Submitted to: Acta Horticulturae
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/20/2003
Publication Date: 7/1/2004
Citation: Kumar, V., Mills, D.J., Anderson, J.D., Mattoo, A.K. 2004. Delayed senescence and disease tolerance of tomato plants cultivated in cover crop mulch correlates with accumulation of specific gene products. Acta Horticulturae. 638:497-502. Interpretive Summary: Conventional vegetable production is heavily dependent upon high chemical inputs in the form of polyethylene-plastic mulch, nitgrogen fertilizer and pesticides. High application of chemicals is a potential contributor to the unfriendly environmental pollution. Interestingly, alternative agriculture practices are in vogue, which have tested cover crops like hairy vetch (Vicia villosa) as a source of on-farm biological inputs that have the potential to reduce erosion and the use of agrochemicals without impacting the yield or quality of the produce. Field-grown, fresh market tomatoes (Lycopersicon esculentum) cultivated in hairy vetch mulches were found to have reduced severity of disease and reduced defoliation as compared to the plants cultivated in plastic mulch. To further understand the basis of these beneficial attributes, we tested whether increased longevity, disease tolerance and reduced defoliation of vetch grown tomato plants are linked to increased expression of specific genes and subsequent accumulation of their products. We identified several key genes that have been implicated in senescene or disease tolerance, one group of which is involved in carbon and nitrogen metabolism. These studies provide a scientific basis for enhanced attributes of vetch grown tomato plants. These data are important to agriculturists and plant biologists interested in finding alternatives to chemicals for increasing quality and production of crops.
Technical Abstract: Vegetable production is heavily dependent upon high off-farm inputs of polyethylene (plastic) mulch, nitrogen fertilizer and pesticides. Such a production practice potentially contributes to the unintentional environmental pollution with fertilizer and pesticides as well as water run off and soil erosion. This raises serious environmental concerns for human and animal health. The integration of on-farm biological inputs into vegetable production system is one potential means of reducing the dependence on off-farm inputs. In recent years, alternative agriculture practices have tested cover crops like hairy vetch (Vicia villosa) as on-farm biological inputs that have the potential to reduce both erosion and the use of agrochemicals without impacting the yield or quality of the produce. Field-grown, fresh market tomato (Lycopersicon esculentum L.)plants cultivated in hairy vetch mulch display reduced defoliation and tolerance to disease as compared to plants cultivated in the plastic mulch. We hve initiated a molecular approach to test whether these beneficial attributes are linked to changes in the expression profiles of one or more specific gene products. The data indicated that vetch-grown tomato plants have increased accumulation of transcripts and proteins that are central to delayed senescence and disease suppression.