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Epigenetic Changes Occurring in Plant Inbreeding. Int J Mol Sci 2023; 24:ijms24065407. [PMID: 36982483 PMCID: PMC10048984 DOI: 10.3390/ijms24065407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 03/01/2023] [Accepted: 03/10/2023] [Indexed: 03/18/2023] Open
Abstract
Inbreeding is the crossing of closely related individuals in nature or a plantation or self-pollinating plants, which produces plants with high homozygosity. This process can reduce genetic diversity in the offspring and decrease heterozygosity, whereas inbred depression (ID) can often reduce viability. Inbred depression is common in plants and animals and has played a significant role in evolution. In the review, we aim to show that inbreeding can, through the action of epigenetic mechanisms, affect gene expression, resulting in changes in the metabolism and phenotype of organisms. This is particularly important in plant breeding because epigenetic profiles can be linked to the deterioration or improvement of agriculturally important characteristics.
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Nihranz CT, Helms AM, Tooker JF, Mescher MC, De Moraes CM, Stephenson AG. Adverse effects of inbreeding on the transgenerational expression of herbivore-induced defense traits in Solanum carolinense. PLoS One 2022; 17:e0274920. [PMID: 36282832 PMCID: PMC9595541 DOI: 10.1371/journal.pone.0274920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 09/06/2022] [Indexed: 01/24/2023] Open
Abstract
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.
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Affiliation(s)
- Chad T. Nihranz
- Department of Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
- School of Integrative Plant Sciences, Cornell University, Ithaca, New York, United States of America
| | - Anjel M. Helms
- Department of Entomology, Texas A&M University, College Station, Texas, United States of America
| | - John F. Tooker
- Department of Entomology, The Pennsylvania State University, University Park, PA, United States of America
| | - Mark C. Mescher
- Department of Environmental Systems Science, Swiss Federal Institute of Technology, Zurich, Switzerland
| | - Consuelo M. De Moraes
- Department of Environmental Systems Science, Swiss Federal Institute of Technology, Zurich, Switzerland
| | - Andrew G. Stephenson
- Department of Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America
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3
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Ha CM, Rao X, Saxena G, Dixon RA. Growth-defense trade-offs and yield loss in plants with engineered cell walls. THE NEW PHYTOLOGIST 2021; 231:60-74. [PMID: 33811329 DOI: 10.1111/nph.17383] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 03/29/2021] [Indexed: 05/18/2023]
Abstract
As a major component of plant secondary cell walls, lignin provides structural integrity and rigidity, and contributes to primary defense by providing a physical barrier to pathogen ingress. Genetic modification of lignin biosynthesis has been adopted to reduce the recalcitrance of lignified cell walls to improve biofuel production, tree pulping properties and forage digestibility. However, lignin-modification is often, but unpredictably, associated with dwarf phenotypes. Hypotheses suggested to explain this include: collapsed vessels leading to defects in water and solute transport; accumulation of molecule(s) that are inhibitory to plant growth or deficiency of metabolites that are critical for plant growth; activation of defense pathways linked to cell wall integrity sensing. However, there is still no commonly accepted underlying mechanism for the growth defects. Here, we discuss recent data on transcriptional reprogramming in plants with modified lignin content and their corresponding suppressor mutants, and evaluate growth-defense trade-offs as a factor underlying the growth phenotypes. New approaches will be necessary to estimate how gross changes in transcriptional reprogramming may quantitatively affect growth. Better understanding of the basis for yield drag following cell wall engineering is important for the biotechnological exploitation of plants as factories for fuels and chemicals.
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Affiliation(s)
- Chan Man Ha
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #311428, Denton, TX, 76203, USA
- Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
| | - Xiaolan Rao
- College of Life Sciences, Hubei University, No. 28 Nanli Road, Hong-shan District, Wuchang, Wuhan, Hubei Province, 430068, China
| | - Garima Saxena
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #311428, Denton, TX, 76203, USA
| | - Richard A Dixon
- BioDiscovery Institute and Department of Biological Sciences, University of North Texas, 1155 Union Circle #311428, Denton, TX, 76203, USA
- Center for Bioenergy Innovation (CBI), Oak Ridge National Laboratory, Oak Ridge, TN, 37831, USA
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Watts S, Kariyat R. Picking sides: feeding on the abaxial leaf surface is costly for caterpillars. PLANTA 2021; 253:77. [PMID: 33661399 DOI: 10.1007/s00425-021-03592-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2021] [Accepted: 02/25/2021] [Indexed: 06/12/2023]
Abstract
MAIN CONCLUSION The study provides us with the evidence that caterpillars tend to feed on the abaxial leaf surface despite the damage caused to them because of higher trichome density. To defend against herbivory, plants have evolved physical and chemical defense mechanisms, including trichomes (hair like appendages on leaves and stem) being one of them. Caterpillars, a major group of insect herbivores are generally found to occupy the abaxial (underside) leaf surface, considered as an avoidance mechanism from biotic and abiotic stresses. Since trichomes are a first line of defense, we examined the correlation between abaxial vs adaxial (above side) trichomes and caterpillar feeding, behavior, and growth. A combination of field, lab and microscopy experiments were performed using tobacco hornworm, Manduca sexta (Lepidoptera: Sphingidae), a Solanaceae specialist caterpillar, and multiple host species. We found that M. sexta caterpillars overwhelmingly preferred to stay and feed on the abaxial leaf surface, but the abaxial leaf surface also had significantly more trichomes, and consequently, caterpillars took significantly longer to commence feeding. In addition, lab-based diet experiment containing shaved trichomes showed that feeding on the abaxial leaf surface with more trichomes also affected caterpillar growth. Taken together, our study shows that although caterpillars prefer to feed on the abaxial leaf surface, they accrue feeding delays and developmental constraints, indicating tradeoffs affecting performance, and exposure to predation and abiotic stressors.
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Affiliation(s)
- Sakshi Watts
- Department of Biology, The University of Texas Rio Grande Valley, Edinburg, TX, 78539, USA
| | - Rupesh Kariyat
- Department of Biology, The University of Texas Rio Grande Valley, Edinburg, TX, 78539, USA.
- School of Earth, Environmental and Marine Sciences, The University of Texas Rio Grande Valley, Edinburg, TX, 78539, USA.
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5
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Kariyat RR, Bentley TG, Nihranz CT, Stephenson AG, De Moraes CM, Mescher MC. Inbreeding in Solanum carolinense alters floral attractants and rewards and adversely affects pollinator visitation. AMERICAN JOURNAL OF BOTANY 2021; 108:74-82. [PMID: 33450062 DOI: 10.1002/ajb2.1594] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 09/17/2020] [Indexed: 06/12/2023]
Abstract
PREMISE Inbreeding depression is well documented in flowering plants and adversely affects a wide range of fitness-related traits. Recent work has begun to explore the effects of inbreeding on ecological interactions among plants and other organisms, including insect herbivores and pathogens. However, the effects of inbreeding on floral traits, floral scents, and pollinator visitation are less well studied. METHODS Using inbred and outbred maternal families of horsenettle (Solanum carolinense, Solanaceae), we examined the effects of inbreeding on traits associated with pollinator attraction and floral rewards. Specifically, we measured corolla size, counted pollen grains per flower, and analyzed floral volatile emissions via gas chromatography and mass spectrometry. We also examined pollinator visitation to experimental arrays of flowering inbred and outbred plants under field conditions. RESULTS Compared to those of outbred plants, flowers of inbred plants exhibited reduced corolla size and pollen production, as well as significantly reduced emission of the two most abundant volatile compounds in the floral blend. Furthermore, bumblebees-the main pollinators of horsenettle-discriminated against inbred flowers in the field: bees were more likely to make initial visits to flowers on outbred plants, visited outbred flowers more often overall, and spent more time on outbred flowers. CONCLUSIONS These results show that inbreeding can (1) alter floral traits that are known to mediate pollinator attraction; (2) reduce the production of floral rewards (pollen is the sole reward in horsenettle); and (3) adversely affect pollinator visitation under field conditions.
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Affiliation(s)
- Rupesh R Kariyat
- Department of Biology and School of Earth, Environmental and Marine Sciences, University of Texas Rio Grande Valley, Edinburg, TX, USA
| | - Thomas G Bentley
- Intercollege Graduate Degree Program in Ecology, The Pennsylvania State University, University Park, Pennsylvania, 16802, USA
| | - Chad T Nihranz
- Intercollege Graduate Degree Program in Ecology, The Pennsylvania State University, University Park, Pennsylvania, 16802, USA
| | - Andrew G Stephenson
- Department of Biology, The Pennsylvania State University, University Park, Pennsylvania, 16802, USA
| | - Consuelo M De Moraes
- Department of Environmental Systems Science, ETH Zürich, Zürich, 8092, Switzerland
| | - Mark C Mescher
- Department of Environmental Systems Science, ETH Zürich, Zürich, 8092, Switzerland
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Tobacco Hornworm ( Manduca sexta) Oral Secretion Elicits Reactive Oxygen Species in Isolated Tomato Protoplasts. Int J Mol Sci 2020; 21:ijms21218297. [PMID: 33167454 PMCID: PMC7663960 DOI: 10.3390/ijms21218297] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 10/31/2020] [Accepted: 11/03/2020] [Indexed: 12/05/2022] Open
Abstract
Plants are under constant attack by a suite of insect herbivores. Over millions of years of coexistence, plants have evolved the ability to sense insect feeding via herbivore-associated elicitors in oral secretions, which can mobilize defense responses. However, herbivore-associated elicitors and the intrinsic downstream modulator of such interactions remain less understood. In this study, we show that tobacco hornworm caterpillar (Manduca sexta) oral secretion (OS) induces reactive oxygen species (ROS) in tomato (Solanum lycopersicum) protoplasts. By using a dye-based ROS imaging approach, our study shows that application of plant-fed (PF) M. sexta OS generates significantly higher ROS while artificial diet-fed (DF) caterpillar OS failed to induce ROS in isolated tomato protoplasts. Elevation in ROS generation was saturated after ~140 s of PF OS application. ROS production was also suppressed in the presence of an antioxidant NAC (N-acetyl-L-cysteine). Interestingly, PF OS-induced ROS increase was abolished in the presence of a Ca2+ chelator, BAPTA-AM (1,2-bis(o-aminophenoxy)ethane-N,N,N′,N′-tetraacetic acid). These results indicate a potential signaling cascade involving herbivore-associated elicitors, Ca2+, and ROS in plants during insect feeding. In summary, our results demonstrate that plants incorporate a variety of independent signals connected with their herbivores to regulate and mount their defense responses.
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Portman SL, Felton GW, Kariyat RR, Marden JH. Host plant defense produces species-specific alterations to flight muscle protein structure and flight-related fitness traits of two armyworms. J Exp Biol 2020; 223:jeb224907. [PMID: 32647018 DOI: 10.1242/jeb.224907] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 06/29/2020] [Indexed: 01/03/2023]
Abstract
Insects manifest phenotypic plasticity in their development and behavior in response to plant defenses, via molecular mechanisms that produce tissue-specific changes. Phenotypic changes might vary between species that differ in their preferred hosts and these effects could extend beyond larval stages. To test this, we manipulated the diet of southern armyworm (SAW; Spodoptera eridania) and fall armyworm (FAW; Spodoptera frugiperda) using a tomato mutant for jasmonic acid plant defense pathway (def1), and wild-type plants, and then quantified gene expression of Troponin t (Tnt) and flight muscle metabolism of the adult insects. Differences in Tnt spliceform ratios in insect flight muscles correlate with changes to flight muscle metabolism and flight muscle output. We found that SAW adults reared on induced def1 plants had a higher relative abundance (RA) of the A isoform of Troponin t (Tnt A) in their flight muscles; in contrast, FAW adults reared on induced def1 plants had a lower RA of Tnt A in their flight muscles compared with adults reared on def1 and controls. Although mass-adjusted flight metabolic rate showed no independent host plant effects in either species, higher flight metabolic rates in SAW correlated with increased RA of Tnt A Flight muscle metabolism also showed an interaction of host plants with Tnt A in both species, suggesting that host plants might be influencing flight muscle metabolic output by altering Tnt This study illustrates how insects respond to variation in host plant chemical defense by phenotypic modifications to their flight muscle proteins, with possible implications for dispersal.
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Affiliation(s)
- Scott L Portman
- Invasive Species and Pollinator Health Research Unit, Western Regional Research Center, United States Department of Agriculture - Agricultural Research Services, 800 Buchanan St, Albany, CA 94710, USA
| | - Gary W Felton
- Department of Entomology, 501 ASI Building, Pennsylvania State University, University Park, PA 16802, USA
| | - Rupesh R Kariyat
- Department of Biology, University of Texas Rio Grande Valley, 1201 W University Drive, Edinburg, TX 78539, USA
- School of Earth, Environment and Marine Sciences, University of Texas Rio Grande Valley, 1201 W University Drive, Edinburg, TX 78539, USA
| | - James H Marden
- Department of Biology, 208 Mueller Laboratory, Pennsylvania State University, University Park, PA 16802, USA
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Herbivory and inbreeding affect growth, reproduction, and resistance in the rhizomatous offshoots of Solanum carolinense (Solanaceae). Evol Ecol 2019. [DOI: 10.1007/s10682-019-09997-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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9
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Schrieber K, Wolf S, Wypior C, Höhlig D, Keller SR, Hensen I, Lachmuth S. Release from natural enemies mitigates inbreeding depression in native and invasive Silene latifolia populations. Ecol Evol 2019; 9:3564-3576. [PMID: 30962911 PMCID: PMC6434559 DOI: 10.1002/ece3.4990] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 01/12/2019] [Accepted: 01/26/2019] [Indexed: 01/01/2023] Open
Abstract
Inbreeding and enemy infestation are common in plants and can synergistically reduce their performance. This inbreeding ×environment (I × E) interaction may be of particular importance for the success of plant invasions if introduced populations experience a release from attack by natural enemies relative to their native conspecifics. Here, we investigate whether inbreeding affects plant infestation damage, whether inbreeding depression in growth and reproduction is mitigated by enemy release, and whether this effect is more pronounced in invasive than native plant populations. We used the invader Silene latifolia and its natural enemies as a study system. We performed two generations of experimental out- and inbreeding within eight native (European) and eight invasive (North American) populations under controlled conditions using field-collected seeds. Subsequently, we exposed the offspring to an enemy exclusion and inclusion treatment in a common garden in the species' native range to assess the interactive effects of population origin (range), breeding treatment, and enemy treatment on infestation damage, growth, and reproduction. Inbreeding increased flower and leaf infestation damage in plants from both ranges, but had opposing effects on fruit damage in native versus invasive plants. Inbreeding significantly reduced plant fitness; whereby, inbreeding depression in fruit number was higher in enemy inclusions than exclusions. This effect was equally pronounced in populations from both distribution ranges. Moreover, the magnitude of inbreeding depression in fruit number was lower in invasive than native populations. These results support that inbreeding has the potential to reduce plant defenses in S. latifolia, which magnifies inbreeding depression in the presence of enemies. However, future studies are necessary to further explore whether enemy release in the invaded habitat has actually decreased inbreeding depression and thus facilitated the persistence of inbred founder populations and invasion success.
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Affiliation(s)
- Karin Schrieber
- Department of Chemical Ecology, Faculty of BiologyBielefeld UniversityBielefeldGermany
- Geobotany & Botanical Garden, Institute of BiologyMartin‐Luther‐University Halle‐WittenbergHalle (Saale)Germany
| | - Sabrina Wolf
- Geobotany & Botanical Garden, Institute of BiologyMartin‐Luther‐University Halle‐WittenbergHalle (Saale)Germany
| | - Catherina Wypior
- Geobotany & Botanical Garden, Institute of BiologyMartin‐Luther‐University Halle‐WittenbergHalle (Saale)Germany
| | - Diana Höhlig
- Geobotany & Botanical Garden, Institute of BiologyMartin‐Luther‐University Halle‐WittenbergHalle (Saale)Germany
| | | | - Isabell Hensen
- Geobotany & Botanical Garden, Institute of BiologyMartin‐Luther‐University Halle‐WittenbergHalle (Saale)Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐LeipzigLeipzigGermany
| | - Susanne Lachmuth
- Geobotany & Botanical Garden, Institute of BiologyMartin‐Luther‐University Halle‐WittenbergHalle (Saale)Germany
- German Centre for Integrative Biodiversity Research (iDiv) Halle‐Jena‐LeipzigLeipzigGermany
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Larose C, Rasmann S, Schwander T. Evolutionary dynamics of specialisation in herbivorous stick insects. Ecol Lett 2018; 22:354-364. [DOI: 10.1111/ele.13197] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 09/01/2018] [Accepted: 11/10/2018] [Indexed: 11/26/2022]
Affiliation(s)
- Chloé Larose
- Department of Ecology and Evolution; University of Lausanne; Lausanne Switzerland
| | - Sergio Rasmann
- Institute of Biology; University of Neuchatel; Rue Emile-Argand 11 CH-2000 Neuchâtel Switzerland
| | - Tanja Schwander
- Department of Ecology and Evolution; University of Lausanne; Lausanne Switzerland
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11
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Axelsson EP, Senior JK. The extended consequences of genetic conductivity: Mating distance affects community phenotypes in Norway spruce. Ecol Evol 2018; 8:11645-11655. [PMID: 30598763 PMCID: PMC6303695 DOI: 10.1002/ece3.4616] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2018] [Revised: 08/24/2018] [Accepted: 08/28/2018] [Indexed: 11/11/2022] Open
Abstract
Anthropogenic landscape-level alterations such as habitat fragmentation and long distance translocation of genetic material are currently altering the genetic connectivity and structure of forest tree populations globally. As the susceptibility of individual trees to dependent organisms is often genetically determined, it is possible that these genetic changes may extend beyond individuals to affect associated communities. To test this, we examined how variation in crossing distance among the progeny of 18 controlled crosses of Norway spruce (Picea abies) populations occurring across central Sweden affected chemical defense, and subsequently, a small community of galling Adelges aphids infecting planted trees at two common garden trails. Although crossing distance did not influence growth, vitality or reproduction in the studied population, it did influence the expression of one candidate defensive chemical compound, apigenin, which was found in higher concentrations within outcrossed trees. We also show that this variation in apigenin induced by crossing distance correlated with susceptibility to one member of the galling community but not the other. Furthermore, the effect of crossing distance on galling communities and the general susceptibility of Norway spruce to infection also varied with environment. Specifically, in the more benign environment, inbred trees suffered greater gall infection than outcrossed trees, which is contrary to general predictions that the effects of inbreeding should be more pronounced in harsher environments. These findings suggest that the effects of variation in crossing distance in forest trees can extend beyond the individual to influence whole communities.
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Affiliation(s)
- Erik Petter Axelsson
- Department of Wildlife, Fish and Environmental StudiesSwedish University of Agricultural SciencesSkogsmarksgrändUmeå
| | - John Keith Senior
- Department of Wildlife, Fish and Environmental StudiesSwedish University of Agricultural SciencesSkogsmarksgrändUmeå
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12
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Kariyat RR, Hardison SB, De Moraes CM, Mescher MC. Plant spines deter herbivory by restricting caterpillar movement. Biol Lett 2017; 13:20170176. [PMID: 28490447 PMCID: PMC5454246 DOI: 10.1098/rsbl.2017.0176] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 04/21/2017] [Indexed: 11/12/2022] Open
Abstract
The spines of flowering plants are thought to function primarily in defence against mammalian herbivores; however, we previously reported that feeding by Manduca sexta caterpillars on the leaves of horsenettle plants (Solanum carolinense) induces increased development of internode spines on new growth. To determine whether and how spines impact caterpillar feeding, we conducted assays with three Solanaceous plant species that vary in spine numbers (S. carolinense, S. atropurpureum and S. aethiopicum) and also manipulated spine numbers within each species. We found that M. sexta caterpillars located experimentally isolated target leaves much more quickly on plants with experimentally removed spines compared with plants with intact spines. Moreover, it took caterpillars longer to defoliate species with relatively high spine numbers (S. carolinense and particularly Satropurpureum) compared with S. aethiopicum, which has fewer spines. These findings suggest that spines may play a significant role in defence against insect herbivores by restricting herbivore movement and increasing the time taken to access feeding sites, with possible consequences including longer developmental periods and increased vulnerability or apparency to predators.
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Affiliation(s)
- Rupesh R Kariyat
- Department of Environmental Systems Science, ETH Zürich, 8092 Zürich, Switzerland
| | - Sean B Hardison
- Department of Biology and Marine Biology, University of North Carolina, Wilmington, NC, USA
| | - Consuelo M De Moraes
- Department of Environmental Systems Science, ETH Zürich, 8092 Zürich, Switzerland
| | - Mark C Mescher
- Department of Environmental Systems Science, ETH Zürich, 8092 Zürich, Switzerland
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13
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Kariyat RR, Smith JD, Stephenson AG, De Moraes CM, Mescher MC. Non-glandular trichomes of Solanum carolinense deter feeding by Manduca sexta caterpillars and cause damage to the gut peritrophic matrix. Proc Biol Sci 2017; 284:20162323. [PMID: 28228510 PMCID: PMC5326521 DOI: 10.1098/rspb.2016.2323] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 02/02/2017] [Indexed: 01/15/2023] Open
Abstract
Plant trichomes constitute a first line of defence against insect herbivores. The pre- and post-ingestive defensive functions of glandular trichomes are well documented and include direct toxicity, adhesion, antinutrition and defence gene induction. By contrast, the defensive functions of non-glandular trichomes are less well characterized, although these structures are thought to serve as physical barriers that impede herbivore feeding and movement. We experimentally varied the density of stellate non-glandular trichomes in several ways to explore their pre- and post-ingestive effects on herbivores. Larvae of Manduca sexta (Sphingidae) initiated feeding faster and gained more weight on Solanum carolinense (Solanaceae) leaves having lower trichome densities (or experimentally removed trichomes) than on leaves having higher trichome densities. Adding trichomes to artificial diet also deterred feeding and adversely affected caterpillar growth relative to controls. Scanning electron and light microscopy revealed that the ingestion of stellate trichomes by M. sexta caterpillars caused extensive damage to the peritrophic membrane, a gut lining that is essential to digestion and pathogen isolation. These findings suggest that, in addition to acting as a physical barrier to deter feeding, trichomes can inhibit caterpillar growth and development via post-ingestive effects.
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Affiliation(s)
- Rupesh R Kariyat
- Department of Environmental Systems Science, Swiss Federal Institute of Technology (ETH Zürich), 8092 Zurich, Switzerland
| | - Jason D Smith
- Department of Biology, Dickinson College, Carlisle, PA 17013, USA
| | - Andrew G Stephenson
- Department of Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Consuelo M De Moraes
- Department of Environmental Systems Science, Swiss Federal Institute of Technology (ETH Zürich), 8092 Zurich, Switzerland
| | - Mark C Mescher
- Department of Environmental Systems Science, Swiss Federal Institute of Technology (ETH Zürich), 8092 Zurich, Switzerland
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14
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McNutt DW, Underwood N. Variation in plant‐mediated intra‐ and interspecific interactions among insect herbivores: effects of host genotype. Ecosphere 2016. [DOI: 10.1002/ecs2.1520] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Affiliation(s)
- David W. McNutt
- Department of Biological Science Florida State University Tallahassee Florida 32306 USA
| | - Nora Underwood
- Department of Biological Science Florida State University Tallahassee Florida 32306 USA
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15
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Wang J, Chung SH, Peiffer M, Rosa C, Hoover K, Zeng R, Felton GW. Herbivore Oral Secreted Bacteria Trigger Distinct Defense Responses in Preferred and Non-Preferred Host Plants. J Chem Ecol 2016; 42:463-74. [PMID: 27294415 DOI: 10.1007/s10886-016-0712-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 05/08/2016] [Accepted: 05/28/2016] [Indexed: 11/30/2022]
Abstract
Insect symbiotic bacteria affect host physiology and mediate plant-insect interactions, yet there are few clear examples of symbiotic bacteria regulating defense responses in different host plants. We hypothesized that plants would induce distinct defense responses to herbivore- associated bacteria. We evaluated whether preferred hosts (horsenettle) or non-preferred hosts (tomato) respond similarly to oral secretions (OS) from the false potato beetle (FPB, Leptinotarsa juncta), and whether the induced defense triggered by OS was due to the presence of symbiotic bacteria in OS. Both horsenettle and tomato damaged by antibiotic (AB) treated larvae showed higher polyphenol oxidase (PPO) activity than those damaged by non-AB treated larvae. In addition, application of OS from AB treated larvae induced higher PPO activity compared with OS from non-AB treated larvae or water treatment. False potato beetles harbor bacteria that may provide abundant cues that can be recognized by plants and thus mediate corresponding defense responses. Among all tested bacterial isolates, the genera Pantoea, Acinetobacter, Enterobacter, and Serratia were found to suppress PPO activity in tomato, while only Pantoea sp. among these four isolates was observed to suppress PPO activity in horsenettle. The distinct PPO suppression caused by symbiotic bacteria in different plants was similar to the pattern of induced defense-related gene expression. Pantoea inoculated FPB suppressed JA-responsive genes and triggered a SA-responsive gene in both tomato and horsenettle. However, Enterobacter inoculated FPB eliminated JA-regulated gene expression and elevated SA-regulated gene expression in tomato, but did not show evident effects on the expression levels of horsenettle defense-related genes. These results indicate that suppression of plant defenses by the bacteria found in the oral secretions of herbivores may be a more widespread phenomenon than previously indicated.
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Affiliation(s)
- Jie Wang
- Department of Ecology, South China Agricultural University, Guangzhou, Guangdong, 510640, China. .,Department of Entomology, Pennsylvania State University, University Park, PA, 16802, USA.
| | - Seung Ho Chung
- Department of Entomology, Cornell University, Ithaca, NY, 14850, USA
| | - Michelle Peiffer
- Department of Entomology, Pennsylvania State University, University Park, PA, 16802, USA
| | - Cristina Rosa
- Department of Plant Pathology and Environmental Microbiology, Pennsylvania State University, University Park, PA, 16802, USA
| | - Kelli Hoover
- Department of Entomology, Pennsylvania State University, University Park, PA, 16802, USA
| | - Rensen Zeng
- Department of Ecology, South China Agricultural University, Guangzhou, Guangdong, 510640, China.,Department of Ecology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, China
| | - Gary W Felton
- Department of Entomology, Pennsylvania State University, University Park, PA, 16802, USA
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