Monitoring Bacterial Infection and Effector Protein Delivery in Plant Cells

Abstract

Source: Lee, H. et. al., Split Green Fluorescent Protein System to Visualize Effectors Delivered from Bacteria During Infection. J. Vis. Exp. (2018)

This video demonstrates a method for monitoring bacterial infection and effector protein delivery in plant cells using split superfolder green fluorescent protein (sfGFP) complementation combined with confocal microscopy. The approach enables precise visualization of effector translocation into the host cell cytosol.

Protocol

NOTE: All steps are performed at room temperature unless stated otherwise.

1. Preparation of Plant Materials (4 Weeks)

1. Preparation for the Nicotiana benthamiana plants
   1. Sow 2 seeds of N. benthamiana on the soil surface of each pot, cover the tray with a plastic dome and allow seeds to germinate in a 25 °C, 60% humidity growth chamber with a 16/8-h light/dark photoperiod cycle.
   2. After two weeks, pick out and discard the smallest seedling in each pot. Continue to grow plants under the same growth conditions as applied for germination in step 1.1.1. Add 1 L of water per tray ev....

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Arabidopsis transgenic lines			Park, E., Lee, H. Y., Woo, J., Choi, D. & Dinesh-Kumar, S. P. Spatiotemporal Monitoring of Pseudomonas syringae Effectors via Type III Secretion Using Split Fluorescent Protein Fragments. Plant Cell. 29 (7), 1571-1584 (2017)
CYTO-sfGFP1-10	ABRC	CS69831
NU-sfGFP1-10	ABRC	CS69832
PT-sfGFP1-10	ABRC	CS69833
MT-sfGFP1-10	ABRC	CS69834
PX-sfGFP1-10	ABRC	CS69835
ER-sfGFP1-10	ABRC	CS69836
GO-sfGFP1-10	ABRC	CS69837
PM-sfGFP1-10	ABRC	CS69838
Organelle-targeted sfGFP1-10OPT plasmid			Park, E., Lee, H. Y., Woo, J., Choi, D. & Dinesh-Kumar, S. P. Spatiotemporal Monitoring of Pseudomonas syringae Effectors via Type III Secretion Using Split Fluorescent Protein Fragments. Plant Cell. 29 (7), 1571-1584 (2017)
CYTO-sfGFP1-10	Addgene	97387
NU-sfGFP1-10	Addgene	97388
PT-sfGFP1-10	Addgene	97389
MT-sfGFP1-10	Addgene	97390
PX-sfGFP1-10	Addgene	97391
ER-sfGFP1-10	Addgene	97392
GO-sfGFP1-10	Addgene	97393
PM-sfGFP1-10	Addgene	97394
ER-sfCherry1-10	Addgene	97403
ER-sfYFP1-10	Addgene	97404
CYTO-sfCFP1-10	Addgene	97405
sfGFP11-tagged Gateway compatible vector for T3SS-based effector delivery system	Park, E., Lee, H. Y., Woo, J., Choi, D. & Dinesh-Kumar, S. P. Spatiotemporal Monitoring of Pseudomonas syringae Effectors via Type III Secretion Using Split Fluorescent Protein Fragments. Plant Cell. 29 (7), 1571-1584 (2017)
pBK-GW-1-2	Addgene	98250	pAvrRpm1:GW:HA-sfGFP11:AvrRpm1t; Resistant to Kanamycin (25 ug/ml)
pBK-GW-1-4	Addgene	98251	pAvrRpm1:GW:HA-2xsfGFP11:AvrRpm1t; Resistant to Kanamycin (25 ug/ml)
pBK-GW-2-2	Addgene	98252	pAvrRpm1:AvrRPM1sp:GW:HA-sfGFP11:AvrRpm1t; Resistant to Kanamycin (25 ug/ml)
pBK-GW-2-4	Addgene	98253	pAvrRpm1:AvrRPM1sp:GW:HA-2xsfGFP11:AvrRpm1t; Resistant to Kanamycin (25 ug/ml)
pBG-GW-1-2	Addgene	98254	pAvrRpm1:GW:HA-sfGFP11:AvrRpm1t; Resistant to Gentamycin (25 ug/ml)
pBG-GW-1-4	Addgene	98255	pAvrRpm1:GW:HA-2xsfGFP11:AvrRpm1t; Resistant to Gentamycin (25 ug/ml)
pBG-GW-2-2	Addgene	98256	pAvrRpm1:AvrRPM1sp:GW:HA-sfGFP11:AvrRpm1t; Resistant to Gentamycin (25 ug/ml)
pBG-GW-2-4	Addgene	98257	pAvrRpm1:AvrRPM1sp:GW:HA-2xsfGFP11:AvrRpm1t; Resistant to Gentamycin (25 ug/ml)
Bacterial strains
Agrobacterium tumefaciens GV3101			Csaba Koncz and Jeff Schell, The promoter of TL-DNA gene 5 controls the tissue-specific expression of chimaeric genes carried by a novel type of Agrobacterium binary vector. Mol Gen Genet. 204,383-396 (1986); Resistant to gentamycin (50 ug/ml) and rifampicin (50 ug/ml)
Pseudomonas syringae pv. Tomato CUCPB5500			Kvitko, B. H. et al. Deletions in the repertoire of Pseudomonas syringae pv. tomato DC3000 type III secretion effector genes reveal functional overlap among effectors. PLoS Pathog. 5 (4) (2009).; Resistant to rifampicin (100 ug/ml)
Media components
Plant germination media			Add 2.165g/L Murashige & Skoog powder, 10 g/L sucrose to water. Adjust to pH 5.8 and add 2.2 g/L phytagel. Autocalve.
Murashige & Skoog medium including vitamins	Duchefa Biochemie	M0222	Store at 4 °C.
Sucrose	Duchefa Biochemie	S0809
Phytagel	Sigma-Aldrich	P8169
LB media			Add 10 g/L tryptone, 5 g/L yeast extract, 10 g/L NaCl to water. For solid media, add 15 g/L micro agar. Autoclave. Allow solution to cool to 55 °C, and add antibiotic if needed.
Tryptone	BD Bioscience	211705
Yeast extract	BD Bioscience	212750
NaCl	Duchefa Biochemie	S0520
Micro agar	Duchefa Biochemie	M1002
King's B media			10 g/L protease peptone #2, 1.5 g/L anhydrous K2HPO4, 15 g/L of agar to water. Autoclave. Cool down to 55 °C and add sterile 15 ml/L glycerol, 5 ml/L MgSO4 to the medium. Add antibiotics if needed.
Proteose peptone	BD Bioscience	212120
Anhydrous K2HPO4	Sigma-Aldrich	1551128 USP
Glycerol	Duchefa Biochemie	G1345
MgSO4	Sigma-Aldrich	M7506
Bacto Agar	BD Bioscience	214010
Mannitol-Glutamate (MG) liquid media			Add 10 g/L of mannitol, 2 g/L of L-glutamic acid, 0.5 g/L of KH2PO4, 0.2 g/L of NaCl, and 0.2 g/L of MgSO4 to water. Adjust to pH 7
Mannitol	Duchefa Biochemie	M0803
L-glutamic acid	Duchefa Biochemie	G0707
KH2PO4	Sigma-Aldrich	NIST200B
Infiltration buffer			10 mM MES (2-(N-morpholino)-ethane sulfonic acid), 10 mM MgCl2, 150 µM acetosyringone. pH 5.6; Prepare a fresh buffer before use.
MES	Duchefa Biochemie	M1503	Prepare 100 mM (pH 5.6) stock in water. Filter sterilize.
MgCl2	Sigma-Aldrich	M8266	Prepare 100 mM stock in water. Autoclave.
Acetosyringone	Sigma-Aldrich	D134406	Prepare 150 mM stock in DMSO.
Confocal microscope equipments/materials
710 laser scanning confocal system	Carl Zeiss
Axio observer Z1 inverted microscope	Carl Zeiss