Genotype and maternal environment affect belowground interactions betweenArabidopsis thalianaand its competitors

Abstract

Ecological interactions between different species are not fixed, but they may depend, at least to some extent, on the particular genotypes involved as well as on the environmental conditions experienced by previous generations. We used a set of natural genotypes of Arabidopsisthaliana, that previously experienced contrasting nutrient and herbivory conditions, to test for the influences of genetic variation and maternal effects on competitive interactions between Arabidopsis and the weedy annuals Anagallisarvensis and Senecio vulgaris. We used activated carbon to discriminate between resource competition and allelopathy components of plant‐plant interactions. There was a clear competitive hierarchy: Senecio>Arabidopsis>Anagallis. Although we found no evidence for allelopathic potential of Arabidopsis, our results indicate that both Anagallis and Senecio exerted negative (direct or indirect) allelopathic effects on Arabidopsis. There were significant differences among Arabidopsis genotypes in their competitive effects on both neighbor species, as well as in their response to competition. Maternal environments significantly influenced not only the growth and fitness of Arabidopsis itself, but also its competitive effect on Anagallis. We found, however, no evidence that maternal environments affected the competitive effect on Senecio or overall competitive response of Arabidopsis. Generally, resource competition played a greater role than allelopathy, and genotype effects were more important than maternal effects. Our study demonstrates that ecological interactions, such as plant competition, are complex and multi‐layered, and that, in particular, the influence of genetic variation on interactions with other species should not be overlooked.

The genetics of intra‐ and interspecific competitive response and effect in a local population of an annual plant species

“…We observed an escape strategy in response to S. media with a crawling growth form and an aggressive response strategy to P. annua with a low spreading growth form. While a crawling growth form may have led to an increased competition for light in A. thaliana , we cannot rule out that optimal phenotypic strategies estimated on above‐ground traits did not result from below‐ground plant–plant interactions (Bossdorf, Shuja & Banta ). For instance, S. media has been described to produce allelopathic water‐soluble phenolics in the soil (Inderjit & Dakshini ), which may have affected A. thaliana growth in our study.…”

Phenotypic differentiation within a foundation grass species correlates with species richness in a subalpine community

“…within plant communities) remain scarce (Bailey et al 2009; but see adams et al 2011; michalet et al 2011; gibson et al 2012) compared with across trophic-level studies, likely due to the diffuse nature of plant-plant interactions and the rarity of feedback effects (Bronstein 2009;michalet et al 2011;schöb et al 2014). Plant community genetic studies have mainly focused on competition or allelopathy (lankau and strauss 2007; Bossdorf et al 2009;silvertown et al 2009), while evolutionary questions associated with positive interactions among plants (i.e. facilitation) such as nurse plant effects remain less documented (but see Valiente-Banuet et al 2006;liancourt and tielbörger 2011;michalet et al 2011;thorpe et al 2011;Butterfield et al 2013).…”

Pitfalls in ecological research – transgenerational effects

“…This demonstrates the need to control for or at least recognize TE in ecological studies. Unfortunately, this can be a challenging task because expression of TE depends on the interaction of parental and offspring environments (Galloway and Etterson 2007;Sultan et al 2009); they can be strongly genotype-specific (Andalo et al 1998;Agrawal 2001Agrawal ,2002Galloway 2001;Riginos et al 2007;Bossdorf et al 2009), the role of transgenerational effects can change during the lifespan of an individual , and importantly, TE can alter phenotypes for more than one generation (Miao et al 1991;Whittle et al 2009). Insight into the mechanisms underlying transgenerational effects might provide clues on how to better control for these effects in ecological studies and how to recognize cases in which their influence should be taken into account in the interpretation of results.…”