Plants are densely colonized by diverse microbial communities. These microbes, which provide important benefit to their host supporting its growth and health, interact with each other and with their ...host plant by exchanging chemical signals, among which volatile organic compounds (VOCs). This review presents some of our current research lines in the field of microbial VOCs, including their bioactivities on both plants and plant pathogens, and the abiotic and biotic factors influencing their emission. Understanding how VOCs emission is regulated in plant-associated microbes is one of the major challenges for both fundamental and translational aspects of this research field.
Members of the fungal genus
(Ascomycota, Hypocreales, Hypocreaceae) are ubiquitous and commonly encountered as soil inhabitants, plant symbionts, saprotrophs, and mycoparasites. Certain species have ...been used to control diverse plant diseases and mitigate negative growth conditions. The versatility of
's interactions mainly relies on their ability to engage in inter- and cross-kingdom interactions. Although
is by far the most extensively studied fungal biocontrol agent (BCA), with a few species already having been commercialized as bio-pesticides or bio-fertilizers, their wide application has been hampered by an unpredictable efficacy under field conditions. Deciphering the dialogues within and across
ecological interactions by identification of involved effectors and their underlying effect is of great value in order to be able to eventually harness
's full potential for plant growth promotion and protection. In this review, we focus on the nature of
interactions with plants and pathogens. Better understanding how
interacts with plants, other microorganisms, and the environment is essential for developing and deploying
-based strategies that increase crop production and protection.
Microbial lifeforms associated with land plants represent a rich source for crop growth- and health-promoting microorganisms and biocontrol agents. Volatile organic compounds (VOCs) produced by the ...plant microbiota have been demonstrated to elicit plant defenses and inhibit the growth and development of numerous plant pathogens. Therefore, these molecules are prospective alternatives to synthetic pesticides and the determination of their bioactivities against plant threats could contribute to the development of control strategies for sustainable agriculture. In our previous study we investigated the inhibitory impact of volatiles emitted by
species isolated from a potato field against the late blight-causing agent
. Besides the well-documented emission of hydrogen cyanide, other
VOCs impeded
mycelial growth and sporangia germination. Current advances in the field support the emerging concept that the microbial volatilome contains unexploited, eco-friendly chemical resources that could help select for efficient biocontrol strategies and lead to a greener chemical disease management in the field.
Bacteria interact with plants in many different ways. In recent years, bacterial production of volatiles has emerged as a novel process by which bacteria modulate plant growth. Exposure to the ...volatiles produced by certain bacterial strains has been shown to lead to up to 5-fold increased plant biomass or to plant death. Despite these drastic growth alterations, the elucidation of the molecules responsible, of the mechanisms of perception by the plant and of the specific metabolic changes induced in planta is still in its infancy. This review summarizes the current knowledge and highlights future lines of research that should increase our knowledge of the volatile-mediated dialog between bacteria and plants.
Late blight caused by
is considered as the most devastating disease of potato and is a re-emerging problem worldwide. Current late blight control practices rely mostly on synthetic fungicides or ...copper-based products, but growing awareness of the negative impact of these compounds on the environment has led to the search for alternative control measures. A collection of
strains isolated from both the rhizosphere and the phyllosphere of potato was recently characterized for
protective effects against
In the present study, we used a leaf disk assay with three different potato cultivars to compare the disease inhibition capacity of nine selected
strains when applied alone or in all possible dual and triple combinations. Results showed a strong cultivar effect and identified strains previously thought to be inactive based on
assays as the best biocontrol candidates. One strain was much more active alone than in combination with other strains, while two other strains provided significantly better protection in dual combination than when applied alone. A subset of five strains was then further selected to determine their mutual influence on each other's survival and growth, as well as to characterize their activity against
in more details. This revealed that the two strains whose dual combination was particularly efficient were only weakly interfering with each other's growth and had complementary modes of action. Our results highlight the potential to harness the crop's native rhizosphere and phyllosphere microbiome through re-assembling strains with differing modes of action into small communities, thereby providing more consistent protection than with the application of single strains. We consider this as a first step toward more elaborate microbiome management efforts, which shall be integrated into global strategies for sustainable control of potato late blight.
Bacteria belonging to the genus Burkholderia are highly versatile with respect to their ecological niches and lifestyles, ranging from nodulating tropical plants to causing melioidosis and fatal ...infections in cystic fibrosis patients. Despite the clinical importance and agronomical relevance of Burkholderia species, information about the factors influencing their occurrence, abundance and diversity in the environment is scarce. Recent findings have demonstrated that pH is the main predictor of soil bacterial diversity and community structure, with the highest diversity observed in neutral pH soils. As many Burkholderia species have been isolated from low pH environments, we hypothesized that acid tolerance may be a general feature of this genus, and pH a good predictor of their occurrence in soils. Using a combination of environmental surveys at trans‐continental and local scales, as well as in vitro assays, we show that, unlike most bacteria, Burkholderia species have a competitive advantage in acidic soils, but are outcompeted in alkaline soils. Physiological assays and diversity analysis based on 16S rRNA clone libraries demonstrate that pH tolerance is a general phenotypic trait of the genus Burkholderia. Our results provide a basis for building a predictive understanding of the biogeographical patterns exhibited by Burkholderia sp.
Airborne medicine Garbeva, Paolina; Weisskopf, Laure
The New phytologist,
04/2020, Letnik:
226, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Like most other eukaryotes, plants do not live alone but in close association with a diverse microflora. These plant-associated microbes contribute to plant health in many different ways, ranging ...from modulation of hormonal pathways to direct antibiosis of plant pathogens. Over the last 15 yr, the importance of volatile organic compounds as mediators of mutualistic interactions between plant-associated bacteria and their hosts has become evident. This review summarizes current knowledge concerning bacterial volatile-mediated plant protection against abiotic and biotic stresses. It then discusses the translational potential of such metabolites or of their emitters for sustainable crop protection, the possible ways to harness this potential, and the major challenges still preventing us from doing so. Finally, the review concludes with highlighting the most pressing scientific gaps that need to be filled in order to enable a better understanding of: the molecular mechanisms underlying the biosynthesis of bacterial volatiles; the complex regulation of bacterial volatile emission in natural communities; the perception of bacterial volatiles by plants; and the modes of actions of bacterial volatiles on their host.
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