Assistant Professor - Plant Health and Microbiomes Auburn University Auburn, AL, USA
Abstract Text: Many plant microbiome studies often have a survivor bias, focused on germinated plants but overlook the assembly process from seed sowing to seedling establishment. However, the results of interactions between indigenous seed and soil microbes can kill seeds before germinating. Therefore, the spermosphere is a keystone growth stage for plants, and by studying the assembly process of microbes from seed to seedling, we can improve the management of seedling disease. Here, we present current knowledge on the microbiome of developing seedlings, emphasizing the spermosphere microbiome. We detailed methods to sample the short-lived spermosphere, revealing crop-specific microbiome assembly within 18 hours of sowing soybean and cotton seeds and identifying key organisms enriched in this habitat. When looking into microbial co-occurrence networks, we identified different hub taxa for cotton or soybean, demonstrating more evidence of crop-specific microbiome selection early in a plant’s life. We have since launched experiments to expand the sampling of soybean spermosphere from different soils around the U.S., revealing microbes commonly enriched in a spermosphere habitat despite different microbial pools. Future work will involve the exploration of the functional convergence of the spermosphere microbiome. Overall, this research enhances management strategies for seedling diseases, identifies key microbes for robust seedling growth and protection, and underscores the significance of early plant microbiome assembly in influencing plant health.
