一氧化氮(NO)在植物逆境响应中的作用

简要介绍了有关一氧化氮(NO)在植物非生物胁迫响应中生理作用的研究现状,并对与这一问题相关的研究趋势作了分析和讨论.     

茉莉酸调控植物生长发育和胁迫的研究进展

植物作为不可移动的生物,感知外界刺激通过改变自身信号转导对其做出反应。植物激素作为重要的信号分子,在植物应对不同生物和非生物胁迫反应中发挥作用,以调节植物生长发育并适应不断变化的环境。茉莉酸是植物体内的重要激素之一,目前它的合成途径、生理作用等已有大量研究,但对其感知环境变化并做出反应的信号转导途径以及与其他植物激素的相互作用方面的研究还有空白之处。本文主要阐述茉莉酸在调控植物生长发育、胁迫应答及其与其他植物激素的相互作用方面的研究进展。     

植物microRNAs在植物发育和非生物胁迫响应中的作用

microRNAs(miRNAs)是一类内源的长度约为22个核苷酸的非编码小分子RNA,其通过对靶基因mRNA进行切割或翻译抑制调节mRNA的表达,在植物中起到重要的作用.主要介绍了植物miRNAs的特征、合成和作用机制,综述了miRNAs在植物生长发育和非生物胁迫响应中的作用.     

WOX家族基因调控植物生长发育和非生物胁迫响应的研究进展

WOX(WUSCHEL-related homeobox)家族是植物特有的一类转录因子家族,其含有由65-66个氨基酸残基组成的同源异型结构域（Homeodomain,HD）。植物WOX家族成员通过在转录水平上调控靶基因表达,从而参与植物的生长发育和对非生物胁迫的响应等重要生物过程。综述了植物WOX家族成员的分类、结构特征,重点介绍了其在植物生长发育（根、茎、叶、花、果实、种子、胚胎）的调控及植物响应非生物（干旱、盐、冷）胁迫方面的功能研究进展,并对研究WOX转录因子的意义及有待解决的问题进行了展望,旨在为进一步研究WOX家族基因的功能提供参考。     

一氧化氮在植物生长发育和抗逆过程中的作用研究进展

NO不仅在植物的抗病过程中发挥重要作用,同时也参与植物生长、发育和对干旱、高盐、高温、低温等非生物胁迫的响应等过程。该文对近年来国内外有关NO在植物生长、发育、非生物胁迫抗性过程中的作用及其与植物激素之间的互作关系等方面的研究进展进行综述,为相关研究提供信息和资料。     

miR169在植物生长发育与非生物胁迫响应中的作用

MicroRNA(miRNA)是一类由内源基因编码的、长度为18～36 bp的小非编码单链RNA分子,通过序列互补降解或抑制其靶标基因转录后的翻译过程,对植物的器官形成、生长发育、维持基因组完整性以及非生物胁迫应答等方面起重要作用.miRNA169家族是植物中广泛存在且较为保守的microRNA家族,调控植物中一类保守...     

红光和远红光在调控植物生长发育及应答非生物胁迫中的作用

光作为重要的环境因子之一,不仅为植物光合作用提供能量,而且作为信号影响植物对外界环境的响应。该文综述了红光和远红光对植物生长发育和非生物胁迫响应的调控作用,重点阐述了光敏色素及下游光信号转录因子整合激素等内源信号调控植物种子萌发、下胚轴伸长、芽发育及开花的分子机制,以及红光和远红光在植物响应盐、干旱及温度胁迫中的作用机制。在挖掘植物感知和响应光环境机理的基础上,利用LED光谱技术对作物进行精确补光,有望提高作物产量、品质和抗逆性,同时推进实现“双碳”目标,减少能源消耗和环境污染。     

BRs在植物响应非生物胁迫中的作用

油菜素甾体(brassinosteroids,BRs)是植物界普遍存在的一类多羟基化的植物甾体激素,不仅调节植物的生长发育过程,还参与植物对生物和非生物胁迫的响应.概述了BRs的生物合成途径以及信号转导途径,重点阐述了BRs参与非生物胁迫应答的分子机制,展望了BRs未来的研究方向,为深入理解BRs介导的非生物胁迫调控网...     

microRNA在玉米生长发育及非生物胁迫响应中的调控功能

microRNA（miRNA）是一类广泛存在于真核生物中长度为20~24 nt的内源非编码小RNA，它们通过对靶基因mRNA进行切割或翻译抑制，在转录后水平调控靶基因的表达。近期研究表明，miRNA参与植物生长发育与逆境胁迫响应的多个重要生物学过程，对作物的农艺性状也起到重要的调控作用。玉米作为重要的粮食、饲料和工业原料，提高其产量和品质对于保障世界粮食安全至关重要，然而与模式植物拟南芥和水稻相比，玉米中miRNA的研究仍然相对较少，理解miRNA在玉米中的功能和调控机理有助于通过分子育种对关键农艺性状进行遗传改良。本文综述了玉米中miRNA的发现与鉴定，系统总结了参与玉米miRNA代谢途径的关键蛋白DCL、AGO和HEN1的研究进展，重点阐述了在玉米生长发育和非生物胁迫响应过程中已开展功能研究miRNA的调控作用，并对玉米miRNA研究当前存在的问题和未来的发展趋势进行了讨论。     

过氧化氢酶在植物生长发育和胁迫响应中的功能研究进展

过氧化氢酶(catalase, CAT)作为过氧化氢(hydrogen peroxide, H₂O₂)的清除酶在植物生长发育和胁迫响应中扮演着十分重要的角色。CAT的功能受到严格调控,其在正常条件下维持适当浓度的H₂O₂作为信号分子以保证植物的生长发育;在胁迫下保持H₂O₂稳态以增强植物耐逆性。本文对近年来CAT在植物生长发育和胁迫响应中的功能研究进展予以综述,特别是翻译后修饰和亚细胞定位对CAT功能的调控,并对植物CAT的调控机理研究进行了展望。     

Constitutive arginine-dependent nitric oxide synthase activity in different organs of pea seedlings during plant development

Nitric oxide (NO) is an important signalling molecule in different animal and plant physiological processes. Little is known about its biological function in plants and on the enzymatic source or site of NO production during plant development. The endogenous NO production from l-arginine (NO synthase activity) was analyzed in leaves, stems and roots during plant development, using pea seedlings as a model. NOS activity was analyzed using a novel chemiluminescence-based assay which is more sensitive and specific than previous methods used in plant tissues. In parallel, NO accumulation was analyzed by confocal laser scanning microscopy using as fluorescent probes either DAF-2 DA or DAF-FM DA. A strong increase in NOS activity was detected in stems after 11 days growth, coinciding with the maximum stem elongation. The arginine-dependent NOS activity was constitutive and sensitive to aminoguanidine, a well-known irreversible inhibitor of animal NOS, and this NOS activity was differentially modulated depending on the plant organ and seedling developmental stage. In all tissues studied, NO was localized mainly in the vascular tissue (xylem) and epidermal cells and in root hairs. These loci of NO generation and accumulation suggest novel functions for NO in these cell types.     

Effect of nitric oxide and putrescine on antioxidative responses under NaCl stress in chickpea plants

Chickpea plants were subjected to salt stress for 48 h with 100 mM NaCl, after 50 days of growth. Other batches of plants were simultaneously treated with 0.2 mM sodium nitroprusside (NO donor) or 0.5 mM putrescine (polyamine) to examine their antioxidant effects. Sodium chloride stress adversely affected the relative water content (RWC), electrolyte leakage and lipid peroxidation in leaves. Sodium nitroprusside and putrescine could completely ameliorate the toxic effects of salt stress on electrolyte leakage and lipid peroxidation and partially on RWC. No significant decline in chlorophyll content under salt stress as well as with other treatments was observed. Sodium chloride stress activated the antioxidant defense system by increasing the activities of peroxidase (POX), catalase (CAT) superoxide dismutase (SOD) and ascorbate peroxidase (APX). However no significant effect was observed on glutathione reductase (GR) and dehydro ascorbate reductase (DHAR) activities. Both putrescine and NO had a positive effect on antioxidant enzymes under salt stress. Putrescine was more effective in scavenging superoxide radical as it increased the SOD activity under salt stress whereas nitric oxide was effective in hydrolyzing H₂O₂ by increasing the activities of CAT, POX and APX under salt stress.     

Signal transduction by nitric oxide in cellular stress responses

Nitric oxide (NO) has received wide attention as a biological signaling molecule that uses cyclic GMP as a cellular second messenger. Other work has supported roles for cysteine oxidation or nitrosylation as signaling events. Recent studies in bacteria and mammalian cells now point to the existence of at least two other pathways independent of cGMP. For the E. coli SoxR protein, signaling occurs by nitrosylation of its binuclear iron-sulfur clusters, a reaction that is unprecedented in gene activation. In intact cells, these nitrosylated centers are very rapidly replaced by unmodified iron-sulfur clusters, a result that points to the existence of an active repair pathway for this type of protein damage. Exposure of mammalian cells to NO elicits an adaptive resistance that confers elevated resistance of the cells to higher levels of NO. This resistance in many cell types involves the important defense protein heme oxygenase 1, although the mechanism by which this enzyme mediates NO resistance remains unknown. Induction of heme oxygenase in some cell types occurs through the stabilization of its mRNA. NO-induced stabilization of mRNA is mediated by pre-existing proteins and points to the existence of an important new signaling pathway that counteracts the damage and stress exerted by this free radical.     

NO对镉胁迫下小麦根系生长发育的生理影响

为了探究外源物一氧化氮（NO）供体硝普钠（sodium nitroprusside,SNP）对Cd²⁺胁迫下小麦根系生长发育和活性氧代谢的影响,以小麦（Triticum aestivum L.）为材料,研究10 mmol/L CdCl₂胁迫下,30 μmol/L硝普钠（含一氧化氮NO）对小麦根系生长发育和活性氧代谢的影响。结果显示,外施SNP后,Cd²⁺胁迫下的小麦根长度、鲜重与干重较单独镉胁迫处理分别上升了48.0%、107.7%和87.3%,根系超氧化物歧化酶（SOD）、过氧化物酶（POD）、过氧化氢酶（CAT）、抗坏血酸过氧化物酶（APX）的活性分别上升了28.5%、7.4%、19.2%和9.8%,根中超氧自由基（O₂^.-）和过氧化氢（H₂O₂）的含量分别降低了80.5％和47.0％;同时外施SNP,使镉胁迫下小麦根中的可溶性糖含量和脯氨酸含量分别上升了24.7％和22.1%;使根中丙二醛（MDA）含量降低了30.2％;使根系活力上升了15.3%。因此,外源NO在一定程度上可以显著提高小麦根的抗氧化能力,增强小麦的抗逆性,缓解镉对小麦根系的毒害,进而促进小麦幼苗根系的生长发育。     

The role of ABA and MAPK signaling pathways in plant abiotic stress responses

As sessile organisms, plants have developed specific mechanisms that allow them to rapidly perceive and respond to stresses in the environment. Among the evolutionarily conserved pathways, the ABA (abscisic acid) signaling pathway has been identified as a central regulator of abiotic stress response in plants, triggering major changes in gene expression and adaptive physiological responses. ABA induces protein kinases of the SnRK family to mediate a number of its responses. Recently, MAPK (mitogen activated protein kinase) cascades have also been shown to be implicated in ABA signaling. Therefore, besides discussing the role of ABA in abiotic stress signaling, we will also summarize the evidence for a role of MAPKs in the context of abiotic stress and ABA signaling.     

Crosstalk between melatonin and nitric oxide in plant development and stress responses

Melatonin is widely involved in plant growth and stress responses as a master regulator. Melatonin treatment alters the levels of endogenous nitric oxide (NO) and NO affects endogenous melatonin content. Melatonin and NO may induce various plant physiological behavior through interaction mechanism. However, the interactions between melatonin and NO in plants are largely unknown. The review presented the metabolism of endogenous melatonin and NO and their relationship in plants. The interactions between melatonin and NO in plant growth and development and responses to environmental stress were summarized. The molecular mechanisms of interaction between melatonin and NO in plants were also proposed.