植物多肽类调节物质磺肽素(PSK)的功能与作用机制

The function and mechanism of peptide regulator phytosulfokine(PSK)in plants

植物磺肽素(phytosulfokine,PSK)是一种新型植物肽类生长调节因子,成熟的PSK是由5个或4个氨基酸构成的磺化短肽[Tyr(SO_(3)H)-Ile-Tyr(SO_(3)H)-Thr-Gln],其中的酪氨酸(Tyr)被磺化修饰。PSK在高等植物中广泛分布,但在低等植物中还未见报道。其在植物中通过细胞膜上的富含亮氨酸的类受体激酶(leucine-rich receptor like kinase protein,LRR-RLK)蛋白家族作为受体向胞内传递信号。拟南芥中报道的PSK受体PSKR具有激酶活性和鸟苷酸环化酶活性双重信号感知作用。PSK调控植物多种生理和生化反应,包括植物细胞的体外分化、细胞的生长、根顶端分生组织细胞和静止中心细胞的调控、花粉管细胞的发育、植物体免疫的调控等;参与非生物胁迫应答,以及和生长素、细胞分裂素、茉莉酸、油菜素内脂等植物激素的协同调控等等。本文总结了近年来PSK在植物生长、发育和逆境应答等中的功能与作用机制的研究进展,并对未来的研究方向作了展望,希望能为今后PSK相关研究提供指导。

Phytosulfokine(PSK)is a new type of plant peptide growth regulator.Mature PSK are short sulfonated peptides[Tyr(SO_(3)H)-Ile-Tyr(SO_(3)H)-Thr-GLn]composed of 5 or 4 amino acids,in which tyrosines(Tyr)are modified by sulfonate.PSK are known to be widely distributed in higher plants,while they have not been reported in lower plants.PSK signaling into cell depends on the transmembrane localized leucine-rich receptor like kinase(LRR-RLK)in plant.The Arabidopsis PSK receptor PSKR was reported to have dual functions in both kinase activity and guanylate cyclase activity.PSK regulate multiple physiological and biochemical processes in plants,including cell differentiation,cell growth,cell development in root apical meristem and quiescent center,pollen tube growth,immune defense and etc.They are also involved in abiotic stress response and synergistic regulation of plant hormones,such as auxin,cytokinins,jasmonates and brassinosteroids.This article reviews recent progresses of PSK research on the functions and mechanisms in plant growth,development and abiotic stress response,and prospects the future research direction,hoping to provide guidance for PSK related research in future.