Activation of floral homeotic genes in Arabidopsis

The identity of floral organs in Arabidopsis thaliana is determined by homeotic genes, which are expressed in specific regions of the developing flower. The initial activation of homeotic genes is accomplished at least in part by the products of two earlier acting genes with overlapping functions. These are the floral meristem-identity genes LEAFY and APETALA1. The requirements of LEAFY and APETALA1 activity vary for different homeotic genes.     

鱼类标志放流技术的研究现状

标志放流（tagging）技术是一种研究鱼类洄游和鱼类资源的方法，先在鱼体做上标志，然后通过重新捕获标志鱼，根据标志放流记录和重捕记录，绘制鱼类标志放流和重捕的分布图，以推测鱼类游动的方向、路线、范围和速度等；若进一步结合鱼体长度、重量和年龄资料，则可研究鱼类的生长和死亡规律，以及检验增殖放流的效果等。此外，根据鱼类标志放流的结果还可估算鱼类种群数量的变动。我国的鱼类标志技术研究起步较晚，有关报道较少，因此，开展这方面的工作非常迫切。本文对鱼类标志方法的研究进展予以综述，以期促进我国鱼类标志技术的应用与发展。     

鱼类标志放流技术的研究现状

标志放流（tagging）技术是一种研究鱼类洄游和鱼类资源的方法,先在鱼体做上标志,然后通过重新捕获标志鱼,根据标志放流记录和重捕记录,绘制鱼类标志放流和重捕的分布图,以推测鱼类游动的方向、路线、范围和速度等;若进一步结合鱼体长度、重量和年龄资料,则可研究鱼类的生长和死亡规律,以及检验增殖放流的效果等。此外,根据鱼类标志放流的结果还可估算鱼类种群数量的变动。我国的鱼类标志技术研究起步较晚,有关报道较少,因此,开展这方面的工作非常迫切。本文对鱼类标志方法的研究进展予以综述,以期促进我国鱼类标志技术的应用与发展。     

出雏前后蛋鸡和肉鸡血清中甲状腺激素水平的比较

用放射免疫分析法测定了出雏前后肉鸡（ＡＡ）和蛋鸡（伊莎）血清中总甲状腺激素（Ｔ３,Ｔ４）和游离甲状腺激素（ＦＴ３,ＦＴ４）的水平,结果表明：肉鸡和蛋鸡血清总Ｔ３水平在１４胚龄和１８胚龄时较低,１日龄时显著上升,肉鸡表现尤为突出。今后 Ｔ３水平的变化在品种间有所不同,肉鸡从１日龄到１０日龄斩下降,１日与５日龄差异显著;恧旧鸡１日龄至５日龄Ｔ３水平显著升高,除１日龄肉鸡Ｔ３水平显著高于蛋鸡外,其它日龄     

Nitric oxide represses the Arabidopsis floral transition

The correct timing of flowering is essential for plants to maximize reproductive success and is controlled by environmental and endogenous signals. We report that nitric oxide (NO) repressed the floral transition in Arabidopsis thaliana. Plants treated with NO, as well as a mutant overproducing NO (nox1), flowered late, whereas a mutant producing less NO (nos1) flowered early. NO suppressed CONSTANS and GIGANTEA gene expression and enhanced FLOWERING LOCUS C expression, which indicated that NO regulates the photoperiod and autonomous pathways. Because NO is induced by environmental stimuli and constitutively produced, it may integrate both external and internal cues into the floral decision.     

两个大白菜FT基因的生物信息学解析

本文利用比较基因组学的方法从大白菜的基因组中解析出两个成花素基因brft1和brft2,并对这两个基因的结构、顺式调控元件以及遗传进化进行了分析。结果表明,brft1和brft2都含有4个外显子,编码区大小均为528 bp,二者预测编码蛋白的序列一致性为90.29%, 说明这两个基因序列存在某种程度的分化。进化分析表明这两个基因应为拟南芥ft和tsf基因的直系同源基因。另外,这两个基因都含有响应激素和逆境信号的顺式调控元件,而且不尽相同,说明这两个基因的表达调控有所不同,可能在功能上存在一定分化。本研究为进一步揭示大白菜ft基因在开花和逆境响应中的功能奠定了基础。     

17 beta-estradiol: inducer of uterine hexokinase

Administration of estradiol to ovariectomized rats induced new synthesis of uterine hexokinase which was prevented by actinomycin D, 5-fluorouracil, cycloheximide, or ethionine. The estradiol-induced increase in uterine hexokinase activity was detectable as early as 4 hours. The increase in enzyme activity was dependent upon the dose of the hormone. The evidence indicates that the increased hexokinase activity induced by 17beta-estradiol may entail an acceleration of the synthesis of certain RNA species.     

浅析芸苔素内酯和ZNC免疫诱抗剂

本文通过介绍植物生长调节剂与生物刺激素的特点、功效,着重分析了芸苔素内酯与一类新兴的生物刺激素—ZNC免疫诱抗剂的功效、活性、安全性及作用机理的不同;ZNC免疫诱抗剂作为一类新开发的生物刺激素产品,具有较强的促生、抗病、抗逆、提高肥料利用率、提高作物产量和品质等功效。     

百合花器官的组织培养

以帝伯、西伯利亚、铁炮、金百合4个品种的花器官为外植体,进行不同品种花器官及同一品种花器官不同部位的组培难易程度试验。结果表明,品种间诱导率存在差异,从易到难的排序为帝伯、西伯利亚、铁炮、金百合;同一品种不同部位的诱导率也存在差异,从易到难的排序为花丝、花托、子房、花冠、花柱、花药。在初代诱导培养基中,以M S 6-BA 0.5m g/L NAA 0.5m g/L和M S 6-BA 1.0m g/L NAA 0.5m g/L较好;在继代增殖培养基中,帝伯和西伯利亚的最适培养基均为M S 6-BA 1.0m g/L NAA 0.2m g/L,而铁炮百合为M S 6-BA 1.0m g/L NAA 0.5m g/L。     

玉米单倍体诱导系间杂交种评价及其杂种优势分析及其杂交组合选育

利用2个诱导系与25个单倍体诱导率呈现梯度变化的材料,采用NCII设计,组配了50个杂交组合,并对其诱导率及农艺性状进行了评价。结果表明,诱导性状的杂种优势不显著,F1代诱导率呈现出接近中亲值或略低于中亲值的特点,但F1的农艺性状较双亲有了显著提升,尤其是在株高、雄穗长度等方面表现出较强的杂种优势。经筛选评价,2个杂交组合诱导率稳定在8.5%以上,可在今后的育种中加以利用。     

雷竹开花生物学特性研究

对浙江省临安市的开花雷竹林的花芽分化、开花征兆、开花林相、开花类型、花器官结构、小花开放及结实情况等开花生物学特性进行了系统观察与研究。结果表明,雷竹为零星开花竹种,开花类型复杂多样;雷竹花序属于典型的无限制花序或称假花序,基本单位为假小穗;雷竹结实率低。     

Field experiments with transformed plants reveal the sense of floral scents

Plants use many means to attract pollinators, including visual cues and odor. We investigated how nonpigment floral chemistry influences nectar removal, floral visitation, florivory, rates of outcrossing, and fitness through both male and female functions. We blocked expression of biosynthetic genes of the dominant floral attractant [benzyl acetone (Nachal1)] and nectar repellent [nicotine (Napmt1/2)] in all combinations in the native tobacco Nicotiana attenuata and measured their effects on plants in their native habitat. Both repellent and attractant were required to maximize capsule production and seed siring in emasculated flowers and flower visitation by native pollinators, whereas nicotine reduced florivory and nectar robbing.     

Milkoscan FT120对原料乳中三聚氰胺快速分析

为了建立一种快速测定原料乳中掺假物质的方法,利用红外光谱,采用主成分分析(PCA)回归方法,以本地区具有代表性原料乳样品集为基础建立标准数据模型.在原料乳中加入三聚氰胺模拟牛奶掺假.通过总结原料乳成分数据的变化规律及调整控制因素以达到预判原料乳掺假和确定掺假物质的检出限的目的.结果表明,该方法具有快速、准确的特点.     

3种FT基因诱导杨树早期开花比较

为了促进杨树早期开花,缩短杨树遗传育种周期,采用农杆菌AGL1介导的转化方法及热激诱导方法,进行了热激启动子HSP控制下的3类FT基因转化2种杨树无性系(353与717)诱导杨树早期开花的比较研究.结果表明:来自拟南芥的FT基因促花效果优于来自杨树的FT1和FT2基因;FT类基因与受体基因型/性别之间互作明显,开花较好...     

An antagonistic pair of FT homologs mediates the control of flowering time in sugar beet

Cultivated beets (Beta vulgaris ssp. vulgaris) are unable to form reproductive shoots during the first year of their life cycle. Flowering only occurs if plants get vernalized, that is, pass through the winter, and are subsequently exposed to an increasing day length (photoperiod) in spring. Here, we show that the regulation of flowering time in beets is controlled by the interplay of two paralogs of the FLOWERING LOCUS T (FT) gene in Arabidopsis that have evolved antagonistic functions. BvFT2 is functionally conserved with FT and essential for flowering. In contrast, BvFT1 represses flowering and its down-regulation is crucial for the vernalization response in beets. These data suggest that the beet has evolved a different strategy relative to Arabidopsis and cereals to regulate vernalization.     

植物花器官发育的分子机理研究进展

植物花器官的发育是由器官特异性基因决定的,这些基因包括ABC模型的A、B、C功能基因,同时还有决定胚珠发育的D功能基因和E功能基因。这些基因的精确表达需要花分生组织特异性基因的激活和多个正负调节因子的调控。在花器官发育过程中,基因存在着复杂的遗传网络调控系统,就此提出了各种调控模型。文章就花发育分子模型的发展和完善、不同模型之间的相互关系以及调控基因之间的相互作用等方面,对植物花器官发育的最新研究进展进行了综述,同时对植物花器官发育机理研究的理论价值和应用前景进行了展望。