蛋白质的变化与植物抗寒性的关系研究进展

蛋白质的变化在植物抗寒生理研究中一直被广泛关注。低温胁迫期间在蛋白质含量变化的同时,还可能发生质的变化,合成新的蛋白质——低温诱导蛋白。综述了低温胁迫期间植物体内蛋白质的变化,重点阐述了抗冻蛋白、脱水蛋白和热激蛋白等3种低温诱导蛋白的特性及其与植物抗寒性的关系,并对该领域今后的研究做了展望,为进一步阐明植物抗寒的分子机制、提高植物的抗寒力提供了新的思路。     

木本植物季节性休眠的分子机制

季节性休眠是多年生木本植物在生态和进化上的一种"权衡"机制,也是植物界多样性生存策略的组成部分.木本植物的休眠反应首先是Ca2+作为信号物质诱导CO/FT基因的表达,进而引起与休眠相关的DAM基因的表达;而低温可以诱导休眠的发生,冷诱导表达的基因CBF和COR在休眠期间也有表达;而与逆境相关的蛋白如脱水蛋白、抗冻蛋白、热激蛋白和热稳定蛋白等也与休眠反应有密切的关系.本文就与木本植物季节性休眠相关的分子机制进行了综述.     

植物抗冻蛋白及抗冻性分子改良

概述了植物抗冻蛋白及其相关基因的研究现状,主要包括植物低温诱导蛋白、具有热滞活性的植物抗冻蛋白及其相关基因的分离、鉴定与表达调控,以及植物抗冻性基因工程研究动态.在此基础上,讨论了该领域研究中的主要问题、发展趋势及近期研究热点.     

抗冻蛋白与植物低温胁迫反应

植物抗冻蛋白是从许多抗冻植物中分离的、参与植物抵御冻害反应的一类新型蛋白.这类抗冻蛋白具有多个亲水性缚冰域,能直接作用于冰晶,阻止冰晶在细胞间隙形成和再结晶.一些植物抗冻蛋白与致病相关蛋白有序列同源性,具有抗冻和抗病双重活性.植物抗冻蛋白的表达和积累,既受控于发育及转录因子调节,又受到低温、短日照、脱水及乙烯等因素的影响.异源超表达抗冻蛋白基因能赋予敏感宿主植物抗冻能力.文中论述了有关植物抗冻蛋白特性和鉴定,抗冻机制和表达调控,以及遗传转化等方面的研究进展.     

复苏植物旋蒴苣苔J结构域蛋白编码基因BhDNAJC2的 克隆、表达与功能

热激蛋白(HSP)是一类在受到逆境刺激后大量表达的蛋白质, 能够帮助蛋白质正确折叠, 促使变性蛋白质降解, 缓解逆境胁迫对生物体的损伤。为揭示热激蛋白在耐旱的复苏植物中的保护作用, 该研究对复苏植物旋蒴苣苔(Boea hygrometrica)HSP40家族中J结构域蛋白BhDNAJC2的编码基因进行了克隆、表达与功能分析。Real-time PCR检测表明, 该基因受脱水、低温、热激等多种逆境条件和脱落酸(ABA)诱导表达。BhDNAJC2-YFP定位于细胞质、内质网和细胞核。过表达BhDNAJC2的拟南芥(Arabidopsis thaliana)株系在干旱、热激、盐胁迫和碱胁迫下均表现出明显的抗逆性。综上所述, BhDNAJC2可能在旋蒴苣苔抗旱、耐热及耐盐碱等胁迫反应中起关键作用。     

用美洲拟鲽抗冻蛋白基因转化植物的问题

评估了我们用美洲拟鲽抗冻蛋白基因转化烟草和国内有人用同一基因转化蕃茄的研究 ,提出植物耐寒性状的提高与转基因植物中抗冻蛋白含量呈正相关是转基因植物成功的关键性指标。同时 ,美洲拟鲽抗冻蛋白的空间结构与冷诱导蛋白相似而且都保护细胞膜免受冻害 ,因而提出了用冷诱导蛋白调节元的顺式作用元件和反式作用因子的调控序列来控制抗冻蛋白基因在植物中冷诱导表达的思路。     

用美洲拟鲽抗冻蛋白基因转化植物的问题

评估了我们用美洲拟鲽抗冻蛋白基因转化烟草和国内有人用同一基因转化蕃茄的研究,提出植物耐寒性状的提高与转基因植物中抗冻蛋白含量呈正相关是转基因植物成功的关键性指标。同时,美洲拟鲽抗冻蛋白的空间结构与冷诱导蛋白相似而且都保护细胞膜免受冻害,因而提出了用冷诱导蛋白调节元的顺式作用元件和反式作用因子的调控序列来控制抗冻蛋白基因在植物中冷诱导表达的思路。     

植物热激蛋白70

植物热激蛋白70(HsP70)由多基因家族编码.除热胁迫外,其它环境因素如低温、干旱等也能诱导HSP70基因的大量表达.HSP70主要参与新生肽的成熟与分拣、变性蛋白的复性或降解等细胞活动.该文介绍HSP70的结构、功能和调控的研究现状.     

热激转录因子在植物抗非生物胁迫中的功能研究进展

植物在遭受环境胁迫时会产生一系列应激反应,而热激转录因子可通过介导热激蛋白或其他热诱导基因的转录和表达,来参与调控植物抵抗逆境胁迫过程和其他生命活动。主要介绍了植物热激转录因子的基本蛋白结构域,阐述了3类热激转录因子在抗极端温度（高温、低温）胁迫、干旱胁迫、高盐胁迫、活性氧胁迫中的功能与作用机制,并探讨和展望了植物热激转录因子在植物育种和提高植物抗逆性的研究中的发展与应用前景,以期为深入研究热激转录因子在调控植物抵抗逆境胁迫中的生物学功能与机制提供理论参考。     

植物的低温蛋白

综述了与植物耐冻性有关的一些植物内源蛋白质或多肽 ,包括低温防护蛋白、抗冻蛋白、植物脱水素、膜关联耐冻性多肽蛋白质。结果表明 ,植物的耐冻性与其低温蛋白 (cold induced proteins)有着密切的关系 ,并指出了抗冻蛋白行使功能的两种可能的作用方式。同时 ,耐冻性与除低温外的其它环境胁迫因子的植物抗性如抗干旱、抗病虫、高盐耐性、乙烯耐性等密切相关     

Multifaceted Role of Salicylic Acid in Combating Cold Stress in Plants: A Review

Plants face different types of stresses, including biotic and abiotic stresses. Among various abiotic stress, low-temperature stress alters various morphological, cytological, physiological, and other biochemical processes in plants. To thrive in such condition’s plants must adopt some strategy. Out of various strategies, the approach of using plant growth regulators (PGRs) gained a prominent role in the alleviation of multiple stresses. Salicylic acid, application triggers tolerance to both biotic and abiotic stresses via regulation of various morpho-physiological, cytological, and biochemical attributes. SA is shown to alleviate and regulate the various cold-induced changes. Both endogenous and exogenously applied SA show an imperative role in the alleviation of cold-induced changes by activating multiple signaling pathways like ABA-dependent or independent pathway, Ca²⁺ signaling pathway, mitogen-activated protein kinase (MAPKs) pathway, reactive oxygen species (ROS), and reactive nitrogen species (RNS) pathways. Activation of these pathways leads to the amelioration of the cold-induced changes by increasing production of antioxidants, osmolytes, HSPs and other cold-responsive proteins like LEA, dehydrins, AFPs, PR proteins, and various other proteins. This review describes the tolerance of cold stress by SA in plants through the involvement of different stress signaling pathways.

     

抗寒类蛋白与冷驯化诱发昆虫耐寒性研究进展

昆虫是变温动物,温度对其生长发育、基本行为及进化途径都会产生很大的影响,种群的繁衍面临如何安全度过漫长而寒冷的冬季的挑战。通过长时间的进化,昆虫获得一系列完整的耐寒策略。绝大多数的昆虫都是耐寒昆虫,在陆地寒冷温度刺激下,昆虫受抗寒基因的调控,体内产生大量抗寒物质,如海藻糖、甘油、山梨醇、抗冻蛋白、热激蛋白等,提高昆虫的耐寒能力,使其得以在低温寒冷的条件下成功越冬。同样,经过冷驯化后的昆虫能显著提高昆虫的耐寒力。近年来,关于昆虫耐寒性、抗寒类蛋白的研究不断开展,研究内容涉及昆虫的耐寒性、抗寒基因HSPs和AFPs的调控、冷驯化诱导抗寒等方面。本文综述了昆虫耐寒性、主要耐寒策略及冷驯化诱发昆虫耐寒性增强等研究内容。有助于全面认识昆虫耐寒性及其作用机制,为天敌昆虫低温储存和提高生物防治等应用打下坚实的基础。     

植物抗寒及其基因表达研究进展

植物经过逐渐降低的温度从而提高抗寒能力 ,这个过程被人们称为低温驯化。植物低温驯化过程是一个复杂的生理、生化和能量代谢变化过程 ,这些变化主要包括膜系统的稳定性、可溶性蛋白的积累和小分子渗透物质 ,比如脯氨酸、糖等 ,这些变化中的一些是植物抗寒必需的 ,而另外一些变化不是必需的。主要对冷害和低温生理生化变化、低温诱导表达基因的功能和作用、低温驯化的调节机制及其信号转导方面进行了综述。通过差别筛选 c DNA文库的方法已经鉴定了许多低温诱导表达、进而提高植物抗寒能力的基因 ,其中有脱水素、COR基因和 CBF1转录因子等。低温信号的感受、转导和调节表达是低温驯化的关键环节 ,低温信号的转导过程与干旱胁迫之间具有一定的交叉 ,这为利用 ABA等来提高植物抗寒能力成为可能 ,相信不久的将来人们可以通过提高植物抗寒能力从而增加经济产量成为现实。     

Plant dehydrins and stress tolerance: Versatile proteins for complex mechanisms

Dehydrins (DHNs), or group 2 LEA (Late Embryogenesis Abundant) proteins, play a fundamental role in plant response and adaptation to abiotic stresses. They accumulate typically in maturing seeds or are induced in vegetative tissues following salinity, dehydration, cold and freezing stress. The generally accepted classification of dehydrins is based on their structural features, such as the presence of conserved sequences, designated as Y, S and K segments. The K segment representing a highly conserved 15 amino acid motif forming amphiphilic a-helix is especially important since it has been found in all dehydrins. Since more than 20 y, they are thought to play an important protective role during cellular dehydration but their precise function remains unclear. This review outlines the current status of the progress made toward the structural, physico-chemical and functional characterization of plant dehydrins and how these features could be exploited in improving stress tolerance in plants.Key words: abiotic stress, dehydration stress, drought, cold acclimation, freezing tolerance, LEA proteins, dehydrins     

Role of Abscisic Acid in Thermal Acclimation of Plants

Abscisic acid (ABA) is a stress hormone that confers resistance to abiotic stressors, including drought, salt, cold, and heat. In general, antioxidant capacity and heat shock proteins (HSPs) mainly mediate ABA to enhance thermal acclimation in plants, but sugar metabolism and signaling also play critical roles in this response in the presence of ABA. Indeed, ABA accelerates sugar metabolism and transports more carbohydrates to spikelets under heat stress, which is beneficial to plants surviving under stressful conditions. Few studies have summarized the interactions among sucrose metabolism, signaling, and hormones in plants during heat stress, but this topic will likely attract more attention in the future. This article reviews the antioxidant capacity, HSPs, sugar metabolism, hormone crosstalk, and their interactions involved in ABA-induced heat tolerance in plants. Clarifying the underlying mechanisms will be invaluable for breeding heat-resistant cultivars and for developing new tissue culture techniques that reduce heat damage in plants.     

Immunogold localization of glucanase-like antifreeze protein in cold acclimated winter rye

Summary Apoplastic antifreeze proteins (AFPs) accumulate in winter rye (Secale cereale L. cv. Musketeer) leaves during cold acclimation. Two of the rye AFPs with molecular masses of 32 and 35 kDa are similar in their amino acid sequences and epitopes to -1, 3-endoglucanase. Localization of these AFPs, which we refer to as glucanase-like proteins (GLPs), was carried out with antiserum raised against the 32 kDa AFP. Specimens from leaves and roots of non-acclimated (NA) plants and cold acclimated (CA) plants were prepared by freeze-substitution for high resolution immunoelectron microscopy. In CA leaves, high levels of GLPs were observed in cell walls of mesophyll cells adjacent to intercellular spaces and in secondary thickenings of xylem vessels. Taken together with the absence of GLPs in vacuoles, these results confirm the apoplastic accumulation of AFPs in CA winter rye. Within the cells of CA leaves, GLPs were localized in cisternae of the rough endoplasmic reticulum, the Golgi apparatus and the plasma membrane, which indicates that GLPs are secreted via an exocytic bulk-flow pathway. The occurrence of high levels of GLPs in CA leaves, their low presence in NA leaves and the lack of GLPs in roots all suggest that there is a correlation between increased accumulation of GLPs and increased freezing tolerance of these plant materials. Furthermore, the localization of GLPs in the immediate vicinity of pathways for free water within the tissues supports the view that these proteins have an important role in the crystallization and/or recrystallization of water when the leaves of CA winter rye are exposed to freezing temperatures.Abbreviations AFP antifreeze protein - BSA bovine serum albumin - CA cold acclimated - GAR goat antirabbit antiserum conjugated with colloidal gold - GLP glucanase-like protein - NA non-acclimated - PBS phosphate buffered saline - PR pathogenesis related