Plant genome size influences stress tolerance of invasive and native plants via plasticity

Abstract

Citation: Meyerson, L. A., P. Py sek, M. Lu canov a, S. Wigginton, C.-T. Tran, and J. T. Cronin. 2020. Plant genome size influences stress tolerance of invasive and native plants via plasticity. Ecosphere 11(5):Abstract. Plant genome size influences the functional relationships between cellular and whole-plant physiology, but we know little about its importance to plant tolerance of environmental stressors and how it contributes to range limits and invasion success. We used native and invasive lineages of a wetland plant to provide the first experimental test of the Large Genome Constraint Hypothesis (LGCH)-that plants with large genomes are less tolerant of environmental stress and less plastic under stress gradients than plants with small genomes. We predicted that populations with larger genomes would have a lower tolerance and less plasticity to a stress gradient than populations with smaller genomes. In replicated experiments in northern and southern climates in the United States, we subjected plants from 35 populations varying in genome size and lineage to two salinity treatments. We measured traits associated with growth, physiology, nutrition, defense, and plasticity. Using AICc model selection, we found all plant traits, except stomatal conductance, were influenced by environmental stressors and genome size. Increasing salinity was stressful to plants and affected most plant traits. Notably, biomass in the high-salinity treatment was 3.0 and 4.9 times lower for the invasive and native lineages, respectively. Plants in the warmer southern greenhouse had higher biomass, stomate density, stomatal conductance, leaf toughness, and lower aboveground percentage of N and total phenolics than in the northern greenhouse. Moreover, responses to the salinity gradient were generally much stronger in the southern than northern greenhouse. Aboveground biomass increased significantly with genome size for the invasive lineage (43% across genome sizes) but not for the native. For 8 of 20 lineage trait comparisons, greenhouse location 9 genome size interaction was also significant. Interestingly, the slope of the relationship between genome size and trait means was in the opposite direction for some traits between the gardens providing mixed support for LGCH. Finally, for 30% of the comparisons, plasticity was significantly related to genome size-for some plant traits, the relationship was positive, and in others, it was negative. Overall, we found mixed support for LGCH and for the first time found that genome size is associated with plasticity, a trait widely regarded as important to invasion success.

Genome size variation and evolution during invasive range expansion in an introduced plant

“…The nature of this interaction was predominantly driven by individuals with small genomes that grew more slowly and produced less biomass overall under cooler growing conditions. A similar interaction effect between genome size and variation in greenhouse conditions on aboveground biomass has also been identified in Phragmites australis (Meyerson et al . 2020).…”

“…The nature of this interaction was predominantly driven by individuals with small genomes that grew more slowly and produced less biomass overall under cooler growing conditions. A similar interaction effect between genome size and variation in greenhouse conditions on aboveground biomass has also been identified in Phragmites australis (Meyerson et al 2020). These interactions suggest that the effect of selection on genome size, and the subsequent relationship between genome size and the traits it influences, will vary across environments.…”

New Insights Into the Evolution of C4 Photosynthesis Offered by the Tarenaya Cluster of Cleomaceae

“…Based on this premise, genome size may affect the tolerance of environmental changes related to latitude, altitude, temperature, precipitation, salinity, and desiccation ( Grime and Mowforth, 1982 ; Otto and Whitton, 2000 ; Díez et al, 2013 ; Wang et al, 2018 ; Silva Artur et al, 2019 ; Zhang et al, 2019 ; Meyerson et al, 2020 ). Therefore, in habitats that can support high productivity and primary metabolic rates (e.g., Atlantic Forest and Amazon rainforest), species with smaller genomes (e.g., T. hassleriana , C. paludosa , and T. microcarpa; Supplementary Table S1 ) predominate, as they can maintain higher metabolic rates and rapidly adjust their physiology to match the environmental conditions ( Simonin and Roddy, 2018 ; Roddy et al, 2020 ).…”

Four priority areas to advance invasion science in the face of rapid environmental change

“…For some native species, global changes create physiologically intolerable or suboptimal conditions that lower relative fitness (Catford et al 2020) or provoke range shifts, further altering community composition and susceptibility to invader impacts (Gallardo and Aldridge 2013;Wallingford et al 2020). Environmental change often affects native and non-native species differentially, modifying their inter-actions and selection pressures through shifting abiotic and biotic ecosystem conditions (Xiao et al 2016;Meyerson et al 2020;Stern and Lee 2020). This issue is well recognized and has been widely investigated for several years, yet the need for research and management solutions through the lens of invasion science is ongoing and increasing.…”