Objective:
To determine the role of, and genetically engineer, cell wall carbohydrate and membrane phospholipid metabolic enzymes that regulate fruit ripening to produce transgenic fruits and vegetables of superior quality that are amenable to fresh-cut processing and have a longer shelf life.

Approach:
Cell wall carbohydrate and membrane phospholipid metabolic enzymes will be suppressed or over-expressed in tomato plants, or specifically in tomato fruit, by transformation of plants with antisense, sense, RNAi, or 3'-UTR random-repeat constructs, enabling assessment of their importance in fruit ripening, softening, and senescence. Constructs including nonspecific constitutively expressed and fruit-specific promoters will be tested. Immunoblots and enzyme assays will be conducted to correlate gene transcript (mRNA) levels with levels of protein expression and enzymatic activity. Transgenic tomato fruit, both whole and sliced, will be evaluated for quality parameters including texture, color (lycopene content), flavor and aroma compounds, and rates of ripening and senescence. BSL-1/BSL1-P re-certified 7/14/08.