Effects of growth stage and fulvic acid on the diversity and dynamics of endophytic bacterial community in Stevia rebaudiana Bertoni leaves

Abstract

The aim of this study was to learn the interactions among the endophytic bacteria, the plant growth, the foliar spray of fulvic acid, and the accumulation of steviol glycosides in the leaves of Stevia rebaudiana. Metagenomic DNA was extracted from the Stevia leaves at different growth stages with or without the fulvic acid treatment; and the diversity of endophytic bacteria in Stevia leaves was estimated by pyrosequencing of 16S rRNA genes. As results, Proteobacteria, Actinobacteria, Bacteroidetes, and Firmicutes were found to be the dominant phyla despite the growth stages and fulvic acid application. Stevia growth stages strongly regulated composition of endophytic community. The genera Agrobacterium (12.3%) and Erwinia (7.2%) dominated in seedling stage were apparently declined in the vegetable and initial flowering stages, while Sphingomonas and Methylobacterium increased in mature leaves at harvest time, which showed that the mature leaves of Stevia preferred to accumulate some certain endophytic bacteria. Sphingomonas and Methylobacterium constituted an important part of the core endophytic community and were positively correlated with the stevioside content and UGT74G1 gene expression, respectively; while Erwinia, Agrobacterium, and Bacillus were negatively correlated with the stevioside accumulation. Fulvic acid treatment accelerated the variation of endophytes along the growth stages and increased the steviol glycosides content. This is the first study to reveal the community composition of endophytic bacteria in the Stevia leaves, to evidence the strong effects of growth stage and fulvic acid application on the endophytes of Stevia, and to demonstrate the correlation between the endophytic bacteria and the steviol glycosides accumulation.

Temporal dynamics of microbial communities in microcosms in response to pollutants

“…The microbial communities were profiled by targeting the V4‐V5 hypervariable regions of the 16S rRNA gene (Yu et al . ) using the Illumina MiSeq (250‐bp paired‐end reads) platform at Macrogen Inc. (Seoul, South Korea; http://www.macrogen.com) as described previously (Jiao et al . ).…”

Inner Plant Values: Diversity, Colonization and Benefits from Endophytic Bacteria

“…Soil that harbors an immensely rich pool of bacterial species is the microbial ‘seed bank’ for roots, and its properties may affect plant physiology and root exudation profiles which in turn profoundly influence the structure of the root endosphere microbiome ( Philippot et al, 2013 ). Studies performed on the endosphere microbiome of different plants, using high-throughput amplicon sequencing, have revealed that host plant species ( Shen and Fulthorpe, 2015 ; Ding and Melcher, 2016 ), genotype ( Marques et al, 2015 ; Rodriguez-Blanco et al, 2015 ), plant organ type ( Hameed et al, 2015 ), developmental stage (e.g., seedling or mature plant) ( Ren et al, 2015a ; Yu et al, 2015 ; de Almeida Lopes et al, 2016 ), growing season (e.g., of trees) ( Shen and Fulthorpe, 2015 ; Ding and Melcher, 2016 ), geographical location (field conditions) ( Edwards et al, 2015 ), soil type ( Edwards et al, 2015 ), host plant nutrient status ( Hameed et al, 2015 ), cultivation practice ( Edwards et al, 2015 ) and fertilization ( Rodriguez-Blanco et al, 2015 ) are among the observed factors that significantly influence the plant endosphere microbiome.…”

Comparison of specific endophytic bacterial communities in different developmental stages of Passiflora incarnata using culture‐dependent and culture‐independent analysis

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