Specialized core bacteria associate with plants adapted to adverse environment with high calcium contents

Abstract

Karst topography is formed from the dissolution of soluble rocks, such as limestone and dolomite. In soils of such a landform, excessive contents of exchangeable calcium seriously limit the growth of vegetations. Researches have proved that rhizosphere microorganisms and endophytes help host plants to adapt to various adverse environments. The adaptive capacity of plants that grow in adverse environment with salt, drought, thermal and heavy metal stresses partially or completely comes from symbiotic microorganisms. By using the high-throughput amplicon sequencing, the bacterial community structures in soil with high calcium contents and roots and leaves of Cochlearia henryi that is commonly seen in karst area were analyzed. The bacteria community structures in these three compartments showed obvious differences. This indicates that C. henryi, which is adaptive to high calcium stress, selectively co-exists with specific bacteria. Although the bacteria community structures in these three compartments differed significantly, there were 73 operational taxonomic units (OTUs) shared by karst soils as well as roots and leaves of C. henryi. The phylogenetic diversity of these 73 OTUs differed significantly from that of overall OTUs detected. There were also obvious differences in KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways and abundance values between the 73 OTUs and overall bacterial communities. A large number of OTUs shared by the karst soils, roots and leaves of C. henryi had close genetic relationship with known stress-resistant bacterial strains. Our results showed that the functional bacteria can be predicted by exploring core bacteria, bacteria shared by soils, adaptable plant roots and leaves. This information will potentially accelerate studies on natural microbial communities which can promote the adaptive capacity of host plants to high calcium stress, and will be valuable for finding microbial strains for field application in karst topography.

Metagenomic Insights and Genomic Analysis of Phosphogypsum and Its Associated Plant Endophytic Microbiomes Reveals Valuable Actors for Waste Bioremediation

“…Along with the main functional categories, metabolism (49.4%), genetic information processing (16.3%), unclassified (14.8%) and environmental information processing (14.7%), xenobiotics, biodegradation and metabolism (2.3%), metabolism of terpenoids and polyketides (2%) and biosynthesis of other secondary metabolites (1%) are also represented. Similar findings were reported in Li et al [48] for plant adaptation to adverse environments with high calcium contents. Given these findings, it was relevant to recover culturable population and to test single bacterial isolates metabolic capacities.…”

Climatic impacts on the bacterial community profiles of cork oak soils

“…4; Table S3). Many of these indicator species were present in the core cork oak microbiome (humid forests: 6 out 28; sub-humid forests: 3 out 11; arid/ semiarid forests: 4 out 21), suggesting the role of the core community for the environmental adaptation of plants as proposed by Li et al (2018). While most indicator OTUs (46%) from humid forests were Acidobacteria (mainly from the Actinobacteriaceae family), this phylum was less represented in sub-humid (18%) and arid/semi-arid forests (5%), which is in agreement with their sensitivity to drier conditions Naylor and Coleman-Derr, 2018).…”

“…Accordingly, the relative abundance of core OTUs is not significantly changed among cork oak forest, except for PG-ER and arid forests (p < 0.05, ANOVA). Indeed, bacterial species of core microbiomes have been described as less susceptible to external disturbance than other bacteria (Toju et al, 2018) and essential for environmental adaptation of plants (Li et al, 2018). The cork oak core microbiome was dominated by Proteobacteria (33.2% of core OTUs and 39.7% of total reads assigned), mainly including Alphaproteobacteria (20.5% and 29.8%, respectively), but also Actinobacteria (19.1% and 24.2%, respectively) and Acidobacteria (19.9% and 20%, respectively).…”

Impact of an antarctic rhizobacterium on root traits and productivity of soybean (Glycine max L.)

“…Through millions of years of co-evolution, rhizosphere symbionts have contributed to the fitness and adaptive plasticity of plant traits (Friesen et al 2011;Rao et al 2016;Timmusk et al 2014;Yang, Kloepper, and Ryu 2009), especially in harsh environments (Goh et al 2013;Gopal and Gupta 2016;Li et al 2018). Several studies have highlighted the ability of plant growth promoting rhizobacterial (PGPR) strains to promote plant growth under abiotic stresses through multiple direct and indirect mechanisms (Yang, Kloepper, and Ryu 2009;Shrivastava and Kumar 2015;Enebe and Babalola 2018).…”