A recent report shows that transient expression of the type three effector of Salmonella 14028 SseF in tobacco plants elicits HR, and this response is dependent on the SGT1 protein . This study suggests that SseF can induce resistant-like response in plants and requires resistance protein signaling components. Üstün et al. and Shirron and Yaron also showed that Salmonella 14028, which is able to deliver the SseF effector, cannot induce HR or any disease-like symptoms in tobacco leaves. Thus, it remains to be determined what would be the biological relevance of ETI in the Salmonella and other human pathogenic bacteria in their interaction with plants in nature.Although S. enterica and E. coli O157:H7 have not been traditionally known to be closely associated with plants and modulate plant’s physiology, the evidence tells us otherwise. An arms-race evolution in both the human pathogen and the plant is therefore, expected. A few studies have addressed whether genetic variability among plant species or within the same plant species can be correlated with differential bacterial behavior and/or colonization of plants. Barak et al. described that different tomato cultivars can harbor different levels of S. enterica population after inoculation via water indicating plant factors may control the ability of bacterial to colonize the phyllosphere. However, they also found that the cultivar with the smallest S. enterica population also had the lowest number of speck lesions when infected with the tomato pathogen Pst DC3000 , suggesting that strong basal defense in this cultivar may account for low bacterial colonization. On a comparative study of S. enterica contamination of several crop species, Barak et al. reported that seedlings from Brassicaceae family have higher contamination than carrot, tomato,vertical farming equipment and lettuce when grown on contaminated soil.
Seedling contamination correlated with the Salmonella population in the phyllosphere of all crop species, except tomato. Golberg et al. reported variations in internalization of Salmonella SL1344 in different leafy vegetables and fresh herbs using confocal microscopy. Internalization incidence was high in iceberg lettuce and arugula, moderate in romaine lettuce, red lettuce, basil, and low in parsley and tomato. Attraction to stomata was seen in iceberg lettuce and basil, not in arugula, parsley, and tomato. Brandl and Amundson reported that the age of romaine lettuce leaves is correlated with population size of E. coli O157:H7 and S. enterica Thompson on leaves.These authors also observed that exudates on the surface of younger leaves have higher nitrogen content than that of older leaves, which may contribute to determining the bacterial population size on the leaf. Thus, it is tempting to speculate that the genetic variability existent among plant genotypes regarding the chemical composition of their organ exudates may be a determinant for human pathogen behavior and ability to colonize plants. Finally, Mitra et al. studied the effect of different methods of inoculation on internalization and survival of E. coli O157:H7 in three cultivars of spinach. Among the organs studied, the spinach phylloplane and the stem provided the most and least suitable niche for this bacterium colonization, respectively. Although the leaf surface was the best “territory” for E. coli, the leaf morphologies of each cultivar affected the ability of this bacterium to survive. Collectively, all these studies point out that the plant genotype, age, leaf morphology, chemical composition of exudates, and the primarily infected organ affect the outcome of bacterial colonization of plants and the process may not be a generalized phenomenon, consequently shaping specific human pathogen and plant interactions.
For the past 43 years, people from across the U.S. and around the world have come to UC Santa Cruz to learn organic farming and ecological horticulture skills and concepts. What began in 1967 as the UCSC Student Garden Project, an informal student apprenticeship with English gardener Alan Chadwick, has since grown into the internationally known Apprenticeship in Ecological Horticulture, offered each year through the Center for Agroecology and Sustainable Food Systems . The six-month, intensive program combines hands-on and classroom work, covering topics ranging from soil fertility management, crop selection and culture, pest and disease management, and greenhouse and irrigation skills, to business planning, marketing, and food system issues. Apprentices work alongside instructors, learning in an “I do, we do, you do” model at the 25-acre UCSC Farm and 3-acre Alan Chadwick Garden. Since its founding, more than 1,300 people have graduated from the Apprenticeship, and have gone on to a variety of careers in sustainable agriculture and food systems-related work. Although CASFS staff members have informally tracked the activities of the Apprenticeship program’s graduates, there has never been a formal survey to find out how Apprenticeship alumni are applying their training and how the program has contributed to their work, volunteer, and personal activities. In 2009 CASFS undertook a comprehensive survey of alumni both to document the impacts of the program and to get suggestions for ways to improve the Apprenticeship. The survey was designed to address two basic questions: Is the Apprenticeship contributing to a more sustainable food system? To what extent did the program contribute to alumni’s activities? A grant from the Foundation for Global Community provided support for the survey and analysis.
The survey found that program graduates are making a major contribution to creating a more sustainable food system. This is reflected in the significant number of alumni involved in a wide range of sustainable food and agriculture efforts, and particularly in teaching others about food production and sustainable food systems. This brief summary provides an overview of the Apprenticeship alumni survey methods and results. A series of graphs detailing the results, with a focus on what all of the respondents have been doing since graduating from the program, is available online at the CASFS website.a A more in-depth analysis of the results and implications for education are presented in, “Achieving Program Outcomes? An Evaluation of Two Decades of Apprenticeship in Ecological Horticulture at the University of California, Santa Cruz Farm and Garden,” by CASFS researcher Jan Perez, UC Davis postdoctoral student Damian Parr, and UCSC graduate student Linnea Beckett, which appears in the inaugural issue of the Journal of Agriculture, Food Systems and Community Development.The survey was designed collaboratively with CASFS staff and input from alumni. Overall, 23 alumni and others pretested versions of the survey. The final survey included both quantitative and open-ended questions. All past apprentices since the founding of the program in 1967 comprised the survey population for the project; this included an estimated 1,200 alumni as of the survey date. The survey was sent to the 648 alumni for whom there was a known email address, drawn from an alumni database that was created in 1997 and updated recently for fundraising efforts and alumni activities. The survey was implemented between June 18 and July 20, 2009.The survey drew a response rate of 60% , which is considered high for a self-administered survey. Approximately 25% of graduates in each class since 1989 responded, with the most responses from those who had graduated in the past 10 years. Respondents were generally European-American, under 30 years of age during their Apprenticeship, from a middle-class or upper-middle class background, and had a 4-year college degree when they started the program .Since finishing the Apprenticeship, 87% of respondents are currently or have been involved in the field of sustainable agriculture and food systems work . Eighty percent volunteered for activities that contribute to sustainable food systems, and 99% used what they learned during the Apprenticeship in their personal lives. In addition, 48% of the alumni from the past 20 years had initiated, created,macetas para fresas or started the work or effort in which they were involved, which speaks to the leadership role that many have assumed since graduating .d Of the 315 respondents who are or have been involved in sustainable food and agriculture work, 93% reported doing some type of farming or gardening work since graduating. Primary job areas include food production , education , landscaping/gardening , retail , and work with non-governmental organizations . People have worked in rural , urban , and peri-urban settings, with many alumni having worked in more than one place since graduating. Two hundred of the respondents reported owning or operating a farm or garden at some point since graduating. Of those people, most grow a mix of vegetables and fruits; they also produce flowers , fruit , animal products , and grain , while 12% are involved in animal production. Those who own or operate a farm or garden employ one or more distribution strategies. These include direct sales to stores or restaurants , farmers’ markets , community supported agriculture efforts , wholesale , farm stand , and farm-to-institution . In addition, 40% donated produce as part of their operation.Education plays a role in the work of a significant number of alumni: 64% of all survey respondents, and 74% of those working in sustainable food and agriculture, reported that they have had jobs that included education activities or programs—particularly around food production and food systems issues and knowledge—as part of their formal goals.
In addition, 55% of those involved in education state they are training future teachers and trainers of sustainable food and agriculture-related topics. These “training the trainer” efforts increase the impacts of the Apprenticeship far beyond those who graduate each year. In terms of influencing social justice, the survey asked alumni if they had attempted to implement various strategies into their sustainable food and agriculture system work, volunteer, or personal activities. Among the responses, 60% reported that they had attempted to increase access to healthy food for those with limited access; 56% had increased inclusion; 48% had addressed inequities in access to information; 45% had fostered sharing of power or ownership; and 41% had increased the income of small- and mid-scale growers. Since these activities could range from buying fair trade coffee to starting a non-profit, we also explored this issue more specifically. We looked at work, volunteer, and personal activities people listed, and identified when they included addressing needs of people who were traditionally under served, worked on hunger or food security issues, or used words such as just, fair, and diversity. At least 35% of the respondents met these criteria. In addition to work endeavors, 80% of alumni have been involved in volunteer activities related to sustainable agriculture and food systems. Thirty three percent report donating time or materials to gardens, farms, schools, and outreach efforts; 28% have been involved in alternative agriculture organizations, as either founders, board or committee members, or as participants in activities; and 17% have led programs, classes and workshops, or served as a mentor. Other volunteer activities include community organizing and international community service . The Apprenticeship has also had an impact on alumni’s personal activities. Fifty-two percent report that the Apprenticeship influenced their purchasing behaviors, including buying local, organic, fair trade, and seasonal foods, as well as supporting farmers’ markets, CSAs, and local farms. Other personal activities include growing their own food or helping others grow food , and educating others .When asked how the Apprenticeship contributed to their subsequent activities, the majority of respondents noted that the program provided knowledge and skills . Survey respondents also reported that the program significantly helped them confirm their values ; provided confidence in their skills and ability ; helped shape their career goals ; and provided a network of people/contacts . Program components identified as most helpful for contributing to Apprenticeship graduate Cathrine Sneed launched The Garden Project to serve former offenders. Today the San Franciscoarea program provides on-the-job training in gardening and tree care. Apprenticeship alumni Jered Lawson and Nancy Vail founded Pie Ranch near Pescadero, California. The educational farm connects urban and rural high school students with the source of their food and provides training in farming skills. alumni achievements are described in Perez, Parr and Beckett .f Based on responses from the last 20 years of graduates, 60% of alumni considered the “hands-on” emphasis to be important to helping them accomplish their post-graduation activities. The next most-cited important program components were the residential living aspect of the program , working with peers , course work , and working with teachers .g This survey confirms that many alumni are participating in creating more sustainable food systems in a variety of ways, including farming, gardening, and educating others.