On March 3, the laboratory of Microecology and Rhizosphere health, led by Professor Shen Qirong, School of resources and environmental science, Nanjing Agricultural University, made important progress in the field of rhizosphere microecology and plant health Health "was published in the international famous academic journal microbiome (if2018 = 10.465). The results show that the rhizosphere protozoa community and its interaction with bacterial community play an important role in the protection of crop health.
As we all know, rhizosphere microbiome is extremely complex, which will change significantly in the whole plant growth process, and has an important impact on plant growth and health. At present, most rhizosphere microbiome researches focus on bacteria and fungi, and it is not clear whether other microorganisms, especially the key microbial predator protozoa, affect plant health. A large number of previous literatures have reported that protozoa can selectively prey on bacteria, which in turn can also produce defense (produce bacteriostatic substances) against protozoa's predation. The interaction between protozoa and bacteria makes us guess that protozoa community and its interaction with bacteria community may play an important role in protecting crop health (Figure 1).
Figure 1: interaction between rhizosphere protozoa and beneficial microorganisms affects plant health
Soil borne bacterial wilt is a kind of destructive bacterial disease, which is very harmful in the world, especially in China. Ralstonia solanacearum (Ralstonia solanacearum) is a kind of pathogen, which can survive in soil and infect plants from roots, so it is difficult to control. Previous studies found that the occurrence of tomato soil borne bacterial wilt was closely related to the structure and functional characteristics of rhizosphere bacterial community (Wei et al., 2019, science advances). In this study, we analyzed the whole rhizosphere microbiome including bacteria, fungi and protozoa, as well as the metabolism genes related to microbial functions, and explored the relationship between these communities and functional genes and the occurrence of soil borne bacterial wilt in the whole plant growth cycle through the continuous collection device of non-destructive rhizosphere soil samples (Xiong et al., 2020, microbiome). We found that the community structure of protozoa can best predict the dynamic change of pathogen in the whole plant growth cycle. At the initial point of plant cultivation, phagocytic protozoa feeding on microorganisms show typical differences between healthy and diseased plants. In the whole plant growth process, the relative abundance of these phagocytic protozoa was negatively correlated with the pathogen of bacterial wilt, which indicated that the interaction between predators and prey would affect the growth of pathogens. In addition, phagocytic protozoa may control the growth of pathogens by enhancing the secondary metabolite related genes (producing bacteriostatic substances) in bacterial communities. This study shows that protozoa, as the top-down structure and function controller of microbial group, have a profound impact on plant health. At present, we have isolated and screened a large number of phagocytic protozoa, and are exploring their biological control potential, in order to use them to regulate the structure and function of microorganisms and protect the health of crops.
The first author of this paper is Nanjing Agricultural University. Dr. Xiong Wu (now a postdoctoral student of Utrecht University in the Netherlands) and Dr. Song Yuqi are the co authors of this paper. Professor Wei Zhong is the corresponding author of this paper. Professor Shen Qirong, Professor Xu Yangchun, Dr Gu Yian, Dr Yang Keming, Professor George kowalchuk, assistant professor Alexandre Jousset and assistant professor Stefan Geisen of Wageningen University all participated in the study.
It is understood that in recent years, the microecology and Rhizosphere Health Laboratory of Nanjing Agricultural University, relying on the national first-class discipline of agricultural resources and environment, under the support of NSFC, 973 project, national key R & D plan and Jiangsu Natural Science Fund, is focusing on the research field of rhizosphere microecology and plant health, to reveal the formation mechanism of disease resistant soil microbial flora Important breakthroughs have been made in the mechanism of the interaction between control and flora, the construction of probiotics, and the regulation of soil microbial community for disease control. Relevant work has been published in international famous journals such as Nature Biotechnology, nature communications, science advances, ecology letters, microbiome, mbio, and soil bio Biochem.
Source: School of resources and environment, Nannong University
Editor: Huang Wenxi
Reviewed by: Li Kejie