title: The effect of light intensity on the assay of the low temperature limit of photosynthesis using msec delayed light emission.
abstract: Steady state millisecond delayed fluorescence (DLE) of intact leaves and cyanobacterial cells was measured continuously with a Becquerel-type phosphoroscope while cooling from the growth temperature to near 0°C or heating from the low to high temperature at about 1°C/min. The temperature of maximum DLE depended upon light intensity. In Anacystis grown at 28 and 38°C DLE maximum occurred near 15 and 23°C, respectively, which are the temperatures where thylakoid membrane lipids have been shown to pass from the liquid crystalline to the mixed solid-liquid crystalline state in these cyanobacteria. In some plants such as field mallow DLE increased continuously as the temperature decreased, whereas in others it rose to a maximum, then decreased. Chilling-sensitive plants such as tomato, sweet potato and Trichospermum, showed DLE maxima around 10-14°C while the chilling-resistant plant, oat, had a maximum near 4°C and field mallow had no maximum above 0°C.
authors.affiliation: National Institute for Basic Biology, 444, Myodaiji Okazaki, Japan.
authors.forename: D C
authors.initials: DC
authors.lastname: Fork
authors.forename: N
authors.initials: N
authors.lastname: Murata