NEW ULTRASTRUCTURAL ASPECTS OF PYRENOIDS OF THE LICHEN PHOTOBIONT TREBOUXZA (MICROTHAMNIALES,CHLOROPHYTA)1

The pyrenoid structure of Trebouxia, a photobiont of two lichen species, Umbilicaria cinereorufescens (Schaer.) Frey and Parmelia sulcata Taylor, was investigated. In both lichen species, the pyrenoid of the photobiont exhibited straight, unbranched, long or short tubules. In the first lichen species, multiple pyrenoids were observed occasionally, while in the second one, homogeneous masses, called protein bodies, appeared between the thylakoids. These protein bodies were previously observed in some other species of the family Umbilicariaceae. Serial sections from single pyrenoids showed that tubules of the Impressa-type pyrenoid were closely associated with pyrenoglobuli. The three-dimensional reconstruction of a complete chloroplast of a P. sulcata algal cell showed that the protein bodies were spatially separate structures. Immunolocalization techniques to detect the presence of ribulose-bisphosphate carboxylase (Rubisco) in the chloroplast showed that this enzyme was present primarily in the pyrenoid matrix. When protein bodies were present in the chloroplast, Rubisco appeared to be localized in these structures. The presence of pyrenoid satellites and protein bodies with reactivity to anti-Rubisco may be related to the nutritional conditions of the thalli.     

COMPARATIVE ULTRASTRUCTURE OF CULTURED SPECIES OF TREBOUXIA1,2

Five species of cultured Trebouxia—T. anticipata, T. decolorans, T. erici, T. gelatinosa, and T. impressa—were examined with the electron microscope. A comparative examination of their pyrenoids revealed pyrenoglobuli associated with single pyrenoid thylakoids. The pyrenoids of T. decolorans, T. erici, and T. gelatinosa possess single thylakoids that cross or deeply penetrate the pyrenoid matrix and are often disposed in parallel arrays. T. anticipata possesses both single and double pyrenoid thylakoids within the matrix. T. impressa possesses vesiculate invaginations of thylakoid membranes into the pyrenoid matrix. The phycobiont. T. erici was examined in detail at the light and electron microscopic levels for pyrenoid alterations associated, with varied environmental regimes and with cell division. A greater amount of starch is present in cells grown in organic culture at 215 lux light intensity than in cells of similar size grown at 1075 or 3600 lux. Pyrenoglobuli are present throughout the life cycle and occur both in aplanospores and in zoospores.     

Zur Morphologie und Systematik desTrebouxia-Phycobionten im Thallus vonUsnea longissima (Lecanorales)

In the lichen genusUsnea different species ofTrebouxia-phycobionts as well as different haustorial types are known. The isolated and cultivated phycobiont ofUsnea longissima Ach. was studied by light- and electron microscopy and resembles in cytomorphological details the type ofTrebouxia impressa Ahmad. In addition to simple wall-to-wall contacts between the symbiotic components also intraparietal (=intrawall-)haustoria could be observed as the normal interaction type.

Frau Prof. Dr.Elisabeth Tschermak-Woess zu ihrem 70. Geburtstag gewidmet.     

The pyrenoid is the site of ribulose 1,5-bisphosphate carboxylase/oxygenase accumulation in the hornwort (Bryophyta: Anthocerotae) chloroplast

Summary Chloroplasts of many species of hornworts (Anthocerotae) have a structure that resembles the pyrenoid of green algae but whether these two structures are homologous has not been determined. We utilized immunogold labelling on thin sections to determine the distribution of ribulose 1,5-bisphosphate carboxylase/oxygenase (RuBisCO), the major protein of algal pyrenoids, in sixteen hornwort species with and without pyrenoids. Several species (Phaeoceros laevis, Anthoceros punctatus, A. formosae, A. laminiferus, Folioceros fuciformis, Folioceros sp.,Dendroceros tubercularis, D. japonicus, D. validus, Notothylas orbicularis, N. temperata, andSpaerosporoceros adscendens) have uniplastidic (or primarily uniplastidic) cells with large prominent multiple pyrenoids. In all of these species, the labelling is found exclusively in the pyrenoid and, with the exception of theFolioceros, Dendroceros, andNotothylas species, the labelling is randomly distributed throughout the pyrenoid. In the exceptional species, the pyrenoids have prominent pyrenoglobuli or other inclusions that are unlabelled. InMegaceros flagellaris andM. longispirus, the cells are multiplastidic (with the exception of the apical cell and some epidermal cells) and the chloroplasts lack pyrenoids.Anthoceros fusiformis andPhaeoceros coriaceus have primarily uniplastidic cells but the chloroplasts lack pyrenoids; only an area of stroma in the center of the plastid devoid of starch, reminiscent of a pyrenoid, is found. In all of the species lacking pyrenoids, RuBisCo is found throughout the stroma, including the stromal spaces made by the so-called channel thylakoids. No preferential accumulation of RuBisCo is found in the pyrenoid-like region inA. fusiformis andP. coriaceus. These data indicate that 1) the hornwort pyrenoid is homologous to algal pyrenoids in the presence of RuBisCo; 2) that at least some of the RuBisCo in the pyrenoid must represent an active form of the enzyme; and 3) that, in the absence of pyrenoids, the RuBisCo is distributed throughout the stroma, as in higher plants.Abbreviations RuBisCo ribulose 1,5-bisphosphate carboxylase/oxygenase     

ULTRASTRUCTURE OF THE PYRENOID OF TREBOUXIA IN RAMALINA MENZIESII TUCK.1,2

Trebouxia sp., the phycobiont of the lichen Ramalina menziesii Tuck., was examined with the electron microscope. Its pyrenoid is characterized structurally as being permeated by interconnected vesiculate membrane systems associated with osmiophilic globules termed pyrenoglobuli. The variety of membrane structure associated with the pyrenoid has been documented with electron micrographs. A model based on serial sections was constructed to show the extent of vesiculation, to demonstrate that the pyrenoglobuli within the pyrenoid matrix are invariably adjacent to the thylakoid membranes within that, matrix, and to emphasize the recurrent thylakoid membrane to pyrenoglobuli relationship. A comparison of the glutaraldehyde-osmium fixation image of the pyrenoglobuli and pyrenoid matrix with the permanganate fixation image has been included. The structure of the pyrenoid matrix in thin section was examined and appears essentially granular.     

Comparative ultrastructure of the zoospores of nine species ofNeochloris (Chlorophyta)

Nine species ofNeochloris can be divided into three groups on the basis of comparative ultrastructure of the flagellar apparatus, the cell wall and the pyrenoid of zoospores. In Group I,N. wimmeri andN. minuta, zoospores are thin-walled, pyrenoids are penetrated by stromal channels, and the basal bodies are in the clockwise absolute orientation and connected by the distal and two proximal fibers. In Group II,N. aquatica, N. vigenis, N. terrestris, N. pyenoidosa, andN. pseudostigmatica, zoospores are naked or covered by fuzzy material, pyrenoids are covered by a continuous starch sheath or invaginated by cytoplasmic channels, basal bodies are directly opposed, the distal fiber is differentiated into a ribbed structure at the central region, a striated microtubule-associated component (SMAC) is continuous between opposite two-membered rootlets and connected to the ribbed structure, proximal ends of basal bodies are covered by partial caps, each two-membered rootlet and a basal body are connected by a striated fiber to the X-membered rootlet associated with the opposite basal body, and the basal bodies, when oriented at wide angles, are joined at their proximal ends by core extensions. In Group III,N. pseudoalveolaris andN. cohaerens, zoospores are naked, pyrenoids are traversed by parallel thylakoids, basal bodies are in the counterclockwise absolute orientation and overlapped, and each X-membered rootlet is connected to the end of the opposite basal body by a terminal cap. It is suggested that the genusChlorococcopsis gen. nov. be erected for the Group I species. Group II, which includes the type species,N. aquatica, should be preserved asNeochloris. The group appears to be closely related to the coenobial generaPediastrum, Hydrodictyon, andSorastrum, and to have affinities with the coenocytic generaSphaeroplea andAtractomorpha as well. It is also suggested that the genusParietochloris gen. nov. be erected in thePleurastrophyceae for the species of Group III.     

Zoospore ultrastructure in species ofTrebouxia andPseudotrebouxia (Chlorophyta)

Zoospore ultrastructure (incl. flagellar apparatus) has been investigated in three species ofTrebouxia (T. glomerata, T. erici, T. pyriformis) and one species ofPseudotrebouxia (P. impressa) using an absolute configuration analysis. Zoospores in all taxa studied are nearly identical in ultrastructure and exhibit a very distinctive disposition of cell organelles: cells are naked, biflagellate and considerably flattened along the plane of flagellar beat, the single contractile vacuole is located anteriorly in the ventral region of the cell, the nucleus is anteriorly to centrally located in the dorsal region of the cell. A single dictyosome is located close to the anterior, ventral edge of the nucleus. The chloroplast occupies a posterior position in the cell and usually has an anterior profile in the left region of the cell. There are two branched mitochondria per cell or a single mitochondrial reticulum with profiles anterior to the nucleus (in the dorsal region of the cell), and posterior to the nucleus. In zoospores ofTrebouxia spp. the posterior mitochondrial profile is associated with a microbody, inP. impressa zoospores the anterior mitochondrial profiles are associated with a microbody. The zoospores contain a distinctive system of three ER-cisternae: one system links to both basal bodies and extends to the nucleus, the other two systems subtend the plasmamembrane on the left and right broad cell surfaces and extend to the posterior region of the cell. The flagellar apparatus is structurally identical to that previously described for zoospores ofFriedmannia israelensis and exhibits basal body displacement by one basal body diameter into the 11/5 o'clock direction, a non-striated distal connecting fiber, a cruciate microtubular root system lacking system I fibers and presence of a single system II fiber which connects the basal bodies with the nucleus and runs parallel to one of the ER-strands. The left flagellar roots (X-roots) are subtended by a complex set of amorphous and striated material that connects each left root with both basal bodies.—This study demonstrates the close systematic relationship between the phycobiontsTrebouxia andPseudotrebouxia and the generaFriedmannia, Pleurastrum, andMicrothamnion and supports recent classification schemes which place all these taxa into a single order separate from otherChlorophyta. Dedicated to Prof. DrElisabeth Tschermak-Woess on the occasion of her 70th birthday.     

Die Stipeln derIrvingioideae undRecchioideae und ihre systematische Wertung nebst Bemerkungen zur Holzanatomie und Palynologie

TheSimaroubaceae generally have no true stipules. The stipule-like appendages of some genera proved to be pseudo- or metastipules (Weberling & Leenhouts 1965). There seem to be some exceptions, however: the generaCadellia (incl.Guilfoylia) andRecchia on the one hand, and theIrvingioideae on the other. As these taxa, with exception ofRecchia, have simple leaves, there are no indications that their stipule-like appendages might be pseudo- or metastipules. In regard to their position and ontogeny these appendages behave completely like true stipules. Assuming the view ofForman, one could conceive a morphological line from the long, broadly inserted axillary stipules of mostIrvingioideae to the small scaly triangular stipules ofIxonanthoideae. The similarities between the stipules ofIrvingioideae andErythroxylaceae (already emphasized byHallier and others), become even more evident when their ontogeny is investigated. TheIrvingioideae, therefore, might be regarded as a separate family (perhaps with some relation to theErythroxylaceae,Hallier) or as a subfamily ofIxonanthaceae (Forman).—In addition to data on stipules some results on the palynology and shoot anatomy of the generaCadellia (incl.Guilfoylia) andRecchia are reported. Their relationship with theSimaroubaceae also appears doubtful. If they are to be included, they represent a somewhat isolated group near the base of the family which otherwise has lost its stipules.

Herrn Univ.-Prof. Dr.Walter Leinfellner zum 70. Geburtstag gewidmet.     

Taxonomy and phylogeny of the tribePlucheeae (Asteraceae)

The tribePlucheeae (Benth.)A. Anderb., has been analysed cladistically by means of a computerized parsimony program (Hennig 86), using theArctotideae as outgroup. The results of the analysis are presented in a consensus tree and one cladogram. Four major monophyletic subgroups can be recognized: TheColeocoma group (3 genera), thePterocaulon group (3 genera), theLaggera group (6 genera), and thePluchea group (12 genera). All recognized genera are described and most genera are supplied with taxonomical notes including comments on their taxonomic status. Genera such asBlumea, Pluchea, andEpaltes are demonstrated to be unnatural assemblages.Monarrhenus andTessaria are both closely related to thePluchea complex. The old generic nameLitogyne Harv. has been taken up for one species ofEpaltes, the genusRhodogeron is reduced to a synonym ofSachsia, and the following new combinations are made;Litogyne gariepina (DC.)A. Anderb., andSachsia coronopifolia (Griseb.)A. Anderb.     

Elektronenoptische Untersuchungen an Flechten

Summary The substructure in the phycobionts of the genus Trebouxia from different lichens is analysed. In the group Trebouxia I and Trebouxia II a further classification according to the differentiation of the chromatophores and their pyrenoids can be made. Trebouxia I: 1. Very long thylakoids are piled together. A few thylakoids curve through the pyrenoid. 2. The thylakoids are arranged like grana- and stromathylakoids in higher plants. In the pyrenoid the thylakoids are extended to canals. Trebouxia II: 1. Long thylakoids are packed very close together. A few of them pass through the pyrenoid in regular intervals. 2. The thylakoids are single or in piles. In the pyrenoid the thylakoids are again extended to canals. 3. The thylakoids are enlarged to vesicles which extend into the pyrenoid in the same form. 4. The thylakoids show all different forms of the above mentioned differentiations.In the different types of chromatophores there are always a large number of osmiophilic plastoglobuli in the pyrenoid matrix. It is discussed whether they are a reservoir in the lipid metabolism of the lichens.     

Phylogenetic analysis ofUlmaceae

A phylogenetic analysis of theUlmaceae, Cannabaceae, Barbeyaceae, andBroussonetia of theMoraceae produced nine equally parsimonious trees with 127 steps. TheUlmoideae (Ulmaceae, sensuGrudzinskaya) are a monophyletic group and distinct from theCeltidoideae. The genusAmpelocera occupies an isolated taxonomic position among the celtidoids. The similarity ofAmpelocera to the fossil celtidoid flowerEoceltis of North America suggests thatAmpelocera posesses an archaic suite of characters, and occupies a primitive position among the celtidoids, theCannabaceae and theMoraceae. The relationships among the other celtidoid taxa,Cannabaceae, andBroussonetia are problematic. TheCannabaceae andBroussonetia of theMoraceae are nested within the celtidoids suggesting that this is a paraphyletic group. The close, but unresolved, relationship of the celtidoids to theMoraceae andCannabaceae observed in this analysis, and the appearance of the celtidoids in the fossil record prior to the ulmoids suggests that the evolutionary relationship of the ulmoids and celtidoids may be more distant than current taxonomic treatments reflect.     

An ultrastructural comparison betweenSpermatozopsis andDunaliella (Chlorophyceae)

The ultrastructure of the type species of the genusDunaliella, D. salina, has been reinvestigated in an attempt to clarify the relationships betweenDunaliella andSpermatozopsis. Dunaliella salina differs in the following ultrastructural characters fromSpermatozopsis (as exemplified byS. similis Preisig etMelkonian): presence of a distinctive surface coat covering the plasmalemma; presence of a prominent pyrenoid (with pairs of thylakoids partially entering the pyrenoid matrix); dictyosomes parabasal; endoplasmic reticulum closely underlying the plasmalemma around most of the cell; contractile vacuoles absent; cell form ovoid to elongated and not spirally twisted; mitochondrial profiles near the flagellar apparatus. Differences in the ultrastructure of the flagellar apparatus: basal body angle more or less fixed; distal connecting fibre cross-striated; system II fibre (rhizoplast) present, associated with mitochondrial profile; system I fibre underlying two-stranded microtubular root; mating structure present. These ultrastructural differences justify distinction between the two taxa at generic level. The problematical status of freshwater species ofDunaliella is briefly discussed.     

Randmusterbildung und Synorganisation bei strahlenden Apiaceendolden

Radiant umbels result from the enlargement of peripheral phyllomes. We find the following patterns: 1) TheOrlaya-type: only one petal in the flower is enlarged. 2) TheCoriandrum-type: one whole and two half petals in the flower are enlarged. 3) TheArtedia-type: two half petals in the flower are enlarged. 4) TheXanthosia-type: the enlargement affects three involucellar bracts of which two become asymmetrical.—The enlargement of the phyllomes can effect the umbellet or the umbel or both. Obviously, this is the reason why many of these inflorescence systems display insufficient degrees of synorganization, with an optimum reached inArtedia and some species ofXanthosia.

Herrn Univ.-Prof. Dr.Walter Leinfellner zum 70. Geburtstag gewidmet.     

SPECIES-SPECIFIC DIFFERENCES OF PYRENOIDS IN CHLORELLA (CHLOROPHYTA)1

The structure of the pyrenoid supports the separation of Chlorella species into two groups based on cell wall chemistry and suggests evolutionary relationships. Chlorella species with a glucan-type wall exhibit quite diverse pyrenoid structures, which may indicate that these species are not closely related. Those species with glucosamine cell walls (C. kessleri, C. sorokiniana, C. vulgaris) are virtually identical in pyrenoid morphology, indicating a closer evolutionary relationship. In the species with glucosamine walls, the thylakoid that penetrates into the pyrenoid matrix, is unijormly double-layered. Pyrenoids in the species with glucan walls show various features: 1) a pyrenoid matrix only, 2) a pyrenoid traversed by a few discs of double thylakoids with many adhering pyrenoglobuli, 3) a pyrenoid penetrated with tubelike structures or 4) a pyrenoid penetrated with many single undulating thylakoids. The pyrenoid structure of the symbiotic Chlorella in Paramecium bursaria resembles those of free-living Chlorella with glucosamine walls.     

Serologische Untersuchungen zur Gliederung derBrassicaceae

The serological investigations support the opinion ofJanchen (1942) to combine the generaBunias, Isatis, andSisymbrium in the tribeSisymbrieae; Cheiranthus, Erysimum, andMatthiola in the tribeHesperideae; andBrassica, Crambe, Sinapis, andSuccowia in the tribeBrassiceae. They further underline the central position of theSisymbrieae and the isolated position of theHeliophileae. In accordance withEigner (1973) theBrassiceae are placed closer to theSisymbrieae than inJanchen; the same holds for thePringleeae. No serological justification could be found to uniteArabis andBarbarea in the tribeArabideae, andAlyssum andLunaria in theAlysseae. From the antigen-systems used among the representatives ofJanchen's Lepidieae the generaLepidium andNeslia show remarkable correspondence both toCamelina andThlaspi, but not toCochlearia which appears distant fromCamelina andThlaspi also.

Teil 1/Part 1.     

Comparison of the Giemsa C-banded and N-banded karyotypes of twoElymus species,E. dentatus andE. glaucescens (Poaceae: Triticeae)

The karyotypes ofElymus dentatus from Kashmir andE. glaucescens from Tierra del Fuego, both carrying genomesS andH, were investigated by C- and N-banding. Both taxa had 2n = 4x = 28. The karyotype ofE. dentatus was symmetrical with large chromosomes. It had 18 metacentric, four submetacentric and six satellited chromosomes. The karyotype ofE. glaucescens resembled that ofE. dentatus, but a satellited chromosome pair was replaced by a morphologically similar, non-satellited pair. The C-banding patterns of both species had from one to five conspicuous and a few inconspicuous bands per chromosome. N-banding differentiated the chromosomes of the constituent genomes by producing bands in theH genome only. TheS genomes of both species were similar with five metacentric and two satellited chromosomes having most conspicuous C-bands at telomeric and distal positions. They resembled theS genome of the genusPseudoroegneria. TheH genomes had four similar metacentric and two submetacentric chromosomes. The seventhH genome chromosome ofE. dentatus was satellited, that ofE. glaucescens nonsatellited, but otherwise morphologically similar. The C-bands were distributed at no preferential positions. TheH genome ofE. dentatus resembles theH genomes of some diploidHordeum taxa.     

Relationships in theAcanthaceae and related families as suggested by cladistic analysis ofrbcL nucleotide sequences

A parsimony analysis of DNA sequences of the chloroplast-encoded generbcL from twelve members of theAcanthaceae s.l., including members of the sometimes segregateThunbergioideae andNelsonioideae, and other families in theBignoniales sensuThorne (1992) is presented. The results largely agree with the classification of theAcanthaceae presented byBremekamp (1965) andThorne (1992) and supportNelsonioideae as a sister group to the rest of theAcanthaceae. Thunbergioideae are placed as a sister toAcanthaceae s.str.Acanthus andAphelandra, both representatives ofAcanthoideae, form a sister group toRuellioideae. An analysis of branch support found that many branches throughout theBignoniales are weakly upheld. This points to the need for further studies in the group using more sequences ofrbcL as well as other data. None of the families ofBignoniales as presently circumscribed (includingAcanthaceae s.l.) were strongly supported, although the larger clade containing the families of theBignoniales was robust.     

Weitere Untersuchungen über Proteinkörper in Zellkernen und ihre taxonomische Bedeutung

In 83 species of the familiesMonotropaceae, Apocynaceae, Oleaceae, Scrophulariaceae, Lentibulariaceae, Bignoniaceae, Martyniaceae, Myoporaceae, Verbenaceae, Lamiaceae, Campanulaceae, andLiliaceae, protein bodies in the cell nuclei have been found, in 68 of these species for the first time. On the basis of their structure in accordance with morphological characters the generaBurgsdorfia, Hesiodia, Olisia, andPhlomoides of theLamiaceae are accepted;Lamium is divided intoLamium, Lamiastrum andOrvala; two new combinations are established:Kickxia campyloceras (Rech. fil. &Esfandiari)Speta andEtornotus papilionaceus (Burm. in L.)Speta. Deviating shape or lack of protein bodies corroborate former taxonomic decisions, e.g. the transfer ofMonotropa toMonotropaceae or the separation ofGaleopsis andLadanum; Veronica schmidtiana should not be included inPseudolysimachion. Systematic affinities are discussed primarily withinScrophulariaceae because nuclear protein bodies have been studied already in many species of this family. ForCampanula patula two 2 x populations are reported.

Herrn Professor Dr. L.Geitler zum 80. Geburtstag gewidmet.     

几种藻类蛋白核的超微结构研究

应用电镜及免疫电镜技术对莱茵藻、小球藻、条浒苔和紫菜等藻类的叶绿体蛋白核的超微结构及主要组成成分进行了观察和研究。结果显示：不同藻类的蛋白核结构不同,显示了藻类蛋白核的多样性。蛋白核为球形或椭圆形,由蛋白质组成。莱茵藻、小球藻和条浒苔的蛋白核外围被淀粉鞘所包围,而紫菜的蛋白核外围无淀粉鞘而直接被叶绿体的类囊体所包围。淀粉鞘由淀粉组成,淀粉鞘的厚薄与藻体藻龄及增养状态有关系。在蛋白核中央,一般都具有由类囊体形成的孔道,使蛋白核与外界联系,小球藻和条浒苔蛋白核具有1条纵向孔道,而莱茵藻和紫菜为多条孔道。金相免疫技术检测结果显示Rubisco和Rubisco活化酶均在蛋白核及淀粉鞘区域中定位,表明蛋白核具有光合作用功能．     

Relationships between species ofLeymus,Psathyrostachys, andHordeum (Poaceae,Triticeae) inferred from Southern hybridization of genomic and cloned DNA probes

We have used total genomic DNA as a probe to size-fractionated restriction enzyme digests of genomic DNA from a range ofTriticeae species from the generaLeymus Hochst.,Psathyrostachys Nevski, andHordeum L., and hybrids betweenHordeum andLeymus to investigate their taxonomic relationships. Genomic Southern hybridization was found to be an effective and simple way to assess the distribution and diversity of essentially species-specific and common, repetitive DNA sequences, and is hence especially useful in evolutionary studies. The DNA sequences ofH. vulgare seem to diverge substantially from those ofH. brachyantherum, H. lechleri, H. procerum, andH. depressum. The genome ofThinopyron bessarabicum shows little homology to those of theLeymus species investigated, confirming thatT. bessarabicum is not an ancestral genome inLeymus. Although the genomes ofLeymus andPsathyrostachys share substantial proportions of DNA sequences, they include divergent repeated sequences as well. Hybridization with a ribosomal DNA probe (pTa 71) showed that the coding regions containing structural genes encoding the 18 S, 5.8 S, and 26 S ribosomal RNA were conserved among the species investigated, whereas the intergenic spacer region was more variable, presenting different sizes of restriction fragments and enabling a classification of the species. The rye heterochromatin probe pSc 119.2 hybridized to DNA fromH. lechleri andT. bessarabicum, but not to DNA from the other species investigated.