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关键词： .correct   define   potentially   transgenic tobacco   Biological activity   alteration   phytochromes   functional regions   FR light   oat   terminal deletion   phyA activity  

摘要： Phytochrome A (phyA) is a red/far-red (FR) light photoreceptor responsible for initiating numerous light-mediated plant growth and developmental responses, especially in FR light-enriched environments. We previously showed that the first 70 amino acids of the polypeptide contain at least two regions with potentially opposite functions (E.T. Jordan, J.R. Cherry, J.M. Walker, R.D. Vierstra [1996] Plant J 9: 243-257). One region is required for activity and correct apoprotein/chromophore interactions, whereas the second appears to regulate phytochrome activity. We have further resolved these functional regions by analysis of N-terminal deletion and alanine-scanning mutants of oat (Avena sativa) phyA in transgenic tobacco (Nicotiana tabacum). The results indicate that the region involved in chromophore/apoprotein interactions contains two separate segments (residues 25-33 and 50-62) also required for biological activity. The region that regulates phyA activity requires only five adjacent serines (Sers) (residues 8-12). Removal or alteration of these Sers generates a photoreceptor that increases the sensitivity of transgenic seedlings to red and FR light more than intact phyA. Taken together, these data identify three distinct regions in the N-terminal domain necessary for photoreceptor activity, and further define the Ser-rich region as an important site for phyA regulation.

关键词： Genetics   Plant evolution  

摘要： While DNA-based markers can provide a wealth of information for the study of plant evolutionary biology, progress is limited by the lack of primers available for PCR. To overcome this limitation, we outlinea protocol for developing oligonucleotide primers targeting regions of low copy-number nuclear genes. This protocol is intended to lead to universally useful primer sets. To test our approach, we designed eight primer sets and tested their abilities to amplify targets from representatives of each dicot and one mono- cot subclass. Five of the eight primer sets amplified targets from at least five of the seven taxa and thus exhibited broad taxonomic usefulness; the remaining primers were rather specific, however, and amplified targets from at mostthree taxa. In only one primer-taxon combination was a complex multiple-banded amplification produced. Overall, the protocol outlined proved quite useful at identifying broadly applicable primers targeted to low copy-number nuclear genes. Wider application of, this approach should be effective at greatly increasing the amount of genetic information available for a diversity of plant nuclear genomes. [ABSTRACT FROM AUTHOR]

关键词： 植物分子生物学   生物技术   匈牙利   农业生物学  

摘要： 一、发展概况 利用重组DNA技术研究玉米线粒体内质粒的分子结构所取得的首批研究成果标志匈牙利植物分子生物学研究的开端。1996年匈报道了转基因苜蓿植株。

关键词： 美丽红山茶   植物生物学特性   山茶科  

摘要： 美丽红山茶（***）特有分布于贵州省赤水市金沙沟自然保护区海拔700～1200m常绿阔叶林中，其花红色美丽，树形美观，果大而籽粒饱满，实为颇具经济价值的园艺观赏和油料植物资源．本文对其形态特征，生态生理、营养生长、开花与结实、果实资源与营养、种子生活力等生物学特性进行了初步研究，以为其科研和生产利用提供参考．

关键词： 豆科   野豌豆属   花   生物学   繁育系统  

摘要： 对东北地区野豌豆属植物花生物学研究表明文中类群均为自花授粉植物，ＡＴＰ酶活性与柱头间的可授性有关。花粉—胚珠比高于Ｃｒｕｄｅｎ标准，开花物候期分化成早春—春季和夏季两种开花类型，表现出在物种形成时地理条件的差异。

关键词： 聚合果   离生心皮   实概念   子房发育   单雌蕊   果实   《辞海》   植物生物学   复雌蕊   高等教育出版社  

摘要： 关于几种果实概念的商榷刘祥栋（辽宁省锦州师范高等专科学校，锦州１２１０００）ＤＩＳＣＵＳＳＩＮＧＯＮＴＨＥＣＯＮＣＥＰＴＯＦＡＦＥＷＦＲＵＩＴＳＬｉｕＸｉａｎｇｄｏｎｇ（ＪｉｎｚｈｏｕＮｏｒｍａｌＣｏｌｅｇｅ，Ｌｉａｏｎｉｎｇ，Ｊｉｎｚｈｏｕ１２１...

关键词： mycelium   nitrogen mobilization   chitin   mycorrhiza   heathland soil  

摘要： Measurements of the chitin content of the rooting horizons of a typical mor-humus heathland soil, indicate that chitin can contain in excess of 20 % of the total nitrogen in the litter (L) horizon and 30 % in the fermentation (F) horizon. Much of this chitin-nitrogen is thought to be contained in the mycelial walls of soil fungi. Experiments were therefore designed to test the hypothesis that such sources of N could be rendered accessible to the ericaceous plants by their fungal endophytes. Mycelium of the ericoid endophyte Hymenoscyphus ericae (Read) Korf & Kernan and of the ectomycorrhizal fungus Suillus bovinus (Fr.) O. Krantze were grown in liquid culture before being killed and added either in the intact condition, or after fractionation, as sole sources of N to sterile media upon which were grown H. ericae in pure culture, or mycorrhizal and non-mycorrhizal plants of Vaccinium macrocarpon Ait. and Calluna vulgaris L. The abilities of the test organisms to utilize the nitrogen contained in the intact mycelial necromass, or in its fractions, were assessed by determining their yields and nitrogen concentrations of their tissues. It was revealed that H. ericae was able to produce significantly higher yield when grown on intact fungal necromass than when provided with equivalent concentrations of N in the form of ammonium. Its yields on mycelial fractions were lower, but still significantly greater than those obtained in the controls lacking N. Significantly greater yields and N contents were also found in the ericaceous plants grown with these nitrogenous substrates in the mycorrhizal condition. Without H. ericae they had no access to the substrates. The possible ecological implications of these results are discussed.

关键词： 植物   抗病性   抗病基因   分子生物学  

摘要： 植物在长期的进化过程中,需要不断地抵抗病原微生物、昆虫甚至食草动物的侵害。在这种长期相互作用、相互影响的共进化过程中,植物逐渐获得了一系列复杂的防御机制来保护自己。这里既有专一性的抗性,也有非专一性抗性,有的表达是组成型的而有的是诱导型的。在植物抵抗病原侵染的过程中,关键环节是病原与寄主植物间的相互识别及其随后诱发的一系列反应。人们虽然对植物抗病机理及植物抗病性在生产应用等方面做了大量的工作,积累了相当多的资料,但由于一直未能克隆到植物的抗病基因,所以在90年代初期以前有关植物抗病性的分子生物学研究进展一直都很缓慢。而最近的几年里,人们克隆到了一些植物的抗病基因,使得对寄主-病原相互作用分子机理的研究得到迅速的发展,并为抗病基因在生产中的应用带来了新的前景。

关键词： 桑寄生植物   生物学特性   危害  

摘要： 桑寄生植物从寄主板栗树的体内吸取水分和矿质营养,对寄主构成危害,其危害程度与寄生植物的生物学特性和环境条件有关,而不同种类的寄生植物对寄主个体和种群造成的危害亦不相同.

关键词： 植物生物学   花粉   种子   散布   湍流   梯度   输送模型  

摘要： 运用梯度──输送理论分析了植物花粉、种子湍流扩散的不同情况,导出了植物花粉、种子散布的湍流扩散模型,并运用此模型研究了亚热带常绿阔叶林优势种四川大头茶的种子散布格局.