Plant structure and systematics research at the Queensland University of Technology (QUT), Brisbane

This article provides a general overview of some of the plant research being conducted by a number of researchers at the Queensland University of Technology (QUT) Brisbane. Details about student projects and research facilities have been limited to those of relevance to plant structure and systematics. Academics, technicians and research students involved in plant research are in the Faculty of Science and Engineering, mainly in the School of Earth, Environment and Biological Sciences (EEBS), with a few exceptions. Our offices and laboratories are housed in a number of different buildings at the Gardens Point campus (e.g., P, Q, R, S, M Blocks) and we have strong collaborative links with Queensland Herbarium (BRI) and Mt Coot-tha Botanic Gardens.

Pharmacokinetics of cimifugin in rat plasma after oral administration of the extract of Saposhnikovia divaricatae root : Determination of cimifugin by high performance liquid chromatography coupled with solid phase extraction

High performance liquid chromatography (HPLC) coupled with the solid phase extraction method was developed for determining cimifugin (a coumarin derivative; one of Saposhnikovia divaricatae's constituents) in rat plasma after oral administration of Saposhnikovia divaricatae extract (SDE), and the pharmacokinetics of cimifugin either in SDE or as a single compound was investigated. The HPLC analysis was performed on a commercially available column (4.6 mm x 200 mm, 5 pm) with the isocratic elution of solvent A (Methanol) and solvent B (Water) (A:B=60:40) and the detection wavelength was set at 250 nm. The calibration curve was linear over the range of 0.100-10.040 microg/mL. The limit of detection was 30 ng/mL. At the rat plasma concentrations of 0.402, 4.016, 10.040 microg/mL, the intra-day precision was 6.21%, 3.98%, and 2.23%; the inter-day precision was 7.59%, 4.26%, and 2.09%, respectively. The absolute recovery was 76.58%, 76.61%, and 77.67%, respectively. When the dosage of SDE was equal to the pure compound calculated by the amount of cimifugin, it was found to have two maximum peaks while the pure compound only showed one peak in the plasma concentration-time curve. The pharmacokinetic characteristics of SDE showed the superiority of the extract and the properties of traditional Chinese medicine.

Phenomenography in the Centre for Information Technology Innovation (CITI)

Phenomenography has its roots in educational research (Marton and Booth, 1997), but has since been adopted in other domains including business (Sandberg, 1994), health (Barnard, McCosker and Gerber, 1999), information science (Bruce, 1999a,b) and information technology (Bruce and Pham, 2001) as well as information systems. Emerging phenomenographic research in areas other than education, has been interdisciplinary, often bringing together technology, education and a host discipline such as health or business. In Australia, phenomenography has been used in information technology (IT) related research primarily in Victoria and Queensland. These studies have pursued the latter two of three established lines of phenomenographic research: 1) the study of conceptions of learning; 2) the study of conceptions in specific disciplines of study and 3) the study of how people conceive of various aspects of their everyday world that have not, for them, been the object of formal studies (Marton 1988, p.189). Information Technology researchers have predominantly pursued the latter two lines of research.

Tensile properties of pumpkin peel and flesh tissue and review of current testing methods

In South and Southeast Asia, postharvest loss causes material waste of up to 66% in fruits and vegetables, 30% in oilseeds and pulses, and 49% in roots and tubers. The efficiency of postharvest equipment directly affects industrial-scale food production. To enhance current processing methods and devices, it is essential to analyze the responses of food materials under loading operations. Food materials undergo different types of mechanical loading during postharvest and processing stages. Therefore, it is important to determine the properties of these materials under different types of loads, such as tensile, compression, and indentation. This study presents a comprehensive analysis of the available literature on the tensile properties of different food samples. The aim of this review was to categorize the available methods of tensile testing for agricultural crops and food materials to investigate an appropriate sample size and tensile test method. The results were then applied to perform tensile tests on pumpkin flesh and peel samples, in particular on arc-sided samples at a constant loading rate of 20 mm min-1. The results showed the maximum tensile stress of pumpkin flesh and peel samples to be 0.535 and 1.45 MPa, respectively. The elastic modulus of the flesh and peel samples was 6.82 and 25.2 MPa, respectively, while the failure modulus values were 14.51 and 30.88 MPa, respectively. The results of the tensile tests were also used to develop a finite element model of mechanical peeling of tough-skinned vegetables. However, to study the effects of deformation rate, moisture content, and texture of the tissue on the tensile responses of food materials, more investigation needs to be done in the future.

Variation in leaf morphology of the invasive cat's claw creeper Dolichandra unguis-cati (Bignoniaceae)

The invasive liana cat’s claw creeper Dolichandra unguis-cati (L.) L.G. Lohmann (syn. Macfadyena unguis-cati (L.) A.H. Gentry) exhibits intraspecific variation in leaf morphology, but this is rarely noted in the published literature. The present study documents variation in leaf morphology in two forms of the species that occur in Australia (long pod and short pod). Leaf morphology is compared between the two forms and the position of the shoots (trunk and ground) at the only two sites in which they co-occur. Leaves were categorised on the basis of leaflet number and the presence or absence of tendrils. Simple leaves were produced mainly on shoots growing along the ground and were more abundant in the short-pod form. Long-pod plants were dominated by bifoliate leaves with tendrils. Cat’s claw creeper exhibits considerably wider variation in leaf morphology than recorded previously. Variations in leaf morphology may be linked to differences in the genotype, developmental stage and plastic responses of the plants. Understanding these variations may have implications for taxonomic delimitation and improved management, particularly biological control involving leaf-feeding insects.

Learning English by walking down the street

With internationalisation and globalisation, English has proliferated in urban spaces around the world. This creates new opportunities for EFL learning and teaching. An English literacy walk is one activity that can be used productively to capitalise on this potential. The activity has roots in: (i) long-established approaches to emergent literacy education for young children; and (ii) pedagogic projects inspired by recent research on linguistic landscapes. Drawing on these traditions, teachers can target reading outcomes involving code, semantic, pragmatic and critical knowledge and skills. We use the four resources model of literate practices to systematically map some of the potential of literacy walks in multilingual, multimodal linguistic landscapes. We suggest tasks and teacher questions that might be used for purposes of explicit teaching of reading during and after literacy walks. Although grounded in Taipei, our ideas might be of interest to EFL teachers in other globalised cities around the world.

GO423 - the second Game On / brIGDA Independant Game Symposium

GO423 was initiated in 2012 as part of a community effort to ensure the vitality of the Queensland Games Sector. In common with other industrialised nations, the game industry in Australia is a reasonably significant contributor to Gross National Product (GNP). Games are played in 92% of Australian homes and the average adult player has been playing them for at least twelve years with 26% playing for more than thirty years (Brand, 2011). Like the games and interactive entertainment industries in other countries, the Australian industry has its roots in the small team model of the 1980s. So, for example, Beam Software, which was established in Melbourne in 1980, was started by two people and Krome Studios was started in 1999 by three. Both these companies grew to employing over 100 people in their heydays (considered large by Antipodean standards), not by producing their own intellectual property (IP) but by content generation for off shore parent companies. Thus our bigger companies grew on a model of service provision and tended not to generate their own IP (Darchen, 2012). There are some no-table exceptions where IP has originated locally and been ac-quired by international companies but in the case of some of the works of which we are most proud, the Australian company took on the role of “Night Elf” – a convenience due to affordances of the time zone which allowed our companies to work while the parent companies slept in a different time zone. In the post GFC climate, the strong Australian dollar and the vulnerability of such service provision means that job security is virtually non-existent with employees invariably being on short-term contracts. These issues are exacerbated by the decline of middle-ground games (those which fall between the triple-A titles and the smaller games often produced for a casual audience). The response to this state of affairs has been the change in the Australian games industry to new recognition of its identity as a wider cultural sector and the rise (or return) of an increasing number of small independent game development companies. ’In-dies’ consist of small teams, often making games for mobile and casual platforms, that depend on producing at least one if not two games a year and who often explore more radical definitions of games as designed cultural objects. The need for innovation and creativity in the Australian context is seen as a vital aspect of the current changing scene where we see the emphasis on the large studio production model give way to an emerging cultural sector model where small independent teams are engaged in shorter design and production schedules driven by digital distribution. In terms of Quality of Life (QoL) this new digital distribution brings with it the danger of 'digital isolation' - a studio can work from home and deliver from home. Community events thus become increasingly important. The GO423 Symposium is a response to these perceived needs and the event is based on the understanding that our new small creative teams depend on the local community of practice in no small way. GO423 thus offers local industry participants the opportunity to talk to each other about their work, to talk to potential new members about their work and to show off their work in a small intimate situation, encouraging both feedback and support.

Prisoners, rights and citizenship

The denial of civil rights to convicts has a long history. Its origins lie in the idea of ‘civil death’. Convicts who were not punished by execution would instead suffer civil death which stripped them of inheritance, family and political rights (Davidson, 2004). In Australia and internationally the removal of prisoners’ voting rights has been a controversial topic which has been a subject of much debate and a number of legislation changes (Davidson, 2004). This article argues that even though the latest amendment to the Australian Electoral legislation is, on the face of it, democratic and inclusive, it is in fact a denial of prisoners’ civil rights, which has its roots in the concept of civil death. My argument is in keeping with the themes of the Crime and Governance thematic group and focuses on my research interests in sociology of deviance, social reactions to crime, and socio-legal topics.

Nuclear gene silencing directs reception of long-distance mRNA silencing in Arabidopsis

In plants, silencing of mRNA can be transmitted from cell to cell and also over longer distances from roots to shoots. To investigate the long-distance mechanism, WT and mutant shoots were grafted onto roots silenced for an mRNA. We show that three genes involved in a chromatin silencing pathway, NRPD1a encoding RNA polymerase IVa, RNA-dependent RNA polymerase 2 (RDR2), and DICER-like 3 (DCL3), are required for reception of long-distance mRNA silencing in the shoot. A mutant representing a fourth gene in the pathway, argonaute4 (ago4), was also partially compromised in the reception of silencing. This pathway produces 24-nt siRNAs and resulted in decapped RNA, a known substrate for amplification of dsRNA by RDR6. Activation of silencing in grafted shoots depended on RDR6, but no 24-nt siRNAs were detected in mutant rdr6 shoots, indicating that RDR6 also plays a role in initial signal perception. After amplification of decapped transcripts, DCL4 and DCL2 act hierarchically as they do in antiviral resistance to produce 21- and 22-nt siRNAs, respectively, and these guide mRNA degradation. Several dcl genotypes were also tested for their capacity to transmit the mobile silencing signal from the rootstock. dcl1-8 and a dcl2 dcl3 dcl4 triple mutant are compromised in micro-RNA and siRNA biogenesis, respectively, but were unaffected in signal transmission. © 2007 by The National Academy of Sciences of the USA.

RNA interference-inducing hairpin RNAs in plants act through the viral defence pathway

RNA interference (RNAi) is widely used to silence genes in plants and animals. It operates through the degradation of target mRNA by endonuclease complexes guided by approximately 21 nucleotide (nt) short interfering RNAs (siRNAs). A similar process regulates the expression of some developmental genes through approximately 21 nt microRNAs. Plants have four types of Dicer-like (DCL) enzyme, each producing small RNAs with different functions. Here, we show that DCL2, DCL3 and DCL4 in Arabidopsis process both replicating viral RNAs and RNAi-inducing hairpin RNAs (hpRNAs) into 22-, 24- and 21 nt siRNAs, respectively, and that loss of both DCL2 and DCL4 activities is required to negate RNAi and to release the plant's repression of viral replication. We also show that hpRNAs, similar to viral infection, can engender long-distance silencing signals and that hpRNA-induced silencing is suppressed by the expression of a virus-derived suppressor protein. These findings indicate that hpRNA-mediated RNAi in plants operates through the viral defence pathway.

RNAi for insect-proof plants

RNA interference induced in insects after ingestion of plant-expressed hairpin RNA offers promise for managing devastating crop pests

Viruses face a double defense by plant small RNAs

Plants fight viral infections with enzymes that digest viral RNA, but viruses retaliate with proteins that suppress these enzymes. To boost their antiviral response plants deploy enzymes with redundant functions.

Synthesis of complementary RNA by RNA-dependent RNA polymerases in plant extracts is independent of an RNA primer

RNA-dependent RNA polymerase (RDR) activities were readily detected in extracts from cauliflower and broccoli florets, Arabidopsis thaliana (L.) Heynh callus tissue and broccoli nuclei. The synthesis of complementary RNA (cRNA) was independent of a RNA primer, whether or not the primer contained a 3′ terminal 2′-O-methyl group or was phosphorylated at the 5′ terminus. cRNA synthesis in plant extracts was not affected by loss-of-function mutations in the DICER-LIKE (DCL) proteins DCL2, DCL3, and DCL4, indicating that RDRs function independently of these DCL proteins. A loss-of-function mutation in RDR1, RDR2 or RDR6 did not significantly reduce the amount of cRNA synthesis. This indicates that these RDRs did not account for the bulk RDR activities in plant extracts, and suggest that either the individual RDRs each contribute a fraction of polymerase activity or another RDR(s) is predominant in the plant extract. © CSIRO 2008.

Cloning and characterization of microRNAs from Brassica napus

A library containing approximately 40,000 small RNA sequences was constructed for Brassica napus. Analysis of 3025 sequences obtained from this library resulted in the identification of 11 conserved miRNA families, which were validated by secondary structure prediction using surrounding sequences in the Brassica genome. Two 21 nt small RNA sequences reside within the arm of a pre-miRNA like stem-loop structure, making them likely candidates for novel non-conserved miRNAs in B. napus. Most of the conserved miRNAs were expressed at similar levels in a F1 hybrid B. napus line and its four double haploid progeny that showed marked variations in phenotypes, but many were differentially expressed between B. napus and Arabidopsis. The miR169 family was expressed at high levels in young leaves and stems, but was undetectable in roots and mature leaves, suggesting that miR169 expression is developmentally regulated in B. napus. © 2007 Federation of European Biochemical Societies.

A suite of novel promoters and terminators for plant biotechnology II. The pPLEX series for use in monocots

A suite of plant expression vectors (pPLEX), constructed from the gene regulation signals from subterranean clover stunt virus (SCSV) genome, has previously been used in dicot transformation for a variety of applications in plant biotechnology. To assess their use for the transformation of monocots, a number of modifications were made to the basic vector series and assessed in rice. In their unmodified forms, the SCSV promoters directed low levels of gene expression, however, insertion of an intron between the promoter and the transgene open reading frame (analogous to the rice actin and maize ubiquitin promoter systems) increased transgene expression 50-fold. The expression patterns from the intron-modified SCSV (segments 4 and 7) promoters were very similar to those directed by the actin or ubiquitin promoters. All promoter systems investigated directed expression that appeared to be constitutive within leaf tissue, and localised to the epidermal and vascular tissues of the root. The pPLEX vectors described here are an important counterpart to the dicot pPLEX series and have the potential to be useful in monocot research and biotechnology.