In collaboration with a international team led by Tobias Züst (Institute of Plant Sciences, University of Bern, Bern, Switzerland) we have published in ELife a paper on the evolution of biochemical defences in Erysimum. In this paper we present the genome assembly of E. cheiranthoides, an important resource to study Erysimum.
Züst T, Strickler SR, Powell AF, Mabry ME, An H, Mirzaei M, York T, Holland CK, Kumar P, Erb M, Petschenka G, Goméz JM, Perfectti F, Müller C, Pires JC, Mueller LA, Jander G. 2020. Independent evolution of ancestral and novel defenses in a genus of toxic plants (Erysimum, Brassicaceae) eLife 9:e51712
Phytochemical diversity is thought to result from coevolutionary cycles as specialization in herbivores imposes diversifying selection on plant chemical defenses. Plants in the speciose genus Erysimum (Brassicaceae) produce both ancestral glucosinolates and evolutionarily novel cardenolides as defenses. Here we test macroevolutionary hypotheses on co-expression, co-regulation, and diversification of these potentially redundant defenses across this genus. We sequenced and assembled the genome of E. cheiranthoides and foliar transcriptomes of 47 additional Erysimum species to construct a phylogeny from 9868 orthologous genes, revealing several geographic clades but also high levels of gene discordance. Concentrations, inducibility, and diversity of the two defenses varied independently among species, with no evidence for trade-offs. Closely related, geographically co-occurring species shared similar cardenolide traits, but not glucosinolate traits, likely as a result of specific selective pressures acting on each defense. Ancestral and novel chemical defenses in Erysimum thus appear to provide complementary rather than redundant functions.
We have published in New Phytologist an analysis of the pollination effectiveness in Erysimum mediohispanicum. In this paper, led by Javier Valverde, we show that including the genetic component in the calculation of pollination effectiveness may allow a more complete quantification of each pollinator’s contribution to the reproductive success of a plant providing information on its mating patterns and long‐term fitness.
The pollination effectiveness of a flower visitor has traditionally been measured as the product of a quantity component that depends on the frequency of interaction and a quality component that measures the per‐visit effects on plant reproduction. We propose that this could be complemented with a genetic component informing about each pollinator’s contribution to the genetic diversity and composition of the plant progeny.
We measured the quantity and quality components of effectiveness of most pollinator functional groups of the generalist herb Erysimum mediohispanicum . We used 10 microsatellite markers to calculate the genetic component as the diversity of sires among siblings and included it into the calculation of the pollination effectiveness.
Functional groups varied in the quantity and quality components, which were shown to be decoupled. Functional groups also differed in the genetic component. This component changed the estimates of pollination effectiveness, increasing the differences between some functional groups and modifying the pollination effectiveness landscape.
Valverde J, Perfectti F, Gómez JM. 2019.
Pollination effectiveness in a generalist plant: adding the genetic component. New Phytologist 223: 354–365