The Nitty Gritty Of Receptors

Question 1

How do we find receptor proteins for PAMPS?

Answer 1

By searching for mutant plants that cannot respond to PAMPs

Question 2

What is Flagellin?

Answer 2

a receptor protein that reacts to a bacterial PAMP?

Question 3

How is Flg encoded?

Answer 3

By an amino acid sequence of 22. Its called flg22

Question 4

how is FLG22 recognized?

Answer 4

• a mutant that carries a mutagene in FLS2 (a protein in the plasma mmembrane) doesn‘t activate defences when treated with Flg22

-FLS2 contains a lot of Leucine ( Leucine rich repeat LRR) -> this is the part that binds Flg22

Question 5

What is a LRR?

Answer 5

• Leucine rich repeat

-Commonly found in proteins involved in defence against pathogens

Question 6

Where are most resistance Proteins containing a LRR domain located?

Answer 6

Intracellular, facing the inside of the cell

(Cf is extracellular -> a resistance protein in tomato plants)

Question 7

What is a TIR domain?

Answer 7

Toll/interleukin 1 receptor domain

A domain similar to the LRR domain that is commonly found in animals but also plants

Question 8

What are Trichomes?

Answer 8

-Little hairs on the plants surface
-they can stop animals from walking on the leaf surface
-if these trichomes are ruptured by movement, the plant detects it and triggers defences

Question 9

How are animals that eat a leaf detected?

Answer 9

The eating generates vibrations -> these vibrations will be transmitted to the other parts of the plant and defences are activated

Question 10

Can plants detect these vibrations without an animal chewing on it?

Answer 10

Yes! If the plants detect these vibrations, defence mechanisms are applied - it can distinguish between these and vibrations caused by wind etc.

Question 11

What do insects leave behind on a plant?

Answer 11

Saliva and regurgitation this helps the plant to recognize them but can also stop defence mechanisms

Question 12

Why do insects regurgigate on plants?

Answer 12

The secretion contains compounds that are capable of supressing plant defences

Question 13

What is damaged self recognition?

Answer 13

The ability of a plant to detect parts of it that are outside of their usual compartments

Question 14

What are HAMPs?

Answer 14

Herbivore associated molecular PatternS

Question 15

What contains HAMPS in insects?

Answer 15

Spit or regurgant

Question 16

What happens to leaves treated with saliva from larvae

Answer 16

They contained less ATP than untreated leaves

The saliva contains enzymes that can degrade ATP (ATP hydrolysing enzymes) -> they are effectors and can suppress plants defences

Question 17

How does the tomato plant protect itself against herbivores?

Answer 17

When an insect is feeding on it, a danger signal is produced in the tissue damaged and in the remote ones. This accumilates proteinase inhibitors (systemin) which prevent the insects from digesting proteins in their diet..

Question 18

How does systemin travel

Answer 18

Through the phloem

Question 19

What does the systemin receptor look like in tomato plants?

Answer 19

It has a LRR domain similar to the r Proteins recognizing PAMPs

Question 20

What are Peps?

Answer 20

Plant elicitor peptides

Question 21

Where are LRR domains found?

Answer 21

In receptors whose job is to detect peptide DAMPS and more

Question 22

How does a plant recognize eggs on its surface?

Answer 22

By the secretions on top of the eggs

Question 23

How do plants respond to eggs?

Answer 23

Similar as to microbes.

Question 24

How do you call the fact that when a plant cell is attacked, the surrounding cells also activate defence

Answer 24

Systemic resistance

Question 25

How does systemic resistance work?

Answer 25

The distant plant tissues are put on alert rather than already getting resistant