植物线粒体巯基亚硝基化修饰蛋白质组学研究进展

蛋白质S-亚硝基化是一氧化氮(NO)与蛋白质半胱氨酸残基(Cys)共价连接形成S-亚硝基硫醇(-SNO)的过程,被认为是植物中体现NO生物活性的最重要途径.线粒体在依赖S-亚硝基化的NO信号转导中起关键作用.综述了应用蛋白质组学技术鉴定的植物线粒体S-亚硝基化蛋白质的特征,为认识线粒体NO调控网络体系中重要的信号与代谢通路(如光呼吸、三羧酸循环、氧化磷酸化、活性氧分子(ROS)稳态,以及蛋白质加工与周转)提供了线索.     

与植物抗逆性有关的转录因子研究概况

转录因子在植物防卫反应和逆境胁迫应答过程中具有重要功能.本文综述了与植物逆境抗性相关的5个转录因子家族:WRKY类、MYB类、bZIP类、NAC类和AP2/EREBP类的研究概况.     

植物谷胱甘肽与抗氧化胁迫

谷胱甘肽是植物中普遍存在的硫醇,在还原硫的贮存和运输、蛋白质和核酸合成方面均有重要作用,且在植物抗逆性方面的作用尤为重要.植物对环境胁迫的耐受能力与谷胱甘肽水平相关,且抗坏血酸和谷胱甘肽两者总是紧密联系.本文综述了近年来谷胱甘肽合成、运输、代谢及其在氧化胁迫中的作用等方面的研究,并以叶绿体中硫氧还蛋白为例介绍了蛋白质谷胱甘肽化的最新研究进展.     

基于叶绿体基因组全序列分析真叶植物叶绿体基因的适应性进化

 真叶植物包括蕨类、裸子植物和被子植物。迄今已积累有较为丰富的真叶植物叶绿体基因组全序列数据。选取了29种真叶植物的叶绿体基因组全序列,采用PAML 软件基于位点间可变ω模型,分别分析了蕨类、裸子植物和被子植物叶绿体基因的适应性进化。结果显示：① 蕨类、裸子植物和被子植物各有6.5%、7.5%和19.2%的叶绿体基因受正选择作用;被子植物经历正选择的叶绿体基因明显比蕨类和裸子植物为多;② 被正选择作用的叶绿体基因主要是遗传系统和光合系统基因,它们的编码产物涉及叶绿体蛋白质合成、基因转录、能量转化与调节及光合作用等过程。推测叶绿体功能基因可能在真叶植物对陆生生态环境的适应过程中起着重要作用。     

植物半胱氨酸可逆氧化修饰蛋白质组学技术研究进展

活性氧(ROS)介导的蛋白质半胱氨酸(Cys)可逆氧化修饰对于调控植物发育和逆境应答过程具有重要意义.近年来新发展起来的高通量氧化还原蛋白质组学技术包括:基于荧光素、生物素-巯基特异性试剂、同位素亲和标签(ICAT)、巯基特异性串联质量标签(CysTMT/iodoTMT),以及iodoTMT与同位素标记相对和绝对定量(i TRAQ)试剂联用等标记技术.这些技术的发展完善为系统研究植物蛋白质氧化还原修饰提供了重要手段.综述了植物Cys可逆氧化修饰蛋白质组学技术的研究进展.     

逆境胁迫下水稻蛋白质组学研究进展

水稻在生长发育过程中要面对各种非生物胁迫如干旱、高盐、温度、重金属和生物胁迫如病虫害等,通过观察水稻在各种胁迫条件下的蛋白质组表达情况,动态分析水稻的蛋白质组变化,对新逆境相关蛋白质进行分离与功能鉴定,这不仅能揭示参与胁迫耐受的蛋白质翻译后调控机制,而且可以增进对耐受胁迫分子机理的认识.综述了水稻应答逆境胁迫蛋白质组学研究的最新研究进展,探讨了存在的主要问题.     

植物糖基化磷脂酰肌醇锚定蛋白LORELEI家族研究进展

植物LORELEI （LRE）蛋白家族是植物糖基化磷脂酰肌醇锚定蛋白（GPI-AP）亚家族的一种,在拟南芥中有4个成员,分别为LRE,LRE-like GPI-AP 1（LLG1）,LLG2和LLG3。这些成员在植物体内的表达位置和功能不同。LRE主要在雌配子体的助细胞、卵细胞和中央细胞表达,在助细胞中表达量最高,另外在受精卵与胚乳中也有部分表达。LRE主要参与高等植物的双受精作用,介导花粉管接受并调控胚胎的早期发育。LLG1在植物各组织器官中都有表达,在营养器官（根和叶）中表达水平最高,主要调控植物生长发育（如根与根毛生长）、盐逆境应答,以及免疫应答过程。LLG2和LLG3主要在成熟花粉粒和花粉管中表达,调控花粉管生长与爆裂,释放精子完成双受精作用。该文综述了植物LRE家族成员组成、蛋白质特征,及其在植物生长发育与逆境应答过程中的作用。     

水杨酸参与生物学过程的交谈机制

作为新型植物激素和信号分子水杨酸广泛参与植物生长和发育的各个过程,介导植物体对生物和非生物逆境胁迫的应答。外源施加水杨酸可改变植物的生长和发育模式,不同环境胁迫可动态调节内源水杨酸水平。外源水杨酸处理或改变内源水杨酸水平或信号转导途径的操作可导致植物体对不同环境胁迫的交叉应答。水杨酸介导植物对不同环境因子应答的交谈机制体现在生理生化、基因表达和蛋白质修饰等多个层面。综述了水杨酸在植物生物学各个方面可能的作用及其机理,重点强调交谈机制。     

一氧化氮在植物中的信号分子功能研究：进展和展望

一氧化氮（NO）是一种生物活性分子,越来越多的证据表明它是生物体内分布最为广泛的信号分子之一．NO作为植物生长发育的一个关键调节因子,能对各种生物或非生物胁迫产生应答,在植物生长发育与环境互作的协调过程中起着中枢性的作用．近年来,对于一氧化氮在植物中分子功能的研究取得了较大进展,特别是其信号转导功能、对基因表达的调控和植物体内NO稳态平衡的维持等方面．文中较全面地介绍了植物体内NO的合成、功能、信号转导、对基因表达的调控以及植物体内NO动态平衡的维持等方面研究的进展,并对该领域今后的研究进行了展望．     

桃树PpADC基因克隆及逆境胁迫表达分析

多胺广泛参与植物生长、发育等生理生化进程和植物逆境应答反应,精氨酸脱羧酶(ADC)是植物多胺生物合成途径中的关键酶.为研究桃树ADC基因的结构和逆境胁迫转录表达情况,试验利用同源序列法克隆桃树PpADC基因,对基因序列、编码蛋白结构等进行生物信息学分析,应用qRT-PCR检测基因PpADC在不同逆境胁迫过程中的转录表达量.结果表明,桃树PpADC基因含有一个2 178 bp的开放阅读框,编码725个氨基酸,基因序列中不含有内含子结构;该基因编码蛋白与白梨精氨酸脱羧酶相似值高达90.14%,系统进化树分析表明PpADC基因与白梨、苹果和湖北海棠等蔷薇科果树ADC基因亲缘关系较近;低温、脱水、盐和乙烯处理能不同程度上调PpADC基因的转录表达水平,表明该基因在桃树应答逆境胁迫过程中发挥重要作用.     

S-nitrosylated protein-disulphide isomerase links protein misfolding to neurodegeneration

Stress proteins located in the cytosol or endoplasmic reticulum (ER) maintain cell homeostasis and afford tolerance to severe insults. In neurodegenerative diseases, several chaperones ameliorate the accumulation of misfolded proteins triggered by oxidative or nitrosative stress, or of mutated gene products. Although severe ER stress can induce apoptosis, the ER withstands relatively mild insults through the expression of stress proteins or chaperones such as glucose-regulated protein (GRP) and protein-disulphide isomerase (PDI), which assist in the maturation and transport of unfolded secretory proteins. PDI catalyses thiol-disulphide exchange, thus facilitating disulphide bond formation and rearrangement reactions. PDI has two domains that function as independent active sites with homology to the small, redox-active protein thioredoxin. During neurodegenerative disorders and cerebral ischaemia, the accumulation of immature and denatured proteins results in ER dysfunction, but the upregulation of PDI represents an adaptive response to protect neuronal cells. Here we show, in brains manifesting sporadic Parkinson's or Alzheimer's disease, that PDI is S-nitrosylated, a reaction transferring a nitric oxide (NO) group to a critical cysteine thiol to affect protein function. NO-induced S-nitrosylation of PDI inhibits its enzymatic activity, leads to the accumulation of polyubiquitinated proteins, and activates the unfolded protein response. S-nitrosylation also abrogates PDI-mediated attenuation of neuronal cell death triggered by ER stress, misfolded proteins or proteasome inhibition. Thus, PDI prevents neurotoxicity associated with ER stress and protein misfolding, but NO blocks this protective effect in neurodegenerative disorders through the S-nitrosylation of PDI.     

NO对新生大鼠心肌细胞PKC活性的影响

利用培养新生大鼠心肌细胞，检测NO前体L-精氨酸(L-arginine,L-Arg)和NO供体硝普钠(sodium nitroprusside,SNP)对PKC活性的影响，并探讨内、外源性NO在PKC激动剂佛波指(phorbol 12-myristate 13-acetate,PMA)激活PKC中的作用.实验结果表明：培养基中加入L-Arg，PKC活性呈剂量依赖性降低；用L-Arg进行预处理，30 min后加入PMA，PKC活性明显降低，与单纯PMA组相比有显著差异；NOS抑制剂L-NAME本身对基础状态PKC活性无明显影响，但可阻断L-Arg对上述2个效应的影响；培养液中加入NO供体SNP，PKC活性呈剂量依赖性降低；用SNP预处理心肌细胞，5 min后加入PMA，PKC活性与单纯PMA组相比有显著性差异.以上结果表明，内、外源性NO均具有剂量依赖性抑制PKC活性的作用，PKC可能是NO对心肌细胞作用的胞内信号传导通路的关键部位或重要信号分子之一；L-Arg通过NOS先生成NO，NO再对PKC起抑制作用.     

Nitric oxide involved in signal transduction of Jasmonic acid-induced stomatal closure of Vicia faba L.

Nitric oxide (NO) and Jasmonic acid (JA) are two key signaling molecules involved in many and diverse biological pathways in plants. Growing evidence suggested that NO signaling interacts with JA signaling. In this work, Our experiment showed that NO exists in guard cell of Vicia faba L., and NO is involved in signal transduction of JAinduced stomata closuring: ( i ) JA enhances NO synthesis in guard cell; ( ii ) both JA and NO induced stomatal closure, and had dose response to their effects; ( iU ) there are synergetic correlation between JA and lower NO concentration in regulation of stomatal movement; (iV) JA-induced stomatal closure was largely prevented by 2-phenyl-4,4,5,5-tetramethylimidazoline-l-oxyl-3-oxide (PTIO), a specific NO scavenger. An inhibitor of NO synthase (NOS) in mammalian cells, N^G-nitro-L-Arg-methyl eater (L-NAME) also inhibits plant NOS, repressing JA-induced NO generation and JA-induced stomatal closure. We presumed that NO mainly comes from NOS after JA treatment.     

UV-B和NO对胞壁蛋白的影响

通过对玉米幼苗叶片细胞壁中蛋白组分、质量分数和过氧化物酶活性的分析检测,证明UV-B光胁迫下,内、外源NO作为UV-B辐射光氧化胁迫的信使负责胁迫信号的转导,激活细胞壁过氧化物酶的活性,致使细胞壁共价键结合蛋白,积累,从而钝化许多功能蛋白质的活力.而没有UV-B光胁迫时,适量的内、外源NO是抑制细胞壁过氧化物酶活性的有效抗胁迫分子,保证细胞壁中足量离子结合和游离蛋白质量分数,维持细胞壁中活跃的代谢功能.因此,在细胞壁中,一氧化氮能够介导UV-B辐射对细胞壁中结构和功能蛋白质的影响,为转导增强UV-B光胁迫的信号分子.     

Protein phosphorylation is involved in the water stress-induced ABA accumulation in the roots ofMalus hupehensis Rehd

Water stress-induced ABA accumulation plays a key role in the root to shoot communication and/or the cell to cell signaling under the soil stresses. The signaling of the water stress itself that leads to the accumulation, however, is less known. In this study, we subjected the roots of Malus hupehensis seedlings to water stress treatment and investigated the ABA accumulation in relation to protein phosphorylation. Our results showed that ABA accumulation could be substantially triggered in 40 min and reached 4 folds in 100 min after treatment with 30% PEG 6000 (polyethylene glycol). The water stress treatment also led to a substantial enhancement of total kinase activity, assessed with histone-Ⅲ as substrate, in 15 min and a maximum enhancement in 30 min before it declined to initial level. The Ca²⁺-dependent kinase activity showed a similar, if not more sensitive, trend. When the roots were fed with labeled ³²P- ATP, water stress enhanced the labeling of proteins, which showed a maximum labeling at 40 min. Two inhibitors of protein kinases, Quercetin and H7, effectively diminished or completely blocked the ABA accumulation under the stress treatment. It is therefore suggest that protein phosphorylation is involved in the signaling of the water stress-induced ABA accumulation.     

Nitric oxide: A potential key point of the signaling network leading to plant secondary metabolite biosynthesis

The endogenous signaling network of plants plays important roles in mediating the exogenous factor-induced biosynthesis of secondary metabolites. Nitric oxide (NO) has emerged as a key signaling molecule in plants recently. Numerous studies demonstrated that the main signaling molecules such as salicylic acid (SA), jasmonic acid (JA), reactive oxygen species (ROS), and NO were not only involved in regulating plant secondary metabolite biosynthesis but also interacted to form a complex signaling network by mutual inhibition and/or synergy. The recent progress in the signal network of plant secondary metabolite biosynthesis has been discussed in this paper. Furthermore, we propose a hypothetical model to show that NO might act as a potential molecular switch in the signaling network leading to plant secondary metabolite biosynthesis.     

Nitric oxide:A potential key point of the signaling network leading to plant secondary metabolite biosynthesis

The endogenous signaling network of plants plays important roles in mediating the exogenous factor-induced biosynthesis of secondary metabolites. Nitric oxide (NO) has emerged as a key signaling molecule in plants recently. Numerous studies demonstrated that the main signaling molecules such as salicylic acid (SA), jasmonic acid (JA), reactive oxygen species (ROS), and NO were not only involved in regulating plant secondary metabolite biosynthesis but also interacted to form a complex signaling network by mutual inhibition and/or synergy. The recent progress in the signal network of plant secondary metabolite biosynthesis has been discussed in this paper. Furthermore, we propose a hypothetical model to show that NO might act as a potential molecular switch in the signaling network leading to plant secondary metabolite biosynthesis.