玉米赤霉烯酮在冬小麦短日春化中的作用

应用酶联免疫技术,研究了冬小麦品种燕大１８１７在不同光周期条件下,体内内源玉米赤霉烯酮和ＡＢＡ含量的变化。结果表明,冬小麦品种燕大１８１７具有短日春化性,苗期经４周ＳＤ处理后转到ＬＤ下能正常抽穗。ＳＤ诱导春化的幼苗茎尖和叶片中ＺＥＮ含量高于未经诱导的ＬＤ幼苗,而在两种光周期条件下生长的幼苗中ＡＢＡ含量变化趋势并无明显差异。     

绞股蓝茎尖组织培养和植株再生研究

以绞股蓝茎尖作为外植体,接种于ＭＳ＋１ｍｇ／Ｌ ＢＡ＋０．１ｍｇ／Ｌ ＮＡＡ的培养基中,茎尖逐渐形成芽苗,芽苗分离后接种于ＭＳ＋１ｍｇ／Ｌ ＢＡ＋０．１ｍｇ／Ｌ ＮＡＡ的培养基中进行增殖培养,同时从增殖的芽苗上不断地诱导出幼苗,将幼苗分离转入不含激素的ＭＳ培养基中,幼苗生根,形成完整的植株。     

烟草Z诱导株的生长及开花

烟草Ｚ诱导株的生长及开花姚坤林,孟繁静（北京农大生物学院,北京１０００９４）ＧＲＯＷＴＨＡＮＤＦＬＯＷＥＩＮＧＯＦＴＨＥＲＥＧＥＮＥＲＡＴＥＤＰＬＡＮＴＳＩＮＤＵＣＥＤＢＹＺＥＡＲＡＬＥＮＯＮＥ￥ＹａｏＫｕｎ－ｌｉｎ;ＭｅｎｇＦａｎ－Ｊｉｎｇ（Ｃｏｌ...     

不同株的熊蜂短膜虫与宿主生存的关系

ＴＨＥＲＥＬＡＴＩＯＮＳＨＩＰＢＥＴＷＥＥＮＤＩＦＦＥＲＥＮＴＳＴＲＡＩＮＳＯＦＣＲＩＴＨＩＤＩＡＢＯＭＢＩＡＮＤＴＨＥＳＵＲＶＩＶＡＬＯＦＴＨＥＩＲＨＯＳＴＢＵＭＢＬＥＢＥＥＳ不同株的熊蜂短膜虫与宿主生存的关系ＫｅｙｗｏｒｄｓＣｒｉｔｈｉｄｉａｂｏ...     

STUDIES ON THE PATTERN OF MEGASPOROGENESIS AND MICROTUBULAR CYTOSKELETON CHANGES IN CYMBIDIUM SINENSE

ＳＴＵＤＩＥＳＯＮＴＨＥＰＡＴＴＥＲＮＯＦＭＥＧＡＳＰＯＲＯＧＥＮＥＳＩＳＡＮＤＭＩＣＲＯＴＵＢＵＬＡＲＣＹＴＯＳＫＥＬＥＴＯＮＣＨＡＮＧＥＳＩＮＣＹＭＢＩＤＩＵＭＳＩＮＥＮＳＥ￥Ｓ．Ｙ．ＺｅｅＸ．Ｌ．Ｙｅ（１ＢｏｔａｎｙＤｅｐａｒｔｍｅｎｔ,Ｕｎｉ...     

半胱胺对大鼠哺乳晚期泌乳量及血液几种激素含量的影响

半胱胺对大鼠哺乳晚期泌乳量及血液几种激素含量的影响ＥＦＦＥＣＴＳＯＦＣＹＳＴＥＡＭＩＮＥＯＮＭＩＬＫＹＩＥＬＤＡＮＤＳＥＶＥＲＡＬＨＯＲＭＯＮＥＳＬＥＶＥＬＳＯＦＢＬＯＯＤＩＮＲＡＴＳＡＴＬＡＴＥＳＴＡＧＥＯＦＬＡＣＴＡＴＩＯＮ关键词半胱胺,大鼠,泌...     

菊苣薄层培养花芽,营养芽分化中内源激素的动态变化

菊苣（Ｃｉｃｈｏｒｉｕｍ ｉｎｔｙｂｕｓＬ．）花梗薄层细胞培养于ＭＳ附加ＮＡＡ 和ＢＡ 或ＩＡＡ 和ＢＡ 的ＭＳ培养基上有花芽或营养芽分化． 花芽分化中内源ＩＡＡ、ＤＨＺ＋ ＤＨＺＲ、ｉＰＡ 含量明显增加,而Ｚ＋ ＺＲ变化不明显．营养芽分化中内源细胞分裂素含量增加明显,而ＩＡＡ 在培养前７ ｄ 含量下降,随后有所增加,在原基形成时含量达原初水平的２／３． 可见,花芽分化比营养芽分化所需内源ＩＡＡ／ＣＴＫ 比值要高     

鹿科动物血清LDH同工酶的比较分析

鹿科动物血清ＬＤＨ同工酶的比较分析ＡＣＯＭＰＡＲＡＴＩＶＥＡＮＡＬＹＳＩＳＯＮＴＨＥＳＥＲＵＭＬＤＨＩＳＯＺＹＭＥＳＩＮＤＥＥＲＳ￥ＷＡＮＧＹｕｎｌｉｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＢｉｏｌｏｇｙ,ＴｉａｎｊｉｎＮｏｒｍａｌＵｎｉｖｅｒｓｉｔｙ）ＬＵＢ...     

天目山土壤原生动物生态背景值研究

天目山土壤原生动物生态背景值研究宋碧玉（武汉水利电力大学环保室,武汉,４３００７２）ＥＣＯＬＯＧＩＣＡＬＢＡＣＫＧＲＯＵＮＤＳＴＵＤＹＯＦＳＯＩＬＰＲＯＴＯＺＯＡＴＩＡＮＭＵＭＯＵＮＴＡＩＮＳ（ＳｏｎｇＢｉｙｕ）（ＷｕｈａｎＵｎｉｖｅｒｓｉｔｙｏｆＨ...     

中国科学院动物研究所兽类标本馆藏模式标本名录

中国科学院动物研究所兽类标本馆藏模式标本名录ＣＡＴＡＬＯＧＵＥＯＦＴＨＥＭＡＭＭＡＬＴＹＰＥＳＰＥＣＩＭＥＮＳＰＲＥＳＥＲＶＥＤＩＮＴＨＥＭＡＭＭＡＬＣＯＬＬＥＣＴＩＯＮＯＦＴＨＥＩＮＳＴＩＴＵＴＥＯＦＺＯＯＬＯＧＹ,ＣＨＩＮＥＳＥＡＣＡＤＥＭＹＯＦ...     

Changes in the Pattern of Cell Division in the Shoot and Root Meristems of Lolium perenne during the Transition from Vegetative to Floral Growth

For Lolium perenne cv. Cropper, a system which resulted in 100%flowering comprised 90 short days (SD) at 4 ?C (vernalization)and 30 SD at 18 ?C followed by 8 long days (LD). The mitoticindex and G1 and G2 percentages were measured in the shoot androot apices of plants following 2, 5 or 8 LD and in SD controlssampled at the beginning and end of induction. Identical measurementswere made in plants given 48 SD at 18 ?C followed by 2, 5 or8 LD; plants remained vegetative in response to this treatmentlacking vernalization. Significant increases in both mitoticindex and meristem size occurred in the shoot apex in LD followingthe vernalizing, but not the non-vernalizing, treatment. A clusterof mitoses in the apical dome of the shoot apex was unique tothe vernalized plants given 5 or 8 LD. However, an increasein root meristem size occurred regardless of vernalization,but a significant increase in the mitotic index was limitedto vernalized plants given 5 or 8 LD. Whilst the vernalization-LDtreatment resulted in an increase in the G2 percentage in theshoot apex following 2, 5 or 8 LD, no such alteration was observedin the root meristem. Thus, the changes to the cell cycle whichcorrelated with flowering were increased mitotic indices andG2 percentages in the shoot apex at each sampling time and increasedmitotic indices in the root apex following 5 and 8 LD. Key words: Cell division, flowering, Lolium perenne L.     

冬小麦低温春化过程中茎尖细胞超微结构的变化与玉米赤霉烯酮的关系

玉米赤霉烯酮(zearalenone, ZEN)是Stob等于1962年首先从玉米赤霉菌培养物中分离出的次生代谢产物,它具有动物雌性激素的作用,也能促进某些真菌形成子实体,被认为是真菌的一种性激素,80年代初发现亦存在于高等植物体内。多年的研究结果表明,ZEN与植物的许多发育过程,包括春化作用、光周期诱导以及授粉受精过程均有密切的关系,可能ZEN参与了小麦成花诱导过程的调控,但其调控机制不明。为进一步研究小麦春化过程中茎尖细胞超微结构的变化与ZEN的相关性,我们以春化过程中的冬小麦幼芽为材料,对茎尖细胞超微结构以及与之相应的ZEN含量变化进行了分析。     

Restricted cell/cell communication in the shoot apex ofSilene coeli-rosa during the transition to flowering is associated with a high mitotic index rather than with evocation

Summary Plants ofSilene coeli-rosa given 5 or more long days (LDs) flowered, even when the LDs were followed by 48 hours of darkness before their return to short days (SDs). The mitotic indices of shoot apices from induced plants shortly after induction were significantly higher than the indices of shoot apices from vegetative plants. Two major mitotic peaks were observed in the shoot apices of plants given 7 long days (LDs) on day 8. One coincided with that reported byFrancis andLyndon (1979).Cell to cell movement was tested in the shoot apices of vegetative and LD treated plants using probes with a molecular size of 749 daltons (fluorescein-hexaglycine) and 847 daltons (fluorescein-leucyl diglutamyl leucine). These probes showed some movement in the shoot apices of both short day (SD) and LD treated plants, but fluorescein-leucyl diglutamyl leucine was immobile in the induced apices of 7 LD plants on day 8 at time intervals which coincided with major mitotic activity in the shoot apex. Symplasmic restriction in the shoot apex was also observed in plants given 8 LDs (i.e., plants not returned to SDs on day 7).In plants that were placed in 48 hours of darkness after the 7 LD treatment or in plants given 5 LDs, there was no strong peak in the mitotic index, even though all these LD treatments resulted in 100% flowering. In such plants no symplasmic restriction was found in the shoot. Thus the symplasmic restriction on day 8 of 7 LD plants is associated with the high mitotic index, but neither of these phenomena is an essential part of the evocation process.Abbreviations F(Glu)₂ L-glutamylglutamic acid conjugated to fluorescein isothiocyanate isomer I (F-) - F(Gly)₆ F-hexaglycine - FLGGL F-leucyl-diglutamyl-leucine - F(PPG)₅ F-the pentamer (propyl-propyl glycine) - LD long day - LDs long days - SD short day - SDs short days     

Developmental Regulation of Low-temperature Tolerance in Winter Wheat

Vernalization and photoperiod genes have wide-ranging effectson the timing of gene expression in plants. The objectives ofthis study were to (1) determine if expression of low-temperature(LT) tolerance genes is developmentally regulated and (2) establishthe interrelationships among the developmental stages and LTtolerance gene expression. LT response curves were determinedfor three photoperiod-sensitive LT tolerant winter wheat (Triticumaestivum L. em Thell) genotypes acclimated at 4 °C under8 h short-day (SD) and 20 h long-day (LD) photoperiods from0 to 112 d. Also, three de-acclimation and re-acclimation cycleswere used that bridged the vegetative/reproductive transitionpoint for each LD and SD photoperiod treatment. A vernalizationperiod of 49 d at 4 °C was sufficient for all genotypesto reach vernalization saturation as measured by minimum finalleaf number (FLN) and confirmed by examination of shoot apicesdissected from crowns that had been de-acclimated at 20 °CLD. Before the vegetative/reproductive transition, both theLD- and SD-treated plants were able to re-acclimate to similarLT₅₀(temperature at which 50% of the plants are killed by LTstress) levels following de-acclimation at 20 °C. De-acclimationof LD plants after vernalization saturation resulted in rapidprogression to the reproductive phase and limited ability tore-acclimate. The comparative development of the SD (non-flowering-inductivephotoperiod) de-acclimated plants was greatly delayed relativeto LD plants, and this delay in development was reflected inthe ability of SD plants to re-acclimate to a lower temperature.These observations confirm the hypothesis that the point oftransition to the reproductive stage is pivotal in the expressionof LT tolerance genes, and the level and duration of LT acclimationare related to the stage of phenological development as regulatedby vernalization and photoperiod requirements. Copyright 2001Annals of Botany Company Triticum aestivum L., wheat, low-temperature tolerance, vernalization, photoperiod, phenological development     

Relationships among vernalization, shoot apex development and frost tolerance in wheat

BACKGROUND AND AIMS: Frost tolerance of wheat depends primarily upon a strong vernalization requirement, delaying the transition to the reproductive phase. The aim of the present study was to learn how saturation of the vernalization requirement and apical development stage are related to frost tolerance in wheat. METHODS: 'Mironovskaya 808', a winter variety with a long vernalization requirement, and 'Leguan', a spring variety without a vernalization requirement, were acclimated at 2 degrees C at different stages of development. Plant development (morphological stage of the shoot apex), vernalization requirement (days to heading) and frost tolerance (survival of the plants exposed to freezing conditions) were evaluated. KEY RESULTS: 'Mironovskaya 808' increased its frost tolerance more rapidly; it reached a higher level of tolerance and after a longer duration of acclimation at 2 degrees C than was found in 'Leguan'. The frost tolerance of 'Mironovskaya 808' decreased and its ability to re-acclimate a high tolerance was lost after saturation of its vernalization requirement, but before its shoot apex had reached the double-ridge stage. The frost tolerance of 'Leguan' decreased after the plants had reached the floret initiation stage. CONCLUSIONS: The results support the hypothesis that genes for vernalization requirement act as a master switch regulating the duration of low temperature induced frost tolerance. In winter wheat, due to a longer vegetative phase, frost tolerance is maintained for a longer time and at a higher level than in spring wheat. After the saturation of vernalization requirement, winter wheat (as in spring wheat) established only a low level of frost tolerance.     

Contents of polyamines during vernalization in wheat and the effect of zearalenone

The contents of endogenous free and conjugated polyamines, putrescine (Put) and spermidine (Spd), were determined during 9 week of vernalization (at 5 °C) in winter wheat seedlings cultivated on Murashige and Skoog media without (MS0) and with 2 mg dm⁻³ zearalenone (MSZEN). At the 4^th week of chilling treatment, which is sufficient to induce generative development in 30 % of plants, the marked increase in free and conjugated forms of Put and free Spd were observed. The presence of ZEN in medium significantly accelerated the vernalization. About 20 % of plants treated with ZEN flowered already after 2 weeks and 40 % after 3 weeks of chilling. Significantly higher content of free Put was determined in roots grown on MSZEN compared with MS0 during the first 5 weeks of vernalization with maximum at the 4^th week. After germination, a marked decrease in free Spd content was observed both in plants grown on MS0 and MSZEN. Application of ZEN significantly slowed down the Spd decline in leaves and roots during the first and second week of vernalization. The content of Spd and its conjugates decreased in vernalized plants after 1 week of cultivation at 20 °C.     

Effect of Photoperiod on the Regulation of Wheat Vernalization Genes VRN1 and VRN2

Wheat is usually classified as a long day (LD) plant because most varieties flower earlier when exposed to longer days. In addition to LD, winter wheats require a long exposure to low temperatures (vernalization) to become competent for flowering. Here we show that in some genotypes this vernalization requirement can be replaced by interrupting the LD treatment by 6 weeks of short day (SD), and that this replacement is associated with the SD down-regulation of the VRN2 flowering repressor. In addition, we found that SD down-regulation of VRN2 at room temperature is not followed by the up-regulation of the meristem identity gene VRN1 until plants are transferred to LD. This result contrasts with the VRN1 up-regulation observed after the VRN2 down-regulation by vernalization, suggesting the existence of a second VRN1 repressor. Analysis of natural VRN1 mutants indicated that a CArG-box located in the VRN1 promoter is the most likely regulatory site for the interaction with this second repressor. Up-regulation of VRN1 under SD in accessions carrying mutations in the CArG-box resulted in an earlier initiation of spike development, compared to other genotypes. However, even the genotypes with CArG box mutations required LD for a normal and timely spike development. The SD acceleration of flowering was observed in photoperiod sensitive winter varieties. Since vernalization requirement and photoperiod sensitivity are ancestral traits in Triticeae species we suggest that wheat was initially a SD–LD plant and that strong selection pressures during domestication and breeding resulted in the modification of this dual regulation. The down-regulation of the VRN2 repressor by SD is likely part of the mechanism associated with the SD–LD regulation of flowering in photoperiod sensitive winter wheat. These authors contributed equally to this work     

Proteomic analysis of shoot tissue during photoperiod induced growth cessation in <Emphasis Type="Italic">V. riparia</Emphasis> Michx. grapevines

Background  

Growth cessation, cold acclimation and dormancy induction in grapevines and other woody perennial plants native to temperate continental climates is frequently triggered by short photoperiods. The early induction of these processes by photoperiod promotes winter survival of grapevines in cold temperate zones. Examining the molecular processes, in particular the proteomic changes in the shoot, will provide greater insight into the signaling cascade that initiates growth cessation and dormancy induction. To begin understanding transduction of the photoperiod signal, Vitis riparia Michx. grapevines that had grown for 35 days in long photoperiod (long day, LD, 15 h) were subjected to either a continued LD or a short photoperiod (short day, SD, 13 h) treatment. Shoot tips (4-node shoot terminals) were collected from each treatment at 7 and 28 days of LD and SD for proteomic analysis via two-dimensional (2D) gel electrophoresis.     

Plasmodesmal Dynamics in Both Woody Poplar and Herbaceous Winter Wheat Under Controlled Short Day and in Field Winter Period

Electron microscopic observation revealed that poplar (Populus deltoides Marsh.) and winter wheat (Triticum aestivum L. cv. Seward 80004) plasmodesmatal structures significantly changed under short day (SD, 8 h light) and in winter period, and such changes differed also noticeably between these two woody and herbaceous plants. Under long day (LD, 16 h light), many plasmodesmata with strong stain appeared in the cell wall of both poplar apical buds and winter wheat young leaf tissues, and connections of cytoplasmic endoplasmic reticulum (ER) with the ER in some plasmodesmata were observed. In addition, the typical “neck type” plasmodesmata were observed in winter wheat young leaf tissues, and their central desmotubules (appressed-ER) could be clearly identified. Under SD, many poplar plasmodesmata showed only a partial structure in the cell wall and appeared to be discontinued; some plasmodesmata swelled in the mid-wall, forming the cavity, and no appressed-ER appeared. In winter wheat, however, no noticeable alterations of plasmodesmata occurred, and the plasmodesmatal structure essentially remained same as it was under LD. In winter period, poplar plasmodesmata had a similar morphology as those observed under SD, however, winter wheat manifested at least two types of significant plasmodesmatal alterations: one plugged by electron-dense materials and the other of reduced neck region compared to those under LD. The above dynamic difference of the two species plasmodesmata under SD and winter period revealed the difference of their dormancy development under those environmental conditions.     

Stem elongation and changes in the levels of gibberellins in shoot tips induced by differential photoperiodic treatments in the long-day plant Silene armeria

The effects of differential photoperiodic treatments applied to shoot tips and mature leaves of the long-day (LD) plant Silene armeria L. on growth and flowering responses, and on the levels of endogenous gibberellins (GAs), were investigated. Gibberellins were analyzed by gaschromatography-mass spectrometry and the use of internal standards. Exposure of mature leaves to LD, regardless of the photoperiodic conditions of the shoot tips, short days (SD), LD, or darkness, promoted elongation of the stems and of the immature leaves. Long-day treatment of the mature leaves modified the levels of endogenous GAs in shoot tips kept under LD, SD, or darkness. In shoot tips kept in LD or darkness the levels of GA₅₃ were reduced, whereas the levels of GA₁₉ and GA₂₀ were increased. The contents of GA₁ were increased in all three types of shoots: SD twofold, LD fivefold, and darkness eightfold. Dark treatment of the shoot tips on plants of which the mature leaves were grown in SD promoted elongation of the immature etiolated leaves and increased the GA₁ content of the shoot tips threefold. However, this treatment did not cause stem elongation. The different photoperiodic treatments applied to the shoot tips did not change the levels of GAs in mature leaves. These results indicate that both LD and dark treatments result in an increase in GA₁ in shoot tips. In addition, it is proposed that LD treatment induces the formation of a signal that is transmitted from mature leaves to shoot tips where it enhances the effect of GA on stem elongation.Abbreviations GA_n gibberellin A_n - LD long day(s) - SD short day(s) We thank Dr. L.N. Mander, Australian National University, Canberra, for providing [²H]-gibberellins and Dr. D.A. Gage, MSU-NIH Mass Spectrometry Facility, East Lansing, for advice with mass spectrometry. This work was supported, in part, by a fellowship from the Spanish Ministry of Agriculture (Instituto Nacional de Investigaciones Agrarias) to M.T., by the U.S. Department of Energy grant No. DE-FG02-91ER20021, and by the U.S. Department of Agriculture grant No. 88-37261-3434 to J.A.D.Z.