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1.
Braz. j. biol ; 83: e245386, 2023. tab, graf
Artigo em Inglês | LILACS, VETINDEX | ID: biblio-1278528

RESUMO

Abstract Herbivory is an interaction with great impact on plant communities since relationships between herbivores and plants are fundamental to the distribution and abundance of species over time and space. The aim of this study was to monitor the rate of leaf expansion in the tree fern Cyathea phalerata and evaluate the damage caused by herbivores to leaves of different ages and whether such damage is related to temperature and precipitation. The study was performed in a subtropical Atlantic Forest fragment located in the municipality of Caraá, in the northeast hillside of Rio Grande do Sul state, in southern Brazil. We monitored 24 mature individuals of C. phalerata with croziers in a population of approximately 50 plants. Leaf expansion rate, percentage of damaged leaves and leaf blade consumption rate by herbivory were calculated. Monthly means for temperature and accumulated rainfall were calculated from daily data. Croziers of C. phalerata were found to expand rapidly during the first and second months after emergence (3.98 cm day-1; 2.91 cm day-1, respectively). Damage caused by herbivory was observed in all of the monitored leaves, but none of the plants experienced complete defoliation. The highest percentage (57%) of damaged leaves was recorded at 60 days of monitoring, and also the highest monthly consumption rate of the blade (6.04%) occurred with young, newly-expanded leaves, while this rate remained between 1.50 and 2.21% for mature leaves. Rates of monthly leaf consumption and damaged leaves showed positive and strong relationship with each other and with temperature. The rapid leaf expansion observed for C. phalerata can be considered a phenological strategy to reduce damage to young leaves by shortening the developmental period and accelerating the increase of defenses in mature leaves.


Resumo A herbivoria é uma interação de grande impacto sobre as comunidades de plantas, uma vez que as relações entre herbívoros e plantas são fundamentais para a distribuição e abundância das espécies ao longo do tempo e do espaço. O objetivo deste estudo foi monitorar a taxa de expansão foliar da samambaia arborescente Cyathea phalerata e avaliar o dano causado por herbívoros a folhas de diferentes idades, assim como verificar se este dano está relacionado à temperatura e à precipitação. O estudo foi realizado em um fragmento de Floresta Atlântica subtropical localizado no município de Caraá, na encosta nordeste do estado do Rio Grande do Sul, no sul do Brasil. Nós monitoramos 24 indivíduos maduros de C. phalerata com báculos em uma população de aproximadamente 50 plantas. A taxa de expansão foliar, a porcentagem de folhas danificadas e a taxa de consumo da lâmina foliar por herbivoria foram calculados. Médias mensais de temperatura e precipitação acumulada foram calculadas a partir de dados diários. Báculos de C. phalerata expandiram rapidamente durante o primeiro e o segundo mês após emergência (3,98 cm dia-1; 2,91 cm dia-1, respectivamente). O dano causado por herbivoria foi observado em todas as folhas monitoradas, mas nenhuma das plantas sofreu desfolhação completa. A maior porcentagem (57%) de folhas danificadas foi registrada aos 60 dias de monitoramento, e também a maior taxa de consumo mensal (6,04%) ocorreu em folhas jovens, recém expandidas, enquanto esta taxa permaneceu entre 1,50 e 2,21% em folhas maduras. As taxas mensais de consumo da lâmina foliar e de folhas danificadas mostraram relação positiva e forte entre si e com a temperatura. A rápida expansão foliar observada em C. phalerata pode ser considerada uma estratégia fenológica para reduzir o dano a folhas jovens, abreviando o período de desenvolvimento e acelerando o aumento das defesas em folhas maduras.


Assuntos
Humanos , Gleiquênias , Herbivoria , Brasil , Florestas , Folhas de Planta
2.
Rev. biol. trop ; 70(1)dic. 2022.
Artigo em Inglês | LILACS-Express | LILACS, SaludCR | ID: biblio-1387716

RESUMO

Abstract Introduction: The study of herbivory is fundamental in ecology and includes how plants invest in strategies and mechanisms to reduce herbivore damage. However, there is still a lack of information about how the environment, plant density, and functional traits influence herbivory in aquatic ecosystems. Objective: To assess if there is a relationship between herbivory, environmental variables, and plant traits two species of Montrichardia, a neotropical aquatic plant. Methods: In September 2018, we studied 78 specimens of Montrichardia arborescens and 18 of Montrichardia linifera, in 18 sites in Melgaço, Pará, Brazil. On each site, we measured water depth, distance to the margin, and plant density. From plants, we measured plant height and leaf thickness, and photographed the leaves to calculate the specific leaf area and percentage herbivory. To identify anatomical structures, we collected fully expanded leaves from three individuals per quadrat. Results: For M. arborescens, plants with thicker leaves and higher specific leaf area have less herbivore damage. For M. linifera, plants from deeper sites and with thicker leaves had more herbivore damage, while plants that grew farther from the margin had less damage. We found anatomical structures related to defense, such as idioblast cells with phenolic compounds, and cells with solid inclusions that can contribute to avoiding severe damage. Conclusions: Herbivory in these Montrichardia species can be explained by a combination of plant and environmental traits (patch isolation and water depth). The main plant traits are leaf thickness and area, but chemical compounds and solid inclusions also help Montrichardia to sustain less damage than other macrophytes.


Resumen Introducción: La herbivoría es fundamental para comprender cómo las plantas invierten en diferentes estrategias para evitar la depredación, lo que implica diferentes mecanismos de defensa. Factores relacionados con el medio ambiente, la densidad de plantas y/o los rasgos funcionales de las plantas pueden influir en la herbivoría en los ecosistemas acuáticos. Sin embargo, todavía falta información sobre cómo esos factores influyen en la herbivoría en los ecosistemas acuáticos y pueden contribuir a la carga de herbivoría. Objetivo: Evaluar si existe una relación entre la herbivoría y las variables ambientales (p. ej., profundidad del agua y distancia al margen), los factores ecológicos (densidad de plantas) y los rasgos estructurales de las plantas (altura, grosor de la hoja y área foliar) e indicar estructuras anatómicas que actúen junto con los rasgos estructurales en el sistema de defensa de especies de Montrichardia. Métodos: Se evaluaron 96 individuos de Montrichardia spp. (78 de M. arborescens y 18 de M. linifera, en 18 sitios) recolectados en septiembre de 2018. En cada sitio, se midió la profundidad del agua, la distancia al margen y la densidad de plantas. De los individuos, medimos la altura de la planta, el grosor de la hoja y fotografiamos las hojas para calcular el área foliar específica y la cantidad de herbivoría (en porcentaje). Para identificar las estructuras anatómicas relacionadas con la defensa de las plantas, se recogió hojas completamente expandidas de tres individuos por cuadrante. Resultados: Para M. arborescens, las plantas con hojas más gruesas y mayor área foliar específica tienen menos daño por herbivoría. Para M. linifera, las plantas con hojas más gruesas y que habitan en sitios más profundos tienen más daño por herbívoros, mientras que las plantas más alejadas del margen tienen menos daño por herbívoros. Se encontró estructuras anatómicas relacionadas con la defensa, como células idioblásticas con compuestos fenólicos y células con inclusiones sólidas que pueden contribuir a evitar daños severos en las características de las hojas. Conclusiones: Nuestros resultados indican que la herbivoría en las especies de Montrichardia podría explicarse por una combinación de características ambientales (aislamiento del parche y profundidad del agua) y de la planta. Descubrimos que los rasgos de las hojas eran factores importantes que impulsaban los cambios en la carga de herbivoría, especialmente el grosor de las hojas y el área foliar específica. Además, las especies de Montrichardia invierten en compuestos químicos e inclusiones sólidas para evitar daños graves en las hojas y, por lo tanto, pueden sufrir menos daños que otras especies de macrófitos.


Assuntos
Flora Aquática , Herbivoria , Defesa das Plantas contra Herbivoria , Ecossistema Amazônico
3.
Naturwissenschaften ; 109(6): 54, 2022 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-36326883

RESUMO

Changes in leaf traits in response to plant-plant interactions affect feeding by insect herbivores. However, the effects of such changes on feeding by vertebrate herbivores remain unclear. We examined the effects of interactions of Aster leiophyllus collected in the field (growing with plants of the same species [aggregated] or with plants of different species [solitary]) or grown in pots (with another A. leiophyllus [intraspecific] or with Carex aphanolepis or Thalictrum baicalense [interspecific]) on the concentration of total phenolics in A. leiophyllus leaves and on sika deer (Cervus nippon) grazing preference in Japan. Deer were presented for 30 s with the first A. leiophyllus leaf (from either aggregated plants or solitary plants) and then for 30 s with the second leaf (solitary or aggregated, respectively). All of the deer presented first with a leaf from a solitary plant ate it, but when deer were presented first with a leaf from an aggregated plant, which had a higher concentration of total phenolics, 50% rejected or left it. About a third of the deer that had been presented first with a leaf from an aggregated plant subsequently rejected the leaf of a solitary plant. The leaves in the intraspecific interaction pot treatment had higher total phenolic concentration and were rejected more by deer than the leaves in the interspecific treatments. Plant-plant interactions affected deer preference, which was also influenced by learning. These results should improve our understanding of both plant grazing by deer and environmental management.


Assuntos
Cervos , Herbivoria , Animais , Cervos/fisiologia , Plantas , Insetos/fisiologia , Folhas de Planta/fisiologia
4.
BMC Genomics ; 23(1): 751, 2022 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-36371160

RESUMO

BACKGROUND: The dung beetle Phelotrupes auratus is a holometabolous insect belonging to the order Coleoptera, and it is widely distributed in Japan. The P. auratus habitat depends on herbivores. P. auratus eats the dung of the herbivores and carries it underground for its young. In this process, herbivore droppings disappear from the ground, not only keeping the ground hygienic but also maintaining good soil conditions for plant growth. In this way, a rich ecosystem is maintained. In recent years, the population of P. auratus has decreased, and the main cause has been the decrease in grazing land. It seems that Japanese dung beetles are mainly dependent on herbivores for nutrient sources. However, the physiological relationship between herbivores and P. auratus has not been well investigated. Here, we investigated the nutritional metabolism system of P. auratus by performing whole gene expression analysis of individuals collected from two areas where the ecosystem is occupied by different herbivores. RESULTS: We obtained 54,635 transcripts from P. auratus from Nara Park and Cape Toi and identified 2,592 differentially expressed genes in the fat bodies of the Nara Park and Cape Toi groups. We annotated P. auratus transcripts using Homo sapiens and Drosophila melanogaster genes as references; 50.5% of P. auratus transcripts were assigned to H. sapiens genes, and 54.0% of P. auratus transcripts were assigned to D. melanogaster genes. To perform gene set enrichment analysis, we chose H. sapiens genes for P. auratus transcript annotation. Principal component analysis and gene set enrichment analysis revealed that the nutritional metabolism of P. auratus from Cape Toi might differ from that of P. auratus from Nara Park. CONCLUSION: We analyzed the nutritional metabolism system of P. auratus from Cape Toi and Nara Park and found that the characteristics of the nutritional metabolism process might depend on the plants consumed by the herbivores. Our findings will contribute to elucidating the relationships among habitat plants, herbivores, and dung decomposers and may aid in the maintenance of sustainable land health cycles.


Assuntos
Besouros , Animais , Besouros/genética , Herbivoria , Ecossistema , Drosophila melanogaster , Plantas/genética , Fezes
5.
BMC Plant Biol ; 22(1): 536, 2022 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-36396998

RESUMO

BACKGROUND: In nature and in cultivated fields, plants encounter multiple stress factors. Nonetheless, our understanding of how plants actively respond to combinatorial stress remains limited. Among the least studied stress combination is that of flooding and herbivory, despite the growing importance of these stressors in the context of climate change. We investigated plant chemistry and gene expression changes in two heirloom tomato varieties: Cherokee Purple (CP) and Striped German (SG) in response to flooding, herbivory by Spodoptera exigua, and their combination. RESULTS: Volatile organic compounds (VOCs) identified in tomato plants subjected to flooding and/or herbivory included several mono- and sesquiterpenes. Flooding was the main factor altering VOCs emission rates, and impacting plant biomass accumulation, while different varieties had quantitative differences in their VOC emissions. At the gene expression levels, there were 335 differentially expressed genes between the two tomato plant varieties, these included genes encoding for phenylalanine ammonia-lyase (PAL), cinnamoyl-CoA-reductase-like, and phytoene synthase (Psy1). Flooding and variety effects together influenced abscisic acid (ABA) signaling genes with the SG variety showing higher levels of ABA production and ABA-dependent signaling upon flooding. Flooding downregulated genes associated with cytokinin catabolism and general defense response and upregulated genes associated with ethylene biosynthesis, anthocyanin biosynthesis, and gibberellin biosynthesis. Combining flooding and herbivory induced the upregulation of genes including chalcone synthase (CHS), PAL, and genes encoding BAHD acyltransferase and UDP-glucose iridoid glucosyltransferase-like genes in one of the tomato varieties (CP) and a disproportionate number of heat-shock proteins in SG. Only the SG variety had measurable changes in gene expression due to herbivory alone, upregulating zeatin, and O-glucosyltransferase and thioredoxin among others. CONCLUSION: Our results suggest that both heirloom tomato plant varieties differ in their production of secondary metabolites including phenylpropanoids and terpenoids and their regulation and activation of ABA signaling upon stress associated with flooding. Herbivory and flooding together had interacting effects that were evident at the level of plant chemistry (VOCs production), gene expression and biomass markers. Results from our study highlight the complex nature of plant responses to combinatorial stresses and point at specific genes and pathways that are affected by flooding and herbivory combined.


Assuntos
Lycopersicon esculentum , Compostos Orgânicos Voláteis , Herbivoria , Lycopersicon esculentum/genética , Lycopersicon esculentum/metabolismo , Plantas/genética , Compostos Orgânicos Voláteis/metabolismo , Glucosiltransferases/genética , Expressão Gênica
6.
Proc Biol Sci ; 289(1986): 20221938, 2022 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-36350206

RESUMO

Herbivorous insects are extraordinarily diverse, yet are found in only one-third of insect orders. This skew may result from barriers to plant colonization, coupled with phylogenetic constraint on plant-colonizing adaptations. The plant-penetrating ovipositor, however, is one trait that surmounts host plant physical defences and may be evolutionarily labile. Ovipositors densely lined with hard bristles have evolved repeatedly in herbivorous lineages, including within the Drosophilidae. However, the evolution and genetic basis of this innovation has not been well studied. Here, we focused on the evolution of this trait in Scaptomyza, a genus sister to Hawaiian Drosophila, that contains a herbivorous clade. Our phylogenetic approach revealed that ovipositor bristle number increased as herbivory evolved in the Scaptomyza lineage. Through a genome-wide association study, we then dissected the genomic architecture of variation in ovipositor bristle number within S. flava. Top-associated variants were enriched for transcriptional repressors, and the strongest associations included genes contributing to peripheral nervous system development. Individual genotyping supported the association at a variant upstream of Gαi, a neural development gene, contributing to a gain of 0.58 bristles/major allele. These results suggest that regulatory variation involving conserved developmental genes contributes to this key morphological trait involved in plant colonization.


Assuntos
Drosophilidae , Animais , Drosophilidae/genética , Herbivoria/genética , Filogenia , Estudo de Associação Genômica Ampla , Drosophila/genética , Genômica
7.
Am Nat ; 200(6): 877-880, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36409986

RESUMO

AbstractIn "The Effects of Plant Compensatory Regrowth and Induced Resistance on Herbivore Population Dynamics," which appeared in The American Naturalist in 2016, Stieha et al. argued that overcompensatory regrowth of plant tissues lost to herbivory ("overcompensation") promotes cyclic herbivore outbreaks. In contrast, they concluded that partial regrowth ("tolerance") stabilizes herbivore dynamics, preventing outbreaks. These conclusions were based on a comparison between two plant-herbivore models that differed in two properties: (1) whether biomass could ever be higher after herbivory and regrowth than before herbivory (i.e., is overcompensatory regrowth possible?) and (2) how much herbivory the plants could withstand before only being able to partially compensate for losses (for overcompensating plants, there was a threshold herbivory level above which this occurred, whereas tolerant plants always showed partial compensation). While Stieha et al. supposed that difference 1 was responsible for the increased propensity for outbreaks in their overcompensation model, we show here that, in fact, difference 2 is responsible. Thus, we conclude that Stieha et al.'s results about "overcompensating" plants apply more broadly: the risk of herbivore outbreaks is elevated whenever plants with low-enough herbivore loads can perfectly compensate or overcompensate for losses to herbivory.


Assuntos
Herbivoria , Insetos , Animais , Plantas , Dinâmica Populacional , Surtos de Doenças
8.
Sci Rep ; 12(1): 19848, 2022 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-36400941

RESUMO

Stickiness of vegetative tissues has evolved multiple times in different plant families but is rare and understudied in flowers. While stickiness in general is thought to function primarily as a defense against herbivores, it may compromise mutualistic interactions (such as those with pollinators) in reproductive tissues. Here, we test the hypothesis that stickiness on flower petals of the High-Andean plant, Bejaria resinosa (Ericaceae), functions as a defense against florivores. We address ecological consequences and discuss potential trade-offs associated with a repellant trait expressed in flowers that mediate mutualistic interactions. In surveys and manipulative experiments, we assess florivory and resulting fitness effects on plants with sticky and non-sticky flowers in different native populations of B. resinosa in Colombia. In addition, we analyze the volatile and non-volatile components in sticky and non-sticky flower morphs to understand the chemical information context within which stickiness is expressed. We demonstrate that fruit set is strongly affected by floral stickiness but also varies with population. While identifying floral stickiness as a major defensive function, our data also suggest that the context-dependency of chemical defense functionality likely arises from differential availability of primary pollinators and potential trade-offs between chemical defense with different modes of action.


Assuntos
Flores , Herbivoria , Simbiose , Plantas , Colômbia
9.
Nat Commun ; 13(1): 7102, 2022 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-36402775

RESUMO

An animal's daily use of time (their "diel activity") reflects their adaptations, requirements, and interactions, yet we know little about the underlying processes governing diel activity within and among communities. Here we examine whether community-level activity patterns differ among biogeographic regions, and explore the roles of top-down versus bottom-up processes and thermoregulatory constraints. Using data from systematic camera-trap networks in 16 protected forests across the tropics, we examine the relationships of mammals' diel activity to body mass and trophic guild. Also, we assess the activity relationships within and among guilds. Apart from Neotropical insectivores, guilds exhibited consistent cross-regional activity in relation to body mass. Results indicate that thermoregulation constrains herbivore and insectivore activity (e.g., larger Afrotropical herbivores are ~7 times more likely to be nocturnal than smaller herbivores), while bottom-up processes constrain the activity of carnivores in relation to herbivores, and top-down processes constrain the activity of small omnivores and insectivores in relation to large carnivores' activity. Overall, diel activity of tropical mammal communities appears shaped by similar processes and constraints among regions reflecting body mass and trophic guilds.


Assuntos
Carnívoros , Florestas , Animais , Herbivoria , Estado Nutricional
10.
Nature ; 611(7935): 301-305, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36323777

RESUMO

Enrichment of nutrients and loss of herbivores are assumed to cause a loss of plant diversity in grassland ecosystems because they increase plant cover, which leads to a decrease of light in the understory1-3. Empirical tests of the role of competition for light in natural systems are based on indirect evidence, and have been a topic of debate for the last 40 years. Here we show that experimentally restoring light to understory plants in a natural grassland mitigates the loss of plant diversity that is caused by either nutrient enrichment or the absence of mammalian herbivores. The initial effect of light addition on restoring diversity under fertilization was transitory and outweighed by the greater effect of herbivory on light levels, indicating that herbivory is a major factor that controls diversity, partly through light. Our results provide direct experimental evidence, in a natural system, that competition for light is a key mechanism that contributes to the loss of biodiversity after cessation of mammalian herbivory. Our findings also show that the effects of herbivores can outpace the effects of fertilization on competition for light. Management practices that target maintaining grazing by native or domestic herbivores could therefore have applications in protecting biodiversity in grassland ecosystems, because they alleviate competition for light in the understory.


Assuntos
Biodiversidade , Herbivoria , Luz , Plantas , Animais , Pradaria , Mamíferos/fisiologia , Nutrientes/metabolismo , Plantas/classificação , Plantas/metabolismo , Plantas/efeitos da radiação , Fertilizantes
11.
Nat Commun ; 13(1): 6412, 2022 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-36376294

RESUMO

Animals possess specialized systems, e.g., neuromuscular systems, to sense the environment and then move their bodies quickly in response. Mimosa pudica, the sensitive plant, moves its leaves within seconds in response to external stimuli; e.g., touch or wounding. However, neither the plant-wide signaling network that triggers these rapid movements nor the physiological roles of the movements themselves have been determined. Here by simultaneous recording of cytosolic Ca2+ and electrical signals, we show that rapid changes in Ca2+ coupled with action and variation potentials trigger rapid movements in wounded M. pudica. Furthermore, pharmacological manipulation of cytosolic Ca2+ dynamics and CRISPR-Cas9 genome editing technology revealed that an immotile M. pudica is more vulnerable to attacks by herbivorous insects. Our findings provide evidence that rapid movements based on propagating Ca2+ and electrical signals protect this plant from insect attacks.


Assuntos
Mimosa , Animais , Mimosa/fisiologia , Cálcio , Folhas de Planta/fisiologia , Insetos , Herbivoria
12.
Sci Rep ; 12(1): 20154, 2022 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-36418431

RESUMO

Understanding the responses of insect herbivores to plant chemical defences is pivotal for the management of crops and pests. However, the mechanisms of interaction are not entirely understood. In this study, we compared the whole transcriptome gene expression of the aphid Macrosiphum euphorbiae grown on two different varieties of tomato that differ in their inducible chemical defences. We used two isogenic lines of tomato with a shared genetic background that only differ in the presence of type IV glandular trichomes and their associated acylsucrose excretions. This works also reports a de novo transcriptome of the aphid M. euphorbiae. Subsequently, we identified a unique and distinct gene expression profile for the first time corresponding to aphid´s exposure to type IV glandular trichomes and acylsugars. The analysis of the aphid transcriptome shows that tomato glandular trichomes and their associated secretions are highly efficient in triggering stress-related responses in the aphid, and demonstrating that their role in plant defence goes beyond the physical impediment of herbivore activity. Some of the differentially expressed genes were associated with carbohydrate, lipid and xenobiotic metabolisms, immune system, oxidative stress response and hormone biosynthesis pathways. Also, the observed responses are compatible with a starvation syndrome. The transcriptome analysis puts forward a wide range of genes involved in the synthesis and regulation of detoxification enzymes that reveal important underlying mechanisms in the interaction of the aphid with its host plant and provides a valuable genomic resource for future study of biological processes at the molecular level using this aphid.


Assuntos
Afídeos , Lycopersicon esculentum , Animais , Afídeos/genética , Lycopersicon esculentum/genética , Lycopersicon esculentum/metabolismo , Tricomas/genética , Perfilação da Expressão Gênica , Herbivoria
13.
BMC Plant Biol ; 22(1): 514, 2022 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-36329386

RESUMO

BACKGROUND: Grazing disturbance usually affects floral display and pollination efficiency in the desert steppe, which may cause pollen limitation in insect-pollinated plants. Effective pollination is essential for the reproductive success of insect-pollinated plants and insufficient pollen transfer may result in pollen limitation. Caragana microphylla Lam is an arid region shrub with ecological importance. Few studies have been conducted on how grazing disturbance influences pollen limitation and pollination efficiency of C. microphylla. Here, we quantify the effect of different grazing intensities on floral display, pollinator visitation frequency and seed production in the Urat desert steppe. RESULTS: In C. microphylla, supplemental hand pollination increased the seed set, and pollen limitation was the predominant limiting factor. As the heavy grazing significantly reduced the seed set in plants that underwent open-pollination, but there was no significant difference in the seed set between plants in the control plots and plants in the moderate grazing plots. Furthermore, there was a higher pollinator visitation frequency in plants in the control plots than in plants in the heavy grazing plots. CONCLUSIONS: We found that pollinator visitation frequency was significantly associated with the number of open flowers. Our findings also demonstrated that seed production is associated with pollinator visitation frequency, as indicated by increased seed production in flowers with higher pollinator visitation frequency. Therefore, this study provides insight into the effect of different grazing intensities on floral display that are important for influencing pollinator visitation frequency and pollination efficiency in desert steppes.


Assuntos
Flores , Herbivoria , Insetos , Pólen , Polinização , Animais , Flores/fisiologia , Insetos/fisiologia , Plantas/parasitologia , Polinização/fisiologia , Clima Desértico , Herbivoria/fisiologia
14.
Sci Rep ; 12(1): 17309, 2022 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-36243783

RESUMO

Global climate change is leading to shifts in abiotic conditions. Short-term temperature stresses induced by marine heatwaves (MHWs) can affect organisms both during and after the events. However, the recovery capacity of organisms is likely dependent on the magnitude of the initial stress event. Here, we experimentally assessed the effect of MHW magnitude on behavioural and physiological responses of a common marine gastropod, Lunella granulata, both during and after the MHW. Self-righting behaviours tended to become faster under moderate MHWs, whereas there was a trend toward these behaviours slowing under extreme MHWs. After a recovery period at ambient temperatures, individuals that experienced extreme MHWs showed persistent small, but not significant, negative effects. Survival and oxygen consumption rates were unaffected by MHW magnitude both during and after the event. While extreme MHWs may have negative behavioural consequences for tropical marine gastropods, their physiological responses may allow continued survival.


Assuntos
Ecossistema , Gastrópodes , Animais , Mudança Climática , Herbivoria , Humanos , Temperatura
15.
Genes (Basel) ; 13(10)2022 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-36292663

RESUMO

Leaves are the primary and critical feed for herbivores. They directly determine the yield and quality of legume forage. <i>Trifolium repens</i> (<i>T. repens</i>) is an indispensable legume species, widely cultivated in temperate pastures due to its nutritional value and nitrogen fixation. Although the leaves of <i>T. repens</i> are typical trifoliate, they have unusual patterns to adapt to herbivore feeding. The number of leaflets in <i>T. repens</i> affects its production and utilization. The <i>KNOX</i> gene family encodes transcriptional regulators that are vital in regulating and developing leaves. Identification and characterization of <i>TrKNOX</i> gene family as an active regulator of leaf development in <i>T. repens</i> were studied. A total of 21 <i>TrKNOX</i> genes were identified from the T. repens genome database and classified into three subgroups (Class I, Class II, and Class M) based on phylogenetic analysis. Nineteen of the genes identified had four conserved domains, except for <i>KNOX5</i> and <i>KNOX9</i>, which belong to Class M. Varying expression levels of TrKNOX genes were observed at different developmental stages and complexities of leaves. <i>KNOX9</i> was observed to upregulate the leaf complexity of T. repens. Research on <i>TrKNOX</i> genes could be novel and further assist in exploring their functions and cultivating high-quality <i>T. repens</i> varieties.


Assuntos
Trifolium , Trifolium/genética , Trifolium/metabolismo , Filogenia , Folhas de Planta/metabolismo , Herbivoria , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
16.
PLoS One ; 17(10): e0274920, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36282832

RESUMO

In addition to directly inducing physical and chemical defenses, herbivory experienced by plants in one generation can influence the expression of defensive traits in offspring. Plant defense phenotypes can be compromised by inbreeding, and there is some evidence that such adverse effects can extend to the transgenerational expression of induced resistance. We explored how the inbreeding status of maternal Solanum carolinense plants influenced the transgenerational effects of herbivory on the defensive traits and herbivore resistance of offspring. Manduca sexta caterpillars were used to damage inbred and outbred S. carolinense maternal plants and cross pollinations were performed to produced seeds from herbivore-damaged and undamaged, inbred and outbred maternal plants. Seeds were grown in the greenhouse to assess offspring defense-related traits (i.e., leaf trichomes, internode spines, volatile organic compounds) and resistance to herbivores. We found that feeding by M. sexta caterpillars on maternal plants had a positive influence on trichome and spine production in offspring and that caterpillar development on offspring of herbivore-damaged maternal plants was delayed relative to that on offspring of undamaged plants. Offspring of inbred maternal plants had reduced spine production, compared to those of outbred maternal plants, and caterpillars performed better on the offspring of inbred plants. Both herbivory and inbreeding in the maternal generation altered volatile emissions of offspring. In general, maternal plant inbreeding dampened transgenerational effects of herbivory on offspring defensive traits and herbivore resistance. Taken together, this study demonstrates that inducible defenses in S. carolinense can persist across generations and that inbreeding compromises transgenerational resistance in S. carolinense.


Assuntos
Solanum , Compostos Orgânicos Voláteis , Solanum/química , Herbivoria , Endogamia , Compostos Orgânicos Voláteis/metabolismo , Folhas de Planta , Fenótipo , Plantas
17.
Sci Rep ; 12(1): 17836, 2022 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-36284143

RESUMO

Despite their abundance and economic importance, the mechanism of plant resistance to sap-feeding insects remains poorly understood. Here we deploy meta-analysis and data synthesis methods to evaluate the results from electrophysiological studies describing feeding behaviour experiments where resistance mechanisms were identified, focussing on studies describing host-plant resistance and non-host resistance mechanisms. Data were extracted from 108 studies, comprising 41 insect species across eight insect taxa and 12 host-plant families representing over 30 species. Results demonstrate that mechanisms deployed by resistant plants have common consequences on the feeding behaviour of diverse insect groups. We show that insects feeding on resistant plants take longer to establish a feeding site and have their feeding duration suppressed two-fold compared with insects feeding on susceptible plants. Our results reveal that traits contributing towards resistant phenotypes are conserved across plant families, deployed against taxonomically diverse insect groups, and that the underlying resistance mechanisms are conserved. These findings provide a new insight into plant-insect interaction and highlight the need for further mechanistic studies across diverse taxa.


Assuntos
Herbivoria , Insetos , Animais , Comportamento Alimentar , Herbivoria/genética , Insetos/fisiologia , Plantas/genética
18.
Ecol Lett ; 25(11): 2525-2539, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36209457

RESUMO

As invasive species spread, the ability of local communities to resist invasion depends on the strength of biotic interactions. Evolutionarily unused to the invader, native predators or herbivores may be initially wary of consuming newcomers, allowing them to proliferate. However, these relationships may be highly dynamic, and novel consumer-resource interactions could form as familiarity grows. Here, we explore the development of effective biotic resistance towards a highly invasive alga using multiple space-for-time approaches. We show that the principal native Mediterranean herbivore learns to consume the invader within less than a decade. At recently invaded sites, the herbivore actively avoided the alga, shifting to distinct preference and high consumptions at older sites. This rapid strengthening of the interaction contributed to the eventual collapse of the alga after an initial dominance. Therefore, our results stress the importance of conserving key native populations to allow communities to develop effective resistance mechanisms against invaders.


Assuntos
Herbivoria , Espécies Introduzidas , Ecossistema , Plantas , Animais
19.
Proc Natl Acad Sci U S A ; 119(42): e2202852119, 2022 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-36215482

RESUMO

Fossilized leaves provide the longest running record of hyperdiverse plant-insect herbivore associations. Reconstructions of these relationships over deep time indicate strong links between environmental conditions, herbivore diversity, and feeding damage on leaves. However, herbivory has not been compared between the past and the modern era, which is characterized by intense anthropogenic environmental change. Here, we present estimates for damage frequencies and diversities on fossil leaves from the Late Cretaceous (66.8 Ma) through the Pleistocene (2.06 Ma) and compare these estimates with Recent (post-1955) leaves collected via paleobotanical methods from modern ecosystems: Harvard Forest, United States; the Smithsonian Environmental Research Center, United States; and La Selva, Costa Rica. Total damage frequency, measured as the percentage of leaves with any herbivore damage, within modern ecosystems is greater than any fossil locality within this record. This pattern is driven by increased frequencies across nearly all functional feeding groups within the Recent. Diversities of total, specialized, and mining damage types are elevated within the Recent compared with fossil floras. Our results demonstrate that plants in the modern era are experiencing unprecedented levels of insect damage, despite widespread insect declines. Human influence, such as the rate of global climate warming, influencing insect feeding and timing of life cycle processes along with urbanization and the introduction of invasive plant and insect species may drive elevated herbivory. This research suggests that the strength of human influence on plant-insect interactions is not controlled by climate change alone but rather, the way in which humans interact with terrestrial landscape.


Assuntos
Fósseis , Herbivoria , Animais , Ecossistema , Florestas , Humanos , Insetos , Folhas de Planta , Plantas
20.
G3 (Bethesda) ; 12(11)2022 11 04.
Artigo em Inglês | MEDLINE | ID: mdl-36218439

RESUMO

The integration of genomic data into genetic evaluations can facilitate the rapid selection of superior genotypes and accelerate the breeding cycle in trees. In this study, 390 trees from 74 control-pollinated families were genotyped using a 36K Axiom SNP array. A total of 15,624 high-quality SNPs were used to develop genomic prediction models for mammalian bark stripping, tree height, and selected primary and secondary chemical compounds in the bark. Genetic parameters from different genomic prediction methods-single-trait best linear unbiased prediction based on a marker-based relationship matrix (genomic best linear unbiased prediction), multitrait single-step genomic best linear unbiased prediction, which integrated the marker-based and pedigree-based relationship matrices (single-step genomic best linear unbiased prediction) and the single-trait generalized ridge regression-were compared to equivalent single- or multitrait pedigree-based approaches (ABLUP). The influence of the statistical distribution of data on the genetic parameters was assessed. Results indicated that the heritability estimates were increased nearly 2-fold with genomic models compared to the equivalent pedigree-based models. Predictive accuracy of the single-step genomic best linear unbiased prediction was higher than the ABLUP for most traits. Allowing for heterogeneity in marker effects through the use of generalized ridge regression did not markedly improve predictive ability over genomic best linear unbiased prediction, arguing that most of the chemical traits are modulated by many genes with small effects. Overall, the traits with low pedigree-based heritability benefited more from genomic models compared to the traits with high pedigree-based heritability. There was no evidence that data skewness or the presence of outliers affected the genomic or pedigree-based genetic estimates.


Assuntos
Herbivoria , Pinus , Melhoramento Vegetal , Animais , Genômica/métodos , Genótipo , Modelos Genéticos , Fenótipo , Pinus/genética , Casca de Planta , Polimorfismo de Nucleotídeo Único , Genoma de Planta
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