Plant Signalling Flashcards
How many years ago did plants move to dry land?
> 450 million years ago
What does sessile mean?
Non-motile have to be able to cope with stress in their environment
What does thigmonasty mean?
An example of plant that follows this?
Response to touch
Mimosa
How does thigmonasty occur?
- Touch > ions flow into outer cells of pulvini
- Upregulation of aquaporin and H+-ATPase (protein pump)
- Turgor increase/decrese due to osmosis
What type of signalling do plants use?
Electrical
Hydraulic
Chemical
How do plants communicate with eachother?
How is it regulated
Plasmodesmata
Callose depositino
What are the components of the plant vascular system?
Xylem (water)
Phloem (sugars)
What are vascular systems important for?
Long distance signalling
What causes guard cells to close?
Signals from drought-stressed roots
What happens when leaves are phosphate-limited?
microRNA (miR399) moves through phloem and promotes phosphate uptake
What is the protein Flowering Locus for?
Promotes plant reproduction
What type of transport allows molecules through the plasmodesmata?
Symplastic transport
What transport allows molecules through the plasma membrane?
Transcellular transport
What transport through extracellular space?
Apoplastic transport
What are the steps in signal perception and transduction in plants?
Perception > Transduction > Response
Can stress perception occur in different organelles?
Yes
What does MAMPs stand for and what are they?
Microbe Associated Molecular Patterns
Conserved molecules in pathogens that can elicit immune responses
How are MAMPs recognised?
Via Pattern Recognition Receptors
-Triggers plant defence responses
What do microbial effectors do?
Suppress the pkant’s imune response and / or contribute to the pathogens visibility
What is a plants secind layer of defense called?
Resistance proteins
What is a plant NLR?
Nucleotide-binding domain and leucine-rich repeat-containing receptor
Give a brief description of the plant innate immune system on exterior of cell
Pathogen > MAMPs > receptors in plants (PRRs) > activation of signalling inside plant cell
What do MAMP/PRR interactions activate?
Immune signalling via ROS
What is ROS?
Antimicrobial activity and stress signalling
How is ROS produced?
PAMP binding triggers phosphorylation of BIK1
Activates the NADPH which then activates NADPH oxidase RBOHD
Triggers ROS production
What pathogens may be present in plant signalling?
Fungi and Oomycetes
Bacteria
Virus
Fungus
What are phytohormones?
Small molecules that regulate the plant life cycle and help plants to cope with stress
What are two important hormones that play a role in plant signalling?
Salicylates
Jasmonates
What does salicylic acid do
Contributes to immunity against specific plant pathogens
What are NahG and NPR1s?
NahG - bacterial enzyme degrading Salycylic acid (SA)
NPR1s- SA receptor
What does SAR do?
Systemic required assistance
Strengthens cells wall
Antimicrobials
What is a key phytohormone for triggering SAR?
Salicylic acid
What is jasmonate receptor?
COI1
What are NINJA and TPL?
co-repressors
