Table 4. Some examples of plant ligand-receptor pairs.

Technique	Ligand-Receptor Pair	Reference
ITC	ABA-PYL5	(Santiago et al., 2009)
	Chitin-CERK1	(Liu et al., 2012)
	ABA-PYL3	(Zhang et al., 2012)
	IDA-HAESA	(Santiago et al., 2016)
	IDA-HAESA-SERK1	(Santiago et al., 2016)
	5-InsP7/InsP6-SPX4	(Wild et al., 2016)
	Ca2+/Mg2+-CML14	(Vallone et al., 2016)
	TDIF-PXY	(Zhang et al., 2016)
	BAK1-BIR1/4	(Ma et al., 2017)
	Zn2+-DRB4	(Chiliveri et al., 2017)
	dsRNA-DRB4	(Chiliveri et al., 2017)
	CIF2-SGN3	(Doblas et al., 2017)
	Lure1.2-PRK6	(Zhang et al., 2017)
	CLE45-BAM3	(Hazak et al., 2017)
	CLE41/42-PXL2	(Mou et al., 2017)
	EPF1/2-ERL1-TMM	(Lin et al., 2017)
	EPFL9-ERL1-TMM	(Lin et al., 2017)
	EPFL9-ERL1	(Lin et al., 2017)
	EPFL4-ERL1-TMM	(Lin et al., 2017)
	EPFL4-ERL1	(Lin et al., 2017)
	BL-BRI1-SERK3	(Hohmann et al., 2018a)
	IDA-HAESA-SERK3	(Hohmann et al., 2018a)
	RALF23-FER	(Xiao et al., 2019)
	RALF23-FER-LLG1/LLG2/LLG3	(Xiao et al., 2019)
	RALF23-LLG1/LLG2/LLG3	(Xiao et al., 2019)
	RALF23-LRE	(Xiao et al., 2019)
SPR	AP1/AP3 promoter-LFY	(Moyroud et al., 2009)
	SA-HMGB3	(Choi et al., 2016)
	GAs-GID1	(Yoshida et al., 2018)
	PSK-PSKR1/2	(Zhang et al., 2018)
	RALF23-LLG2	(Xiao et al., 2019)
GCI	BL-BRI1	(Hohmann et al., 2018b)
	BL-BRI1-SERK3	(Hohmann et al., 2018b)
	IDA-HAESA	(Hohmann et al., 2018b)
	IDA-HAESA-SERK3	(Hohmann et al., 2018b)
	CIF2-SGN3	(Okuda et al., 2020)
	Pep1-PEPR1	(Okuda et al., 2020)
	Pep2-PEPR1	(Okuda et al., 2020)
	Cle9-BAM1	(Okuda et al., 2020)
	Flg22-FLS2	(Okuda et al., 2020)
	Flg22-FLS2-SERK3	(Okuda et al., 2020)
	Elf18-EFR-SERK3	(Okuda et al., 2020)
	Pep1-PEPR1-SERK1	(Okuda et al., 2020)
	Pep1-PEPR1-SERK3	(Okuda et al., 2020)
BLI	dsDNA-CaM7	(Kumar et al., 2016)
	RALF4-LRX8	(Mecchia et al., 2017)
	SPL9-HMGA	(Wang et al., 2019b)
	SCRM-MPK6	(Putarjunan et al., 2019)
QCM	Stomagen/MEPF2/LURE2-ERECTA	(Lee et al., 2015)
	Stomagen/MEPF2-TMM	(Lee et al., 2015)
	FIP1-FIN219	(Chen et al., 2017)
AUC	ABA-PYL3	(Zhang et al., 2012)
DSF	Strigolactone-DWARF14 (Kd not calculated)	(Seto et al., 2019)
FA	JAs-COI1/JAZ	(Takaoka et al., 2019)
	dsDNA-HMGB1/11	(Roy et al., 2016)
MST	5-InsP7/InsP6-SPX4	(Wild et al., 2016)
	RALF4-LRX8	(Mecchia et al., 2017)
	CIF2-SGN3	(Doblas et al., 2017)
	RALF1/34-THE1	(Gonneau et al., 2018)
	Chlorophyll-LIL3	(Mork-Jansson and Eichacker, 2018)
	3-OH-FAs-LORE	(Kutschera et al., 2019)
	RALF23-FER	(Xiao et al., 2019)
	ERD14-GSTF9	(Nguyen et al., 2020)
FRET	Glc-FLIPglu	(Deuschle et al., 2006)
	Arg-QBP	(Bogner and Ludewig, 2007)
	ABA-ABAleon	(Waadt et al., 2014)
Radiolabeling	Ethylene-ETR1	(Schaller and Bleecker, 1995)
	CLV3-CLV1	(Ogawa et al., 2008)
	SA-NPR1	(Wu et al., 2012)
	ABA-PYL1/PYL2-HAB1	(Soon et al., 2012)
	ATP-DORN1	(Choi et al., 2014)
	Acri-PIPPo-HSL2	(Butenko et al., 2014)
	Auxin-TIR1-Aux/IAA	(Hellmuth and Calderón Villalobos, 2016)
	NAD+-LecRK-I.8	(Wang et al., 2017)
	SA-NPR3/4	(Ding et al., 2018)
HDX-MS	Oleyl sulfate (OS)-SLO	(Offenbacher et al., 2018)