1-甲基环丙烯对低温贮藏的香蕉果实后熟的影响

香蕉果实先在6℃下贮藏不同时间后转入常温用1-甲基环丙烯(1-MCP)处理或先以1-MCP处理后转入6℃下贮藏不同时间,然后在常温下用乙烯利处理,结果表明, 经1-MCP处理过的果实对乙烯不敏感,后熟过程受抑;而未经1-MCP处理的果实能够后熟,并有明显的呼吸及乙烯峰出现.     

香蕉一个Ⅲ类酸性几丁质酶基因与果实成熟关系的研究

为了解Ⅲ类酸性几丁质酶基因(MaCHⅢ)与香蕉果实采后成熟过程的相互关系,对经乙烯和1-甲基环丙烯(1-MCP)处理的巴西香蕉果实采后乙烯释放量、Ⅲ类酸性几丁质酶基因(MaCHⅢ)表达以及几丁质酶活性进行了测定.结果显示:(1)乙烯催熟处理的香蕉果实,乙烯释放量比对照处理的果实提前15 d达到高峰;1-MCP处理的香蕉果实,乙烯生物合成和果实成熟明显受到了抑制.(2)外源乙烯加速了MaCHⅢ基因的下调表达和Ⅲ类酸性几丁质酶活性的下降,MaCHⅢ表达量和Ⅲ类酸性几丁质酶活性分别在采后第3天和第4天下降到最小值.(3)1-MCP处理使MaCHⅢ基因呈现上调表达,Ⅲ类酸性几丁质酶活性上升,MaCHⅢ基因表达量和Ⅲ类酸性几丁质酶活性分别在采后18 d和25 d达到高峰.研究表明,MaCHⅢ基因可能与香蕉果实采后成熟呈负相关.     

低温对梨(Pyrus communis L.)果实后熟过程中乙烯合成和反应的影响(英文)

Passe Crassane梨果实采后需经过 6 0～ 80d的低温处理才能正常后熟。为了明确低温促进果实成熟的机理 ,对果实进行了低温和低温结合 1 MCP(1 甲基环丙烯 ,乙烯作用抑制剂 )和丙烯 (乙烯类似物 )处理。研究发现 :果实经低温处理后 ,乙烯合成前体———ACC含量大幅度升高 ,而未经低温处理的果实 ,无论贮藏在空气中或用丙烯 1 0 0 0μl/L处理 ,果实中ACC、M ACC含量均保持较低水平。但冷藏前用 1 MCP处理可抑制冷藏果实或冷藏后升温的果实ACC含量的增高。这说明果实的后熟过程与低温和依赖乙烯的ACC合成酶的活性和基因的表达密切相关。未经冷藏的果实于 2 0℃下用丙烯处理 ,果实不能自发合成乙烯 ,但当果实经过冷藏后再用丙烯处理 ,则果实对丙烯的反应能力随冷藏时间延长而增强。为了进一步了解低温诱导的乙烯反应过程。我们对乙烯受体基因进行了研究。定量PCR分析结果表明 ,与拟南芥ETR1同源的基因的表达不受低温的调节。但冷藏后升温 ,或在升温后用丙烯处理时 ,mRNA含量降低。这些结果说明 ,低温可能是通过影响乙烯信号转导途径下游的其它因子而调节依赖乙烯的ETR1基因和ACC合成酶基因的表达 ,从而影响果实的成熟过程     

香蕉MaBTB基因的表达分析及亚细胞定位

利用荧光定量PCR分析在不同处理下的香蕉采后果实中MaBTB基因的表达,在正常成熟的果实中,MaBTB基因的表达与乙烯的释放量呈正相关;相反,在1-MCP处理的香蕉果实中,该基因的表达相对变化不明显;用乙烯处理的香蕉果实,其表达量在第3天达到高峰,比正常成熟的早11 d。这些结果表明MaBTB基因在香蕉采后果实中是受乙烯诱导表达的。最后,亚细胞定位分析表明MaBTB基因定位在细胞核上。     

香蕉ASR的特征和采后表达分析

从香蕉cDNA文库中获得香蕉ASR全长cDNA序列,命名为MaASR。构建遗传进化树发现MaASR与单子叶植物中的芭蕉科植物的亲缘关系较近。对正常成熟和乙烯处理的香蕉果实各时期内源ABA的含量进行测定,结果表明,在正常成熟的香蕉果实中,成熟早期(0-2 d),内源ABA含量相对较低,第8天ABA含量达到最大,随后迅速下降。在乙烯处理的香蕉果实中,ABA含量急剧上升,第3天ABA含量达到高峰,随后逐渐下降。利用荧光定量RT-PCR对MaASR在正常成熟和乙烯处理后的果实中的表达情况进行分析,在自然成熟的果实中,MaASR在采后2 d达到高峰,而后迅速下降,在6-16 d时一直保持较低水平。在经外源乙烯诱导的果实中,MaASR表达水平没有表现出剧烈变化的趋势,整体表达量较低。表明MaASR对乙烯信号有应答,但应答强度较低,其表达趋势与ABA的含量或者信号强度呈负相关。     

柿果实采后氧化还原电位与乙烯合成和相关酶活性的关系

该研究以广西特色柿品种‘恭城月柿''为材料,在采后贮藏过程中对其氧化还原电位(ORP)、乙烯生物合成量、硬度、色差、抗氧化酶及细胞壁降解酶活性的变化进行了测定,初步探讨柿果实氧化还原电位与乙烯生物合成和相关酶活性的关系。结果表明:贮藏期果实的硬度整体呈下降趋势,乙烯利处理果实的硬度从采后3 d即急速下降,至贮藏末期始终显著低于对照。贮藏前14 d果实转色较缓慢,采后15 d乙烯利处理果实的总色差ΔE值快速上升至29.6,转色完全,显著高于对照的11.9。在贮藏前期处理和对照果实的ORP均稳定在7.5 mv·g^-1,采后15 d乙烯利处理果实的ORP快速上升至11.9 mv·g^-1,是对照组的1.4倍。乙烯利处理果实的乙烯生物合成量在贮藏前期呈较低水平,采后15 d乙烯生成量急剧增加至0.372 μL·kg^-1·h^-1的高峰,对照乙烯生成量则始终维持在0.033 μL·kg^-1·h^-1的较低水平。可见,乙烯生成量的增加与ORP的上升关系密切。此外,抗氧化酶中的过氧化物酶(POD)和细胞壁降解酶中的β-D-半乳糖苷酶(β-D-Gal)活性与ORP呈极显著正相关,表明二者受果实ORP变化的影响。因此,经乙烯利处理柿果实的ORP贮藏末期显著上升,促进乙烯生物合成量的急剧增加,诱导抗氧化酶POD和细胞壁降解酶 β-D-Gal活性增强,导致果实急速后熟软化。柿果实ORP可能作为开关调控1-氨基环丙烷-1-羧酸(ACC)生成乙烯这一生物化学反应,即打破ORP的稳定状态引发乙烯合成的启动。     

枇杷成花相关基因EjWRKY12的克隆及表达分析（“园艺植物种质资源挖掘与利用”专题约稿）

以库尔勒香梨为试材,在大蕾期喷施不同浓度乙烯利,调查库尔勒香梨萼片脱落率,观测果实生长发育进程和落果情况,测定成熟期果实品质,并基于主成分分析法对乙烯利处理下的果实品质进行综合评价,以揭示乙烯利对库尔勒香梨果实生长发育进程和果实品质的影响,为筛选最优乙烯利浓度应用于提高库尔勒香梨果实品质提供理论依据和技术支持。结果表明：(1)2021年自然生长状态下(对照)库尔勒香梨萼片脱落时间为9 d,不同浓度乙烯利处理后脱落时间会缩短1~2 d,且随着处理浓度梯度的升高,萼片脱落时间和萼片脱落高峰提前。(2)库尔勒香梨果实生长发育期约为130 d,乙烯利处理下和自然状态下的果实生长发育均呈“S”型曲线的变化趋势;乙烯利处理明显加快了果实成熟的速度,果实在花后110 d左右已达到成熟标准,从而可以确定合理的采收时间,并以300 mg·L^-1乙烯利处理下脱萼果和宿萼果的纵横径和单果重增长最大;乙烯利处理下库尔勒香梨在第二次果实膨大期间落果较多,在花后50 d和110 d左右出现落果高峰,并以200 mg·L^-1乙烯利处理对库尔勒香梨果形指数和落果率的影响最明显。(3)300 mg·L^-1乙烯利处理对库尔勒香梨果实品质影响最大,宿萼果纵、横径和单果重较对照分别显著增加5.02%、10.90%和11.40%,脱萼果鲜干比重、可溶性固形物含量、VC含量和可溶性糖含量比对照分别显著提高5.67%、12.03%、21.48%和10.22%,脱萼果硬度和可滴定酸含量比对照分别显著降低10.10%和19.75%。(4)主成分分析显示,各浓度乙烯利处理下库尔勒香梨综合品质得分从高到低依次为300 mg·L^-1脱萼果、300 mg·L^-1宿萼果、200 mg·L^-1宿萼果、200 mg·L^-1脱萼果、100 mg·L^-1脱萼果、100 mg·L^-1宿萼果、CK脱萼果和CK宿萼果。研究发现,大蕾期喷施乙烯利促进了库尔勒香梨萼片的脱落,明显加快了果实的生长发育进程,并可有效提高果实品质,且以300 mg·L^-1乙烯利处理对库尔勒香梨果实品质改善效果最优。     

低温对梨（Pyrus communis L.）果实后熟过程中乙烯合成和反？…

Ｐａｓｓｅ－Ｃｒａｓｓａｎｅ梨果实采后需经过６０－８０ｄ的低温处理才能正常后熟。为了明确促进果实成熟的机理,对果实进行了低温结合１－ＭＣＰ（１－甲基环丙烯,乙烯作用抑制剂）和丙烯（乙烯类似物）处理。研究发现：果实经低温处理后,乙烯合成前体－－ＡＣＣ含量大幅度升高,而未经低温处理的果实,无论贮藏在空气中或用丙烯１０００μｌ／Ｌ处理,果实中ＡＣＣ、Ｍ－ＡＣＣ含量均保持较低水平。但冷藏前用１－ＭＣＰ处理     

新型乙烯受体抑制剂—1—甲基环丙烯在采后园艺作物中的应用

近年来,随着1－甲苯环丙烯（1－methylcyclopropene,1-MCP)作为乙烯受体抑制剂的发现,为控制乙烯敏感型的采后果实后熟和采后蔬菜,切花衰老提供了亲的技术手段,文章从1－MCP的作用机理和特点对其在采后园艺作物中的应用前景作了简述。     

PRO—LONG涂膜处理对后熟香蕉果实乙烯形成以及其它有关生…

香蕉果实采后以商业上推荐使用的１．５％Ｐｒｏ－ｌｏｎｇ溶液处理,贮藏于２０℃和７５％相对湿度下,分别测定果实的ＡＣＣ含量、ＭＡＣＣ含量、ＥＦＥ酶活性、乙烯释放、叶绿素含量的变化和果实的硬度变化。结果表明,ＰＲＯ－ＬＯＮＧ处理延缓了香蕉果实果皮的叶绿素降解、硬度的下降以及乙烯释放的增加。在后熟过程中,处理果实的ＡＣＣ含量发生积累。ＡＣＣ含量的高峰在乙烯释放高峰和ＥＦＥ酶活性高峰之前出现。与对照比较,     

Responses of banana fruit to treatment with 1-methylcyclopropene

Experiments were conducted to determine levels of 1-methylcyclopropene (1-MCP) exposure needed to prevent ethylene-stimulated banana fruit ripening, characterise responses of ethylene-treated fruit to subsequent treatment with 1-MCP, and to test effects of subsequent ethylene treatment on 1-MCP-treated fruit softening. Fruit softening was measured at 20°C and 90% relative humidity. One hour exposure at 20°C to 1000 nl 1-MCP/l essentially eliminated ethylene-stimulated ripening effects. Exposure for 12 h at 20°C to just 50 nl 1-MCP/l was similarly effective. Fruit ripening initiated by ethylene treatment could also be delayed with subsequent 1-MCP treatment. However, 1-MCP treatment only slowed down ripening of ethylene-treated fruit when applied at 1 day after ethylene and was ineffective when applied 3 or 5 days after ethylene treatment. The ripening response of fruit treated with 1-MCP and subsequently treated with ethylene varied with interval time between 1-MCP and ethylene treatments. As time increased, the response of 1-MCP-treated fruit to ethylene was enhanced. Responses to 0.1, 1, 10 or 100 µl ethylene/l concentrations were similar. Enzyme kinetic analysis applied to 1-MCP effects on ethylene-induced softening of banana fruit suggested that 1-MCP inhibition is by noncompetitive antagonism of ethylene binding.     

CO2和1-MCP组合处理对磨盘柿贮藏效果的影响

以磨盘柿采后果实为材料,研究1-MCP的处理以及CO2脱涩与1-MCP组合处理对磨盘柿室温和0~1℃贮藏过程中果实硬度、可溶性单宁含量、总抗坏血酸(TAA)含量以及抗氧化活性的影响。结果显示:(1)贮藏过程中柿果实硬度随时间延长呈下降趋势,室温贮藏CO2处理5 d、CO2处理后进行1-MCP(CO2//1-MCP)处理10 d、1-MCP处理后进行CO2(1-MCP//CO2)处理15 d、CO2与1-MCP同时(CO2+1-MCP)处理30 d均完全软化,0~1℃贮藏75 d后硬度最高的是CO2+1-MCP处理(12.43 kg.cm-2),最低的是CO2//1-MCP处理(2.80 kg.cm-2),甚至低于CO2处理(5.71 kg.cm-2);(2)柿果实可溶性单宁和总抗坏血酸(TAA)含量与脱涩有关,CO2处理、CO2//1-MCP处理、1-MCP//CO2处理和CO2+1-MCP处理大幅低于CK和1-MCP处理,1-MCP处理抑制了可溶性单宁和TAA含量的下降;(3)室温贮藏中除CO2处理之外的处理柿果实总酚含量呈小幅上升趋势,0~1℃贮藏中CK、1-MCP处理、1-MCP//CO2处理和CO2+1-MCP处理的总酚含量稳定在9.91~12.38 mg.g-1FW之间,CO2处理和CO2//1-MCP处理于30 d之后迅速下降,至75 d时分别只有6.83和6.32 mg.g-1FW;(4)各组处理柿果实ABTS自由基清除能力和氧自由基清除能力值(ORAC)的变化趋势与总酚含量大致相当。研究发现,1-MCP能有效阻止磨盘柿果实贮藏期间的硬度、可溶性单宁含量、TAA含量以及抗氧化活性的下降,CO2脱涩与1-MCP处理的不同顺序对硬度和抗氧化活性影响巨大,但对可溶性单宁和TAA含量影响甚微;先CO2脱涩后1-MCP处理对磨盘柿贮藏效应影响不大,1-MCP处理和高浓度CO2脱涩同时进行是磨盘柿脱涩保鲜的最优方案。     

Growth inhibition of pollen tubes by blocking the aromatic or branched-chain amino acid pathways of biosynthesis

A number of organic molecules that appear to block the ethylene receptor have been discovered recently. For example, on irradiation with visible light, diazocyclopentadiene (DACP), gives rise to some potent but as yet unidentified inhibitor compounds. Some synthetic cyclopropenes have been shown to bind to the ethylene receptor and prevent the physiological action of ethylene for extended periods. Cyclopropene (CP). 1-methylcyclopropene (1-MCP) and 3,3-dimethylcyclopropene (3,3-DMCP) have been shown to prevent ethylene effects in a number of plants. As low a concentration as 0.5 nl l⁻¹ of 1-MCP is sufficient to protect carnation ( Dianthus caryophyllus ) flowers for several days against ethylene, and 0.7 nl l⁻¹ 1-MCP or CP will prevent the ripening of banana ( Musa sapientum ) for 12 days at 24°C. Some plant organs require higher concentrations of these inhibitors. Complete inhibition of ethylene effects in pea seedlings requires treatment with 40 n1 1⁻¹ of 1-MCP. These novel inhibitors appear to be suitable for many commercial applications including extending the vase life of cut flowers and the display life of potted plants. Since 1-MCP apparently is non-toxic at concentrations that are active, it may in future be available for regulating the ripening of fruits and preventing the deleterious effects of ethylene in vegetables.     

Analysis of physiological and biochemical changes in kiwifruit (Actinidia deliciosa cv. Allison) after the postharvest treatment with 1-Methylcyclopropene

Kiwifruits have limited shelf life under ambient conditions. However, it is necessary to extend its life so as to make it available for longer time in the market and to make it commercial fruits in India. Hence, the present study was designed to observe the effect of different concentrations of 1-Methylcyclopropene (1-MCP) on physiological and biochemical parameters which have great influence on post harvest life and quality of kiwifruits. Kiwifruits cv. Allison was treated with different concentrations of 1-Methylcyclopropene (0.5 μL/L, 1 μL/L, 2 μL/L) and un-treated fruits served as control. 1-MCP treatment was given for 24 h at 20°C. After treatments, the fruits were transferred to ambient storage, and observations on different physiological and biochemical parameters were recorded at 3 days interval. Our results indicated that all concentrations of 1-MCP delayed ripening of kiwifruits but 2 μL/L concentrations was the most effective in doing so. Fruits treated with 1-MCP at 2 μL/L started ripening after 12th day of storage whereas untreated fruits started ripening even on 6th day. Polygalactouronase (PG) and lipoxygenase (LOX) enzyme activities were lesser in 1-MCP treated fruits than control. 1-MCP treated fruits respired less and evolved lesser ethylene.     

The use of 1-methylcyclopropene (1-MCP) on fruits and vegetables

The recent availability of the inhibitor of ethylene perception, 1-methylcyclopropene (1-MCP), has resulted in an explosion of research on its effects on fruits and vegetables, both as a tool to further investigate the role of ethylene in ripening and senescence, and as a commercial technology to improve maintenance of product quality. The commercialization of 1-MCP was followed by rapid adoption by many apple industries around the world, and strengths and weaknesses of the new technology have been identified. However, use of 1-MCP remains limited for other products, and therefore it is still necessary to speculate on its commercial potential for most fruits and vegetables. In this review, the effects of 1-MCP on fruits and vegetables are considered from two aspects. First, a selected number of fruit (apple, avocado, banana, pear, peaches and nectarines, plums and tomato) are used to illustrate the range of responses to 1-MCP, and indicate possible benefits and limitations for commercialization of 1-MCP-based technology. Second, an outline of general physiological and biochemical responses of fruits and vegetables to the chemical is provided to illustrate the potential for use of 1-MCP to better understand the role of ethylene in ripening and senescence processes.     

1-甲基环丙烯采后处理对樱桃番茄果实成熟过程的影响

研究了不同浓度(0、0.035、0.07和0.11μL/L)的乙烯受体竞争性抑制剂1-甲基环丙烯(1-MCP)采后处理对绿熟期樱桃番茄的乙烯合成、果实软化、果实色素(叶绿素、茄红素、β-胡萝卜素)含量消长的影响.0.07 μL/L及其以上浓度的1-MCP降低了前期乙烯合成,同时推迟了乙烯释放高峰,但0.035 μL/L浓度的1-MCP处理并不能抑制内源乙烯合成.1-MCP显著延迟了果实软化和叶绿素降解,但并不影响这两个过程的启动.茄红素合成的启动和积累均受到了1-MCP抑制,而1-MCP并不推迟β-胡萝卜素合成的启动,只抑制其积累.这些结果提示了乙烯调节成熟生理过程的不同机制.对于绿熟期的樱桃番茄,0.07～0.11μL/L的1-MCP是实用的有效处理浓度.1-MCP有效浓度可能用于了解果实的乙烯受体水平和乙烯敏感性.     

Effect of Abscisic Acid on Banana Fruit Ripening in Relation to the Role of Ethylene

Abstract The role of abscisic acid (ABA) in banana fruit ripening was examined with the ethylene binding inhibitor, 1-methylcyclopropene (1-MCP). ABA (0, 10⁻⁵, 10⁻⁴, or 10⁻³ mol/L) was applied by vacuum infiltration into fruit. 1-MCP (1 μL/L) was applied by injecting a measured volume of stock gas into sealed glass jars containing fruit. Fruit ripening, as judged by ethylene evolution and respiration associated with color change and softening, was accelerated by 10⁻⁴ or 10⁻³ mol/L ABA. ABA at 10⁻⁵ mol/L had no effect. The acceleration of ripening by ABA was greater at 10⁻³ mol/L than at 10⁻⁴ mol/L. ABA-induced acceleration of banana fruit ripening was not observed in 1-MCP treated fruit, especially when ABA was applied after exposure to 1-MCP. Thus, ABA's promotion of ripening in intact banana fruit is at least partially mediated by ethylene. Exposure of ABA-treated fruit to 0.1 μL/L ethylene for 24 h resulted in increased ethylene production and respiration, and associated skin color change and fruit softening. Control fruit (no ABA) was unresponsive to similar ethylene treatments. The data suggest that ABA facilitates initiation and progress in the sequence of ethylene-mediated ripening events, possibly by enhancing the sensitivity to ethylene. Received 29 January 1999; accepted 16 January 2000