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Full-Text Articles in Life Sciences

Seorious Business: Structural Proteins In Sieve Tubes And Their Involvement In Sieve Element Occlusion [Review Article], Michael Knoblauch, Daniel R. Froelich, William F. Pickard, Winfried S. Peters Mar 2014

Seorious Business: Structural Proteins In Sieve Tubes And Their Involvement In Sieve Element Occlusion [Review Article], Michael Knoblauch, Daniel R. Froelich, William F. Pickard, Winfried S. Peters

Winfried S. Peters

The phloem provides a network of sieve tubes for long-distance translocation of photosynthates. For over a century, structural proteins in sieve tubes have presented a conundrum since they presumably increase the hydraulic resistance of the tubes while no potential function other than sieve tube or wound sealing in the case of injury has been suggested. Here we summarize and critically evaluate current speculations regarding the roles of these proteins. Our understanding suffers from the suggestive power of images; what looks like a sieve tube plug on micrographs may not actually impede translocation very much. Recent reports of an involvement of …


A Guide To Southern Temperate Seagrasses, Kathryn Mcmahon, Michelle Waycott, Paul Lavery Jan 2014

A Guide To Southern Temperate Seagrasses, Kathryn Mcmahon, Michelle Waycott, Paul Lavery

Kathryn McMahon

No abstract provided.


Combined Morphological And Molecular Phylogeny Of The Clusioid Clade (Malpighiales) And The Placement Of The Ancient Rosid Macrofossil Paleoclusia, Brad Ruhfel, Peter Stevens, Charles Davis Dec 2012

Combined Morphological And Molecular Phylogeny Of The Clusioid Clade (Malpighiales) And The Placement Of The Ancient Rosid Macrofossil Paleoclusia, Brad Ruhfel, Peter Stevens, Charles Davis

Brad R. Ruhfel

Premise of research. The clusioid clade is a member of the large rosid order Malpighiales and contains∼1900 species in five families: Bonnetiaceae, Calophyllaceae, Clusiaceae sensu stricto (s.s.), Hypericaceae, and Podostemaceae. Despite recent efforts to clarify their phylogenetic relationships using molecular data, no such data are available for several critical taxa, including especially Hypericum ellipticifolium (previously recognized in Lianthus), Lebrunia, Neotatea, Thysanostemon, and the second-oldest rosid fossil (∼90 Ma), Paleoclusia chevalieri. Here, we (i) assess congruence between phylogenies inferred from morphological and molecular data, (ii) analyze morphological and molecular data simultaneously to place taxa lacking molecular data, and (iii) use ancestral …


Plant Classification And Nomenclature In Ndumba, Papua New Guinea Highlands, Terence Hays Nov 2012

Plant Classification And Nomenclature In Ndumba, Papua New Guinea Highlands, Terence Hays

Terence Hays

Traditionally, the terms "ethnobotany" and "ethnozoology" have designated little more than the study of plant and animal utilization. In the past two decades, however, the ways in which the components of given biological environments are locally perceived and categorized have received increasing attention. Not only has the study of ethnobiological classification been recognized as essential to a wide variety of ethnographic concerns (cf. Frake 1962; Bulmer 1967), but the discovery of possible universals in folk classification systems promises to enrich our understanding of human cognitive processes as well (Berlin et al. 1973; Brown 1977).

The paucity of comprehensive studies of …


The Effect Of Light Intensity On Seed Production And Quality In A Number Of Australian Wild Oat (Avena Fatua L.) Lines, Steve Adkins, Leisa Armstrong Feb 2012

The Effect Of Light Intensity On Seed Production And Quality In A Number Of Australian Wild Oat (Avena Fatua L.) Lines, Steve Adkins, Leisa Armstrong

Leisa Armstrong

Several aspects of the maternal environment (e.g. air temperature, soil moisture, soil nutritional status and photoperiod) are known to influence seed production and quality in a range of plant species. However, little is known about the effect of other environmental factors, such as the light intensity perceived by the developing plant, on these seed characters. This is particularly important when elucidating the persistence mechanisms of annual weeds that may produce seeds under a crop canopy. Therefore, the aim of the present study was to determine the effect of light intensity on the reproductive characteristics of a number of wild oat …