Injury, Endogenous Starch Production, and Nucleolar Enlargement in Lemon Fruit Juice Vesicles

Excision of lemon fruit juice vesicles from their natural connectionwith the fruit wall is the minimal physical stimulus neededfor initiating the physiological processes which lead to endogenousstarch production in this tissue system. Endogenous starch formationoccurs in the juice vesicle cells over a wide range of environmentalconditions and takes place concomitantly with the phenomenonof nucleolar enlargement.     

405 nm-Excited Fluorescence Spectra of the Juice of the Lemon (Citrus x Limon)

A 405 nm diode laser is used to excite fluorescence of juices of raw and ripe lemons. Emission bands appear approximately at 520 nm and 670 nm. Fluorescence intensity ratio F520/F670 is determined for the two stages. Variation in the fluorescence intensity ratio is observed during the process of ripening or growth of the fruit. Time-resolved spectra at this excitation wavelength reveal two decay times at both the stages at the emission wavelength of 520 nm, and two decay times at the raw stage and one decay time at the ripe stage at 670 nm.