Data from: Complex multitrophic species interactions and fitness costs: Intricate consequences of jasmonate and salicylate induced plant defenses
Data files
Mar 17, 2026 version files 242.93 KB
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Plant_Defense_Community_Data_JAE.xlsx
228.26 KB
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README.md
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Abstract
Induced plant defenses regulated by jasmonic acid (JA) and salicylic acid (SA) initiate a cascade of effects, from defense expression to changes in arthropod community structure and species interactions, that can ultimately influence plant fitness. Yet the long-term consequences of these processes remain poorly understood, particularly in perennial tropical systems. We investigated how activation of JA and SA signaling pathways shapes arthropod community composition and plant reproductive success in Trichogoniopsis adenantha (Asteraceae), a glandular trichome-bearing shrub native to the Brazilian Atlantic rainforest. Using chemical elicitors, we induced JA and SA defenses for up to 16 months and monitored herbivore and predator assemblages, herbivory patterns, trichome expression, pyrrolizidine alkaloid concentrations, and plant short-term fecundity. JA-elicited plants exhibited higher pyrrolizidine alkaloid levels in flowers, reduced leaf herbivory, and lower seed damage by pre-dispersal seed predators. However, these plants experienced increased colonization by sap-feeding insects. In contrast, SA-elicited plants were more vulnerable to chewing herbivores but more resistant to sap-feeders. Despite similar reductions in seed predation across both treatments, JA and SA induction significantly reduced ovary fertilization, likely due to changes in floral traits and decreased pollinator visitation, ultimately imposing substantial fitness costs. Additionally, seasonal turnover in arthropod communities was accompanied by temporal variation in how defenses structured species composition and abundance. Our findings demonstrate that phytohormone-mediated defenses can simultaneously induce resistance and susceptibility across herbivore guilds, with divergent impacts on predator associations. Although defense induction reduced herbivore damage, it compromised short-term fecundity, revealing trade-offs between defense and reproduction. By linking induced defenses to multi-trophic interactions over time, this study highlights the ecological complexity of plant defense strategies in biodiverse tropical ecosystems.
Journal: Journal of Animal Ecology
Authors
- Dr. Monica F. Kersch-Becker
- Guilherme P. Pinheiro
- Thaís S. Schweller
- Dr. Martin Pareja
- Dr. Victoria Marie Pocius
- Dr. José R. Trigo
- Dr. Gustavo Q. Romero
Contact Information
- Dr. Monica F. Kersch-Becker: mfkb@psu.edu
File Description
Main File:
This repository contains one Excel workbook:
Plant_Defense_Community_Data_JAE.xlsx (Microsoft Excel Workbook)
The workbook includes eight worksheets (tabs) corresponding to different components of the experiment. Each worksheet is described below.
Experimental Overview
This field experiment evaluated the effects of plant defense elicitation on plant growth, chemical defenses, arthropod community structure, herbivory, and reproduction.
Treatments
C – Untreated control
J – Jasmonic acid (JA) elicitation
S – Salicylic acid (SA) elicitation
Treatments were randomized within 23 spatial blocks and replicated across independent trials conducted at different time periods.
The experimental unit is the individual plant.
Worksheet Descriptions
Worksheet 1: 1_morfoespecies_permanova
Description:
Plant-level cumulative abundance of each arthropod morphospecies recorded per plant across the entire experimental period. These data were used to construct community dissimilarity matrices for multivariate analyses (e.g., PERMANOVA).
Core variables:
- Plant_ID – Unique identifier for each plant sampled in the experiment (character string).
- Treatment – Experimental treatment assigned to each plant (factor): C = Control; J = Jasmonic acid (JA) elicitation; S = Salicylic acid (SA) elicitation.
- Block – Spatial replicate within the experimental design (levels 1–23) used to account for field heterogeneity; treatments were randomized within each block.
- Trial – Independent experimental run conducted at a different time period, representing a full temporal replication of all treatments.
- Final_height – Plant height measured at the end of the experimental period (numeric, cm).
- Days_alive – Number of days each plant remained alive and was monitored during the experimental period (integer, days).
All additional columns represent the presence/absence (coded as 0 = absent, 1 = present) of individual arthropod morphospecies recorded for each plant across the monitoring period.
Morphospecies were defined based on morphological characteristics and identified to the lowest feasible taxonomic level (species, genus, family, or order).
Worksheet 2: 2_Growth_phenology_herbivory
Plant growth and herbivory responses to treatments.
Key variables include:
- Plant_ID – Unique identifier for each plant sampled in the experiment (character string).
- Treatment – Experimental treatment assigned to each plant (factor): C = Control; J = Jasmonic acid (JA) elicitation; S = Salicylic acid (SA) elicitation.
- Block – Spatial replicate within the experimental design (levels 1–23) used to account for field heterogeneity; treatments were randomized within each block.
- Trial – Independent experimental run conducted at a different time period, representing a full temporal replication of all treatments.
- Days_alive – Number of days each plant remained alive and was monitored during the experimental period (integer, days).
- Initial_height – Plant height measured at the beginning of the experiment prior to treatment application (numeric, cm).
- Final_height – Plant height measured at the end of the experimental period (numeric, cm).
- Sum_lost_leaves – Cumulative number of leaves lost per plant during the experimental period (integer count).
- Sum_new_leaves – Cumulative number of newly produced leaves per plant during the experimental period (integer count).
- Log_final_height – Natural logarithm of Final_Height; used in statistical analyses.
- Herbivory_percentage – Mean foliar herbivory per plant across the experimental period, expressed as percent leaf area damaged (%). Monthly herbivory was calculated as a weighted average based on visually assigned leaf damage categories (0%, <5%, <25%, <50%, <75%, <99%), and monthly estimates were averaged across all survey months for each plant.
- Herbivory_proportion – Mean foliar herbivory per plant expressed as a proportion (0–1), calculated by dividing Herbivory_percentage by 100.
- arcsine_sqrt_herbivory_proportion – Arcsine square-root transformation of Herbivory_proportion (arcsin(√p); radians), used in statistical analyses to stabilize variance of proportional data bounded between 0 and 1.
Worksheet 3 3_Infested_uninfested
This dataset includes plant-level ovary production, ovary damage status (infested vs. uninfested), and viable seed counts used to model the probability of producing viable seeds as a function of plant defense treatment and flowerhead condition.
Key variables:
- Plant_ID – Unique identifier for each individual plant sampled in the experiment (character string).
- Treatment – Experimental treatment assigned to each plant (factor): C = Control; J = Jasmonic acid (JA) elicitation; S = Salicylic acid (SA) elicitation.
- Block – Spatial replicate within the experimental design (levels 1–23) used to account for field heterogeneity; treatments were randomized within each block.
- Trial – Independent experimental run conducted at a different time period, representing a full temporal replication of all treatments.
- Infested – Flowerhead-level condition indicating ovary damage status (categorical: Y = damaged flowerhead; N = undamaged flowerhead). Used to evaluate whether flowerhead damage influenced the probability of producing viable seeds.
- Sum(Ach_Fert_Undamaged) – Number of viable (fertilized and undamaged) ovaries per plant (integer count). Used as the numerator in binomial models estimating the probability of producing viable seeds relative to total ovary production. Plant-level values were obtained by averaging the number per flowerhead.
- Sum(#Ovaries) – Total number of ovaries produced per plant (integer count), calculated by summing ovary counts across all flowerheads for each plant. Used as the denominator in binomial generalized linear models, estimating the probability of producing viable seeds.
Worksheet 4: 4_Trichomes
This datasheet includes plant-level counts of glandular and non-glandular trichomes, summed from two leaf discs (0.5 cm diameter) per plant and pooled across both leaf surfaces.
Key variables:
- Plant_ID – Unique identifier for each individual plant sampled in the experiment (character string).
- Treatment – Experimental treatment assigned to each plant (factor): C = Control; J = Jasmonic acid (JA) elicitation; S = Salicylic acid (SA) elicitation.
- total_simple – Total number of non-glandular (simple) trichomes per plant (integer count), obtained by summing counts from two 0.5 cm diameter leaf discs collected from the first leaf produced after treatment application. Trichomes were counted on both abaxial and adaxial leaf surfaces using a stereomicroscope.
- total_glandular – Total number of glandular trichomes per plant (integer count), obtained by summing counts from two 0.5 cm diameter leaf discs collected from the first leaf produced after treatment application. Trichomes were counted on both abaxial and adaxial leaf surfaces using a stereomicroscope.
Counts were obtained from two 0.5 cm diameter leaf discs and pooled across both leaf surfaces.
Worksheet 5: 5_Pyrrolizidine_Alkaloids
This datasheet contains tissue-specific pyrrolizidine alkaloid (PA) concentrations measured from individual plants. Samples were collected from senescent, mature, and young leaves, as well as inflorescence buds and open inflorescences. PA concentrations (µg mg⁻¹ dry weight) were quantified using a colorimetric assay, and a log-transformed variable is provided for use in statistical analyses.
Key variables:
- Plant_ID – Unique identifier for each individual plant sampled in the experiment (character string).
- Treatment – Experimental treatment assigned to each plant (factor): C = Control; J = Jasmonic acid (JA) elicitation; S = Salicylic acid (SA) elicitation.
- tissue – Plant tissue type sampled for pyrrolizidine alkaloid (PA) quantification (categorical): senescent leaves, mature leaves, young leaves, inflorescence buds, or open inflorescences. Approximately 300 mg of tissue was collected per sample.
- Alkaloid_mass – Pyrrolizidine alkaloid (PA) concentration in the sampled tissue, expressed as micrograms of PA per milligram of dry tissue mass (µg mg⁻¹ dry weight).
- ln_Alkaloid_mass – Natural log–transformed PA concentration calculated as ln(Alkaloid_mass + 1). This transformed variable was used in statistical analyses. PA concentrations were quantified using a colorimetric assay.
Worksheet 6: 6_Cumulative_abundances_of_arthropods
This datasheet includes plant-level cumulative arthropod abundances, functional guild totals, species richness, and Shannon diversity values calculated across the experimental period.
Includes:
- Plant_ID – Unique identifier for each individual plant sampled in the experiment (character string).
- Treatment – Experimental treatment assigned to each plant (factor): C = Control; J = Jasmonic acid (JA) elicitation; S = Salicylic acid (SA) elicitation.
- Block – Spatial replicate within the experimental design (levels 1–23) used to account for field heterogeneity; treatments were randomized within each block.
- Trial – Independent experimental run conducted at a different time period, representing a full temporal replication of all treatments.
- Richness – Species richness per plant, calculated as the total number of arthropod morphospecies recorded across the experimental period (integer count).
- Diversity – Shannon diversity index (H′) calculated per plant based on cumulative morphospecies abundances across the experimental period (unitless index).
- Morphoespecies abundances (Sum(Geometriae_sp1), Sum(clubionidae_sp1), Sum(P.rubrolineata), Sum(Misumenops argenteus), Sum(Nabidae_sp1), Sum(Macrolophus_aragarcanus), Sum_Whitefly,
- Feeding guild totals (e.g., Sum_Chewers, Sum(Mines), Sum_Gallers, Sum_Suckers_without_whiteflies, Sum_omnivores, Sum_all_carnivores)
- seed_production – Total number of viable seeds produced per plant across the experimental period (integer count), summed across all flowerheads.
- days_alive – Number of days each plant remained alive and was monitored during the experimental period (integer, days).
- All abundance values are cumulative integer counts.
Worksheet 7: 7_temporal_abundances
This datasheet includes repeated plant-level arthropod abundance data collected across sampling dates used to analyze temporal community dynamics.
Includes:
- Plant_ID – Unique identifier for each individual plant sampled in the experiment (character string).
- Treatment – Experimental treatment assigned to each plant (factor): C = Control; J = Jasmonic acid (JA) elicitation; S = Salicylic acid (SA) elicitation.
- Block – Spatial replicate within the experimental design (levels 1–23) used to account for field heterogeneity; treatments were randomized within each block.
- Trial – Independent experimental run conducted at a different time period, representing a full temporal replication of all treatments.
- Date – Calendar date on which arthropod sampling was conducted MM-DD-YYYY format). Each date corresponds to a discrete sampling event.
- season – Seasonal grouping assigned to each sampling date (categorical): Dry Year 1, Wet Season, or Dry Year 2. Seasons were defined based on climatic conditions and used to group sampling dates for analysis. The remaining columns represent abundance counts of morphospecies or feeding guilds totals per plant per sampling date.
Worksheet 8: 8_pre-dispersal_seed_predators
This datasheet integrates cumulative plant-level pre-dispersal seed predator, parasitoid, and reproductive metrics across plants to assess treatment effects.
Includes:
- Plant_ID – Unique identifier for each individual plant sampled in the experiment (character string).
- Treatment – Experimental treatment assigned to each plant (factor): C = Control; J = Jasmonic acid (JA) elicitation; S = Salicylic acid (SA) elicitation.
- Block – Spatial replicate within the experimental design (levels 1–23) used to account for field heterogeneity; treatments were randomized within each block.
- Trial – Independent experimental run conducted at a different time period, representing a full temporal replication of all treatments.
- N(Flowerhead) – Cumulative number of flowerheads recorded per plant across the entire experimental period (integer count). Values represent the total number summed across all sampling dates.
- Sum(Trupanea) – Cumulative number of Trupanea individuals recorded per plant across the entire experimental period (integer count). Values represent the total abundance summed across all sampling dates.
- Sum(Melanagromyza) – Cumulative number of Melanagromyza individuals recorded per plant across the entire experimental period (integer count). Values represent the total abundance summed across all sampling dates.
- Sum(Geometridae_sp2)– Cumulative number of Geometridae individuals recorded per plant across the entire experimental period (integer count). Values represent the total abundance summed across all sampling dates.
- Sum(#Ovaries) – Cumulative number of ovaries recorded per plant across the entire experimental period (integer count). Values represent the total number summed across all sampling dates.
- Sum(#Damaged_ovaries) – Cumulative number of damaged ovaries recorded per plant across the entire experimental period (integer count). Values represent the total number summed across all sampling dates.
- Sum(#Parasitoids) – Cumulative number of parasitoids recorded per plant across the entire experimental period (integer count). Values represent the abundances summed across all sampling dates.
- fertlized_sum – Cumulative number of fertilized ovaries recorded per plant across the entire experimental period (integer count). Values represent the total number summed across all sampling dates.
Worksheet 9 :metadata
Purpose: Explains variable names and units for all other sheets.
Context: Ensures clarity and reuse of the dataset.