week 8 - what happens after perception

Question 1

what are phytohormones

Answer 1

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

Question 2

how do hormones move in plants

Answer 2

through xylem or phloem

across cellular membranes

through regulated transport proteins

Question 3

hormone receptors in plants can be

Answer 3

membrane bound or soluble

Question 4

role of salicylic acid in plants

Answer 4

SA contributes to immunity against specific plant pathogens

SA regulates immune signalling through NPR1

Question 5

what does SA trigger

Answer 5

SA is a key signalling phytohormone for triggering SAR

Question 6

triggering SAR steps

Answer 6

1. binding of a pathogen to plasma membrane induces a signal transduction pathway (STP)
2. the STP causes a hypersensitive response (HR) which kills infected plant cells. before they die, they release antimicrobial molecules
3. dying cells release SA, which is transported throughout the plant
4. in healthy cells, SA induces a STP that produces antimicrobial molecules, preventing further infection. this response is known as a systemic acquired resistance (SAR)

Question 7

what happens during systemic acquired resistance (SAR)

Answer 7

strengthening of the cell wall

antimicrobials (phytoalexins, chitinases, PR proteins)