Compensation for floral herbivory in Solanum carolinense: identifying mechanisms of tolerance

Abstract

While a plant's capacity to tolerate damage by herbivores can be studied as a single trait, it is important to recognize that tolerance is generally a result of the combined action of several different traits. Here, we report on a pair of experiments to identify mechanisms for tolerating floral herbivory in Solanum carolinense, an andromonoecious perennial herb that regularly suffers from high levels of florivory. We measured the effect of actual and simulated florivory on host-plant fitness and assessed which plant traits exhibited plasticity in response to florivory. In addition, for each of nine plant genets, we calculated tolerance indices and determined which traits were genetically correlated with tolerance. Traits that served to help S. carolinense tolerate florivory in terms of sexual reproduction included initiating more inflorescences, aborting fewer buds prior to anthesis and fewer ovaries after

Additive and non-additive effects of simulated leaf and inflorescence damage on survival, growth and reproduction of the perennial herb Arabidopsis lyrata

“…This is consistent with the general prediction that the removal of photosynthetically active tissue is detrimental to plant Wtness (Hendrix 1988;Crawley 1989;Marquis 1992). Damage to Xowers and inXorescences reduces the potential to produce fruits and seeds (Louda and Potvin 1995;Rebek and O'Neil 2005), but plants can at least partly compensate for Xoral damage by, for example, extending their Xowering period (Pilson and Decker 2002), altering allocation to Xowers among inXorescences (Garrish and Lee 1989) and/or initiating additional inXorescences (Wise et al 2008). Consistent with previous studies, inXorescence damage stimulated the production of new inXorescences in the present study.…”

“…Loss of leaf tissue can lead to the mobilisation of stored resources from root to shoot (Danckwerts 1993), but can also modify photosynthetic rates in remaining leaf tissue (Retuerto et al 2006) and leaf longevity (Mabry and Wayne 1997). Loss of inXorescences can, among other things, lead to maturation of fruits in a greater proportion of open Xowers (Wise et al 2008), but can also increase resource storage in root (Huhta et al 2009), which is opposite to the expected response to leaf damage. Further work is required to identify the mechanisms giving rise to the non-additive eVects documented in the present study.…”

Cumulative herbivory outpaces compensation for early floral damage on a monocarpic perennial thistle

“…Plant tolerance often occurs via a combination of traits, each of which contributes to compensation and helps minimize impacts on plant fitness (Wise et al 2008). Flowering patterns resulting from strong apical control can provide a significant early season investment plus a reservoir of delayed flower heads to provide additional fitness through time.…”

“…For instance, compensatory allocation to subsequent or additional flowers can minimize the influence of herbivore floral damage on plant fitness (e.g., Pilson and Decker 2002;Brody et al 2007;Wise et al 2008), and even increase within-year fitness relative to undamaged plants (overcompensation, e.g., Paige 1992; Lennartsson et al 1998;Agrawal 2000). However, resulting phenological delays or under-allocated resource reserves may limit fitness gains, particularly if a tolerance response is not triggered (Lehtilä 2000;Järemo and Palmqvist 2001;Klimešová et al 2014).…”

Elevated carbon dioxide concentrations indirectly affect plant fitness by altering plant tolerance to herbivory

“…Because tolerance may be aVected by the characteristics of undamaged plants ("constitutive traits"), damaged plants ("induced traits"), or plastic changes in trait values (Strauss et al 2003;Wise et al 2008), we conducted three series of partial correlation analyses to identify traits contributing to variation in tolerance. We calculated the partial correlations between tolerance and the accession mean values for traits (rosette diameter, aboveground biomass, height, stem number, Xowering date, reXowering time, and senescence date) measured on either clipped or unclipped plants, as well as the change in trait values after clipping, in each CO 2 environment.…”