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Masaki Yahata, Hisato Kunitake, Tsutomu Yabuya, Kensuke Yamashita, Yukiko Kashihara, and Haruki Komatsu

The authors are grateful to Dr. Masahiro Mii, Faculty of Horticulture, Chiba University, for his advice and critical reading of this manuscript. This research was supported by Diet and Cancer Prevention: Exploring Research Technology, Miyazaki

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James E. Frelichowski and John A. Juvik

Sesquiterpene carboxylic acids (SCA) are synthesized by leaf trichomes of a wild tomato species Lycopersicon hirsutum accession LA 1777 and confer resistance to the tomato pests Helicoverpa zea (Boddie) and Spodoptera exigua (Hubner). Larvae of both species exhibited a reduction in survival and growth rate with altered feeding behavior when exposed to SCA in choice and no-choice insect bioassays. Larvae of both species were reared on artificial insect diets with SCA added at 0, 10 and 60 mg SCA per g of diet. All larvae perished in the 60 mg·g–1 treatment which is comparable to the levels of SCA found on LA 1777. H. zea and S. exigua showed about 35% and 60% reduction in survival to adult and 38% to 22% increase in life cycle duration, respectively, in the 10 mg·g–1 treatment relative to the control. Similar reductions in growth rate and survival were observed when larvae were reared on leaves coated with SCA. Choice bioassays with control (0 mg SCA/g leaf) and 60 mg SCA/g treated leaf tissue demonstrated 2.3-fold increase in larval avoidance and 50% reduction in feeding on treated leaves. Our results suggest that breeding for SCA synthesis in tomato would produce lines with increased resistance to the tomato pests H. zea and S. exigua. Backcross breeding procedures using LA 1777 have initiated the introgression of the SCA genes into cultivated tomato germplasm. Studies of inheritance of genes coding for SCA synthesis are underway to reveal allelic interactions and facilitate there introgression into the cultivated tomato germplasm.

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Masaki Yahata, Hisato Kunitake, Kiichi Yasuda, Kensuke Yamashita, Haruki Komatsu, and Ryoji Matsumoto

manuscript. The authors thank Mr. Yasuhiro Okuno for kindly providing the experimental materials. This research was supported by Diet and Cancer Prevention: Exploring Research Technology, Miyazaki Prefecture Collaboration of Regional Entities for the

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Masaki Yahata, Seiichi Harusaki, Haruki Komatsu, Kayo Takami, Hisato Kunitake, Tsutomu Yabuya, Kensuke Yamashita, and Pichit Toolapong

Research Center, for kindly providing `Banpeiyu' pummelo and `Ruby Red' grapefruit. This research was supported by Diet and Cancer Prevention: Exploring Research Technology, Miyazaki Prefecture Collaboration of Regional Entities for the Advancement of

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I.L. Goldman

Plants are the foundation for a significant part of human medicine and for many of the most widely used drugs designed to prevent, treat, and cure disease. Folkloric information concerning traditional remedies for disease has had inestimable value in establishing familial and cultural linkages. During the 20th century, modern medical science in the U.S. and other developed countries ushered in a new era focused on synthetic medicines. Even though many of these compounds were based on natural compounds found in plants, the drive towards synthetic pharmaceuticals created a knowledge gap concerning the health functionality of plants, crops, and food. Paralleling this development, biochemists and nutritional scientists pioneered the discovery of vitamins during the early decades of the 20th century. This research paved the way for dietary guidelines based on empirical data collected from animal feeding trials and set the stage for the current emphasis on phytonutrients. Three primary stages characterize the use of fruits and vegetable in human health. The first stage concerns the observation that many fruit and vegetable crops were originally domesticated for their medicinal properties. Making their way into the diet for this purpose, fruit and vegetable crops remained on the fringe from a culinary point of view. The second stage began when the role of vitamins became more widely understood, and fruit and vegetable plants were quickly recognized as a rich source of certain vitamins, minerals, and fiber. At this point, they became more than just an afterthought in the diet of most U.S. citizens. Cartoon icons such as Popeye made the case for the health functionality of leafy greens, while parents schooled their children on the virtues of carrots (Daucus carota), broccoli (Brassica oleracea), and green beans (Phaseolus vulgaris). This renaissance resulted in large increases in fresh fruit and vegetable consumption across the country, a trend that continues to this day. The third phase can be characterized by the recognition that fruit and vegetable crops contain compounds that have the potential to influence health beyond nutritional value. These so-called functional foods figure prominently in the dietary recommendations developed during the last decades of the 20th century. In recent years, surveys suggest nearly two-thirds of grocery shoppers purchase food specifically to reduce the risk of, or manage a specific health condition. Evidence abounds that consumers, including Baby Boomers, choose foods for specific health benefits, such as the antioxidant potential of vegetables, suggesting high levels of nutritional literacy. Clinical and in vitro data have, to some degree, supported the claims that certain foods have the potential to deter disease, however much research remains to be conducted in order to definitively answer specific dietary-based questions about food and health.

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Harvey E. Arjona and Frank B. Matta

Passion fruit has become a popular addition to our diet and is currently grown in the United States. Passion fruit shelf life could be extended if green mature fruit can be induced to ripen after exposure to ethylene. Greenhouse grown purple passion fruits were harvested in a green mature stage 55 and 60 days after anthesis (DAA) and stored for 10 days at 10°C. After storage half of the fruits were treated with 10 ppm ethylene for 35 hours and stored at room temperature (21°C) for 48 hours. The juice of treated and non-treated fruit was analyzed for comparison with juice of vine-ripened fruit. Total soluble solids and pH of the juice did not differ in green mature fruits harvested 55 and 60 DAA.. compared to vine-ripened fruits (70-80 DAA). Sucrose content decreased and fructose and glucose increased after storage, regardless of ethylene treatment. Fruits harvested 55 and 60 DAA, with or without ethylene and stored for 10 days, developed the same sugar content, soluble solids and pH as those that ripened on the vine.

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Manette Schönfeld and Cary A. Mitchell

CowPea (Vigna unguiculata (L.) Walp.) is a candidate species for inclusion in a space-deployed Controlled Ecological Life Support System (CELSS) because it contributes to a balanced diet with its moderate protein content, high complex carbohydrate content, and low fat content, and because leaves and unripe pods as well as dry seeds are edible. Pour harvest scenarios were compared in the experimental line IT84S-2246 under controlled conditions with and without CO2 enrichment. Plants kept vegetative by removal of flowers and periodically stripped of fully expanded leaves yielded as much as either mixed-harvest scenario in which leaves were stripped at either 1- or 2-week intervals until pods started forming. The 2-week harvest scenario outyielded the 1-week scenario by 15 to 25%. The seed-only control produced the same amount of seeds as the 2-week leaf harvest scenario, but had lower total edible biomass because leaves were not harvested. Under 1000 ppm CO2, all treatments yielded from 30 to 70% more edible biomass than under non-CO2-enriched conditions. Research sponsored by NASA Cooperative Agreement NCC 2-100.

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Winand K. Hock

One of the major misconceptions in contemporary society is the widespread belief that our food supply is unsafe. The public's perception of risk is quite different than scientific assessment of risk. While scientists see microbial contamination as the key issue (100 to 10,000X greater risk than from exposure to pesticide residues), consumers appear to be most concerned about the effects of synthetic pesticides and fertilizers in the food they buy. Consumers equate “synthetic” with harmful or bad and “natural” with safe or good, yet they ignore the fact that 99.9% of all pesticides humans are exposed to are naturally occurring. Americans eat approximately 1.5 g. of natural pesticides per person per day, or about 10,000 times more than synthetic pesticide residues. Although few plant toxins have been tested for carcinogenicity so far, of those tested about half are rodent carcinogens. Contrary to public perception, environmental pollution accounts for only 2% of all cancers. By contrast, smoking, diet and other personal lifestyle choices account for more than 75%.

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Abhava M. Dandekar, Gale H McGranahan, Sandra L. Uratsu, Charles Leslie, J. Steven Tebbets, and Patrick V. Vail

Insecticidal crystal protein fragments (ICPFs) of Bacillus thuringiensis (Bt) encoded by cryIA(c) gene were shown in diet incorporation studies to be lethal to codling moth (CM; Cydia pomonella) the key insect pest for walnut. However transformed walnut tissues expressing cryIA(c) with Bt codon usage patterns and native DNA sequence revealed very low levels of expression in planta. To correct this problem synthetic versions of one of these genes, cryIA(c) was used to transform walnut tissue. A total of 61 individual transgenic embryo lines were obtained. 34% of these lines (21/61) were high expressors (“class A”) demonstrating 80 to 100% mortality of first in star CM larvae and displaying no further larval development. Twelve clones (20%) were designated “class B” and these showed a marked retardation of larval development and a mortality between 40 to 79%. Embryos from the remaining 28 lines designated “class C” (46%). although transformed, were indistinguishable from the control (untransformed embryos) and showed a mortality of 0 to 39%.

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C.L. Mackowiak, J.L. Garland, and R.M. Wheeler

As humans explore the solar system, life support will need to be increasingly self-sufficient. Growing higher plants and using recycling technologies can improve self-sufficiency. Sodium is an essential mineral for humans, but not typically for plants. Recycling sodium back to humans through food crops may reduce the need for sodium supplements in the human diet. However, if sodium from waste streams is added to the plant system in greater quantities than it is removed, then plant toxic levels may result. The recommended daily sodium requirement is 3000 mg per person. Based on a 20-m2 growing area per person, 150 mg·m–2 sodium would need to be removed each day. Most crops will not remove enough salt when grown at very low sodium levels; however, when grown in 20 mM sodium, plant uptake may meet the 3000 mg/d human sodium requirement without affecting yields. We grew four different salad crops (lettuce, radish, spinach, and table beet) hydroponically and calculated plant uptake rates and partitioning with 0, 20, 40, or 80 mM sodium supplemented nutrient solutions (corresponding to ≈1.4, 4.0, 8.0, and 13.0 dS·m–1 electrical conductivity). Sodium at 40 and 80 mM reduced edible yields. Sodium replaced tissue potassium in most cases, whereas calcium and magnesium concentrations were much less affected, particularly at 20 mM sodium. This data will be used to model sodium flows within a bioregenerative life support system and determine the feasibility of sodium recycling using food crops.