Supported by the National Natural Science Foundation of China (Nos. 42090060, 41922053, 42007025 and 42007038) and the National Key Research and Development Program of China (No. 2018YFD1000800)
Soil-borne pathogenic bacteria threaten health of the soil-plant system and sustainable development of the agriculture. The soil ecosystem is complicated with tangled interactions of abiotic and biotic factors. Before contacting and invading the host plant root system, pathogenic bacteria often encounter sudden changes in abiotic factors, such as pH, oxygen content and types and contents of nutrients or biotic stresses, like competition, parasitism and predation of other soil microorganisms. Pathogenic bacteria have numerous capabilities, like biofilm formation, metabolism, movement, virulence, DNA repair, and resistance to bacteriophages, antibiotics, and other environmental stresses, which are essential for them to survive in the soil and infect host plants. To adapt to the complicated and variable soil biotic and abiotic environment, pathogenic bacteria have to trade off dynamically between survival and virulence so as to maintain the balance between survival, spread, proliferation and infection in soil and to maximize their adaptability in the soil environment. A systematic understanding of the processes and mechanisms of the survival-virulence trade-off of soil-borne pathogenic bacteria is the key to establishing efficient and precise ecological prevention and control strategies. To this end, this review first introduces the trade-off theory and survival-virulence trade-off of soil-borne pathogenic bacteria. Soil-borne pathogenic bacteria allocate more resources either on survival or virulence for adaption to for adaption to the environment. It is costly for pathogenic bacteria to resist stresses while producing virulent secretions. They have to reduce the production of virulent secretions to achieve the ability to resist stresses. Viable but non-cultivable status and phenotypic conversion are two typical phenomena of the survival-virulence trade-off in soil borne pathogenic bacteria to optimize the balance of viability and pathogenicity. In the second section, this paper elaborates on how abiotic and biotic factors influencing the survival-virulence trade-off of the pathogenic bacteria in the soil environment. Soil is a complex and constantly changing living habitat for bacteria, containing various stressful factors to threaten the existence of pathogenic bacteria. Harsh environmental factors can trigger resistant systems in the bacteria, which is rather costly, thus leading to a cut-down investment in the expression of virulent features. So this paper analyzed and summarized those phenomena from the perspective of mechanism. In the third section, this paper focused on this trade-off pattern in the process of pathogenic bacteria moving from bulk soil to root surface:migration from soil to rhizosphere, colonization and proliferation in rhizosphere and invasion to root surface, since the infection of host plants is a continuous and dynamic process varying temporally and spatially. The last section of this paper proposed several research topics relative to the survival-virulence trade-off theory:1) explore impacts of biotic and abiotic factors on survival and virulence characteristics of pathogenic bacteria; 2) enhance the understanding of the multi-level interactions in the rhizosphere micro-food web and the superimposition of biotic and abiotic factors on the survival-virulence trade-off in soil-borne pathogenic bacteria; 3) investigate the molecular mechanism of adaptive evolution of pathogenic bacteria. This paper calls for establishment of an ecological prevention and control strategy for soil-borne diseases based on the survival-virulence trade-off theory. Moreover, it is expected that this paper may provide certain theoretical reference for sustainable development of the green agriculture.
韦中,王佳宁,江高飞,王孝芳,徐阳春,沈其荣.土传病原细菌的生存与致病权衡[J].土壤学报,2022,59(2):324-333. DOI:10.11766/trxb202008310399 WEI Zhong, WANG Jianing, JIANG Gaofei, WANG Xiaofang, XU Yangchun, SHEN Qirong. Survival-virulence Trade-off of Soil-borne Pathogenic Bacteria[J]. Acta Pedologica Sinica,2022,59(2):324-333.复制