Diazotroph Paenibacillus triticisoli BJ-18 Drives the Variation in Bacterial, Diazotrophic and Fungal Communities in the Rhizosphere and Root/Shoot Endosphere of Maize

Abstract

Application of diazotrophs (N2-fixing microorganisms) can decrease the overuse of nitrogen (N) fertilizer. Until now, there are few studies on the effects of diazotroph application on microbial communities of major crops. In this study, the diazotrophic and endospore-forming Paenibacillus triticisoli BJ-18 was inoculated into maize soils containing different N levels. The effects of inoculation on the composition and abundance of the bacterial, diazotrophic and fungal communities in the rhizosphere and root/shoot endosphere of maize were evaluated by sequencing the 16S rRNA, nifH gene and ITS (Inter Transcribed Spacer) region. P. triticisoli BJ-18 survived and propagated in all the compartments of the maize rhizosphere, root and shoot. The abundances and diversities of the bacterial and diazotrophic communities in the rhizosphere were significantly higher than in both root and shoot endospheres. Each compartment of the rhizosphere, root and shoot had its specific bacterial and diazotrophic communities. Our results showed that inoculation reshaped the structures of the bacterial, diazotrophic and fungal communities in the maize rhizosphere and endosphere. Inoculation reduced the interactions of the bacteria and diazotrophs in the rhizosphere and endosphere, while it increased the fungal interactions. After inoculation, the abundances of Pseudomonas, Bacillus and Paenibacillus in all three compartments, Klebsiella in the rhizosphere and Paenibacillus in the root and shoot were significantly increased, while the abundances of Fusarium and Giberella were greatly reduced. Paenibacillus was significantly correlated with plant dry weight, nitrogenase, N2-fixing rate, P solubilization and other properties of the soil and plant.

Biofertilization containing Paenibacillus triticisoli BJ-18 alters the composition and interaction of the protistan community in the wheat rhizosphere under field conditions

“…In this study, biofertilizer application significantly increased wheat yield and improved some rhizosphere physicochemical properties (including nitrogenase activity, total N, organic matter, and available P) of rhizosphere soil. The increased soil nitrogenase activity and total N can be explained by the fact that the biofertilizer applied in this study contained N 2 ‐fixing bacteria ( P. triticisoli BJ‐18), and N 2 ‐fixing bacteria carried nitrogenase genes (Li, Zhang, et al, 2021; Yongbin et al, 2020). Although the phosphate‐solubilizing capacity of P. triticisoli BJ‐18 was very low, the soil available P still increased, which may be due to the other enriched indigenous phosphate‐solubilizing microorganisms under the induction of P. triticisoli BJ‐18 (Li, Zhang, et al, 2021; Xie et al, 2016).…”

“…As a microbiome‐based product, biofertilizer is eco‐friendly and inexpensive, which can provide essential nutrients for plants and increase soil fertility after application. With the development of high‐throughput sequencing, more and more researches focus on the impact of biofertilizer application on the crop microbiome (Li, Zhang, et al, 2021; Lu et al, 2020). Protists are a ubiquitous group of microscopic eukaryotes; however, they are taxonomically ill‐defined and usually ignored in most previous studies of the crop microbial community (Sapp et al, 2018).…”

“…In addition to the promotion to plant growth and soil quality, biofertilizer could further affect the soil community composition of microorganisms (Li, Zhang, et al, 2021; Lu et al, 2020) and macroorganisms (Finch et al, 2018) after the application. For example, the application of Bacillus subtilis biofertilizer not only increased pakchoi yield but also mitigated NH 3 volatilization by changing the bacterial community composition and functional gene abundances (Sun et al, 2020).…”

“…Biofertilizer containing biocontrol agent Bacillus amyloliquefaciens NJN‐6 could increase bacterial abundance, decrease fungal abundance, and change the abundances of some potential taxa ( Sphingobium , Dyadobacter , Cryptococcus , Fusarium , Ralstonia , and Burkholderia ) involved in suppression of banana Fusarium wilt disease (Fu et al, 2017). Paenibacillus triticisoli BJ‐18 could survive and propagate in the plant rhizosphere, root, and shoot, and its application leads to the enrichment of some potential beneficial microorganisms ( Pseudomonas , Paenibacillus , Klebsiella , and Bacillus ), and the decrease of some plant pathogens (Li, Zhang, et al, 2021), and thus it was identified as a good candidate as the biofertilizer (Li, Li, et al, 2019; Li, Shi, et al, 2019; Yongbin et al, 2020). However, an increasing number of studies have focused on bacterial and fungal responses to biofertilization, while soil protistan community response to biofertilizer is rarely investigated, which limits our comprehensive understanding of how biofertilization influences the whole microbial community.…”

Bacterial Communities of Sediments in a Seawater-Freshwater Transition Zone During the Wet and Dry Seasons in Pearl River Estuary

“…Network analysis has been increasingly used as a critical tool for exploring microbial community symbiosis patterns in ecosystem studies [46,47]. In this study, salt stress suppressed the potential interactions within microbial communities, especially in ZH (Fig.…”