Changes of Root Endophytic Bacterial Community Along a Chronosequence of Intensively Managed Lei Bamboo (Phyllostachys praecox) Forests in Subtropical China.

Xiaoping Zhang,Xing Wen,Chuanbao Yang,Guibin Gao,Fangyuan Bian,Xuhua Du,Xu Gai,Zheke Zhong

doi:10.3390/microorganisms7120616

Xiaoping Zhang, Xing Wen + Show 6 more

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https://doi.org/10.3390/microorganisms7120616

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Journal: Microorganisms	Publication Date: Nov 26, 2019
Citations: 10	License type: CC BY 4.0

Affiliation: China National Bamboo Research Center

Abstract

Endophytic bacteria widely exist inside plant tissues and have an important role in plant growth and development and the alleviation of environmental stress. However, little is known about the response of root-associated bacterial endophytes of Lei bamboo (Phyllostachys praecox) to intensive management, which is a common management practice for high bamboo shoot production in subtropical China. In this study, we comparatively investigated the root endophytic bacterial community structures in a chronosequence of intensively managed (5a, 10a, 15a, and 20a) and extensively managed plantations (as control, Con). The results showed that endophytic Proteobacteria was the dominant bacterial phylum in the bamboo roots. Intensive management significantly increased (p < 0.05) the bacterial observed species and Chao1 (except 5a) indices associated with bamboo roots. The relative abundances of Firmicutes, Bacteroidetes, and Actinobacteria (except 15a) in the intensively managed bamboo roots significantly increased (p < 0.05) compared with those in Con, while the relative abundance of Proteobacteria significantly decreased in intensively managed bamboo roots (p < 0.05). The phyla Proteobacteria, Actinobacteria, Bacteroidetes, and Firmicutes were the biomarkers in Con, 5a, 15a, and 20a, respectively. Redundancy analysis (RDA) showed that soil alkali-hydrolysable N (AN), available phosphorus (AP), available K (AK), and total organic carbon (TOC) were significantly correlated (p < 0.05) with the bacterial community compositions. Our results suggest that the root endophytic microbiome of Lei bamboo was markedly influenced by intensive management practices, and the available nutrient status could be the main driving factor for such shifts. Although heavy fertilization in the intensive management system increased the diversity indices, the rapid changes in root endophyte communities and their relevant functions might indicate a high risk for sustainable management.

Highlights

The plant-associated microbiome plays an important role in plant health and productivity [1] and has attracted substantial attention from researchers in recent years [2,3,4]
The results showed that the relative abundances of Firmicutes and Bacteroidetes significantly increased (p < 0.05), while the relative abundance of Proteobacteria significantly decreased (p < 0.05) in intensive management roots compared with Con roots
The results revealed that the two principal components explained 61.40% of the variability in the bacterial comMmicruoonrgitayni,smasn2d019t,h7,e6r1e6 was a significant difference in the bacterial community composition7 sof 12 (ANOSIM, p = 0.001)

Summary

Introduction

The plant-associated microbiome plays an important role in plant health and productivity [1] and has attracted substantial attention from researchers in recent years [2,3,4]. Endophytes are typically defined as microorganisms inhabiting inner plant tissues without harming the host or eliciting strong defense responses [5,6]. Numerous studies have shown that endophytes have beneficial effects on plants, such as providing nutrients, stress tolerance, and pathogen and disease resistance [7,8,9]. Endophytes are applied for contaminant degradation [10,11] and phytoremediation [12,13]. Due to these important roles, endophytes have immense potential for sustainable agriculture [14,15,16]. Researchers have found that root-associated endophytic communities are affected by environmental perturbances caused by different agriculture management practices, and the interaction between the changes in endophytes and management practices could be crucial for sustainable management and C sequestration [17,18,19,20]

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