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

Abstract

The seed microbiome of crop wild relatives is a potential reservoir of beneficial traits that potentially improve their host plant resilience to fluctuating environments and pathogenic threats. Herein, we studied the seed microbiome of three species of the medicinal genus Panax (P. vietnamensis, P. japonicas, and P. stipuleanatus) collected from seven locations in Southwest China. We used qPCR and metabarcoding high-throughput sequencing to target both endophytic bacteria and fungi. Seed bacterial absolute abundance (1.1 × 109∼1.0 × 107 gene copy numbers per gram seed) was substantially higher than that of fungi (7.6 × 105∼3.7 × 102). Host plant genotype was the main driver of seed microbiome composition for both bacteria and fungi. Panax growing hypothermal environments significantly shaped their seed endophytic bacterial but not fungal microbiota. The three Panax species’ seeds harbored unique microbes [averaged ∼150 amplicon sequence variants (ASVs)], sharing only 12 bacterial ASVs (half affiliated to Halomonas) and four fungal ASVs. Network analysis showed that the Panax seed endophytic bacteria tend to form inter-weaved functional modules that are majorly connected by core members from the genus Halomonas, Pseudomonas, and Pantoea. These genera have been associated with nutrient cycling, plant, disease suppression, and tolerance to environmental fluctuation. Together, these novel insights may shade light on the ecological strategies of wild Panax plants adaptation to their thermal environment by possessing abundant beneficial seed endophytic bacteria.

Endophytic bacterial communities in wild rice (Oryza officinalis) and their plant growth-promoting effects on perennial rice

“…In addition to their hereditary potential, wild plants utilize the plant-associated microbiome to expand their environmental adaptability, nutrient utilization efficiency and tolerance to biotic and abiotic stresses ( Cordovez et al., 2019 ; White et al., 2019 ; Liu et al., 2022a ). The main members of the phytomicrobiome originate from the endosphere, phyllosphere and rhizosphere ( Singh et al., 2020 ).…”

The metagenomics of soil bacteria and fungi and the release of mechanical dormancy in hard seeds

“…It has been reported that fungi can release mechanical dormancy by biomechanically breaking the pericarp of Lepidium didymum ( Sperber et al., 2017 ). However, little is known about the relationships between beneficial and pernicous microorganisms (fungi and bacteria) and seed quality ( Liu et al., 2022 ).Some of microorganisms stimulated seed germination, seedling health and growth ( Shade et al., 2017 ; Del Carmen Orozco-Mosqueda et al., 2020 ; Liu et al., 2022 ). For example, wild Panax plants adapt to their thermal environment by harboring abundant beneficial seed endophytic bacteria ( Liu et al., 2022 ).…”

“…However, little is known about the relationships between beneficial and pernicous microorganisms (fungi and bacteria) and seed quality ( Liu et al., 2022 ).Some of microorganisms stimulated seed germination, seedling health and growth ( Shade et al., 2017 ; Del Carmen Orozco-Mosqueda et al., 2020 ; Liu et al., 2022 ). For example, wild Panax plants adapt to their thermal environment by harboring abundant beneficial seed endophytic bacteria ( Liu et al., 2022 ). Some of microorganisms caused seed deterioration, including for seeds retained the hard-seeded characteristic.…”