SwePub
Sök i SwePub databas

  Utökad sökning

Träfflista för sökning "WFRF:(Korall P) "

Sökning: WFRF:(Korall P)

  • Resultat 1-9 av 9
Sortera/gruppera träfflistan
   
NumreringReferensOmslagsbildHitta
1.
  • Korall, Petra, 1968-, et al. (författare)
  • Phylogeny of selaginellaceae : Evaluation of generic subgeneric relationships based on rbcL gene sequences
  • 1999
  • Ingår i: International journal of plant sciences. - 1058-5893 .- 1537-5315. ; 160:3, s. 585-594
  • Tidskriftsartikel (refereegranskat)abstract
    • A cladistic analysis based on rbcL gene sequences from a representative sample of 18 species yields three most parsimonious trees that strongly support monophyly of Selaginellaceae. Within Selaginellaceae, the morphologically distinctive subgenus Selaginella is resolved as sister group to a clade composed of all other species, here termed the rhizophoric clade. In the rhizophoric clade, subgenus Stachygynandrum is paraphyletic to subgenera Ericetorum, Tetragonostachys, and Heterostachys. Monophyly of Ericetorum and Tetragonostachys is strongly corroborated. Results support a close relationship between "resurrection plants" in Stachygynandrum and the mat-forming or tufted drought-tolerant species of Tetragonostachys, indicating a common origin of xerophytism in these groups. A close relationship for all isophyllous species, as hypothesized in many classifications, is not supported by the rbcL data. Leaf isophylly and reduction in Ericetorum and Tetragonostachys most probably represent independent reversals of the marked anisophyllous condition in Stachygynandrum, Leaf reduction is one of a suite of characters that may have evolved in response to seasonal drought.
  •  
2.
  • Magnuson, Ann, et al. (författare)
  • Mimicking electron transfer reactions in photosystem II: Synthesis and photochemical characterization of a ruthenium(II) tris(bipyridyl) complex with a covalently linked tyrosine
  • 1997
  • Ingår i: Journal of the American Chemical Society. - : The American Chemical Society (ACS). - 1520-5126 .- 0002-7863. ; 119:44, s. 10720-10725
  • Tidskriftsartikel (refereegranskat)abstract
    • In the natural photosynthetic reaction center photosystem II, absorption of a photon leads to photooxidation of the primary electron donor P-680, which subsequently retrieves electrons from a tyrosyl residue, functioning as an interface to the oxygen-evolving manganese complex. In a first step toward mimicking these reactions, we have made a Ru(II)-polypyridine complex with an attached tyrosyl moiety. The photoexcited ruthenium complex played the role of P-680 and was first oxidized by external accepters. Combined transient absorbance and EPR studies provided evidence that the Ru(III) formed was reduced by intramolecular electron transfer from the attached tyrosine, with a rate constant of 5 x 10(4) s(-1). Thus we show that a tyrosine radical could be formed by light-induced electron transfer reactions, and we indicate future directions for developing a closer analogy with the photosystem II reactions.
  •  
3.
  • Ferm, Julia, et al. (författare)
  • Phylogeny of the Neotropical legume genera Zygia and Marmaroxylon and close relatives
  • 2019
  • Ingår i: Taxon. - 0040-0262 .- 1996-8175. ; 68:4, s. 661-672
  • Tidskriftsartikel (refereegranskat)abstract
    • The Neotropical legume genera Zygia and Marmaroxylon have traditionally been considered closely related and are sometimes treated as congeners. They have been referred to the mimosoid tribe Ingeae based on their possession of flowers with basally fused stamen filaments. However, their systematic status and position have not been analysed in a phylogenetic context. This study provides the first molecular phylogeny of Zygia and Marmaroxylon and closely related mimosoid legume genera, particularly from the tribe Ingeae. DNA sequence data were derived from the nuclear external transcribed spacer (ETS) and the internal transcribed spacer (ITS), and from the chloroplast psbA‐trnHand trnL‐trnF regions, and were analysed using Bayesian inference. In all, 29 species of Zygia and 7 species of Marmaroxylon were included in the study along with representative species from the closely related genera Abarema, Acacia s.str., Archidendropsis, Calliandra, Chloroleucon, Cojoba, Faidherbia, Havardia, Hydrochorea, Inga, Leucochloron, Macrosamanea, Pithecellobium, Pseudosamanea, Samanea, Senegalia, Vachellia and Zapoteca. The results show that neither Zygia nor Marmaroxylon are monophyletic as presently circumscribed. Furthermore, these two genera are not monophyletic together. None of the nine presently recognized sections of Zygia that contain more than one species are shown to be monophyletic. Two of the monospecific sections of Zygia, sect. Ingopsis (Z. inundata) and sect. Pseudocojoba (Z. sabatieri), were found in a clade together with species of Inga. Marmaroxylon ocumarense and M. magdalenae, previously treated as synonyms (as Zygia), are not conspecific, and are found in a clade with Macrosamaneaand in a clade with species of Abarema and Hydrochorea, respectively. Our results also show the Inga alliance to be non‐monophyletic. In correspondence with the results presented, all species referred to Marmaroxylon, except for M. ocumarense and M. magdalenae, are here included in Zygia, and Z. inundata is treated in Inga, in which genus it was first described.
  •  
4.
  •  
5.
  • Korall, Petra, 1968-, et al. (författare)
  • PHYLOGENETIC RELATIONSHIPS IN SELAGINELLACEAE BASED ON RBCL SEQUENCES
  • 2002
  • Ingår i: American Journal of Botany. - 0002-9122 .- 1537-2197. ; 89:3, s. 506-517
  • Tidskriftsartikel (refereegranskat)abstract
    • A phylogenetic framework is developed for the clubmoss family Selaginellaceae based on maximum parsimony analyses of molecular data. The chloroplast gene rbcL was sequenced for 62 species, which represent nearly 10% of living species diversity in the family. Taxa were chosen to reflect morphological, geographical, and ecological diversity. The analyses provide support for monophyly of subgenera Selaginella and Tetragonostachys. Stachygynandrum and Heterostachys are polyphyletic. Monophyly of Ericetorum is uncertain. Results also indicate a large number of new groupings not previously recognized on morphological grounds. Some of these new groups seem to have corresponding morphological synapomorphies, such as the presence of rhizophores (distinctive root-like structures), aspects of rhizophore development, and leaf and stem morphology. Others share distinctive ecological traits (e.g., xerophytism). For many groups, however, no morphological, ecological, or physiological markers are known. This could reflect patchy sampling and a lack of detailed knowledge about many species. Despite a lengthy fossil record dating from the Carboniferous Period, cladogram topology indicates that most of the living tropical species are probably the products of more recent diversifications. Resurrection plants, extreme xerophytes characterized by aridity-driven inrolling of branches and rapid revival on rehydration, have evolved at least three times in quite different clades.
  •  
6.
  •  
7.
  •  
8.
  • Sun, L C, et al. (författare)
  • Binuclear ruthenium-manganese complexes as simple artificial models for photosystem II in green plants
  • 1997
  • Ingår i: Journal of the American Chemical Society. - : The American Chemical Society (ACS). - 1520-5126. ; 119:30, s. 6996-7004
  • Tidskriftsartikel (refereegranskat)abstract
    • As part of a project aimed at developing models for photosystem II (PSII) in green plants, we have prepared a series of model compounds (7, 8, and 13). In these compounds, a photosensitizer, ruthenium(II) tris(bipyridyl) complex (to mimic the function of P-680 in PSII), was covalently linked to a manganese(II) ion through different bridging ligands. The structures of the compounds were characterized by electron paramagnetic resonance measurements and electrospray ionization mass spectrometry. The interaction between the ruthenium and manganese moieties within the complex was probed by steady-state and time-resolved emission measurements. When the binuclear complexes are exposed to flash photolysis in the presence of an electron acceptor such as methylviologen (MV2+), it could be shown that after the initial electron transfer from the excited state of Ru(II) in compound 7, forming Ru(III) and MV+., an intramolecular electron transfer from coordinated Mn(II) to the photogenerated Ru(III) occurred with a first-order rate constant of 1.8 x 10(5) s(-1), regenerating Ru(II). This is believed to be the first supramolecular system where a manganese complex has been used as an electron donor to a photo-oxidized photosensitizer, Possible extensions to develop the manganese donor, and thus to approach the function of reaction center in PSII, are indicated.
  •  
9.
  •  
Skapa referenser, mejla, bekava och länka
  • Resultat 1-9 av 9

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt Stäng

Kopiera och spara länken för att återkomma till aktuell vy