Table 1.

List of plant proteins with antiviral activity confirmed in different sets of experiments.

Protein	Family	Source Plant	Target Virus	Reference
a. Proteins with antiviral properties observed in experiments involving mutant plants (Figure 1a)
AGO1	AGO	Arabidopsis thaliana	BMV	[30]
			CMV	[31,32]
			TCV	[33]
			TuMV	[34]
		Nicotiana benthamiana	ToRSV	[35]
		Oryza sativa	RSV	[36]
AGO2	AGO	Arabidopsis thaliana	TCV	[37,38]
			CMV	[37]
			CMV	[32]
			PVX	[39]
			TRV	[40]
			TuMV	[41,42]
		Nicotiana benthamiana	TBSV	[43]
AGO4	AGO	Arabidopsis thaliana	BCTV	[44,45]
			CMV	[46,47]
			TRV	[40]
		Nicotiana benthamiana	PVX	[48]
AGO5	AGO	Arabidopsis thaliana	PVX	[49]
			TuMV	[42]
AGO7	AGO	Arabidopsis thaliana	TCV	[33]
			TuMV	[42]
AGO10	AGO	Arabidopsis thaliana	TuMV	[42]
AGO18	AGO	Oryza sativa	RDV, RSV	[36]
BTR1	RBP	Arabidopsis thaliana	ToMV	[50]
DCL2 and DCL4 (together)	DCLs	Arabidopsis thaliana	PVX	[51]
			TuMV	[34]
			BMV	[30]
			TCV	[33]
DCL4	DCL	Arabidopsis thaliana	PVX	[51]
			TuMV	[34]
		Nicotiana benthamiana	PVX	[51]
DRB3	RBP	Arabidopsis thaliana	CaLCuV, BCTV	[45]
DRB4	RBP	Arabidopsis thaliana	TYMV	[52,53]
			TCV	[54]
RDR1	RDR	Arabidopsis thaliana	TuMV	[34]
		Nicotiana benthamiana	TMV	[55]
RDR6	RDR	Arabidopsis thaliana	TCV	[54]
			TuMV	[34]
			BMV	[30]
UPF1	Helicase	Arabidopsis thaliana	PVX	[56]
b. Proteins with antiviral properties observed in experiments using GM plants (Figure 1b)
AGO2	AGO	Arabidopsis thaliana	CMV	[57]
			PVX	[49]
AGO5	AGO	Arabidopsis thaliana	CMV	[57]
			PVX	[49]
APUM5	RBP	Arabidopsis thaliana	CMV, TuMV	[58]
AtGRP7	RBP	Arabidopsis thaliana	TMV	[59]
BTR1	RBP	Arabidopsis thaliana	ToMV	[50]
CaPR10	PR-10	Capsicum annuum	TMV	[22,58]
NIK1	kinase	Arabidopsis thaliana	CaLCuV	[13]
PAP	RIP	Phytolacca ameriacana	PVY, PVX, CMV	[60]
PAP II	RIP	Phytolacca americana	TMV, PVX	[61]
PAP-C	RIP	Phytolacca americana	PVX	[62]
PIP	RIP	Phytolacca insularis	PVY, PVX, PLRV	[63]
PR2a	PR-2	Nicotiana tabacum	TMV	[23]
PR3	PR-3	Nicotiana tabacum	TMV	[23]
RDR1	RDR	Nicotiana tabacum	PVY	[64]
Trichosanthin	RIP	Trichosanthes kirilowii	TuMV	[65]
c. Proteins exhibiting antiviral activity in vitro (Figure 1c)
CirA	AMP	Chassalia parvifolia	HIV	[66]
CirB	AMP	Chassalia parvifolia	HIV	[66]
Kalata B1	AMP	Oldenlandia affinis	HIV	[28]
Kalata B8	AMP	Oldenlandia affinis	HIV	[67]
Limenin	AMP	Phaseolus limensis	HIV-1	[29]
Lunatusin	AMP	Phaseolus lunatus	HIV-1	[68]
Phaseococcin	AMP	Phaseolus coccineus ‘Minor’	HIV-1	[69]
Sesquin	AMP	Vigna sesquipedalis cv.	HIV-1	[70]
Stellarmedin A	PR-9	Stellaria media	HSV-2	[21]
unnamed	AMP	Phaseolus vulgaris cv.	HIV-1	[71]

Table 1 presents antiviral proteins for which antiviral activity was detected using different experimental approaches. Section (a) lists proteins for which antiviral activity was observed in experiments involving mutant plants and gene knockout technology. The gene of interest was inactivated and after virus inoculation the loss-of-function mutant plants were compared with controls. Several studies employing gene silencing are also presented in this section. Section (b) lists antiviral proteins which were analyzed using genetically modified (GM) plants—transgenic plants or plants overexpressing the gene of interest (GOI). Briefly, the GOI from one plant was introduced to the other plant usually using Agrobacterium-mediated infiltration. Such GM plants were compared with controls after virus inoculation. For some proteins experiments on both mutant plants and GM plants were conducted therefore they appear in both sections of the table. Section (c) lists antiviral proteins which were first isolated from plants and afterwards their properties were studied in different in vitro assays. Virus name abbreviations: BCTV—Beet curly top virus, BMV—Brome mosaic virus, CaLCuV—Cabbage leaf curl virus, CaMV—Cauliflower mosaic virus, CMV—Cucumber mosaic virus, HIV—Human immunodeficiency virus, PLRV—Potato leafroll virus, PVX—Potato virus X, PVY—Potato virus Y, RDV—Rice dwarf virus, RSV—Rice stripe virus, TBSV—Tomato bushy stunt virus, TCP—Tomato crinkle virus, TCV—Turnip crinkle virus, TMV—Tobacco mosaic virus, ToMV—Tomato mosaic virus, ToRSV—Tomato ringspot virus, TRV—Tobacco rattle virus, TuMV—Turnip mosaic virus.