Academic literature on the topic 'Plant biology not elsewhere classified'

BackgroundThe diet of the koala (Phascolarctos cinereus) is comprised almost exclusively of foliage from the genusEucalyptus(family Myrtaceae).Eucalyptusproduces a wide variety of potentially toxic plant secondary metabolites which have evolved as chemical defences against herbivory. The koala is classified as an obligate dietary specialist, and although dietary specialisation is rare in mammalian herbivores, it has been found elsewhere to promote a highly-conserved but low-diversity gut microbiome. The gut microbes of dietary specialists have been found sometimes to enhance tolerance of dietary PSMs, facilitating competition-free access to food. Although the koala and its gut microbes have evolved together to utilise a low nutrient, potentially toxic diet, their gut microbiome has not previously been assessed in conjunction with diet quality. Thus, linking the two may provide new insights in to the ability of the koala to extract nutrients and detoxify their potentially toxic diet.MethodThe 16S rRNA gene was used to characterise the composition and diversity of faecal bacterial communities from a wild koala population (n = 32) comprising individuals that predominately eat either one of two different food species, one the strongly preferred and relatively nutritious speciesEucalyptus viminalis, the other comprising the less preferred and less digestible speciesEucalyptus obliqua.ResultsAlpha diversity indices indicated consistently and significantly lower diversity and richness in koalas eatingE. viminalis. Assessment of beta diversity using both weighted and unweighted UniFrac matrices indicated that diet was a strong driver of both microbial community structure, and of microbial presence/absence across the combined koala population and when assessed independently. Further, principal coordinates analysis based on both the weighted and unweighted UniFrac matrices for the combined and separated populations, also revealed a separation linked to diet. During our analysis of the OTU tables we also detected a strong association between microbial community composition and host diet. We found that the phyla Bacteroidetes and Firmicutes were co-dominant in all faecal microbiomes, with Cyanobacteria also co-dominant in some individuals; however, theE. viminalisdiet produced communities dominated by the generaParabacteroidesand/orBacteroides, whereas theE. obliqua-associated diets were dominated by unidentified genera from the family Ruminococcaceae.DiscussionWe show that diet differences, even those caused by differential consumption of the foliage of two species from the same plant genus, can profoundly affect the gut microbiome of a specialist folivorous mammal, even amongst individuals in the same population. We identify key microbiota associated with each diet type and predict functions within the microbial community based on 80 previously identifiedParabacteroidesand Ruminococcaceae genomes.

Abstract We conducted a phytosociological study of the communities hosting the rare and endangered fern Adiantum capillus-veneris in the foothills of the Julian Alps, in Karst and in Istria. Based on a comparison with similar communities elsewhere in the southern Alps (northern Italy) we classified most of the recorded stands into the syntaxa Eucladio-Adiantetum eucladietosum and -cratoneuretosum commutati. Releves from the southern Julian Alps, located in comparatively slightly colder and moister local climate and the dolomite bedrock are classified into the new subassociation -hymenostylietosum recurvirostri subass. nova. Stands with the abundant occurrence of the liverwort Conocephalum conicum, are classified in to the new subassociation -conocephaletosum conici subass. nova. Stands in conglomerate rock shelters along the Soča at Solkan are classified into the new association Phyteumato columnae-Adiantetum ass. nova, a community of transitional character between the classes Adiantetea capilli-veneris and Asplenietea trichomanis.

Plant communities are described from an area on the Yukon – Kuskokwim (Y-K) delta of Alaska that is used extensively for brood rearing by three species of geese. Earlier studies identified plant species important as food for young geese, but few studies describe or quantify plant communities. We classified species presence or absence information from over 700 quadrats using a two-way indicator species analysis (TWINSPAN) and then tested for agreement of signatures on colour infrared air photos with the identified communities. Sedges were found to dominate all but the wettest and driest communities. Most of the brood-rearing area was covered by Carex ramenskii and Carex rariflora meadows, ponds, Carex mackenziei-dominated pond margins, and C. ramenskii and grass levee meadows. Our interpretation of airphotos accurately predicted vegetation community classes, which will facilitate future studies of habitat selection by geese during the time they are rearing young. The TWINSPAN classification was comparable to classifications of studies conducted elsewhere on the Y-K delta. The interpretation of air photos will enable the identification and evaluation of wetland vegetation complexes and potential goose brood-rearing areas away from our study site. Key words: air-photo interpretation, Alaska, plant communities, salt marsh, Yukon – Kuskokwim delta.

Dirty panicle disease in coconuts (Cocos nucifera) was first observed in the KU-BEDO Coconut BioBank, Nakhon Pathom province, Thailand. The occurrence of the disease covers more than 30% of the total coconut plantation area. The symptoms include small brown to dark brown spots and discoloration of male flowers. Herein, three fungal strains were isolated from infected samples. Based on the morphological characteristics the fungal isolates, they were classified into two genera, namely, Alternaria (Al01) and Fusarium (FUO01 and FUP01). DNA sequences of internal transcribed spacer (ITS), glyceraldehyde 3-phosphate dehydrogenase (GAPDH), translation elongation factor 1-α (tef1-α), and RNA polymerase II second largest subunit (rpb2) revealed Al01 as Alternaria burnsii, whereas DNA sequences of ITS, rpb2, and tef1-α identified FUO01 and FUP01 as Fusarium clavum and F. tricinctum, respectively. A pathogenicity test by the agar plug method demonstrated that these pathogens cause dirty panicle disease similar to that observed in natural infections. To the best of our knowledge, this is the first report on the novel dirty panicle disease in coconuts in Thailand or elsewhere, demonstrating that it is associated with the plant pathogenic fungi A. burnsii, F. clavum, and F. tricinctum.

The term mycoparasitism applies strictly to those relationships in which one living fungus acts as a nutrient source for another, but fungicolous relationships may also be included in which nutrient exchange has not been shown. Fungicolous fungi have a constant but indeterminate association with another fungus, and it can be difficult to demonstrate a true parasitic relationship. Mycoparasitic relationships can be necrotrophic or biotrophic, and can be classified on the basis of the host–parasite interface as contact necrotrophs, invasive necrotrophs, haustorial biotrophs, intracellular biotrophs, or fusion biotrophs depending on the intimacy of the relationship. In natural ecosystems, it is proposed that mycoparasitic relationships play an important role in the development of fungal communities. Two specific examples have been chosen to illustrate the general principles of mycoparasitism: the necrotrophic invasion of spores of arbuscular mycorrhizal fungi and the biotrophic invasion of mucoralean hosts by haustorial mycoparasites. Key words: mycoparasitism, fungicolous fungi, arbuscular mycorrhizal fungi, fungal ecology.

Viola PyrenaicaRamond Ex Dc in the Northern Part of the Dinaric Mountains (The Plateaus of Trnovski Gozd and Nanos, Slovenia)The article describes new localities of a south-European montane speciesViola pyrenaicain the Julian Alps and in the Trnovski gozd and Nanos plateaus (the northern part of the Dinaric mountains). It has been established that in the localities known so far in Slovenia, the species grows on similar sites as elsewhere in the Alps and other mountain ranges of the Balkan Peninsula, above all on overgrown screes, stony grasslands, on forest edges, in light forests on stony ground and in tall herb communities on calcareous bedrock in the submontane, montane and subalpine belt (450 to 1600 m a.s.l.). The floristic composition of the communities in which it grows is presented in four tables. On the Trnovski gozd plateau it was found in various successional stages of abandoned pastures or grasslands of the associationGenisto sericeae-Seslerietum kalnikensisand in open coppice stands of hop hornbeam and flowering ash, which are classified into the associationSeslerio autumnalis-Ostryetum carpinifoliae.

Kegode, G. O. and Darbyshire, S. J. 2013. The Biology of Canadian Weeds. 152. Artemisia biennis Willd. Can. J. Plant Sci. 93: 643–658. Artemisia biennis Willd. (biennial wormwood, armoise bisannuelle) is an annual or biennial species native to western North America. Closely related species occur in Eurasia and South America which are sometimes considered conspecific. Spreading elsewhere in North America occurred along transportation corridors soon after European settlement and it has since been introduced to other parts of the world. As an economically important weed its impact appears to be increasing, possibly due in part to reduced tillage practices. The most significantly affected regions are the Prairie Provinces of Canada and the northern Great Plains in the United States. Many cereal, oilseed, pulse, vegetable and forage crops are affected where it can reduce yields at relatively low densities. A wide range of soil and moisture conditions are tolerated and it can form dense populations in disturbed habitats where its competitive ability is enhanced by prolific seed production, indeterminate seedling emergence and allelopathic effects. Although tolerant of a number of herbicides in different classes, good control can be achieved through careful timing and split application strategies.

AbstractIn Europe, some non-native tree species (NNT) are classified as invasive because they have spread into semi-natural habitats. Yet, available risk assessment protocols are often based on a few limited case studies with unknown representativeness and uncertain data quality. This is particularly problematic when negative impacts of NNT are confined to particular ecosystems or processes, whilst providing valuable ecosystem services elsewhere. Here, we filled this knowledge gap and assessed invasion risks of two controversially discussed NNT in Germany (Quercus rubra L., Pseudotsuga menziesii (Mirb.) Franco) for broad forest types using large scale inventory data. For this purpose, establishment success of natural regeneration was quantified in terms of cover and height classes. The current extent of spread into protected forest habitats was investigated in south-west Germany using regional data. Establishment was most successful at sites where the NNT are abundant in the canopy and where sufficient light is available in the understory. Natural regeneration of both NNT was observed in 0.3% of the total area of protected habitats. In forest habitats with sufficient light in the understory and competitively inferior tree species, there is a risk that Douglas fir and red oak cause changes in species composition in the absence of management interventions. The installation of buffer zones and regular removal of unwanted regeneration could minimize such risks for protected areas. Our study showed that forest inventories can provide valuable data for comparing the establishment risk of NNT amongst ecosystem types, regions or jurisdictions. This information can be improved by recording the abundance and developmental stage of widespread NNT, particularly in semi-natural ecosystems.

A major structural component of the inner face of the nuclear envelope in vertebrates and invertebrates is the nuclear lamina, an array of 1–3 extrinsic membrane proteins, lamins A, B and C. These proteins are highly homologous to intermediate filaments and are classified as type V. We report the first purification, antigenic characterization and immunocytochemical localization of putative plant lamin proteins from pea nuclei. We conclude that plant cells contain this ancestral class of intermediate filaments in their nuclei and that regulation of nuclear envelope assembly/disassembly and mitosis in plants may be similar to that in animal cells.

The marine diatom Nitzschia dentatum sp. nov. isolated from seawater samples of Kudat and N. johorensis sp. nov. isolated from beach sand samples of Sibu Island, Malaysia, have been described in this paper. Morphological identification, molecular phylogeny and toxin analyses were executed on the pure non-axenic algal cultures designated as KD89 and PS8, respectively. The main distinguishing feature of N. dentatum sp. nov. compared to other species is the jaggedcingulum structure which is only unique to this species. Meanwhile, N. johorensis sp. nov.is strongly characterized by the ‘hantzschioid’and ‘nitzschioid’ symmetry dimorphisms; a common diagnostic feature but rarely described in other Nitzschia species. Identification of both strains was made based on the frustule diagnostic features and verified using the partial large ribosomal subunit DNA sequences. The results have confirmed that these two speciesare independent entities and novel species that have not been documented elsewhere. A notable finding from the Maximum Likelihood (ML), Maximum Parsimony (MP) and Bayesian Index (BI) analyses have also revealed that Nitzschia species that have indentation in the middle of valves have been consistently grouped as same clade with high bootstrap values. The extracts of both species did not show detectable amount of domoicacid and have therefore, been classified as non-toxic. This discovery contributes to the documentation of Nitzschia species worldwide.Bangladesh J. Plant Taxon. 24(2): 183–196.

The primary aim of the thesis is to provide a comprehensive investigation of the osmotic dehydration processes in plant tissue. Effort has been concentrated on the modelling for simulating the processes. Two mathematical models for simulating the mass transfer during osmotic dehydration processes in plant tissues are developed and verified using existing experimental data. Both models are based on the mechanism of diffusion and convection of any mobile material that can transport in plant tissues. The mass balance equation for the transport of each constituent is established separately for intracellular and extra-cellular volumes with taking into account the mass transfer across the cell membrane the intracellular and extra-cellular volumes and the shrinkage of the whole tissue. The contribution from turgor pressure is considered in both models. Model two uses Darcy’s law to build the relation between shrinkage velocity and hydrostatic pressure in each volume because the plant tissue can be considered as the porous medium. Moreover, it has been extended to solve the multi-dimensional problems. A lot of efforts have been made to the parameter study and the sensitivity analyses. The parameters investigated including the concentration of the osmotic solution, diffusion coefficient, permeability of the cell membrane, elastic modulus of the cell wall, critical cell volume etc. The models allow us to quantitatively simulate the time evolution of intracellular and extra-cellular volumes as well as the time evolution of concentrations in each cross-section.

Breast cancer (BC) is the most common and most lethal cancer among women worldwide. More than a million and a half are diagnosed every year with more than 600,000 deaths among women worldwide. It is estimated than 1 in every 7 women will develop breast cancer in their life time. It is a major public health concern with high economic cost as well. BC is a multidimensional construct. Several dimensions of this construct have never been examined before in the United Arab Emirates (UAE). This study investigated major facets of the Quality of life (QOL) among women with BC in the UAE, compared it with a sample of age matched healthy group of women without any neoplastic background, changes in serum biomarkers of women with BC and to detect the impact of the disease on these biomarkers at the beginning of the disease before treatment started and then again 12 months later following treatment for the cancer and the role of ghrelin hormone in BC and depression at a tissue level and at serum level. In order to examine QOL with its all dimensions among women with BC, an epidemiological case-control study was conducted recruiting a sample of 300 women, 155 women with BC and 145 age-matched healthy women without any neoplastic background as a control group. This was carried out by using a series of standardized psychometric tools in addition to conducting a psychiatric diagnostic interview. Moreover, blood biomarker results were reviewed retrospectively for cases and controls at the beginning and then 12 months following treatment for BC. In relation to the histopathological characteristics and treatment modalities for BC, all pathology, medical and oncology data for 155 women with BC was retrieved from the computer system and analyzed retrospectively. Finally, in relation to ghrelin hormone, all mammary morphological types, normal, benign and malignant were examined with immunohistochemistry for the expression of ghrelin and its functioning receptor (GHS-R1a). Serum of the same women, whose mammary tissue sections were examined by IHC, was tested for ghrelin serum level to find out its link to BC and depression. This was carried out by Enzyme-Linked Immunosorbent Assay (ELISA). The results have demonstrated that women with BC had poor QOL in comparison to the control group. They had poor view of their body image and sexuality and moreover physical disability rate was high. They also tended to suppress negative emotions to a great extent. Anxiety symptoms were also high. Major depressive disorders and post traumatic disorders were lower among women with BC compared to healthy controls. Several risk factors turned to be linked to BC. These included age, having night shift work, hypertension, diabetes mellitus, oral contraceptive pills, hormonal replacement therapy and not breast feeding. In terms of significant traumatic life events, the Arabic version of the CESC English scale showed to have high validity and reliability among women with BC in the UAE. The results also showed that the levels of several serum haematological and biochemical markers seemed to be abnormal among women with BC compared to healthy control. These included elevated levels of platelet, basophils, liver enzymes, lactate dehydrogenase and tumour serum markers. On the other hand, they were low levels of serum magnesium, C-reactive protein and creatinine. Analysis of histopathological characteristics indicated that the aggressive biological nature of the disease was at the late stage and presentation to medical services for treatment. Clinically, women with BC seemed to have all treatment modalities for BC with high rate of mastectomy and axillary clearance. Regarding ghrelin hormone and it relation to BC, the results showed that malignant mammary tissues had an exclusive and differential immune-reactivity to ghrelin hormone, whereas its receptor, the GHS-R1a, was immune-reactive all mammary tissue morphological types. In addition, more metastasis to the lymph nodes was significantly correlated with more immune-reactivity to ghrelin receptor. The results for gene expression for pro-ghrelin, ghrelin and its receptors were inconclusive It is concluded that breast cancer is the most common cancer among women in the UAE. It attacks women at an earlier age than their counterparts in the West. More attention should to be allocated to the QOL and the unmet psychosocial needs of women with BC. This in turn would improve compliance to treatment and prognosis as well. It is also recommended that awareness campaigns and early screening should be applied for early detection of the disease to prevent late presentation to the medical services and other complications.

As far back as the 1920s, Otto Warburg observed that cancerous cells display an altered state of metabolism surrounding lipid biosynthesis. However, only until recently has metabolic reprogramming been a recognised hallmark of the disease. The number of cancer cases diagnosed is set to triple by 2030, demonstrating the need for disease prevention, improved diagnostic testing and personalised treatment therapies. However, with some cancers occurring in the brain and spinal cord, the type of treatment available can become challenging due to their locality. Such cancer types include meningioma and glioma which are the most common brain tumours diagnosed. An initial study involving human meningioma tissue revealed unusually high levels of the phosphatidylserine enriched with docosahexaenoic acid (DHA). In this study, the metabolism surrounding lipid biosynthesis was examined to establish if such alterations in lipid profiles were related to an altered state of metabolism. From the results gained, it can be suggested that meningioma does have an altered state of metabolism, evolving around serine as opposed to DHA. From the grade I and grade II meningioma tissues immunochemically examined, positive expressions of pyruvate kinase isoform 2 (PKM2) and phosphoglycerate dehydrogenase (PHGDH) were shown. Therefore, the results demonstrated that within meningioma tissues, serine can allosterically regulate the flux through glycolysis. The association that serine presence alone can alter the metabolic flux was demonstrated in the model organism, Lipomyces starkeyi. Those L. starkeyi cells supplemented with serine, displayed a 50% reduction in the amount of radiolabelled acetate taken up during exponential and stationary growth phases. The radiolabelled study also highlighted that with serine presence, de novo lipid biosynthesis was altered. Once synthesised, these neutral lipids go on to be 4 stored in membrane bound organelles. Within the phenotype of cancerous cells, such storage of neutral lipids into lipid droplets prevent lipotoxicity. The light microscopy study of L. starkeyi cells supplemented with serine demonstrated that the formation of such lipid droplets was enhanced during lipid accumulation. These findings suggest that the production, storage and mobilisation of lipids within serine supplemented cells are adapted to cellular requirements, promoting a cancerous phenotype. In order to gain an insight into the potential impact that an altered metabolic state may give to meningioma, a liposomal study was developed. Supplementation of both phosphatidylserine-consisting liposomes, as well as tumour-derived liposomes, enhanced the cellular viability of the non-cancerous cell line, SVG, during exponential phase. The supplementation of meningioma-derived liposomes also increased the viability of the non-cancerous human fetal glial SVG cell line, similar to that observed with phosphatidylserine containing liposomal preparations. Therefore, the data suggest that in fact, the phospholipid (phosphatidylserine), rather than the fatty acid (DHA) plays a role in cellular viability. It is concluded that the results gained from this study can be used clinically in the diagnosis and management of meningioma as well as other diseased cells displaying ectopic lipid accumulation. The observation that meningioma has an altered biochemistry may provide guidance when histologically grading meningioma tumours. For those tumours expressing the enzymes involved in serine biosynthesis, such as PKM2 and PHGDH, a targeted treatment therapy surrounding enzyme inhibitors can be examined. By targeting serine biosynthesis, the resources needed to enable a cancerous phenotype are depleted. Future research can examine such targeted therapies utilizing either the developed model organism, L. starkeyi or the conventional SVG and U87 cell lines.

A low technology fermentation system for biodegradation of cellulose based waste material is described. Using a substrate of thermally bonded paper plastic laminate in a defined mineral salts medium the cellulolytic nicrofungus Trichoderma viride XXI 2% 458 was shown to effect the separation of the laminate into its components by enzymic degradation of the paper. This aerobically induced separation occurred within 14 days compared to upto 90 days by purely physical means. Growth of the fungus within the fermentation system was found to provide conditions that control the growth of contaminating microorganisms. Carbonolytic enzyme activity of Trichoderma viride was investigated by measurenent of substrate weight loss and by reduction in the viscosity of soluble substrate analogues when acted upon by filtrate front-the fermentation systais. An investigation of the effect of changes in carbon to nitrogen ratios during fermentation indicated that maximum carbonolytic enzyme activity occurred at a carbon to nitrogen ratio of 0.6:1 within this system. An examination of three other cellulolytic fungi in order to assess their potential as biodegradative organisms within the fermentation system showed that under microthermophilic conditions only Acrenonium stricturn approached the biodegradative activity of Trichoderma viride at mesophilic temperatures. The products of fermentation by Trichoderma viride were examined; protein levels in the residual cellulolytic substrate following biodegradation of paper plastic laminate were determined and found to reach levels of up to 9% following 35 days fermentation. The amino acid composition of protein produced by Trichoderma viride when grown on a range of substrates was determined and found to contain a wide range of essential and non essential amino acids. An investigation of mycotoxins both in the culture medium and residual paper component was undertaken. Comparisons with eleven common mycotoxin standards revealed no positive identifications under the conditions investigated.

"The hypothesis that primary C and N (sucrose and ureides) transport solutes may play a role as osmotica in the control of oxygen diffusion into the infected zone of the legume nodule was considered" -- p. i.

Industrial hemp (Cannabis sativa L.) production is experiencing a significant increase in worldwide production since regaining popularity in many countries since the 1990's. Currently, production in Australia is very limited, and no major grain or fibre processing facilities yet exist, owing to the lack of suitable low THC (A9-tetrahydrocannibinol) varieties. Hemp production in subtropical regions of Australia is particularly limited as short day lengths (photoperiods) result in early plant maturity, and thus, poor yielding crops. The aim of this research is to determine the viability of a new variety of hemp, bred specifically for subtropical production whilst determining the effects of day length and plant density on yield and flowering time. Trials were conducted in Bundaberg, QLD in 2010-2012 in both field and controlled environment (plastic house) settings. Plant densities of 100, 200, 300 and 400 plants m-2 were compared for fibre production and densities of 50, 80, 100 and 150 plants m2 were compared for grain production to assist in the establishment of appropriate commercial sowing rates. Harvested fibre yields were greatest at 300 plants m2 whereas grain yields were greatest at 150 plants m2, with the potential of even higher yields at densities greater than 150 plants m2. Photoperiod experiments were conducted in a controlled plastic house evaluating plant responses to varying photoperiods. Treatments comparing ambient day length, 13 hour 40 minute fixed photoperiod and 14 hour 40 minute fixed photoperiod determined that a 13 hour 40 minute photoperiod did not significantly prolong vegetative growth compared to natural day lengths in the hemp variety BundyGem but at 14 hours 40 minutes maturity times were significantly delayed, thereby contributing to greater plant height and fibre yield. Previous research also suggests that a critical photoperiod of between 14 and 16 hours is required before flowering is delayed in hemp. This theory was supported by a field experiment whereby successive plantings of BundyGem throughout the spring/summer period of 2011/2012, flowered at the same age despite subtle changes in day length for the growing period (never exceeding 13 hours 40 minutes). This research confirms that subtropical fibre hemp is not yet suitable for subtropical production in Australia with existing varieties due to the limitation of photoperiod on yield. Grain production may still be viable despite early plant maturity with yields comparable with those produced in Europe and Canada.

The phenylpropanoid pathway gives rise to a wide variety of specialized metabolites, but the majority of carbon flux going through this pathway is directed towards the synthesis of the lignin monomers: p-coumaryl alcohol, coniferyl alcohol and sinapyl alcohol. Lignin is a major impediment in biomass saccharification, which negatively affects animal feed and biofuel production. In an effort to improve biomass for the latter purposes, researchers have altered the polymer through genetic manipulations and generated biomass with lower recalcitrance to saccharification; however, in many cases these efforts have resulted in plant dwarfism. To date, we do not have a full understanding of the extent of lignin modifications a plant is able to tolerate without affecting its growth. More importantly, the mechanism that links dwarfism and modifications in lignin content and composition remains unknown. To contribute to answering these questions, we designed a strategy to incorporate a novel monomer into the lignin of Arabidopsis thaliana. We used mutants in genes that code for enzymes and regulators of the phenylpropanoid pathway to redirect the pathway’s flux towards the synthesis of p-coumaraldehyde and prevent the incorporation of p-coumaryl alcohol. Despite being mutated for the genes typically considered to be required for monolignol biosynthesis, the plants we generated continue to incorporate p-coumaryl alcohol into their lignin. This result suggests that the pathway’s architecture has not been completely elucidated and that there are more enzymes involved in lignification than previously thought. Additionally, we explored the connection between perturbations in phenylpropanoid metabolism and plant growth, by using an inducible system to track the changes in gene expression and metabolism that occur when phenylpropanoid metabolism is restored in a lignin biosynthetic mutant. The use of an inducible system allowed us to not only determine the metabolic processes affected in this mutant, but the proximal sequence of events that lead to restored growth when a functional copy of the mutant gene is induced. Finally, we redirected the flux through the pathway to assess the effects of simultaneously modulating lignin content and composition. Through this project we discovered that redirecting phenylpropanoid flux towards the synthesis of sinapyl alcohol in lignin-deficient mutant backgrounds, results in plant dwarfism. The growth impairment of these mutants can be overcome by providing exogenous coniferyl alcohol, suggesting that dwarfism in these mutants is caused by deficiency in coniferyl alcohol and/or derivatives thereof and not lignin alone. Altogether these projects allowed us to define the cellular processes affected by perturbations in phenylpropanoid homeostasis and the role of other phenylpropanoids besides lignin in this process.

Buffel grass (Cenchrus ciliaris) is an introduced, summer growing, perennial tufted tussock grass which is used extensively in improved pastures in the grazing industry. Since 1993 there has been an increasing level of dieback in buffel grass in districts of Central Queensland districts, involving red leaf symptoms and occurring in roughly circular patches. There is a potential for this condition to destroy large areas, ultimately resulting in loss of production for beef, dairy and sheep farmers who use this grass in improved pastures. This is the first multifaceted study of buffel grass dieback (BGD). Areas showing signs of dieback have previously been the subject of extensive testing for soil fertility factors, soil chemistry, nematodes and phytoplasmas, with few conclusive results. Therefore, one of the aims of this project was to find the cause of buffel grass dieback. Specific objectives included describing the plant and field symptoms, determining factors responsible for plant death, and determining the method of spread. A complete description of the symptoms was made at plant, patch and paddock levels. Symptoms of Buffel Grass Dieback (BGD) presented as a reddening of the leaves starting from the tip and progressively moving towards the ligule. The red symptoms range from bright red, to dark red, to bronze (RHSPCC red group 45: A, B; 46: A, B; greyed-orange group 166: A; 177; A) (The Royal Horticultural Society, 2001). Symptoms first appeared on the tips of the older leaves and progressively moved down the leaf. The next oldest leaf then showed symptoms, and so on, with the youngest leaf showing symptoms last. Any tillers followed the same pattern, regardless of whether symptoms on the primary shoot had progressed past the point at which the tiller was produced. The amount of time from new growth to the appearance of the red symptoms seemed to be directly proportional to the amount of rainfall. That is, the more rain, the longer it took for symptoms to develop. The amount of subsequent rainfall seemed to influence the time it took for plants to succumb to the condition. That is, when there was adequate water and lush growth plants grew faster than the spread of the condition. When plants became water stressed, the condition overtook growth and the plants succumbed. Symptomatic leaves did not always have a clear red-green boundary. Occasionally, BGD symptoms progressed faster down one half of the leaf. Red symptoms were invariably more vivid on the adaxial surface of the leaves than on the abaxial surface. Roots of affected plants appeared stunted compared to roots of unaffected plants. Roots of affected plants often displayed soft, darker, ovoid sunken regions, which were possibly lesions. The BGD condition appeared to become dormant as buffel grass became dormant. That is, if the dieback condition killed the plant before the onset of dormancy, no new shoots were produced subsequent to a rainfall event. However, if dormancy occurred before the plant succumbed to the condition, new shoots were produced after rain, and the cycle repeated with symptoms first appearing in the oldest leaf. Patches were roughly circular and ranged from 2 m diameter to over 60 m diameter. Adjacent patches often coalesced and further enlarged. Symptoms first appeared on the periphery of an existing patch, where during the last cycle the plants had become dormant before succumbing to the condition. Symptoms progressively moved outwards from the periphery of the patch, at a rate of approximately 5 cm per week. Patch spread was irregular and did not correspond with soil compaction or land slope, though the condition may spread more rapidly downhill due to runoff. BGD affected plants weighed approximately two thirds that of unaffected plants. They were noticeably shorter and had shorter leaves and internodes, with the difference in height attributed to internodes rather than leaf length. BGD affected plants also had fewer tillers than unaffected plants of the same age. Although the numbers of leaves per tiller were the same as un-affected plants, the overall result was a decreased amount of foliage available for grazing, thereby decreasing productivity of livestock. In fact, the loss of productivity was twofold, since cattle had been observed to selectively graze unaffected plants. BGD affected plants had fewer seed heads, shorter seed fascicles, and a higher proportion of non-viable embryos compared to unaffected plants. Therefore, not only did BGD affected plants succumb and die, but there were fewer seedlings to replace them. This could have detrimental consequences for the sustainability of an improved pasture. At the cellular level, there was no discernable difference in cell size between BGD affected plants and unaffected plants in either roots or leaves. However, the roots of BGD affected plants were more damaged at the cellular level, with the cortex mostly sloughed off and the mesophyll cells disrupted. The bulliform and mesophyll cells of BGD affected leaves were more irregular in shape. The bundle sheath cells of BGD affected leaves appeared disrupted, with chloroplasts not in their usual alignment. There also seemed to be a breakdown of chloroplasts. The leaf pigment data concurred with the premise of a breakdown of chloroplasts. Red symptomatic leaves had lower concentrations of chlorophylls a and b compared to green leaves on the same plant. Red symptomatic leaves also had higher concentrations of anthocyanins and carotenoids. It appears that, in red symptomatic leaves, chlorophylls were being destroyed and anthocyanins were being excessively produced. There was no discernible difference in the phloem vessels of BGD affected and unaffected plants, both in the roots and the leaves. However, the xylem of both roots and leaves was partially occluded by structures tentatively identified as tyloses. These structures could also have been local accumulations of phenols or polyphenols, or in some cases the remnants of partially decomposed cells. These occlusions seemed more severe in the roots than in the leaves. Possible inclusion bodies were also found in the mesophyll cells of BGD affected leaves. Inclusion bodies are usually a sign of pathogen infection. However, there were no pathogens detected in the histology work. Chemical analyses were made of BGD affected plants, as well as of the soil in which they were growing, concluding that both plants and soil in the BGD affected paddock surveyed were deficient in nitrogen, phosphorus, sulfur and zinc. A survey was made of other plant species present in the vicinity of the dieback condition, with particular attention given to those species which have reported allelopathic effects. In addition, a study was made on other plant species which also appear to be affected by the dieback condition. Microbial isolations were regularly made from both plant and soil material. The isolates obtained were tested for proof of pathogenicity using Kochs Postulates, but none proved to be the causal agent of BGD. The mode of transmission of the condition was studied, and BGD was found to be soilborne. Whether root contact is necessary for successful transmission was not established. Possible methods of controlling the condition were investigated. While none of the treatments successfully controlled the condition, one of the treatments investigated, Amistar (a systemic fungicide), greatly reduced symptom severity. Although the cause of BGD was not found, several important discoveries were made concerning its effect and spread, and many possible causes of the condition were eliminated. It is likely that BGD is caused by a disease complex, with potential pathogens including soilborne fungi and/or viruses. Several abiotic factors such as water and nutritional stress may be contributing causal agents, weakening the plants and making them more susceptible to a pathogen. . More work is needed to conclusively identify the primary causal agent of this potentially costly condition.

"Pisonia grands R. Br. (Nyctaginaceae) is a large tropical tree whose distribution is restricted to coral cays, in particular those with high seasonal nesting seabird populations. These trees are often the dominant plant species found on coral cays. This is the case for the chosen study site on North West Island, a coral cay which lies off the Central Queensland coast within the Mackay Capricorn section of the Great Barrier Reef. Coral cays are almost entirely composed of coral rubble and sand and as a result the substrate pH (c. 9.0) and many ions are found as insoluble salts. The high pH, abundance of calcium, lack of water and high seasonal input of nitrates from nesting seabirds, are possible influences on the biosynthesis of oxalates which are found in high concentrations in P. grandis. The aims of this study are twofold. The first aim was to investigate the influence of environmental factors, such as pH and nitrate concentration, on the biosynthesis of oxalate in Pisonia grandis leaf. The second aim was to purify and characterise the enzyme glycolic acid oxidase (E.C. 1.1.3.1) (GAO), an enzyme involved in the biosynthesis of oxalate..." --abstract.. Pisonia grandis R. Br. (Nyctaginaceae) is a large tropical tree whose distribution is restricted to coral cays, in particular those with high seasonal nesting seabird populations. These trees are often the most dominant plant species found on coral cays. This is the case for the chosen study site on North West Island, a coral cay which lies off the Central Queensland coast within the Mackay Capricorn section of the Great Barrier Reef. Coral cays are almost entirely composed of coral rubble and sand and as a result the substrate pH is high (c. 9.0) and many ions are found as insoluble salts. The high pH, abundance of calcium, lack of water and high seasonal input of nitrates from nesting seabirds, are possible influences on the biosynthesis of oxalates which are found in high concentrations in P. grandis. The aims of this study were twofold. The first aim was to investigate the influence of environmental factors, such as pH and nitrate concentration, on the biosynthesis of oxalate in Pisonia grandis leaf. The second aim was to purify and characterise the enzyme glycolic acid oxidase (E.C. 1.1 .3.1) (GAO), an enzyme involved in the biosynthesis of oxalate. P. grandis was grown in a hydroponic system which was constructed in a glasshouse. The effect of variations in light intensity, pH and the concentrations of nitrate, calcium and sodium chloride in the nutrient sol ution on leaf oxalate concentration was investigated. A small diurnal variation in leaf soluble oxalate concentration was observed (O.5mmol/g DW at 07:00hrs and 0.62 mmol/g/DW at 19:00hrs) which was consistent with the notion that an intermediate in the formation of oxalate was derived from photosynthesis or photorespiration. In all other experimental regimes leaf oxalate concentrations were shown to vary in response to changes in the excess cation content of the leaves. These hydroponic studies suggested that changes in leaf excess cation concentration, and associated changes in intracellular pH, stimulate changes in the biosynthesis of oxalate in Pisonia. GAO was isolated to purity from the leaves of P. grandis and was found to be similar to GAO from other sources. The holoenzyme was found to be a hexamer (M.Wt. 250000) of subunits with molecular weight 44000. In vitro, with glycolate substrate, GAO had a pH optima of 7.0 and a Km of O.4mM. The enzyme exhibited partial competitive inhibition by oxalate (Ki 2.75mM) and was irreversibly inhibited by phydroxymercuribenzoate. Phenyllactate and iodoacetate did not inhibitthe enzyme preparation. These studies were repeated for glyoxylate and lactate as the enzyme substrates. The pH optima determined for GAO in vitro with glycolate and glyoxylate substrates, in conjunction with the pH optima reported for aminotransferase enzymes, supports the notion that leaf oxalate participates in a biochemical pH stat within the leaves of Pisonia grandis.

Longhorn Beetles — Cerambycidae are one of the most easily recognised groups of beetles, a family that worldwide encompasses over 33,000 species in 5,200 genera. With over 1,400 species classified in 300 genera, this is the sixth largest among 117 beetle families in Australia. These beetles often attack and kill living forest or orchard trees and develop in construction timber (like European House borer, introduced to WA), causing serious damages. Virtually all Cerambycidae feed on living or dead plant tissues and play a significant role in all terrestrial environments where plants are found. Larvae often utilise damaged or dead trees for their development, and through feeding on rotten wood form an important element of the saproxylic fauna, speeding energy circulation in these habitats. Many species are listed as quarantine pests because of their destructive role to the timber industry. This volume provides a general introduction to the Australian Cerambycidae with sections on biology, phylogeny and morphology of adult and larvae, followed by the keys to the subfamilies and an overview of the 74 genera of the subfamily Lamiinae occurring in Australia. All Lamiinae genera are diagnosed, described and illustrated and an illustrated key to their identification is provided. A full listing of all included Australian species with synonymies and bibliographic citations is also included. Biologists worldwide, curators and staff at natural history museums, quarantine/inspection services, entomologists and collectors - many of these beetles are collector's items. Winner of the 2016 J.O. Westwood Medal Winner of the 2014 Whitley Medal

AbstractBoth poultry meat and eggs provide high-quality animal protein [containing sufficient amounts and proper ratios of amino acids (AAs)] for human consumption and, therefore, play an important role in the growth, development, and health of all individuals. Because there are growing concerns about the suboptimal efficiencies of poultry production and its impact on environmental sustainability, much attention has been paid to the formulation of low-protein diets and precision nutrition through the addition of low-cost crystalline AAs or alternative sources of animal-protein feedstuffs. This necessitates a better understanding of AA nutrition and metabolism in chickens. Although historic nutrition research has focused on nutritionally essential amino acids (EAAs) that are not synthesized or are inadequately synthesized in the body, increasing evidence shows that the traditionally classified nutritionally nonessential amino acids (NEAAs), such as glutamine and glutamate, have physiological and regulatory roles other than protein synthesis in chicken growth and egg production. In addition, like other avian species, chickens do not synthesize adequately glycine or proline (the most abundant AAs in the body but present in plant-source feedstuffs at low content) relative to their nutritional and physiological needs. Therefore, these two AAs must be sufficient in poultry diets. Animal proteins (including ruminant meat & bone meal and hydrolyzed feather meal) are abundant sources of both glycine and proline in chicken nutrition. Clearly, chickens (including broilers and laying hens) have dietary requirements for all proteinogenic AAs to achieve their maximum productivity and maintain optimum health particularly under adverse conditions such as heat stress and disease. This is a paradigm shift in poultry nutrition from the 70-year-old “ideal protein” concept that concerned only about EAAs to the focus of functional AAs that include both EAAs and NEAAs.

Abstract The stem nematode Ditylenchus dipsaci is a migratory endoparasitic nematode of worldwide importance. D. dipsaci was long considered as a species with up to 30 different host races with specific host crop spectra. However, more recent phylogenetic studies showed that isolates from agricultural plant species, including sugar beet, should be considered as D. dipsaci sensu stricto. It is regulated as a quarantine species in many countries and classified as a regulated non-quarantine pest in the European Union to avoid further spread of this nematode by infested seeds or planting material. This chapter discusses the economic importance, distribution, host range, damage symptoms, biology and life cycle, interactions with other nematodes and pathogens, recommended integrated nematode management, and management optimization of D. dipsaci. Future research requirements and future developments are also mentioned.

Abstract For most transgenic crops, the purported ecological risk from transgenic-host hybridization and introgression to unintended host species is negligible. Nonetheless, there remains a risk-associated focus on the potential for gene flow in the governance and regulation of crop biotechnology. Because of uncertainties in the large world of biology as well as regulatory certainties (regulations will likely not diminish), researchers and stakeholders have a great interest in eliminating or substantially decreasing gene flow from transgenic crops. To that end, numerous approaches have been investigated for limiting transgene flow via hybridization and introgression to unintended hosts. While such bioconfinement may be accomplished by ecological and management strategies as discussed elsewhere in this book, this chapter focuses on mitigating unintended gene flow from engineered crops by way of genetic engineering itself. The chapter will mainly discuss the manipulation of relatively simple means to alter plant sexual reproduction and plant growth and development to control transgene flow, with the desired outcome being the prevention of transgenes from moving and/or introgression into free-living unintended hosts. These approaches include: (i) decreasing or delaying flowering; (ii) eliminating pollen production via male sterility or selective male sterility; (iii) removing transgenes from pollen or eggs by gene use restriction technologies; and (iv) kill switches. Emerging synthetic biology approaches that may be used for transgene bioconfinement are explored. Taken together, the same molecular biology strategies that are used to improve crops can also help assure their biosafety.

Abstract The words defined in this section represent terminology common to molecular biology integrated with certain phrases useful in biochemistry, microbiology, and genetics. A few terms are defined within other definitions; these are also printed in boldfaced type. Words in italics are themselves defined elsewhere although italics may also be used for scientific names and even for emphases.

Abstract The range of M. arctoides extends from eastern Bangladesh eastwards through southern China and into the Malayan peninsula and Vietnam. It is declining, or has become rare in India, Thailand, and Malaysia but its status elsewhere in its range is unknown (Wolfheim 1983). It is not classified as threatened by the IUCN (1990).

Vitamin A is one of four vitamins classified historically as lipid-soluble vitamins. The aqueous insolubility of vitamins A, D, E, and K mean there are specialized carrier proteins in serum and in target cells to chaperone these hydrophobic vitamins and their coenzyme forms. Most dietary vitamin A comes from the plant C40 polyene beta-carotene, that is cleaved in the human GI tract to the pair of all-trans-retinal C20 aldehydes. Dietary supplements provide the more stable all-trans-retinyl palmitate ester. The aldehyde and the two electron oxidized acid, all-trans-retinoic acid, are two vitamer forms with dramatically distinct functions. The 11-cis geometric isomer of retinal, bound in imine linkage to a lysine residue in the retinal protein opsin, is the molecular visual pigment, isomerizing back to the all-trans-retinal. Separately, the retinoic acid acts as a hormone, binding in target cells to the vitamin A receptor, heterodimerizing in the nucleus and acting as transcriptional activator to control expression of hundreds of genes in target tissues.

Dispersal is a term used for the dissemination of detached reproductive structures from parent plants to a new site. Disseminules include spores, seeds, fruits, whole inflorescences, whole plants, fragments of the parent plant, bulbs and bulbils. Fruit attributes related to a particular dispersal agent or dispersal syndromes are complex and have resulted from millions of years of evolution. In practice, dispersal is mainly local, although some species of sea coasts are well adapted for long-distance dispersal. Knowledge of the modes of plant dispersal is vital to the study of coastal dune ecology because of the clear correlation between diversity and dispersal mechanisms. From the evolutionary point of view, dispersal improves fitness of species: the progeny is able to colonize a new site and extend the range of the species. The fitness here will be defined as getting to a coastal site by using any vector for dispersal, colonization of the new site (germination, establishment and reproduction) and dispersal of the propagules of the immigrant from the new site. Dispersal confers many benefits to the populations of plant species. It reduces competition for limited space and resources in the parental location and the more widely dispersed the propagules, the greater are the chances for the offspring to colonize elsewhere. Dispersal increases the chances of survival and evolution of more fit strains of a species by occupying more diverse habitats than the parents, and speciation may eventually occur in response to new selective pressures. For species adapted to live along sea coasts, dispersal by sea is primarily directed for dissemination to another site by the sea coast. During dispersal several physiological changes may occur in the disseminules that facilitate colonization of the species at the new habitat. For example, Barbour (1972) reported that immersion of upper fruits of Cakile maritima in seawater stimulated their subsequent germination under controlled conditions. Seed coat dormancy may also be broken by abrasion of seeds in sand while being rolled along the sand surface. Considering the large number of species along coasts and on islands, only a very few species may be successfully disseminated in seawater.

There is a wide variety of plant, animal, and microbial life in mangrove forests because of their location at the boundary between terrestrial and marine environments. Because of their central role in the development and upkeep of the mangrove ecosystem, microbes also serve as a useful and significant source of biotechnologically engineered materials. Microbes are essential to the health of the mangrove ecosystem's productivity by aiding in the decomposition and mineralization of leaf litter at a number of different phases of the process. They are capable of recycling nutrients; they can generate or consume gases affecting the global climate; they can remove contaminants; they can process anthropogenic trash. Mangrove environment microorganisms provide a large supply of antimicrobial substances and also create a broad spectrum of major health-boosting chemicals such as enzymes, antitumors, insecticides and immune modulators. However, unlike other ecosystems, mangrove ecosystems have never had their microbial diversity described. Despite the rich diversity of microbiological conditions in mangrove ecosystems, only around 5 percent of species have been classified, and many of them remain enigmas in terms of their ecological importance and practical use. Microbial diversity must be fully utilised to reach its potential, and modern molecular biology and genetics technologies show considerable promise. This Chapter, therefore, attempts to examine and analyze the microbial diversity of mangrove ecosystems in many aspects, such as agricultural, pharmaceutical, industrial, environmental, and medical possibilities.

The earth’s surface supports living organisms and their environments to form the biosphere, a thin film of life around the planet. Organisms participate in interacting systems or communities, and these communities are coupled to their environments by the transfer of matter and energy and by movements of air, water, and organisms. Human activities in Monteverde and elsewhere can drastically alter forest ecosystems. Textbooks on ecosystem ecology typically include such topics as community structure and composition (including plant growth forms, vertical structure, niche space, species diversity), communities and environments (species distributions along environmental gradients, community classification, succession), production (food chains and webs, decomposition and detritus, photosynthesis), and nutrient cycling (mineral nutrition of organisms, soil development, biogeochemistry). Our understanding of tropical ecosystem ecology generally falls short of what we know of other aspects of tropical biology. There are far more studies concerning population biology, autecology, and life history of tropical organisms than nutrient cycling, productivity, and landscape ecology. This pattern is true in Monteverde and in such well-studied tropical forests as La Selva, Barro Colorado Island (BCI), and the Luquillo National Forest (Lugo and Lowe 1995, McDade et al. 1994). Logistical blocks to ecosystem research exist because collaborating teams of scientists are typically needed to tackle the multiple disciplines that ecosystem-level questions require, which demands a large infrastructure and budget. Temporal problems exist because ecosystem-level phenomena (e.g., tree mortality and forest regeneration) may involve time scales longer than the life of a single granting period or lifetime of a researcher. A strong academic base for ecosystem ecology is lacking because the pool of existing studies is too small to draw patterns and extrapolate trends. These obstacles have not often been overcome in Monteverde. No Monteverde institution has provided the infrastructure to support ecosystem research (e.g., laboratory facilities, meteorological station, technical library). Some community members have negative feelings about experimental manipulations and destructive sampling sometimes needed to answer ecosystem ecology questions. From the 1970s to the 1990s, Organization for Tropical Studies (OTS) courses were in Monteverde and in such well-studied tropical forests as La Selva, Barro Colorado Island (BCI), and the Luquillo National Forest (Lugo and Lowe 1995, McDade et al. 1994).

“How many of you who moved to Colorado from Texas or Florida took into account that you were nearly tripling your annual dose of natural radiation by studying here?” That is the first question I ask students in my radiation biology class at Colorado State University, and of course none of the students considered that they were increasing their exposure to radiation by a large factor simply by moving here to live. And none of them would have used that as a reason to not study here. In contrast, if they were moving near a nuclear power plant in their state, they might have had second thoughts, even though they would be exposed to far less radiation than by coming to Fort Collins, Colorado. There is no place on earth where you are not exposed to radiation. As I said in the previous chapter, life evolved in a radiation environment. But where does the radiation come from, and why is it higher in Colorado than elsewhere in the United States? Are there other areas in the world where it is even higher? Do we get a lot more cancer in Colorado than in other lower radiation states because we are exposed to more radiation? These are important questions—they help us to understand the risk from a particular dose of radiation and put into perspective the exposure to radiation from the nuclear fuel cycle. We are exposed to radiation that comes from the skies, from the earth, and from our food. These are all natural sources, and there is not much we can do about it except decide where we want to live. But our decisions as to where we want to live almost certainly do not take into account the exposure to background levels of radiation from natural sources. The other main not-so-natural source of radiation exposure comes from medical procedures, a source that is increasing rapidly.

Biology is a fairly complicated initial subject because it involves knowledge of biodiversity. Google Lens is a unique, mobile software that allows you to recognition species and genus of the plant student looking for. The article devoted to the analysis of the efficiency of the functioning of the Google Lens related to botanical objects. In order to perform the analysis, botanical objects were classified by type of the plant (grass, tree, bush) and by part of the plant (stem, flower, fruit) which is represented on the analyzed photo. It was shown that Google Lens correctly identified plant species in 92.6% cases. This is a quite high result, which allows recommending this program using during the teaching. The greatest accuracy of Google Lens was observed under analyzing trees and plants stems. The worst accuracy was characterized to Google Lens results of fruits and stems of the bushes recognizing. However, the accuracy was still high and Google Lens can help to provide the researches even in those cases. Google Lens wasn’t able to analyze the local endemic Ukrainian flora. It has been shown that the recognition efficiency depends more on the resolution of the photo than on the physical characteristics of the camera through which they are made. In the article shown the possibility of using the Google Lens in the educational process is a simple way to include principles of STEM-education and “New Ukrainian school” in classes.

Whiteflies are sap-sucking insects that harbor obligatory symbiotic bacteria to fulfill their dietary needs, as well as a facultative microbial community with diverse bacterial species. The sweetpotato whitefly Bemisia tabaci (Gennadius) is a severe agricultural pest in many parts of the world. This speciesconsists of several biotypes that have been distinguished largely on the basis of biochemical or molecular diagnostics, but whose biological significance is still unclear. The original objectives of the project were (i) to identify the specific complement of prokaryotic endosymbionts associated with select, well-studied, biologically and phylogeographically representative biotypes of B. tabaci, and (ii) to attempt to 'cure’ select biotypes of certain symbionts to permit assessment of the affect of curing on whitefly fitness, gene flow, host plant preference, and virus transmission competency.To identify the diversity of bacterial community associated with a suite of phylogeographically-diverseB. tabaci, a total of 107 populations were screened using general Bacteria primers for the 16S rRNA encoding gene in a PCR. Sequence comparisons with the available databases revealed the presence of bacteria classified in the: Proteobacteria (66%), Firmicutes (25.70%), Actinobacteria (3.7%), Chlamydiae (2.75%) and Bacteroidetes (<1%). Among previously identified bacteria, such as the primary symbiont Portiera aleyrodidarum, and the secondary symbionts Hamiltonella, Cardinium and Wolbachia, a Rickettsia sp. was detected for the first time in this insect family. The distribution, transmission, and localization of the Rickettsia were studied using PCR and fluorescence in situ hybridization (FISH). Rickettsia was found in all 20 Israeli B. tabaci populations screened as well as some populations screened in the Arizona laboratory, but not in all individuals within each population. FISH analysis of B. tabaci eggs, nymphs and adults, revealed a unique concentration of Rickettsia around the gut and follicle cells as well as its random distribution in the haemolymph, but absence from the primary symbiont housing cells, the bacteriocytes. Rickettsia vertical transmission on the one hand and its partial within-population infection on the other suggest a phenotype that is advantageous under certain conditions but may be deleterious enough to prevent fixation under others.To test for the possible involvement of Wolbachia and Cardiniumin the reproductive isolation of different B. tabacibiotypes, reciprocal crosses were preformed among populations of the Cardinium-infected, Wolbachia-infected and uninfected populations. The crosses results demonstrated that phylogeographically divergent B. tabaci are reproductively competent and that cytoplasmic incompatibility inducer-bacteria (Wolbachia and Cardinium) both interfered with, and/or rescued CI induced by one another, effectively facilitating bidirectional female offspring production in the latter scenario.This knowledge has implications to multitrophic interactions, gene flow, speciation, fitness, natural enemy interactions, and possibly, host preference and virus transmission. Although extensive and creative attempts undertaken in both laboratories to cure whiteflies of non-primary symbionts have failed, our finding of naturally uninfected individuals have permitted the establishment of Rickettsia-, Wolbachia- and Cardinium-freeB. tabaci lines, which are been employed to address various biological questions, including determining the role of these bacteria in whitefly host biology.