Novel Pseudomonas sp. SCA7 Promotes Plant Growth in Two Plant Families and Induces Systemic Resistance in Arabidopsis thaliana

• Published in: Frontiers in microbiology Vol. 13
• Main Authors: Kuhl-Nagel, Theresa, Rodriguez, Patricia Antonia, Gantner, Isabella, Chowdhury, Soumitra Paul, Schwehn, Patrick, Rosenkranz, Maaria, Weber, Baris, Schnitzler, Jörg-Peter, Kublik, Susanne, Schloter, Michael, Rothballer, Michael, Falter-Braun, Pascal
• Format: Journal Article
• Language: English
• Published: Frontiers Media S.A 27-06-2022
• Subjects: Arabidopsis thaliana; biocontrol; Microbiology; PGPB; plant-microbe interactions; Pseudomonas; Triticum aestivum L
• ISSN: 1664-302X; 1664-302X
• DOI: 10.3389/fmicb.2022.923515

Pseudomonas
sp. SCA7, characterized in this study, was isolated from roots of the bread wheat
Triticum aestivum
. Sequencing and annotation of the complete SCA7 genome revealed that it represents a potential new
Pseudomonas
sp. with a remarkable repertoire of plant beneficial functions.
In vitro
and
in planta
experiments with the reference dicot plant
A. thaliana
and the original monocot host
T. aestivum
were conducted to identify the functional properties of SCA7. The isolate was able to colonize roots, modify root architecture, and promote growth in
A. thaliana
. Moreover, the isolate increased plant fresh weight in
T. aestivum
under unchallenged conditions. Gene expression analysis of SCA7-inoculated
A. thaliana
indicated a role of SCA7 in nutrient uptake and priming of plants. Moreover, confrontational assays of SCA7 with fungal and bacterial plant pathogens revealed growth restriction of the pathogens by SCA7 in direct as well as indirect contact. The latter indicated involvement of microbial volatile organic compounds (mVOCs) in this interaction. Gas chromatography-mass spectrometry (GC-MS) analyses revealed 1-undecene as the major mVOC, and octanal and 1,4-undecadiene as minor abundant compounds in the emission pattern of SCA7. Additionally, SCA7 enhanced resistance of
A. thaliana
against infection with the plant pathogen
Pseudomonas syringae pv. tomato
DC3000. In line with these results, SA- and JA/ET-related gene expression in
A. thaliana
during infection with
Pst
DC3000 was upregulated upon treatment with SCA7, indicating the ability of SCA7 to induce systemic resistance. The thorough characterization of the novel
Pseudomonas
sp. SCA7 showed a remarkable genomic and functional potential of plant beneficial traits, rendering it a promising candidate for application as a biocontrol or a biostimulation agent.