Evolutionary constraint on low elevation range expansion: Defense-abiotic stress-tolerance trade-off in crosses of the ecological model .

Most transplant experiments across species geographic range boundaries indicate that adaptation to stressful environments outside the range is often constrained. However, the mechanisms of these constraints remain poorly understood. We used extended generation crosses from diverged high and low elevation populations.

Effect of Drought on Herbivore-Induced Plant Gene Expression: Population Comparison for Range Limit Inferences.

Low elevation "trailing edge" range margin populations typically face increases in both abiotic and biotic stressors that may contribute to range limit development. We hypothesize that selection may act on ABA and JA signaling pathways for more stable expression needed for range expansion, but that antagonistic crosstalk prevents their simultaneous co-option. To test this hypothesis, we compared high and low elevation populations of Boechera stricta that have diverged with respect to constitutive levels of glucosinolate defenses and root:shoot ratios; neither population has high levels of both traits.

Plant chemical defense allocation constrains evolution of tolerance to community change across a range boundary.

Because transplant experiments show that performance usually decreases across species range boundaries, some range limits might develop from factors and processes that prevent adaptation to stressful environments. Here, we determined whether an ecological cost of plant defense involving stress associated with changes in the local plant community may contribute to range limit development in the upland mustard species Boechera stricta. In a common garden experiment of 499 B.

Major transcriptome reprogramming underlies floral mimicry induced by the rust fungus Puccinia monoica in Boechera stricta.

Pucciniamonoica is a spectacular plant parasitic rust fungus that triggers the formation of flower-like structures (pseudoflowers) in its Brassicaceae host plant Boecherastricta. Pseudoflowers mimic in shape, color, nectar and scent co-occurring and unrelated flowers such as buttercups. They act to attract insects thereby aiding spore dispersal and sexual reproduction of the rust fungus.

Plant chemical defence allocation constrains evolution of local range.

Many species of plants in the wild are distributed spatially in patches, the boundaries of which may occur and change because of a complicated interplay between myriad environmental stressors and limitations of, or constraints on, plant coping mechanisms. By examining genetic variation and co-variation among marker-inferred inbred lines and sib-families of an upland wild mustard species within and just a few meters across a natural patch boundary, we show that the evolution of tolerance to the stressful environment outside the patch may be constrained by allocation to glucosinolate compounds (GS) that are defensive against generalist insect herbivores. Several potential stressors were associated with the patch boundary, but carbon isotope ratios indicated that sib-families with smaller stomatal apertures maintained performance better in response to late season dry conditions, suggesting that drought was an important stressor.