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1.
PLoS One ; 16(10): e0258235, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34679089

RESUMO

Carnivorous plants feed on animal prey, mainly insects, to get additional nutrients. This carnivorous syndrome is widely investigated and reported. In contrast, reports on herbivores feeding on carnivorous plants and related defenses of the plants under attack are rare. Here, we studied the interaction of a pitcher plant, Nepenthes x ventrata, with a generalist lepidopteran herbivore, Spodoptera littoralis, using a combination of LC/MS-based chemical analytics, choice and feeding assays. Chemical defenses in N. x ventrata leaves were analyzed upon S. littoralis feeding. A naphthoquinone, plumbagin, was identified in Nepenthes defense against herbivores and as the compound mainly responsible for the finding that S. littoralis larvae gained almost no weight when feeding on Nepenthes leaves. Plumbagin is constitutively present but further 3-fold increased upon long-term (> 1 day) feeding. Moreover, in parallel de novo induced trypsin protease inhibitor (TI) activity was identified. In contrast to TI activity, enhanced plumbagin levels were not phytohormone inducible, not even by defense-related jasmonates although upon herbivory their level increased more than 50-fold in the case of the bioactive jasmonic acid-isoleucine. We conclude that Nepenthes is efficiently protected against insect herbivores by naphthoquinones acting as phytoanticipins, which is supported by additional inducible defenses. The regulation of these defenses remains to be investigated.


Assuntos
Planta Carnívora/fisiologia , Herbivoria/fisiologia , Naftoquinonas/farmacologia , Compostos Fitoquímicos/farmacologia , Sarraceniaceae/fisiologia , Ácido Abscísico/farmacologia , Animais , Planta Carnívora/efeitos dos fármacos , Ciclopentanos/farmacologia , Dieta , Herbivoria/efeitos dos fármacos , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Oxilipinas/farmacologia , Reguladores de Crescimento de Plantas/análise , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/fisiologia , Inibidores de Proteases/farmacologia , Ácido Salicílico/farmacologia , Sarraceniaceae/efeitos dos fármacos , Spodoptera/efeitos dos fármacos , Spodoptera/fisiologia
2.
Physiol Plant ; 173(3): 1221-1229, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34346074

RESUMO

Suberin, as a lipid polyester barrier, limits the movement of gas, water, and solutes, and plays important roles in plant protection and growth. In this study, a CDS encoding glycerol-3-phosphate acyltransferase 5 (GPAT5) was cloned from Sarracenia purpurea to investigate the gene function. SpGPAT5 shares 72% identity and 80% similarity to AtGPAT5 that is required for suberin synthesis. Fluorol Yellow 088 staining showed that the S. purpurea pitcher (specific leaf) tube contained more suberin in the adaxial surface compared to the lid, and SpGPAT5 transcripts were detected in the pitcher. Previous reported Atgpat5-1 phenotypes were complemented with SpGPAT5 showing that the Atgpat5-1 seed coat had increased permeability of tetrazolium red and the mutant was sensitive to salt. We also found that SpGPAT5 was able to revert the hyperhydric phenotype of Atgpat5-1 under high humidity. Thus, this study suggests that SpGPAT5 can functionally replace AtGPAT5 and contributes to plant tolerance to high humidity, which maybe assist in understanding the role of suberin-associated waxes in S. purpurea pitchers for water retention.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Sarraceniaceae , 1-Acilglicerol-3-Fosfato O-Aciltransferase , Aciltransferases/genética , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Glicerol , Umidade , Fosfatos
3.
Molecules ; 26(9)2021 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-33919120

RESUMO

Rare carnivorous plants representing the genus Sarracenia are perceived as very interesting to scientists involved in various fields of botany, ethnobotany, entomology, phytochemistry and others. Such high interest is caused mainly by the unique capacity of Sarracenia spp. to attract insects. Therefore, an attempt to develop a protocol for micropropagation of the Sarracenia alata (Alph.Wood) Alph.Wood, commonly named yellow trumpets, and to identify the specific chemical composition of volatile compounds of this plant in vitro and ex vivo was undertaken. Thus, the chemical volatile compounds excreted by the studied plant to attract insects were recognized with the application of the headspace solid-phase microextraction (HS-SPME) coupled with the GC-MS technique. As the major volatile compounds (Z)-3-hexen-1-ol (16.48% ± 0.31), (E)-3-hexen-1-ol acetate (19.99% ± 0.01) and ß-caryophyllene (11.30% ± 0.27) were identified. Further, both the chemical assumed to be responsible for attracting insects, i.e., pyridine (3.10% ± 0.07), and whole plants were used in in vivo bioassays with two insect species, namely Drosophila hydei and Acyrthosiphon pisum. The obtained results bring a new perspective on the possibilities of cultivating rare carnivorous plants in vitro since they are regarded as a valuable source of bioactive volatile compounds, as including ones with repellent or attractant activity.


Assuntos
Interações Hospedeiro-Parasita , Insetos , Sarraceniaceae/química , Sarraceniaceae/parasitologia , Compostos Orgânicos Voláteis/análise , Compostos Orgânicos Voláteis/química , Madeira/química , Animais , Bioensaio , Carga Parasitária , Desenvolvimento Vegetal , Brotos de Planta/química , Brotos de Planta/parasitologia
4.
Ecology ; 102(5): e03308, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33577089

RESUMO

The importance of climate, habitat structure, and higher trophic levels on microbial diversity is only beginning to be understood. Here, we examined the influence of climate variables, plant morphology, and the abundance of aquatic invertebrates on the microbial biodiversity of the northern pitcher plant Sarracenia purpurea. The plant's cup-shaped leaves fill with rainwater and support a miniature, yet full-fledged, ecosystem with a diverse microbiome that decomposes captured prey and a small network of shredding and filter-feeding aquatic invertebrates that feed on microbes. We characterized pitcher microbiomes of 108 plants sampled at 36 sites from Florida to Quebec. Structural equation models revealed that annual precipitation and temperature, plant size, and midge abundance had direct effects on microbiome taxonomic and phylogenetic diversity. Climate variables also exerted indirect effects through plant size and midge abundance. Further, spatial structure and climate influenced taxonomic composition, but not phylogenetic composition. Our results suggest that direct effects of midge abundance and climate and indirect effects of climate through its effect on plant-associated factors lead to greater richness of microbial phylotypes in warmer, wetter sites.


Assuntos
Microbiota , Sarraceniaceae , Ecossistema , Florida , Cadeia Alimentar , Interações Microbianas , Filogenia , Quebeque
5.
Ecol Lett ; 24(1): 94-101, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33079483

RESUMO

Incremental increases in a driver variable, such as nutrients or detritus, can trigger abrupt shifts in aquatic ecosystems that may exhibit hysteretic dynamics and a slow return to the initial state. A model system for understanding these dynamics is the microbial assemblage that inhabits the cup-shaped leaves of the pitcher plant Sarracenia purpurea. With enrichment of organic matter, this system flips within three days from an oxygen-rich state to an oxygen-poor state. In a replicated greenhouse experiment, we enriched pitcher-plant leaves at different rates with bovine serum albumin (BSA), a molecular substitute for detritus. Changes in dissolved oxygen (DO) and undigested BSA concentration were monitored during enrichment and recovery phases. With increasing enrichment rates, the dynamics ranged from clockwise hysteresis (low), to environmental tracking (medium), to novel counter-clockwise hysteresis (high). These experiments demonstrate that detrital enrichment rate can modulate a diversity of hysteretic responses within a single aquatic ecosystem, and suggest different management strategies may be needed to mitigate the effects of high vs. low rates of detrital enrichment.


Assuntos
Ecossistema , Sarraceniaceae , Modelos Biológicos , Folhas de Planta
6.
Mol Phylogenet Evol ; 154: 106961, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32956799

RESUMO

Heliamphora is a genus of carnivorous pitcher plants endemic to the Guiana Highlands with fragmented distributions. We present a well resolved, time-calibrated, and comprehensive Heliamphora phylogeny estimated using Bayesian inference and maximum likelihood based on nuclear genes (26S, ITS, and PHYC) and secondary calibration. We used stochastic mapping to infer ancestral states of morphological characters and ecological traits. Our ancestral state estimations revealed that the pitcher drainage structures characteristic of the genus transformed from a hole to a slit in single clade, while other features (scape pubescence and hammock-like growth) have been gained and lost multiple times. Habitat was similarly labile in Heliamphora, with multiple transitions from the ancestral highland habitats into the lowlands. Using a Mantel test, we found closely related species tend to be geographically closely distributed. Placing our phylogeny in a historical context, major clades likely emerged through both vicariance and dispersal during the Miocene with more recent diversification driven by vertical displacement during the Pleistocene glacial-interglacial thermal oscillations. Despite the dynamic climatic history experienced by Heliamphora, the temperature changes brought by global warming pose a significant threat, particularly for those species at the highest elevations.


Assuntos
Filogenia , Filogeografia , Sarraceniaceae/classificação , Áreas Alagadas , Teorema de Bayes , Funções Verossimilhança , Modelos Biológicos , Nucleotídeos/genética , Fenótipo , América do Sul
7.
Sci Rep ; 10(1): 18953, 2020 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-33144625

RESUMO

Herpes simplex virus type-1 (HSV-1), one of the most widely spread human viruses in the Herpesviridae family, causes herpes labialis (cold sores) and keratitis (inflammation of the cornea). Conventional treatment for HSV-1 infection includes pharmaceutical drugs, such as acyclovir and docosonal, which are efficacious but maintain the potential for the development of viral drug resistance. Extracts from the carnivorous pitcher plant, Sarracenia purpurea, have previously been shown to inhibit the replication of HSV-1. In this study, we demonstrate that S. purpurea extracts can inhibit the replication of HSV-1 by two distinct mechanisms of action. These extracts directly inhibit extracellular virions or viral attachment to the human host cell as well as inhibiting the expression of viral immediate-early, early and late genes when added at various times post-infection. This botanical has previously been shown to inhibit the replication of poxviruses through the inhibition of early viral gene transcription. These results support a broader anti-viral activity of S. purpurea extracts against both pox and herpes viruses.


Assuntos
Antivirais/uso terapêutico , Extratos Vegetais/uso terapêutico , Sarraceniaceae/química , Animais , Antivirais/efeitos adversos , Antivirais/química , Western Blotting , Sobrevivência Celular/efeitos dos fármacos , Chlorocebus aethiops , Infecções por Herpesviridae/prevenção & controle , Herpesvirus Humano 1/efeitos dos fármacos , Herpesvirus Humano 1/patogenicidade , Extratos Vegetais/efeitos adversos , Extratos Vegetais/química , Reação em Cadeia da Polimerase em Tempo Real , Células Vero
8.
Am J Bot ; 107(11): 1606-1613, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33145765

RESUMO

PREMISE: The association of carnivory (an adaptation to nutrient-poor soils) with fire has been described as a paradox, given increases in nutrient availability that often accompany fire. The nutrients that increase in availability following fire, however, may not be the same as those provided by prey and may not reduce nutrient limitation if accompanied by even greater increases in light. METHODS: Using a factorial experiment in the field, we examined how simulated fire (clipping plus nitrogen-free fertilizer addition) and prey-derived nutrient availability (prey exclusion) interacted to influence carnivorous potential in Sarracenia alata and belowground competition with its neighbors (manipulated via trenching). We hypothesized that simulated fire combined with prey exclusion would (1) increase the potential for prey capture relative to shade avoidance, hereafter, relative prey-capture potential (RPCP), and/or (2) increase belowground competition with neighboring plants. RESULTS: Sarracenia alata increased RPCP in response to the combination of simulated fire and prey exclusion, despite increases in phosphorus and other nutrients associated with the simulated fire treatment, suggesting that prey capture potential increases in response to increased nitrogen limitation resulting from increases in light and/or phosphorus after fire. We found no evidence of belowground competition. CONCLUSIONS: The potential importance of carnivory in Sarracenia alata increases following fire. This result helps to explain the paradoxical association of carnivorous plants with fire by demonstrating the potential for prey-derived nutrient limitation to increase rather than decrease in response to increases in light and nutrients other than nitrogen following fire.


Assuntos
Incêndios , Sarraceniaceae , Carnivoridade , Nitrogênio , Fósforo
9.
Yale J Biol Med ; 93(2): 277-281, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32607088

RESUMO

Oral herpes labialis, more commonly known as cold sores, are a common encountered viral infection involving herpes simplex virus-1 (HSV-1). Although relatively benign, these lesions can be both unsightly and clinically difficult to manage. Prescription standards of care and over-the-counter agents, such as docosonal, have often shown only limited efficacy in both decreasing lesional pain and reducing duration of lesional symptomology and are not without potential side effects. Despite some success with acute remediation, recurrent episodes often occur, with seemingly no imparted protection or suppression against future outbreaks. This case report involves the successful treatment of oro-facial herpes labialis with a synergistic botanical blend with marked reduction in symptoms, pain score, and lesion duration. Monitoring and evaluation post-treatment and application during future prodromal symptoms was also performed demonstrating additional reduction in the frequency of subsequent outbreaks. This case report supports the use of this treatment for prodromal and acute treatment of oro-facial herpes infection and appears to impart a reduction in the frequency of future outbreaks.


Assuntos
Eleutherococcus , Glycyrrhiza , Herpes Labial , Hypericum , Lavandula , Melissa , Sarraceniaceae , Cicatrização/efeitos dos fármacos , Adulto , Analgésicos/farmacologia , Anti-Inflamatórios/farmacologia , Antivirais/farmacologia , Composição de Medicamentos , Feminino , Géis/farmacologia , Herpes Labial/diagnóstico , Herpes Labial/fisiopatologia , Herpes Labial/terapia , Humanos , Prevenção Secundária/métodos , Simplexvirus/efeitos dos fármacos , Resultado do Tratamento
10.
Anal Chem ; 92(16): 11018-11028, 2020 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-32658454

RESUMO

Hydrogen/Deuterium Exchange (HDX) coupled with Mass Spectrometry (HDX-MS) is a sensitive and robust method to probe protein conformational changes and protein-ligand interactions. HDX-MS relies on successful proteolytic digestion of target proteins under acidic conditions to localize perturbations in exchange behavior to protein structure. The ability of the protease to produce small peptides and overlapping fragments and provide sufficient coverage of the protein sequence is essential for localizing regions of interest. While the acid protease pepsin has been the enzyme of choice for HDX-MS studies, recently, it was shown that aspartic proteases from carnivorous pitcher plants of the genus Nepenthes are active under low-pH conditions and cleave at basic residues that are "forbidden" in peptic digests. In this report, we describe the utility of one of these enzymes, Nepenthesin II (NepII), in a HDX-MS workflow. A systematic and statistical analysis of data from 11 proteins (6391 amino acid residues) digested with immobilized porcine pepsin or NepII under conditions compatible with HDX-MS was performed to examine protease cleavage specificities. The cleavage of pepsin was most influenced by the amino acid residue at position P1. Phe, Leu, and Met are favored residues, each with a cleavage probability of greater than 40%. His, Lys, Arg, or Pro residues prohibit cleavage when found at the P1 position. In contrast, NepII offers advantageous cleavage to all basic residues and produces shortened peptides that could improve the spatial resolution in HDX-MS studies.


Assuntos
Enzimas Imobilizadas/química , Pepsina A/química , Proteólise , Animais , Biocatálise , Deutério/química , Medição da Troca de Deutério , Espectrometria de Massas , Sarraceniaceae/enzimologia , Especificidade por Substrato , Suínos
11.
PLoS One ; 15(5): e0232835, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32384101

RESUMO

Many plant species harbor communities of symbionts that release nutrients used by their host plants. However, the importance of these nutrients to plant growth and reproductive effort is not well understood. Here, we evaluate the relationship between the communities that colonize pitcher plant phytotelmata and the pitcher plants' vegetative growth and flower production to better understand the symbiotic role played by phytotelma communities. We focus on the mountain variety purple pitcher plant (Sarracenia purpurea var. montana), which occurs in small and isolated populations in Western North Carolina. We found that greater symbiont community diversity is associated with higher flower production the following season. We then examined geographic variation in communities and found that smaller plant populations supported less diverse symbiont communities. We relate our observations to patterns of community diversity predicted by community ecology theory.


Assuntos
Artrópodes/fisiologia , Biota/fisiologia , Sarraceniaceae/crescimento & desenvolvimento , Simbiose/fisiologia , Animais , Biodiversidade , Chironomidae/crescimento & desenvolvimento , Chironomidae/metabolismo , Copépodes/metabolismo , Culicidae/metabolismo , Flores/crescimento & desenvolvimento , Larva , Ácaros/metabolismo , Ciclo do Nitrogênio , Dispersão Vegetal , Folhas de Planta/crescimento & desenvolvimento , Reprodução , Sarraceniaceae/metabolismo
12.
ACS Appl Mater Interfaces ; 12(18): 21080-21087, 2020 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-32293863

RESUMO

Achieving effective dropwise capture and ultrafast water transport is essential for fog harvesting. In nature, cactus uses the conical spine with microbarbs to effectively capture fog, while Sarracenia utilizes the trichome with hierarchical microchannels to quickly transport water. Herein, we combined their advantages to present a novel configuration, a spine with barbs and hierarchical channels (SBHC), for simultaneous ultrafast water transport and high-efficient fog harvesting. This bioinspired SBHC exhibited the fastest water transport ability and the highest fog harvesting efficiency in comparison with the spine with hierarchical channels (SHCs), the spine with barbs and grooves (SBG), and the spine with barbs (SB). Based on the fundamental SBHC unit, we further designed and fabricated a two-dimensional (2D) spider-web-like fog collector and a three-dimensional (3D) cactus-like fog collector using direct laser structuring and origami techniques. The 2D spider-web and 3D cactus-like fog collectors showed high-efficient fog collection capacity. We envision that this fundamental understanding and rational design strategy can be applied in fog harvesting, heat transfer, liquid manipulation, and microfluidics.


Assuntos
Materiais Biomiméticos/química , Água/química , Cactaceae/química , Cobre/química , Lasers , Sarraceniaceae/química , Tempo (Meteorologia) , Molhabilidade
13.
Sci Rep ; 10(1): 6575, 2020 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-32313042

RESUMO

Carnivorous pitcher plants produce specialised pitcher organs containing secretory glands, which secrete acidic fluids with hydrolytic enzymes for prey digestion and nutrient absorption. The content of pitcher fluids has been the focus of many fluid protein profiling studies. These studies suggest an evolutionary convergence of a conserved group of similar enzymes in diverse families of pitcher plants. A recent study showed that endogenous proteins were replenished in the pitcher fluid, which indicates a feedback mechanism in protein secretion. This poses an interesting question on the physiological effect of plant protein loss. However, there is no study to date that describes the pitcher response to endogenous protein depletion. To address this gap of knowledge, we previously performed a comparative RNA-sequencing experiment of newly opened pitchers (D0) against pitchers after 3 days of opening (D3C) and pitchers with filtered endogenous proteins (>10 kDa) upon pitcher opening (D3L). Nepenthes ampullaria was chosen as a model study species due to their abundance and unique feeding behaviour on leaf litters. The analysis of unigenes with top 1% abundance found protein translation and stress response to be overrepresented in D0, compared to cell wall related, transport, and signalling for D3L. Differentially expressed gene (DEG) analysis identified DEGs with functional enrichment in protein regulation, secondary metabolism, intracellular trafficking, secretion, and vesicular transport. The transcriptomic landscape of the pitcher dramatically shifted towards intracellular transport and defence response at the expense of energy metabolism and photosynthesis upon endogenous protein depletion. This is supported by secretome, transportome, and transcription factor analysis with RT-qPCR validation based on independent samples. This study provides the first glimpse into the molecular responses of pitchers to protein loss with implications to future cost/benefit analysis of carnivorous pitcher plant energetics and resource allocation for adaptation in stochastic environments.


Assuntos
Metabolismo Energético/genética , Proteínas de Plantas/genética , Sarraceniaceae/genética , Transcriptoma/genética , Sequência de Aminoácidos/genética , Animais , Fotossíntese/genética , Folhas de Planta/genética , Folhas de Planta/metabolismo , RNA-Seq , Sarraceniaceae/enzimologia , Sarraceniaceae/crescimento & desenvolvimento
14.
Nat Commun ; 11(1): 1440, 2020 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-32188849

RESUMO

Niche construction through interspecific interactions can condition future community states on past ones. However, the extent to which such history dependency can steer communities towards functionally different states remains a subject of active debate. Using bacterial communities collected from wild pitchers of the carnivorous pitcher plant, Sarracenia purpurea, we test the effects of history on composition and function across communities assembled in synthetic pitcher plant microcosms. We find that the diversity of assembled communities is determined by the diversity of the system at early, pre-assembly stages. Species composition is also contingent on early community states, not only because of differences in the species pool, but also because the same species have different dynamics in different community contexts. Importantly, compositional differences are proportional to differences in function, as profiles of resource use are strongly correlated with composition, despite convergence in respiration rates. Early differences in community structure can thus propagate to mature communities, conditioning their functional repertoire.


Assuntos
Microbiota/genética , Análise de Sequência de DNA , Biodiversidade , Dióxido de Carbono/metabolismo , Sarraceniaceae/microbiologia , Especificidade da Espécie
15.
Sci Rep ; 9(1): 18286, 2019 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-31797904

RESUMO

Dispersal is key for maintaining biodiversity at local- and regional scales in metacommunities. However, little is known about the combined effects of dispersal and climate change on biodiversity. Theory predicts that alpha-diversity is maximized at intermediate dispersal rates, resulting in a hump-shaped diversity-dispersal relationship. This relationship is predicted to flatten when competition increases. We anticipate that this same flattening will occur with increased temperature because, in the rising part of the temperature performance curve, interspecific competition is predicted to increase. We explored this question using aquatic communities of Sarracenia purpurea from early- and late-successional stages, in which we simulated four levels of dispersal and four temperature scenarios. With increased dispersal, the hump shape was observed consistently in late successional communities, but only in higher temperature treatments in early succession. Increased temperature did not flatten the hump-shape relationship, but decreased the level of alpha- and gamma-diversity. Interestingly, higher temperatures negatively impacted small-bodied species. These metacommunity-level extinctions likely relaxed interspecific competition, which could explain the absence of flattening of the diversity-dispersal relationship. Our findings suggest that climate change will cause extinctions both at local- and global- scales and emphasize the importance of intermediate levels of dispersal as an insurance for local diversity.


Assuntos
Biodiversidade , Microbiota , Sarraceniaceae/microbiologia , Mudança Climática , Dinâmica Populacional , Temperatura
16.
J R Soc Interface ; 16(158): 20190323, 2019 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-31480920

RESUMO

We show how anisotropic, grooved features facilitate the trapping and directed transport of droplets on lubricated, liquid-shedding surfaces. Capillary action pins droplets to topographic surface features, enabling transport along the feature while inhibiting motion across (or detachment from) the feature. We demonstrate the robustness of this capillary-based mechanism for directed droplet transport on slippery surfaces by combining experiments on synthetic, lubricant-infused surfaces with observations on the natural trapping surface of a carnivorous pitcher plant. Controlling liquid navigation on synthetic surfaces promises to unlock significant potential in droplet-based technologies. Our observations also offer novel insight into the evolution of the Nepenthes pitcher plant, indicating that the 'pitfall' trapping mechanism is enhanced by the lubricant-infused, macroscopic grooves on the slippery peristome surface, which guide prey into the trap in a way that is more tightly controlled than previously considered.


Assuntos
Modelos Biológicos , Sarraceniaceae/fisiologia , Água/metabolismo , Transporte Biológico Ativo/fisiologia , Sarraceniaceae/anatomia & histologia , Propriedades de Superfície
17.
J Exp Bot ; 70(13): 3379-3389, 2019 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-31120525

RESUMO

The lipid-derived jasmonate phytohormones (JAs) regulate a wide spectrum of physiological processes in plants such as growth, development, tolerance to abiotic stresses, and defence against pathogen infection and insect attack. Recently, a new role for JAs has been revealed in carnivorous plants. In these specialized plants, JAs can induce the formation of digestive cavities and regulate enzyme production in response to different stimuli from caught prey. Appearing to be a new function for JAs in plants, a closer look reveals that the signalling pathways involved resemble known signalling pathways from plant defence mechanisms. Moreover, the digestion-related secretome of carnivorous plants is composed of many pathogenesis-related (PR) proteins and low molecular weight compounds, indicating that the plant carnivory syndrome is related to and has evolved from plant defence mechanisms. This review describes the similarities between defence and carnivory. It further describes how, after recognition of caught insects, JAs enable the carnivorous plants to digest and benefit from the prey. In addition, a causal connection between electrical and jasmonate signalling is discussed.


Assuntos
Ciclopentanos/metabolismo , Drosera/metabolismo , Oxilipinas/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Sarraceniaceae/metabolismo , Ciclopentanos/imunologia , Oxilipinas/imunologia , Imunidade Vegetal , Metabolismo Secundário , Transdução de Sinais , Viridiplantae/metabolismo
18.
Oecologia ; 190(1): 169-178, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30941498

RESUMO

The effects of resource pulses on natural communities are known to vary with the type of pulse. However, less is known about mechanisms that determine the responses of different species to the same pulse. We hypothesized that these differences are related to the size of the species, as increasing size may be correlated with increasing competitive ability and decreasing tolerance to predation. A factorial experiment quantified the magnitude and timing of species' responses to a resource pulse using the aquatic communities found in the leaves of the carnivorous pitcher plant, Sarracenia purpurea. We added prey to leaves and followed the abundances of bacteria and bacterivores (protozoa and rotifers) in the presence and absence of a top predator, larvae of the mosquito Wyeomyia smithii. Resource pulses had significant positive effects on species abundances and diversity in this community; however, the magnitude and timing of responses varied among the bacterivore species and was not related to body size. Larger bacterivores were significantly suppressed by predators, while smaller bacterivores were not; predation also significantly reduced bacterivore species diversity. There were no interactions between the effects of the resource pulse and predation on protozoa abundances. Over 67 days, some species returned to pre-pulse abundances quickly, others did not or did so very slowly, resulting in new community states for extended periods of time. This study demonstrates that species-specific differences in responses to resource pulses and predation are complex and may not be related to simple life history trade-offs associated with size.


Assuntos
Rotíferos , Sarraceniaceae , Animais , Bactérias , Cadeia Alimentar , Comportamento Predatório
19.
Artigo em Inglês | MEDLINE | ID: mdl-30868226

RESUMO

In specialized pollination systems, floral scents are crucial for flower-pollinator communication, but key volatiles that attract pollinators are unknown for most systems. Deceptive Ceropegia trap flowers are famous for their elaborate mechanisms to trap flies. Recent studies revealed species-specific floral chemistry suggesting highly specialized mimicry strategies. However, volatiles involved in fly attraction were until now identified in C. dolichophylla and C. sandersonii, only. We here present data on C. stenantha for which flower scent and pollinators were recently described, but volatiles involved in flower-fly communication stayed unknown. We performed electrophysiological measurements with scatopsid fly pollinators (Coboldia fuscipes) and identified 12 out of 13 biologically active floral components. Among these volatiles some were never described from any organism but C. stenantha. We synthesized these components, tested them on antennae of male and female flies, and confirmed their biological activity. Overall, our data show that half of the volatiles emitted from C. stenantha flowers are perceived by male and female fly pollinators and are potentially important for flower-fly communication in this pollination system. Further studies are needed to clarify the role of the electrophysiologically active components in the life of scatopsid fly pollinators, and to fully understand the pollination strategy of C. stenantha.


Assuntos
Dípteros , Flores/química , Polinização , Sarraceniaceae/química , Animais , Comportamento Animal , Feminino , Masculino , Odorantes , Compostos Orgânicos Voláteis/química
20.
Am Nat ; 193(2): 227-239, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30720361

RESUMO

Gaining knowledge of how ecosystems provide essential services to humans is of primary importance, especially with the current threat of climate change. Yet little is known about how increased temperature will impact the biodiversity-ecosystem functioning (BEF) relationship. We tackled this subject theoretically and experimentally. We developed a BEF theory based on mechanistic population dynamic models, which allows the inclusion of the effect of temperature. Using experimentally established relationships between attack rate and temperature, the model predicts that temperature increase will intensify competition, and consequently the BEF relationship will flatten or even become negative. We conducted a laboratory experiment with natural microbial microcosms, and the results were in agreement with the model predictions. The experimental results also revealed that an increase in both temperature average and variation had a more intense effect than an increase in temperature average alone. Our results indicate that under climate change, high diversity may not guarantee high ecosystem functioning.


Assuntos
Mudança Climática , Ecossistema , Modelos Biológicos , Sarraceniaceae , Temperatura
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