DELAYED SENESCENCE AND DISEASE TOLERANCE OF TOMATO PLANTS CULTIVATED IN COVER CROP MULCH CORRELATES WITH ACCUMULATION OF SPECIFIC GENE PRODUCTS

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 have 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.