DOI: 10.5061/dryad.m905qfv18
title: Disentangling the influence of water limitation and simultaneous above and belowground herbivory on plant tolerance and resistance to stress

description: 1. Plants face multiple biotic and abiotic stressors simultaneously. Many
 species can tolerate and resist stress, but countermeasures differ between
 roots and leaves. Since herbivores and environmental conditions modulate
 costs and benefits of plant defense traits, stress responses are
 context-dependent. We examined whole-plant tolerance and resistance
 responses to individual and combined effects of above and belowground
 herbivory under variable water conditions. 2. We manipulated water
 availability and access by two common herbivores (Spodoptera exigua
 caterpillars and Meloidogyne incognita nematodes) to Solanum lycocarpum.
 Plants were either watered based on historical regional averages or the
 30% reduction predicted by IPCC studies. Herbivory treatments included
 isolated above (AG) and belowground (BG) attacks, simultaneous (AGBG)
 attacks, and no-herbivory controls. We then parameterized generalized
 linear mixed-effects models with data on plant survival, leaf and root
 biomass accumulation, root complexity and terpenoid concentration. 3.
 Foliar herbivory increased terpenoid concentrations in roots relative to
 no-herbivory plants under control water but decreased in both roots and
 leaves under drought. Similarly, root feeders increased concentrations of
 terpenoids in leaves under control water but decreased concentrations only
 in roots under drought. Plants challenged with AGBG herbivory had greater
 whole-plant biomass (i.e., tolerance) and lower total concentrations of
 defensive compounds (i.e., resistance) than plants exposed to no-herbivore
 controls, regardless of water conditions. Importantly, the capacity of
 plants to grow or produce terpenoids changes when herbivory level is
 considered. In plants exposed to AGBG herbivory, greater nematode
 infection was related to decreases in whole-plant biomass and marginal
 increases in total terpenoid concentration. Ultimately, accounting only
 for individual AG and BG responses would have led to different conclusions
 and underestimated the magnitude of S. lycocarpum’s compensatory
 responses. A “whole-plant” approach revealed that belowground herbivory is
 the primary driver of tolerance in plants surviving moderate water stress.
 4. Synthesis. Whole-plant responses to stress in variable environments are
 complex, and their comprehensive understanding requires accounting for
 belowground herbivores and root responses. 
description: The experiment was conducted in a shadehouse at the city of
 Uberlandia, MG, Brazil. The experiment was conducted by the first author
 as part of her PhD thesis and therefore the data was collected, processed
 and analyzed by her. This data set is the raw data transcript from field
 and lab notes to excel file. The data have not been
 processed, therefore all the analyzes process (e.g., transformation to
 square root) was done direct in R.  Note that the
 control data for root length and architecture, as well as leaf and root
 dry biomass and terpenoid concentration (non-herbivory, AG herbivory and
 BG herbivory under control water) were originally presented in Mundim et
 al. (2017).
description: Metadata  column name explanation replicate plant replicate number of each treatment Sample name given when to the original sample at the shadehouse (same number represent the same plant) treat.water treatment of water. D = drought; C = control treat.herb treatment of herbivory. X= no herbivory; AG = caterpillar; BG = nematode; AGBG = both (simultaneous herbivory) treat treatments of water and herbivory together, in order as the graph.*  plant.part plant part the data refer to. L = leaf; R=root roots.complex root spread (measured at the end of the study) using the method centripetal link-based ordering system length.roots.final root total length account at the end of the study total.days.alive total number of days alive dry.weight final dry weight (L or R) (in grams) dry.weight.whole.plant final total plant dry weight (Leaf, root and stem) (in grams) terpenoid terpenoid concentration (μmol/g dry mass) in Leaf or Root  total.terpenoid terpenoic concentration of leaf + root (μmol/g dry mass) herb.perct leaf damage cumulative leftover (summed percentage of caterpillar herbivory over time) nemat.galls total number of nematode galls at the end of the study Ngall.per.Rootdw amount of nematode infection (number of galls per dry weight (g) of roots) *CX = control water and no-herbivory DX = drought and no-herbivory CAG= control water and caterpillar DAG = drought and caterpillar CBG = control water and nematode DBG = drought and nematodes CABG= control water and both herbivory  DABG = drought and both herbivory)   NA = no data or not applicable 0 = biological zero