Diversity Utility and Potential of Actinobacteria in the Agro-Ecosystem

Selvakumar, Govindan; Panneerselvam, Periyasamy; Ganeshamurthy, A. N.

doi:10.1007/978-3-319-05936-5_2

Cited by 13 publications

(10 citation statements)

References 111 publications

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“…The microbial production of other growth regulators, such as jasmonic and abscisic acids, can also improve plant performance under stressful soil conditions ( Forchetti et al, 2010 ). In addition, extensive crosstalk exists among different signaling pathways ( Selvakumar et al, 2014 ), leading to the possibility that specific signaling components may integrate inputs from multiple hormones to enhance plant tolerance. Several plant-promoting characteristics, such as ACC deaminase activity and siderophore-mediated iron assimilation, are widely distributed in bacteria and fungi.…”

Section: Discussionmentioning

confidence: 99%

Drought Stress Triggers Shifts in the Root Microbial Community and Alters Functional Categories in the Microbial Gene Pool

et al. 2021

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Drought is a major threat to crop productivity and causes decreased plant growth, poor yields, and crop failure. Nevertheless, the frequency of droughts is expected to increase in the coming decades. The microbial communities associated with crop plants can influence how plants respond to various stresses; hence, microbiome manipulation is fast becoming an effective strategy for improving the stress tolerance of plants. The effect of drought stress on the root microbiome of perennial woody plants is currently poorly understood. Using Populus trees as a model ecosystem, we found that the diversity of the root microbial community decreased during drought treatment and that compositional shifts in microbes during drought stress were driven by the relative abundances of a large number of dominant phyla, including Actinobacteria, Firmicutes, and Proteobacteria. A subset of microbes, including Streptomyces rochei, Bacillus arbutinivorans, B. endophyticus, B. megaterium, Aspergillus terreus, Penicillium raperi, Trichoderma ghanense, Gongronella butleri, and Rhizopus stolonifer, was isolated from the drought-treated poplar rhizosphere soils, which have potentially beneficial to plant fitness. Further controlled inoculation experiments showed that the isolated bacterial and fungal isolates positively impacted plant growth and drought tolerance. Collectively, our results demonstrate the impact of drought on root microbiome structure and provide a novel example of manipulating root microbiomes to improve plant tolerance.

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Section: Discussionmentioning

confidence: 99%

Drought Stress Triggers Shifts in the Root Microbial Community and Alters Functional Categories in the Microbial Gene Pool

et al. 2021

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“…Specific members of the phylum Actinobacteria have also shown considerable potential in agro-environment due to their quorum quenching activity. Several Actinobacteria have the ability to colonize plant surfaces and thereby exclude plant pathogens either by competition or through inhibition by antibiotic production ( Selvakumar et al, 2014 ). Over the last decade, a total of six actinobacterial genera: Arthrobacter ( Flagan et al, 2003 ), Microbacterium ( Wang et al, 2012 ), Mycobacterium ( Chen and Xie, 2011 ), Nocardioides ( Yoon et al, 2006 ), Rhodococcus ( Park et al, 2006 ; Latour et al, 2013 ), and Streptomyces ( Chen and Xie, 2011 ; Ooka et al, 2013 ) have been reported for their quorum quenching activity.…”

Section: Quorum Quenching Activity In Actinobacteriamentioning

confidence: 99%

“…They play a key role in natural geochemical cycles, especially through their ability to decompose organic matter. Actinobacteria are also abundant in the rhizosphere and produce a wide range of biologically active metabolites, thereby influencing plant development ( Selvakumar et al, 2014 ). Many Actinobacteria are also known pathogens of plants and animals.…”

Section: Introductionmentioning

confidence: 99%

Quorum Sensing: An Under-Explored Phenomenon in the Phylum Actinobacteria

et al. 2016

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Quorum sensing is known to play a major role in the regulation of secondary metabolite production, especially, antibiotics, and morphogenesis in the phylum Actinobacteria. Although it is one of the largest bacterial phylum, only 25 of the 342 genera have been reported to use quorum sensing. Of these, only nine have accompanying experimental evidence; the rest are only known through bioinformatic analysis of gene/genome sequences. It is evident that this important communication mechanism is not extensively explored in Actinobacteria. In this review, we summarize the different quorum sensing systems while identifying the limitations of the existing screening strategies and addressing the improvements that have taken place in this field in recent years. The γ-butyrolactone system turned out to be almost exclusively limited to this phylum. In addition, methylenomycin furans, AI-2 and other putative AHL-like signaling molecules are also reported in Actinobacteria. The lack of existing screening systems in detecting minute quantities and of a wider range of signaling molecules was a major reason behind the limited information available on quorum sensing in this phylum. However, recent improvements in screening strategies hold a promising future and are likely to increase the discovery of new signaling molecules. Further, the quorum quenching ability in many Actinobacteria has a great potential in controlling the spread of plant and animal pathogens. A systematic and coordinated effort is required to screen and exploit the enormous potential that quorum sensing in the phylum Actinobacteria has to offer for human benefit.

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“…2018; Araujo et al 2020). Some members are known for their ability to secrete diverse types of metabolites such as antibiotics and extracellular enzymes (Selvakumar et al 2014). The relatively high abundance of Actinobacteria found could be influenced by the timing of the soil sampling before rice sowing.…”

Section: Discussionmentioning

confidence: 99%

“…The relatively high abundance of Actinobacteria found could be influenced by the timing of the soil sampling before rice sowing. The stress imposed during the fallow time after the use of herbicides in the previous pasture or cover crop established conditions of dry soil with a high contribution of organic residues that favored this group (Selvakumar et al 2014; Araujo et al 2020). Firmicutes was the bacterial phylum with the second highest relative abundance (19.9%) but without differences between rotations.…”

Section: Discussionmentioning

confidence: 99%

Microbial community structure in rice, crops, and pastures rotation systems with different intensification levels in the temperate region of Uruguay

Martínez

2021

Preprint

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Rice is an important crop in Uruguay associated mostly with livestock production in a rice and pasture rotation system since the 1920s. However, in recent years there has been interest in intensifying the production in some of these systems to satisfy market demands and increase income. Intensification occurs by augmenting the rice frequency in the rotation, including new crops like sorghum and soybean, or shortening the pasture phase. A long-term experiment was established in 2012 in the main rice producing area of Uruguay with the objective to study the impact of intensification in rice rotations. After the first cycle of rotation soils from seven rotation phases were sampled and microbial communities were studied by means of high-throughput sequencing of Illumina NovaSeq 6000. Archaeal/bacterial and fungal community composition were studied (16S rRNA and 18S gene regions) detecting 3662 and 807 bacterial and fungal Operational Taxonomic Units (OTUs), respectively. Actinobacteria, Firmicutes and Proteobacteria were the most common bacterial phyla. Among them, only Proteobacteria differed significantly between rotations. Although most fungal OTUs were unidentified, Ascomycota, Basidiomycota and Mucoromycota were the most abundant fungal classes within identified taxa. Bacterial communities differed between rotations forming three groups according to the percentage of rice in the system. Fungal communities clustered in four groups, although not well differentiated, and mostly associated with the antecessor crop. Only P and C:N varied between rotations among soil physicochemical variables after six years, and individual bacterial OTUs appeared weakly influenced by P, pH, Mg and fungal OTUs by P. The results suggest that after six years, bacteria/archaeal communities were influenced by the time with rice in the rotation, and fungal communities were more influenced by the antecessor crop. More studies are needed to associate fungal communities with certain rotational or environmental variables. Some taxa were associated with a particular rotation, and some bacterial taxa were identified as biomarkers. Fungal indicator taxa were not identified at the species level for any rotation.

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Diversity Utility and Potential of Actinobacteria in the Agro-Ecosystem

Cited by 13 publications

References 111 publications

Drought Stress Triggers Shifts in the Root Microbial Community and Alters Functional Categories in the Microbial Gene Pool

Drought Stress Triggers Shifts in the Root Microbial Community and Alters Functional Categories in the Microbial Gene Pool

Quorum Sensing: An Under-Explored Phenomenon in the Phylum Actinobacteria

Microbial community structure in rice, crops, and pastures rotation systems with different intensification levels in the temperate region of Uruguay

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