Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 8 of 8

Full-Text Articles in Life Sciences

Suberin Biosynthesis And Deposition In The Wound-Healing Potato (Solanum Tuberosum L.) Tuber Model, Kathlyn Natalie Woolfson Dec 2018

Suberin Biosynthesis And Deposition In The Wound-Healing Potato (Solanum Tuberosum L.) Tuber Model, Kathlyn Natalie Woolfson

Electronic Thesis and Dissertation Repository

Suberin is a heteropolymer comprising a cell wall-bound poly(phenolic) domain (SPPD) covalently linked to a poly(aliphatic) domain (SPAD) that is deposited between the cell wall and plasma membrane. Potato tuber skin contains suberin to protect against water loss and microbial infection. Wounding triggers suberin biosynthesis in usually non-suberized tuber parenchyma, providing a model system to study suberin production. Spatial and temporal coordination of SPPD and SPAD-related metabolism are required for suberization, as the former is produced soon after wounding, and the latter is synthesized later into wound-healing. Many steps involved in suberin biosynthesis remain uncharacterized, and the mechanism(s) that regulate …


Investigating The Role Of Brachypodium Distachyon Cellulose Synthase 8 In Gluconacetobacter Diazotrophicus Colonization, Xuan Yang Dec 2018

Investigating The Role Of Brachypodium Distachyon Cellulose Synthase 8 In Gluconacetobacter Diazotrophicus Colonization, Xuan Yang

Electronic Thesis and Dissertation Repository

Nitrogen is an essential nutrient for plant growth. Significant amount of nitrogen fertilizer is applied to crop field to maintain high yield. Alternatives to chemical nitrogen fertilizer are needed to reduce the costs of crop production and offset environmental damage. Gluconacetobacter diazotrophicus is a nitrogen fixing bacterium that was originally isolated from sugarcane and has been proposed as a possible biofertilizer for monocot crop production. However, the colonization of G. diazotrophicus in most monocot crops is limited and deep understanding of the response of the host plants to G. diazotrophicus colonization is still lacking. In this study, research was conducted …


Characterization Of The Coat Protein Of Turnip Mosaic Virus And Its Arabidopsis Interactors In The Virus Infection Process, Zhaoji Dai Nov 2018

Characterization Of The Coat Protein Of Turnip Mosaic Virus And Its Arabidopsis Interactors In The Virus Infection Process, Zhaoji Dai

Electronic Thesis and Dissertation Repository

Viruses are infectious and obligate intracellular parasites. Turnip mosaic virus (TuMV) is a member of the genus Potyvirus which comprises many agriculturally important viral pathogens that threaten crop production. Potyviruses are fully dependent on the host cellular machinery to fulfil their infection cycle in plant hosts. It is well accepted that viral coat protein (CP) is a multifunctional protein that plays key roles in virus propagation and host-virus interactions. This dissertation project aimed to investigate the role of CP in TuMV cell-to-cell movement, to identify the host interactors of TuMV CP, and further to characterize their roles in TuMV infection. …


Phylogeny, Heat-Stress And Enzymatic Heat-Sensitivity In The Antarctic Psychrophile, Chlamydomonas Sp. Uwo 241, Marc Possmayer Sep 2018

Phylogeny, Heat-Stress And Enzymatic Heat-Sensitivity In The Antarctic Psychrophile, Chlamydomonas Sp. Uwo 241, Marc Possmayer

Electronic Thesis and Dissertation Repository

Psychrophilic species, micro-organisms which are unable to grow at temperatures of or above 20°C, are abundant in perennially cold ecosystems across the globe. Intensifying scientific investigation of these organisms from ecological to molecular scales has underscored the ability of life on Earth to adapt to environments which seem inhospitable due to high or low temperatures, high salinity, pressure and light, and ultra-low nutrient availability. Psychrophilic organisms that are also photosynthetic represent a much more limited group than psychrophiles generally, as their habitats must be well buffered against the warming influence of the infra-red energy accompanying sunlight. Photosynthetic psychrophiles face the …


Plant Stimuli-Responsive Biodegradable Polymers For The Use In Timed Release Fertilizer Coatings, Spencer Heuchan Aug 2018

Plant Stimuli-Responsive Biodegradable Polymers For The Use In Timed Release Fertilizer Coatings, Spencer Heuchan

Electronic Thesis and Dissertation Repository

The use of nitrogen-based fertilizers continues to accelerate with human population growth and increases in global food requirements. Enhanced efficiency fertilizers (EEFs) have been developed to improve the synchronization between nutrient supply and crop nutrient demand. However, many of the current controlled release fertilizers are coated with non-degradable polymers that contribute to accumulation of microplastics within ecosystems. This thesis describes research towards the development of a new class of fertilizer coatings using a self-immolative polymer known as poly (ethyl glyoxylate) (PEtG). PEtG itself does not have suitable properties to produce a viable coating but once blended with another degradable polyester …


Defective Aba-Mediated Sugar Signalling Pathway In An Established Arabidopsis Thaliana Cell Suspension Culture Explains Its Stay-Green Phenotype At High Sugar Concentrations, Avery Mccarthy Jun 2018

Defective Aba-Mediated Sugar Signalling Pathway In An Established Arabidopsis Thaliana Cell Suspension Culture Explains Its Stay-Green Phenotype At High Sugar Concentrations, Avery Mccarthy

Electronic Thesis and Dissertation Repository

An unusual sugar insensitive phenotype was identified in an established cell suspension culture of Arabidopsis thaliana. We characterized the physiology, biochemistry and genetics of the sugar insensitive cell culture, in order to identify factors contributing to the phenotype. Chlorophyll levels of the cell suspension culture were insensitive to high sucrose (6-15% w/v) and maintained a green phenotype. Immunoblotting indicated that levels of key photosynthetic proteins (PsaA, Lhcb2 and Rubisco) increased as a function of external sucrose concentration. The green cell culture was photosynthetically competent based on light-dependent, CO2-saturated rates of O2 evolution as well as Fv/Fm …


Evaluating Plant Root Uptake Of Dsrna For Application In Pest Management, Kaitlyn Ludba Jun 2018

Evaluating Plant Root Uptake Of Dsrna For Application In Pest Management, Kaitlyn Ludba

Electronic Thesis and Dissertation Repository

The greenhouse whitefly Trialeurodes vaporariorum is an agricultural pest that damages crops by feeding on plant sap and by vectoring plant viruses. Control of whiteflies has been managed through application of insecticides, but this strategy is not entirely effective and alternative control strategies are needed. In this thesis, I evaluated the efficacy of RNA interference as a means to control whiteflies on greenhouse-grown tomatoes. I found that root uptake of dsRNA synthesized from the v-ATPase subunit A gene caused significant gene knock-down and mortality in feeding whiteflies. This effect was, however, sensitive to the concentration of dsRNA delivery, and concentration …


Effects Of Elevated Temperature, Elevated Co2 And Photoperiod On Conifer Carbon Fluxes, Joseph R. Stinziano Apr 2018

Effects Of Elevated Temperature, Elevated Co2 And Photoperiod On Conifer Carbon Fluxes, Joseph R. Stinziano

Electronic Thesis and Dissertation Repository

Increasing temperatures due to rising atmospheric CO2 concentrations will have direct effects on plant physiology, specifically photosynthetic carbon uptake. Changes in photosynthetic carbon uptake will alter feedbacks between vegetation and atmospheric CO2, and changes in forest carbon dynamics will be important in determining whether vegetation amplifies or attenuates the effects of anthropogenic CO2 emissions on climate. Coniferous trees, which are a large component of the boreal forest, are understudied in relation to thermal acclimation of photosynthesis and temperature effects on growth. In the present work, I assess the impact of rising temperatures on carbon fluxes in …