TC - Plant Microbiome Above Ground II Flashcards
What are the tools for studying seed microbiomes? (7)
- Cultivable Microorganisms
- DNA Metabarcoding
- Metagenomics
- Metatranscriptomics
- Metaproteomics
- Microscopic Visualization of Seed Endophytes
- Seed Activation & Sterilization Process
What is the focus of Cultivable Microorganisms in studying seed microbiomes? (3)
- Deep functional characterisation
- Limited to culturable microorganisms
- Direct application for biotechnological capabilities
What does DNA Metabarcoding provide? (3)
- Routine assessment of complex microbial communities
- Detailed descriptions of community structure
- No functional information
What insights does Metagenomics reveal? (3)
- Genes present in the microbial community
- Partial reconstruction of community structure
- Involves multiple genomes (Genome 1, 2, etc.)
What is the purpose of Metatranscriptomics? (2)
- Focuses on actively expressed microbial genes
- Analyzes only living cells
What are the advantages of Microscopic Visualization of Seed Endophytes? (3)
- High-resolution observation of all cells
- Avoids cultivation restrictions and PCR biases
- Validates molecular analyses and explores plant-microbe interactions
What is the sterilization process used in seed activation? (2)
- NaClO + EtOH (sodium hypochlorite + ethanol)
- Soaking seeds before analysis
How do plants assemble their seed microbiome? (4)
Researchers have not entirely resolved the details about how plants assemble their seed microbiomes.
What is known is that:
- There is a link between plant genetics and the seed microbiome.
- Gram-negative bacteria such as Pseudomonas spp., Pantoea spp., etc. prevail in most plant species
- Plants can use microorganisms from soils they are grown in to equip their seeds
- Pollinators play a certain role in shaping the seed microbiome
What is the diversity of seed-associated microorganisms across plant species? (3)
- All studied plants contain tens to hundreds of species
- Significant variation in seed-endophytic microbial communities
Example: Tomato exhibits greater diversity compared to others
How do bacterial and fungal communities differ in plant seeds?
Most studied plant species harbor more diverse bacterial communities than fungal ones
How does the seed microbiota support plants? (3)
- Protects from biotic and abiotic stress
- Supports seed germination
- Improves overall plant fitness and growth
How does Sphingomonas melonis protect rice seeds against a phytopathogenic bacterium? (5)
Protects against the harmful pathogen Burkholderia plantarii.
- Provide resistance to this destructive pathogen.
- It also reduces levels of the pathogen’s toxin, tropolone, which is hepatotoxic and a potential carcinogen.
- Produces anthranilic acid, which disrupts the virulence signals of B. plantarii, making the pathogen harmless.
Sphingomonas melonis was isolated and enriched to protect rice plants that lack it in their seeds.
How does Pantoea deleyi protect barnyard grass from herbicides? (4)
- Acts as a seed endophyte that protects against herbicide effects
- Accumulates in seeds after G4 and G5 generations of herbicide exposure
- Reprograms the plant’s transcriptome
- Increases expression of cytochrome P450 monooxygenase and glutathione transferase genes, which inactivate herbicides
How does growing plants in sterile soil affect seed microbiome diversity and plant fitness? (3)
- Growing plants in sterile soil over generations (G0 to G3) leads to a decline in seed microbiome diversity
- It negatively impacts plant phenotype (health and development).
- This reduction results in decreased plant fitness, manifested as smaller, weaker plants with reduced biomass.
