Chitosanase may enhance anti-fungal defense responses in transgenic tobacco

Chitosanase is an enzyme, similar to chitinase, capable of hydrolyzing the β-1,4-linkages between N-acetyl-D-glucosamine and D-glucosamine residues in partially acetylated chitosan polymers found in fungal cell walls. When attacked by pathogenic fungi, many plants exploit this hydrolytic action as a component of a larger post-attack defense response, but these enzymes may also play a role in the initial plant-pathogen interaction via the generation of elicitors resulting from the hydrolysis of fungal cell walls. To gain insight into these mechanisms, a Paenbacillus chitosanase was cloned, sequenced, and modified for plant expression. The modified gene was delivered to tobacco (Nicotiana tabacum L. cv. Xanthine) leaf disks via Agrobacterium tumenfaciensmediated transformation. Whole plants were regenerated from the transformed cells. The putative transformants were tested for transgene integration, transcription, and translation. Confirmed transformants were then screened for enhanced responses to a Rhizoctonia solani cellwall preparation by measuring time-course production of hydrogen peroxide, phenylalanine ammonia lyase, and peroxidase. These compounds play roles at different points in a pathogenesis-related signal transduction pathway and thus allow for an initial assessment of the global defense response. Preliminary data suggest that transgenic tobacco constitutively expressing a Paenbacillus chitosanase may activate pathogenesis-related defense responses more quickly than wild type tobacco

Chitosanase May Enhance Anti-Fungal Defense Responses in Transgenic Tobacco

Fungicides are expensive, dangerous, and can be harmful to the environment, but they are often necessary for profitable farming operations. New technologies may soon allow farmers to replace these chemicals with genetically engineered plants producing antifungal enzymes that degrade fungal cell walls. To explore this option, a Paenbacillus chitosanase gene was cloned, sequenced, and modified for plant expression. The modified gene was delivered to tobacco (Nicotiana tabacum L cv. Xanthine) leaf disks via Agrobacterium tumenfaciens-mediated transformation. The putative GMOs were tested for transgene integration, transcription, and translation. Confirmed transformants were then screened for enhanced responses to a Rhizoctonia solani cell wall preparation by measuring time-course production of hydrogen peroxide, phenyalanine ammonia lyase, and peroxidase. These compounds play roles at different points in a pathogensis-related signal transduction pathway and, thus, allow for an initial assessment of the global defense response. Preliminary data suggest that transgenic tobacco constitutively expressing a Paenbacillus chitosanase may activate pathogenesis-related defense responses more quickly than wild type tobacco

Energy spectrum of turbulent fluctuations in boundary driven reduced magnetohydrodynamics

The nonlinear dynamics of a bundle of magnetic flux ropes driven by stationary fluid motions at their endpoints is studied, by performing numerical simulations of the magnetohydrodynamic (MHD) equations. The development of MHD turbulence is shown, where the system reaches a state that is characterized by the ratio between the Alfven time (the time for incompressible MHD waves to travel along the field lines) and the convective time scale of the driving motions. This ratio of time scales determines the energy spectra and the relaxation toward different regimes ranging from weak to strong turbulence. A connection is made with phenomenological theories for the energy spectra in MHD turbulence.Comment: Published in Physics of Plasma

Experiment Checkout During Postmanufacturing Checkout of the Apollo Telescope Mount

The postmanufacturing checkout of the Apollo Telescope Mount (ATM) offers a real challenge for both the technology of today and the technology of tomorrow. The objective of this discussion is to explain the sequence of tests to be performed on t he ATM experiments to assure flight readiness, based on current preliminary planning information. Checkout means the verification of all operating systems. The challenge is to define tests today to check out experiments that will be built and flown tomorrow. The engineering state-ofthe art is identified today for a vehicle, including the experiments, that is scheduled to fly in 1972

Energy Options for Future Humans on Titan

We review the possibilities for in situ energy resources on Titan for use by future humans, including chemical, nuclear, wind, solar, geothermal and hydropower. All of these options, with the possible exception of geothermal, represent effective sources of power. Combustion of methane (after electrolysis of the native water), in combination with another source of power such as nuclear, is a viable option; another chemical source of energy is the hydrogenation of acetylene. The large seas Kraken and Ligeia potentially represent effective sources of hydropower. Wind power, particularly at altitudes ~40 km, is expected to be productive. Despite the distance from the sun and the absorbing atmosphere, solar power is (as on Earth) an extremely efficient source of power on Titan

Application of Fall Nitrogen Increased Spring Tall Fescue Yield

Late season nitrogen fertilization is a practice that has long been implemented in turfgrass production. This practice involves applying nitrogen from September through December and results in an extended green period in the fall without stimulating excessive shoot growth. The longer green period results in higher levels of carbohydrate reserves and enhanced root growth compared with a spring-summer fertilization program. In addition to these benefits, sods fertilized in late fall have been shown to green up two to six weeks earlier in the spring. Limited research has considered the impact of late fall nitrogen applications on grass growth in hayfields and pastures. The objective of this study was to evaluate the impact of late fall nitrogen fertilization on dry matter production of an established tall fescue stand. In 2020 and 2021, the study was conducted at the UK Research and Extension Center located in Princeton, KY. The experimental design was a random complete block with four replications. In early December 2020 and 2021, 0, 34, 67, and 101 kg ha-1 was applied as ammonium nitrate, ammonium sulfate, and Anuvia SYMTRX 20S. An additional 90 kg ha-1 was applied as urea to all plots the following spring. Plots were harvested on 13-May-2021 and 24-May-2022 using a self-propelled sickle bar type forage harvester equipped with load cells. Averaged across sources, first harvest yields ranged from 3428 to 5675 and 3929 to 5831 kg ha-1 in 2021 and 2022, respectively. Fall applied nitrogen resulted in a linear increase in dry matter yield of 25.0 and 21.2 kg ha-1 in 2021 and 2022, respectively. Nitrogen sources had no impact on dry matter yield (P \u3e 0.05). Plots receiving fall applied nitrogen also initiated growth earlier in the spring

Graduate Teaching Assistant Training: Preparing Instructors to Assist ESL Students in the Introductory Public Speaking Course

Much research identifies the need to assist English as a Second Language (ESL) students in our classrooms. Some communication educators have addressed this need by enrolling students in special sections of introductory courses for ESL students only. With a focus specifically on graduate teaching assistant (GTA) training, this paper suggests ways to assist ESL students, along with native speaking students, enrolled in regular sections of the introductory public speaking course. We first identify steps for assessing whether an ESL student is appropriately enrolled in a course. We then focus on ways instructors can assist ESL students with: 1) pronunciation, comprehensibility, and listening, 2) thinking rhetorically, and 3) delivery skills

On computational procedures for Value Iteration in inventory control

Dynamic programming (DP) is often seen in inventory control to lead to optimal ordering policies. When considering stationary demand, Value Iteration (VI) may be used to derive the best policy. In this paper, our focus is on the computational procedures to implement VI. Practical implementation requires bounding carefully the state space and demand in an adequate way. We illustrate with small cases the challenge of the implementation. We also show that handling service level constraints is not straightforward from a DP point of view. Moreover, when taking the age distribution into account for perishable products, the curse of dimensionality provides an additional challenge.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech. Proyecto nacional RTI2018-09599