Figure 4. Survey of Zamia phyllosphere microbiota and metabolites reveals potential ecological functions. a. Core members of the bacterial endophyte community (892 ASVs) of six species (Z. elegantissima ,Z. nana , Z. pseudomonticola, Z. pseudoparasitica, Z. skinneri, Z. stevensonii ) identified using 16S-RNA amplicon sequencing (n = 28). The nitrogen-fixing cyanobacteriaDesmonostoc was observed in 30% of the samples with relative abundance up to 20%. b. Leaf fungal endophyte variants (10343 ASVs) of two species (Z. pseudoparasitica and Z. nana ) identified using ITS1 amplicon sequencing (n = 127). The generaColletotrichum is the most prevalent fungal endophyte in >50% of the samples studied. c. Foliar metabolome composition of Z. nana and Z. pseudoparasitica summarized into two dimensions with non-metric multidimensional scaling (NMDS) based on the Bray-Curtis dissimilarity index indicating the correlation between the metabolome and the microbiome. Solid lines correspond to regressions with p-value = <0.05 and dashed lines with p-value = 0.1. Modified from Sierra et al. (in review)
Cycas panzhihuaensis genome
Cycads offer a unique opportunity to uncover shared genomic traits exclusive to seed-producing plants. The first cycad genome was recently published and this high-quality 10.5 Gb chromosome-level assembly immediately provided a plethora of insights (Liu et al ., 2022). The Cycas panzhihuaensis genome contains evidence of an ancient whole-genome duplication event in the common ancestor of living gymnosperms and key innovations enabling seed formation are evident in the genome, including expansions of gene families regulating embryo development, secondary growth, and pollen tube formation. The genome also shows remarkable expansions of genes involved in chemical defenses, stress tolerance, and disease resistance, which may help explain the higher extant species diversity of cycads compared to Gingko . We elaborate further on a few particularly exciting findings from the genome. Overall, the high-quality C. panzhihuaensis genome assembly and annotation sheds light on the origin and evolution of cycads and provides insights into genetic innovations underlying seed plant success (Liu et al. , 2022).