Plant Microbiome and Its Link to Plant Health: Host Species, Organs and Pseudomonas syringae pv. actinidiae Infection Shaping Bacterial Phyllosphere Communities of Kiwifruit Plants

Abstract

Pseudomonas syringae pv. actinidiae (Psa) is the causal agent of the bacterial canker, the most devastating disease of kiwifruit vines. Before entering the host tissues, this pathogen has an epiphytic growth phase on kiwifruit flowers and leaves, thus the ecological interactions within epiphytic bacterial community may greatly influence the onset of the infection process. The bacterial community associated to the two most important cultivated kiwifruit species, Actinidia chinensis and Actinidia deliciosa, was described both on flowers and leaves using Illumina massive parallel sequencing of the V3 and V4 variable regions of the 16S rRNA gene. In addition, the effect of plant infection by Psa on the epiphytic bacterial community structure and biodiversity was investigated. Psa infection affected the phyllosphere microbiome structures in both species, however, its impact was more pronounced on A. deliciosa leaves, where a drastic drop in microbial biodiversity was observed. Furthermore, we also showed that Psa was always present in syndemic association with Pseudomonas syringae pv. syringae and Pseudomonas viridiflava, two other kiwifruit pathogens, suggesting the establishment of a pathogenic consortium leading to a higher pathogenesis capacity. Finally, the analyses of the dynamics of bacterial populations provided useful information for the screening and selection of potential biocontrol agents against Psa.

Pseudomonas syringae pv. actinidiae: Ecology, Infection Dynamics and Disease Epidemiology

“…syringae. The synergistic copresence of two pathovars has been previously observed [73], suggesting that, in nature, they may be active as a pathogenic consortium rather than independent pathogens.…”

First Insights into the Microbiome of a Mangrove Tree Reveal Significant Differences in Taxonomic and Functional Composition among Plant and Soil Compartments

“…Mangrove forests are also rich sources of honey, and diverse medicinal, cosmetic, and other products [2,3]. In addition, they now attract many eco-tourists, anglers, and birdwatchers, thus contributing to incomes of countries with coastal mangroves [2,3] Plants microbiomes play crucial roles in their health and productivity [4]. Many researchers have successfully applied knowledge acquired about plant microbiomes to produce specific inocula for crop protection [5,6].…”

“…Such inocula can stimulate plant growth by releasing phytohormones and enhancing uptake of some mineral nutrients (particularly phosphorus and nitrogen) [6][7][8]. However, most of the plant microbiome studies have focused on the model plant Arabidopsis thaliana and economically important crop plants, such as barley (Hordeum vulgare), corn (Zea mays), soybean (Glycine max), rice (Oryza sativa), and wheat (Triticum aestivum), but there is less information on microbiomes of tree species [4,6]. Plant microbiomes are determined by plant-related factors (e.g., genotype, organ, species, and health status) and environmental factors (e.g., land use, climate, and nutrient availability) [4,8].…”

“…However, most of the plant microbiome studies have focused on the model plant Arabidopsis thaliana and economically important crop plants, such as barley (Hordeum vulgare), corn (Zea mays), soybean (Glycine max), rice (Oryza sativa), and wheat (Triticum aestivum), but there is less information on microbiomes of tree species [4,6]. Plant microbiomes are determined by plant-related factors (e.g., genotype, organ, species, and health status) and environmental factors (e.g., land use, climate, and nutrient availability) [4,8]. Two of the plant-related factors, plant species and genotypes, have been shown to play significant roles in shaping rhizosphere and plant microbiomes, as tree genotypes and species are associated with specific microbial communities [7].…”

WITHDRAWN: Genotype-Dependent Recruitment of the Strawberry Holobiome

“…Several studies suggest that biological control agents isolated from the microbiome of the host plant have a superior e cacy in comparison to non-indigenous microbial inoculants [27][28][29] . Thus, the characterization of the native microbiome is a key step for the successful selection of bene cial microorganisms against plant diseases 1 . Unfortunately, the complete microbiome of cultivated strawberry has not yet been described, hindering the identi cation and selection of the most effective indigenous microorganisms to improve plant tness and fruit quality and/or provide resistance to biotic and abiotic stresses.…”