Table 1.

Plant HDP candidates.

Peptide name	Peptide information	Peptide origin	Antimicrobial activity	Immunomodulation-related activity	References
MsDef1	MsDef1 (Medicago sativa Defensin 1) belongs to the defensin family	Alfalfa (Medicago sativa)	Purified MsDef1 inhibits fungal growth	Purified MsDef1 inhibits root growth (suggesting immune response activation)	(22, 23)
DEF2	DEF2 belongs to the defensin family	Tomato (Solanum lycopersicum)	DEF2-containing foliar extracts inhibit fungal growth	Ectopically-expressed DEF2 perturbs tomato plant development and reduces seed production (trade-off between growth and defense)	(24)
IbACP	IbACP (Ipomea batatas anti-cancer peptide) probably derives from the N-terminus of a PR-5/TLP precursor	Sweet potato (Ipomea batatas)	IbACP precursor belongs to the TLP family, whose members are well-established AMPs	Purified IbACP induces tomato cell culture alkalinisation (suggesting immune response activation)	(25)
PdPR5-1	PdPR5-1 (Prunus domestica Pathogenesis-related Protein 5 1) belongs to the Thaumatin-Like Protein (TLP) family	European plum (Prunus domestica)	PdPR5-1 belongs to the TLP family, whose members are well-established AMPs	Ectopically-expressed PdPR5-1 induces the expression of plant defense pathways (suggesting immune response activation)	(26)
CaAMP1	CaAMP1 (Capsicum annuum antimicrobial protein 1) is a 186-amino-acid antimicrobial protein from pepper	Pepper (Capsicum annuum)	Purified CaAMP1 inhibits the growth of bacteria, fungi, and oomycetes	Ectopically-expressed CaAMP1 modulates the expression of plant defense-related proteins (suggesting immune response modulation)	(27, 28)
RISP	RISP (Rust-Induced Secreted Protein) is a 82-amino-acid peptide that belongs to a Salicaceae-specific family of Cysteine-rich, cationic, secreted peptides	Poplar (Populus trichocarpa)	Purified RISP inhibits fungal growth	Purified RISP triggers poplar cell culture alkalinisation (suggestive of immune response activation)	(7)