Identifying Lepidopteran resistance within hcf mutants

Abstract only availableSouthwestern corn borer (SWCB) and fall armyworm (FAW) feeding on maize causes extensive crop damage in the United States. Previous proteomic analysis comparing resistant and susceptible lines of maize indicates genes found in the photosystem II pathway are highly expressed in the resistant line. The high chlorophyll fluorescence (hcf) mutants have defects in photosystem I or photosystem II genes. A preference test was performed comparing hcf mutants to their wild-type siblings. Oy, pg, and g mutants were also compared to their wild-type siblings to ensure that color was not a factor in feeding differences. SWCB preferred the wild-type over hcf11-N1205A and hcf49-N1480 mutants, indicating these genes may be resistance factors. Oy1-Andrew and hcf13-N1097B mutants were preferred by SWCB compared to their wild-type siblings, indicating these genes increase susceptibility to feeding damage. hcf49-N1480, hcf7-N1029D, and pg15-N340B had reduced FAW damage compared to wild-type siblings, indicating they may increase resistance to feeding damage. hcf44-N1278B showed increased susceptibility to FAW feeding compared to its wild-type sibling. An antibiosis test was performed using hcf mutants. Photographs and larval weights were taken at the end of the four days. Tissue damage areas were analyzed using AlphaEaseFC software. From the data, hcf7-N1029D and hcf50-N1481 had reduced larval weights for both FAW and SWCB indicating these genes have antibiotic properties and can reduce larval feeding damage. The mutants evaluated for effects of pigmentation displayed varying results indicating color differences associated with some hcf mutants are unlikely to be responsible for the differences in feeding behavior observed. These genes identified here may be useful in increasing resistance to FAW and SWCB in commercial hybrids.MU Monsanto Undergraduate Research Fellowshi

Identifying Lepidopteran resistance within hcf mutants

Abstract only availableSouthwestern corn borer (SWBC) and fall armyworm (FAW) feeding on maize causes extensive crop damage in the United States. Total crop loss is valued at approximately 300 million dollars annually. Previous proteomic analysis comparing resistant and susceptible lines of maize has shown genes found in the photosystem II pathway are highly expressed in the resistant line. The high chlorophyll fluorescence mutants have defects in photosystem I or photosystem II genes. Preliminary feeding trials indicate hcf mutants have resistance to Lepidopteran feeding. A preference test was performed comparing hcf mutants to their wild-type siblings. Oy , pg , and g mutants were also compared to their wild-type siblings to ensure that the pigmentation was not a factor in insect resistance. Leaf tissue from both the hcf mutant and the wild-type plant were pinned to a piece of moist filter paper within a petri dish. A single SWCB or FAW was placed in between the two samples and allowed to choose which tissue sample it preferred. There were five replicates per genotype. Pictures were taken after four days and tissue damage area was assessed using AlphaEaseFC software. A few hcf mutants showed increased resistance to feeding than their wild-type siblings, while most hcf mutants did not. SWCB preferred the wild-type over hcf11-N1205A and hcf49-N1480 mutants, indicating these genes may be resistance factors. Some hcf mutants were preferred by SWCB, indicating they may represent susceptibility genes. These genotypes were Oyl-Andrew and hcf13-N1097B . hcf49-N1480 , hcf7-N1029D , and pg15-N340B had reduced FAW damage compared to wild-type siblings, indicating they may confer resistance. The genotype hcf44-N1278B showed increased susceptibility to FAW feeding compared to its wild-type sibling. Further analysis will be needed to examine the resistance capabilities of the hcf11-N1205A , hcf7-1029D , pg15-N340B , and hcf49-N1480 genotypes. The mutants evaluated for effects of pigmentation displayed varying results indicating color differences associated with some hcf mutants are unlikely to be responsible for the differences observed. This experiment has provided data showing that some hcf mutants confer resistance to insect feeding. These genes may be useful in increasing resistance to FAW and SWCB in commercial hybrids.Life Sciences Mission Enhancement Progra

Lepidopteran preference test of Glossy mutants and Glossy15 allels for maize resistance [abstract]

Abstract only availableFaculty Mentor: Georgia Davis, AgronomyEvery year fall armyworm and Southwestern corn borer cause severe yield loss in maize. Both fall armyworm and the Southwestern corn borer are known to specifically attack the whorl leaf tissue resulting in major crop losses. Over the past few years maize resistant lines have been developed. In our study we have compared the larval feeding habits of both insects on resistant and susceptible genotypes, and on maize mutants that affect epicuticular wax formation. A previous study has shown that the Glossy15 and Glossy8 genes have Lepidopteran resistance in maize during the whorl stage. Our objectives in this study are to analyze both fall armyworm and Southwestern corn borer feeding preferences on various glossy mutants, and to further examine thier feeding habits on different alleles of the Glossy15 gene. In both studies we compared feeding preferences on three inbreds ( Mp705, Oh28, and Va35 ) to the glossy mutants. Mp705 has resistance to whorl stage Lepidopteran feeding while Oh28 and Va35 are susceptible. An inbred adult leaf was placed directly next to a glossy mutant adult leaf in a Petri dish. We then placed a single larva between the two adult leaves. We evaluated the larvae preference by using the AlphaEaseFC software. With this software we measured the areas of damaged leaf tissue. In the first study we have concluded that the adult leaves of bm1 , Gl1 , gl2-PF , Gl3 , Gl7 , Gl14 , and gl15-Sprague are very susceptible to insect feeding. There was no preference for adult leaves of bm4 , Gl4 , Gl11 , gl3-N531 , gl13-U440B , Gl18 , gl18-N166A , and Gl21 . However, we have found that Gl8 , gl15-KEW , and gl15-LAM exhibit some resistance. We also examined insect preference on different allels of Glossy15 gene. We observed allelic differences; gl15-63 and gl15-L are susceptible to insect feeding, while gl15-S , gl15-H , gl15-956 , and gl15-94317 have no preference. The goal of this study is to determine which mutants and alleles are more resistant than the others. The resistant alleles can then be inserted into different maize lines to improve resistance to Lepidopteran insects

Quantitative trait loci for seminal root angle and number in the maize IBM population

Abstract only availableIn maize, seminal roots develop and the primary root system deteriorates as the plant matures. The seminal roots comprise the majority of the root system of the adult plant and give the plant stability against lodging. Because seminal roots are the primary means of water uptake in the adult plant, their development under drought conditions is vital. Previous research has suggested that seminal root angle and abscisic acid (ABA) level are correlated in maize. Additional research has shown that ABA levels are related to drought tolerance. This study focuses on identifying quantitative trait loci (QTL) that affect seminal root angle and the number of seminal roots entering the soil from each node. The QTL generated for seminal root angle and number per node can then be used to evaluate the relationship with drought tolerance. A set of 94 mapping lines from the intermated B73 x Mo17 (IBM) mapping population was used to measure the angle between the seminal root and the stalk. The number of seminal roots entering the soil from the first two nodes was measured as well. Molecular markers evenly distributed throughout the genome were used to run the QTL analysis using QTL Cartographer Version 1.16. The following QTL analyses were run: seminal root angle, number of roots entering soil from the first node above ground, and number of roots entering soil from the second node. Three QTL were found for seminal root angle, two QTL for the number of roots at the first node above ground, and three QTL for the number of roots at the second node above ground. These QTL positions were then compared to previously known QTL for drought tolerance and root traits.Plant Genomics Internship @ M

The ramosa1 gene plays a role in shoot-borne root patterning in Zea mays L.

Abstract only availableMaize brace roots are the aerial portion of the shoot-borne root system that facilitates physical anchorage and water and nutrient acquisition. Shoot-borne roots develop from axillary meristems. Axillary meristems can also give rise to leaves and tillers and are important in inflorescence development. Evidence is accumulating that similar genes are involved in at least the early stages of axillary meristems development regardless of meristems fate. According to a previous quantitative loci mapping study on brace roots architecture the ramosa1 gene is a positional candidate for controlling brace root variation. ramosa1 (ra1) affects the development of maize tassels by suppressing tassel branching and promoting spikelet pair formation. Mutations in the ra1 results in a greater number of tassel branches that grow increasingly shorter near the apex of the tassel. A correlation analysis between tassel traits and root traits was performed using 25 diverse maize lines. The results show a significant and positive correlation between various brace roots traits and tassel branch length, a trait controlled by ra1. Further more, a comparison of ramosa1 mutant to wild-type plants revealed statistically significant differences in root phenotypes with the ra1 mutants producing fewer brace roots at a node and fewer nodes with brace roots. This suggest that ra1 is part of both the inflorescence and shoot-borne root development programs Mutations in ra1 appear to have opposite effects on maize brace roots relative to tassels indicating that the role of ra1 may differ depending developmental phase. This research was supported by the NSF UMEB Program, Life Science Mission Enhancement, and USDA ARS.NSF Undergraduate Mentoring in Environmental Biolog

Influence of miRNA on brace root patterning in Zea mays L.

Abstract only availableBrace roots reduce lodging by providing support and represent the majority of the root system in adult plants. Previous quantitative trait locus mapping results showed that Teopod1 (Tp1), Teopod2 (Tp2), and Corngrass1 (Cg1), all mapped in chromosome regions which influence brace root patterning. Tp1 and Tp2 are semi-dominant mutants and Cg1 is a dominant mutant that result in delayed-phase-change and overlap between the juvenile and reproductive phases. Gibberellic acid (GA) promotes phase change and exogenous GA alters Tp1 and Tp2 phenotype . Prior analysis of GA mutants in our laboratory and others indicates that GA affects brace root patterning. We performed a means comparison between Tp1 and Tp2 and their wild-type siblings and identified significant differences in brace roots traits, specifically, mutants exhibited more nodes with brace roots and more brace roots at a node than their wild-type counterparts. Cg1 encode a member of the miR156 family which is known to target squamosa promoter-binding (SPB)-like proteins. Tp1 and Tp2 have also been suggested to encode members of the miR156 family. To further validate the role of miRNA156 in brace root patterning, we performed association analysis with available sequence from the parents of the nested association mapping (NAM) population and brace root trait data. Preliminary analysis supports the involvement of miRNA156 family members in brace root patterning. Additional sequencing of miRNA156 in a larger group of maize lines is underway to provide a more robust dataset for association analysis.Missouri Academy at Northwest Missouri State Universit

Modeling the relationship between light perception traits and brace root development in Zea mays L. [abstract]

Abstract only availableMaize (Zea mays L.) brace roots are responsible for physical stability in the soil and for water and nutrient acquisition in maize. The objective of this project is to investigate how traits related to light perception affect brace root development. Previous work has shown that light perception affects total root development and that reduced lighting conditions cause a decline in all root growth, even more drastically than in the rest of the plant (Y. Hébert, E. Guingo, and O. Loudet, 2001). Trait data for 98 diverse lines were collected primarily from 2004 to 2005 for traits related to light perception and maturity. Correlation analysis and multiple regression analysis were performed to produce models that identify traits significantly affecting brace root development and their interactions. Our model shows that in 2005, light perception traits were not as significant as in 2004 indicating that the effect of light perception on brace root number may be environmentally dependent. This could be because the much hotter temperatures in 2005 caused the light perception mechanism to be saturated masking the interaction, whereas in 2004, the temperate environment caused the expression of the light perception and brace root interaction. The experimental model will then be validated using data collected on the identified traits from 25 diverse lines grown in the field

Traits associated with brace root characters implicate light and hormonal signaling pathways [abstract]

Abstract only availableMaize brace roots provide the plant with access to water and nutrients in the soil, increase stability, and improve lodging resistance. The goal of this study is to connect brace root traits to traits linked to developmental and hormonal pathways, and light perception by multiple regression and correlation analysis. Two replications of twenty-seven diverse lines of maize were planted and measured for light perception traits, maturity and phase transition traits, in the summer of 2007. Forward selection and backwards elimination multiple regression and correlation analysis were performed in SAS. A significance threshold of 0.05 for entry or elimination was used in the multiple regression analysis. Model R-squared values had a range of 0.47 to 0.64. The variables significant for the number of nodes with brace roots and the number of brace roots at node one were related to the growth hormone gibberellic acid (GA) such as average internode length and juvenile and transition leaf number. Soil node diameter and ear height were also linked to root traits and are under the genetic control of the light response regulators phytochromes B1 and B2. A proposed model showing how GA and light perception affect plant development is reported. This research was funded by the Undergraduate Mentoring in Environmental Biology and The Life Science Mission Enhancement programs.NSF Undergraduate Mentoring in Environmental Biology; The Life Science Mission Enhancement Progra

One health research in Northern Tanzania – challenges and progress

East Africa has one of the world’s fastest growing human populations—many of whom are dependent on livestock—as well as some of the world’s largest wildlife populations. Humans, livestock, and wildlife often interact closely, intimately linking human, animal, and environmental health. The concept of One Health captures this interconnectedness, including the social structures and beliefs driving interactions between species and their environments. East African policymakers and researchers are recognising and encouraging One Health research, with both groups increasingly playing a leading role in this subject area. One Health research requires interaction between scientists from different disciplines, such as the biological and social sciences and human and veterinary medicine. Different disciplines draw on norms, methodologies, and terminologies that have evolved within their respective institutions and that may be distinct from or in conflict with one another. These differences impact interdisciplinary research, both around theoretical and methodological approaches and during project operationalisation. We present experiential knowledge gained from numerous ongoing projects in northern Tanzania, including those dealing with bacterial zoonoses associated with febrile illness, foodborne disease, and anthrax. We use the examples to illustrate differences between and within social and biological sciences and between industrialised and traditional societies, for example, with regard to consenting procedures or the ethical treatment of animals. We describe challenges encountered in ethical approval processes, consenting procedures, and field and laboratory logistics and offer suggestions for improvement. While considerable investment of time in sensitisation, communication, and collaboration is needed to overcome interdisciplinary challenges inherent in One Health research, this can yield great rewards in paving the way for successful implementation of One Health projects. Furthermore, continued investment in African institutions and scientists will strengthen the role of East Africa as a world leader in One Health research

Afferent thermosensory function in relapsing-remitting multiple sclerosis following exercise-induced increases in body temperature

In multiple sclerosis (MS), increases in body temperature result in transient worsening of clinical symptoms (heat-sensitivity/Uhthoff's phenomenon). While the impact of heat-sensitivity on efferent physiological function has been investigated, the effects of heat stress on afferent sensory function in MS are unknown. Hence, we quantified afferent thermosensory function in MS following exercise-induced increases in body temperature with a novel quantitative sensory test. Eight relapsing-remitting MS patients (3M/5F; 51.4 ± 9.1 y; EDSS score: 2.8 ± 1.1) and 8 age-matched controls (CTR; 5M/3F; 47.4 ± 9.1 y) rated perceived magnitude of two cold (26; 22°C) and warm (34; 38°C) stimuli applied to the dorsum of the hand, pre and post 30-min cycling in the heat (30°C air; 30% RH). Exercise produced similar increases in mean body temperature in MS (+0.39°C [95%CI: +0.21, +0.53] P = 0.001) and CTR (+0.41°C [95%CI: +0.25, +0.58] P = 0.001). These changes were sufficient to significantly decrease thermosensitivity to all cold (26°C stimulus: -9.1% [95%CI: -17.0, -1.5], P = 0.006; 22°C stimulus: -10.6% [95%CI: -17.3, -3.7], P = 0.027), but not warm, stimuli in MS. Contrariwise, CTR showed sensitivity reductions to colder stimuli only (22°C stimulus: -9.7% [95%CI: -16.4, -3.1], P = 0.011). The observation that reductions in thermal-sensitivity in MS were confined to the myelinated cold-sensitive pathway, and extended across a wider (including milder/colder) temperature range than what is observed in CTR, provides novel evidence on the impact of rising body temperature on afferent neural function in MS. Also, our findings support the use of our novel approach to investigate afferent sensory function in MS during heat stress. This article is protected by copyright. All rights reserved