Endophytic Bacterial Structure Research Articles

Endophytic bacterial community structure and diversity of the medicinal plant Mirabilis himalaica from different locations

Endophytic bacteria play important roles in medicinal plant growth, abiotic stress, and metabolism. Mirabilis himalaica (Edgew.) Heimerl is known for its medicinal value as Tibetan traditional plant; however, little is known about the endophytic bacteria associated with this plant in different geographic conditions and vegetal tissues. To compare the endophytic bacterial community associated with this plant in different geographic conditions and vegetal tissues, we collected the leaves, stems, and roots of M. himalaica from five locations, Nongmu college (NM), Gongbujiangda (GB), Zhanang County (ZL), Lang County (LX), and Sangri County (SR), and sequenced the 16S rRNA V5-V7 region with the Illumina sequencing method. A total of 522,450 high-quality sequences and 4970 operational taxonomic units (OTUs) were obtained. The different tissues from different locations harbored unique bacterial assemblages. Proteobacteria and Actinobacteria were the dominant phyla in all the samples, while the dominant genera changed based on the different tissues. The endophytic bacterial structures in the leaf and stem tissues were different compared to root tissues. Redundancy analysis (RDA) showed that the endophytic bacterial community was significantly correlated with pH, available phosphorus (AP), total phosphorus (TP), total nitrogen (TN), and soil organic matter (SOM). These findings suggested that the geographic conditions, climate type, ecosystem type, and tissues determined the endophytic bacterial composition and relative abundances. This conclusion could facilitate an understanding of the relationship and ecological function of the endophytic bacteria associated with M. himalaica and provide valuable information for artificial planting of M. himalaica and identifying and applying functional endophytic bacteria.

Composition and diversity of endophytic bacterial community in seeds of super hybrid rice ‘Shenliangyou 5814’ (Oryza sativa L.) and its parental lines

Super hybrid rice is one of the important research achievements in the field of rice super-high yield breeding in China. Compared with general high-yield rice, the yield potential of super hybrid rice is relatively high, and the average yields per hectare can exceed 10.5 t. This study aimed to study the endophytic bacterial community among a super hybrid rice combination and its parental lines and to reveal the potential relationship and association of endophytic bacteria between rice genotypes and their genetic relevance. In this research, through high-throughput sequencing based on Illumina Hiseq 2500 platform, the seeds of super hybrid rice variety ‘Shenliangyou 5814’ (sample C) and its parental lines ‘Y58S’ (sample M) and ‘C4114’ (sample F) independently cultivated by China were used as plant materials to study their endophytic bacterial structure and diversity. The number of OTUs for sample M, F and C was 327, 288 and 283 respectively, and among them 218 endophytic OTUs coexisted in the 3 samples. Pantoea (18.6–31.1%) was the first dominant groups shared in all three samples, and other dominant shared groups belonged to Methylobacterium (4.48%~17.65%), Sphingomonas (4.0%~11.4%), Rhizobium (5.69–8.78%), Microbacterium (3.85%~9.41%) and Pseudomonas (4.13%~5.68%). Although Principal Coordinates Analysis (PCoA) and Non-metric Multidimensional Scaling (NMDS) analysis showed that there were obvious differences in endophytic bacterial community composition and structure among the 3 samples, the dominant endophytic bacterial genus sample C and its parental lines remained consistency. This study would provide scientific clues for the future research on the vertical transmission of endophytes between rice generations.