在伤信号传导中茉莉酸与水杨酸的关系

近年来,发现茉莉酸和水杨酸都是植物体对外界伤害作出反应,表达抗性基因的信号分子。水杨酸可抑制茉莉酸类的合成及其所诱导的蛋白基因的表达;茉莉酸能阻止病原侵染后所产生的水杨酸的增加。茉莉酸信号转导途径和水杨酸信号转导途径存在着交叉,小GTP结合蛋白和细胞分裂素可能起着信号开关的作用。     

茉莉酸及其信号传导研究进展

茉莉酸及其衍生物茉莉酸甲酯等统称为茉莉酸盐,是广泛存在于植物中的一种生长调节物质,在植物细胞中起着非常重要的作用.茉莉酸作为信号分子广泛参与调节植物的生长发育和胁迫响应过程.本文主要就茉莉酸的生物合成、茉莉酸的信号传导途径和调控机制、茉莉酸的信号传导途径与乙烯、脱落酸、水杨酸和一氧化氮信号传导途径的相互关系进行了综述.     

茉莉酸甲酯与水杨酸在诱导黑麦草颖花开放中的拮抗效应

在意大利黑麦草完全没有开颖的情况下,１mmol.L^-1MeJA处理体穗２min,１１h内可使其单穗颖花开放数达２５左右,表现出明显的诱导效应,滞后期约为１６０min;10mmol.L^-1和１mmol.L^-1的ＳＡ对MeJA诱导的开颖效应均有抑制作用,这种抑制作用可被MeJA处理解除。     

水杨酸、茉莉酸和乙烯介导的防卫信号途径相互作用的研究进展

乙烯、水杨酸和茉莉酸是植物体内主要的几个防御信号途径,也是研究比较多的几个信号途径。很多试验证明不同的防御信号途径相互间存在相互作用,他们或相互抑制,或相互促进。从这三种信号途径相互间的作用,及作用的联系点进行综述。     

系统素、茉莉酸在番茄系统伤反应中的作用

当植物受到机械损伤或昆虫伤害时,植物体会在受伤部位产生伤信号分子启动防御基因的系统表达,蛋白酶抑制剂基因是防御基因的一典型代表.番茄是研究植物系统伤信号很好的模式植物,目前,三种类型的番茄系统伤信号突变体被鉴定出来,通过对番茄系统伤信号突变体进行功能分析并在它们之间进行相互嫁接实验,研究结果表明系统素和茉莉酸通过同一信号通路来激活防御基因的系统表达.系统素(或它的前体原系统素)在受伤部位激活茉莉酸的合成,使之达到系统反应的水平,应对外来伤害;茉莉酸或其衍生物是重要的系统伤信号分子,它诱导伤防御基因的系统表达.植物的系统伤反应可比做动物的炎症反应,它们之间有许多相似之处.     

植物伤反应中的茉莉酸类信号

植物伤反应包括伤信号的产生、传递、感知和转导。植物伤反应信号通路是一网络系统。茉莉酸类是植物伤反应中的重要信号分子,乙烯、ABA、系统素、水杨酸、过氧化氢等也参与伤信号转导。伤反应信号通路与其他生物、非生物胁迫反应信号通路交互作用,使植物能够在时空上对不同的胁迫做出正确响应。     

茉莉酸类在伤信号转导中的作用机制

茉莉酸是伤反应所必须的信号分子。文章介绍伤信号转导中茉莉酸类的作用及其与系统素、乙烯、脱落酸、寡糖素、电子流等其他信号分子的关系和其作用的可能机制。     

植物防循御反应中水杨酸与茉莉酸的“对话”机制

水杨酸和茉莉酸是介导植物防御反应的两种重要信号分子。它们的生物合成途径迥然不同、对PRs以及防御反应的诱导方面具有相对独立性;虽然两者之间存在若干相互拮抗现象,但它们在介导植物防御反应中却又表现出一定的协同效应。本文综述了两者关系研究中的一些新进展,并提出该领域亟待解决的有关问题,以期为了解、调控和利用植物防御反应提供理论依据。     

茉莉酸甲酯和水杨酸对西洋参愈伤组织生长和皂苷形成的影响CSCD

本文旨在探究不同诱导子对西洋参愈伤组织生长、相关酶活性及其人参皂苷含量的影响,在西洋参愈伤组织中,应用HPLC检测了添加诱导子茉莉酸甲酯(methyl jasmonate,MeJA)和水杨酸(salicylic acid,SA)后西洋参愈伤组织皂苷生物合成的变化。结果显示,MeJA抑制生长,但SA对其生长影响较小;2种诱导子均可以显著激活西洋参愈伤组织中超氧化物歧化酶(superoxide dismutase,SOD)、过氧化氢酶(catalase,CAT)、过氧化物酶(peroxidase,POD)活性和丙二醛(malondialdehyde,MDA)含量;培养基中MeJA浓度为100μmol/L时,愈伤组织中总皂苷含量和产量均达到最大值,人参皂苷Rg_(1)、Re、Rb_(1)、Rc的含量最高,在SA诱导子试验组中,当SA浓度为300μmol/L时,西洋参愈伤组织中总皂苷含量和产量均达到最大值,人参皂苷Rb_(1)的含量最高。结果表明,在西洋参愈伤组织中添加适当浓度MeJA和SA诱导子会提高人参皂苷化合物含量,其中以MeJA诱导人参总皂苷的效果最好,同时也会影响西洋参愈伤组织的生长量。说明在培养过程中添加外源诱导子,有利于提高西洋参愈伤组织中皂苷含量。     

Studies of Signal Transduction of Salicylic Acid in Cucumber Cells

For the first time, the signal transduction pathway of salicylic acid (SA) was investigated by using 3H-labelling, thin-layer chromatography and anion exchange column chromatography. It was found that SA stimulated the activity of membrane bound phospholipase C (PLC), accelerated the bm&down of phosphatidylinositol-4-monophosphate (PIP) and phosphatidylinositol-4,5-bisphos- phate (PIP2) and increased the levels of inositol-1,4-bisphosphate (IP2), inositol-1, 4,5-trisphos- phate (IP3) and diacylglycerol (DAG). These indicated that signal transduction of SA was probably accomplished through the mediation of phosphatidylinositide signal transduction system in cucumber ( Cucumis sativa L. ).     

葡萄幼苗高温锻炼过程中与水杨酸相关的信号转导的初步研究

对无性繁殖的‘京秀’葡萄 (Vitisviniferacv.Jingxiu)幼苗高温锻炼 1 2h或外施水杨酸 (SA)后 1 2h发现 ,两种处理引起葡萄内源ABA含量的变化趋势相似 ,即在处理后 1h急剧升高 ,然后又迅速下降 ,并保持这种低水平到处理结束 ,而脂氧合酶 (LOX)活性并没有表现出和ABA相似的变化趋势。高温锻炼期间 ,葡萄叶片内自由态SA含量与ABA变化趋势相似 ,表现出一种典型的化学信号分子特征。而SA合成的限速酶苯丙氨酸解氨酶 (PAL)也表现出和前两者相似的变化趋势。推测SA单独或通过ABA诱导葡萄抗热性。     

水杨酸在植物抗病中的作用

水杨酸是一种重要的能激活植物抗病防卫反应的内源信号分子,本文首先介绍了水杨酸的基本性质及水杨酸在植物抗病中的作用,然后从水杨酸与水杨酸结合蛋白的相互作用以及水杨酸介导的信号传导途径与非水杨酸介导的信号途径等方面初步探讨了水杨酸诱导植物抗病性的作用机制,最后总结了研究水杨酸作用机制对植物抗性生理和抗性分子生物学发展的意义。     

水杨酸、茉莉酸和乙烯在调控蚕豆气L运动中的相互关系

以蚕豆下表皮为材料研究了水杨酸、(±)茉莉酸和乙烯对气孔运动的影响及其相互关系。结果表明,在一定范围内,水杨酸和乙烯利都可诱导气孔关闭,并且二者能够相互增强其作用强度;(±)茉莉酸能够促进气孔开度增大,加入(±)茉莉酸减弱了乙烯利对气孔运动的影响,(±)茉莉酸和乙烯利存在拮抗效应。降低内源乙烯的水平可以增强(±)茉莉酸促进气孔张开的作用、降低水杨酸的诱导气孔关闭效应。而水杨酸和(±)茉莉酸之间的关系比较复杂。     

Inverse correlation between jasmonic acid and salicylic acid during early wound response in rice

This study presents a kinetic analysis of the response to wounding in rice plants. In particular, jasmonic acid, salicylic acid, and lipoxygenase activity were measured in leaves of wounded rice plants during the early tillering phase. The results show that endogenous jasmonic acid transiently increases to a maximum 30 min after wounding (jasmonic acid burst) and lipoxygenase activity increases after the jasmonic acid burst, but not after the second smaller peak of endogenous jasmonic acid 23 h after wounding. In contrast, endogenous salicylic acid decreases during the jasmonic acid burst, such that the kinetic profiles of jasmonic acid and salicylic acid are inversely correlated during the early response to wounding. It is proposed here that the increase in endogenous jasmonic acid and the decrease in endogenous salicylic acid may contribute for establishing the efficient negative cross-talk between jasmonic acid and salicylic acid signaling pathways during the early response to wounding in rice.     

AtPTR3, a wound-induced peptide transporter needed for defence against virulent bacterial pathogens in <Emphasis Type="Italic">Arabidopsis</Emphasis>

Mutation in the wound-induced peptide transporter gene AtPTR3 (At5g46050) of Arabidopsis thaliana has been shown to affect germination on media containing a high salt concentration. The heterologous expression in yeast was utilized to verify that the AtPTR3 protein transports di-and tripeptides. The T-DNA insert in the Atptr3-1 mutant in the Arabidopsis ecotype C24 revealed two T-DNA copies, the whole vector sequence, and the gus marker gene inserted in the second intron of the AtPTR3 gene. An almost identical insertion site was found in the Atptr3-2 mutant of the Col-0 ecotype. The AtPTR3 expression was shown to be regulated by several signalling compounds, most clearly by salicylic acid (SA), but also methyl jasmonate (MeJA) and abscisic acid. Real-time PCR experiments suggested that the wound-induction of the AtPTR3 gene was abolished in the SA and JA signalling mutants. The Atptr3 mutant plants had increased susceptibility to virulent pathogenic bacteria Erwinia carotovora subsp. carotovora and Pseudomonas syringae pv. tomato, and produced more reactive oxygen species when grown on media containing paraquat or rose bengal. Public microarray data suggest that the AtPTR3 expression was induced by Pseudomonas elicitors and by avirulent P. syringae pathovars and type III secretion mutants. This was verified experimentally for the hrpA mutant with real-time PCR. These results suggest that AtPTR3 is one of the defence-related genes whose expression is reduced by virulent bacterium by type III dependent fashion. Our results suggest that AtPTR3 protects the plant against biotic and abiotic stresses.     

脂氧合酶、茉莉酸和水杨酸对猕猴桃果实后熟软化进程中乙烯生物合成的调控

20℃下后熟果实的LOX活性增加先于自由基产生和乙烯生成;JA处理对果实后熟软化启动期(采后1d)和果实快速软化期(采后5d)果实切片中的LOX活性、自由基产生和乙烯生物合成有促进作用,至果实软化后期(采后7d)这种效应消失;亚油酸只在采后1d果实切片中促使LOX活性和乙烯生成;SA处理抑制了果实后熟进程中组织切片的LOX活性、自由基产生和乙烯的生物合成;SA和JA对LOX活性和乙烯生物合成具有明显的拮抗作用。     

Phospholipase Dδ is Involved in Wounding Induced Phosphatidic Acid Formation in Arabidopsis

Phosphalipase D (PLD) hydrolyzes phospholipids into phosphatidic acid (PA). PLDα1 and δ are the two most abundant members of the 12 member PLD family in Arabidopsis. PLDα1 has been demonstrated having role in the wounding induced PA signalling. However, whether and how PLDδ is involved in wounding induced PA formation remained unclear. In the present study, the membrane lipids response to wounding was profiled in Wassilewskija (WS) and PLDδ knockout mutant (PLDδ KO) of Arabidopsis. The levels of most lipids, including monogalactosyldiacylglycerol, digalactosyldiacylglycerol, phosphatidylcholine and phosphatidylglycerol had decreased rapidly within 30min after wounding in the two Arabidopsis genotypes. In contrast, the level of PA increased sharply and significantly 30min after wounding. It continued to increase until peaking at 1h post wounding in WS and 3h post wounding in PLDδ KO, and then decreased. The PA levels were similar in the two genotypes in untreated leaves and in leaves 6h after wounding. However, these levels were lower in PLDδ KO than in WS from 30min to 3h post wounding. The significant difference of PA level between the two genotypes occurred 30min after wounding, when it was about 20% lower in PLDδ KO than in WS. These results show that PLDδ is involved in wounding induced PA formation in Arabidopsis, but its absence induces PA response later and with less intensity than PLDα1.