Plant Signalling

Question 1

How many years ago did plants move to dry land?

Answer 1

> 450 million years ago

Question 2

What does sessile mean?

Answer 2

Non-motile have to be able to cope with stress in their environment

Question 3

What does thigmonasty mean?

An example of plant that follows this?

Answer 3

Response to touch

Mimosa

Question 4

How does thigmonasty occur?

Answer 4

• Touch > ions flow into outer cells of pulvini
• Upregulation of aquaporin and H+-ATPase (protein pump)
• Turgor increase/decrese due to osmosis

Question 5

What type of signalling do plants use?

Answer 5

Electrical
Hydraulic
Chemical

Question 6

How do plants communicate with eachother?

How is it regulated

Answer 6

Plasmodesmata

Callose depositino

Question 7

What are the components of the plant vascular system?

Answer 7

Xylem (water)

Phloem (sugars)

Question 8

What are vascular systems important for?

Answer 8

Long distance signalling

Question 9

What causes guard cells to close?

Answer 9

Signals from drought-stressed roots

Question 10

What happens when leaves are phosphate-limited?

Answer 10

microRNA (miR399) moves through phloem and promotes phosphate uptake

Question 11

What is the protein Flowering Locus for?

Answer 11

Promotes plant reproduction

Question 12

What type of transport allows molecules through the plasmodesmata?

Answer 12

Symplastic transport

Question 13

What transport allows molecules through the plasma membrane?

Answer 13

Transcellular transport

Question 14

What transport through extracellular space?

Answer 14

Apoplastic transport

Question 15

What are the steps in signal perception and transduction in plants?

Answer 15

Perception > Transduction > Response

Question 16

Can stress perception occur in different organelles?

Answer 16

Yes

Question 17

What does MAMPs stand for and what are they?

Answer 17

Microbe Associated Molecular Patterns

Conserved molecules in pathogens that can elicit immune responses

Question 18

How are MAMPs recognised?

Answer 18

Via Pattern Recognition Receptors

-Triggers plant defence responses

Question 19

What do microbial effectors do?

Answer 19

Suppress the pkant’s imune response and / or contribute to the pathogens visibility

Question 20

What is a plants secind layer of defense called?

Answer 20

Resistance proteins

Question 21

What is a plant NLR?

Answer 21

Nucleotide-binding domain and leucine-rich repeat-containing receptor

Question 22

Give a brief description of the plant innate immune system on exterior of cell

Answer 22

Pathogen > MAMPs > receptors in plants (PRRs) > activation of signalling inside plant cell

Question 23

What do MAMP/PRR interactions activate?

Answer 23

Immune signalling via ROS

Question 24

What is ROS?

Answer 24

Antimicrobial activity and stress signalling

Question 25

How is ROS produced?

Answer 25

PAMP binding triggers phosphorylation of BIK1
Activates the NADPH which then activates NADPH oxidase RBOHD
Triggers ROS production

Question 26

What pathogens may be present in plant signalling?

Answer 26

Fungi and Oomycetes
Bacteria
Virus
Fungus

Question 27

What are phytohormones?

Answer 27

Small molecules that regulate the plant life cycle and help plants to cope with stress

Question 28

What are two important hormones that play a role in plant signalling?

Answer 28

Salicylates

Jasmonates

Question 29

What does salicylic acid do

Answer 29

Contributes to immunity against specific plant pathogens

Question 30

What are NahG and NPR1s?

Answer 30

NahG - bacterial enzyme degrading Salycylic acid (SA)

NPR1s- SA receptor

Question 31

What does SAR do?

Answer 31

Systemic required assistance

Strengthens cells wall
Antimicrobials

Question 32

What is a key phytohormone for triggering SAR?

Answer 32

Salicylic acid

Question 33

What is jasmonate receptor?

Answer 33

COI1

Question 34

What are NINJA and TPL?

Answer 34

co-repressors