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1.
作为固着生物,植物需要面对持续变化的环境,不断地受到温度和其他非生物因素的影响。未来植物所面临的平均环境温度将会随着全球气候变暖逐渐上升,因此高温愈发成为影响植物生长发育、地理分布及产量的非生物胁迫因子。了解植物对高温胁迫的适应机制,有助于开发耐热品种,改善温暖气候地区植物的生长状况以及提高作物的生产力。植物体中,在分子水平,转录组学及蛋白质组学联合揭示了mRNA以及蛋白水平的植物应答高温胁迫的基因表达模式变化;另外高温胁迫广泛涉及植物体内多种信号转导机制。因此,本综述主要从植物响应高温胁迫分子水平上的转录组、蛋白质组学方面,以及信号转导等方面全面总结了植物响应高温胁迫的研究进展,并对未来的研究前景进行了展望,为了解近几年高温胁迫研究动态和高温胁迫常见研究方式,解析植物高温胁迫耐受机理以及耐高温品种的培育提供参考。  相似文献   

2.
低温胁迫是限制植物生长发育和地理分布最主要的环境因子之一,影响植物细胞膜系统、抗氧化系统、光合作用、次生代谢等诸多方面,对农业生产和发展有严重影响。因此,揭示作物在冷胁迫下的生理及分子机制是十分必要的,这有助于培育耐寒作物品种,从而减少生产损失,扩大作物种植面积,具有重要的生产价值和经济效益。目前,基于RNA-seq技术进行植物低温胁迫分子机制深度解析在拟南芥、水稻、油菜、茶树、小麦、烟草、高粱等重要作物上得到了发展应用。本研究综述了近年来植物在低温胁迫或低温适应过程中的转录组学研究现状,以期为高通量测序技术在植物抗性研究方面提供方法借鉴和理论基础。  相似文献   

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吴昊  李燕敏  谢传晓 《作物杂志》2018,34(5):1-2054
热胁迫是农作物生产中的环境限制因子,影响作物生长发育并导致农作物减产与降低农产品品质。作物耐热性生理生化、基因发掘与分子机制研究将为农业生产与耐热新品种培育奠定基础。综述了热胁迫逆境对作物营养生长阶段和生殖生长阶段的影响,重点阐述了开花期与子粒灌浆期等作物产量形成关键时期受热害时作物的生理与发育,介绍了作物主要的4种热响应方式,即膜流动性改变、蛋白质解折叠、细胞骨架解聚和代谢物变化,总结了Hsf热激转录因子的调控与耐热分子机制,并展望了应用生物技术创制作物耐热新种质与遗传改良的可行性。本文为作物耐热性生理基础、基因发掘、分子机制与育种途径等研究提供参考。  相似文献   

5.
DNA methylation is responsive to various biotic and abiotic stresses. Heat stress is a serious threat to crop growth and development worldwide. Heat stress results in an array of morphological, physiological and biochemical changes in plants. The relationship between DNA methylation and heat stress in crops is relatively unknown. We investigated the differences in methylation levels and changes in the cytosine methylation patterns in seedlings of two rapeseed genotypes (heat-sensitive and heat-tolerant) under heat stress. Our results revealed that the methylation levels were different between a heat-tolerant genotype and a heat-sensitive one under control conditions. Under heat treatment, methylation increased more in the heat-sensitive genotype than in the heat-tolerant genotype. More DNA demethylation events occurred in the heat-tolerant genotype, while more DNA methylation occurred in the heat-sensitive genotype. A large and diverse set of genes were affected by heat stress via cytosine methylation changes, suggesting that these genes likely play important roles in the response and adaption to heat stress in Brassica napus L. This study indicated that the changes in DNA methylation differed between heat-tolerant and heat-sensitive genotypes of B. napus in response to heat stress, which further illuminates the molecular mechanisms of the adaption to heat stress in B. napus.  相似文献   

6.
Increasing severity of high temperature worldwide presents an alarming threat to the humankind. As evident by massive yield losses in various food crops, the escalating adverse impacts of heat stress (HS) are putting the global food as well as nutritional security at great risk. Intrinsically, plants respond to high temperature stress by triggering a cascade of events and adapt by switching on numerous stress‐responsive genes. However, the complex and poorly understood mechanism of heat tolerance (HT), limited access to the precise phenotyping techniques, and above all, the substantial G × E effects offer major bottlenecks to the progress of breeding for improving HT. Therefore, focus should be given to assess the crop diversity, and targeting the adaptive/morpho‐physiological traits while making selections. Equally important is the rapid and precise introgression of the HT‐related gene(s)/QTLs to the heat‐susceptible cultivars to recover the genotypes with enhanced HT. Therefore, the progressive tailoring of the heat‐tolerant genotypes demands a rational integration of molecular breeding, functional genomics and transgenic technologies reinforced with the next‐generation phenomics facilities.  相似文献   

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Increased climatic variability and more frequent episodes of extreme conditions may result in crops being exposed to more than one extreme temperature event in a single growing season and could decrease crop yields to the same extent as changes in mean temperature. The developmental stage of the crop exposed to increased temperatures will determine the severity of possible damage experienced by the plant. It is not known whether or not the damaging effects of heat episodes occurring at different phenological stages are additive. In the present study, the interaction of high‐temperature events applied at the stages of double ridges and anthesis in Triticum aestivum (L.) cv. Chablis was investigated. Biomass accumulation of control plants and that of plants experiencing high temperatures during the double‐ridge stage were similar and were reduced by 40 % when plants were subjected to a heat event at anthesis. Grain number on the main and side tillers declined by 41 %, and individual grain weight declined by 45 % with heat stress applied at the double‐ridge stage and anthesis or at anthesis alone. The harvest index was reduced from 0.53 to 0.33. Nitrogen contents in leaves were reduced by 10 % at the double‐ridge stage and by 25 % at anthesis. The maximum rates of CO2 assimilation increased with heat stress at the double‐ridge stage and higher rates were maintained throughout the growing season. The results clearly indicate that an extreme heat event at the double‐ridge stage does not affect subsequent growth or the response of wheat to heat stress at anthesis.  相似文献   

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Heat stress is one of the major limitations to crop productivity worldwide. Global warming effects are expected to increase the number of hot days and increase the probability and intensity of heat stress events. Short periods (3–5 days) of heat stress with maximum temperatures exceeding 35°C often occur during late spring and early summer in some pyrethrum growing regions of Australia. These heat stress events usually coincide with pyrethrum flowering period. Pyrethrum is a perennial herbaceous plant which is commercially grown for extraction of pyrethrins which accumulate in the achenes of the flowers and are used as a natural insecticide. This experiment was conducted to understand the effects of timing of short periods of heat stress on flower development and pyrethrum yield. Plants were subjected to short periods of high temperature treatments (12 hr at 35–40°C) for three consecutive days at three flower maturity stages (early, mid, late). Control plants were grown at ambient temperature (10–25°C) throughout the flowering period. Exposure of pyrethrum plants to short periods of high temperature during the flowering period caused a significant reduction in the flower and pyrethrin yield. This was associated with the reduction in flower size and accelerated flower senescence. Exposure of pyrethrum plants to heat stress significantly increased the rate of flower development resulting in a shorter flowering period. Overall, plants grown under control treatment showed slower rate of flower development and longer duration flowering period. This resulted in longer duration of pyrethrin accumulation and higher yield of pyrethrins per flower. Timing and duration of heat stress significantly influenced pyrethrin yield per flower. Heat stress caused more severe yield reductions at early flowering than later in the flowering period. Research focusing on agronomic strategies, phenology and breeding for tolerance to heat stress is therefore important to cope with future climate changes and to obtain maximum pyrethrin yield.  相似文献   

10.
为了对海藻糖在植物抗逆过程中的作用有进一步理解,本综述对海藻糖应答非生物胁迫的进展进行了阐述。海藻糖是一种在植物体内广泛存在的非还原性二糖分子,在植物生长发育过程中起到重要作用。在植物应对非生物胁迫过程中,海藻糖在维持植物体内渗透压,保持膜结构,参与信号转导过程等方面发挥了重要作用,对作物栽培和育种改良有着重要的意义。根据近年来对海藻糖的研究进展,本综述重点对植物中海藻糖生物合成途径中的酶类,以及海藻糖在调控植物响应干旱、盐害、高温和低温胁迫方面的作用进行归纳总结。同时,对外源海藻糖对植物生长和发育的影响进行了总结,并对海藻糖可能的研究方向进行预测。为深入解析植物响应非生物胁迫的分子机制并将海藻糖应用于作物的栽培和改良提供了依据。  相似文献   

11.
Phosphorus (P) is the second most growth limiting macronutrient after nitrogen and plays several important roles in all organisms including plants. In soil, P is available in both organic and inorganic forms. P deficiency reduces the growth and yield of several crop plants. Plants respond to P deficiency by the phenotypic changes especially by the modification of root architecture. Molecular marker‐assisted breeding (MAB) has been proposed as an important tool to identify and develop improved varieties of crop plants with efficient P‐use efficiency (PUE). Identification of quantitative trait loci (QTLs) for traits related to PUE has been considered as the first step in marker‐assisted selection (MAS) and improvement of crop yield programmes. In this review, we describe in detail on architectural changes of roots under P deficiency that are reported in various crops and discuss the efforts made to improve PUE using molecular marker tools. Details on QTLs identified for low P‐stress tolerance in various crop plants are presented. These QTLs can be used to improve PUE in crop plants through MAS and breeding, which may be beneficial to improve the yields under P‐deficient soil. Development of new and improved varieties using MAB will limit the use of non‐renewable fertilizers and improve PUE of key crop plants in low input agriculture.  相似文献   

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金属伴侣蛋白在植物抵抗重金属胁迫和低温、干旱、高盐等非生物胁迫中发挥重要作用,但其应对热胁迫时发挥作用的报道还很少。前期研究从辣椒中分离到一个能够响应热胁迫的金属伴侣蛋白基因CaHPP7,通过生物信息学和定量分析发现该基因的氨基酸序列含有1个HMA结构域,且其表达受高温、Cu2+、Cd2+等重金属,以及ABA(Abscisic acid)、MeJA(Jasmonic acid methylester)和SA(Salicylic acid)等外源信号物质的诱导。为了进一步明确CaHPP7基因在植物重金属和热胁迫抗性形成中的功能,利用基因沉默和过表达技术改变Ca HPP7的表达水平。结果显示,基因沉默表达后,辣椒对铜和热胁迫的抗性都降低,表现为离体叶圆片叶绿素含量下降程度显著高于未沉默植株;而基因过表达后,拟南芥对铜和热胁迫的抗性都升高,其中热胁迫下表现为幼苗存活率高于对照,叶圆片叶绿素含量减少程度低于对照;铜胁迫下表现为种子发芽率高于对照,幼苗生长的受抑制程度和叶圆片叶绿素含量下降程度均低于对照。故推测CaHPP7基因在植物应对高温和铜胁迫的过程中起正调控作用。本研究结果将为进一步揭示植物抗逆性形成的分子机制提供理论依据,也将为农作物抗逆新品种的选育提供参考。  相似文献   

14.
油菜素甾醇类化合物在水稻生长发育及抗逆中的研究进展   总被引:1,自引:1,他引:0  
油菜素甾醇类化合物(BRs)是一类新的植物激素,对植物生长发育与抗逆等有重要的调控作用。以水稻为对象,从器官发育与生长、籽粒灌浆、叶片光合作用与衰老以及作物的抗热、抗冷和抗盐性等方面综述了BRs的作用,从BRs对作物生长发育的分子机理以及BRs在作物生产上的应用方面讨论了今后研究的重点。  相似文献   

15.
茄科蔬菜是典型的喜温性植物,由于本身无法躲避低温伤害,田间生产中易遭受低温胁迫。MicroRNA(miRNA)作为一种小分子RNA,是非蛋白质编码基因产物之一。低温胁迫下miRNA被激活,通过负调控靶基因、降解靶基因、抑制翻译等过程,调控相关基因表达,使植物从生理和分子水平上发生变化以响应低温胁迫。本研究主要从低温胁迫对茄科蔬菜的生理水平和转录水平的影响,miRNA差异表达、miRNA响应表达及miRNA与其靶基因作用模式两大方面进行阐述,以期揭示茄科作物中miRNA低温胁迫下相应的分子机制,为培育耐冷新品种提供坚实的理论依据和技术支撑。  相似文献   

16.
由于其固有的生长方式,植物常常会面临诸如干旱、盐碱、极端温度和病虫害等不利因素的影响,因此,植物在漫长的进化过程中发展出一套精巧的调控机制来应对自然界中的各种环境和生物胁迫,并维持其正常的生长发育。植物基因表达的分子调控网络十分复杂,包括转录水平、转录后水平、翻译水平和翻译后水平等多个层次。转录因子介导的转录水平上的调控对于基因表达调控发挥着至关重要的作用,转录因子与靶基因启动子区的顺式元件相互作用来调控下游基因的表达。热激转录因子(heat shock factor,HSF)是真核生物中广泛存在的一类转录因子,通过识别热激元件(heat shock element,HSE)调控基因表达,从而参与植物的各种生命活动。植物HSF数量众多、功能多样、调控机制复杂精巧,不仅能够影响植物对高温、干旱、重金属等胁迫的抗性以及植物的抗病性,还参与了对植物配子形成和根发育等过程的调控。本综述归纳了植物中HSF的基本结构和分类、HSF受到的调控,重点介绍了HSF在应答各种胁迫条件和调控植物生长发育中的研究进展,并对植物HSF研究中有待进一步阐明的问题进行了探讨和展望,以期为植物的抗逆性改良和分子育种中潜在候选基因的选择提供参考依据。  相似文献   

17.
Chickpea (Cicer arietinum L.) is a dry season food legume largely grown on residual soil moisture after the rainy season. The crop often experiences moisture stress towards end of the crop season (terminal drought). The crop may also face heat stress at the reproductive stage if sowing is delayed. The breeding approaches for improving adaptation to these stresses include the development of varieties with early maturity and enhanced abiotic stress tolerance. Several varieties with improved drought tolerance have been developed by selecting for grain yield under moisture stress conditions. Similarly, selection for pod set in the crop subjected to heat stress during reproductive stage has helped in the development of heat‐tolerant varieties. A genomic region, called QTL‐hotspot, controlling several drought tolerance‐related traits has been introgressed into several popular cultivars using marker‐assisted backcrossing (MABC), and introgression lines giving significantly higher yield than the popular cultivars have been identified. Multiparent advanced generation intercross (MAGIC) approach has been found promising in enhancing genetic recombination and developing lines with enhanced tolerance to terminal drought and heat stresses.  相似文献   

18.
High temperature and drought stress are projected to reduce crop yields and threaten food security. While effects of heat and drought on crop growth and yield have been studied separately, little is known about the combined effect of these stressors. We studied detrimental effects of high temperature, drought stress and combined heat and drought stress around anthesis on yield and its components for three wheat cultivars originating from Germany and Iran. We found that effects of combined heat and drought on the studied physiological and yield traits were considerably stronger than those of the individual stress factors alone, but the magnitude of the effects varied for specific growth‐ and yield‐related traits. Single grain weight was reduced under drought stress by 13%–27% and under combined heat and drought stress by 43%–83% but not by heat stress alone. Heat stress significantly decreased grain number by 14%–28%, grain yield by 16%–25% and straw yield by 15%–25%. Cultivar responses were similar for heat but different for drought and combined heat and drought treatments. We conclude that heat stress as imposed in this study is less detrimental than the effects of those other studied stresses on growth and yield traits.  相似文献   

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Wheat cellular thermotolerance is related to yield under heat stress   总被引:3,自引:0,他引:3  
Cellular thermotolerance in terms of cellular membrane thermostability is often implied as an indication of crop heat tolerance and it is therefore considered as a possible selection criterion for heat tolerance. While there is ample genetic variability for cellular thermotolerance in wheat and other crop plants its relations to yield under heat stress is not sufficiently established. This study was performed to assess the genetic relations in wheat between cellular thermotolerance and yield under heat stress. In one study the co-segregation among cellular membrane thermostability (CMS), yield under chronic heat stress and yield under non-stress conditions was evaluated in a random inbred line (RIL) population of a cross between heat resistant (Danbata) and heat susceptible (Nacozari) cultivars. In a second study the same association was evaluated for yield under heat stress in 49 F7 breeding lines randomly selected from a breeding program. CMS was assayed in growth chamber grown and heat-hardened seedlings. Yield was evaluated under Mediterranean summer irrigated conditions where chronic heat stress caused a reduction in mean yield of the RIL population by 47% as compared with the normal winter growing conditions (non-stress). The RILs varied significantly (p<0.05) for CMS, biomass and yield under stress and non-stress conditions. The two parent cultivars did not differ in biomass or yield under non-stress (winter) conditions but they widely differed for both traits under heat stress. Yield of RILs under heat stress was well distributed between the extreme values of the parent cultivars. There was a significant RIL by season interaction for biomass (F = 9.74; p<0.0001) and yield (F = 10.08; p<0.0001), indicating specific adaptation to heat stress of certain lines in terms of their productivity. Broad-sense heritability for yield was high and nearly the same in the winter (h 2=0.71)and the summer (h 2=0.67). Broad-sense heritability for CMS was high (h 2=0.74). CMS was positively and significantly (p<0.01) correlated across 98 RILs with biomass (r = 0.60* *) and yield (r = 0.53**) under stress but rot with biomass or yield under non-stress conditions. The 49 breeding lines varied significantly (p<0.01) for CMS and yield under chronic heat stress in the summer season. CMS and yield were significantly correlated (r = 0.56**) across lines. Overall the associations between CMS and yield under heat stress were reasonably strong and significant but not perfect. Other factors besides cellular thermostability may support yield under heat stress. CMS alone cannot be used as the exclusive selection criterion for heat tolerance in wheat breeding. lt may be valuable as a supplemental criterion in the final breeding stages or as a rough selection tool to reduce a large population into the most likely heat tolerant core at the early stages of the breeding program.  相似文献   

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