Anemochore Seeds Harbor Distinct Fungal and Bacterial Abundance, Composition, and Functional Profiles

Abstract

Many plants adapted to harsh environments have evolved low seed mass (‘light seeds’) with specific dispersal strategies, primarily either by wind (anemochory) or water (hydrochory). However, the role of their seed microbiota in their survival, and their seed microbial abundance and structure, remain insufficiently studied. Herein, we studied the light seed microbiome of eight anemochores and two hydrochores (as controls) collected from four provinces in China, using qPCR and metagenomic sequencing targeting both bacteria and fungi. Substantial variations were found for seed endophytic fungi (9.9 × 1010~7.3 × 102 gene copy numbers per seed) and bacteria (1.7 × 1010~8.0 × 106). Seed microbial diversity and structure were mainly driven by the plant genotype (species), with weak influences from their host plant classification level or dispersal mode. Seed microbial composition differences were clear at the microbial phylum level, with dominant proportions (~75%) for Proteobacteria and Ascomycota. The light seeds studied harbored unique microbial signatures, sharing only two Halomonas amplicon sequence variants (ASVs) and two fungal ASVs affiliated to Alternaria and Cladosporium. A genome-level functional profile analysis revealed that seed bacterial microbiota were enriched in amino acid, nucleoside, and nucleotide biosynthesis, while in fungal communities the generation of precursor metabolites and respiration were more highly represented. Together, these novel insights provide a deeper understanding of highly diversified plant-specific light seed microbiota and ecological strategies for plants in harsh environments.

Composition and Diversity of the Culturable Endophytic Community of Six Stress-Tolerant Dessert Plants Grown in Stressful Soil in a Hot Dry Desert Region

“…This may be attributed to the fact that several EF genera were shared between more than one host plant and between more than one plant family. However, several wild plant seeds shared only two core microbes, and they had unique endophytic microbiota [ 78 ]. Possibly, wild plants acquired their endophytic microbiota from the surrounding soils, and the soil microbiome could enter and be differently distributed within plant tissues, especially for endophytic fungi.…”

Wild Panax plants adapt to their thermal environment by harboring abundant beneficial seed endophytic bacteria

“…Of the c. 200 seeds removed from each plant, 50 seeds were used for surface disinfection. The method followed that used for wild plant seeds using ethanol and bleach (Liu et al, 2022). Then, the seeds were surface dried under aseptic conditions and stored at -20 • C prior to DNA extraction.…”

“…Spermatophytes dominate the plant kingdom and have developed a special strategy of adapting to harsh environments such as evolving low seed mass with wind or water dispersal mode, or transmitting beneficial seed microbes from plant generation to another (Shade et al, 2017;Liu et al, 2022). Plentiful studies have shown that there are a great diversity of endophytic microorganisms, some of which stimulated seed germination, seedling health and growth (Shade et al, 2017;Orozco-Mosqueda and Santoyo, 2020;Liu et al, 2022).…”

“…Spermatophytes dominate the plant kingdom and have developed a special strategy of adapting to harsh environments such as evolving low seed mass with wind or water dispersal mode, or transmitting beneficial seed microbes from plant generation to another (Shade et al, 2017;Liu et al, 2022). Plentiful studies have shown that there are a great diversity of endophytic microorganisms, some of which stimulated seed germination, seedling health and growth (Shade et al, 2017;Orozco-Mosqueda and Santoyo, 2020;Liu et al, 2022). Understanding the factors that affect the presence of key microbial taxa can improve our ability to modify the plant microbiome and improve host plant fitness (Abdullaeva et al, 2020;Rego et al, 2020;Kusstatscher et al, 2021;Shao et al, 2021;Walsh et al, 2021).…”

“…Understanding the factors that affect the presence of key microbial taxa can improve our ability to modify the plant microbiome and improve host plant fitness (Abdullaeva et al, 2020;Rego et al, 2020;Kusstatscher et al, 2021;Shao et al, 2021;Walsh et al, 2021). Seed endophytes are dynamic and highly diverse (Shade et al, 2017;Liu et al, 2022). The identification of shared and keystone microbes could shed light on microbial consortia and their interactive roles (Orgiazzi et al, 2013;Bjork et al, 2018).…”