Plant growth-promoting and non-promoting rhizobacteria from avocado trees differentially emit volatiles that influence growth of Arabidopsis thaliana

Although not fully understood, molecular communication in the rhizosphere plays an important role regulating traits involved in plant–bacteria association. Burkholderia phytofirmans PsJN is a well-known plant-growth-promoting bacterium, which establishes rhizospheric and endophytic colonization in different plants. A competent colonization is essential for plant-growth-promoting effects produced by bacteria. Using appropriate mutant strains of B. phytofirmans, we obtained evidence for the importance of N-acyl homoserine lactone-mediated (quorum sensing) cell-to-cell communication in efficient colonization of Arabidopsis thaliana plants and the establishment of a beneficial interaction. We also observed that bacterial degradation of the auxin indole-3-acetic acid (IAA) plays a key role in plant-growth-promoting traits and is necessary for efficient rhizosphere colonization. Wildtype B. phytofirmans but not the iacC mutant in IAA mineralization is able to restore promotion effects in roots of A. thaliana in the presence of exogenously added IAA, indicating the importance of this trait for promoting primary root length. Using a transgenic A. thaliana line with suppressed auxin signaling (miR393) and analyzing the expression of auxin receptors in wild-type inoculated plants, we provide evidence that auxin signaling in plants is necessary for the growth promotion effects produced by B. phytofirmans. The interplay between ethylene and auxin signaling was also confirmed by the response of the plant to a 1-aminocyclopropane-1-carboxylate deaminase bacterial mutant strain.

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The Plant Growth-Promoting Fungus Penicillium simplicissimum GP17-2 Induces Resistance in Arabidopsis thaliana by Activation of Multiple Defense Signals

Plant and Cell Physiology ◽

10.1093/pcp/pcm144 ◽

2007 ◽

Vol 48 (12) ◽

pp. 1724-1736 ◽

Cited By ~ 99

Author(s):

Md. M. Hossain ◽

F. Sultana ◽

M. Kubota ◽

H. Koyama ◽

M. Hyakumachi

Keyword(s):

Arabidopsis Thaliana ◽

Plant Growth ◽

Penicillium Simplicissimum ◽

Plant Growth Promoting ◽

Growth Promoting

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Characterization of Selected Plant Growth-Promoting Rhizobacteria and Their Non-Host Growth Promotion Effects

Microbiology Spectrum ◽

10.1128/spectrum.00279-21 ◽

2021 ◽

Author(s):

Di Fan ◽

Donald L. Smith

Keyword(s):

Arabidopsis Thaliana ◽

Plant Growth ◽

Plant Growth Promotion ◽

Growth Promotion ◽

Plant Growth Promoting Rhizobacteria ◽

Content Type ◽

Host Growth ◽

Plant Growth Promoting ◽

Growth Promoting

There are pressing needs to reduce the use of agrochemicals, and PGPR are receiving increasing interest in plant growth promotion and disease protection. This study follows up our previous report that the four newly isolated rhizobacteria promote the growth of Arabidopsis thaliana .

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Plantibacter flavus, Curtobacterium herbarum, Paenibacillus taichungensis, and Rhizobium selenitireducens Endophytes Provide Host-Specific Growth Promotion of Arabidopsis thaliana, Basil, Lettuce, and Bok Choy Plants

Applied and Environmental Microbiology ◽

10.1128/aem.00383-19 ◽

2019 ◽

Vol 85 (19) ◽

Cited By ~ 2

Author(s):

Evan Mayer ◽

Patricia Dörr de Quadros ◽

Roberta Fulthorpe

Keyword(s):

Arabidopsis Thaliana ◽

Plant Growth ◽

Root Growth ◽

Plant Growth Promotion ◽

Growth Promotion ◽

Plant Growth Promoting Bacteria ◽

Bacterial Endophytes ◽

Content Type ◽

Plant Growth Promoting ◽

Growth Promoting

ABSTRACT A collection of bacterial endophytes isolated from stem tissues of plants growing in soils highly contaminated with petroleum hydrocarbons were screened for plant growth-promoting capabilities. Twenty-seven endophytic isolates significantly improved the growth of Arabidopsis thaliana plants in comparison to that of uninoculated control plants. The five most beneficial isolates, one strain each of Curtobacterium herbarum, Paenibacillus taichungensis, and Rhizobium selenitireducens and two strains of Plantibacter flavus were further examined for growth promotion in Arabidopsis, lettuce, basil, and bok choy plants. Host-specific plant growth promotion was observed when plants were inoculated with the five bacterial strains. P. flavus strain M251 increased the total biomass and total root length of Arabidopsis plants by 4.7 and 5.8 times, respectively, over that of control plants and improved lettuce and basil root growth, while P. flavus strain M259 promoted Arabidopsis shoot and root growth, lettuce and basil root growth, and bok choy shoot growth. A genome comparison between P. flavus strains M251 and M259 showed that both genomes contain up to 70 actinobacterial putative plant-associated genes and genes involved in known plant-beneficial pathways, such as those for auxin and cytokinin biosynthesis and 1-aminocyclopropane-1-carboxylate deaminase production. This study provides evidence of direct plant growth promotion by Plantibacter flavus. IMPORTANCE The discovery of new plant growth-promoting bacteria is necessary for the continued development of biofertilizers, which are environmentally friendly and cost-efficient alternatives to conventional chemical fertilizers. Biofertilizer effects on plant growth can be inconsistent due to the complexity of plant-microbe interactions, as the same bacteria can be beneficial to the growth of some plant species and neutral or detrimental to others. We examined a set of bacterial endophytes isolated from plants growing in a unique petroleum-contaminated environment to discover plant growth-promoting bacteria. We show that strains of Plantibacter flavus exhibit strain-specific plant growth-promoting effects on four different plant species.

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Arabidopsis thaliana: a model for studies of colonization by non-pathogenic and plant-growth-promoting rhizobacteria

Functional Plant Biology ◽

10.1071/pp01048 ◽

2001 ◽

Vol 28 (9) ◽

pp. 975

Author(s):

Kenneth J. O'Callaghan ◽

Richard A. Dixon ◽

Edward C. Cocking

Keyword(s):

Arabidopsis Thaliana ◽

Plant Growth ◽

Stress Responses ◽

Plant Defence ◽

Plant Growth Promoting Rhizobacteria ◽

Molecular Data ◽

Flavonoid Metabolism ◽

Plant Growth Promoting ◽

Plant Genes ◽

Growth Promoting

This paper originates from an address at the 8th International Symposium on Nitrogen Fixation with Non-Legumes, Sydney, NSW, December 2000 Arabidopsis thaliana L. has many features favoring its use as a model in studies of plant-growth-promoting rhizobacteria (PGPR), such as diazotrophs. Several niches are colonized in the root system of Arabidopsis, including xylem, and intact colonized roots can be observed microscopically without sectioning of tissues. Studies of plant genes involved in colonization are facilitated by the ease with which plants are transformed and by the availability of mutant lines and other accessions obtainable from stock centers. Lines of Arabidopsis carrying reporter gene fusions are helping to reveal the pattern of expression of previously cloned plant genes induced by rhizobacteria. Studies utilizing indole-3-acetic acid (IAA)-producing PGPR and Arabidopsis that contain an auxin-responsive GUS fusion suggest that plants perceive IAA released by bacteria in the rhizosphere. The role of flavonoids in the colonization of non-legumes is being assessed using transgenic Arabidopsis with altered flavonoid metabolism and using tt mutants, which lack functional versions of specific genes for flavonoid metabolism. Studies of plant defence and of stress responses are producing molecular data on plant genes induced by inoculation of Arabidopsis roots with non-pathogens.

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