枸杞成熟与干制过程中多糖积累的蛋白质组学 研究进展

随着后基因组时代的到来,蛋白质组学越来越广泛地应用到生命科学领域,目前主要应用于医学、生物学、植物学,近些年在食品科学方面也进行了相关研究。应用蛋白质组学在植物生长发育和成熟衰老方面的研究比较常见,但在加工环节中的应用并不多见。该方法能通过研究植物体相关蛋白质而在本质上动态地揭示植物从生长发育到成熟衰老过程的机制,为研究枸杞果实成熟及干制过程中多糖积累提供了新的思路和理论支撑。本文综述了枸杞果实成熟及干制过程中多糖积累的研究进展,简单介绍蛋白质组学、蛋白质组学的研究技术及其在植物及加工环节中的研究进展,并展望蛋白质组学技术在枸杞果实成熟及干制过程中多糖积累的研究前景,为今后蛋白质组学的应用与发展提供一定的参考和理论依据。     

脱落酸调控非跃变型果实成熟的分子机制研究进展

果实成熟是果实生长发育和衰老过程中的重要阶段,目前对跃变型果实成熟的分子机制研究取得了明显突破,而对非跃变型果实成熟机制的研究相对滞后。本文以脱落酸(abscisic acid,ABA)调控非跃变型果实成熟机制为核心,总结了目前ABA在果实成熟中的研究进展,并结合最新micro RNAs研究技术,提出了ABA在调控非跃变型果实成熟中的研究方向。     

活性氧在果实成熟和衰老中的作用及调控机制

活性氧在果实成熟及衰老阶段含量呈总体升高,且先后出现两个高峰的动态变化特征。近10年研究逐渐揭示了活性氧在果实成熟及衰老中扮演的重要调控功能。该文从活性氧在植物生长发育和抗逆中的作用、在果实成熟及衰老过程中的动态变化、参与调控果实成熟与衰老、调控果实成熟与衰老的机制、稳态调控技术在延缓果实成熟及衰老中的应用等5方面进行综述。并对该领域未来的研究方向进行展望,以期给相关学者提供参考。     

采前钙处理对冬枣成熟衰老过程中相关酶的影响

以采前经过0.2?Cl2喷洒处理5次的冬枣果实为材料,通过研究果实成熟衰老过程中蛋白质、LOX、SOD、POD和PPO活性的变化,探讨钙对果实成熟衰老的影响。结果表明,采前钙处理降低了冬枣LOX活性,提高了SOD、POD和PPO的活性,提高了冬枣采后抗氧化能力,延缓了冬枣的衰老进程。     

冬枣果实发育过程中非标记定量蛋白质组学分析

考察冬枣不同成熟阶段的蛋白质组,分析差异表达蛋白质及功能,为研究冬枣成熟发育机制提供理论依据.采集开花后第55(幼果期)、76(果实膨大期)、96(果实白熟期)、116天(果实脆熟期)的沾化冬枣样品,利用非标记定量蛋白质组学技术对4个阶段冬枣样品蛋白质组进行分析,各阶段样品与前一阶段相比,得到差异表达蛋白质,并进行基因...     

减压贮藏对鲜枣保鲜效果的影响

以梨枣和冬枣为试材 ,研究了减压贮藏对鲜枣保鲜效果的影响。结果表明 :梨枣和冬枣属于非跃变型果实 ,减压贮藏在一定程度上抑制了枣果的呼吸强度 ,减缓了淀粉降解和VC 的损失 ,减慢了枣果的转红速度 ,从而延缓了果实的成熟与衰老。     

1-MCP应用于芒果贮藏保鲜的研究进展

呼吸跃变型水果芒果对乙烯非常敏感。1-MCP是一种有效的乙烯作用抑制剂,它能抑制乙烯所诱导的与果实后熟相关的一系列生理生化反应,进而延缓采后呼吸跃变型果实的衰老进程,保持果实的贮藏品质。综述了1-MCP的作用机理及1-MCP对采后芒果的呼吸速率、乙烯产量、果实品质及生理病害等生理生化指标的研究现状,同时介绍了1-MCP结构类似物以及1-MCP结合其他保鲜方法的应用情况,并对1-MCP应用前景进行了展望,以期为1-MCP在芒果贮藏保鲜中的应用和研究提供参考。     

脱落酸的生物合成及对水果成熟的调控研究进展

作为一种重要的植物激素,脱落酸（abscisic acid,ABA）除具有引起植物芽体休眠、叶子脱落、气孔关闭、抑制植株生长和增强植物抗逆性等生理作用外,在果实生长发育和成熟衰老的过程中也具有重要的调控作用。高等植物组织中ABA生物合成主要是通过C40类胡萝卜素的间接途径来实现的。植物内源ABA的含量水平处于动态平衡状态,受其生物合成和分解代谢等因素影响,在此过程中有关基因转录表达水平和酶活性起着关键作用。内源ABA含量的升高会导致水果成熟和果肉软化,ABA可能同时调控了呼吸跃变型和呼吸非跃变型水果的成熟衰老。探究ABA的生物合成及其调控作用,对揭示水果的生长发育、品质形成、着色软化、成熟衰老等过程具有重要的现实意义。本文综述了ABA及其生成代谢相关基因调控水果成熟的研究进展,并展望了ABA在提高水果品质、延长水果货架期等方面的商业应用。     

减压贮藏对鲜枣保鲜效果的影响

以梨枣和冬枣为试材，研究了减压贮藏对鲜枣保鲜效果的影响。结果表明：梨枣和冬枣属于非跃变型果实，减压贮藏在一定程度上抑制了枣果的呼吸强度，减缓了淀粉降解和Vc的损失，减慢了枣果的转红速度，从而延缓了果实的成熟与衰老。     

外源一氧化氮熏蒸处理对番茄采后品质的影响

以跃变型果蔬番茄为试材,观测了不同浓度NO(5、10、15、20、50、100μl/L)气体对番茄采后失重、呼吸强度、果肉硬度及可溶性固形物的影响.结果表明:在室温条件下,5～20μl/L的外源NO处理能够有效控制果实的采后重量损失、果肉硬度下降,调控果实呼吸变化,控制果实可溶性固形物的变化,说明NO处理能够延缓番茄果实的采后成熟及衰老过程.     

The role of polyamines in the improvement of the shelf life of fruit

Polyamines are natural compounds involved in many growth and developmental processes with ubiquitous presence in all cells. Fruits have been the main plant organ in which a comprehensive research has been developed to get a better understanding of the role of polyamines, both endogenous and exogenous, especially during the ripening and senescence processes. The purpose of this review is to describe the latest advances about the relationship between polyamines and fruit ripening and post-harvest storage.     

香蕉MaWRKY31转录因子的特性及对MaACS1、MaACO1和MaSAG1的调控

从香蕉果实中克隆得到1个WRKY转录因子,命名为Ma WRKY31。氨基酸序列比对及进化树分析发现Ma WRKY31具有一个典型的WRKY结构域,与拟南芥WRKY31和番茄Sl WRKY6同源性较高,且同属于第Ⅱ类b亚族。实时荧光定量聚合酶链式反应表明外源乙烯处理诱导了Ma WRKY31的表达,并且随着香蕉果实的成熟衰老,其表达明显增强。亚细胞定位和转录活性分析显示Ma WRKY31定位于细胞核,是一种核蛋白,并且具有转录激活活性。双荧光素酶瞬时表达分析显示,Ma WRKY31可以激活乙烯合成基因Ma ACS1和Ma ACO1,以及成熟衰老相关基因Ma SAG1的启动子活性。这些结果表明Ma WRKY31可能通过调控乙烯合成和成熟衰老相关基因的表达来参与香蕉果实成熟衰老过程,加深了对香蕉果实成熟衰老转录调控机制的认识。     

Relation of Chemical Structure to Plant Growth-regulator Activity in the Pineapple Plant: Retarding Senescence of Pineapple Fruit with Applications of 2,4,5-Trichlorophenoxyacetic Acid and 1-Naphthaleneacetic Acid

SUMMARY: The effectiveness of 1-naphthaleneacetic acid (SNA) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) in markedly retarding further ripening of pineapple fruit and thus extending its marketable life as a fresh fruit has been demonstrated. The effects are evident at different stages of maturity and ripeness, different fruit densities, and from both pre-harvest and post-harvest applications. As little as 1 ppm of 2,4,5-T has noticeable effect, and 100 ppm appears optimum for senescence delay. For SNA, 500 ppm is an optimum level for dipping fruit. A brief wetting of the fruit is adequate. The crowns remain in better condition when not treated with growth regulator. Refrigeration can supplement the effect of the chemical in retarding senescence. Lower temperatures can retard some of the changes which even treated fruit will show, and the chemical can retard ripening changes that otherwise may take place, albeit slowly, under normal refrigeration of pineapple fruit.     

果实表面蜡质合成及乙烯和APETALA2/乙烯响应因子调控作用的研究进展

蜡质在保持果实良好外观、品质和营养成分,延缓果实衰老和延长果实货架期等方面具有重要作用。乙烯作为重要的果实激素,参与胁迫信号响应并调控果实生长发育和成熟衰老进程。目前,果实蜡质合成与转运途径被逐步阐明,同时参与该途径的蜡质合成酶和转运蛋白编码基因也在逐步被鉴定并完成功能验证,这些基因的表达可能受到乙烯和乙烯信号系统的调控。因此本文重点综述了果实蜡质的合成和调控,乙烯调控园艺作物果实蜡质合成,APETALA2/乙烯响应因子（APETALA2/ethylene-responsive factors,AP2/ERFs）调控模式植物、农作物和园艺作物果实蜡质合成等的研究进展,以期为调控果实蜡质合成的结构基因和AP2/ERFs转录因子的分析提供参考。     

NO延缓新鲜果蔬成熟衰老和提高抗性效果及作用机制研究进展

一氧化氮（nitric oxide,NO）作为一种重要的信号分子,在调节果蔬的生理及品质方面起着重要作用。本文重点介绍了采后NO处理果蔬,对延缓成熟、减轻冷害和增强抗病性的效果,概述了NO抑制果蔬成熟衰老,通过激活抗氧化体系、维持能量水平、保护细胞膜和调控CBF抗冷途径增强抗冷性,通过杀伤病原菌、调节次生代谢过程、病程相关蛋白和抗病基因的表达提高抗病性的作用机制,同时对NO在果蔬采后基础和应用方面的研究进行了展望。     

Lipoxygenase activity associated to fruit ripening and senescence in chayote (Sechium edule Jacq. Sw. cv. “virens levis”)

Lipoxygenase (LOX) enzyme activity and their putative isoforms were investigated during postharvest life in chayote fruit (Sechium edule Jacq. Sw. cv. “virens levis”). Possible associations of LOX with fruit quality parameters are discussed. Five LOX isoforms were identified (SeLOX‐1 to ?5) displaying different activity patterns during ripening and senescence as well as in roots, stems, and leaves. The probable role of SeLOX‐5 as a specific isoform linked to senescence was examined. The highest relative activity of LOX was registered in fruit tissue, followed by leaves, stem, and roots. Correlations were found between LOX and fruit composition variables such as the contents of linoleic (LA) and linolenic (LNA) acids, weight loss, CO₂ and ethylene production rates. LOX activity, and LA and LNA concentration decreased from Day 1 to Days 13–17, when early seed germination events became visible, indicating a transition stage between late fruit ripening and early senescence characterized by a deteriorative process.

Practical applications

Detrimental effects on fruit composition variables such as dehydration, weight loss, wilting, and sprouting symptoms, have been reported as the main causes that reduce the commercial quality and shelf life in chayote fruit and prevent their export to distant markets. To the best of our knowledge, the association of lipoxygenase (LOX) enzymes to non‐climacteric fruit ripening—like chayote—or their loss of commercial quality during prolonged shelf life has not yet been described. This is the first study that explores the role of chayote LOX activity in fruit, identifies various specific LOX isoforms associated to ripening or to the senescence process and provides new evidence that supports the hypothesis that putative LOX isoforms might be related to several postharvest detrimental effects on chayote fruit. This information could be useful to food processors or packers to pursue better profitability and consumer satisfaction.     

Phenylpropanoid Metabolism in Ripening Fruits

Abstract: Ripening of fleshy fruit is a differentiation process involving biochemical and biophysical changes that lead to the accumulation of sugars and subsequent changes in tissue texture. Also affected are phenolic compounds, which confer color, flavor/aroma, and resistance to pathogen invasion and adverse environmental conditions. These phenolic compounds, which are the products of branches of the phenylpropanoid pathway, appear to be closely linked to fruit ripening processes. Three key enzymes of the phenylpropanoid pathway, namely phenylalanine ammonia lyase, O‐methyltransferase, and cinnamyl alcohol dehydrogenase (CAD) have been reported to modulate various end products including lignin and protect plants against adverse conditions. In addition, peroxidase, the enzyme following CAD in the phenylpropanoid pathway, has also been associated with injury, wound repair, and disease resistance. However, the role of these enzymes in fruit ripening is a matter of only recent investigation and information is lacking on the relationships between phenylpropanoid metabolism and fruit ripening processes. Understanding the role of these enzymes in fruit ripening and their manipulation may possibly be valuable for delineating the regulatory network that controls the expression of ripening genes in fruit. This review elucidates the functional characterization of these key phenylpropanoid biosynthetic enzymes/genes during fruit ripening processes.     

Decrease in Fruit Moisture Content Heralds and Might Launch the Onset of Ripening Processes

Abstract: It is known that fruit ripening is a genetically programmed event but it is not entirely clear what metabolic cue(s) stimulate the onset of ripening, ethylene action notwithstanding. Here, we examined the conjecture that fruit ripening might be evoked by an autonomously induced decrease in tissue water status. We found decline in water content occurring at the onset of ripening in climacteric and nonclimacteric fruit, suggesting that this phenomenon might be universal. This decline in water content persisted throughout the ripening process in some fruit, whereas in others it reversed during the progression of the ripening process. Applied ethylene also induced a decrease in water content in potato (Solanum tuberosum) tubers. In ethylene‐mutant tomato (Solanum lycopersicum) fruit (antisense to1‐aminocyclopropane carboxylate synthase), cold‐induced decline in water content stimulated onset of ripening processes apparently independently of ethylene action, suggesting cause‐and‐effect relationship between decreasing water content and onset of ripening. The decline in tissue water content, occurring naturally or induced by ethylene, was strongly correlated with a decrease in hydration (swelling) efficacy of cell wall preparations suggesting that hydration dynamics of cell walls might account for changes in tissue moisture content. Extent of cell wall swelling was, in turn, related to the degree of oxidative cross‐linking of wall‐bound phenolic acids, suggesting that oxidant‐induced wall restructuring might mediate cell wall and, thus, fruit tissue hydration status. We propose that oxidant‐induced cell wall remodeling and consequent wall dehydration might evoke stress signaling for the onset of ripening processes. Practical Application: This study suggests that decline in fruit water content is an early event in fruit ripening. This information may be used to gauge fruit maturity for appropriate harvest date and for processing. Control of fruit hydration state might be used to regulate the onset of fruit ripening.     

Changes in free and protein-bound amino acids in elderberry fruit (Sambucus nigra) during maturation

Elderberry fruit was analysed for free and protein-bound amino acids during ripening and senescence. Maturation was characterised by an appreciable decrease in the total amino acid content, free and bound, and an increase of the total free amino acid concentration. The latter was mainly due to the massive rise of leucine, tyrosine, and phenylalanine which occurred during the late stages in the ripening process. These three amino acids accounted for 68 % of the total free amino acid content in ripe fruit vs 9% in the green fruit. The transition from optimal ripeness to senescence was associated with a slight increase of the total protein-bound and free amino acid contents. Assessment of the nutritional value of elderberry protein by comparison to whole egg revealed a chemical score of 0.94 for the total essential amino acids, indicating elderberry to be a good source of high biological value protein and thus a suitable source of raw material for a variety of food and dietary products.