Seed mucilage interacts with soil microbial community and physiochemical processes to affect seedling emergence on desert sand dunes

Abstract

Seedling emergence is a critical stage in the establishment of desert plants. Soil microbes participate in plant growth and development, but information is lacking with regard to the role of microbes on seedling emergence. We applied the biocides (captan and streptomycin) to assess how seed mucilage interacts with soil microbial community and physiochemical processes to affect seedling emergence of Artemisia sphaerocephala on the desert sand dune. Fungal and bacterial community composition and diversity and fungal-bacterial interactions were changed by both captan and streptomycin. Mucilage increased soil enzyme activities and fungal-bacterial interactions. Highest seedling emergence occurred under streptomycin and mucilage treatment. Members of the phyla Firmicutes and Glomeromycota were the keystone species that improved A. sphaerocephala seedling emergence, by increasing resistance of young seedlings to drought and pathogen. Seed mucilage directly improved seedling emergence and indirectly interacted with the soil microbial community through strengthening fungal-bacterial interactions and providing favourable environment for soil enzymes to affect seedling emergence. Our study provides a comprehensive understanding of the regulatory mechanisms by which soil microbial community and seed mucilage interactively promote successful establishment of populations of desert plants on the barren and stressful sand dune.

Soil bacterial and fungal communities and associated nutrient cycling in relation to rice cultivation history after reclamation of natural wetland

“…Structural equation modelling (SEM) (Hu et al, 2019) was used to evaluate the direct and indirect relationships between soil physiochemical parameters, microbial community structure and alpha diversity, and microbial functions. The bacterial and fungal community structure and diversity were expressed by the NMDS axis 1 score and Shannon index, respectively.…”

A Seed Mucilage-Degrading Fungus From the Rhizosphere Strengthens the Plant-Soil-Microbe Continuum and Potentially Regulates Root Nutrients of a Cold Desert Shrub

“…Activities of soil enzymes including phosphatase, N-acetyl-glucosaminidase, β-glucosidase, and cellobiohydrolase were measured using fluorimetric substrates. Detailed procedure for these measurements was previously reported (Hu et al 2019).…”

“…Seed traits related to dormancy and germination strategies are significant contributors to adaptation to environmental variation and long-term species demographics under natural conditions, as reported in a guild of coexisting species in the desert (Huang et al 2016;Liu et al 2019). Seed mucilage is such a trait that plays important roles in helping desert plants adapt to the variable environment (Gutterman et al 1973).…”

“…In turn, the soil microbial community can utilize these monosaccharides as substrates, thereby increasing microbial biomass and exerting a beneficial effect on the soil microbial community (Yang et al 2012b). In addition, the mucilage biodegradation products strengthen fungal-bacterial interactions and reduce resource competition between fungi and bacteria by providing a carbon source (Hu et al 2019).…”

Mucilage Secretion from Plants: Friends or Foes?

“…For example, root mucilage of Melastoma malabathricum, an aluminum accumulator, exhibited physical and chemical characteristics distinct from maize root mucilage, and could enhance uptake and accumulation of aluminum but not several other cations (Watanabe et al, 2008). Both seed and root mucilage can interact with a variety of microorganisms and likely are ecologically important in the life cycles of some plant species, especially those grown in harsh environments (Hu et al, 2018;Van Deynze et al, 2018).…”