Investigations into the mechanisms of activation of the MrRUN1 and - - PowerPoint PPT Presentation

▶
investigations into the mechanisms of activation of the
SMART_READER_LITE
LIVE PREVIEW

Investigations into the mechanisms of activation of the MrRUN1 and - - PowerPoint PPT Presentation

Nov 06, 2023 310 likes •511 views

Investigations into the mechanisms of activation of the MrRUN1 and MrRPV1 resistance proteins and the signal transduction pathways leading to resistance to grapevine powdery and downy mildew Ian Dry, Ling Yin, Laura Davies, Junjie Qu, XinLong Li,

slide-1
SLIDE 1

Ian Dry, Ling Yin, Laura Davies, Junjie Qu, XinLong Li, Hayden Burdett, Simon Williams, Jiang Lu & Bostjan Kobe

CSIRO Agriculture & Food

Investigations into the mechanisms of activation of the MrRUN1 and MrRPV1 resistance proteins and the signal transduction pathways leading to resistance to grapevine powdery and downy mildew

slide-2
SLIDE 2

Tempranillo + MrRPV1 Tempranillo Portan Portan + MrRUN1

slide-3
SLIDE 3

MrRUN1 & MrRPV1 encode TIR-NB-LRR proteins

TIR NB LRR

Signal transduction ATP hydrolysis Effector recognition

Current model of TIR-NB-LRR activation (based on L6 rust resistance protein)

ADP bound “OFF” ATP bound “ON” effector

Immune responses TIR self-association Signaling partner(s) recruitment Activation Resting Immune responses

TIR = Toll/Interleukin receptor domain NB = Nucleotide-binding domain LRR = Leucine-rich repeat domain

slide-4
SLIDE 4

MrRUN1 & MrRPV1 encode TIR-NB-LRR proteins

TIR NB LRR

Signal transduction ATP hydrolysis Effector recognition

Current model of TIR-NB-LRR activation (based on L6 rust resistance protein)

ADP bound “OFF” ATP bound “ON” effector

Activation Resting

slide-5
SLIDE 5

MrRUN1 & MrRPV1 encode TIR-NB-LRR proteins

TIR NB LRR

Signal transduction ATP hydrolysis Effector recognition

Current model of TIR-NB-LRR activation (based on L6 rust resistance protein)

ADP bound “OFF” ATP bound “ON” effector

Immune responses TIR self-association Signaling partner(s) recruitment Activation Resting Immune responses

slide-6
SLIDE 6

MrRPV1:MrRUN1-LRR

NB LRR TIR

MrRUN1:MrRPV1-LRR

NB LRR TIR

Transgenics recovered

LRR domain is involved in pathogen effector recognition

10 20 30 40 50 60 70

% PCD in penetrated cells

Powdery mildew inoculation

% Sporulation

20 40 60 80 100

Downy mildew inoculation

slide-7
SLIDE 7

MrRUN1 & MrRPV1 encode TIR-NB-LRR proteins

TIR NB LRR

Signal transduction Effector recognition

Current model of TIR-NB-LRR activation (based on L6 rust resistance protein)

ADP bound “OFF” ATP bound “ON” effector

Immune responses TIR self-association Signaling partner(s) recruitment Activation Resting Immune responses

?

slide-8
SLIDE 8

MrRGA2-TIR:YFP

  • N. tabacum cv. White Burley – 5 dpi

MrRPV1-TIR MrRPV1-TIR:YFP Agro only MrRPV1-Full Length

TIR NB LRR TIR TIR YFP

The TIR domain induces cell death in tobacco

slide-9
SLIDE 9

Crystal structure of MrRUN1 and MrRPV1 TIR domains reveals a conserved dimeric interface

αAE Interface

αA αE αA αE

slide-10
SLIDE 10

αA αA αE αE

H42 H42 D41 D41 E170 E170 S171 S171

MrRPV1

D41-S171 & H42-E170

αA αA αE αE

H45 H45 D44 D44 E176 E176 S177 S177

MrRUN1

D44-S177 & H45-E176

Dimer formation is required for TIR signal transduction

Agro alone MrRPV1-TIR D41A MrRPV1-TIR MrRPV1-TIR R49A MrRPV1-TIR H42A MrRPV1-TIR Williams, Yin et al. (2016) Front. Plant Sci. 7:1850

slide-11
SLIDE 11

MrRUN1 & MrRPV1 encode TIR-NB-LRR proteins

TIR NB LRR

Signal transduction Effector recognition

Current model of TIR-NB-LRR activation (based on L6 rust resistance protein)

ADP bound “OFF” ATP bound “ON” effector

Immune responses TIR self-association Signaling partner(s) recruitment Activation Resting Immune responses

 

slide-12
SLIDE 12

Many organisms have proteins with TIR domains

Ve et al. (2015) Apoptosis 20:250-61

slide-13
SLIDE 13

SARM1 = sterile alpha and Toll/interleukin-1 receptor motif-containing 1

Gerdts et al. (2016) Neuron 89: 449-460

Nicotinamide NAD+ ADP-ribose

Essuman et al. (2017) Neuron 93, 1334-1343

NADase SARM1-TIR

OH

slide-14
SLIDE 14

A conserved glutamate residue is required for NAD cleavage activity in SARM1-TIR

MrRPV1-TIR MrRPV1-TIR E100A L6-TIR L6-TIR E135A MrRUN1-TIR MrRUN1-TIR E100A

B C C

slide-15
SLIDE 15

ADP bound “OFF” ATP bound “ON” effector

TIR

  • ligomerization

Proposed mode of action of MrRUN1 & MrRPV1

Activation Resting

NADase activity?

Signalling Immune responses

Tempranillo + MrRPV1 Tempranillo Portan Portan + MrRUN1

slide-16
SLIDE 16

Stilbene synthases PR proteins Receptor-like kinases Transcription factors Heat-shock 70s Calcium-binding proteins Phenylalanine ammonia lyases Cytochrome P450s Ascorbate oxidases Other

Effector-triggered MrRPV1-dependent gene expression in transgenic downy mildew resistant Shiraz

  • 85 genes found to be significantly upregulated in MrRPV1-Shiraz vs control

Shiraz at 18hpi with downy mildew

slide-17
SLIDE 17

Is effector-triggered MrRPV1 resistance mediated by stilbenes?

Pv growth inhibited Activated MrRPV1 Stilbene biosynthesis Programmed cell death Reduced availability

  • f nutrition

RESISTANCE

slide-18
SLIDE 18