Abstract: The invention provides phenylalanine ammonia-lyase (PAL) sequences, and constructs and methods related thereto. In one aspect, Lactuca sativa PAL sequences are isolated and characterized. The invention also provides novel sequences associated with PAL polynucleotide sequences and methods using recombinant techniques to express proteins from such sequences. In addition, methods are provided for using such sequences to transform host cells and alter wound induced gene activity or expression.

Abstract: The invention provides phenylalanine ammonia-lyase (PAL) sequences, and constructs and methods related thereto. In one aspect, Lactuca sativa PAL sequences are isolated and characterized. The invention also provides novel sequences associated with PAL polynucleotide sequences and methods using recombinant techniques to express proteins from such sequences. In addition, methods are provided for using such sequences to transform host cells and alter wound induced gene activity or expression.

Abstract: A method of preventing wound-induced browning in lettuce by applying a short thermal stress induced by immersing the lettuce in water at approximately 40.degree. C. to approximately 60.degree. C. for approximately 360 seconds or less. Alternatively, forced-air heating could be used if the air was at a relative humidity of near 100% to prevent water loss. After heat-shocking the lettuce, the lettuce can be vacuum cooled to effectively cool and dry the lettuce. The heat-shock effect is so persistent that lettuce will not show any browning even after being held for approximately 15 days in the air at 5.degree. C. This treatment could eliminate the need to store fresh-cut lettuce in low oxygen, and or high carbon dioxide modified atmospheres to prevent browning during marketing. It would also allow the use of vacuum cooling to cool the processed lettuce. It would also prevent browning of cored, whole heads of lettuce.

Abstract: A sensing apparatus and method for qualitatively and quantitatively analyzing small amounts of selected oxidizable gases in a carrier gas including the associated electronic circuitry is described. The apparatus preferably includes two semi-conductor type sensing elements in electrical parallel so that the difference in resistance of the two sensors can be detected, which can be of the N or P type and which decrease or increase in electrical resistance as a function of the concentration of an oxidizable gas. Also, a method for determining fruit maturity and ripeness by the detection of ethylene in the internal atmosphere of a fruit is described which preferably uses the apparatus with the semi-conductor type sensing elements, but can use other variable resistance type gas sensing means.

Abstract: A sensing apparatus and method for qualitatively and quantitatively analyzing small amounts of selected oxidizable gases in a carrier gas including the associated electronic circuitry is described. The apparatus preferably includes two semi-conductor type sensing elements in electrical parallel so that the difference in resistance of the two sensors can be detected, which can be of the N or P type and which decrease or increase in electrical resistance as a function of the concentration of an oxidizable gas. Also, a method for determining fruit maturity and ripeness by the detection of ethylene in the internal atmosphere of a fruit is described which preferably uses the apparatus with the semi-conductor type sensing elements, but can use other variable resistance type gas sensing means.