转反义ACS加工番茄材料的获得及其当代表现

采用农杆菌介导法将反义ACS基因导入加工番茄美东、UC-82中,用Southern杂交检测所获得的9株再生植株,结果表明有3株再生植株的染色体中有外源基因的插入。所获得的再生植株在基因转化处理当代表现各异,其中3号植株成熟延迟明显。果实转红后的色泽与对照在感官上无明显差异。转基因植株的表型观察与分子检测结果相吻合。     

Production of offspring from vacuum-dried mouse spermatozoa and assessing the effect of drying conditions on sperm DNA and embryo development

Freeze-dried sperm (FD sperm) are of great value because they can be stored at room temperature for long periods of time, However, the birth rate of offspring derived from FD sperm is low and the step in the freeze-drying process particularly responsible for low offspring production remains unknown. In this study, we determined whether the drying process was responsible for the low success rate of offspring by producing vacuum-dried sperm (VD sperm), using mouse spermatozoa dried in a vacuum without being frozen. Transfer of embryos fertilized with VD sperm to recipients resulted in the production of several successful offspring. However, the success rate was slightly lower than that of FD sperm. The volume, temperature, and viscosity of the medium were optimized to improve the birth rate. The results obtained from a comet assay indicated that decreasing the drying rate reduced the extent of DNA damage in VD sperm. Furthermore, even though the rate of blastocyst formation increased upon fertilization with VD sperm, full-term development was not improved. Analysis of chromosomal damage at the two-cell stage through an abnormal chromosome segregation (ACS) assay revealed that reduction in the drying rate failed to prevent chromosomal damage. These results indicate that the lower birth rate of offspring from FD sperm may result from the drying process rather than the freezing process.     

Ethylene treatment of ‘Hayward’ kiwifruits (Actinidia deliciosa) during ripening and its influence on ethylene biosynthesis and antioxidant activity

The aim of this investigation was to assess the influence of ethylene treatment on ethylene biosynthesis and on antioxidant activity in kiwifruits during ripening. Kiwifruits were treated with ethylene of 100 μg ml⁻¹ at 20 °C for 24 h and then the ripening process at the same temperature was observed for 10 additional days. It was found that in treated fruits: (a) the flesh firmness in the early stage of ripening was significantly decreased in treated samples, (b) the contents of free sugars, soluble solids, ethylene, respiration and sensory value were increased and were significantly higher than in untreated fruits, (c) the ethylene biosynthesis was increased simultaneously with increase in 1-aminocyclopropane-1-carboxylic acid (ACC) content, ACC synthase (ACS) and ACC oxidase (ACO) activities, (d) the polyphenols content and the related antioxidant activity were increased significantly higher than in the untreated fruits and (e) the acidity and pH were not influenced by ethylene treatment.     

牡丹ACS基因克隆及序列分析

ACC合成酶(ACS)是乙烯生物合成的关键酶。为了明确牡丹ACC合成酶基因的结构,基于报道的牡丹ACScDNA(DQ337250)序列,设计一对特异性PCR扩增引物,以洛阳红牡丹(Paeonia suffuticosa Andr.)新鲜叶片总DNA为模板,用高保真DNA聚合酶KOD-Plus成功地扩增出长度约为2 200bp的PCR产物;用pMD18-T载体对PCR产物进行了克隆,测序结果表明,牡丹ACS基因序列全长2 251bp,含4个外显子和3个内含子,剪接位点均为保守的5′供位GU与3′受位AG模式,4个外显子分别居于1-174、267-398、483-643、1 240-2 251bp;序列已提交至GenBank数据库,其登录号为FJ769773;牡丹ACS蛋白由492个氨基酸组成,与苹果、枇杷、西洋梨、天竺葵等ACS的相似性达74%～76%;生物信息学分析预测牡丹ACS蛋白的分子量为54.9kD,等电点为6.8,是一个定位于细胞质的不稳定的非分泌亲水蛋白。     

苹果果实成熟过程中ACC 合成酶基因作用机理研究进展

 苹果（Malus × domestica Borkh.）果实贮藏期的长短直接决定着其采后的经济价值,其与果实在室温下的软化率有直接的关系。乙烯能够调控苹果成熟和软化过程,因此,苹果果实软化和乙烯之间的关系得到了广泛的研究。ACC合成酶（1–氨基环丙烷–1–羧酸合成酶,ACS）是植物乙烯合成中的关键酶,通过检索苹果全基因组序列,共发现20个ACC合成酶（ACS）基因,其中MdACS1和MdACS3已经被证明与苹果果实成熟有着直接关系,并在不同的时空点调控果实成熟过程。对ACS基因调控苹果果实成熟过程的最新研究进展进行了综述,并提出了ACS基因调控苹果果实成熟和乙烯合成的分子模型,同时也对本领域今后的研究方向作了展望。     

磨盘和富有柿果实ACS基因片段的克隆

利用RT-PCR的方法,从磨盘、富有柿果实中克隆了ACC合成酶(ACS)的3个DNA片段。序列分析表明：Mopan-ACS1、Mopan-ACS2与平核无柿果实DK-ACS1的核苷酸同源性为75．6％,氨基酸同源性分别为98.7％和98.2％。Fuyu-ACS与DK-ACS1的核苷酸同源性为99．2％,氨基酸的同源性为99．4％。3个片段编码的氨基酸序列中,均含有植物ACS的保守氨基酸区和不变氨基酸残基。     

AOA对牡丹切花花期叶片和花瓣生理的影响

以不同浓度(0、0.25、0.50、0.75 mmol/L)的氨基氧乙酸(AOA)对待放牡丹"赵粉"进行处理,测定花期叶片、花瓣的生理生化变化。结果表明,在牡丹切花的整个花期中,叶片的叶绿素含量和可溶性蛋白含量均在花开初期上升,在盛花期达到峰值后下降。经AOA处理后,与对照组相比,其花期花瓣中可溶性糖含量、超氧化物歧化酶(SOD)和过氧化物酶(POD)活性均升高,花瓣中超氧阴离子(O2-.)产生速率、花瓣浸出液相对电导率(REC)在整个花期均降低;AOA使牡丹花期花瓣的ACC合成酶(ACS)酶带推迟表达,并使原有酶带减弱。其中0.25 mmol/L AOA保鲜效果最佳。     

Regulation of Propylene and 1-Methylcyclopropene on Expressions of ACS and ACO Genes in Persimmon Fruits

The regulation of postharvest treatment with propylene and 1-MCP on ethylene release rate and expressions of 1- aminocyclopropane-l-carboxylic acid synthase （ACS） and 1-aminocyclopropane-1-carboxylic acid oxidase （ACO） genes in Fuping Janshi persimmon （Diospyros kaki L.） fruit were investigated. Fruits were treated with propylene and 1-MCP, then stored at 20℃, ethylene release rate of the treated fruits was measured at regular intervals and RNA was extracted for Northern blotting analysis. The results suggested that treatment with propylene accelerated the expressions of ACS and ACO genes and then enhanced the ethylene biosynthesis, while treatment with 1-MCP inhibited the expressions of two genes and their ethylene biosynthesis. Furthermore, different effects on expressions caused by treatments with propylene and 1-MCP existed in various fruit tissues, the inhibitory effect on ACS and ACO genes by 1-MCP was the strongest in pericarp, followed by pulp and core tissues, in the area near fruit stalk, the inhibitory effect was the weakest. While the enhanced effect on ACS and ACO genes by propylene increased from pulp, core, and pericarp to the area near fruit stalk. Expression of each member of ACS and ACO families in various tissues was also completely different, in control and propylene treatment, DKACS3 gene just expressed in the area near fruit stalk and did not express in other tissues, but DKACS2 gene expressed in four tissues by treatment with propylene.     

甜瓜ACS基因家族成员的鉴定及其表达特性分析

乙烯在高等植物生长发育等多个方面都具有重要的调控作用,而ACS(1-aminocyclopropane-1-carboxylic acid(ACC)synthase,1-氨基环丙烷-1羧酸合成酶)是乙烯生物合成途径的限速酶,由多基因家族编码,不同的发育、环境、激素刺激等信号诱导不同的ACS基因表达.本研究以甜瓜品种'河...     

龙眼乙烯合成途径基因鉴定及响应ACC处理的分析

[目的]S-腺苷甲硫氨酸合成酶(SAMS)、1-氨基环丙烷-1-羧酸合成酶(ACS)和1-氨基环丙烷-1-羧酸氧化酶(ACO)是植物合成乙烯的3个关键酶,从全基因组水平鉴定龙眼SAMS、ACS和ACO(DlSAMS、DlACS和DlACO)基因家族,并进行生物信息学、体细胞胚早期不同阶段及不同浓度1-氨基环丙烷-1-羧...