The genetics underlying natural variation of plant–plant interactions, a beloved but forgotten member of the family of biotic interactions

Abstract

Despite the importance of plant-plant interactions on crop yield and plant community dynamics, our understanding of the genetic and molecular bases underlying natural variation of plant-plant interactions is largely limited in comparison with other types of biotic interactions. By listing 63 quantitative trait loci (QTL) mapping and global gene expression studies based on plants directly challenged by other plants, we explored whether the genetic architecture and the function of the candidate genes underlying natural plant-plant interactions depend on the type of interactions between two plants (competition versus commensalism versus reciprocal helping versus asymmetry). The 16 transcriptomic studies are unevenly distributed between competitive interactions (n = 12) and asymmetric interactions (n = 4, all focusing on response to parasitic plants). By contrast, 17 and 30 QTL studies were identified for competitive interactions and asymmetric interactions (either weed suppressive ability or response to parasitic plants), respectively. Surprisingly, no studies have been carried out on the identification of genetic and molecular bases underlying natural variation in positive interactions. The candidate genes underlying natural plant-plant interactions can be classified into seven categories of plant function that have been identified in artificial environments simulating plant-plant interactions either frequently (photosynthesis, hormones), only recently (cell wall modification and degradation, defense pathways against pathogens) or rarely (ABC transporters, histone modification and meristem identity/life history traits). Finally, we introduce several avenues that need to be explored in the future to obtain a thorough understanding of the genetic and molecular bases underlying plant-plant interactions within the context of realistic community complexity.

The role of genetics in mainstreaming the production of new and orphan crops to diversify food systems and support human nutrition

“…Insights into plant species' interactions in natural ecosystems may be useful for designing improved crop-crop interactions. Studies reporting the genetics (and epigenetics; Alonso et al, 2019) of reciprocal helping between plants are, however, currently relatively scarce, although strategies have been outlined through which natural genetic variants underlying mutualisms between pairs of plant species could be characterised (Subrahmaniam et al, 2018). Obvious 'interaction traits', likely to influence resource-use complementarity or conflict among crops, are those related to plant architecture, growth rate, mycorrhizal associations and phenology (Vandermeer, 1992;Litrico & Violle, 2015).…”

Progress Towards Plant Community Transcriptomics: Pilot RNA-Seq Data from 24 Species of Vascular Plants at Harvard Forest

“…Genomic analyses of single species, although important, do not capture the larger patterns occurring within an interacting community of plants. Trancriptome profiling or genome sequencing of multiple species and individuals within a community will open new, integrative avenues of analyses and allow us to address existing questions that require sampling of floras and communities (Bragg et al, 2015;Fitzpatrick and Keller, 2015;Bowsher et al, 2017;Han et al, 2017;Swenson and Jones, 2017;Zambrano et al, 2017;Matthews et al, 2018;Subrahmaniam et al, 2018;Breed et al, 2019) . This is especially true for understanding responses to climate change where community level analyses are needed to capture the interacting dynamics of different species responses (Liu et al, 2018;Komatsu et al, 2019;Snell et al, 2019) .…”

A Framework for Collective Behavior in Plant Inspired Growth-Driven Systems, Based on Kinematics of Allotropism

“…As mentioned in the Introduction, collective dynamics of plant organs are expected to emerge as a result of local plant-plant dynamical interactions, where for example one plant root senses a signal emanating from a neighboring root and, similarly to common tropic responses, reorients its growth according to the direction of the stimulus. Indeed plants have the ability to perceive the nature and intensity of the interactions with neighboring plants through diverse signals, transmitted either above or below ground [40][41][42]. These signals can be classified as: (i) indirect signals, corresponding to environmental factors modified by the presence of neighbors, such as light and uptake of nutrients; and (ii) direct signals, corresponding to molecules directly produced by neighboring plants, such as aerial volatile organic compounds (VOCs), soluble root exudates, or microbiome and other intermediates.…”