Analysis of Plant and Fungal Transcripts from Resistant and Susceptible Phenotypes of Challenged by .

is the causal pathogen of myrtle rust disease of Myrtaceae. To gain understanding of the initial infection process, gene expression in germinating urediniospores and in -inoculated leaves were investigated via analyses of RNA sequencing samples taken 24 and 48 h postinoculation (hpi). Principal component analyses of transformed transcript count data revealed differential gene expression between the uninoculated control plants that correlated with the three plant leaf resistance phenotypes (immunity, hypersensitive response, and susceptibility).

Impacts of Myrtle Rust Induced Tree Mortality on Species and Functional Richness within Seedling Communities of a Wet Sclerophyll Forest in Eastern Australia.

is an introduced plant pathogen known to have caused significant declines in populations of several Australian native Myrtaceae species. However, limited research has focused on the impacts of the pathogen on plant communities in the aftermath of its invasion. This study investigated the relationship between disease impact level, plant species diversity, and functional richness in seedling communities in a wet sclerophyll forest in southeast Queensland.

Both Constitutive and Infection-Responsive Secondary Metabolites Linked to Resistance against (Myrtle Rust) in .

is a fungal plant pathogen that infects species within the Myrtaceae, causing the disease myrtle rust. Myrtle rust is causing declines in populations within natural and managed ecosystems and is expected to result in species extinctions. Despite this, variation in response to exist within some species, from complete susceptibility to resistance that prevents or limits infection by the pathogen.

Imminent Extinction of Australian Myrtaceae by Fungal Disease.

Myrtle rust is a fungal disease that has spread rapidly across the globe, arriving in Australia in 2010. The tree species Rhodomyrtus psidioides is nearly extinct in the wild as a result of the disease, leading to potential disruption of ecosystem function. Many other Myrtaceae may also be threatened and unprecedented impacts of the disease are predicted.

Resistance of New Zealand Provenance , and to .

Resistance to the pandemic strain of was identified in New Zealand provenance , , and plants. Only 1 -resistant plant was found (of the 570 tested) and no resistant plants of either or were found. Three types of resistance were identified in .

Comparison of host susceptibilities to native and exotic pathogens provides evidence for pathogen-imposed selection in forest trees.

The extent to which spatial structuring of host resistance in wild plant populations reflects direct pathogen-imposed selection is a subject of debate. To examine this issue, genetic susceptibilities to an exotic and a coevolved native fungal pathogen were compared using two Australian host tree species. Damage to common host germplasm of Corymbia citriodora ssp.

Lessons from the Incursion of Myrtle Rust in Australia.

Austropuccinia psidii (myrtle rust) is a globally invasive neotropical rust of the Myrtaceae that came into international prominence following extensive damage to exotic Eucalyptus plantations in Brazil in the 1970s and 1980s. In 2005, myrtle rust established in Hawaii (USA), and over the past 12 years has spread from the Americas into Asia, the Pacific, and South Africa. Myrtle rust was detected in Australia in 2010, and the response and ultimately unsuccessful eradication attempt was a lesson to those concerned about the threat of exotic pests and diseases to Australia's environment.

Aerial Mapping of Forests Affected by Pathogens Using UAVs, Hyperspectral Sensors, and Artificial Intelligence.

The environmental and economic impacts of exotic fungal species on natural and plantation forests have been historically catastrophic. Recorded surveillance and control actions are challenging because they are costly, time-consuming, and hazardous in remote areas. Prolonged periods of testing and observation of site-based tests have limitations in verifying the rapid proliferation of exotic pathogens and deterioration rates in hosts.

Impact of Austropuccinia psidii (myrtle rust) on Myrtaceae-rich wet sclerophyll forests in south east Queensland.

In April 2010, Austropuccinia psidii (formerly Puccinia psidii) was detected for the first time in Australia on the central coast of New South Wales. The fungus spread rapidly along the east coast and can now be found infecting vegetation in a range of native forest ecosystems with disease impacts ranging from minor leaf spots to severe shoot and stem blight and tree dieback. Localised extinction of some plant species has been recorded.

Screening Eucalyptus cloeziana and E. argophloia Populations for Resistance to Puccinia psidii.

Disease screening to determine the threat Puccinia psidii poses to plantation and native eucalypts in Australia was undertaken in half-sib families of two contrasting eucalypt species, Eucalyptus cloeziana and E. argophloia. Artificial inoculation with a single-lesion isolate of P.

Ceratocystis species, including two new species associated with nitidulid beetles, on eucalypts in Australia.

The genus Ceratocystis includes important fungal pathogens of trees, including Eucalyptus spp. Ironically, very little is known regarding the diversity or biology of Ceratocystis species on Eucalyptus species in Australia, where most of these trees are native. The aim of this study was to survey for Ceratocystis spp.

Phylogeny of the Quambalariaceae fam. nov., including important Eucalyptus pathogens in South Africa and Australia.

The genus Quambalaria consists of plant-pathogenic fungi causing disease on leaves and shoots of species of Eucalyptus and its close relative, Corymbia. The phylogenetic relationship of Quambalaria spp., previously classified in genera such as Sporothrix and Ramularia, has never been addressed.

Three new Lasiodiplodia spp. from the tropics, recognized based on DNA sequence comparisons and morphology.

Botryosphaeria rhodina (anamorph Lasiodiplodia theobromae) is a common endophyte and opportunistic pathogen on more than 500 tree species in the tropics and subtropics. During routine disease surveys of plantations in Australia and Venezuela several isolates differing from L. theobromae were identified and subsequently characterized based upon morphology and ITS and EF1-alpha nucleotide sequences.

Leptin: a review of its peripheral actions and interactions.

Following the discovery of leptin in 1994, the scientific and clinical communities have held great hope that manipulation of the leptin axis may lead to the successful treatment of obesity. This hope is not yet dashed; however the role of the leptin axis is now being shown to be ever more complex than was first envisaged. It is now well established that leptin interacts with pathways in the central nervous system and through direct peripheral mechanisms.

Characterization of leptin binding in bovine kidney membranes.

The interactions of leptin with its receptor and other leptin binding sites is not well described or understood. We have used Scatchard analysis of saturation binding data to characterize the affinity of leptin for binding sites in bovine kidney membranes. 125I-Leptin was used in saturation studies, over a range of concentrations from 50 pM to 9 nM.

The effects of the ciliate Paramecium cf. caudatum Ehrenberg on toxin producing Cylindrospermopsis isolated from the Fitzroy River, Australia.

The large ciliate Paramecium cf. caudatum Ehrenberg was found to be a successful grazer of toxin producing Cylindrospermopsis in the laboratory. The feeding rate increased with increasing cell concentration to 1367 cell animal hr-1 at 4.

Differential effects of dexamethasone and clenbuterol on rat growth and on beta2-adrenoceptors in lung and skeletal muscle.

Beta-adrenergic agonists increase growth rate, but their efficacy is reduced over time as the number of beta2-adrenoceptors in muscle decreases. Dexamethasone increases beta2-adrenoceptor density in many tissues, but this effect has not been reported in skeletal muscle. In this study, male rats were treated daily for 10 d with either clenbuterol (4 mg/kg of feed), dexamethasone (.

Evaluation of the somatogenic activity of bovine placental lactogen with cell lines transfected with the bovine somatotropin receptor.

Studies have shown that bovine placental lactogen (bPL) has partial somatogenic activity in vivo even though binding results clearly indicate bPL does not cause homodimerization of the bovine somatotropin receptor (bST-R). To help understand the receptor binding versus biological activity of bovine somatotropin (bST) and bPL we have developed a homologous model system. Full length bST-R was stably transfected into a murine lymphoid cell line, Ba/F3 and a hamster kidney cell line, BHK.

Leptin: its pharmacokinetics and tissue distribution.

Objective: The pharmacokinetics and tissue distribution of leptin in rats was investigated.

Design: A catheter was inserted in the right jugular vein of rats on the day prior to experiment. The next day, blood was sampled and then a tracer dose of radioiodinated hormone was administered via the catheter.

Effect of corticosterone on beta-adrenoceptor density in rat skeletal muscle.

Corticosteroid hormones increase the density of beta-adrenoceptors in some tissues and may be able to prevent the anabolic effects of beta-agonists from becoming attenuated. The aim of this study was to find a suitable dose of corticosterone that would up-regulate beta2-adrenoceptors in skeletal muscle without arresting the animal's growth. Male rats were given five daily injections of corticosterone at 0, 6.

Characteristics of cyanopindolol analogues active at the beta 3-adrenoceptor in rat ileum.

1. Cyanopindolol (CYP) is a potent antagonist at the beta 3-adrenoceptor in rat ileum. Several analogues of CYP and pindolol were synthesized that also produced antagonist effects at the beta 3-adrenoceptor.

Atypical responses of rat ileum to pindolol, cyanopindolol and iodocyanopindolol.

1. Pindolol, cyanopindolol (CYP) and iodocyanopindolol (IodoCYP) have been reported to act either as antagonists, agonists or partial agonists at the beta 3-adrenoceptor in different preparations. A comprehensive investigation has not yet been described with these compounds tested in one tissue from one species.

Cardiovascular effects of clenbuterol are beta 2-adrenoceptor-mediated in steers.

The mechanism through which the repartitioning agent clenbuterol increases heart rate was investigated. First, the relative importance of the beta 1- and beta 2-adrenoceptors was established in rat and bovine right atria in vitro. The positive chronotropic and inotropic effects of (+/-)isoproterenol in rat and bovine right atria, respectively, were markedly antagonized (P < .

Anabolic effects of the beta 2-adrenoceptor agonist salmeterol are dependent on route of administration.

It is reported that a long duration of action is required for beta 2-adrenoceptor agonists to evoke an anabolic response. In the present study, we compare the potency of clenbuterol with that of the new long-acting compound salmeterol, when given at equimolar doses to female Wistar rats by different routes of administration. Given orally for 10 days, salmeterol had no effect on growth at a dose of 120 micrograms/day, whereas at 2.

Growth, nitrogen metabolism, and cardiac responses to clenbuterol and ketoclenbuterol in rats and underfed cattle.

Two beta-adrenoceptor agonists, clenbuterol and ketoclenbuterol, were examined for their effects on growth and cardiac tissue. In female rats, clenbuterol caused a 48% increase in weight gain (P < .05), with improved feed efficiency (26%; P < .