyze the diversity of AM fungi growing in a vineyard.

Krimpsiekte in South Africa: Historical perspectives

Krimpsiekte, also known as cotyledonosis or nentain sheep and goats, has been recognised as a disease entity since 1775. However, it was only in 1891 that Veterinary Surgeon Soga reproduced the condition by dosing Cotyledon (= Tylecodon) ventricosus leaves to goats. Professor MacOwan, a botanist, confirmed the identity of these nenta plants. From a South African veterinary toxicological point of view the date 1891 is of considerable historical significance as this was the first time that a plant was experimentally demonstrated to be toxic to livestock in South Africa. A chronological account of the history of krimpsiekte research is provided.

PHARMACOGNOSTICAL, PHYTOCHEMICAL AND ANTIBACTERIAL EVALUATION OF MAHONIA LESCHENAULTIA TAKEDA. (ROOT WOOD & ROOT BARK).

Objective: Pharmacognostical, Phytochemical and Antibacterial evaluation of Mahonia leschenaultii Takeda. (root wood, root bark, stem wood, stem bark and leaves.) Methods: The present study has been undertaken to evolve the Pharmacognostical, Phytochemical and Antibacterial standard. In Pharmacognostical study determination of ash values and extractive values were carried out. In Phytochemical study Extraction procedure and Fluorescence analysis were carried out. In Antibacterial study the antibacterial activity of different methanolic extracts (root wood, root bark, stem wood, stem bark and leaves extracts.) of different concentration (50 µg/ml, 100 µg/ml, 150 µg/ml and 200 µg/ml) and standard drug (Ampicillin trihydrate) at the concentration of 100 µg/ml were carried out by cylinder-plate method. Results and Discussion: Pharmacognostical studies such as ash values and extractive values were carried out to confirm the identity of plant and to ascertain the quality and purity of crude drug. Phytochemical study such as Fluorescence analysis shows fluorescence compound in the extracts. The antibacterial study shows the moderate antibacterial activity against Staphylococcus aureus and Escherichia coli in comparison to standard drug (Ampicillin trihydrate). Conclusion: Pharmacognostical studies were carried out to confirm the identity and to ascertain the quality and purity of the crude drug. Phytochemical studies were carried out to confirm the presence, nature of the crude extracts. The extracts of (root wood, root bark, stem wood, stem bark and leaves) of different concentration (50 µg/ml, 100 µg/ml, 150 µg/ml and 200 µg/ml) evaluated for antibacterial activity and showed moderate antibacterial activity as compared to standard drug at the concentration of 100 µg/ml. The methanolic extract is more active against Escherichia coli in comparison to Staphylococcus aureus. Keywords: Mahonia leschenaultii Takeda. Root wood, Root bark, Stem wood, Stem bark and leaves, Ampicillin trihydrate.Â

Factors influencing egg parasitism in sub-social insects: insights from the treehopperAlchisme grossa(Hemiptera, Auchenorrhyncha, Membracidae)

Subsocial insects rely on maternal care in order to enhance offspring survival. Subsocial Hoplophorionini treehoppers defend their egg masses from predatory and parasitoid attacks. Egg parasitic wasps are important enemies of the Membracidae. We examined parasitism patterns and female defence mechanisms in the Hoplophorionini treehopper Alchisme grossa (Fairmaire). We examined the effect of aggregations of egg-guarding females, spatial aggregations of host plants and female A. grossa, and host plant identity on the incidence of egg mass parasitism. Additionally, we measured the effect of female maternal care strategies on reducing the amount of parasitism on their egg masses. Aggregation of egg-guarding females on a single host plant was the most important factor affecting egg mass parasitism. Increased numbers of aggregated females lowered both parasitism risk and parasitism levels on their egg masses. When spatial clumping of host plants and egg-guarding females occurred simultaneously, parasitism risk was also reduced. Maternal care strategies such as coverage of the egg mass by the females' pronota and intensity of female defensive behaviour also seemed to lower parasitism on egg masses. A reduction of parasitism by female aggregation on host plants can be explained by a selfish herd dilution effect. This dilution effect was potentiated by a possible cooperation between aggregated egg-guarding females on the host plant. The present study provides a new dimension to sub-sociality in Hoplophorionini treehoppers.

Mycorrhizal fungal growth responds to soil characteristics, but not host plant identity, during a primary lacustrine dune succession

Soil factors and host plant identity can both affect the growth and functioning of mycorrhizal fungi. Both components change during primary succession, but it is unknown if their relative importance to mycorrhizas also changes. This research tested how soil type and host plant differences among primary successional stages determine the growth and plant effects of arbuscular mycorrhizal (AM) fungal communities. Mycorrhizal fungal community, plant identity, and soil conditions were manipulated among three stages of a lacustrine sand dune successional series in a fully factorial greenhouse experiment. Late succession AM fungi produced more arbuscules and soil hyphae when grown in late succession soils, although the community was from the same narrow phylogenetic group as those in intermediate succession. AM fungal growth did not differ between host species, and plant growth was similarly unaffected by different AM fungal communities. These results indicate that though ecological filtering and/or adaptation of AM fungi occurs during this primary dune succession, it more strongly reflects matching between fungi and soils, rather than interactions between fungi and host plants. Thus, AM fungal performance during this succession may not depend directly on the sequence of plant community succession.

A new method for evaluating flowering synchrony to support the temporal isolation of genetically modified crops from their wild relatives

Hybridization between crops and their wild relatives potentially threatens the genetic identity of the wild plants, particularly in the case of genetically modified crops. Only a few studies have examined the use of temporal isolation to prevent hybridization, and the indices used in those studies, (e.g., the days of flowering overlap), are not precise to evaluate the degree of synchrony in flowering. Here we propose a flowering similarity index that can compare the degree of flowering synchrony between two relevant species and measure the efficiency of temporal isolation. The results showed that the flowering similarity index predicts the likelihood of hybridization much better than the number of flowering-overlap days, regardless of different flowering patterns among cultivars. Thus, temporal isolation of flowering or flowering asynchrony is the most effective means in preventing hybridization between crops and their wild relatives.

Fertilization and plant diversity accelerate primary succession and restoration of dune communities

Plant species richness can increase primary production because plants occupy different niches or facilitate each other (“complementarity effects”) or because diverse mixtures have a greater chance of having more productive species (“selection effects”). To determine how complementarity and selection influence dune restoration, we established four types of plant communities [monocultures of sea oats (Uniola paniculata), bitter panicgrass (Panicum amarum) and saltmeadow cordgrass (Spartina patens) and the three-species mixture] under different soil treatments typical of dune restorations (addition of soil organic material, nutrients, both, or neither). This fully factorial design allowed us to determine if plant identity, diversity and soil treatments influenced the yield of both the planted species and species that recruited naturally (volunteers). Planted species responses in monocultures and mixtures varied among soil treatments. The composition of the plantings and soils also influenced the abundance of volunteers. The mixture of the three species had the lowest cover of volunteers. We also found that the effect of diversity on production increased with fertilizer. We partitioned the biodiversity effect into complementarity and selection effects and found that the increase in the diversity effect occurred because increased nutrients decreased dominance by the largest species and increased complementarity among species. Our findings suggest that different planting schemes can be used to meet specific goals of restoration (e.g., accelerate plant recovery while suppressing colonization of non-planted species).