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1.
Nat Commun ; 12(1): 503, 2021 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-33479227

RESUMO

The source of oxygen to Earth's atmosphere is organic carbon burial, whilst the main sink is oxidative weathering of fossil carbon. However, this sink is to insensitive to counteract oxygen rising above its current level of about 21%. Biogeochemical models suggest that wildfires provide an additional regulatory feedback mechanism. However, none have considered how the evolution of different plant groups through time have interacted with this feedback. The Cretaceous Period saw not only super-ambient levels of atmospheric oxygen but also the evolution of the angiosperms, that then rose to dominate Earth's ecosystems. Here we show, using the COPSE biogeochemical model, that angiosperm-driven alteration of fire feedbacks likely lowered atmospheric oxygen levels from ~30% to 25% by the end of the Cretaceous. This likely set the stage for the emergence of closed-canopy angiosperm tropical rainforests that we suggest would not have been possible without angiosperm enhancement of fire feedbacks.


Assuntos
Atmosfera/química , Retroalimentação Fisiológica , Fogo , Magnoliopsida/metabolismo , Oxigênio/metabolismo , Algoritmos , Carbono/metabolismo , Ecossistema , Fósseis , Magnoliopsida/crescimento & desenvolvimento , Modelos Teóricos , Fatores de Tempo
2.
PLoS One ; 15(9): e0238914, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32946472

RESUMO

The Atlantic Forest is considered the fourth most important biodiversity hotspot. Although almost 96% of its original area has been devastated, a large part of its remaining conserved area is inhabited by traditional communities. This research focused on two Quilombola communities who reside within the Núcleo Picinguaba of the Serra do Mar State Park, State of São Paulo, Brazil. The objective was to use a combination of ethnoecological and ecological approaches to select priority species for which to develop participatory conservation and sustainable management plans in protected areas in Brazil. We collaborated with community members to collect ethnobotanical and ethnoecological data and then measured the abundance of native species in local forests through phytosociological sampling. We used this information to assess the degree of threat to useful species using the Conservation Priority Index, adding an additional layer of analysis based on habitat successional categories. We then overlayed those useful species identified as highest risk locally with those federally listed as threatened or endangered. Based on this, we identified three species as priority for the development of sustainable management plans: Virola bicuhyba, Cedrella fissilis and Plinia edulis.


Assuntos
Conservação dos Recursos Naturais/métodos , Espécies em Perigo de Extinção/estatística & dados numéricos , Magnoliopsida/crescimento & desenvolvimento , Oceano Atlântico , Brasil/etnologia , Ecossistema , Etnobotânica , Florestas , Humanos , Magnoliopsida/classificação
3.
PLoS One ; 15(9): e0239268, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32991580

RESUMO

Nitraria sibirica Pall. is a shrub species belonging to the family of Nitrariaceae. It plays pivotal role in arid ecosystems since it is tolerant to high salinity and drought. This species is widely distributed throughout Mongolia and it is mostly found in arid ecosystems of Mongolian Gobi Desert. In this study, we developed allometric equations for estimating above-ground biomass of N. sibirica using various structural descriptors and pinpointed the best models. Variables that precisely predicted above-ground biomass were a combination of basal diameter, crown area, and height. The allometric growth equation constructed is not merely helpful to achieve accurate estimations of the above-ground biomass in shrub vegetation in the Gobi Desert of Mongolia, but also can provide a reference for the above-ground biomass of Nitraria species growing in analogous habitats worldwide. Therefore, our research purposes an important advance for biomass estimation in Gobi ecosystems and complements previous studies of shrub biomass worldwide. This study provides reasonable estimates of biomass of N. sibirica, which will be valuable in evaluations of biological resources, especially for quantifying the main summer diet of Gobi bears, and also can be an alternative tool for assessing carbon cycling in Gobi Desert.


Assuntos
Clima Desértico , Ecossistema , Magnoliopsida/crescimento & desenvolvimento , Biomassa , Mongólia , Estações do Ano
4.
PLoS One ; 15(9): e0232313, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32960879

RESUMO

Pollination services and honeybee health in general are important in the African savannahs particularly to farmers who often rely on honeybee products as a supplementary source of income. Therefore, it is imperative to understand the floral cycle, abundance and spatial distribution of melliferous plants in the African savannah landscapes. Furthermore, placement of apiaries in the landscapes could benefit from information on spatiotemporal patterns of flowering plants, by optimising honeybees' foraging behaviours, which could improve apiary productivity. This study sought to assess the suitability of simulated multispectral data for mapping melliferous (flowering) plants in the African savannahs. Bi-temporal AISA Eagle hyperspectral images, resampled to four sensors (i.e. WorldView-2, RapidEye, Spot-6 and Sentinel-2) spatial and spectral resolutions, and a 10-cm ultra-high spatial resolution aerial imagery coinciding with onset and peak flowering periods were used in this study. Ground reference data was collected at the time of imagery capture. The advanced machine learning random forest (RF) classifier was used to map the flowering plants at a landscape scale and a classification accuracy validated using 30% independent test samples. The results showed that 93.33%, 69.43%, 67.52% and 82.18% accuracies could be achieved using WorldView-2, RapidEye, Spot-6 and Sentinel-2 data sets respectively, at the peak flowering period. Our study provides a basis for the development of operational and cost-effective approaches for mapping flowering plants in an African semiarid agroecological landscape. Specifically, such mapping approaches are valuable in providing timely and reliable advisory tools for guiding the implementation of beekeeping systems at a landscape scale.


Assuntos
Criação de Abelhas/métodos , Monitoramento Ambiental/métodos , Magnoliopsida/crescimento & desenvolvimento , Animais , Abelhas/fisiologia , Conjuntos de Dados como Assunto , Pradaria , Quênia , Aprendizado de Máquina , Fotografação , Polinização
5.
PLoS One ; 15(6): e0234045, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32544208

RESUMO

A study was conducted to determine the impact of applying different sources of Mg, namely kieserite, ground magnesium limestone (GML) and Mg-rich synthetic gypsum (MRSG) on an acid tropical soil, oil palm growth and production. Besides high amount of Mg and Ca, MRSG contains S. Exchangeable Ca in the untreated soil of the plantation was 0.64 cmolc kg-1, but its critical level to sustain oil palm growth was 0.9 cmolc kg-1. MRSG was applied in the plantation as Mg-fertilizer; however, since Ca is also a limiting nutrient, oil palm growth was correlated (r = 0.69) with Ca supplied by the MRSG. Mg needed to sustain oil palm production is normally supplied by kieserite. Its requirement can be met at a lower cost compared to that of the kieserite by using MRSG. Due to MRSG treatment, exchangeable Ca in the soil increased steadily to satisfy the requirement of oil palm for fruit bunches production. From the glasshouse and field study, it was observed that MRSG applied at 1.5 times the recommended rate gave results comparable to that of the kieserite. MRSG treatment resulted in the increase of soil pH to >5 that precipitated Al3+ as inert Al-hydroxides, which eventually enhanced oil palm seedlings growth. Thus, MRSG can also replace GML to increase soil pH and satisfy the Ca and Mg requirement of oil palm. It can be concluded that MRSG has the potential to be used as a source of Mg as well as Ca for oil palm grown on acidic soil.


Assuntos
Sulfato de Cálcio/química , Sulfato de Cálcio/farmacologia , Magnésio/química , Magnoliopsida/efeitos dos fármacos , Magnoliopsida/crescimento & desenvolvimento , Solo/química , Calibragem , Concentração de Íons de Hidrogênio , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento
6.
PLoS One ; 15(6): e0234327, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32516354

RESUMO

Massive declines in insect biodiversity and biomass are reported from many regions and habitats. In urban areas, creation of native wildflower meadows is one option to support insects and reduce maintenance costs of urban green spaces. However, benefits for insect conservation may depend on previous land use, and the size and location of new wildflower meadows. We show effects of conversion of roadside plantings-from exotic shrubs into wildflower meadows-on (1) the abundance of 13 arthropod taxa-Opiliones, Araneae, Isopoda, Collembola, Orthoptera, Aphidoidea, Auchenorrhyncha, Heteroptera, Coleoptera, Nematocera, Brachycera, Apocrita, Formicidae-and (2) changes in maintenance costs. We assessed the influence of vegetation type (meadow vs. woody), meadow age, size, location (distance to city boundary), and mowing regime. We found many, but not all, arthropod taxa profiting from meadows in terms of arthropod activity abundance in pitfall traps and arthropod density in standardized suction samples. Arthropod number in meadows was 212% higher in pitfall traps and 260% higher in suction samples compared to woody vegetation. The increased arthropod number in meadows was independent of the size and isolation of green spaces for most taxa. However, mowing regime strongly affected several arthropod taxa, with an increase of 63% of total arthropod density in unmown compared to mown meadow spots. Costs of green space maintenance were fivefold lower for meadows than for woody vegetation. Our study shows that (1) many different arthropod taxa occur in roadside vegetation in urban areas, (2) replacement of exotic woody vegetation by native wildflower meadows can significantly increase arthropod abundance, especially if meadow management permits temporarily unmown areas, and (3) maintenance costs can be considerably reduced by converting woody plantings into wildflower meadows. Considering many groups of arthropods, our study provides new insights into possible measures to support arthropods in urban environments.


Assuntos
Conservação dos Recursos Naturais/economia , Conservação dos Recursos Naturais/métodos , Insetos/metabolismo , Animais , Biodiversidade , Biomassa , Cidades , Ecossistema , Meio Ambiente , Espécies Introduzidas/economia , Magnoliopsida/crescimento & desenvolvimento , Plantas , Solo , Microbiologia do Solo
7.
Proc Natl Acad Sci U S A ; 117(15): 8649-8656, 2020 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-32234787

RESUMO

For more than 225 million y, all seed plants were woody trees, shrubs, or vines. Shortly after the origin of angiosperms ∼140 million y ago (MYA), the Nymphaeales (water lilies) became one of the first lineages to deviate from their ancestral, woody habit by losing the vascular cambium, the meristematic population of cells that produces secondary xylem (wood) and phloem. Many of the genes and gene families that regulate differentiation of secondary tissues also regulate the differentiation of primary xylem and phloem, which are produced by apical meristems and retained in nearly all seed plants. Here, we sequenced and assembled a draft genome of the water lily Nymphaea thermarum, an emerging system for the study of early flowering plant evolution, and compared it to genomes from other cambium-bearing and cambium-less lineages (e.g., monocots and Nelumbo). This revealed lineage-specific patterns of gene loss and divergence. Nymphaea is characterized by a significant contraction of the HD-ZIP III transcription factors, specifically loss of REVOLUTA, which influences cambial activity in other angiosperms. We also found the Nymphaea and monocot copies of cambium-associated CLE signaling peptides display unique substitutions at otherwise highly conserved amino acids. Nelumbo displays no obvious divergence in cambium-associated genes. The divergent genomic signatures of convergent loss of vascular cambium reveals that even pleiotropic genes can exhibit unique divergence patterns in association with independent events of trait loss. Our results shed light on the evolution of herbaceousness-one of the key biological innovations associated with the earliest phases of angiosperm evolution.


Assuntos
Câmbio/química , Genoma de Planta , Magnoliopsida/genética , Nymphaea/genética , Proteínas de Plantas/genética , Madeira/química , Câmbio/genética , Câmbio/crescimento & desenvolvimento , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Magnoliopsida/crescimento & desenvolvimento , Nymphaea/crescimento & desenvolvimento , Filogenia , Transcriptoma , Madeira/genética , Madeira/crescimento & desenvolvimento
8.
PLoS One ; 15(3): e0230155, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32155231

RESUMO

Agriculture is the dominating land-use in the EU member states covering nearly half of the surface area. Using herbicides to reduce weed competition in agricultural areas can adversely affect Non-Target Terrestrial Plants (NTTP) growing in field margins. According to the EFSA Scientific Opinion on NTTPs an important protection goal is to maintain the biodiversity of plant species in agricultural areas. EFSA recommends to include also non-crop species mentioned in OECD guidelines (OECD 208 and 227) in the testing and to assess not only vegetative but also generative endpoints during the plant life-cycle such as flowering and seed production. The objectives of this study were to evaluate the feasibility of assessing generative endpoints of crop and non-crop species for NTTP regulatory testing under greenhouse conditions and to assess if generative endpoints are more sensitive than vegetative endpoints. The experimental design consisted of one control and four herbicide (Atlantis® WG) application rates, with 6 replicates each. The application rates of the test substance were the maximum field rate and 30%, 10% and 3% of the field rate. Biomass, plant height, flowering, seed production as well as seedling emergence of the F1 generation were assessed. The study shows a feasible approach to assess vegetative and generative endpoints of (non-) crops species under greenhouse conditions on the basis of the OECD guideline 227. The vegetative endpoints plant height and biomass were not more sensitive if assessed during the generative growth stage when compared to the vegetative growth stage of the plants. In contrast to that, the generative endpoint seed production was partly more sensitive in comparison to the vegetative endpoints biomass and plant height. For regulatory NTTP studies, 5 or more test substance rates at non-lethal levels should be tested so to allow the determination of ER10/50 values for vegetative and generative endpoints.


Assuntos
Herbicidas/efeitos adversos , Herbicidas/análise , Testes de Toxicidade/métodos , Biodiversidade , Biomassa , Produtos Agrícolas/metabolismo , Estudos de Viabilidade , Herbicidas/toxicidade , Magnoliopsida/crescimento & desenvolvimento , Sementes/crescimento & desenvolvimento , Especificidade da Espécie
9.
Int J Mol Sci ; 21(6)2020 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-32183075

RESUMO

Seed plants usually undergo various developmental phase transitions throughout their lifespan, mainly including juvenile-to-adult and vegetative-to-reproductive transitions, as well as developmental transitions within organ/tissue formation. MicroRNAs (miRNAs), as a class of small endogenous non-coding RNAs, are involved in the developmental phase transitions in plants by negatively regulating the expression of their target genes at the post-transcriptional level. In recent years, cumulative evidence has revealed that five miRNAs, miR156, miR159, miR166, miR172, and miR396, are key regulators of developmental phase transitions in plants. In this review, the advanced progress of the five miRNAs and their targets in regulating plant developmental transitions, especially in storage organ formation, are summarized and discussed, combining our own findings with the literature. In general, the functions of the five miRNAs and their targets are relatively conserved, but their functional divergences also emerge to some extent. In addition, potential research directions of miRNAs in regulating plant developmental phase transitions are prospected.


Assuntos
Regulação da Expressão Gênica de Plantas , Magnoliopsida/genética , MicroRNAs/genética , Desenvolvimento Vegetal , Regulação da Expressão Gênica no Desenvolvimento , Magnoliopsida/crescimento & desenvolvimento , Magnoliopsida/metabolismo , MicroRNAs/metabolismo
10.
Int J Mol Sci ; 21(3)2020 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-32050457

RESUMO

Phyllotaxis describes the periodic arrangement of plant organs most conspicuously floral. Oscillators generally underlie periodic phenomena. A hypothetical algorithm generates phyllotaxis regulated by the Hechtian growth oscillator of the stem apical meristem (SAM) protoderm. The oscillator integrates biochemical and mechanical force that regulate morphogenetic gradients of three ionic species, auxin, protons and Ca2+. Hechtian adhesion between cell wall and plasma membrane transduces wall stress that opens Ca2+ channels and reorients auxin efflux "PIN" proteins; they control the auxin-activated proton pump that dissociates Ca2+ bound by periplasmic arabinogalactan proteins (AGP-Ca2+) hence the source of cytosolic Ca2+ waves that activate exocytosis of wall precursors, AGPs and PIN proteins essential for morphogenesis. This novel approach identifies the critical determinants of an algorithm that generates phyllotaxis spiral and Fibonaccian symmetry: these determinants in order of their relative contribution are: (1) size of the apical meristem and the AGP-Ca2+ capacitor; (2) proton pump activity; (3) auxin efflux proteins; (4) Ca2+ channel activity; (5) Hechtian adhesion that mediates the cell wall stress vector. Arguably, AGPs and the AGP-Ca2+ capacitor plays a decisive role in phyllotaxis periodicity and its evolutionary origins.


Assuntos
Sinalização do Cálcio , Ácidos Indolacéticos/metabolismo , Desenvolvimento Vegetal , Reguladores de Crescimento de Planta/metabolismo , Proteínas de Plantas/metabolismo , Cálcio/metabolismo , Parede Celular/metabolismo , Magnoliopsida/crescimento & desenvolvimento , Magnoliopsida/metabolismo , Mucoproteínas/metabolismo , Periodicidade , Plantas/metabolismo
11.
Environ Pollut ; 261: 114204, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32097793

RESUMO

Antibiotic and heavy metal pollution of aquatic environments are issues of serious concern, and the macrophyte Myriophyllum aquaticum may provide a viable solution for the removal of these contaminants. However, the toxic effects of coexisting tetracyclines (TCs) and Cu(II) on this plant species are currently unclear. In the present study, we constructed wetland microcosms planted with M. aquaticum and spiked these with three TCs (tetracycline, oxytetracycline, and chlortetracycline) and Cu(II) at concentrations ranging from 100 to 10,000 µg/L to investigate how Cu(II) influences the growth and tolerance responses of plants to TCs. After 12 weeks, we found that TCs had accumulated in the plants, and that plant growth and characteristics were significantly affected by the levels of both TCs and Cu(II). While low Cu(II) levels had a synergistic effect on the accumulation of TCs, high levels were observed to reduce accumulation. However, low levels of TCs and Cu(II) had a hormesis effect on plant growth, with plant biomass and leaf chlorophyll content decreasing and the malondialdehyde content and activities of antioxidant enzymes gradually increasing with an increase in TC dosage. The coexistence of low levels of Cu(II) was, however, found to alleviate these adverse effects. Principal component analysis revealed a close relationship among plant biomass, chlorophyll content, malondialdehyde content, and antioxidant enzyme activities. Considering that the Cu/TC ratio was shown to markedly affect M. aquaticum growth, the respective proportions of these pollutants should be taken into consideration in the future design of constructed wetlands.


Assuntos
Cobre , Magnoliopsida , Tetraciclinas , Áreas Alagadas , Antibacterianos/farmacologia , Cobre/farmacologia , Magnoliopsida/efeitos dos fármacos , Magnoliopsida/crescimento & desenvolvimento , Tetraciclinas/farmacologia , Poluentes Químicos da Água/farmacologia
12.
Nat Commun ; 11(1): 545, 2020 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-31992718

RESUMO

Severe droughts have the potential to reduce forest productivity and trigger tree mortality. Most trees face several drought events during their life and therefore resilience to dry conditions may be crucial to long-term survival. We assessed how growth resilience to severe droughts, including its components resistance and recovery, is related to the ability to survive future droughts by using a tree-ring database of surviving and now-dead trees from 118 sites (22 species, >3,500 trees). We found that, across the variety of regions and species sampled, trees that died during water shortages were less resilient to previous non-lethal droughts, relative to coexisting surviving trees of the same species. In angiosperms, drought-related mortality risk is associated with lower resistance (low capacity to reduce impact of the initial drought), while it is related to reduced recovery (low capacity to attain pre-drought growth rates) in gymnosperms. The different resilience strategies in these two taxonomic groups open new avenues to improve our understanding and prediction of drought-induced mortality.


Assuntos
Secas , Árvores/crescimento & desenvolvimento , Adaptação Fisiológica , Mudança Climática , Cycadopsida/crescimento & desenvolvimento , Ecologia , Florestas , Magnoliopsida/crescimento & desenvolvimento , Mortalidade , Solo/química , Especificidade da Espécie , Estresse Fisiológico , Análise de Sobrevida , Árvores/classificação , Água
13.
New Phytol ; 225(2): 999-1010, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31505049

RESUMO

Clonal growth of plants is attained by a number of morphologically different organs (e.g. stolons, rhizomes, and roots), which are not functionally equivalent. Consequently, these clonal growth organ (CGO) types can determine functional traits that are associated with clonality, although little is known about their evolutionary flexibility or the constraining role they play on clonal traits. We investigated the rates of evolutionary change by which individual CGOs are acquired and lost using a set of 2652 species of Central European flora. Furthermore, we asked how these individual CGOs constrain functionally relevant clonal traits, such as lateral spread, number of offspring, and persistence of connections. We show that plants can easily switch in evolution among individual types of CGO and between clonal and nonclonal habits. However, not all these transitions are equally probable. Namely, stem-based clonal growth and root-based clonal growth constitute evolutionarily separate forms of clonal growth. Clonal traits are strongly constrained by individual CGO types. Specifically, fast lateral spread is attained by stolons or hypogeogenous rhizomes, and persistent connections are attained by all rhizome types. However, the ease with which clonal organs appear and disappear in evolution implies that plants can overcome these constraints by adjusting their morphologies.


Assuntos
Evolução Biológica , Magnoliopsida/crescimento & desenvolvimento , Células Clonais , Funções Verossimilhança , Especificidade de Órgãos , Filogenia
14.
Funct Integr Genomics ; 20(1): 133-149, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31414312

RESUMO

Plants can regenerate new individuals under appropriate culture conditions. Although the molecular basis of shoot regeneration has steadily been unraveled, the role of age-dependent DNA methylation status in the regulation of explant regeneration remains practically unknown. Here, we established an effective auxin/cytokinin-induced shoot regeneration system for the resurrection plant Boea hygrometrica via direct organogenesis and observed that regeneration was postponed with increasing age of donor plants. Global transcriptome analysis revealed significant upregulation of genes required for hormone signaling and phenylpropanoid biosynthesis and downregulation of photosynthetic genes during regeneration. Transcriptional changes in the positive/negative regulators and cell wall-related proteins involved in plant regeneration, such as ELONGATED HYPOCOTYL5 (HY5), LATERAL ORGAN BOUNDARIES DOMAIN, SHOOT-MERISTEMLESS, and WUSCHEL, were associated with the regeneration process. Comparison of DNA methylation profiling between leaves from young seedlings (YL) and mature plants (ML) revealed increased asymmetrical methylation in ML, which was predominantly distributed in promoter regions of genes, such as HY5 and a member of ABA-responsive element (ABRE) binding protein/ABRE binding factor, as well as genes encoding glycine-rich cell wall structural protein, CENTRORADIALIS-like protein, and beta-glucosidase 40-like essential for shoot meristem and cell wall architecture. Their opposite transcription response in ML explants during regeneration compared with those from YL demonstrated the putative involvement of DNA methylation in regeneration. Moreover, a significant lower expression of DNA glycosylase-lyase required for DNA demethylation in ML was coincident with its postponed regeneration compared with those in YL. Taken together, our results suggest a role of promoter demethylation in B. hygrometrica regeneration.


Assuntos
Metilação de DNA , Magnoliopsida/genética , Regulação da Expressão Gênica de Plantas , Ontologia Genética , Genoma de Planta , Magnoliopsida/crescimento & desenvolvimento , Magnoliopsida/fisiologia , Reguladores de Crescimento de Planta/fisiologia , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Folhas de Planta/fisiologia , Brotos de Planta/fisiologia , Regeneração/genética , Plântula/genética , Transcriptoma
15.
Chemosphere ; 245: 125552, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31846788

RESUMO

Genotypic variability has been considered for years as a key attribute in species adaptation to new environments. It has been extensively studied in a context of chemical resistance, but remains poorly studied in response to chemical exposure in a context of global change. As aquatic ecosystems are particularly affected by environmental changes, we aimed to study how genotypic variability could inflect the sensitivity of aquatic plants to chemicals. Seven genotypes of Myriophyllum spicatum were exposed to three copper concentrations at 0, 0.15 and 0.5 mg/L. The sensitivity of the different genotypes was assessed through several endpoints such as relative growth rate (RGR) and morphological traits, as well as physiological markers, such as plant biomacromolecular composition. Our results showed that genotypes exhibited significant differences in their life-history traits in absence of chemical contamination. Some trait syndromes were observed, and three growth strategies were identified: (1) biomass production and main shoot elongation, (2) dry matter storage with denser whorls to promote resource conservation and (3) lateral shoot production. An up to eightfold difference in sensitivity for growth-related endpoints was observed among genotypes. Differences in sensitivity were partly attributed to morphological life-history traits. Our results confirm that genotypic variability can significantly affect M. spicatum sensitivity to Cu, and may influence the outcomes of laboratory testing based on the study of one single genotype. We recommend including genotypic variation as an assessment factor in ecological risk assessment and to study this source of variability more in depth as a possible driver of ecosystem resilience.


Assuntos
Cobre/toxicidade , Saxifragales/fisiologia , Poluentes Químicos da Água/toxicidade , Biomassa , Ecossistema , Genótipo , Magnoliopsida/crescimento & desenvolvimento , Magnoliopsida/fisiologia , Plantas , Medição de Risco
16.
Protoplasma ; 257(2): 371-390, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31659470

RESUMO

The terrestrial carnivorous species Utricularia dichotoma is known for a great phenotypic plasticity and unusual vegetative organs. Our investigation on 22 sources/populations revealed that after initiation of a leaf and two bladders on a stolon, a bud was formed in the proximal axil of the leaf, developing into a rosette with up to seven organs. The first two primordia of the bud grew into almost every possible combination of organs, but often into two anchor stolons. The patterns were generally not population specific. The interchangeability of organs increased with increasing rank in the succession of organs on stolon nodes. A high potential of switching developmental programs may be successful in a fluctuating environment. In this respect, we were able to show that bladders developed from anchor stolons experimentally when raising the water table. Anatomical structures were simple, lacunate and largely homogenous throughout all organs. They showed similarities with many hydrophytes, reflecting the plant's adaptation to (temporarily) submerged conditions. The principal component analysis was used in the context of dynamic morphology to illustrate correlations between organ types in the morphospace of U. dichotoma, revealing an organ specific patchwork of developmental processes for typical leaves and shoots, and less pronounced for a typical root. The concept and methods we applied may prove beneficial for future studies on the evolution of Lentibulariaceae, and on developmental morphology and genetics of unusual structures in plants.


Assuntos
Magnoliopsida/anatomia & histologia , Magnoliopsida/crescimento & desenvolvimento , Magnoliopsida/metabolismo , Filogenia , Folhas de Planta/anatomia & histologia , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Brotos de Planta/anatomia & histologia , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/metabolismo
17.
PLoS One ; 14(12): e0226551, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31856213

RESUMO

The widely accepted "endozoochory syndrome" is assigned to angiosperm diaspores with a fleshy, attractive tissue and implies the existence of adaptations for protection against digestion during gut passage. This syndrome has led diaspore fleshiness to be emphasized as the exclusive indicator of endozoochory in much of the ecology and biogeography research. Crucially, however, endozoochory in nature is not limited to frugivory, and diaspores without "external flesh" are commonly dispersed, often over long distances, via birds and mammals by granivory. A key question is: are such diaspores somehow less prepared from an architectural point of view to survive gut passage than fleshy diaspores? To answer this question, we selected 11 European angiosperm taxa that fall outside the classical endozoochory syndrome yet are known to be dispersed via endozoochory. We studied their seed coat/pericarp morphology and anatomy both before and after gut passage through granivorous waterfowl, and determined their seed survival and germinability. We found no fundamental differences in the mechanical architecture of the seed coat and pericarp between these plants dispersed by granivory and others dispersed by frugivory. Neither diaspore traits per se, nor dormancy type, were strong predictors of diaspore survival or degree of damage during gut passage through granivores, or of the influence of gut passage on germinability. Among our 11 taxa, survival of gut passage is enabled by the thick cuticle of the exotesta or epicarp; one or several lignified cell layers; and diverse combinations of other architectural elements. These protection structures are ubiquitous in angiosperms, and likely to have evolved in gymnosperms. Hence, many angiosperm diaspores, dry or fleshy, may be pre-adapted to endozoochory, but with differing degrees of specialization and adaptation to dispersal mechanisms such as frugivory and granivory. Our findings underline the broad ecological importance of "non-classical endozoochory" of diaspores that lack "external flesh".


Assuntos
Adaptação Fisiológica , Aves/fisiologia , Frutas , Intestinos/fisiologia , Magnoliopsida/fisiologia , Dispersão de Sementes , Animais , Fenômenos Biomecânicos , Digestão , Germinação , Magnoliopsida/crescimento & desenvolvimento
18.
BMC Plant Biol ; 19(1): 554, 2019 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-31842763

RESUMO

BACKGROUND: Gametogenesis is a key step in the production of ovules or pollen in higher plants. The sex-determination aspects of gametogenesis have been well characterized in the model plant Arabidopsis. However, little is known about this process in androdioecious plants. Tapiscia sinensis Oliv. is a functionally androdioecious tree, with both male and hermaphroditic individuals. Hermaphroditic flowers (HFs) are female-fertile flowers that can produce functional pollen and set fruits. However, compared with male flowers (MFs), the pollen viability and number of pollen grains per flower are markedly reduced in HFs. MFs are female-sterile flowers that fail to set fruit and that eventually drop. RESULTS: Compared with HF, a notable cause of MF female sterility in T. sinensis is when the early gynoecium meristem is disrupted. During the early stage of HF development (stage 6), the ring meristem begins to form as a ridge around the center of the flower. At this stage, the internal fourth-whorl organ is stem-like rather than carpelloid in MF. A total of 52,945 unigenes were identified as transcribed in MF and HF. A number of differentially expressed genes (DEGs) and metabolic pathways were detected as involved in the development of the gynoecium, especially the ovule, carpel and style. At the early gynoecium development stage, DEGs were shown to function in the metabolic pathways regulating ethylene biosynthesis and signal transduction (upstream regulator), auxin, cytokinin transport and signalling, and sex determination (or flower meristem identity). CONCLUSIONS: Pathways for the female sterility model were initially proposed to shed light on the molecular mechanisms of gynoecium development at early stages in T. sinensis.


Assuntos
Flores/crescimento & desenvolvimento , Genes de Plantas , Magnoliopsida/crescimento & desenvolvimento , Árvores/crescimento & desenvolvimento , Flores/genética , Magnoliopsida/anatomia & histologia , Magnoliopsida/genética , RNA-Seq , Análise de Sequência de RNA , Diferenciação Sexual/genética , Árvores/anatomia & histologia , Árvores/genética
19.
Sci Rep ; 9(1): 15568, 2019 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-31666538

RESUMO

The population synchrony of tree seed production has attracted widespread attention in agriculture, forestry and ecosystem management. Oaks usually show synchronisation of irregular or intermittent sequences of acorn production, which is termed 'masting'. Tree crops such as citrus and pistachio show a clear two-year cycle (period-2) termed 'alternate bearing'. We identified period-3 dominant phase synchronisation in a population of Zelkova serrata. As 'period-3' is known to provide evidence to imply chaos in nonlinear science, the observed period-3 phase synchronisation of Zelkova serrata is an attractive real-world phenomenon that warrants investigation in terms of nonlinear dynamics. Using the Hilbert transform, we proposed a procedure to determine the fractions of periods underlying the survey data and distinguished the on-year (high yield year) and the off-year (low yield year) of the masting. We quantified the effects of pollen coupling, common environmental noise and individual variability on the phase synchronisation and demonstrated how the period-3 synchronisation emerges through a border-collision bifurcation process. In this paper, we propose a model that can describe diverse behaviours of seed production observed in many different tree species by changing its parameters.


Assuntos
Magnoliopsida/fisiologia , Magnoliopsida/crescimento & desenvolvimento , Modelos Biológicos , Dinâmica não Linear , Sementes/crescimento & desenvolvimento
20.
PLoS One ; 14(10): e0223949, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31622402

RESUMO

The Ligurian Sea is one of the most studied Mediterranean basins. Since the beginning of the last century, many research expeditions have characterized its benthic and pelagic fauna through scuba diving and trawl surveys. However, a large knowledge gap exists about the composition of benthic communities extending into the so-called mesophotic or twilight depth range, currently under intense pressure from commercial and recreational fishing. A series of visual surveys, carried out by means of remotely operated vehicles between 2012 and 2018, were conducted along the Ligurian deep continental shelf and shelf break, between 30 and 210 m depth, in order to characterize the main benthic biocoenoses dwelling at this depth range and to determine the most relevant environmental factors that explain their spatial distribution. Deep circalittoral communities of the Ligurian Sea were represented by a mixture of species belonging to the deepest extension of shallow-water habitats and deep circalittoral ones. Twelve major biocoenoses were identified, each one characterized by specific preferences in depth range, substrate type and seabed slope. Those biocoenoses included gorgonian and hydrozoan forests, dense keratose sponge grounds, Dendrophyllia cornigera gardens, bryozoan beds and soft-bottom meadows of sabellid polychaetes and soft-corals. Other less common aggregations included six forests of black corals and two populations of Paramuricea macrospina. A georeferenced database has been created in order to provide information to managers and stakeholders about the location of the identified communities and high-diversity areas, aiming to facilitate sustainable long-term conservation of the Ligurian benthic ecosystem.


Assuntos
Organismos Aquáticos/crescimento & desenvolvimento , Tecnologia de Sensoriamento Remoto/instrumentação , Animais , Antozoários/classificação , Antozoários/crescimento & desenvolvimento , Organismos Aquáticos/classificação , Biodiversidade , Briozoários/classificação , Briozoários/crescimento & desenvolvimento , Mergulho , Magnoliopsida/classificação , Magnoliopsida/crescimento & desenvolvimento , Mar Mediterrâneo , Poríferos/classificação , Poríferos/crescimento & desenvolvimento , Especificidade da Espécie
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