We keep finding ways beneficial microbes affect traits of the organisms on which they live. I, @ChandraJack1, @symbiomics & @ME_Frederickson ask the obvious follow-up: how do traits evolve when selection acts on variation in both host and microbe genomes? Our manuscript is out now at ProcB: https://doi.org/10.1098/rspb.2020.2483
One key insight is that counter-intuitiively, conflict can increase mutualism. When hosts and microbes have fitness peaks at different trait values, this evolutionary conflict can actually cause hosts to depend MORE on microbes for optimal trait expression, thereby enhancing the degree of mutualism we would obsesrve.
Another key insight is that the evolution of traits in multiple genomes may favor local adaptation. If hosts are paired with microbes with which they did not share an evolutionary history, this would likely lead to trait mis-expression and appear as a signal of increased fitness with local microbes.
Tire wear particles are abundant and ubiquitous, but what are the consequences? and what can we do about it? I am happy to have been a part of this insightful piece in @csmonitor by Lindsey McGinnis @BylineLindsey featuring some truly innovative work by @Tyre_Collective, in addition to a small bit on my favorite tiny plant (duckweed, obviously) https://www.csmonitor.com/Environment/2020/1109/A-pollution-solution-where-the-rubber-meets-the-road?src=shared
Work led by Rebecca T Batstone shows that microbes evolve to benefit local hosts. One neat aspect of our work is that benefits occurred because loci increasing microbe fitness on local hosts also increased the fitness of local hosts — e.g. microbes were neither “altruistic” nor “cheaters.” Indeed alleles underlying mutual benefits more commonly contributed to evolved microbial differences for host and microbe growth than expected by chance.
See article: Experimental evolution makes microbes more cooperative with their local host genotype
Hear Rebecca discuss our results
Co-occurring winter stressors reduce duckweed survival and growth, as well as benefits from microbiomes, at AJB:
Resilience to multiple stressors in an aquatic plant and its microbiome
Duckweed host a much simpler microbiome, yet different microbiomes still shift host growth & traits, as in terrestrial plants, at Microbial Ecology:
Mutualistic Outcomes Across Plant Populations, Microbes, and Environments in the Duckweed Lemna minor
Low elevation teosinte
High elevation teosinte
Teosinte phenotypes that differ from low elevation, warm sites (later flowering, larger root mass) to high elevation, cold sites (early flowering, small roots) are shifted by root microbes. More interesting yet, microbes shift the genetic variation and covariation between traits, potentially altering plant responses to selection pressures, e.g. climate change.
manuscript online on biorxiv here
Check out a recording of my talk at Evolution 2019 if you are interested.
Hubbard et al 2019 find that root microbes drive a substantial amount of plant defense in Boechera stricta, and that plant and root-microbe pathways to defense are different. I opine here on what separate pathways mean for evolution of plant defense, and what alternate knock-on effects of microbe- and plant- driven defense on insects could mean for tri-trophic interactions.