Dynamic changes in the endophytic bacterial community during maturation of Amorphophallus muelleri seeds

Abstract

The seed microbiota is considered to be the starting point of the accumulation of plant microbiota, which is conducive to the preservation and germination of seeds and the establishment and development of seedlings. Our understanding of the colonization and migration dynamics of microbial taxa during seed development and maturation is still limited. This study used 16S rRNA high-throughput sequencing to investigate the dynamic changes in the composition and diversity of the endophytic bacterial community during maturation of Amorphophallus muelleri seeds. The results showed that as seeds matured (green to red), the Shannon index of their endophytic bacterial community first decreased and then increased, and the ACE and Chao1 indices of the endophytic bacterial community decreased gradually. The Shannon, ACE, and Chao1 indices of the endophytic bacterial community in the seed coat first decreased and then increased. Principal coordinate analysis of the bacterial communities revealed that the seed coat at different maturity stages showed significantly distinct bacterial communities and formed different clusters according to maturity stage. The bacterial communities of green and red seeds showed a clear separation, but they both overlapped with those of yellow seeds, indicating that some core taxa were present throughout seed maturation, but their relative abundance was dynamically changing. As the seeds grew more mature, the relative abundance of some bacterial communities with plant growth-promoting traits and others correlated with plant resistance (e.g., Burkholderia-Caballeronia-Paraburkholderia, Bacillus, Pseudomonas, Bradyrhizobium, Streptomyces) tended to increase and peaked in fully mature seeds and seed coats. The endophytic bacterial community of A. muelleri seeds seems to be driven by the seed maturation state, which can provide a theoretical basis for a comprehensive understanding of the assembly process of the microbial community during A. muelleri seed maturation.

Soil microbiome of shiro reveals the symbiotic relationship between Tricholoma bakamatsutake and Quercus mongolica

“…Species of the genera Bacillus and Paenibacillus were significantly high in abundance in the T. matsutake shiro ( Oh et al, 2016 ). Sphingomonas species are endophytic bacteria of ECM fungi, such as in T. matsutake cotyledons ( Liu et al, 2021 ), which possess the ability to degrade aromatic compounds and exhibit metabolic activity against toxic pollutants ( Yang C. et al, 2022 ; Yang M. et al, 2022 ). Thus, several of the abovementioned bacteria may contribute to the growth and development of T. bakamatsutake and its root-colonizing mycelia.…”

“…Norank_f__67–14 and Solirubrobacter species belong to the order Solirubrobacterales, which increases phosphorus flow and inhibits the flow of toxic aluminum and manganese from the soil to the plant, thereby promoting high crop yields ( Wang et al, 2022 ). Nocardioides and Pseudonocardia are highly metabolically active against toxic pollutants, and their secretions exert antimicrobial activity ( Carr et al, 2012 ; Singha and Pandey, 2021 ; Yang C. et al, 2022 ; Yang M. et al, 2022 ). Therefore, T. bakamatsutake aggregates Actinobacteria to degrade soil contaminants, secrete antibiotics to suppress pathogenic bacteria, and provide nutrients for itself, thereby aiding its own growth and development and the oak environment.…”

“…Bacterial competition for ecological niches was considered in this study. Bradyrhizobium and norank_f__Xanthobacteraceae , which are nitrogen-fixing rhizobia (Rhizobiales) that promote the growth and root development of some plants ( Yang C. et al, 2022 ; Yang M. et al, 2022 ), were highly abundant in all the samples. Therefore, Rhizobiales are symbionts of T. bakamatsutake ; however, they were lower in abundance in the Tb groups than in the CK groups, which is notable.…”

The endophytic fungal community plays a crucial role in the resistance of host plants to necrotic bacterial pathogens

“…To avoid contamination from environmental microorganisms, we sterilized the surface of the tissue segments used for endophytic microbial detection before shearing. The plant material was rinsed with sterile water 3 times, soaked in 75% ethanol for 30 seconds, rinsed with sterile water 3 times, soaked in 3% sodium hypochlorite solution for 3 minutes, and finally rinsed with sterile water 3 times (Yang et al, 2022). After surface sterilization, the tissue segments were cut and thoroughly mixed using a sterile scalpel on an ultraclean workbench.…”

“…Pcc 96 h AM_PC96S (Yang et al, 2022). After surface sterilization, the tissue segments were cut and thoroughly mixed using a sterile scalpel on an ultraclean workbench.…”