Plant Biology Commons^™

Cytotoxic And Antimicrobial Activities Of The Constituents Of Ten Plant Species From Tanzania, Joan J. E. Munissi

Tanzania Journal of Science

This paper reports on the antimicrobial and cytotoxicity activities of crude extracts from the plant species Clemaptosis scabiosifolia (Ranunculaceae), Diospyros mafiensis (Ebenaceae), Dolichos kilimandscharicus (Leguminosae), Gnidia kraussiana (Thymelaeaceae), Hugonia castaneifolia (Linaceae), Neorautanenia mitis (Pappilionaceae), Tagetes minuta (Asteraceae), Uvaria acuminata (Annonaceae), Vernonia amygdalina (Asteraceae) and Zanha africana (Sapindaceae). All crude extracts were screened for their cytotoxicities in the brine shrimp lethality test (BST). Fractions and pure compounds from Hugonia castaneifolia, Diospyros mafiensis and Uvaria acuminata were tested for their cytotoxicity and antimicrobial activities against ten microorganisms, namely Candida albicans, Bacillus anthracis, Escherichia coli, Klebsiela pneumoniae, Proteus sp., Pseudomonas aeruginosa, Salmonella typhimurium, …

Plant Diet Selectivity And Some Environmental Parameters At Foraging Sites Of Wattled Crane (Bugeranuscarunculatus) In Malagarasi Wetlands, Tanzania, Jasson R.M. John

Tanzania Journal of Science

Wattled Crane Bugeranuscarunculatusis a threatened wetland-dependent bird species of sub-Saharan Africa with a declining population throughout its range due to habitat degradation. Ecological studies on this species have come from large populations in Botswana and Zambia. Little is known of the isolated small populations, especially those in Tanzania where about 200individuals survive. This study reports observations made on vegetation height, water depth and consumption of plant tubers at foraging locations of the Wattled Crane in Malagarasi-MuyovoziRamsar Site. Foraging birds preferred wet habitats with short vegetation. Birds fed mainly on Pycreusnitidus and Cyperusarticulatusplant tubersbut not those of Eleocharis, a chief food …

Strategies To Overcome Antagonism Of Quizalofop-P-Ethyl When Applied In Mixture With Other Herbicides, Lucas C. Webster

LSU Master's Theses

A field study was conducted in 2017 and 2018 at the LSU Agricultural Center H. Rouse Caffey Rice Research Station (RRS) near Crowley, LA. to evaluate the influence of different adjuvants in overcoming the antagonism of quizalofop when mixed with bispyribac in Louisiana rice production. The antagonism of quizalofop mixed with bispyribac plus HCOC at 14 DAIT was overcome with a neutral interaction observed at 28 DAIT for barnyardgrass control with an observed control of 91%, compared with an expected control of 97%. The addition of COC, SNS or HCOC into a mixture of quizalofop plus bispyribac provided synergistic or …

The Tripartite Interaction Between Arbuscular Mycorrhizal Fungi, Rice, And Insects, Lina Bernaola Alvarado

LSU Doctoral Dissertations

Losses caused by pests remain an important limitation to achieving high rice yields in the United States. Arbuscular mycorrhizal fungi (AM fungi) are able to modify plant physiology by increasing plant growth or inducing defense responses against insect herbivores. However, studies of the role of AM fungi in agroecological factors, including natural occurrence, plant resistance, soil dependency, and plant tolerance, with specific regards to pests that feed on rice plants have not been conducted before. A three-year study revealed natural occurring colonization by AM fungi on rice roots sampled in four rice-producing areas in the southern United States. Overall, rice-AM …

Development Of A Nitrogen Recommendation Tool For Corn Considering Static And Dynamic Variables, Laila A. Puntel, Agustin Pagani, Sotirios V. Archontoulis

Department of Agronomy and Horticulture: Faculty Publications

Many soil and weather variables can affect the economical optimum nitrogen (N) rate (EONR) for maize. We classified 54 potential factors as dynamic (change rapidly over time, e.g. soil water) and static (change slowly over time, e.g. soil organic matter) and explored their relative importance on EONR and yield prediction by analyzing a dataset with 51 N trials from Central-West region of Argentina. Across trials, the average EONR was 113 ± 83 kg N ha⁻¹ and the average optimum yield was 12.3 ± 2.2 Mg ha⁻¹, which is roughly 50% higher than the current N rates used …

A Stimulatory Role For Cytokinin In The Arbuscular Mycorrhizal Symbiosis Of Pea, Dane M. Goh, Marco Cosme, Anna B. Kislala, Samantha Mulholland, Zakaria M.F. Said, Lukáš Spíchal, R.J. Neil Emery, Stéphane Declerck, Frédérique C. Guinel

Biology Faculty Publications

The arbuscular mycorrhizal (AM) symbiosis between terrestrial plants and AM fungi is regulated by plant hormones. For most of these, a role has been clearly assigned in this mutualistic interaction; however, there are still contradictory reports for cytokinin (CK). Here, pea plants, the wild type (WT) cv. Sparkle and its mutant E151 (Pssym15), were inoculated with the AM fungus Rhizophagus irregularis. E151 has previously been characterized as possessing high CK levels in non-mycorrhizal (myc^-) roots and exhibiting high number of fungal structures in mycorrhizal (myc⁺) roots. Myc^- and myc⁺ plants were …

Mitotic Recombination And Rapid Genome Evolution In The Invasive Forest Pathogen Phytophthora Ramorum, Angela L. Dale, Nicolas Feau, Sydney E. Everhart, Braham Dhillon, Barbara Wong, Julie Sheppard, Guillaume J. Bilodeau, Avneet Brar, Javier F. Tabima, Danyu Shen, Clive M. Brasier, Brett M. Tyler, Niklaus J. Grünwald, Richard C. Hamelin

Department of Plant Pathology: Faculty Publications

Invasive alien species often have reduced genetic diversity and must adapt to new environments. Given the success of many invasions, this is sometimes called the genetic paradox of invasion. Phytophthora ramorum is invasive, limited to asexual reproduction within four lineages, and presumed clonal. It is responsible for sudden oak death in the United States, sudden larch death in Europe, and ramorum blight in North America and Europe. We sequenced the genomes of 107 isolates to determine how this pathogen can overcome the invasion paradox. Mitotic recombination (MR) associated with transposons and low gene density has generated runs of homozygosity (ROH) …

Using Drones For Precision Agriculture, Jiyul Chang, Madhav P. Nepal

iLEARN Teaching Resources

In this teaching module, students will learn what Precision Agriculture is and how to apply drone into Precision Agriculture practices. To use data (images) taken by drone, students will learn the basic theory of Remote Sensing. Using images, students learn how to make NDVI (Normalized Difference Vegetation Index) maps and how to apply drone (remote sensing technique) in agriculture.

Arabinose Substitution Effect On Xylan Rigidity And Self-Aggregation, Utsab Shrestha, Sydney Smith, Sai Venkatesh Pingali, Hui Yang, Mai Zahran, Llyod Breunig, Liza Wilson, Daniel Cosgrove, Hugh O'Neill, Loukas Petridis

Publications and Research

Substituted xylans play an important role in the structure and mechanics of the primary cell wall of plants. Arabinoxylans (AX) consist of a xylose backbone substituted with arabinose, while glucuronoarabinoxylans (GAX) also contain glucuronic acid substitutions and ferulic acid esters on some of the arabinoses. We provide a molecular-level description on the dependence of xylan conformational, selfaggregation properties and binding to cellulose on the degree of arabinose substitution. Molecular dynamics simulations reveal fully solubilized xylans with a low degree of arabinose substitution (lsAX) to be stiffer than their highly substituted (hsAX) counterparts. Small-angle neutron scattering experiments indicate that both wild-type …

Seasonal Origins Of Soil Water Used By Trees, Scott T. Allen, James W. Kirchner, Sabine Braun, Rolf T. W. Siegwolf, Gregory R. Goldsmith

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Rain recharges soil water storages and either percolates downward into aquifers and streams or is returned to the atmosphere through evapotranspiration. Although it is commonly assumed that summer rainfall recharges plant-available water during the growing season, the seasonal origins of water used by plants have not been systematically explored. We characterize the seasonal origins of waters in soils and trees by comparing their midsummer isotopic signatures (δ2H) to seasonal isotopic cycles in precipitation, using a new seasonal origin index. Across 182 Swiss forest sites, xylem water isotopic signatures show that summer rain was not the predominant water source …

Phylogenetic And Biogeographic Controls Of Plant Nighttime Stomatal Conductance, Kailiang Yu, Gregory R. Goldsmith, Yujie Wang, William R. L. Anderegg

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The widely documented phenomenon of nighttime stomatal conductance (g_sn) could lead to substantial water loss with no carbon gain, and thus it remains unclear whether nighttime stomatal conductance confers a functional advantage. Given that studies of g_sn have focused on controlled environments or small numbers of species in natural environments, a broad phylogenetic and biogeographic context could provide insights into potential adaptive benefits of g_sn.

We measured g_sn on a diverse suite of species (n = 73) across various functional groups and climates‐of‐origin in a common garden to study the phylogenetic and biogeographic/climatic controls …

Extending The Osmometer Method For Assessing Drought Tolerance In Herbaceous Species, Robert J. Griffin-Nolan, Troy W. Ocheltree, Kevin E. Mueller, Dana M. Blumenthal, Julie A. Kray, Alan K. Knapp

Biological, Geological, and Environmental Faculty Publications

Community-scale surveys of plant drought tolerance are essential for understanding semi-arid ecosystems and community responses to climate change. Thus, there is a need for an accurate and rapid methodology for assessing drought tolerance strategies across plant functional types. The osmometer method for predicting leaf osmotic potential at full turgor ((o)), a key metric of leaf-level drought tolerance, has resulted in a 50-fold increase in the measurement speed of this trait; however, the applicability of this method has only been tested in woody species and crops. Here, we assess the osmometer method for use in herbaceous grassland species and test whether …

Transcriptomic Response Is More Sensitive To Water Deficit In Shoots Than Roots Of Vitis Riparia (Michx.), Vedbar Singh Khada, Kimberly Vaughn, Juan Xie, Padmapriya Swaminathan, Qin Ma, Grant Cramer, Anne Y. Fennell Dr

Agronomy, Horticulture and Plant Science Faculty Publications

Background: Drought is an important constraint on grapevine sustainability. Vitis riparia, widely used in rootstock and scion breeding, has been studied in isolated leaf drying response studies; however, it is essential to identify key root and shoot water deficit signaling traits in intact plants. This information will aid improved scion and rootstock selection and management practices in grapevine. RNAseq data were generated from V. riparia roots and shoots under water deficit and well-watered conditions to determine root signaling and shoot responses to water deficit.
Results: Shoot elongation, photosynthetic rate, and stomatal conductance were significantly reduced in water deficit (WD) treated …

Distribution And Population Structure Of The Invasive Nitellopsis Obtusa (Desv. In Loisel.) J. Groves And Native Species Of Characeae In The Northeast U.S.A., Robin Sleith

Dissertations, Theses, and Capstone Projects

Freshwater ecosystems are some of the most biologically diverse environments on Earth. Billions of humans rely on functioning freshwater ecosystems for drinking water and many other services. These ecosystems are increasingly threatened by human impacts including nutrient pollution, invasive species, and climate change. Here I contribute four research chapters that investigate freshwater diversity and ecosystem threats using the Characeae, a family of freshwater green macroalgae, as a study system. Characeae are a diverse and ancient group with more than 500 extant species and a fossil history spanning at least 250 million years. These algae are macrophytes in freshwater ecosystems, and …

Refernment: An R Package For Annotating Rna Editing In Plastid Genomes, Tanner A. Robison, Paul G. Wolf

Biology Faculty Publications

PREMISE OF THE STUDY: In the absence of cDNA, the annotation of RNA editing in plastomes must be done manually, representing a significant time cost to those studying the organellar genomes of ferns and hornworts.

METHODS AND RESULTS: We developed an R package to automatically annotate apparent nonsense mutations in plastid genomes. The software successfully annotates such sites and results in no false positives for data with no sequencing or assembly errors.

CONCLUSIONS: Compared to manual annotation, ReFernment offers greater speed and accuracy for annotating RNA editing sites. This software should be especially useful for researchers generating large numbers of …

An Albino Mutant In Brassica Rapa Maps To The Pdx2 Locus On Chromosome 10, Beatriz M. Garcia

STAR Program Research Presentations

We have identified an albino mutant in the plant Brassica rapa. This recessive mutation could provide insights into the photosynthetic pathways of all plants. Previously the mutation was mapped to chromosome 10 of Brassica rapa. To narrow down the chromosomal region containing the albino mutation, we grew a segregating population of plants. DNA was extracted from albino and wildtype (green) plants and genotyped using PCR markers on chromosome 10. The genotype detected using the INDEL2 marker perfectly predicted whether a plant was albino or WT. This indicates that the INDEL2 marker is tightly linked to the albino mutation. INDEL2 is …

Response Surface Analysis Of Genomic Prediction Accuracy Values Using Quality Control Covariates In Soybean, Diego Jarquin, Reka Howard, George L. Graef, Aaron Lorenz

Department of Agronomy and Horticulture: Faculty Publications

An important and broadly used tool for selection purposes and to increase yield and genetic gain in plant breeding programs is genomic prediction (GP). Genomic prediction is a technique where molecular marker information and phenotypic data are used to predict the phenotype (eg, yield) of individuals for which only marker data are available. Higher prediction accuracy can be achieved not only by using efficient models but also by using quality molecular marker and phenotypic data. The steps of a typical quality control (QC) of marker data include the elimination of markers with certain level of minor allele frequency (MAF) and …

Identification Of Climate And Genetic Factors That Control Fat Content And Fatty Acid Composition Of Theobroma Cacao L. Beans, Guiliana M. Mustiga, Joe Morrissey, Joseph Conrad Stack, Ashley Duval, Stefan Royaert, Johannes Jansen, Carolina Bizzotto, Cristiano Villela-Dias, Linkai Mei, Edgar B. Cahoon, Ed Seguine, Jean Philippe Marelli, Juan Carlos Motamayor

Center for Plant Science Innovation: Faculty Publications

The main ingredients of chocolate are usually cocoa powder, cocoa butter, and sugar. Both the powder and the butter are extracted from the beans of the cacao tree (Theobroma cacao L.). The cocoa butter represents the fat in the beans and possesses a unique fatty acid profile that results in chocolate’s characteristic texture and mouthfeel. Here, we used a linkage mapping population and phenotypic data of 3,292 samples from 420 progeny which led to the identification of 27 quantitative trait loci (QTLs) for fatty acid composition and six QTLs for fat content. Progeny showed extensive variation in fat levels …

Drought-Responsive Genes, Late Embryogenesis Abundant Group3 (Lea3) And Vicinal Oxygen Chelate, Function In Lipid Accumulation In Brassica Napus And Arabidopsis Mainly Via Enhancing Photosynthetic Efficiency And Reducing Ros, Yu Liang, Kai Kang, Lu Gan, Shaobo Ning, Jinye Xiong, Shuyao Song, Lingzhi Xi, Senying Lai, Yongtai Yin, Jianwei Gu, Jun Xiang, Shisheng Li, Baoshan Wang, Maoteng Li

Center for Plant Science Innovation: Faculty Publications

Drought is an abiotic stress that affects plant growth, and lipids are the main economic factor in the agricultural production of oil crops. However, the molecular mechanisms of drought response function in lipid metabolism remain little known. In this study, overexpression (OE) of different copies of the drought response genes LEA3 and VOC enhanced both drought tolerance and oil content in Brassica napus and Arabidopsis. Meanwhile, seed size, membrane stability and seed weight were also improved in OE lines. In contrast, oil content and drought tolerance were decreased in the AtLEA3 mutant (atlea3) and AtVOC-RNAi of Arabidopsis and in both …

Fad2 Gene Radiation And Positive Selection Contributed To Polyacetylene Metabolism Evolution In Campanulids1[Open], Tao Feng, Ya Yang, Lucas Busta, Edgar B. Cahoon, Hengchang Wang, Shiyou Lü

Center for Plant Science Innovation: Faculty Publications

Polyacetylenes (PAs) are bioactive, specialized plant defense compounds produced by some species in the eudicot clade campanulids. Early steps of PA biosynthesis are catalyzed by Fatty Acid Desaturase 2 (FAD2). Canonical FAD2s catalyze desaturation, but divergent forms can catalyze hydroxylation, conjugation, acetylenation, and epoxygenation. These alternate reactions give rise to valuable unusual fatty acids, including the precursors to PAs. The extreme functional diversity of FAD2 enzymes and the origin of PA biosynthesis are poorly understood from an evolutionary perspective. We focus here on the evolution of the FAD2 gene family. We uncovered a core eudicot-wide gene duplication event giving rise …