REAGENT or RESOURCE	SOURCE	IDENTIFIER
Bacterial and virus strains
Sinorhizobium meliloti 2011	Lerouge et al.30	N/A
Agrobacterium rhizogenes strain ARqua1	Boisson-Dernier et al.31	N/A
S. meliloti strain exoH	Bertram-Drogatz et al.24	N/A
S. meliloti strain exoY	Bertram-Drogatz et al.24	N/A
S. meliloti strain nodA	Southwick et al.25	N/A
Escherichia coli strain BL21 CP	Thermo Fisher Scientific, https://www.thermofisher.com	N/A
Chemicals, peptides, and recombinant proteins
Alexa Fluor 488 Phalloidin	Thermo Fisher Scientific, https://www.thermofisher.com	Cat# A12379
FM4-64	Thermo Fisher Scientific, https://www.thermofisher.com	Cat# T13320
Amoxicillin	Sigma-Aldrich, https://www.sigmaaldrich.com	Cat# A8523
Plant Total RNA-Kit	Sigma-Aldrich, https://www.sigmaaldrich.com	Cat#STRN250-1KT
DNase I	Thermo Fisher Scientific, https://www.thermofisher.com	Cat# EN0521
SuperScriptIII reverse Transcriptase (Invitrogen)	Thermo Fisher Scientific, https://www.thermofisher.com	Cat#18080093
Experimental models: Organisms/strains
Medicago truncatula cultivar Jemalong	Heritage Seeds Pty, Adelaide, AU	Jemalong
Medicago truncatula ecotype R108 Tnt1 insertion line NF9730 (syfo1-1), originally obtained from Noble Research Institute LLC, Ardmore, USA.	This paper and Tadege et al.32	NF9730
Medicago truncatula ecotype R108 Tnt1 insertion line NF9495 (syfo1-2), originally obtained from Noble Research Institute LLC, Ardmore, USA.	This paper and Tadege et al.32	NF9495
Medicago truncatula ecotype R108 Tnt1 insertion line NF20350 (syfo1L-1), originally obtained from Noble Research Institute LLC, Ardmore, USA.	This paper and Tadege et al.32	NF20350
Medicago truncatula ecotype R108 Tnt1 insertion line NF15608 (syfo1L-2), originally obtained from Noble Research Institute LLC, Ardmore, USA.	This paper and Tadege et al.32	NF15608
Oligonucleotides
For qRT-PCR and genotyping oligos see Table S4	This paper	N/A
Recombinant DNA
Sub-cloning for LIII expression pattern construct: ProSYFO1:NLS-2xGFP	This paper	N/A
Sub-cloning for LIII FRAP construct, protoplast localization: ProUbi:SYFO1:GFP	This paper	N/A
Sub-cloning for LIII plasmolysis construct: ProUbi:SYFO1ECD:GFP	This paper	N/A
Sub-cloning for LIII localization construct: ProSYFO1:SYFO1ECD/TDM:GFP	This paper	N/A
Sub-cloning for LIII FRAP construct: ProUbi:SYFO1ΔPRR:GFP	This paper	N/A
Sub-cloning for LIII complementation construct: ProSYFO1:SYFO1ΔPRR:GFP	This paper	N/A
Sub-cloning for LIII localization construct: ProSYFO1:SYFO1:GFP	This paper	N/A
Sub-cloning for LIII actin marker construct: Pro35S:mCherry:ABD2:mCherry	This paper and Sheahan et al.33	N/A
Sub-cloning for LIII construct module as prescreen marker: ProUbi:NLS-2xCerulean	Liang et al.34	N/A
Sub-cloning for LIII construct module as prescreen marker: ProUbi:NLS-mCherry	Liang et al.34	N/A
Expression pattern analysis: ProSYFO1:NLS-2xGFP // ProUbi:NLS-mCherry	This paper	N/A
FRAP full length: ProUbi:SYFO1:GFP// ProUbi:NLS-mCherry	This paper	N/A
Plasmolysis / localization: ProUbi:SYFO1ECD:GFP// ProUbi:NLS-mCherry	This paper	N/A
FRAP truncated version: ProUbi:SYFO1ΔPRR:GFP// ProUbi:NLS-mCherry	This paper	N/A
Complementation: ProSYFO1:SYFO1ΔPRR:GFP// ProUbi:NLS-mCherry	This paper	N/A
Localization and complementation: ProSYFO1:SYFO1:GFP// ProUbi:NLS-mCherry	This paper	N/A
Co-localization between actin and SYFO1: ProUbi:SYFO1:GFP// Pro35S:mCherry:ABD2:mCherry	This paper	N/A
Localization: ProSYFO1:SYFO1ECD/TMD:GFP// ProUbi:NLS-mCherry	This paper	N/A
Recombinant protein purification: 6xHis-AtFH8FH1FH2	This paper	N/A
Recombinant protein purification: 6xHis-SYFO1FH1FH2	This paper	N/A
Vector pDEST17 for recombinant protein purification	Thermo Fisher Scientific, https://www.thermofisher.com	Cat#C600003
Software and algorithms
All statistical tests have been carried out using the IBM SPSS Statistics software	IBM SPSS Statistics, Version 26	https://www.ibm.com/analytics/spss-statistics-software
All boxplots have been generated using Rstudio	Rstudio, Version 1.3.1073	https://www.rstudio.com
Adobe Illustrator was used for editing and typesetting	Adobe Illustrator, Adobe Illustrator CS7	https://www.adobe.com/products/illustrator.html
ZEN (black version) was used for FRAP data processing	ZEN 2.3	https://www.zeiss.com/microscopy/int/products/microscope-software/zen.html
tBLASTn	tBLASTn v2.8.1+	https://ftp.ncbi.nlm.nih.gov/blast/xecutable/blast+/LATEST
SymDB database	SymDB database	http://symbiogenomesdb.uv.es
MAFFT	MAFFT v7.407	https://mafft.cbrc.jp/alignment/server
trimAl	trimAl v1.4 rev22	http://trimal.cgenomics.org
IQ-TREE	IQ-TREE	http://www.iqtree.org/release/v1.4.2/
ModelFinder	ModelFinder	http://iqtree.cibiv.univie.ac.at
signal v5.0	signal v5.0	http://www.cbs.dtu.dk/services/SignalP
TMHMM	TMHMM v2.0c	http://www.cbs.dtu.dk/services/TMHMM/
RELAX program	RELAX program	http://www.datamonkey.org/RELAX
PAL2NAL program	Suyama et al.35	http://www.bork.embl.de/pal2nal/