Botany Commons^™

Understanding Rice Adaptation To Varying Agro-Ecosystems: Trait Interactions And Quantitative Trait Loci, Shalabh Dixit, Alexandre Grondin, Cheng-Ruei Lee, Amelia Henry, Thomas-Mitchell Olds, Arvind Kumar

Department of Agronomy and Horticulture: Faculty Publications

Background: Interaction and genetic control for traits influencing the adaptation of the rice crop to varying environments was studied in a mapping population derived from parents (Moroberekan and Swarna) contrasting for drought tolerance, yield potential, lodging resistance, and adaptation to dry direct seeding. A BC₂F₃-derived mapping population for traits related to these four trait groups was phenotyped to understand the interactions among traits and to map and align QTLs using composite interval mapping (CIM). The study also aimed to identify QTLs for the four trait groups as composite traits using multivariate least square interval mapping (MLSIM) …

Overexpression Of Sbmyb60 Impacts Phenylpropanoid Biosynthesis And Alters Secondary Cell Wall Composition In Sorghum Bicolor, Erin D. Scully, Tammy Gries, Gautam Sarath, Nathan A. Palmer, Lisa Baird, Michelle J. Serapiglia, Bruce S. Dien, Akwasi A. Boateng, Zhengxiang Ge, Deanna L. Funnell-Harris, Paul Twigg, Thomas E. Clemente, Scott E. Sattler

Department of Agronomy and Horticulture: Faculty Publications

The phenylpropanoid biosynthetic pathway that generates lignin subunits represents a significant target for altering the abundance and composition of lignin. The global regulators of phenylpropanoid metabolism may include MYB transcription factors, whose expression levels have been correlated with changes in secondary cell wall composition and the levels of several other aromatic compounds, including anthocyanins and flavonoids. While transcription factors correlated with downregulation of the phenylpropanoid biosynthesis pathway have been identified in several grass species, few transcription factors linked to activation of this pathway have been identified in C4 grasses, some of which are being developed as dedicated bioenergy feedstocks. In …

Aquaporins Contribute To Aba-Triggered Stomatal Closure Through Ost1-Mediated Phosphorylation, Alexandre Grondin, Olivier Rodrigues, Lionel Verdoucq, Sylvain Merlot, Nathalie Leonhardt, Christophe Maurel

Department of Agronomy and Horticulture: Faculty Publications

Stomatal movements in response to environmental stimuli critically control the plant water status. Although these movements are governed by osmotically driven changes in guard cell volume, the role of membrane water channels (aquaporins) has remained hypothetical. Assays in epidermal peels showed that knockout Arabidopsis thaliana plants lacking the Plasma membrane Intrinsic Protein 2;1 (PIP2;1) aquaporin have a defect in stomatal closure, specifically in response to abscisic acid (ABA). ABA induced a 2-fold increase in osmotic water permeability (P_f) of guard cell protoplasts and an accumulation of reactive oxygen species in guard cells, which were both abrogated in …

A Dedicated Type Ii Nadph Dehydrogenase Performs The Penultimate Step In The Biosynthesis Of Vitamin K1 In Synechocystis And Arabidopsis, Abdelhak Fatihi, Scott Latimer, Stefan Schmollinger, Anna Block, Patrick Dussault, Wim F.J. Vermaas, Sabeeha S. Merchant, Gilles J. Basset

Department of Agronomy and Horticulture: Faculty Publications

Mutation of Arabidopsis thaliana NAD(P)H DEHYDROGENASE C1 (NDC1; At5g08740) results in the accumulation of demethylphylloquinone, a late biosynthetic intermediate of vitamin K₁. Gene coexpression and phylogenomics analyses showed that conserved functional associations occur between vitamin K biosynthesis and NDC1 homologs throughout the prokaryotic and eukaryotic lineages. Deletion of Synechocystis ndbB, which encodes for one such homolog, resulted in the same defects as those observed in the cyanobacterial demethylnaphthoquinone methyltransferase knockout. Chemical modeling and assay of purified demethylnaphthoquinone methyltransferase demonstrated that, by virtue of the strong electrophilic nature of S-adenosyl-Lmethionine, the transmethylation of the demethylated precursor …

Proteomic Profiling Of Maize Opaque Endosperm Mutants Reveals Selective Accumulation Of Lysine-Enriched Proteins, Kyla J. Morton, Shangang Jia, Chi Zhang, David R. Holding

Department of Agronomy and Horticulture: Faculty Publications

Reduced prolamin (zein) accumulation and defective endoplasmic reticulum (ER) body formation occurs in maize opaque endosperm mutants opaque2 (o2), floury2 (fl2), defective endosperm*B30 (DeB30), and Mucronate (Mc), whereas other opaque mutants such as opaque1 (o1) and floury1 (fl1) are normal in these regards. This suggests that other factors contribute to kernel texture. A liquid chromatography approach coupled with tandem mass spectrometry (LC-MS/MS) proteomics was used to compare non-zein proteins of nearly isogenic opaque endosperm mutants. In total, 2762 proteins were identified that were enriched for biological processes such as protein transport and folding, amino acid biosynthesis, …

Tonoplast Sugar Transporters (Sbtsts) Putatively Control Sucrose Accumulation In Sweet Sorghum Stems, Saadia Bihmidine, Benjamin T. Julius, Ismail M. Dweikat, David M. Braun

Department of Agronomy and Horticulture: Faculty Publications

Carbohydrates are differentially partitioned in sweet versus grain sorghums. While the latter preferentially accumulate starch in the grain, the former primarily store large amounts of sucrose in the stem. Previous work determined that neither sucrose metabolizing enzymes nor changes in Sucrose transporter (SUT) gene expression accounted for the carbohydrate partitioning differences. Recently, 2 additional classes of sucrose transport proteins, Tonoplast Sugar Transporters (TSTs) and SWEETs, were identified; thus, we examined whether their expression tracked sucrose accumulation in sweet sorghum stems. We determined 2 TSTs were differentially expressed in sweet vs. grain sorghum stems, likely underlying the massive difference in sucrose …

Selection For Silage Yield And Composition Did Not Affect Genomic Diversity Within The Wisconsin Quality Synthetic Maize Population, Aaron Lorenz, Timothy M. Beissinger, Renato Rodrigues Silva, Natalia De Leon

Department of Agronomy and Horticulture: Faculty Publications

Maize silage is forage of high quality and yield, and represents the second most important use of maize in the United States. The Wisconsin Quality Synthetic (WQS) maize population has undergone five cycles of recurrent selection for silage yield and composition, resulting in a genetically improved population. The application of high-density molecular markers allows breeders and geneticists to identify important loci through association analysis and selection mapping, as well as to monitor changes in the distribution of genetic diversity across the genome. The objectives of this study were to identify loci controlling variation for maize silage traits through association analysis …

A Roadmap For Functional Structural Variants In The Soybean Genome, Justin E. Anderson, Michael B. Kantar, Thomas Y. Kono, Fengli Fu, Adrian O. Stec, Qijian Song, Perry B. Cregan, James E. Specht, Brian W. Diers, Steven B. Cannon, Leah K. Mchale, Robert M. Stupar

Department of Agronomy and Horticulture: Faculty Publications

Gene structural variation (SV) has recently emerged as a key genetic mechanism underlying several important phenotypic traits in crop species. We screened a panel of 41 soybean (Glycine max) accessions serving as parents in a soybean nested association mapping population for deletions and duplications in more than 53,000 gene models. Array hybridization and whole genome resequencing methods were used as complementary technologies to identify SV in 1528 genes, or approximately 2.8%, of the soybean gene models. Although SV occurs throughout the genome, SV enrichment was noted in families of biotic defense response genes. Among accessions, SV was nearly eightfold less …

Overexpression Of The Transporters Atzip1 And Atmtp1 In Cassava Changes Zinc Accumulation And Partitioning, Eliana Gaitán-Solis, Nigel J. Taylor, Dimuth Siritunga, William Stevens, Daniel P. Schachtman

Department of Agronomy and Horticulture: Faculty Publications

Zinc deficiency in humans is a serious problem worldwide with an estimated one third of populations at risk for insufficient zinc in diet, which leads to impairment of cognitive abilities and immune system function. The goal of this research was to increase the bioavailable zinc in the edible portion of cassava roots to improve the overall zinc nutrition of populations that rely on cassava as a dietary staple. To increase zinc concentrations, two Arabidopsis thaliana genes coding for ZIP1 and MTP1 were overexpressed with a tuber-specific or constitutive promoter. Eighteen transgenic events from four constructs, out of a total of …

Genetic Control Of Morphometric Diversity In The Maize Shoot Apical Meristem, Samuel Leiboff, Xianran Li, Heng-Cheng Hu, Natalie Todt, Jinliang Yang, Xiao Li, Xiaoqing Yu, Gary J. Muehlbauer, Marja C.P. Timmermans, Jianming Yu, Patrick S. Schnable, Michael J. Scanlon

Department of Agronomy and Horticulture: Faculty Publications

The maize shoot apical meristem (SAM) comprises a small pool of stem cells that generate all above-ground organs. Although mutational studies have identified genetic networks regulating SAM function, little is known about SAM morphological variation in natural populations. Here we report the use of high-throughput image processing to capture rich SAM size variation within a diverse maize inbred panel. We demonstrate correlations between seedling SAM size and agronomically important adult traits such as flowering time, stem size and leaf node number. Combining SAM phenotypes with 1.2 million single nucleotide polymorphisms (SNPs) via genome-wide association study reveals unexpected SAM morphology candidate …

Differential Expression Analysis In Rna-Seq By A Naive Bayes Classifier With Local Normalization, Yongchao Dou, Xiaomei Guo, Lingling Yuan, David R. Holding, Chi Zhang

Department of Agronomy and Horticulture: Faculty Publications

To improve the applicability of RNA-seq technology, a large number of RNA-seq data analysis methods and correction algorithms have been developed. Although these new methods and algorithms have steadily improved transcriptome analysis, greater prediction accuracy is needed to better guide experimental designs with computational results. In this study, a new tool for the identification of differentially expressed genes with RNA-seq data, named GExposer, was developed. This tool introduces a local normalization algorithm to reduce the bias of nonrandomly positioned read depth. The naive Bayes classifier is employed to integrate fold change, transcript length, and GC content to identify differentially expressed …

Soil And Crop Response To Stover Removal From Rainfed And Irrigated Corn, Ian Kenney, Humberto Blanco-Canqui, Deann R. Presley, Charles W. Rice, Keith Janssen, Brian Olson

Department of Agronomy and Horticulture: Faculty Publications

Excessive corn (Zea mays L.) stover removal for biofuel and other uses may adversely impact soil and crop production. We assessed the effects of stover removal at 0, 25, 50, 75, and 100% from continuous corn on water erosion, corn yield, and related soil properties during a 3-year study under irrigated and no-tillage management practice on a Ulysses silt loam at Colby, irrigated and strip till management practice on a Hugoton loam at Hugoton, and rainfed and no-tillage management practice on a Woodson silt loam at Ottawa in Kansas, USA. The slope of each soil was <1%. One year after removal, complete (100%) stover removal resulted in increased losses of sediment by 0.36–0.47 Mg ha-1 at the irrigated sites, but, at the rainfed site, removal at rates as low as 50% resulted in increased sediment loss by 0.30 Mg ha-1 and sediment-associated carbon (C) by 0.29 kg ha-1. Complete stover removal reduced wet aggregate stability of the soil at the irrigated sites in the first year after removal, but, at the rainfed site, wet aggregate stability was reduced in all years. Stover removal at rates ≥ 50%resulted in reduced soil water content, increased soil temperature in summer by 3.5–6.8 °C, and reduced tem-perature in winter by about 0.5 °C. Soil C pool tended to decrease and crop yields tended to increase with an increase in stover removal, but 3 years after removal, differences were not significant. Overall, stover removal at rates ≥50% may enhance grain yield but may increase risks of water erosion and negatively affect soil water and temperature regimes in this region.

First Record On Secondary Pollen Presentation In The Cucurbitaceae Family, Shivani Jadeja

School of Biological Sciences: Faculty Publications

Aim – Secondary pollen presentation in flowers has been described only in a few species across about 25 plant families. The first report of secondary pollen presentation in the Cucurbitaceae family is given here.

Key result – Sechium talamancensis, endemic to high elevations in Costa Rica, presents nearly 39% of its pollen secondarily on the distal ends of its petals. The remaining pollen is presented on the anthers, the primary pollen presenters.

Significance – Closely related and commercially important congeners of S. talamancensis do not show secondary pollen presentation. Potential selective advantages of the phenomenon that differentiates S. talamancensis …

Helmintos Parásitos De Fauna Silvestre En Las Costas De Guerrero, Oaxaca Y Chiapas, México, Griselda Pulido-Flores, Scott Monks, Jorge Falcón-Ordaz, Juan Violante-González

Estudios en Biodiversidad

La costa sureste del Pacífico en México es rica en biodiversidad, en parte por la posición en la intersección de las corrientes oceánicas ecuatoriales. Sin embargo, los helmintos son un grupo de organismos que ha sido poco estudiado en la región y los registros están en diversas fuentes de información. El propósito de este trabajo es juntar todos los registros de las diferentes especies de hemintos en uno solo. Los registros publicados de helmintos parásitos de vertebrados de la zona incluyen 192 especies de Digenea, Monogenea, Cestoda, Acanthocephala, Nematoda e Hirudinea. Los Digenea son los mejor representados con 34 familias …

Revisión Bibliográfica De Algunos Términos Ecológicos Usados En Parasitología, Y Su Aplicación En Estudios De Caso, Christian Elizbeth Bautista-Hernández, Scott Monks, Griselda Pulido-Flores, Amado Erick Rodríguez-Ibarra

Estudios en Biodiversidad

Se realizó una revisión bibliográfica de los términos ecológicos usados en parasitología, de acuerdo con Margolis et al. (1982), Esch et al. (1990), Bush et al. (1997), Bush et al. (2001) y Zander, (2001), que hasta 1982 era un conflicto en parasitología, ya que a que no existían conceptos establecidos para esta área del conocimiento, debido a que esta disciplina se enfocaba principalmente en investigaciones médicas. Aunado a esto, se incurría en conflictos con los conceptos ecológicos como hábitat, sitio, localidad entre otros de igual valor. Con base en lo anterior Margolis et al. (1982) propusieron el desarrollo de nuevos …

Revisión Del Uso De Céstodos Como Indicadores De Contaminación Por Metales Pesados En Mamíferos De Medios Terrestres, Jorge Falcón-Ordaz, Scott Monks, Griselda Pulido-Flores

Estudios en Biodiversidad

En México son pocos los estudios realizados con invertebrados para conocer la concentración de metales pesados en el ambiente, los primeros trabajos fueron realizados con organismos acuáticos. Sin embargo, la necesidad de conocer la contaminación ambiental en medios terrestres ha llevado a los investigadores a utilizar otras herramientas, por ejemplo los helmintos, que se utilizan como bioindicadores de contaminación ambiental basados en su capacidad de absorción, y concentración de contaminantes del medio en su cuerpo. El uso de bioindicadores es ventajoso y económico comparado con el análisis directo de contaminantes por que solo las fracciones que están biológicamente disponibles son …

Nuevos Registros Y Redescripción De Rhabdochona Xiphophori Caspeta-Mandujano, Moravec Y Salgado- Maldonado, 2001 (Nematoda: Rhabdochonidae) En El Estado De Hidalgo, México, Jorge Falcón-Ordaz, Scott Monks, Griselda Pulido-Flores, Christian Elizbeth Bautista-Hernández, Sarahi Hernández-Hernández

Estudios en Biodiversidad

Teniendo en cuenta la diversidad de los ecosistemas acuáticos en México y la infinita riqueza de especies de peces en el país, la lista actual de nemátodos parásitos de peces de agua dulce en México está incompleta. Hasta la fecha en México el género Rhabdochona se encuentra registrado como parásito en una amplia gama de familias de peces de agua dulce. El objetivo del presente trabajo es redescribir ejemplares de Rhabdochona xiphophori parásita de Xiphophorus malinche colectados de dos localidades del estado de Hidalgo y compararlos morfológicamente.

Importancia De Las Aves Ictiófagas Como Hospederos Finales De Helmintos, En Dos Lagunas Costeras Del Estado De Guerrero, México, Juan Violante-González, Griselda Pulido-Flores, Scott Monks, Agustín A. Rojas-Herrera, Miguel A. Melo-García, Sergio García-Ibáñez, Edgar León Esparza-Ibarra, Edvino Larumbe-Morán, Jonatan Carbajal-Violante

Estudios en Biodiversidad

Se examinó la composición y riqueza de comunidades de helmintos en tres especies de aves ictiófagas: Ardea alba, Nyctanassa violacea y Phalacrocorax brasilianus en dos lagunas costeras del estado de Guerrero, México. La helmintofauna estuvo constituida por 23 especies: 17 digéneos, un acantocéfalo, dos céstodos y tres nemátodos. Cinco especies (Ascocotyle longa, Mehrastomum minutum, Riberoia ondatrae, Southwellina hispida y Contracaecum multipapillatum) co-ocurrieron en las tres especies de aves de ambas lagunas. Los niveles de infección de un 50% de las especies identificadas, variaron significativamente entre las especies de aves y lagunas. A nivel componente, la riqueza de especies varió significativamente …

Evaluación De Las Infracomunidades De Tres Especies De Peces En Dos Localidades De La Huasteca Hidalguense, Christian Elizbeth Bautista-Hernández, Scott Monks, Griselda Pulido-Flores

Estudios en Biodiversidad

Uno de los problemas más severos y menos controlados en México es el gran número de especies introducidas en las cuencas del país, hecho que pone en peligro la existencia de muchas de las especies endémicas. Además, las especies introducidas pueden transportar sus parásitos, que con frecuencia afectan a las poblaciones de especies endémicas. Anteriormente se realizó un estudio de las comunidades de parásitos de tres especies de peces, dos endémicas y una exótica (Xiphophorus birchmanni, Pseudoxiphophorus bimaculata y Amatitlania nigrofasciata). En ese trabajo se realizó el análisis de éstas comunidades evaluándolas a nivel infracomunidad, además se calculó la caracterización …

Parasitofauna De Peces De Lagunas Costeras Del Estado De Guerrero, México, Juan Violante-González, Griselda Pulido-Flores, Scott Monks, Agustín A. Rojas-Herrera, Jaime Salvador Gil-Guerrero, Sergio García-Ibáñez, Jonatan Carbajal-Violante

Estudios en Biodiversidad

No obstante que los parásitos representan un porcentaje muy importante de la biodiversidad global a nivel mundial, en muchas ocasiones son excluidos de estudios con este enfoque, debido principalmente a que han sido considerados durante muchos años, como simples agentes causantes de enfermedad. A partir de los datos obtenidos de varios estudios parasitológicos de peces y aves, efectuados en algunas lagunas costeras del estado de Guerrero a lo largo de varios años, se presenta un análisis global de la riqueza de la parasitofauna de peces, en estos altamente productivos y complejos sistemas acuáticos. La parasitofauna total estuvo constituida por 66 …