Protein profiles in pin and thrum floral organs of distylous Averrhoa carambola L.

Floral organs (tepal, stamen, style, including stigma, and ovary) from immature and mature (1 day prior to anthesis) flower buds of pin and thrum morphs of Averrhoa carambola were subjected to one and two-dimensional IEF/SDS-PAGE gel electrophoresis and visualized by silver staining. One-dimensional gel electrophoresis of organ extracts from mature floral buds showed a number of protein bands common to all organs in both pin and thrum morphs. In the stamen and style, these bands differed in intensity between the two morphs. Under two-dimensional gels, the differences in protein profiles between the two morphs were more distinct in these organs. When compared with polypeptide spots from leaflets, a total of 14 floral organ-specific polypeptides was detected, the majority appearing in the stamen, followed by the style but none in the ovary. In the stamen, most of these polypeptides were detected in both the pin and thrum morphs. However, in the style, a 72-kDa polypeptide was detected exclusively in the pin morph, and this was also the most abundant floral organ-specific polypeptide. Floral organ-specific polypeptides of 45 kDa (detected in stamens of the thrum morph) and 70 kDa (detected in stamen and style of both morphs) were found to bind concanavalin A.     

Characterization of a connexin homologue in cultured soybean cells and diverse plant organs

Antibodies were prepared against ratliver connexin (27-kDa polypeptide subunit of cell gap junctions found between contacting animal cells) and a putative soybean (Glycine max (L.) Merr.) connexin (29-kDa polypeptide) previously isolated from cultured soybean root cells (SB-1 cell line). The antibodies were utilized to examine the intracellular localization of soybean connexin in these cultured soybean cells and to probe for the presence of a soybean-type connexin in petals, fruits, and leaves from a variety of plants. As judged by specific reactivity on immunoblots, both antibodies against the 27-kDa polypeptide (ratliver connexin) and against the 29-kDa polypeptide (operationally termed soybean connexin) were utilized to demonstrate immunological relatedness of the 27-kDa (rat liver) and the 29-kDa (soybean) polypeptide. Immunofluorescent localization of the putative soybean connexin in cultured soybean cells utilizing these probes demonstrated a peripherally localized punctate pattern of labeling at areas of contact between cells. Use of antibody to the soybean connexin as a probe on immunoblots of extracts from petals, fruits and leaves demonstrated that the soybean-type connexin is present in a large number of different plants.Abbreviations kDa kilodalton - IgG immunoglobulin G - NEPHGE non-equilibrium pH gradient electrophoresis - SDS-PAGE sodium dodecyl sulfate polyacrylamide gel electrophoresis     

Biochemical differentiation in the tobacco flower probed with monoclonal antibodies

We have isolated a series of monoclonal antibodies that react to antigens in flowers of Nicotiana tabacum L. (tobacco) displaying specificity or preferentiality in their cell and tissue distributions. We immunized mice with extracts from tobacco flowers and then screened the hybridomas by enzyme-linked immunosorbent assay (ELISA) against extracts from leaves, sepals, petals, stamens and pistils; twenty five were chosen from the total screened. The antigens detected by about half of the antibodies were periodate-sensitive, implying that the epitopes were carbohydrate. Competition ELISA assays were used to determine if any antibodies were reacting to the same epitopes. Western blot analysis showed that while some antibodies reacted to specific bands, the bulk either failed to react or reacted to multiple bands, consistent with a glyco-conjugate nature for many of the antigens. Analysis of the spatial pattern of antigen distribution within tobacco flowers by immunolocalization showed that some antibodies recognized epitopes that were limited to very specific cells and tissues. We used the immunolocalization technique to analyze a mutant with stigmoid anthers: an antibody recognizing a pistil transmitting-tract antigen also reacted to cells in stigmoid anthers. Our results with this antibody set imply that biochemical differentiation within the tobacco flower includes cell-and tissue-specific glyco-moeities, and also that similarities, at the biochemical level, exist between a normal floral organ and the abnormal organ in a phenotype with a developmental switch.Abbreviations ELISA enzyme-linked immunosorbent assay - Fg immunoglobulin - kDa kilodalton     

Characterization of vacuolar polypeptides of barley mesophyll cells by two-dimensional gel electrophoresis and by their affinity to lectins

Vacuoles were isolated from primary leaves of barley (Hordeum vulgare L.) by mechanical breakage of protoplasts, and their polypeptide composition analyzed by two-dimensional gel electrophoresis. Vacuoplasts which consist of the vacuole, a portion of the plasmalemma and of the cytoplasma were prepared from protoplasts by ultracentrifugation. By comparing the vacuolar polypeptide pattern with polypeptide patterns of isolated chloroplasts and of vacuoplasts, vacuolar polypeptides could clearly be distinguished from polypeptides derived from cross-contaminating cell compartments. At least 14 polypeptides of apparent molecular mass between 12 and 76 kilodaltons and an isoelectric point between 4.5 and 7.6 could be attributed to the tonoplast fraction of the vacuole, and 35 polypeptides to the soluble fraction of the vacuole. Several lectins with different specificity were employed to characterize the degree and nature of glycosylation of vacuolar polypeptides. Concanavalin A bound to a large number of polypeptides. Three out of the 14 tonoplast polypeptides exhibited detectable carbohydrate moieties and almost two-thirds of the surveyed soluble polypeptides were glycosylated.Abbreviations IEF isoelectric focussing - kDa kilodalton - SDS-PAGE sodium dodecyl sulfate-polyacrylamide gel electrophoresis     

IS POLYPLOIDY NECESSARY FOR TISSUE DIFFERENTIATION IN HIGHER PLANTS?

Measurements of relative DNA per nucleus of cells from various tissues show that cell differentiation can occur in the absence of polyploidy in higher plants. In Pisum polyploidy was present in roots, sepals, pods, pistils, and stamens but not in petals or leaves. In Triticum cells of leaves exhibited some polyploidy, but no polyploid cells were present in mature roots. No polyploid cells were found in any tissue of Helianthus examined (roots, cotyledons, stems, leaves, sepals, petals, pistils, and stamens). Therefore, as a general rule, polyploidy should not be considered essential in tissue or organ differentiation of higher plants. In Helianthus polyploidy is unnecessary for the completion of the life cycle.     

Heterotopic expression of class B floral homeotic genes supports a modified ABC model for tulip (Tulipa gesneriana)

In higher eudicotyledonous angiosperms the floral organs are typically arranged in four different whorls, containing sepals, petals, stamens and carpels. According to the ABC model, the identity of these organs is specified by floral homeotic genes of class A, A+B, B+C and C, respectively. In contrast to the sepal and petal whorls of eudicots, the perianths of many plants from the Liliaceae family have two outer whorls of almost identical petaloid organs, called tepals. To explain the Liliaceae flower morphology, van Tunen et al. (1993) proposed a modified ABC model, exemplified with tulip. According to this model, class B genes are not only expressed in whorls 2 and 3, but also in whorl 1. Thus the organs of both whorls 1 and 2 express class A plus class B genes and, therefore, get the same petaloid identity. To test this modified ABC model we have cloned and characterized putative class B genes from tulip. Two DEF- and one GLO-like gene were identified, named TGDEFA, TGDEFB and TGGLO. Northern hybridization analysis showed that all of these genes are expressed in whorls 1, 2 and 3 (outer and inner tepals and stamens), thus corroborating the modified ABC model. In addition, these experiments demonstrated that TGGLO is also weakly expressed in carpels, leaves, stems and bracts. Gel retardation assays revealed that TGGLO alone binds to DNA as a homodimer. In contrast, TGDEFA and TGDEFB cannot homodimerize, but make heterodimers with PI. Homodimerization of GLO-like protein has also been reported for lily, suggesting that this phenomenon is conserved within Liliaceae plants or even monocot species.these authors contributed equally to this work     

蓝堇草属(毛茛科)花形态发生的扫描电子显微镜观察

花的发生和发育过程研究可以发现早期进化的轨迹,为系统发育的研究提供重要线索。蓝堇草属(Leptopyrum)为毛茛科唐松草亚科一单种属,仅包含蓝堇草一种,其花的发生和发育过程仍为空白。为了深入理解唐松草亚科乃至毛茛科花发育多样性和演化规律,该文运用扫描电子显微镜(SEM)观察了蓝堇草各轮花器官的形态发生和发育过程。结果表明:该属植物所有的萼片、花瓣、雄蕊和雌蕊均为螺旋状发生,花器官排列式样也为螺旋状; 5枚萼片原基宽阔,5枚花瓣原基圆球形、位于萼片原基的间隔,且在后期表现为延迟发育现象,雄蕊原基较小、为圆球形; 花瓣原基和雄蕊原基连续发生,无明显的时空间隔,但与萼片原基有时空间隔; 心皮原基为马蹄形对折,柱头组织由单细胞乳突组成; 胚珠倒生、具单珠被。该属花器官螺旋状排列、胚珠具单珠被在唐松草亚科中是独有的性状,花发育形态学证据支持了该属的特殊性。     

Mutations associated with floral organ number in rice

How floral organ number is specified is an interesting subject and has been intensively studied in Arabidopsis thaliana. In rice (Oryza sativa L.), mutations associated with floral organ number have been identified. In three mutants of rice, floral organ number 1 (fon1) and the two alleles, floral organ number 2-1 (fon2-1) and floral organ number 2-2 (fon2-2), the floral organs were increased in number centripetally. Lodicules, homologous to petals, were rarely affected, and stamens were frequently increased from six to seven or eight. Of all the floral organs the number of pistils was the most frequently increased. Among the mutants, fon1 showed a different spectrum of organ number from fon2 -1 and fon2 -2. Lodicules were the most frequently affected in fon1, but pistils of more than half of fon1 flowers were unaffected; in contrast, the pistils of most flowers were increased in fon2 -1 and fon2-2. Homeotic conversion of organ identity was also detected at a low frequency in ectopically formed lodicules and stamens. Lodicules and stamens were partially converted into anthers and stigmas, respectively. Concomitant with the increased number of floral organs, each mutant had an enlarged apical meristem. Although meristem size was comparable among the three mutants and wild type in the early phase of flower development, a significant difference became apparent after the lemma primordium had differentiated. In these mutants, the size of the shoot apical meristem in the embryo and in the vegetative phase was not affected, and no phenotypic abnormalities were detected. These results do not coincide with those for Arabidopsis in which clavatal affects the sizes of both shoot and floral meristems, leading to abnormal phyllotaxis, inflorescence fasciation and increased floral organs. Accordingly, it is considered that FON1 and FON2 function exclusively in the regulation of the floral meristem, not of the vegetative meristem.Abbreviation DIC differential interference contrast This work was supported in part by Grant-in-Aid for Scientific Research on Priority Areas from the Ministry of Education, Science and Culture of Japan.     

Two-Dimensional Electrophoretic Analysis of Salicylic Acid-Induced Changes in Polypeptide Pattern of Barley Leaves

The salicylic acid-induced changes in the polypeptide patterns of barley (Hordeum vulgare L.) leaves have been analysed using two-dimensional gel electrophoresis. An optimized 2-D PAGE protocol was used and gave reproducible 2-D gels from leaf crude protein extracts with a high number of detected polypeptides. When applied for 24 h SA affected the expression of a number of soluble proteins. Most of them appeared to be down-regulated. Although no abundant expression of specific proteins was observed, we detected three polypeptides that were present only in SA-treated leaves.     

秦岭石蝴蝶人工种群花器变异现象研究

以人工栽培的秦岭石蝴蝶为实验材料,通过观察并记录花器官形态和数目的变化,初步探讨秦岭石蝴蝶花器变异规律,并分析了导致其变异的诱因。结果显示:(1)在观察的1 996朵秦岭石蝴蝶花朵中,发现了17种花冠变异类型、5种萼片变异类型和7种可育雄蕊变异类型,总变异率分别为34.57%、38.38%和32.67%。(2)秦岭石蝴蝶花梗或可分支,花梗苞片数目2～3枚。(3)相关性分析结果表明,下唇数目与可育雄蕊数目呈正相关,相关系数为0.927 4,而上唇数目与可育雄蕊数目呈负相关,相关系数为-0.481 1,结合花型图示分析这可能与秦岭石蝴蝶雄蕊着生于花冠下唇内侧近基部有关。该研究统计的秦岭石蝴蝶变异类型丰富,可能对于今后秦岭石蝴蝶的系统进化、花器官发育、生殖生态以及分子遗传方面研究奠定了基础,也为培育不同观赏价值的品种提供思路。     

基于扫描电镜技术的天葵属(毛茛科)花器官发生研究

毛茛科天葵属为东亚特有类群,但其花器官的发生过程仍不清晰。该研究利用扫描电子显微镜观察了天葵［S. adoxoides (DC.) Makino］花器官的发生过程,以揭示毛茛科花形态的多样性和演化规律,为进一步探讨天葵属与近缘类群的亲缘关系提供发育形态学证据。结果表明：(1)天葵萼片、花瓣和雄蕊均为螺旋状发生,轮状排列;不育雄蕊的数目和位置不定,心皮轮状发生。(2)天葵萼片原基为宽阔的新月形,其他花器官为窄的半球形。(3)天葵花发育后期,花瓣有延迟发育现象,花瓣原基基部发育为浅囊状,心皮原基马蹄形对折,胚珠倒生、双珠被、具胎座附属物。(4)天葵属与耧斗菜属、尾囊草属的花发育性状存在相似性,支持分子系统学证据的三者近缘的观点;天葵属的花性状的特殊表现为：花直径较小,雄蕊、不育雄蕊和心皮数目较少,花器官没有形成明显的直列线,内珠被较长等。     

The lithium-chloride-soluble cell-wall layers of Chlamydomonas reinhardii contain several immunologically related glycoproteins

Cell-wall glycoproteins of the unicellular green alga Chlamydomonas reinhardii have been purified from LiCl extracts of intact cells by gel exclusion chromatography and preparative sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Antibodies were raised against several polypeptide components isolated from the LiCl extracts. All these antibodies specifically reacted with the cell surface of formaldehyde-fixed cells. They showed cross-reactivity with the different antigens and were also reactive against some other polypeptides present in the LiCl extracts of intact wild-type cells as shown by double-diffusion assays and immunoblot analyses. These antigens were largely missing in LiCl extracts from the cell-wall-deficient mutant CW-15. The pattern of immunologically related cell-wall polypeptides of C. reinhardii varied during the vegetative cell cycle and was found to be also dependent on the growth conditions. Dot-immunobinding assays on chemically modified cell-wall glycoproteins demonstrated differences between the various antibodies with respect to their specificities. Differences were observed especially with respect to their reactivities against chemically deglycosylated cell-wall polypeptides. Chemical deglycosylation generally reduced the binding of the different antibodies indicating that all these antibodies recognize carbohydrate side chains. Only two of these antibody preparations, raised against cell-wall glycoproteins of relative molecular mass 35 and 150 kilodaltons, were found to be strongly reactive against deglycosylated cell-wall polypeptides. When these antibodies were saturated with cell-wall-derived glycopeptides in order to abolish the binding to carbohydrate side chains, they still recognized the same cell-wall polypeptides as did the untreated antibodies. These findings indicate that the cross-reactivity of the different cell-wall polypeptides with the antibodies is not exclusively the consequence of similar glycosylation patterns but is also the result of the presence of similar structures within the non-glycosylated stretches of the polypeptide backbones. Cell walls isolated from growing tobacco pollen tubes contained a single polypeptide component which showed crossreactivity with the antibodies to the cell-wall glycoproteins of C. reinhardii.Abbreviations BSA bovine serum albumin - IgG immunoglobulin G - kDa kilodalton - M_r relative molecular mass - PBS phosphate-buffered saline - SDS-PAGE sodium dodecyl sulfate-polyacrylamide gel electrophoresis - Tris 2-amino-2-(hydroxymethyl)-1,3-propanediol     

Studies in the morphology and systematics of berberidaceae

The floral vasculature in three allied genera,Plagiorhegma, Jeffersoria andAchyls is investigated, and the results are compared with those ofEpimedium andVancouveria which are related closely toPlagiorhegma andJeffersonia. The vasculature in the receptacle ofPlagiorhegma andJeffersonia is similar, but that ofAchlys is much simpler. Slightly different trace patterns are observed in the sepals ofPlagiorhegma andJeffersonia. InJeffersonia, the 3-trace condition leaving 2 or 3 gaps is most frequently observed, but inPlagiorhegma traces of a double nature leaving a single gap are more frequent. The traces to the innermost sepals, petals and stamens are usually of a double nature leaving a single gap in both genera. Regular division and fusion are not observed in the receptacular stele. The vascular differentiation between sepals and petals is more advanced inPlagiorhegma andJeffersonia than inEpimedium andVancouveria. InAchlys, the traces are all staminal and single throughout their course. Two parts recognized in the pistils ofPlagiorhegma, Jeffersonia andAchlys are traversed by independent vasculature. The comparisons of pistil morphology including vasculature ofPlagiorhegma, Jeffersonia, Achlys, Epimedium andVancouveria lead to the interpretation that the pistils are based on the same morphological plan. The probable evolutionary trend in pistil is then suggested in these five genera.     

Floral development in Adonideae (Ranunculaceae)

Floral development and floral phyllotaxis in species of Adonis, Callianthemum, and Trollius (Ranunculaceae) were studied with scanning electron microscopy. The floral organs are initiated in spiral sequence and the flowers have spiral phyllotaxis. The sepal primordia are broad, crescent-shaped, and truncate, but those of petals, stamens, and carpels are rather hemispherical. A relatively long plastochron appears to be present between the last sepal and the first petal as compared with the short and equal plastochrones of all subsequent floral organs. Maturation of the stamens within the androecium appears to be centripetal. The carpels have a short ascidiate zone. Placentation is uniformly lateral, even in Adonis and Callianthemum, which have only one fertile ovule per carpel (versus median in other genera of Ranunculoideae with a single fertile ovule). In Adonis and Callianthemum at the tip of the carpel the ventral slit is gaping and the stigma is broadly exposed, whereas in Trollius the stigma is narrower and more pronouncedly decurrent along the ventral slit. The petals in Callianthemum and Trollius are more conspicuously delayed in development than those in Adonis as compared with sepals and stamens. A short carpel stipe is formed early in Callianthemum but later in Adonis and Trollius. In Trollius farreri (commonly having only five carpels in contrast to other species of Trollius) the carpels form a single (spiral) series. Thus floral development is similar in all three genera and, at a lower level, Adonis and Callianthemum are especially close but have different autapomorphies, which reflects the current classification of the genera.     

Differential protein synthesis in response to sulphate and phosphate deprivation: Identification of possible components of plasma-membrane transport systems in cultured tomato roots

Isolated roots of Lycopersicon esculentum Mill., cultured in axenic conditions were starved of sulphate or phosphate, and uptake capacities for the respective oxyanion-transport systems were observed for several days after sulphate or phosphate withdrawal. Sulphate-uptake capacity of the intact roots, measured in a 20-min period, increased from a control level of 100 nmol · g^–1 · h^–1 to 1100 nmol · g^–1 · h^–1 in 10 d, and phosphate-uptake capacity increased from 500 to 1400 nmol · g^–1 · h^–1 over 4 d. Newly synthesised polypeptides of these root cultures were pulse-labelled in vivo for 2 h, by adding [³H]leucine to the culture medium. The tissue was immediately homogenised and soluble and membrane fractions were prepared. A highly purified plasma-membrane fraction was separated from the crude microsomal membrane fraction using an aqueous two-phase partitioning technique. All fractions were analysed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis and autoradiography. A 28-kilodalton (kDa) soluble polypeptide, and 36-, 43-, and 47-kDa plasma-membrane polypeptides were observed to have increased labelling after 4 d of sulphate deprivation. Longer periods resulted in additional polypeptides with increased [³H]leucine incorporation. The synthesis of a 25-kDa membrane polypeptide and a 65-kDa soluble polypeptide was increased after 4 d of phosphate deprivation. Two-dimensional electrophoresis afforded greater resolution of the plasmamembrane polypeptides, confirming increased synthesis of the 36-kDa polypeptide and the presence of the 28-kDa polypeptide in the plasma-membrane preparation from sulphate-starved roots. These polypeptides were also observed in protein-stained two-dimensional gels as low-abundant protein components of the plasmamembrane fraction. It is suggested that the 36-kDa polypeptide may be a component of the plasma-membrane sulphate-transport system and that the 25-kDa polypeptide may be a component of a phosphate-transport system.Abbreviations kDa kilodalton(s) - PAGE polyacrylamide gel electrophoresis - pI isoelectric point - SDS Sodium dodecyl sulphate This work was supported by the Agricultural and Food Research Council via grants-in-aid to Long Ashton Research Station. We are also grateful for discussions with our colleagues D.T. Clarkson (LARS) and J.-C. Davidian (ENSA/INRA, Montpellier).     

Role of ABA in stamen and pistil development in the normal and solanifolia mutant of tomato (Lycopersicon esculentum)

Summary The role of abscisic acid (ABA) in stamen and pistil development of the normal and solanifolia (sf/sf) mutant of tomato (Lycopersicon esculentum Mill.) was analyzed. The solanifolia mutant produces flowers with separate floral organs, unlike the fused organs of normal flowers, and has greater number of carpels and locules per ovary than the normal. Applications of 10^–5 M ABA to normal floral buds produced flowers with separate stamens, but higher concentrations (10^–4 M ABA) resulted in the complete suppression of stamen growth or stamens that were devoid of anthers. ABA at both 10^–4 and 10^–5 M also induced an increase in the number of carpels and locules in normal flowers, but not in mutant ones. Analysis of endogenous ABA by a radioimmunoassay revealed that the pistils of mutant flowers contained a significantly higher level of ABA than those of normal flowers, but there was no difference in the ABA content of the stamens. The non-fusion of the stamens and the high number of carpels and locules in solanifolia mutant flowers may be explained by the high level of ABA in the floral apex during the initiation and development of carpels.     

A phloem-specific,lectin-like protein is located in pine sieve-element plastids by immunocytochemistry

Two co-purifying phloem polypeptides of 24 and 25 kilodaltons (kDa) were isolated from homogenates of Pinus sabiniana Dougl. phloem by differential centrifugation, selective solubilization and electrophoresis, and rabbit antibodies raised against them. The antisera were found to be specific for doublet bands between 23 and 25 kDa in Western blots of whole phloem extracts of Pinus species; no xylem polypeptides were labelled, nor did labelling occur in blots of phloem extracts from other genera in the Pinaceae. Solubilized phloem polypeptides bind strongly to chitin (oligomeric N-acetylglucosamine) columns and are sensitive to thiol reagents, both characteristics which relate them to phloemspecific lectins isolated from angiosperm species (C. Allen, 1979, Biochem. J. 183, 133–137; A.K. Gietl et al., 1979, Planta 144, 367–371). Fluorescence microscopy and immuno-gold electron microscopic cytochemistry demonstrated antigenic sites specifically associated with protein crystals peculiar to the sieve-element plastids of the Pinaceae.Abbreviations DAB diamino benzidine tetrachloride - FITC fluorescein isothiocyanate - kDa kilodalton - PBS phosphate-buffered saline - PP phloem polypeptide(s) - SDS-PAGE Sodium dodecyl sulphate-polyacrylamide gel electrophoresis - Tris 2-amino-2-(hydroxymethyl)-1,3-propanediol     

黄瓜AGAMOUS同源基因的分离和表达(英文)

黄瓜花发育的早期均有雌蕊和雄蕊原基的分化,但在发育过程中,由于雌蕊或雄蕊的发育受到阻滞,导致雄花和雌花的形成。近年来在拟南芥和金鱼草等植物中遗传学的研究表明,花器官的特征是由同源异形基因决定的。在拟南芥中,由于ＡＧ在决定雄蕊和雌蕊特征方面起重要作用,本研究利用 ＲＴ－ＰＣＲ技术,从黄瓜的雌、雄蕊中分离出 ＡＧ的同源基因,并对其在花发育过程中的表达和可能作用进行了分析。首先,根据ＡＧ同源基因的保守区域设计５’简并引物５’－ＧＡ（Ａ／Ｇ）ＡＴ（Ｔ／Ｃ／Ａ）ＡＡ（Ｔ／Ｃ／Ａ）ＡＡ（Ｇ／Ａ）（Ａ／Ｃ）Ｇ（Ｇ／Ｔ／Ｃ）ＡＴＣＧＡ（Ｃ／Ａ）ＡＡＣ－３’,然后进行３’,ＲＡ ＣＥ ＰＣＲ,扩增出约１ｋｂ大小的片段,序列分析表明该片段含有非常保守的ＭＡＤＳ ｂｏｘ。进而,利用５’ ＲＡＣＥ ＰＣＲ得到全长度的ｃＤＮＡ。该ｃＤＮＡ的核苷酸序列与ＣＵＭ１（黄瓜 ＭＡＤＳ ｂｏｘ ｇｅｎｅ１）同源性高达９７％。 ＣＵＭ１在接牵牛中过量表达可引起花萼变为心皮状和花瓣变为雄蕊,说明ＣＵＭ１为ＡＧ的同源基因。基于该基因与ＣＵＭ１序列上的高度同源,我们认为其为黄瓜的ＡＧ同源基因。该基因命名为ＣＭＢ１,基因银行登记号为ＡＦ２８６６４９。Ｓｏｕｔｈｅｒ     

Fruit removal in soybean induces the formation of an insoluble form of ribulose-1,5-bisphosphate carboxylase/oxygenase in leaf extracts*

In some soybean (Glycine max (L.) Merr.) cultivars, fruit removal does not delay the apparent loss of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco, EC 4.1.1.39) activity and abundance or the decline in photosynthesis. Analysis of leaf extracts from defruited plants indicated a time-dependent increase in both Rubisco activity and abundance in a 30000 · g pellet fraction in cultivars which had been reported to lose all Rubisco protein from the supernatant fraction. Attempts to solubilize the pelleted Rubisco by increasing the buffer volume/tissue ratio or by adding alkylphenoxypolyethoxyethanol (Triton X-100), ethylenediaminetetraacetic acid (EDTA), or NaCl were unsuccessful. However, treatment of the pellets with denaturants such as 8 M urea or 5% (w/v) sodium dodecyl sulfate (SDS) did release Rubisco from the pellet. Redistribution of protein to the pellet fraction appeared to be specific for Rubisco since the amount of ribulose-5-phosphate kinase (EC 2.7.1.19) found in the pellet fraction of leaf extracts of control and defruited plants was small and constant over time. The loss of soluble Rubisco, and the concomitant increase in insoluble Rubisco, in response to fruit removal varied with genotype and was reproducible in both field and greenhouse environments. In addition, the effect was influenced by node position and light; lower and-or shaded leaves exhibited less Rubisco in the pellet fraction than leaves from the top of the plant that was fully exposed to sunlight. When isolated by sucrose-density-gradient centrifugation, the insoluble Rubisco was found to co-purify with a 30-kDa (kilodalton) polypeptide. These results indicate that alteration of the source/sink ratio by removing fruits results in the formation of an insoluble form of Rubisco in leaf extracts of soybean. Whether or not Rubisco exists as an insoluble complex with the 30-kDa polypeptide in intact leaves of defruited plants remains to be determined.Abbreviations kDa kilodalton - PGA kinase 3-phosphoglyceric acid kinase (EC 2.7.2.3) - Rubisco ribulose-1,5-bisphosphate car-boxylase/oxygenase (EC 4.1.1.39) - Ru5P kinase ribulose-5-phosphate kinase (EC 2.7.1.19) - SDS-PAGE sodium dodecyl sulfatepolyacrylamide gel electrophoresis     

Two-dimensional patterns of soluble proteins including three hydrolytic enzymes of mature pollen of tristylous <Emphasis Type="Italic">Lythrum salicaria</Emphasis>

Lythrum salicaria, now a widespread invasive species, exhibits tristyly, a form of heteromorphic selfincompatibility. In tristyly, each plant exhibits one (and only one) of three morphologically different floral forms. Moreover, each flower produces two types of stamens, and these two exhibit different incompatibility reactions. Differences between stamens of a single flower must be the result of epigenetic phenomena and for that reason, we performed two-dimensional gel electrophoresis (2-DE) to analyze fractions of soluble proteins derived from the pollen coat and protoplast including three hydrolytic enzymes from the six different stamen types (two from each of three floral forms). There were significant differences in the 2-D protein profiles both between pollen from the same flower and between the same type of pollen from two different flowers, in the pollen coat as well as in the protoplast extracts. In five of the six samples of pollen fractions, characteristic peptides were found. Quantitative differences between pollen from the same flower were observed in case of esterases. Furthermore, analysis of proteases and acid phosphatases revealed also qualitative differences between these enzymes in pollen from the same flower.