谷氨酸受体蛋白调控植物生长与胁迫应答的研究进展

Research Advances in Plant Growth and Stress Response Regulation Mediated by Glutamate Receptor-like Proteins

植物谷氨酸受体(glutamate receptor-like,GLRs)是动物离子型谷氨酸受体(inotropic glutamate receptors,iGluRs)的同源蛋白,在开花植物中具有多个拷贝,常以功能冗余的基因家族形式共同调节植物生长发育和逆境应答过程。GLRs在植物中发挥作用的机制与其动物同源蛋白既有类似之处,但又表现出植物特异性。iGluRs在哺乳动物的神经系统中发挥重要作用。在iGluRs介导的神经传导中,由突触前膜释放的神经递质识别并结合突触后膜的iGluRs,iGluRs介导的阳离子内流引起突触后膜的去极化,形成动作电位的传递,构成神经传导的基础。过去20多年的研究发现,植物GLRs也可以作为离子通道蛋白,通过调节跨膜离子流行使功能。本文系统综述了植物谷氨酸受体的蛋白结构和演化特征,并对已报道的重要功能位点进行阐释;总结了近些年来对植物谷氨酸受体蛋白在植物生长发育不同时期,以及多种生物和非生物逆境应答中的功能的研究进展,并比较了其与动物iGluRs作用机制的异同;提出并梳理了该领域仍待解决的重要科学问题;最后展望了该蛋白家族在作物耐逆育种中的重要应用前景和价值,以期为改良作物耐逆性状提供线索。

Plant glutamate-like receptors(GLRs)are homologous to the inotropic glutamate receptors(iGluRs)in animals.Flowering plants often possess multiple GLR members that redundantly regulate plant growth and development,as well as responses to environmental stimuli.Plant GLRs share common action mechanisms as their animal homologues,but also display plant-specific features.In mammalian cells,iGluRs play vital roles in the central nervous system.During the process of neurotransmission mediated by iGluRs,presynapse-released neurotransmitters recognize and bind to postsynaptic iGluRs,leading to cation fluxes across the postsynaptic membrane and eventually depolarized the membrane.This depolarization is also known as action potential,the formation of which is fundamental to neurotransmission.During the past twenty years,plant GLRs have also been shown functioning as ion channels that mediate ion fluxes across various membranes.In this review,we comprehensively summarized the protein structural and evolutionary features of plant GLRs and discussed the residual sites that were reported functionally important for GLRs.Following this,we reviewed the latest research progress on GLR roles during different stages of plant growth and development,as well as during the responses to various biotic and abiotic stresses.Similarities and differences in the action mechanism of GLRs were compared to their animal homologues.We then pointed out what remains important to be investigated in the field.Finally,we prospected the important applicable potential and values of this protein family,aiming at providing clues for designing stress resilient crops.