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Summary White oak (Quercus alba) is an abundant forest tree species across eastern North America that is ecologically, culturally, and economically important.We report the first haplotype‐resolved chromosome‐scale genome assembly ofQ. albaand conduct comparative analyses of genome structure and gene content against other published Fagaceae genomes. We investigate the genetic diversity of this widespread species and the phylogenetic relationships among oaks using whole genome data.Despite strongly conserved chromosome synteny and genome size acrossQuercus, certain gene families have undergone rapid changes in size, including defense genes. Unbiased annotation of resistance (R) genes across oaks revealed that the overall number of R genes is similar across species – as are the chromosomal locations of R gene clusters – but, gene number within clusters is more labile. We found thatQ. albahas high genetic diversity, much of which predates its divergence from other oaks and likely impacts divergence time estimations. Our phylogenetic results highlight widespread phylogenetic discordance across the genus.The white oak genome represents a major new resource for studying genome diversity and evolution inQuercus. Additionally, we show that unbiased gene annotation is key to accurately assessing R gene evolution inQuercus.
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Evolutionary transition to the ectomycorrhizal habit in the genomes of a hyperdiverse lineage of mushroom‐forming fungi
Summary The ectomycorrhizal (ECM) symbiosis has independently evolved from diverse types of saprotrophic ancestors. In this study, we seek to identify genomic signatures of the transition to the ECM habit within the hyperdiverse Russulaceae.We present comparative analyses of the genomic architecture and the total and secreted gene repertoires of 18 species across the order Russulales, of which 13 are newly sequenced, including a representative of a saprotrophic member of Russulaceae,Gloeopeniophorella convolvens.The genomes of ECM Russulaceae are characterized by a loss of genes for plant cell wall‐degrading enzymes (PCWDEs), an expansion of genome size through increased transposable element (TE) content, a reduction in secondary metabolism clusters, and an association of small secreted proteins (SSPs) with TE ‘nests’, or dense aggregations of TEs. Some PCWDEs have been retained or even expanded, mostly in a species‐specific manner. The genome ofG. convolvenspossesses some characteristics of ECM genomes (e.g. loss of some PCWDEs, TE expansion, reduction in secondary metabolism clusters).Functional specialization in ECM decomposition may drive diversification. Accelerated gene evolution predates the evolution of the ECM habit, indicating that changes in genome architecture and gene content may be necessary to prime the evolutionary switch.
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- Award ID(s):
- 2030779
- PAR ID:
- 10633794
- Author(s) / Creator(s):
- ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; more »
- Publisher / Repository:
- Wiley
- Date Published:
- Journal Name:
- New Phytologist
- Volume:
- 233
- Issue:
- 5
- ISSN:
- 0028-646X
- Page Range / eLocation ID:
- 2294 to 2309
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1111/nph.17892
