Improving crop health by synthetic microbial communities: Progress and prospects.

Crop health directly affects yields and food security. At present, agrochemicals such as fertilizers and pesticides are mainly used in agricultural production to promote crop health. However, long-term excessive utilization of agrochemicals will damage the ecological environment of farmlands and increase the safety risk of agricultural products. It is urgent to explore efficient and environment-friendly agricultural products. Rhizosphere microbiome are considered as the second genome of plants, which are closely related to crop health. Understanding the key functional microbes, microbe-microbe interactions, and plant-microbe interactions are fundamental for exploring the potential of beneficial microbes in promoting crop health. However, due to the heterogeneity and complexity of the natural environment, stimulating the function of indigenous microorganisms remains uncertain. Synthetic microbial community (SynCom) is an artificial combination of two or more different strain isolates of microorganisms, with different taxonomic, genetic, or functional characteristic. Because of the advantages of maintaining species diversity and community stability, SynCom has been widely applied in the fields of human health, environmental governance and industrial production, and may also have great potential in promoting crop health. We summarized the concept and research status of SynCom, expounded the principles and methods of constructing SynCom, and analyzed the research on the promotion of crop health by exploring the mechanism of plant-microbe interactions, promoting plant growth and development, and improving stress resistance. Finally, we envisaged the future prospects to guide the using SynCom to improve crop health.

Quantitative detection of the Ralstonia solanacearum species complex in soil by qPCR combined with a recombinant internal control strain.

IMPORTANCE: DNA-based detection and quantification of soil-borne pathogens, such as the Ralstonia solanacearum species complex (RSSC), plays a vital role in risk assessment, but meanwhile, precise quantification is difficult due to the poor purity and yield of the soil DNA retrieved. The internal sample process control (ISPC) strain RsPC we developed solved this problem and significantly improved the accuracy of quantification of RSSC in different soils. ISPC-based quantitative PCR detection is a method especially suitable for the quantitative detection of microbes in complex matrices (such as soil and sludge) containing various PCR inhibitors and for those not easy to lyse (like Gram-positive bacteria, fungi, and thick-wall cells like resting spores). In addition, the use of ISPC strains removes additional workload on the preparation of high-quality template DNA and facilitates the development of high-throughput quantitative detection techniques for soil microbes.