Plant Biology Commons^™

Heterologous Minor Coat Proteins Of Citrus Tristeza Virus Strains Affect Encapsidation, But The Coexpression Of Hsp70h And P61 Restores Encapsidation To Wild-Type Levels, Satyanarayana Tatineni, Siddarame Gowda, William O. Dawson

Department of Plant Pathology: Faculty Publications

The long flexuous bipolar virions of Citrus tristeza virus (CTV), a Closterovirus, are encapsidated with two capsid proteins at opposite ends: the minor coat protein (CPm) encapsidates the 5′ 630 nts of the genomic RNA and the major coat protein encapsidates the remainder of the genome. In this study, we found encapsidation of CTV CPm in the absence of other assembly-related proteins is highly specific in contrast to most plant viruses that allow virion assembly by a range of heterologous coat proteins. Heterologous CPms with 95–96% amino acid identity from related strains in CTV-CPm, a replicon with CPm as …

Soil And Root Populations Of Fluorescent Pseudomonas Spp. Associated With Seedlings And Field-Grown Plants Are Affected By Sorghum Genotype, Deanna L. Funnell-Harris, Jeffrey F. Pedersen, Scott E. Sattler

Department of Plant Pathology: Faculty Publications

Sorghum [Sorghum bicolor (L.) Moench] is valued for bioenergy, feed and food. Potential of sorghum genotypes to support differing populations of root- and soil-associated fluorescent Pseudomonas spp. or Fusarium spp., in two soils, was assessed. Culturable pseudomonads were enumerated from roots and soil of sorghum (Redlan and RTx433) and wheat (Lewjain) seedlings repeatedly grown in cycled soils in the growth chamber. Pseudomonads and Fusarium spp. were assessed from roots and soil of field-grown sorghum along with biological control traits hydrogen cyanide (HCN) and 2,4-diacetylphlorogluconol (phl) production. After four 4-week cycles, soil associated with Redlan seedlings had greater numbers …

Brown Midrib Mutations And Their Importance To The Utilization Of Maize, Sorghum, And Pearl Millet Lignocellulosic Tissues, Scott E. Sattler, Deanna L. Funnell-Harris, Jeffrey F. Pedersen

Department of Plant Pathology: Faculty Publications

Brown midrib mutants have been isolated in maize (Zea mays), sorghum (Sorghum bicolor) and pearl millet (Pennisetum glaucum) arising by either spontaneous or chemical mutagenesis. The characteristic brown coloration of the leaf mid veins is associated with reduced lignin content and altered lignin composition, traits useful to improve forage digestibility for livestock. Brown midrib phenotype is correlated with two homologous loci in maize (bm1 and bm3) and sorghum (bmr6 and bmr12), which encode cinnamyl alcohol dehydrogenase (CAD) and a caffeic O-methyl transferase (COMT). These enzymes are involved in the last …

Upper Canopy Collection And Identification Of Grapevines (Vitis) From Selected Forests In The Southeastern United States, Sydney E. Everhart

Department of Plant Pathology: Faculty Publications

Woody grapevines (Vitis spp.) are common in the deciduous forests of the southeastern United States. Their growth habit makes leaf collection challenging and polymorphic leaves make identification of species difficult. Mature grapevines can grow up to 48 cm in diameter at breast height and reach the upper canopy of trees more than 35 m in height. Leaf morphology is the most readily available character used for species identification. However, most mature grapevines do not produce leaves below the upper canopy and if they do, these leaves are morphologically indistinguishable from other species. In order to sample leaves from …

Regulation Of Septum Formation By The Bud3–Rho4 Gtpase Module In Aspergillus Nidulans, Haoyu Si, Daniela Justa-Schuch, Stephan Seiler, Steven D. Harris

Department of Plant Pathology: Faculty Publications

The ability of fungi to generate polarized cells with a variety of shapes likely reflects precise temporal and spatial control over the formation of polarity axes. The bud site selection system of Saccharomyces cerevisiae represents the best-understood example of such a morphogenetic regulatory system. However, the extent to which this system is conserved in the highly polarized filamentous fungi remains unknown. Here, we describe the functional characterization and localization of the Aspergillus nidulans homolog of the axial bud site marker Bud3. Our results show that AnBud3 is not required for polarized hyphal growth per se, but is involved in septum …

An In Vitro Method For The Analysis Of Infection-Related Morphogenesis In Fusarium Graminearum, William R. Rittenour, Steven D. Harris

Department of Plant Pathology: Faculty Publications

Fusarium graminearum is a significant pathogen of many cereal crops. With its genetic tractability, ease of culture, genome sequence availability and economic significance, F. graminearum has become the subject of intensive molecular research. Although molecular tools have been developed to enhance research into virulence determinants of F. graminearum, simple assays for infection-related development are lacking. As such, the objective of this study was to develop an in vitro protocol for the analysis of infection-related morphogenesis in F. graminearum. We demonstrate that two morphologically distinct hyphal structures are produced by F. graminearum during the invasion of detached wheat glumes: subcuticular hyphae …

Global Assessment Of Nitrogen Deposition Effects On Terrestrial Plant Diversity : A Synthesis, R. Bobbink, K. Hicks, J. Galloway, T. Spranger, R. Alkemade, M. Ashmore, M. Bustamante, S. Cinderby, E. Davidson, F. Dentener, B. Emmett, J. W. Erisman, M. Fenn, Frank S. Gilliam, A. Nordin, L. Pardo, W. Devries

Biological Sciences Faculty Research

Atmospheric nitrogen (N) deposition is a recognized threat to plant diversity in temperate and northern parts of Europe and North America. This paper assesses evidence from field experiments for N deposition effects and thresholds for terrestrial plant diversity protection across a latitudinal range of main categories of ecosystems, from arctic and boreal systems to tropical forests. Current thinking on the mechanisms of N deposition effects on plant diversity, the global distribution of G200 ecoregions, and current and future (2030) estimates of atmospheric N-deposition rates are then used to identify the risks to plant diversity in all major ecosystem types now …

The Role Of Taabf1 In Abscisic Acid-Mediated Suppression Of 𝒶-Amylase Gene Expression In Cereal Grains, Lauren J. Harris

Honors Theses

The phytohormones gibberellin (GA) and abscisic acid (ABA) regulate important developments events in germinating seeds. Specifically, GA induces the expression of hyrolase genes, like the α-amylase gene Amy32b, which mobilizes starch reserves to be used by the embryo, and ABA suppresses this induction. Recent advancements identified ABA and GA receptors and key components in the signaling pathways, however, the mechanism of crosstalk between the hormones remains largely unknown. To further elucidate the mechanism of ABA suppression of GA-induced genes, we focused on the transcription factor TaABF1, a member of the ABA response element binding factor family. TaABF1 has been shown …

Comparison Between In Vitro And In Vivo Antibacterial Activity Of Curcuma Zedoaria From Malaysia., Behrooz Banisalam

Student Works (2010-2019)

The rhizomes of the Zingiberaceae family are vegetables widely used in many Asian countries and their medicinal functions have been broadly discussed and accepted in many traditional recipes. In this study, the antimicrobial activity of extracts of Curcuma zedoaria from Malaysia was compared between two systems as in vitro and in vivo. The comparison was performed against four bacterial strains including two gram negative strains (E.coli and Pseudomonas aeruginosa) and two gram positive strains (Bacillus cereus and Staphylococcus aureus) using the agar well diffusion method. Extracts were made in three different solvents; petroleum ether, chloroform and methanol extracts exhibited antibacterial …

Development Of Protocols For Tissue Culture And Mutagenesis In Two Variegated Sansevieria Sp., Irmawati Akma Abdul Hapiz

Student Works (2010-2019)

Studies were conducted to develop the tissue culture protocol and mutagenesis through Gamma ray irradiation for two variegated Sansevieria species known as Sansevieria trifasciata var. Laurentii (goldband Sansevieria) and Sansevieria trifasciata var. Hahnii (birdnest Sansevieria). Seven combinations of BAP and NAA were chosen which are represented by letter A= 1.00 mg/I BAP, B = 1.00 mg/I BAP + 0.25 mg/I NAA, C = 2.00 mg/I BAP + 0.50 mg/I NAA, D = 2.00 mg/I BAP + 1.00 mg/I NAA, E = 3.00 mg/I BAP + 1.00 mg/I NAA, F = 4.00 mg/I BAP + 1.00 mg/I NAA and G = …

Structural And Functional Divergence Of A 1-Mb Duplicated Region In The Soybean (Glycine Max) Genome And Comparison To An Orthologous Region From Phaseolus Vulgaris, Jer-Young Lin, Robert M. Stupar, Christian Hans, D. L. Hyten, Scott A. Jackson

Department of Agronomy and Horticulture: Faculty Publications

Soybean (Glycine max) has undergone at least two rounds of polyploidization, resulting in a paleopolyploid genome that is a mosaic of homoeologous regions. To determine the structural and functional impact of these duplications, we sequenced two ~1-Mb homoeologous regions of soybean, Gm8 and Gm15, derived from the most recent ~13 million year duplication event and the orthologous region from common bean (Phaseolus vulgaris), Pv5. We observed inversions leading to major structural variation and a bias between the two chromosome segments as Gm15 experienced more gene movement (gene retention rate of 81% in Gm15 versus 91% in …

The Wheat Bzip Factor, Taabf1, Mediates Aba-Induced Gene Expression In Bombarded Barley Aleurone Layers, Benjamin R. Keyser

Honors Theses

The plant hormone Abscisic acid (ABA) plays a central role in maturation and germination in seeds, as well as mediating adaptive responses to abiotic environmental stresses. ABA induces the expression of many genes, including late-embryogenesis-abundant genes such as HVA1. To elucidate the ABA signaling pathway leading to HVA1 expression, we focus on the bZIP factor TaABF1. Analysis of the interplay between ABA and TaABF1 in the aleurone cells of imbibing cereal grains indicated that the two are not additive in their induction of the HVA1 promoter. A synthetic ABA analog, PBI-51, did not specifically inhibit the effect of exogenous ABA …

Functional Analysis Of B And C Class Floral Organ Genes In Spinach Demonstrates Their Role In Sexual Dimorphism, D Noah Sather, Maja Jovanovic, Edward M. Golenberg

Wayne State University Associated BioMed Central Scholarship

Abstract

Background

Evolution of unisexual flowers entails one of the most extreme changes in plant development. Cultivated spinach, Spinacia oleracea L., is uniquely suited for the study of unisexual flower development as it is dioecious and it achieves unisexually by the absence of organ development, rather than by organ abortion or suppression. Male staminate flowers lack fourth whorl primordia and female pistillate flowers lack third whorl primordia. Based on theoretical considerations, early inflorescence or floral organ identity genes would likely be directly involved in sex-determination in those species in which organ initiation rather than organ maturation is regulated. In this …

Molecular Studies Of 5-Azacytidine-Induced Early-Flowering Lines Of Flax, Megan A. House

Theses and Dissertations (Comprehensive)

Several early-flowering flax (Linum usitatissimum L.) lines were derived from treatment of germinating seeds with 5-azacytidine in 1990. These lines are also shorter, have fewer leaves, and their DNA is hypomethylated, relative to their corresponding controls. The work presented in this thesis used early-flowering and control lines of the Royal (R) flax genotype, and the Large (L) flax genotroph. Firstly, levels of cytosine methylation were measured over a 24-hour period in the early-flowering line RE2 and its control (RC), using an HPLC method. Secondly, to determine the response of the flax lines to short-day conditions, control and early-flowering …

Don't Judge A Book By Its Cover: The Curious Case Of Wild Ginger Pollination, W. John Hayden

Biology Faculty Publications

What pollinates wild ginger? This seems like an easy question. The inconspicuous little flowers are held close to the forest floor, often completely hidden by a dense canopy of ginger leaves above. Flower color is rather drab, dominated by brown and maroon hues. Wind pollination seems completely unlikely and flowers pollinated by bees, butterflies, moths, or hummingbirds are always much more showy and accessible to these flying creatures. Flies, however, given their natural inclination to seek carrion as a food source for their babies (i.e. maggots), are often attracted to brown and maroon flowers. And because their actual quarry, animal …

Morphogenesis And Tissue Culture Studies Of Gerbera Jamesonii Bolus Ex. Hook F., Nor Azlina Hasbullah

Student Works (2010-2019)

In vitro regeneration of Gerbera jamesonii Bolus ex. Hook f. was successfully carried out in this study. Petiole and leaf explants from 8-week-old aseptic seedlings were used as source of explants. Different response was observed when different explants were cultured on the culture media. MS (Murashige and Skoog, 1962) supplemented with 2.0 mg/l BAP and 0.5 mg/l NAA was identified as the optimum medium for shoot regeneration, while petiole explant was identified as the most responsive explant in this study. Petiole explants regenerated shoots (94.3 } 2.5 %) and produced 9.3 } 0.6 shoots per explant. MS basal medium was …

Studies Of Antioxidant And Angiotensin Converting Enzyme Inhibitory Activity Of Orthosiphon Stamineus (Misai Kucing)., Che Wan Imanina Che Wan Takwa

Student Works (2010-2019)

Abstract NA

Physiological And Biochemical Attributes Of Red-Fleshed Dragon Fruit, Hylocereus Polyrhizus., Punitha R. Vasanthan

Student Works (2010-2019)

An understanding of the postharvest parameters is essential for the successful market introduction of red-fleshed dragon fruit, Hylocereus polyrhizus, which has been recently developed as fruit crop. In this study, fruit at three different harvest maturities were evaluated in terms of physiological and biochemical aspects. Fruit which were harvested at complete red stage maintained their quality for up to one week. On the other hand, fruit harvested at early maturity attained the physical properties of fruit ripened on the plant (firmness reduced, peel colour changes, pH increased) but they contained noticeably lower concentrations of soluble sugars suggesting that fruit can …

Marine Algae As A Source Of Photosensitisers For Photodynamic Therapy Of Cancer., Tang Yee Voon

Student Works (2010-2019)

Photodynamic therapy (PDT) involves the intravenous administration of a photosensitiser that preferentially localises in cancerous tissues more than the surrounding normal tissues. Subsequent illumination of photosensitiser generates reactive oxygen species that cause irreversible photo-damage to the cancer cells. To date, most photosensitisers that have been approved for clinical use or are currently in clinical trials are cyclic tetrapyrroles which are derived or inspired by naturally occurring chlorophyll and its degradation products. Some non-tetrapyrrolic photosensitisers have also been found in nature suggesting that there are potential photosensitisers with interesting structures in nature. To this end, this thesis outlines the collection of …

Molecular Characterization And Expression Analysis Of Putative Rpk1 And Putative Clv1 In Malaysian Indica Rice (Oryza Sativa L.) Cv.Mr219 And Malaysian Wild Rice (Oryza Rufipogon) Irgc105491., Law Yee Song

Student Works (2010-2019)

Two candidate yield-related genes, putative Receptor-like Protein Kinase 1 (putative RPK1) and putative CLAVATA1 Receptor Kinase (putative CLV1), were selected for molecular characterization and expression analysis. This was carried out using in four rice lines comprising the parents and two BC₂F₇ lines from a local rice breeding program, with Malaysian rice variety, Oryza sativa ssp. indica cv. MR219 as recurrent parent, and Oryza rufipogon (IRGC105491) as donor parent. Approximately 2.8 kb and 2.6 kb putative RPK1 cDNA nucleotide sequences were obtained from Oryza rufipogon and Oryza sativa ssp. indica cv. MR219 respectively. However, only 402 …