Phytosulfokine peptides, their receptors, and functions

Abstract

Phytosulfokines (PSKs) are a class of disulfated pentapeptides and are regarded as plant peptide hormones. PSK-α, -γ, -δ, and -ϵ are four bioactive PSKs that are reported to have roles in plant growth, development, and immunity. In this review, we summarize recent advances in PSK biosynthesis, signaling, and function. PSKs are encoded by precursor genes that are widespread in higher plants. PSKs maturation from these precursors requires a sulfation step, which is catalyzed by a tyrosylprotein sulfotransferase, as well as proteolytic cleavage by subtilisin serine proteases. PSK signaling is mediated by plasma membrane-localized receptors PSKRs that belong to the leucine-rich repeat receptor-like kinase family. Moreover, multiple biological functions can be attributed to PSKs, including promoting cell division and cell growth, regulating plant reproduction, inducing somatic embryogenesis, enhancing legume nodulation, and regulating plant resistance to biotic and abiotic stress. Finally, we propose several research directions in this field. This review provides important insights into PSKs that will facilitate biotechnological development and PSK application in agriculture.

Response surface methodology mediated optimization of phytosulfokine and plant growth regulators for enhanced protoplast division, callus induction, and somatic embryogenesis in Angelica Gigas Nakai

“…Enhanced protoplast division, which results in the production of calluses and embryogenic masses, has been demonstrated in several species when PSK is added to the culture media. Li et al [ 26 ] and Shen et al [ 54 ] have clarified the potential mechanism of interaction with PSK with its receptors of the plasma membrane and subsequent signal transduction, gene expression, and cell growth and development. PSK will attach to its receptors at the cell surface known as PSK receptor proteins (PSKRs) during PSK signal transduction.…”

“…capitata , Daucus species, Fagophyrum tataricum , and Nicotiana benthamiana [ 20 – 25 ]. PSK is reported to be involved in other physiological responses including the promotion of cell growth, development, reproduction, somatic embryogenesis, and plant regeneration [ 26 ]. Therefore, in the current study, we utilized PSK, in addition to 2,4-D and KN for induction of cell division, micro-callus formation, and induction of embryogenic callus in Angelica gigas protoplast cultures.…”

Unraveling a Small Secreted Peptide SUBPEP3 That Positively Regulates Salt-Stress Tolerance in Pyrus betulifolia

“…PLANT PEPTIDE CONTAINING SULFATED TYROSINE (PSY) promotes cell proliferation and expansion [29]. Phytosulfokine (PSK) is a 5-aa tyrosine sulfated peptide that mainly promotes cell proliferation [30,31]. Casparian strip integrity factor 1 (CIF) peptides function to promote the accumulation of hydrophobic substances such as lignin and can regulate the formation of the Casparian band and embryonic cuticle.…”

Comparative Analysis of Small Secreted Peptide Signaling during Defense Response: Insights from Vascular and Non-Vascular Plants

“…Some members of the RALF family were Previously, PSK peptides were shown to regulate the immune response to biotrophic and necrotrophic pathogens in an antagonistic manner in Arabidopsis (Y. Li et al, 2024). The genes belonging to the PSK family were differentially regulated in vascular plants but not in P. patens.…”