生长素与乙烯对兰花授粉后花发育的调节作用

以朵丽蝶兰为材料,对乙烯和生长素调节的授粉后花的发育进行了研究。实验结果显示,切花和植株上的花授粉后,乙烯的产生和发育无明显差异;花瓣的衰老,子房发育,花粉萌发和花粉管的伸长受乙烯调节;与切花相比,植株上花的子房内无ＡＣＣ合酶和ＡＣＣ氧化酶ｍＲＮＡ的积累。     

生长素与乙烯对兰花授粉后花发育的调节作用(英文)

以朵丽蝶兰为材料,对乙烯和生长素调节的授粉后花的发育进行了研究。实验结果显示,切花和植株上的花授粉后,乙烯的产生和花的发育无明显差异;花瓣的衰老、子房发育、花粉萌发和花粉管的伸长受乙烯调节;与切花相比,植株上花的子房内无ＡＣＣ合酶和ＡＣＣ 氧化酶ｍＲＮＡ 的积累。用生长素运输抑制剂２ ［（１ｎａｐｈｔｈａｌｅｎｙｌａｍｉｎｏ）ｃａｒｂｏｎｙｌ］ ｂｅｎｚｏｉｃａｃｉｄ（ＮＰＡ） 处理柱头,授粉诱导的子房发育在很大程度上受到抑制, 表明授粉后子房的发育需要转运来的生长素。     

授粉诱导兰花花部乙烯生物合成基因在转录水平上的表达

朵丽蝶兰（Ｄｏｒｉｔａｅｎｏｐｓｉｓｈｙｂｒｉｄａ Ｈｏｒｔ．）的花授粉后,测定乙烯的产生,并分析授粉后花部各器官乙烯生物合成的ＡＣＣ合成酶和ＡＣＣ氧化酶两个基因转录水平上的表达。授粉后在花部均可探测到ＡＣＣ合成酶和ＡＣＣ氧化酶的ｍ ＲＮＡ。在花部不同器官之间,此两种酶的ｍ ＲＮＡ的积累水平均表现出一些差异。ＡＣＣ合成酶的ｍ ＲＮＡ 积累与ＡＣＣ氧化酶相比,具有更明显的特异性。而ＡＣＣ氧化酶ｍ ＲＮＡ 的积累水平远比ＡＣＣ合成酶高     

授粉诱导蝴蝶兰雌蕊中乙烯合成和ACC氧化酶基因表达

对蝴蝶兰（Ｐｈａｌａｅｎｏｐｓｉｓ “Ｇｅｎｅｒａｌｋｕ”ｈｏｒ．）在授粉后乙烯的合成和１－氨基环丙烷－１－羧酸（ＡＣＣ）氧化酶基因的表达进行了研究。实验结果显示在授粉后１２、２４ 和４８ ｈ,柱头和花柱中乙烯的产生和ＡＣＣ氧化酶ｍ ＲＮＡ 的积累显著下降,而子房中则明显上升,表明授粉后雌蕊中乙烯的产生与ＡＣＣ氧化酶基因的表达密切相关。此外,授粉后雌蕊的柱头中合成的乙烯相对量最多,花柱次之,子房中则较少     

植物乙烯生物合成研究进展

本文对植物体内乙烯生物合成途径中控制ＡＣＣ合成及代谢的三种酶：ＡＣＣ合酶,ＡＣＣ氧化酶和ＡＣＣ：Ｎ－丙二酰基转移酶的特性、基因家庭及其表达等方面的问题进行了评述。     

乙烯和1-氨基环丙烷-1-羧酸合酶基因参与玫瑰花发育过程中细胞程序化死亡的调控

作为植物有性繁殖器官--花的花瓣通常生命周期短,其中有一个敏感的、严格控制的细胞程序化死亡过程.为了揭示细胞程序化死亡过程中发生的反应或者其组成成分,解释玫瑰花发育过程中的细胞程序化死亡过程的机理,测定了在整个花发育过程中玫瑰花瓣的乙烯释放速率、ACC合酶基因的转录产物(mRNA)、ACC合酶活性以及ACC含量.结果显示在花发育过程前期(阶段1、2)检测不到乙烯产生,在花瓣完全绽开时花瓣中乙烯开始产生.在花发育后期(阶段4、5)花的衰老与乙烯释放速率的升高同时发生.在花发育前期没有ACC合酶基因的转录产物积累,该基因在花瓣完全绽开时开始表达,在花发育后期逐渐增强.ACC合酶活性与ACC含量的变化趋势与乙烯的一致.在玫瑰花发育后期乙烯诱导和调控花瓣的细胞程序化死亡.ACC合酶基因、ACC合酶以及ACC都是玫瑰花瓣程序化死亡过程中的重要调控因子.     

花同源异型基因FBP2调节叶片中过氧化物酶的表达

对碧冬茄和烟草的野生型以及ＲＢＰ２转化植ｔｒａｎｓｆｏｒｍａｎｔ）叶片中过氧化物酶（ＰＯＤ）的特笥做了分析,结果表明ＦＢＰ２在花中的可以调节叶片特异ＰＯＤ的表达,并影响其活性。此外,ＦＢＰ２在花中的表达还影响叶片内源植物生长物质的水平以及多酚氧化酶（ＰＰＯ）和过氧化氢酶（ＣＡＴ）的活性。结果表明：花同源异型基因不仅调控花器官的发育,而且参与营养器官代谢的调节,使之适应于生殖器官的生长发育。     

紫外线对大鼠晶状体抗氧化酶mRNA表达水平的影响

为探讨紫外线对晶状体的损伤机制,用ＲＴ－ＰＣＲ方法（ｒｅｖｅｒｓｅｔｒａｎｓｃｒｉｐｔｉｏｎ－ｐｏｌｙｍｅｒａｓｅｃｈａｉｎｒｅａｃｔｉｏｎ,反转录聚合酶链反应）,研究经紫外线照射后大鼠晶状体抗氧化相关酶,包括铜锌－超氧化物歧化酶（ｃｏｐｐｅｒ－ｚｉｎｃ－ｓｕｐｅｒｏｘｉｄｅｄｉｓｍｕｔａｓｅ,Ｃｕ－Ｚｎ－ＳＯＤ）,谷胱甘肽过氧化物酶（ｇｌｕ－ｔａｔｈｉｏｎｅｐｅｒｏｘｉｄａｓｅ,ＧＳＨ－Ｐｘ）和过氧化氢酶（ｃａｔａｌａｓｅ,ＣＡＴ）等ｍＲＮＡ的表达．结果显示,短时间的照射（２～５ｍｉｎ）,抗氧化相关酶的ｍＲＮＡ表达水平有增高表现,随后其ｍＲＮＡ表达水平开始下降,１５ｍｉｎ时抗氧化相关酶ｍＲＮＡ的表达下降更为明显,与对照组相比有非常显著性差异（Ｐ＜０．００１）．照射后２４ｈ,抗氧化相关酶的ｍＲＮＡ表达有不同程度的恢复;照射后４８ｈ,其ｍＲＮＡ表达水平基本恢复,与对照组相比没有显著性差异．从而从基因水平上初步探讨了紫外线的氧化损伤机制     

果实成熟的基因工程研究

乙烯是催化果实成熟的内源植物激素。本文简要介绍用植物基因工程的手段分离和鉴定出乙烯合成和果实成熟有关的多聚半乳糖醛酸酶、ＡＣＣ氧化酶、ＡＣＣ合酶及ＡＣＣ脱氨酶的基因。并利用反意ＲＮＡ技术将它们的反意ＲＮＡ转入番茄中,得到了相应的反意转基因植株和果实,实现了在基因水平上对果实成熟的调控,开辟了植物育种的新途径。     

人白介素－3基因表达调节的研究

报导了ｈ－ＩＬ－３基因表达调节研究的结果：（１）人静止的外周血淋巴细胞几乎不表达ＩＬ－３ｍＲＮＡ,但受丝裂原ＰＨＡ的刺激后则诱导ＩＬ－３ｍＲＮＡ表达,ＴＰＡ与ＰＨＡ联合处理,使ＩＬ－３ｍＲＮＡ的蓄积进一步增加,但ＴＰＡ单独不足以诱导ＩＬ－３ｍＲＮＡ蓄积;（２）Ａ２３１８７／ＴＰＡ能代替ＰＨＡ／ＴＰＡ的刺激,并直接诱导ＩＬ－３ｍＲＮＡ表达;（３）ＴＲＥＯＤＮ处理则显著抑制ＰＨＡ／ＴＰＡ诱导的ＩＬ－３ｍＲＮＡ表达。这些结果揭示：ｈ－ＩＬ－３基因的表达在转录及转录后水平被调节,而且是可诱导的,诱导ｈ－ＩＬ－３基因表达、需要Ｃａ２＋依赖及ＰＫＣ依赖的两个信息转导系统,Ｆｏｓ蛋白是反式激活ＩＬ－３基因表达的转录因子,ＰＫＣ依赖的转导系统,可能与ＩＬ－３ｍＲＮＡ的稳定性有关。     

Expression of Ethylene Biosynthetic Genes Regulated by Pollination associated Factors in Doritaenopsis hybrida Flowers

Pollination of flowers initiates postpollination development in orchid ( Doritaenopsis hybrida Hort. ) flowers, including perianth senescence, stigma closure, and ovary development. Because ethylene is thought to play a key role in coordinating these developmental changes, the authors studied the temporal and spatial patterns of expression of genes encoding 1-aminocyclopropane-l-carboxylic acid (ACC) synthase and ACC oxidase following pollination-associated factor treatments in orchid flowers. Both ACC synthase and ACC oxidase mRNA accumulation in the various parts of the flowers is induced by auxin, and ethylene, but not by emasculation. The patterns of both ACC synthase and ACC oxidase mRNA accumulation are similar in all floral organs following auxin and ethylene treatments. Further, in situ hybridization analysis indicates that the ACC oxidase mRNA is localized in epidermal and parenchyma cells of the stigma after auxin and ethylene treatments. The putative roles of auxin, ethylene and emasculation are discussed in terms of the regulation of ACC synthase and ACC oxidase gene expression in flowers.     

Pollination-Induced Expression of Ethylene Biosynthetic Genes at Transcription Level in Orchid Flowers

The authors investigated pollination-induced ethylene production and expression patterns of genes encoding 1-aminocyclopropane-l-carboxylate (ACC) synthase and ACC oxidase in orchid flowers (Doritaenopsis hybrida Hort. ). Following pollination both ACC synthase and ACC oxidase mRNAs were detected in the different organs of flowers, and the patterns of both ACC synthase and ACC oxidase mRNA accumulation were similar, mRNA accumulation of ACC synthase mRNA was more organ-specific than that of ACC oxidase mRNA. However, ACC oxidase mRNAs were much more abundant than ACC synthase mRNAs in the flower organs.     

Three 1-Aminocyclopropane-1-Carboxylate Synthase Genes Regulated by Primary and Secondary Pollination Signals in Orchid Flowers

The temporal and spatial expression patterns of three 1-aminocyclopropane-1-carboxylate (ACC) synthase genes were investigated in pollinated orchid (Phalaenopsis spp.) flowers. Pollination signals initiate a cascade of development events in multiple floral organs, including the induction of ethylene biosynthesis, which coordinates several postpollination developmental responses. The initiation and propagation of ethylene biosynthesis is regulated by the coordinated expression of three distinct ACC synthase genes in orchid flowers. One ACC synthase gene (Phal-ACS1) is regulated by ethylene and participates in amplification and interorgan transmission of the pollination signal, as we have previously described in a related orchid genus. Two additional ACC synthase genes (Phal-ACS2 and Phal-ACS3) are expressed primarily in the stigma and ovary of pollinated orchid flowers. Phal-ACS2 mRNA accumulated in the stigma within 1 h after pollination, whereas Phal-ACS1 mRNA was not detected until 6 h after pollination. Similar to the expression of Phal-ACS2, the Phal-ACS3 gene was expressed within 2 h after pollination in the ovary. Exogenous application of auxin, but not ACC, mimicked pollination by stimulating a rapid increase in ACC synthase activity in the stigma and ovary and inducing Phal-ACS2 and Phal-ACS3 mRNA accumulation in the stigma and ovary, respectively. These results provide the basis for an expanded model of interorgan regulation of three ACC synthase genes that respond to both primary (Phal-ACS2 and Phal-ACS3) and secondary (Phal-ACS1) pollination signals.     

Pollination-Induced Ethylene Synthesis and 1-Aminocyclopropane-1-Carboxylate Oxidase Gene Expression in the Gynoecium of Phalaenopsis Orchid Flower

Pollination-induced ethylene production plays an important role in regulating flower development. As gynoecium is one of the more important parts in Phalaenopsis orchid flower, the authors have investigated ethylene production and 1-aminocyclopropane-l-carboxylate (ACC) oxidase gene expression in gynoecium following pollination. Experimental studies revealed that ethylene production and ACC oxidase mRNA accumulation decreased steadily in stigma and style, in contrast, exhibited a crescendo increase in the ovary at 12.24 and 48 h after pollination, indicating a close relationship between ethylene production and ACC oxidase gene expression in the gynoecium. In addition ethylene production was found most in stigma and least in ovary among the three parts after pollination.     

Pistil-Specific and Ethylene-Regulated Expression of 1-Aminocyclopropane-1-Carboxylate Oxidase Genes in Petunia Flowers

The differential expression of the petunia 1-aminocyclopropane-1-carboxylate (ACC) oxidase gene family during flower development and senescence was investigated. ACC oxidase catalyzes the conversion of ACC to ethylene. The increase in ethylene production by petunia corollas during senescence was preceded by increased ACC oxidase mRNA and enzyme activity. Treatment of flowers with ethylene led to an increase in ethylene production, ACC oxidase mRNA, and ACC oxidase activity in corollas. In contrast, leaves did not exhibit increased ethylene production or ACC oxidase expression in response to ethylene. Gene-specific probes revealed that the ACO1 gene was expressed specifically in senescing corollas and in other floral organs following exposure to ethylene. The ACO3 and ACO4 genes were specifically expressed in developing pistil tissue. In situ hybridization experiments revealed that ACC oxidase mRNAs were specifically localized to the secretory cells of the stigma and the connective tissue of the receptacle, including the nectaries. Treatment of flower buds with ethylene led to patterns of ACC oxidase gene expression spatially distinct from the patterns observed during development. The timing and tissue specificity of ACC oxidase expression during pistil development were paralleled by physiological processes associated with reproduction, including nectar secretion, accumulation of stigmatic exudate, and development of the self-incompatible response.     

Regulatory mechanisms of ethylene biosynthesis in response to various stimuli during maturation and ripening in fig fruit (Ficus carica L.).

In order to obtain a greater uniformity of maturation, the growth of the fig fruit (Ficus carica L.) can be stimulated by the application of either olive oil, ethrel/ethephon or auxin. The three treatments induce ethylene production in figs. In this study, we investigated the regulatory mechanisms responsible for oil, auxin and ethylene induced ethylene production in figs. The ethylene production in response to olive oil, auxin, and propylene treatments and during ripening were all induced by 1-methylcyclopropene (1-MCP) and inhibited by propylene indicating a negative feedback regulation mechanism. Three 1-aminocyclopropane-1-carboxylic acid (ACC) synthase genes (Fc-ACS1, Fc-ACS2 and Fc-ACS3) and one ACC oxidase gene (Fc-ACO1) were isolated and their expression patterns in response to either oil, propylene or auxin treatment in figs determined. The expression patterns of Fc-ACS1 and Fc-ACO1 were clearly inhibited by 1-MCP and induced by propylene in oil treated and ripe fruits indicating positive regulation by ethylene, whereas Fc-ACS2 gene expression was induced by 1-MCP and inhibited by propylene indicating negative regulation by ethylene. The Fc-ACS3 mRNA showed high level accumulation in the auxin treated fruit. The inhibition of Fc-ACS3 gene by 1-MCP in oil treated and in ripe fruits suggests that auxin and ethylene modulate the expression of this gene by multi-responsive signal transduction pathway mechanisms. We further report that the olive oil-induced ethylene in figs involves the ACC-dependent pathway and that multiple ethylene regulatory pathways are involved during maturation and ripening in figs and each specific pathway depends on the inducer/stimulus.