Nature and Organization of Polygenic Control of a Metric Trait: Seeds serve Nitrogen Fixation in Blue-Green Algae (Cyanobacteria). Nitrogenase is the Investigation on the Role of Zinc in the Human Diet. Investigators at Virginia Polytechnic Institute and State University have provided new insights into the human need for zinc and the hazards of inadequate zinc intake. Administration of therapeutic levels of steroids to rats has been found to cause shifts in cellular zinc, leading to depletion in some tissues and accumulation in others. Interactions have also been discovered between sugarregulating hormones and tissue zinc. In another study, lack of dietary zinc has been found to increase the body's requirement for vitamin E. This may be especially important in explaining the role of zinc in pregnancy and childbirth. Clinical studies with zinc at Tulane University and the Universities of Colorado and California have provided further support for the possibility that dietary zinc may be submarginal in certain population groups (e.g., children and pregnant women). Photosynthetic Adaptation of Desert Annuals to Temperature and Light. Many areas of the Southwest are too dry or too hot for production of agricultural crops, but some native plant species thrive there. An investigator at the Carnegie Institution in California is studying how these plants adapt to extreme environments. A new technique has been developed for measuring photosynthesis of plants growing in their native habitat. These species have also been studied under controlled conditions in the lab. Some of the arid land plants are extraordinarily efficient during the short period when conditions are relatively favorable for growth. Other species adapt to high temperature by changing the optimum temperature for photosynthesis. The change involved a change in the lipids of the membranes and the rate at which key biochemical reactions occur. Specificity of Plant-Microbe Interactions. A primary goal in plant pathology is to understand the molecular interaction between the pathogen, a cause of disease, and the host. A scientist at Utah State University is studying the interaction between beans and Pseudomonas bacteria. While one species of Pseudomonas has evolved to be pathogenic on beans, others lack this ability and exist as organisms living on dead or decaying organic matter. This research has investigated the defense mechanisms plants use to limit the spread and development of avirulent or non-pathogenic strains of Pseudomonas. Research has focused on the concept that plant cell walls produce substances that trap and immobilize avirulent bacteria in a matrix. These substances, or agglutinins as they are called, are produced as a result of recognition of the bacteria by the plant. The structure of agglutinins and their relation to normal wall components is an area of active study. Components of bacterial cell walls play a key role in determining whether or not the bacterium is pathogenic or avirulent. The compounds responsible for pathogenicity are under investigation and their structure and function is also an area of study. The research will provide information on the molecular events that govern the specificity of interaction of beans with pseudomonads and will indicate generalities in the mechanisms by which plants defend themselves from microbial challenges. Sequencing Nitrogenase Genes from Rhizobium Meliloti and Klebsiella Pneumoniae. Nitrogenase is the enzyme which catalyzes the conversion of molecular nitrogen to ammonia in nitrogen-fixing bacteria with the subsequent production of amino acids that the host plant requires. A Harvard geneticist has developed a method for accurately determining the location of mutations on the chromosomal fragment which contains the genes for the structure of nitrogenase. This method has been used to construct a detailed physical map of the nitrogen fixation gene cluster of the bacterium, Klebsiella pneumoniae. Comparisons are now being made between the nucleotide sequences of the structural genes for nitrogenase from this bacterium with that from one involved in symbiotic relationship with alfalfa. Various genetic manipulations that can be made using this method would make it possible to 1) determine the amino acid sequences of the two different components of nitrogenase, 2) study the mechanism of action of this important enzyme by construction mutants with lesions at specific amino acids and 3) locate regions on the gene that are involved in enzyme control. Carnitine Content of Foods Consumed in the United States. Carnitine is an absolute requirement for production of energy from fat. Although the infant's diet contains a large number of fat calories the infant does not appear to have a fully developed capability for synthesizing carnitine. The major source of carnitine for the infant is in the mother's milk. Investigators at Vanderbilt University have shown that the infant fed a soy protein formula or maintained on intravenous feeding receives no carnitine, although many calories are supplied as fat. Since it has also been shown that carnitine is extremely low in a vegetarian diet one must consider the possibility that the breast milk of vegetarian mothers may have depressed carnitine content. When infants have inadequate tissue carnitine, they frequently suffer from severe hypoglycemia. Cloning of Photosynthetic Genes in a Blue-Green Alga. A long-sought goal of plant researchers is to produce more efficient crop plants. New techniques for manipulating genes, "genetic engineering", have raised the possibility that genes for photosy thesis could be isolated, mutated, and inserted back into plant cells. A project at the University of Missouri is concerned with this possibility. The investigator has discovered that a blue-green alga contains small pieces of DNA called plasmids. Genes for certain reactions of photosynthesis can be inserted into the plasmid and as the algal cell grows, the plasmid carrying the desired gene will be reproduced. The technique now being developed, will be useful for cloning genes from crop plants and for development of a gene bank of desired characteristics. Pheromones/Kairomones of Scale Insect Pests. Studies are underway to collect and identify the sex pheromone of a number of pest scale species such as the San Jose scale, walnut scale, citrus snow scale, and Florida red scale. Insects were cultured in the laboratory and a greenhouse bioassay (biological test) established. Airborne collections from female scales on host material were obtained and pheromones purified by chromatography. After bioassay of fractions the active compounds were identified by chemical and physical methods. The mating pheromone components of San Jose scale were identified. These components have been used in a number of field studies to monitor the population dynamics of this pest species. Mating pheromones have also been identified for California red scale and yellow scale. Work is currently underway at Cornell University for Florida red scale and obscure mealy bug. The synthetic attractants are used to develop potent and specific monitoring traps for the abundance of individual species. They are useful in pest management programs that depend upon sensitive monitoring information. RURAL DEVELOPMENT RESEARCH Under Title V of the Rural Development Act of 1972, funds have been allocated to the 50 States and Puerto Rico, and to the four regional rural development centers to "...provide research and investigation in all fields that have as their purpose the development of useful knowledge and information to assist those planning, carrying out, managing, or investing in facilities, services, businesses, or other enterprises, public and private, that may contribute to rural development." The following is a description of current activities and selected examples of accomplishments from these appropriated funds: Current activities: Annual Plans of Work are developed jointly by Agricultural Experiment Stations and Extension to meet specific local or State needs, and are approved by a broadly based State Rural Development Advisory Council and by the Secretary of Agriculture. The program is administered by the Land-Grant Institutions of 1862 and involves 1890 Land-Grant Institutions and other public and private colleges and universities. Increasing the capacity of colleges and universities to perform the public service roles of research, transfer and application of knowledge in rural development is an important objective of Title V. In the past year, approximately 65 research and 110 research/extension projects have been conducted under this program. A wide range of topics has been explored, such as the enhancement of the capacities of local agencies and community-based organizations, the improvement of low and moderate income housing, the protection of the environment, and the improvement of opportunities for families with small farms. Selected examples of recent progress: Determining Community Development Priorities. Scientists in Wisconsin have Successfully established a model for determining development priorities in a community; for determining the type and level of consensus existing between citizens, elected officials and community leaders; and for improving communication and agreement on priorities. Survey methodologies have been tested and improved as one of the tools used in this project. A how-to-do-it handbook on "community needs assessment techniques" is anticipated for distribution to community agencies and leaders. Efficient Delivery of Public Services. Researchers in Mississippi have developed computerized budgets for various levels of services and sizes of communities. Budgets have been completed for rural health clinics, transportation for elderly residents, fire protection, emergency medical services, and solid waste disposal. In the latter case, a computer program has been devised to efficiently design routing plans for gathering solid waste. These programs permit communities to make reliable financial plans when considering and designing these public services. The research results are being made available through Extension. ANIMAL HEALTH AND DISEASE RESEARCH The Animal Health and Disease Research (Section 1433, Public Law 95-113) program is directed to improving the health and productivity of animals and the welfare of producers and consumers of animal products; protecting human health through control of animal diseases transmissible to humans; minimizing livestock and poultry losses due to transportation and handling; and facilitating the effective treatment and prevention of animal diseases. The following is a description of current activities and selected examples of accomplishments from these appropriated funds: Current activities: $5 million was appropriated for the first time in Recommendations of the Animal Health Science Research Advisory Board have State Comprehensive Plans for animal health research, approved by SEA-CR, In Fiscal Year 1980 there were more than 330 projects conducted under Section Selected examples of recent progress: Anaplasmosis Control by Use of Antibiotics. Scientists at Oklahoma's Agricultural Experiment Station found that continuous feeding of chlorotetracy line medicated feed or a salt-mineral mix prevented the development of clinical disease to cattle on pasture even when the animals |