bluuebunny/crossref_metadata_2025 huggingface dataset:
Pollen Presenter Morphology and Anatomy in Banksia and Dryandra
Authors: Ladd PG , Alkema AJ , Thomson GJ
Published: December 2005

Style shape, and pollen presenter morphology and anatomy, are similar in Banksia L.f, and Dryandra
R.Br. There are four style shapes-straight, bowed, s-shaped and hooked. However, in Dryandra,
s-shaped and hooked styles are uncommon. The stigma in all cases is contained within the pollen
presenter, but there is variation in the location of the stigmatic groove on the presenter, from truly apical
(terminal), obliquely terminal to rarely located at the base of the presenter as in B. ericifolia. There is
also variation in whether the pollen is deposited over the stigmatic groove in bud or the slit is free of
pollen at anthesis. In Banksia, 73% of species studied have the groove covered with pollen, while in
Dryandra, a somewhat lower proportion of species (50%) has this configuration. Pollen cohesion on the
presenter varies from sticky to loose but is mostly slightly sticky. Similar pollen presenter forms occur
in both genera, but in Dryandra, the generally less elaborate shapes are more frequent than is the case in
Banksia. Anatomically, the pollen presenters are quite complex, with several cell layers concentrically
disposed around the central transmitting tissue. There is considerable variation in the epidermal cells of
the presenters between species. In most, the cells are small and thick-walled, but in B. ilicifolia, they are
very thin-walled and enlarged into elongated projections. Similar forms occur in other species.
In B. tricuspis, the epidermal cells are enlarged, regularly rounded in shape and become smaller and
thick-walled near the stigmatic groove. Underlying the epidermis, polyphenol-containing cells and
sclerenchyma vary in proportion between species and also in their location within the presenter.
The variation in wall characteristics of epidermal cells and the proportion of sclerenchyma in different
species is likely to be related to maximising pollination success within an environment containing a
variety of pollinator behaviours. Although vertebrates are important in pollinating many species,
invertebrates are likely to be the primary pollinators of a significant number of the other species in
both genera.
Embryogenic Callus Induction and Plant Regeneration in Triticum tauschii, the Diploid D-Genome Donor for Bread Wheat (Triticum aestivum)
Authors: Afsharsterle S , Pang ECK , Brown JS , Kollmorgen JF
Published: December 2005

Immature embryos of seven accessions of Triticum tauschii (Coss.) Schmal. were used to produce embryogenic callus suitable for initiation of suspension cultures. Several modifications of Murashige and Skoog basal medium (MS) were evaluated for callus induction from scutellar tissues of embryos. Nodular, embryogenic calli were induced from all accessions when MS medium was supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D) and a mixture of L-glutamine, L-asparagine and L-proline. Early differentiation of these embryogenic calli was overcome by substituting Dicamba for 2,4-D. Addition of 575 mg L-1 of L-proline gave a rapid increase in the production of nodular embryogenic callus in most of the accessions. Using this protocol, the embryogenic capacity of this type of callus was maintained for more than a year following further modification of the MS medium. A clear genotype dependency as well as media effects on the production of callus were observed.
The Effect of Salicylic Acid on Resistance in Wheat (Triticum aestivum) Seedling Roots Against the Take-All Fungus, Gaeumannomyces graminis var tritici
Authors: Seah S , Sivasithamparam K , Turner DW
Published: December 2005

The effect of salicylic acid (SA) applied as foliar dip, foliar wipe, root drench or pre-germination soak on the susceptibility of wheat (Triticum aestivum L.) seedlings to Gaeumannomyces graminis (Sacc.) Arx & Olivier var. tritici Walker (take-all fungus, Ggt) was studied. It was hypothesised that an increase in SA concentration applied using these methods would increase the resistance in wheat seedling roots against Ggt. Leaves (by foliar wipe and foliar dip) and roots (by root drench) of 1-2-week-old wheat seedlings grown in Lancelin sand, were treated with 0, 0.1 or 1 mM SA, and treatments of 0, 0.1 or 0.5 mM SA were applied in a pre-germination soak method. Ggt infection reduced (P Ͱ4 0.05) chlorophyll content and concentration and root length (P Ͱ4 0.10). Experiments that were conducted suggested that the SA treatments failed to induce a resistance response because they did not stimulate phenylalanine ammonia-lyase and peroxidase activities in the wheat seedling roots. Therefore, SA applied using these methods was not effective in reducing the susceptibility of wheat seedlings to Ggt. The chemical or biological induction of resistance in plant roots and its applicability as a root disease control strategy requires further clarification.
Molecular Differentiation Within and Between Eucalyptus risdonii, E. amygdalina and Their Hybrids Using RAPD Markers
Authors: Sale MM , Potts BM , West AK , Reid JB
Published: December 2005

Random amplified polymorphic DNA (RAPD) studies of a natural hybrid swarm between Eucalyptus amygdalina Labill. and E. risdonii Hook.f. and nearby allopatric stands revealed that, despite clear morphological differences, all bands were shared between species. However, frequency differences revealed genetic divergence between species, populations within species, and individuals within populations. Variation was greatest between individuals within populations and lowest between species. For both species, the direction of variation which distinguished the two populations was in a different direction to that which separated the two species, suggesting population differences were not due to introgression but were the result of genetic isolation and/or strong localised selection. Several morphologically typical individuals with intermediate RAPD profiles were detected in the hybrid swarm and nearby allopatric samples of both species, suggesting that some cryptic introgression may be occurring. Controlled F1 crosses generally had closer genetic affinity to E. risdonii, raising the possibility that some parents used may have been advanced generation hybrids. While natural hybrids selected for their intermediate leaf phenotype were usually also intermediate between the two species using RAPD markers, some deviated markedly toward E. risdonii. The study suggests that morphological appearance does not necessarily reflect genetic (RAPD) status and in some cases detectable RAPD differences between spatially close populations of the same species may be as great or greater than the differences between species.
Diversity Patterns of Woody Species on a Latitudinal Transect From the Monsoon Tropics to Desert in the Northern Territory, Australia
Authors: Bowman DMJS
Published: December 2005

A belt transect, made up of 15 contiguous cells (width, 3.5° of longitude; length, 1° of latitude), was
established from the monsoon tropics on the central north coast of the Northern Temtory (11°S) to the
central Australian desert on the South Australian border (26°S). On this transect, mean annual rainfall
was found to have a negative exponential decay with latitude, with arid conditions commencing at
around 18"s-the limit of the monsoonal rains. The mean elevation of each cell steadily increased from
the north coast to reach a maximum average elevation of 700 m at around 23°S. The mean alphadiversity
(quadrat species richness), and mean beta-diversity (turnover of species along an
environmental gradient) was determined for each of the 15 cells by sub-sampling a large 20 × 20 m
quadrat data set (N > 2000) collected during the course of the Northern Territory 1:106 vegetation
mapping program. It was found that there was little within-cell variation of beta-diversity of woody
species which occurred in at least five quadrats, as approximated by the first axis of a detrended
correspondence analysis (DCA) of these data. The mean first axis DCA scores were strongly correlated
with latitude (r = 0.99); thus, there is no evidence for a floristic disjunction in the composition of
common woody species between the monsoon tropics and desert. Mean alpha-diversity had a bimodal
distribution on the latitudinal transect, with the maximum mean quadrat richness in the monsoon tropics
and a second smaller peak occurred in central Australia, with the lowest levels of alpha-diversity to the
south of the limit of the monsoon rains. This pattern was mirrored by the mean number and mean
Shannon-Wiener diversity of 1:106 vegetation map units on the transect. It was found that 81% of the
variance of mean alpha-diversity was explained by mean annual rainfall and mean elevation for the 15
cells. The increase in mean alpha-diversity in central Australia appears to be related to environmental
heterogeneity associated with mountainous terrain. It is possible that the central Australian mountains
are a refuge for plants that were more widespread during the last ice-age. It is unknown whether the
woody species diversity patterns are in equilibrium with the prevailing climate. More data on the
palaeo-environments of the Northern Territory are required to answer this question.
Occurrence of Terpenoid Aldehydes and Lysigenous Cavities in the 'glandless' Seeds of Australian Gossypium Species
Authors: Brubaker CL , Benson CG , Miller C , Leach DN
Published: December 2005

The presence of lysigenous cavities filled with terpenoid aldehydes (generically termed 'gossypol') in most tissues of cultivated cottons and their relatives imparts natural resistance to a variety of insect, fungal, and bacterial pests. Deposition of terpenoid aldehydes in cultivated cotton seed, however, renders cottonseed oils and protein meals toxic to non-ruminant animals, including humans. Seeds of the so-called 'glandless-seeded' Australian Gossypium L. species (Gossypium subgenus Sturtia (R.Br.) Tod.) reportedly lack terpenoid aldehydes, and thus may represent an important genetic resource in the development of cottonseed oils and protein meals free of these toxins. Information supporting this assertion, however, is fragmentary and contradictory. To resolve this, seeds of all known Australian Gossypium species were surveyed chemically and anatomically. Immature lysigenous cavities were present in seeds of all 18 species. Lysigenous cavities of sect. Sturtia and sect. Hibiscoidea Tod. seeds were unpigmented and invisible to the naked eye, while pigmented, macroscopically visible lysigenous cavities occurred in all the sect. Grandicalyx (Fryxell) Fryxell seeds. HPLC (high performance liquid chromatography) analysis revealed that sect. Sturtia and sect. Hibiscoidea seeds did not contain detectable levels of terpenoid aldehydes, but that sect. Grandicalyx seeds contained gossypol.
Regulation of Plant Phenolic Synthesis: From Biochemistry to Ecology and Evolution
Authors: Matsuki M
Published: December 2005

The molecular and biochemical regulation of phenolic synthesis can be summarised as: (1) carbohydrates are partitioned in a manner ensuring growth; (2) carbohydrates are available for phenolic synthesis mainly during cell differentiation and after leaf maturation as the 'overflow'; (3) synthesis of a particular phenolic compound is specific to cell type and developmental stage; and (4) synthesis of certain phenolic compounds can be induced, independently of cell type, by factors such as wounding, microbial infection, and UV light. Recent advances in the understanding of the regulation of phenolic synthesis raises the question as to whether between-site and temporal variation in the amount and type of plants phenolics is due mostly to selection pressure by herbivores. Interdisciplinary studies by biochemists and ecologists are needed for a better understanding of the regulation of phenolic synthesis and plant-herbivore interactions mediated by secondary metabolites.
Germination and Seedling Survival Studies of Xanthorrhoea australis in the Warby Range State Park, North-Eastern Victoria, Australia
Authors: Curtis NP
Published: December 2005

Germination of Xanthorrhoea australis R.Br. was affected by temperature, stratification, the time of seed collecting, and light. Ninety eight percent of seeds germinated at the optimum temperature, 15-20°C, in the laboratory which matched field conditions during times of reliable rainfall. A varying temperature of 20-12°C brought seeds sown in soils out of dormancy 6 weeks earlier than those under a fixed temperature regime. The germination of seeds stratified at 4°C for 11 weeks was 90% compared with 40% for unstratified seeds. For spring- and autumn-picked seeds, germination in the dark was 98%; but for spring-picked seed, germination in light was 90% compared with 60% for autumn-picked seed, with both picked in the same year. After a simulated summer, when temperatures decreased, seeds in light (or on the soil surface) had 3% germination, while those in the dark (buried) had 40% germination. In field trials using five different substrates, germination of buried seed ranged from 30% to 55%, with a seedling survival in the first post-fire autumn of 28-43%, which was significantly greater (P < 0.001) than that of the surface-sown seed. However, in cabinet trials with the same substrates, there was no significant difference between germination in buried and surface-sown seeds (25-40% germination). The lower germination in the field of surface-sown seeds could be explained by loss due to seed predation, and lack of moisture, causing incomplete imbibition and water stress on seedling survival. These findings show that to establish X. australis in areas degraded by soil pathogens, fire or clearing, seeds should be sown in the late winter at a depth of 3 mm, with protection from grazing.
Timetable of Stigmatic Receptivity and Development and Pollen Tube Growth in Chamelaucium uncinatum (Myrtaceae)
Authors: Obrien SP
Published: December 2005

The stigma of Chamelaucium uncinatum Schauer is small and unreceptive at anthesis, but increases in size and becomes fully receptive 7 days after anthesis. After germination, pollen tubes grow intercellularly through the stigma and transmitting tissue of the style. Chamelaucium uncinatum has a single loculus containing six ovules with axile placentation. The transmitting tissue skews to one side within the ovary and the pollen tubes grow into the placenta via an invagination along one end of the loculus. Pollen tubes are smooth-walled in the transmitting tissue of the style and ovary, but within the loculus pollen tubes produce short side branches. Secondary pollen presentation occurs in C. uncinatum with the stigmatic region being used as a pollen presenter. If the self-pollen is not removed from the stigma prior to the onset of receptivity self-pollination may occur.
The Reservation Status of Plant Species and Vegetation Types in the Northern Territory
Authors: Woinarski JCZ , Connors G , Oliver B
Published: December 2005

The terrestrial conservation reserve system of the Northern Territory comprises 83 reserves covering 3.79% of the land area. This system includes representation of only 63 of the 112 vegetation types recognised in the Northern Territory at 1:1000000 scale. Of these, only 31 are represented to at least 5% of their extent. The reserve system has a strong geographic bias, with very poor representation of vegetation types occurring across a broad band in the mid-latitudes of the Northern Territory. Broad vegetation categories which are particularly poorly reserved include tussock grasslands, chenopod shrublands, Acacia woodland and hummock grasslands: by contrast, closed forests and floodplains have > 20% of their extent reserved. In some contrast to the poor reservation extent of vegetation types, 80% of the 3632 named native vascular plant species known from the Northern Territory have been recorded from reserves. The distribution of the 743 unreserved plants is mapped, and coincides reasonably well with the pattern of unreserved vegetation types. The high proportion of the flora which is reserved is due in part to judicious (or fortuitous) reserve placement-for example, one reserve, Kakadu, contains almost half of the plant species known from the Northern Territory. There are substantial taxonomic and ecological biases in the reported reservation rates for NT plants. Rainforest plants tend to be reasonably well reserved (80% of 585 species), but designated threatened plants are poorly reserved(44% of 553 species). Due to its largely intact environment, the Northern Territory offers an unusually good opportunity for the establishment of a comprehensive reserve network. However, most of the unreserved plants and vegetation types occur on either freehold Aboriginal lands or pastoral leaseholds, suggesting that substantial enhancement of the existing reserve network may not be simple.
Epicuticular Wax Structure and Regeneration on Developing Juvenile Eucalyptus Leaves
Authors: Wirthensohn MG , Sedgley M
Published: December 2005

Eighteen species of Eucalyptus L'Hér. were studied for changes in wax morphology of juvenile foliage with leaf age using environmental scanning electron microscopy. Three species were studied for wax regeneration following removal from the adaxial surface of day 16 and day 30 leaves (16 and 30 days following lamina separation, respectively) while still attached to the tree. For each leaf age, four leaves per species were sampled at 0, 1, 3, 9 and 15 days after wax removal. All species had tube wax on juvenile leaves but there were differences between the species, in the length and conformation of tubes and percentage surface area covered by wax. Tube length was greatest in day 30 leaves, but tube diameter was narrower than day 0 leaves (unfolding leaves). There were significant differences in wax structure between the proximal and distal ends of day 0 leaves of 10 species, and tubes were observed crystallising from amorphous wax deposits in the proximal area only. Significant wax regeneration occurred more rapidly on day 16 leaves than day 30 leaves. Wax morphology was consistent across six species of the series Viminales. Thirteen species of Eucalyptus are recommended for the cut foliage industry.
Growth Suppression of Some Wood-Decay and Other Fungi by Bacillus subtilis
Authors: Dass C , Teyegaga A
Published: December 2005

The antagonistic activity of an isolate of Bacillus subtilis was examined against five wood-decay fungi (Coriolus spp., Poria sp., Stereum sp., Hexagonia discopoda, and Schizophyllum commune) and five other fungi (Candida sp., Fusarium sp., Curvularia geniculata, Penicillium digitatum, and Trichoderma viride). The effect of the bacterium on the fungi was tested using aerated growth on potato dextrose agar, non-aerated (partially anaerobic) growth on potato dextrose agar, and growth in potato dextrose broth supplemented with cell-free filtrate of broth in which B. subtilis was previously cultured. All 10 fungal species were inhibited by water-soluble factors produced by the bacterium. Nine of the 10 species were adversely affected by volatiles synthesised by the bacterium. Varying degrees of inhibition were observed in the fungi in response to the presence of cell-free filtrate of B. subtilis in broth medium. The results of this study confirm the dual nature (production of antifungal volatile compounds in addition to water-soluble agents) of antagonism manifested by B. subtilis and the thermostable property of the antifungal factors it synthesises. It also broadens the range of fungi proven to be inhibited by the bacterium.
Preface introducing the 'Turner Reviews'
Authors: Attiwill Peter , Ball Marilyn , Lamont Byron
Published: December 2005

This issue of Australian Journal of Botany sees the first in a new series of scholarly
reviews to be called the .Turner Reviews. in honour of John Stewart Turner, Ph.D. (Cantab.),
FAA (1908.1991). John Turner was Professor of Botany and Plant Physiology at The
University of Melbourne from 1938 to 1973. He was a foundation member of the Advisory
Committee of the Australian Journal of Botany. The present Advisory Committee initiated
the Turner Reviews in recognition of Turner.s wide-reaching influences on several
generations of botanists and conservationists in Australia (see Rowan and Ashton, this
volume).
The Turner Reviews aim to provide critical, state-of-the-art evaluations that advance our
knowledge in current, key areas of botanical research. The Turner Reviews will be
commissioned by invitation, and will be numbered in sequence. A number of free reprints in
a distinctive cover will be provided free of charge to authors.
A Reviews Subcommittee has been formed to select authors and to oversee the refereeing
process. The members are Dr Peter Attiwill, Dr Marilyn Ball and Professor Byron Lamont.
We would greatly appreciate advice and suggestions on prospective reviewers for this
important new series.

Peter Attiwill
School of Botany
The University of Melbourne
Parkville, Vic. 3052
Phone 03 9344 5068
Fax 03 9344 6857
Email p.attiwill@botany.unimelb.edu.au

Marilyn Ball
Australian National University
Research School of Biological Sciences
GPO Box 475
Canberra ACT 0200
Phone 02 6249 5057
Fax 02 6249 5095
Email mball@rsbs-central.anu.edu.au

Byron Lamont
School of Environmental Biology
Curtin University of Technology
GPO Box U 1987
Perth WA 6001
Phone 08 9266 7784
Fax 08 9266 2495
Email rlamontb@cc.curtin.edu.au
John Stewart Turner
Authors: Rowan Kingsley S. , Ashton David H.
Published: December 2005

Acacia saligna (Labill.) H.Wendl, a potential crop for
forage and wood production, is considered highly drought-resistant. The aim of
this study was to characterise some of the physiological traits contributing
to drought resistance in A. saligna. Two experiments
were conducted: (i) 4-year-old A. saligna were grown in
the field under dryland and irrigated treatments and (ii) 6-month-old A. saligna were grown in pots and irrigated to replenish 100% of the
transpiration demand (control), or 75% 50% or 25% of the
control. Soil-water deficits in the field elicited an increase in osmotic
potential in phyllodes. Stomatal conductance was negatively correlated with
air vapor pressure deficit under drought conditions in both experiments,
whereas under irrigation in the field it was correlated with solar radiation.
In the field, dry matter (DM) production under irrigation was only 14%
greater (not significant) than under dryland. In the pot experiment, DM
production was significantly reduced, and water use efficiency (WUE) and
chlorophyll content increased with reduced availability of water. The greater
WUE induced by drought could have resulted from stomatal regulation and
increased chlorophyll content. Carbon isotope ratios were correlated with the
WUE, and may be utilised for selection to further improve the WUE of
A. saligna under drought conditions.
Obituary: Sidney Herbert James 1933-1998
Authors: Hopper Stephen D. , Barlow Bryan A.
Published: December 2005

Conservation of Australian plants depends on a spectrum of activities from
descriptive and experimental biological studies to active management and
restoration of wild ecosystems by local communities who value their native
biota. On the basis of the premise that available resources for conservation
will not allow for all threatened biodiversity to be saved, some systematists
and conservation geneticists argue that phylogenetic relationships should be
used to set conservation priorities. The principle advocated is that
characters, not species number, should become the currency of conservation,
that cladistic analysis of phylogenetic pattern provides a predictive means of
modelling the underlying distribution of characters among taxa, and that
priority should be given to that subset of taxa with the greatest number of
character states.
This approach has been applied for some time in the conservation of genetic
resources within species (e.g. Eucalyptus caesia), and
has been an extra impetus for action with taxonomically isolated endangered
species such as the recently discovered araucarian Wollemi pine
(Wollemia nobilis). However, most plant conservation
activity in Australia has paid little heed to phylogenetic relationships.
Degree of threat has been a driving motivation, with endangered species
receiving legislative and management attention irrespective of their
systematic relationships. Moreover, the current revolution in understanding
plant phylogeny associated with DNA sequence studies highlights the need for
caution in accepting results of morphologically based analyses. A series of
studies on the kangaroo paw and bloodroot family Haemodoraceae highlights this
cautionary tale.
The derivation of phylogenetic principles relevant to ecosystem and landscape
processes is a new field of some promise to conservation managers. An
understanding of the Gondwanan origins and landscape evolution of the
south-west Australian flora provides a useful case study. Scaling up
phylogenetic knowledge of genetic resources within species, and of the
evolutionary relationships of taxa to an integrated overview of best
management practices for all taxa at the local landscape level, is perhaps the
most effective contribution phylogeneticists might make to help conserve
Australian plants.
Preface to 'Genetics and Conservation of Australian Flora'
Authors: Coates David J. , Hopper Stephen D.
Published: December 2005

Conservation of Australian plants depends on a spectrum of activities from
descriptive and experimental biological studies to active management and
restoration of wild ecosystems by local communities who value their native
biota. On the basis of the premise that available resources for conservation
will not allow for all threatened biodiversity to be saved, some systematists
and conservation geneticists argue that phylogenetic relationships should be
used to set conservation priorities. The principle advocated is that
characters, not species number, should become the currency of conservation,
that cladistic analysis of phylogenetic pattern provides a predictive means of
modelling the underlying distribution of characters among taxa, and that
priority should be given to that subset of taxa with the greatest number of
character states.
This approach has been applied for some time in the conservation of genetic
resources within species (e.g. Eucalyptus caesia), and
has been an extra impetus for action with taxonomically isolated endangered
species such as the recently discovered araucarian Wollemi pine
(Wollemia nobilis). However, most plant conservation
activity in Australia has paid little heed to phylogenetic relationships.
Degree of threat has been a driving motivation, with endangered species
receiving legislative and management attention irrespective of their
systematic relationships. Moreover, the current revolution in understanding
plant phylogeny associated with DNA sequence studies highlights the need for
caution in accepting results of morphologically based analyses. A series of
studies on the kangaroo paw and bloodroot family Haemodoraceae highlights this
cautionary tale.
The derivation of phylogenetic principles relevant to ecosystem and landscape
processes is a new field of some promise to conservation managers. An
understanding of the Gondwanan origins and landscape evolution of the
south-west Australian flora provides a useful case study. Scaling up
phylogenetic knowledge of genetic resources within species, and of the
evolutionary relationships of taxa to an integrated overview of best
management practices for all taxa at the local landscape level, is perhaps the
most effective contribution phylogeneticists might make to help conserve
Australian plants.
Research Trends in Photochromism: Control of Photochromism in Rigid Polymer Matrices and other Advances
Authors: Evans Richard A. , Such Georgina K.
Published: December 2005

Photochromism is receiving increasing attention because of its current application in high value-added ophthalmic lenses and potential applications in data storage and molecular switching. The performance of photochromic dyes, such as spirooxazines, chromenes, and diarylethenes, in polymers is important because the above applications require the dyes to be in a host polymer. The dyes can be broadly divided into P (photo) and T (thermal) types depending on the availability of a thermal decolouration route. Current research themes for the two types are presented with an emphasis on a new method of manipulating switching speeds in polymer matrices.
Temperature-Dependent Cooperative Coiling of Helical Conformers of Enantiopure Oligo(Tertiary Phosphines)
Authors: Swiegers Gerhard F. , Wild S. Bruce
Published: December 2005

The specific optical rotation of an enantiopure, syndiotactic hexa(tertiary phosphine) displays a marked temperature dependence that is consistent with the cooperative formation of helically coiled conformers in solution.
Synthesis of N-Substituted γ-Methylene γ-Lactams
Authors: Adhikari Raju , Jones Dionne A. , Liepa Andris J. , Nearn Roland H.
Published: December 2005

N-Substituted cyanoacetamides 1 were condensed with 1,2-diketones 2 under base catalysis to form γ-hydroxy γ-lactams 3. Treatment of 3 with acids gave novel fungicidal γ-methylene γ-lactams 4. The exocyclic double bond of 4b reacted reversibly with 4-toluene sulfinate.
A taxonomic revision and morphological variation within Eucalyptus series Subulatae subseries Decussatae and Decurrentes (Myrtaceae) of Australia
Authors: Nicolle D.
Published: December 2005

Morphological variation within Eucalyptus series Subulatae subseries Decussatae and Decurrentes was assessed by adult and seedling characteristics for 321 individuals representing 91 populations from across the broad geographical distribution of both the subseries. All previously recognised taxa from the subseries are included. Based on examination of adult and seedling morphology and phenetic analyses of morphological variation, eleven taxa (eight species) are recognised within E. subser. Decussatae. Adult morphology is most important in distinguishing taxa in this subseries, although seedling characters are also useful discriminators of some taxa, most notably E. aspersa and E. yalatensis. The previously recognised E. eucentrica is weakly distinguished from E. socialis, and E. socialis s.l. (i.e. including E. eucentrica) forms four adjacent groups in ordination analyses based on adult characters and adult and seedling characters combined. Four subspecies of E. socialis are recognised. Eucalyptus socialis subsp. viridans Nicolle subsp. nov. is described to accommodate green-leaved populations of E. socialis from the Peninsulas and southern Murray Mallee regions in South Australia. Eucalyptus socialis subsp. victoriensis Nicolle subsp. nov. is described to accommodate coarse-leaved, budded and fruited populations of E. socialis from the Great Victoria Desert in Western Australia and South Australia. A new combination is also made [E. socialis subsp. eucentrica (L.A.S. Johnson & K.D. Hill) Nicolle comb. nov.]. Based on the examination of variation in adult and seedling morphology and phenetic analyses of morphological variation, 11 or 12 taxa within E. subser. Decurrentes are recognised. Eucalyptus transcontinentalis subsp. semivestita is considered to be synonymous with E. moderata and the circumscription of this species is greatly modified. A new taxonomy for both the subseries is presented, based on extensive field, seedling and herbarium examination of all taxa in the series and phenetic analyses. Descriptions and keys to the taxa within the subseries are presented.
Additions to Lissanthe (Styphelioideae: Ericaceae) in Western Australia: L. synandra sp. nov. and L. pleurandroides comb. nov.
Authors: Crayn Darren M. , Hislop Michael , Heslewood Margaret M.
Published: December 2005

The genus Lissanthe R.Br. (Styphelioideae: Ericaceae) has been recently revised but further field and herbarium studies have brought to light two further species from southern Western Australia. Parsimony analysis of plastid atpB–rbcL spacer sequence data confirms the placement of these two species in Lissanthe. Thus, L. synandra Crayn & Hislop is described as new and L. pleurandroides (F.Muell.) Crayn & Hislop is transferred from Leucopogon. Lissanthe synandra is unique in the genus in having angled branchlets, corolla lobes that remain almost completely closed, and anthers that are fused and cohere around the style and stigma, forming a synandrium. Illustrations and distribution maps are provided for both species. A key to species of Lissanthe is included.
α4β1-dependent adhesion strengthening under mechanical strain is regulated by paxillin association with the α4-cytoplasmic domain
Authors: Alon Ronen , Feigelson Sara W. , Manevich Eugenia , Rose David M. , Schmitz Julia , Overby Darryl R. , Winter Eitan , Grabovsky Valentin , Shinder Vera , Matthews Benjamin D. , Sokolovsky-Eisenberg Maya , Ingber Donald E. , Benoit Martin , Ginsberg Mark H.
Published: December 2005

The capacity of integrins to mediate adhesiveness is modulated by their cytoplasmic associations. In this study, we describe a novel mechanism by which α4-integrin adhesiveness is regulated by the cytoskeletal adaptor paxillin. A mutation of the α4 tail that disrupts paxillin binding, α4(Y991A), reduced talin association to the α4β1 heterodimer, impaired integrin anchorage to the cytoskeleton, and suppressed α4β1-dependent capture and adhesion strengthening of Jurkat T cells to VCAM-1 under shear stress. The mutant retained intrinsic avidity to soluble or bead-immobilized VCAM-1, supported normal cell spreading at short-lived contacts, had normal α4-microvillar distribution, and responded to inside-out signals. This is the first demonstration that cytoskeletal anchorage of an integrin enhances the mechanical stability of its adhesive bonds under strain and, thereby, promotes its ability to mediate leukocyte adhesion under physiological shear stress conditions.
Yeast phosphatidylinositol 4-kinase, Pik1, has essential roles at the Golgi and in the nucleus
Authors: Strahl Thomas , Hama Hiroko , DeWald Daryll B. , Thorner Jeremy
Published: December 2005

Phosphatidylinositol 4-kinase, Pik1, is essential for viability. GFP-Pik1 localized to cytoplasmic puncta and the nucleus. The puncta colocalized with Sec7-DsRed, a marker of trans-Golgi cisternae. Kap95 (importin-β) was necessary for nuclear entry, but not Kap60 (importin-α), and exportin Msn5 was required for nuclear exit. Frq1 (frequenin orthologue) also is essential for viability and binds near the NH2 terminus of Pik1. Frq1-GFP localized to Golgi puncta, and Pik1 lacking its Frq1-binding site (or Pik1 overexpressed in frq1Δ cells) did not decorate the Golgi, but nuclear localization was unperturbed. Pik1(Δ10-192), which lacks its nuclear export sequence, displayed prominent nuclear accumulation and did not rescue inviability of pik1Δ cells. A Pik1-CCAAX chimera was excluded from the nucleus and also did not rescue inviability of pik1Δ cells. However, coexpression of Pik1(Δ10-192) and Pik1-CCAAX in pik1Δ cells restored viability. Catalytically inactive derivatives of these compartment-restricted Pik1 constructs indicated that PtdIns4P must be generated both in the nucleus and at the Golgi for normal cell function.
Raf-1 sets the threshold of Fas sensitivity by modulating Rok-α signaling
Authors: Piazzolla Daniela , Meissl Katrin , Kucerova Lucia , Rubiolo Cristina , Baccarini Manuela
Published: December 2005

Ablation of the Raf-1 protein causes fetal liver apoptosis, embryonic lethality, and selective hypersensitivity to Fas-induced cell death. Furthermore, Raf-1–deficient cells show defective migration as a result of the deregulation of the Rho effector kinase Rok-α. In this study, we show that the kinase-independent modulation of Rok-α signaling is also the basis of the antiapoptotic function of Raf-1. Fas activation stimulates the formation of Raf-1–Rok-α complexes, and Rok-α signaling is up-regulated in Raf-1–deficient cells. This leads to increased clustering and membrane expression of Fas, which is rescued both by kinase-dead Raf-1 and by interfering with Rok-α or its substrate ezrin. Increased Fas clustering and membrane expression are also evident in the livers of Raf-1–deficient embryos, and genetically reducing Fas expression counteracts fetal liver apoptosis, embryonic lethality, and the apoptotic defects of embryonic fibroblasts. Thus, Raf-1 has an essential function in regulating Fas expression and setting the threshold of Fas sensitivity during embryonic life.
Distinct roles of Akt1 and Akt2 in regulating cell migration and epithelial–mesenchymal transition
Authors: Irie Hanna Y. , Pearline Rachel V. , Grueneberg Dorre , Hsia Maximilian , Ravichandran Preethi , Kothari Nayantara , Natesan Sridaran , Brugge Joan S.
Published: December 2005

The Akt family of kinases are activated by growth factors and regulate pleiotropic cellular activities. In this study, we provide evidence for isoform-specific positive and negative roles for Akt1 and -2 in regulating growth factor–stimulated phenotypes in breast epithelial cells. Insulin-like growth factor-I receptor (IGF-IR) hyperstimulation induced hyperproliferation and antiapoptotic activities that were reversed by Akt2 down-regulation. In contrast, Akt1 down-regulation in IGF-IR–stimulated cells promoted dramatic neomorphic effects characteristic of an epithelial–mesenchymal transition (EMT) and enhanced cell migration induced by IGF-I or EGF stimulation. The phenotypic effects of Akt1 down-regulation were accompanied by enhanced extracellular signal–related kinase (ERK) activation, which contributed to the induction of migration and EMT. Interestingly, down-regulation of Akt2 suppressed the EMT-like morphological conversion induced by Akt1 down-regulation in IGF-IR–overexpressing cells and inhibited migration in EGF-stimulated cells. These results highlight the distinct functions of Akt isoforms in regulating growth factor–stimulated EMT and cell migration, as well as the importance of Akt1 in cross-regulating the ERK signaling pathway.
Expression of mutant huntingtin in glial cells contributes to neuronal excitotoxicity
Authors: Shin Ji-Yeon , Fang Zhi-Hui , Yu Zhao-Xue , Wang Chuan-En , Li Shi-Hua , Li Xiao-Jiang
Published: December 2005

Huntington disease (HD) is characterized by the preferential loss of striatal medium-sized spiny neurons (MSNs) in the brain. Because MSNs receive abundant glutamatergic input, their vulnerability to excitotoxicity may be largely influenced by the capacity of glial cells to remove extracellular glutamate. However, little is known about the role of glia in HD neuropathology. Here, we report that mutant huntingtin accumulates in glial nuclei in HD brains and decreases the expression of glutamate transporters. As a result, mutant huntingtin (htt) reduces glutamate uptake in cultured astrocytes and HD mouse brains. In a neuron–glia coculture system, wild-type glial cells protected neurons against mutant htt-mediated neurotoxicity, whereas glial cells expressing mutant htt increased neuronal vulnerability. Mutant htt in cultured astrocytes decreased their protection of neurons against glutamate excitotoxicity. These findings suggest that decreased glutamate uptake caused by glial mutant htt may critically contribute to neuronal excitotoxicity in HD.
The mobile nucleoporin Nup2p and chromatin-bound Prp20p function in endogenous NPC-mediated transcriptional control
Authors: Dilworth David J. , Tackett Alan J. , Rogers Richard S. , Yi Eugene C. , Christmas Rowan H. , Smith Jennifer J. , Siegel Andrew F. , Chait Brian T. , Wozniak Richard W. , Aitchison John D.
Published: December 2005

Nuclear pore complexes (NPCs) govern macromolecular transport between the nucleus and cytoplasm and serve as key positional markers within the nucleus. Several protein components of yeast NPCs have been implicated in the epigenetic control of gene expression. Among these, Nup2p is unique as it transiently associates with NPCs and, when artificially tethered to DNA, can prevent the spread of transcriptional activation or repression between flanking genes, a function termed boundary activity. To understand this function of Nup2p, we investigated the interactions of Nup2p with other proteins and with DNA using immunopurifications coupled with mass spectrometry and microarray analyses. These data combined with functional assays of boundary activity and epigenetic variegation suggest that Nup2p and the Ran guanylyl-nucleotide exchange factor, Prp20p, interact at specific chromatin regions and enable the NPC to play an active role in chromatin organization by facilitating the transition of chromatin between activity states.
Influences on neural lineage and mode of division in the zebrafish retina in vivo
Authors: Poggi Lucia , Vitorino Marta , Masai Ichiro , Harris William A.
Published: December 2005

Cell determination in the retina has been under intense investigation since the discovery that retinal progenitors generate clones of apparently random composition (Price, J., D. Turner, and C. Cepko. 1987. Proc. Natl. Acad. Sci. USA. 84:156–160; Holt, C.E., T.W. Bertsch, H.M. Ellis, and W.A. Harris. 1988. Neuron. 1:15–26; Wetts, R., and S.E. Fraser. 1988. Science. 239:1142–1145). Examination of fixed tissue, however, sheds little light on lineage patterns or on the relationship between the orientation of division and cell fate. In this study, three-dimensional time-lapse analyses were used to trace lineages of retinal progenitors expressing green fluorescent protein under the control of the ath5 promoter. Surprisingly, these cells divide just once along the circumferential axis to produce two postmitotic daughters, one of which becomes a retinal ganglion cell (RGC). Interestingly, when these same progenitors are transplanted into a mutant environment lacking RGCs, they often divide along the central-peripheral axis and produce two RGCs. This study provides the first insight into reproducible lineage patterns of retinal progenitors in vivo and the first evidence that environmental signals influence the orientation of cell division and the lineage of neural progenitors.
Transition from hemifusion to pore opening is rate limiting for vacuole membrane fusion
Authors: Reese Christoph , Mayer Andreas
Published: December 2005

Fusion pore opening and expansion are considered the most energy-demanding steps in viral fusion. Whether this also applies to soluble N-ethyl-maleimide sensitive fusion protein attachment protein receptor (SNARE)– and Rab-dependent fusion events has been unknown. We have addressed the problem by characterizing the effects of lysophosphatidylcholine (LPC) and other late-stage inhibitors on lipid mixing and pore opening during vacuole fusion. LPC inhibits fusion by inducing positive curvature in the bilayer and changing its biophysical properties. The LPC block reversibly prevented formation of the hemifusion intermediate that allows lipid, but not content, mixing. Transition from hemifusion to pore opening was sensitive to guanosine-5′-(γ-thio)triphosphate. It required the vacuolar adenosine triphosphatase V0 sector and coincided with its transformation. Pore opening was rate limiting for the reaction. As with viral fusion, opening the fusion pore may be the most energy-demanding step for intracellular, SNARE-dependent fusion reactions, suggesting that fundamental aspects of lipid mixing and pore opening are related for both systems.
Desmoplakin assembly dynamics in four dimensions
Authors: Godsel Lisa M. , Hsieh Sherry N. , Amargo Evangeline V. , Bass Amanda E. , Pascoe-McGillicuddy Lauren T. , Huen Arthur C. , Thorne Meghan E. , Gaudry Claire A. , Park Jung K. , Myung Kyunghee , Goldman Robert D. , Chew Teng-Leong , Green Kathleen J.
Published: December 2005

The intermediate filament (IF)–binding protein desmoplakin (DP) is essential for desmosome function and tissue integrity, but its role in junction assembly is poorly understood. Using time-lapse imaging, we show that cell–cell contact triggers three temporally overlapping phases of DP-GFP dynamics: (1) the de novo appearance of punctate fluorescence at new contact zones after as little as 3 min; (2) the coalescence of DP and the armadillo protein plakophilin 2 into discrete cytoplasmic particles after as little as 15 min; and (3) the cytochalasin-sensitive translocation of cytoplasmic particles to maturing borders, with kinetics ranging from 0.002 to 0.04 μm/s. DP mutants that abrogate or enhance association with IFs exhibit delayed incorporation into junctions, altering particle trajectory or increasing particle pause times, respectively. Our data are consistent with the idea that DP assembles into nascent junctions from both diffusible and particulate pools in a temporally overlapping series of events triggered by cell–cell contact and regulated by actin and DP–IF interactions.
Caspase-dependent immunogenicity of doxorubicin-induced tumor cell death
Authors: Casares Noelia , Pequignot Marie O. , Tesniere Antoine , Ghiringhelli François , Roux Stéphan , Chaput Nathalie , Schmitt Elise , Hamai Ahmed , Hervas-Stubbs Sandra , Obeid Michel , Coutant Frédéric , Métivier Didier , Pichard Evelyne , Aucouturier Pierre , Pierron Gérard , Garrido Carmen , Zitvogel Laurence , Kroemer Guido
Published: December 2005

Systemic anticancer chemotherapy is immunosuppressive and mostly induces nonimmunogenic tumor cell death. Here, we show that even in the absence of any adjuvant, tumor cells dying in response to anthracyclins can elicit an effective antitumor immune response that suppresses the growth of inoculated tumors or leads to the regression of established neoplasia. Although both antracyclins and mitomycin C induced apoptosis with caspase activation, only anthracyclin-induced immunogenic cell death was immunogenic. Caspase inhibition by Z-VAD-fmk or transfection with the baculovirus inhibitor p35 did not inhibit doxorubicin (DX)-induced cell death, yet suppressed the immunogenicity of dying tumor cells in several rodent models of neoplasia. Depletion of dendritic cells (DCs) or CD8+T cells abolished the immune response against DX-treated apoptotic tumor cells in vivo. Caspase inhibition suppressed the capacity of DX-killed cells to be phagocytosed by DCs, yet had no effect on their capacity to elicit DC maturation. Freshly excised tumors became immunogenic upon DX treatment in vitro, and intratumoral inoculation of DX could trigger the regression of established tumors in immunocompetent mice. These results delineate a procedure for the generation of cancer vaccines and the stimulation of anti-neoplastic immune responses in vivo.
Carbon monoxide ameliorates chronic murine colitis through a heme oxygenase 1–dependent pathway
Authors: Hegazi Refaat A.F. , Rao Kavitha N. , Mayle Aqila , Sepulveda Antonia R. , Otterbein Leo E. , Plevy Scott E.
Published: December 2005

Heme oxygenase (HO)-1 and its metabolic product carbon monoxide (CO) play regulatory roles in acute inflammatory states. In this study, we demonstrate that CO administration is effective as a therapeutic modality in mice with established chronic colitis. CO administration ameliorates chronic intestinal inflammation in a T helper (Th)1-mediated model of murine colitis, interleukin (IL)-10–deficient (IL-10−/−) mice. In Th1-mediated inflammation, CO abrogates the synergistic effect of interferon (IFN)-γ on lipopolysaccharide-induced IL-12 p40 in murine macrophages and alters IFN-γ signaling by inhibiting a member of the IFN regulatory factor (IRF) family of transcription factors, IRF-8. A specific signaling pathway, not previously identified, is delineated that involves an obligatory role for HO-1 induction in the protection afforded by CO. Moreover, CO antagonizes the inhibitory effect of IFN-γ on HO-1 expression in macrophages. In macrophages and in Th1-mediated colitis, pharmacologic induction of HO-1 recapitulates the immunosuppressive effects of CO. In conclusion, this study begins to elucidate potential etiologic and therapeutic implications of CO and the HO-1 pathway in chronic inflammatory bowel diseases.